SiC semiconductor substrate and fabrication method of the SiC semiconductor substrate

A fabrication method of an SiC semiconductor substrate, comprising:

• forming a first graphene layer directly on an Si plane of an SiC single crystal substrate serving as a basis;
• epitaxially growing a first layer formed of a single-crystal SiC semiconductor via the first graphene layer;
• forming a second graphene layer directly on an Si plane of the first layer, the second graphene layer having a first surface formed directly on the Si plane of the first layer, and a second surface opposed to the first surface and having a flat surface on an entirety of the second surface;
• forming a polycrystal SiC semiconductor substrate via the second graphene layer;
• removing the single crystal substrate serving as the basis from the first graphene layer;
• eliminating the first graphene layer to expose a C plane of the first layer;
• forming a second layer on the C plane of the first layer by CVD growth;
• removing the polycrystal SiC semiconductor substrate;
• and
• eliminating the second graphene layer.