Patent ID: 7582159

Claim:
A method for producing a single crystal by Czochralski method by pulling a seed crystal from a raw material melt, comprising: immersing the seed crystal into the raw material melt; and growing the single crystal by rotating and pulling the seed crystal, wherein: the single crystal is pulled while controlling a value of V/G (mm 2 /K·min) within a range of values of V/G (mm 2 /K·min); and the range of values of V/G (mm 2 /K·min), including a defect region and/or a defect-free region, is controlled according to Tmax(° C.); wherein: V (mm/min) is a single crystal pulling rate of pulling the single crystal; G (K/mm) is a temperature gradient at a solid-liquid interface, in a range of a melting point of the raw material and 1400° C.; Tmax(° C.) is a highest temperature of the raw material melt at an interface between a quartz crucible inner wall and the raw material melt; and the range of values of V/G (mm 2 /K·min) is: (A) from −0.000724 [mm 2 /(° C.·K·min)]×Tmax(° C.)+1.31 (mm 2 /K·min) to less than −0.000724 [mm 2 /(° C.·K·min)]×Tmax(° C.)+1.38 (mm 2 /K·min); or (B) −0.000724 [mm 2 /(° C.·K·min)]×Tmax(° C.)+1.38 (mm 2 /K·min) or more; or (C) from −0.000724 [mm 2 /(° C.·K·min)]×Tmax(° C.)+1.31 (mm 2 /K·min) to −0.000724 [mm 2 /(° C.·K·min)]×Tmax(° C.)+1.35 (mm 2 /K·min).