Analysis of short-circuit break-down point in 3.3 kV SiC-MOSFETs

To identify short-circuit (SC) failure mechanism in 3.3 kV silicon carbide metal-oxide-semiconductor field-effect transistors (SiC-MOSFETs), we analyzed the break-down point and device degradation of the 3.3 kV SiC-MOSFETs using our proposed SC test method. The proposed test method enabled the application of a SC stress larger than the SC capability of the device without break-down, which facilitates the analysis of SC degradation. Degradation of the gate oxide in the junction field-effect transistor (jFET) area in the SiC-MOSFETs resulted in deterioration of the break-down characteristics and was the starting point of the SC failure. Therefore, improved reliability of the gate oxide can increase the SC capability of the SiC-MOSFETs.