Kinetics model incorporating both the chemical and mechanical effects on material removal for copper chemical mechanical polishing

A comprehensive model for the copper material removal in a chemical mechanical polishing (CMP) process is presented in which both chemical and mechanical effects are taken into consideration. The chemical effects describing the role of oxidizer, complexing agent come into play through the formation of chemically modified surface layer on the copper surface that, in turn, is removed by mechanical effects. Meanwhile there is also heating of the copper surface due to friction during the polishing process, which additionally decreases chemical activation energy and increases the chemical reaction rate. In addition, the removal rate and the coupled effects of the chemical additives are determined from a close-form equation, making use of the concepts of chemical–mechanical equilibrium and chemical kinetics. The model prediction trends are consistent with the published experimental data. This paper aided the understanding of the mechanism of chemical and mechanical interactions during polishing.