Evidence of Frequency-dependent SiC Power MOSFET Capacitances in the Fast and Slow Switching Transients

Inhalt:
This paper investigates the frequency (f)-dependent behavior of SiC power MOSFET during switching transients by means of double-pulse test (DPT) measurements and a calibrated virtual twin of the experimental setup. A discrepancy between the measurements and the simulations observed for slow, but not for fast turn-off switching events indicates a f-dependent C-V device characteristics that is not captured by the virtual twin implementing frequency-independent MOSFET models. We show that the f-dependent C-V device characteristics are related to a presence of interface defects at the SiC-oxide interface.