A method and apparatus for electroprocessing a substrate is provided. In one embodiment, a method for electroprocessing a substrate includes the steps of biasing a first electrode to establish a first electroprocessing zone between the electrode and the substrate, and biasing a second electrode disposed radially inward of the first electrode with a bias that is different than the bias applied to the first electrode. In one embodiment, the first electrode is coated with an inert material and in this way the same polish rate is obtained with a lower potential level applied to the first electrode.