Patent ID: 8710586

Claim:
A SiC semiconductor device comprising: a substrate having a first conductive type or a second conductive type and made of SiC; a drift layer disposed on the substrate, made of SiC, and having the first conductive type, wherein the drift layer has an impurity concentration lower than the substrate; a base region disposed on the drift layer, made of SiC, and having the second conductive type; a source region disposed in a surface portion of the base region, made of SiC, and having the first conductive type, wherein the source region has an impurity concentration higher than the drift layer; a contact layer electrically coupling between the source region and the base region, and disposed in another surface portion of the base region; a trench disposed on a surface of the source region to penetrate the source region and the base region, and having a longitudinal direction; a gate insulation film disposed on an inner wall of the trench; a gate electrode disposed in the trench via the gate insulation film; an interlayer insulation film covering the gate electrode, and having a contact hole, from which the source region and the contact layer are partially exposed; a source electrode electrically coupling with the source region and the contact layer via the contact hole; a drain electrode disposed on a backside of the substrate opposite to the drift layer; and a metal silicide film, wherein: the source region includes a first source region and a second source region; the second source region has an impurity concentration higher than the first source region; the second source region is disposed at a position shallower than the first source region and includes a first part and a second part, as well as a first portion and a second portion; the first part of the second source region is covered with the interlayer insulation film, and the second part of the second source region is disposed under the contact hole; the first part of the second source region includes the first portion at a first position near a surface of the second source region and the second portion at a second position deeper than the first position; the first portion of the first part of the second source region has an impurity concentration lower than the second portion of the first part of the second source region; the metal silicide film is disposed on the second part of the second source region; the metal silicide film is made of metal silicide including metal, which is equal to metal of the source electrode; and the metal silicide film has a thickness, which is larger than a thickness of the first portion of the first part of the second source region.