The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Stephen E. Saddow - One of the best experts on this subject based on the ideXlab platform.
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Optical Control of Microwave-Integrated Circuits Using High-Speed Gaas and Si Photoconductive Switches
IEEE Transactions on Microwave Theory and Techniques, 1995Co-Authors: Stephen E. Saddow, Chi H. LeeAbstract:An optoelectronic attenuator suitable for the optical control of microwave-integrated circuits is presented. High-speed photoconductive switches are embedded in planar microwave transmission lines fabricated on both semi-insulating Gaas and high-resistivity silicon substrates, and a fiber pigtailed semiconductor laser diode is used to control the microwave signal level on these high-speed lines. Forty-five dB of microwave attenuation was demonstrated with a silicon coplanar waveguide-photoconductive switch, while up to 8.5 dB of attenuation was achieved with a Gaas Device. In addition, the optically induced phase delay through the silicon Device was observed to be as large as 180°. The microwave performance of these photoconductive Devices has been fully characterized and their suitability for various optical control applications compared. So that one can optimize the laser diode/Gaas photoconductive Device interaction, the Gaas Device has been characterized as a function of laser photon energy, switch temperature, and applied dc electric field, and the optimum operating point has been determined through experiment
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Optical control of microwave-integrated circuits using high-speed Gaas and Si photoconductive switches
IEEE Transactions on Microwave Theory and Techniques, 1995Co-Authors: Stephen E. SaddowAbstract:An optoelectronic attenuator suitable for the optical control of microwave-integrated circuits is presented. High-speed photoconductive switches are embedded in planar microwave transmission lines fabricated on both semi-insulating Gaas and high-resistivity silicon substrates, and a fiber pigtailed semiconductor laser diode is used to control the microwave signal level on these high-speed lines. Forty-five dB of microwave attenuation was demonstrated with a silicon coplanar waveguide-photoconductive switch, while up to 8.5 dB of attenuation was achieved with a Gaas Device. In addition, the optically induced phase delay through the silicon Device was observed to be as large as 180/spl deg/. The microwave performance of these photoconductive Devices has been fully characterized and their suitability for various optical control applications compared. So that one can optimize the laser diode/Gaas photoconductive Device interaction, the Gaas Device has been characterized as a function of laser photon energy, switch temperature, and applied dc electric field, and the optimum operating point has been determined through experiment.
Chi H. Lee - One of the best experts on this subject based on the ideXlab platform.
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Optical Control of Microwave-Integrated Circuits Using High-Speed Gaas and Si Photoconductive Switches
IEEE Transactions on Microwave Theory and Techniques, 1995Co-Authors: Stephen E. Saddow, Chi H. LeeAbstract:An optoelectronic attenuator suitable for the optical control of microwave-integrated circuits is presented. High-speed photoconductive switches are embedded in planar microwave transmission lines fabricated on both semi-insulating Gaas and high-resistivity silicon substrates, and a fiber pigtailed semiconductor laser diode is used to control the microwave signal level on these high-speed lines. Forty-five dB of microwave attenuation was demonstrated with a silicon coplanar waveguide-photoconductive switch, while up to 8.5 dB of attenuation was achieved with a Gaas Device. In addition, the optically induced phase delay through the silicon Device was observed to be as large as 180°. The microwave performance of these photoconductive Devices has been fully characterized and their suitability for various optical control applications compared. So that one can optimize the laser diode/Gaas photoconductive Device interaction, the Gaas Device has been characterized as a function of laser photon energy, switch temperature, and applied dc electric field, and the optimum operating point has been determined through experiment
Y. Crosnier - One of the best experts on this subject based on the ideXlab platform.
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(Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P barrier layer grown by gas source molecular beam epitaxy for V-band (Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P/In/sub 0.2/Ga/sub 0.8/As/Gaas power pseudomorphic HEMT
Conference Proceedings. 2000 International Conference on Indium Phosphide and Related Materials (Cat. No.00CH37107), 2000Co-Authors: Mohammed Zaknoune, O. Schuler, F. Mollot, Xavier Wallart, D. Théron, Stphane Piotrowicz, Y. CrosnierAbstract:In this paper, we report the design, fabrication and for the first time power characterization in V-band of (Al,Ga)InP/InGaas/Gaas power Pseudomorphic High Electron Mobility Transistors grown by Gas Source Molecular Beam Epitaxy. The GaInP/InGaas/Gaas, AlGaInP/InGaas/Gaas, AlInP/InGaas/Gaas Pseudomorphic HEMT structures have been studied from the point of view of the growth as well as the technological process. For the three barrier materials, 0.1/spl times/100-/spl mu/m/sup 2/ T-gate Devices were characterized in small signal and large signal conditions at 60 GHz. The best of them, the single side doped GaInP/InGaas/Gaas structure exhibit an impressive current density of 780 mA/mm, a transconductance of 700 mS/mm and a cut-off frequency of 120 GHz. Power characterizations have been performed at 60 GHz. The Ga/sub 0.5/In/sub 0.5/P/In/sub 0.2/Ga/sub 0.8/As/Gaas Device has demonstrated a maximum output power density of 560 mW/mm.
