Silicon carbide semiconductor device, inverter circuit using the same, and method for manufacturing silicon carbide semiconductor device

Abstract

A SiC semiconductor device includes a substrate of a first conductivity type, a buffer layer of the first conductivity type on the substrate, a low-concentration layer on the buffer layer, a first deep layer and a JFET portion on the low-concentration layer, a current diffusion layer of the first conductivity type disposed on the JFET portion and having an impurity concentration higher than the low-concentration layer, a second deep layer of a second conductivity type disposed on the first deep layer, a base layer of the second conductivity type disposed on the current diffusion layer and the second deep layer, an impurity region of the first conductivity type disposed in a surface layer portion of the base layer, and a trench gate structure penetrating the impurity region and the base layer and reach the current diffusion layer. The JFET portion is formed with defect portions.