| 摘要 |
The present invention provides an acidic aqueous polishing composition suitable for polishing a silicon nitride-containing substrate in a chemical-mechanical polishing (CMP) process. The composition, at point of use, preferably comprises about 0.01 to about 2 percent by weight of at least one particulate ceria abrasive, about 10 to about 1000 ppm of at least one non-polymeric unsaturated nitrogen heterocycle compound, 0 to about 1000 ppm of at least one cationic polymer, optionally, 0 to about 2000 ppm of at least one polyoxyalkylene polymer, and an aqueous carrier therefor. The cationic polymer preferably is selected from a poly(vinylpyridine) polymer, a quaternary ammonium-substituted acrylate polymer, a quaternary ammonium-substituted methacrylate polymer, or a combination thereof. Methods of polishing substrates and of selectively removing silicon nitride from a substrate in preference to removal of polysilicon using the compositions are also provided. |
