Method for manufacturing silicon carbide epitaxial substrate

A method for manufacturing a silicon carbide epitaxial substrate, the method comprising:

• forming a first silicon carbide layer on a first silicon carbide substrate by epitaxial growth, using a first ammonia gas as a dopant gas;
• measuring a thickness of the first silicon carbide layer and a carrier concentration of the first silicon carbide layer;
• calculating formation conditions for a second silicon carbide layer;
• and
• forming the second silicon carbide layer on a second silicon carbide substrate by epitaxial growth, using a second ammonia gas as a dopant gas, wherein
• when a flow rate of the first ammonia gas in the forming of the first silicon carbide layer by epitaxial growth is defined as a first flow rate, a formation time of the first silicon carbide layer in the forming of the first silicon carbide layer by epitaxial growth is defined as a first formation time, the thickness of the first silicon carbide layer is defined as a first thickness, the carrier concentration of the first silicon carbide layer is defined as a first concentration, a target thickness of the second silicon carbide layer is defined as a second thickness, and a target carrier concentration of the second silicon carbide layer is defined as a second concentration,
• in the calculating of the formation conditions for the second silicon carbide layer, a second formation time of the second silicon carbide layer is calculated as a value obtained by multiplying a value obtained by dividing the second thickness by the first thickness, by the first formation time, and a second flow rate of the second ammonia gas in the forming of the second silicon carbide layer by epitaxial growth is calculated as a value obtained by multiplying a value obtained by dividing the second concentration by the first concentration, by the first flow rate,
• in the forming of the second silicon carbide layer by epitaxial growth, the second silicon carbide layer is formed using the second formation time and the second flow rate, and
• the forming of the first silicon carbide layer by epitaxial growth and the forming of the second silicon carbide layer by epitaxial growth are performed using an identical apparatus.