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Topic: ? has the ONR been up 2?(tech) | Topic page views:
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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:20 PM
This is an enormous list of ONR research contracts that have been granted, all technical in nature and validated and verified by the referrences given. Title: THz-Bandwidth, Deep Submicron, Regrown-Base Transfer-Substrate HBTs
PI: Mark Rodwell THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Department of Electrical and Computer Engineering Address: CHEADLE HALL RM 3227 Santa Barbara, CA 93106 (805) 893-3244 Funding Agency: Office of Naval Research PR Number: 00PR00014-00 Award Number: N000149910041 Current End Date: 30-Sep-2001 Scientific Officer: John Zolper Objective: A low parasitic heterostructure bipolar transistor (LP-HBT) will be scaled down to an emitter width of 0.1 microns to achieve the first THz transistor. Approach: A transfer substrate flip wafer process is being developed for a low parasitic heterojunction bipolar transistor (LP-HBT) whereby the n-type semiconductor under the p-type base contact region is removed to dramatically reduce the base-collector capacitance. The structure will be scaled down to a 0.1 micron emitter width that should produce the first THz transistor. The work will employ an InP collector to improve the breakdown properties over previous devices. Progress: This program seeks to develop very high speed transistors (HBTs) using a transferred-substrate technique. By scaling the devices to very small dimensions, HBTs have been produced with power-gain cutoff frequencies as high as 1080 GHz, 3.5:1 higher than any other HBT and 1.8:1 higher than any other kind of transistor. Efforts to obtain high current-gain cutoff frequencies have resulted in a record 254 GHz ft, and a number of wafers have been processed with the recent goal of obtaining much higher ft. Title: Piezoelectric Doping for GaN Heterojunction Bipolar Transistors PI: Peter Asbeck THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SAN DIEGO 0934 Department of Electrical Engineering Address: 9500 GILMAN DRIVE La Jolla, CA 920930407 (619) 534-6713 Funding Agency: Office of Naval Research PR Number: 00PR00026-00 Award Number: N000149810539 Current End Date: 31-Mar-2001 Scientific Officer: John Zolper Objective: Use strong piezoelectric effect in AlGaN/GaN layers grown in SiC to achieve enhanced hole densities and thereby produce high power heterostructure bipolar transistors in this material system. Approach: Holes densites on the order of 2e18 cm-3 will be generated in the base of a AlGaN/GaN collector-up HBT grown on SiC. This will be accomplished by growing a graded AlGaN layer in the base of the transistor. The hole enhancement will first be studied in diode test structures prior to complete HBT fabrication. Complete collector-up HBTs will be fabricated and characterized at dc and microwave frequencies. Following successful demonstration of the collector-up HBT, novel designs will be implemented to reduce extrinsic emitter injection either by ion implantation or selective area lateral epitaxial overgrowth. Progress: Preliminary designs of the HBT has been developed. Material structures have been specified and are ready for growth at partnering institutions. Simulation studies of the hole concentration expected in the base layer have been carried out based on the piezoelectric effect and the incorporation of Mg acceptors. Stress relaxation in 3 dimensions has been studied in a finite element simulation, to determine if the piezoelectric charge will be significantly modified at the edges of the devices. For the collector-up device, current confinement in the intrinsic emitter was studied. It was found that it is critical to minimize current spreading in the extrinsic emitter region. A novel structure for improvement in base contacts based on piezoelectric doping has been devised, and structures for potential implementation of the concept have been designed. Acceptor-like doping from spontaneous and piezoelectric polarization in AlGaN/GaN HBT structures was theoretically evaluated. Experimental samples to measure this doping (together with that from modulation doping using Mg) were designed. After epitaxial growth at NCSU (Prof. R. Davis), the samples were measured. Results confirm doping contributions of the magnitude expected. Structures with n-type base regions (hot electron transistors) have also been designed and are being fabricated. Title: Materials Physics & Electron Transport Issues in Superconducting Electronics PI: Robert Buhrman CORNELL UNIVERSITY School of Applied & Engineering Physics Address: 120 DAY HALL ITHACA, NY 14853 (607) 255-3732 Funding Agency: Office of Naval Research PR Number: 00PR00092-01 Award Number: N000149710142 Current End Date: 31-Oct-2002 Scientific Officer: Deborah Van Vechten Objective: To provide output from the PI's previous efforts regarding the cause and remedies of inhomogeneous oxygen distribution in YBCO to applications such as high performance HTS filters, high current density (Jc) conductors, and HTS Josephson junctions wherein such inhomogenities may deleteriously impact performance. Improved ability to apply HTS materials to Navy problems should result. Approach: To collaborate with several other groups. Whether the 5-10x improvement following ozone treatment of the Jc of large angle grain boundaries is reproduced in the predominantly small angle case of IBAD textured tape will be tested in conjunction with 3M and Stanford. The impact of the same treatment on microwave surface loss and IP3 will be tested at NIST. Details of the effect of ion beams on the surface of YBCO will be studied to look for both surface passivation coatings and improved uniformity junction tunnel barriers. A small effort will look at normal metal barriers for NbN based junctions in order that we have a self-shunted option for this higher temperature digital material. Progress: Inhomogeneous oxygenation produces variation in the superconducting properties of HTS materials and, if the material is used as a barrier in a Josephson junction structure, to non-reproducible tunneling characteristics. It is thus significant that doping, as with Co in the most common barrier material, produces local stress fields that reduce the oxygen binding energy and lead to inhomogeneous concentrations. As a result only ozone annealing can produce full oxygenation. When done to grain boundary and engineered interface junctions, a Jc independent IcRn product results, a strong virtue. This understanding should assist the development of improved HTS JJ. A modified Blonder-Tinkham-Klapwijk model has been successfully used to directly measure the interface scattering and spin polarization of electrons traversing a clean ferromagnetic-superconductor interface. Title: PLASMA WAVE ELECTRONICS DEVICE UTILIZING TWO-DIMENSIONAL ELECTRON FLUID PI: Michael Shur RENSSELAER POLYTECHNIC INSTITUTE Address: Thornton Hall Charlottesville, VA 22903 (804) 942-4270 Funding Agency: Office of Naval Research PR Number: 00PR00187-00 Award Number: N000149810210 Current End Date: 04-Jan-2001 Scientific Officer: John Zolper Objective: Develop theory and experimentally demonstrate the application of the plasma wave properties of the two dimensional electron gas in high mobility transistors as a high frequency detector. Approach: The non-linear theory will be developed for an arbitary load, for wide bandgap semiconductors, for detectivity, and for the analysis of detector arrays. The experimental work will involve the design, fabrication, and characterization of non-resonant and resonant detectors, and for detector arrays. Progress: Investigations were performed on microwave GaN-based HEMT detectors and, for the first time, terahertz GaAs-based HEMT detectors. Both types of transistors operated at frequencies much higher than their cutoff frequency. The gate voltage dependence is in good agreement with the theory developed under the program. Polarization dependencies were discovered. The measured temperature dependence of the detector responsivity suggests a high viscosity of the electronic fluid. A new theory was developed that predicts the dynamic range of the terahertz HEMT detector.In the past year, we demonstrated experimentally the first terahertz (2.5 THz) detector utilizing an AlGaAs/GaAs High Electron Mobility Transistor (HEMT). The bias dependence of the measured detector responsivity is in agreement with the analytical detector theory. Also, this detector is sensitive to the polarization of the terahertz radiation. We have performed modeling and characterization of 0.25 micron GaN-based HEMTs including the noise characteristics and the electron mobility since high-mobility samples are required for GaN terahertz detector fabrication. Theoretically, we have studied the detector large signal theory and the nonlinear detector theory for an arbitrary load. We have also studied the influence of scattering of carriers on the "shallow water wave instability" of the surface plasma waves in a HEMT. Title: Broadband Microwave Traveling Wave Power Amplifiers PI: Kevin Webb PURDUE RESEARCH FOUNDATION Department of Electrical Engineering Address: Hovde Hall, 3rd Floor West Lafayette, IN 47907 (317) 494-3373 Funding Agency: Office of Naval Research PR Number: 00PR00192-00 Award Number: N000149810371 Current End Date: 30-Sep-1999 Scientific Officer: John Zolper Objective: To design and fabricate high power traveling wave amplifier circuits using AlGaN/GaN transistors developed under the Cornell MURI. The proposal is configured to parallel the MURI in time frame and option structure. Approach: To perform detailed characterization of high power transistors developed under the Cornell MURI and to develop nonlinear models for these devices. These device models will then be used to design high power traveling wave amplifiers. Said amplifiers will be fabricated and tested under this contract. Progress: In collaboration with Prof. Eastman, et al., from Cornell, the PI has designed high efficiency Class A traveling wave and distributed (compact) monolithic GaN HEMT amplifiers that have no drain line dummy termination. These designs used a nonlinear HEMT model derived from measured data. Forthcoming experimental data is expected to support the design concept, which can then be transferred to a Class B push-pull design. Prior to achieving these designs, investigatations will be performed of fundamental issues related to broadband amplifiers and device models, including stability, matched terminations, drain and gate line matching, the basis and accuracy of the HEMT model, and physical implementation strategies. Fabrication of these amplifiers is underway at Cornell. Title: Ultra-Linear Dynamically Programmable Analog to Digital Converter PI: Oleg Mukhanov HYPRES INC Address: 175 CLEARBROOK ROAD ELMSFORD, NY 10523 (914) 592-1190 Funding Agency: Office of Naval Research PR Number: 00PR00211-02 Award Number: N0001499C0089 Current End Date: 30-Dec-2000 Scientific Officer: Deborah Van Vechten Objective: Seek a dynamically programmable analog to digital converter wherein the performance may be programmed from 19 effective bits of resolution with 116 dB spur-free-dynamic-range (SFDR) at 20 MHz sampling speed to 9 effective bits resolution with a 70 dB SFDR at 2 GS/s. Approach: Low transition temperature superconductors, in particular Nb, will be used to fabricate the circuits using Rapid Single Flux Quantum (SFQ) logic. All demonstrations to be done using liquid He cooling. A high-speed single bit quantizer will produce quantized pulses at a rate dependent on the input signal current. The time at which these pulses arrive at the synchronizer is resolved and determines the digital data stream. Both on-chip superconductive decimation and ratio programmable room temperature decimation will be used to vary the sample speed and accuracy of the final samples. The work will increase the number of synchronizer elements and thus timing accuracy within a clock cycle and increase the clock speed of the current design. Perfection of chemical mechanical polishing, improved lithographic resolution of devices, and an increase in the speed of the interface to room temperature circuits is required for success. Progress: A complete 20 GHz ADC design was finished, including a new front-end and a new digital filter. The circuit showed 20 GHz operation of the separate ADC sections after the first design iteration, substantially higher than the previous maximum of 13 GHz. A 25 GHz digital filter design was completed and operated properly in a four-bit implementation in the standard 3-um process. Room temperature interface and decimination filtering components were successfully tested up to 1 GS/s. Operation to 240 GHz was demonstrated in a toggle flip-flop fabricated using SUNY's 1.5-um process. The in-house 1.5-um process has demonstrated high-Jc 100 shunted-JJ arrays and the conversion of digital cell library to this new process has begun. Title: High Speed Analog to Digital Converter with Large Dynamic Range & Programmable PI: Joseph Jensen HRL LABORATORIES LLC Address: 3011 MALIBU CANYON ROAD MALIBU, CA 90265 (310) 317-5250 Funding Agency: Office of Naval Research PR Number: 00PR00237-00 Award Number: N0001499C0144 Current End Date: 08-Apr-2002 Scientific Officer: Deborah Van Vechten Objective: Continue development of Pi Sigma Delta analog to digital converters demonstrated earlier using non ONR funding. This work will demonstrate the most critical component of an ADC, which, once finished, using lower technical risk components, is expected to meet the performance specifications expressed in the AMRFS BAA ONR 98-022 and so enable the concept of reconfigurable, multi-function receive apertures. Approach: Utilize a pi sigma delta analog-to-digital converter architecture consisting of 8 separate delta-sigma-modulator channels employing 4th order modulators clocked at 8GSPS. Different band width modes will utilize different numbers of channels (the narrower the BW, the fewer the channels). The modulator circuit sections will be implemented in 200 GHz fT, fmax low parasitic InP HBT IC technology. The decoder/ digital filter section required for a complete ADC will be implemented in software and the measured data will be processed off-line. A circuit layout database for the pi sigma delta-modulator section will be created and two iterations of this section will be fabricated, packaged in a commercially available high-speed package and tested for functionality in beam steering receivers. Progress: Work on the detailed circuit plans began in late spring 1999. The architecture planned uses a constellation of eight delta-sigma modulator channels clocked at 8 GSPS and combined so that the errors introduced by the modulators must be uncorrelated and cancel. A mathematical model has been developed to allow behavioral simulation of the planned continuous time DS modulators using conventional discrete time simulation tools for the noise transfer function. Title: The Effects of Impurities on Junction Behavior in High-Temperature PI: Michael Flatte UNIVERSITY OF IOWA Physics and Astronomy Address: Iowa City, IO 522421479 (319) 335-0201 Funding Agency: Office of Naval Research PR Number: 00PR00238-00 Award Number: N000149910313 Current End Date: 31-Dec-2001 Scientific Officer: Deborah Van Vechten Objective: Calculate the effect of different classes of impurities in the vicinity of free or interface surfaces on the behavior of superconductors and use the calculational results to explain experimental results of other ONR supported researchers. Approach: Apply the calculational approach for interface electronic structure developed under the previous ONR grant to calculate the supercurrent transport through arbitrary transparency junctions, the effect of strong and potentially time-dependent impurities such as uncompensated spin copper atoms, identify signatures in the IV curves of oxygen vacancies and excess concentration of cobalt atoms. Also include complexity of proper multi-band tight binding models of the band structure into the calculations. Progress: Parametrized versions of multiple electronic bands were included into the calculations of impurity effects on junction behavior. Good correspondence was found with STM measurements by J. C. Davis on impure BSCCO. Work to include the CuO chains also found in YBCO are mostly done and supercomputer time for these more complex calculations has been secured. Title: EXPERIMENTS ON SUPERCONDUCTIVITY AT MICROWAVE AND RADIO FREQUENCIES PI: Nai-Phuan Ong THE TRUSTEES OF PRINCETON UNIVERSITY Physics Dept. Address: FIFTH FLOOR NEW SOUTH BUILDING Princeton, NJ 085440636 (609) 248-4347 Funding Agency: Office of Naval Research PR Number: 00PR00239-00 Award Number: N000149810081 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: To understand the systematics of the truly inherent effects which occur when high temperature superconductors are subjected to simultaneous dc magnetic fields B and rf signals. The plasma resonance(perpendicular to the ab planes) phenomena will be evaluated for use as an absorption based sensor in the 30-300 GHz range. The basic nature of the photon detection process will be clarified by distinguishing thermal conduction by phonons and quasiparticles. An improved scanning microwave absorption probe will allow vortex pinning sites to be unambiguously identified and correlated to the sites of excess energy dissipation in thin film resonators supplied by Lucent Technologies. The work will improve our understanding of the HTS materials and our ability to build low loss, high power transmit, as well as receive, rf filters and more efficient microwave sensors. Approach: The experiments utilizing tilted magnetic fields to demonstrate the existence of plasma resonances will be extended up to 100 GHz and to lower temperatures using cavity techniques and Bi 2212. The determinants of the width and intensity of the resonance will be the chief focus. The same crystals will be used to investigate phonon vs. quasiparticle heat conduction near the phase transition (B field dependent) recently discovered by the PI. A near field scanning microwave absorption sensor will be constructed to operate in the 10-20 GHz range and used to explore the surface of untwinned YBCO crystals and films and submicron spheres of superconductors. This work will be correlated to work of ONR supported theorists. The device will also be used to improve the understanding of losses in YBCO rf filters in the 1-40 GHz band and could help improve tunnel barriers in the ramp edge Josephson junctions used in HTS digital logic. Progress: Detailed field dependence measurements of the thermal conductivity of YBCO have allowed unambiguous separation of the electronic and phononic contributions. The derived quasiparticle (electronic) mean free path increases smoothly from 0.1 micron at 90K to 0.5 micron at 10K. A scanned 25 to 110 GHz microwave spectrometer has been constructed and used to observe for the first time antiferromagnetic (AF) resonance lines in a manganite and cyclotron resonance in a 2D electron gas (GaAs-AlGaAs). Title: Expansion of Josephson Effect & Macroscopic Quantum Interference in Superfluid 3He PI: James Davis THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BERKELEY Department of Physics Address: 366 Le Conte Hall Berkeley, CA 94720 (510) 642-4505 Funding Agency: Office of Naval Research PR Number: 00PR00240-00 Award Number: N000149411008 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: To complete a proof of concept demonstration of a superfluid quantum interference gyroscope having rotational sensitivity approaching 10^-9 of the earth's rotation rate. The goal of the expansion is to improve likelihood of successful completion of N00014-94-1-1008 which is developing a gyroscope predicted to have orders of magnitude with greater sensitivity than any existing unit. Approach: A toroidal shaped container, ultimately measuring a meter in diameter, will be micromachined in Si and interrupted symmetrically by arrays of 0.1 micron pores through a Si3N4 membranes placed across the ring. At each pore the superfluid mass flow equivalent of the Josephson effect in Dayem bridges will be manifested as a phase dependent difference in the flow rates between the arms, induced by the rotation of the torus. By measuring the critical current of 3He flowing in this system of channels, eventually with 1 part in 10^4 accuracy, the rotational phase contribution can be determined. This Sagnac effect should allow the rotational rate of the Earth to be determined. The approach of the expansion is to fund supply of cryogens more adequately so that actual experiments can be conducted for 8 months a year rather than only the 4 month allowed by current funding levels. Progress: The similarities and differences of superfluid 3He and superconducting Josephson junction were investigated: both display Fiske and Shapiro effects and the Current-Phase relation depends on sin (phase difference) near Tc. However, discrepancies appear at low temperatures and the superfluid case displays two intrinsic dissipation processes. Completion of a rotating cryostat and improved acoustic isolation chamber will enhanced the sensitivity of the gryoscope to be demonstrated early in fy00. Title: FUNDAMENTAL PROCESSES IN SUPERCONDUCTING NANOSTRUCTURES PI: Michael Tinkham THE PRESIDENT AND FELLOWS OF HARVARD COLLEGE Department of Physics Address: Pierce Hall Cambridge, MA 02138 (617) 495-3735 Funding Agency: Office of Naval Research PR Number: 00PR00241-00 Award Number: N000149610108 Current End Date: 31-Oct-2001 Scientific Officer: Deborah Van Vechten Objective: To understand the physics that determines the behavior of Single Electron tunneling Transistors (SET) and to work issues such as their connections to the outside world and operating temperatures which will effect their device applicability. These devices have features less than 100 nm in size in 2 if not 3 directions and are dominated by quantum mechanical effects. One dimensional strings of nanoparticles offer the possibility of elevated temperature operation and in any case appropriate size scale leads must be provided. Ultra small grains are revealing for the first time ever the detail of many particle energy states. Andreev reflection is visible and important to the tunneling process in superconducting SET. SET are still in their early stages of development but they are expected to be important in the mid term once commercial drivers push main stream solid state electronics into this size scale. The physics they reveal could halt the historic trend in electronics to smaller and smaller scale devices. Approach: In the smallest grains investigated, both the single particle (electron) energy levels and their perturbations due to the other electrons are directly observable for the first time. Using techniques of self-assembly, it is possible to string together tens of nanoparticles. Doing so allows a single set of electrodes to control a larger signal and thus allows higher temperature operation despite thermal noise. Carbon nanotubes are also being explored as growth templates for direct deposition of wiring in SET circuits and for the physics they exemplify. Superconducting SET continue to be studied in the context of what they reveal about Andreev scattering, a critical effect in the push for new HTS devices. Progress: Extremely small size devices have different electrical performance. Wires 50% smaller in diameter (10 nm) than previously reported displayed a 10^3 wider resistive transition and non-zero residual resistance. This places a lower bound on superconducting wire size. A record charge sensitivity of 10-5 e/Hz has been achieved at 100 kHz in a 1 MHz bandwidth in a cryogenic electrometer. The physics of lightning was used to assemble conducting micron-long chains of ~30 nm diameter particles. Title: SUPERCONDUCTORS IN AN EXTERNAL FIELD PI: Vladmir Kresin U S DEPARTMENT OF ENERGY OAKLAND OPERATIONS OFFICE Department of Energy Address: 1 CYCLOTRON ROAD, MS90-1070 BERKELEY, CA 94720 (510) 486-4126 Funding Agency: Office of Naval Research PR Number: 00PR00242-00 Award Number: N0001498F0052 Current End Date: 30-Oct-2000 Scientific Officer: Deborah Van Vechten Objective: To develop and validate by direct comparison to experimental data a detailed, predictive theory of the high temperature superconductors (HTS). Specifically the role of spin-flip scattering in determining the microwave surface resistance and energy relaxation processes, the mechanism of photoinduced superconductivity, and the importance of 'electronic sound'. The first three topics are directly relevant to improving the performance of these HTS materials in high performance filters, an important Navy application. Approach: Work directly with experimentalists in trying to model the effects observed. The PI has developed a model whereby spin-flipping scattering by magnetic impurities becomes frustrated when the directions of the individual moments becomes correlated. This model will be extended to predict microwave surface resistance and comparison made to data from Wuppertal on the dependence of (and especially reduction in) Rs on applied magnetic field. The role of magnetic scattering on the energy relaxation process which follows high energy absorption events will be investigated jointly with 3 other theorists. The mechanism of long term photoinduced superconductivity will be modeled in conjunction with European researchers. Work will also proceed on the issue of explaining existing heat capacity measurements in terms of the unusual plasmon excitation spectrum caused in part by the anisotropy of the HTS materials. It is anticipated that when NRL experimentalists complete measurements of proximity effect samples of HTS and LTS or semiconducting materials, an active exchange will follow. Progress: Earlier models of the IV of step-edge junctions were successfully generalized to deal with the less damaged interface of bicrystal grain boundary junctions. The effect of an inhomogeneous distribution of critical temperatures on the collective behavior of devices was analyzed and used to explain why overdoped Tl-based cuprates display the magnetic and resistive signatures of superconductivity at different temperatures. The unusual superconducting properties of the borocarbides were understood. Title: A Microscopic Description of the Josephson Junction Interface PI: James Freericks GEORGETOWN UNIVERSITY Physics Department Address: 37th & O Streets Washington, DC 20057 (202) 687-6159 Funding Agency: Office of Naval Research PR Number: 00PR00243-00 Award Number: N000149910328 Current End Date: 30-Dec-2002 Scientific Officer: Deborah Van Vechten Objective: Historically the tunnel barriers of superconducting Josephson junctions have been selected in terms of the fabrication compatibility with the superconductor - no chemical reactivity or interdiffusion, stability at process temperatures, flatness of layers - and simple measures of its electrical properties, especially the resistivity. This approach has not yet worked well for the high transition temperature materials. This award seeks to actually model from first principles electrical transport through a barrier for a variety of materials which are insulating for different physical reasons and to do this for both s and d wave (LTS and HTS) superconductors. Once complete, this work will provide important guidance as to how to select the most appropriate barrier for HTS JJ, important information if the HTS materials are to be applied to Navy relevant high performance signal processing requirements in advanced systems such as AMRFS. Approach: A microscopic lattice model for charge transport which averages over the planes parallel to the interfaces that define the Josephson junction and retains the perpendicular to the interface variation is to be developed. The model will be solved numerically to determine the critical current and the junction resistance. The solution will use either dynamical mean-field theory or more sophisticated methods such as the dynamical cluster approximation depending on the locality of the fluctuations. The model parameters (electron density, electron-electron interaction strength, bandwidth, etc.) and the types of interface (semiconductor, Mott insulator, polaronic insulator, antiferromagnetic insulator, Kondo insulator, etc.) will be varied to determine how to optimize the properties of the Josephson junction for both s and d wave superconductors. Progress: Successfully developed algorithms to predict the temperature dependence of the critical current from the phase difference between the superconductors and the junction resistance. The code (which uses fast continued-fraction representations inmomentum space) is over two orders of magnitude more computationally efficient than conventional Bogliubov-Degennes methods. Testing for doped semiconductor barriers nearly complete; comparison to experiment on InAs devices arranged. Title: Optimization of Jc in BSCCO Tapes PI: Eric Hellstrom THE BOARD OF REGENTS OF THE UNIVERSITY OF WISCONSIN Dept of Materials Sci & Engineering Address: 750 UNIVERSITY AVENUE MADISON, WI 53706 (608) 263-9462 Funding Agency: Office of Naval Research PR Number: 00PR00244-00 Award Number: N000149910323 Current End Date: 30-Jun-2000 Scientific Officer: Deborah Van Vechten Objective: The critical current density of long conductors made of BSCCO 2212 superconductors is much lower than that of short wires. The reason is hypothesized to be the difficulty in achieving interconnected and properly aligned 2212 grains from a melt whose composition is in the single phase regime - the 2212 phase melts incongruently. The goal of this work is to see if starting compositions in the "primary phase" regime (from whose melt 2212 phase crystals form directly) will end up producing well oriented, interconnected assemblies of grains that can support high current density, even though second phase species will necessarily be present. Power applications of HTS materials will be enabled by the work. Approach: Prepare powders with several compositions within the primary phase regime and determine the reaction, liquification and solidification temperatures using thermo-gravimetric analysis. Use quench studies and SEM analysis to monitor the phase evolution and homogeneity of the finished tape. Compare to conventionally processed tapes. Title: A Cryogenic Loop for Cooling Spatially-Separate Electronics Components PI: Reza Shekarriz ADVANCED THERMAL AND ENVIRONMENTAL CONCEPTS INC Address: 11890 Old Baltimore Pike Beltsville, MD 207050000 (301) 931-1449 Funding Agency: Office of Naval Research PR Number: 00PR00245-02 Award Number: N0001499C0145 Current End Date: 15-Jun-2000 Scientific Officer: Deborah Van Vechten Objective: To determine if electro-hydro-dynamical pumping (EHD) can provide the fluid drive required to realize spatially localized cryogenic cooling via substrate channels for both superconducting and optimized semi-conducting chips. Performance goals are 0.1 to 10 W of heat lift at 70-80K and low electromagnetic noise. If successful, the use of high performance cryogenic filters and digital signal processors in spatially constrained settings (such as AMRFS receive arrays) and in close physical proximity to electronics not requiring cooling will be enabled. This will help the Navy derive benefit from the significant advantages these devices offer. Approach: Conduct a feasibility study by constructing a model heat loop in the laboratory which utilizes EHD electrodes in MEMs scale channels as the pump. Test its cooling capacity against an electrical heater as a function of drive voltage in the 0-10V range using nitrogen as a single phase liquid and gas and as a fluid which evaporates at the site to be cooled. Determine the heat lift available and the electromagnetic noise created by the flow. Progress: The prototype pump has been designed and tested at room temperature using a laboratory standard fluid. Plans for testing at GSFC with liquid nitrogen and at low temperatures are well advanced. Title: SPIN INJECTION AT FERROMAGNET - SEMICONDUCTOR AND FERROMAGNET - SUPERCONDUCTOR INTERFACES PI: Mark Johnson NAVAL RESEARCH LABORATORY Materials Science and Technology Division Address: 4555 Overlook Avenue SW Washington, DC 203755320 (202) 404-8485 Funding Agency: Office of Naval Research PR Number: 00PR00246-01 Award Number: N0001400WR20011 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: Work is needed to increase the on-state resistance of an individual mesoscopic magnetoquenched superconducting valve if the read-out of stored value is to be a simple to implement operation. These MMSV may be useful as dense, low power, non-volatile and rad hard memory for superconducting digital circuits if this problem can be solved. Currently the lack of memory with these characteristics forces superconducting logic circuits to utilize semiconducting memory which cannot be located in close proximity to the processors or very small (<4 KB), superconducting memories. Superconducting circuits could thus become much more functional and useful in Naval receivers. Approach: Use N metal overlayer to tune the Tc of the superconducting stripe driven normal by the fringing B field closer to the bias temperature of the memory element. Doing that should increase the volume driven normal in the on state and thereby the resistance in normal state. Progress: Development of the Mesoscopic Magnetoquenched Superconducting Valve (MMSV) device is continuing. Initial Nb samples show a factor of 2 suppression of Ic at 4K which can be made much larger by decreasing the bridge's Tc. Other devices demonstrated switching of the spin polarization by current pulses in write wires and a two magnetic layer variant that has higher potential packing density than the 1 layer projected 1 Mbyte per cm2. Designs are complete for switching speed testing at HYPRES. Title: Doped SrTi03 Films for Josephson PI: John Price THE REGENTS OF THE UNIVERSITY OF COLORADO Department of Physics Address: 206 armory Campus Boulder, CO 803090019 (303) 492-2484 Funding Agency: Office of Naval Research PR Number: 00PR00247-00 Award Number: N000149910360 Current End Date: 31-May-2002 Scientific Officer: Deborah Van Vechten Objective: SrTiO3 (STO) can be shifted from an insulator to a low carrier density (super) conductor by doping with Nb. While pure STO is studied in thin film form due to the utility as its voltage tunable dielectric constant, the doped form is a potential tunnel barrier for YBCO based HTS Josephson junctions. The goal of this award is to test the latter application -an improved junction fabrication process, especially an improved tunnel barrier- which is required if the highly useful digital applications superconductivity enables are to be realized at temperatures much above 10K. Approach: A previous ONR award explored the dopant dependent properties of Nb:STO and learned how to make the films reproducible. This award will develop an SNS HTS junction technology based on YBCO/Nb:STO/YBCO trilayers (which could be etched to define junctions in processes paralleling that of Nb/AlOx/Nb trilayers in LTS) and bilayers (which defines the junction by removing S material). This approach will utilize the low defect density and extreme stability, even to oxygen loss, of Nb:STO and its excellent epitaxial compatibility with both YBCO and substrate materials. Material will be deposited at U Colorado and, in some cases, finished into junctions as part of collaborations with NIST (Benz, Ono) and others who are expert in HTS JJ fabrication and test. Another collaboration with Freericks at Georgetown will help define the physics of tunneling using single devices that can be made to undergo the metal insulator transition and some work will be done to look at FET style devices using bilayer samples. Progress: Nb-doped strontium titanate thin films may enable nm scale bilayer HTS Jospehson junction fabrication. Nb doping the target controllably produces metallic films: carrier concentrations > 1?1019 cm-3 and mobility > 70 cm2/Vs. Ar was added to the deposition system to improve the uniformity of ion bombardment. Hc2T(T) measurements indicate the material is a very low carrier density s wave superconductor, as well as the first example of a thermodynamically stable and field depletable superconductor. Title: RESONANT QUANTUM EXCITATION IN OXIDE SUPERCONDUCTORS PI: T. Venkatesan UNIVERSITY OF MARYLAND AT COLLEGE PARK Department of Physics Address: College Park, MD 20742 (301) 405-7320 Funding Agency: Office of Naval Research PR Number: 00PR00248-00 Award Number: N000149810284 Current End Date: 28-Feb-2000 Scientific Officer: Deborah Van Vechten Objective: To shed experimental light on the relationship between the structure and chemical constituents of the unit cell in real samples (with defects) and the appearance of superconductivity in the high transition temperature materials. The resonant response to optical absorption will be utilized. Approach: To determine whether the recently observed, frequency dependent, enhanced pair-breaking following photon absorption is a true resonant phenomena in YBCO. Then formulate a model of the effect which identifies the causal structural and compositional features and test using other superconductors. Progress: Temperature dependent fine structure in the pair breaking resonance has been detected. The spacing appears to correspond to that expected from antiferromagnetic fluctuations in oxygen depleted regions. The current hypothesis is that the term is from the electronic density phase segregation known as stripes. This hypothesis will be evaluated in the renewal effort. Title: Lumped Josephson Junction Arrays for High Performance Communication, Networking, and Radar PI: Samuel Benz U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Electromagnetic Technology Division Address: 325 BROADWAY BOULDER, CO 80303 (303) 497-5258 Funding Agency: Office of Naval Research PR Number: 00PR00249-00 Award Number: N0001499F0042 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: Develop the ability to fabricate an electrically "lumped" series array of superconducting Josephson junctions that will enable a super-conducting digital-to-analog converter capable of directly generating arbitrary wave forms with useful voltage amplitudes and phase noise low enough to be useful in Doppler radar. Such units are expected to be able to operate over the range of carrier frequencies and functionalities appropriate to AMRFS. "Distributed" arrays display greater frequency sensitivity and generally poorer performance, especially in regard to the maximum voltage swing. Approach: To act as a lumped element at 20 GHz, the array must occupy less than 2 x 2 microns. Yet to produce by itself a 1 V signal amplitude, that area must contain of the order of 30,000 junctions that work together to produce over 10^14 SFQ pulses per second. Ramp edge HTS junctions are impossibly large. Arrays with a variety of junction spacings will be produced in HTS using both electron and ion beam damage at Cambridge University (separate ONR award). LTS versions using from Nb/PdAu bilayers and e beam written lithography could be made at NIST if essential. Junction uniformity, interactions, and suitability for application to the DAC will be investigated. Progress: A focused ion beam is being used to etch arrays of superconductor-normal metal-superconductor junctions by controllably removing a portions of the top layer of S every 200 nm or less. Small arrays have been fabricated and delivered to NIST using Nb/PdAu bilyers. More complex coupling effects appear for spacings <~150nm. The reproducibly high-quality junctions showed Josephson coupling which scaled qualitatively with barrier properties and temperature as expected. Title: HTS Lumped Josephson Junction Arrays for High Performance Communication, Networking and Radar PI: Mark Blamire UNIVERSITY OF CAMBRIDGE Department of Materials Science and Metallurgy Funding Agency: Office of Naval Research PR Number: 00PR00250-00 Award Number: N000149910146 Current End Date: 30-Nov-2000 Scientific Officer: Deborah Van Vechten Objective: Develop the ability to fabricate an electrically "lumped" series array of superconducting Josephson junctions that will enable a super-conducting digital-to-analog converter capable of directly generating arbitrary wave forms with useful voltage amplitudes and phase noise low enough to be useful in Doppler radar. Such units are expected to be able to operate over the range of carrier frequencies and functionalities appropriate to AMRFS. "Distributed" arrays display greater frequency sensitivity and generally poorer performance, especially in regards to the maximum voltage swing. Approach: To act as a lumped element at 20 GHz, the array must occupy less than 2 x 2 microns. Yet to produce by itself a 1 V signal amplitude, that area must contain of the order of 30,000 junctions that work together to produce over 10^14 SFQ pulses per second. In this work arrays with a variety of the repeat distances between junctions below 100 nm will be produced in HTS using both electron and ion beam damage. Junction uniformity, independence of operations, and suitability for application to the DAC will be investigated. Progress: A focused ion beam is being used to etch arrays of superconductor-normal metal-superconductor junctions by controllably removing a portions of the top layer of S every 200 nm or less. Small arrays have been fabricated and delivered to NIST using Nb/PdAu bilyers. More complex coupling effects appear for spacings <~150nm. The reproducibly high-quality junctions showed Josephson coupling which scaled qualitatively with barrier properties and temperature as expected. Title: HIGH-RESOLUTION ANGLE - AND SPIN-RESOLUTION PHOTOEMISSION STUDIES OF INTERFACE ISSUES OF MAGNETIC AND SUPERCONDUCTING MATERIALS PI: Zhixun Shen THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY Sponsored Projects Address: 125 PANAMA ST JORDAN QUAD BIRCH Stanford, CA 943054055 (415) 723-4659 Funding Agency: Office of Naval Research PR Number: 00PR00251-00 Award Number: N000149810195 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: To improve our understanding of the surface physics of both high temperature superconductors and magnetic materials and the interfaces which form when they are layered on one another. For the magnetic materials, the goal is to determine the angle and spin resolved density of states in the magnetic state and understand how these impact the transport of spin polarized current into overlayers of normal metals. Superconducting materials will then be added to form spin current sensing devices. A second effort will look at the viability of stabilizing the surface states revealed by low temperature cleaving by gaseous passivation. If successful, this could lead to the development of ways of avoiding degraded surface layers in fabricating HTS structures such as the Josephson junctions used in digital electronics. The former effort is part of the DRI on spin-injection devices. Improvements in the quality of circuits delivered to Navy applications requiring high performance electronics such as ship self defense and AMRFS is predicted. Approach: To fabricate extremely high quality samples and measure them extremely accurately. The magnetic/normal metal work will be done by taking high quality single crystals such as Ni and Co, cleaning the surface well, and depositing layers of Cu, Ag, and Au (different spin-orbit scattering) a few atomic layer thick on top. These would then be measured with angle resolved photo-emission (APRES) having 4 meV energy resolution, LEED, and STM in-situ with the deposition at a new facility at the Advanced Light Source. SMOKE will be used to measure the magnetic properties. The surface passivation work has already shown there is a disordering of the well-order bare surface as the temperature is raised. By adding gases to the cleavage chamber and monitoring using ARPES as the temperature is changed, the chemical shifts caused by the adsorbate can be deduced. If any are found that substantially delay the onset of disorder (H is similarly used to passivate dangling bonds in amorphous Si), then industrial contacts will be solicited to intentionally add the reactive species to the deposition environment near the end and after the deposition. Questions to be answered are whether, and how uniformly, the gas is incorporated and with what effect on the electrical properties of subsequently processed devices. The structure of "engineered interfaces" (intentionally oxygen depleted) will also be determined. Progress: The technical problems of introducing ozone into a UHV environment have been solved to the point where degradation of a newly exposed YBCO surface by contaminant water and CO2 is mostly under control. This is a necessary first step toward being able to detect the shifts in surface oxygen states using ARPES and to study potential YBCO passivation structures, the goal of this work. Title: Growth & Microwave Studies of Nonlinear Dielectric Films for Tunable High Temperature Superconductor Microwave Electronics PI: Charles Rogers THE REGENTS OF THE UNIVERSITY OF COLORADO Dept of Physics Address: Boulder, CO 803090019 (303) 492-4476 Funding Agency: Office of Naval Research PR Number: 00PR00252-00 Award Number: N000149710141 Current End Date: 30-Sep-2002 Scientific Officer: Deborah Van Vechten Objective: To enable thin-film capacitors with wide tuning (>30%) and dielectric loss tangents below 2 x 10-4, an order of magnitude better than achieved today. In combination with the small fields required to tune (1 V/mm) STO, these properties will enable wide-band tunable filters and other microwave circuit elements of interest to the Navy in systems such as AMRFS. Approach: The origin of dielectric losses in STO thin films will be understood via a systematic study of film growth conditions, liftoff processes, and their impact on microwave dielectric response. In addition to these processing studies, the dielectric response dependence on temperature, electric field and applied strain will be studied. Progress: Efforts have focused on improving the dielectric properties of STO via optimization of growth conditions and monitoring using in situ optical ellipsometry. The resultant STO films on LAO substrates have the highest dielectric tuning and lowest microwave losses ever reported at microwave frequencies. A method for lifting-off epitaxial films of STO was developed that produced films with twice as large dielectric tuning as the best films on LAO and approaching those observed in bulk STO crystal. The existence of In situ optics allows more rapid reoptimi-zation of growth conditions when chamber instrumentation is altered and essentially needs recalibration. Title: Expansion of "Demonstrations of Ultra-High-Speed and Dense Circuits using Unique Nb IC Fabrication†PI: Theodore Van Duzer THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BERKELEY Regents/Sponsored Projects Address: 336 Sproul Hall Berkeley, CA 94720 ( 51) 064-3306 Funding Agency: Office of Naval Research PR Number: 00PR00308-02 Award Number: N000140010003 Current End Date: 30-Sep-2002 Scientific Officer: Deborah Van Vechten Objective: Will advance state-of-the-art in digital superconducting electronics both in regard to processing speed of minimal sized ADC and ability to realize complex circuits. The clock speed aspect will include fabrication using UCB demonstrated output 10 GHz amplifiers and 10 fold larger Jc devices of circuits designed at Northrop Grumman to provide performance well beyond the Walden curve needed in systems such as AMRFS. The complex circuit will initially be the digital SQUID of SUNY-SB which is expected to strongly enable the application of SQUIDs to medicine, especially heart disease detection, by eliminating the costly (>$1M) need for a magnetically shielded testing environment. Approach: This work will confirm the high device quality possible with an NbN/TaN/NbN layer structure and measure the spread in junction parameters. Since they have much thicker barriers, achieving the <2% parameter spreads needed to yield a functional circuit is expected to be easier than for the currently standard device structure. Title: Noise and Superconducting Devices PI: Clare Yu THE REGENTS OF THE UNIVERSITY OF CALIFORNIA IRVINE Dept. of Physics & Astronomy Address: 115 ADMINISTRATION BUILDING IRVINE, CA 92717 (949) 824-6216 Funding Agency: Office of Naval Research PR Number: 00PR00309-00 Award Number: N000140010005 Current End Date: 30-Oct-2003 Scientific Officer: Deborah Van Vechten Objective: Electrical noise in the circuit is the factor which limits the detection range and sensitivity of SQUID sensor based systems such as the unexploded ordnance finding system of NCSC-Panama City. At the other extreme of frequency, phase noise may limit the functionality of high speed digital systems. This award will devise ways to remove the current error of factors of 10 or more from predictions of noise performance based on fundamental theory and provide guidance to improving performance. Approach: This small scale effort will start by reviewing the literature on noise in SQUIDs and simulations of bit error rates and other manifestations of digital phase noise. Then the theoretical literature will be surveyed to find the most relevant fundamental research. Finally these existing theories will be combined to produce a predictive model and the result compared to existing noise data. Title: Microwave Losses in Tunable Device PI: S. Sridhar NORTHEASTERN UNIVERSITY Distinguished Professor of Physics Address: Physics Dept Boston,, MA 02115 (617) 373-2930 Funding Agency: Office of Naval Research PR Number: 00PR00310-00 Award Number: N000140010002 Current End Date: 30-Sep-2002 Scientific Officer: Deborah Van Vechten Objective: To increase the performance advantage of superconducting rf filters by testing a magnetic loss hypothesis and, if proven, frustrating the loss mechanism. The resultant materials improvement will make such HTS filters the obvious candidates for use in Navy multifunction rf systems such as AMRFS. Approach: The possible relationship between microwave loss and non-linear behavior and the motion of fluctuating localized regions of antifer-romagnetic order within globally superconducting samples will be explored. If a causal relationship is proven to exists, methods of reducing the undesirable behavior will be devised. Title: Process Development for High Speed Superconductor Logic PI: James Lukens THE RESEARCH FOUNDATION OF THE STATE UNIVERSITY OF NEW YORK AT STONY BROOK Department of Physics Address: W-5510 MELVILLE LIBRARY STONY BROOK, NY 117943300 (516) 632-8081 Funding Agency: Office of Naval Research PR Number: 00PR00319-00 Award Number: N000149910374 Current End Date: 28-Feb-2002 Scientific Officer: Deborah Van Vechten Objective: To dramatically increase the clock speed at which moderately complex Nb Josephson junction circuits have been demonstrated to operate. The world's record circuit speed of 770 GHz, ~10X the fastest demonstrated semiconductor circuit, was done for a quite simple divide-by-2 circuit. Success in this effort will allow technology transfer to industry and an increase in clock speeds from about 15 GHz today for useful circuits such as ADC to about 100 GHz. Once there, they will be of great utility to systems such as AMRFS that want to process wide ranges of the electromagnetic spectrum at one time and without any frequency down-conversion. Approach: To improve the process spreads and design rules as the linewidth is shrunk first to 1.5 microns and then 0.8 microns, and finally to 0.5 or less. At each stage work to increase the complexity of the circuit demonstrated without deteriorating the yield. Progress: The initial goal of the ADC critical components demonstration has been defined to use junctions 1 micron on a side. The resultant devices will have junction areas nearly an order of magnitude smaller that those made with present HYPRES technology. Initial discussions of design rules were conducted and an initial fabrication run this summer at Stony Brook based on HYPRES circuit layouts planned. Title: Ka-band HBT Phased Array Technology PI: Marko Afendykiw NAVAL AIR WARFARE CENTER WEAPONS DIVISION RF Guidance & Analysis Branch Address: Code 087 China Lake, CA 935556001 (619) 939-2845 Funding Agency: Office of Naval Research PR Number: 00PR00371-00 Award Number: N0001400WR20050 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: This work seeks means of providing high performance amplifiers at 40 GHz and below with acceptable 1/f noise figures to be used in missile tracking and intercept E/M systems. Specific objectives include an output power of 1.5 watts at 30% duty cycle, 200 nanosecond pulse width, and 24 db gain with 30% power added efficiency. The effort is divided between industry and in-house. Approach: GaAlAs:GaAs heterojunction bipolar transistors will be designed and tested. Performance will be optimized by achieving higher gain via a better tradeoff between collector transit time and breakdown voltage and by reducing parasitic capacitance between collector and base regions. Further improvement will be achieved by better thermal design. Contract effort is focused on device topological configuration improvements to reduce parasitics and the use of InP/InGaAs to achieve power and low noise in a single material and device type. In-house the approach has been to develop extensive testing and evaluation of the HBT technology that is being developed. Test capabilities include linear and non-linear network analysis, on-wafer characterization and passive load-pull system. Progress: During this period collector under cut AlGaAs/GaAs HBTs were modelled and tested. Modelling shows the expected improvement in the maximum frequency of oscillation, however; this was not seen experimentally in the large signal power or gain. The speculation was that the lack of experimental improvement was due to reduced thermal properties of the under cut HBT. Work was also initiated on an InGaP collector HBT that should offer superior performance over the AlGaAs/GaAs device due to better breakdown and surface properties. Title: Frequency Converters PI: Dean Nathans SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO NCCOSC RDTE DIV Address: Naval Command, Control & Ocean Surveillance Center San Diego, ca 921525001 (619) 553-1283 Funding Agency: Office of Naval Research PR Number: 00PR00372-01 Award Number: N0001400WX20045 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: To develop integrated circuits implementing L-band and higher microwave band functions for high rate communications, sensor and information systems. A reduced size(MMIC) synthesizer with low phase noise is desired for use in UAVs. The synthesizer should provide for the possibility of incorporation of frequency hopping capability. Also desired is a miniaturized RF translater that through monolithic integration(bandpass filters, RF preamp, mixer, l.O., IF filter/amp) would produce a common module that could be used in multiple receiver spread spectrum TDMA systems such as JTIDS and MIDS. Approach: The frequency synthesizer exploits GaAs X-band HBT MMIC technology together with a commercially available phase detector IC. The RF translater is also expected to exploit MMIC technology. Progress: The contract to Hittite is continuing with a modified design to reduce the fabrication cost of the monolithic RF translator. Cost sharing from the MIDS program office was negotiated and the funding level from ONR was adjusted to move the program forward. Title: MICROWAVE TUNABLE ACTIVE FILTERS PI: Christen RAUSCHER NAVAL RESEARCH LABORATORY CODE 6851 Address: NAVAL RESEARCH LABORATORY WASHINGTON, dc 203755347 (202) 767-3526 Funding Agency: Office of Naval Research PR Number: 00PR00373-00 Award Number: N0001400WR20016 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: Develop techniques to realize compact, highly-selective tunable microwave filters for use in high-dynamic-range, multifunction transmit-receive and receive-only modules. Approach: Will focus on two main tasks: 1) the derivation and experimental demonstration of improved circuit architectures and 2) the development and demonstration of an improved semiconductor varactor technology. Progress: Work has concentrated on demonstrating a new low-loss heterostructure varactor for use in a tunable notch filter, and on developing a suitable test bed for verifying device performance. After extensive computer simulations, heterostructure material was grown to specification by MBE, comprising 15 layers of 50 Angstrom thick Si-doped GaAs interleaved with 1000 Angstom thick layers of undoped AlGaAs. The test-bed circuit encompasses two frequency-tunable bandpass filters separated by an MMIC amplifier, and is designed to maintain constant instantaneous bandwidth across the tuning range. Varactors and test filter are in the final stages of fabrication and assembly, respectively. Work has focused on the realization of heterostructure varactor diodes for use in a tunable notch filter, and on the development of a suitable test-bed circuit for verifying device performance. Two diode fabrication runs were completed, employing layered GaAs-AlGaAs material grown previously by MBE. A tunable active bandpass filter, to serve as test bed, was successfully implemented in hybrid-integrated-circuit form. The circuit was tested, using conventional GaAs varactor diodes. As predicted, the response maintained a constant absolute passband width across the specified 6-7 GHz tuning range. Title: ULTRA HIGH SPEED InP BASED E/D HEMT ANALOG TO DIGITAL CONVERTERS PI: Ilesanmi Adesida THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN DEPARTMENT OF ELECTRICAL & COMPUTER ENGR. Address: 208 N. WRIGHT STREET URBANA, il 61801 (217) 244-6379 Funding Agency: Office of Naval Research PR Number: 00PR00374-00 Award Number: N000149810376 Current End Date: 28-Feb-2001 Scientific Officer: John Zolper Objective: To demonstrate A/D converters with state-of-the-art InP based high electron mobility transistors. Approach: InP based enhancement and depletion mode HEMTs will be fabricated using selective recess etching to achieve high performance and high yield A/D circuits. Progress: Work has focused on improving the performance of enhancement-mode InAlAs/InGaAs/InP HEMTs. Whereas previous work on HEMTs utilized heterostructures with electron sheet density of 0.7E+12 cm-3, new layers have a sheet density of 1.0E+12 cm-3. The aim is to enhance the unity current-gain cut-off frequency to well over 100 GHz. A novel Pt/Mo gate metallization is being developed for the E-mode HEMTs in order to ensure a reliable self-limiting Pt reaction with InAlAs for a more uniform threshold voltage. This will also allow a single-step annealing process for the gate and ohmic metallizations. Work has commenced on developing realistic circuit models for HEMTs. Simple circuits have been designed and laid out consisting of differential pairs of E/D HEMTs in order to determine device matching characteristics. Title: Wide Bandgap Broad Bandwidth HBT Amplifiers PI: William Schaff CORNELL UNIVERSITY Department of Electrical Engineering Address: 415 Phillips Hall Ithaca, NY 14853 (607) 255-3974 Funding Agency: Office of Naval Research PR Number: 00PR00375-00 Award Number: N000149810015 Current End Date: 14-Oct-2000 Scientific Officer: John Zolper Objective: To develop and demonstrate heterostructure bipolar transistor (HBT) amplifiers with required bandwidth, linearity, and efficiency. The dominant element in development of these amplifiers will be the capabilities of the HBT. This program will develop a GaN-emitter SiC-base-collector HBT suitable for meeting high performance amplifier requirements. While the high temperature capability of wide bandgap transistors required for high power operation is known, HBT device parasitics need to be minimized for amplifier applications. Approach: Both materials growth and device process developments will be undertaken to develop a high performance GaN/SiC HBT. Starting with commercially available SiC epitaxial layers of the the collector and subcollector, additional SiC and/or GaN layers will be grown by either chemical vapor deposition or molecular beam epitaxy. High level p-type doping of SiC, as required for the HBT base, will be developed via either epitaxial growth or ion implantation. Flip chip bonding will be applied to the HBT to optimize heat removal from devices during high power operation to enhance circuit efficiencies. Class B power amplifier will be developed based on the proposed HBT. The amplifiers will be designed to minimize backward wave propogation on the trans-mission line. This will involve new circuit design approaches. Progress: Modelling was performed of WBG HBT DC characteristics. Developed alternative HBT designs to include piezoelectric effects. Developed single step techniques for epitaxial growth of GaN on SiC for formation of GaN emitters on a SiC base and collector. Began fabrication of Base-Collector diodes to characterize deep levels in p-SiC which might limit electron lifetimes and HBT gain. Began design of HBT process including: layout of e-beam lithography masking for cascade probe RF HBT transistors and characterization of dry etching. The project remains on schedule. Established spontaneous and piezoelectric effects in AlGaN/SiC base-emitter junction designs. Began process development to address the polarization effects -patterned base mesas to extend nitride critical thickness AlGaN emitters to raise valence band offset for 4H SiC heterostructures. Began evaluation of nitride/carbide inter-face intermixing. Conceived a wafer bonding process to mate N-face GaN with Si-face SiC. -------------------------- More ----->
