Patent ID: 7645702
Filing Date: 2010-01-12
Classification: H01L

Abstract:
1. A manufacturing method of a silicon wafer, including: an etching process ( a double surface polishing process ( wherein the acid etching solution includes hydrofluoric acid, nitric acid, acetic acid, and water, respectively, wherein, when the resistivity of the silicon wafer is below 1 Ω·cm, the mixing ratio of hydrofluoric acid, nitric acid, acetic acid, and water is hydrofluoric acid: nitric acid: and water=1:1 to 5:3 to 8:3 to 7 by percent by weight, wherein, when the resistivity of the silicon wafer is above 1 Ω·cm, the mixing ratio of hydrofluoric acid, nitric acid, acetic acid, and water is hydrofluoric acid: nitric acid: and water=1:5 to 9:1 to 6:1 to 5 by percent by weight, wherein a total removal depth in the acid etching is 5 to 7 μm, wherein sodium hydroxide aqueous solution of 40 to 60 percent by weight is used in the alkali etching solution of said etching process ( wherein a total removal depth in the alkali etching is 13 to 15 μm, wherein, in said double surface simultaneous polishing process ( making a polishing removal depth B in said rear surface is 2 to 6 μm , and making a difference (A−B) between said polishing removal depth A and said polishing removal depth B is 3 to 4 μm.