A process for chemical-mechanical polishing a substrate containing tungsten includes the steps of providing a substrate; providing a polishing composition which contains: water, an oxidizing agent, guar gum, a dicarboxylic acid, a source of iron ions, a colloidal silica abrasive and optionally a pH adjusting agent; providing a chemical mechanical polishing pad which has 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 to remove at least some of the tungsten. The process can reduce static corrosion rate and inhibit dishing of the tungsten and erosion of underlying dielectrics.
