Reliability Analysis for Commercial SiC MOSFETs in Single Pulse and Repetitive Surge Current Test

SiC MOSFET Body diodes are expected to compete against SiC schottky barrier diodes (SBD) in high power applications. To investigate the surge capability of the body diodes in commercial SiC MOSFETs, single pulse and repetitive surge current tests are processed on the DUTs. In single pulse surge current test, the DUTs are stressed to failure. Compared with the body diodes in SiC trench-gate MOSFETs, the body diodes in SiC planar-gate MOSFETs tend to show better surge capability at all rated current levels. On the other hand, in repetitive surge current test, the degradation of electrical parameters is observed after hundreds of pulse cycles. The degradation mechanism of bipolar degradation and oxide layer degradation has been analyzed.