Plasma uniformity control by gas diffuser hole design

• US 8,083,853 B2
• Filed: 07/12/2004
• Issued: 12/27/2011
• Est. Priority Date: 05/12/2004
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Choi, Soo Young, White, John M., Wang, Qunhua, Hou, Li, Kurita, Shinichi, Won, Tae Kyung, Anwar, Suhail, Park, Beom Soo, Tiner, Robin L., Kim, Ki Woon
• Primary Examiner(s): LUND, JEFFRIE ROBERT
• Application Number:
  US10/889,683
• Publication Number:
  US 20050251990A1
• Time in Patent Office: 2,724 Days
• Field of Search: 118/715, 118/723.R, 118/723.E, 156/345.33, 156/345.34, 156/345.43, 156/345.47
• US Class Current: 118/715
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/455 characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• CPC Class Codes: H01J 2237/327 Arrangements for generating the plasma
• CPC Class Codes: H01J 2237/3321 CVD [Chemical Vapor Deposition]
• CPC Class Codes: H01J 2237/3323 uniformity
• CPC Class Codes: H01J 2237/3325 large area
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32541 Shape
• CPC Class Codes: H01J 37/32596 Hollow cathodes
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling
• CPC Class Codes: Y10T 29/49996 Successive distinct removal operations

Abstract

Embodiments of a gas diffuser plate for distributing gas in a processing chamber are provided. The gas distribution plate includes a diffuser plate having an upstream side and a downstream side, and a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate. The gas passages include hollow cathode cavities at the downstream side to enhance plasma ionization. The depths, the diameters, the surface area and density of hollow cathode cavities of the gas passages that extend to the downstream end can be gradually increased from the center to the edge of the diffuser plate to improve the film thickness and property uniformity across the substrate. The increasing diameters, depths and surface areas from the center to the edge of the diffuser plate can be created by bending the diffuser plate toward downstream side, followed by machining out the convex downstream side. Bending the diffuser plate can be accomplished by a thermal process or a vacuum process. The increasing diameters, depths and surface areas from the center to the edge of the diffuser plate can also be created computer numerically controlled machining. Diffuser plates with gradually increasing diameters, depths and surface areas of the hollow cathode cavities from the center to the edge of the diffuser plate have been shown to produce improved uniformities of film thickness and film properties.

Claims

1. A gas distribution plate assembly for a plasma processing chamber, comprising:

a planar diffuser plate element having an edge, a center, an upstream side and a downstream side, wherein the upstream side and the downstream side are parallel; and

inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;

an orifice hole having a first diameter; and

a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the size of the hollow cathode cavities of the inner gas passages is less than the size of the hollow cathode cavities of the outer gas passages.

2. The gas distribution plate assembly of claim 1, wherein the second diameters are between about 0.1 inch to about 1.0 inch.

3. The gas distribution plate assembly of claim 1, wherein the second diameters are between about 0.1 inch to about 0.5 inch.

4. The gas distribution plate assembly of claim 1, wherein the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch.

5. The gas distribution plate assembly of claim 1, wherein the depths of the cones or cylinders are between about 0.1 inch to about 1.0 inch.

6. The gas distribution plate assembly of claim 1, wherein flaring angles of the cones are between about 10 degrees to about 50 degrees.

7. The gas distribution plate assembly of claim 1, wherein flaring angles of the cones are between about 20 degrees to about 40 degrees.

8. The gas distribution plate assembly of claim 1, wherein the second diameters are between about 0.1 inch to about 1.0 inch, the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch, and flaring angles of the cones are between about 10 degrees to about 50 degrees.

9. The gas distribution plate assembly of claim 1, wherein a spacing between the downstream ends of the hollow cathode cavities of adjacent gas passages is at most about 0.6 inch.

10. The gas distribution plate assembly of claim 1, wherein the thickness of the diffuser plate element is between about 0.8 inch to about 3.0 inch.

11. The gas distribution plate assembly of claim 1, wherein the diffuser plate element is rectangular.

12. The gas distribution plate assembly of claim 11, wherein the diffuser plate element size is at least 1,200,000 mm².

13. The gas distribution plate assembly of claim 1, each gas passage further comprising:

a first bore extending from the upstream side to the orifice hole, the first bore having a third diameter greater than the first diameter and a tapered, beveled, chamfered, or rounded bottom; and

a tapered, beveled, chamfered, or rounded surface of the hollow cathode cavity coupled to the orifice hole.

