Method and apparatus for an improved baffle plate in a plasma processing system

• US 20040063333A1
• Filed: 09/30/2002
• Published: 04/01/2004
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Nakayama, Hiroyuki, Mitsuhashi, Kouji, Takase, Taira, Saigusa, Hidehito
• Granted Patent: US 7,166,166 B2
• Time in Patent Office: Days
• US Class Current: 438/758
• CPC Class Codes: H01J 37/32431 Constructional details of the reactor

Abstract

The present invention presents an improved baffle plate for a plasma processing system, wherein the design and fabrication of the baffle plate advantageously provides for a uniform processing plasma in the process space with substantially minimal erosion of the baffle plate.

Claims

1. An improved baffle plate in a plasma processing system comprising:

a canted ring comprising an upper surface, a lower surface, an inner radial edge coupled to said upper surface and said lower surface, an outer radial edge coupled to said upper surface and said lower surface, and at least one passageway coupled to said upper surface and to said lower surface and configured to permit the flow of a gas therethrough, wherein said upper surface comprises a first mating surface proximate said outer radial edge, said lower surface comprises a second mating surface proximate said outer radial edge, said inner radial edge comprises an inner edge surface, and each of said at least one passageway comprises an internal passageway surface; and

a protective barrier coupled to a plurality of exposed surfaces of said baffle plate, wherein said exposed surfaces comprise said upper surface excluding said first mating surface, said lower surface excluding said second mating surface, said inner edge surface of said inner radial edge, and said internal passageway surface of each of said at least one passageway.

2. The improved baffle plate as recited in claim 1, wherein at least one passageway comprises a slot.

3. The improved baffle plate as recited in claim 2, wherein said slot comprises an entrance area and an exit area, wherein said entrance area is larger than said exit area.

4. The improved baffle plate as recited in claim 1, wherein at least one passageway comprises an orifice.

5. The improved baffle plate as recited in claim 1, wherein said canted ring further comprises a plurality of fastening receptors and a plurality of mounting through-holes coupled to said upper surface and said lower surface of said baffle plate and configured to receive fastening devices in order to couple said baffle plate to said plasma processing system.

6. The improved baffle plate as recited in claim 5, wherein each of said plurality of fastening receptors comprises an entrant cavity, an exit through-hole, and an inner receptor surface.

7. The improved baffle plate as recited in claim 1, wherein said baffle plate comprises a metal.

8. The improved baffle plate as recited in claim 1, wherein said metal comprises aluminum.

9. The improved baffle plate as recited in claim 1, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

10. The improved baffle plate as recited in claim 9, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

11. The improved baffle plate as recited in claim 9, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

12. The improved baffle plate as recited in claim 1, wherein said protective barrier comprises at least one of Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

13. The improved baffle plate as recited in claim 1, wherein said protective barrier comprises a minimum thickness and said minimum thickness is constant across at least one of said exposed surfaces.

14. The improved baffle plate as recited in claim 1, wherein said protective barrier comprises a minimum thickness and said minimum thickness is variable across at least one of said exposed surfaces.

15. The improved baffle plate as recited in claim 1, wherein at least one of said upper surface and said lower surface is inclined at an angle.

16. The improved baffle plate as recited in claim 15, wherein a range of said angle comprises 0 to 60 degrees.

17. A method of producing an improved baffle plate of a plasma processing system, said method comprising the steps:

fabricating said baffle plate, said baffle plate comprising a canted ring having an upper surface, a lower surface, an inner radial edge, an outer radial edge, and at least one passageway coupled to said upper surface and to said lower surface and configured to permit the flow of a gas therethrough, wherein said upper surface comprises a first mating surface proximate said outer radial edge, said lower surface comprises a second mating surface proximate said outer radial edge, said inner radial edge comprises an inner edge surface, and each of said at least one passageway comprises an internal passageway surface; and

forming a protective barrier on exposed surfaces, said exposed surfaces comprising said upper surface excluding said first mating surface, said lower surface excluding said second mating surface, said inner edge surface of said inner radial edge, and said internal passageway surface of each of said at least one passageway.

18. The method as recited in claim 17, wherein said method further comprises the steps:

anodizing said baffle plate to form a surface anodization layer on said baffle plate; and

machining said exposed surfaces on said baffle plate to remove said surface anodization layer.

19. The method as recited in claim 17, wherein said method further comprises the steps:

masking said exposed surfaces to prevent formation of a surface anodization layer;

anodizing said baffle plate to form a surface anodization layer on said baffle plate; and

unmasking said exposed surfaces on said baffle plate.

20. The method as recited in claim 17, wherein said baffle plate comprises a metal.

21. The method as recited in claim 20, wherein said metal comprises aluminum.

22. The method as recited in claim 17, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

23. The method as recited in claim 22, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

24. The method as recited in claim 22, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

25. The method as recited in claim 17, wherein said protective barrier comprises at least one of Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

26. The method as recited in claim 17, wherein said protective barrier comprises a minimum thickness and said minimum thickness is constant across at least one of said exposed surfaces.

27. The method as recited in claim 17, wherein said protective barrier comprises a minimum thickness and said minimum thickness is variable across at least one of said exposed surfaces.

28. The method as recited in claim 17, wherein said fabricating comprises at least one of machining, casting, polishing, forging, and grinding.

29. The method as recited in claim 17, wherein said forming a protective barrier further comprises polishing the protective barrier on at least one of said plurality of exposed surfaces.

30. The method as recited in claim 17, wherein at least one passageway comprises a slot.

31. The method as recited in claim 30, wherein said slot comprises an entrance area and an exit area, wherein said entrance area is larger than said exit area.

32. The method as recited in claim 17, wherein at least one passageway comprises an orifice.

33. The method as recited in claim 17, wherein said baffle plate further comprises a plurality of fastening receptors and a plurality of mounting through-holes coupled to said upper surface and said lower surface of said baffle plate and configured to receive fastening devices in order to couple said baffle plate to said plasma processing system.

34. The method as recited in claim 33, wherein each of said plurality of fastening receptors comprises an entrant cavity, an exit through-hole, and an inner receptor surface.

35. The method as recited in claim 17, wherein said exposed surfaces further comprise at least one of said first mating surface, said second mating surface, and said outer edge surface.

36. The method as recited in claim 17, wherein at least one of said upper surface and said lower surface is inclined at an angle.

37. The method as recited in claim 36, wherein a range of said angle comprises 0 to 60 degrees.