Effects of Polyvinyl Alcohol on Silicon Chemical Mechanical Polishing

The effect of polyvinyl alcohol (PVA) in alkaline slurry on the silicon wafer surface during chemical mechanical polishing (CMP) was investigated. This investigation found that PVA is adsorbed onto the colloidal silica abrasive and silicon wafer surface, and that the adsorption amount increases in accordance with PVA concentration. Characterization and analysis were given by measuring the pH, viscosity, removal rate, the adsorption amount of PVA on the surface of colloidal silica particles, contact angle and local point defects of silicon wafer surface.