14. The assembly of claim 1, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

15. The assembly of claim 1, wherein the orifice holes are configured uniformly among the gas passages.

16. The assembly of claim 1, wherein the orifice holes are configured non-uniformly among the gas passages.

17. A gas distribution plate assembly for a plasma processing chamber, comprising:

a diffuser plate element having an edge, a center, an upstream side and a downstream side; and

inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;

an orifice hole having a first diameter, wherein a length of the orifice divided by the first diameter is between 2 and 3.33; and

a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the hollow cathode cavity surface area density of the inner gas passages is less than the hollow cathode cavity surface area density of the outer gas passages.

18. The gas distribution plate assembly of claim 17, wherein the second diameters are between about 0.1 inch to about 1.0 inch.

19. The gas distribution plate assembly of claim 17, wherein the second diameters are between about 0.1 inch to about 0.5 inch.

20. The gas distribution plate assembly of claim 17, wherein the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch.

21. The gas distribution plate assembly of claim 17, wherein the depths of the cones or cylinders are between about 0.1 inch to about 1.0 inch.

22. The gas distribution plate assembly of claim 17 wherein flaring angles of the cones are between about 10 degrees to about 50 degrees.

23. The gas distribution plate assembly of claim 17, wherein flaring angles of the cones are between about 20 degrees to about 40 degrees.

24. The gas distribution plate assembly of claim 17, wherein the second diameters are between about 0.1 inch to about 1.0 inch, the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch, and flaring angles of the cones are between about 10 degrees to about 50 degrees.

25. The gas distribution plate assembly of claim 17, wherein a spacing between the downstream ends of the hollow cathode cavities of adjacent gas passages is at most about 0.6 inch.

26. The gas distribution plate assembly of claim 17, wherein the thickness of the diffuser plate element is between about 0.8 inch to about 3.0 inch.

27. The gas distribution plate assembly of claim 17, wherein the diffuser plate element is rectangular.

28. The gas distribution plate assembly of claim 27, wherein the diffuser plate element size is at least 1,200,000 mm².

29. The gas distribution plate assembly of claim 17, each gas passage further comprising:

a first bore extending from the upstream side to the orifice hole, the first bore having a third diameter greater than the first diameter and a tapered, beveled, chamfered, or rounded bottom; and

a tapered, beveled, chamfered, or rounded surface of the hollow cathode cavity coupled to the orifice hole.

30. The assembly of claim 17, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

31. The assembly of claim 17, wherein the orifice holes are configured uniformly among the gas passages.

32. The assembly of claim 17, wherein the orifice holes are configured non-uniformly among the gas passages.

33. A gas distribution plate assembly for a plasma processing chamber, comprising:

a diffuser plate element having an edge, a center, an upstream side and a down stream side; and

a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;

an orifice hole having a first diameter, wherein a length of the orifice divided by the first diameter is between 2 and 3.33; and

a hollow cathode cavity that is downstream of the orifice hole and intersects the downstream side of the diffuser plate element, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, the densities of the hollow cathode cavities increase from the center to the edge of the diffuser plate element, and the hollow cathode cavity volume density or the hollow cathode cavity surface area density increases from the center to the edge of the diffuser plate element.

34. The gas distribution plate assembly of claim 33, wherein the densities of the hollow cathode cavities are between about 10% to about 100%.

35. The gas distribution plate assembly of claim 33, wherein the densities of the hollow cathode cavities are between about 30% to about 100%.

36. The gas distribution plate assembly of claim 33, wherein the second diameters are between about 0.1 inch to about 1.0 inch.

37. The gas distribution plate assembly of claim 33, wherein the second diameters are between about 0.1 inch to about 0.5 inch.

38. The gas distribution plate assembly of claim 33, wherein the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch.

39. The gas distribution plate assembly of claim 33, wherein the depths of the cones or cylinders are between about 0.1 inch to about 1.0 inch.

40. The gas distribution plate assembly of claim 33, wherein flaring angles of the cones are between about 10 degrees to about 50 degrees.

41. The gas distribution plate assembly of claim 33, wherein flaring angles of the cones are between about 20 degrees to about 40 degrees.

42. The gas distribution plate assembly of claim 33, wherein the second diameters are between about 0.1 inch to about 1.0 inch, the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch, and flaring angles of the cones are between about 10 degrees to about 50 degrees.

43. The gas distribution plate assembly of claim 33, wherein the thickness of the diffuser plate element is between about 0.8 inch to about 3.0 inch.

