Electrostatic chuck and method of making same

Patent metadata

Field	Value
Publication number	US-10497598-B2
Application number	US-201515111591-A
Country	US
Kind code	B2
Filing date	Feb 6, 2015
Priority date	Feb 7, 2014
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

An electrostatic chuck includes a ceramic structural element, at least one electrode disposed on the ceramic structural element, and a surface dielectric layer disposed over the at least one electrode, the surface layer activated by a voltage in the electrode to form an electric charge to electrostatically clamp a substrate to the electrostatic chuck. The surface dielectric layer comprises: (i) an insulator layer of amorphous alumina, of a thickness of less than about 5 microns, disposed over the at least one electrode; and (ii) a stack of dielectric layers disposed over the insulator layer. The stack of dielectric layers includes: (a) at least one dielectric layer including aluminum oxynitride; and (b) at least one dielectric layer including at least one of silicon oxide and silicon oxynitride.

First claim

What is claimed is:

1. An electrostatic chuck comprising:
a ceramic structural element;
at least one electrode disposed on the ceramic structural element; and
a surface dielectric layer disposed over the at least one electrode, the surface dielectric layer activated by a voltage in the electrode to form an electric charge to electrostatically clamp a substrate to the electrostatic chuck, the surface dielectric layer comprising:
(i) an insulator layer of amorphous alumina, of a thickness of less than 5 microns, disposed over the at least one electrode; and
(ii) a stack of dielectric layers disposed over the insulator layer, the stack of dielectric layers including:
(a) at least one dielectric layer including aluminum oxynitride; and
(b) at least one dielectric layer including at least one of silicon oxide and silicon oxynitride.

2. The electrostatic chuck of claim 1 , wherein the surface dielectric layer has a thickness in a range of between 22 μm and 122 μm.

3. The electrostatic chuck of claim 1 , wherein the surface dielectric layer includes a silicon nitride layer.

4. The electrostatic chuck of claim 1 , wherein the surface dielectric layer includes a silicon oxynitride layer.

5. The electrostatic chuck claim 1 , wherein at least one of the insulator layer and the dielectric layers is an electrically insulating layer.

6. The electrostatic chuck of claim 5 , wherein the electrically insulating layer is deposited with the thin film deposition technique of atomic layer deposition.

7. The electrostatic chuck of claim 5 , wherein the electrically insulating layer is deposited with a thin film deposition technique selected from the group consisting of chemical vapor deposition, plasma enhanced chemical vapor deposition, physical vapor deposition, electron beam deposition, spray coating, atmospheric plasma deposition, high pressure plasma deposition, electrochemical deposition, and sputter deposition.

8. The electrostatic chuck of claim 5 , wherein the surface dielectric layer is conformal.

9. The electrostatic chuck of claim 5 , wherein the surface dielectric layer has a thickness between 22 micron and 122 microns.

10. The electrostatic chuck of claim 9 , wherein the surface dielectric layer has a thickness between 22 microns and 70 microns.

11. The electrostatic chuck of claim 10 , wherein the surface dielectric layer has a thickness between 25 microns and 50 microns.

12. The electrostatic chuck of claim 1 , wherein the surface dielectric layer has the ability to hold an electrical peak voltage of more than 500V that is applied between the top and bottom of the surface dielectric layer.

13. The electrostatic chuck of claim 12 , wherein the surface dielectric layer has the ability to hold an electrical peak voltage of more than 1000V that is applied between the top and bottom of the surface dielectric layer.

14. The electrostatic chuck of claim 1 , wherein the surface dielectric layer is stable at temperatures between −150° C. and +750° C.

15. The electrostatic chuck of claim 1 , wherein the surface dielectric layer fulfills the function of at least one of: (1) high strength dielectric barrier, (2) dielectric layer with inherently low metals contamination and low particle source, (3) a plasma etch resistant surface, (4) an abrasion resistant surface.

16. The electrostatic chuck of claim 1 , wherein the insulator layer of amorphous alumina is deposited by atomic layer deposition over the at least one electrode.

