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Title: An AlN/Al{sub 0.85}Ga{sub 0.15}N high electron mobility transistor

Abstract

An AlN barrier high electron mobility transistor (HEMT) based on the AlN/Al{sub 0.85}Ga{sub 0.15}N heterostructure was grown, fabricated, and electrically characterized, thereby extending the range of Al composition and bandgap for AlGaN channel HEMTs. An etch and regrowth procedure was implemented for source and drain contact formation. A breakdown voltage of 810 V was achieved without a gate insulator or field plate. Excellent gate leakage characteristics enabled a high I{sub on}/I{sub off} current ratio greater than 10{sup 7} and an excellent subthreshold slope of 75 mV/decade. A large Schottky barrier height of 1.74 eV contributed to these results. The room temperature voltage-dependent 3-terminal off-state drain current was adequately modeled with Frenkel-Poole emission.

Authors:
; ; ; ; ; ; ; ;  [1]
  1. Sandia National Laboratories, PO Box 5800, Albuquerque, New Mexico 87185-1085 (United States)
Publication Date:
OSTI Identifier:
22594428
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; BREAKDOWN; ELECTRIC POTENTIAL; ELECTRON MOBILITY; ELECTRONS; EMISSION; GALLIUM NITRIDES; HEIGHT; SCHOTTKY BARRIER DIODES; TEMPERATURE RANGE 0273-0400 K; TRANSISTORS

