Surface shape and contact pressure evolution in two component surfaces: application to copper chemical mechanical polishing

Two defects that arise from the polishing process in integrated circuits technology are erosion and dishing. In this manuscript a generic numerical model that is capable of describing these defects from a mechanics perspective is presented. This numerical model formulates evolution of surface shape for an initially. at sample made up of two distinct materials with different wear rates under constant average polishing pressure. A two parameter elastic foundation model is used for contact pressure calculations. Qualitatively, the results compare favorably to published experimental data collected for copper chemical mechanical polishing. Although entirely mechanical, such modeling may perhaps provide insight into the mechanics of the surface defects and errors encountered during polishing.