SPICE Model of SiC MOSFET Including the Trapped Charge at SiC/SiO2 Interface

A simulation program with integrated circuit emphasis (SPICE) model of silicon carbide (SiC) metal-oxide- semiconductor field-effect transistor (MOSFET) has been developed. The model has employed three segmented current expressions to describe SiC MOSFET operating in cut-off region, linear region and saturation region. The leakage current between the drain and the source of SiC MOSFET has been introduced, also including the leakage current of gate oxide. A mobility model incorporating the trapped charge at SiC/SiO2 interface has been exploited to describe the behavior of channel carrier under different temperature range. An electrical-thermal network model has been developed to simulate the self-heating effect of SiC MOSFET under switching operation and high current stress. Switching circuit and short-circuit experiment have verified the developed SPICE model of SiC MOSFET. By the model, the effect imposed by the interface trapped charge on the switching performance and short-circuit failure of SiC MOSFET has been discussed, and the results have shown that high density of interface trapped charge can delay the turn-on and increase the on-state resistance, which leads to the improvement of switching loss for SiC MOSFET, in addition, the interface trapped charge decreases the saturation current and delays the failure of SiC MOSFET under short-circuit case. © 2019 Chin. Soc. for Elec. Eng.