High temperature performances of normally-off p-GaN gate AlGaN/GaN HEMTs on SiC and Si substrates for power applications

We analyse high temperature effects (up to 420 °C) in the performances of p-GaN gate normally-off AlGaN/GaN HEMTs on Si and SiC substrates for power applications. With increasing temperature, IDMAX (R ON ) decreases (increases) and the threshold voltage slightly decreases independently of the substrate and doping. The room temperature (RT) DC IV characteristics of the devices after 90 min at temperatures above 300 °C are not affected. Step stress experiments at 420 °C show more than twofold decrease of the blocking capabilities compared to RT. Finally, thermal activation of the vertical leakage current has been analysed up to 180 °C.