Patent ID: 7081422

Claim:
A manufacturing process for an annealed wafer comprising the steps of: performing first heat treatment of a silicon single crystal wafer manufactured from a silicon single crystal pulled by means of a Czochralski method at a temperature in the range of 600 to 1100° C. to form oxide precipitates in the bulk of the wafer, and thereafter, performing second heat treatment at a temperature in the range of 1150 to 1300° C., wherein the first heat treatment is a two stage heat treatment including a precipitate nuclei forming heat treatment performed at a temperature in the range of 600 to 900° C. and a precipitate growing heat treatment following the precipitate nuclei forming heat treatment, performed at a temperature in the range of 950 to 1100° C, and wherein the second heat treatment is performed in a hydrogen atmosphere, an argon atmosphere, or a mixed gas atmosphere thereof.