A5008672841- Semiconductor Quantum Structures and Devices
- Radio Frequency Integrated Circuit Design
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor materials and devices
- GaN-based semiconductor devices and materials
- Photonic and Optical Devices
- Advanced Semiconductor Detectors and Materials
- Semiconductor Lasers and Optical Devices
- Microwave Engineering and Waveguides
- Ga2O3 and related materials
- Quantum and electron transport phenomena
- Semiconductor materials and interfaces
- Silicon Carbide Semiconductor Technologies
- Advanced Photonic Communication Systems
- Integrated Circuits and Semiconductor Failure Analysis
- Nanowire Synthesis and Applications
- Acoustic Wave Resonator Technologies
- Superconducting and THz Device Technology
- Advanced Power Amplifier Design
- ZnO doping and properties
- Microwave and Dielectric Measurement Techniques
- Electronic and Structural Properties of Oxides
- Physics of Superconductivity and Magnetism
- Chalcogenide Semiconductor Thin Films
- Ferroelectric and Negative Capacitance Devices
ETH Zurich
2015-2024
École Polytechnique Fédérale de Lausanne
2006-2014
Board of the Swiss Federal Institutes of Technology
2011
Simon Fraser University
1999-2009
University of California, Santa Barbara
1991-2005
Burnaby Hospital
2003
Nortel (Canada)
1994-1995
Technical University of Munich
1993-1994
Carleton University
1990
We report 55-nm gate AlInN/GaN high-electron-mobility transistors (HEMTs) featuring a short-circuit current gain cutoff frequency of fT = 205 GHz at room temperature, new record for GaN-based HEMTs. The devices source maximum density 2.3 A/mm V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</sub> 0 and show measured transconductance 575 mS/mm, which is the highest value reported to date nonrecessed nitride Comparison state-of-the-art...
We report a new generation of high-performance AlGaN/GaN high-electron-mobility transistors (HEMTs) grown on high-resistivity Si (111) substrates. map out small- and large-signal device performances against technological parameters such as the gate length source-drain contact separation. first performance for GaN-on-Si technology offering an output power 2 W/mm associated peak power-added efficiency 13.8% (peak 18.5%) at 40 GHz without any field plate. The offers measured transconductances...
We report MOCVD-grown NpN InP/GaAsSb/InP abrupt double heterojunction bipolar transistors (DHBTs) with simultaneous values of f/sub T/ and MAX/ as high 300 GHz for J/sub C/=410 kA/cm/sup 2/ at V/sub CE/=1.8 V. The devices maintain outstanding dynamic performances over a wide range biases including the saturation mode. In this material system p+ GaAsSb base conduction band edge lies 0.10-0.15 eV above InP collector band, thus favoring use nongraded base-collector designs without current...
Small-signal equivalent circuit (SSEC) models prove indispensable to a broad range of activities, ranging from the understanding device physics, analysis performance, characterization and comparison fabrication processes, bottom-up construction large-signal models, extraction intrinsic noise parameters, design monolithic microwave integrated circuits (MMICs). Because SSEC model links physical structure its behavior, it allows performance as function geometry. A physically representative can...
We report a new InP/GaAsSb double heterojunction bipolar transistor (DHBT) emitter fin architecture with record <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f}_{\mathrm {MAX}} =1.2$ </tex-math></inline-formula> THz, simultaneous {T}} =475$ GHz, and notation="LaTeX">$BV_{\mathrm {CEO}} =5.4$ V. The resulting {CEO}}\,\times \,{f}_{\mathrm =6.48$ THz-V is unparalleled in semiconductor technology. Devices...
We present a study of interface roughness scattering in not-intentionally-doped AlSb/InAs/AlSb quantum wells grown by molecular beam epitaxy on [001] GaAs semi-insulating substrates. The low-temperature mobility is found to be limited for well widths below 100 Å. measured mobilities are accounted Gold’s theoretical treatment [A. Gold, Phys. Rev. B 35, 723 (1987)], once it suitably modified account the band nonparabolicity InAs. experimental electron density dependence indicates lateral...
We report the fabrication and characterization of 30-nm-gate fully passivated AlInN/GaN high-electron mobility transistors (HEMTs) with cutoff frequencies <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> xmlns:xlink="http://www.w3.org/1999/xlink">MAX</sub> simultaneously exceeding 200 GHz at a given bias point. The current gain frequency does not vary significantly for 2.5 <;...
We report the first 94-GHz (W-band) large-signal performance of AlInN/GaN high-electron-mobility transistors (HEMTs) grown on high-resistivity silicon (111) substrates. A maximum output power density 1.35 W/mm and peak power-added-efficiency 12% are measured at 94 GHz. The devices exhibit a dc current drain 1.6 A/mm transconductance 650 mS/mm. In small-signal operation, cutoff frequencies f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub>...
We demonstrate high-speed InAs/AlSb-based heterostructure field-effect transistors (HFET's) displaying greatly improved charge control properties and enhanced high-frequency gate performance. Microwave devices with a 0.5×84 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> exhibit peak unity current gain cut-off frequency of f <sub xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> =93 GHz. The HFET usable operational range was extended...
