Hole-transmission enhancement in 4H-silicon carbide light triggered thyristor for low loss *

Abstract

Abstract In this paper, a 20 kV silicon carbide (SiC) light triggered thyristor (LTT) with n-type blocking base is simulated using Synopsys Sentaurus TCAD. In order to reduce the power dissipation, a method that enhances the hole-transmission through electric field induced by gradual doping profile in the n-buffer layer is proposed. The results indicate that the method enhancing the hole-transmission is effective in reducing the power loss of SiC LTT with n-type blocking base. By changing the doping profile of n-buffer layer from uniform to gradual, both on-state loss and switching loss are efficiently reduced. Compared to the conventional SiC LTT with 2.5 μm thick n-buffer layer, when the doping gradient is 1.0 × 1021 cm−4, the on-state and the switching losses of the hole-transmission enhanced SiC LTT are reduced by 34.7% and 17.9%, respectively.