This study presents the possibility of scratch reduction on wafer in CMP by applying the ultrasonic and megasonic energy into the slurry which might contain large abrasive particles. Experiments were conducted to verify the dispersion ability of agglomerated particles by applying ultrasonic, megasonic waves and analyze the particle distribution of used slurry in case, of sonic energy assisted or none. And the dispersion stability of megasonic waves was investigated through the experiment of stability of the dispersed slurry, Finally, to confirm that the distribution of particles in slurry by ultrasonic waves was actually related to scratches on wafer when CMP was done, tungsten blanket wafer was processed, by CMP to compare and investigate scratches on wafer.