Method for manufacturing silicon carbide epitaxial substrate, method for manufacturing silicon carbide semiconductor device, and apparatus for manufacturing silicon carbide epitaxial substrate

Abstract

In forming of a silicon carbide layer, when an X axis indicates a first value representing, in percentage, a value obtained by dividing a flow rate of silane by a flow rate of hydrogen and a Y axis indicates a second value representing a flow rate of ammonia in sccm, the first value and the second value fall within a quadrangular region surrounded by first coordinates, second coordinates, third coordinates, and fourth coordinates in XY plane coordinates. The first coordinates are (0.05, 6.5×10). The second coordinates are (0.05, 4.5×10). The third coordinates are (0.22, 1.2×10). The fourth coordinates are (0.22, 1.3×10). After the forming of the silicon carbide layer, an average value of carrier concentration of the silicon carbide layer is more than or equal to 1×10cmand less than or equal to 2×10cm.