A simple analytical model of 4H-SiC MOSFET for high temperature circuit simulations

Abstract

Recently, significant work has been carried out to develop a technology based on 4H-SiC semiconductors aimed to utilize the unique physical and electrical properties of this material to achieve improved performance in high-power and high-temperature electronic circuits. This work is an effort to develop an analytical model for the 4H-SiC based n-channel enhancement mode MOSFET (NMOS). Here, a simple SPICE level-1 model of Si MOSFET has been modified to express the I-V characteristics of 4H-SiC MOSFET at the temperature ranging from 250 to 4000 °C. The model has been developed by using the verilog-AMS coding in which the thermal effects on intrinsic carrier density, band-gap, channel mobility and the threshold voltage have been incorporated. The performance of a differential amplifier based on this model has also been evaluated. It has been found that, in comparison to Si NMOS differential amplifier, the amplifier based on 4H-SiC MOSFET is more thermally stable. This clearly shows the suitability of the 4H-SiC MOSFET for harsh environment electronic circuits where Si MOSFET can not with stand.