17. The electrostatic chuck of claim 16 , wherein the insulator layer has a thickness in a range of between 0.5 μm and 2 μm.

18. The electrostatic chuck of claim 17 , wherein the thickness of the insulator layer is 1 μm.

19. The electrostatic chuck of claim 1 , wherein the stack of dielectric layers includes:
i) a first dielectric layer deposited over the insulator layer, the first dielectric layer including silicon oxide;
ii) the at least one dielectric layer including aluminum oxynitride, deposited as a second dielectric layer over the first dielectric layer; and
iii) the at least one dielectric layer including at least one of silicon oxide and silicon oxynitride, deposited as a third dielectric layer over the second dielectric layer, the third dielectric layer including silicon oxide.

20. The electrostatic chuck of claim 19 , wherein the first dielectric layer has a thickness in a range of between 10 μm and 50 μm.

21. The electrostatic chuck of claim 20 , wherein the thickness of the first dielectric layer is 20 μm.

22. The electrostatic chuck of claim 19 , wherein the second dielectric layer has a thickness in a range of between 1 μm and 20 μm.

23. The electrostatic chuck of claim 22 , wherein the thickness of the second dielectric layer is 10 μm.

24. The electrostatic chuck of claim 19 , wherein the third dielectric layer has a thickness in a range of between 10 μm and 50 μm.

25. The electrostatic chuck of claim 24 , wherein the thickness of the third dielectric layer is 20 μm.

26. The electrostatic chuck of claim 1 , wherein the ceramic structural element includes alumina.

27. The electrostatic chuck of claim 1 , wherein the ceramic structural element includes aluminum nitride.

28. The electrostatic chuck of claim 1 , wherein the ceramic structural element includes silicon nitride.

29. The electrostatic chuck of claim 1 , wherein the at least one electrode includes at least one of: aluminum, titanium, molybdenum, silver, platinum, gold, nickel, tungsten, chromium, vanadium, ruthenium, iron, palladium, nickel-cobalt ferrous alloy, manganese, and a nitride.

30. The electrostatic chuck of claim 29 , wherein the at least one electrode includes titanium nitride.

31. The electrostatic chuck of claim 1 , wherein the at least one electrode comprises a thickness of less than 0.5 microns.

32. The electrostatic chuck of claim 1 , wherein the at least one electrode comprises a thickness of less than 0.25 microns.

33. The electrostatic chuck of claim 1 , wherein the stack of dielectric layers includes:
i) the at least one dielectric layer including aluminum oxynitride, being a first dielectric layer disposed over the insulator layer; and
ii) the at least one dielectric layer including at least one of silicon oxide and silicon oxynitride, being a second dielectric layer disposed over the first dielectric layer.

34. The electrostatic chuck of claim 33 , wherein the thickness of the first dielectric layer is 10 μm.

35. The electrostatic chuck of claim 33 , wherein the second dielectric layer has a thickness in a range of between 40 μm and 50 μm.

36. The electrostatic chuck of claim 1 , wherein a substrate contacting surface of the electrostatic chuck comprises a plurality of protrusions extending to a height above portions of the substrate contacting surface of the electrostatic chuck surrounding the plurality of protrusions.

37. The electrostatic chuck of claim 36 , wherein the plurality of protrusions comprise a height of between 3 microns and 15 microns.

38. The electrostatic chuck of claim 37 , wherein the plurality of protrusions comprise a height of between 6 microns and 8 microns.

39. The electrostatic chuck of claim 36 , whe

Assignees

• Entegris Inc

Inventors

• Cooke Richard A
• Neff Wolfram
• Waldfried Carlo
• Rybczynski Jakub
• Hanagan Michael
• Krull Wade

Classifications

• H10P72/0602

  Temperature monitoring · CPC title

• H10P72/72

  using electrostatic chucks · CPC title

• H10P72/722 Primary

  Details of electrostatic chucks · CPC title

• H01L21/6833 Primary

  Electricity · mapped topic

• H01L21/67248

  Electricity · mapped topic