Synergy between dodecylbenzenesulfonic acid and isomeric alcohol polyoxyethylene ether for nano-scale scratch reduction in copper chemical mechanical polishing

In this paper, dodecylbenzenesulfonic acid (DBSA) and isomeric alcohol polyoxyethylene ether (iAEO) are tested as additives to basic silica-based slurries with the goal of reducing scratching during copper chemical mechanical polishing (CMP) in 14 nm ultra large scale integration. DBSA and iAEO can reduce scratch defects by more than 86% and exhibit stable scratch densities over 14 h of pad lifetime. Various analytical results including particle size distributions, large particle counts, dynamic mechanical analyses, and scanning electron microscope data reveal that the synergistic effects of DBSA and iAEO may improve particle dispersibility, enhance tribological behavior, increase pad water uptake, and effectively remove polishing byproducts from the pad.