Patent ID: 6227944
Filing Date: 2001-05-08
Classification: B24C

Abstract:
A method of processing a semiconductor wafer sliced from a single-crystal ingot and having front and back surfaces, said method comprising the steps, in order, of:(a) subjecting the front and back surfaces of the wafer to a lapping operation to reduce the thickness of the wafer and to remove damage caused during slicing of the wafer;(b) subjecting the wafer to an etching operation in which the wafer is immersed in a chemical etchant to further reduce the thickness of the wafer and to further remove damage remaining after the lapping operation;(c) subjecting the wafer to a double-side polishing operation in which material is concurrently and uniformly removed from the front and back surfaces of the wafer to uniformly remove damage caused by the lapping and etching operations, thereby improving the flatness of the wafer and leaving polished front and back surfaces; and(d) subjecting the back surface of the wafer to a back surface damaging operation in which subsurface damage is induced in the back surface of the wafer to provide gettering sites for extrinsic gettering while the front surface is substantially protected against being damaged or roughened.