44. The gas distribution plate assembly of claim 33, wherein the diffuser plate element is rectangular.

45. The gas distribution plate assembly of claim 44, wherein the diffuser plate element size is at least 1,200,000 mm².

46. The assembly of claim 33, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

47. The assembly of claim 33, wherein the orifice holes are configured uniformly among the gas passages.

48. The assembly of claim 33, wherein the orifice holes are configured non-uniformly among the gas passages.

49. A plasma processing chamber, comprising:

a planar diffuser plate element having an edge, a center, an upstream side and a downstream side, wherein the upstream side and the downstream side are parallel;

a RF power source coupled to the diffuser plate element;

inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;

an orifice hole having a first diameter; and

a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the size of the hollow cathode cavities of the inner gas passages is less than the size of the hollow cathode cavities of the outer gas passages; and

a substrate support adjacent the downstream side of the diffuser plate element.

50. The plasma processing chamber of claim 49, wherein the second diameters are between about 0.1 inch to about 1.0 inch.

51. The plasma processing chamber of claim 49, wherein the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch.

52. The plasma processing chamber of claim 49, wherein flaring angles of the cones are between about 10 degrees to about 50 degrees.

53. The plasma processing chamber of claim 49, wherein the second diameters are between about 0.1 inch to about 1.0 inch, the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch, and flaring angles of the cones are between about 10 degrees to about 50 degrees.

54. The plasma processing chamber of claim 49, wherein a spacing between the downstream ends of the hollow cathode cavities of adjacent gas passages is at most about 0.6 inch.

55. The plasma processing chamber of claim 49, wherein the thickness of the diffuser plate element is between about 0.8 inch to about 3.0 inch.

56. The plasma processing chamber of claim 49, wherein the diffuser plate element is rectangular.

57. The plasma processing chamber of claim 56, wherein the diffuser plate element size is at least 1,200,000 mm².

58. The plasma processing chamber of claim 49, each gas passage further comprising:

a first bore extending from the upstream side to the orifice hole, the first bore having a third diameter greater than the first diameter and a tapered, beveled, chamfered, or rounded bottom; and

a tapered, beveled, chamfered, or rounded surface of the hollow cathode cavity coupled to the orifice hole.

59. The chamber of claim 49, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

60. The chamber of claim 49, wherein the orifice holes are configured uniformly among the gas passages.

61. The chamber of claim 49, wherein the orifice holes are configured non-uniformly among the gas passages.

62. A plasma processing chamber, comprising:

a diffuser plate element having an edge, a center, an upstream side and a downstream side;

a RF power source coupled to the diffuser plate element;

inner and outer gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;

an orifice hole having a first diameter, wherein a length of the orifice divided by the first diameter is between 2 and 3.33; and

a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and the hollow cathode cavity surface area density of the inner gas passages is less than the hollow cathode cavity surface area density of the outer gas passages; and

a substrate support adjacent the downstream side of the diffuser plate element.

63. The plasma processing chamber of claim 62, wherein the second diameters are between about 0.1 inch to about 1.0 inch.

64. The plasma processing chamber of claim 62, wherein the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch.

65. The plasma processing chamber of claim 62, wherein flaring angles of the cones are between about 10 degrees to about 50 degrees.

66. The plasma processing chamber of claim 62, wherein the second diameters are between about 0.1 inch to about 1.0 inch, the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch, and flaring angles of the cones are between about 10 degrees to about 50 degrees.

67. The plasma processing chamber of claim 62, wherein a spacing between the downstream ends of the hollow cathode cavities of adjacent gas passages is at most about 0.6 inch.

68. The plasma processing chamber of claim 62, wherein the thickness of the diffuser plate element is between about 0.8 inch to about 3.0 inch.

69. The plasma processing chamber of claim 62, wherein the diffuser plate element is rectangular.

70. The plasma processing chamber of claim 69, wherein the diffuser plate element size is at least 1,200,000 mm².

71. The plasma processing chamber of claim 62, each gas passage further comprising:

a first bore extending from the upstream side to the orifice hole, the first bore having a third diameter greater than the first diameter and a tapered, beveled, chamfered, or rounded bottom; and

a tapered, beveled, chamfered, or rounded surface of the hollow cathode cavity coupled to the orifice hole.

72. The chamber of claim 62, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

73. The chamber of claim 62, wherein the orifice holes are configured uniformly among the gas passages.

74. The chamber of claim 62, wherein the orifice holes are configured non-uniformly among the gas passages.

75. A plasma processing chamber, comprising:

a planar diffuser plate element having an edge, a center, an upstream side and a down stream side, wherein the upstream side and the down stream side are parallel;

a RF power source coupled to the diffuser plate element;

a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;

an orifice hole having a first diameter; and

a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, and surface area densities of hollow cathode cavities of the plurality of gas passages increase from the center to the edge of the diffuser plate element; and

a substrate support adjacent the downstream side of the diffuser plate element.

76. The plasma processing chamber of claim 75, wherein the surface area densities of the hollow cathode cavities of the plurality of gas passages are between about 10% to about 100%.

