Patent ID: 7601642

Claim:
A method for processing a silicon wafer comprising: a slicing step ( 11 ) in which a single crystal ingot is sliced into thin disc-like wafers; a lapping step ( 13 ) in which the surface of each wafer is lapped to be planar; an alkaline cleaning step ( 14 ) in which the wafer is subjected to alkaline cleaning to be removed of contaminants resulting from preceding machining; and an etching step ( 16 ) in which the wafer is alternately transferred between two groups of etching tanks one of which contain acidic etching solutions and the other alkaline etching solutions, wherein: a beveling step ( 12 ) is introduced between the slicing step ( 11 ) and the lapping step ( 13 ), in which the wafer is immersed in an acidic solution containing hydrofluoric acid (HF) and nitric acid (HNO 3 ) at a volume ratio of ⅛ to ½ (HN/HNO 3 ) so that degraded superficial layers occurring on the front and rear surfaces of the wafer as a result of machining can be removed and the edge surface of the wafer can be beveled.