Disclosed is a method of chemically-mechanically polishing a substrate. The method comprises, consists of, or consists essentially of (a) contacting a substrate containing at least one Group III-V material, with a polishing pad and a chemical-mechanical polishing composition comprising water, abrasive particles having a negative surface charge, and an oxidizing agent for oxidizing the Group III-V material in an amount of from about 0.01 wt. % to about 5 wt. %, wherein the polishing composition has a pH of from about 2 to about 5; (b) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate; and (c) abrading at least a portion of the substrate to polish the substrate. In some embodiments, the Group III-V material is a semiconductor that includes at least one element from Group III of the Periodic Table and at least one element from Group V of the Periodic Table.