Patent ID: 6120350
Filing Date: 2000-09-19
Classification: B24B,B24D

Abstract:
A process for polishing semiconductor wafers using a wafer polishing machine having a rotating polishing pad including a polishing surface defined by a radially inner boundary and a radially outer boundary, the polishing surface having a cross sectional profile between its radially inner and outer boundaries, the process comprising the steps of:polishing at least one face of each of a first plurality of semiconductor wafers;monitoring the cross sectional profile to determine whether the profile of the polishing surface from said first plurality of wafers becomes more curved in shape than permitted by a process tolerance amount;if the determined shape of the profile of the polishing surface from said first plurality of wafers is more curved than the process tolerance amount, shaping the polishing pad, said step of shaping the polishing pad comprising the steps of:engaging a pad shaping tool with the polishing surface, the tool having at least two discontinuous pad shaping surfaces that simultaneously engage the polishing surface, said pad shaping surfaces located in spaced apart positions relative to each other on the tool;rotating the polishing pad while preventing translational movement of the tool so that the pad shaping tool shapes the polishing surface; andpolishing at least one face of each of a second plurality of semiconductor wafers;monitoring the cross sectional profile to determine whether the profile of the polishing surface from said second plurality of wafers becomes more curved in shape than permitted by the process tolerance amount;if the determined shape of the profile of the polishing surface from said second plurality of wafers is more curved than the process tolerance amount, optimizing a size of the pad shaping surfaces of the tool to produce improved wafer flatness.