Patent ID: 7211175

Claim:
An apparatus for an electrochemical process that comprises deposition of metal on a surface of a wafer and/or removal of at least a portion of metal on a surface of a wafer, the apparatus comprising: at least one reference electrode in operable communication with a control circuit; an electrode sufficient to serve as a counter electrode during the electrochemical process; and a holder sufficient for placing the wafer in an electrolyte, the holder comprising: a power lead in operable communication with a power supply, the power lead comprising at least one power contact sufficient for contacting the surface of the wafer and communicating power to the surface of the wafer such that the surface of the wafer serves as a cathode or an anode during the electrochemical process; and at least one sense lead in operable communication with the control circuit, the sense lead comprising at least one sense contact, spatially separated from the power contact, sufficient for contacting the surface of the wafer, the sense lead not carrying appreciable current and being sufficient for sensing potential at at least one point on the surface of the wafer during the electrochemical process.