R. Gaška

Sensor Electronic Technology (United States)

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M. S. Shur

Rensselaer Polytechnic Institute

389

G. Simin

University of South Carolina

152

Jinwei Yang

Anhui Medical University

145

X. Hu

Guangxi University

M. Asif Khan

Northumbria University

ГТ

Г. Тамулайтис

Vilnius University

M. Shatalov

Minsk Regional Institute of Education Development

Jianping Zhang

Chinese Academy of Sciences

AŽ

A. Žukauskas

Vilnius University

Nezih Pala

Florida International University

Cooperative Institutions

University of South Carolina

Rensselaer Polytechnic Institute

Vilnius University

Sensor Electronic Technology (United States)

Centre National de la Recherche Scientifique

Russian Academy of Sciences

Sensors (United States)

Physico-Technical Institute

DEVCOM Army Research Laboratory

University of California, Santa Barbara

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AlGaN/GaN metal–oxide–semiconductor heterostructure field-effect transistors on SiC substrates

Applied Physics Letters (2000)

M. Asif Khan X. Hu Ahmad Tarakji G. Simin J. Yang

We report on AlGaN/GaN metal–oxide–semiconductor heterostructure field-effect transistors (MOS-HFETs) grown over insulating 4H–SiC substrates. We demonstrate that the dc and microwave performance of the MOS-HFETs is superior to that of conventional AlGaN/GaN HFETs, which points to the high quality of SiO2/AlGaN heterointerface. The MOS-HFETs could operate at positive gate biases as high as +10 V that doubles the channel current as compared to conventional AlGaN/GaN HFETs of a similar design. The gate leakage current was more than six orders of magnitude smaller than that for the conventional AlGaN/GaN HFETs. The MOS-HFETs exhibited stable operation at elevated temperatures up to 300 °C with excellent pinch-off characteristics. These results clearly establish the potential of using AlGaN/GaN MOS-HFET approach for high power microwave and switching devices.

Wide-bandgap semiconductor

10.1063/1.1290269

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Citations (348)

5-TERMINAL THz GaN BASED TRANSISTOR WITH FIELD- AND SPACE-CHARGE CONTROL ELECTRODES

Selected topics in electornics and systems (2009)

G. Simin M. S. Shur R. Gaška

Charge control

10.1142/9789814287876_0002

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Citations (0)

Internal quantum efficiency in AlGaN with strong carrier localization

Applied Physics Letters (2012)

J. Mickevičius Г. Тамулайтис M. S. Shur M. Shatalov Jinwei Yang

The emission efficiency droop and internal quantum efficiency (IQE) in AlGaN epilayers and heterostructures were investigated by studying photoluminescence intensity dependence on excitation power density at different temperatures in the range from 8 to 300 K in three AlGaN samples with similar Al content (33%-35%) and different strength of carrier localization: an epilayer and multiple quantum wells with well widths of 5.0 and 2.5 nm. It is shown that the phenomena leading to the efficiency droop strongly influence the photoluminescence intensity dependence on temperature and, therefore, affect the estimation of IQE based on this dependence. A procedure to optimize the determination of IQE is proposed.

Quantum Efficiency

Wide-bandgap semiconductor

Intensity

Emission intensity

Power density

10.1063/1.4767657

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Citations (55)

Enhanced Power and Breakdown in III-N RF Switches With a Slow Gate

IEEE Electron Device Letters (2011)

A. Sattu J. Deng Daniel Billingsley Jinwei Yang M. S. Shur

We show that III-nitride radio-frequency switches with a composite slow/fast gate have higher maximum switching power and breakdown voltage compared with conventional switches of the same type. The composite gate design includes an additional “slow gate” electrode formed under the metal gate using a low-conducting InGaN layer. The “slow gate” covers the entire source-drain spacing. The addition of the “slow gate” layer not only offers a lower insertion loss and higher isolation but, as shown in this letter, also increases the power handling capability by “delaying” switch self-modulation under high-power stress. We also show that, the “slow gate” design increases breakdown voltage.

