Patent ID: 7071079

Claim:
A method for producing an epitaxial wafer, comprising: pulling a silicon single crystal, in which nitrogen is doped to a concentration of 10 13 to 10 14 atoms/cm 3 , by Czochralski method, processing the silicon single crystal into a wafer to produce a silicon single crystal wafer, subjecting the silicon single crystal wafer to a two-stage heat treatment so that a density of oxide precipitates having such a size that a gettering capability can be achieved in bulk of the wafer may be 10 8 /cm 3 or more, the two-stage heat treatment consisting of: heating the silicon single crystal wafer at 600° C.–1000° C. for 0.5 hours to 8 hours, and subsequently heating the silicon single crystal wafer at 800° C.–1150° C. for 0 hour to 10 hours; and subjecting the silicon single crystal wafer to epitaxial growth.