Impact of repetitive UIS on modern GaN power devices

In this paper we present the results from repetitive Unclmped Inductive Switching — UIS measurements on power GaN HEMTs. Experimental analysis was performed on two types of power devices — normally ON and OFF HEMTs. UIS test was used to simulate real switching conditions in which power device has to operate. Analysis has shown that charge trapping effects on interfaces and in bulk layer have strong impact on electrical performance of devices. DLTS study was performed on virgin and short and long stressed sample for better understanding of trapping effects.