Effect of buffer layer structure on electrical and structural properties of AlGaN/GaN high electron mobility transistors

AlGaN/GaN high electron mobility transistors (HEMTs) with similar active layers structures were grown on SiC or sapphire substrates using different buffer layer structures, including GaN of different thickness (1 or 2 μm) or composite AlGaN/GaN buffers. The highest density of hole traps was observed in the buffer on sapphire, while the lowest density of hole traps was obtained in the thick (2 μm) GaN buffer on SiC. The reverse leakage currents in HEMTs were lower in the devices grown on SiC substrates and the on-off ratios improved by two orders of magnitude for thicker GaN buffers or composite AlGaN/GaN buffers compared to a standard 1 μm GaN buffer. The maximum drain-source currents and tranconductances were all larger for the devices on SiC compared to sapphire.

[1]  E. Ozbay,et al.  Growth of high crystalline quality semi-insulating GaN layers for high electron mobility transistor applications , 2006 .

[2]  U. K. Mishra,et al.  Metalorganic chemical vapor deposition growth of high optical quality and high mobility GaN , 1995 .

[3]  Aly E. Fathy,et al.  Development of ultra wideband, high efficiency, distributed power amplifiers using discrete GaN HEMTs , 2009, IET Circuits Devices Syst..

[4]  I. Omura,et al.  Demonstration of 13.56-MHz class-E amplifier using a high-Voltage GaN power-HEMT , 2006, IEEE Electron Device Letters.

[5]  R. J. Shul,et al.  GAN : PROCESSING, DEFECTS, AND DEVICES , 1999 .

[6]  Hongtao Xu,et al.  A high-efficiency class-E GaN HEMT power amplifier at 1.9 GHz , 2006, IEEE Microwave and Wireless Components Letters.

[7]  D. Kim,et al.  Self-Aligned AlGaN/GaN High Electron Mobility Transistors , 2008, 2007 65th Annual Device Research Conference.

[8]  T. Egawa,et al.  Breakdown Enhancement of AlGaN/GaN HEMTs on 4-in Silicon by Improving the GaN Quality on Thick Buffer Layers , 2009, IEEE Electron Device Letters.

[9]  Amir Dabiran,et al.  Deep traps responsible for hysteresis in capacitance-voltage characteristics of AlGaN∕GaN heterostructure transistors , 2007 .

[10]  W. Hoke,et al.  Influence of AlN nucleation layer on the epitaxy of GaN/AlGaN high electron mobility transistor structure and wafer curvature , 2005 .

[11]  Zhan-guo Wang,et al.  MOCVD-grown high-mobility Al0.3Ga0.7N/AlN/GaN HEMT structure on sapphire substrate , 2007 .

[12]  S. Keller,et al.  AlGaN/GaN high electron mobility transistors with InGaN back-barriers , 2006, IEEE Electron Device Letters.

[13]  Zoya Popovic,et al.  GaN HEMT PA with over 84% power added efficiency , 2010 .

[14]  N. B. Smirnov,et al.  Comparison of hole traps in n-GaN grown by hydride vapor phase epitaxy, metal organic chemical vapor deposition, and epitaxial lateral overgrowth , 2011 .

[15]  A. Kurdoghlian,et al.  GaN double heterojunction field effect transistor for microwave and millimeterwave power applications , 2004, IEDM Technical Digest. IEEE International Electron Devices Meeting, 2004..

[16]  N. B. Smirnov,et al.  Deep Hole Traps in N-GaN Films Grown by Hydride Vapor Phase Epitaxy , 2002 .

[17]  Rongming Chu,et al.  MOCVD-Grown AlGaN Buffer GaN HEMTs With V-Gates for Microwave Power Applications , 2009, IEEE Electron Device Letters.

[18]  N. B. Smirnov,et al.  Deep traps in high resistivity AlGaN films , 1998 .

[19]  H. Morkoç,et al.  Luminescence properties of defects in GaN , 2005 .

[20]  S. Denbaars,et al.  V-Gate GaN HEMTs With Engineered Buffer for Normally Off Operation , 2008, IEEE Electron Device Letters.

[21]  S. Pearton,et al.  Electrical and structural properties of AlN/GaN and AlGaN/GaN heterojunctions , 2008 .

[22]  R Fagotti,et al.  Concurrent Hex-Band GaN Power Amplifier for Wireless Communication Systems , 2011, IEEE Microwave and Wireless Components Letters.