Scratching of Patterned Cu/Dielectric Surface Layers by Pad Asperities in CMP

Abstract—In chemical-mechanical polishing (CMP), as the rough polymer pad slides over patterned structures of metal interconnects and dielectrics the pad asperities themselves, though soft, may scratch the relatively hard layers. The fully plastically deformed pad asperities with high interfacial friction are the primary sources of pad scratching. In this paper, scratching of Cu/dielectric li…