Effect of random surface charge distribution on transport in 4H-SiC MOSFETs

The study of random fluctuation of surface charges in 4H-SiC MOSFETs indicates that the surface charge variation gives rise to a shift in threshold voltage of the device. A small change in transconductance is observed when large amount of randomness is considered at the surface. Furthermore, the surface mobility changes significantly along the channel at low gate biases. But at high gate biases, the relative randomness in the surface mobility is greatly reduced leading to almost no change in the transconductance and current at high gate biases in 4H-SiC MOSFETs.