Polishing carrier head with piezoelectric pressure control
AssigneeApplied Materials, Inc.
InventorsBrian J. Brown, Andrew J. Nagengast, Justin Ho Kuen Wong
Life of this patent
Estimating the term…
Abstract
A carrier head for holding a substrate in a polishing system includes a housing, a first flexible membrane secured to the housing to form one or more pressurizable chambers to apply 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, the plurality of piezoelectric actuators positioned 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.
Claims20
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.
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, the first flexible membrane having a central membrane section having a lower surface to control pressure on a central portion of a substrate;
- a plurality of independently operable piezoelectric actuators supported by the housing, the plurality of piezoelectric actuators positioned radially outward of the first flexible membrane and at different angular positions;
- and
- an edge control ring that is more rigid than the first flexible membrane, wherein the edge control ring is a separate piece coupled to and extending below and spanning the plurality of piezoelectric actuators such that the plurality of piezoelectric actuators control a tilt of the edge control ring as a whole relative to the housing, the edge control ring positioned to apply pressure to an annular region on the substrate surrounding the central portion of the substrate.
A polishing system, comprising:
- a platen to support a polishing pad;
- a drive shaft;
- a carrier head for holding a substrate in the polishing system, the carrier head including
- a housing secured to and moveable by the drive shaft,
- a plurality of independently operable piezoelectric actuators supported by the housing, the plurality of piezoelectric actuators independently controllable,
- an edge control ring positioned to apply pressure to an edge portion of the substrate, wherein the edge control ring is a separate piece extending below and spanning and coupled to the plurality of piezoelectric actuators such that the plurality of piezoelectric actuators control a tilt of the edge control ring as a whole relative to the housing;
- and
- a control system configured to control voltages applied to the plurality of piezoelectric actuators such that a position at which a highest pressure is applied to the edge portion of a back surface of the substrate undergoes precession in conjunction with precession of the substrate in the carrier head.
Dependencies are inferred from the claim text.