An improved I-V model of 4H-SiC MESFETs incorporating substrate trapping, surface trapping and thermal effects

摘要

An improved analytical model for the DC characteristics of 4H-SiC MEtal Semiconductor Field Effect Transistors (MESFETs) is proposed. The model takes into account three major effects namely substrate trapping, surface trapping and thermal effects to describe the DC behavior of the device. The analytical model of I-V characteristics incorporate Caughey-Thomas model of field dependence electron mobility, substrate trapping of electrons by multiple deep level traps (which is the characteristic of 4H-SiC) and two-dimensional analysis of charge distribution under the gate. The collapse of drain current is observed on the I-V characteristics. This unique model proposed is a complete model which takes into consideration all the critical material defects and thermal effects with trapping. Hence the model behavior is very close to real time MESFET.