A Locally Relevant Prestonian Model for Wafer Polishing

Chemical mechanical planarization (CMP) is the primary method of wafer-scale planarization used in the manufacture of advanced integrated circuits. Preston's model, which was introduced in the 1920s for glass polishing, is an important component of much of the recently published work on CMP modeling. As applied, Prestonian models are effective in describing the average behavior of a process but are ineffective in providing fundamental understanding and locally relevant information regarding a chosen process. To date, there are still very few quantitative wafer-scale CMP removal rate and uniformity models. In this work, a locally relevant expression for material removal rate based on Preston's equation is presented. It incorporates localized kinematics and stress calculations. The model predictions are compared to experimental results for silicon dioxide polishing on a dual-axis CMP platform.