Patent ID: 8748948

Claim:
A SiC semiconductor device comprising: a SiC substrate made of intrinsic SiC having semi-insulating property and including a first surface; a first conductive type SiC layer disposed in a surface portion of the substrate on the first surface; a second conductive type SiC layer disposed in another surface portion of the substrate on the first surface; an insulation separation layer made of intrinsic SiC for isolating the first conductive type SiC layer from the second conductive type SiC layer, wherein the insulation separation layer is part of the substrate, wherein the insulation separation layer and another part of the substrate other than the insulation separation layer are made of a same type of SiC; a first conductive type channel JFET disposed in one of the first conductive type SiC layer and the second conductive type SiC layer; and a second conductive type channel JFET disposed in the other of the first conductive type SiC layer and the second conductive type SiC layer, wherein the first conductive type channel JFET and the second conductive type channel JFET provide a complementary junction field effect transistor, wherein the insulation separation layer has a box shape, wherein the uppermost surface of the box shape is open, and wherein the second conductive type SiC layer is disposed entirely within the insulation separation layer in the box shape so that the second conductive type SiC layer is insulated, by the insulation separation layer in the box shape, from the first conductive type SiC layer and the SiC substrate.