Negative Bias Temperature Instability in 4H-SiC MOSFETs Investigated by On-the-fly Methods

Negative bias temperature instability (NBTI) in 4H-SiC MOSFETs were investigated by on-the-fly threshold-voltage (OTF-ΔV
th
) and on-the-fly charge-pumping (OTF-CP) measurements. With these measurements, the threshold voltage shift was accurately measured over a wide time range without the effect of relaxation after stress removal. Possible NBTI mechanisms for 4H-SiC MOSFETs were discussed based on the obtained results.