The effects of the variation of chemical mechanical planarization (CMP) process parameters on slurry hydrodynamics and removal rate are studied using physically based models. The two models which are developed to describe and fundamentally understand the CMP process are (i) the lubrication model for slurry flow and (ii) the mass transport model for material removal. The mass transport model is developed for copper CMP. Conditions for stable operation and reduced wafer scratching are identified from the lubrication model. The mass transport model takes into account the chemical reaction at the wafer surface, the slurry flow hydrodynamics, and the presence of abrasive particles. The polish rates predicted by the model agree well with those measured experimentally.