Patent ID: 10418478

Abstract:
On a surface of an n-type silicon carbide epitaxial layer on an n+-type silicon carbide substrate, first and second p+-type base regions are formed in the n-type silicon carbide epitaxial layer, an n-type region is formed in the n-type silicon carbide epitaxial layer, a p-type base layer is formed on the n-type region, an n+-type source region and a p++-type contact region are formed in the p-type base layer, and a trench is formed to a position shallower than the second p+-type base region and penetrates the p-type base layer. A first sidewall angle of the trench at a position of the p-type base layer is 80° to 90° with respect to a main surface. A difference of the first sidewall angle and a second sidewall angle of the trench at a position deeper than a boundary of the p-type base layer and the n-type region is 1° to 25°.