Method of chemical mechanical polishing

摘要

A method of planarizing a substrate employs two separate chemical mechanical polishing (CMP) steps. In the first CMP step, the substrate is polished using a first CMP slurry solution and a polishing pad. A diluting solution is then applied to the polishing pad to remove slurry of the first CMP step. In the second CMP step, after applying the diluting solution to the polishing pad to remove the first slurry, second CMP slurry solution is applied to the polishing pad to facilitate additional planarization of the substrate. In a particular embodiment of this invention, the diluting solution comprises a buffer solution having a pH level corresponding to a pH level of one of the first or second CMP slurry solution. In accordance with another aspect of this embodiment, a plurality of different diluting solutions are applied to the polishing pad intermediate the respective first and second CMP steps.