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

• US 20040060661A1
• 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: Nishimoto, Shinya, Nakayama, Hiroyuki, Mitsuhashi, Kouji
• Granted Patent: US 7,147,749 B2
• Time in Patent Office: Days
• US Class Current: 156/345.43
• CPC Class Codes: C23C 16/4404 Coatings or surface treatment on the inside of the reaction chamber or on parts thereof
• 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 37/32532 Electrodes
• CPC Class Codes: Y10S 156/916 Differential etching apparatus including chamber cleaning means or shield for preventing deposits

Abstract

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

Claims

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

an electrode plate comprising a first surface for coupling said upper electrode to an upper assembly, a second surface comprising a plasma surface and a mating surface for mating said electrode plate with said plasma processing system, a peripheral edge, and a plurality of gas injection orifices coupled to said first surface and said second surface;

a deposition shield coupled to said electrode plate, said deposition shield comprising a cylindrical wall having an inner surface contiguous with said plasma surface, an outer surface contiguous with said mating surface, and a distal end surface, wherein said distal end surface comprises a distal end lip surface; and

a protective barrier coupled to exposed surfaces of said upper electrode, said exposed surfaces comprising said plasma surface, said inner surface, and said distal end lip 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 plurality of gas injection orifices.

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

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 fourth sealing feature to seal said diagnostics port to said upper electrode.

5. The upper electrode as recited in claim 1, wherein said protective barrier comprises Al₂O₃.

6. The upper electrode as recited in claim 1, wherein said protective barrier comprises a mixture of Al₂O₃ and Y₂O₃.

7. 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.

8. The upper electrode as recited in claim 7, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

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

10. 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.

11. 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.

12. The upper electrode as recited in claim 1, wherein said electrode plate and said deposition shield comprises one or more fastening through-holes coupled to said first surface of said electrode plate and a distal end mating surface of said distal end surface, and configured to couple said electrode plate and said deposition shield to said plasma processing system, each of said one or more fastening through-holes comprises a third sealing feature in order to seal said one or more fastening through-holes with said upper assembly.

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 11, wherein said exposed surfaces includes said injection surface of said plurality of gas injection orifices.

18. The upper electrode as recited in claim 12, wherein said exposed surfaces comprises said interior surface of said diagnostics port.

19. The upper electrode as recited in claim 1, wherein said deposition shield further comprises an opening in order to access said process space through said deposition shield.

20. The upper electrode as recited in claim 19, wherein said opening comprises a first opening surface, a second opening surface, and a mating surface.

21. The upper electrode as recited in claim 20, wherein said mating surface comprises at least one tapped hole and a fastening surface coupled thereto.

22. The upper electrode shield as recited in claim 20, wherein said exposed surfaces further comprise said first opening surface of said opening, and said mating surface of said opening in said deposition shield.

23. The upper electrode as recited in claim 21, wherein said exposed surfaces further comprise said first opening surface of said opening, and said mating surface excluding said fastening surface of said opening in said deposition shield.

42. The upper electrode as recited in claim 1, wherein at least one gas injection orifice (100) has a length that is at least 1.0 mm.

43. The upper electrode as recited in claim 1, wherein said upper electrode further comprises:

a diagnostics port (120) having an interior surface (128) coupled to said first surface (82) and said plasma surface (90); and

a fourth sealing feature (122) located on said first surface (82), surrounding said diagnostic port (120), and configured to receive a seal.

44. The upper electrode as recited in claim 43, wherein said exposed surfaces further comprise said interior surface (128).

45. The upper electrode as recited in claim 1, wherein said upper electrode further comprises an opening (130) coupled between said outer surface (74) and said inner surface (72).

46. The upper electrode as recited in claim 45, wherein said opening (130) comprises a first opening surface (132) coupled to the inner surface (72), a second opening surface (134) coupled to the outer surface (74), and a mating surface (136) coupled to the first opening surface (132) and to the second opening surface (134).

47. The upper electrode as recited in claim 46, wherein said mating surface (136) comprises at least one tapped hole (138) and a fastening surface (140) coupled thereto.

48. The upper electrode shield as recited in claim 46, wherein said exposed surfaces further comprise said first opening surface (132) and said mating surface (136) excluding said fastening surface (140).

24. An upper electrode for a plasma processing chamber comprising:

a cylindrical element having a first surface (82), a mating surface (92), a peripheral edge (94) coupled to said first surface (82) and said mating surface (92), an outer surface (74) coupled to said mating surface (92), an inner surface (72) coupled to said outer surface (74) by a distal end surface (76), and a plasma surface (90) coupled to said inner surface (72),

wherein said first surface (82) comprises a coupling surface (82a) for coupling said upper electrode to said plasma processing chamber and a plenum cavity (84), and said distal end surface (76) comprises a distal end lip surface (78), said cylindrical element further comprising a plurality of gas injection orifices (100) coupled to said plenum cavity (84) and said plasma surface (90); and

a protective barrier coupled to exposed surfaces of said upper electrode, said exposed surfaces comprising said plasma surface (90), said inner surface (72), and said distal end lip surface (78).

