US Patent 7425250 Electrochemical mechanical processing apparatus

A system for electrochemical mechanical polishing of a conductive surface of a wafer is provided. The system includes a wafer holder to hold the wafer and a belt pad disposed proximate to the wafer to polish the conductive surface. Application of a potential difference between conductive surface and an electrode and establishing relative motion between the belt pad and the conductive surface result in material removal from the conductive surface. Electrical contact to the surface is provided through either contacts embedded in the belt pad or contacts placed adjacent the belt pad.