Patent ID: 8916880

Claim:
An epitaxial wafer comprising: a semiconductor substrate; and an epitaxial layer provided on said semiconductor substrate, said epitaxial layer being doped with the same dopant as a dopant doped into said semiconductor substrate and including a plurality of low concentration layers and at least one high concentration layer, wherein a doping concentration of said dopant in said plurality of low concentration layers is lower than that in said semiconductor substrate, said at least one high concentration layer is arranged between said low concentration layers, and the thickness of said at least one high concentration layer is smaller than that of said low concentration layer, and a doping concentration of said dopant in said at least one high concentration layer is equal to that in said semiconductor substrate, and said semiconductor substrate and said epitaxial layer are made of silicon carbide and a buffer layer arranged between said semiconductor substrate and said epitaxial layer, a doping concentration of said dopant in said buffer layer being lower than that in said semiconductor substrate and higher than that in said low concentration layer.