[Edited 1 times, lastly by Alpha-Theta on 07-25-2002]

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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:21 PM
Title: High Resolution Transferred-Substrate HBT Microwave / RF ADCs PI: Mark Rodwell THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Department of Electrical and Computer Engineering Address: CHEADLE HALL ROOM 3227 Santa Barbara, CA 93106 (805) 893-3244 Funding Agency: Office of Naval Research PR Number: 00PR00441-00 Award Number: N000149810830 Current End Date: 31-Aug-2001 Scientific Officer: Deborah Van Vechten Objective: Seeks new approaches to versatile analog to digital converters wherein the resolution-bandwidth relationship can be dynamically reprogrammed and wherein new low parasitic heterojunction bipolar transistors are employed to increase performance. Approach: Low parasitic, transferred substrate heterojunction bipolar transistors will be used with deep submicron lithographic resolution and connected in a delta-sigma configuration. Progress: UCSB has completed definition of the operating parameters and detailed design of the individual subcircuits of a >20 GHz clock, single-bit quantizer based, delta- sigma design. Masks layout (4 ADC design variants) used up to 350 HBTs. Distortion cancellation techniques were invoked to insure the needed SFDR and the electroplated copper substrate perfected to dissipate sufficient heat. Fabrication and testing has begun. UCSD has begun work on mismatch-shaping DACs with reduced gate count. Title: Multifunction Wideband, High Resolution, 1 GHz Analog-Digital Converter (ADC) PI: William Skones TRW INCORPORATED SPACE AND TECHNOLOGY DIVISION Electronic Systems Group; M/S M5/1454 Address: One Space Park Redondo Beach, CA 90278 (310) 813-2420 Funding Agency: Office of Naval Research PR Number: 00PR00442-02 Award Number: N000149920004 Current End Date: 30-Mar-2002 Scientific Officer: Deborah Van Vechten Objective: Develop a hybrid ADC consisting of a new 3 bit sigma delta ADC composed of high fT InP HBTs with the loop residual sampled by a 9 GaAs Nyquist Subranging ADC developed under other government contracts. This ADC is expected to meet the performance specifications expressed in the AMRFS BAA ONR 98-022 and so enable the concept of reconfigurable, multi-function receive apertures. Approach: Use a hybrid architecture to achieve the high SINAD of sigma delta ADCs and the high SFDR of a Nyquist ADC without going to the very high sample rate required in a pure sigma delta design. Utilize both the current state of the art Ft>100 GHz InGaAs/InAlAs/InP IC technology and the >200 GHz improvement currently under ONR funded development. Correct the DAC errors outside the loop and work hard to improve the loop filter performance. FPGA will be used in the back end combining logic to prove the design before custom ASIC production. Progress: The initial iteration of design work has nearly completed the detailed circuit designs. HBT device improvement continues with toggle flip flops executing at above 65 GHz. Title: A Study of the Switching Speed of Magnetoquenched Superconductive Devices & their Applicability to Practical Superconductive Electronics PI: Steven Kaplan HYPRES INC Address: 175 Clearbrook Rd Elmsford, NY 10523 (914) 592-1190 Funding Agency: Office of Naval Research PR Number: 00PR00444-00 Award Number: N0001499C0128 Current End Date: 31-Dec-2001 Scientific Officer: Deborah Van Vechten Objective: Mesoscopic Magnetoquenched Superconducting Valves (MMSV) were demonstrated using lead for the superconductor in fy98 at NRL under ONR support. These devices are a leading possibility for on-chip memories for use with niobium (Nb) based digital circuits operating in 100 GHz SFQ logic systems at 4 K. The objective of this effort is define more clearly the set of requirements for such memory and help evaluate the MMSV and other magnetic concepts. The devices are needed for the proposed petaflop computer to provide low power, fast cache memory close to the central processors, a function currently without good candidate devices. They also could be used in high fidelity DRFM applications and in the beam/function control portions of the AMRFS system. Approach: The approach is to work with Dr. Johnson of NRL and Prof. Beasley at Stanford to jointly test the viability of alternative magnetic memory devices for 4K digital systems. HYPRES will facilitate fabrication of niobium MMSV devices by providing wafers with Nb films on ground planes to NRL as needed and collaboratively design masks for high speed tests of the basic devices, to be done at HYPRES. Dr Kaplan will help Dr Beasley define the requirements of a memory device used by and near a high speed (100 GHz) SFQ superconducting circuit. Suitable probes will also be designed (8 high speed and multiple low speed lines) and purchased for use in testing at both NRL and HYPRES. Progress: Designs have been iterated and are ready for fabrication. New probe is on order. Title: Low-Loss High Speed Tunable Filters PI: Salvador Talisa NORTHROP GRUMMAN CORPORATION Address: PO Box 746 MS 1110 Baltimore, MD 21203 (410) 993-2910 Funding Agency: Office of Naval Research PR Number: 00PR00445-00 Award Number: N0001499C0157 Current End Date: 30-May-2001 Scientific Officer: Deborah Van Vechten Objective: To demonstrate room temperature pass band filters that can be switched as to center frequency by a set of MEMS actuated capacitors in combination with printed inductors. Units with 16 center frequencies in the 1-5 GHz band will be demonstrated, but preliminary designs for the 4-20 band will also be produced. Critical parameters include insertion loss <0.5 dB so that they can be used before the LNA in receivers, TOI >60 dB because there will be multiple signals received by every element, and switching times less than 1 microsecond. Low cost and MMIC compatibility are also requirements. These filters are needed to achieve adequate isolation in the AMRFS multiple simultaneous function context. Approach: The MEMS switches and filter designs have already demonstrated sufficient Q, TOI, power handling, and low insertion loss and LTCC is an appropriate packaging material. Similar switches have shown no failure after the equivalent of 10 yrs of switching every 200 microsec. What is most required is to decrease the MEMS switching time from a few microsec to less than 1 by modifying the geometrical design of the fixed electrode and its interaction with the moving electrode and shaping the control pulse. Measurements will be made of the noise added by these passive devices, but is expected to be low. Progress: This effort will combine MEMS, fixed lumped-element filters and low-temperature cofired ceramic (LTCC) packaging. The initial work will demonstrate switchable tuning of high Q filters using MEMS and proprietary miniature (lumped) inductors. Title: DENSELY PACKED ARRAYS FOR ANTI-JAM GPS PI: Donald Bowling NAVAL AIR WARFARE CENTER WEAPONS DIVISION Weapons Division Address: China Lake, CA 935556001 (760) 939-3089 Funding Agency: Office of Naval Research PR Number: 00PR00446-01 Award Number: N0001400WX20392 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: GPS receivers are one of the important applications where typical units lack sufficient size to deploy conventional halfwave length antennas due to the relatively large wavelength of the frequency used. This effort seeks to develop densely packed arrays of electrically small elements capable of active null steering to provide maximal protection against jamming. Approach: The effort will focus on alternative designs for densely packed arrays of electrically small elements that would fit within the 4 inch footprint of already deployed F-18 units. A capability to switch from omni-directional sensitivity to a mode where pattern nulls are dynamically pointed at jammers will be designed in. Selected designs will be simulated using IE3D and Aerospace Corp. adaptive beam steering capabilities program. The best design will then be fabricated in both normal metal and high temperature superconductors. Testing in TEM cell will determine both whether the design functions as expected and how much of a performance advantage the HTS version offers. A digitally beam-formed densely packed array will be demonstrated, with integrated cryocooler if HTS, by the end of the program. Progress: Sequential scanning of linear arrays is the basic element in the production of virtual doppler effects. Issues of mutual coupling of elements and the effect of various smoothing functions on the power spectral density were studied. Hardware construction is complete and tests begun to confirm the simulations using a 12 element array. Title: 100 nm Fabrication Science and TFSOS/SOI Device R&D PI: Isaac Lagnado SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO Center RDT&E Division (NRaD) Address: SAN DIEGO, CA 921525000 (619) 553-2682 Funding Agency: Office of Naval Research PR Number: 00PR00447-00 Award Number: N0001400WX20105 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Develop an advanced high speed, low power, and high density integrated circuit technology with feature sizes that are readily down-scalable to the 0.18-0.10 micron regime based on the use of ultra-thin, fully depleted silicon films on sapphire. This inherently radiation tolerant technology will be used to enhance reliability, cost effectiveness, and performance of current and future Navy systems. Approach: Techniques to realize CMOS devices with channel lengths <0.25um will be developed using fully depleted thin-film silicon-on-sapphire (TFSOS) technology. Use of Si/Ge and operation at cryoelectronic temperatures (77K) will be investigated to enhance device performance. TFSOS technology will be the basis for implementing A/D converters, artificial neural networks, and UHF/L band transceivers for communications applications. Title: High Power Electronics Building Block (PEBB) - Programmable High Density PEBB Power Supply PI: Isaac Lagnado SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO Center RDT&E Division (NRaD) Address: SAN DIEGO, CA 921525000 (619) 553-2682 Funding Agency: Office of Naval Research PR Number: 00PR00448-00 Award Number: N0001400WR20049 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Develop technology for providing the manufacturing and commercialization base for a power supply technology for the Power Electronic Building Block (PEBB) with high power density (>150-200 watts per cubic inch), low profile (<0.2 in) and programmable multiple low voltage outputs that are immune to the harsh EMI environment expected from the PEBB. Approach: Techniques to realize high efficiency, high power density, low output power will be developed by use of a soft switched power converter topology. Techniques for the power supply to operate in a high EMI environment will be developed by use of electrostatic shielded matrix magnetics. A low volume, low profile supply will be developed through use of a high operating frequency (>2 MHz) for passive component size reduction and chip-on-board packaging. This program will be partially funded by the Electronics Program and partly by the PEBB Program. Title: Workshop on Doping, Dopants and Low Field Carrier Dynamics in Wide Gap Semiconductors PI: Alexander Scott TMS Structural Materials Division Address: 420 Commonwealth Drive Warrendale, PA 150867514 (724) 776-9000 Funding Agency: Office of Naval Research PR Number: 00PR00449-00 Award Number: N000149910766 Current End Date: 30-Jun-2000 Scientific Officer: Colin Wood Objective: To address transport problems in wide gap semiconductors. Approach: By assembling experts in the field it is expected that possible solutions will be rapidly identified. Title: Electron Emission from cBN & Related Wide Bandgap Systems PI: Roy Clarke THE REGENTS OF THE UNIVERSITY OF MICHIGAN Applied Physics Program Address: H. M. Randall Laboratory of Physics Ann Arbor, MI 481091120 (734) 764-4466 Funding Agency: Office of Naval Research PR Number: 00PR00450-01 Award Number: N000149910337 Current End Date: 31-Dec-2002 Scientific Officer: Colin Wood Objective: Seeks to better understand the crystalline defects in cubic boron nitride so as to better exploit this new material system for enhanced electromagnetic system applications. Approach: Cubic boron nitride films will be synthesized on lithographically defined field tip arrays on single crystalline silicon at the University of Michigan. These films will then be analyzed by x-ray scattering, cathodoluminescnce, RHEED and related tools to determine the nature of defects in the material. Progress: The first task of the project, testing of the UHV cold-cathode emission station, has been accomplished according to the proposal timetable. The second task, to characterize emission from silicon field emitter arrays in collaboration with Pang's group, is also successfully accomplished within the proposal timeline. The third task, to coat these arrays with cubic boron nitride for improved emission characteristics, is underway. Being explored is self-assembled nano-tip arrays as a cheaper and more convenient alternative to conventional lithography. We have formed a collaboration with Dr. Kevin Jensen (NRL) and Jim Severns (Praxis) to transfer some of the UM's coated nano-tip technology to their field emitter array program for space applications. One student supported by the grant has graduated with a Ph.D. during this reporting period and has taken a position as Staff Scientist with Seagate Technology. Title: A STUDY OF GROWTH MORPHOLOGY AND DEFECT GENERATION IN ALUMINUM NITRIDE CRYSTALS GROWN BY SUBLIMATION PI: James Edgar KANSAS STATE UNIVERSITY Department of Chemical Engineering Address: Durland Hall Manhattan, KS 665065102 (785) 532-5584 Funding Agency: Office of Naval Research PR Number: 00PR00452-00 Award Number: N000149910104 Current End Date: 30-Nov-2001 Scientific Officer: Colin Wood Objective: To investigate unique and efficacious means of preparing semiconductor grade aluminum nitride single crystals. Approach: Crystals to be grown by sublimation under reduced nitrogen atmospheric pressure at temperatures in excess of 2250C. Progress: Thick films of AlN have been grown as a first step to bulk crystal growth. Future research is aimed at improving lifetime of equipment against degradation by aluminum at high temperatures. Once this is solved there are no forseen obstacles to growth of commercial scale AlN semiconductor substrates. Title: Novel Deposition and Characterization of Cubic Boron Nitride Films by MOCVD Method PI: Gary Harris HOWARD UNIVERSITY Office of Research Administration Address: 2400 Sixth St., NW Washington, DC 20059 (202) 806-6595 Funding Agency: Office of Naval Research PR Number: 00PR00454-01 Award Number: N000149710935 Current End Date: 31-Jul-2000 Scientific Officer: Colin Wood Objective: To prepare single crystal semiconducting (cubic lattice) boron nitride (BN) for use in ultra-violet countermeasures. Approach: Metal organic vapor phase depostion (MOCVD) will be used to epitaxially grow epitaxial films on thin buffer layers with close lattice match, such as AlN, or AlP. Progress: The epitaxial growth of boron nitride and aluminum boron nitrides have been carried out employing low-pressure chemical vapor deposition methods. Both (0001)sapphire and (100) silicon have been used as substrates. Atomic force microscopy, Auger electron spectroscopy, Hall mobility measurement and X-ray diffraction studies have been performed to characterize the layers. AES data confirm the deposition of both AlN and BN layers on Si with roughness less than 10 nm. The layers are currently polycrystalline. Currently growth conditions are being optimized to improve the crystalline quality desirably to cubic structure. Title: DEVICE PROPERTIES OF SiGeC ALLOYS AND HETEROJUNCTIONS PI: James Kolodzey UNIVERSITY OF DELAWARE Department of Electrical Engineering Address: 77-79 East Delaware Avenue Newark, DE 19716 (302) 831-1154 Funding Agency: Office of Naval Research PR Number: 00PR00456-00 Award Number: N000149310393 Current End Date: 28-Feb-2000 Scientific Officer: Colin Wood Objective: To experimentally determine the physical and electronic properties of Si(1-x-y)Ge(x)C(y) and how they vary with compositional parameters; understand the results in terms of conventional semiconductor energy band theory; and assess the suitability of the material for electronic and optoelectronic device appplications. Approach: Layers of Si(1-x-y)Ge(x)C(y) will be grown using PECVD and MBE. Their properties will be characterized using physical, electrical, and optical measurements. Heterojunctions and heterojunction device structures will be fabricated and characterized. Progress: It was found that the optimum substrate temperature for good surface morphology was 600 C for SiGeC alloys, and 450 C for GeC alloys. The optical absorption coefficients of SiGeC and SiGeCSn alloys were determined using FTIR. It was found that the absorption edge near the bandgap energy varied with composition, but not linearly. It appears that the addition of C increases the bandgap energy for Ge-rich alloys - but this finding is controversial because other groups (Princeton, ASU) claim C decreases the bandgap, therefore; this result is being checked. The discrepancy may be that samples used in the present work are thick and relatively strain-free whereas groups claiming C decreases bandgap reported on thin strained layers. A SiGeC/Si p-n heterojunction diode was fabricated with nearly ideal current-voltage characteristics, and significant photoresponse. The hole mobility in SiGeC and GeC was found to be higher than in pure Si by a factor of three. Title: INVESTIGATION ON NITRIDE SEMICONDUCTORS ON ZnO SUBSTRATES AND ZnO HETEROSTRUCTURES PI: Hadis Morkoc VIRGINIA COMMONWEALTH UNIVERSITY Dept. of Electrical Engineering & Physics Address: 601 West Main Street Richmond, VA 23284 (217) 333-0722 Funding Agency: Office of Naval Research PR Number: 00PR00457-00 Award Number: N000149810139 Current End Date: 30-Nov-2000 Scientific Officer: Colin Wood Objective: To improve epitaxial nitride semiconductor films to be suitable for exploitation as high power microwave devices for military systems. Approach: Zinc oxide substrates will be used instead of the less well lattice matched sapphire or SiC. Progress: Inversion domain free GaN may be grown on ZnO which decomposes at high temperatures and under ammonia, necessitating a low temperature GaN buffer layer grown with RF activated N source. A new MBE system has been installed; characterized GaN films on inexpensive Si substrates are studied; installed an EPI RF source; obtained ZnO substrates from Cermet, albeit a-plane, and are acquiring c-plane substrates from Air Force Research Laboratories. Soon, we will be well positioned to begin growing GaN films on ZnO substrates. Title: ADVANCED MATERIAL INTEGRATION FOR Sb-BASED BIPOLAR TRANSISTORS PI: Karl Hobart NAVAL RESEARCH LABORATORY ES&T Division Address: ES&T Division Washington, DC 203755347 (202) 404-8542 Funding Agency: Office of Naval Research PR Number: 00PR00458-00 Award Number: N0001400WR20048 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: Endeaver to wafer bond antimonide semiconductor films and ICs to SiC polycrystaline silicon carbide substrates.This will allow low parasitic, high thermally stable electronics for true time delay microwave radar systems. Approach: Will use Vander Waals forces between extremely flat and polished surfaces at moderate temperature. Under vacuum conditions, and with correct chemical surface treatment most materials will bond very strongly to each other. Using undercutting of base films it is expected that semiconductor structures for ultra fast devices and circuits will develop in this program. Progress: A new source of high resistivity (>10^5 ohm-cm)100mm diameter poly-crystalline SiC has been determined and substrates have been procured; these poly-SiC substrates have been successfully polished to <0.2 nm rms roughness for bonding; the Smart-Cut process for GaSb has been optimized for cleaving temperature and damage reduction; GaSb substrates coated with APCVD SiO2 are presently being polished by CMP to prepare for bonding. Title: Direct Digital SynthesizerULTRA HIGH SPEED DDS FOR ELECTRONIC BEAM STEERING PI: Augusto Gutierrez TRW INCORPORATED SPACE AND TECHNOLOGY DIVISION Electronic Systems & Technology Funding Agency: Office of Naval Research PR Number: 00PR00471-01 Award Number: N0001498C0111 Current End Date: 08-Jul-2001 Scientific Officer: Max Yoder Objective: This work seeks the direct digital synthesis and modulation of RF signals to 18GHz. Approach: Low parasitic heterojunction bipolar transistors will be exploited to develop logic capable of operating from a 100 GHz low phase noise clock. Progress: Excellent progress has been made in InP DHBT technology during this year. A viable production solid source phosphorus technology was developed as it was necessary to achieve maximum analog performance with ultra high frequency. Excellent InP DHBT devices with > 800v Early voltage were developed as necessary for precision DAC current sources. The contractor also developed an initial undercut collector etching capability using the anisotropic etching characteristics of InP which will allow them to achieve minimum collector-base capacitance while simultaneously providing low base resistance. This approach will provide the device performance for a producible high analog LSI yield THz HBT for the 100 GHz DDS. Progress has been made on undercut InP DHBT technology. The recent lots have demonstrated greater current handling and high ft, and fmax > 190 GHz. The undercut devices have yielded the world's fastest digital circuit, a static frequency divide by 2 prescaler operating to > 63 GHz. This was achieved while dissipating only 63 mW of power in the core divider circuit. Although this was the first design with preliminary models, the divider design simulation matched the measured circuit performance to within 10%. Based on these results DDS architecture design has begun and the continuation of improvement on MBE profile and process to improve ft, and fmax. Title: Analog to Digital Conversion PI: Isaac Lagnado SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO Center RDT&E Division (NRaD) Address: SAN DIEGO, CA 921525000 (619) 553-2682 Funding Agency: Office of Naval Research PR Number: 00PR00477-01 Award Number: N0001400WX20104 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Develop technology for providing high performance, low power, radiation tolerant analog-to-digital converters that can be used in Navy surveillance, EW, and communications systems applications. Approach: Analog-to-digital converters using CMOS fully depleted thin-film silicon-on-sapphire technology with feature sizes <0.25um will be utilized to implement A/Ds with sigma-delta as well as flash architectures. Current emphasis is on the development of a 16 bit, 125 MSPS ADC using the sigma-delta approach for applications to ASW. A 4-bit, 20 GSPS ADC using T-gate and SiGe devices will serve as the quantizer for a 10-bit, two-step flash, 2.5 GSPS ADC for surveillance and EW applications. Development of an 18 bit, 100 KSPS, 1 mW ADC will be pursued to meet the demands of on-site signal processing in unattended, remotely controlled systems. Title: Resonant Quantum Excitation in HTS: A Probe of the Striped Phase and Its Influence on Microwave Properties PI: T. Venkatesan UNIVERSITY OF MARYLAND AT COLLEGE PARK Department of Physics Address: College Park, MD 20742 (301) 405-7320 Funding Agency: Office of Naval Research PR Number: 00PR00478-00 Award Number: N000140010028 Current End Date: 31-Dec-2002 Scientific Officer: Deborah Van Vechten Objective: To determine if phase segregation of electrons in high temperature superconductors into dynamically fluctuating antiferromagnetic and superconducting regions is the source of the observed resonant pair breaking effect and of the nonlinearities which result in inter-modulation distortion in HTS filters. If so, the optical measurements can be used to create overwhelmingly superior materials (IP3>100 dB) for use in Navy multifunction rf systems such as AMRFS. Approach: Fabricate thin film samples of materials expected to have wide range of behavior of stripes (parent antiferromagnets, plane vs chain doped YBCO, 214 LSCO with stripes stabilized by Nb doping and under varied stress due to substrates). Measure optical response and correlate to microwave loss measurements of Sridhar, IP3 measurements at NIST, and previous studies of psuedogap. Use silver doped YBCO to test Mannhart's assertion that antiferromagnetic regions exist in grain boundaries by reducing the number of grain boundaries. The PI will produce the samples needed for his own and collaborators efforts. Title: Theory of Transport Processes in Nitride Structures PI: Brian Ridley UNIVERSITY OF ESSEX Department of Physics Address: Wivenhoe Park Colchester, VA 222175660 (607) 256-4369 Funding Agency: Office of Naval Research PR Number: 00PR00479-00 Award Number: N000149910014 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: PI will calculate and model electrical carrier transport at low and high electric fields in wide bandgap compound semiconductors. He will provide insight to operation of devices under investigation by ONR funded PIs. Approach: Calculational theory and code developed over the last two decades will be used for theoretical modelling and prediction. Progress: A post.doc. RA, Dr. Ceyhun Butulay, joined Essex 1 January 1999. An exact solution of the Boltzmann equation for the low-field drift mobility in GaN associated with polar-optical-phonon scattering was obtained and published. Inclusion of electron-electron and acoustic-phonon scattering has now given us an upper limit to the bulk mobility. An extension to the 2D case has been made. A calculation of the low-field mobility in AlGaN will be presented at the Nitride Conference in Montpellier in July. Results of a study of piezoelectric scattering was presented at the Spring meeting of the MRS. The effect of Wannier-Stark quantization on the impact-ionization rate in bulk material has been published. Title: Low Energy Electron Microscopy Investigations of Fundamental Mechanisms in Group III Nitride Growth PI: Max Lagally THE BOARD OF REGENTS OF THE UNIVERSITY OF WISCONSIN Materials Science and Engineering Address: 750 University Avenue Madison, WI 53706 (608) 263-2078 Funding Agency: Office of Naval Research PR Number: 00PR00482-01 Award Number: N000149610323 Current End Date: 30-Sep-2002 Scientific Officer: Colin Wood Objective: To optimize the growth of GaN by application of Low Energy Electron microscopy real time to the epitaxial growth surface. Si quantum dots embedded in GaN films will be investigated for light emission and high power microwave applications relevant to the US Navy. Approach: Low-energy electron microscopy (LEEM) will be used to investigate the homoepitaxial growth of GaN on single crystal GaN substrates. The morphological aspects of the growth front will be studied as a function of growth parameters such as nitrogen pressure, deposition rate, temperature and substrate condition in order to determine quantitative thermodynamic and kinetic mechanisms. A novel atomic nitrogen source will be fabricated and installed in the LEEM. In this source a CO2 laser fires into the throat of a nozzle creating a nitrogen plasma. The plasma then expands and is neutralized by collisional recombination. Its composition is then frozen by the nozzle expansion. Progress: Low-energy electron microscopy (LEEM) has been used to investigate the homoepitaxial growth of GaN on single crystal GaN substrates. The morphological aspects of the growth front studied as a function of growth parameters such as nitrogen pressure, deposition rate, temperature and substrate condition have been used to determine quantitative thermodynamic and kinetic mechanisms. A novel atomic nitrogen source has been fabricated and installed in the LEEM. Using the new LEEM GaN chamber the PI has observed facetted growth of GaN on GaN/sapphire at low temperatures. PI has identified regions on LEO GaN suitable (because they have large, step-free regions) for investigating nucleation and initial growth. PI has tested the plasma source using oxygen, and has found that a significant hyperthermal component of O atoms is produced. PI has nearly completed the STM/GaN growth chamber and will grow GaN on Si(111), for purposes of integrating GaN/Si using multi-orientation SOI. PI has investigated patterned Si(001) and SOI in the LEEM, and has achieved large (~15m) step-free pedestals. Title: INTERFACIAL BONDING RESEARCH FOR COMPLIANT SUBSTRATES PI: David Miller THE PENNSYLVANIA STATE UNIVERSITY Science Center Address: 1049 Camino Dos Rios, P.O.Box 1085 Thousand Oaks, CA 91360 (805) 373-4275 Funding Agency: Office of Naval Research PR Number: 00PR00484-00 Award Number: N000149710951 Current End Date: 30-Jun-2000 Scientific Officer: Colin Wood Objective: To determine parameters of preparation of bonded substrates for molecular beam epitaxy of lattice mismatched electronic materials. Approach: Examine the effects of interfacial chemistry, gas, oxide and contami-nants, as well as surface finish and topography on the temperatures, conditions and results of bonded GaAs on Si. Progress: The PI has focused on two areas: relaxed epitaxial growth of InGaAs on a twist-bonded GaAs compliant substrates and GaAs compliant substrates bonded with intermediate SiO2 or indium oxide layers; and relaxed epitaxial growth of InGaAs on a compliant substrate fabricated by epitaxial growth of an AlAs/GaAs structure with the subsequent oxidation of the AlAs. They have developed methods to improve the cleanliness and smoothness of the surfaces of both types of compliant substrates for subsequent epitaxial growth and have successfully produced intact GaAs layers as thin as 30 nm on top of oxidized AlAs in stripes 100 micron wide. They have successfully grown GaAs epitaxially over these thin layers. So far, however, large areas of dislocation-free epitaxial material grown on these compliant substrates have not been achieved, in part because lattice-mismatched epitaxy still nucleates poorly on these surfaces.The postdoc previously supported by this program was hired by industry (QED, Inc., Bethlehem, PA) in February 1999 and a new postdoc with extensive material growth experience has been hired. Research focus has been shifted from thin GaAs on oxidized AlAs to twist-bonded materials and the use of bonded wafers using antimonide compliant layers. Careful characterization of InGaAs layers grown on thick GaAs substrates has been done as preparation for growth of InGaAs on these complaint substrates. Two papers were published last year reporting results from this project. Title: USE OF PIEZOELECTRIC CHARGE IN HEMT'S ON GaAs AND InP SUBSTRATES PI: Lester Eastman CORNELL UNIVERSITY School of Electrical Engineering Address: 120 Day Hall Ithaca, NY 14853 (607) 255-4369 Funding Agency: Office of Naval Research PR Number: 00PR00485-00 Award Number: N000149810161 Current End Date: 31-Dec-2000 Scientific Officer: Colin Wood Objective: To fabricate and investigate improvements of Field effect transistor operation and performance using piezo-electric fields in the C-direction of the crystals and thus avoid the need for dopant incorporation and control during epitaxial film growth. Approach: The PI will determine the magnitude of the Piezo electronic co-efficients in GaAs/AlInGaAs heterostructures in the (111) direction. Once determined FET devices will be designed, built and characterized, and the performance advantages evaluated. Progress: Initial experiments on oriented GaInAs on GaAs substrates have demonstrated the extent of Piezo-electric effect. Calculations are underway to determine the extent of spontaneous polarization to distinguish it from strain induced polarization effects. Attempts to achieve piezoelectrically-induced holes with (III)B GaAs substrates have been tried without success. The expected hole sheet density is well below 1 x 1012/cm2 and is masked by background donors in the buffer layer. The use of (III)B InP, to induce a 2DEG, where the density is expected to be 2-3 x 1012/cm2, is being studied. Lattice matched InGaAs and InAlAs have been achieved and growths of lattice-matched InGaAs covered with strained In1-yAlyAs will be made. Using a thin barrier of the latter, at the critical layer thickness, the 2 DEG density will be determined. Title: P-Type Doping in GaN PI: Fred Schubert THE TRUSTEES OF BOSTON UNIVERSITY College of Engineering Address: 44 Cummington Street Boston, MA 022152407 (617) 353-1910 Funding Agency: Office of Naval Research PR Number: 00PR00486-00 Award Number: N000149810194 Current End Date: 30-Nov-2000 Scientific Officer: Colin Wood Objective: To produce higher hole concentrations in GaN for much reduced resistance contacts, and lower parasitic series resistance in AMRFS related devices. Approach: PI will prepare oscilliatory compositional superlattices of Mg saturated GaN /InN films by molecular beam epitaxy. This will change the band structure thereby reducing the effective mass and thence the activation energy, and allowing low resistance contacts for AMRFS related devices. Progress: Instabilities in Hall measurements from samples of GaN grown on Sapphire have been discovered. A time dependant scan technique that leads to 3 orders of magnitude increased accuracy has been developed. Also discovered is that when using ethylene glycol as a solvent peroxide can be used and etchant such as phosphoric acid to define facets on c plane GaN on Sapphire. Mg-doped AlGaN/GaN superlattices are investigated in order to enhance the doping properties of GaN which suffers from low carrier activation due to an acceptor activation energy of 200 meV. Demonstrated that the activation energy of acceptors is reduced to 70 meV and 58 meV in AlGaN/GaN superlattices with 10% and 20% Al content, respectively. The free hole concentration of the superlattice with 20% Al content is 8 x 10^18 cm^-3 at 400 K. The doping properties improve with increasing Al content of the superlattices, in agreement with theoretical model. Title: Supplimental funding for N0001496-1-1008 PI: Thomas Myers WEST VIRGINIA UNIVERSITY RESEARCH CORPORATION ON BEHALF OF WEST VIRGINIA UNIVERSITY Department of Physics Address: P.O. Box 6315 Morgantown, WV 265066315 (304) 293-3422 Funding Agency: Office of Naval Research PR Number: 00PR00488-02 Award Number: N000149611008 Current End Date: 30-Sep-2002 Scientific Officer: Colin Wood Objective: This program seeks to determine and exploit the mechanism whereby hydrogen atoms enhance the stability of group III nitride thin films in vacuum, which enhances apparent growth rate during molecular beam epitaxy. Approach: Reflection electron diffraction and molecular desorption spectroscopy will be used as real-time probes of the surface stoichiometry, crysta-linity, and smoothness during thin film growth of the group III nitrides. MBE with elemental group III and nitrogen plasma sources will be employed. Progress: Atomic hydrogen stabilizes the growing GaN surface during molecular beam epitaxy (MBE), allowing higher temperatures necessary for high quality material. Study of defects affecting surface morphology suggest the majority of MBE growth results in a crystal polarity which enhances defect formation, indicating that growth initiation must be changed. The PI will continue to investigate growth kinetics of GaN, InN and InGaN (including the effect of atomic hydrogen) to understand growth processes and allow alloy growth at GaN-compatible temperatures. Title: GROWTH AND FABRICATION OF GaN-BASED HETEROJUNCTION BIPOLAR TRANSISTORS PI: April Brown GEORGIA TECH APPLIED RESEARCH CORPORATION GEORGIA INSTITUTE OF TECHNOLOGY School of Electrical and Computer Engineering Address: 212 Pettite Building Atlanta, GA 303320250 (404) 894-5161 Funding Agency: Office of Naval Research PR Number: 00PR00489-00 Award Number: N000149810209 Current End Date: 31-Dec-2000 Scientific Officer: Colin Wood Objective: To develop heterojunction bipolar transistors for high power microwave operation without active cooling. Approach: This program will utilize and exploit piezo-electric fields within heterojunction nitride semiconductor based bipolar transistor multilayer structures. These will be grown at GA Tech by MBE, and processed at U Illinois. Progress: This project has demonstrated: 1.) the first growth of a device quality nitride structure on lithium gallate, a low cost alternative substrate 2.) the elimination of the low temperature buffer normally required to nucleate the nitride films on heterogeneous substrates (this buffer is a source of defects that limits the device performance), 3.) the lowering of dislocation densities to the low 1e8 per cm2 range without the need for expensive multistep processes such as Lateral Epitaxial Overgrowth, and 4.) much improved AlGaN material quality (a critical part of the heterostructure) as evidenced by a 50% narrower X-ray diffraction width as compared to material grown on sapphire, HVPE GaN and silicon carbide. Have recently replaced Oxford rf plasma source with an EPI plasma source (July 99) and have realized increased growth rates (x3) and preliminary indications of increased p-type doping efficiency and control on sapphire and LGO substrates. Have designed heterostructures for achieving polarization (sponta-neous and piezoelectric) enhancements on cation- and anion-terminated growth faces. The achievement of a reproducible p-type doping is necessary to realize such enhancement. Theoretical studies of GaN/AlGaN HBT structures indicate that in the absence of piezoelectric effects and using a best estimate of the mobility and a free hole concentration of 1 cm2/V-s and 5.0 E18 respectively that the maximum value of fmax is about 3.5 GHz for a 0.075 micron wide base. Have also found that grading the heterojunction as opposed to using an abrupt heterojunction results in a 20% improvement in the integrated hole density when piezoelectric field effects are included. Title: Glasses and Fibers PI: Ishwar Aggarwal NAVAL RESEARCH LABORATORY Code 5603 Address: 4555 Overlook Avenue Washington, DC 20375 (202) 767-9316 Funding Agency: Office of Naval Research PR Number: 00PR00495-01 Award Number: N0001400WX20494 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To increase the time-bandwidth product of present delay line technology and analog communication links by using fiber optics and related componentry. Approach: IR fibers and cable/AR coating will be developed. Purification and fiberization techniques will be developed to reduce the glass-cladd fiber loss to <0.3dB/m and increase the average fiber bend strength to >100kpsi. Ruggedized, vibration-proof cables which can tolerate the environmental conditions expected in harsh environment will be investigated. Progress: Glass cladd chalcogenide fibers have been developed, AR-coated and successfully used in the lab for IR jamming of missile seeker at Sanders. The IR cables are required for the Tri-Service ATIRCM Program for aircraft protection. In this system, the IR fiber is needed to connect the ATIRCM laser to the Jam Head, and thus replace the current Optical Coupler, which is cumbersome, heavy and difficult to align. Because of the importance of fiber for the ATIRCM program, the NRL IR fiber effort is currently being supported by the U.S. Army CECOM. NRL has a CRADA with Corning, Inc. for IR fiber amplifier development. Title: Mid-IR Type-II Quantum Well and Interband Cascade Lasers PI: Jerry Meyer NAVAL RESEARCH LABORATORY Optical Sciences Division Address: Code 5613 Washington, DC 203755338 (202) 767-3276 Funding Agency: Office of Naval Research PR Number: 00PR00496-00 Award Number: N0001400WX20321 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To develop two new mid-IR sources, the type-II quantum well laser and the type-II interband cascade laser, which are projected to produce on the order of 1 W quasi-cw output power per facet at ambient or TE-cooler operating temperatures with near-diffraction-limited beam quality. Approach: Two new semiconductor mid-IR sources, the type-II quantum well laser (T2QWL) and the type-II interband cascade laser (T2ICL), which overcome the disadvantages of previous type-I and type-II approaches, and will consequently produce higher output powers at higher operating temperatures. A four-constituent (InAs-GaInSb-InAs-GaALSb) structure will be utilized. This structure is expected to be superior to the type-II superlattice(SL) because it displaces 2D dispersion relations for both electrons and holes. Progress: Electrically-pumped mid-IR lasers with type-II superlattice active region have yeilded record operating temperatures, pulsed output powers, and threshold current densities. The maximum power of 430 mW at 100 K is near the highest observed for interband diodes at 2.9 um, and the peak output of 100 mW at 200 K is higher than any previous result for > 2.9 um. The threshold current density was as low as 120 A/cm2 at 80 KK, and for all T>180 K the threshold current density values were the lowest ever reported for this wavelength range (e.g., 1.1 kA/cm2 at 200 K). Title: Optical Receivers PI: Ronald Esman NAVAL RESEARCH LABORATORY Code 5672 Address: 4555 Overlook Ave Washington, DC 203755320 (202) 767-9359 Funding Agency: Office of Naval Research PR Number: 00PR00497-00 Award Number: N0001400WR20052 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To develop high-current photodetectors for use in state-of-the art photonic systems. This program emphasizes high current photodetectors and photodetectors interfaced with electronics(OEICs). Approach: Devices capable of detecting greater than 50 to 100 mA at 5 to 20 GHz and 100 to 200 mA below 5 GHz will be designed and fabricated. These devices will transition into various specific photonic systems which will perform more effectively than current electronic systems as well as providing new and advanced capabilities. Progress: Have achieved <4V Vpi at 20 GHz at 1.3 micron in etched ridge device. Tunable laser tuning range extended to 22 nm with the following paramters: 4.5 linewidth enhancement factor, 20 mA threshold, 0 dBm into the fiber, >45 dB SMSR. Longterm wavelength stability of SSG-DBR lasers was investigated indicating degradation leading to unacceptable mode hops (~5nm). Tuning algorithms to mitigate this degradation were developed and successfully tested. Long term verification of this concept is underway. Title: Optical Transmitters PI: Ronald Esman NAVAL RESEARCH LABORATORY Code 5672 Address: 4555 Overlook Ave Washington, DC 203755320 (202) 767-9359 Funding Agency: Office of Naval Research PR Number: 00PR00498-00 Award Number: N0001400WX20091 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To increase the time-bandwidth product of present delay line technology and analog communication links by using fiber optics and related componentry. Approach: To increase the time-bandwidth product of delay lines the bandwidth of the components used in the delay line, namely; the laser diode transmitter and the p-i-n diodes photodetector are being increased. The development of the optical amplifier at 1.3 um and 1.5 um makes it necessary to develp components and systems at these wavelengths. Progress: Initial studies of Sampled Grating, Distributed Bragg Reflector (SGDBR) lasers indicate that they represent a very promising technology. They have a very good spurious mode suppression ratio (MSR>40dB), output powers on the order of 10 mW, and tuning ranges of up to 80 nm. Static characterization of the SGDBR devices shows relatively well-behaved CW operation. Approximately 10 mW CW power is available from this device. Have achieved <4V Vpi at 20 GHz at 1.3 micron in etched ridge device. Tunable laser tuning range extended to 22 nm with the following paramters: 4.5 linewidth enhancement factor, 20 mA threshold, 0 dBm into the fiber, >45 dB SMSR. Long term wavelength stability of SSG-DBR lasers was investigated indicating degradation leading to unacceptable mode hops (~5nm). Tuning algorithms to mitigate this degradation were developed and successfully tested. Long term verification of this concept is underway. Title: High Power 2.0 and 1.5um Fiber Source PI: Lew Goldberg NAVAL RESEARCH LABORATORY Department of Physics Address: Washington, DC 203755000 (202) 767-9079 Funding Agency: Office of Naval Research PR Number: 00PR00500-01 Award Number: N0001400WR20114 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To develop high-power fiber amplifiers and lasers for use in remote sensing and laser countermeasure applications. The proposed research will result in high efficiency and compact fiber-based coherent optical sources suitable for use in 1.5 um eye-safe remote measurement systems such as micro-Doppler and LSADAR and as a 2.0 um pump for mid-IR optical parametric oscillator for laser countermeasure applications. Approach: The laser systems will rely on the use of optical fiber gain medium. The propagation loss of a silica fiber is approximately 10dB/km at 2.0 um. For typical fiber lengths of few tens of meters, the propagation loss in silica fiber at 2.0 um is therefore negligibly small. In the proposed 2.0 um fiber laser, a Tm doped fiber is pumped by a 1.5 um fiber laser constructed using a double cladding fiber containing a large Er/Yb co-doped core. The Er/Yb co-doped fiber laser is cladding-pumped by fiber-coupled 980 um laser diode bars. Progress: Tm doped fibers and crystals were characterized to determine their slope efficiency when pumped by 800 nm light. Based on these measurements a preliminary Tm doped fiber preform design was finalized and fabrication was initiated. The fiber preform was designed to have cladding ratio and doping concentration compatible with a double cladding fiber. Fiber amplifier based on double cladding fibers and side-pumping through a V-groove were demonstrated, generating up to 1.7 W at 1.5 um and 4 W at 1um. Record electrical-to-optical conversion efficiencies (42% for a Yb doped fiber amplifier) were demonstrated. Title: 3-Band IRFPA Technology PI: Joseph Omaggio NAVAL RESEARCH LABORATORY Code 6810 Address: 4555 Overlook Avenue SW Washington, DC 20375 (202) 767-9184 Funding Agency: Office of Naval Research PR Number: 00PR00502-01 Award Number: N0001400WX20197 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To develop the technology for three band imaging, staring, infrared focal plane arrays. These focal planes detect in three bands in the 3-12 micron part of the IR spectrum. Approach: A three stacked photodiode approach to be pursued. In this approach the widest bandgap diode detects photons with energies up its semi-conductor bandgap and acts as a filter on the high wavelength end for the next two diodes. Only band 2 and 3 radiation is transmitted. Diode number 2 detects radiation in band 2 and transmits band 3 radiation which is detected in diode 3. This results in three co-located detectors which detect in distinctly different IR bands. Title: ENHANCED SIGNAL PROCESSING ON THE FOCAL PLANE ARRAY PI: Ken Sarkady NAVAL RESEARCH LABORATORY Code 5635 Address: 4555 Overlook Avenue SW Washington, DC 20375 (202) 767-5899 Funding Agency: Office of Naval Research PR Number: 00PR00508-00 Award Number: N0001400WX20340 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To develop adaptive IRFPAs with on-chip electronics to enhance the dynamic range to 120 dB, and to implement offset and nonuniformity correction. Increased dynamic range is required for Background Limited Infrared Performance(BLIP) in long-wave IRFPA's and to enable either mid-wave or long-wave IRFPA's to adapt to varying backgrounds such as cold sky and hot desert. Approach: The work involves current subtraction at the detector integration site where the value of current subtracted is unique for each pixel and is programmed by off focal plane electronics. This technique will allow compensation for detector and MOSFET threshold nonuniformities at the integration site thus relieving dynamic range requirements on down stream analog electronics. Progress: Two FPAs were hybridized and tested in a laboratory dewar using a laboratory test set. Since the use of the laboratory test did not allow adaptive loop closure the adaptive FPA was operated in an open loop mode. In this mode a factor of three improvement in integration time (two-three in sensitivity) was demonstrated. The remaining camera boards were fabricated and tested. Currently the camera electronics are integrated with the FPA. Title: Internal High-Speed Laser Modulation PI: Michael Shur RENSSELAER POLYTECHNIC INSTITUTE Address: Thornton Hall Charlottesville, VA 22903 (804) 942-4270 Funding Agency: Office of Naval Research PR Number: 00PR00510-00 Award Number: N000149810075 Current End Date: 31-Dec-2000 Scientific Officer: Yoon Park Objective: The proposed project will focus on developing a new device technology for high-speed internal modulation in semiconductor heterostructure lasers. This technique is based on the concepts of vertical and lateral Modulation Shutter(MS) implemented in the novel semiconductor ridge waveguide laser with lateral current injection. Approach: Modulation Shutters are controlled by external voltage and are designed to suppress stimulated emission in quantum well laser heterostructure by introducing lossy sections "shutter" into the active region. Since very small fractions of the active region are involved, dramatic increase in the modulation frequency and higher modulation linearity, which is critical for analog circuit applications, is expected. Progress: Proof of the concept modulation of the LCI laser output by split electrodes was demonstrated at low temperatures. N Fabrication process has been optimized and now it is possible to stop etch on GaAs contact layer laying at the distance 40 nm above InGaAs active region. Diffusion from spin-on Zn doped silicon dioxide by open tube diffusion was performed on test GaAs semi-insulating samples and on a piece of LCI laser epi-wafer. Results of the diffusion at 750C indicate that this diffusion procedure is able to intermix active region layers and dope p-region to a concentration as high as 5E18 cm-3. Measurements of the LCI laser sample and new diffusion runs on the rest of the samples is in progress. Title: Uncooled Photon Detector for IR Imaging PI: Manijeh Razeghi NORTHWESTERN UNIVERSITY Department of Electrical Engineering & Computer Science Address: 225 N. Campus Drive Evanston, IL 602083118 (847) 491-7251 Funding Agency: Office of Naval Research PR Number: 00PR00511-00 Award Number: N000149910630 Current End Date: 30-Apr-2002 Scientific Officer: Yoon Park Objective: The realization of high performance uncooled infrared photo detectors by the growth of low dimensional structures. The possibility of multi-color detectors with these low dimensiional structures is to be investigated. Approach: The use of quantum-dot (QD) structure for infrared detectors will be pursued. The design and fabrication of quantum dot infrared detector of both type-I and type-II band align schemes will be attempted by MBE and MOCVD. This can significantly (or almost completely) suppress the optical phonon-relaxation for intersubband system or Auger recombination rate (for infrared system). Progress: Uncooled infrared detectors in the mid and long wavelength ranges have been developed using InAsSb/AlInSb heterostructures on GaAs substrates. The detectors show the maximum reported detectivity of 1x108 cmHz1/2/W at 8mm at room temperature without any optical immersion or passivation. The detectivity improved by more than one order of magnitude after optical immersion. Also demonstrated was the first growth of InTlSb and room temperature operating 8-11 ?m photoconductors on GaAs. Demonstrated room temperature operating 8-12 ?m InSbBi photoconductors on GaAs. Recently, infrared photoresponse up to 15 ?m was obtained from III-V quaternaries such as InAsSbBi and InTlAsSb. Title: Optical Amplifiers & Light Emitters for Integrated Optoelectronics PI: Dietrich Langer UNIVERSITY OF PITTSBURGH Dept. of Electrical Engineering Address: 350 THACKERAY HALL PITTSBURGH, PA 15260 (412) 624-9663 Funding Agency: Office of Naval Research PR Number: 00PR00513-00 Award Number: N000149910663 Current End Date: 30-Apr-2002 Scientific Officer: Yoon Park Objective: To develop the design of devices, the appropriate material and the appropriate processing technology for such optoelectronic components that lend themselves to integration. Approach: To develop opto-electronic components which are suitable for monolithic integration on a single substrate, fabrication of various guided-optics devices, such as waveguide lasers, amplifiers and splitters, all based on low-loss silicate glass doped with or without erbium. Progress: Preliminary parameters for the deposition of semiconducting and insulating films have been established. These included GaN and ZnO films on silicon or sapphire substrates for development of various functional devices based on wide bandgap materials. Both Prof. Langer and Prof. Kim attended and contributed to the WOFE'99 Conference. An updated version of earlier computer programs for the design of optical waveguides was obtained and is being adapted. Title: Integrated Laser/Modulator Sources for Mm-Wave Optical Fiber Links PI: Peter Asbeck THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SAN DIEGO 0934 Department of Electrical Engineering Address: 9500 GILMAN DRIVE La Jolla, ca 920930407 (619) 534-6713 Funding Agency: Office of Naval Research PR Number: 00PR00515-00 Award Number: N000149910010 Current End Date: 30-Sep-2001 Scientific Officer: Yoon Park Objective: To develop an integrated source that combines a high power, low noise optical source, coupled to a high bandwidth electroabsorption modulator optimized for high sensitivity, and high linearlity. The monolithic combination of the two provides major benefits over the discrete implementations by providing highlight coupling efficiency and polarization control, and will constitute an easy-to-use versatile subsystem component for antenna remoting. Approach: Application of the integrated source to high frequency links will be investigated. A narrow-band high frequency link will be demonstrated, measured and analyzed. In addition a variety of new opportunities for subsystem design based on the availability of the optical link technology will be explored. Progress: MQW electroabsorption modulator structures for 1.55um operation have been grown by MOCVD and optimized with respect to detuning of laser frequency from modulator absorption edge. Structures for coupled laser/modulator structures have been compared theoretically with beam propagation calculations. MOCVD selective area growth (with SiO2 masking on InPsubstrates) has been refined, in order to allow growth of integrated structures. Application of this approach to novel HBT structures is also being explored. -------------MORE---------> 
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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:23 PM
