Journal ArticleDOI
Short-Channel Effect Limitations on High-Frequency Operation of AlGaN/GaN HEMTs for T-Gate Devices
Gregg H. Jessen,Robert C. Fitch,James K. Gillespie,Glen D. Via,Antonio Crespo,D. Langley,D.J. Denninghoff,M. Trejo,Eric R. Heller +8 more
TLDR
In this paper, an empirically based physical model is presented to predict the expected extrinsic fT for many combinations of gate length and commonly used barrier layer thickness (tbar) on silicon nitride passivated T-gated AlGaN/GaN HEMTs.Abstract:
AlGaN/GaN high-electron mobility transistors (HEMTs) were fabricated on SiC substrates with epitaxial layers grown by multiple suppliers and methods. Devices with gate lengths varying from 0.50 to 0.09 mum were fabricated on each sample. We demonstrate the impact of varying the gate lengths and show that the unity current gain frequency response (fT) is limited by short-channel effects for all samples measured. We present an empirically based physical model that can predict the expected extrinsic fT for many combinations of gate length and commonly used barrier layer thickness (tbar) on silicon nitride passivated T-gated AlGaN/GaN HEMTs. The result is that even typical high-aspect-ratio (gate length to barrier thickness) devices show device performance limitations due to short-channel effects. We present the design tradeoffs and show the parameter space required to achieve optimal frequency performance for GaN technology. These design rules differ from the traditional GaAs technology by requiring a significantly higher aspect ratio to mitigate the short-channel effects.read more
Citations
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Journal ArticleDOI
Scaling of GaN HEMTs and Schottky Diodes for Submillimeter-Wave MMIC Applications
Keisuke Shinohara,D. Regan,Yan Tang,Andrea Corrion,David F. Brown,Joel C. Wong,John F. Robinson,Helen Fung,Adele E. Schmitz,Thomas C. Oh,S. Kim,Peter Chen,Robert G. Nagele,Alexandros Margomenos,Miroslav Micovic +14 more
TL;DR: In this article, the authors report state-of-the-art high frequency performance of GaN-based high electron mobility transistors (HEMTs) and Schottky diodes achieved through innovative device scaling technologies such as vertically scaled enhancement and depletion mode (E/D mode) AlN/GaN/AlGaN double-heterojunction HEMT epitaxial structures.
Journal ArticleDOI
N-polar GaN epitaxy and high electron mobility transistors
Man Hoi Wong,Stacia Keller,Sansaptak Dasgupta Nidhi,Daniel J Denninghoff,Seshadri Kolluri,David F. Brown,Jing Lu,Nicholas Fichtenbaum,Elaheh Ahmadi,Uttam Singisetti,Alessandro Chini,Siddharth Rajan,Steven P. DenBaars,James S. Speck,Umesh Mishra +14 more
TL;DR: In this article, the progress of N-polar (Al, In, Ga)N materials for Npolar heterostructures are developed using molecular beam epitaxy and metalorganic chemical vapor deposition.
Journal ArticleDOI
Barrier-Layer Scaling of InAlN/GaN HEMTs
Farid Medjdoub,Mohammed Alomari,J.-F. Carlin,M. Gonschorek,Eric Feltin,M. A. Py,Nicolas Grandjean,Erhard Kohn +7 more
TL;DR: In this article, the characteristics of high-electron mobility transistors with barrier thickness between 33 and 3 nm, which are grown on sapphire substrates by metal-organic chemical vapor deposition, were discussed.
Journal ArticleDOI
Very high channel conductivity in low-defect AlN/GaN high electron mobility transistor structures
Amir M. Dabiran,Andrew M. Wowchak,Andrei Osinsky,J. Q. Xie,B. Hertog,B. Cui,Dwight C. Look,Peter Chow +7 more
TL;DR: In this paper, a low defect AlN/GaN high electron mobility transistor (HEMT) structure with very high values of electron mobility and sheet charge density was grown by plasma-assisted molecular beam epitaxy (MBE) on sapphire and SiC.
Journal ArticleDOI
Effect of Optical Phonon Scattering on the Performance of GaN Transistors
TL;DR: In this paper, a model based on optical phonon scattering is developed to explain peculiarities in the current drive, transconductance, and high-speed behavior of short-gate-length GaN transistors.
References
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Journal ArticleDOI
30-W/mm GaN HEMTs by field plate optimization
Yifeng Wu,Adam William Saxler,Marcia Moore,R.P. Smith,Scott Sheppard,P. Chavarkar,T. Wisleder,Umesh K. Mishra,P. Parikh +8 more
TL;DR: In this article, a GaN high-electron-mobility-transistors (HEMTs) on SiC were fabricated with field plates of various dimensions for optimum performance, and an enhancement in radio frequency (RF) current-voltage swings was achieved with acceptable compromise in gain, through both reduction in the trapping effect and increase in breakdown voltages.
Journal ArticleDOI
High-power AlGaN/GaN HEMTs for Ka-band applications
Tomas Palacios,Arpan Chakraborty,Siddharth Rajan,Christiane Poblenz,Stacia Keller,Steven P. DenBaars,James S. Speck,Umesh K. Mishra +7 more
TL;DR: In this paper, the authors report on the fabrication and high-frequency characterization of AlGaN/GaN high-electron mobility transistors (HEMTs) grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD).
Journal ArticleDOI
Undoped AlGaN/GaN HEMTs for microwave power amplification
L.F. Eastman,V. Tilak,Joseph A. Smart,B.M. Green,E.M. Chumbes,Roman Dimitrov,Hyungtak Kim,Oliver Ambacher,Nils Weimann,T. Prunty,M. J. Murphy,William J. Schaff,James R. Shealy +12 more
TL;DR: In this paper, a two-dimensional electron gas (2DEG) is induced using the strong spontaneous and piezoelectric polarization inherent in the AlGaN/GaN structures, and three-dimensional nonlinear thermal simulations are made to determine the temperature rise from heat dissipation in various geometries.
Journal ArticleDOI
AlGaN/GaN high electron mobility transistors with InGaN back-barriers
Tomas Palacios,Arpan Chakraborty,Sten Heikman,Stacia Keller,Steven P. DenBaars,Umesh K. Mishra +5 more
TL;DR: In this paper, a GaN/ultrathin InGaN/GaN heterojunction was used to provide a backbarrier to the electrons in an AlGaN and GaN high-electron mobility transistor (HEMT).
Journal ArticleDOI
AlGaN/GaN HEMTs on SiC with over 100 GHz f/sub T/ and low microwave noise
TL;DR: In this paper, high performance AlGaN/GaN high electron mobility transistors (HEMTs) with 0.12 /spl mu/m gate-length have been fabricated on an insulating SiC substrate.