Methods and apparatus for forming multi-layer structures using adhered masks

• US 20050023145A1
• Filed: 05/07/2004
• Published: 02/03/2005
• Est. Priority Date: 05/07/2003
• Status: Abandoned Application

• Current Assignee: Microfabrica Incorporated (Technoprobe S.P.A.)
• Original Assignee: Microfabrica Incorporated (Technoprobe S.P.A.)
• Inventors: Smalley, Dennis R., Cohen, Adam L., Lockard, Michael S., Frodis, Uri, Kilgo, Marvin M. III, Thomassian, Jill R.
• Application Number:
  US10/841,272
• Publication Number:
  US 20050023145A1
• Time in Patent Office: Days
• US Class Current: 205/118
• CPC Class Codes: C25D 1/00 Electroforming
• CPC Class Codes: C25D 1/003 3D structures, e.g. superposed patterned layers
• CPC Class Codes: C25D 1/20 Separation of the formed objects from the electrodes with no destruction of said electrodes
• CPC Class Codes: C25D 5/02 Electroplating of selected surface areas
• CPC Class Codes: C25D 5/022 using masking means
• CPC Class Codes: C25D 5/10 Electroplating with more than one layer of the same or of different metals for bearings C25D7/10
• CPC Class Codes: C25D 5/14 two or more layers being of nickel or chromium, e.g. duplex or triplex layers
• CPC Class Codes: C25D 5/48 After-treatment of electroplated surfaces
• CPC Class Codes: C25D 5/50 by heat-treatment

Abstract

Numerous electrochemical fabrication methods and apparatus are provided for producing multi-layer structures (e.g. having meso-scale or micro-scale features) from a plurality of layers of deposited materials using adhered masks (e.g. formed from liquid photoresist or dry film), where two or more materials may be provided per layer where at least one of the materials is a structural material and one or more of any other materials may be a sacrificial material which will be removed after formation of the structure. Materials may comprise conductive materials that are electrodeposited or deposited in an electroless manner. In some embodiments special care is undertaken to ensure alignment between patterns formed on successive layers.

Claims

1. A process for forming a multilayer three-dimensional structure, comprising:

(a) forming and adhering a layer of material to a substrate or previously formed layer; and

(b) repeating the forming and adhering operation of (a) a plurality of times to build up a three-dimensional structure from a plurality of adhered layers, where successive layers are adhered to previously formed layers;

wherein the formation of at least one layer comprises;

(i) forming and adhering a desired pattern of masking material on the substrate or previously formed layer, wherein the patterning of the masking material results in at least one void in the material that exposes a portion of the substrate or of a previously formed layer;

(ii) depositing a conductive material into the at least one void in the masking material; and

wherein the masking material comprises a dry film photoresist.

2. A process for forming a multilayer three-dimensional structure, comprising:

(a) forming and adhering a layer of material to a substrate or previously formed layer; and

(b) repeating the forming and adhering operation of (a) a plurality of times to build up a three-dimensional structure from a plurality of adhered layers, where successive layers are adhered to previously formed layers;

wherein the formation of at least one layer comprises;

(i) forming and adhering a desired pattern of masking material on the substrate or previously formed layer, wherein the patterning of the masking material results in at least one void in the material that exposes a portion of the substrate or of a previously formed layer;

(ii) depositing a conductive material into the at least one void in the masking material; and

wherein the formation of the at least one layer additionally comprises removing the masking material, depositing a second material, and planarizing the deposited first and second materials to a desired height.

3. A process for forming a multilayer three-dimensional structure, comprising:

(a) forming and adhering a layer of material to a substrate or previously formed layer; and

(b) repeating the forming and adhering operation of (a) a plurality of times to build up a three-dimensional structure from a plurality of adhered layers, where successive layers are adhered to previously formed layers;

wherein the formation of at least one layer comprises;

(i) forming and adhering a desired pattern of masking material on the substrate or previously formed layer, wherein the patterning of the masking material results in at least one void in the material that exposes a portion of the substrate or of a previously formed layer;

(ii) depositing a conductive material into the at least one void in the masking material; and

wherein the formation of the at least one layer additionally comprises removing the masking material and depositing a dielectric material, and wherein the formation of a subsequent layer comprises depositing a seed layer on at least a portion of the at least one layer.

