Patent ID: 7977219

Claim:
A manufacturing method for a silicon wafer comprising: producing a silicon single crystal ingot grown by Czochralski process; slicing the silicon single crystal ingot into plural silicon wafers; performing a first heat treatment process on the silicon wafer while introducing a first gas having an oxygen gas in an amount of 0.01 vol. % or more and 1.00 vol. % or less and a rare gas, the first heat treatment process comprising: rapidly heating the silicon wafer to a first temperature of 1300° C. or higher and a melting point of silicon or lower at a first heating rate; and keeping the silicon wafer at the first temperature; and after the first heat treatment process, performing a second heat treatment process on the silicon wafer while stopping introducing the first gas and instead, introducing a second gas having an oxygen gas in an amount of 20 vol. % or more and 100 vol. % or less and a rare gas, the second heat treatment process comprising: keeping the silicon wafer at the first temperature; and rapidly cooling the silicon wafer from the first temperature at a first cooling rate.