Surface integrity of silicon wafers in ultra precision machining
Journal
International Journal of Advanced Manufacturing Technology
Journal Volume
29
Journal Issue
3-4
Pages
372-378
Date Issued
2006
Author(s)
Abstract
Silicon wafers are the most extensively used material for integrated circuit (IC) substrates. Before taking the form of a wafer, a single crystal silicon ingot must go through a series of machining processes, including slicing, lapping, surface grinding, edge profiling, and polishing. A key requirement of the processes is to produce extremely flat surfaces on work pieces up to 350mm in diameter. A total thickness variation (TTV) of less than 15μm is strictly demanded by the industry for an 0.18μm IC process. Furthermore, the surfaces should be smooth (Ra<10nm) and have minimum subsurface damage (<10μm) before the final etching and polishing. The end product should have crack-free mirror surfaces with a micro-roughness less than 1.8̊. In this paper, experiments are conducted to investigate the effects of various parameters on the subsurface damage of ground silicon wafers.
SDGs
Type
journal article