4. A process for forming a multilayer three-dimensional structure, comprising:

(a) forming and adhering a layer of material to a substrate or previously formed layer; and

(b) repeating the forming and adhering operation of (a) a plurality of times to build up a three-dimensional structure from a plurality of adhered layers, where successive layers are adhered to previously formed layers;

wherein the formation of at least one layer comprises;

(i) forming and adhering a desired pattern of masking material on the substrate or previously formed layer, wherein the patterning of the masking material results in at least one void in the material that exposes a portion of the substrate or of a previously formed layer;

(ii) depositing a conductive material into the at least one void in the masking material; and

wherein the formation of the at least one layer additionally comprises depositing a seed layer on the substrate, or previously formed layer, which comprises only conductive material, prior to forming and adhering the mask material.

5. A process for forming a multilayer three-dimensional structure, comprising:

(a) forming and adhering a layer of material to a substrate or previously formed layer; and

(b) repeating the forming and adhering operation of (a) a plurality of times to build up a three-dimensional structure from a plurality of adhered layers, where successive layers are adhered to previously formed layers;

wherein the formation of at least one layer comprises;

(i) forming and adhering a desired pattern of masking material on the substrate or previously formed layer, wherein the patterning of the masking material results in at least one void in the material that exposes a portion of the substrate or of a previously formed layer;

(ii) depositing a conductive material into the at least one void in the masking material; and

wherein the at least one layer, after it is completed, comprises at least three different materials located in different lateral positions on the layer.

6. A process for forming a multilayer three-dimensional structure, comprising:

(a) forming and adhering a layer of material to a substrate or previously formed layer; and

(b) repeating the forming and adhering operation of (a) a plurality of times to build up a three-dimensional structure from a plurality of adhered layers, where successive layers are adhered to previously formed layers;

wherein the formation of at least one layer comprises;

(i) forming and adhering a desired pattern of masking material on the substrate or previously formed layer, wherein the patterning of the masking material results in at least one void in the material that exposes a portion of the substrate or of a previously formed layer;

(ii) depositing a conductive material into the at least one void in the masking material; and

wherein the formation of the at least one layer additionally comprises optically aligning a position of the patterning of the dielectric material by using a focused image of an alignment mark that is located at on least one of (1) the substrate, (2) a carrier on which the substrate sits, or (3) previously deposited material that is located on the substrate.

7. A system for electrodepositing layers of material on a substrate, the system comprising:

an electrodeposition tank having electrodeposition bath therein;

a carrier acting as a first electrode having a first polarity, the carrier having a carrier body to which the substrate is electrically connected, the substrate being immersed in the electrodeposition tank;

a second electrode having a second polarity opposite from the first polarity, the second electrode being immersed in the electrodeposition tank; and

a power source electrically connected to the carrier and the second electrode such that material from the second electrode is electrodeposited onto the substrate through the electrodeposition bath.

8. The system of claim 7, wherein the substrate is affixed to the carrier body.

9. The system of claim 8, wherein the substrate is affixed to the carrier body by a solidifiable adhesive material.

10. The system of claim 8, wherein the substrate is affixed to the carrier body by a mechanical bond.

11. The system of claim 7, wherein the carrier body has a surface that provides a reference for controlling a thickness of the one or more layers of material deposited on the substrate.

12. The system of claim 7, wherein the carrier body is perforated by at least one aperture formed through the carrier body, wherein the substrate is bonded to the carrier body by a material formed in the at least one aperture.

13. The system of claim 7, wherein the carrier body comprises a fixed datum surface for measuring a thickness of the one or more layers of material.

14. The system of claim 7, wherein a material previously deposited on portions of the carrier body form a floor of the electrodeposition tank.

