Plating apparatus and method

• US 6,391,166 B1
• Filed: 01/15/1999
• Issued: 05/21/2002
• Est. Priority Date: 02/12/1998
• Status: Expired due to Term

• Current Assignee: ACM Research (Shanghai), Inc.
• Original Assignee: ACM Research (Shanghai), Inc.
• Inventors: Wang, Hui
• Primary Examiner(s): Valentine, Donald R.
• Assistant Examiner(s): LEADER, WILLIAM T
• Application Number:
  US09/232,864
• Time in Patent Office: 1,222 Days
• Field of Search: 204/198, 204/199, 204/228.7, 204/224.R, 204/272, 204/275.1, 204/276, 205/133, 205/136
• US Class Current: 204/224.00R
• CPC Class Codes: C25D 21/12 Process control or regulation controlling or regulating in general G05
• CPC Class Codes: C25D 5/026 using locally applied jets of electrolyte
• CPC Class Codes: C25D 5/08 Electroplating with moving electrolyte e.g. jet electroplating using locally applied jets of electrolyte C25D5/026
• CPC Class Codes: C25D 5/18 Electroplating using modulated, pulsed or reversing current
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00

Abstract

An apparatus for plating a conductive film directly on a substrate with a barrier layer on top includes anode rod (1) placed in tube (109), and anode rings (2), and (3) placed between cylindrical walls (107) and (105), (103) and (101), respectively. Anodes (1), (2), and (3) are powered by power supplies (13), (12), and (11), respectively. Electrolyte (34) is pumped by pump (33) to pass through filter (32) and reach inlets of liquid mass flow controllers (LMFCs) (21), (22), and (23). Then LMFCs (21), (22) and (23) deliver electrolyte at a set flow rate to sub-plating baths containing anodes (3), (2) and (1), respectively. After flowing through the gap between wafer (31) and the top of the cylindrical walls (101), (103), (105), (107) and (109), electrolyte flows back to tank (36) through spaces between cylindrical walls (100) and (101), (103) and (105), and (107) and (109), respectively. A pressure leak valve (38) is placed between the outlet of pump (33) and electrolyte tank (36) to leak electrolyte back to tank (36) when LMFCs (21), (22), (23) are closed. A wafer (31) held by wafer chuck (29) is connected to power supplies (11), (12) and (13). A drive mechanism (30) is used to rotate wafer (31) around the z axis, and oscillate the wafer in the x, y, and z directions shown. Filter (32) filters particles larger than 0.1 or 0.2 μm in order to obtain a low particle added plating process.

Claims

1. An apparatus for plating a film on a substrate, comprising:

a substrate holder configured to position the substrate to receive a plating electrolyte;

at least two anodes configured to supply plating current to the substrate, wherein the at least two anodes are separated by an insulating wall enclosing each of the at least two anodes;

at least two flow controllers configured to supply the plating electrolyte;

a control system coupled to said at least two anodes and said at least two flow controllers to provide electrolyte and plating current to successive portions of the substrate to provide a uniform thickness film on the substrate by successive plating of the film on the substrate.

2. The apparatus of claim 1, wherein the insulating wall of each anode is of the same height.

3. The apparatus of claim 1, wherein the insulating wall of each anode is of a different height.

4. The apparatus of claim 1, wherein the insulating wall of each anode proximate to a center of the substrate is higher than the insulating wall of each anode proximate to an edge of said substrate.

5. The apparatus of claim 1, wherein a first portion of the insulating wall of each anode proximate a center of the substrate being lower than another portion of the insulating wall of each anode proximate an edge of said substrate.

6. The apparatus of claim 1, wherein the at least two flow controllers are separate valves for selectively supplying the plating electrolyte to portions of the substrate adjacent each of the at least two anodes, the apparatus further comprising at least one pump coupled to the separate valves.

7. The apparatus of claim 6, wherein the at least one pump comprises two pumps.

8. The apparatus of claim 6, further comprising a pressure leak valve coupled to an outlet of the at least one pump.

9. The apparatus of claim 1, wherein the at least one control system is configured to selectively supply plating current to said at least two anodes.

