Understanding Electrical Parameter Degradations of P-GaN HEMT Under Repetitive Short-Circuit Stresses

In this letter, comprehensive static and dynamic electrical parameter degradations of p-GaN gate high electron mobility transistor (HEMT) under repetitive short-circuit (SC) stresses are presented. Meanwhile, the mechanisms behind those degradations are first distinguished. The results indicate that both the gate region and the access region are damaged by the SC stresses, dominating the shifts of electrical parameters. Moreover, a method by modeling the output capacitance is proposed to characterize damages in access region. Finally, the switching characteristics after the stresses are investigated, it is found that the switching speed benefits from the increase in the gate leakage current. Considering the aging of p-GaN HEMT under long-term operation conditions, all the damages brought by repetitive SC stresses should be eliminated to prevent the failure of p-GaN gate and the increase in conduction loss.