15. The system of claim 7, the carrier body comprises a surface having a recess therein for receiving the substrate such that a surface of the substrate is made parallel to the surface of the carrier body.

16. The system of claim 7, wherein the carrier body comprises alignment targets for aligning photomasks used in subsequently patterning the one or more layers of material.

17. The system of claim 7, wherein the carrier body is formed from a conductive material.

18. The system of claim 7, wherein the carrier body comprises a conductive material on at least a portion of the carrier body.

19. The system of claim 7, wherein the substrate is formed from a conductive material.

20. The system of claim 7, wherein the substrate is coated with a conductive material on at least a portion of the substrate.

21. The system of claim 7, wherein the carrier body comprises a contacting member for making electrical contact with the substrate on at least one surface of the substrate.

22. The system of claim 7, wherein a material previously formed on the carrier body forms a seal with the electrodeposition tank which prevents electrodeposition onto any portion the carrier body other than the sealing material.

23. A system for controlling thickness of layers formed on a substrate, comprising:

a carrier for holding the substrate during formation of one or more layers of material on the substrate, the carrier comprising a carrier body having a surface that provides a reference for measuring a thickness of the one or more layers of material formed on the substrate; and

a planarization fixture for supporting the carrier body during planarization of the one or more layers of material, the planarization fixture having at least one surface adapted to mate with the reference surface of the carrier body such that surfaces of the one or more layers of material formed on the substrate are parallel to the reference surface after planarization.

24. The system of claim 23, further comprising measurement indicators for measuring a thickness of the one or more layers of material formed on the substrate based on the reference surface.

25. The system of claim 24, wherein the measurement indicators measure the thickness by comparing a position of the reference surface to a position of a surface of the one or more layers of material formed on the substrate.

26. The system of claim 25, wherein a plurality of measurement indicators are placed at various radii from a center of the substrate to measure the thickness.

27. The system of claim 25, wherein the measurement indicators are sensors.

28. The system of claim 27, wherein the measurement indicators are dial indicators.

29. The system of claim 27, wherein the measurement indicators are LVDT (linear variable differential transformer)-based distance gauges.

30. The system of claim 27, wherein the measurement indicators are non-contact sensors based on at least one of light, eddy currents, and capacitance.

31. The system of claim 27, wherein the planarization fixture comprises:

moveable stages having thereon the at least one surface adapted to mate with the reference surface of the carrier body; and

a planarization plate for planarizing a surface of the one or more layers of material formed on the substrate, the planarization plate being parallel to the carrier body when the carrier body is supported by the moveable stage.

32. The system of claim 31, wherein the moveable stages comprise coplanar stops parallel with the at least one surface adapted to mate with the reference surface such that the surface of the one or more layers of material formed on the substrate becomes parallel to the reference surface after planarization.

33. The system of claim 32, wherein the coplanar stops are supported by the planarization plate.

34. The system of claim 31, wherein the moveable stages are adapted to raise and lower the carrier body in directions perpendicular to the planarization plate.

35. The system of claim 31, wherein the moveable stages comprise two moveable stages located on opposite one another.

36. The system of claim 32, wherein the coplanar stops are aligned to be parallel with the at least one surface adapted to mate with the reference surface using an autocollimator.

37. The system of claim 36, wherein the alignment is done when the carrier body is supported by the at least one surface adapted to mate with the reference surface.

38. The system of claim 31, wherein the planarization plate comprises a lapping plate formed from at least one of copper, tin-antimony, cast iron, and copper-resin composite.

39. A method for aligning targets, comprising:

providing a first imaging device for focusing on a first target to produce a first image;

providing a second imaging device for focusing on a second target to produce a second image; and

comparing the first and second images to determine a degree of misalignment between the first and second targets.

40. The method of claim 39, further comprising recording the first and second images.

41. The method of claim 39, wherein optical axes of the first and second imaging devices are not coaxial.

42. The method of claim 39, wherein comparing the first and second images comprises superimposing the first image on the second image.