Title: A1GaN/GaN Ultra-Violet Photodetectors PI: Joe Campbell THE UNIVERSITY OF TEXAS AT AUSTIN Microelectronics Research Center Address: PO BOX 7726 AUSTIN, TX 787137726 (512) 471-9669 Funding Agency: Office of Naval Research PR Number: 00PR00517-01 Award Number: N000149910304 Current End Date: 28-Feb-2002 Scientific Officer: Yoon Park Objective: To develop the materials, processing, and simulation technologies for the growth and fabrication of high-performance UV AlGaN/GaN photodetectors for military and space-based applications. Approach: The two most crucial issues for UV photodetectors are the development of UV focal plane arrays and increasing sensitivity. The program will develop the materials capabilities that will permit the high device yeilds and spatial uniformity that will be required for practical arrays. From a device perspective, the processing and fabrication technologies to realize arrays will be developed. In addition, the wafers will be spatially mapped with the intent of correlating materials characteristics with critical device parameters such as the dark current. In order to improve the sensitivity of the photodetectors avalanche photodiodes will be developed. Reliability issues also will be addressed in this program. Progress: To develop AlGaN/GaN photodiodes and focal plane arrays. Recently, we have achieved improved performance by incorporating a semi-transparent p-contact on our Al0.13Ga0.87N/GaN photodiodes. The heterojunction separates the absorption region from the surface which improves the quantum efficiency (57% at 360 nm and >30% at 290 nm). Full-coverage of the metal contact has eliminated lateral variations in the device characteristics, particularly the temporal response. Devices that have been designed as avalanche photodiodes have achieved modest gains (M~10) with good pulse response. Work on improving the spatial uniformity of the gain is in progress. Title: III-V Nitride UV Detector Arrays Fabricated by Combining HVPE Lateral Epitaxial Overgrowth and MBE Methods PI: Theodore Moustakas THE TRUSTEES OF BOSTON UNIVERSITY College of Engineering Address: 44 Cummington St, 4th Floor Boston, MA 02215 (617) 353-5431 Funding Agency: Office of Naval Research PR Number: 00PR00518-00 Award Number: N000149910309 Current End Date: 31-Jan-2002 Scientific Officer: Yoon Park Objective: To fabricate large area p-i-n GaN/AlGaN heterojunction UV photodetectors and photodetector arrays with very low dark current, high responsivity and large visible light rejection. Approach: Very low dark currrent devices will be obtained through the development of low threading dislocation and large area GaN uniform substrates or arrays by the Lateral Epitaxial Overgrowth (LEO) approach using HVPE method. These substrates will be used for the homoepitaxial growth of the p-AlGaN, i-GaN and n-GaN by the MBE method. Progress: Several oxide VCSEL epitaxial designs were optimized for single-mode emission, then grown and processed with wide parameter variations. Larger-aperture devices were multi-mode and were superior to all other multi-mode VCSELs in fiber coupling. This design was chosen for Picolight's 850nm fiber optic products. Other designs were inferior. Only very small apertures (<4um) were single-mode. High stress reduced the higher-order modes. Progress was made in 1300nm VCSELs in this program and separately. Scaling favors single-mode output at 1300nm compared to 850nm. Based on progress so far, we expect to exceed the originally proposed goal of a 1300nm VCSEL emitting 1mW, single-mode at 85 degrees C. Title: JSEP FELLOWSHIP FOR WILLIAM WEEKS PI: Kenneth Jenkins THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN Coordinated Science Laboratory Address: 1101 West Springfield Avenue Champaign, IL 61820 (217) 333-2510 Funding Agency: Office of Naval Research PR Number: 00PR00521-00 Award Number: N000149810064 Current End Date: 22-Sep-2000 Scientific Officer: Colin Wood Objective: Improve data retrieval from 2 dimensional storage media. Approach: Recognizing the similarities in mathematics of full surface storage devices and those of phase transition problems and using models of theoretical physics, 2 dimensional modulation codes will be developed for optimized low latency data retrieval from optical digital storage media. Progress: Progress was made in the first year of this JSEP fellowship. Report will be submittered on Oct 1 for inclusion in JSEP progress reports section. Title: Highly linear, high Power Amplifiers with 6-18 GHz Bandwidth PI: Brian Thibeault WIDEGAP TECHNOLOGY LLC Address: 6266 Marlborough Drive Goleta, CA 93117 (805) 967-9433 Funding Agency: Office of Naval Research PR Number: 00PR00540-00 Award Number: N0001498C0013 Current End Date: 09-Dec-2000 Scientific Officer: John Zolper Objective: Under this contract high-power 6-18 GHz amplifiers will be developed using AlGaN/GaN HEMTs. Maximum achievable power from a single amplifier and from a module will be demonstrated. Ultralinear device designs will also be explored. Approach: Under this contract four areas will be explored: 1) Traveling wave amplifier with a suppressed backward wave will be designed, 2) Class B quasi-complementary amplifier unit cells will be designed, 3) AlGaN/GaN HEMTs will be constructed and packaged in flip-chip carriers, and 4) efficient power combining will be implemented in the 5-20 GHz range. Progress: In the first 3 quarters of the program, feasible device designs, processing technologies and scaling laws for large periphery devices have been established and produced state-of-the-art, up to 6-mm-wide, devices. 4-mm device achieved 5-W output power along with 53% PAE at 4 GHz, while a 6-mm transistor exhibited 6-W output power with 33% PAE. Both output powers are believed to be the highest reported to date for GaN FETs. The first linearity measurements of GaN HEMTs were also conducted at WiTech and pointed to excellent potential. Broad-band amplifiers were designed using both the resistive-feedback scheme and the lossy input-match scheme, and are ready for mask layout. Title: InP-Based Pulsed W-Band IMPATT Transmitter Technology PI: Marko Afendykiw NAVAL AIR WARFARE CENTER WEAPONS DIVISION RF Guidance & Analysis Branch Address: Code 087 China Lake, CA 935556001 (619) 939-2845 Funding Agency: Office of Naval Research PR Number: 00PR00541-00 Award Number: N0001400WX20090 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: Seeks means of providing W-band signals with solid state technology so as to be adaptable to missile front end configurations. At present the focus is on the development of IMPATT devices capable of 4 watts peak power at 30% duty and 300nS pulse waveform. This is mostly an in-house effort supported by an industrial supply of diodes and a companion university modeling effort. Approach: Diamond thermal heat spreaders and novel rectangular cavities will be used to provide IMPATT performance and efficiency of at least 4 watts peak power in 300 nanosecond pulses per diode. New IMPATT diodes and materials will be explored to achieve the 4 watts of output power. InP IMPATTs will be emphasized in FY97 with a goal to increase the output of GaAs IMPATT designs by a factor of 8. Work on IMPATT diode combiners will continue in the direction of assembling and testing a 21 watt peak IMPATT transmitter using previously developed 1.4 watt IMPATT devices. Progress: Work has focused on the development of InP IMPATT diodes at 35 and 94 GHz since InP should out perform GaAs devices. Initial IMPATT wafer were grown at the University of Texas and process technology was developed at Raytheon. The initial InP devices had incorrect doping profiles due to Sn diffusion. This has been overcome in subsequent runs by modifying the growth sequence. P-ohmic contacts were demonstrated at Raytheon with a specific contact resisitance of ~5e-7 ohms-cm2 using Rh-Au contacts on p+ InGaAs. Title: OPTICAL AND STRUCTURAL PROPERTIES OF LATERAL EPITAXIAL GaN LAYERS FOR POWER MICROWAVE DEVICES PI: Jaime Freitas NAVAL RESEARCH LABORATORY CODE 6874 Address: 4555 OVERLOOK AVENUE S. W. WASHINGTON, DC 203755347 (202) 404-4536 Funding Agency: Office of Naval Research PR Number: 00PR00543-00 Award Number: N0001400WX20089 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: PI will characterize GaN films grown by three ACI competitors on Si for optical and electrical behaviour. Approach: PI will use photo, and cathodo-luminescence techniques for optical characterization, and Hall, and C-V for electrical measurements. Progress: The structural, optical, and electronic properties of lateral epitaxial overgrown (LEO) GaN films deposited on Si substrate by three university -based crystal growth have been evaluated. Screening and assessment of materials received from these universities with optical techniques consisting of Raman scattering (RS) for structural information and photoluminescence (PL) spectroscopy for electronic information is employed. Techniques such as optical microscopy, spatially resolved PL and cathodoluminescence (CL), and real-color CL to establish the morphological/areal variation of the electronic properties of the overgrown layer are also used. Although each University team has made great progress, problems remain. The film morphology of the continuous layers precludes the use of the LEO-GaN/Si for free-standing GaN sustrate as well as for device fabrication. In addition, the present lack of control of the intrinsic electronics properties of these continuous layers and the uncoalesced layers will make very difficult the fabrication of high yield electronic devices. Title: GaN LATERAL EPITAXIAL OVERGROWTH ON SILICON FOR AFFORDABLE POWER MICROWAVE DEVICES PI: Steven Denbaars THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Materials Dept. College of Engineering Address: Cheadle Hall, Room 3227 Santa Barbara, CA 93106 (805) 893-8511 Funding Agency: Office of Naval Research PR Number: 00PR00544-01 Award Number: N000149810401 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: To develop an inexpensive supply of 'zero-defect' GaN semiconductor epitaxial films. Approach: Using a GaP lattice matched buffer and newly developed epitaxial layer overgrowth, GaN epitaxial films will be deposited by metal-organic chemical vapor growth. Progress: As a result of surface partitioning and other surface preparation techniques, the PI has developed the best transferable technology for transitioning epitaxial GaN on Si to EMCORE LTD. Title: Epitaxial Layer Overgrowth of II-VI Semiconductors PI: Ishwara Bhat RENSSELAER POLYTECHNIC INSTITUTE Center for Integrated Electronics Address: Troy, NY 12180 (518) 276-2786 Funding Agency: Office of Naval Research PR Number: 00PR00545-00 Award Number: N000149810767 Current End Date: 15-Aug-2000 Scientific Officer: Colin Wood Objective: To extend the useful IR wavelength of HgCdTe detector arrays for FLIR application. Approach: Lateral epitaxy on pattered substrates of Si will be used for nucleation and deposition of CdTe, and subsequently CdZnTe, and eventually HgCdTe films with several orders of magnitude reduction in defect densities. Progress: Student hired, and SiO2 masked silicon substrate templates for LEO growth have been ordered. Conditions for nucleation on Si are being investigated. Title: High Power Broadband Amplifiers for 1-18 GHz Naval Radar PI: Mark Rodwell THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Department of Electrical and Computer Engineering Address: CHEADLE HALL ROOM 3227 Santa Barbara, CA 93106 (805) 893-3244 Funding Agency: Office of Naval Research PR Number: 00PR00546-00 Award Number: N000149810750 Current End Date: 30-Sep-2001 Scientific Officer: John Zolper Objective: To demonstrate a solid state power amplifier producing 2 Watts of power over 1 -18 GHz. This will serve as the driver stage for a Microwave Power Module under development by NRL. Approach: Both circuit and transistors improvements will be addressed to achieve the desired broadband power amplifier performance. Circuit work will include a cascode-delay-matched traveling-wave amplifier and resistive-feedback Ft-doubler configurations. The circuits will initially be implemented with InP-based transfer substrate HBTs and latter, as the device technologies mature, GaN HEMTs and HBTs. Title: Millimeter-wave AlGaN/GaN HEMT Power Amplifier Technology PI: Yifeng Wu NITRES INC Address: 5655 Lindero Canyon Rd STE 404 Westlake Village, CA 91362 (805) 967-9433 Funding Agency: Office of Naval Research PR Number: 00PR00548-00 Award Number: N0001400C0004 Current End Date: 31-Oct-2002 Scientific Officer: John Zolper Objective: Develop AlGaN/GaN high electron transistors for power generation up to 35 GHz. Approach: AlGaN/GaN high electron transistor power performance will be extended up to 35 GHz by device scaling and implementation of a recessed gate technology. Title: MICROWAVE POWER MODULE PI: Richard Abrams NAVAL RESEARCH LABORATORY Code 6844 Address: 4555 Overlook Ave S.W. Washington, DC 203755347 (202) 404-7163 Funding Agency: Office of Naval Research PR Number: 00PR00552-00 Award Number: N0001400WX20103 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Develop compact, lightweight, highly efficient and affordable RF transmitters that will enable new Navy and defense system applications, yet be suitable for retrofit or mid-life upgrades of existing electronic attack, radar, and communication systems. Approach: Investigate the scientific issues and trade-offs relevant to the MPM's capability to deliver high power with extremely high efficiency and high linearity across broad bandwidths. Develop the power module RF trans-mitter technology base to exploit the best features of solid-state and vacuum-electronics technology. Demonstrate microwave and milli-meter-wave power module technology with various capabilities of interest to electronic warfare, radar, and communication systems and applications. Progress: Northrop Grumman Corp. designed, fabricated, and characterized a vacuum power booster that produced 100-watt (CW) from 3- to 18-GHz; they will extend the frequency performance to 2 GHz, using harmonic injection techniques. Lockheed Martin/Sanders established harmonic injection proof-of-principle as a technique to reduce harmonic output power; they will develop a brass-board version of a 2- to 18-GHz MPM using a Litton vacuum power booster. Northrop Grumman defined the benchmark 2-D array architecture and three candidate architectures using MPMs and will complete a preliminary analysis of these arrays. The non-linear large signal code CHRISTINE was validated for efficiency optimization at Northrop Grumman Corp. Title: SUPPORTING TECHNOLOGY PI: David Abe NAVAL RESEARCH LABORATORY CODE 6843 Address: 4555 OVERLOOK AVENUE SW WASHINGTON,, DC 203755347 (202) 767-0033 Funding Agency: Office of Naval Research PR Number: 00PR00556-00 Award Number: N0001400WX20152 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Develop new materials and technologies that can be used to extend the performance of broad classes of vacuum power amplifiers. Approach: Materials for vacuum electronic power devices will emphasize the development of materials to replace toxic BeO-SiC as well as develop new materials to enable vacuum electronic devices to operate at increased power densities. Noise reduction in linear beam amplifiers will be addressed through theoretical and experimental investigations of ion-relaxation noise, one of the most common sources of noise in CW linear beam tubes. Progress: HPCS conformal SiC coatings have been produced with tailored electro-magnetic loss properties using additives (carbon black, dendritic copper). The coatings exhibit acceptable adherence to copper RF cavity walls and excellent high vacuum properties down to 10-9 torr. Cavity Qs as low as 34 have been achieved in S-band, demonstrating that the material has potential as an alternative to BeO-SiC for bandwidth control in vacuum amplifiers. AlN composites with thermal conductivities as high as 204 W/m-K have been produced by microwave sintering with a factor of four improvement in processing time. In a second task, an ion noise model for the AEGIS AN/SPG-62 coupled-cavity TWT has been developed for the 2-D particle-in-cell code, OOPIC. Simulations are continuing and in the process of being compared with experiment. Title: HIGH PERFORMANCE MILLIMETER WAVE DEVICES PI: Bruce Danly NAVAL RESEARCH LABORATORY Code 6840 Address: 4555 Overlook Ave SW Washington, DC 20375 (202) 767-0032 Funding Agency: Office of Naval Research PR Number: 00PR00557-01 Award Number: N0001400WX20185 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Explore and develop high power millimeter wave vacuum electronic amplfiiers having enhanced gain, bandwidth, and efficiency with reduced physical and operational constraints. Power level requirements are system and frequency specific, spanning watts to thousands of kilowatts in the MMW frequency band. Approach: Fast-wave devices that include gyrotrons with reduced size and weight with higher efficiencies than can be achieved in currently-available devices will be developed. Strong emphasis will be placed on coupling of theory with experiment. Slow-wave devices that address system-specific needs for the Army are being developed through Project Reliance agreements. Progress: The first testing of the 94-GHz high average-power gyro-klystron amplifier has been completed. A team composed of NRL, Litton, Communication and Power Industries, and University of Maryland developed this amplifier. In low-duty testing, this amplifier achieved 115 kW peak power and 600 MHz instantaneous bandwidth. In high duty testing, the device achieved 10.1 kW average power, 90 kW peak power, at an efficiency of 33% (RF power divided by input power). Development of subsequent devices with wider bandwidth, and for airborne and space-based platforms is underway. Title: MODELING AND SIMULATION PI: Baruch Levush NAVAL RESEARCH LABORATORY code 6841 Address: 4555 Overlook Ave SW Washington, DC 203755347 (202) 767-0003 Funding Agency: Office of Naval Research PR Number: 00PR00558-00 Award Number: N0001400WX20153 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Develop an advanced computer-based capability for vacuum electronic devices (VEDs) to enhance design, development, and manufacture, resulting in higher performance and reliability with lower costs and shorter development times. The activities in this project will support the on-going development of the vacuum power booster for the Microwave Power Module(MPM) project, as well as development of fast-wave and slow-wave devices in the High-Power Millimeter-Wave Project. Military applications in radar, electronic warfare, and communications depend on the successful execution of these projects. This project will also investigate new techniques that offer promise for improving the performance of CFAs for the AEGIS SPY-I system while maintaining or reducing present life cycle costs. Approach: This project will establish a new design methodology that will be applied to a sequence of vacuum electronic devices over the next five years. The initial three-year effort will focus primarily on tools to design helix TWTs and crossed-field amplifiers through the development of three-dimensional, unstructured-grid codes for gun and collector design, for cold-test, and for large-signal analysis. The long-term plan calls for the three dimensional large-signal code to be extended to coupled-cavity TWTs and klystrons. These three-dimensional codes will also enable stability studies of linear TWTs as part of an overall design methodology based on numerical simulation. Progress: An accurate model for the tape helix has been developed, implemented and tested in the 1-D large signal code (CHRISTINE) for modeling helix TWTs. A modified Jacobi-Davidson method has been implemented in the 3-D electromagnetic code (CTLSS) enabling it to find eigen-modes of electro-magnetic cavities containing RF absorbing dielectric materials. Fast parametric codes for designing periodic permanent magnet circuits for TWTs have been developed. The development of a 3-D gun/collector electrostatic code (MICHELLE) based on an unstructured numerical mesh has been initiated. Title: ADVANCED EMITTER TECHNOLOGY PI: Keven Jensen NAVAL RESEARCH LABORATORY Code 6841 Address: 4555 Overlook Ave SW Washington, DC 203755347 (202) 767-3114 Funding Agency: Office of Naval Research PR Number: 00PR00559-00 Award Number: N0001400WX20102 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Investigate electron sources and advanced cold cathodes for high power RF sources characterized by higher current density, lower emittance, more uniform emission, and greater robustness in a power tube environment for the purpose of providing higher efficiency, lower noise, and longer operating life for vacuum electronic devices. Approach: Develop advanced thermionic (scandate) cathode technology by developing fabrication techniques for scandate cathodes and transferring the process to industry; evaluate, characterize, and life test fabricated scandium cathodes; idenfify the scandate cathode emission and failure mechanism. Develop advanced cold cathodes by characterizing the transport properties of emitter materials, with emphasis on wide bandgap materials; investigate electron injection mechanisms and develop theoretical models of injection, transport and emission. Develop secondary emission cathode materials by resolving performance limits in BeO cathodes, investigate diamond and alternative emitter materials, and investigate the secondary emission process. Progress: An emission test vehicle has been designed, constructed and tested. Homogenous coatings of rhenium and Sc2O3 have been successfully deposited on the surface of dispenser cathodes using a magnetron sputter-coater equipped with a unique segmented foil target and rotating holder. The scandium component is then oxidized prior to activation. In initial tests of the coated cathodes, emission current densities of up to 53 A/cm2 have been measured in pulse mode at an anode potential of 1,200 volts and a temperature of 1050oCMoBr. A patent disclosure has been filed to protect the technology if deemed appropriate. Title: Defect Reduction in A1GaN/GaN Ultravoilet Photodetectors PI: Hadis Morkoc VIRGINIA COMMONWEALTH UNIVERSITY Dept. of Electrical Engineering & Physics Address: 601 West Main Street Richmond, VA 23284 (217) 333-0722 Funding Agency: Office of Naval Research PR Number: 00PR00567-00 Award Number: N000149910628 Current End Date: 30-Apr-2002 Scientific Officer: Yoon Park Objective: To develop the materials and processing technologies for high performance UV AlGaN/GaN photodetectors that can be integrated into UV focal plane-arrays. Approach: Initial detectors would be of GaN pin variety to establish base line figures for detectivity and noise. For the solarblind region of the spectrum, considering the difficulties associated with p-type doping, Schottky barrier varieties will be explored. In parallel doping schemes, such as modulation, doping will be explored in effort to develop pin varieties for the solar blind region also. Progress: A frontal attack has been launched to prepare GaN, AlN and AlGaN on saphire and SiC substrates for reducing point defects utilizing PL and CL, high resolution X-Ray diffraction and AFM. One of the MBE systems is being equipped with diagnostics and parameter control apparatus for precise control of all the critical parameters. The MOCVD system is nearly up with some heat damage to the sample holder. Title: Picosecond Time-Resolved Photoluminescence Studies of III-Nitride Materials and Structures PI: Jiang Hongxing KANSAS STATE UNIVERSITY Dept. of Physics Address: Anderson Hall, Room #10 Manhattan, KS 66506 (785) 532-1627 Funding Agency: Office of Naval Research PR Number: 00PR00568-00 Award Number: N000149910444 Current End Date: 31-Mar-2002 Scientific Officer: Yoon Park Objective: To address the fundamental issues which have not yet been fully explored but are proven to profoundly influence GaN/AlGaN Quantum Well and heterojunction device performance: 1) alloy dependent optical and optoelectronic properties of AlGaN epilayers with high AlN fractions and 2) structural parameter dependent optical transitions and carrier dynamics in GaN/AlGaN QWs and heterostructures. Approach: Picosecond time-resolved photoluminescence will be employed to study optical transitions and carrier dynamics in GaN/AlGaN QW structures and mechanisms of optical transitions in AlGaN epilayers with high AlN mole fractions. The results of the research will provide input for developing suitable materials quality and device designs for applications such as UV detectors, UV emitters, field effect transistors, and electron emitters. Progress: The III-nitride microdisc and microrings have been fabricated by inductively-coupled-plasma dry etching from GaN/AlGaN and InGaN/GaN multiple quantum well (MQW) structures. With respect to the original MQWs, the intrinsic transitions from both the wells and barriers exhibited an approximate 10-fold increase in both recombination lifetime and quantum efficiency upon formation of microdiscs. Optical resonance modes have been observed in GaN microstructures. Preliminary results imply a bright future for III-nitride micro-size optoelectronic devices, including micro-LEDs, micro-LED arrays, microcavity lasers, and vertical cavity surface emitting lasers. Title: Analog Signal Processing Devices and PI: Fritz Kub NAVAL RESEARCH LABORATORY Code 6813 Address: 4555 Overlook Avenue SW Washington, DC 203755347 (202) 767-3862 Funding Agency: Office of Naval Research PR Number: 00PR00577-02 Award Number: N0001400WX20051 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Develop high frequency adaptive processor circuits for application to a variety of Navy system needs with particular emphasis on co-site interference cancelers for application to surveillance, communications, and jammer systems. Develop a Continuous Wavelet Transform (CWT) circuit to reduce the volume and power, compared to a digital approach, that can be applied to communications and EW applications. Develop high dynamic range photodetector/amplifier arrays that can be used in acousto-optic channelizers for EW applications. Approach: Techniques to realize high frequency adaptive processor circuits using CMOS VLSI technology will be developed. Continuous time tapped delay lines coupled with on-chip offset correction circuitry will be used to implement the LMS algorithm. Techniques to realize the recently-invented analog Continuous Wavelet Transform (CWT) circuit as well as the photodetector/amplifier arrays using CMOS VLSI technology will also be developed. Title: INFRARED SPATIAL INTERFEROMETRY PI: Charles Townes THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BERKELEY SPACE SCIENCE LABORATORY Address: 336 SPROUL HALL BERKELEY, CA 947207450 (510) 642-1128 Funding Agency: Office of Naval Research PR Number: 00PR00601-01 Award Number: N000149610737 Current End Date: 31-Dec-2000 Scientific Officer: Edward Kennedy Objective: The Navy has national responsibility for the position measurements of stars and other astronomical objects for the purpose of precise navigation. In addition, understanding fluctuations in the atmosphere aid in the imaging and transmission of optical and infrared waves through the atmosphere. Approach: A third telescope is being added to enable phase closure measurements. In addition thermal measurements along the optical paths and acoustic radar measurements of the fluctuations in the path are being added to the data collection to better understand the effects on imaging and propagation of infrared waves through the atmosphere. Progress: The two-telescope interferometer on Mt. Wilson has been operating well, with upgrades made last and this year. A very recent upgrade allows the telescope to be opened or closed by a single operator, rather than requiring two persons. Another involves new computer programming which increases flexibility of the system. A graduate student has completed his work and a second will finish during the summer of 1999. One new graduate student has entered the program. Interferometry on spectral lines was carried out and has yielded important new information about formation of molecules around stars. Installation commencing shortly on a new base for the telescope to approximately double the baseline length available. Title: HF Heater to ELF/VLF Conversion Studies PI: Harvey Rowland NAVAL RESEARCH LABORATORY Plasma Physics Division Address: ATTN CODE 3310 Washington, DC 203755320 (202) 767-6644 Funding Agency: Office of Naval Research PR Number: 00PR00602-00 Award Number: N0001400WR20023 Current End Date: 30-Sep-2000 Scientific Officer: Edward Kennedy Objective: To devise theoretical models and appropriate software capable of determining how improvements can be made to current or future techniques for generating ELF through VLF frequencies through active interaction of high power HF radio waves with plasma at ionospheric heights. Successful development of this technique will afford alternative means for gener-ating signals useful for submarine communications and for geophysical probing. Approach: The absorption of HF energy in the D and E regions of the ionosphere will be calculated as a function of the HF frequency and electron density profile. The induced modification of the ionospheric conductivity will be determined. The three dimensional perturbation of the electrojet current will be calculated for a selection of onospheric conditions corresponding to real experimental situations. Software models developed will allow evaluation of various efficiency enhancement schemes including beam painting and rapid pulsing. Results and products will be in a form that may be used for experimental verification at active ionospheric research facilities. Progress: Significant progress has been made this year in research to model the generation of ELF/VLF waves by HF heaters. This work has been published (Rowland, Journal of Geophys. Res.,104, 4319, 1999) and presented at the Ionospheric Workshop 1999 in Santa Fe. Examples of our 3D simulations are shown on our web page at wwwppd.nrl.navy.mil under whatsnew-Haarp simulations. Title: SINGLE ELECTRON CAPACITANCE SPECTROSCOPY PI: Raymond Ashoori MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 13-2053 Address: RM E19 702 77 MASSACHUSETTS AVE CAMBRIDGE, MA 02139 (617) 253-5585 Funding Agency: Office of Naval Research PR Number: 00PR00613-00 Award Number: N000149310633 Current End Date: 30-Sep-2001 Scientific Officer: Larry Cooper Objective: To fabricate and develop the physical understanding of the nanometer scale semiconductor device structures which will be the devices used in future electronic systems. The focus will be on effects which are dominated by single electrons. Approach: The single electron capacitance spectroscopy technique will be used to study a variety of single electron effects in semiconductor nano-structures. Few electron systems will be studied along with charging of single defects and single impurities in such structures. High resolution studies of quantum Hall systems at interfaces will be studied as well as the spectroscopy of traps in quantum wells. Charging of quantum dots and coupled quantum dots will be studied using the subsurface charge accumulation technique. Dangling bond states at the Si/SiO(2) interface will also be investigated using the SECS technique. The investigator will further develop the time resolved capacitance technique and apply it to several tunneling problems. Progress: A single electron transistor has been integrated on top of a quantum dot in which the number of electrons moving off and on the dot can be controlled one by one. The SET acts as an extremely sensitive electro-meter which senses the charge in motion in buried structures beneath the SET. This method has the potential to study charge motion in defects and impurities in semiconductor heterostructures, buried beneath the SET. Title: THEORY AND APPLICATIONS OF MICROSCOPIC PROPERTIES OF SEMICONDUCTOR INTERFACES PI: Milan Jaros UNIVERSITY OF NEWCASTLE UPON TYNE Research Services Unit Address: 6 Kensington Terrace NewcastleUponTyneNE1 7RU, TX Funding Agency: Office of Naval Research PR Number: 00PR00614-00 Award Number: N0001490J1644 Current End Date: 30-Nov-2000 Scientific Officer: Larry Cooper Objective: The design and analysis of novel electron and optical devices in semi-conductor microstructures requires sophisticated calculations. These calculations will be used to probe new concepts for nonlinear materials and explain experimental results. Approach: The investigator will continue to develop the pseudopotential techniques for application to semiconductor microstructures. Structures of interest include heterojunctions with Type II band offsets, disorder effects at interfaces, and systems of reduced dimensionality, such as quantum wires and boxes. Structures will be explored which predict enhanced optical nonlinearities in the infrared range of wavelengths. These tasks will be chosen in order to explain the complex optical spectra observed in these structures. Progress: Transport calculations have been carried out for electrons moving in the plane of InAs/GaSb heterojunctions. The scattering lifetimes are determined for a variety of interface imperfection models. A full perturbed Hamiltonian is used in a T-matrix based scattering calculation. The results indicate clearly that Sb atoms on As sites at the interface have a much stronger scattering rate than for As on Sb sites. This indicates efforts should focus on eliminating such Sb defects in the growth of the materials. The estimated difference in rates is a factor of 30x. Consideration of larger defect islands was also made. In one case involving 49 Sb atoms, the lifetime reduction factor is over 1000. Title: Monte Carlo Approach to Quantum Transport in Mesoscopic Systems Based on Electron Wigner Paths PI: Carlo Jacoboni INSTITUTO NAZIONALE DI FISICA DELLA MATERIA Address: Via Dell'Acciaio, 139 Genova Italy, TX 45553 (616) 958-6046 Funding Agency: Office of Naval Research PR Number: 00PR00615-01 Award Number: N000149810777 Current End Date: 30-Jun-2003 Scientific Officer: Larry Cooper Objective: To develop a theoretical basis and a computer modeling code which can be used in the simulation of quantum effect nanoelectronic devices in support of electron device development programs. Approach: Based on previous work, the Wigner trajectory concept will be extended and developed for implementation using Monte Carlo methods. Phonon scattering will be included and consideration will be given to the issue of open contacts and the effects of the boundaries. The code will be optimized for efficient computer usage to include many scattering events. Progress: The mathematical formalism to implement quantum transport of electrons in open nanostructures has been completed and implemented in a numerical simulation code. Computer limitations allow for no more than 2 electron-phonon scattering events, which means that trajectories can be followed for about 100 femtoseconds. Computer optimization will be needed. Title: DEFECT PROCESSES IN WIDE BANDGAP SEMICONDUCTORS PI: George Watkins LEHIGH UNIVERSITY Department of Physics Address: 526 BRODHEAD AVENUE BETHLEHEM, PA 18015 (610) 758-3961 Funding Agency: Office of Naval Research PR Number: 00PR00616-00 Award Number: N000149410117 Current End Date: 31-Oct-2000 Scientific Officer: Larry Cooper Objective: To understand the role of defects and impurities in wide bandgap semi-conductors which control the conductivity and the degradation in devices. Approach: Various spectroscopic techniques will be applied to studies of impurities and defects in the wide bandgap II-VI and III-V semiconductor materials. These will include EPR, DLTS,FTIR and ODMR. The issues involved include doping efficiency, donor and acceptor identification, role of native defects (induced by high energy electron beam irradiation at low temperature) and various complex defects. Hydrogen will be implanted to examine the effects of complex defects associated with hydrogen. In-situ electron irradiation at varible temperature will probe the motion of induced defects such as vacancies and interstitials. These will be correlated with optical characterization results. Emphasis will be placed on various GaN epitaxial materials, including the LEO materials, and on bulk AlN samples. Progress: It has been shown that the processing of GaN devices, such as formation of dielectrics, plasma etching, wet etching, etc., results in the in-diffusion of hydrogen at low temperatures, which readily passivates acceptor impurities. The outdiffusion and hydrogen trapping-detrapping processes in much more complex in heterostructure samples. While post process annealing is used to activate p-type doping, experiments involving deuterium show that the H(2) is removed much more readily from the surface regions than from the deeper (bulk) regions. Significant removal of H(2) requires temperatures above 800 C. IR spectroscopy was used to probe hydrogen related defects by measuring local mode vibrational frequencies. By comparing these frequencies with theoretical predictions for various types of defect-hydrogen pairs, it is concluded that hydrogen couples to gallium vacancies and not to nitrogen vacancies in implanted samples. Title: Developing Functionality in Quantum Dots PI: Jonothan Bird ARIZONA STATE UNIVERSITY Dept of Electrical Engineering Address: Box 871603 Tempe, AZ 852871603 (602) 965-7421 Funding Agency: Office of Naval Research PR Number: 00PR00618-00 Award Number: N000149910326 Current End Date: 30-Apr-2002 Scientific Officer: Larry Cooper Objective: To devise various quantum dot and coupled quantum dot structures and to investigate the transport of electrons in such structures which could form the basis for future nanoelectronic devices and circuits. Approach: Quantum dot and coupled quantum dot devices will be fabricated on semiconductor heterostructures and the transport of electrons into and through such structures measured as a function of temperature, voltage and magnetic field. The fundamental quantum effects of dephasing of the electron wavefunction due to environmental effects will be explored. Separately, an external electrode configuration will be used to effect a nonlocal control of the resonant quantum states in the dots to study the possibility of a transistor effect, by nonlocal controlled switching. Progress: A localization effect has been observed in open quantum dots formed in the split gate structures on GaAs/AlGaAs heterojunctions. Low temperature measurements of electron conductance through the dots as a function of temperature and gate bias indicate that there is a localization effect which causes an extra resistance. The authors conclude that remnant disorder in the dot, with contributions from random impurities and scattering from interface roughness features, are causing the effect. Additionally, the gate voltage dependence indicates that part of the increased resistance is attributed to backscattering effects on electrons at the entrance and exit to the dot. Title: EXTENSIONS AND APPLICATIONS OF MAGNETIC RESONANCE FORCE MICROSCOPY PI: Daniel Rugar INTERNATIONAL BUSINESS MACHINE RESEARCH LAB Address: 650 Harry Road San Jose, ca 951206099 (408) 927-2027 Funding Agency: Office of Naval Research PR Number: 00PR00619-00 Award Number: N0001498C0070 Current End Date: 31-Mar-2000 Scientific Officer: Larry Cooper Objective: To develop a highly sensitive magnetic resonance force microscope (MRFM) and demonstrate the capability of this tool to identify individual defects in electronic structures. Approach: Microcantilevers will be employed which have force sensitivities of 1 aN or better. Sharp ferromagnetic tips will be used with tip diameters of 50 nm or smaller, and the magnetic field gradients of these tips will be carefully measured using MRFM techniques. The MRFM will be operated at temperatures approaching 1 K. The enhanced MRFM will be used to detect single electron spins associated with defects in a silicon dioxide sample. The detection of individual defects in semiconductor structures will also be investigated. Progress: Microcantilevers made in silicon, silicon nitride and polysilicon have been studied to determine the factors affecting the mechanical Q factors of such structures, in preparation for their use in measuring small forces in various atomic force microscopies. It has been found that Q decreases as the thickness of the cantilever decreases. Measurements at low pressures, 0.001 milliliter and below indicate that surface effects can take place where contamination or oxidation of silicon can affect the mechanical properties. Generally, there are surface mechanisms which are a dominating factor in reducing Q, and so surface treatments must be considered for optimizing performance. Title: ELECTRON TRANSPORT IN SEMICONDUCTOR HETEROSTRUCTURES & IN MESOSCOPIC SYSTEMS PI: Karl Hess THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN Beckman Institute Address: 109 Coble Hall Champaign, IL 618206242 (217) 333-2186 Funding Agency: Office of Naval Research PR Number: 00PR00621-00 Award Number: N000149810604 Current End Date: 30-Nov-2000 Scientific Officer: Larry Cooper Objective: To develop computer simulation methods to study the operation of quantum based lasers and electron transport devices. Physical mechanisms which influence the performance limitations of both optoelectronic and electronic devices will be illuminated. Approach: Semiclassical and quantum transport theory methods will be developed for investigation of electronic transport phenomena and problems related to the collection of charge in quantum wells, wires and dots under lasing conditions. Particular attention is directed toward the effects of phonons in these systems, as they influence the electron distributions and resultant gain processes. The limitations on modulation rates will be determined and alternate device concepts proposed. Hot electron degradation in silicon based, short channel FET structures will be studied in concert with deuterium substitution for hydrogen as the passivation species at Si/SiO(2) interfaces. Both high energy (6 eV) and low energy (<3 eV) electron processes will be investigated. The multi-electron vibrational mode excitation mechanism will be studied. Progress: MINILASE II, the laser simulation code has been extended so that it can now accurately model Separate Confinement Heterostructure lasers, and their frequency modulation properties. This code bypasses the usual rate equation approach by calculating physics based simulations of both electron and hole transport consistently with solutions of the Helmholtz equation for the photons to determine carrier distributions in both space and time and to evaluate the gain functions throughout the device. Comparisons with available data for modulation of quantum well lasers is very good, and it is now possible to explore the various aspects of the device which determine its performance, i.e., limitations in modulation response, materials influence, etc. It can now be used as a design tool in a workstation environment. Title: Research in Microstructure Electronics PI: David Ferry ARIZONA STATE UNIVERSITY Electrical Engineering Address: Box 871603 Tempe, AZ 852871603 (602) 965-2750 Funding Agency: Office of Naval Research PR Number: 00PR00623-00 Award Number: N000149610110 Current End Date: 31-Oct-2001 Scientific Officer: Larry Cooper Objective: To develop theoretical and computer simulation methods to analyze the physical performance of ultrasmall semiconductor devices and to understand the nature of transport processes in nanometer scale structures. Approach: Quantum transport theories will be developed which include short-time and non-equilibrium effects in nanometer scale semiconductor structures. Two particle and two time Green's functions analysis will be developed in order to deal with ultrasmall structures in which random spatial distributions of impurities are accounted for and in which all phase interference effects are included. Waveguiding effects and single electron, or charge granularity, effects will be accounted for by developing methods to deal with many body interactions in a realistic fashion. The effects of the environment, contacts and material fluctuations will also be considered. Silicon and GaAs systems will be addressed. Progress: As electron devices become smaller in dimensions, quantum effects become large and directly influence the design and operation of devices, or the devices are essentially quantum effect dominated. In addition, when such devices are close enough together, the question of quantum interactions between devices has to be answered. In order to describe and evaluate such effects in real devices, there must be formalism and simulation method which can address the question of where dissipation and deco-herence of electron wavefunctions occurs, i.e., in the contacts. A new approach to this problem has been formulated using non-Hermitian imaginary potentials in the form of time dependent density matrix tech-niques. This formalism allows for trapping and detrapping, and the decay of the wavefunctions in the region between the coherent region and the contact or decoherence region. It will now be possible to develop device simulation methods which correctly include the contacts. Decoherence and dissipation can now be taken into account in a realistic way. Title: NOVEL DEVICES FOR NOVEL COMPUTATIONAL PI: Thomas McGill CALIFORNIA INSTITUTE OF TECHNOLOGY Department of Applied Physics Address: 1200 E. California Boulevard Pasadena, CA 91125 (626) 395-4849 Funding Agency: Office of Naval Research PR Number: 00PR00624-00 Award Number: N000149810567 Current End Date: 31-Mar-2001 Scientific Officer: Larry Cooper Objective: To explore semiconductor heterojunction materials and devices in which quantum phenomena can be exploited in novel devices for computation and signal processing. Approach: A variety of device structures will be fabricated based on hetero-junction materials made from InAs/AlSb/GaSb thin film semiconductors. These materials will explore novel device concepts such as, velocity modulated transistors, static random access memory, quantum dots, and spin transistors. Materials will be grown and characterized as appropriate. Device simulations as well as circuit simulations for incorporation of such quantum devices will be carried out. Progress: Modeling and simulation of tunneling devices is very difficult since it involves a coupling of quantum transport effects with semiclassical descriptions. The exploration of the Tunnel Switched Diode device for possible applications as a Transistorless SRAM, as a photodetector, chemical-sensitive switching and as an element of a neural network, requires better understanding of its operation, and the effects of different materials, layer thicknesses, doping effects, etc. The new results on this project were determined by the development of a new approach to the simulation problem, by coupling the Drift-Diffusion method with Quantum Transmitting Boundary conditions. The method has been applied to the tunneling problem in MOS structures and correctly predict the transport properties and the development of depletion and inversion layers. The case for the TSD is more difficult, since the bistability is very sensitive to choices of carrier lifetime terms, layer thicknesses and the fact that both electron and hole tunneling have to be taken into account. However, it is shown that much of the operation of these devices can be described, although the values chosen for the material parameters is very critical if the bistable properties are to be explained. Title: DEVELOPMENT OF GaN MOSFETS AND MISFETS PI: Cammy Abernathy UNIVERSITY OF FLORIDA COLLEGE OF ENGINEERING Address: 417 WEIL HALL GAINESVILLE, FL 32611 (352) 392-0693 Funding Agency: Office of Naval Research PR Number: 00PR00643-00 Award Number: N000149810204 Current End Date: 31-Dec-2000 Scientific Officer: John Zolper Objective: Study formation of insulating layers, including GdGaO and AlNV, on SiC and GaN. Approach: Insulating materials will be deposited by MOMBE on SiC and GaN. Structural and electrical properties will be characterized. Progress: The following was accomplished: 1) installation a gas-source molecular beam epitaxy system for depostion of oxide dielectrics, 2) development of a pre-deposition cleaning procedure for reduced interfacial leakage, and 3) demonstration of the first GaN MOSFET. This depletion mode MOSFET exhibited improved breakdown performance relative to Schottky devices and showed a unity current gain cut-off frequency of 3.1 GHz and a maximum oscillation frequency of 9.1 GHz at Vds = 25 V and Vg = - 20V. Title: Theory of Surface Processes and Interface Formation in Semiconductors PI: Jerzy Bernholc NORTH CAROLINA STATE UNIVERSITY Dept. of Physics Address: BOX 7514 RALEIGH, NC 276957514 (919) 737-3126 Funding Agency: Office of Naval Research PR Number: 00PR00657-00 Award Number: N000149610161 Current End Date: 14-Dec-2001 Scientific Officer: Larry Cooper Objective: Theoretical modelling and computer simulation methods will be developed and applied to various problems in epitaxial growth of semiconductor films and interface formation. Approach: Theoretical methods including computer simulation techniques for parallel supercomputing environments will be developed and applied to various problems in surface processes and interface formation in semi-conductors. Problems of interest include: semiconductor growth mechanisms; passivation and etching; formation and electronic properties of heterojunctions. The GW approach will be developed which will be used to calculate the optical properties of the RDS response for various semiconductor surfaces. These will be used to evaluate the experimental results being obtained for in-situ characterization of various growing layers. Progress: Significant progress has been made in developing ab initio calculations for describing Reflectance Difference Spectra for the MOCVD growth of InP. Comparison of calculated optical reflectance spectra for the several postulated surface structures of the InP surface, for In-rich to P-rich conditions are in good qualitative agreement with measured spectra. The shapes and energies are unique for the atomic structures suggested. Whether In-In or P-P bonding arrangements or the In-P bonding dominates can be determined, as the spectral signatures are unique. Comparison with experiment is difficult since the surface may have a mix of different structures, depending upon defects, temperature, kinetic effects, etc. These results are an important step in the direction of eventually being able to observe in real-time and in-situ, the structure of a growing film. Title: A THEORETICAL PROBE INTO THE ELECTRONIC, GEOMETRIC, AND DYNAMICAL PROPERTIES OF SEMICONDUCTORS PI: John Joannopoulos MASSACHUSETTS INSTITUTE OF TECHNOLOGY Research Laboratory of Electronics Address: 77 Massachusetts Avenue Cambridge, MA 021394307 (617) 253-4806 Funding Agency: Office of Naval Research PR Number: 00PR00658-00 Award Number: N000149710545 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To develop ab initio theory for studying heteoepitaxial films of semiconductor materials which will produce improved substrate materials for electronic devices. Approach: Ab initio theoretical techniques will be used to address the issue of lattice matching in heteroepitaxial semiconductor systems. The geometric structure and quasiparticle structure for interface systems will be calculated. Systematic studies of a new approach to forming optimized mismatched systems will be made. The idea of creating a new class of "pseudo" materials by choosing atoms from the II, III, IV and V groups to simultaneously optimize both charge (in the bonds) and ion size will be evaluated. Total energy optimization techniques will be used to find the best cases for growing III-V layers on Si substrates. One emphasis will be to formulate growth of a III-V alloy with direct optical gap at 1.5 microns. Progress: The growth of many semiconductor heterostructures is constrained by the requirement of matching lattice constants, and in the case of hetervalent systems, controlling the charge transfer across interfaces which can lead to large internal electric fields. Using ab initio calculation methods, a new approach has been proposed, in which the effective bandgap of the material is constrained to a preset value at the same time as the lattice mismatch problem is minimized. This is an example of computer design of materials. For the example of designing a direct gap semiconductor grown lattice matched to Silicon with a bandgap for use in the 1.55 micron optical devices, the interface layer involves combinations of either group V and group II, or of group III and group VI. These are chosen to control the charge exchange. Elements are chosen which have appropriate ionic radii. For the example chosen, the lattice mismatch to silicon is 0.08%, thermal expansion mismatch is zero at 350K and the bandgap is equivalent to a wavelength of 1.59 microns. Title: WIDEBAND TRANSFERRED SUBSTRATE AlGaN-GaN HETEROJUNCTION BIPOLAR TRANSISTORS FOR MICROWAVE POWER APPLICATIONS PI: Mark Rodwell THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Department of Electrical and Computer Engineering Address: CHEADLE HALL ROOM 3227 Santa Barbara, CA 93106 (805) 893-3244 Funding Agency: Office of Naval Research PR Number: 00PR00676-00 Award Number: N000149810061 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: The Navy operates multiple radar systems on its vessels with carrier frequencies in the 6-22 GHz range and with 100 - 1000 W per phased array antenna desired. For this application, solid state-power amplifiers are desirable due to their reliabilitiy. The power amplifiers then must have high linearity and 6-22 GHz bandwidth. The proposed program addresses the development of high-power microwave transistors for this application. Approach: AlGaN microwave field effect transistors (FETs) with 50-100 GHz f(max) and 100-200 V breakdown have been demonstrated. While AlGaN/GaN heterojunction bipolar transistors (HBTs) may compete with such FETs for 6-22 GHz power applications. The program will develop AlGaN/GaN HBTs with 50-200 V breakdown voltages and 100-500 GHz f(max). To this end, substrate transfer processes, low-resistance p-Ohmic contacts, and wafer fusion will be explored. Progress: During this period, the first AlGaN/GaN heterojunction bipolar transistor was demonstrated. The structure was grown by MOCVD on a sapphire substrate. Preliminary measurements showed a DC current gain of 3. A Si doped (N-type) GaN sub-collector was followed by an undoped collector and a Mg doped (P-type) base. The Si doped emitter (n~ 5 x 10 18 /cm3) was grown with an Al0.1Ga0.9N barrier layer to increase emitter injection efficiency into the strongly doped base. In an effort to reduce extrinsic base resistance associated with a high p-contact resistance and high bulk resistivity, selective regrowth was used to create a thick Mg doped pad for the base contacts. The additional extrinsic base thickness is intended to reduce bulk resistivity under the contact and repair damage caused by a chlorine dry etch. The common emitter IV characteristics suggested a high early voltage due to acceptor doping in the base of approximately 4 x 1019/ cm3. The present thrust is focused on fixing base contact problems, introducing a graded base for improved transit efficiency, and developing submicron emitter technology to be used with RF devices. Title: High Resolution Transferred-Substrate HBT Microwave / RF ADCs PI: Mark Rodwell THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Department of Electrical and Computer Engineering Address: CHEADLE HALL ROOM 3227 Santa Barbara, CA 93106 (805) 893-3244 Funding Agency: Office of Naval Research PR Number: 00PR00683-00 Award Number: N000149810068 Current End Date: 14-Nov-2000 Scientific Officer: Max Yoder Objective: Seeks to exploit low parasitic heterojunction bipolar transistor technology using a transferred substrate approach so as to obtain digital logic devices operating at 100 GHz that are capable of direct digital synthesis of signals as well as integral phase and frequency modulation. Approach: A transferred substrate approach will be used to create low parasitic heterojuncion bipolar transistors wherein the base to collector parasitic capacitance is greatly reduced and in which these transistors will scale in two dimensions so as to operate at extremely low power. Progress: The low parasitic transferred substrate process has been developed from the point of being a single-transistor process to the point where ICs of a few hundred transistors can be fabricated. Two generations of analog ICs have been demonstrated in the process, including amplifiers of record 85 GHz bandwidth and record 360 GHz gain-bandwidth product. Extremely fast first-generation digital ICs (master-slave latches) have been demonstrated in the process with 48 GHz clock frequencies; 2:1 multiplexers and demultiplexers, W-band VCOs, and 30 GHz digital phase-lock-loops and are fabricated (but not yet tested). Designs for 100 GHz master-slave flip-flops have been completed and await fabrication. Initial design of 50 GHz adder-accumulators (for DDS) have been completed, and also await fabrication. Title: BONDING DEFECTS AT SEMICONDUCTOR/INSULATOR INTERFACES III PI: Gerald Lucovsky NORTH CAROLINA STATE UNIVERSITY College of Physical & Math Sciences Address: Box 8202 Raleigh, NC 276958202 (919) 515-3301 Funding Agency: Office of Naval Research PR Number: 00PR00684-00 Award Number: N000149810562 Current End Date: 31-Mar-2001 Scientific Officer: Larry Cooper Objective: To develop technology and understanding of the formation of dielectric films on silicon with emphasis on the formation of interface bonds and related defect formation which affects nanoscale electron devices. Approach: Real-time linear and nonlinear optical characterization systems will be built and applied to the study of various semiconductor/insulator interfaces for in-situ growth studies. These will be carried out in conjunction with experiments, modeling and theory to address interface planarity, defects and defect precursors at the atomistic level. Silicon, GaN, AlGaN, and SiC will be among the systems under study. Insulators will include oxides, nitrides and oxynitrides. Progress: Using a variety of experimental techniques to probe the interface be-tween insulator films and silicon substrates, it is shown that enhanced performance for p-mos and n-mos transistors can be obtained when nitrogen is added to the processing. A 5 % monolayer addition to the first oxygen-silicon interface, followed by a thin SiO-2 film and a final oxynitride film can reduce tunneling currents by factors up to a hundred over normal thermal oxide insulators. These new insulators are compatible with the remote plasma processing techniques developed by the P.I., who has demonstrated that device quality insulators can be prepared at ultra low processing temperatures of about 300 degrees centigrade rather than the usual thermal oxides formed at 1000 degrees C. Title: Development of a Superconducting Semiconductor PI: John Dow ARIZONA STATE UNIVERSITY Dept. of Physics & Astronomy Address: ASB 210 Tempe, AZ 852871504 (602) 423-8540 Funding Agency: Office of Naval Research PR Number: 00PR00690-03 Award Number: N000149410147 Current End Date: 30-Nov-2000 Scientific Officer: Larry Cooper Objective: To understand the atomic-scale phenomena involved in the interfacial formation of ferromagnetic metals on semiconductors and on high temperature superconductors and to determine their effects on spin injected electronics. The origin of superconductivity in the cuprate oxides will be studied. Approach: Low temperature STM measurments will be made on cleaved oxide super-conductor materials. Chemical and defect/impurity effects on the nature of the superconducting properties will be studied. Theoretical studies of the processes of spin polarized electrons interacting with dimensionally confined magnon states in thin film metals on semicon-ductors will be made. In addition, spin flip scattering processes at imperfect interfaces and with magnetic impurities in semiconductors will be studied using first principle calculations of the materials. Progress: There is further evidence to indicate that the model for High Temperature Superconductivity in which the conductivity is due to hypocharged oxygen and not the the cuprate planes. This model has predicted superconductivity for several rare-earth substituted homologues of a variety of cuprate plane materials. The results indicate that when magnetic ions are coupled with the cuprate planes, supercon-ductivity is not affected. Magnetic ions will cause Cooper pair breaking in the superconducting current. Thus, the planes are not the source of superconductivity. In the case of the PrBa(2)Cu(3)O(7), the usual theories indicate that this material is not a superconductor. However, there are now many experiments indicating that it does superconduct, if the Pr ion is not on the Ba site, which is the site nearest the hypo-charged chains. Title: INNOVATIVE NANOTECHNOLOGY AND NANODEVICES PI: Stephen Chou THE TRUSTEES OF PRINCETON UNIVERSITY Electrical Engineering Department Address: E-Quad Princeton, NJ 085445263 (612) 624-5599 Funding Agency: Office of Naval Research PR Number: 00PR00693-00 Award Number: N000149810234 Current End Date: 30-Nov-2000 Scientific Officer: Larry Cooper Objective: To explore innovative nanofabrication technology and various nanoscale electron devices which can form the foundation of advanced electronic and optical systems. Approach: Novel nanofabrication technologies will be explored and developed including nanoimprint lithography and various patterned substrate approaches which includes self assembly aspects. Nanoelectronic devices such as stacked quantum dot transistors and Aharonov-Bohm ring transistors will be fabricated in silicon and their electronic properties determined. The AB ring will be studied in terms of its magnetic field sensitivity. Patterned substrates, using nanoimprint lithography methods, will be used to explore formation of new materials. This will be followed by studies which show intelligent or controlled growth or self-assembly. Progress: Nanoimprint lithography techniques have been used to prepare a pattern of small mesas on a silicon surface. Subsequently, Ge atoms are deposited on the surface and allowed to migrate and self assemble into quantum dot structures. AFM is used in-situ to characterize the size, shape and position of the dots. The new result is that while lattice mismatched strain (between silicon and germanium) causes the self assembly, the mesa pattern controls the positioning of the dots. Further, the size and shape of the mesas controls the size and shape of the dots. This is an excellent demonstration of the patterning approach to controlling self-assembled quantum dots with contribution of Nano-imprint Lithography for positioning the dots. This is an important step toward developing quantum dot lasers and detectors, and perhaps a way to create circuits based on Quantum Dot Cellular Automata. Title: CHARACTERIZATION OF MAGNETIC INTERFACES PI: Yves Idzerda NAVAL RESEARCH LABORATORY Materials Science and Technology Division Address: NRL 6345 Washington, DC 203755320 (202) 767-3603 Funding Agency: Office of Naval Research PR Number: 00PR00695-00 Award Number: N0001400WR20038 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To develop x-ray scattering based techniques for studying magnetic materials and to apply them to the study of various magnetic multilayer materials which are under consideration for new magnetoelectronic applications. Approach: Circularly polarized soft x-rays from the Brookhaven synchrotron will be used in the development of the X-Ray Magnetic Scattering