Patent ID: 9548211
Date: 2017-01-17
CPC Classifications: C09G,H01L

Claim:
1. A chemical-mechanical polishing (CMP) method for selectively removing silicon carbide from the surface of substrate in preference to silicon dioxide, the method comprising the steps of: (a) contacting a surface of the substrate with a polishing pad and an aqueous CMP composition; and (b) causing relative motion between the substrate and the polishing pad while maintaining a portion of the aqueous CMP composition in contact with the surface between the pad and the substrate for a period of time sufficient to abrade at least a portion of the silicon carbide present in the substrate from the surface; wherein the aqueous CMP composition contains a particulate alumina-doped colloidal silica abrasive present at a concentration in the range of about 0.1 to about 5 percent by weight, wherein the particulate alumina-doped colloidal silica abrasive is about 600 to about 800 ppm of aluminum based on the particulate weight, and an acidic buffering agent providing a pH in the range of about 2 to about 7, the aqueous CMP composition being capable of abrading silicon carbide present on the surface of the substrate at a higher removal rate than the concurrent abrading of silicon dioxide present on the surface of the substrate.