Analysis of V-TH Degradation and Recovery Behaviors of p-GaN Gate HEMTs Under Forward Gate Bias

In this work, detailed V-TH degradation and recovery behaviors of p-GaN gate high electron mobility transistors (HEMTs) are studied under forward gate bias and elevated temperatures. Based on multiple time evolving stress/recovery experiments, the abrupt negative Delta V-TH behavior at initial recovery time at low V-GS level as well as the suppressed V-TH shift at high temperature have been observed. It is experimentally found that trapped electrons are more rapid-recoverable than the holes, and the carrier trapping effect is mitigated due to the strengthened carrier emission and recombination process across the AlGaN barrier at elevated temperatures. The ON-resistance (R-ON) degradation behavior is also investigated within the same experiment, and the trapped holes at the passivation/AlGaN interface result in a decrease in R-ON.