Patent ID: 7670466

Claim:
An apparatus for removing material from a microfeature workpiece, comprising: a support member configured to releasably carry a microfeature workpiece at a polishing position; first and second electrodes positioned to conduct electrical current to a microfeature workpiece when the microfeature workpiece is carried by the support member, at least one of the first and second electrodes being spaced apart from the microfeature workpiece when the microfeature workpiece is carried by the support member; a polishing medium disposed between the at least one electrode and the support member, at least one of the polishing medium and the support member being movable relative to the other, the polishing medium having a polishing surface, the polishing surface having a recess positioned to receive a polishing liquid, the recess having a recess surface facing the support member and spaced apart from the polishing surface to allow the polishing liquid in the recess to form a gap in the polishing liquid between the microfeature workpiece and the recess surface; and a processor having a machine-executable medium containing instructions that cause the processor to perform a method comprising controlling formation of the gap in the polishing liquid to achieve a target electropolishing rate for removing material from the microfeature workpiece.