A comparative study of channel designs for SiC MOSFETs: Accumulation mode channel vs. inversion mode channel

Abstract

This paper provides detailed comparison of electrical characteristics of accumulation mode and inversion mode 1.2 kV SiC MOSFETs, including performance at high temperatures (up to 200 °C). Statistical data measured from over 50 dies on 6-inch SiC wafers was used for this comparison. It is concluded that the accumulation mode SiC MOSFET provides a lower specific on-resistance than the inversion mode MOSFET due to a higher channel mobility (∼ 22 cm2/V·s) while achieving a reasonable threshold voltage (∼ 2.3 V). Based on statistical data analyses, a strong correlation between the threshold voltage and the field effect channel mobility was identified.