US Patent 7534277 Slurry composition for secondary polishing of silicon wafer

Disclosed is a slurry composition for secondary polishing of silicon wafers comprising: 2˜10 weight % of colloidal silica having an average particle size of 30˜80 nm; 0.5˜1.5 % by weight of ammonia; 0.2˜1 weight % of a hydroxyalkycellulose-based polymer for modifying rheology of the composition; 0.03˜0.5 weight % of a polyoxyethylenealkylamine ether-based nonionic surfactant; 0.01˜1 weight % of a quaternary ammonium base and the balance of deionized water.