A system, composition, and a method for planarizing or polishing a composite substrate are provided. The planarizing or polishing system comprises (i) a polishing composition comprising (a) about 0.5 wt. % or more of fluoride 5 ions, (b) about 1 wt. % or more of an amine, (c) about 0.1 wt. % or more of a base, and (d) water, and (ii) an abrasive. The present invention also provides a method of planarizing or polishing a composite substrate comprising contacting the substrate with a system comprising (i) a polishing composition comprising (a) about 0.5 wt. % or more of fluoride ions, (b) about 1 wt. % or more of an amine, (c) about 0.1 wt. % or more of a base, and (d) water, and (ii) an abrasive.