Electron mobility models for 4H, 6H, and 3C SiC [MESFETs

Abstract

Models for the electron mobility in the three most important silicon carbide (SiC) polytypes, namely, 4H, 6H, and 3C SiC are developed. A large number of experimental mobility data and Monte Carlo (MC) results reported in the literature have been evaluated and serve as the basis for the model development. The proposed models describe the dependence of the electron mobility on doping concentration, temperature, and electric field. The low-field mobility in 4H SiC is much higher than in 6H and 3C in the doping range interesting for RF power transistors (10/sup 16/ cm/sup -3/ ...10/sup 18/ cm/sup -3/), whereas the saturation velocities in the three polytypes investigated are nearly the same (slightly above 2/spl times/10/sup 7/ cm/s at 300 K). The models developed can be easily incorporated into numerical device simulators.