Patent ID: 7456106
Filing Date: 2008-11-25
Classification: B24B,C30B,H01L

Abstract:
1. A method for producing a silicon wafer comprising: a slicing step of slicing a single-crystal ingot into thin disc-like wafers; and then a chamfering step of chamfering the wafer obtained from the slicing step; and then a lapping step for flattening the chamfered wafer; and then a rear-surface mild lapping step for abrading away part of processing distortions produced on the rear surface of the wafer during the chamfering and lapping steps; and then a rear-surface mild polishing step for abrading away part of roughness on the rear surface of the mildly lapped wafer wherein the thickness of the superficial layer removed from the surface during the mild lapping step is from 0.1-1.0 μm; and then an etching step for etching away with alkali solution the remains of processing distortions on the front and rear surfaces of the wafer; and then a front-surface mirror-polishing step for mirror-polishing the front surface of the etched wafer; and then a cleaning step for cleaning the mirror-polished wafer.