Apparatus for determining metal CMP endpoint using integrated polishing pad electrodes

1. Field of the Invention A polishing system includes a polishing tool having a platen, a polishing pad, and a controller. The platen is adapted to have the polishing pad attached thereto. The polishing pad includes a polishing surface and a back surface that is opposite the polishing surface. At least one sender electrode and at least one response electrode is disposed in the polishing pad. The controller is coupled to the polishing tool. A method includes polishing a conductive process layer of a wafer using a polishing pad of a polishing tool having at least one sender electrode and at least one response electrode disposed therein. A signal is provided to the at least one sender electrode. The signal provided to the at least one sender electrode is monitored with at least one of a group of the at least one response electrode, the at least one response electrode communicating with the at least one sender electrode through the conductive process layer of the wafer. Endpoint of the polishing process is determined based on the signal received by the at least one response electrode.