10. The apparatus of claim 1, further comprising an inlet and a plurality of nozzles facing said substrate holder.

11. The apparatus of claim 1, further comprising at least one electrolyte return path.

12. The apparatus of claim 1, wherein said substrate holder is configured to oscillate in a horizontal direction.

13. The apparatus of claim 1, wherein said substrate holder is rotatable around a vertical axis.

14. The apparatus of claim 1, further comprising a temperature control device configured to maintain said electrolyte at a constant temperature.

15. The apparatus of claim 1, further comprising a tank and a filter coupled to said at least two flow controllers configured to circulate electrolyte.

16. The apparatus of claim 1, wherein said control system comprises at least two DC power supplies operable in constant current mode.

17. The apparatus of claim 1, wherein said control system comprises at least two DC power supplies operable in constant voltage mode.

18. The apparatus of claim 17, wherein the at least two DC power,supplies are operable in a constant voltage mode and a constant current mode.

19. The apparatus of claim 1, wherein said control system comprises at least two pulse power supplies.

20. The apparatus of claim 19, the at least two pulse power supplies operable in one of bipolar pulse, modified sine-wave, unipolar pulse, pulse reverse, pulse-on-pulse or duplex pulse mode.

21. The apparatus of claim 19, said at least two pulse power supplies operable in a phase shift mode.

22. The apparatus of claim 1, said control system comprising at least one charge monitor to measure the thickness of film being plated.

23. The apparatus of claim 22, wherein said control system controls the thickness of the film being plated on the substrate based on input received from the at least one charge monitor.

24. The apparatus of claim 1, wherein each of said at least two anodes has one of a circular, elliptical or polygonal shape.

25. The apparatus of claim 24, wherein the polygonal shape is a triangle, square, rectangle or pentagon.

26. The apparatus of claim 24, wherein each of said at least two anodes comprises at least two sub-anodes positioned to form the one of a circular, elliptical or polygonal shape.

27. The apparatus of claim 26, wherein the sub-anodes are electrically isolated from each other.

28. The apparatus of claim 1, wherein said control system further includes a logic table configured to recheck continuity of the film.

29. The apparatus of claim 1, further comprising a plurality of electrolyte flow channels;

and

each of said at least two flow controllers includes a valve and an outlet from one of said plurality of electrolyte flow channels.

30. The apparatus of claim 29, wherein each valve and outlet is radially positioned relative to a center of the substrate.

31. The apparatus of claim 29, wherein each of said at least two flow controllers is connected to a pump;

and

said control system is configured to close the valve of one of the flow controllers.

32. The apparatus of claim 29, wherein each of said at least two anodes is a single electrode.

33. The apparatus of claim 29, wherein said at least two anodes comprises at least two electrically connected electrodes, each of the electrodes being in a different one of the plurality of electrolyte flow channels.

34. The apparatus of claim 1, wherein said substrate holder is movable into the electrolyte to immerse the substrate completely into the electrolyte, and said substrate holder is movable away from the electrolyte.

35. An apparatus for plating a film on a substrate, comprising:

a substrate holder configured to position the substrate to receive a plating electrolyte;

at least one anode configured to supply plating current to the substrate;

at least one flow controller configured to control plating electrolyte received by the substrate;

at least three cylindrical walls, a first of the cylindrical walls positioned under a center portion of the substrate located closer to the substrate relative a second one of the cylindrical walls located under a second portion of the substrate peripheral to the center portion;

a drive mechanism coupled to said substrate holder configured to move said substrate holder to cause one or more portions of the substrate to receive the plating electrolyte; and

at least one control system coupled to said at least one anode and said at least one flow controller to provide electrolyte and plating current to successive portions of the substrate to provide a uniform thickness film on the substrate by successive plating of the film on the substrate.

