Method for manufacturing silicon carbide semiconductor substrate

A method for manufacturing a silicon carbide semiconductor substrate comprising steps of:

• preparing a seed substrate;
• performing vapor phase etching onto a surface of said seed substrate;
• epitaxially growing silicon carbide on said surface;
• and
• prior to the step of epitaxially growing, increasing a temperature of said seed substrate to a film formation temperature employed in the step of epitaxially growing,
• the step of increasing the temperature being performed such that the temperature of said seed substrate is increased to a temperature for vacuum baking, said seed substrate is then maintained at said temperature for vacuum baking, the temperature is then started to be increased again to said film formation temperature, and an etching gas used in the step of performing the vapor phase etching is supplied to said seed substrate when the temperature is started to be increased again,
• said etching gas being hydrogen gas,
• at a point of time when the temperature of said seed substrate is increased to said film formation temperature, a flow rate of said etching gas becoming equal to a flow rate when used as carrier gas in the step of epitaxially growing, by increasing the flow rate of said etching gas after starting to supply said etching gas to said seed substrate,
• the step of performing the vapor phase etching including a step of etching the surface of said seed substrate at the film formation temperature employed in the step of epitaxially growing,
• a carbon-atom containing gas being supplied to said seed substrate from a point of time in the step of etching the surface of said seed substrate at said film formation temperature.