AlGaN/GaN high-electron mobility transistor "hot" parasitic source and drain resistances R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S,D</sub> are determined under operating biases through wideband S-parameter measurements, without the use of "ColdFET" biasing conditions. Both xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> found to increase dramatically over ColdFET values, both for...
Grown on a (111) high-resistivity silicon substrate, 0.1-mum gate AlInN/GaN high-electron mobility transistors (HEMTs) achieve maximum current density of 1.3 A/mm, an extrinsic transconductance 330 mS/mm, and peak gain cutoff frequency as high f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> = 102 GHz, which is the highest value reported so far for nitride-based devices substrates, well any AlInN/GaN-based HEMT regardless substrate...
We report high-speed fully passivated deep submicrometer (Al,Ga)N/GaN high-electron mobility transistors (HEMTs) grown on (111) high-resistivity silicon with current gain cutoff frequencies of as high f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> = 107 GHz and maximum oscillation reaching xmlns:xlink="http://www.w3.org/1999/xlink">MAX</sub> 150 GHz. Together, these are the highest values achieved for GaN-based HEMTs implemented...
The development of InP/GaAsSb DHBTs is reviewed and contextualized with respect to other III-V high-speed technologies. Pertinent material properties challenges in the proper assessment f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Max</sub> are discussed. An iterative de-embedding algorithm involving no additional test structures/measurements shown yield correct fMAx from unilateral gain data for both HEMTs.
We report on the physical operation and performance of MOCVD-grown abrupt heterojunction InP/GaAs/sub 0.51/Sb/sub 0.49//InP double bipolar transistors (DHBTs). In particular, effect InP collector thickness breakdown voltage current gain cutoff frequency is assessed a f/sub T/ 106 GHz reported for DHBT with 400 /spl Aring/ base 2000 BV/sub CEO/ 8 V. show that InP/GaAsSb/InP DHBTs are characterized by weak variation as function temperature. Finally, we also demonstrate high maximum oscillation...
The authors report the fabrication and temperature-dependent characterization of InAs/AlSb quantum-well heterojunction field-effect transistors (HFETs). Devices with electron sheet concentrations 3.8*10/sup 12/ cm/sup -2/ low-field mobilities 21000 2//V-s have been realized through use Te delta -doping sheets in upper AlSb barrier. One device a 2.0- mu m gate length showed peak extrinsic transconductance 473 mS/mm at room temperature. Gate leakage current, operating current density, were...
The realization of high-performance 0.1-mum gate AlGaN/GaN high-electron mobility transistors (HEMTs) grown on high-resistivity silicon substrates is reported. Our devices feature cutoff frequencies as high f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> = 75 GHz and xmlns:xlink="http://www.w3.org/1999/xlink">MAX</sub> 125 GHz, the highest values reported so far for HEMTs silicon. microwave noise performance competitive with results...
We study the performance of staggered lineup NpN InP/GaAsSb/InP abrupt double heterojunction bipolar transistors (DHBTs) intended for ultrahigh speed applications. With a peak fT 305 GHz (and fMAX=300 GHz), DHBTs are currently fastest ever implemented, and as such may challenge sub-100 nm gate InP HEMTs > 40 Gb/s applications: previously published criteria suggest current device should be suitable 80–100 OEICs. feature high breakdown voltages low offset knee voltages, extremely drive levels...
We report on ultrahigh-speed 80 nm AlInN/GaN high-electron-mobility transistors (HEMTs) grown (111) high-resistivity silicon substrates. The devices feature a peak measured transconductance gM = 415 mS/mm, maximum current of 1.43 A/mm with ratio ION/IOFF > 106, and gain oscillation cutoff frequencies fT 143 GHz fMAX 176 GHz, which are the highest ever achieved for any GaN HEMTs results demonstrate outstanding potential low-cost high-performance millimeter-wave electronics.
We report the large-signal performance of high electron mobility transistors (HEMTs) fabricated on GaN- and AlN-capped AlInN/GaN epilayers grown semi-insulating SiC substrates. Large-signal measurements at 10 40 GHz are presented with both gate drain dynamic loadlines to clarify factors limiting high-power performance. Devices show a marginal advantage in terms higher current reduced dispersion, but GaN-capped perform better short-channel effects channel control. In operation GHz, device...
We present the results of a systematic study low-field electron transport as function well width for InAs/AlSb quantum wells grown on nominally [100]-oriented, GaAs semi-insulating substrates. Both room-temperature and low-temperature mobilities are significantly reduced in narrow due to dominance interface roughness scattering. The mobility peaks widths around 125 Å, then decays again, most probably onset scattering by misfit dislocations nucleated exceeds critical layer thickness imposed...
While current collapse affects AlGaN∕GaN heterojunction field-effect transistors (HFETs) around room temperature, it gradually gives place to a enhancement with cooling—below 200K, electrically stressed devices do show higher currents than in their prestressed state. This behavior can be explained by increased levels of channel impact ionization at lower temperatures. The positive hole charge generated compensates (and eventually dominates) the parasitic negative that is responsible for...