43. A method for determining a priority for forming a sacrificial material and a structural material on a substrate, comprising:

(a) analyzing features to be formed on the substrate;

(b) determining whether a feature to be formed on the substrate has a predefined characteristic;

(c) determining whether a feature determined in (b) to have the predefined characteristic is a positive feature or a negative feature;

(d) forming the structural material first if it is determined in (c) that the feature is a negative feature; and

(e) forming the sacrificial material first if it is determined in (c) that the feature is a positive feature.

44. The method of claim 43, wherein the predefined characteristic is a minimum feature size.

45. The method of claim 43, wherein the predefined characteristic is an aspect ratio.

46. A method for forming both small positive and negative features in the same layer of a substrate, comprising:

(a) depositing a first patternable mold material on the layer;

(b) patterning the first patternable mold material to form a first pattern;

(c) depositing a first material in the first pattern formed in (b);

(d) removing the first patternable mold material to expose areas of the layer not having the first material deposited thereon;

(e) depositing a second patternable mold material over the layer;

(f) patterning the second patternable mold material to form a second pattern;

(g) depositing a second material in the second pattern formed in (f);

(h) removing the second patternable mold material to expose areas of the layer not having the first or second materials deposited thereon;

(i) blanket depositing the first material over the second material and the exposed areas of the layer; and

(j) planarizing the layer.

47. The method of claim 46, wherein depositing first and second materials comprises depositing the first and second materials by electrodeposition.

48. The method of claim 46, wherein the first and second materials are metals.

49. The method of claim 46, wherein the first material is copper and the second material is nickel.

50. A method for forming more than two materials on the same layer, comprising:

(a) depositing a first patternable mold material on the layer;

(b) patterning the first patternable mold material to form a first pattern;

(c) depositing a first material in the first pattern formed in (b);

(d) removing the first patternable mold material to expose areas of the layer not having the first material deposited thereon;

(e) depositing a second patternable mold material over the layer;

(f) patterning the second patternable mold material to form a second pattern;

(g) depositing a second material in the second pattern formed in (f);

(h) removing the second patternable mold material to expose areas of the layer not having the first or second materials deposited thereon;

(i) blanket depositing a third material over the second material and the exposed areas of the layer; and

(j) planarizing the layer.

51. The method of claim 50, wherein depositing first, second and third materials comprises depositing the first, second and third materials by electrodeposition.

52. The method of claim 50, wherein the first, second and third materials are metals.

53. The method of claim 50, wherein the first material is copper, the second material is nickel and the third material is silver.

54. A method for preparing a layer having formed thereon a feature consisting of a first material for deposition of a second material adjacent to the first material, comprising:

(a) depositing a patternable mold material over the first material; and

(b) patterning the patternable mold material to form an aperture adjacent to the first material, the aperture exposing a side portion and a top portion of the first material.

55. A method for forming an alignment target on a substrate, comprising:

forming a first patternable mold material on the substrate;

patterning the first patternable mold material to form a first aperture;

forming a first material in the first aperture to form an alignment target within the first aperture;

removing the first patternable mold material;

forming a second patternable mold material on the substrate so as to cover the alignment target; and

forming the second patternable mold material to form a second aperture wider than and fully enclosing the alignment target.

56. The method of claim 55, further comprising forming a non-conductive material in the second aperture such that the alignment target is enclosed in the non-conductive material.

57. The method of claim 56, further comprising forming a non-adherent material over the non-conductive material.

58. The method of claim 55, wherein forming the first material in the aperture comprises forming the first material by electrodeposition.

59. The method of claim 56, wherein forming the non-conductive material comprises forming the non-conductive material by electrodeposition.

60. The method of claim 57, wherein forming the non-adherent material comprises forming the non-adherent material by electrodeposition.

61. The method of claim 56, wherein forming the non-conductive material comprises forming the non-conductive material by blanket depositing and etching the non-conductive material.

62. The method of claim 57, wherein forming the non-adherent material comprises forming the non-adherent material by depositing and etching the non-adherent material.

63. The method of claim 56, wherein forming the first material in the aperture comprises forming the first material by electrodeposition.

