Characterisation of 1200 V SiC-MOSFETs - Influence of Repetitive Short-Circuit Events on Device Parameters

In this study, the impact of short-circuit (SC) events on 1200 V power SiC-MOSFETs is investigated. Therefore, trench and planar devices in the TO263-7 SMD-package were stressed with different pulse times of SC-type I. In order to understand the resulting failure mechanisms and to detect potential degradation of the MOSFETs, a static characterisation of device parameters were carried out before and in between the SC-events. Particular the gate threshold voltage Vth shows instabilities for SiC-devices under different stress conditions. The short-circuit behaviour as well as the static characterisation are discussed with regard to critical failures and the observation of degradations effects.