Friction from Chemical Mechanical Polishing (CMP) of integrated circuits can cause damage to surface and sub-surface layers. To understand potentially damaging CMP friction, a model is presented which separates the contributions of: 1) bare pad asperity to substrate junction contacts, 2) slurry nanoparticles in the pad asperity contacts, and 3) a proposed substrate area where slurry particles adhere to and are swept along with the moving asperity contact. The model is used to interpret data from pin-on-disk friction experiments performed with a fused silica wafer and various polymer polishing pad materials, flooded with 100 nm diameter silica nanoparticle slurries. The results showed that only 18% of the pad asperity junction contact area had active particles and contacts outside of the asperity area were 38 times of the asperity junction area. This suggests that 93% of CMP material removal activity results from particles outside of the asperity/substrate contact.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.