36. An apparatus for plating a film on a substrate, comprising:

a substrate holder configured to position the substrate to receive a plating electrolyte;

at least one anode configured to supply plating current to the substrate;

at least one flow controller configured to control electrolyte received by the substrate;

at least three cylindrical walls displaceable with respect to the substrate, to compensate for a gap between the substrate and each of the cylindrical walls to cause one or more portions of the substrate to receive the electrolyte;

at least one control system coupled to said at least one anode and said at least one flow controller to provide electrolyte and plating current to successive portions of the substrate to provide a uniform thickness film on the substrate by successive plating of the film on the substrate.

37. The apparatus of claim 36 in which said at least one anode comprises at least two anodes.

38. The apparatus of claim 37, in which said at least one flow controller additionally comprises at least two valves for controlling flow of electrolyte to different portions of the substrate.

39. An apparatus for plating a film on a substrate, comprising:

a substrate holder configured to position the substrate above an electrolyte surface;

a first drive mechanism configured to move said substrate holder toward and away from the electrolyte surface to cause a portion of a surface of the substrate to contact the electrolyte;

a bath for the electrolyte;

at least one anode mounted in said bath;

a second drive mechanism coupled to said bath and configured to rotate said bath about a vertical axis to form a substantially parabolic shape of the electrolyte surface; and

a control system in communication with said first and second drive mechanisms and said at least one anode to provide electrolyte and plating current to successive portions of the substrate to provide a uniform thickness film on the substrate by successive plating of the film on of the substrate.

40. The apparatus of claim 39, further comprising at least one flow controller to supply additional electrolyte during plating.

41. The apparatus of claim 39, wherein said at least one anode comprises a plurality of anodes.

42. The apparatus of claim 39, further comprising a third drive mechanism coupled to said substrate holder configured to rotate said substrate holder around an axis perpendicular to the surface of the substrate.

43. An apparatus for plating a film on a substrate, comprising:

a substrate holder configured to position the substrate above an electrolyte surface;

a first drive mechanism configured to move said substrate holder toward and away from the electrolyte surface to cause a portion of a surface of the substrate to contact the electrolyte;

a second drive mechanism coupled to said substrate holder and configured to rotate said substrate holder around an axis perpendicular to the surface of the substrate;

a third drive mechanism coupled to said substrate holder and configured to tilt said substrate holder with respect to the electrolyte surface;

a bath for the electrolyte;

at least one anode mounted in said bath; and

a control system in communication with said first, second and third drive mechanisms and to said at least one anode to provide electrolyte and plating current to successive portions of the substrate to provide a uniform thickness film on the substrate by successive plating of the film on the substrate.

44. The apparatus of claim 43, further comprising at least one flow controller to supply additional electrolyte during plating.

45. The apparatus of claim 43, wherein said at least one anode comprises a plurality of anodes.

46. The apparatus of claim 43, wherein the third drive mechanism is configured to tilt the substrate holder in a tilting angle from about 0 to 180 degrees.

47. The apparatus of claim 43, further comprising:

a fourth drive mechanism coupled to said bath to rotate said bath about a vertical axis to form a substantially parabolic shape of the electrolyte surface.

48. An apparatus for plating a film on a substrate, comprising:

a receptacle having a first section, a second section, and a third section,

wherein said first section is disposed in said second section and said second section is disposed in said third section;

a substrate holder configured to hold the substrate and position the substrate within said receptacle;

a fluid inlet configured to deliver an electrolyte into said receptacle; and

an anode configured to apply a current to the electrolyte to plate the film on the substrate.

49. The apparatus of claim 48, wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section configured to deliver the electrolyte into said first section; and

a second fluid inlet disposed in said second section configured to deliver the electrolyte into said second section.

50. The apparatus of claim 49, further comprising a fluid outlet disposed in said third section configured to remove the electrolyte from said receptacle.

51. The apparatus of claim 48, wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section configured to deliver the electrolyte into said first section; and

a second fluid inlet disposed in said third section configured to deliver the electrolyte into said third section.

52. The apparatus of claim 51, further comprising a fluid outlet disposed in said second section configured to remove the electrolyte from said receptacle.

