Power Cycling Test on 3.3kV SiC MOSFETs and the Effects of Bipolar Degradation on the Temperature Estimation by VSD-Method

In this work the impact of bipolar degradation on the temperature estimation during power cycling of high voltage SiC MOSFETs by means of the body-diode voltage drop is investigated. The results indicate that the voltage drop is subject to drift for devices prone to bipolar degradation even at moderate current densities in the regime of common sensing currents for the V_SD-method. Hence, the criteria of the sensing current for the V_SD-method are not only good sensitivity and linearity while avoiding self-heating but must consider possible drift of the calibration curve.