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

• US 20040061447A1
• 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 7,166,200 B2
• Time in Patent Office: Days
• US Class Current: 315/111.21
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/3255 Material

Abstract

The present invention presents an improved upper electrode for a plasma processing system, wherein the design and fabrication of an electrode plate coupled to an upper assembly advantageously provides gas injection of a process gas with substantially minimal erosion of the electrode plate.

Claims

1. An upper electrode for a plasma processing system comprising:

an electrode plate comprising a first surface for coupling said electrode plate to an upper assembly, a second surface comprising a plasma surface configured to face a processing space in said plasma processing system and a mating surface for mating said electrode plate with said plasma processing system, a peripheral edge, and one or more gas injection orifices coupled to said first surface and said second surface and configured to couple a processing gas to said processing space; and

a protective barrier coupled to a plurality of exposed surfaces of said electrode plate, said exposed surfaces comprising said plasma surface.

2. The upper electrode as recited in claim 1, wherein said electrode plate further comprises a plenum cavity coupled to said first surface, configured to receive said processing gas, and configured to distribute said processing gas to said one or more gas injection orifices.

3. The upper electrode as recited in claim 1, wherein said electrode plate further comprises a first sealing feature coupled to said first surface and configured to seal said electrode plate to said upper assembly.

4. The upper electrode as recited in claim 1, wherein said electrode plate further comprises a diagnostics port for coupling a diagnostics system to said plasma processing system and a second sealing feature to seal said diagnostics port to said upper assembly.

5. The upper electrode 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.

6. The upper electrode as recited in claim 5, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

7. The upper electrode as recited in claim 5, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

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

9. The upper electrode as recited in claim 1, wherein said gas injection orifice comprises an entrant region, and an exit region, wherein said exit region comprises an injection surface.

10. The upper electrode as recited in claim 1, wherein said diagnostics port comprises an entrant cavity, and an exit through-hole, wherein said exit through-hole comprises an interior surface.

11. The upper electrode as recited in claim 9, wherein said protective barrier is coupled to said injection surface of said gas injection orifice.

12. The upper electrode as recited in claim 10, wherein said protective barrier is coupled to said interior surface of said fastening receptor.

13. The upper electrode 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 upper electrode as recited in claim 1, wherein said protective barrier comprises a variable thickness, said variable thickness ranging from 0.5 microns to 500 microns.

15. The upper electrode as recited in claim 1, wherein at least one gas injection orifice has a diameter that is at least 0.1 mm.

16. The upper electrode as recited in claim 1, wherein at least one gas injection orifice has a length that is at least 1.0 mm.

17. The upper electrode as recited in claim 9, wherein said exposed surfaces further comprise said injection surface of said one or more gas injection orifices.

18. The upper electrode as recited in claim 10, wherein said exposed surfaces further comprise said interior surface of said diagnostics port.

19. The upper electrode as recited in claim 1, said electrode plate further comprising a metal.

20. The upper electrode as recited in claim 19, wherein said metal comprises aluminum.

21. The upper electrode as recited in claim 1, wherein said first surface comprises an anodization layer.

22. The upper electrode as recited in claim 1, wherein said plenum cavity comprises an anodization layer.

23. The upper electrode as recited in claim 1, wherein said mating surface comprises a metallic surface.

24. A method of producing an electrode plate for a plasma processing system, said method comprising the steps:

fabricating said electrode plate, said electrode plate comprising a first surface for coupling said electrode plate to an upper assembly, a second surface comprising a plasma surface configured to face a processing space in said plasma processing system and a mating surface for mating said electrode plate with said plasma processing system, a peripheral edge of said electrode plate, and one or more gas injection orifices coupled to said first surface and said second surface and configured to couple a processing gas to said processing space; and

forming a protective barrier on a plurality of exposed surfaces, said exposed surfaces comprising said plasma surface.

