High selectivity CMP slurry

The present invention provides a chemical mechanical polishing slurry and, more particularly, a chemical mechanical polishing slurry that exhibits a high selectivity for silicon dioxide in preference to silicon nitride over a broad pH range. The present invention provides a chemical mechanical polishing slurry for use in removing a first substance from a surface of an article in preference to silicon nitride by chemical mechanical polishing. The chemical mechanical polishing slurry according to the invention includes an abrasive, an aqueous medium, and an organic polyol that does not dissociate protons, said organic polyol including a compound having at least three hydroxyl groups that are not dissociable in the aqueous medium, or a polymer formed from at least one monomer having at least three hydroxyl groups that are not dissociable in the aqueous medium. In the preferred embodiment, ceria particles are used as the abrasive and the organic polyol is selected from the group consisting of mannitol, sorbitol, mannose, xylitol, sorbose, sucrose, and dextrin. The chemical mechanical polishing slurry can further optionally include acids or bases for adjusting the pH within an effective range of from about 2 to about 12. The present invention also provides a method of selectively removing a first substance such as silicon dioxide in preference to silicon nitride from a surface of an article by chemical-mechanical polishing.