method and in XMCD, to investigate a variety of heteromagnetic materials. Materials of interest include ferromagnetic films deposited on oxides, semiconductors, colossal magneto-resistive materials, high temperature superconducting materials, normal metals and other ferromagnetic materials. Issues of interest are the nature of magnetic roughness at interfaces, the correlation with chemical roughness or interdiffusion, quantifying the correlation of domain structure between layers, and the role of alloying between layers. These studies will be carried out in coordination with other studies, elsewhere, on issues of spin transport, spin tunneling and spin filtering effects in such materials. Progress: Using circularly polarized synchrotron radiation and spin polarized photoelectron scattering techniques, the local order of magnetic moments and the effects of thermal vibrations on such moments in thin films of iron can be characterized. By measuring the temperature dependence of the magnetic EXAFS signal and comparing the results with theoretical analysis, it can be concluded that in addition to the thermal vibrational effects there is the probability of magnetic fluctuations affecting the local (atomic) magnetic moments of the iron atoms which affect the scattering paths of the photoelectrons. This technique has the potential for characterizing the local magnetic structure in ferromagnetic metals and magnetic semiconductors. Title: SPIN INJECTION & PROPAGATION IN HYBRID MAGNETIC/SEMICONDUCTOR QUANTUM STRUCTURES PI: Nitin Samarth THE PENNSYLVANIA STATE UNIVERSITY Department of Physics Address: 110 TECHNOLOGY CENTER BUILDING UNIVERSITY PARK, PA 168027000 (814) 863-0136 Funding Agency: Office of Naval Research PR Number: 00PR00712-00 Award Number: N000149910071 Current End Date: 31-Oct-2001 Scientific Officer: Larry Cooper Objective: The fundamental processes associated with the injection and transport of spin polarized carriers in hybrid semiconductor/magnetic quantum structures will be explored and used to devise a novel and new class of devices for applications in nanoelectronics. Approach: Various heterojunction materials systems will be grown using II-VI and III-V semiconductors in quantum well configurations; in addition, magnetic components will be added by incorporating Mn ions into the materials as well as the growth of ferromagnetic films on top of the heterostructures. The injection of spin carriers by injection through contacts or by optical pulse absorption will be attempted and the transport in various fields will be studied. Picosecond pulse techniques will be used along with NSOM technology. Spin FETs and RTDs will be fabricated. Progress: Methods for growing quantum wells in modulation doped ZnTe/CdMnSe materials have been developed. These thin film materials are shown to have a high mobility 2 Dimensional Electron Gas. The inclusion of Mn ions results in spin dependent transport phenomena, and in these samples, there is little effect of the Mn ions on the 2DEG mobility. There are results to show that the magnetoresistance of the 2DEG can be modulated by the external field. Title: Superconducting RF Systems for Navy Applications PI: Anna Leese SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO Code D721 Address: SPAWAR (619) 553-2619 Funding Agency: Office of Naval Research PR Number: 00PR00719-00 Award Number: N0001400WR20092 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: To continue the progress begun in fy99 toward demonstrating the benefit of superconducting out of band rejection filters, both for existing FRPA GPS antennas (for potential near term insertion on AV8B and F18) and to protect the new Lm band from intentional jamming of the C/A band. Determine whether Navy systems' needs, e.g., for a low Bit Error Rate (BER) in digital communications links such as Link 16, and for SIGINT functions can be significantly better served by superconducting filters. Approach: The phase 1 program was so successful that Darpa has agreed to fund an optimization of its cryocooler in fy00 with the goal of reducing the heat load, weight and volume to the point where it is easy to insert it between the FRPA antenna and the GPS EA-4 AEU and MAGR receiver, without lengthening the cool-down time of 2 filters to more than 30 min. Filter design methods will be sought to reduce differential group delay at band edges without degrading rejection possibilities. GPS JPO will be briefed on Darpa funded design of new Lm band filters and experimental results of testing phase 1 unit. Title: Spin Injection & Propogation in Hybrid Magnetic Semiconductor Quantum Structures PI: David Awschalom THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Address: Santa Barbara, CA 931065100 (805) 893-2121 Funding Agency: Office of Naval Research PR Number: 00PR00738-00 Award Number: N000149910077 Current End Date: 31-Oct-2001 Scientific Officer: Larry Cooper Objective: To develop hybrid magnetic/semiconductor materials and device structures and to explore the physical processes of injection and transport of spin polarized carriers in such materials. Approach: Various semiconductor-magnetic metal and semiconductor-magnetic semiconductor materials will be prepared and investigated using transport and optical characterization techniques. The physics of spin injection via low resistance contact or via optical injection will be studied. Coherent spin propagation on nanosecond timescales will be studied along with methods to control the drift of the carriers. Both electric and gradient magnetic fields will be used. The materials will include both II-VI and III-V semiconductors. Mn doped III-V nano-structures will be developed for use as spin injection contacts. Progress: Optical techniques have been used to probe the spin coherence in quantum structures based on ZnSe/ZnCdSe double quantum well films. Linearized pump-probe experiments of the spin coherence of the an injected spin polarized electron and hole distribution were made in both Faraday and Voigt geometries. The Faraday rotation of the propagating light oscillates in time. However, for the Faraday geometry the oscillations decay in a few picoseconds. For the Voigt geometry it takes 20 times longer. From this it is deduced that the holes, constrained by the geometry, are shown to spin scatter much more rapidly than the electrons. This means the electrons in the conduction band are free to process independently for much longer times. Title: HIGH SPEED LOGIC FOR ELECTRONIC BEAM PI: Joseph Jensen HUGHES AIRCRAFT COMPANY Address: 3011 MALIBU CANYON ROAD MALIBU, CA 90265 (310) 317-5250 Funding Agency: Office of Naval Research PR Number: 00PR00746-00 Award Number: N0001498C0081 Current End Date: 27-Apr-2001 Scientific Officer: Max Yoder Objective: This work seeks to exploit low parasitic HBT technology to achieve a direct digital synthesizer capable of synthesizing signals from audio through X-band and modulating same with frequency or phase modulation. Approach: Low parasitic heterojunction bipolar transistors will be used to develop direct digital synthesizers. Progress: Simulations are being performed on the 4-to-1 mux for the delta-sigma DAC and the initial schematics of the 12-bit DAC design have been completed to the scaled lower parasitic process. The critical sub-circuits (e.g., Type D, master-slave flip-flop) have been demonstrated to operate at 70 GHz clock speed. Title: Wideband Digital Delay Elements for True Time Delay Beam Steering PI: Kenneth Elliott HRL LABORATORIES LLC Address: 3011 Malibu Canyon Road Malibu, CA 90265 (301) 317-5450 Funding Agency: Office of Naval Research PR Number: 00PR00748-00 Award Number: N0001499C0159 Current End Date: 03-May-2002 Scientific Officer: Max Yoder Objective: Seeks digital means of providing differential intra-clock-pulse delay from zero to 7 nanoseconds with increments of 0.25 picoseconds in an integrated circuit compatible with direct digitally synthesized signals for purposes of electromagnetic beam steering. Approach: Low parasitic heterojunction bipolar transistors will be used to design low phase noise switched linear and non-linear differential delay lines compatible for use in 100 GHz logic circuits. Title: QUANTUM TRANSPORT AND ELECTRIC FIELD DEPENDENT PROCESSES PI: Gerald IAFRATE UNIVERSITY OF NOTRE DAME DEPARTMENT OF ELECTRICAL ENGINEERING Address: UNIVERSITY OF NOTRE DAME NOTRE DAME, in 46556 (219) 631-8673 Funding Agency: Office of Naval Research PR Number: 00PR00758-00 Award Number: N000149910364 Current End Date: 31-Jan-2002 Scientific Officer: Larry Cooper Objective: To develop a theoretical formalism which can be used to describe the phenomena of quantum transport effects in semiconductor nanostructures, in order to explain the performance of such nanoelectronic devices. Approach: A complete theory of Bloch oscillations will be developed and used to study radiation output from such oscillations. This analysis will include the effects of elastic and inelastic scattering processes on dephasing and delocalization in nanostructures. The full density matrix will be used. Further, a detailed theory describing the influence of static and time dependent electric fields on threshold phenomena pertinent to the operation of nanoelectronic devices, i.e., optical absorption, Auger scattering, resonant tunneling, etc. will be developed. The nonlinear dependence of electric field strength will be investigated in tunneling through band engineered structures. Progress: Various problems of quantum transport have been set up in which the Liouville equation for the one particle density matrix including time dependent and homogeneous field conditions are included. A time varying basis for the wave functions is used, so that Zener tunneling and memory effects can be properly accounted for. Multiband models for semiconductors are being used to study Bloch dynamics in multi-quantum well and superlattice device structures, such as Bloch oscillators, QWIPs, etc. Progress: New start. No progress to report. Title: Origins of Nonlinear Microwave Response of HTS materials & Devices PI: Ronald Ono U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Cryoelectronic Metrology Group Address: 325 Broadway Boulder, CO 80303 (303) 497-3988 Funding Agency: Office of Naval Research PR Number: 00PR00759-00 Award Number: N0001400F0007 Current End Date: 30-Sep-2002 Scientific Officer: Deborah Van Vechten Objective: To investigate the source of nonlinear behavior in HTS microwave films and devices and improve the quality of commercially available state-of-the-art films. Non-linear behavior occurs in all HTS microwave devices, although isn't severe until power levels become significant-IP3 is above 40 dBm. Thus by determining the materials causes of the intermodulation distortion, how to optimize HTS filters for a wider range of practical applications -from today's low power, receive only filters to wide dynamic range filters of use in AMRFS- will be clearer. Moreover, methods of screening material before device fabrication can be de-veloped. This should lower costs, as well as improve performance, of fielded high performance devices. Approach: The previously observed relationship between the geometry-independent figure of merit, the nonlinear scaling current density J0, and the nonlinear response of the patterned transmission lines will be further investigated and the correlations to the behavior of the microwave surface resistance and dc current dependent penetration depth explored. Different HTS film processes (such as ozone annealing), and different film growth methods will reveal the systematics of Jo and determine how to raise it a factor of 2 without degrading Rs. Most samples will come from collaborations with industry partners and other ONR-funded research groups, including the group investigating the effect of dynamic antifer-romagnetic stripes. The abilities to measure Rs(J, B) and harmonic pro-duction at low power levels will be improved. Title: Characterization of the Inductive Nonlinearity of Thin Oxide Superconducting Films PI: John Claassen NAVAL RESEARCH LABORATORY Code 6345 Materials Physics Branch Funding Agency: Office of Naval Research PR Number: 00PR00767-00 Award Number: N0001400WR20064 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: To prove the ability of low frequency magnetic penetration depth measurements on unpatterned films to predict the intermodulation distortion and IP3 of the same films, once patterned, at microwave frequencies. This ability would provide a way of prescreening material before the construction of microwave filters and a simple handle for optimizing the material. Improved performance filters for use in Navy Sigint receivers, and possibly multi-function systems such as AMRFS, should result. Approach: To improve the existing magnetic penetration depth measurement system to remove a large thermal artifact. Measure samples provided by ONR supported PI. Collaborate with Drs. Ono and Booth of NIST, Boulder on developing the interpretation of the measurements. Title: Novel Superconductor ADC Capable of Operating in Interleave Mode PI: Vasili SEMENOV THE RESEARCH FOUNDATION OF THE STATE UNIVERSITY OF NEW YORK AT STONY BROOK DEPARTMENT OF PHYSICS AND ASTRONOMY Address: STATE UNIVERSITY OF NEW YORK STONY BROOK, NY 117943800 (516) 632-8931 Funding Agency: Office of Naval Research PR Number: 00PR00770-00 Award Number: N000140010026 Current End Date: 30-Sep-2002 Scientific Officer: Deborah Van Vechten Objective: To demonstrate the benefit of separating the comparitor function and the DAC function of a sigma delta class ADC by building a time interleaved ADC. Exceptional speed and accuracy will be obtained which may allow direct reception at rf. Technologies to transfer signals between chips will also be demonstrated, e.g., the signal will be demultiplexed and the decimation function performed on a different chip at a slower clock speed. Approach: Design, implement, and test and ADC based on a non-destructive comparitor and separate phase generator. Time interleave at least 4 quantizer units and demux the data stream. Use a generic, separate chip for a slower speed programmable decimation filter. Effective sample rates in excess of 100 GSps are expected, especially in years 2 and 3 where finer lithography (1.5 micron and less) will be used and the basic clock speed will be increased past 20 GHz. Title: GaN Power Devices PI: Steven Binari NAVAL RESEARCH LABORATORY Electronics Science and Technology Division Address: 4555 Overlook Avenue , S.W. Washington, DC 203755320 (202) 767-2535 Funding Agency: Office of Naval Research PR Number: 00PR00786-00 Award Number: N0001400WR20043 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: To develop microwave devices and circuits based on wide bandgap refractory materials with emphasis on GaN and related AlGaIn/N materials. The work is in-house at NRL. Approach: The effort shall focus on the design, fabrication, testing and optimization of several highpower, microwave, discrete GaN devices. These will include but not limited to MESFETs, HEMTs and HBTs. A major output of the approach is the generation of a continuously evolving S&T base for GaN and related materials which supports future designs of these power devices which can transition to a product-oriented environment. Progress: A power density of 2.3 W/mm has been demonstrated at 3 GHz with a AlGaN/GaN HEMT grown at NRL. Ungated drain currents up to 1 A/mm have been achieved. Detailed studies of trapping effects in AlGaN/GaN HEMTs have been performed using pulsed I/V characterization. Initial results suggest the traps are associated with the GaN buffer layer and not the surface or AlGaN barrier. Improvements in GaN HEMT materials and device design led to an fT of 52 GHz for a 0.2 um gate length. HEMT power performance was also improved. At 3.8 GHz, a power density of 2.9 W/mm with 30% PAE and 9.8 dB gain was measured for 150 um gate-width devices. At 9.5 GHz, 2.0 W/mm was obtained. The microwave power output was found to be correlated with the degree of gate lag. Title: Computation as a Means of Understanding the Operation of Future Devices PI: Dragica Vasileska ARIZONA STATE UNIVERSITY Department of Electrical Engineering Address: P. O. Box 875706 Tempe, AZ 852875706 (602) 965-6651 Funding Agency: Office of Naval Research PR Number: 00PR00787-00 Award Number: N000149910318 Current End Date: 28-Feb-2002 Scientific Officer: Larry Cooper Objective: To develop computational methods to provide descriptive and predictive capability for semiconductor device performance. Approach: Computation methods will be extended and new advances incorporated for the modeling of ultrashort channel FET devices and of quantum dot structures. The effects of random numbers of impurities and their location in the channel will be determined using physics based models. Quantum effects due to confinement in narrow channels and quantum dots will be studied. New methods such as 2D and 3D Green' Function implementations will be developed to include the effects of intra-collisional field effects and interference phenomena associated with scattering from defects and impurities will be included in the codes. Monte Carlo models will be extended to 2Da nd 3D with full inclusion of electron-electron and electron-impurity interactions, also, with full band structure models to account for strain effects and other constraints. Title: Equipment Expansion: Continuing Research on Mechanisms & Control of Semiconductor Growth & Deposition Experiment PI: David Aspnes NORTH CAROLINA STATE UNIVERSITY Department of Physics Address: Box 7514 Raleigh, NC 276958202 (919) 515-4261 Funding Agency: Office of Naval Research PR Number: 00PR00788-01 Award Number: N000149310255 Current End Date: 31-Oct-2001 Scientific Officer: Larry Cooper Objective: To develop optical and analytic techniques for monitoring the atomic scale processes of Organo-Metallic Chemical Vapor Deposition epitaxial crystal growth. Approach: A dual purpose spectral-ellipsometer/reflection-difference-spectrometer will be used in the realtime, in situ investigation of heteroepitaxy of various heterojunction systems. Combined with closed loop control capability, the composition, strain and ordering of alloys will be monitored and controlled for OMCVD growth of these semiconductor systems. Correlating the RD spectra, which can be taken in real time, with light scattering experiments to measure surface/interface roughness, the optimiztion of film growth will monitor the onset of roughness and attempt to control or overcome such effects. A data base for RD spectra in alloys of the system InGaAsP will be determined. This material will be used as a vehicle to validate this system approach to controlled growth of semiconductors. A separate issue is that of strain determination in combination with interface chemistry and surface reconstruction. Efforts will be made to combine the measurements in a manner to allow control of the strain in the growth, as the film is growing. Title: SPIN INJECTION AND TRANSPORT IN METAL / SEMICONDUCTOR HETEROSTRUCTURES PI: Berend Jonker NAVAL RESEARCH LABORATORY Materials Physics Branch Address: ATTN CODE 3310 WASHINGTON, DC 203755320 (202) 404-8015 Funding Agency: Office of Naval Research PR Number: 00PR00789-00 Award Number: N0001400WR20042 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: Methods will be developed to form magnetic contacts to various semi-conductor materials and the effects of spin injected currents on the optical and electronic properties of device structures will be studied for possible applications in optoelectronics and electronics. Approach: Magnetic material contacts will be formed on various semiconductors including GaAs, ZnSe, ZnMnSe and Si. Contact materials will include Fe, Co, MnGa and MnAl. Experiments in which spin polarized electrons are injected into various semiconductor structures, such as quantum well and 2DEG layers will be carried out to investigate the magnetic field effects on magneto-optical properties such as polarization, emission, and Faraday rotation. Spin lifetimes will be measured. Spin scattering at interfaces and spin diffusion lengths will be studied. Title: Monolithically Integrated 1.3 um Emitting Transceivers on GaAs Substrates PI: P. Dapkus UNIVERSITY OF SOUTHERN CALIFORNIA Dept Contracts & Grants Address: University Park Los Angeles, CA 900891147 (213) 740-4414 Funding Agency: Office of Naval Research PR Number: 00PR00790-00 Award Number: N000149910305 Current End Date: 28-Feb-2002 Scientific Officer: Yoon Park Objective: To develop monolithic transceivers operating at 1.3um for application to ultrahigh bandwidth fiber optic data communications networks and analog RF systems. The proposed monolithic integration and the use of vertical cavity lasers in the transceivers will reduce system cost, increase bandwidth and improve reliability. Active regions for lasers and detectors on GaAs substrates that emit and detect light at 1.3 um will be developed and they will be incorporated with field effect transistors into monolithically integrated transcievers. Approach: The program will seek to develop new active region materials based on quantum dots and novel heterostructures with oscillator strength at 1.3 um sufficient to support the operation of lasers and efficient detectors. These active regions will be incorporated into vertical cavity lasers and resonant cavity detectors and integrated with field effect transistors using the AlAs oxide integration technology. The integrated transcievers will be tested for application to digital and analog systems. Title: Intensified Photo-Diode (IPD) Detector Development PI: V. Contarino NAVAL AIR WARFARE CENTER AIRCRAFT DIVISION Code 4.5.5.6 EO Sensors Branch Address: Naval Air Warfare Center Patuxent River, md 206701161 (301) 342-2022 Funding Agency: Office of Naval Research PR Number: 00PR00813-00 Award Number: N0001400WX20229 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To extend lifetime and reduce signal induced noise in the IPD (Intensified Photo-Diode) detector. Approach: To increase the lifetime of the photo-cathode in pulsed LIDAR systems, several methods will be devised to prevent the ions and X-rays from getting back to the photocathode,thus preventing the damage and afterpulse. Design a curved focusing path that would allow a fieldstop to block both the ions and electrons. An electro-static focusing approach will be employed, and /or add a grid just behind the photocathode to reduce the energy a photoelectron would need to exit. Title: Monolithic & Vertical Integration of Resonant Tunneling Diodes and FET's for Cellular Neural Networks PI: Leon CHUA THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BERKELEY Address: Electronics Research Laboratory Berkeley, CA 94720 (510) 642-3209 Funding Agency: Office of Naval Research PR Number: 00PR00819-01 Award Number: N000149910339 Current End Date: 28-Feb-2002 Scientific Officer: Larry Cooper Objective: To explore the implementation of Resonant Tunneling Devices into CNN architecture designs for the purpose of reducing cell size, number of components, new cell designs, and to consider possible enhancements in circuit speed. Approach: Truth tables will be constructed for all possible locally Boolean CNN B-templates and to map this table on to RTD-FET CNN cells via analytical and constrained nonlinear optimization techniques. RTD device parameters will be chosen as appropriate to available research devices. The process will be universal allowing for a mapping which is independent of the choice of the FET structure. The second phase will be to develop a computer program to automate the mapping algorithm and to develop a library of B-templates. A final phase will be to explore more versatile RTD-FET cells and structures capable of executing more general CNN templates, such as feedforward and feedback templates. Progress: Development has begun on RTD-FET based Boolean cells for the CNN architecture. A versatile and efficient RTD based CNN is designed which implements a Boolean function with 9 input variables, each representing a weighted input of a neighbor cell. This early design indicates the number of circuit elements can be greatly reduced compared to CMOS techniques. --------------MORE------> 
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Alpha-Theta
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ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:24 PM
Title: Magnetic Metal/Semiconductor PI: Chris Palmstrom UNIVERSITY OF MINNESOTA Department of Chemical Engineering and Materials Science Address: 421 Washington Avenue SE Minneapolis, MN 55455 (612) 625-7558 Funding Agency: Office of Naval Research PR Number: 00PR00822-00 Award Number: N000149910233 Current End Date: 31-Dec-2001 Scientific Officer: Larry Cooper Objective: To establish the technology for making magnetic contacts to III-V semiconductor films in the develoment of magnetoelectronic devices. Approach: Epitaxial ferromagnetic contact layers will be grown on InGaAs semi-conductor films using MBE growth techniques. The issues of lattice match, interdiffusion, and strain on the ferromagnetic properties of the contacts will be studied using various surface and interface character-ization techniques, including in-situ STM analysis. Transport measure-ments of spin polarized carriers will be made on these materials to determine the effects of interface properties on spinflip scattering effects. The transport of spin polarized carriers in the semiconductor films will be studied using the usual probe techniques, with and without applied magnetic and electric fields, which are used to modulate the carrier distribution. Progress: The epitaxial growth of Ni-2MnGa on GaAs has been demonstrated in an MBE grown lattice matched film by first preparing a very thin template layer on the GaAs with ScErAs. The NiMnGa film grows epitaxially in a tetragonal single crystal form. The film is ferromagnetic as seen in magnetometry measurements. The thickness of the film is surprising in view of the large lattice mismatch of 3%. For thicknesses up to 300 Angstroms, the film is growing pseudomorphically as seen in X-ray diffraction. Title: Transport in GaN Materials & Devices PI: Stephen Goodnick ARIZONA STATE UNIVERSITY Department of Electrical Engineering Address: Box 875706 Tempe, AZ 852875706 (602) 965-3424 Funding Agency: Office of Naval Research PR Number: 00PR00823-01 Award Number: N000149910385 Current End Date: 30-Apr-2002 Scientific Officer: Larry Cooper Objective: To measure the transport of electrons in GaN and AlGaN/GaN epitaxial materials and to correlate these measurements with computer simulation models. Approach: High field and low field measurements of the transport of electrons in GaN and GaAlN/GaN epitaxial films will be carried out using Schottky gated structures and microwave time of flight techniques. The goal is to obtain velocity-field curves for various materials and to correlate these properties with Monte Carlo simulations of transport in these materials. The effects of various inhomogeneities in the materials will be studied, i.e. defects such as dislocations. Carrier relaxation mechanisms will be investigated using fast pulse optical measurements. Progress: Low field velocity-field curves have been measured and will soon be extended to the high field region. Full band Monte Carlo simulations have been initiated. Electron-phonon interactions have been calculated based on the calculated Density of States. A deformation potential has been derived. Title: QUANTUM CIRCUITS PI: Robert Westervelt THE PRESIDENT AND FELLOWS OF HARVARD COLLEGE Division of Applied Sciences Address: Holyoke Center Room 440 Cambridge, MA 02138 (617) 495-3296 Funding Agency: Office of Naval Research PR Number: 00PR00826-00 Award Number: N000149910347 Current End Date: 31-Jan-2002 Scientific Officer: Larry Cooper Objective: To investigate the behavior of coupled quantum devices and explore their potential applications in ultra-low power circuit implementations. Approach: Quantum dot structures will be formed on semiconductor heterojunction materials with various gate control capability. Coupling between dots occurs either by quantum tunneling or by electromagnetic field inter-actions. Coulomb trap memory elements will be investigated. The coupled dots will be treated as basic elements of a quantum circuit which includes quantum phase coherence and entanglement for possible consideration in quantum computing. All devices will be fabricated with nanometer scale dimensions. Progress: Quantum tunneling has been studied in two coupled quantum dots. Electrostatic gates on the surface of a GaAs/AlGaAs heterostructure were used to create the dots. An adjustable quantum point contact between the dots allowed for variable coupling. In a high magnetic field the Quantum Hall Effect is observed with the transport occuring through edge states running around the edge of each dot. A new effect has not been explained, it is the observation that interdot energy is dependent upon the interdot conductance. Title: Novel Approaches to the Study of Transport in Nanometer-Scale Semiconductor Devices PI: Fausto Rossi INSTITUTO NAZIONALE DI FISICA DELLA MATERIA INFM - Dipartimento di Fisica Address: Corso Duca degli Abruzzi 24 Funding Agency: Office of Naval Research PR Number: 00PR00828-00 Award Number: N000149910462 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To develop Quantum Monte Carlo simulation methods which will be used to describe various nanoelectronic devices. Approach: This project has two tasks, one is to develop a Quantum Monte Carlo approach to solve the quantum kinetic equations which represent open quantum structures with both coherent and dissipative processes; second, to calculate the electronic states of nanostructures, such as silicon quantum dots, where the effectvie mass approximation breaks down. In each case realistic band structure effects must be considered. Thus, Tight Binding bandstructure calculations will be made for inclusion in the transport modeling. Progress: In preparation for the transport calculations, a fully three dimensional set of basis states has been derived. For the case of a one dimensional quantum problem, such as for tunneling through a barrier, the scattering states are defined, based on the transfer matrix method. These are much more realistic than the use of plane waves and are more natural when realistic boundary conditions are included. The boundary conditions are critical and are currently being introduced within a constant potential injection model. Title: Microscopic Properties of Defects & Interfaces in III-V Semiconcuctors with 6.1 A Lattice Constants PI: Craig Taylor UNIVERSITY OF UTAH Office of Sponsored Programs Address: 1471 FEDERAL WAY SALT LAKE CITY, UT 84102 (801) 581-8751 Funding Agency: Office of Naval Research PR Number: 00PR00829-00 Award Number: N000149910361 Current End Date: 28-Feb-2000 Scientific Officer: Larry Cooper Objective: To use a variety of optical spectroscopies to investigate the properties of InAs/GaSb/AlSb heterojunction materials and to determine the effects of defects, impurities and interface inhomogeneities on such properties. Approach: Microscopic characterization of defects in bulk materials and at buried interfaces in InAs/GaSb/AlSb binary and ternary heterojunction materials will be made using a variety of optical spectroscopies, including Photo-luminescence, ODMR, FEL based internal photoemission (to obtain bandoffsets), etc. The strain in such heteroepitaxy materials will be determined using NMR techniques in collaboration with NRL scientists. Microwave Modulated PL will be used to measure surface recombination velocities at buried interfaces and correlated with the defect studies. Progress: Using the technique of microwave modulated Photoluminescence, the surface recombination velocity for InAs/GaSb heterojunction materials has been measured. Title: Optical Studies of the Influence of Microscopic Structure on the Optoelectronic Properties of 6.1-Angstrom III-V Binary Superlattices PI: Thomas Hasenberg UNIVERSITY OF IOWA Divsion of Sponsored Programs Address: 100 Gilmore Hall Iowa City, IO 52242 (319) 335-1119 Funding Agency: Office of Naval Research PR Number: 00PR00830-00 Award Number: N000149910379 Current End Date: 31-Jan-2000 Scientific Officer: Larry Cooper Objective: To grow semiconductor epitaxial films based on InAs/GaSb/AlSb compounds and to investigate their properties using optical techniques and provide information for optimizing these materials for device applications. Approach: MBE will be used to grow a variety of two layer superlattice materials in the 6.1 Angstrom family of semiconductors. Their structural properties will be measured to determine effects of strain and defects at the interface. Carrier lifetimes and transport properties will be measured using optical techniques coupled with fast pulse injection. Measurements will be made of recombination, transport and on spin relaxation in superlattices. Theoretical support will provide band-structure information for the superlattice structures and models of spin relaxation provided to help deduce the processes involved. Progress: Spin lifetimes for carriers in bulk GaAs and InAs as well as for GaAs/AlGaAs and InGaAs/InP quantum wells using a 14 bulk band wavefunction basis. The D'yakonov-Perel scattering mechanism is considered for calculating the lifetimes. The theoretical results are in excellent agreement with the measured values. Title: Nanoelectronic Circuit Technologies PI: Richard Kiehl UNIVERSITY OF MINNESOTA Department of Electrical & Computer Engineering Address: 4-174 EE/CSCI Bldg Minneapolis, MN 55455 Funding Agency: Office of Naval Research PR Number: 00PR00837-00 Award Number: N000149910367 Current End Date: 31-Mar-2002 Scientific Officer: Larry Cooper Objective: To develop technology, devices and materials to support concepts of nanoelectronic circuits based on single electron tunneling and its application to high density, low power electronics. Approach: Analysis will be made of multiple valued Tunneling Phase Logic circuitry and attempts to validate the concept in simple circuits to implement a Residual Number System logic. The logic gates will be formed in silicon using metal particles which form at sites controlled by strain. Stressor patterns will be prepared and the self-assembly of metal dots will be investigated for various stressor geometries. Patterns in the form of Quantum Cellular Automata cells will be prepared. Progress: Progress has been made in determining the most useful operation modes for single electron tunneling phase logic gates. A detailed analysis has been made for how the mapping between the sum of the input signals and the final output state of a multiple valued TPL gate affects its functionality. Title: Broadband Isolators for Multifunction PI: Denis Webb NAVAL RESEARCH LABORATORY Code 6850 Address: 4555 Overlook Avenue (202) 767-3312 Funding Agency: Office of Naval Research PR Number: 00PR00909-00 Award Number: N0001400WR20059 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: Develop simulation and testing capability for wideband circulator and isolators. Approach: Simulation capabilities for circulators and isolators will be expanded to handle 6-port analysis, non-round geometries, and thermal considerations. NRL will analyze simulation and design data from an ONR contractor (EMA) who is developing circulators and isolators for AMRFS. Small signal and high power testing of supplied components to be performed. Progress: EMA's results for specific round circulators with radially-varying properties were replicated using NRL's Green's function code. The integral-equation method-of-moments code for treating the transmission-line isolator configuration has been tested and is now capable of analyzing microstrip circuits on simple magnetically biased gyrotropic material. Propagation constant vs. frequency examples have been run for the case of zero loss. The existing 2DFE code was modified to provide field plotting capability. Field plot results for a standard circulator were calculated, compared identically with the Green's function solver, and presented at the ONR AMRFS Workshop. Coding efforts were begun to generalize our existing 2DFE solver to allow for several enhancements needed to study new wideband circulator designs. The code is being rewritten to allow multiple and variable port locations, allowing employment of additional degrees of freedom in optimizing the wideband design of the isolator. Title: Chemical Beam Epitaxy of High Quality GaN & InGaN PI: Phillip Cohen UNIVERSITY OF MINNESOTA Department of Electrical and Computer Engineering Address: 200 Union Street, S.E. Minneapolis, MN 55455 (612) 625-5517 Funding Agency: Office of Naval Research PR Number: 00PR00946-00 Award Number: N000149710063 Current End Date: 30-Sep-2002 Scientific Officer: Colin Wood Objective: To improve understanding of atomic scale processes of epitaxial growth of Wide gap semiconductor epitaxial films. Approach: The proposed research will improve understanding and thence quality of epitaxial thin film crystal growth by use of a novel in situ scanning tunneling microscope at elevated temperatures. Progress: Quantitative surface structure measurements of GaN continue. PI has reported the first observation of macrostep formation and layer-by-layer sublimation of GaN. These measurements were possible using a new octupole RHEED system and exceptionally smooth, epitaxial films grown on bulk GaN crystals obtained from Unipress (Poland). The quantitative electron diffraction data are now being compared to theory to obtain the atomic positions of surface atoms. Using atomic force microscopy 2-3 nm highmacrosteps were observed under low Ga fluxes. Large (1000 nm), atomically smooth hillocks were observed under excess Ga. These indicate the step edge barriers depend on NH3 flux and the diffusion of Ga over 1000 nm distances. Title: Fundamental Limits to Small Scale Magnetoresistive Memory and Sensors PI: Peter Levy NEW YORK UNIVERSITY Department of Physics Address: 15 WASHINGTON PLACE APT H-1 NEW YORK, NY 10003 (212) 998-7737 Funding Agency: Office of Naval Research PR Number: 00PR00959-00 Award Number: N000149611207 Current End Date: 30-Nov-2001 Scientific Officer: Larry Cooper Objective: To investigate the effects of nanometer dimensions on the magnetic and magnetoelectronic properties of thin film magnetic materials and of magnetic device structures, and to establish a fundamental base of knowledge and understanding for advanced device development. Approach: Single magnetic metal films and multilayer films will be grown with varying thicknesses; spin valve structures will be included. The effects of thickness on domain properties will be studied and correlated with magnetostatic and magnetoelectronic properties. Arrays of such structures will be fabricated to study the effects of inter-device coupling. Nanofabrication methods will be applied to polycrystalline and single crystal metal multilayers and to magnetic tunnel junctions. This includes electron beam lithography techniques in order to achieve dimensions as small as tens of nanometers. Materials characterization techniques will include Kerr microscopy, Near-Field Kerr microscopy, Magnetic Force Microscopy, and Photoelectron Emission Microscopy. Appropriate electron transport measurements will be made in correlation with the above characteristics. Theory will address the basic scattering mechanisms in these complex materials. Computer simulation of micro-magnetic models will be carried out to understand the magnetostatic properties of these structures and to explore the effects of inter-device coupling. Progress: The effects of shape and size of GMR film structures on the exchange biasing effects have been studied in CoFe/IrMn and NiFe/IrMn elements produced by ion beam sputtering. Electron beam lithography and ion milling are used to produce regular arrays of submicron elements and transport structures. Magnetization processes have been probed using MOKE, MFM, and transport measurements. Title: Studies of Deep Levels and Optimization of MBE and MOCVD Grown GaN , AlGaN, and InGaN for HEMTs PI: James Speck THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Materials Department Address: Santa Barbara, CA 93106 (805) 893-8005 Funding Agency: Office of Naval Research PR Number: 00PR00968-00 Award Number: N000140010063 Current End Date: 31-Dec-2002 Scientific Officer: John Zolper Objective: Optimize the growth and characterize deep level traps in GaN, InGaN, and AlGaN for high electron mobility transistors. Approach: GaN, InGaN, and AlGaN will be grown by MBE and MOCVD for application to HEMTs. Detailed studies of trap density and energy levels will be carried out using controlled growth experiments in collaboration with Prof Ringel at Ohio State. InGaN growth will be further optimized for use as the channel in high power HEMTs. Title: Investigations of Deep Levels & their Physical Sources in GaN and Related Alloys PI: Steven Ringel OHIO STATE UNIVERSITY RESEARCH FOUNDATION Dept. of Electrical Engineering Address: 2015 Neil Avenue Columbus, OH 432101272 (614) 292-6904 Funding Agency: Office of Naval Research PR Number: 00PR00970-00 Award Number: N000140010055 Current End Date: 31-Dec-2002 Scientific Officer: John Zolper Objective: Quantify traps in GaN, AlGaN, InGaN, and related materials grown under various conditions. Approach: Deep level optical spectroscopy (DLOS), secondary ion mass spectroscopy (SIMS), electron beam induced current (EBIC), and Hall effect, among other techniques, will be used to study deep trap levels in the wide bandgap III-Nitride semiconductors. The studies will be closely coupled to controlled growth experiments at UCSB (Prof Speck and DenBaars) to correlate growth conditions and trap cross sections and concentration with device results. Title: Third Workshop on Surfaces & Interfaces of Mesoscopic Devices PI: Karl Hess THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN Beckman Institute Address: 109 Coble Hall Champaign, IL 618206242 (217) 333-2186 Funding Agency: Office of Naval Research PR Number: 00PR01007-00 Award Number: N000140010059 Current End Date: 30-Nov-2000 Scientific Officer: Larry Cooper Objective: To provide a forum to discuss the latest advances and issues in the area of mesoscopic devices and materials. Approach: A special workshop will be held in Maui, Hawaii on 13-17 December 1999 with invited speakers and contributed papers presented in the areas of quantum dots, lithography for 10 nm devices, nanoscale interconnects, single electron devices, quantum circuitry, STM processing and nano-optics. Title: Twenty-seventh Annual Conference on the Physics and Chemistry of Semiconductor Interfaces PI: C. Schulte INSTITUTE FOR POSTDOCTORAL STUDIES Address: PO Box 10146 Scottsdale, AZ 852710146 (602) 423-8540 Funding Agency: Office of Naval Research PR Number: 00PR01018-00 Award Number: N000140010058 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To organanize a conference and provide a forum to discuss the advancements and issues involved in development of semiconductor electronics. Approach: The 27th Annual Conference on the Physics and Chemistry of Semiconductor Interfaces will be organized in Salt Lake City, Utah for 16-20 January 2000. Topics to be discussed include heterojunctions, contacts, insulators, and a variety of materials such as silicon, III-V semiconductors, and dilute magnetic semiconductors. Title: JSEP FELLOWSHIP PI: James Harris THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY Department of Electrical Engineering Address: 125 Panama Street Stanford, CA 943054125 (415) 723-9775 Funding Agency: Office of Naval Research PR Number: 00PR01167-00 Award Number: N000149810107 Current End Date: 31-Oct-2000 Scientific Officer: Colin Wood Objective: The Fellow will examine the limits of micromachined tunnel devices for feedback control of accurate micro-miniature MEMs positioners. Approach: Tunnel devices offer extreme sensitivty to applied pressure. These will be studied for extremely fine manipulator feedback control. Progress: Kevin Gilbert completed his second year in the Ph.D. program in the Department of Electrical Engineering. His coursework this year focuses on areas of advanced semiconductor devices, processing and circuit design. Kevin's coursework this year has continued to focus in the areas of semiconductor devices and circuits. In the winter, Kevin passed the qualifying exams to enter candidacy in the doctoral program at Stanford. For his research into micromachined cantilevers, much of this year has been spent on finite element modeling of the electrical and mechanical response of the cantilevers. A mask set has been designed and built and he is currently working on developing the cantilever fabrication process. Title: MICROSCOPIC STUDIES OF INTERFACES, SURFACES, AND FILMS OF WIDE BANDGAP MATERIALS USING BALLISTIC ELECTRON EMISSION MICROSCOPY PI: Jonathan Pelz OHIO STATE UNIVERSITY RESEARCH FOUNDATION Department of Physics Address: 1960 Kenny Road Columbus, OH 432101063 (614) 292-8388 Funding Agency: Office of Naval Research PR Number: 00PR01170-00 Award Number: N000149310607 Current End Date: 31-Oct-2000 Scientific Officer: Colin Wood Objective: To develop a new technique for inspecting the quality of buried interfaces in metal/semiconductor and metal/insulator/semiconductor structures with nanometer spatial resolution. Approach: Ballistic electron emission microscopy (BEEM) will be used to monitor the conduction band structure in the base semiconductor, to characterize the spatial variations of interface properties, to investigate hot-electron-induced interface modification, and to study the dependence of interface electronic properties on the atomic-scale structure and chemistry of the interface, all with nanometer spatial resolution. These techniques will be applied to the various polytypes of SiC and wide bandgap nitride semiconductors. Progress: The first BEEM measurements made on Pd/4H-SiC samples show two distinct voltage thresholds. This indicates the existence of a higher-lying conduction band minimum (CBM) which has never before been seen experimentally. There is a recent theoretical prediction of such a higher-lying CBM at approximately 0.11 to 0.13 eV above the lowest CBM. The BEEM value is 0.14 eV. BEEM measurements on Pd and Pt contacts on 6H-SiC indicate a single threshold and a spatial uniformity of better than 0.03 eV, unlike the much wider spread seen in conventional measurements. These measurements will be continued and extended to other polytypes of SiC. Title: A NEW APPROACH FOR FABRICATION AND OPTOELECTRONIC INTEGRATION OF WIDE-BANDGAP MATERIALS PI: Mohamed-Ali Hasan UNIVERSITY OF NORTH CAROLINA AT CHARLOTTE CC Cameron Applied Research Center Address: Charlotte, NC 28223 (704) 510-6414 Funding Agency: Office of Naval Research PR Number: 00PR01179-00 Award Number: N000149810572 Current End Date: 01-Apr-2001 Scientific Officer: Colin Wood Objective: To reduce cost and effort of producing large area (6" dia. ) GaN and SiC semiconductor layer structures. Approach: Porous silicon will be used as a lateral epitaxial overgrowth (LEO) template. Progress: A major investment was made on setting up and cleaning the molecular beam epitaxy (MBE)/gas-source MBE (GS-MBE) facility for the proposed work. For 3C-SiC carbide, the deposition was carried out using two approaches. In the first, methane was used to convert porous Si into SiC. This method resulted in partial conversion but the structure remained porous. FTIR showed clear but small SiC signal. While this structure is usable for devices such as gas detectors, radiation detectors, and solarcells, it is clearly useless for devices requiring planar and multilayer structures. In the second method, trimethylsilane was used. In this case, the top portion of the porous Si structure was converted and filled with the formation of a continuous overlayer of SiC on the structure. FTIR showed a strong and well defined SiC signal. Secondary ion mass-spectrometry (SIMS) results indicated a stoichiometric SiC with very low content of oxygen (as low as in the Si substrate-possibly the SIMS resolution limit) or other contamination. However, due to the high surface area of porous Si and its exposure to air prior to growth of SiC, the oxygen signal rose abruptly in the porous portion of the SIMS profile defining the boundaries of the underlying porous layer. At the same time the SIMS count rate of Si and C decreased gradually, as expected, with increasing depth in the porous layer. The gradual decrease indicates a filling and conversion of the top portion of the porous layer. Atomic force microscopy (AFM) showed large flatterraces separated by steep and high steps. Preparations for the growth of group III-nitrides are essentially complete. A RF atomic source with modified plasma zones as well as an effusion cell for Al were purchased and installed in the system. The capability for transmission electron microscopy (TEM) including sample preparation and a dark room for film/image processing were also completed. Title: Nanostructured Wide Band Gap Semiconductors PI: Wilson Ho CORNELL UNIVERSITY Department of Physics Address: Clark Hall Ithaca, NY 148532501 (607) 255-3555 Funding Agency: Office of Naval Research PR Number: 00PR01180-00 Award Number: N000149910967 Current End Date: 30-Jun-2002 Scientific Officer: Colin Wood Objective: Investigate growth of high crystalline perfection GaN on Si. Approach: The reduced plastic flow temperature associated with nano-structured Si substrate surfaces will allow dislocations to be formed in the Si rather than in the much 'harder' GaN during epitaxial overgrowth. Progress: New start. No progress to report. Title: MBE InN/InAlN HEMTs. PI: William Schaff CORNELL UNIVERSITY Department of Electrical Engineering Address: 415 Phillips Hall Ithaca, NY 14853 (607) 255-3974 Funding Agency: Office of Naval Research PR Number: 00PR01186-00 Award Number: N000149910936 Current End Date: 30-Jul-2002 Scientific Officer: Colin Wood Objective: To demonstrate superior power microwave performance from an InN based HEMT. Approach: Molecular Beam Epitaxy will be used to determine if low carrier concentration InN and InAlN alloys with less than 5% Al can be deposited with good electrical (low background impurity) structural and optical properties. These will be processed into discrete high power microwave devices, and tested for DC to high frequency power microwave. Title: MOCVD of InN/AlInN HEMTs PI: Steven Denbaars THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Materials Dept. College of Engineering Address: Cheadle Hall, Room 3227 Santa Barbara, CA 93106 (805) 893-8511 Funding Agency: Office of Naval Research PR Number: 00PR01187-00 Award Number: N000149910934 Current End Date: 31-Jul-2000 Scientific Officer: Colin Wood Objective: To investigate the use of indium nitride active layers for most efficient power microwave HEMTs. Approach: Indium nitride/aluminum indium nitride will be grown by MOVPE and processed into high electron mobility 2DEG structure FETs. Progress: New start. No progress to report. Title: Alternative Approaches to p-type Doping of GaN PI: Gary Wicks UNIVERSITY OF ROCHESTER The Institute of Optics Address: Rochester, NY 14627 (716) 275-4867 Funding Agency: Office of Naval Research PR Number: 00PR01190-00 Award Number: N000149611061 Current End Date: 30-Jul-2002 Scientific Officer: Colin Wood Objective: The PI seeks to prepare Boron Nitride and Phosphide cubic films for UV detectors, emitters, and low electron affinity electron emitters. Approach: The proposer shall develop and employ an evaporation source for boron which is suitable, together with super heated nitrogen and, or ammonia for growth of BN by molecular beam epitaxy. Progress: The elemental boron effusion cell was used extensively this FY. The solubility of B in GaN is found to be ~2% and that in AlN greater than 6%. The upper limit is yet to be determined. A crack-free nucleation process for GaN on 3" Si was developed in conjunction with the BMDO funded effort at RTI. Title: GaN Piezoelectric Microwave Devices PI: Michael Wojtowicz TRW INCORPORATED SPACE AND TECHNOLOGY DIVISION Space and Electronics Address: R6/2573 One Space Park Redondo Beach, CA 90278 (310) 814-1713 Funding Agency: Office of Naval Research PR Number: 00PR01192-00 Award Number: N000149830019 Current End Date: 25-Sep-2000 Scientific Officer: Colin Wood Objective: To demonstrate High power heterojunction bipolar transistors in nitride semiconductor films. Approach: Molecular beam epitaxy will be used to grow precisely defined epitaxial group III nitride heterojunctions with built in strain fields in the c-plane of sapphire substrates. The strain field will cause a charge separation at the emitter base heterojunction. The assocated field will create the necessary 1e 14 cm-2 holes for low base resistance. Progress: Equipment and staff have been acquired for the program. Student at GaTech identified and initial experimental growths and modeling started. Title: Wide Band Gap Bipolar & Heterojunction Bipolar Transistors PI: Michael Shur RENSSELAER POLYTECHNIC INSTITUTE Address: Thornton Hall Charlottesville, VA 22903 (804) 942-4270 Funding Agency: Office of Naval Research PR Number: 00PR01193-00 Award Number: N000149610682 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: Seeks to better understand and exploit unique properties of nitride-based semiconductor materials. Emphasis will be on new transistor structures including HBTs and Induced Base Transistors. Approach: The large piezoelectric constants found in nitrides will be used to model the effects on strain at interfaces. Dislocation density problems currently encountered will be addressed to determine how they create dipole fields within the lattice. Deformation tensors will be determined. Optimum designs for microwave transistors will be developed. Progress: New device concepts were developed based in polarization induced holes for AlGaN/GaN HBTs. Initial studies of Induced Base Transistors (IBTs) were developed for the AlGaN/GaN system and look promising as an all n-type alternative to HBTs. Title: SYNTHESIS OF SINGLE CRYSTALS OF GROUP III NITRIDES IN SUPERCRITICAL AMMONIA PI: Joseph Kolis CLEMSON UNIVERSITY Department of Chemistry Address: Box 345702 Clemson, SC 296345702 (864) 656-4739 Funding Agency: Office of Naval Research PR Number: 00PR01194-00 Award Number: N000149810834 Current End Date: 14-Aug-2001 Scientific Officer: Colin Wood Objective: The PI will develop a process for growth of GaN bulk crystals. Approach: Crystal boules will be crystalized from high temperature, high pressure liquid ammonia solutions of GaN, using metal amides as electrolyte solubilizers. This process is analogous to the hydrothermal process used for preparation of oscillator grade quartz. Progress: PI has made impressive headway in solubilizing GaN in high pressure ammonia solution at high pressures. He has been able to nucleate spontaneously GaN buk crystals on the order of 0.1 mm in dimension. Title: Fabrication of AlGaN-GaN-InN High Electron Mobility Transistors PI: Umesh Mishra THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Office of Research Address: Rm 3227 Cheadle Hall Santa Barbara, CA 931062050 (805) 893-4036 Funding Agency: Office of Naval Research PR Number: 00PR01203-00 Award Number: N000149611024 Current End Date: 30-Sep-2002 Scientific Officer: Colin Wood Objective: The PI seeks to prepare films of GaN with radically reduced point and extended defect densities. Approach: The PI will use lateral Molecular beam epitaxial overgrowth seeded through etched holes in oxide films deposited on GaAs or similar substrates. Progress: Lateral overgrowth on the order of 50 microns has been demonstrated. A growth system based upon Chloride vapor transport for more equilibrium and faster deposition has been constructed, and will be used to increase the lateral to vertical growth rate ratio. This will allow much larger islands of defect free GaN films. Title: Investigation of Long Range Order in AlGaN Films (Growth of GaN by Ionized Nitrogen Cluster Beam Epitaxy) PI: Theodore Moustakas THE TRUSTEES OF BOSTON UNIVERSITY College of Engineering Address: 44 Cummington St, 4th Floor Boston, MA 02215 (617) 353-5431 Funding Agency: Office of Naval Research PR Number: 00PR01210-00 Award Number: N000149810213 Current End Date: 30-Sep-2002 Scientific Officer: Colin Wood Objective: To investigate presence, occurance, and possible elimination of polytype inclusions in hexagonal nitride semiconductors. Approach: Scanning probe techniques will be used on cross sections of MBE films prepared under different nucleation and growth conditions. Progress: PI will divert much of the ordering effort to investigate the growth of nitride semiconductors from elemental gallium and nitrogen cluster beams with energy per molecule tuned from 1000 to 1 electron volt. In this way enormous growth rates of high crystal perfection semiconductor group III nitride epitaxial films, and possibly bulk substrates may be possible. PI has found that ordering in the nitride alloy systems GaN/AlN depends strongly upon the growth temperature, pressure and growth rate. Ordering was found to reduce the band gap narrowing up to 500meV. Photo conductive detectors fabricated from these partially ordered alloys had gains several orders of magnitude higher than detectors fabricated on pure GaN films. Monte Carlo simulations are used to describe the mechanism of ordering in the absorption-limited growth regime. Title: LOCALIZED ELECTRONIC STATES AT GaN HETEROJUNCTION INTERFACES PI: Leonard Brillson OHIO STATE UNIVERSITY RESEARCH FOUNDATION Joseph C. Wilson Center of Technology Address: 800 PHILLIPS ROAD W114 WEBSTER, NY 14580 (716) 422-6468 Funding Agency: Office of Naval Research PR Number: 00PR01211-00 Award Number: N000140010042 Current End Date: 30-Sep-2002 Scientific Officer: Colin Wood Objective: To understand depth distribution of defects in Nitride power semiconductor epitaxial films. Approach: High spatial and energy resolution cathodoluminescence inside scanning electron (transmission) microscope. Title: Nanolithographically Controlled Nucleation of GaN and Growth of InGaN Quantum Dots on Foreign and Compliant Substrates PI: P. Dapkus UNIVERSITY OF SOUTHERN CALIFORNIA Dept Contracts & Grants Address: University Park Los Angeles, CA 900891147 (213) 740-4414 Funding Agency: Office of Naval Research PR Number: 00PR01276-00 Award Number: N000149810598 Current End Date: 30-Oct-2001 Scientific Officer: Colin Wood Objective: PI will optimize the crystal perfection of GaN and AlN epitaxial films for microwave and opto-electronic applications. Approach: PI will determine the optimum growth parameters for Lateral Epitaxial Overgrown by modeling and metal organic chemical vapor phase epitaxial growth on nanolithographically patterned substrates. Progress: Low defect GaN has been grown by epitaxial lateral overgrowth on sapphire and Si/AlOx substrates. Pyramidal faceted overgrowths merge without defects at the interface. The reactor has been modified to allow the facet angle to be closed after merging. Current efforts are devoted to reducing the size of ELO openings to submicron dimensions by e-beam and block copolymer lithography. Title: Expanding Studies on Technology for Transferred Electron Devices to address GaN Growth on Porous Substrates PI: Dimitris Pavlidis THE REGENTS OF THE UNIVERSITY OF MICHIGAN Department of Electrical Engineering & Computer Science Address: 1301 Beal Avenue Ann Arbor, MI 481092122 (734) 647-1778 Funding Agency: Office of Naval Research PR Number: 00PR01317-01 Award Number: N0001492J1552 Current End Date: 31-May-2001 Scientific Officer: John Zolper Objective: The PI will develop GaN Gunn diodes for very high performance (power) Gunn diodes for low noise local oscillators and e/m generation at microwave frequencies. Approach: GaAs technology, modeling, and practices will be mapped over to GaN and GaN/AlGaN heterojunction, hot electron injection transfered electron devices. Progress: Progress in nitride epitaxy has led to the preparation of low defect density Gunn diodes. The PI is utilizing his MOCVD system to prepare samples of controlled doping profiles for GaN Gunn diodes with mmwave oscillator powers in excess of 100 mW.

