Patent ID: 7384871
Filing Date: 2008-06-10
Classification: C09G,H01L

Abstract:
1. A method for polishing of a semiconductor wafer, the semiconductor wafer having copper interconnect metal and residual copper, comprising steps of: contacting the wafer with a polishing composition, the polishing composition comprising oxidizer, 0 to 1% by weight abrasive, copper inhibitor for the interconnect metal, 0.01 to 15% by weight copper complexing agent, the complexing agent being selected from acetic acid, citric acid, glycolic acid, lactic acid, malic acid, oxalic acid, salicylic acid, succinic acid, tartaric acid, thioglycolic acid, glycine, alanine, aspartic acid, ethylene diamine, trimethyl diamine, malonic acid, gluteric acid, 3-hydroxybutyric acid, propionic acid, phthalic acid, isophthalic acid, 3-hydroxy salicylic acid, 3,5-dihydroxy salicylic acid, gallic acid, gluconic acid, pyrocatechol, pyrogallol, tannic acid, including salts and mixtures thereof, sodium diethyl dithiocarbamate, ethyl acetoacetate and mixtures thereof, 0.01 to 5% by weight modified cellulose, the modified cellulose having carboxylic acid functionality and a molecular weight between 1K and 250K, 0.01 to 5% by weight copolymer of acrylic acid and methacrylic acid, and balance water, wherein the copolymer of acrylic acid and methacrylic acid has a monomer ratio (acrylic acid/methacrylic acid) in the range of 1:9 to 9:1 and the copolymer has a molecular weight in the range of 1K to 1000K; and clearing residual copper from the wafer with a polishing pad and the modified cellulose and copolymer of the polishing composition without excessive dishing of the copper interconnect metal wherein clearing time for clearing residual copper from the wafer is less than thirty seconds.