53. The apparatus of claim 48, further comprising:

a fluid outlet configured to remove the electrolyte from said receptacle; and

an electrolyte reservoir configured to hold the electrolyte, wherein said fluid inlet and said fluid outlet are connected to said electrolyte reservoir.

54. The apparatus of claim 53, further comprising at least one mass flow controller connected between said electrolyte reservoir and said fluid inlet.

55. The apparatus of claim 53, further comprising at least one fluid pump connected between said electrolyte reservoir and said fluid inlet.

56. The apparatus of claim 55, wherein said fluid pump is a diaphragm pump.

57. The apparatus of claim 55, further comprising a pressure leak valve disposed between the outlet of said pump and said electrolyte reservoir.

58. The apparatus of claim 53, further comprising:

a heater configured to heat the electrolyte in said electrolyte reservoir;

a temperature sensor configured to detect the temperature of the electrolyte in said electrolyte reservoir; and

a heater controller configured to control the temperature of the electrolyte in said electrolyte reservoir.

59. The apparatus of claim 48, further comprising at least one power supply connected to the substrate and said anode.

60. The apparatus of claim 59, wherein said power supply is configured to operate in direct current (DC) mode.

61. The apparatus of claim 59, wherein said power supply is configured to operate in pulse modes.

62. The apparatus of claim 61, wherein said power supply is configured to operate using a bipolar pulse, a modified sine-wave, unipolar pulse, pulse reverse, or duplex pulse.

63. The apparatus of claim 59 in which said power supply is configured to operate in a constant current mode.

64. The apparatus of claim 63 in which said power supply is further configured to operate in a constant voltage mode.

65. The apparatus of claim 59 in which said power supply is configured to operate in a constant voltage mode.

66. The apparatus of claim 48, further comprising a drive mechanism configured to rotate the substrate.

67. The apparatus of claim 48 in which said substrate holder is configured to move the substrate relative to said anode.

68. The apparatus of claim 63 in which said anode is configured to move relative to the substrate.

69. The apparatus of claim 48, wherein said anode further comprises:

a first anode disposed in said first section; and

a second anode disposed in said second section.

70. The apparatus of claim 48, wherein said anode further comprises:

a first anode disposed in said first section; and

a second anode disposed in said third section.

71. An apparatus for plating a film on a substrate, comprising:

a receptacle having a first section, a second section, and a third section,

wherein said first section is disposed in said second section and said second section is disposed in said third section;

a substrate holder;

a fluid inlet disposed in said receptacle; and

an anode disposed in said receptacle.

72. The apparatus of claim 71, wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section; and

a second fluid inlet disposed in said second section.

73. The apparatus of claim 72, wherein said anode comprises:

a first anode disposed in said first section; and

a second anode disposed in said second section.

74. The apparatus of claim 71, wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section; and

a second fluid inlet disposed in said third section.

75. The apparatus of claim 74, wherein said anode comprises:

a first anode disposed in said first section; and

a second anode disposed in said third section.

76. The apparatus of claim 71, further comprising:

a fluid outlet disposed in said receptacle; and

an electrolyte reservoir, wherein said fluid inlet and said fluid outlet are connected to said electrolyte reservoir.

77. The apparatus of claim 76, wherein said fluid outlet is disposed in said second section.

78. The apparatus of claim 76, wherein said fluid outlet is disposed in said third section.

79. An apparatus for plating a film on a substrate, comprising:

a receptacle having;

a first section,

a second section, wherein said first section is disposed in said second section, and

a third section, wherein said second section is disposed in said third section;

a fluid inlet disposed in said receptacle; and

an anode disposed in said receptacle.

80. The apparatus of claim 79, wherein said anode comprises:

a first anode disposed in said first section; and

a second anode disposed in said second section.

81. The apparatus of claim 80, wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section; and

a second fluid inlet disposed in said second section.

82. The apparatus of claim 79, wherein said anode comprises:

a first anode disposed in said first section; and

a second anode disposed in said third section.

83. The apparatus of claim 82, wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section; and

a second fluid inlet disposed in said third section.

