The material removal rate during chemical mechanical polishing (CMP) depends sensitively on pattern geometry and density. Different material removal rates in CMP result in excessive erosion of the dielectric layer or dishing of metal lines. An analytical model for step height reduction is proposed using a linear system method. The magnitude spectra and the phase spectra of a specified CMP process are given. The evolutions of polishing height in the up area and polishing height in the down area for different pattern density, pad stiffness, and down pressure and slurry selectivity are presented and compared with the experimental data. The evolution of the topography on the wafer surface is simulated. The influences of the polish parameters on the step height reduction on CMP at different cases are discussed. (C) 2007 The Electrochemical Society.