Modeling effect of chemical–mechanical synergy on material removal at molecular scale in chemical mechanical polishing

This paper proposed a novel mathematical model to fully describe the influence of chemical mechanical synergy (CMS) on material removal in chemical mechanical polishing (CMP) of wafer at molecular scale. A general equation is derived on the basis of molecular scale removal mechanism and micro-contact theory. It is shown that the relative velocity-removal rate relation follows the trend similar to that observed from the effects of pressure and oxidizer concentration on material removal not discussed by previous models. Furthermore, the parameters of the poling pad, wafer and operating variables in CMP process that are not available in other complex models are formulated into the model. The model predictions are good agreement with the published experimental data. In addition, the present study also lends further credence to the molecular scale removal mechanism of CMP process in addition to its underlying theoretical foundation.