Patent ID: 6936542
Filing Date: 2005-08-30
Classification: C09G,H01L

Abstract:
1. A method for chemical mechanical polishing copper, barrier material and dielectric material, the method which comprises the steps of: a) providing a first chemical mechanical polishing slurry comprising (i) 1-10 wt. % silica particles, (ii) 1-12 wt. % oxidizing agent, and (iii) 0-2 wt. % corrosion inhibitor and cleaning agent, wherein said first slurry has a higher removal rate on copper relative to a lower removal rate on said barrier material; b) chemical mechanical polishing a semiconductor wafer surface with said first slurry; c) providing a second chemical mechanical polishing slurry comprising (i) 1-10 wt. % silica particles, (ii) 0.1-1.5 wt. % oxidizing agent, and (iii) 0.1-2 wt. % carboxylic acid, having a pH in a range from about 2 to about 5, wherein the amount of (ii) is not more than the amount of (iii), and wherein said second slurry has a higher removal rate on said barrier material relative to a lower removal rate on said dielectric material and an intermediate removal rate on copper; and d) chemical mechanical polishing said semiconductor wafer surface with said second slurry.