High conductivity electrostatic chuck

Patent metadata

Field	Value
Publication number	US-9692325-B2
Application number	US-201113818339-A
Country	US
Kind code	B2
Filing date	Sep 8, 2011
Priority date	Sep 8, 2010
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

In accordance with an embodiment of the invention, there is provided an electrostatic chuck comprising a conductive path covering at least a portion of a workpiece-contacting surface of a gas seal ring of the electrostatic chuck, the conductive path comprising at least a portion of an electrical path to ground; and a main field area of a workpiece-contacting surface of the electrostatic chuck comprising a surface resistivity in the range of from about 10 8 to about 10 12 ohms per square.

First claim

What is claimed is:

1. An electrostatic chuck, comprising:
a conductive path covering at least a portion of a workpiece-contacting surface of a gas seal ring of the electrostatic chuck, the conductive path comprising a coating covering at least a portion of an outside edge of the gas seal ring and at least a portion of an outside edge of the electrostatic chuck and comprising at least a portion of an electrical path to ground, the conductive path comprising a surface resistivity in the range of from about 10 5 ohms per square to about 10 7 ohms per square; and
a main field area of a workpiece-contacting surface of the electrostatic chuck comprising a surface resistivity in the range of from about 10 8 to about 10 12 ohms per square, the main field area comprising at least one embossment extending above surrounding portions of the main field area; and
a conductive coating on a workpiece-contacting surface of the at least one embossment.

2. An electrostatic chuck according to claim 1 , wherein the conductive path comprises diamond-like carbon.

3. An electrostatic chuck according to claim 2 , wherein the conductive path comprises doped diamond-like carbon.

4. An electrostatic chuck according to claim 3 , wherein the conductive path comprises hydrogenated carbon doped with nitrogen.

5. An electrostatic chuck according to claim 1 , wherein the conductive path comprises a coating of a thickness less than about 1 micron.

6. An electrostatic chuck according to claim 1 , wherein the conductive path wraps underneath an insulator layer of the electrostatic chuck.

7. An electrostatic chuck according to claim 1 , wherein the main field area comprises silicon carbide.

8. An electrostatic chuck according to claim 7 , wherein the main field area comprises a surface resistivity in the range of from about 10 9 to about 10 11 ohms per square.

9. An electrostatic chuck according to claim 1 , wherein the electrostatic chuck comprises a conductive grounding layer, at least a portion of which is underneath an insulator layer of the electrostatic chuck, the conductive grounding layer electrically contacting the conductive path.

10. An electrostatic chuck according to claim 9 , wherein at least a portion of an outside edge of the conductive grounding layer is covered by the conductive path.

11. An electrostatic chuck according to claim 9 , wherein the conductive grounding layer electrically contacts a grounding pin of the electrostatic chuck.

12. An electrostatic chuck according to claim 9 , further comprising an electrically conductive epoxy layer underlying at least a portion of the conductive grounding layer.

13. An electrostatic chuck according to claim 1 , wherein the conductive path of the electrostatic chuck and the conductive coating on the workpiece-contacting surface of the at least one embossment each comprise a diamond like carbon coating.

14. An electrostatic chuck according to claim 1 , wherein a base of the electrostatic chuck comprises a chamfered area on one or more edges of the base.

15. An electrostatic chuck according to claim 14 , wherein the conductive path electrically contacts the base through a conductive epoxy in the chamfered area.

16. An electrostatic chuck according to claim 15 , wherein the conductive path comprises a coating covering at least a portion of an outside edge of the electrostatic chuck, the conductive path wrapping underneath an insulator layer of the electrostatic chuck.

17. An electrostatic chuck according to claim 1 , further comprising at least one conductive pattern on the workpiece-contacting surface of the electrostatic chuck, the at least one conductive pattern electrically contacting the conductive path.

18. An electrostatic chuck according to claim 17 , wherein the at least one conductive pattern comprises a metal coated with a conductive coating.

19. An electrostatic chuck according to claim 17 , wherein the at least one conductive pattern comprises at least one of: a spoke extending towards the center of the electrostatic chuck; a ring around a gas hole of the electrostatic chuck; and a trace between two embossments on the workpiece-contacting surface of the electrostatic chuck.

20. An electrostatic chuck according to claim 1 , wherein the main field area of the electrostatic chuck comprises a polymer.

21. An electrostatic chuck according to claim 20 , wherein the main field area comprises at least one embossment extending above surrounding portions of the main field area, the at least one embossment comprising a polymer.

22. An electrostatic chuck according to claim 20 , wherein the main field area comprises a surface resistivity in the range of from about 10 8 to about 10 10 ohms per square.

23. An electrostatic chuck according to claim 20 , wherein the conductive path comprises a conductive coating, the conductive coating also covering at least a portion of the main field area.

24. An electrostatic chuck, comprising:
a conductive path electrically connected to at least a portion of a workpiece-contacting surface of the electrostatic chuck, the conductive path comprising a coating covering at least a portion of an outside edge of the electrostatic chuck and comprising at least a portion of an electrical path to ground; and
a main field area of a workpiece-contacting surface of the electrostatic chuck comprising a surface resistivity in the range of from about 10 8 to about 10 10 ohms per square, the main field area comprising a blanket layer and at least one embossment extending above surrounding portions of the main field area, the blanket layer and the at least one embossment each comprising a polymer comprising carbon nanotubes;
the conductive path further comprising a portion extending from under the blanket layer to the coating covering the at least a portion of the outside edge of the electrostatic chuck; and
a conductive coating on a workpiece-contacting surface of the at least one embossment.

25. An electrostatic chuck according to claim 24 , wherein the polymer comprises at least one of: carbon nanotube filled polyether imide; carbon nanotube filled polyether ether ketone; and carbon nanotube filled polyimide.

Assignees

• Suuronen David
• Stone Lyudmila
• Blake Julian
• Stone Dale K
• Cooke Richard A
• Donnell Steven
• Venkatraman Chandra
• Entegris Inc
• Varian Semiconductor Equipment Ass Inc

Inventors

• Suuronen David
• Stone Lyudmila
• Blake Julian
• Stone Dale K
• Cooke Richard A
• Donnell Steven
• Venkatraman Chandra

Classifications

• H10P72/722

  Details of electrostatic chucks · CPC title

• H10P72/72

  using electrostatic chucks · CPC title

• H10P72/76

  using mechanical means, e.g. clamps or pinches · CPC title

• H10P72/70 Primary

  for supporting or gripping · CPC title

• H02N13/00 Primary

  Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect · CPC title