Impact of the Level of Negative Gate Voltage on the Temperature Measurement during Power Cycling Testing of SiC MOSFETs

Inhalt:
In this work, test specimens from two different manufacturers with an RDS(ON) of 80 mOmega with a blocking capability of 1.2 kV in TO-247 housing were selected to investigate the influence of the level of negative gate voltage for accurate temperature measurement during power cycling. All devices failed with an increase in forward voltage, confirmed by the failure analysis. No influence of different magnitudes of negative gate voltage on the power cycling stability was found. However, a shift of the threshold voltage by up to 1.5 V is possible depending on the test conditions, which has a strong influence on the temperature measurement when the n-channel is not completely closed.