Abstract: In an effort to explore the contribution of the pad, which is usually full of pores, to the performance of chemical mechanical polishing (CMP), a three-dimensional flow model of CMP is presented by assuming the fluids in the porous layer complied with Darcy law, I.e., the flow velocity is proportional to the pressure gradient and inverse proportional to the viscosity. The flow equation is deduced accordingly and, by taking advantage of the multilevel technique and line relaxation technique, numerical simulations are carried out to reveal the relationships between the load capacities and operational parameters (including pivot height, roll angle and pitch angle), under conditions with different porous parameters and different thicknesses of the porous layer. The little porous parameter will lead to prominent increase of load capability (for instance, the load and the moment predicted), which is still augmented by the thicker layer parameter. This will result in a higher material removal of CMP. A pad full with larger pores will lead deduction in load capability, facilitating the free flow of the fluids through the pores. The research will add some insights to the mechanism of CMP technique.

Key words: Chemical mechanical polishing(CMP) Porous layer, Flow property