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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:26 PM
Title: In-P-Based Integrated VCSEL Transmitters & Microcavity Light Emitting Diodes PI: Pallab Bhattacharya THE REGENTS OF THE UNIVERSITY OF MICHIGAN Department of Electrical Engineering and Comp Address: 3003 SOUTH STATE STREET ANN ARBOR, MI 481091274 (313) 763-6678 Funding Agency: Office of Naval Research PR Number: 00PR01388-01 Award Number: N000149610024 Current End Date: 30-Sep-2002 Scientific Officer: Yoon ParkObjective: To design and fabricate transmitters for application in very high speed small signal and large signal optical communication systems. Lasers based on InP/InGaAsP technology will be integrated monolithically with modulators to provide high speed, low chirp modulation. A novel scheme using a multi-laser gain-switched system will be demonstrated to produce large signal optical modulation. Finally, designs for long-wavelength microcavity lasers for very low threshold output will be studied. Approach: Programs are geared to providing high speed light emission and modulation. Device design and fabrication will be carried out to use state-of-the-art growth and processing to achieve a laser-driver chip for internal modulation of lasers. An OEIC is designed to couple monolithically a laser with a Starke effect external modulator. Integration of up to 10 gain-switched lasers will be carried out to produce large signal modulation of lasers. The architecture will produce up to 40 Gbps signals. Title: A Proposal for the Organization of the Sixth Workshop on Wide Bandgap Nitrides PI: Hadis Morkoc VIRGINIA COMMONWEALTH UNIVERSITY Dept. of Electrical Engineering & Physics Address: 601 West Main Street Richmond, VA 23284 (217) 333-0722 Funding Agency: Office of Naval Research PR Number: 00PR01409-00 Award Number: N000140010062 Current End Date: 31-Dec-2000 Scientific Officer: Yoon Park Objective: To bring together experts from over the world to address issues and determine where group III-nitride materials and device technology is moving. Specific goals to identify problems facing III-nitirde technology and make recommendations on promising routes for resolution. Approach: In this meeting scientists and engineers from all over the world will discuss the broad subjects coverng technology of III-Nitrides. Title: International Workshop on ZnO PI: David Look WRIGHT STATE UNIVERSITY Physics Address: Office of Grants & Contracts Dayton, OH 45435 (937) 255-1725 Funding Agency: Office of Naval Research PR Number: 00PR01417-00 Award Number: N000149911054 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To assess the state of the art in ZnO bulk and epitaxial materials and the future possibilities of producing superior electronic and photonic frm these materials. Approach: Approximately 50-75 participants from the USA and several foreign countries are expected to attend to discuss the state of the art in ZnO materials and devices. Progress: New start. No progress to report. Title: All-fiber Integral High Speed Modulator & Source for Compact, Lightweight, Electro-Optic Systems PI: Kerry Vahala CALIFORNIA INSTITUTE OF TECHNOLOGY Dept. of Appied Physics Address: MAIL STOP 213-6 PASADENA, CA 91125 (818) 395-2144 Funding Agency: Office of Naval Research PR Number: 00PR01420-00 Award Number: N000140010072 Current End Date: 30-Sep-2002 Scientific Officer: Yoon Park Objective: To demonstrate a multi-length addressable all-fiber modulator based on control of critical coupling and integrate this device with fiber DFB lasers to create all-fiber multi-wavelength source consisting of a single strand of optical fiber. Approach: Employ highly efficient coupling to silica micro-sphere whispering gallery modes using a single mode optical fiber in which a fiber optic taper has been prepared. The taper is fabricated by heating a portion of the fiber in a flame while pulling the unheated fiber sections to either side of this portion in opposing directions to achieve a narrow neck (typically 5 microns). A glass micro-sphere (typically 200-300 microns in diameter) is then attached to the taper to achieve coupling to WGMs. Title: Large Adaptive Two-Color IR Sensors PI: L. Kozlowski ROCKWELL SCIENCE CENTER LLC Address: 1049 Camino Dos Rios Thousand Oaks, CA 91360 (805) 373-4267 Funding Agency: Office of Naval Research PR Number: 00PR01421-00 Award Number: N0001499C0227 Current End Date: 30-Apr-2002 Scientific Officer: Yoon Park Objective: To develop large, high performance two-color IR focal plane arrays at lowest possible risk. This program will yield successive breakthroughs in the performance and size of two color FPAs by exploiting the latest silicon multiplexer and HgCdT detector technologies. Approach: Based on the adaptive multiplexer development at 18 um pixel pitch in 0.25um CMOS, an adaptive 1024x640 two-color FPA at 25um pixel pitch will be developed and a 1280 x1024 array will be designed. Title: Symposium J: Advanced Materials and Techniques for Nanolithography PI: Robert Pachavis MATERIALS RESEARCH SOCIETY Director of Finance Address: 506 Keystone Drive Warrendale, PA 15086 (724) 779-8313 Funding Agency: Office of Naval Research PR Number: 00PR01588-00 Award Number: N000140010065 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To organize the Symposium on Advanced Materials and Techniques for Nanolithography for the purpose of having open discussion on the latest advances in the technology of fabricating nanoscale electron devices. Approach: The symposium will be held in conjunction with the Fall Meeting of MRS in Boston, MA on 29 Nov to 3 December. Papers will be presented to cover such topics as: advanced lithographies; advanced resists and characterization; electron, ion and photon beam soft lithography; new concepts in materials design; and nonconventional methods. Title: 4 Gbit/in^2 Non-Volatile RAM PI: K. Bussmann NAVAL RESEARCH LABORATORY NRL 6345 Funding Agency: Office of Naval Research PR Number: 00PR01609-00 Award Number: N0001400WX20397 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: Demonstrate an ultra high density non-volatile random access memory test vehicle based upon vertical giant magneto resistance memory elements and determine the ultimate limits in density and operating speed for this technology. Approach: Utilize advancements in Si-based technology to realize high density non-volatile memories compatible with Si processing. Memory characteristics including transport parameters and switching characterisitics using mininum feature sizes of 200nm, 100nm, and 75nm will be investigated. Title: Retargeting LSI Rapid Single Flux Quantum Circuits to a Sub-micron Fabrication PI: Darren Brock HYPRES INC Address: 175 Clearbrook Rd Elmsford, NY 10523 (914) 592-1190 Funding Agency: Office of Naval Research PR Number: 00PR01712-00 Award Number: N0001400C0024 Current End Date: 30-Sep-2001 Scientific Officer: Deborah Van Vechten Objective: To make existing superconducting design methodologies compatible with accepted semiconductor IC industry CAD file formats/design artifacts, so as to be able to use these tools in designing superconducting circuits, and increase the level of design automation. At the same time, the new effects impacting ultra-compact physical layouts with minimum geometries below 1 mm will be investigated and the results incorporated into the design rules. These improvements will facilitate the ability to develop full-function radio frequency integrated circuits operating at and above 100 GHz in military systems (radar, EW, comms) front ends. Approach: The benchmark digital speed circuit has run 10x faster (750 GHz) in superconducting technology than in any semiconductor material and >100x faster than silicon. The approach is thus to develop ways to utilize semiconductor CAD tools to design more general superconducting circuits, incorporating the required sub-micron features and non-linearities of Josephson devices. This requires reconstruction of some of the tools designed specifically for superconductors to make the design data set format consistent. Investigation of issues, especially electromagnetic interactions among elements, that will become important as circuit shrink is also planned. Title: High Resolution STM Imaging & Spectroscopy of Static Stripes in High Temperature Superconductors PI: James Davis THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BERKELEY Department of Physics Address: 366 Le Conte Hall Berkeley, CA 94720 (510) 642-4505 Funding Agency: Office of Naval Research PR Number: 00PR01721-00 Award Number: N000140010066 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: To use a high spatial resolution STM to find experimental evidence of static charge/spin stripes in a perovskite superconductor. Such stripes have been hypothesized to be responsible for microwave loss by some and, in dynamic form, as a fundamental causal mechanism for superconductivity. If found, their characteristics should much more severely constrain theories of HTS and allow their material nonlinear characteristics to be improved. This will benefit Navy applications, especially in high performance rf filters where currently the IMD limits wide band applications. Approach: Use a high spatial resolution Scanning Tunneling Microscope to look for static stripes in oxygen under doped YBCO, Zn doped BSCCO, and Nd-doped LSCO at concentrations where other measurements have suggested they should occur. Spatially periodic fluctuations in the energy gap and amplitude of the coherence peak will be sought. STM is an ideal tool given its ability to image topography on atomic scale, measure the local density of states at any given point, and map the density at a specific energy across the surface. Samples will be prepared by low temperature cleaving in the STM instrument. Title: Optical Electronic & Optoelectronic Material & Device Research PI: A. Yariv CALIFORNIA INSTITUTE OF TECHNOLOGY Department of Electrical Eng and Applied Physics Address: Mail Stop 213-6 Pasadena, CA 91125 (818) 405-0928 Funding Agency: Office of Naval Research PR Number: 00PR01841-00 Award Number: N000140010104 Current End Date: 31-Oct-2002 Scientific Officer: Yoon Park Objective: To conduct promising research in terms of basic importance and potential applications, and, in large part, a new and largely innovative set of projects which are both conceptually and technologically in the forefront of today's optical communication research. Approach: Selected research areas of both theoretical and practical importance will be pursued. Areas include mode-locked lasers for high-speed A/D sampling, amplitude-phase correlation effects in semiconductor lasers and their effect on signal and noise propagation in fiber, high-order polarization mode dispersion and its control, and mode conversion phenomenon and devices based on optical gratings in fibers. Title: Study of Replacement of Surface Navy Tube Transmitters with Solid State Alternatives PI: Joe Smolko RAYTHEON COMPANY Address: P.O. Box 1201 Tewksbury, MA 018764169 (978) 858-4169 Funding Agency: Office of Naval Research PR Number: 00PR01906-00 Award Number: N0001400M0004 Current End Date: 23-Dec-1999 Scientific Officer: John Zolper Objective: Determine the potential for replacement of vacuum tube transmitters with solid state alternatives in surface Navy systems. Approach: A study will be performed to access the potential improvement in system performance, reduced maintainance, and cost for replacing vacuum tube transmitters with solid state alternative in surface Navy systems. Title: Solid State Transmitter Replacement Study for SPY-1 adn MK-99 Transmitters PI: Mahesh Kumar LOCKHEED MARTIN GOVERNMENT ELECTRONIC SYSTEMS Government Electronic Systems Address: 199 Borton Landing Rd Moorestown, NJ 080570927 Funding Agency: Office of Naval Research PR Number: 00PR01907-03 Award Number: N0001400M0006 Current End Date: 31-Mar-2000 Scientific Officer: John Zolper Objective: Perform a study to determine the potential for replacing vacuum tube transmitters with solid state modules in SPY-1 and MK-99. Approach: A detailed trade study will be perfrom to quantifiy the potential for replacing vaccum tube transmitters in 2 key Navy systems (SPY-1 and MK-99). Title: ACI program for the Lateral Epitaxial Overgrowth of GaN on Si PI: Ian FERGUSON EMCORE CORPORATION Address: SOMERSET, NJ 08873 (732) 271-9090 Funding Agency: Office of Naval Research PR Number: 00PR01955-00 Award Number: N0001499C0337 Current End Date: 30-Dec-2001 Scientific Officer: Colin Wood Objective: To create a viable industrial supply of inexpensive semiconductor GaN films. Approach: Films will be grown by metal organic vapor phase deposition on Si substrates using the technology developed at UC Santa Barbara under phase 1 of this ACI program, under the AMRFS umbrella. Title: Characterization of Local Electronic Properties in Nitride Semiconductors PI: Edward Yu THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SAN DIEGO 0934 Electrical & Computer Engineering Address: 9500 Gilman Drive La Jolla, CA 920930407 (619) 534-6619 Funding Agency: Office of Naval Research PR Number: 00PR02043-00 Award Number: N000140010135 Current End Date: 30-Sep-2001 Scientific Officer: Colin Wood Objective: To determine the defect density distribution and electrical (energy level) characteristics in GaN emiconductors. Approach: A scanning capacitance probe will be used to measure local surface electric fields associated with dislocations and point defects. Title: A Plan to Verify and Determine the Source of Intense Heater Induced ELF and VLF Signals in the Ionosphere PI: Michael Kelley CORNELL UNIVERSITY Electrical Engineering Address: Electrical Engineering Department Ithaca, NY 14853 (607) 255-2944 Funding Agency: Office of Naval Research PR Number: 00PR02138-00 Award Number: N000149910248 Current End Date: 30-Sep-2001 Scientific Officer: Edward Kennedy Objective: The Navy must maintain vital communiation links to fleet elements. The submarine force uses frequencies in the ELF/VLF range to achieve strategic connectivity. Existing communication transmitting facilities require large spaces to support the necessary antenna installation. The objective is to study a potentially new approach for generation of ELF/VLF communication signals through ionospheric modification. If successful, improvements in physical assets and annual operating cost may be possible. Approach: ELF/VLF generation experiments are regularly conducted at several active ionospheric modification research facilities in the US and elsewhere. Known techniques for signal generation are currently less than sufficient to be competitive on a technical performance basis with the existing Naval installations (although there are proposed theoretical techniques for improving on this). The work in this effort will determine if data previously acquired under a cooperative experiment may indicate a new, unidentified mechanism for ionospherically generated ELF/VLF, and, if so, develop a theory that can be evaluated and proven experimentally under controlled conditions. Progress: Rocket data from the Coqui Dos campaign at Arecibo continues to be evaluated. There is strong evidence that ELF fluctuations were created by amplitude modulation of the heater beam. Recent efforts have led to a scheme for demodulation of the HF signal detected on the rocket below the reflection point. It is very clear that an ELF component (below 20 Hz) is present in the demodulated data. The current effort is to compare this to the simultaneous ELF signal directly measured by the electric field receivers. The AM modulation was recorded using a heterodyned system and the magnetic field signal from a search coil. Results of this work will be published during the next year.Additional experiments are being designed to reproduce these results. A prototype experiment was performed in August 1999 using the FAST satellite. Working with Dr. Zwi at the HAARP site and Dr. Carlson of U.C. Berkeley, the HAARP heater was modulated at ELF during two passes of FAST below 1500 km. The data from that experiment are currently being analyzed. Title: Linear Wide Band Vacuum Electronic Power Amplifier PI: Phil Ballagh LITTON SYSTEMS INC Electron Devices Division Address: 960 Industrial Rd San Carlos, CA 940704194 (650) 591-2513 Funding Agency: Office of Naval Research PR Number: 00PR02271-00 Award Number: N000140030017 Current End Date: 14-Apr-2001 Scientific Officer: Ingham Mack Objective: Develop a linear, wideband booster TWT that with only modest modifi-cations to electrical design parameters and/or operating voltages and currents, that can be used in ECM, radar, and communication applications. Approach: Modeling and simulation tools will be employed with prototype tubes built, tested, and fully characterized. External linearization methods will be studied and incorporated as necessary. Title: Development & Validation of Multi-Frequency Design Codes for Linear High Power PI: David Chernin SCIENCE APPLICATIONS INTERNATIONAL CORP P.O. Box 1303 Address: 10260 Campus Point Drive San Diego, CA 92121 (703) 734-5808 Funding Agency: Office of Naval Research PR Number: 00PR02274-00 Award Number: N000140020006 Current End Date: 30-Sep-2002 Scientific Officer: Baruch Levush Objective: Develop simulation technology for traveling wave tubes and klystrons. Approach: Extend 1D simulation codes to 2D for TWT's and klystrons and validate codes by comparison with experiment. Title: To Organize the ONR Superconducting Electronics Program Review and Conference PI: S. Sridhar NORTHEASTERN UNIVERSITY Distinguished Professor of Physics Address: Physics Dept. Boston,, MA 02115 (617) 373-2930 Funding Agency: Office of Naval Research PR Number: 00PR02401-00 Award Number: N000140010118 Current End Date: 15-Apr-2000 Scientific Officer: Deborah Van Vechten Objective: To organize logistics for the program review of the ONR superconducting electronics program, including the invitational workshop on antiferromagnetic stripes in mixed valance oxides. The program review helps to unify the PIs and allow more facile coordination of their efforts in behalf of the Navy. Both 6.1 and 6.2 program PIs attend. Approach: To support the conference through deposits that are required by the hotel and help with administrative costs. To cover travel costs for 8 people not currently supported by ONR who will be invited to speak. Title: 100 GHz DUAL CHANNEL PM/AM NOISE MEASUREMENT SYSTEM PI: Fred Walls U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY NIST 847.30 Address: 325 Broadway (303) 497-3207 Funding Agency: Office of Naval Research PR Number: 00PR02417-00 Award Number: N0001499F0373 Current End Date: 30-Jun-2000 Scientific Officer: Deborah Van Vechten Objective: This award will allow the time and frequency (standards) division of NIST to establish a first in the nation phase and amplitude noise measurement system in the frequency range 75-110 GHz. Such measurements are needed to determine the relative noise performance of candidate digital signal processing technologies and both oscillators and amplifiers in this frequency range. Low noise performance is critical to the performance of advanced rf systems such as AMRFS. Approach: The award will purchase equipment necessary to construct a dual channel measurement system in which a cross-correlation spectrum analyzer is used to reduce the noise level of the measurements by averaging the independent results of the two channels. Calibration of the system and initial measurements on 4 ONR selected 100 GHz circuits are also included. Progress: The required pair of precision 10 GHz sources have been ordered and will be delivered in Feb, 2000. The definition of the less critical components has begun. Title: PM/AM Noise Measurements in Support of 100 GHz Research PI: Fred Walls U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Address: 325 Broadway (303) 497-3207 Funding Agency: Office of Naval Research PR Number: 00PR02417-01 Award Number: N0001400F0415 Current End Date: 30-Sep-2002 Scientific Officer: Deborah Van Vechten Objective: This award will allow the time and frequency (standards) division of NIST to utilize the just established phase and amplitude noise measurement system in the frequency range 75-110 GHz to provide feedback on the success of components constructed for application in AMRFS systems. Such measurements will determine the relative noise performance of candidate digital signal processing technologies and both oscillators and amplifiers in this frequency range. NIST's expertise in these measurements will also be passed to the industrial community via a NIST sponsored workshop to be held in the summer of 2000 in Boulder on phase and amplitude noise measurements. Approach: The renewal of this award will fund additional dual channel AM/PM noise measurements with reduced noise level via cross-correlation averaging the independent results of the two spectrum analyzer channels. In addition, a workshop on noise measurement techniques will be held at NIST in summer of FY00. Vendors of the AMRFS program will receive consulting advice on phase noise if there is a demand for such instead of for calibrations. Progress: The required pair of precision 10 GHz sources to build a 100 GHz system have been delivered and how to construct the less critical components has been determined. Measurement capacity should be in place before the end of the base award in June 2000. Title: Laser Annealing of Ferroelectric Thin Films PI: James Horwitz NAVAL RESEARCH LABORATORY Interactions with Surfaces Address: University of Rhode Island Kingston, RI 028810801 Funding Agency: Office of Naval Research PR Number: 00PR02499-00 Award Number: N0001400RC20016 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: Microwave loss in ferroelectrics has been shown to correlate to film stress by NRL and oxygen vacancies are the presumed cause. Laser annealing is known from the semiconductor industry to allow structural defect annealing without long range dopant diffusion or interface reactions. This award will help fund an effort to see if laser annealing in an oxygen environment will correct the oxygen deficiency or otherwise reduce the stress in ferroelectric thin films. Films are used in high performance rf filters to provide voltage controllable tuning of the filter characteristics. Approach: Collaborate with researchers at the Ashtarak (Armenia) Institute for Physical Research to modify a laser patterning system developed in FY98-99 to perform laser annealing in the IR. Use this system to attempt laser annealing of ferroelectric thin films. Measure the changes in stress and microwave loss induced by the processing. Use these funds to cost share the non-U S expenses in a NICOP proposal on this topic. Title: JOINT SERVICES GRADUATE FELLOWSHIP PROGRAM PI: Jonathan Allen MASSACHUSETTS INSTITUTE OF TECHNOLOGY Research Laboratory Address: RM E19 702 77 MASSACHUSETTS AVE Cambridge, MA 021394307 (617) 253-2509 Funding Agency: Office of Naval Research PR Number: 00PR02591-00 Award Number: N000149810039 Current End Date: 14-Oct-2000 Scientific Officer: Colin Wood Objective: To improve methods for generation and study of Bose Einstein condensates. Approach: Experimental methodology will be tightened up by redesign of equipment for more uniform constraining magnetic fields, and freedom from vibration, faster cool down and better temperature control, etc. Progress: Research assistant Stamper Kurn has made extremely good progress on Bose Einstein condensate research: specifically, he has observed a Freshbach resonance, which modifies resonance in Bose Einstein condensates; he has created BE condensates above the BE temperature by application of IR; and developed and demonstrated a new kind of quantum fluid - a 3 componentspinor Bose condensate. Title: Ohmic Contacts to P-Type SiC PI: John Crofton MURRAY STATE UNIVERSITY Dept. of Physics & Engineering Physics Funding Agency: Office of Naval Research PR Number: 00PR02638-00 Award Number: N000149910785 Current End Date: 31-Aug-2000 Scientific Officer: John Zolper Objective: Develop low specific resistance ohmic contacts to p-SiC for bipolar devices. Approach: The PI will study alloys of Al/Ti and Al/Si to develop ohmic contacts to p-SiC with the low specific contact resistance reported for Al alone but with improved morphology and reduced spiking. Progress: We are looking at different Al to Ti ratios and the effect they have on ohmic contacts to p-type SiC. In addition, the effect of introducing small amounts of Si is also being studied. Reducing the Al concentration in an Al-Ti alloy does not appear to hurt the contact's electrical properties. In addition, preliminary results indicate that the intro-duction of a few weight percent of Si to Al does not adversely affect the electrical properties of the contact. Further tests are underway to see if the reduction of Al and or the introduction of Si may help prevent the large degree of Al penetration into the SiC material. Title: Workshop on Polarization Effects in Semiconductors PI: Shari Allwood ALLWOOD AND ASSOCIATES INC Address: 8279 Midland Rd Mentor, OH 44060 (440) 951-1380 Funding Agency: Office of Naval Research PR Number: 00PR02660-00 Award Number: N000140010134 Current End Date: 30-Nov-2000 Scientific Officer: Colin Wood Objective: Conduct a Meeting of world experts to challenge prolems of polarization effects in power microwave devices for AMRFS. Title: Microstructure & Electronic Properties of InGaN Quantum Wells PI: Fernando Ponce ARIZONA STATE UNIVERSITY Physics & Astronomy Address: PO Box 871504 Tempe, AZ 852871504 (480) 727-6260 Funding Agency: Office of Naval Research PR Number: 00PR02703-00 Award Number: N000140010133 Current End Date: 31-Dec-2000 Scientific Officer: Colin Wood Objective: To determine the charge state and density of threading dislocations in nitride semiconductors. Approach: Electron beam holography in transmission electron microscope will image and quantify charge centers in semiconductor thin films. Title: ONR-312 Electronics Program Triennial PI: Bette Treadwell DANIEL EKE AND ASSOCIATES PC Address: 818 Roeder Road, Suite 702 Silver Spring, MD 20910 (301) 589-6963 Funding Agency: Office of Naval Research PR Number: 00PR03028-00 Award Number: N0001498D04180006 Current End Date: 31-Dec-1999 Scientific Officer: Max Yoder Objective: To provide logistic support and management services for Ocean Atmosphere and Space Department internal reviews. Approach: Contractor will prepare and distribute information packets; maintain and update appropriate mailing lists; arrange for audio-visual equipment; and create and maintain event database and provide administrative support on-site. Title: ONR-312 Electronics Program Triennial PI: Bette Treadwell DANIEL EKE AND ASSOCIATES PC Address: 818 Roeder Road, Suite 702 Silver Spring, MD 20910 (301) 589-6963 Funding Agency: Office of Naval Research PR Number: 00PR03028-01 Award Number: N0001498D04180007 Current End Date: 31-Dec-1999 Scientific Officer: John Zolper Objective: To provide logistic support and management services for ONR 312, Electronics, AMRFS 2000 Gathering. Approach: Contractor will prepare and distribute information packets; maintain and update appropriate mailing lists; arrange for audio-visual equipment; and create and maintain event database and provide administrative support on-site, such as nametags, scoresheets and folders for panel, and final report. Title: Workshop on Next Generation MM-Wave Solid State Power: Materials, Devices & Systems PI: Shari Allwood ALLWOOD AND ASSOCIATES INC Address: 8279 Midland Rd Mentor, OH 44060 (440) 951-1380 Funding Agency: Office of Naval Research PR Number: 00PR03085-00 Award Number: N000140010150 Current End Date: 31-Dec-2000 Scientific Officer: John Zolper Objective: Convene experts to explore new approaches to generating mm-wave (>30 GHz) solid state power. Approach: A topical workshop will be held where experts will discuss the material and device challenges to increasing power available from solid state sources at mm-wave frequencies. Title: Low Defect Density GaN Substrates from GaN Boules PI: Robert Vaudo ADVANCED TECHNOLOGY MATERIALS INC Address: 7 Commerce Dr. Danbury, ct 06810 (203) 207-9368 Funding Agency: Office of Naval Research PR Number: 00PR03219-00 Award Number: N000140030013 Current End Date: 31-Dec-2002 Scientific Officer: Ingham Mack Objective: Develop a manufacturing process that yields 2" diameter (minimum), semi-insulating GaN substrates with defect densities < 1x104 / cm2 and prototype substrates with 2.5" diameter (minimum). Approach: Commercially-viable GaN substrates will first be developed by growing HVPE GaN boules on lattice matched GaN seed crystals. HVPE LEO seeds will also be investigated to reduce the defect density. The most promising aspects of the HVPE-optical liftoff, HVPE boule growth, and HVPE LEO processes will then be combined to produce the final wafer product. Wafer manufacturing, including slicing, sizing, flatting, polishing, and final surface finishing of the GaN wafers will be an integral part of the program. Title: Synthesis of P-type ZnO Films & p-n PI: Henry White UNIVERSITY OF MISSOURI COLUMBIA Dept of Physics & Astronomy Funding Agency: Office of Naval Research PR Number: 00PR03564-00 Award Number: N000149910288 Current End Date: 31-Jul-2000 Scientific Officer: Yoon Park Objective: The primary goal of this program is to grow and characterize high quality p-type and n-type ZnO films with high carrier concentrations on single crystal substrates, and to fabricate p-n junctions. Secondary goals are the development of materials processing for bandgap modulation, and the development of optical devices such as LEDs and laser diodes. The suitability of several growth techniques to obtain ZnO films with high optical quality and low defect density will be explored. Approach: P-type ZnO films will be grown. Films will be characterized by x-ray, Hall probe, photoluminescence, and atomic force microscopy. The technique used for growth will be developed further and several enhancements and other approaches will be explored. Pulsed laser deposition using ZnO targets will be used to create Zn, O and ZnO molecules as a precursors to film formation. The impact of oxygen plasma environments on the growth of ZnO film will be investigated. MBE techniques will also be employed for ZnO film growth. Title: Bulk Single Crystal Growth of Group III Nitrides in Supercritical Ammonia PI: Joseph Kolis CLEMSON UNIVERSITY Department of Chemistry Address: Box 345702 Clemson, SC 296345702 (864) 656-4739 Funding Agency: Office of Naval Research PR Number: 00PR03597-01 Award Number: N000140010200 Current End Date: 31-Dec-2002 Scientific Officer: Colin Wood Objective: To develop a technology for growth of 2" and larger diameter substrates for power microwave electronics. Approach: PI will determine conditions for optimized growth rate and crystal quality of GaN growth from super critical ammonia solutions. Progress: PI has determined a phase spce data base for temperature, pressure, and solubilizing salts for aminothermal growth of GaN. Title: Growth of Single Crystals and Fabrication of GaN and AlN wafers PI: Zlatko Sitar NORTH CAROLINA STATE UNIVERSITY MATERIALS SCIENCE AND ENGINEERING Address: CAMPUS BOX 7919 RALEIGH, nc 276957919 (919) 515-8637 Funding Agency: Office of Naval Research PR Number: 00PR03598-00 Award Number: N000140010192 Current End Date: 30-Dec-2000 Scientific Officer: Colin Wood Objective: To generate procedures and techniques for industrial preparation of nitride semiconductor sustrates. Approach: Sublimation of Ga, and Al under nitrogen atmosphere with additional ammonia in the case of GaN. Title: 4 Gbit/in(2) NVRAM Deposition and Testing PI: Dexin Wang NONVOLATILE ELECTRONICS INC Address: 11409 Valley View Dr. Eden Prairie, MN 55344 (612) 996-1608 Funding Agency: Office of Naval Research PR Number: 00PR03618-00 Award Number: N0001400C0100 Current End Date: 31-Jan-2003 Scientific Officer: Larry Cooper Objective: To provide circuit design and testing of a novel form of Magnetic Random Access Memory from storage elements designed at NRL. Approach: NVE will design the appropriate circuit layouts for the current control of the read and write functions on the Vertical GMR elements designed at NRL. 2 kilobit memory circuits will be designed, fabricated and tested. Fabrication will include deposition of metals as per the NRL design, processing for circuit layout of control wires and readout. Testing will include wafer validation, single bit and multiple bit sensing. Switching time effects will be determined. Title: 11th International Winterschool on New Developments in Solid State Physics "Low-Dimensional Systems: Fundamentals and Applications" PI: Helmut Heinrich UNIVERSITY OF LINZ Institut fur Experimentalphysik Address: A-4040 Linz Linz, AZ 22217 (703) 696-4248 Funding Agency: Office of Naval Research PR Number: 00PR03620-00 Award Number: N000140010236 Current End Date: 31-Jan-2001 Scientific Officer: Larry Cooper Objective: To provide a forum for discussions of the latest understanding of the electronic properties of low dimensional electron devices. Approach: The 11th International Winterschool on New Developments in Solid State Physics-Low Dimensional Systems: Fundamentals and Applications will be organized on 21-25 February 2000 in Mauterndorf, Austria. Lectures and discussions will address topics such as phonon assisted tunneling in nanodevices, spin systems for quantum computing, terahertz frequency processes in semiconductor nanostructures, and optical properties of quantum dots. Title: 2 Inch Bulk GaN Single Crystal Growth from Liquid Phase PI: Vladimir DMITRIEV TECHNOLOGIES AND DEVICES INTERNATIONAL INC Address: 8660 DAKOTA DRIVE GAITHERSBURG, MD 20877 (301) 208-8342 Funding Agency: Office of Naval Research PR Number: 00PR03621-00 Award Number: N0001400C0168 Current End Date: 14-Feb-2001 Scientific Officer: Colin Wood Objective: 2 inch diameter single crystal GaN will be grown. Approach: PI will seed and grow bulk GaN crystals from atmospheric nitrogen saturated Ga + other metal alloy solution. Title: Magnetism & Transport in Semiconductors PI: Mark Van Schilgaarde U S DEPARTMENT OF ENERGY SANDIA NATIONAL LABORATORY Computational Materials Science Address: Albuquerque, NM 871850151 (925) 294-3794 Funding Agency: Office of Naval Research PR Number: 00PR03634-00 Award Number: N0001499F0152 Current End Date: 31-Mar-2001 Scientific Officer: Larry Cooper Objective: To provide ab initio theory for the bandstructure of various semi-conductors, semiconductor heterojunctions and for ferromagnetic semiconductor-metal heteromaterials. To calculate transport properties in support of device concepts based on spin polarized electron transport. Approach: An all electron GW code will be developed and applied to calculations of bandstructure for various materials, including III-V compound semiconductors with accurate band gap determinations. Additional calculations will address the same materials doped or alloyed with Mn or Fe to investigate the ferromagnetic properties of these materials. These calculations will provide the basis for studying the processes of exchange interactions and spin dynamics in these materials. Transport of spin polarized carriers in these heterojunction materials will be assessed, with emphasis on spin flip scattering mechanisms. Separate code development will lead to calculations of magneto optical properties for Mn doped III-V compounds. Progress: Initial results for LDA calculations for Mn and Fe impurities in GaN have been obtained. At the 1% level of doping, there is a definite appearance of majority spin electrons in the gap, and the minority electrons resonant with the conduction band. At the 3% level, the majority levels are pushed down into the valence band and since there are 4 electrons available to fill 5 states, the result is an acceptor state, and the material is metallic in nature. With Fe doping, because there are only 4 states to fill, the material is insulating. More work is needed in order to get bandgap widths correct (always underestimated in LDA) which will affect the spin splitting and thus change the effect of doping on the conductivity. Title: Magnetic Nanostructure: Support of the Gordon Research Conference PI: Carlyle Storm GORDON RESEARCH CONFERENCES Director of Gordon Conferences Address: West Kingston, RI 028920984 (401) 783-4011 Funding Agency: Office of Naval Research PR Number: 00PR03638-00 Award Number: N000140010191 Current End Date: 31-Jan-2001 Scientific Officer: Larry Cooper Objective: To provide a forum for discussing the latest developments in the physics and material properties of magnetic nanostructures. Approach: The Gordon Research Conference on Magnetic Nanostructures will be organized and administered on 13-18 February 2000 in Ventura, California. Topics for discussion include: nanoscale magnetism, multilayered magnetic films, spin dependent tunneling, new materials, magnetic sensors, and others. Title: HIPAS support to HAARP/HIPAS Science PI: Alfred Wong THE REGENTS OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES Department of Physics Address: 405 Hilgard Avenue Los Angeles, CA 900241547 (213) 825-1642 Funding Agency: Office of Naval Research PR Number: 00PR03656-01 Award Number: N0001496C0040 Current End Date: 30-Apr-2000 Scientific Officer: Edward Kennedy Objective: To investigate the auroral ionosphere under natural and highly stimulated conditions in order to determine the impact on military navigation, communication, and surveillance systems. Approach: ELF generation experiments are performed at the HIPAS facility in Alaska. The HF frequency can be changed rapidly between two specific frequencies, and the polarization of the HF wave can be changed rapidly between O and X mode. Also, a capability has been implemented to steer the HF beam rapidly so that the centroid of the electrojet can be tracked. An enhanced optical diagnostics capability has been developed, including a LIDAR for detecting excited molecular nitrogen ions. Progress: A new type of Stimulated Electromagnetic Emission (SEE) experiment was performed in which emissions from the ionosphere were measured following short-pulse, low-duty-cycle heating at 2.85 MHz. Typical pulse widths were 25 to 125 ms with interpulse periods of 250 ms to 10 s. Under these conditions heating effects are not cumulative, and large scale thermal and density perturbations are minimized. Two different types of SEE spectra were observed, not previously seen under CW heating. Most of the time a weak type spectrum was observed consisting of broad featureless sidebands; the downshifted sideband is somewhat stronger; the bandwidths are about 25 kHz (downshifted) compared to 15 kHz (upshifted). The strong type spectrum has sidebands which are about 20 dB stronger, and the bandwidths are about 40 kHz (downshifted) and 25 kHz (upshifted). The upshifted sideband is often characterized by a distinctive modulation. All observed features of the data were successfully interpreted using strong Langmuir turbulence theory including the observed modulations due to interference between upward and downward traveling waves. _------------MORE----------> 
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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:27 PM
Title: 1.3/1.55 um HIGH INJECTION HETEROJUNCTION BIPOLAR TRANSISTOR FOR IMPROVED FIBER OPTIC LINK PERFORMANCE PI: Paul Enquist RESEARCH TRIANGLE INSTITUTE Office of Research Contracts Address: 3040 Cornwallis Rd Research Triangle Park, NC 277092194 (919) 541-6190 Funding Agency: Office of Naval Research PR Number: 00PR03662-00 Award Number: N0001498C0035 Current End Date: 31-Dec-2000 Scientific Officer: Yoon Park Objective: To develop and evaluate a novel 1.3/1.5um high injection heterojunction bipolar transistor (HIHBT) external modulator technology in order to achieve a significant improvement in fiber optic link performance. Approach: A waveguide HBT with an active region within the base optimized for maximum absorption and index change with minimum base-emitter RF drive is under development. The base and collector comprise the optical cavity to simultaneously optimize transit time and optical confinement. Active biasing further minimizes charging times. Progress: High Injection Heterojunction Bipolar Transistor (HIHBT) was fabricated and tested for improved fiber optic link performance. Index and optical power profiles of HIHBT have been simulated. HIHBT mask layout and fabrication process is completed. The first HIBT showed B~70 for 500A In.6Ga 4 as well in the base of the transistor. Optimization of electron accumulation with potential well base to enhance optical modulation is undergoing further research.Initial HIHBT laser and modulator devices fabricated last year were optically tested this year. Adequate testing was complicated by the ~ 1.8 micron operating wavelength that was epitaxially limited. Extended wavelength characterization capability from 1.3 to 2.0 microns is in progress and scheduled for completion later this FY. Improved devices for preferred 1.3 and 1.55 micron operation using GaAsSb/AlInAs superlattices have been designed and a vendor qualified for delivery of these structures. HIHBT laser and modulator fabrication from these structures is scheduled later this FY. Title: Quantum 1/f Noise and Decoherence Effects Applied to Low Dimensionalality Nanostructures, UHF and Low-Power PI: Peter Handel UNIVERSITY OF MISSOURI 341 Woods Hall Address: 8001 Natural Bridge Rd St. Louis, MO 63121 (314) 553-5021 Funding Agency: Office of Naval Research PR Number: 00PR03673-00 Award Number: N000140010199 Current End Date: 31-Jan-2001 Scientific Officer: Larry Cooper Objective: To develop an understanding of the sources of 1/f noise in quantum devices and to provide direction for the improvement of the noise and decoherence properties of nanoelectronic devices. Approach: The concepts of quantum 1/f noise generation in electron devices will be used to study the various noise sources in Resonant Tunneling Diodes and in spin polarized electron transport devices. The decoherence mechanisms which impact on quantum tunneling and on spin flip processes will be studied. These results will be used to predict the noise performance of such devices and to correlate such results with the materials and geometries of relevant devices. In particular, phase noise and amplitude noise will be monitored as they impact on digital switching devices. Title: A Study of the Switching Speed of Magnetoquenched Superconductive Devices & Their Applicability to Practical Superconductive Electronics PI: Steven Kaplan HYPRES INC Address: 175 Clearbrook Rd Elmsford, NY 10523 (914) 592-1190 Funding Agency: Office of Naval Research PR Number: 00PR03749-01 Award Number: N0001400C0311 Current End Date: 14-Apr-2002 Scientific Officer: Deborah Van Vechten Objective: To continue to determine the applicability of mesoscopic magnetoquenched superconducting valve (MMSV) logic devices to niobium based Josephson junction technological needs for memory and field programmable devices in conjunction with the Naval Research Laboratory (NRL). This technology is a good candidate for the custom high speed digital processors needed in future generations of rf multi-function systems. Approach: HYPRES will collaborate with NRL in the design, fabrication and test of MMSV devices to determine their characteristics and switching speed. The switching speed will be measured using sample probes fabricated for this project, along with a 1 GHz pattern generator and digital oscilloscope. The resolution of this measurement should be less than 150 ps. The threshold curve of SQUIDs will be measured, to determine how the magnetic field of one device affects others. The I-V curve of quenched devices will be modeled with a resistively-shunted junction model. In fy00 this will be done with pure Nb devices and in fy01 with bilayers with lower transition temperatures. Title: Sb-Based III-V Quantum Devices and Circuits for Ultra-High Frequency Digital Signal Processing Applications PI: David Chow HRL LABORATORIES LLC Dept. of Electrical Engineering Address: 3011 MALIBU CANYON ROAD MALIBU, CA 902654737 (310) 317-5330 Funding Agency: Office of Naval Research PR Number: 00PR03836-00 Award Number: N000149830010 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To develop a novel new digital signal processing circuit technology with speed-power product capability which is orders of magnitude better than can be expected using conventional silicon technology. Approach: The unique properties of Resonant Interband Tunneling Diodes(RITDs) based on InAs/AlSb/GaSb heterojunctions will be used in the development of ultra-high frequency Digital Signal Processing circuits. Optimization procedures for the growth of the materials will be developed. Stacked devices will be designed and tested in circuit simulation programs. Various basic circuits will be evaluated, such as ADCs, digital multipliers and RITD logic gates for FFTs. Particular attention will address the issues of controlled interface morphology in the hetero-junction system which must be improved. Circuits will be fabricated and tested. Progress: The physics based RTD model has been optimized by fitting to real device parameters. The InAs HFET model has also been developed for use in the SPICE simulations. Several growth runs have been completed for developing the IC fabrication and processing. The structures are based on the NRL HFET designs. At Notre Dame, the processing schemes for etching and formation of ohmic contacts are undergoing continuing development. Improvements in the e-beam system have been made and will be used in the gate formation of the HFETs. Equipment for high speed digital measurments has been installed for measurements up to 50 GHz. One main issue has yet to be overcome. Nonuniformity of HFET performance across the chip has not been resolved. Title: High Speed Resonant Tunneling Circuits PI: Gary Frazier RAYTHEON COMPANY DBA RAYTHEON SYSTEMS COMPANY Address: 13588 North Central Expwy. Dallas, TX 752430246 (972) 995-2844 Funding Agency: Office of Naval Research PR Number: 00PR03837-00 Award Number: N000149830013 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To develop novel Multi-gigahertz digital signal processing circuits for insertion into various digital systems. These novel circuits will utilize the unique speed and power advantages of Resonant Tunneling Diodes to achieve enhanced level of digital performance. Approach: Resonant Tunneling Diodes coupled with Heterojunction Field Effect Transistors will be combined into novel digital signal processing circuits. A complete development program will be undertaken in which the design, fabrication, and testing of the devices and circuits will be completed. Specific circuits will include shift registers, data latches, and multiplexers. These circuits will be integrated with True Time Delay networks, code generators, FFT, Data Multiplexers, and Ultra-low power microwave memory for consideration in the AMRFS system, ATM and broadband wireless networks. III-V semiconductor materials based on InP and InGaAs layers will be grown for proper integration of RTDs and HFETs. Various digital circuits operating at 25 GHz will be designed and fabricated. Circuits will be designed using SPICE codes and advanced codes provided by the University of Michigan. Circuits will include on-chip test circuits for testing at the higher digital frequencies. Progress: Shift registers and latches that operate at 10 GHz were designed, fabricated and tested. Based on these results the design of the 25GHz circuits was completed. S-parameter measurments were made on test structures at 100 GHz and the results used SPICE modeling of the 25 GHz circuits. Latch circuits were tested at frequencies up to 40 GHz with only 325 microwatts of static power. 