| 摘要 |
A method for polishing a patterned semiconductor wafer is provided to ensure good metal removal rates, with metal clearing, and low dishing of the metal interconnects and to reduce green staining generated by Cu-benzotriazole precipitate. A method for polishing a patterned semiconductor wafer containing a copper interconnect metal with a polishing pad includes the steps of: (a) providing an aqueous polishing solution, the polishing solution containing an benzotriazole (BTA) inhibitor and a complexing compound of the formula 1, where R is hydrogen or a carbon-containing compound, the complexing compound being capable of complexing copper ions 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 Cu^+1 ions to Cu^+2 ions to prevent the polishing from precipitating the Cu-BTA precipitate on the patterned wafer and polishing pad.
|
