Evaluation of Silicon Wafer Polishing Pads Rheological Behavior of Polishing Pads and Improvement of Wafer Flatness

Abstract

Some new easy-to-use equipment for measuring quantitatively the rheological deformation characteristics of the polishing pads has been developed. The main results, using the measuring equipment, are as follows : (1) With processing time, peripheral side of the polishing pad deforms elastically more than center side, (2) The four-element rheology model showed good agreement with the experimental results, (3) A new parameter α, which is derived from the four-element model and is related to the elastic modulus, was found to be significant for the wafer flatness.