Investigation of high-temperature-reverse-bias (HTRB) degradation on AlGaN/GaN HEMTs

AlGaN/GaN HEMTs are performed to the HTRB stress experiments to investigate the degradation phenomena. Several degradation characteristics of DC parameters such as the reduction of saturated drain current, the increase of gate leakage current and on-resistance, and the shift of threshold voltage are identified. The degradation mechanism is ascribed to the trapping of electrons in the region under the gate and the access region of gate to drain. The degradation speed of the bottom fingers is faster than the upside fingers, which meant the improvement of thermal design is important for the reliability enhancement of AlGaN/GaN HEMTs.