| 摘要 |
A slurry for copper polishing has a pH between 7.5 and 12. In a particular embodiment of the present invention, a slurry for polishing copper has a pH between 8 and 11.5, and includes a siO<SUB>2 </SUB>abrasive, a (NH<SUB>4</SUB>)<SUB>2</SUB>S<SUB>2</SUB>O<SUB>8 </SUB>oxidizer, a benzotriazole corrosion inhibitor, and a K<SUB>3</SUB>PO<SUB>4</SUB>/K<SUB>2</SUB>HPO<SUB>4 </SUB>buffer. A copper polish slurry, in accordance with the present invention, operates with a high pH of greater than approximately 7.5. In this range the slurry has a low static etch due to formation of a robust, protective layer. This slurry may additionally have S<SUB>2</SUB>O<SUB>8</SUB><SUP>-2 </SUP>or Fe(CN)<SUB>6 </SUB><SUP>-3 </SUP>as an oxidizer and can thus offer a high polish rate on the order of 7,000 to 10,000 angstroms per minute which does not decrease significantly during polishing. Such an inventive slurry offers a wide CMP process window such that the slurry and process parameters can be optimized to yield low recess, erosion, and dishing on patterned wafers.
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