A process for forming a conductive structure on a substrate is provided. The substrate has a copper seed layer that is partially exposed through a plurality of openings in a masking layer such as a photoresist. The masking layer is formed on the seed layer. The process electroplates copper through the openings and onto the seed layer. During the copper electroplating process the surface of the masking layer is mechanically swept. The process forms planar conductive material deposits filling the plurality of holes in the masking layer. The upper ends of the conductive deposits are substantially co-planar.