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Title: Density-dependent electron transport and precise modeling of GaN high electron mobility transistors

We report on the direct measurement of two-dimensional sheet charge density dependence of electron transport in AlGaN/GaN high electron mobility transistors (HEMTs). Pulsed IV measurements established increasing electron velocities with decreasing sheet charge densities, resulting in saturation velocity of 1.9 × 10{sup 7 }cm/s at a low sheet charge density of 7.8 × 10{sup 11 }cm{sup −2}. An optical phonon emission-based electron velocity model for GaN is also presented. It accommodates stimulated longitudinal optical (LO) phonon emission which clamps the electron velocity with strong electron-phonon interaction and long LO phonon lifetime in GaN. A comparison with the measured density-dependent saturation velocity shows that it captures the dependence rather well. Finally, the experimental result is applied in TCAD-based device simulator to predict DC and small signal characteristics of a reported GaN HEMT. Good agreement between the simulated and reported experimental results validated the measurement presented in this report and established accurate modeling of GaN HEMTs.
Authors:
; ; ; ; ;  [1] ; ;  [2] ;  [3] ;  [1] ;  [4]
  1. Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)
  2. Raytheon Integrated Defense Systems, Andover, Massachusetts 01810 (United States)
  3. Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)
  4. (United States)
Publication Date:
OSTI Identifier:
22482256
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 15; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CHARGE DENSITY; DENSITY; ELECTRON MOBILITY; ELECTRON-PHONON COUPLING; GALLIUM NITRIDES; PHONONS; SIGNALS; SIMULATION; SIMULATORS; TRANSISTORS; VELOCITY