Patent ID: 10573524

Abstract:
A process for chemical mechanical polishing a substrate containing titanium nitride and titanium is provided comprising: providing a polishing composition, containing, as initial components: water; an oxidizing agent; a linear polyalkylenimine polymer; a colloidal silica abrasive with a positive surface charge; a carboxylic acid; a source of ferric ions; and, optionally pH adjusting agent; wherein the polishing composition has a pH of 1 to 4; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein at least some of the titanium nitride and at least some of the titanium is polished away with a selectivity between titanium nitride and titanium.