25. The upper electrode as recited in claim 24, wherein said upper electrode further comprises at least one sealing feature (86a, 86b) located on said first surface (82) outside said plenum cavity (84) and configured to receive a seal.

26. The upper electrode as recited in claim 24, wherein said upper electrode further comprises:

a plurality of fastening through-holes (112) coupled to said first surface (82) and a distal end mating surface (77) of said distal end surface (76), and configured to receive a fastening device, and

a plurality of sealing features (86c), each sealing feature located on said first surface (82), surrounding one of the through-holes (112), and configured to receive a seal.

27. The upper electrode as recited in claim 24, wherein said upper electrode further comprises a plurality of fastener receptors (110) coupled to said first surface (82) and configured to receive a fastener.

28. The upper electrode as recited in claim 24, wherein each gas injection orifice (100) comprises an entrant region (102) coupled to said plenum cavity (84), and an exit region (104), said exit region (104) comprising an injection surface (106) coupled to said plasma surface (90).

29. The upper electrode as recited in claim 28, wherein said exposed surfaces include each injection surface (106) of said plurality of gas injection orifices (100).

30. The upper electrode as recited in claim 24, further comprising a metal.

31. The upper electrode as recited in claim 30, wherein said metal comprises aluminum.

32. The upper electrode 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.

33. The upper electrode as recited in claim 32, wherein said III-column element comprises at least one of Yttrium, Scandium, and Lanthanum.

34. The upper electrode as recited in claim 32, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

35. The upper electrode as recited in claim 24, wherein said protective barrier comprises at least one of Al₂O₃, Y₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

36. The upper electrode as recited in claim 24, wherein said first surface (82) comprises an anodization layer.

37. The upper electrode as recited in claim 24, wherein said plenum cavity (84) comprises an anodization layer.

38. The upper electrode as recited in claim 24, wherein said mating surface (92) comprises a metallic surface.

39. The upper electrode 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.

40. The upper electrode as recited in claim 24, wherein said protective barrier comprises a variable thickness, said variable thickness ranging from 0.5 microns to 500 microns.

41. The upper electrode as recited in claim 24, wherein at least one gas injection orifice (100) has a diameter that is at least 0.1 mm.

49. A method for producing an upper electrode for a plasma processing chamber, said method comprising:

fabricating a cylindrical element having a first surface (82), a mating surface (92), a peripheral edge (94) coupled to said first surface (82) and said mating surface (92), an outer surface (74) coupled to said mating surface (92), an inner surface (72) coupled to said outer surface (74) by a distal end surface (76), and a plasma surface (90) coupled to said inner surface (72),

wherein said first surface (82) comprises a coupling surface (82a) for coupling said upper electrode to said plasma processing chamber and a plenum cavity (84), and said distal end surface (76) comprises a distal end lip surface (78), said cylindrical element further comprising a plurality of gas injection orifices (100) coupled to said plenum cavity (84) and said plasma surface (90); and

forming a protective barrier on a plurality of exposed surfaces of said upper electrode, wherein said exposed surfaces comprise said plasma surface (90), said inner surface (72), and said distal end lip surface (78).

50. The method as recited in claim 49, wherein said upper electrode further comprises at least one sealing feature (86a, 86b) located on said first surface (82) outside said plenum cavity (84) and configured to receive a seal.

51. The method as recited in claim 49, wherein said upper electrode further comprises:

a plurality of fastening through-holes (112) coupled to said first surface (82) and a distal end mating surface (77) of said distal end surface (76), and configured to receive a fastening device, and a plurality of sealing features (86c), each sealing feature located on said first surface (82), surrounding one of the through-holes (112), and configured to receive a seal.

52. The method as recited in claim 49, wherein said upper electrode further comprises a plurality of fastener receptors (110) coupled to said first surface (82) and configured to receive a fastener.

53. The method as recited in claim 49, wherein each gas injection orifice (100) comprises an entrant region (102) coupled to said plenum cavity (84), and an exit region (104), said exit region (104) comprising an injection surface (106) coupled to said plasma surface (90).

54. The method as recited in claim 53, wherein said exposed surfaces include each injection surface (106) of said plurality of gas injection orifices (100).

55. The method as recited in claim 49, further comprising a metal.

56. The method as recited in claim 55, wherein said metal comprises aluminum.

57. The method as recited in claim 49, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

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

59. The method as recited in claim 57, wherein said Lanthanon element comprises at least one of Cerium, Dysprosium, and Europium.

60. The method as recited in claim 49, wherein said protective barrier comprises at least one of Y₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

61. The method as recited in claim 49, wherein said first surface (82) comprises an anodization layer.

62. The method as recited in claim 49, wherein said plenum cavity (84) comprises an anodization layer.

63. The method as recited in claim 49, wherein said mating surface (92) comprises a metallic surface.

64. The method as recited in claim 49, wherein said protective barrier comprises a minimum thickness and said minimum thickness is constant across at least one of said exposed surfaces.