Metal gate

Gate driver

Switching time

Modulation (music)

10.1109/led.2011.2126557

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Citations (2)

High Magnetic Field Studies of AlGaN/GaN Heterostructures Grown on Bulk GaN, SiC, and Sapphire Substrates

MRS Proceedings (2000)

W. Knap E. Borovitskaya M. S. Shur R. Gaška G. Karczewski

Cyclotron resonance

Electron cyclotron resonance

Landau quantization

Shubnikov–de Haas effect

10.1557/proc-639-g7.3

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Citations (3)

GENERATION-RECOMBINATION NOISE IN GaN-BASED DEVICES

Selected topics in electornics and systems (2004)

S. L. Rumyantsev Nezih Pala M. S. Shur M. E. Levinshteǐn R. Gaška

Font

10.1142/9789812562364_0010

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Citations (1)

High-power microwave 0.25-μm gate doped-channel GaN/AlGaN heterostructure field effect transistor

IEEE Electron Device Letters (1998)

Q. Chen Jinwei Yang R. Gaška M.A. Khan M. S. Shur

We report on the high-power performance of the 0.25-μm gate Doped-Channel GaN/AlGaN Heterostructure Field Effect Transistors (DC-HFETs). At a drain bias voltage of 18 V and drain bias current of 46 mA, these 100-μm wide devices exhibit high gain at 8.4 GHz with a power density reaching 1.73 W/mm. The devices also display high gain at moderate power over a wide range of frequencies. This high gain at high frequency is a result of an optimal doping level in the AlGaN layer that gives rise to a high sheet charge density while maintaining a high-channel electron mobility. These results demonstrate the excellent microwave power capability of the GaN/AlGaN based heterostructure field effect transistors.

Wide-bandgap semiconductor

10.1109/55.658598

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Citations (97)

Small- and Large-Signal Performance of III-Nitride RF Switches With Hybrid Fast/Slow Gate Design

IEEE Microwave and Wireless Components Letters (2011)

A. Sattu Jinwei Yang R. Gaška Md. Bilal Khan M. S. Shur

We report on the small-signal and power performance of AlGaN/GaN RF switches with novel gate design incorporating regular metal gate deposited over a “slow” gate electrode formed by a low-conducting InGaN film. SPDT RF switch MMICs using hybrid “fast/slow” gate AlGaN/GaN MOSHFETs show superior transmission characteristics while maintaining the same high-power and high-linearity performance as the switches based on conventional MOSHFETs.

Linearity

RF switch

SIGNAL (programming language)

Transmission gate

10.1109/lmwc.2011.2138686

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Citations (6)

Attenuation of Surface Acoustic Waves by Carbon Nanotubes

MRS Proceedings (2002)

D. Čiplys Sergey Rumyantsev M. S. Shur Róbert Vajtai Bingqing Wei

Acoustic attenuation

10.1557/proc-750-y5.46

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Citations (0)

Lifetime of nonequilibrium carriers in high‐Al‐content AlGaN epilayers

physica status solidi (a) (2004)

J. Mickevičius R. Aleksiejūnas M. S. Shur Г. Тамулайтис R. S. Qhalid Fareed

Abstract AlGaN epilayers with different aluminum molar fractions have been comparatively studied by photoluminescence (PL) and light‐induced transient grating (LITG) techniques. The carrier diffusion length determined by LITG is shown to be close to the average distance between two first‐neighbor dislocations, which was roughly estimated by using the dislocation density obtained by etch pit technique. For epilayers containing the same amount of Al, the carrier lifetime and PL intensity are inversely proportional to the density of the dislocations, which limit the carrier lifetime by serving as nonradiative recombination centers. For AlGaN epilayers with similar lifetimes but with different Al contents, the PL intensity decreases with increasing Al fraction, which is explained by the Al content dependence of the radiative recombination rate. It is demonstrated that introduction of AlN/AlGaN superlattices on sapphire substrates by using Migration Enhanced Metal Organic Chemical Vapor Deposition (MEMOCVD TM ) enables growth of AlGaN with an increased nonequilibrium carrier lifetime and enhanced photoluminescence intensity. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Carrier lifetime

Intensity

10.1002/pssa.200406903

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Citations (21)