25. The method as recited in claim 24, wherein said method further comprises the steps:

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

machining said exposed surfaces on said electrode plate to remove said surface anodization layer prior to forming said protective barrier on said exposed surfaces.

26. The method as recited in claim 24, wherein said method further comprises the steps:

masking said exposed surfaces on said electrode plate;

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

unmasking said exposed surfaces prior to forming said protective barrier on said exposed surfaces.

27. The method as recited in claim 24, wherein said fabricating comprises at least one of machining, casting, polishing, forging, and grinding.

28. The method as recited in claim 24, wherein said forming said protective barrier further comprises polishing said protective barrier on at least one of said exposed surfaces.

29. The method as recited in claim 24, wherein said electrode plate further comprises a plenum cavity coupled to said first surface, configured to receive said processing gas, and configured to distribute said processing gas to said plurality of gas injection orifices.

30. The method as recited in claim 24, wherein said electrode plate further comprises a first sealing feature coupled to said first surface and configured to seal said electrode plate to said upper assembly.

31. The method as recited in claim 24, wherein said electrode plate further comprises a diagnostics port for coupling a diagnostics system to said plasma processing system and a second sealing feature to seal said diagnostics port to said upper assembly.

32. The method as recited in claim 24, wherein said gas injection orifice comprises an entrant region, and an exit region, wherein said exit region comprises an injection surface.

33. The method as recited in claim 31, wherein said diagnostics port comprises an entrant cavity, and an exit through-hole, wherein said exit through-hole comprises an interior surface.

34. The method as recited in claim 32, wherein said exposed surfaces further comprise said injection surface of said one or more gas injection orifices.

35. The method as recited in claim 33, wherein said exposed surfaces further comprise said interior surface of said diagnostics port.

36. The method as recited in claim 24, said electrode plate further comprising a metal.

37. The method as recited in claim 36, wherein said metal comprises aluminum.

38. The method as recited in claim 24, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

39. The method as recited in claim 38, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

40. The method as recited in claim 38, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

41. The method as recited in claim 24, wherein said protective barrier comprises at least one of Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

42. The method as recited in claim 24, wherein said protective barrier comprises a minimum thickness and said minimum thickness is constant across at least one of said exposed surfaces.

43. The method as recited in claim 24, wherein said protective barrier comprises a varible thickness and said variable thickness ranging from 0.5 microns to 500 microns.

44. The method as recited in claim 24, wherein said first surface comprises an anodization layer.

45. The method as recited in claim 24, wherein said plenum cavity comprises an anodization layer.

46. The method as recited in claim 49, wherein said mating surface comprises a metallic surface.

47. The method as recited in claim 24, wherein at least one gas injection orifice has a diameter that is at least 0.1 mm.

48. The method as recited in claim 24, wherein at least one gas injection orifice has a length that is at least 1.0 mm.

49. The method as recited in claim 24, wherein said fabricating comprises at least one of machining, casting, polishing, forging, and grinding.

50. The method as recited in claim 24, wherein said forming a protective barrier further comprises polishing at least one of said exposed surfaces.

51. The method as recited in claim 24, wherein said exposed surfaces further comprise all surfaces remaining on said electrode plate.

52. A method of producing an electrode plate capable of being coupled to an upper assembly of a plasma processing system, said method comprising the steps:

fabricating said electrode plate, said electrode plate comprising a first surface for coupling said electrode plate to said upper assembly, a second surface comprising a plasma surface configured to face a processing space in said plasma processing system and a mating surface for mating said electrode plate with said plasma processing system, a peripheral edge of said electrode plate, and one or more gas injection orifices coupled to said first surface and said second surface and configured to couple a processing gas to said processing space;

anodizing said electrode plate to form a surface anodization layer on said electrode plate;

machining exposed surfaces on said electrode plate to remove said surface anodization layer, said exposed surfaces comprising said plasma surface of said second surface of said electrode plate; and

forming a protective barrier on the exposed surfaces.

