Patent ID: 6368189
Filing Date: 2002-04-09
Classification: B24B

Abstract:
A wafer polishing head for polishing a wafer on a polishing pad, said polishing head comprising:a retaining ring having an interior cylindrical surface and defining an interior cylindrical pocket sized to carry said wafer and to laterally restrain movement of said wafer when said wafer is moved relative to said polishing pad while being polished against said polishing pad; a substrate subcarrier attached to said retaining ring by a primary diaphragm; a substrate attachment stop plate; and a resilient sealing member defining a first pressure zone, said resilient sealing member extending from a first surface of said stop plate adjacent said retaining ring interior cylindrical surface to receive and support said wafer and coupled for fluid communication to a first pressurized pneumatic fluid; said resilient sealing member defining a second pressure zone radially interior to said first pressure zone and extending between said first surface of said stop plate and said wafer when said wafer is attached to said polishing head during polishing of said wafer and coupled for fluid communication to a second pressurized pneumatic fluid, said first surface of said stop plate not being in contact with a wafer back side surface during polishing of said wafer; said first and said second pressurized fluids being adjusted to achieve predetermined polishing pressures over regions of a front side surface of said wafer.