84. The apparatus of claim 79, further comprising a fluid outlet disposed in said receptacle.

85. The apparatus of claim 84, wherein said fluid outlet is disposed in said second section.

86. The apparatus of claim 85, wherein said fluid outlet is disposed in said third section.

87. The apparatus of claim 79, further comprising section walls that divide said first section, said second section, and said third section.

88. The apparatus of claim 87, wherein at least one of said section walls is moveable.

89. The apparatus of claim 87, wherein at least one of said section walls is divided into at least two sections.

90. An apparatus for plating a film on a substrate, comprising:

a receptacle configured to receive electrolyte and the substrate,

wherein said receptacle is divided into at least a first section, a second section, and a third section, and

wherein said first section and second section are separated by a first section wall, and said second section and third section are separated by a second section wall;

a first fluid inlet configured to apply electrolyte to a first portion of the substrate; and

a second fluid inlet configured to apply electrolyte to a section portion of the substrate.

91. The apparatus of claim 90, wherein said first fluid inlet is disposed in said first section and said second fluid inlet is disposed in said second section.

92. The apparatus of claim 91, further comprising a fluid outlet disposed in said third section.

93. The apparatus of claim 91, further comprising:

a first anode disposed in said first section; and

a second anode disposed in said second section.

94. The apparatus of claim 90, wherein said first fluid inlet is disposed in said first section and said second fluid inlet is disposed in said third section.

95. The apparatus of claim 94, further comprising a fluid outlet disposed in said second section.

96. The apparatus of claim 94, further comprising:

a first anode disposed in said first section; and

a second anode disposed in said third section.

97. The apparatus of claim 90, wherein said first section wall and said second section wall have different height.

98. The apparatus of claim 97, wherein said first section wall is taller than said second section wall.

99. The apparatus of claim 97, wherein said second section wall is taller than said first section wall.

100. An apparatus for plating a film on a substrate, comprising:

a receptacle divided into at least a first section and a second section by a section wall,

wherein said first section is adjacent a first portion of the substrate when the substrate is positioned within said receptacle, and

wherein said second section is adjacent a second portion of the substrate when the substrate is positioned within said receptacle; and

at least one fluid inlet configured to supply an electrolyte into said receptacle; and

at least one anode configured to apply a charge to said electrolyte.

101. The apparatus of claim 100, wherein said at least one fluid inlet is disposed within said first section of said receptacle.

102. The apparatus of claim 100, wherein said at least one anode is disposed within said first section of said receptacle.

103. The apparatus of claim 100, wherein the substrate is a semiconductor wafer, and section wall has a circular shape.

104. An apparatus for plating a film on a substrate, comprising:

a receptacle having a first section wall that lies within a second section wall,

wherein the tops of said section walls are adjacent the bottom surface of the substrate when the substrate is positioned within said receptacle, and

wherein the section walls have different height;

a fluid inlet configured to apply an electrolyte into said receptacle; and

an anode configured to apply a charge to said electrolyte.

105. The apparatus of claim 104, wherein said first section wall is taller than said second section wall.

106. The apparatus of claim 104, wherein said second section wall is taller than said first section wall.

107. The apparatus of claim 104, wherein said section walls are adjustable.

108. The apparatus of claim 104, wherein the receptacle is divided into a first section, a second section, and a third section by said first section wall and said second section wall, and wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section configured to apply said electrolyte to a first portion of the bottom surface of the substrate when the substrate is disposed within said receptacle; and

a second fluid inlet disposed within said second section configured to apply said electrolyte to a second portion of the bottom surface of the substrate when the substrate is disposed within said receptacle.

109. The apparatus of claim 104, wherein the receptacle is divided into a first section, a second section, and a third section by said first section wall and said second section wall, and wherein said fluid inlet comprises:

a first fluid inlet disposed in said first section configured to apply said electrolyte to a first portion of the bottom surface of the substrate when the substrate is positioned within said receptacle; and

a second fluid inlet disposed in said third section configured to apply said electrolyte to a second portion of the bottom surface of the substrate when the substrate is positioned within said receptacle.