Patent ID: 11890715
Assignee: APPLIED MATERIALS, INC.
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. A carrier head for holding a substrate in a polishing system, comprising:
a housing;
a first flexible membrane secured to the housing to form one or more pressurizable chambers to apply downward pressure through a central membrane portion of the first flexible membrane to a central portion of a substrate; and
a plurality of independently operable piezoelectric actuators supported by the housing and positioned only radially outward of the central membrane portion and at different angular positions so as to independently adjust pressure on a plurality of angular zones in an annular outer region of the substrate surrounding the central portion of the substrate, and wherein the central membrane portion through which pressure from the one or more pressurizable chambers is applied is positioned only radially inward of the plurality of independently operable piezoelectric actuators.