Surface treated abrasive particles for tungsten buff applications

A chemical-mechanical polishing composition comprising:

• (a) an alumina abrasive, wherein the alumina is surface-coated with a copolymer comprising a combination of sulfonic acid monomeric units and carboxylic acid monomeric units, or wherein the abrasive is surface-coated with a copolymer comprising a combination of sulfonic acid monomeric units and phosphonic acid monomeric units,
• (b) an oxidizing agent,
• (c) an organic phosphonic acid, and
• (d) water,
• wherein the polishing composition has a pH of about 2 to about 5.

A method of chemically mechanically polishing a substrate comprising:

• (i) providing a substrate,
• (ii) providing a polishing pad,
• (iii) providing a chemical-mechanical polishing composition comprising:
• (a) an abrasive selected from the group consisting of alumina, ceria, titania, zirconia, and combinations thereof, wherein the abrasive is surface-coated with a copolymer comprising a combination of sulfonic acid monomeric units and carboxylic acid monomeric units, or wherein the abrasive is surface-coated with a copolymer comprising a combination of sulfonic acid monomeric units and phosphonic acid monomeric units,
• (b) an oxidizing agent, and
• (c) water,
• wherein the polishing composition has a pH of about 2 to about 5,
• (iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition, and
• (v) moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to abrade at least a portion of the substrate to polish the substrate.