Investigation of the effect of temperature during off-state degradation of AlGaN/GaN High Electron Mobility Transistors

AlGaN/GaN High Electron Mobility Transistors were found to exhibit a negative temperature dependence of the critical voltage (V-CRI) for irreversible device degradation to occur during bias-stressing. At elevated temperatures, devices exhibited similar gate leakage currents before and after biasing to V-CRI, independent of both stress temperature and critical voltage. Though no crack formation was observed after stress, cross-sectional TEM indicates a breakdown in the oxide interfacial layer due to high reverse gate bias. (C) 2011 Elsevier Ltd. All rights reserved.