Simulation of chemical-mechanical polishing is important because the chip-level planarity and wafer-level uniformity dependent on many dynamic factors are difficult to control. CHAMPS (chemical mechanical planarization simulator) has been developed for predicting and optimizing the thickness distribution after the CMP process using the chip level pattern density and an elastic spring model including equipment parameters. In this work, the results of CMP simulation are shown to agree well with the measured data. This simulator can be used to optimize CMP process conditions and to generate design rules for filling dummy patterns which are used to improve planarity and uniformity.