Repetitive Short Circuit Energy Dependent $V_{\text{TH}}$ Instability of 1.2kV SiC Power MOSFETs

Repetitive short circuit energy ( ESC) dependent threshold voltage VTH instabilities of 1.2kV SiC power MOSFETs are characterized. A bidirectional VTH shift behavior, i.e. negative shift at lower ( ESC) and positive shift at higher ( ESC), was revealed. The VTH shifts under repetitive SC tests are attributed to the SC pulse phase according to the results of high temperature reverse bias (HTRB) and dynamic high temperature gate bias (HTGB) tests. The underlying mechanisms of the complex VTH shift behavior are explained in a unified framework by taking into account the junction temperature ( Tj) increase with higher ESC. TCAD device simulation is used to help analyze the mechanisms.