Comprehensive Evaluation of Bias Temperature Instabilities on 4H-SiC MOSFETs Using Device Preconditioning

In comparison to silicon based devices, MOSFETs based on silicon carbide show more complex threshold voltage variations caused by positive and negative gate bias stress. We show that the majority of the voltage shift in standard JEDEC-like bias temperature instability measurements originates from stress independent measurement parameters like timing and switching conditions. A more sophisticated bias temperature instability measurement technique using device preconditioning is presented allowing for more accurate and nearly delay time independent extraction of the permanent voltage shift component within typical industrial timescales.