Method for manufacturing silicon carbide semiconductor device and silicon carbide semiconductor device

A method for manufacturing a silicon carbide semiconductor device, comprising:

• forming a silicon carbide epitaxial film on a silicon carbide substrate;
• flattening a surface of the epitaxial film by using chemical mechanical polishing to thereby obtain a flattened surface, of the epitaxial film, having an arithmetic mean roughness Ra of 0.3 nm or less;
• thermally oxidizing the flattened surface of the epitaxial film to form a sacrificial oxide;
• removing the sacrificial oxide;
• and
• cleaning, by using deionized water, a surface of the epitaxial film exposed by the removing of the sacrificial oxide,
• wherein the forming, the flattening, the thermally oxidizing, and the removing are performed sequentially without any intervening processing operations.