Impact of carrier injections on the threshold voltage in p-GaN gate AIGaN/GaN power HEMTs

We investigated the threshold voltage (V-TH) shift in p-GaN gate AIGaN/GaN power HEMTs under both forward and reverse gate bias conditions at different temperatures. With increasing forward gate bias, the V-TH first positively shifted and then decreased. While at the reverse gate bias, V-TH shifts monotonically increased towards the positive direction. Positive V-TH shifts were due to electron trapping while its decrease was attributed to the optical pumping by the internal electroluminescence (EL). The EL emission from the p-GaN gate region was captured. A light illumination test was performed to verify the effectiveness of optical pumping. (C) 2019 The Japan Society of Applied Physics