Modelling of SiC MOSFET power devices incorporating physical effects

Abstract

An improved semi-physical model for a SiC MOSFET incorporated with relevant physical effects and temperature characteristics is proposed based on the EKV model. A simulation analysis of the Junction Field Effect Transistor (JFET) effect, Drain Induced Barrier Lowering (DIBL) effect, channel length modulation effect, velocity saturation effect, and interface trap charge effect in SiC MOSFET devices is performed using Sentaurus TCAD. Based on the influence of physical effects on the characteristics of SiC MOSFET devices, mathematical corrections r(V_gs) and r(V_ds), which can describe the relevant physical effects, are introduced into the original EKV model. The capacitance is accurately modelled to achieve the required match between the transient characteristics of the devices. The accuracy of the model is verified by static tests and double-pulse experiments. Results show that the improved model can do a better job of simulating the actual operating conditions of the device. In addition, its accuracy and applicability are greatly improved, providing a semi-physical model with a wider range of applicability for the simulation of SiC MOSFETs in power electronic systems.