65. The method as recited in claim 49, wherein said protective barrier comprises a variable thickness, said variable thickness ranging from 0.5 microns to 500 microns.

66. The method as recited in claim 49, wherein at least one gas injection orifice (100) has a diameter that is at least 0.1 mm.

67. The method as recited in claim 49, wherein at least one gas injection orifice (100) has a length that is at least 1.0 mm.

68. The method as recited in claim 49, wherein said upper electrode further comprises:

a diagnostics port (120) having an interior surface (128) coupled to said first surface (82) and said plasma surface (90); and

a fourth sealing feature (122) located on said first surface (82), surrounding said diagnostic port (122), and configured to receive a seal.

69. The method as recited in claim 68, wherein said exposed surfaces further comprise said interior surface (128).

70. The method as recited in claim 49, wherein said upper electrode further comprises an opening (130) coupled between said outer surface (74) and said inner surface (72).

71. The method as recited in claim 70, wherein said opening (130) comprises a first opening surface (132) coupled to the inner surface (72), a second opening surface (134) coupled to the outer surface (74), and a mating surface (136) coupled to the first opening surface (132) and to the second opening surface (134).

72. The method as recited in claim 71, wherein said mating surface (136) comprises at least one tapped hole (138) and a fastening surface (140) coupled thereto.

73. The method as recited in claim 72, wherein said exposed surfaces further comprise said first opening surface (132) and said mating surface (136) excluding said fastening surface (140).

74. The method as recited in claim 49, wherein said method further comprises the steps:

anodizing said cylindrical element to form a surface anodization layer on said cylindrical element; and

machining said exposed surfaces on said cylindrical element to remove said surface anodization layer prior to forming said protective barrier on said exposed surfaces.

75. The method as recited in claim 49, wherein said method further comprises the steps:

masking said exposed surfaces on said cylindrical element;

anodizing said cylindrical element to form a surface anodization layer on said cylindrical element; and

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

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

77. The method as recited in claim 49, wherein said forming said protective barrier further comprises polishing said protective barrier on at least one of said exposed surfaces.

78. The method as recited in claim 49, wherein said exposed surfaces further comprise all surfaces remaining on said electrode plate and said deposition shield.

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

fabricating said electrode plate and said deposition shield, said electrode plate comprising a first surface for coupling said upper electrode 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 a plurality of gas injection orifices coupled to said first surface and said second surface and configured to couple a processing gas to said processing space, and said deposition shield comprising a cylindrical wall having an inner surface contiguous with said plasma surface of said electrode plate, an outer surface contiguous with said mating surface of said electrode plate, and a distal end surface, wherein said distal end surface comprises a distal end lip surface;

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

machining exposed surfaces on said electrode plate with said deposition shield to remove said surface anodization layer, said exposed surfaces comprising said plasma surface of said second surface of said electrode plate, said inner surface of said cylindrical wall of said deposition shield, said distal end lip surface of said deposition shield; and

forming a protective barrier on the exposed surfaces.

80. The method as recited in claim 79, 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.

81. The method as recited in claim 79, wherein said electrode plate further comprises at least one of a first sealing feature and a second sealing feature coupled to said first surface and configured to seal said electrode plate to said upper electrode.

82. The method as recited in claim 79, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

83. The method as recited in claim 79, wherein said protective barrier comprises at least one of Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

84. The method as recited in claim 79, wherein said fabricating comprises at least one of machining, casting, polishing, forging, and grinding.

85. The method as recited in claim 79, wherein said forming a protective barrier further comprises polishing said protective barrier on at least one of said exposed surfaces.

86. The method as recited in claim 79, wherein said deposition shield further comprises an opening in order to access said process space through said deposition shield.

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

fabricating said electrode plate and said deposition shield, said electrode plate comprising a first surface for coupling said upper electrode 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 a plurality of gas injection orifices coupled to said first surface and said second surface and configured to couple a processing gas to said processing space, and said deposition shield comprising a cylindrical wall having an inner surface contiguous with said plasma surface of said electrode plate, an outer surface contiguous with said mating surface of said electrode plate, and a distal end surface, wherein said distal end surface comprises a distal end lip surface;

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, said inner surface of said cylindrical wall of said deposition shield, said distal end lip surface of said deposition shield;

anodizing said electrode plate with said deposition shield to form said surface anodization layer on said electrode plate with said deposition shield;

unmasking said exposed surfaces; and

forming a protective barrier on the exposed surfaces.

88. The method as recited in claim 87, 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.

89. The method as recited in claim 87, wherein said protective barrier comprises a compound containing at least one of a III-column element and a Lanthanon element.

90. The method as recited in claim 87, wherein said compound comprises Yttria (Y₂O₃), Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, and DyO₃.

91. The method as recited in claim 87, wherein said fabricating comprises at least one of machining, casting, polishing, forging, and grinding.

92. The method as recited in claim 87, wherein said forming a protective barrier further comprises polishing said protective barrier on at least one of said exposed surfaces.

93. The method as recited in claim 87, wherein said deposition shield further comprises an opening in order to access said process space through said deposition shield.