64. The method of claim 56, wherein forming the first material in the aperture comprises forming the first material by depositing and etching the non-adherent material.

65. A method for electroplating a layer of material on a substrate, comprising:

forming a conductive layer over a non-conductive surface of the substrate;

forming a target in the conductive layer such that the target is electrically isolated from the remainder of the conductive layer by the non-conductive surface of the substrate; and

electroplating the layer of material over the conductive layer such that the conductive layer is plated and the target is un-plated.

66. A method for patterning odd and even layers of patternable material formed sequentially on a substrate, comprising:

patterning the odd layers using first photomasks having a first layout of alignment shapes and new target shapes, the first layout having a first orientation relative to the substrate; and

patterning the even layers using second photomasks having a second layout of alignment shapes and new target shapes, the second layout having a second orientation relative to the substrate different from the first orientation.

67. The method of claim 66, wherein the second orientation is 180 degrees opposite the first orientation.

68. A method for forming layers on a substrate, comprising:

providing a first patternable mold material of a first type to be used in forming a first layer on the substrate; and

providing a second patternable mold material of a second type used in forming a second layer on the substrate.

69. The method of claim 68, wherein the first type of patternable mold material is a dry film photoresist and the second type of patternable mold material is a liquid photoresist.

70. The method of claim 68, wherein the first type of patternable mold material is a positive photoresist and the second type of patternable mold material is a negative photoresist.

71. A method for forming layers on a substrate, comprising:

forming a first layer of a patternable mold material on the substrate;

forming at least one additional layer of the patternable mold material on the first layer; and

patterning the first layer and the at least one additional layer.

72. A method for forming on a surface a layer of material having an object incorporated therein, the method comprising:

forming a first layer of patternable mold material on a first surface;

forming a first aperture in the first layer of patternable mold material for receiving an object;

placing the object in the first aperture; and

forming a first material in the first aperture such that the first material encases the object.

73. The method recited in claim 72, further comprising:

removing the first layer of patternable mold material;

forming a first layer of second material on the first surface adjacent to the first material encasing the object; and

removing the first material.

74. The method recited in claim 73, further comprising planarizing the first and second materials before removing the first material.

75. The method recited in claim 74, wherein the first and second materials are planarized such that upper surfaces of both the first and second materials are above an upper level of the object.

76. The method recited in claim 74, wherein the first and second materials are planarized to a level such that an upper portion of the object is planarized.

77. The method recited in claim 72, wherein forming a first material in the first aperture comprises:

forming a second layer of patternable mold material over the first layer of patternable mold material;

forming a second aperture in the second layer of patternable mold material; and

depositing the first material through the second aperture into the first aperture.

78. The method recited in claim 72, wherein placing the object in the first aperture comprises flowing the object onto a surface of the first layer of patternable mold material such that the object falls into the first aperture.

79. The method recited in claim 72, wherein placing the object in the first aperture comprises rolling the object onto a surface of the first layer of patternable mold material such that the object falls into the first aperture.

80. The method recited in claim 72, wherein the object comprises one of a plurality of objects and wherein placing the object in the first aperture comprises pouring the plurality of objects onto a surface of the first layer of patternable mold material such that the object falls into the first aperture.

81. The method recited in claim 80, wherein ones of the plurality of objects not falling into the first aperture are removed from the surface of the first layer of patternable mold material.

82. The method recited in claim 72, wherein placing the object in the first aperture comprises using a pick and place machine to place the object into the first aperture.

83. The method recited in claim 72, wherein placing the object in the first aperture comprises:

forming a second layer of patternable mold material over the first layer of patternable mold material;

forming a second aperture in the second layer of patternable mold material; and

forcing the object through the second aperture into the first aperture.

84. The method recited in claim 73, wherein forming a first layer of second material around the first material encasing the object comprises:

forming a second layer of patternable mold material on the first surface;

forming apertures in the second layer of patternable mold material;

forming a third material in the apertures in the second layer of patternable mold material;

removing the second layer of patternable mold material to expose areas of the first surface not covered by the third material; and

depositing the second material over the exposed areas of the first surface, the first material and the third material.

