CMP PAD displacement and slurry flow characteristics: finite element analysis

摘要

This paper reports on a fully three-dimensional finite element analysis of the stress and deformation field of a porous compliant polishing pad of finite thickness in contact with a rigid wafer; coupled to a FEM flow analysis of the slurry. The pad deformation is governed by the classical linear elasticity equations. The porous nature of the pad is accounted for by the Reynolds equation of hydrodynamic lubrication for thin film flow. The linkage between the solid contact stress and the effective fluid film is through a model that relates the contact pressure of the pad asperities and the effective surface separation distance.