Methods for manufacturing silicon carbide single crystal ingot and silicon carbide single crystal wafer

A method for manufacturing a silicon carbide single crystal ingot, comprising:

• supplying a raw material gas containing hydrogen gas, monosilane, and hydrocarbon gas to a space in which a seed crystal made of silicon carbide is placed;
• and
• growing a silicon carbide single crystal on the seed crystal by keeping a monosilane partial pressure at 4 kPa or more and heating the space to a temperature of 2400° C. to 2700° C., wherein
• in the supplying and the growing, the temperature of the space and supply of the raw material gas are controlled such that a temperature gradient of a growth crystal surface of the silicon carbide single crystal in a radial direction is 0.1° C./mm or less, and a radius of curvature of the growth crystal surface is 4.5 m or more, thereby to produce a silicon carbide single crystal ingot having a growth length of 3 mm or more and an internal stress of 10 MPa or less.