1Kbit SRAM were designed, fabricated and tested. The memory cell requires an area of only 200 square microns and operated up to 3.5 GHz. Compared to CMOS memory, the TSRAM operates 30 times faster at 3 times lower power. Title: Nanoscale Interface Characterization by UHV STM Spectroscopy PI: Joseph Lyding THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN Beckman Institute-Advanced Science/Technology Address: 801 SOUTH WRIGHT STREET CHAMPAIGN, IL 618204262 (217) 333-8370 Funding Agency: Office of Naval Research PR Number: 00PR03846-00 Award Number: N000140010234 Current End Date: 31-Dec-2002 Scientific Officer: Larry Cooper Objective: To develop improved techniques for characterizing the atomic scale imaging of semiconductor surfaces and to apply it to several problems involving the adsorption of various atoms and molecules to these surfaces. Approach: STM based CITS and EELS will be developed for application to surface imaging and surface spectroscopy of metal films forming on semiconductor surfaces. UHV capability will allow for experiments of single atoms adsorbed on silicon surfaces. Electronic properties will be determined by CITS and chemical properties by EELS. Magnetic atoms and carbon-60 molecules will be the systems of interest. Title: Spin Carrier Injection and Oxide Growth at Interfaces PI: Norman Tolk VANDERBILT UNIVERSITY Departemtn of Physics and Astronomy Address: Center for Molecular and Atomic Studies at Su Nashville, TN 37235 (615) 322-2786 Funding Agency: Office of Naval Research PR Number: 00PR03852-00 Award Number: N000140010238 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To advance understanding of the effects of interface phenomena in semiconductor heterostructures using advanced laser light sources. Materials will be chosen for their potential for advanced devices. Approach: The properties of the heterointerfaces of several electronic material systems will be characterized using the advanced laser facilities at Vanderbilt. The FEL and other short pulse lasers will be used to determine band offsets, carrier lifetimes, optical recombination, spin flip scattering times, and others. Using the SHG approach, the properties of charge effects on the silicon-silicon dioxide interface properties will be measured. In-situ characterization is important so that the effects can be monitored as the insulator film begins to form. Magnetic semiconductor films will be studied in magnetic fields to characterize the effects of field controlled band offsets and spin flip scattering events. Title: Dual Use Bandpass Modulators for RF Signal Conversion PI: John Przybysz NORTHROP GRUMMAN CORPORATION ELECTRONIC SENSORS AND SYSTEMS DIVISION Electronic Sensors and Systems Division Address: 1745A WEST NURSERY RD Linthicum, MD 210900000 (410) 765-7652 Funding Agency: Office of Naval Research PR Number: 00PR04121-00 Award Number: N000140030022 Current End Date: 19-Mar-2003 Scientific Officer: Deborah Van Vechten Objective: To prove that a superconducting, oversampled ADC can outperform its semiconductor competition in conventional narrow band, low pass versions and can be generalized in a straight-forward manner into revolutionary narrow band, bandpass designs. The first realization of the latter will be matched to the GPS 1.5 GHz band and serve to provide jamming resistance to this militarily critical signal. Commercialization will be first pursued at the technically easier, lower wireless communications frequencies. Demonstration of a pass band adc at these frequencies will enable construction of ultra-wide band receivers which do not down-convert the signal, separate digitization and output signal generation functions, and are truly multi-functional. Approach: In the first year, the existing second order, low pass, sigma delta ADC design will be iterated and fabricated in >3X reduced line width to allow clock speeds above the demonstrated 2.5 GHz. Export of data to semiconducting electronics at sampling speed will be worked. The issues involved in shifting to a band pass design will be investigated via software simulations. Experimental fabrication and testing of the band pass design will begin in the second year and culminate at the end of this funding with a test of noise shaping and the SNR and SFDR achieved in the GPS 1.5 GHz band. Initially the fabrication will be done at UC Berkeley under a separate ONR award, but later the new, reduced line width process at NG will take over. NG will also collaborate with another ONR award participants at SUNY SB (which will develop the digital resampling filters needed for the wide band receiver architecture) to define the signal interfaces and extent of preprocessing of the data in the ADC digitizers. Title: Ultrafast Optoelectronic Input-Output Interface for Superconducitng Digital Electronics PI: Roman Sobolewski UNIVERSITY OF ROCHESTER Dept of EE & Laboratory for Laser Energies Funding Agency: Office of Naval Research PR Number: 00PR04124-00 Award Number: N000140010237 Current End Date: 30-Sep-2001 Scientific Officer: Deborah Van Vechten Objective: Superconducting digital electronics represents one of the prime contenders for the role of high speed signal conversion and digital processing in Navy direct rf reception systems due to their suitability for use in 100 GHz or higher logic circuits. However, there are currently difficulties with getting the processed signals out of the low temperature environment at high speed without large heat loads (3X that of processor) thanks to the losses and thermal conductivity of copper leads. Reciprocally, optical communications systems need help with switching and routing, simple computational tasks. (It is estimated that by the year 2006, nearly 13% of developed world households will be connected to interactive broadband fiber services, requiring very high capacity networks with complex switchboards and routers.) The system concept that is being explored is the combination of low loss optical fiber data transmission with superconducting logic. This will complete work on optical to electronic conversion using hot electron bolometers and explore a new class of electrical to optical converters, magneto-optical modulators (MO). By the end of the work, it should be clear if MO are a good choice for data transmission at speeds to 100 GHz per optical channel with low thermal loading. Approach: The MO modulator has distinct advantages over EO devices since MO are current not voltage driven, just like superconducting circuits. Currents of the required 1 mA magnitude flowing in a microwave microstrip line (MSL) built on a polarization-sensitive MO active medium and interacting with cw light delivered to low temperature by an optical fiber is expected to achieve at least 10% phase modulation for a single pass of SFQ signals with band widths above 100 GHz. EuSe or EuS biased at 4K are both expected to be suitable MO materials when a commercial green light laser is used. A Mach-Zehnder interferometer on the output will convert the phase modulation to amplitude modulation and strip off the unmodulated light signal. The MO modulators will be characterized in the frequency domain using GHz-range microwave sources and a 50-GHz bandwidth oscilloscope. Time-domain characterization will include analysis of the device optical response as the current pulse propagates in the MO transmission line using a unique femtosecond Ti:Sapphire laser/amplifier system and a cryogenic electro-optic (EO) sampler. TRW will be a collaborator. Title: Lumped Josephson Junction Arrays for Low Phase Noise Arbitrary Waveform Synthesizers PI: Samuel Benz U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Electromagnetic Technology Division Address: 325 BROADWAY BOULDER, CO 80303 (303) 497-5258 Funding Agency: Office of Naval Research PR Number: 00PR04125-00 Award Number: N0001400F0154 Current End Date: 30-Sep-2001 Scientific Officer: Deborah Van Vechten Objective: The next innovation in rf transmitters will use a digital pulse train to represent the desired output signal until just before the signal is actually transmitted. The performance of the system when used in a Doppler radar mode is a very strong function of the phase and amplitude purity of the waveform. Passing the pulse train through an array of Josephson junctions is known to improve this purity by >40 dB.This work will continue the development of electrically lumped versions of these arrays that are expected to be much easier to use than distributed arrays and more wide band in their response. Approach: Large numbers of junctions (>10^4) must be in the array if it is to produce a sizable voltage. For its response to be lumped at the highest frequency used, all the devices must be located within a small fraction of a wavelength at the highest frequency. Thus junctions must be less than 100 nm apart. Both vertically stacked SNS arrays (Nb/Ti/Nb? and NbN/MgO/NbN? are being tried) and laterally arrayed junctions (suitable for YBCO devices) are being investigated. Title: Solid State Module & Components II PI: Jeff Lynch NORTHROP GRUMMAN CORPORTION Electronic Sensors & Systems Sector Address: PO Box 17319 Baltimore, MD 21203 (410) 765-4972 Funding Agency: Office of Naval Research PR Number: 00PR04206-00 Award Number: N0001400C0152 Current End Date: 24-Jan-2001 Scientific Officer: John Zolper Objective: To increase the upper frequency limit of a high power SiC static induction transistor. Approach: An inverted SiC SIT structure will be studied that employs an implanted p-gate. The inverted device has lower parasitic capacitance and hence should exhibit a higher cut off frequency. Title: Gordon Research Conference:Chemistry and Physics of Nanostructure Fabrication PI: Carlyle Storm GORDON RESEARCH CONFERENCES Director of Gordon Conferences Funding Agency: Office of Naval Research PR Number: 00PR04220-00 Award Number: N000140010235 Current End Date: 31-May-2001 Scientific Officer: Larry Cooper Objective: To provide a forum to discuss the latest results in the methods of the fabrication of nanoscale electronic devices. Approach: The Gordon Conference on Chemistry and Physics of Nanostructure Fabrication will be organized in Tilton College, New Hampshire on 23-28 July 2000. A forum will be provided to discuss results in the methods for fabrication of nanostructure electronic devices. Topics will include: proximal probe fabrication, manipulation and measurement; single electron phenomena; quantum devices; novel devices; chemical and biological nanostructures. Title: A Variable Digital Time Delay Element PI: S. Kent RAYTHEON COMPANY DBA RAYTHEON SYSTEMS COMPANY Address: 3100 W Lomita Blvd Torrance, CA 905092999 (310) 517-6256 Funding Agency: Office of Naval Research PR Number: 00PR04226-00 Award Number: N0001499C0180 Current End Date: 30-Apr-2000 Scientific Officer: John Zolper Objective: Develop a circuit design for a variable digital time delay element in accordance with the AMRFS low (1-5 GHz) and high (4-20 GHz) bands. Approach: The contractor will perform a design study to develop a digital variable time delay element in accordance with the AMRFS low and high bands. Implementation of the design in SiGe, InP and GaAs based circuit technology will be examined. A complete circuit design and recomendation for implementation will be delivered. Progress: The major tasks completed include System Requirements & Program Development, which was used to establish the primary system requirements. The development of filter coefficients has progressed as planned, producing methods for generating coefficients. The filter structures have been examined. The basic FIR structure has been examined, and it presents a proven approach to filter-implemented delays. Development of the Farrow structure is underway and its effectiveness is being assessed. Preliminary results indicate a modified structure is preferred and increased attention to coefficient design is necessary. Title: MEMs Tunable Planar Micromachined & Bulk Acoustic Waver Filters PI: Peter Petre HRL LABORATORIES LLC Address: 3011 Malibu Canyon Rd Malibu, CA 90265 (310) 317-5919 Funding Agency: Office of Naval Research PR Number: 00PR04230-00 Award Number: N0001499C0178 Current End Date: 30-Apr-2002 Scientific Officer: John Zolper Objective: Develop a discretely tunable pre-select filter module for the 4-20 GHz frequency band and a 3- to 5- channel integrated filter module for the 1 - 5 GHz frequency band compatible with AMRFS specifications. Approach: Contractor will develop a Microelectromechanical System-based (MEMs) discretely tunable 32-channel integrated pre-select filter module for the high frequency (4 to 20 GHz) AMRFS system and a MEMS discretely tunable 3- to 5-channel Bulk Acoustic Wave (BAW) integrated filter module for the low frequency (1 to 5 GHz) AMRFS. Progress: A new MEMs switch is designed and is being fabricated that is modeled to have switching speeds approaching 1 ms. Material development of high quality thin film AlN for SAW filters is completed. Packaging technology for integration of miniature filter banks is under development, including substrate vias. Title: Low Noise Amplifiers PI: Armand Poirier SANDERS A LOCKHEED MARTIN COMPANY Microwave Space & Mission Electronics Division Address: 65 Spit Brook Rd Nashua, NH 030610868 (603) 885-5090 Funding Agency: Office of Naval Research PR Number: 00PR04235-00 Award Number: N0001499C0164 Current End Date: 30-Mar-2001 Scientific Officer: John Zolper Objective: Demonstrate a low noise amplifier over 4 to 20 GHz to achieve the AMRFS goals of NF = 1.0 dB, TOI > 32 dBm, SOI > 40 dB, gain = 20 dB, and DC power = 0.6 W. Approach: The contractor will develop enhanced linearity PHEMTs and throroughly characterize the devices for nonlinear and low noise behavior. Advanced circuit techniques, including a wide band balun, will be employed to achieve the required second and third order intercepts for linearity. Progress: New start. No progress to report. Title: Wideband GaAs Metamorphic HEMT LNA for Advanced Multifunction RF Systems PI: William Hoke RAYTHEON SYSTEMS COMPANY Address: Advanced Device Center Andover, MA 01810 (978) 470-9592 Funding Agency: Office of Naval Research PR Number: 00PR04236-00 Award Number: N0001499C0177 Current End Date: 31-May-2002 Scientific Officer: John Zolper Approach: The contractor will advance the state-of-the-art of metamorphic high electron mobility transistors (MHEMT) for use in a 4-20 GHz low noise amplifier (LNA) in accordance with the AMRFS system specifications. Both device and circuit level innovations, including an active cold load, will be explored to achieve the noise figure, gain, and bandwidth Progress: The progam was started 21 July 1999. Initial circuit implentation of an active cold load were realized in 1-5 GHz LNA with an effective load temperature of 80 K realized. This technique is being applied to circuits designed for 4-20 GHz operation. New device structures are being explored to improve linearity by increasing the transistor breakdown. Title: Interfacial Magnetospectroscopy of Advanced Magnetic Layered Systems PI: Yves Idzerda NAVAL RESEARCH LABORATORY Materials Science and Technology Division Address: NRL 6345 Washington, DC 203755320 (202) 767-3603 Funding Agency: Office of Naval Research PR Number: 00PR04246-00 Award Number: N0001400WR20242 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To investigate the magnetic properties of the interface between various electronic materials which determine the transport spin polarized carriers. Approach: Polarized synchrotron radiation sources will be used to characterize the magnetic properties of various electronic materials in thin film form. Metal-semiconductor and insulator-semiconductor films will be included. X-ray Magnetic Circular Dichroism and X-ray Resonant Magnetic Scattering techniques will be used to determine the chemical specific sources of magnetic properties at these interfaces. Title: Surfaces and Interfaces in InxGa1-xAs in Single Quantum Wells and in PI: Harry Wieder THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SAN DIEGO 0934 Electrical & Computer Engineering Address: 9500 Gilman Drive, USCD La Jolla, CA 920930407 (619) 534-2486 Funding Agency: Office of Naval Research PR Number: 00PR04261-00 Award Number: N000140010328 Current End Date: 31-Jan-2001 Scientific Officer: Larry Cooper Objective: To determine and control the effects of alloying in InGaAs/InP heterojunctions leading to optimization of the transport properties of these materials. Approach: Heterojunction materials of InGaAs/InP thin films will be grown with various levels of In. Electronic and transport measurements will be made to understand the role of surface states and their contribution to the accumulation of electrons at the interface. Varying the In content will be used to deduce the relationship between the surface state levels and the location of the Fermi level. Title: ADMINISTRATIVE & ENGINEERING SERVICES IN SUPPORT OF THE ADVISORY GROUP ON ELECTRON DEVICES (AGED) PI: Mark Pacer WRIGHT PATTERSON AFB Address: 2241 AVIONICS CIRCLE WPAFB, OH 454337322 (937) 255-4831 Funding Agency: Office of Naval Research PR Number: 00PR04277-00 Award Number: N0001400MP20052 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: To provide technical and management support for the DoD Advisory Group on Electron Devices, the AGED Executive Director, and the Electronics portion DoD Reliance Technology Panel for Sensors, Electronics, and Battlespace Environments. The function of AGED is to provide technical advice to assist the DoD, Military Departments, and NASA plan and direct electronic device programs to meet present and future system needs. Approach: The AGED Main Group and Working Groups, which consists of representatives from each of the Services as well as private industry, hold meetings on a regular basis to plan and hold Special Technology Area Reviews to help determine future directions of the Services' Electronics programs. Through the DoD Reliance Panel on Sensors, Electronics, and Battlespace Environments, the AGED Secretariat assists in gathering the appropriate technical and financial information so that a jointly-planned Electronics program can be more effectively implemented. Progress: During FY99 the contractor prepared for, assisted in running, and performed the necessary follow-up on the following: 6 Meetings each of the AGED Main Group, Working Groups A, B, and C, TPED, and the 1999 TARA. Three STARs were conducted on the subjects of Reliability, Packaging, and Low Cost Lasers. In addition, the contractor assisted in providing information and material for meeting the needs of DDR&E, AGED, and TPED. Title: ADMINISTRATIVE & ENGINEERING SERVICES IN SUPPORT OF THE ADVISORY GROUP ON ELECTRON DEVICES (AGED) PI: Mark Pacer AIR FORCE MATERIAL COMMAND Address: 2241 AVIONICS CIRCLE WPAFB, OH 454337322 (937) 255-4831 Funding Agency: Office of Naval Research PR Number: 00PR04279-00 Award Number: N0001400MP20054 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: To provide technical and management support for the DoD Advisory Group on Electron Devices, the AGED Executive Director, and the Electronics portion DoD Reliance Technology Panel for Sensors, Electronics, and Battlespace Environments. The function of AGED is to provide technical advice to assist the DoD, Military Departments, and NASA plan and direct electronic device programs to meet present and future system needs. Approach: The AGED Main Group and Working Groups, which consists of representatives from each of the Services as well as private industry, hold meetings on a regular basis to plan and hold Special Technology Area Reviews to help determine future directions of the Services' Electronics programs. Through the DoD Reliance Panel on Sensors, Electronics, and Battlespace Environments, the AGED Secretariat assists in gathering the appropriate technical and financial information so that a jointly-planned Electronics program can be more effectively implemented. Title: Electronics and Magnetism at the Nanometer Scale PI: Joseph Stroscio U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Electron and Optical Physics Division Address: OFFICE OF COMPTROLLER BLDG 101 A807 Gaithersburg, MD 20899 (301) 975-3716 Funding Agency: Office of Naval Research PR Number: 00PR04293-00 Award Number: N0001400F0278 Current End Date: 30-Sep-2002 Scientific Officer: Larry Cooper Objective: To determine the magnetic and structural properties of nanometer scale structures fabricated on semiconductor and metal surfaces and determine the device implications. Approach: A novel low noise scanning tunneling microscope will be used to image the atomic structure of semiconducting and metallic surfaces and to identify the surface atoms using spectroscopic techniques. This information will be correlated with magnetic properties determined by SMOKE and SEMPA. Novel new techniques will be explored for determining the magnetic properties of such films. One approach will be spin dependent tunneling. Another approach will be polarization analysis of luminescence caused by spin dependent tunneling. Progress: STM measurements on Mn deposited on Fe surfaces have been made as a function of Mn thickness. Mn islands form as coverage increases with a unique development of various size islands. SEMPA measurements of the interlayers exchange coupling show clearly the switching between negative and positive coupling as the number of layers changes between odd and even values. These observations are in agreement with the Sloncewski torsion model. Title: Support for Advisory Group on Electron Devices (AGED) and DoD Technology Panel on Electron Devices (TPED) PI: Ted Reiss US ARMY RESEARCH LABORATORY Sensors & Electron Devices Directorate Address: 2800 Powder Mill Road Adelphi, MD 207831197 (301) 394-1193 Funding Agency: Office of Naval Research PR Number: 00PR04320-01 Award Number: N0001400MP20089 Current End Date: 30-Sep-2000 Scientific Officer: Ingham Mack Objective: To provide technical and management support for the DoD Advisory Group on Electron Devices, the AGED Executive Director, and the Electronics portion DoD Reliance Technology Panel for Sensors, Electronics, and Electronic Warfare. The function of AGED is to provide technical advice to assist the DoD, Military Departments, and NASA plan and direct electronic device programs to meet present and future system needs. Approach: The AGED Main Group and Working Groups, which consists of represen-tatives from each of the Services as well as private industry, holds meetings on a regular basis to plan and hold Special Technology Area Reviews to help determine future directions of the Services' Electronics programs. Through the DoD Reliance Panel on Sensors, Electronics, and Electronic Warfare, the AGED Secretariat assists in gathering the appropriate technical and financial information so that a jointly-planned and executed program can be more effectively implemented. Progress: New start. No progress to report. Title: Programmable Digital Re-Sampling Filter for a Generic Wide-Band AMRFS Receiver Element PI: Joseph Jensen HRL LABORATORIES LLC Address: 3011 MALIBU CANYON ROAD MALIBU, CA 90265 (310) 317-5250 Funding Agency: Office of Naval Research PR Number: 00PR04447-00 Award Number: N0001400C0167 Current End Date: 30-Nov-2000 Scientific Officer: Deborah Van Vechten Objective: To conceptualize and evaluate alternative architectures for a novel class of digital filter units that will enable the AMRFS goal of making the entire sampled rf spectrum available to an arbitrary number of simultaneous users via an unrestrained number of beams. The Navy needs high speed, large dynamic range RF receivers and supporting digital processors in high performance radars to provide ship self-defense and more generally needs multiple simultaneous beams and reallocatable functionality beams to create affordable, high performance rf systems for future platforms. Approach: The architectural study of the filter units considered for this application will address the AMRFS requirements of angular resolution of the center line of incoming wave-fronts, sharpness in the passband edges of multiple passbands, decimation, and minimization of circuit complexity. The resulting design should be largely optimized for realization behind every array element and in any 100 GHz digital technology. Title: Cooperative Research on a Novel Josephson Junction Structure for High Speed Digital Applications PI: John Ketterson NORTHWESTERN UNIVERSITY Department of Physics and Astronomy Address: 633 Clark Street - Room 2-502 Evanston, IL 60208 (312) 491-5468 Funding Agency: Office of Naval Research PR Number: 00PR04558-00 Award Number: N000140010025 Current End Date: 30-Dec-2002 Scientific Officer: Deborah Van Vechten Objective: Superconducting digital electronics is a promising 100 GHz capable digital technology which could find Navy application in wide band, multi-function rf systems. However, it is not clear that the device geometry used for the past 10 yrs is optimal for such high clock speeds. This work will insure international collaboration and thereby aid in the investigation of whether a promising alternative structure (SINIS) is in fact easier to fabricate with little variation among devices. Approach: Support twice yearly meetings of the 2 ONR sponsored U.S. groups with the 3 E.U. sponsored groups and a Ukranian theorist actively studying the alternative device structure to discuss recent progress and technical issues. Title: Solar Blind Detector Array Program PI: Bruce Baran LOCKHEED MARTIN CORPORATION IR Imaging Systems Address: 2 Forbes Rd Lexington, MA 021737393 (781) 863-3574 Funding Agency: Office of Naval Research PR Number: 00PR04579-00 Award Number: N0001499C0138 Current End Date: 09-May-2002 Scientific Officer: Yoon Park Objective: The goal is to develop the technologies necessary to produce AlGaN photodetectors which are suitable for vehicle self-protection systems. The application requires UV focal plane arrays which are capable of counting photons. Approach: A consortium consisting of Lockheed Martin, Epitronics, Emcore and University consultants will be formed. The contractor will attack issuses involved in materials, device design and systems engineering in developing the vehicle self-production technology. Low noise Avalanche Photodiodes, with internal gain, will be developed. All devices fabricated to date have noise characteristics many orders of magnitude away from the established needs. Issues to improve gain and noise will be addressed in this program. The program will address the issues such as (1) the improvement of the material quality, (2) the development of low damage etch processes and (3) the design and development of an ultra-low noise readout structure. A 128 x 128 AlGaN focal plane array wiil be fabricated. Progress: New start. No progress to report. Title: Advanced Physical Vapor Transport Growth of Pure & Modified AIN Crystals PI: N. Singh NORTHROP GRUMMAN CORPORATION ELECTRONIC SENSORS AND SYSTEMS DIVISION Science & Technology Center Funding Agency: Office of Naval Research PR Number: 00PR04588-00 Award Number: N0001400C0214 Current End Date: 30-Sep-2001 Scientific Officer: Colin Wood Objective: To use the high surface mobility of haloenated group IV molecules in increasing the growth rate and reducing defect densities of SiC bulk crystal growth for wide gap semiconductor electronics. Approach: PI will use halogenated vapor sources of carbon and silicon for growth of SiC boules. Title: Growth of Bulk Gan by LPE PI: Michael Spencer CORNELL UNIVERSITY Department of Electrical Engineering Address: 120 Day Hall Ithaca, NY 14852 (607) 255-6271 Funding Agency: Office of Naval Research PR Number: 00PR04592-00 Award Number: N000149810071 Current End Date: 30-Mar-2003 Scientific Officer: Colin Wood Objective: Preparation of semiconductor grade GaN bulk crystals as substrates for high quality epitaxial films. Approach: GaN will be recrystalized from molten metalic solutions. Progress: All first round modifications to equipment are placed. Early growth runs have shown remarkably improved crystal quality. However the seed crystal problem is not resolved. PI will try to procure small seeds from the High Pressure Institute in Poland. Title: Ultra Wideband, High Power, Isolators for AMRFS Proposal PI: J. Adam NORTHROP GRUMMAN CORPORATION ELECTRONIC SENSORS AND SYSTEMS DIVISION Electronic Sensors & Systems Division Funding Agency: Office of Naval Research PR Number: 00PR04615-00 Award Number: N0001400C0173 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: To model, design, and fabricate a prototype 1-5 GHz isolator with < 0.5 dB insertion loss and > 20 dB isolation. Approach: The approach will be to first perform extensive modeling and design comparisons of potential isolator designs, down select the best approach, and then fabricate a prototype part. Title: Robust AlGaN/GaN MODFET LNA's PI: Mehran Matloubian HRL LABORATORIES LLC Address: 3011 Malibu Canyon Road Malibu, CA 90265 (310) 317-5363 Funding Agency: Office of Naval Research PR Number: 00PR04616-00 Award Number: N0001400C0174 Current End Date: 31-Mar-2001 Scientific Officer: John Zolper Objective: To study the trade-offs between survivability and low noise performance of AlGaN MODFETs and hybrid amplifiers. Approach: Various AlGaN MODFET structures will be grown, fabricated, and characterizated for survivability and microwave noise at 10 GHz. Device circuit and large signal models will be developed to determine the controlling device factors for the noted performance. Title: Ultra-Wideband AlGaN Amplifier Development PI: Rowan Messham NORTHROP GRUMMAN CORPORATION Funding Agency: Office of Naval Research PR Number: 00PR04660-00 Award Number: N0001495C0171 Current End Date: 31-Jul-2001 Scientific Officer: John Zolper Objective: The research will focus on the development of an ultra-wideband AlGaN/GaN amplifier. This expands on the small signal amplifier task of the orginal contract. An amplifier will be fabricated from AlGaN/GaN high electron mobility transistors (HEMT) grown on SiC substrates. Material will be prepared both via a low dislocation density laterial epitaxial overgrowth (LEO) process and conventional direct epitaxy on SiC. Device performance goals include power density > 4 W/mm ay 10 and 18 GHz with breakdown voltages > 50 V. A distributed amplifer will be designed and fabricated to produce 3 W over the full 1 - 18 GHz bandwidth. As a preliminary task, a 1 W, 1 - 18 GHz amplifer will be produced as a drop in replacement for the present GaAs power amplifier in the microwave power module (MPM) under development by Northrup Grummond for The Naval Research Laboratory. The final phase of the contract will involve designing a power combining amplifer to deliver >50 W of power over 1 - 18 GHz. Approach: AlGaN/GaN HEMTs wafers will be grown by Prof. Bob Davis at NCSU and delivered to Northrup Grumman for processing. Device modeling will be done by Prof Michael Shur at RPI. Both LEO and conventional epitaxial structures will be studied. At least 2 process runs of 0.25 micron HEMTs will be made. Various surface passivation techniques, including dielelectric and undoped GaN surface layers, will be studied to improved high frequency gain. High voltage passive components will be developed. Source inductance will be reduced through wafer vias. Via holes will also be used under inductors, along with airbridge interconnects, to reduce the capacitance under biasing inductors. Progress: 0.7 micron gate length AlGaN/GaN HEMTs grown on SiC have achieved 2 W at 10 GHz. The HEMT had an fmax of 35 GHz and Imax of 1.2 A/mm. A hybrid distributed SiC amplfier delivered a record 6.8 W over band from 3-9 GHz. Initial studies of an undoped GaN passsivation layer to reduce trapping effects were performed and reduced trapping was achieved. Title: HVPE Growth of Semi-Insulating GaN Buffer Layers for Microwave Device Applications PI: R. Molnar HANSCOM AIR FORCE BASE Funding Agency: Office of Naval Research PR Number: 00PR04662-00 Award Number: N0001400MP20070 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: To generate a low cost electronic grade substrate supply for lattice matched nitride semiconductor high power electronics. Approach: PI will introduce boron nitride liners to the reaction tube to reduce Si and O concentrations/electrical conductivity of these films, and will develop laser induced substrate-epilayer separation. Title: Low Temperature Preparation of 4H SiC (0001) Surfaces for Epitaxial Growth Utilizing a Novel Atomic Hydrogen Source PI: John Wolan MISSISSIPPI STATE UNIVERSITY Chemical Engineering Address: PO Box 6156 Mississippi State, ms 39762 (601) 325-8249 Funding Agency: Office of Naval Research PR Number: 00PR04667-00 Award Number: N000140010276 Current End Date: 30-Mar-2003 Scientific Officer: Colin Wood Objective: Very high crystal perfection SiC surfaces for low breakdown leakage devices. Approach: Low temperature atomic hydrogen beams in vacuum will impinge upon SiC surfaces, thus etching away surface through sub-surface residual damage from cutting and polishing of bulk SiC crystals, without introducing macroscopic damage. Title: Heteroepitaxy of Device Quality B-GaN on B-SiC Conversion Layers PI: Charter Stinespring WEST VIRGINIA UNIVERSITY RESEARCH CORPORATION ON BEHALF OF WEST VIRGINIA UNIVERSITY Department of Chemical Engineering Address: PO BOX 6845 617 N SPRUCE STREET MORGANTOWN, WV 265066845 (304) 293-2111 Funding Agency: Office of Naval Research PR Number: 00PR04671-00 Award Number: N000140010293 Current End Date: 28-Feb-2001 Scientific Officer: Colin Wood Objective: To develop a supply of cubic wide gap semiconductor heterojunctions for high power semiconductor electronic components. Approach: Silicon surfaces will be coated by methyl radicals to form silicon carbide monolayers. The silicon carbide will then be used to nucleate beta GaN epitaxial thin firms for HBTs. Title: Engineered Interface Electronic Structures of III-Nitride Heterostructures PI: Robert Nemanich NORTH CAROLINA STATE UNIVERSITY Department of Physics Address: Campus Box 8202 Raleigh, NC 276958202 (919) 515-3225 Funding Agency: Office of Naval Research PR Number: 00PR04813-00 Award Number: N000140010292 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To use in-situ surface analysis techniques for investigations of the growth of heterojunction materials involving SiC and GaN with the goal of optimizing the properties of such materials by engineering the interface between the dissimilar materials. Approach: Photo Electron Emission Microscopy will be used to monitor the electronic and structural properties of the growth of thin GaN films on SiC substrates. Tunable radiation from a Free Electron Laser will be used as a probe of the chemical/electronic nature of the buried interfaces. The spectroscopic equipment will be used in-situ with a UHV growth chamber for real-time characterization of the growing film. Spatial resolution for monitoring surface morphology will achieve 10 nanometers. Title: Strain and Oxygen Stoichiometry Effects on High Temperature Superconductor Thin Films and Devices PI: Xiaoxing Xi THE PENNSYLVANIA STATE UNIVERSITY Department of Physics Address: 104 Davey Laboratory University Park, PA 16802 (814) 863-5350 Funding Agency: Office of Naval Research PR Number: 00PR04822-00 Award Number: N000140010294 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: To determine whether the formation of spatial stripes of differing electron density in mixed valency compounds is impacted by the global stress in the film and to define the effect of such stripes on the electrical properties of the materials. Approach: Fabricate thin film samples of La2-x SrxCuO4-delta on vicinal substrates that have separately varied stress and oxygen content. Personally investigate the impact of these 2 parameters and the degree of in-plane order on the transition temperatures in the superconducting state and into a low temperature tetragonal phase. Distribute as agreed (after consultation with ONR PO) samples to other researchers who will examine other aspects of their electrical properties. Title: Integrated Electronics for Vertical (CPP) GMR MRAM PI: John Anderson NONVOLATILE ELECTRONICS INC Address: 11409 Valley View Rd Eden Prairie, MN 553443617 (612) 829-9217 Funding Agency: Office of Naval Research PR Number: 00PR04875-00 Award Number: N0001400C0236 Current End Date: 31-Aug-2002 Scientific Officer: Larry Cooper Objective: To develop the technology and designs to implement a magnetic memory concept for high density, non-volatile circuits for both commercial and military applications. Approach: CMOS circuit designs will be made to support the control (read/write) of vertical MRAM elements. CMOS circuits will be fabricated at a foundry and returned for further processing of MRAM memory circuits as a separate process. Processing will include mask development, deposition of metal layers and read/write metalization followed by chemical-mechanical polishing and packaging will follow. Testing of memory function for small modular memory blocks, and then for multiple modules, will be followed by full chip level integration of a 2 Kilobit memory demonstration. Progress: This is an SBIR effort. Title: High Speed Quantum Devices and Circuits PI: Harold Grubin SCIENTIFIC RESEARCH ASSOCIATES INC Division of Marine Biology and Address: 50 NYE ROAD PO BOX 1058 GLASTONBURY, CT 06033 (203) 659-0333 Funding Agency: Office of Naval Research PR Number: 00PR04876-00 Award Number: N0001400C0237 Current End Date: 31-May-2002 Scientific Officer: Larry Cooper Objective: To develop a computer simulation code for the design of semiconductor tunneling devices which can provide data necessary for the design of quantum-device based, high frequency circuits. Approach: Quantum transport models for quantum tunneling in semiconductor devices based on the Wigner Function. Transport equations will be developed to include large signal switching effects. The modeling will be applied to resonant tunneling relaxation oscillations as a demonstration of the design capability of the simulator. The RTRO will be optimized for 100+ Gigahertz clock applications. Noise sources will be studied and the effects of circuit designs which can reduce 1/f noise will be considered. The simulator will be optimized for commercial marketing, and will require development of appropriate user interfaces. Simulations will be validated with comparisons to device performance obtained from various groups performing experiments on approved device models. Progress: This is an SBIR effort. Title: Workshop on Wide Bandgap Bipolar Devices - Proceedings Distribution PI: Shari Allwood ALLWOOD AND ASSOCIATES INC Address: 8279 Midland Rd Mentor, OH 44060 (440) 951-1380 Funding Agency: Office of Naval Research PR Number: 00PR04903-00 Award Number: N000140010318 Current End Date: 09-Jul-2000 Scientific Officer: John Zolper Objective: Dessiminate information on progress in wide bandgap bipolar devices. Approach: A workshop was held in February 1999 on wide bandgap bipolar devices and manuscripts were submitted by attendees to a special issue of Solid State Electronics. The issue is now being distributed to the workshop attendees. Title: Interfacing Magnetoelectronics with Biochemistry Processes PI: Jeffrey Byers NAVAL RESEARCH LABORATORY Materials Science and Technology Address: NRL 6345 Washington, DC 203755320 (202) 767-6147 Funding Agency: Office of Naval Research PR Number: 00PR05198-00 Award Number: N0001400WX21069 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To develop novel nanoscale magnetic devices and use them to manipulate receptor-ligand interactions in biomolecular systems. Further, the technique of using magnetic nanoparticles, coupled to biomolecular species, as a method to control biomolecular processes will be validated. Approach: Nanometer scale magnetic devices will be fabricated so that the fringing fields can be controlled. Magnetic multilayer structures will be tailored to engineer the fringing field of the device. Magnetic nanoparticles will be biofunctionalized with appropriate ligands for study of controlled ligand-receptor processes. AFM techniques, coupled with DNA molecules tethered to solid surfaces will manipulate the nanoparticles for attachment to the DNA. Magnetic field manipulation of the nanoparticles by the fringing field devices will then permit exploration of controlled biomolecular processes. One study will use avidin (with a fluorescein group) as the protein receptor and the molecule biotin as the ligand. Then flourescence measurments can resolve the competition of the biotin and the fluorescein binding for the receptor site. Title: A Cryogenic Loop for Cooling Spatially Separate Electronics PI: Jeffery Didion NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Address: Mail Code 545 Greenbelt, MD 207710000 (301) 286-4363 Funding Agency: Office of Naval Research PR Number: 00PR05201-00 Award Number: N0001400F0216 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: Determine whether and how efficiently nitrogen may be pumped using a static electric field. The answers will strongly impact whether localized spot cooling can be used to reduce the total refrigeration cost of advanced superconducting circuits that require cryogenic conditions. Such a reduction will make more facile the actual fielding of such circuits in rf systems where their superior performance would be highly useful. Approach: ATEC is building a static E field pump for use in testing N in both gas and liquid phase. NASA Goddard will supply a testing facility capable of achieving operating temperatures between 20 and 80K with which to test the ATEC apparatus. NASA will also provide well skilled personnel to both help design and evaluate the results of the experiment and operate the apparatus. Title: Magnetism in Low Dimensional Systems PI: Robert Celotta U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY National Institute of Standards and Technolog Address: OFFICE OF COMPTROLLER BLDG 101 A807 GAITHERSBURG, MD 20899 (301) 975-3710 Funding Agency: Office of Naval Research PR Number: 00PR05280-00 Award Number: N0001400F0220 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To develop understanding of the micromagnetic properties of thin magnetic films leading to the optimization of magnetic field sensors and nanomagnetic data storage elements. Approach: The SEMPA technique will be used to image the properties of various thin magnetic films. High resolution images (10 nanometers) of the domain and other micromagnetic properties will be taken and analyzed. Films will be grown by MBE on metal or semiconductor substrates. Lithographic procedures will be used to pattern small structures for investigation of the micromagnetic structure. Applied magnetic fields, in situ, will allow for studies of the switching phenomena of these microstructures. -------MORE--------> 
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Alpha-Theta
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ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:29 PM
Title: AMFRS Architecture Study Program PI: Mike Fitelson NORTHROP GRUMMAN CORPORATION ELECTRONIC SENSORS AND SYSTEMS DIVISION Electronic Sensors and Systems Group Address: 7323 Aviation Blvd Linthicum, MD 210900000 (410) 765-2547 Funding Agency: Office of Naval Research PR Number: 00PR05293-00 Award Number: N0001400C0208 Current End Date: 14-Apr-2002 Scientific Officer: Max Yoder Objective: This work seeks to determine the impact of advances in new electronic devices and circuits relating to efficient, linear, broadband, high power RF amplification and to logic operating at 100 GHz or higher. The work further seeks to define the architectures required to best exploit these advances and to define cost optimized multifunctional architectures and their operational impact. Approach: The contractor shall conduct parametric studies including device and component performance capability, operational requirements, cost, and impact (including life cycle costs) to achieve multifunctional RF systems. Title: Advanced Multifunction RF System Architecture Concepts PI: Ron Kasparek TRW INCORPORATED SPACE AND TECHNOLOGY DIVISION Space & Electronics Group Address: One Space Park Redondo Beach, CA 90278 (310) 813-5612 Funding Agency: Office of Naval Research PR Number: 00PR05301-00 Award Number: N000140020005 Current End Date: 14-Apr-2002 Scientific Officer: Max Yoder Objective: This work seeks to parametrically investigate new component and circuitry technologies with Navy electromagnetic system requirements and provide the basis for new RF architectures, their projected life cycle costs, optimized insertion times, and impact on platform performance on 21st century Naval combatants. Approach: New component technologies such as ultra stable clocks, 100 GHz logic, efficient, highpower, broadband, linear solid state microwave and millimeter wave amplifiers will be parametrically compared in architectures necessary for 21st century platform performance. Multifunctional simultaneous signal capability with low radar cross section are among the system performance objectives. Title: Solid State vs. Tube Based Transmit RF System Study PI: Mike Fitelson NORTHROP GRUMMAN CORPORTION Electronic Sensors and Systems Group Address: 7323 Aviation Blvd Linthicum, MD 210900000 (410) 765-2547 Funding Agency: Office of Naval Research PR Number: 00PR05311-00 Award Number: N0001400C0241 Current End Date: 31-Jul-2000 Scientific Officer: Max Yoder Objective: This work seeks to compare the relative merits of solid state vs. vacuum tube technology for new systems and for modifications of old systems. Approach: A comparative analysis will be conducted using various functionality parameters (e.g., EW, radar, Communications) vs. the projected capabilities of vacuum tubes and wide bandgap solid state devices to fulfill the performance needed for the various functionalities. Title: New RF Architectures for AMRFS Effort PI: William Mulqueen LOCKHEED MARTIN GOVERNMENT ELECTRONIC SYSTEMS Government Electronic Systems Address: P.O. Box 1027, 199 Borton Landing Road Moorestown, NJ 080570927 (856) 722-2991 Funding Agency: Office of Naval Research PR Number: 00PR05315-00 Award Number: N0001400C0210 Current End Date: 14-Apr-2002 Scientific Officer: Max Yoder Objective: This work seeks to parametrically investigate new component and circuitry technologies with Navy electromagnetic system requirements and provide the basis for new RF architectures, their projected life cycle costs, optimized insertion times, and impact on platform performance on 21st century Naval combatants. Approach: New component technologies such as ultra stable clocks, 100 GHz logic, efficient, highpower, broadband, linear solid state microwave and millimeter wave amplifiers will be parametrically compared in architectures necessary for 21st century platform performance. Multifunctional simultaneous signal capability with low radar cross section are among the system performance objectives. Title: High Performance MEMS Tunable Filters for AMRFS PI: Andrew Brown M SQUARED TECHNOLOGIES LLC Address: 305 N. Holbrook Plymouth, MI 48170 (734) 647-1794 Funding Agency: Office of Naval Research PR Number: 00PR05419-00 Award Number: N0001400C0235 Current End Date: 14-Jun-2001 Scientific Officer: John Zolper Objective: To investigate, design, build, and test novel tunable filters based on MEMS switches and high-Q fixed capacitors. Approach: The approach is based on a novel "combinational" MEMS switch/capacitor design that results in a wide tuning range with very fine frequency control in a small physical space. Title: Development of High Power, Wide Bandwidth MMIC Amplifier Using AlGaN/GaN HEMT Technology on Semi-insulating 4H-SiC PI: Scott Sheppard CREE INC Address: 4600 Silicon Drive Durham, NC 27703 (919) 361-5709 Funding Agency: Office of Naval Research PR Number: 00PR05423-00 Award Number: N0001499C0172 Current End Date: 09-Sep-2002 Scientific Officer: John Zolper Objective: Demonstrate a 4-20 GHz power amplifier based on AlGaN/GaN HEMTs for the AMRFS high band system. Approach: The contractor will advance the state-of-the-art high power AlGaN/GaN HEMTs on semi-insulating 4H SiC substrates over the 4-20 GHz frequency range. This will involve studies of the optimum epitaxial device structure and device configuration. Process modules (e.g. through wafer vias) will be demonstrated to facilitate broad band amplifier designs. Device reliability will be accessed at Cree and at NRL on parts supplied by Cree. Two circuit approaches will be examined including reactively matched and a distribtured amplifier to maximize power, gain, efficiency, and linearity (intermodulation) over the frequency band. Progress: The contract was signed in 8 September 1999. The first device process runs have been initiated and a kick-off meeting was held at the contractors site. Title: Development of High Power, Broadband SiC MESFET MMICs PI: Scott Allen CREE INC Address: 4022 Stirrup Creek Drive Durham, NC 27713 (919) 361-5709 Funding Agency: Office of Naval Research PR Number: 00PR05424-00 Award Number: N0001499C0173 Current End Date: 25-Aug-2002 Scientific Officer: John Zolper Objective: The contractor will develop SiC MESFET and MMIC technology for the AMRFS 1-5 GHz transmit array. Approach: The contractor will demonstrate a hybrid 300 W SiC MESFET class B push-pull power amplifier opeating over 1-5 GHz in accordance with the AMRFS specifications for gain, efficiency, linearity, and physcial size. Discrete SiC MESFETs will also be supplied to NRL for reliability testing. Progress: The contract was signed on 24 August 1999. A kick-off meeting was held at the contractors site in October. The first transistor lots are underway and circuit design has started. Title: Fabrication and Properties of Free Standing Nitride Semiconductor Films Deposited by a Novel Low Temperature PI: Jaime Freitas NAVAL RESEARCH LABORATORY CODE 6874 Address: 4555 OVERLOOK AVENUE S. W. WASHINGTON, DC 203755347 (202) 404-4536 Funding Agency: Office of Naval Research PR Number: 00PR05514-00 Award Number: N0001400RC20040 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: This NICOP collaborative program will optimize the electronic properties of Group III nitride semiconductor films. Approach: Epitaxial GaN and other group III nitride films will be deposited by plasma assisted and simultaneous optical energy assisted techniques. Title: Measurement of the Electromagnetic Compatibility of an Electrohydrodynamic Pump with High Tc Squid Based Magnetic PI: Ted Clem COASTAL SYSTEMS STATION DAHLGREN DIVISION Dahlgren Funding Agency: Office of Naval Research PR Number: 00PR05551-00 Award Number: N0001400WR20276 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: The proven performance of SQUID gradiometers in finding buried mines would be much more accessible for autonomous mine field mapping if the packaging can be shrunk down until it closely approximates the size of the sensor. Doing that requires a method of circulating refrigerant in narrow tubing that surrounds the sensor without introducing interferring electromagnetic noise. The objective is to determine the magnitude of the problem when a macroscopic scale electro-hydro-dynamical pump is used. Approach: To take the inch scale EHD pump built for proving that liquid nitrogen can be pumped to the lab at Panama City Fl that has developed all the SQUID magnetic anomoly sensors. Noise spectral power curves will be taken as a function of EHD drive voltage levels and spatial separation and an estimate made of the minimum separation of the pump from the HTS sensors in a redesigned dewar if the EHD pump is providing the refri-gerant circulation. Title: 100 GHz Low Phase Noise Clock Expansion PI: Jerome Luine TRW INCORPORATED SPACE AND TECHNOLOGY DIVISION Funding Agency: Office of Naval Research PR Number: 00PR05576-01 Award Number: N000149820013 Current End Date: 31-Oct-2000 Scientific Officer: Deborah Van Vechten Objective: To establish the feasibility of and demonstrate a 100 GHz, low phase noise clock integrated circuit which is based on superconducting SFQ logic. The proposed circuit requires the achievement of coherent oscillation of many Josephson junctions connected in parallel and the maintenance of the signal purity through several subsequent circuit functions. The most mature fabrication technology, Nb, will be used along with custom InP output amplifiers developed for other programs by TRW. The work will demonstrate a circuit that is generally useful for high speed signal processing, including A/D and D/A, and in doing digital true time delay beam steering. Both are needed by the Navy in the context of ship self-defense and AMRFS. Approach: The approach will do circuit designs using SFQ logic, optimize the designs by simulation, fabricate them in Nb technology, and test the resultant chips. Each component of the circuit will be separately designed, built, and tested before the combined circuit is attempted. Title: High-Performance Waveform Generators for Advanced Radar PI: John Przybysz NORTHROP GRUMMAN CORPORATION ELECTRONIC SENSORS AND SYSTEMS DIVISION Electronic Sensors and Systems Division Address: 1745A WEST NURSERY RD Linthicum, MD 210900000 (410) 765-7652 Funding Agency: Office of Naval Research PR Number: 00PR05609-00 Award Number: N0001499C0632 Current End Date: 31-May-2001 Scientific Officer: Deborah Van Vechten Objective: To provide ship self defense, there is a strong technological need for large spur free dynamic range, low phase noise waveform generators. These capabilities will help find and identify small and stealthy targets and provide considerable enhancement to target detection in the presence of clutter. This program will compare 4 technologies potentially capable of delivering such signal generators and allow the Navy a clear choice of the best technology for future advanced systems. Approach: The phase 1 program develops HBTs, transferred substrate HBTs, and Josephson superconductive circuits for the purpose of demonstrating the best spur free dynamic range (SFDR) and lowest phase noise. In addition, GaAs MESFETs will be measured to provide COTS performance comparisons. Northrop Grumman will also examine waveform generator protocols to maximize overall system agility, including the generation of simultaneous beams with an array antenna. Title: Support for IEEE/Cornell Conference August 7-9, 2000 PI: Gerald Witt AIR FORCE OFFICE OF SCIENTIFIC RESEARCH Physics & Electronics Address: 801 North Randolph Street Rm 732 Arlington, VA 22203 (703) 696-8571 Funding Agency: Office of Naval Research PR Number: 00PR05633-00 Award Number: N0001400MP20084 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: Increase student participation in the Cornell Conference on High Performance Devices. Approach: The funds will go to supporting student travel and registration fees for the Cornell Conference on High Performance Devices. There will be matching funds from AFOSR. Title: Compact High Power Multiplexers for AMRFS PI: Jeffrey Pond NAVAL RESEARCH LABORATORY Microwave Technology Address: Code 6850 washington, DC 20375 (202) 767-2862 Funding Agency: Office of Naval Research PR Number: 00PR06109-00 Award Number: N0001400WR20283 Current End Date: 30-Sep-2000 Scientific Officer: John Zolper Objective: To develop a compact, highpower filter for uses in a multiplexer or channelizer. Approach: A Mobias strip resonator will be developed which will reduce the resonator size by 4 times while maintaining highpower capabilitiy. This is accomplished by taking advantage of the phase shift associated with a resonator based on Mobias strip configuration. A 2-channel prototype diplexer with 4-pole channel filters will be implemented in the first year. Title: Developing Design Tools for the Fabrication of RTD-Based Cellular Neural Networks PI: Leon Chua THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BERKELEY Electrical Engineering & Computer Science Address: 336 Sproul Hall Berkeley, CA 94720 (510) 642-3209 Funding Agency: Office of Naval Research PR Number: 00PR06182-00 Award Number: N000140010507 Current End Date: 30-Apr-2001 Scientific Officer: Larry Cooper Objective: To develop simulation software which can be used by developers for designing CNN circuits to be used in image processing applications. Approach: A SPICE based simulation program will be developed in which the RTD device is implemented as the nonlinear element in the CNN cell design. The SPICE parameters will be selected which allows for optimization of the circuits. A template design module will be developed which can be used for mapping retinal functions into the CNN simulations. Cell designs will be explored for evaluation of the RTD-CNN as a potential artificial retina. Title: Real Time CNN Image Processing System for Challenging Military Imaging Applications & Implementation of Biocentric Algorithms PI: Leon Chua TERAOPS Address: 1051 Cragmont Avenue Berkeley, CA 94708 (510) 848-7652 Funding Agency: Office of Naval Research PR Number: 00PR06183-00 Award Number: N0001400C0295 Current End Date: 31-Dec-2002 Scientific Officer: Larry Cooper Objective: To devise Cellular Nonlinear Network designs to implement retina inspired algorithms for image processing applications, and to provide hardware processors for testing. Approach: Computer hardware will be developed in which to demonstrate the CNN algorithms for image processing based on digital computation. Retina studies will provide such bio-inspired algorithms. This hardware will be tested on platforms at China Lake. Based on these studies, key features required of an analog CNN processor will be determined. These features will be the basis for implementing complex spatio-temporal image processing in such areas as image fusion, motion detection, and target recognition. Key components for the analog circuitry will be designed, fabricated and tested. Title: International Specialist Meeting on Bulk Nitride Growth and Related Techniques PI: Shari Allwood ALLWOOD AND ASSOCIATES INC Address: 8279 Midland Rd Mentor, OH 44060 (440) 951-1380 Funding Agency: Office of Naval Research PR Number: 00PR06190-00 Award Number: N000140010505 Current End Date: 30-Apr-2001 Scientific Officer: Colin Wood Objective: To increase U.S. knowledge and expertise on bulk nitride substrate preparation, and more rapid commercialization. Title: Silicon Carbide Materials Research & Technology Development PI: Tangali Sudarshan SOUTH CAROLINA RESEARCH INSTITUTE College of Engineering Address: Office of Research Columbia, SC 29208 (803) 777-7302 Funding Agency: Office of Naval Research PR Number: 00PR06243-00 Award Number: N000140010563 Current End Date: 31-Dec-2001 Scientific Officer: Colin Wood Objective: To determine and establish a sound technology for SiC crystal growth, epitaxy and high voltage device fabrication. Approach: Modelling of growth and epitaxy environments