Patent ID: 7083507

Claim:
A substrate holding apparatus for holding a substrate to be polished and pressing said substrate against a polishing surface, said substrate holding apparatus comprising: a top ring body for holding a substrate; a seal ring to be brought into contact with an upper surface of a peripheral portion of the substrate when held by said top ring body; a support member for supporting said seal ring; a contact member mounted on a lower surface of said support member and disposed in a space formed by the substrate, said seal ring and said support member when the substrate is held by said top ring body, said contact member having an elastic membrane to be brought into contact with the substrate when held by said top ring body; a first pressure chamber defined in said contact member; a second pressure chamber defined outside of said contact member; a fluid source for independently supplying a fluid into, or creating a vacuum in, said first pressure chamber and said second pressure chamber; and a communicating portion formed in a lower surface of said elastic membrane of said contact member for allowing fluid supplied to said first pressure chamber to contact a contact surface of the substrate when held by said top ring body.