Silicon carbide semiconductor substrate, method of manufacturing a silicon carbide semiconductor device, and silicon carbide semiconductor device

A silicon carbide semiconductor substrate comprising:

• a semiconductor substrate made of silicon carbide;
• and
• an n-type epitaxial layer provided on a surface of the semiconductor substrate and made of silicon carbide, the n-type epitaxial layer containing nitrogen and vanadium, wherein
• the n-type epitaxial layer has a nitrogen concentration that is at most 1×1015/cm3, and
• the n-type epitaxial layer has a vanadium concentration that is lower than the nitrogen concentration of the n-type epitaxial layer.

A silicon carbide semiconductor device comprising:

• a semiconductor substrate made of silicon carbide;
• an n-type epitaxial layer provided on a front surface of the semiconductor substrate, the n-type epitaxial layer containing nitrogen and vanadium;
• a p-type region provided in a surface layer of the n-type epitaxial layer on a side of the n-type epitaxial layer facing toward the semiconductor substrate;
• a predetermined element structure constituted by the p-type region;
• a first electrode electrically connected with the p-type region;
• and
• a second electrode provided at a rear surface of the semiconductor substrate, wherein
• the n-type epitaxial layer has a nitrogen concentration that is at most 1×1015/cm3, and
• the n-type epitaxial layer has a vanadium concentration that is lower than the nitrogen concentration of the n-type epitaxial layer.