Revised Channel Mobility Model for Predictive TCAD Simulations of 4H-SiC MOSFETs

We present a revised channel mobility model for 4H-SiC MOSFETs. Mobility measurements are performed on 4H-SiC lateral MOSFET test structures in the temperature range of 25-175 °C. We observe that the temperature and P-well concentration dependence of channel mobility cannot be predicted by popular mobility models available within commercial TCAD tools. A careful investigation revels that channel mobility components need to be revised and replaced using a comprehensive model that accurately describes the predominant scattering mechanisms. We present a well calibrated channel mobility model for 4H-SiC using a revised treatment of bulk, surface roughness and surface phonon components. An excellent agreement with measured data is obtained using this model, making it more suitable for predictive device simulation using TCAD tools.