85. The method recited in claim 84, wherein the third material is the same as the first material.

86. The method recited in claim 73, further comprising forming a second layer of second material over the first layer of second material such that the object is secured within the first layer of second material by the second layer of second material.

87. The method recited in claim 72, wherein the object comprises at least one of a sphere, an integrated circuit, a lens, a mirror, a fiber optic strand and a needle probe.

88. A structure formed on a substrate, comprising a plurality of layers of structural material formed one over another, at least one of the plurality of layers having an object incorporated therein.

89. The structure recited in claim 88, wherein the object comprises at least one of a sphere, an integrated circuit, a lens, a mirror, a fiber optic strand and a needle probe.

90. A method for forming a structure on a surface, comprising:

building a plurality of layers on the surface, the plurality of layers including both a structural material and a sacrificial material; and

after building the plurality of layers, removing the sacrificial material from the plurality of layers;

wherein the sacrificial material is a patternable mold material.

91. A method for forming a structure on a surface, comprising:

forming a first layer of patternable mold material;

patterning first apertures in the first layer of patternable mold material;

depositing a first structural material into the first apertures;

forming a second layer of patternable mold material over the first layer of patternable mold material and the first structural material;

patterning second apertures into the second layer of patternable mold material; and

depositing a second structural material into the second apertures.

92. The method recited in claim 91, further comprising removing the first and second layers of patternable mold material.

93. The method recited in claim 91, wherein the first structural material is the same as the second structural material.

94. The method recited in claim 91, further comprising:

forming a third layer of patternable mold material over the second layer of patternable mold material and the second structural material;

patterning third apertures into the third layer of patternable mold material; and

depositing a third structural material into the third apertures.

95. The method recited in claim 94, further comprising removing the first, second and third layers of patternable mold material.

96. The method recited in claim 94, wherein the first structural material, the second structural material and the third structural material are the same material.

97. A method for forming structures and dicing lanes on a substrate, comprising:

forming a first layer of patternable mold material on a surface;

patterning first apertures in the first layer of patternable mold material;

forming a first material in the first apertures; and

removing the first layer of patternable mold material to expose portions of the surface, a plurality of the exposed portions of the surface functioning as dicing lanes.

98. The method recited in claim 97, further comprising:

forming a second layer of patternable mold material over the first material and the exposed portions of the surface;

patterning the second layer of patternable mold material to remove portions of the second layer of patternable mold material not covering the plurality of the exposed portions of the surface functioning as dicing lanes; and

forming a second material on exposed portions of the surface not functioning as dicing lanes.

99. The method recited in claim 98, further comprising removing remaining portions of the second layer of patternable mold material not removed during the patterning of the second layer of patternable mold material.

100. A method for forming an array of structures, comprising:

forming a first layer of patternable mold material on a surface;

exposing the first layer of patternable mold material using a first photomask to form a first pattern of soluble and insoluble portions of the first layer of patternable mold material, the first pattern for forming an array of structures having a first number of structures; and

exposing the first pattern using a second photomask different from the first photomask to form a second pattern of soluble and insoluble portions of the first layer of patternable mold material from the first pattern, the second pattern for forming an array of structures having a second number of structures different from the first number of structures.

101. The method recited in claim 100, further comprising:

removing the soluble portions of the first layer of patternable mold material to form first apertures in the first layer of patternable mold material; and

forming a first material in the first apertures.

102. The method recited in claim 101, further comprising:

removing the insoluble portions of the first layer of patternable mold material to form second apertures; and

forming a second material in the second apertures.

103. The method recited in claim 102, further comprising planarizing the first and second materials.

104. The method recited in claim 100, wherein the patternable mold material is a positive patternable mold material.

105. The method recited in claim 100, wherein the patternable mold material is a negative patternable mold material.

106. The method recited in claim 102, wherein the first material is a structural material and the second material is a sacrificial material.

107. The method recited in claim 102, wherein the first material is a sacrificial material and the second material is a structural material.