Doping engineering to enhance performance of a silicon carbide power device

Abstract

The doping of the drift layer of a 1-D SiC power device is designed to vary in steps, instead of traditional constant doping, and we show an experimental reduction of the resistance of the drift region below that achieved with constant doping by 7.34%. Sensitivity of doping design to material properties affects the improvement in characteristics. Stepped epitaxial doping presented here permits shrinkage of ∼ 3% of the die in typical commercial devices between 600 V and 1700 V while keeping the same electrical characteristics. Higher number of doping steps approach the ideal of an accurately graded epitaxy, with a tradeoff between increasing performance gains and increasing process complexity.