77. The plasma processing chamber of claim 75, wherein the second diameters are between about 0.1 inch to about 1.0 inch.

78. The plasma processing chamber of claim 75, wherein the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch.

79. The plasma processing chamber of claim 75, wherein flaring angles of the cones are between about 10 degrees to about 50 degrees.

80. The plasma processing chamber of claim 75, wherein the second diameters are between about 0.1 inch to about 1.0 inch, the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch, and flaring angles of the cones are between about 10 degrees to about 50 degrees.

81. The plasma processing chamber of claim 75, wherein the thickness of the diffuser plate element is between about 0.8 inch to about 3.0 inch.

82. The plasma processing chamber of claim 75, wherein the diffuser plate element is rectangular.

83. The plasma processing chamber of claim 82, wherein the diffuser plate element size is at least 1,200,000 mm².

99. The chamber of claim 75, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

100. The chamber of claim 75, wherein the orifice holes are configured uniformly among the gas passages.

101. The chamber of claim 75, wherein the orifice holes are configured non-uniformly among the gas passages.

84. A gas distribution plate assembly for a plasma processing chamber, comprising:

a planar diffuser plate element having an edge, a center, an upstream side and a downstream side and the diffuser plate is divided into a number of concentric zones, wherein the upstream side and the downstream side are parallel; and

a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate element from the center to the edge of the diffuser plate element, each gas passage having;

an orifice hole having a first diameter; and

a hollow cathode cavity that is downstream of the orifice hole and is at the downstream side, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate element, the first diameters are substantially uniform from the center to the edge of the diffuser plate element, the gas passages in each zone are identical and the volume or surface area of hollow cathode cavities of gas passages in each zone gradually increase from the center to the edge of the diffuser plate element.

85. The gas distribution plate assembly of claim 84, wherein the number of concentric zones is at least two.

86. The gas distribution plate assembly of claim 84, wherein the hollow cathode cavities have densities between about 10% to about 100%.

87. The gas distribution plate assembly of claim 84, wherein the densities of the hollow cathode cavities are between about 30% to about 100%.

88. The gas distribution plate assembly of claim 84, wherein the second diameters are between about 0.1 inch to about 1.0 inch.

89. The gas distribution plate assembly of claim 84, wherein the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch.

90. The gas distribution plate assembly of claim 84, wherein flaring angles of the cones are between about 10 degrees to about 50 degrees.

91. The gas distribution plate assembly of claim 84, wherein the second diameters are between about 0.1 inch to about 1.0 inch, the depths of the cones or cylinders are between about 0.1 inch to about 2.0 inch, and flaring angles of the cones are between about 10 degrees to about 50 degrees.

92. The gas distribution plate assembly of claim 84, wherein a spacing between the downstream ends of the hollow cathode cavities of adjacent gas passages is at most about 0.6 inch.

93. The gas distribution plate assembly of claim 84, wherein the thickness of the diffuser plate element is between about 0.8 inch to about 3.0 inch.

94. The gas distribution plate assembly of claim 84, wherein the diffuser plate element is rectangular.

95. The gas distribution plate assembly of claim 94, wherein the diffuser plate element size is at least 1,200,000 mm².

96. The assembly of claim 84, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

97. The assembly of claim 84, wherein the orifice holes are configured uniformly among the gas passages.

98. The assembly of claim 84, wherein the orifice holes are configured non-uniformly among the gas passages.

102. A diffuser plate, comprising:

a body having an edge, a center, a top surface and a bottom surface, wherein the bottom surface is concave;

a plurality of gas passages between the top surface and the bottom surface, from the center to the edge of the body wherein each gas passage has;

an orifice hole having a first diameter, wherein a length of the orifice divided by the first diameter is between 2 and 3.33; and

a hollow cathode cavity that is downstream of the orifice hole and intersects the bottom surface, the hollow cathode cavity having a cone or cylinder shape and a second diameter at the downstream side that is greater than the first diameter, the second diameters or the depths or a combination of both of the cones or cylinders increases from the center to the edge of the diffuser plate, the first diameters are substantially uniform from the center to the edge of the diffuser plate, and the size of the hollow cathode cavities increases from the center to the edge of the diffuser plate; and

an outer region and an inner region wherein the body between the top and the bottom of the outer region is thicker than the body between the top and the bottom of the inner region.

103. The diffuser plate of claim 102, wherein the top surface is substantially flat.

104. The plate of claim 102, wherein the orifice holes are shaped to promote an even flow of gas therethrough.

105. The plate of claim 102, wherein the orifice holes are configured uniformly among the gas passages.

106. The plate of claim 102, wherein the orifice holes are configured non-uniformly among the gas passages.