A carrier head that has a base assembly and a flexible membrane. The flexible membrane has a generally circular main portion with a lower surface that provides a substrate-mounting surface and a plurality of concentric annular portions extending from the main portion and secured to the base assembly. The volume between the base assembly and the flexible membrane forming a plurality of pressurizable chambers.
CROSS-REFERENCE TO RELATED APPLICATIONS
Under 35 U.S.C. .sctn.1.20, this application is a continuation of and claims priority to U.S. application Ser. No. 09/712,389, filed on Nov. 13, 2000 now U.S. Pat. No. 6,857,945, which claims priority to U.S. Provisional Application Ser. No. 60/220,641, filed Jul. 25, 2000. The disclosure of the prior applications are considered part of and are incorporated by reference in the disclosure of this application.
A carrier head for chemical mechanical polishing of a substrate includes a base and a flexible membrane extending beneath the base. The flexible membrane includes a central portion with an outer surface providing a substrate receiving surface, a perimeter portion connecting the central portion to the base, and at least one flap extending from an inner surface of the central portion. The flap divides a volume between the flexible membrane and the base into a plurality of chambers, and the flap includes a laterally extending first section and an angled second section extending beneath the first section and connecting the laterally extending first section to the central portion.
