Polishing copper-containing patterned wafers

摘要

An aspect of the invention provides a method for polishing a patterned semiconductor wafer containing a copper interconnect metal with a polishing pad. The method includes the following: a) providing an aqueous polishing solution, the polishing solution containing an benzotriazole (BTA) inhibitor and a copper complexing compound and water; b) polishing the patterned wafer with the aqueous polishing solution and the polishing pad in a manner that dissolves copper into Cu |1 ions, the Cu |1 ions and BTA inhibitor having a concentration where [BTA] * [Cu 1 ] > than Ksp for Cu-BTA precipitate if the aqueous solution did not contain the complexing compound; and c) oxidizing at least some of the copper ions to prevent the polishing from precipitating the Cu-BTA precipitate.