will enable improved SiC bulk crystal growth and wafering. Title: 2000 Core Electronics Program Planning and Assessment Review Support PI: Charles Chamberlain CACI TECHNOLOGIES INC Address: 14151 Park Meadow Drive (703) 679-3184 Funding Agency: Office of Naval Research PR Number: 00PR06513-00 Award Number: N0001499D05180002 Current End Date: 30-Apr-2000 Scientific Officer: Ingham Mack Objective: Provide technical and management services to the ONR Electronics Applied Research program. Approach: A Program Assessment and Planning Meeting will be held from 11-14 April 2000. The contractor will facilitate the review by providing a meeting space to accomodate a minumum of 50 people, prepare and provide an evaluation book for each of 12 evaluators, summarize the written comments and numerical scores from each evaluator, and provide the results to ONR within ten days of the review. These results will have a very strong influence on the projects to be selected for FY 2001 funding. Title: 2000 RF Requirements and S&T Opportunities Workshops Support PI: Charles Chamberlain CACI TECHNOLOGIES INC Address: 14151 Park Meadow Drive (703) 679-3184 Funding Agency: Office of Naval Research PR Number: 00PR06513-01 Award Number: N0001499D05180003 Current End Date: 14-Sep-2000 Scientific Officer: Ingham Mack Objective: Provide technical and management services to the ONR Electronics Applied Research program. Approach: Two workshops will be held at NRL - one on 10-11 May and the other on 25-27 July 2000. The contractor will facilitate the review by making arrangements for the agendas, notifying invitees, maintaining a record of presentations, and providing analysis and sorting of written and oral material presented at the workshops. The results of the worhshops are expected to l have a strong influence on the future of the ONR Vacuum/Solid State Electronics Applied Research Program. Title: Modeling, Optimization, and Testing of Plse Tube Refrigerators PI: Ray Radebaough U S DEPARTMENT OF COMMERCE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Physical & Chemical Properties Division M.S. 838.09 Address: 325 Broadway Boulder, CO 80303 (303) 497-3710 Funding Agency: Office of Naval Research PR Number: 00PR06541-00 Award Number: N0001400F0323 Current End Date: 30-Mar-2002 Scientific Officer: Deborah Van Vechten Objective: In order to win fleet acceptance of superconducting electronics, it is very necessary that it be packaged in such a way that the user need not be aware that the chips are operating at cryogenic temperatures and that only electricity is added to the box to make the unit operational for years at a time. This award will provide detailed state of the art theoretical guidance to a fledgling vendor supported under an ONR SBIR phase 2 as to whether and how pulse tube coolers can supply the Navy's needs for both small (electronics) and large (electric ship motor) systems at 4 and 10K temperatures using commercial refrigerator compressors (cheap). If successful, these will be among the first pulse tubes (no cold working parts, long MTFB) to operate at such low temperatures and the only ones with an appropriate heat lift for electronics. Single 10" high, rack mounted units are expected to result from the combined effort, ca. a 10x volume reduction from current units. Approach: Consult heavily with pulse tube vendor (ART) regarding design details and measurements, do simulations of performance using NIST developed software, measure laboratory demonstration units. Help define Navy requirements and insure they will be met by final system designs. Title: Fabrication and Properties of Free Standing Nitride Semiconductor Films Deposited by a Novel Low Temperature PI: Jaime Freitas NAVAL RESEARCH LABORATORY CODE 6874 Address: 4555 OVERLOOK AVENUE S. W. WASHINGTON, DC 203755347 (202) 404-4536 Funding Agency: Office of Naval Research PR Number: 00PR06564-00 Award Number: N0001400WX21026 Current End Date: 30-Sep-2001 Scientific Officer: Colin Wood Objective: This NICOP collaborative program will optimize the electronic properties of Group III nitride semiconductor films. Approach: Epitaxial GaN and other group III nitride films will be deposited by plasma assisted and simultaneous optical energy assisted techniques. Title: High Speed Magnetic Switching at Low Power for Thin Film Magnetic Devices PI: Jian-Gang Zhu CARNEGIE MELLON UNIVERSITY Department of Elec. & Comp. Eng. Funding Agency: Office of Naval Research PR Number: 00PR06704-00 Award Number: N000140010602 Current End Date: 30-Mar-2003 Scientific Officer: Larry Cooper Objective: To develop and apply computer simulation methods for describing high speed switching processes in nanomagnetic structures being considered for digital electronic applications. Approach: Numerical methods for describing the magnetization phenomena in thin film magnetic structures will be extended to include dynamic switching processes. The Landau-Lifshitz-Gilbert equations will be the basis for calculating the magnetization of structures which include effects of size, shape, edge effects, exchange coupling, and materials parameters. Various switching modes will be considered and the effects of energy damping. The effect of spin polarized currents on switching speed will be modeled. Title: Collaborative Investigations of IDFS for Naval Applications PI: Elie Baghdady ADCOM SYSTEMS TECHNOLOGY INC Address: ADCOM SYSTEMS TECHNOLOGY INC PEABODY, MA 01960 (781) 899-5905 Funding Agency: Office of Naval Research PR Number: 00PR06708-00 Award Number: N0001400M0147 Current End Date: 30-Dec-2000 Scientific Officer: Deborah Van Vechten Objective: To formulate an experimentally validated simulation model of the IDFS concept and confirm that it has the properties claimed for it. If proven, this concept will enable a digital array to preferentially listen in specific directions independent of the number of interfering, in band signals coming from other directions. This capability will be very useful in securing the communications links on which CEC rests. Approach: The approach is to develop, in collaboration with Don Bowling, Navy employee at NAWC, a MathCad simulation of the IDFS concept and define experiments for Mr Bowling to perform that will verify the simulation. The issues to be addressed include dechopping of unidirectional commutated, multiple signals and wideband signals, plus issues such as the relationship between data sample rate and the size of the angular acceptance cone around the desired signal and effect of IFDS on encoded signals and our ability to resolve them. The experimental work is to be done at NAWC-CL using existant government owned hardware. Four one week visits by Dr Baghdady are planned and frequent email communication will be used to exchange simulation programming, results, and discussions of technical issues. Title: Superconducting Cable Design and Test PI: Andrew Smith TRW INCORPORATED SPACE AND TECHNOLOGY DIVISION Address: TRW Space & Electronics Group Redondo Beach, ca 902780000 (310) 814-6792 Funding Agency: Office of Naval Research PR Number: 00PR06713-00 Award Number: N0001400C0350 Current End Date: 30-Sep-2002 Scientific Officer: Deborah Van Vechten Objective: To supplement the materials development effort performed at Neocera under an ONR SBIR phase 2 award and collaboratively develop a low thermal and electrical loss ribbon cable for use with superconducting components. For 4-10 K digital systems, these cables will be used to transfer analog signals in and digital out with minimal heat load. For the 77K microwave community these cables will provide lower power dissipation interconnects and allow co-located components such as semiconductor LNA to self-bias to somewhat warmer temperatures. The cables will be an enabling technology for superconducting electronics by easing the fabrication of the required cryogenic packaging. Approach: The approach is provide technical guidance as to the design of ribbon cables and testing of the thermal and microwave performance of completed prototypes. TRW will also address the issue of end connectors. Neocera, funded separately under 00pr06467-00, will focus on the materials and fabrication technology development side of the effort. Title: Class D/E Delta-Sigma Switched Mode Power Amplifiers PI: Mark Rodwell THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Department of Electrical and Computer Engineering Address: CHEADLE HALL ROOM 3227 Santa Barbara, CA 93106 (805) 893-3244 Funding Agency: Office of Naval Research PR Number: 00PR06740-00 Award Number: N000140010653 Current End Date: 30-May-2003 Scientific Officer: John Zolper Objective: Develop a high power pulse mode amplifier at 5 GHz for amplification of a digital pulse stream and subsequent integration to generate an arbitrary analog waveform. Approach: A current controlled class D amplifier and/or class E amplifier will be designed and built using AlGaN HEMTs to amplify digital pulse streams for synthesis of analog wave forms up to 5 GHz. Title: High Power Channelizer Filters PI: Peter Petre HRL LABORATORIES LLC Address: 3011 Malibu Canyon Rd Malibu, CA 90265 (310) 317-5919 Funding Agency: Office of Naval Research PR Number: 00PR06811-00 Award Number: N0001400C0347 Current End Date: 30-May-2001 Scientific Officer: John Zolper Objective: Develop high power channelizer filters to cover the AMRFS bands of 1-5 GHz. Design a channelizer filter for 4-20 GHz. Approach: A 4-channel, highpower, channelizer will be developed to cover 1-5 GHz. A miniature version will also be designed that will meet the size constraints of the AMRFS system. A 6-channel, high power channizer, will also be designed to cover 4-20 GHz. Title: Long Path VLF Diagnostics of Modified D-Region for HAARP PI: Umran Inan THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY Department of Electrical Eng./STAR Laboratory Address: 125 Panama Street Stanford, CA 943054125 (415) 723-4994 Funding Agency: Office of Naval Research PR Number: 00PR06815-00 Award Number: N000140010643 Current End Date: 28-Feb-2003 Scientific Officer: Edward Kennedy Objective: To develop a more detailed understanding of the relationship between physical processes occurring in the ionosphere, particularly the D-region, and the propagation of communication signals in the ELF/VLF bands. Approach: The propagation of communication signals in the ELF/VLF frequency ranges is by a waveguide mechanism in which the earth's surface serves as one wall and the ionospheric D or E regions serve as the upper wall. Variations in the structure of the ionospheric boundary can affect the amplitude and phase of signals received at long ranges. The approach of this effort will be to use a unique diagnostic tool developed to take advantage of Navy comm signals in the VLF band to develop data relating both naturally occurring as well as artificially induced ionospheric variations to the quality and reliability of such signals using sophisticated algorithms that, in turn, can provide insight into improvements to signal and equipment design. Title: A Simulation and Experimental Program to Enhance the Efficiency of ELF/VLF Generation at HAARP PI: Harvey Rowland NAVAL RESEARCH LABORATORY Plasma Physics Division Address: ATTN CODE 3310 Washington, DC 203755320 (202) 767-6644 Funding Agency: Office of Naval Research PR Number: 00PR06824-00 Award Number: N0001400WR20300 Current End Date: 30-Sep-2000 Scientific Officer: Edward Kennedy Objective: To evaluate potentially dramatic improvements to the generation of ELF/VLF signals through ionospheric interactions. These techniques, which have been developed and studied both theoretically and using computer models, will be evaluated experimentally at the HAARP ionospheric interaction facility. Approach: This effort will follow the general approach of selecting promising theoretical techniques, evaluating the optimum method using previously developed computer models and converting the technique into an experimental program to be conducted at the HAARP ionospheric interaction facility. Expected improvements to the generation of ELF/VLF will be evaluated by comparison of experimental results with computer predictions and revision of experimental plan if warranted. The effort will verify the predicted signal quality improvements in a methodical manner, selecting the most promising techniques initially and modifying the experimetal plan as results are obtained. Title: Application of and Enhancement to Arctic Infrastructure for the Study of Long-Term Change in the Earth's Polar Mesosphere PI: Michael Kelley CORNELL UNIVERSITY Electrical Engineering Address: Electrical Engineering Department Ithaca, NY 14853 (607) 255-2944 Funding Agency: Office of Naval Research PR Number: 00PR06878-00 Award Number: N000140010658 Current End Date: 30-Apr-2005 Scientific Officer: Edward Kennedy Objective: To expand Naval knowledge of the Arctic upper atmosphere and mesosphere, two regions that have not been studied extensively, particularly in the areas of electrical characteristics and the resulting impact on modern Naval communication and surveillance systems. The research will utilize and capitalize on the availability of sophisticated diagnostic instruments installed at the HAARP ionospheric observatory in Alaska. Approach: The research will employ instruments installed at the HAARP Observatory to detect and characterize the existence of mesospheric features as they are created, drift and dissipate over multiple seasons. There is evidence that the frequency and geographical extent of these structures are correlated with global change and may have an increasing impact on electromagnetic systems operating in the Arctic. The effort will use existing or planned radar systems operating over a wide variety of frequency ranges in the study. Coordination with other Arctic facilities will be maintained to optimize the research plan and promote synergistic results. It may also be possible to combine the electro-magnetic studies using HAARP with in-situ sampling using rockets from the Poker Flat research range in Fairbanks. Title: Microwave Power HBTs with Regrowth Base Regions PI: Fan Ren UNIVERSITY OF FLORIDA Chemical Engineering Address: P.O. Box 116005, Dept. of Chemical Engineering Gainesville, fl 326116005 (352) 392-4727 Funding Agency: Office of Naval Research PR Number: 00PR07038-00 Award Number: N000149910454 Current End Date: 01-Mar-2001 Scientific Officer: John Zolper Objective: To develop AlGaN/GaN heterojunction bipolar transistors with reduced base resistance by using selective regrowth. Approach: Selective area regrowth of the extrinsic base and/or the emitter of AlGaN/GaN HBTs will be developed to overcome the inherently high base sheet resistance and surface degradation associated with applying conventional HBT processing to this material system. Progress: A large area HBT with C-doped GaAs re-grown base contact layer was made. A pnp HBT with higher doping p-emitter layer was received and C-doped GaAs is being grown for base contacts to see if better contact resistance can be realized. A mask set has been prepared for small area HBTs and three batches of samples are being processed. Two of the batches are fabricated with a dielectricside-wall process and the other one use super-lattice AlGaN/GaN p-contactlayer. The structure was designed for a 500 nm GaNregrown in the small emitter area ( 2 * 4 micron sq), but around 1000 nm was obtained in the first regrowth experiment. Small area devices for rf measurement are expected in the next period. --------MORE-------> 
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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:30 PM
Title: Eighth van der Ziel Quantum 1/f Noise Symposium PI: Peter Handel UNIVERSITY OF MISSOURI 341 Woods Hall Address: 8001 Natural Bridge Rd St. Louis, MO 63121 (314) 553-5021 Funding Agency: Office of Naval Research PR Number: 00PR07050-00 Award Number: N000140010665 Current End Date: 31-May-2001 Scientific Officer: Larry Cooper Objective: To provide a forum for discussion of the sources and impact of quantum 1/f noise in semiconductor devices which will lead to improved devices for the Navy. Approach: To organize the VIII International van der Ziel Symposium on Quantum 1/f Noise in St. Louis, MO on 5-6 June 2000. A forum will be provided to discuss recent theory and experiments on this topic. Areas for discussion include: theory if quantum 1/f noise; 1/f noise in nano-electronic devices; effects of number and recombination fluctuations; general properties of quantum noise. Title: Direction of Arrival Dependent Signal Modulation Through Time-Varying Array Patterns: A Preliminary, Mathematical Study PI: Jeffrey Coleman NAVAL RESEARCH LABORATORY Radar Division Code 5341 Address: 4555 Overlook Ave SW Washington, DC 203755336 (703) 404-8843 Funding Agency: Office of Naval Research PR Number: 00PR07061-00 Award Number: N0001400WR20311 Current End Date: 30-Sep-2000 Scientific Officer: Deborah Van Vechten Objective: Ten years ago E. Baghdady introduced the concept of inducing an angle of arrival dependent Doppler frequency shift to allow signals in the same as-radiated frequency band to be separated in a receiver. The ability of such a system to cope with jamming signals would be revolutionary, but the difficulty in realizing the concept using analog hardware has contributed to the absence of proof of concept despite 2 SBIR phase 2 awards. This award will generalize the equations which describe the translation of signals from individual elements in an antenna array into a final combined signal to deal with construction of composite signals representing moving phase centers. Once these linear but time dependent schemes of signal processing have been defined, evaluation of the optimal manner of using them to reject in-band signals based on their angle of arrival should be possible. Approach: Investigate the potential of time varying arrays (elements and their processing software) realizable through application of existing digital signal processing approaches. In particular, define how to realize a time varying FIR filter in the case where the antenna elements are identical. Title: III-V Nitride Heterojunction Bipolar Transistors for Power Amplifiers PI: Russell Dupuis THE UNIVERSITY OF TEXAS AT AUSTIN Microelectronics Research Center Funding Agency: Office of Naval Research PR Number: 00PR07066-00 Award Number: N000149910479 Current End Date: 26-May-2001 Scientific Officer: John Zolper Objective: To model and fabricate an AlGaN/GaN heterojunction bipolar transistor (HBT) for microwave power amplifiers. Approach: To develop a detailed Monte Carlo model of the performance of AlGaN HBTs based on realistic material and processing parameters. The modeling will be used to guide an experimental demonstration of AlGaN HBTs for microwave power amplifiers. Progress: Progress has been made on growing and processing AlGaN HBTs and GaN BJT. Of particular note has been work on controlling the Mg dopig profile at the base/emitter junction. Functional DC HBTs have been demonstrated but with low current gain. Issues related to contact spiking and their role on junction leakage are being examined. Title: Gordon Research Conference on Point and Line Defects in Semiconductors PI: Carlyle Storm GORDON RESEARCH CONFERENCES Director of Gordon Conferences Funding Agency: Office of Naval Research PR Number: 00PR07164-00 Award Number: N000140010676 Current End Date: 31-May-2001 Scientific Officer: Larry Cooper Objective: To discuss research results and directions in the study of point and line defects in semiconductors which will lead to improved performance of electronic devices. Approach: The Gordon Research Conference on Point and Line Defects in semiconductors will be organized to provide a forum for discussing results and issues on the properties and effects of defects and impurities in various semiconductor materials. Topics will include: defects in ZnO; diffusion of impurities in Si; defects in Si/Ge; defects in compound semiconductors; defects in devices; extended defects and interfaces. Title: Electronic Structure & Interfaces of Narrow-Gap (6.1-A) III-V Semiconductors PI: Donald Wolford IOWA STATE UNIVERSITY Dept. of Physics & Astronomy & Microelectronics Research Center Address: 211 Beardshear Hall Ames, IA 50011 (515) 294-5769 Funding Agency: Office of Naval Research PR Number: 00PR07167-00 Award Number: N000140010675 Current End Date: 30-Nov-2001 Scientific Officer: Larry Cooper Objective: To develop understanding of the electronic properties of various heterostructure materials in the narrow gap III-V semiconductors which will be developed into low power electronic devices. Approach: Optical spectroscopies, using short pulse lasers, will be used to investigate the bandstructure, transport and radiative properties of heteroepitaxial structures based on various combinations of InAs, GaSb, and AlSb semiconductors. Diamond anvil cells will be used to modulate the band gap of these materials in order to map out bandstructure, defect states, and recombination mechanisms. Band offsets will be measured. A wide variety of band gap engineered structures will be investigated to explore differences due in Type I and Type II heterojunctions. Title: Spin Effects in Mesoscopic Systems PI: Aron Pinczuk THE TRUSTEES OF COLUMBIA UNIVERSITY IN THE CITY OF NEW YORK Dept. of Applied Physics and Applied Mathmatics Funding Agency: Office of Naval Research PR Number: 00PR07367-00 Award Number: N000140010714 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To provide a forum to discuss the latest research progress in the area of spin polarized electrons in nanoscale devices. Approach: An International Conference on Spin Effects in Mesoscopic Systems will he held in Cortona, Italy on 29 Jun-2 Jul 2000. Topics which address the issues and problems in understanding and controlling the spin degree of freedom of electrons in nanoscale devices. Topics will include spin coherence in low dimensional semiconductors; spin polarized transport; spin electronics in quantum computation; Kondo effect in quantum dots; metal-insulator transition; ferromagnetic heterostructures; optical spectroscopy of low dimensional structures. Title: 7th International Workshop on Computational Electronics (IWCE-7) PI: John Barker THE UNIVERSITY OF GLASGOW Nanoelectronics Research Centre Funding Agency: Office of Naval Research PR Number: 00PR07371-00 Award Number: N000140010713 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To provide a forum to discuss the latest results in the development of methods for simulations of semiconductor device performance which are to be used in the design of electronic devices. Approach: An international workshop will be organized with invited speakers presenting their results on methods and solutions to problems in device simulations. Topics of interest include: simulation of doping effects in MOSFETS; 3D simulations of ultrasmall MOSFETs; optoelectronic device simulation; Monte Carlo particle modeling; quantum transport methods and results. Title: Nanoimprint for T-Gate MESFET MMICs PI: Stephen Chou THE TRUSTEES OF PRINCETON UNIVERSITY Electrical Engineering Department Address: E-Quad Princeton, NJ 085445263 (612) 624-5599 Funding Agency: Office of Naval Research PR Number: 00PR07384-00 Award Number: N000140010711 Current End Date: 30-Jun-2001 Scientific Officer: John Zolper Objective: Demonstrated fully functional GaAs MESFETs with sub 0.5 micron T-gates fabricated with nano-imprint lithography. This will enable rapid throughput manufacturing of microwave circuits by replacing the time consuming (>4 hours per wafer) electron beam process presently used for gate definition. Approach: A single step, full wafer, nano-imprint lithography process will be developed for realizing the proper photoresist profile to produce low resistance T-gates for microwave transistors. A nano-imprint process for low parasitic air bridge interconnects will also demonstrated. The work will be done in collaboration with Anadigics with functional circuits demonstrated at the end of the program. Title: Development of Porous SiC Buffer Layers for SiC Bulk and Epitaxial Growth PI: Vladimir DMITRIEV TECHNOLOGIES AND DEVICES INTERNATIONAL INC Address: 8660 DAKOTA DRIVE GAITHERSBURG, MD 20877 (301) 208-8342 Funding Agency: Office of Naval Research PR Number: 00PR07398-00 Award Number: N0001400C0428 Current End Date: 30-Sep-2001 Scientific Officer: Colin Wood Approach: Use of Epitaxial SiC films on porous substrates as reduced defect density seeds for bulk SiC crystal growth. Title: Depth Profiling Analysis of Thin Semiconductor Films of SiC, Diamond, and III-V Nitrides by Trace Element Accelerator Mass Spectrometry PI: Floyd McDaniel UNIVERSITY OF NORTH TEXAS Research and Grants Address: Avenue C & Chestnut Denton, TX 752655936 (940) 565-3251 Funding Agency: Office of Naval Research PR Number: 00PR07409-00 Award Number: N000140010760 Current End Date: 14-May-2002 Scientific Officer: Colin Wood Objective: Identify and elimiate unwanted and deleterious electrically active impurities in wide gap semiconductors. Approach: PI will use the very high resolution Mass spectrometer system at University of North Texas. Title: Fabrication Technology for Vertical Magnetoresistive Random Access Memory based on Nanoimprint Lithography PI: Jian Wang NANONEX CORPORATION Address: 7 Foulet Drive Princeton, NJ 08450 (609) 683-3973 Funding Agency: Office of Naval Research PR Number: 00PR07428-00 Award Number: N0001400C0399 Current End Date: 31-Jul-2002 Scientific Officer: Daniel Purdy Objective: Demostrate decreased size, increased speed, and increased density of the Non-Volatile RAM using nano-imprint lithography technology. Approach: Implement a unique approach utilizing NIL to obtain 10 nm wide posts within the device. Title: Development of Multi-layer Films for Non Volatile Magnetic Random Access Memory (MRAM) Applications PI: Patrick Taylor UNIVERSITY OF IDAHO College of Mines & Earth Sciences Address: Dept. of Materials, Metallurgical, Mining & Geological Engineering Moscow, ID 838443024 (208) 885-6769 Funding Agency: Office of Naval Research PR Number: 00PR07461-00 Award Number: N000140010735 Current End Date: 30-Sep-2001 Scientific Officer: Larry Cooper Objective: To establish facilities for the processing of magnetic device materials and to develop processing technologies for the fabrication of magnetic memory elements. Approach: Various equipment will be purchased and installed including e-beam lithography, plasma enhanced CVD deposition system, and sputtering systems. GMR based metals will be deposited and processed for implementing a magnetic memory device in which current is transported perpendicular to the films. Electro-deposition, plasma etching and CVD methods will be developed and optimized. Materials will be characterized for magnetic and structural properties including Auger Emission Spectro-scopy to monitor impurity incorporation and STM/AFM to monitor structural properties of interfaces. Title: Investigation of the Thermodynamic & Kinetic Factors Involved in Synthesis of III-N Thin Films PI: Nathan Newman ARIZONA STATE UNIVERSITY Chemical Biological and Materials Engineering Funding Agency: Office of Naval Research PR Number: 00PR07497-00 Award Number: N000140010783 Current End Date: 30-May-2001 Scientific Officer: Colin Wood Objective: To improve the understanding of the parameters limiting the growth of thin films of GaN by molecular beam epitaxy. Approach: Reflection electron diffraction and desorption mass spectrometry will be used to determine the kinetics, and energetics of MBE deposition from activated nitrogen and group III elemental beams. Progress: A reactive III-N MBE growth/plasma-characterization system has been successfully designed, assembled and fully-tested (7/98). The system is able to synthesize III-N material with mono-energetic beams of activated nitrogen at substrate temperatures as high as 1800 C. Methods have been developed (1) to produce high-flux (>1015 cm-2s-1) mono-energetic beams of atomic nitrogen (utilizing Penning ionization in N2/noble gas plasmas) and (2) to tune the kinetic energy of high-flux (>10^15 cm-2s-1) mono-energetic molecular nitrogen beams between 1 and 40 eV. In the upcoming year, kinetic and thermodynamic barriers of III-N synthesis will be investigated under meta-stable growth conditions. Growth of AlN under these ultra-high temperature conditions (>~1700 C) has been initiated to facilitate unprecedented growth rates and improved film quality.The thermochemistry of AlN Selective Energy Epitaxy was investigated using 1-50 eV activated-nitrogen beams and 1000-1400 C substrate temperatures. AlN films with <2 arc minute (0002) rocking curve widths are routinely synthesized using >30 eV kinetic energy and ~1075 C substrate temp. Higher temperatures (>1150 C) result in sticking coefficients (<0.05). In-situ anneals (1350 C) improve film quality, albeit with a moderate decomposition rate(~200 Angstroms/hr). The mosaic nature of the initial seed layer is optimized using elevated substrate temp. (>1150 C) and SiC substrates. Title: Compound Semiconductor Roadmap for Defense Electronics PI: Gary Westling COMPUTER SYSTEMS CENTER INC Address: 6225 Brandon Ave Springfield, VA 22150 (703) 866-4000 Funding Agency: Office of Naval Research PR Number: 00PR07640-00 Award Number: N0001400A0001 Current End Date: 30-Jun-2003 Scientific Officer: Colin Wood Objective: Increase efficiency and application/direction of federal research funds in semiconductor electronics. Approach: Develop and maintain web site for national semiconductor research, with help and input from all potential recipients of such funding. Title: Advanced Fabrication Technology for Nonvolatile Magnetic Memory PI: Gary Prinz NAVAL RESEARCH LABORATORY Materials Science & Technology Branch Funding Agency: Office of Naval Research PR Number: 00PR07648-00 Award Number: N0001400WX21155 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To develop technologies for the wafer scale fabrication of VRAM elements using lithography, deposition and etching processes. Approach: Deep UV contact printing will be developed at NRL in order to fabricate 0.2 micron scale VRAM devices. Electroplating techniques will be developed to overcome the limitations to sputtering approaches. Title: Switching-Mode Microwave Amplifiers for Complex RF Signals PI: Peter Asbeck THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SAN DIEGO 0934 Department of Electrical Engineering Address: 9500 GILMAN DRIVE La Jolla, ca 920930407 (619) 534-6713 Funding Agency: Office of Naval Research PR Number: 00PR07667-00 Award Number: N000140010784 Current End Date: 14-Jun-2002 Scientific Officer: John Zolper Objective: Develop high efficiency, high linearity pulse mode microwave amplifiers. Approach: Refine signal encoding algorithms for switching mode amplifiers with complex rf signals to minimize digital noise generation. A low frequency(0.1 to 0.5 Ghz) class D amplifier will be demonstrated with complex signals using GaAs PHEMTS to validate the approach. In year two, higher power, 5 GHz pulse mode amplifiers will be demonstrated with AlGaN HEMTs. Title: High Temp Epitaxial Growth of Silicon Carbide Layers & Structures PI: Marek Skowronski CARNEGIE MELLON UNIVERSITY Dept. of Metallurgical Engineering Funding Agency: Office of Naval Research PR Number: 00PR07749-00 Award Number: N000140010786 Current End Date: 30-May-2001 Scientific Officer: Colin Wood Objective: Lower dislocation densities in Bulk and epitaxial Silicon Carbide. Approach: Build and commission a high temperature furnace system for growth on porous SiC. The fulfilment of this program will depend upon DURIP capital equipment grant for second growth furnace. Title: Influence of Seed Preparation on the Quality of SiC Bulk Grown Crystals PI: Yuri Khlebnikov BANDGAP TECHNOLOGIES INC President Address: 800 N Lucas ST Apt U7 West Columbia, SC 29169 (803) 794-3125 Funding Agency: Office of Naval Research PR Number: 00PR07760-00 Award Number: N0001400C0441 Current End Date: 30-Jun-2001 Scientific Officer: Colin Wood Objective: Two order of magnitude reduction in SiC substrate threading dislocation density. Approach: Porous SiC surfaces will be used as seed crystals for sublimation (PVT) growth of bulk SiC crystal boules. Title: High Temperature Epitaxial Growth of SIC PI: Tangali Sudarshan UNIVERSITY OF SOUTH CAROLINA College of Engineering Address: Office of Research Columbia, SC 29208 (803) 777-7302 Funding Agency: Office of Naval Research PR Number: 00PR07782-00 Award Number: N000140010812 Current End Date: 31-May-2001 Scientific Officer: Colin Wood Objective: To reduce the surface topography and improve purity of epitaxial SiC semiconductor films. Approach: Modified heating elements and reactor design/control will be used to allow 300 centigrade degree increase in operating temperature with good temperature uniformity. Title: Interfacing Magnetoelectronics with Biochemistry Processes PI: Jeffrey Byers NAVAL RESEARCH LABORATORY Materials Science and Technology Address: NRL 6345 Washington, DC 203755320 (202) 767-6147 Funding Agency: Office of Naval Research PR Number: 00PR07816-00 Award Number: N0001400WR20327 Current End Date: 30-Sep-2000 Scientific Officer: Larry Cooper Objective: To develop an AFM based nanolithographic process for organizing DNA structures with nanomagnetic devices. Approach: The dip-pen method for controlling the assembly of DNA to a substrate will be developed in which DNA strands will be tethered to magnetic structures fabricated by nanolithographic processes. Title: Exploration of Digital-layer Alloys of 6.1 A Materials for Spintronic and Spinphotonic Applications PI: Bruce Mccombe NEW YORK STATE UNIVERSITY Department of Physics Address: Room 239 Fronczak Hall Buffalo, NY 14260 (716) 645-2389 Funding Agency: Office of Naval Research PR Number: 00PR07835-00 Award Number: N000140010819 Current End Date: 30-Nov-2000 Scientific Officer: Larry Cooper Objective: To develop semiconductor heterostructure materials in which Mn atoms have been inserted to generate magnetic semiconductor structures in which spin polarized carriers can be used to produce a novel spintronics technology. Approach: Thin layers of MnGa and MnSbwill be integrated into various multilayer structures involving InAs/GaSb heterojunctions and quantum wells. The bonding interactions between these heterojunctions will be studied using magneto-transport and magneto-optical experiments in order to determine the basic physical processes which affect mobility and band offsets. These studies will be utilized to optimize the materials for incorportation of thin layers of MnGa which provide magnetic properties in quantum well and in superlattice structures. These materials will be evaluated for potential use as magnetic semiconductors in spin polarized electron devices. Title: Solid-State Dynamics and Carrier Transport in Supervelocity Semiconductors PI: K. Kim NORTH CAROLINA STATE UNIVERSITY Dept. of Electrical and Computer Engineering Address: BOX 7514 Raleigh, NC 276957911 (919) 515-5229 Funding Agency: Office of Naval Research PR Number: 00PR07836-00 Award Number: N000140010801 Current End Date: 31-Dec-2002 Scientific Officer: Larry Cooper Objective: To study the basic physical processes involving electron spin dynamics in semiconductor nanostructures and develop novel device concepts based on control of spin polarized carriers. Approach: Monte Carlo based simulations of spin polarized transport in semiconductor nanostructures in the III-V semiconductor system will be carried out. Spin-flip scattering mechanisms will be investigated for various structures in which band structure engineering principles are utilized to optimize transport. Device concepts, in which external or internally generated magnetic fields are used to control flow of spin polarized currents, will be explored for use in electronic or optical applictions of nanoelectronics. Using the model of single electron quantum dots which are placed in adjacent positions, the quantum entanglement of spin wave functions will be modeled in order to explore their possible utilization in quantum computing schemes. Title: Probing Electronic Phase Segregation and Fluctuations in HTS Superconductors on the Nanometer Scale PI: Jim ECKSTEIN THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN DEPARTMENT OF PHYSICS Address: DEPARTMENT OF PHYSICS URBANA,, IL 61801 (217) 244-7709 Funding Agency: Office of Naval Research PR Number: 00PR07912-00 Award Number: N000140010802 Current End Date: 31-Dec-2000 Scientific Officer: Deborah Van Vechten Objective: The high temperature superconductors and ferroelectric materials have several unusual properties in common: high oxygen permeability, mixed valence metal ions, multiple coherent electron states, and unexpectedly high microwave loss coefficients. To test whether the former are the cause of the latter due to the formation of nm scale electronic phase inhomogeneities in response to atomic scale defects. The goal is to learn how to improve the rf properties of the materials by over an order of magnitude, an improvement that would enhance their functionality in Navy receivers. Approach: The approach is to construct a variety of samples with atomic layer by layer deposition control and study them essentially in situ with a scanning tunneling microscope that records both the primary signal and the noise on that signal and can monitor the evolution of the systematic behavior with temperature. Title: Growth and in situ Characterization of Al-Ga1N Films PI: Randall Feenstra CARNEGIE MELLON UNIVERSITY Department of Physics Address: Pittsburgh, PA 15213 (412) 268-6961 Funding Agency: Office of Naval Research PR Number: 00PR08008-00 Award Number: N000149610214 Current End Date: 30-Nov-2001 Scientific Officer: Colin Wood Objective: To optimize the growth of epitaxial films of wide bandgap semiconduc-tors, especially GaN and AlN, for Navy applications in high temperature electronics and electrooptic systems. Approach: Epitaxial layers of GaN and AlN will be grown on sapphire and SiC substrates by reactive molecular beam epitaxy using an rf-plasma nitrogen source. These films will be characterized in situ using scanning tunneling microscopy, atomic force microscopy, scanning tunneling luminescence and more conventional techniques in order to study the initial stages of growth and devise methods for improving epitaxial layer quality. Progress: Scanning tunneling microscopy and reflection high-energy electron diffraction have been used to probe and explain the four primary structures of GaN c plane surfaces. The conclusion is that MOVPE produces predominantly Ga terminaterd /polarity surfaces, whereas MBE produces predominantly the nitrogen face, with inversion domains. Title: Development of Innovative Optical Microresonator Structures for Application in UV and Violet Photodetectors PI: Arto Nurmikko BROWN UNIVERSITY Center for Advanced Materials Research Address: PO Box 1929 Providence, RI 02912 (401) 863-2869 Funding Agency: Office of Naval Research PR Number: 00PR08037-00 Award Number: N000140010835 Current End Date: 30-Jun-2001 Scientific Officer: Yoon Park Objective: To develp new design and fabrication techniques to enhance performance and powerful spectral tailoring such as required for rejection solar radiation residues for detectors and emitters. Approach: New types of microcavity structures will be fabricated. These structures will enhance the spectral isolation of those wavelengths of interest and enhance their interactions with the detector or light emitter material. Title: Multi-Color Light Emitting Diodes Based on InGaN Quantum Dots PI: Patrick Kung MP TECHNOLOGIES LLC Address: 1500 Sheridan Road, Unit 8A Wilmette, IL 60091 (847) 491-7251 Funding Agency: Office of Naval Research PR Number: 00PR08045-00 Award Number: N0001400C0455 Current End Date: 31-Jul-2003 Scientific Officer: Yoon Park Objective: To investigate the potential and determine the feasibility of InGaN quantum dots for multi-color and white LED applications, which would not require the use of phosphors. Approach: InGaN quantum dot will be used to acheive efficient light emitting devices, which can simultaneously emit different wavelengths, thus making this approach desirable for multi-color and white LEDs. ----UGGh STILL ALOT MORE!-----> 
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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:32 PM
Title: Heterojunction Devices Based on Silicon Carbide Alloyed with Germanium PI: James Kolodzey UNIVERSITY OF DELAWARE Department of Electrical Engineering Address: 77-79 East Delaware Avenue Newark, DE 19716 (302) 831-1154 Funding Agency: Office of Naval Research PR Number: 00PR08055-00 Award Number: N000140010834 Current End Date: 30-Jun-2001 Scientific Officer: John Zolper Objective: Develop SiC:Ge alloys to enable band gap engineered heterostructures in the SiC materials system. Approach: Ge will be introduced at >1 atomic percent into the SiC crystal lattice by ion implantation and during chemical vapor deposition. The existance of a new heterostructure system, analogous to SiGe, will be explored, and if successful, applied to heterostruture devices such as HBTs. Title: Investigation of Jet Vapor Deposited Silicon ONO Films at Gate Dielectrics for SiC & GaN Devices PI: James Cooper PURDUE RESEARCH FOUNDATION Electrical Engineering Address: HOVDE HALL THIRD FLOOR W. LaFayette, IN 479071021 (765) 494-3514 Funding Agency: Office of Naval Research PR Number: 00PR08056-00 Award Number: N000140010831 Current End Date: 30-Jun-2001 Scientific Officer: John Zolper Objective: Demonstrate SiC and GaN metal insulator field effect transistors using jet vapor deposited (JVD) oxynitride (ONO) films. Approach: JVD ONO films developed at Yale University will be applied to SiC (Purdue Univ) and GaN (USCB) devices to reduce surface trapping and to enable MISFETs. Title: A NEW APPROACH FOR FABRICATION AND OPTOELECTRONIC INTEGRATION OF WIDE-BANDGAP MATERIALS PI: Mohamed-Ali Hasan UNIVERSITY OF NORTH CAROLINA AT CHARLOTTE CC Cameron Applied Research Center (704) 510-6414 Funding Agency: Office of Naval Research PR Number: 00PR01179-01 Award Number: N000149810572 Current End Date: 01-Apr-2001 Scientific Officer: Colin Wood Objective: To reduce cost and effort of producing large area GaN and SiC semiconductor layer structures. Approach: Porous silicon will be used as a lateral epitaxial overgrowth (LEO) template. Progress: A major investment was made on setting up and cleaning the molecular beam epitaxy (MBE)/gas-source MBE (GS-MBE) facility for the proposed work. For 3C-SiC carbide, the deposition was carried out using two approaches. In the first, methane was used to convert porous Si into SiC. This method resulted in partial conversion but the structure remained porous. FTIR showed clear but small SiC signal. While this structure is usable for devices such as gas detectors, radiation detectors, and solarcells, it is clearly useless for devices requiring planar and multilayer structures. In the second method, trimethylsilane was used. In this case, the top portion of the porous Si structure was converted and filled with the formation of a continuous overlayer of SiC on the structure. FTIR showed a strong and well defined SiC signal. Secondary ion mass-spectrometry (SIMS) results indicated a stoichiometric SiC with very low content of oxygen (as low as in the Si substrate; possibly the SIMS resolution limit) or other contamination. However, due to the high surface area of porous Si and its exposure to air prior to growth of SiC, the oxygen signal rose abruptly in the porous portion of the SIMS profile defining the boundaries of the underlying porous layer. At the same time the SIMS count rate of Si and C decreased gradually, as expected, with increasing depth in the porous layer. The gradual decrease indicates a filling and conversion of the top portion of the porous layer. Atomic force microscopy (AFM) showed large flat terraces separated by steep and high steps. Preparations for the growth of group III-nitrides are essentially complete. A RF atomic source with modified plasma zones as well as an effusion cell for Al were purchased and installed in the system. The capability for transmission electron microscopy (TEM) including sample preparation and a dark room for film/image processing are completed. Title: COMPACT, INTEGRATED, MULTI-CHANNEL OPTICAL TIME-DELAY MODULE PI: Michael Hamilton THE BOEING COMPANY (253) 657-9031 Funding Agency: Office of Naval Research PR Number: 00PR02809-02 Award Number: N0001498C0127 Current End Date: 28-Feb-2000 Scientific Officer: Yoon Park Objective: Develop a practical, compact, high performance True TimeDelay (TTD) module that supports simultaneous multiple broadband RF beams. The module will consist of an LiNbO3 switch array interconnected to silica-on-silcon optical waveguide delay lines, have a time-delay resolution of no more than 500 picoseconds and be able to provide time delays of at least 2 nanoseconds. The throughput loss of this module is to be less than 10 dB. Approach: The concept is based on the combination of efficient, high-speed switching in a Lithium Niobate (LiNbO3) switch array, and low-loss optical waveguide delay lines formed in silica-on-silicon (SOS) integrated optical circuits. The capacity of the latter for tight-bend-radii optical waveguides, with essentially lossless and highly isolated planar optical waveguides, is the basis for high-density multi-layered true time delay (TTD) modules capable of addressing multiple antenna elements or aperture sub-arrays. Progress: A multi-channel time delay module was designed, fabricated, and tested. There are two pairs of channels incorporated in the device, with four bits of time delay in each channel. The time delays for each pair are complementary in the sense that the dual outputs are appropriate for feeding subarrays that are symmetrically placed with respect to the array center. The total delay in each channel is about 48 inches in free space. This delay is accomplished by selecting appropriate lengths of optical fiber that are binary-related in length. Access to the fibers is by an integrated array lithium niobate directional coupler switches. All switches for all channels are incorporated in a common integrated optical substrate. Including fiber connector losses, the excess optical loss for the various delays ranged between 5.8-7.5 dB. The design was motivated by a desire to provide true-time-delay steering at the subarray level for a very-large, very-wideband phased array. Title: Modification of Semiconductor Materials Growth with X-ray Standing Wavefields PI: Richard Matyi THE BOARD OF REGENTS OF THE UNIVERSITY OF WISCONSIN (608) 263-1716 Funding Agency: Office of Naval Research PR Number: 00PR02819-00 Award Number: N000149910741 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: PI will attempt to grow epitaxially perfect Si films on arbitrary substrates. Approach: PI will use synchrotron radiation to produce a 2 dimensional standing wave matrix. He will use the associated electric field to influence the deposition geometries and crystal quality of Si epitaxial films on arbitrary (SiO2) substrates without regard to lattice parameter match or chemical interactions. Progress: A precision manipulator suitable for maintaining X-ray standing wave conditions during CVD growth has been designed and is under construction. All components to this UHV-compatible system have been ordered. Tungsten hexafluoride and disilane have been selected as model systems for proof-of-principle experiments. The X-ray source for this work is in transit and is scheduled for installation during the first week of November, 1999. Both plane-wave monochromator and Bone-Hart interferometer approaches are being examined for suitability in establishing the required XSW wavefield. Title: Program on Spintronics: Electronically and Photonically -controlled Magnetism in Semiconductors PI: Nitin Samarth THE PENNSYLVANIA STATE UNIVERSITY Department of Physics (814) 863-0136 Funding Agency: Office of Naval Research PR Number: 00PR03141-02 Award Number: N000149911093 Current End Date: 30-Sep-2004 Scientific Officer: Larry Cooper Objective: To prepare various III-V and II-VI semiconductor heterostructure materials and to explore their properties for spin polarized transport in support of novel spintronic device development. Approach: MBE will be used to grow thin film heterostructures of various ZnMnSe/ZnSe /MnSb/MnSe thicknesses, with optimized lattice matches. The Manganese doping will be vaired to obtain optimum transition temperatures for the ferromagnetic semi-conductors. Optical and transport measurements will be carried out to determine the properties of optically injected magnetism and to observe the effects on transport of external fields. Contact studies will be carried out to determine the effects of interface scattering on spin injection efficiency. Other materials, such as InMnAs/InAs/ MnAs/MnSe, will be incorporated as well. Exchange pinning will be explored in these magnetic semiconductor materials to determine if antiferromagnetic pinniing layers can be developed for all semiconductor spin valve devices. Progress: Nanoscale patterning of quantum wires into ZnSe/Zn(Cd,Mn)Se quantum well films has resulted in magnetic quantum wire structures. Photoluminescence spectroscopy measurements have been used to explore the carrier and exciton dependent properties of such structures as a function of wire width and magnetic field. The PL intensity is affected by wire width and is explained as due to a combination of strain relaxation effects on splitting of heavy hole and light hole bands. Other effects include spin flip scattering at surfaces which increases as the width decreases. An important conclusion is that the sp-d exchange splitting in such magnetic systems is not affected by the size reduction. These experiments indicate that quantum wires may be useful in magneto-electronic device concepts where magnetism controls the carrier transport, exciton dynamics and polarization properties of devices. Title: Solid State Terahertz Source for Sensing and Satellite Communication PI: James Allen THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Quantum Institute (805) 893-3982 Funding Agency: Office of Naval Research PR Number: 00PR03311-01 Award Number: N000149910935 Current End Date: 30-Jun-2003 Scientific Officer: Larry Cooper Objective: To develop semiconductor superlattice and related multiquantum well structures which produce Terahertz radiation with milliwatts of power for applications in sensing and satellite communication. Approach: Semiconductor superlattice structures will be grown using various III-V materials, including GaAs/AlGaAs and InAs/GaSb/AlSb. Device modeling procedures will be used to calculate expected performance and assist in the design of the desired structures. Quasi-optic arrays of such devices will be designed and modeled in order to optimize terahertz emission. Device-device interactions must be incorporated in the design. Quasi-optic arrays, incorporated in appropriate cavity structures, will be modeled. Of particular importance is developing the methods for supporting and stabilizing a uniform field. A microwave driven terahertz oscillator will be tested and subharmonic locking will be explored by harmonic mixing in a Schottky detector. Progress: Circuit simulations have been carried out to determine the best design for stabilizing the electric field in the superlattice using sidewall shunts. Appropriate dimensions have been extracted. Experiments on GaAs/AlGaAs superlattices for frequencies from 120 Ghz to 2.5 Thz have been made and the modeling analysis indicates the critical nature of the contact resistance for the quasi optic array. Title: Synthesis of P-type ZnO Films & p-n PI: Henry White UNIVERSITY OF MISSOURI COLUMBIA Dept of Physics & Astronomy (573) 882-3625 Funding Agency: Office of Naval Research PR Number: 00PR03564-01 Award Number: N000149910288 Current End Date: 31-Jul-2000 Scientific Officer: Yoon Park Objective: The primary goal of this program is to grow and characterize high quality p-type and n-type ZnO films with high carrier concentrations on single crystal substrates, and to fabricate p-n junctions. Secondary goals are the development of materials processing for bandgap modulation, and the development of optical devices such as LEDs and laser diodes. The suitability of several growth techniques to obtain ZnO films with high optical quality and low defect density will be explored. Approach: P-type ZnO films will be grown. Films will be characterized by x-ray, Hall probe, photoluminescence, and atomic force microscopy. The technique used for growth will be developed further and several enhancements and other approaches will be explored. Pulsed laser deposition using ZnO targets will be used to create Zn, O and ZnO molecules as a precursors to film formation. The impact of oxygen plasma environments on the growth of ZnO film will be investigated. MBE techniques will also be employed for ZnO film growth. Progress: Pulsed laser deposition is being used for growth of p-type ZnO for use in laser and light emitting diodes and other devices. A p-n junction was fabricated. A new vacuum growth chamber was constructed to improve p-type doping. Title: RAPID PROTOTYPING OF INTEGRAL POWER SOURCES AND DEVICES USING INK-JET