The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 25, 2017
Filed:
Jul. 11, 2012
William Ward, Glen Ellyn, IL (US);
William Ward, Glen Ellyn, IL (US);
Cabot Microelectronics Corporation, Aurora, IL (US);
Abstract
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.