Effect of Surface Profile on the Material Removal Rate Distribution in CMP Process

Abstract

Material removal rate (MRR) distribution is a major concern in CMP process. In the published literatures, both experimental and theoretical research, MRR distribution is given without considering the surface profile of wafer. In this paper, the effect of surface profile on the MRR is analyzed based on the Preston equation and the contact pressure distribution calculated by the mixed lubrication model. It is found that the MRR distribution is dramatically affected by the profile of wafer surface, and whatever the polishing pad is conditioned in situ, the MRR distribution will be uniform at last. In addition, the wear of the pad surface induces a decrease of MRR.