Surface adsorption mechanism of water-soluble polymer in polishing slurry

Final polishing process is important to make a clean surface for silicon (Si) semiconductor wafers. Final polishing progresses with slurry, and typical final polishing slurry includes water-soluble polymer to reduce defects. In this study, we examined the water-soluble polymer behavior in slurry in terms of its adsorption mechanism to wafer- and/or abrasive- surface. As a result, we confirmed correlation in the water-soluble polymer adsorption to abrasive and wettability of polished wafer surface. From this result, we considered that silica abrasives behave as a 'carrier' for the water-soluble polymer to the Si wafer surface. We also developed final polishing slurry which gave high wettability of the polished wafer to reduce defects on the surface by using electrostatic effect dosed salts based on the above adsorption mechanism. Keywords: Planarization, Chemical-mechanical Polishing, silicon, polymer, surface adsorption