skip to main content


Title: Al 0.85Ga 0.15N/Al 0.70Ga 0.30N High Electron Mobility Transistors with Schottky Gates and Large On/Off Current Ratio over Temperature

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 ideal 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.
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ; ORCiD logo [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 2162-8769; 659496
Grant/Contract Number:
AC04-94AL85000; NA0003525
Accepted Manuscript
Journal Name:
ECS Journal of Solid State Science and Technology
Additional Journal Information:
Journal Volume: 6; Journal Issue: 12; Journal ID: ISSN 2162-8769
Electrochemical Society
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
36 MATERIALS SCIENCE; HEMT; high electron mobility transistor; Ultra-wide-bandgap
OSTI Identifier: