Failure modes and mechanism analysis of SiC MOSFET under short-circuit conditions

Abstract The preliminary characterization study and analysis of the short-circuit (SC) capability of SiC MOSFET have been reported in recent years. However, the failure modes of the SiC MOSFET under various SC conditions and their physical mechanisms are unclear. The purpose of this paper is to extensively investigate the SC ruggedness, failure modes and internal physical mechanisms of the SiC MOSFET. The influence of major limiting factors on the failure mode of the SiC MOSFET is experimentally studied, including gate drive voltage, DC bus voltage, case temperature and die sizing. Two SC failure mechanisms, the thermal runaway and gate interlayer dielectric breakdown of the SiC MOSFET are identified as the root reason of failure by means of microscopic failure analysis techniques.