53. The method as recited in claim 52, wherein said electrode plate further comprises a plenum cavity coupled to said first surface, configured to receive said processing gas, and configured to distribute said processing gas to said one or more gas injection orifices.

54. The method as recited in claim 52, wherein said electrode plate further comprises a first sealing feature coupled to said first surface and configured to seal said electrode plate to said upper assembly.

55. The method as recited in claim 52, wherein said electrode plate further comprises a diagnostics port for coupling a diagnostics system to said plasma processing system and a second sealing feature to seal said diagnostics port to said upper assembly.

56. The method as recited in claim 52, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

57. The method as recited in claim 56, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

58. The method as recited in claim 56, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

59. The method as recited in claim 56, wherein said compound comprises Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

60. The method as recited in claim 52, wherein said fabricating comprises at least one of machining, casting, polishing, forging, and grinding.

61. The method as recited in claim 52, wherein said forming a protective barrier further comprises polishing said protective barrier on at least one of said exposed surfaces.

62. The method as recited in claim 52, wherein said gas injection orifice comprises an entrant region, and an exit region, wherein said exit region comprises an injection surface.

63. The method as recited in claim 55, wherein said diagnostics port comprises an entrant cavity, and an exit through-hole, wherein said exit through-hole comprises an interior surface.

64. The method as recited in claim 62, wherein said exposed surfaces further comprise said injection surface of said one or more gas injection orifices.

65. The method as recited in claim 63, wherein said exposed surfaces further comprise said interior surface of said diagnostics port.

66. A method of producing an electrode plate capable of being coupled to an upper assembly of a plasma processing system, said method comprising the steps:

fabricating said electrode plate, said electrode plate comprising a first surface for coupling said electrode plate to said upper assembly, a second surface comprising a plasma surface configured to face a processing space in said plasma processing system and a mating surface for mating said electrode plate with said plasma processing system, a peripheral edge of said electrode plate, and one or more gas injection orifices coupled to said first surface and said second surface and configured to couple a processing gas to said processing space;

masking exposed surfaces on said electrode plate to prevent formation of a surface anodization layer, said exposed surfaces comprising said plasma surface of said second surface of said electrode plate;

anodizing said electrode plate to form said surface anodization layer on said electrode plate;

unmasking said exposed surfaces; and

forming a protective barrier on the exposed surfaces.

67. The method as recited in claim 66, wherein said electrode plate further comprises a plenum cavity coupled to said first surface, configured to receive said processing gas, and configured to distribute said processing gas to said one or more gas injection orifices.

68. The method as recited in claim 66, wherein said electrode plate further comprises a first sealing feature coupled to said first surface and configured to seal said electrode plate to said upper assembly.

69. The method as recited in claim 66, wherein said electrode plate further comprises a diagnostics port for coupling a diagnostics system to said plasma processing system and a second sealing feature to seal said diagnostics port to said upper assembly.

70. The method as recited in claim 66, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

71. The method as recited in claim 67, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

72. The method as recited in claim 67, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

73. The method as recited in claim 67, wherein said compound comprises Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

74. The method as recited in claim 66, wherein said fabricating comprises at least one of machining, casting, polishing, forging, and grinding.

75. The method as recited in claim 66, wherein said forming a protective barrier further comprises polishing said protective barrier on at least one of said exposed surfaces.

76. The method as recited in claim 66, wherein said gas injection orifice comprises an entrant region, and an exit region, wherein said exit region comprises an injection surface.

77. The method as recited in claim 69, wherein said diagnostics port comprises an entrant cavity, and an exit through-hole, wherein said exit through-hole comprises an interior surface.

78. The method as recited in claim 76, wherein said exposed surfaces further comprise said injection surface of said one or more gas injection orifices.

79. The method as recited in claim 77, wherein said exposed surfaces further comprise said interior surface of said diagnostics port.