A New Degradation Mechanism in High-Voltage SiC Power MOSFETs

The phenomenon of recombination-induced stacking faults in high-voltage p-n diodes in SiC has been previously shown to increase the forward voltage drop due to reduction of minority carrier lifetime. In this paper, it has been shown that, for the first time, this effect is equally important in unipolar devices such as high-voltage MOSFETs. If the internal body diode is allowed to be forward biased during the operation of these devices, then the recombination-induced SFs will reduce the majority carrier conduction current and increase the leakage current in blocking mode. The effect is more noticeable in high-voltage devices where the drift layer is thick and is not expected to impact 600–1200-V devices.