A process for chemical mechanical polishing a substrate containing tungsten to at least reduce dishing of tungsten features of 100 μm or less. The process includes providing a substrate containing tungsten features of 100 μm or less; providing a polishing composition, containing, as initial components: water; an oxidizing agent; arginine or salts thereof; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive; and, optionally, a pH adjusting agent; and, optionally, a surfactant; and, optionally, a biocide; 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 some of the tungsten is polished away from the substrate and yet at least reducing dishing of the tungsten features of 100 μm or less.