Carrier head with segmented substrate chuck

Patent metadata

Field	Value
Publication number	US-11325223-B2
Application number	US-201916688348-A
Country	US
Kind code	B2
Filing date	Nov 19, 2019
Priority date	Aug 23, 2019
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

A carrier head for a chemical mechanical polishing apparatus includes a carrier body, an outer membrane assembly, an annular segmented chuck, and an inner membrane assembly. The outer membrane assembly is supported from the carrier body and defines a first plurality of independently pressurizable outer chambers. The annular segmented chuck supported below the outer membrane assembly, and includes a plurality of concentric rings that are independently vertically movable by respective pressurizable chambers of the outer membrane assembly. At least two of the rings having passages therethrough to suction-chuck a substrate to the chuck. The inner membrane assembly is supported from the carrier body and is surrounded by an innermost ring of the plurality of concentric rings of the chuck. The inner membrane assembly defines a second plurality of independently pressurizable inner chambers and has a lower surface to contact the substrate.

First claim

What is claimed is:

1. A carrier head for a chemical mechanical polishing apparatus, the carrier head comprising:
a carrier body;
an outer membrane assembly supported from the carrier body and defining a first plurality of independently pressurizable outer chambers;
an annular segmented chuck supported from the outer membrane assembly, the segmented chuck including a plurality of concentric rings positioned below the outer membrane assembly that are individually vertically movable with respect to the carrier body by respective pressurizable chambers of the outer membrane assembly to apply pressure to an outer portion of a substrate, at least two of the rings having passages therethrough to suction-chuck a substrate to the segmented chuck; and
an inner membrane assembly supported from the carrier body, the inner membrane assembly surrounded by an innermost ring of the plurality of concentric rings of the segmented chuck, the inner membrane assembly defining a second plurality of individually pressurizable inner chambers and having a lower surface to apply pressure to a central portion of the substrate surrounded by the outer portion of the substrate, wherein the concentric rings are less flexible than the inner and outer membrane assemblies.

2. The carrier head of claim 1 , further comprising a cushion extending below and secured to the segmented chuck and configured to contact the substrate.

3. The carrier head of claim 2 , wherein the cushion is comprised of concentric rings.

4. The carrier head of claim 2 , wherein the cushion includes vacuum channels aligned with the passages through the rings.

5. The carrier head of claim 2 , wherein the cushion spans a gap between adjacent concentric rings of the segmented chuck.

6. The carrier head of claim 2 , wherein the cushion extends below the inner membrane assembly.

7. The carrier head of claim 6 , wherein the cushion spans multiple individually pressurizable chambers of the inner membrane assembly.

8. The carrier head of claim 1 , wherein the inner membrane assembly includes an inner membrane having a plurality of flaps to divide a volume below the carrier body into the plurality of inner chambers.

9. The carrier head of claim 8 , wherein the outer membrane assembly includes an outer membrane having a plurality of flaps to divide a volume below the carrier body into the plurality of outer chambers.

10. The carrier head of claim 9 , wherein the inner membrane and outer membrane are portions of a unitary membrane.

11. The carrier head of claim 1 , further comprising an upper carrier body and a lower carrier body.

12. The carrier head of claim 1 , further comprising an edge-control ring surrounding and vertically movable relative to an outermost ring of the plurality of concentric rings of the chuck.

13. The carrier head of claim 12 , comprising a pressurizable chamber to control positioning of the edge-control ring relative to the carrier body.

14. The carrier head of claim 1 , wherein the lower surface of the inner membrane assembly is substantially coplanar with lower surfaces of the concentric rings.

15. The carrier head of claim 1 , wherein the lower surface of the inner membrane assembly is exposed so as to directly contact the substrate.

16. A chemical mechanical polishing system, comprising:
a platen to support a polishing pad;
a carrier head including
a carrier body,
an outer membrane assembly supported from the carrier body and defining a first plurality of independently pressurizable outer chambers,
an annular segmented chuck supported from the outer membrane assembly, the segmented chuck including a plurality of concentric rings positioned below the outer membrane assembly that are individually vertically movable with respect to the carrier body by respective pressurizable chambers of the outer membrane assembly to apply pressure to an outer portion of a substrate, at least two of the rings having passages therethrough to suction-chuck a substrate to the segmented chuck, and
an inner membrane assembly supported from the carrier body, the inner membrane assembly surrounded by an innermost ring of the plurality of concentric rings of the segmented chuck, the inner membrane assembly defining a second plurality of individually pressurizable inner chambers and having a lower surface to apply pressure to a central portion of the substrate surrounded by the outer portion the substrate, wherein the concentric rings are less flexible than the inner and outer membrane assemblies;

a pressure source coupled to the inner chambers and the outer chambers; and
a controller connected to the pressure source.

17. The system of claim 16 , wherein the carrier head includes a retaining ring connected to the carrier body and surrounding the segmented chuck.

18. The system of claim 16 , further comprising a cushion extending below and secured to the segmented chuck and configured to contact the substrate.

19. The system of claim 18 , wherein the cushion includes vacuum channels aligned with the passages through the rings and connected to the pressure source.

20. The system of claim 16 , wherein the carrier head includes an edge-control ring surrounding and vertically movable relative to an outermost ring of the plurality of concentric rings of the chuck.

21. A method for chemical mechanical polishing, comprising:
placing a substrate into a carrier head;
polishing the substrate using pressure applied to an outer portion of the substrate from an outer membrane assembly that defines a first plurality of independently pressurizable outer chambers with the pressure applied to the outer portion transferred through a plurality of individually vertically movable concentric rings of a segmented chuck of the carrier head and pressure applied to a central portion of the substrate surrounded by the outer portion from an inner membrane assembly of the carrier head that defines a second plurality of individually pressurizable inner chambers surrounded by the segmented chuck, wherein the concentric rings are less flexible than the inner and outer membrane assemblies; and
during polishing, preventing the substrate from moving laterally by chucking the substrate to the carrier head using the segmented chuck.

Assignees

• Applied Materials Inc

Inventors

• Zuniga Steven M
• Gurusamy Jay

Classifications

• B24B37/32 Primary

  Retaining rings · CPC title

• B24B37/34

  Accessories · CPC title

• B24B37/005

  Control means for lapping machines or devices · CPC title

• H10P72/0428

  Apparatus for mechanical treatment or grinding or cutting · CPC title