Methods of controlling deposition of metal on field regions of a substrate in an electroplating process are provided. In one aspect, a dielectric layer is deposited under plasma on the field region of a patterned substrate, leaving a conductive surface exposed in the openings. Electroplating on the field region is reduced or eliminated, resulting in void-free features and minimal excess plating. In another aspect, a resistive layer, which may be a metal, is used in place of the dielectric. In a further aspect, the surface of the conductive field region is modified to change its chemical potential relative to the sidewalls and bottoms of the openings.