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(AlxGa1-x)0.5In0.5P barrier layer grown by gas source molecular beam epitaxy for V-band (Al xGa1-x)0.5In0.5P/In0.2 Ga0.8As/Gaas power pseudomorphic HEMT
Indium Phosphide and Related Materials, 2000. Conference Proceedings. 2000 International Conference on, 2000Co-Authors: Mohammed Zaknoune, O. Schuler, F. Mollot, Xavier Wallart, D. Théron, Stphane Piotrowicz, Y. CrosnierAbstract:In this paper, we report the design, fabrication and for the first time power characterization in V-band of (Al,Ga)InP/InGaas/Gaas power Pseudomorphic High Electron Mobility Transistors grown by Gas Source Molecular Beam Epitaxy. The GaInP/InGaas/Gaas, AlGaInP/InGaas/Gaas, AlInP/InGaas/Gaas Pseudomorphic HEMT structures have been studied from the point of view of the growth as well as the technological process. For the three barrier materials, 0.1×100-μm2 T-gate Devices were characterized in small signal and large signal conditions at 60 GHz. The best of them, the single side doped GaInP/InGaas/Gaas structure exhibit an impressive current density of 780 mA/mm, a transconductance of 700 mS/mm and a cut-off frequency of 120 GHz. Power characterizations have been performed at 60 GHz. The Ga0.5In 0.5P/In0.2Ga0.8As/Gaas Device has demonstrated a maximum output power density of 560 mW/mm
S.p. Denbaars - One of the best experts on this subject based on the ideXlab platform.
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Improved composition and thickness control of III-V epitaxy in a metalorganic chemical vapor deposition process
Proceedings of 1995 34th IEEE Conference on Decision and Control, 1995Co-Authors: R.s. Smith, A.l. Holmes, C.m. Reaves, S.p. DenbaarsAbstract:Metalorganic chemical vapor deposition (MOCVD) is a promising technology for the fabrication of high speed electronic and opto-electronic Devices. Commercial application of this technique is limited by a high degree of process variance. This paper describes work in progress on the development of a closed loop MOCVD facility for Gaas Device fabrication. Critical system disturbances, which degrade the growth rate uniformity and reproducibility, and subsequent Device performance, are identified. A control system is designed and implemented to regulate the supply of gallium to the reactor. The controller performance is investigated by growing GaInAs/InP superlattices. Post-growth tests clearly illustrate that the compensated samples have better precision in alloy composition and thickness.
R. F. Kopf - One of the best experts on this subject based on the ideXlab platform.
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Low-temperature dry etching of tungsten, dielectric, and trilevel resist layers on Gaas
Plasma Chemistry and Plasma Processing, 1994Co-Authors: S J Pearton, C. R. Abernathy, J. R. Lothian, R. F. KopfAbstract:Dry etching of common masking materials used in Gaas Device technology, was examined down to temperatures of −30°C. The etch rates of SiN_x, SiO_2, and W in SF_6/Ar are reduced below 0°C, but the anisotropy of the etching is improved at low temperature. Microwave enhancement of the SF_6/Ar discharges produces increases in etch rates of several times at 25°C, but much lower increases at −30°C substrate temperature. The underlying Gaas surface shows increased S and F coverage after low-temperature etching, but these species are readily removerd either by an ex-situ wet chemical cleaning step or an in-situ H_2 plasma exposure. Photoresist etching is less sensitive to temperature, and anisotropic profiles are produced between −30 and +60°C in pure O_2 discharges.
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High Density Magnetically Confined Dry Etching of Metallization and Dielectrics in Gaas Device Technology
MRS Proceedings, 1994Co-Authors: Stephen J. Pearton, C. R. Abernathy, J. R. Lothian, R. F. Kopf, A. KatzAbstract:ABSTRACTDry etching of common masking materials used in Gaas Device technology was examined down to temperatures of −30°C. The etch rates of SiNx, SiO2 and W in SF6/Ar are reduced below 0°C, but the anisotropy of the etching is improved at low temperature. Microwave enhancement of the SF6/Ar discharges produces increases in etch rates of several times at 25°C, but much lower increases at −30°C substrate temperature. The underlying Gaas surface shows increased S and F coverage after low temperature etching, but these species are readily removed either by an ex-situ wet chemical cleaning step or an in-situ H2 plasma exposure. Photoresist etching is less sensitive to temperature and anisotropic profiles are produced between −30 and + 60°C in pure 02 discharges.
