Silicon carbide semiconductor device and method of manufacturing silicon carbide semiconductor device

Abstract

A silicon carbide (SiC) semiconductor device, including a SiC substrate, a first SiC layer formed on the substrate, first and second impurity layers selectively formed in the first SiC layer, a second SiC layer formed on the first SiC layer, a third impurity layer selectively formed in the second SiC layer and on the second impurity layer, a third SiC layer formed on the second SiC layer, a fourth impurity layer selectively formed in the third SiC layer, a trench that penetrates the fourth impurity layer and the second and third SiC layers, a bottom thereof reaching the first impurity layer, and a gate electrode formed in the trench via a gate insulating film. The first SiC layer has first and second regions adjacent respectively to the first and second impurity layers on a side facing the substrate, an impurity concentration at the first region being lower than that at the second region.