CHEMOMECHANICAL POLISHING METHOD AND SLURRY COMPOSITION THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide slurry for polishing a semiconductor wafer during metal interconnection formation and a polishing method using it. SOLUTION: At first, a first oxidizing agent comprising a first slurry preferably containing ferric nitride for removing excessive metal of metallic interconnection is used. The slurry leaves metallic residue in a surface of a wafer. Metallic residue and a liner material are removed by using a second slurry which contains another oxidizing agent, preferably potassium iodate solution and has affinity which is larger to both metallic residue and a liner material than to a lower side dielectric. The slurry remarkably reduces scratch of a lower side dielectric. The metallic interconnection is effective in reduction of an entire of a resistance of a wafer and reduction of the number of short circuits, and enables a lower side dielectric to be protected forcibly. Overpolish of a wafer and its related problem can be avoided.