In this paper, 1200 V asymmetric trench silicon carbide (SiC) metal–oxide–semiconductorfield-effect transistors (MOSFETs) are investigated by experiment under multiple unclamped inductive switching (UIS) events. The degradation degree of electrical characteristics and failure modes are evaluated under various avalanche energy ratio. Meanwhile, Focus Ion Beam (FIB) cut illustrates the cross-section of damage point. For low energy ratio condition, the increasing of R_on demonstrates that thermal fatigue is main root of failure. However, burn out of field oxide and metal Al is shown under high energy ratio.

Failure mode,Asymmetric Trench,SiC MOSFET,Multiple UIS