Patent ID: 7648622

Claim:
A method of electropolishing a conductive surface on a wafer, comprising: positioning the conductive surface in proximity to a polisher having at least one cathode surface and at least one anode surface; rotating the wafer; linearly moving the conductive surface parallel to a first direction and over both at the at least one anode surface and the at least one cathode surface so as to vary an exposure of relative surface areas of the conductive surface to the at least one cathode surface and the at least one anode surface; electropolishing the conductive surface, wherein as the conductive surface is moved, less than 50% of the conductive surface is exposed to the at least one anode surface, wherein as the conductive surface is moved, an edge portion of the conductive surface is exposed to the at least one anode surface, wherein electropolishing of the conductive surface occurs at a faster rate at a central portion of the conductive surface than at the edge portion; and reversing a polarity of voltage on the at least one cathode surface and the at least one anode surface after the central portion is electropolished.