Research on Degradation and Failure Mechanisms of Unclamped-Inductive-Switching Characteristics of p-GaN Hemt Device

Single UIS and repetitive UIS experiment are performed in this article to expound physical failure mechanisms in P-GaN Hemt devices. Vpeak versus Ipeak as the metric to evaluate the degradation of electrical parameters. In single UIS test, different load inductors, off-gate voltage and ambient temperature are chosen as variables to observe the failure phenomena in device under test(DUT), while in repeated UIS tests, threshold voltage, on-state resistant, blocking characteristics and gate leakage current degradation and recovery are concluded and analyzed that Vth presents a negatively shifting, Ron and BV will restore to their initial value, gate leakage shows a significant reduction at first and then after a duration of lagging will gradually recover to some extent but unable to achieve to its initial value. Combing failure point analysis by decaping with TCAD simulation validation, hole trapping and detrapped dominate Vth and Igss degradation, while Ron and BV degradation are dominated by electron traps in buffer.