Effect of SiO2/SiC interface on inversion channel electron mobility of 4H-SiC n-MOSFET

Abstract

A model for inversion channel electron mobility of 4H-SiC n-MOSFET is proposed based on device physics of semiconductor. The effect of interface states, lattice, ionized impurities, and surface roughness scatterings on the mobility is considered in this model, where the interface-state scattering mechanism includes electrically-shielded effect of carriers. The influence of some factors, such as interface states, surface roughness, on the mobility is investigated using the model. The simulated results indicate that the interface states and the surface roughness are major influence on inversion channel electrons mobility, in which the maximum mobility depends on the interface-state density, and surface-roughness scattering limits the electron mobility under high field. The model can be well used for device simulation.