Patent ID: 7527722
Filing Date: 2009-05-05
Classification: B24B,H01L

Abstract:
1. An apparatus comprising: a platen; a polishing pad disposed over said platen; a segmented cathode disposed around edge of said polishing pad and between said platen and a rear surface of said polishing pad; a slurry disposed on said polishing pad; a wafer disposed on said polishing pad and said slurry, said wafer having a body that is electrically conductive; a wafer carrier to hold said wafer; a chiller or heater to circulate a fluid within said platen and within said wafer carrier; a segmented anode disposed between a rear surface of said body of said wafer and said wafer carrier, said segmented anode being partitioned into small components that may be electrically adjusted separately to change polishing rates and polishing selectivities for different materials in a surface layer of said wafer; an enclosure disposed around said platen and said wafer carrier; a power supply to apply a voltage or current between said segmented cathode and said segmented anode; and a computer to vary said voltage or said current to improve uniformity of said polishing rates and said polishing selectivities.