Trap Dynamic Detection of GaN HEMT under Repetitive Short Circuit Degradation.

Short circuit (SC) failure of the emerging GaN HEMT is one of the major issues in reliability design for the next generation high-power semiconductor systems. Although many investigations report relevant phenomena about thermal dynamic influence, charging and discharging process, and trapping effects, the origin of the degradation is still under debate. Identifying the internal behavior of the GaN HEMT structures becomes the most challenging issue for understanding the degradation mechanisms. Here, we investigate the trapping and de-trapping process under repetitive short circuit stress, analyze the representation of threshold instability and build the voltage spectra estimation to reveal the behaviors of trapping affecting the SC degradations. The proposed model supports predicting GaN HEMTs' dynamic behaviors under real SC processes.