Patent ID: 7700394

Claim:
A method for manufacturing a silicon wafer, produced by slicing a silicon single-crystal rod to obtain a silicon wafer, subjecting the silicon wafer to a first heat treatment to form oxygen precipitate nuclei therein, and then subjecting the silicon wafer to a second heat treatment which grows the oxygen precipitate nuclei to form oxygen precipitates therein, and further then subjecting the silicon wafer having the oxygen precipitates formed therein to a third heat treatment in a semiconductor device manufacturing process, the method for manufacturing the silicon wafer comprising: setting a plurality of types of oxygen concentrations within the range of 10×10 17 to 18×10 17 atoms/cm 3 (ASTM F-121, 1979) and thermal histories for manufacture of the wafer; calculating each of a diagonal length L (nm) and a density D (pieces/cm 3 ) of the oxygen precipitates in the silicon wafer after the second heat treatment step to form the oxygen precipitates and immediately before the third heat treatment step of the device manufacturing process by solving a Fokker-Planck equation using respective combinations of the plurality of types of oxygen concentrations and thermal histories as input parameters; calculating a maximum heat stress S (MPa) acting in a tangent line direction of an outer peripheral portion of the silicon wafer in the third heat treatment step of the device manufacturing process based on a structure and a third heat treatment temperature of a third heat treatment furnace used in the third heat treatment step of the device manufacturing process; and determining an oxygen concentration and a thermal history satisfying the following expression (1) in the plurality of types of oxygen concentrations and thermal histories: 12000× D −0.26 ≦L≦ 51000× S −1.55 (1).