In order to increase the polishing rate for a silicon wafer,the composite abrasive slurry was used in Chemical Mechanical Polishing(CMP).Zeta potentials of silica abrasives and polystyrene particles in the slurry were measured at various pH values,and the mechanism of interactions between silica abrasives and polymer particles was analyzed.Small silica abrasives were observed to attach onto the surfaces of the polystyrene particles and some resin particles.Then,the composite abrasive slurry was obtained by adding some polymer particles into single abrasive slurry.In comparison with the polishing performance of traditional CMP and CMP using composite abrasive slurry,the mechanism of material removal of CMP using composite abrasive slurry was proposed,and the influence of craft parameters on the polishing rate was studied through the experiments.Experimental results indicate that the polishing rate is 180 nm/min with single silica abrasive slurry,and 273 nm/min,324 nm/min with the silica abrasive/polystyrene particle composite slurry and silica abrasive/ resin particle composite slurry respectively.These data show that the removal rate with composite abrasive slurry is improved significantly and the wafer surface roughness Ra is 0.2 nm.