A method of processing a substrate having a conductive material layer disposed thereon is provided which includes positioning the substrate in a process apparatus and supplying a first polishing composition between to the substrate. The polishing composition comprises a first chelating agent, a second chelating agent, a first corrosion inhibitor, a second corrosion inhibitor, a suppressor, a solvent, and an inorganic acid based electrolyte to provide a pH between about 3 and about 10.