Polishing compositions and methods for removing conductive materials from a substrate surface are provided. The method includes providing a substrate comprising dielectric feature definitions, a barrier material disposed in the feature definitions, and a bulk conductive material disposed on the barrier material in an amount sufficient to fill feature definitions; polishing the substrate to substantially remove the bulk conductive material; polishing a residual conductive material to expose feature definitions, comprising: applying a first voltage for a first time period, wherein the first voltage is less than the critical voltage; and applying a second voltage for a second time period, wherein the second voltage is greater than the critical voltage.