Patent ID: 6431959
Filing Date: 2002-08-13
Classification: B24B,H01L

Abstract:
A system for minimizing a defect level of a polysilicon workpiece, the system comprising:a first chemical mechanical planarization polishing station including a first polishing pad having a first polishing surface for receiving the workpiece and a first chemical slurry applied to the first polishing surface, wherein the first chemical slurry comprises a basic solution containing at least a 50 percent concentration of colloidal silica particles that is diluted in the range of 18:1 to 22:1 with deionized water; a second chemical mechanical planarization polishing station including a second polishing pad having a second polishing surface for receiving the workpiece and a second chemical slurry applied to the second polishing surface; and wherein the first polishing pad has a hardness different than a hardness of the second polishing pad and the first chemical slurry is different from the second chemical slurry.