Citation Formats

Baca, Albert G., Armstrong, Andrew M., Allerman, Andrew A., Douglas, Erica A., Sanchez, Carlos A., King, Michael P., Coltrin, Michael E., Fortune, Torben R., and Kaplar, Robert J. An AlN/Al{sub 0.85}Ga{sub 0.15}N high electron mobility transistor. United States: N. p., 2016. Web. doi:10.1063/1.4959179.
Baca, Albert G., Armstrong, Andrew M., Allerman, Andrew A., Douglas, Erica A., Sanchez, Carlos A., King, Michael P., Coltrin, Michael E., Fortune, Torben R., & Kaplar, Robert J. An AlN/Al{sub 0.85}Ga{sub 0.15}N high electron mobility transistor. United States. doi:10.1063/1.4959179.
Baca, Albert G., Armstrong, Andrew M., Allerman, Andrew A., Douglas, Erica A., Sanchez, Carlos A., King, Michael P., Coltrin, Michael E., Fortune, Torben R., and Kaplar, Robert J. 2016. "An AlN/Al{sub 0.85}Ga{sub 0.15}N high electron mobility transistor". United States. doi:10.1063/1.4959179.
@article{osti_22594428,
title = {An AlN/Al{sub 0.85}Ga{sub 0.15}N high electron mobility transistor},
author = {Baca, Albert G. and Armstrong, Andrew M. and Allerman, Andrew A. and Douglas, Erica A. and Sanchez, Carlos A. and King, Michael P. and Coltrin, Michael E. and Fortune, Torben R. and Kaplar, Robert J.},
abstractNote = {An AlN barrier high electron mobility transistor (HEMT) based on the AlN/Al{sub 0.85}Ga{sub 0.15}N heterostructure was grown, fabricated, and electrically characterized, thereby extending the range of Al composition and bandgap for AlGaN channel HEMTs. An etch and regrowth procedure was implemented for source and drain contact formation. A breakdown voltage of 810 V was achieved without a gate insulator or field plate. Excellent gate leakage characteristics enabled a high I{sub on}/I{sub off} current ratio greater than 10{sup 7} and an excellent subthreshold slope of 75 mV/decade. A large Schottky barrier height of 1.74 eV contributed to these results. The room temperature voltage-dependent 3-terminal off-state drain current was adequately modeled with Frenkel-Poole emission.},
doi = {10.1063/1.4959179},
journal = {Applied Physics Letters},
number = 3,
volume = 109,
place = {United States},
year = 2016,
month = 7
}
  • An AlN barrier high electron mobility transistor (HEMT) based on the AlN/Al 0.85Ga 0.15N heterostructure was grown, fabricated, and electrically characterized, thereby extending the range of Al composition and bandgap for AlGaN channel HEMTs. An etch and regrowth procedure was implemented for source and drain contact formation. A breakdown voltage of 810 V was achieved without a gate insulator or field plate. Excellent gate leakage characteristics enabled a high I on/I off current ratio greater than 10 7 and an excellent subthreshold slope of 75 mV/decade. A large Schottky barrier height of 1.74 eV contributed to these results. In conclusion,more » the room temperature voltage-dependent 3-terminal off-state drain current was adequately modeled with Frenkel-Poole emission.« less
  • AlGaN-channel high electron mobility transistors (HEMTs) are among a class of ultra wide-bandgap transistors that are promising candidates for RF and power applications. Long-channel Al xGa 1-xN HEMTs with x = 0.7 in the channel have been built and evaluated across the -50°C to +200°C temperature range. These devices achieved room temperature drain current as high as 46 mA/mm and were absent of gate leakage until the gate diode forward bias turn-on at ~2.8 V, with a modest -2.2 V threshold voltage. A very large I on/I off current ratio, of 8 × 10 9 was demonstrated. A near idealmore » subthreshold slope that is just 35% higher than the theoretical limit across the temperature range was characterized. The ohmic contact characteristics were rectifying from -50°C to +50°C and became nearly linear at temperatures above 100°C. An activation energy of 0.55 eV dictates the temperature dependence of off-state leakage.« less
  • The optimization of heavily strained Ga{sub 0.25}In{sub 0.75}As/Al{sub 0.48}In{sub 0.52}As high electron mobility transistor structures is discussed in detail. The growth parameters and the channel layer interfaces were optimized in order to maximize the mobility of the two-dimensional electron gas. Structures composed of an 11 nm thick channel layer and a 4 nm thick spacer layer exhibited electron mobilities as high as 15 100 cm{sup 2}/Vs and 70 000 cm{sup 2}/Vs at 300 and 77 K, respectively, for channels including InAs strained layers. The sheet carrier density was kept above 2.5 × 10{sup 12} cm{sup −2} throughout the entire study.
  • Ammonia molecular-beam epitaxy has been used to grow high-quality epilayers of GaN and AlGaN/GaN heterostructure field-effect transistor (HFET) structures on insulating 4H-SiC. The growth process, which used a magnetron sputter epitaxy deposited buffer layer of AlN, has been described previously. Ex situ pretreatment of the SiC substrate was found to be unnecessary. For a single 2.0 {mu}m thick silicon doped epilayer, a room temperature (RT) electron mobility of 500 cm2/Vs was measured at a carrier density of 6.6{times}10{sup 16}cm{sup {minus}3}. For the HFET structure, a room temperature mobility of 1300 cm2/Vs at a sheet carrier density of 3.3{times}10{sup 12}cm{sup {minus}2}more » was observed, increasing to 11000 cm2/Vs at 77 K. The surface morphology of the layers indicated a coalesced mesa structure similar to what we observed for growth on sapphire, but with a lower overall defect density and correspondingly larger grain size. The observation of well-resolved Shubnikov de Haas oscillations at fields as low as 3 T indicated a relatively smooth interface. {copyright} 2001 American Institute of Physics.« less
  • We have investigated the temperature dependence of ballistic mobility in a 100 nm-long InGaAs/InAlAs metamorphic high-electron-mobility transistor designed for millimeter-wavelength RF applications. To extract the temperature dependence of quasi-ballistic mobility, our experiment involves measurements of the effective mobility in the low-bias linear region of the transistor and of the collision-dominated Hall mobility using a gated Hall bar of the same epitaxial structure. The data measured from the experiment are consistent with that of modeled ballistic mobility based on ballistic transport theory. These results advance the understanding of ballistic transport in various transistors with a nano-scale channel length that is comparable tomore » the carrier's mean free path in the channel.« less