An Approach to Model Temperature Effects of Interface Traps in 4H-SiC

In 4H silicon carbide MOSFETs, threshold voltage varies with temperature. It is believed that this is caused by trapping of inversion electrons at high density of interface-traps (Dit) present at the SiC/SiO2 interface in 4H-SiC MOSFETs. In this work, we present an approach to model the interface trap density as a function of temperature that includes the effect of band gap narrowing. Using the temperature dependent trap charge density, we can estimate the variation of mobile inversion layer charge density, which in turn, explains the threshold voltage behavior with temperature in 4H-SiC MOSFETs.