| 摘要 |
The manufacturing method of a silicon wafer of the present invention includes an etching process ( 14 ) storing acid etching solution and alkali etching solution in plural etching tanks, respectively, and immersing a silicon wafer gone through a lapping process and having degraded superficial layers in the acid etching solution and the alkali etching solution in order so as to remove the degraded superficial layers; and a double surface polishing process ( 16 ) to simultaneously polish the front and rear surfaces of the wafer after the etching process; wherein sodium hydroxide aqueous solution of 40 to 60 percent by weight is used in the alkali etching solution of the etching process, and the polishing removal depth A in the wafer front surface is made 5 to 10 mum in the double surface simultaneous polishing process, and the polishing removal depth B in the rear surface is made 2 to 6 mum, and a difference (A-B) between the polishing removal depth A and the polishing removal depth B is made 3 to 4 mum. The manufacturing method of the present invention provides a silicon wafer, in which both sides of the wafer have a highly accurate flatness and small surface roughness, and moreover, which is a single surface mirror-polished wafer with the front and rear surfaces of the wafer identifiable by visual observation, and excellent in flatness when held by a stepper chuck and the like. |
