Silicon carbide substrate, semiconductor device, and methods for manufacturing them

摘要

A silicon carbide substrate has a first main surface, and a second main surface opposite to the first main surface. A region including at least one main surface of the first and second main surfaces is made of single-crystal silicon carbide. In the one main surface, sulfur atoms are present at not less than 60×1010 atoms/cm2 and not more than 2000×1010 atoms/cm2, and carbon atoms as an impurity are present at not less than 3 at % and not more than 25 at %. Thereby, a silicon carbide substrate having a stable surface, a semiconductor device using the substrate, and methods for manufacturing them can be provided.

主权项

1. A silicon carbide substrate, comprising:
a first main surface; and a second main surface opposite to said first main surface, a region including at least one main surface of said first and second main surfaces consisting essentially of single-crystal silicon carbide, sulfur atoms being present in said one main surface at not less than 80×1010 atoms/cm2 and not more than 800×1010 atoms/cm2, and carbon atoms as an impurity being present in said one main surface at not less than 3 atomic percent (at %) and not more than 25 atomic percent (at %).