Modeling and simulation of material removal in planarization process

In planarization processes, material removal analysis is essential to the estimation of the wear rate and non-uniformity. A model that describes the material removal of a pad with rough surface grinding by using abrasive grains is developed. A collection of micro-contact spots is identified and the deformation approach is subsequently calculated. Elastic-plastic theory and the wear model are used to construct the expression for the magnitude of material removal as a function of the indentation depth. First, the indentation depth of micro-contact spots in the asperity of the pad and the deformation of the flat part of pad are obtained by using elastic-plastic theory. Then, the material removal caused by individual micro-contacts is calculated with the help of wear theory. Finally, the macroscopic wear volume is found by summing the volumetric wear of each individual micro-contact. Moreover, the pad dressing process is introduced to demonstrate the developed model for material removal. A parametric study is conducted to explore the influence on the material removal results and the planarization interfacial phenomena of operational parameters. These parameters compose of the applied down force, rotational speed of dresser, and the density of abrasive grains. The results provide a detailed picture of the interface phenomena and yield an insight into the physical effects of the operating parameters in the planarization processes.