High Temperature Operation of Al0.45Ga0.55N/Al0.30Ga0.70N High Electron Mobility Transistors

AlGaN-channel high electron mobility transistors (HEMTs) are among a class of ultra wide-bandgap transistors that have a bandgap greater than similar to 3.4 eV, beyond that of GaN and SiC, and are promising candidates for RF and power applications. Long-channel AlxGa1-xN HEMTs with x = 0.3 in the channel have been built and evaluated across the -50 degrees C to + 200 degrees C temperature range. Room temperature drain current of 70 mA/mm, absent of gate leakage, and with a modest -1.3 V threshold voltage was measured. A very large I-on/I-off current ratio, greater than 10(8) was demonstrated over the entire temperature range, indicating that off-state leakage is below the measurement limit even at 200 degrees C. Combined with near ideal subthreshold slope factor that is just 1.3x higher than the theoretical limit across the temperature range, the excellent leakage properties are an attractive characteristic for high temperature operation. (c) The Author(s) 2017. Published by ECS. All rights reserved.