PRINTING PI: Subash Narang SRI INTERNATIONAL Polymer Chemistry and Technology Dept. (650) 859-2119 Funding Agency: Office of Naval Research PR Number: 00PR04031-01 Award Number: N0001498C0172 Current End Date: 21-Jun-2000 Scientific Officer: Colin Wood Objective: Program will develop rapid prototyping of passive electronic circuit elements. Approach: Conventional ink jet printing process will be modified for higher resolution and flexibility of deposition medium. Progress: The PI has demonstrated outstanding advances and progress toward the goal of ink jet and screen printing, and maskless patterning printing of passive components from data driven application software, and hardware.The deposition of precursors containing metals, ceramics, and polymers has surpassed resolution and deposition speeds. Title: Solid State Terahertz Sources PI: G. Haddad THE REGENTS OF THE UNIVERSITY OF MICHIGAN Dept. of Electrical Engineering (313) 863-6678 Funding Agency: Office of Naval Research PR Number: 00PR04186-01 Award Number: N000149910915 Current End Date: 19-Jun-2003 Scientific Officer: John Zolper Objective: To develop waveguides, high Q components, and active solid-state devices operating in the THz region of the electromagnetic spectrum. Approach: Micromachining technology will be used to develop low loss waveguides and high-Q filters for application to electronic systems operating from 0.3 to 10 THz. GaN Gunn diodes will be developed as solid state sources of electromagnetic radiation from 0.3 THz and above. Progress: Transient hydrodynamic simulations were carried out in order to evaluate the large-signal properties of the GaN oscillators by harmonic analysis. The results showed that GaN NDR devices offer at least twice the frequency capability of their GaAs -based counterparts while their output power is of the order of 10'5W/cm2 which is two orders of magnitude higher. Experimental investigations of MOCVD growth of n+ GaN/n GaN /n+ GaN NDR structures using variable n GaN layer doping and thickness have been carried out. Following optimization of the individual layers of this structure the complete structure was grown and satisfactory optical and structuralcharacteristics results were obtained. The processes needed to batch fabricate these elements are also being developed. During the past 2 months the design, fabrication and experimental characterization of micromachined waveguide to FGC transitions in Ka band has been compeleted. These transitions have a loss of 0.4 dB per transition and a return loss better than 12 dB over the entire Ka bandwidth. Title: Direct Writing Cicuit Elements for a Credit Card GPS by MAPLE DW for the DARPA MICE Program PI: Michael Duignan POTOMAC PHOTONICS (202) 459-3031 Funding Agency: Office of Naval Research PR Number: 00PR04204-00 Award Number: N0001499C0236 Current End Date: 30-May-2003 Scientific Officer: Colin Wood Objective: The NRL technology for direct writing of prototype (rapid) circuits will be tech transfered to Potomac Photonics. Approach: The process consists of laser ablation of a rapidly moving powder loaded tape. The stage holding the sample substrate is precision moved to allow direct writing of passive and some active electronic components on any matrix at extremely low temperatures. Title: Multimaterial Integration by Laser Driven Liquid Phase Epitaxy PI: Daniel Ehrlich REVISE INC. (781) 272-9888 Funding Agency: Office of Naval Research PR Number: 00PR04209-00 Award Number: N0001499C0265 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: PI will develop red LEDs on Si for free space, and chip-bus communications. Approach: PI will use laser-driven epitaxy with high spatial resolution on Si substrates for GaN, and InGaN semiconductor film growth. Title: Hierarchical CAD Tools & Thermoelectric Fluidic Devices for Active Refrigeration & Control of Thermo Integrated Circuits (Arctic) PI: Andrzej Przekwas CFD RESEARCH CORP (256) 726-4806 Funding Agency: Office of Naval Research PR Number: 00PR04211-00 Award Number: N0001499C0196 Current End Date: 10-Aug-2002 Scientific Officer: Colin Wood Objective: To increase the current capability to remove waste heat from circuits and devices. Approach: Using CAD designed devices, thermo-electric and fluidic principles will be used to maximize heat removal from integrated circuits and devices. Devices will have effective monolithically integrated thermoelectric cooling components. Fluids will be engineered to circulate, and remove heat from the back and front of ICs, by evaporation and condensation, and power devices, more efficiency than is current 'state of the art' technology. Title: Integrated Thermal Management Using Laminate and Ceramic-MEMS Technologies PI: William Jones FLORIDA INTERNATIONAL UNIVERSITY Mehanical Engineering (305) 348-2345 Funding Agency: Office of Naval Research PR Number: 00PR04217-00 Award Number: N000149910480 Current End Date: 31-Mar-2002 Scientific Officer: Colin Wood Objective: To maximize power capability of military electronics systems, by active removal of waste electrically generated heat. Approach: By integrating micro-electro-mechanical operators directly with integrated circuits and power devices, fluid flow can be moved rapidly and efficiently past surfaces extremely close to hot spot regions of electronic components. Together with state of the art ceramic substrates, heat removal from power devices and monolithic circuits is expected to be increased by an order of magnitude compared to present state of the art. Title: EDIFICE: Embedded Droplet Impingement for Integrated Cooling of Electronics PI: Cristina Amon CARNEGIE MELLON UNIVERSITY Institute for Complex Engineered (412) 268-3651 Funding Agency: Office of Naval Research PR Number: 00PR04218-00 Award Number: N000149910481 Current End Date: 31-Mar-2002 Scientific Officer: Colin Wood Objective: To improve noise, power, and efficiency performance of electronic circuits and systems. Approach: The PIs at Carnegie Melon University will develop models, theories, and technologies for circuits and devices with monolithically integrated fluid - phase change coolers. The cooling will be programed to operate in localized regions of the circuits, and 'on-demand' by on-chip/carrier control circuitry. Micro mechanical machining and manufacturing techniques will also be developed. Title: Mesoscale Integrated Conformal Electronics PI: Marcelino Essien OPTOMEC DESIGN COMPANY (505) 761-8250 Funding Agency: Office of Naval Research PR Number: 00PR04252-01 Award Number: N0001499C0243 Current End Date: 30-Mar-2003 Scientific Officer: Colin Wood Objective: To develop a commercial tool for rapid prototyping of electronic circuits. The demonstration vehicle is a GPS receiver on a credit-card-size substrate. Approach: PI and his collaborators will use fine focus laser beam to direct dry particles from independent jet dispensers. They will be directed down hollow glass optical fibers, which will entrain the particles by virtue of the high laser beam-generated electric field. The outlet end of the optical particle guide fiber is directed at a mechanial precision movement stage which will allow writing of patterns and components such as dielectrics, metals and thin film battery components. Title: Direct Writing Circuit Elements for a Credit Card GPS by MAPLE DW PI: D. Chrisey NAVAL RESEARCH LABORATORY Division of Condensed Matter and Radiation (202) 767-4800 Funding Agency: Office of Naval Research PR Number: 00PR04570-00 Award Number: N0001400WR20251 Current End Date: 30-Sep-2000 Scientific Officer: Colin Wood Objective: To direct write (without mask) a fully functional credit card sized GPS receiver. Approach: The PI will use a focused laser to ablate the required passive and active elements onto a resistive substrate from a supply tape. The tape is loaded with dry powder material and condences on the substrate with very high resolution ~10 microns. Title: Seven-Segment Organic Polymer Based Light-Emitting Devices on Plastic PI: Jerzy Kaniki THE REGENTS OF THE UNIVERSITY OF MICHIGAN Department of Electrical and Computer Science (734) 936-2122 Funding Agency: Office of Naval Research PR Number: 00PR04574-00 Award Number: N000149910958 Current End Date: 14-Jul-2001 Scientific Officer: Colin Wood Objective: Organic alpha-numeric LED components will be developed for flexible, conformal displays. Approach: Organic alpha-numeric light emitting diodes will be developed by attention to the chemical composition, preparation and emission behaviour of the conducting phosphor, and the transparent, flexible contact materials such as ITO. Title: AlxGa1-xN for Solar-Blind Focal Plane PI: Manijeh Razeghi NORTHWESTERN UNIVERSITY Department of Electrical Engineering & Computer Science (847) 491-7251 Funding Agency: Office of Naval Research PR Number: 00PR04577-01 Award Number: N000149910016 Current End Date: 31-Dec-2001 Scientific Officer: Yoon Park Objective: To develop the AlGaN material technology for low dark current, high solar blindness ultraviolet(UV) photodetector focal plane arrays(FPAs). A major goal is to strive toward defect-free AlGaN. Approach: Various III-V nitride alloys will be grown by MOCVD for detection of UV in the spectral range of 250-300nm. Back side illumination will be employed to increase a high fill factor and to be compatible with In bump bonding technology to Silicon based read-out circuitry. In this program novel growth methods such as lateral epitaxyal overgrwoth (LEO) that can allow defect-free growth of GaN nearly independent of substrate will be pursued. Progress: Wide bandgap AlxGa1-xN semiconductors were grown on Al2O3 substrate by MOCVD for the entire compositional range (0 Title: Solar Blind Detector Array Program PI: Bruce Baran LOCKHEED MARTIN CORPORATION IR Imaging Systems (781) 863-3574 Funding Agency: Office of Naval Research PR Number: 00PR04579-00 Award Number: N0001499C0138 Current End Date: 09-May-2002 Scientific Officer: Yoon Park Objective: The goal of this program is to develop the technologies necessary to produce AlGaN photodetectors which are suitable for vehicle self-protection systems. The application requires UV focal plane arrays which are capable of counting photons. Approach: A consortium consisting of Lockheed Martin, Epitronics, Emcore and University consultants will be formed. The contractor will attack issuses involved in materials, device design and systems engineering in developing the vehicle self-production technology. Low noise Avalanche Photodiodes, with internal gain, will be developed. All devices fabricated to date have noise characteristics many orders of magnitude away from established needs. Issues to improve gain and noise will be addressed in this program. The program will address issues such as (1) improvement of material quality, (2) development of low damage etch processes and (3) design and development of an ultra-low noise readout structure. A 128 x 128 AlGaN focal plane array will be fabricated. Title: Ultrathin Solarblind Silicon Photodetectors PI: Steven Brueck REGENTS OF THE UNIVERSITY OF NEW MEXICO Electrical Engr. & Computer Engr. (505) 272-7800 Funding Agency: Office of Naval Research PR Number: 00PR04580-00 Award Number: N000149910660 Current End Date: 30-Apr-2001 Scientific Officer: Yoon Park Objective: To evaluate, both theoretically and experimentally, the potential of ultra-thin (~5 to 20-nm thick) Si films for deep ultraviolet detectors. Approach: Nanostructuring of the Si films offers a potential advantage of that which will be investigated. The approach to use commercially available silicon-on-insulator (SOI) materials with ~200 nm thick Si layers and further thin the active region by controlled oxidation. Both bonded and etch-back (BESOI) and ion implanted (SIMOX) wafers will be investigated. Initial experiments will concentrate on metal-semiconductor-metal (MSM) detector configurations because of their ease of fabrication and and top-surface-only access requirements. Progress: A first set of metal-semiconductor-metal detectors both on bulk Si and 50-nm thick silicon-on-insulator (SOI) materials has been made. As expected, preliminary characterization at both 364 nm and 633 nm shows a significant decrease of the red response for the SOI detectors without impacting the UV response. Title: Novel Approaches to III-V Nitride Solar Blind Photodetectors for Vehicle Self-Protection Technologies PI: Russell Dupuis THE UNIVERSITY OF TEXAS AT AUSTIN Microelectronics Research Center (512) 471-0537 Funding Agency: Office of Naval Research PR Number: 00PR04583-01 Award Number: N000149910231 Current End Date: 31-Dec-2001 Scientific Officer: Yoon Park Objective: The demonstration of solar blind Resonant Cavity-Avalanche Photodiodes(RC-APD) operating at wavelengths shorter than 290 nm, where the greatest interest for military and space-based application exists. Approach: The use of AlGaN heterostructures to fabricate p-i-n detectors with transparent windows for improved performance will be explored. The processing technology to fabricate mesa-isolated AlGaN p-i-n photodiodes will be developed. This includes the design of specialized photolithography mask sets incorporating a wide variety of device structures including photodetectors, test diodes, and arrays. Device simulations employing optimized UV solar-blind APD design will also be conducted. Title: Surface Engineering of Field Emitter Cathodes for Field Emitter Displays PI: Akintunde Akinwande MASSACHUSETTS INSTITUTE OF TECHNOLOGY (617) 258-7974 Funding Agency: Office of Naval Research PR Number: 00PR04586-00 Award Number: N000149610802 Current End Date: 30-Apr-2001 Scientific Officer: Colin Wood Objective: Seeks to improve efficiency and uniformity of cathode arrays for flat panel displays. Approach: Use of rare earth hexaboride and other coatings to reduce work functions and integrate focusing electrode and current limiting resistors with cathode tip arrays. Use of novel scanning Maxwell Stress microscope will give nanometer scale resolved information on NEA surface behaviour. Progress: A fully integrated electron emission and electron trajectory simulation program in 3D that uses boundary element method has been demonstrated. Models were verified with experimental data for both electron emission and spot size on the phosphor screen. The results are significant because this allows the prediction of spot size as a function of device geometry. Simulation of the Moly cone deposition process has been demon-strated. The input parameters to the simulation program are beam collimation, parting layer thickness and bevel angle. Title: Models, Sensors, and Controls for E Beam Deposition PI: Jonathan Storer MINNESOTA MINING AND MANUFACTURING COMPANY 3M Metal Matrix Composites Program (651) 733-6462 Funding Agency: Office of Naval Research PR Number: 00PR04594-00 Award Number: N000149830015 Current End Date: 31-Jan-2001 Scientific Officer: Deborah Van Vechten Objective: To develop the mathematical and physical tools required to build a well functioning, production scale, e-beam evaporation based deposition system to fabricate YBCO as a tape product on an underlying IBAD deposited buffer layer of MgO. The base program develops the individualcomponents and the option to be negotiated in fy00 will intergrate them into a fully functional system. YBCO has properties inherently better suited to magnet and power applications than the BSCCO materials that have been developed in extruded wire form. Thus if a manufacturable technology for kilometer lengths of highly oriented YBCO tape can be developed, it may come to dominate the large scale applications. In the naval arena, these include mine sweeping and electric propulsion, plus energy storage for pulsed power applications including catapult launchers and power conditioning. Approach: To develop a vertically integrated team which combines development work in universities (CalTech, Cornell, Illinois, Michigan, Stanford, and the Courant Institute), LLNL, and small companies on critical components with a large company interested in combining them into a manufacturing technology. Include improvement of real time process monitors and develop new techniques to quantitatively interpret the measurement results in real time. Optimize the integration of the several monitors into a single package which is consistent with the underlying physics and thereby achieve process control. Progress: A technical review meeting was held at 3M in Nov 99 where all program elements reported good progress, especially the RHEED modeling and in situ YBCO composition control. The MgO growth modeling revealed that the interaction of the ions with island nucleation must be included for the physics to be correct. Actual installation of reel to reel hardware at 3M is proceeding rapidly. It is not yet clear which textured substrate method nor which YBCO growth method is to be preferred. Title: SENSORS AND MODELS FOR E-BEAM DEPOSITION PI: KEN WESTERBERG U S DEPARTMENT OF ENERGY OAKLAND OPERATIONS OFFICE Lawrence Livermore National Laboratory (510) 442-9890 Funding Agency: Office of Naval Research PR Number: 00PR04595-00 Award Number: N0001498F0420 Current End Date: 01-Oct-2000 Scientific Officer: Anna Tsao Objective: To design and demonstrate an atomic absorption, laser based, real time sensor for an optically thick species, namely copper, being evaporated by an e-beam source. The goal is to develop a method of achieving excellent compositional control of YBCO for continuous tape development and power applications. Approach: Upgrade and utilize an existing 15 kW Temescal rod fed e-beam source to produce a high evaporation rate source of copper. Develop a deposition rate controller based on 325 nm laser light and the group velocity delay, atomic absorption technique originated at LLNL. Improve the MELT code which simulates evaporation by customizing it to the case of copper being heated with a time shared e-beam source. Collaborators include Stanford, Cornell, and 3M. Progress: The existing version of the MELT simulation package has been successfully tested against data from 3M on the Ti-Al-V material system. Model modifications required for use with Y and Cu rod is well advanced.The collaboration with Stanford on the Cu vapor sensor is determining the signal to noise ratio of the group velocity delay. Calulations of plume evolution and interaction has begun but is not yet at realistic (for commercial systems) deposition rates. Title: Development of Low-loss Tunable Dielectric Based on Oxide Thin Film Technology by Reactive Evaporation PI: Vladimir Matijasevic CONDUCTUS (408) 523-9487 Funding Agency: Office of Naval Research PR Number: 00PR04601-01 Award Number: N0001498C0287 Current End Date: 31-Mar-2001 Scientific Officer: Deborah Van Vechten Objective: To develop deposition technology that provides a factor of 10 improvement in the figure of merit of voltage tunable ferroelectric materials. This should be sufficient to provide 5% center frequency tuning of sharp skirted filters having Q's in excess of 10,000 and correspondingly low insertion losses. Such filters should be applied on alarge scale in the front end of naval rf systems. The option period would demonstrate the applicability of such tuned filter devices in a beam forming network suitable for use on a low-earth-orbit communications satellite. Approach: To develop the reactive co-evaporation deposition (sequential source MBE) technique to deposit a wide range of titanate thin films and experimentally determine which have the better characteristics when it comes to the figure of merit (delta dielectric const/epsilon tan delta) and intermodulation products. Correlate structural properties to losses and design, build, and test high performance tunable microwave devices using the improved materials. Progress: Design efforts to prove that current quality STO is adequate to electromagnetically trim a Q=10,000 filter have been successful in 2 pole designs and are being extended to additional poles. The reactive coevaporation chamber has been brought back on line and produced films >5x smoother than PLD made films and with compatible microwave properties. Efforts to establish real time compositional control have begun. Title: NEW FABRICATION METHODS FOR SUB-100 nm FEATURE-SIZE DEVICES USING THIN IMAGING LAYERS AND LOW ENERGY ELECTRON BEAMS PI: Harold Craighead CORNELL UNIVERSITY School of Applied and Engineering Physics (607) 255-8707 Funding Agency: Office of Naval Research PR Number: 00PR04771-00 Award Number: N000149810377 Current End Date: 28-Feb-2001 Scientific Officer: John Zolper Objective: To develop practical techniques for fabricating electronic devices with feature sizes less than 100 nm. Approach: A low energy (1 keV) electron beam will be used for exposure. This beam is produced by a microcolumn which is small enough that large arrays can be used to form a practical exposure tool. Various candidate resist materials will be evaluated including self-assembled monolayers and top-surface imaging polymeric layers. All parameters of the exposure process will be evaluated experimentally and theoretically. Prototype devices will be fabricated and tested. Progress: During this period, electron-beam patterning of 3-aminopropyltriethoxysilane (APTS) was studied. In the present study amine functionalized monolayers were patterned with various electron beam energies and doses. The study indicated that these monolayers are very sensitive to low energy (1-2 keV) electrons. At higher energies (>5 keV) the backscattered or secondary electrons destroy the amine group in the unexposed regions. Selective deposition of other materials for use as robust etch masks will be explored in the next period. Studies on charge induced pattern distortions showed that the charge induced pattern distortion is negligible in low energy electron beam lithography proces-sing of patterns using thin resist on high conductivity substrates such as Si or insulating substrates coated with conducing layers. On the other hand, patterns exposed in thin resist on insulating substrates show significant pattern placement error and pattern distortion at electron beam energies > 2keV. At 1 keV the distortion is comparatively smaller. In the future, studies will be performed on the charging effect in multilayer top surface imaging resists and also other bilayer resist used for low energy electron beam lithography. Title: ADVANCED SILICON PHOTONICS PI: Bahram Jalali THE REGENTS OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES Electrical Engineering Department (310) 825-9655 Funding Agency: Office of Naval Research PR Number: 00PR04873-00 Award Number: N000149510675 Current End Date: 30-Sep-2000 Scientific Officer: Yoon Park Objective: To develop an affordable receiver subsystem for application in dense wavelength division multiplexed (WDM) networks. This will be accomplished by leveraging the mature and low cost silicon substrate and processing technology. The goal is to focus on demonstration of 2.5 Gbit fiber optic front-end ICs in commercial CMOS technology. Approach: The proposed receiver consists of high resolution optical wavelength demultiplexers, long-wavelength photodetectors and low-power CMOS electronics, all integrated on a silicon-on-insulator(SOI) wafer. Ultra-high bit rate incoming signals are optically demultiplexed on-chip,using Mach-Zehnder waveguide interferometers which feed the light directly into integrated photodetectors. Electronics processing is performed at moderate speed using conventional CMOS circuits. Progress: This research program is to develop the process for fabricating 1-D photonic bandgap structures on silicon-on-insulator(SOI) wafers. This involves defining and etching structures with 0.1um width and 0.2um pitch. The SNR-200 e-beam resist was used to develop an e-beam process for defining the structure. With this process periodic structures as low as 0.3um were sucessfully defined. It was decided that it will be difficult to achieve this feature with less than 0.3um with the SNR resist. Title: Design & Diagnostic Tool for Manufacturing of Advanced Nanoscale Layered Materials PI: W Butler U S DEPARTMENT OF ENERGY OAK RIDGE OPERATIONS OFFICE Metals & Ceramics Division (423) 574-4845 Funding Agency: Office of Naval Research PR Number: 00PR04885-00 Award Number: N0001499F0205 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To develop computer simulation methods and codes for use in the design of thin film magnetic films and the control of vapor phase deposition techniques associated with those materials. Approach: Ab initio theory techniques, such as the Locally Scalable Multiple Scattering theory, will be used to calculate the properties of various materials, properties such as electronic and magnetic structure. Methods will be considered which will allow for more efficient calculations, for use by experimental design of Giant Magnetoresistive thin films. Spin polarized transport of carriers in multilayer films will be addressed using the Boltzmann equation with the further refinement of scattering-in terms. Interfacial properties, such as roughness, will be included in the analysis. A model will be developed for the nonlocal frequency dependent conductivity of these layered materials. This computational module will be used in evaluating ellipsometric data taken on the growing films, for the ultimate purpose of determining in real time control parameters for film optimization. All of the work will be carried out in close coordination with Cambridge Hydrodynamics Corp. which is providing overall program direction and management of the experimental program. Progress: Calculations have been completed for the band structure of various ferromagnetic metal/semiconductor/ferromagnetic metal sandwich structures and the transport properties indicated for spin dependent quantum tunneling. It is shown that majority and minority electrons from the metals tunnel through different parts of the E vs. k space, i.e., the Brouilloin zone. Title: Atomic Scale Characterization and Optimization of Interface Structure in 6.1 A. III-V Based Resonant Tunneling Devices Fabricated by Molecular Beam Epitaxy PI: Lloyd Whitman NAVAL RESEARCH LABORATORY Chemistry Division (202) 404-8845 Funding Agency: Office of Naval Research PR Number: 00PR05279-00 Award Number: N0001400WR20271 Current End Date: 31-Mar-2001 Scientific Officer: Larry Cooper Objective: To use in-situ characterization techniques in the development of optimized growth procedures for the MBE growth of III-V semiconductor materials for applications in Resonant Tunneling Devices. Approach: The growth of InAs/AlSb/GaSb heterojunction materials will be optimized in the MBE system by coupling in-situ STM and RHEED measurements in the growth chamber. Issues of interface roughness, such as islanding and interface diffusion will be monitored and used to optimize growth conditions, such as substrate temperature and flux concentrations. RTD devices will be fabricated and tested to correlate optimized device performance with the interfacial properties of thin films. Information will be exchanged with Hughes Research Labs and other members of the DARPA VIP program. Progress: STM measurements on the growth of AlSb and GaSb heteroepitaxial layers have been made for a variety of temperature and III/V flux rates. There is very strong evidence for the formation of novel (4x3) reconstructions on the III-Sb (001) surfaces which dominate the nucleation and growth. There are complex arrangements of Al dimers on these surfaces which determine formation of islands. Ab-initio calculations for the various reconstructions are in excellent agreement with both the morphology as well as STM images for empty and filled states. Title: Interfacial Transport Properties of Thin Film Magnetic Multilayers PI: Robert Buhrman CORNELL UNIVERSITY School of Applied & Engineering Physics (607) 255-3732 Funding Agency: Office of Naval Research PR Number: 00PR05553-00 Award Number: N000149610849 Current End Date: 31-Dec-2000 Scientific Officer: Larry Cooper Objective: To understand the physical mechanisms involved in the transport of spin polarized electrons in magnetic multilayer materials and to correlate these with the atomic scale properties of various materials combinations in support of advanced device development. Approach: Unique nanocontact experiments will be made to understnd the transport of spin polarized electrons across a variety of metal multilayer interfaces. GMR materials will be prepared and electron spectroscopies used to understand spin flip scattering at interfaces. High resolution STEM will be used to characterize the magnetic and chemical properties of these materials on scales of 1 nanometer. Strain will be measured in these interfaces. BEEM experiments will be carried out to understand the high energy transport in consideration of possible applications of magnetic devices coupled with silicon electronics. Progress: Probes of the domain structure in iron films from the nanocontact transport indicate that the high current densities of the probe current is able to rotate the domains. Title: Virtual Integrated Prototyping for Epitaxial Growth Phase III: Control of Interface Morphology in III-V PI: Jennifer Zinck HRL LABORATORIES LLC (310) 317-5913 Funding Agency: Office of Naval Research PR Number: 00PR05554-00 Award Number: N0001498C0325 Current End Date: 22-Feb-2002 Scientific Officer: Larry Cooper Objective: To develop process modeling software which can be applied to the controlled MBE growth of semiconductor heterojunction materials for implementation as resonant tunneling devices. Approach: Modeling programs will be developed which simulate epitaxial growth in MBE systems for InAs/AlSb semiconductor films. Sensors such as Photoelectron Emission Oscillations and RHEED will be developed and modeled in describing the properties of the growing films, such as chemical stoichiometry, roughness, island size, etc. The simulation of RTD behavior will be coupled with the parameters defining the epitaxial material quality. The growth of epitaxial layers will be modeled using the MBE system parameters, such as growth rate, substrate temperature, nature of the chemical interface, etc. All phases of the system will then be incorporated into an overall system which controls actuators, such as temperature controllers, shutters, and substrate rotation. STM experiments will be used to validate the morphology models. A software bundle will be demonstrated which can optimize the growth of designed materials for implementing Resonant Tunneling Devices. Progress: The first version of the control system algorithms for the MBE system have been developed and used to simulate the growth of InAs/GaSb films by correlating the RHEED signal with control of the group III element. It is shown that control of effective layer by layer growth will be possible through this closed loop control process. The RHEED envelope decay rate is directly associated with the group III flux. The Photoemission Oscillation technique has been evaluated by developing a theoretical model of the oscillations due to effects such as interface roughness, bond types and anion-cation interdiffusion. The results are in agreement with STM measurements for various surface reconstructions present on the growing surface. Title: Design and Diagnostic Tool for Manufacturing of Advanced Nanoscale Layered PI: Steven Orzag CAMBRIDGE HYDRODYNAMICS INCORPORATED TCOD (609) 683-1515 Funding Agency: Office of Naval Research PR Number: 00PR05571-00 Award Number: N0001498C0318 Current End Date: 14-Mar-2001 Scientific Officer: Anna Tsao Objective: In order to expedite the development of materials for GMR MRAM applications, the manufacturing capability for thin magnetic film materials will be established through development of simulation methods coupled with control systems integrated together for designing and developing a growth and characterization facility. Approach: GMR materials design will be established through implementation of ab initio theories of such materials, optimized to maximize GMR effect. The modeling of the growth of such films based on molecular dynamics simulations will be pursued in parallel. Once the studies have led to optimized parameters, a growth system will be designed, This system will incorporate various in-situ sensors which will provide characterization data to be used by a control system for implementing the optimized manufacturing environment. The modeling will then be used as the basis for building a growth chamber for such materials. Progress: Modeling of the transport in the GMR films has been developed including interface roughness as atomic scattering terms. The transmission coefficients for minority and majority carriers in the metal layers can then be calculated. One major result which emphsizes the importance of complex band structure, is that a Co impurity atom in copper has a much weaker scattering cross section for majority carriers than for minority carriers by a factor of 40. Density Functional Theory methods have been developed for exploring the effects of surfactant atoms at the growth interface to modulate growth modes. Results indicate that surfactants can control growth on certain facets of the growing metal films. An experimental development indicates that low energy ion beams can affect the morphological growth of the films by biasing the target and providing a separate ion flux in Ion Beam Deposition systems. ------MORE-----> 
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Alpha-Theta
Superior

ª×µ»ƒ³²² 694 posts, May 2002
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posted 06-07-2002 02:33 PM
Title: Low Voltage Modulators Based on Semiconductor Microresonators PI: P. Dapkus UNIVERSITY OF SOUTHERN CALIFORNIA Dept Contracts & Grants (213) 740-4414 Funding Agency: Office of Naval Research PR Number: 00PR05955-00 Award Number: N0001400C0292 Current End Date: 14-Jun-2003 Scientific Officer: Yoon Park Objective: To demonstrate ultralow voltage optical modulators based on optoelectronic interactions enhanced by modulation near a resonance of a high Q optical resonator for application to radio frequency light wave circuits. Approach: The low voltage modulators will be optimized for operation at 1.55 um at modulation frequencies up to 20 GHz. The use of the resonator to enhance the electro- absorption, electro-refraction and electro-optic effects in semiconductors has the potential to reduce the voltage level required for full signal modulation to less than 0.1 V with low insertion loss. Resonator-coupled modulator configurations with tailored transfer characterics will be examined to provide modulators with the required linearity. Title: Microphotonic RF Receiver Components PI: Anthony Levi UNIVERSITY OF SOUTHERN CALIFORNIA Electrical Engineering Department (213) 740-7318 Funding Agency: Office of Naval Research PR Number: 00PR05956-00 Award Number: N000140010458 Current End Date: 31-Mar-2004 Scientific Officer: Yoon Park Objective: To development a new class of photonic components which enable efficient RF-to-optical receivers for advanced wireless communication and front-end antenna applications. Approach: The base technology to be developed makes use of small disk-shaped optical resonators fabricated in LiNbO3. These microphotonicresonator components can be configured for direct RF-to-optical conversion and for electrically tunable microphotonic filter components for optical signal processing. Title: High Q and Voltage Tunable Dielectric Films by MOCVD for Phased Array Radar PI: Sandwip Dey ARIZONA STATE UNIVERSITY Dept. of Chemical Bio. & Materials (602) 965-7493 Funding Agency: Office of Naval Research PR Number: 00PR06009-00 Award Number: N000140010471 Current End Date: 30-Dec-2001 Scientific Officer: Deborah Van Vechten Objective: To determine if liquid source injection MOCVD is a cost-effective way of fabricating low loss, thick films of novel ferroelectric materials for use in phase shifters at frequencies up to 20 GHz. Approach: Use sol-gel techniques to determine best composition from list supplied by E. Cross, use LSI-MOCVD to fabricate films on buffered Si wafers, measure and optimize micro-structural and microwave properties, transition to industry. Title: Terahertz Detection Based on Photon-Assisted Tunneling in Double Quantum PI: Dennis Olona U S DEPARTMENT OF ENERGY ALBUQUERQUE OPERATIONS OFFICE Laboratory PRograms Division (925) 294-3794 Funding Agency: Office of Naval Research PR Number: 00PR06236-01 Award Number: N0001499F0416 Current End Date: 31-Jul-2002 Scientific Officer: Edgar Martinez Objective: To develop a long wave-length far infrared photodetector based on photon assisted tunneling in a quantum well structure, responding at frequencies from 0.3 to 10 Terahertz. Approach: A 2D-2D double quantum well semiconductor device will be fabricated using molecular beam epitaxy techniques. Contacts will be arranged so that each quantum well can be contacted separately. Barrier thicknesses and carrier mobility will be varied and optimized. Bowtie antenna coupled photodetectors will be designed and fabricated. Photon assisted tunneling processes will be investigated theoretically for analyzing detector response and to assist in design. Measurements of response will be implemented using organic gas lasers and the Free Electron Laser at University of California at Santa Barbara. Progress: Designs for the bowtie antennas coupled to the double quantum well devices were completed and masks fabricated. Devices were made and tested in DC mode and then tested with the FEL radiation at UC Santa Barbara. The DC characteristics were very good, showing tunable response with the back and front gate voltage control. Under FEL radiation, the characteristics are broadened, which is attributed to electron heating by applied fields. New designs are being attempted which will avoid this heating problem. Title: Program on Spintronics: Electronically and Photonically Controlled Magnetism in Semiconductors PI: Chris Palmstrom UNIVERSITY OF MINNESOTA Department of Chemical Engineering and Materials Science (612) 625-7558 Funding Agency: Office of Naval Research PR Number: 00PR06414-01 Award Number: N000149911005 Current End Date: 30-Sep-2004 Scientific Officer: Larry Cooper Objective: To develop the materials and growth processes for forming ferromagnetic contacts to magnetic semiconductors and to provide the basis for spintronics devices. Approach: Various materials will be developed in MBE processing which form contacts to the III-V semiconductors and to Mn doped semiconductors. Lattice matched ferromagnetic contacts will be devised using interfacial layers to modulate the strain. Ferromagnetic metals, Heusler alloys and Mn based III-V materials will be used as contacts. STM and AFM measurements will be used to probe the atomic structure of the layers in order to determine optimum growth conditions. Progress: Ni(2)MnGa and Fe(x)Co(1-x) films have been grown successfully on GaAs. Both films are ferromagnetic with critical temperatures above room temperature. Pseudomorphic growth occurs when either ScErAs and NiGa interlayers are prepared for the overgrowth. It is shown that the GaAs surface orientation controls the magnetic anisotropy of the films. Title: Program on Spintronics: Electronically and Photonically Controlled Magnetism in Semiconductors PI: Sankar Das Sarma UNIVERSITY OF MARYLAND AT COLLEGE PARK Departmentt of Physics (301) 405-6145 Funding Agency: Office of Naval Research PR Number: 00PR06415-01 Award Number: N000149911095 Current End Date: 30-Sep-2004 Scientific Officer: Larry Cooper Objective: To develop an understanding of the transport of spin polarized carriers in magnetic semiconductor films and heterostructures using theoretical methods. Approach: Theoretical methods for spin polarized electron and hole transport will be applied to the III-V based semiconductor films and heterostructures in which manganese doping has modified the band structure and the basic interactions between charges and ions. Band structure calculations will provide appropriate parameters for exploring such inter-actions and to describe the effects of band mismatch, orbital differences across inter-faces, and to determine scattering processes. Of basic concern is the issue of spin coupling across the interface between the ferromagnetic semiconductor and a paramag-netic semiconductor. Understanding of spin dynamics at interfaces is crucial to the development of many potential device applications. Progress: A quantitative theory of spin polarized transport across a semiconductor-superconductor interface has been developed. The transport phenomena demonstrates the Andreev reflection effect. The results indicate the strength of this method for measuring the spin polarization strength of the transmitted current. Title: DNA Directed Assembly of Semiconductor Quantum Dots PI: D. Awschalom THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Quantum Institute (805) 893-2121 Funding Agency: Office of Naval Research PR Number: 00PR06424-00 Award Number: N000149910728 Current End Date: 30-Apr-2001 Scientific Officer: Larry Cooper Objective: To explore the properties of semiconductor nanocrystals attached to DNA strands for possible implementation in computing architectures. Approach: Semiconductor nanocrystals will be formed using colloidal chemistry techniques. Strands of DNA will be used as templates for attaching the nanocrystals in regular order and spacing on the strands. Time dependent near field optical spectroscopies will be used to inject spin polarized carriers in these crystals and to explore the time dependence of the spin states and the transport from dot to dot. Progress: Pump-probe experiments have been performed on semiconductor nanocrystals embedded in a glass matrix. Coherence and spin-dependent nonlinear effects resulting from the optical Stark effect are observed. Shifts are dependent on the relative polarizations of the optical pulses. Nanocrystal development continues in which procedures for producing water soluble, bio-compatible quantum dots of various sizes. Other procedures for binding DNA to particle surfaces are also in development, and simple patterns of nanocrystals are being formed using DNA. Title: Spintronics: Physics & Devices Based on InAs/A1Sb/GaSb Heterojunctions & Compatible Magnetic Materials PI: Thomas McGill CALIFORNIA INSTITUTE OF TECHNOLOGY Department of Applied Physics (626) 395-4849 Funding Agency: Office of Naval Research PR Number: 00PR06486-00 Award Number: N000149911006 Current End Date: 31-Jul-2002 Scientific Officer: Larry Cooper Objective: To develop semiconductor materials and device structures to exploit the potential of controled electron spin transport for novel electronic and optical devices. Approach: Thin film materials based on the InAs/GaSb/AlSb semiconductor system will be grown according to designs provided by theoretical models of quantum devices. Manganese will be incorporated into these materials to generate ferromagnetic properties in the semiconductors. Materials will be grown in a MBE system such that contamination and oxide formation can be eliminated. A separate metalization chamber will be used to provide ferromagnetic contact to the semiconductor structures. In-situ and ex-situ characterization techniques of wide variety will be used to assure controlled properties of the materials. Computer simulation and theory will be used to design appropriate heterostructures for exploiting spin transport. Electric field effects at interfaces will be explored to measure their effects on spin orbit coupling terms to provide spin splitting. The Rashba effect will also be studied. Various device structures will be formed and measured. Polarized light emission will be used to determine the spin injection process across interfaces. Three terminal devices will be fabricated and the injection and transport of spin polarized carriers between contacts will be determined. Control of the spin carriers will be done by applied external electric and magnetic fields. Progress: Deposition of Ni and Fe on InAs has been explored but according to xray analysis, there is no epitaxy for thin films. For thicker films there is evidence of NiAs and InNi compounds at the interface. Simulations of the band structure of AlSb/GaSb/InAs/AlSb heterostructures have been calculated and have led to predictions of the spin splitting due to the Rashba effect with Rashba coefficients calculated to be 38 x 10(10) eV.cm. This term is due to the spin-orbit interaction and the asymmetry of the structure. Title: Advanced Lasers and Detector Integrated System (ALADINS) PI: Manijeh Razeghi NORTHWESTERN UNIVERSITY Department of Electrical Engineering & Computer Science (847) 491-7251 Funding Agency: Office of Naval Research PR Number: 00PR06573-00 Award Number: N000140010590 Current End Date: 30-Apr-2004 Scientific Officer: Yoon Park Objective: To demonstrate low threshold continuous wave edge emitting AlGaInN based UV-blue lasers operating in the 365 to 450 nm range. Efficient AlGaInN based photodetectors operating in the same spectral bandwidth and a simple demonstration system will also be demonstrated to validate the technology developed. Approach: A simple demonstration system integrating a UV-blue AlGaInN laser and photodetector will be first designed, then actually built and tested in an effort to evaluate the technology developed for these devices, and provide a basis for future more sophisticated systems. Title: Blue and UV Lasers Formed by Selected Area Growth PI: P. Dapkus UNIVERSITY OF SOUTHERN CALIFORNIA Dept Contracts & Grants (213) 740-4414 Funding Agency: Office of Naval Research PR Number: 00PR06577-00 Award Number: N000140010591 Current End Date: 30-Apr-2004 Scientific Officer: Yoon Park Objective: To employ selective area epitaxial growth techniques to the fabrication of high performance blue and UV lasers in AlGaN/GaN/InGaN material system. To demonstrate: blue and UV BH InGaN/GaN/AlGaN lasers, low threshold lasers with integrated mirrors, nanostructure active region lasers formedby block copolymer nanolithography, and phase coupled laser arrays for high brightness blue and UV sources. Approach: Selective area growth techniques in combination with lateral epitaxial overgrowth will be used to reduce the dislocation density of active regions of edge emitting lasers in this system. Selective area growth of dislocation free mesas will be used to form more perfect optical waveguides and mirrors by utilizing the natural facets that form during the growth along certain orientations of the crystal. Facet-dependent incorporation of In will be used to form a buried heterostructure without growth interruption. Title: Program on Spintronics:Electronically and Photonically controlled Magnetism in Semiconductors PI: Stephan Von Molnar FLORIDA STATE UNIVERSITY Department of Physics (850) 644-2246 Funding Agency: Office of Naval Research PR Number: 00PR06585-01 Award Number: N000149911094 Current End Date: 30-Sep-2004 Scientific Officer: Larry Cooper Objective: To develop magnetic contacts of EuGdS on III-V semiconductor films for implementation of spin injection into magnetoelectronic devices. Approach: EuGdS films will be prepared on III-V semiconductors to provide injection and detector contacts for spin controlled electronic and optical devices. Subbandgap light will be used to inject carriers at the interface to remove the Schottky barriers and enhance the spin injection. Low temperatures will be used, in order to remain below the ferromagnetic transition temperature of these materials. Progress: EuS films are being grown in a metal/EuS/superconductor junction configuration to test the filter effect of the EuS of electron spin transport. Magneto transport measurements have been made on CrO(2) films grown on TiO(2) and positive magnetoresistance results interpreted in terms of magnetic scattering as a function of temperature. More recently, CrO(2) small grain single crystals have been grown epitaxially on GaSb and are shown to be ferromagnetic. Title: Program on Spintronics: Electronically and Photonically-controlled Magnetism in Semiconductors PI: D. Awschalom THE REGENTS OF THE UNIVERSITY OF CALIFORNIA SANTA BARBARA Quantum Institute (805) 893-2121 Funding Agency: Office of Naval Research PR Number: 00PR06586-02 Award Number: N000149911096 Current End Date: 29-Sep-2004 Scientific Officer: Larry Cooper Objective: Semiconductor materials will be developed and the phenomena associated with spin polarized carriers can be explored and exploited for possible applications in electronics and optics. Approach: Various compounds of the III-V semiconductors alloyed with Manganese have demonstrated magnetic properties. Epitaxial methods will be used to produce such materials in thin film and heterostructure forms. Optical and electronic injection of spin polarized carriers will be shown and used to explore the transport and lifetime effects in these materials. This effort will be a focal point for a multi-faceted program of materials science, physical characterization, theoretical descriptions, and device exploration. Ultrafast and magnetic field controlled phenomena will be investigated for possible applications in optics and electronics. Progress: Efficient transport of spin polarized electrons has been observed in a ZnSe-GaAs heterojunction. The experiment demonstrates that spin information can be transmitted across a heterojunction barrier and that recombination times are long for such systems. Title: Infrared Laser Sources Based on Quantum PI: Dennis Deppe THE UNIVERSITY OF TEXAS AT AUSTIN Microelectronics Resource Center (512) 471-4960 Funding Agency: Office of Naval Research PR Number: 00PR06596-00 Award Number: N000140010651 Current End Date: 30-Apr-2004 Scientific Officer: Yoon Park Objective: To develop infrared light sources based on quantum dots(QDs). They include development of low threshold QD infrared laser/light sources operating in the 10 um to 20 um wavelength range based on the cascaded emission from InGaAs QDs. Approach: The infrared light sources in the 10 to 20 um range will be accomplished through shape-engineering of InAs and InGaAS QDs to control discreet energy level separation. Title: Flexible, Polymer, Electrostatic Actuator for Valves and Relays PI: Scott Goodwin-Johansson MCNC (919) 248-1964 Funding Agency: Office of Naval Research PR Number: 00PR06604-00 Award Number: N0001499C0237 Current End Date: 31-May-2001 Scientific Officer: Colin Wood Objective: PI will develop polymer remote valves for fluidic applications in corrosive or unfriendly environments. The valve will consist of a flap and seat. Both flap and seat will contain one electrode of an electrostatic pair. Operation will be by application of voltage across the two electrodes, and vice versa. Approach: The valve will consist of a polymer flap and seat. Both flap and seat will contain one electrode of an electrostatic pair. Operation will be by application of voltage across the two electrodes, and vice versa. Title: Spatial Spectral Functions Based on Fiber-Coupled High-Q Silica Microsphere PI: Kerry Vahala CALIFORNIA INSTITUTE OF TECHNOLOGY Dept. of Appied Physics (818) 395-2144 Funding Agency: Office of Naval Research PR Number: 00PR06615-00 Award Number: N000140010650 Current End Date: 30-Apr-2004 Scientific Officer: Yoon Park Objective: To develop a taper-coupled microsphere (TCM) laser to be used in a sensor system and transmission system. Approach: A rare earth doped microsphere is coupled to a fiber taper and pumped optically through the taper to achieve lasing action. Lasing power can then be coupled conveniently through the same fiber taper used to pump the spherical gain medium. With an erbium-doped sphere, the pumping could occur either at 980 nm or at 1480 nm, both wavelengths for which pigtailed pump diodes are available. Title: Thermal Spraying of Meso Electronic Multi Layers and Sensors PI: Sanjay Sampath THE RESEARCH FOUNDATION OF THE STATE UNIVERSITY OF NEW YORK AT STONY BROOK Center for Thermal Spray Research (516) 632-9512 Funding Agency: Office of Naval Research PR Number: 00PR06760-00 Award Number: N000140010654 Current End Date: 30-May-2003 Scientific Officer: Colin Wood Objective: Rapid prototyping of circuit elements, and boards. Approach: Thermal spray process (plasma assisted). Title: A 3D Stacked Smart Multispectral Imaging System Using Heterogenous Integration of Independently Optimized IR and UV Detector Materials with Si CMOS Circuitry PI: Nan Marie Jokerst GEORGIA TECH APPLIED RESEARCH CORPORATION GEORGIA INSTITUTE OF TECHNOLOGY (404) 894-8911 Funding Agency: Office of Naval Research PR Number: 00PR06762-00 Award Number: N000149910974 Current End Date: 14-Jul-2001 Scientific Officer: Colin Wood Objective: To create a monolithic technology for UV, IR staring array, and Si CMOS control circuitry. Approach: Integration will be achieved through wafer fusion (careful surface preparation/polishing, and ultra-clean contact bonding) of selectively lifted off circuits/arrays on common substrate. Title: Integration of High Powered, Wideband-Gap Microwave Devices with Data Processing Circuits on a Single Chip PI: Thomas McGill CALIFORNIA INSTITUTE OF TECHNOLOGY Department of Applied Physics (626) 395-4849 Funding Agency: Office of Naval Research PR Number: 00PR06765-00 Award Number: N000149910972 Current End Date: 14-Apr-2001 Scientific Officer: Colin Wood Objectiv | |