Electrochemical fabrication methods including use of surface treatments to reduce overplating and/or planarization during formation of multi-layer three-dimensional structures

• US 7,109,118 B2
• Filed: 05/07/2004
• Issued: 09/19/2006
• Est. Priority Date: 05/07/2003
• Status: Expired due to Fees

• 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., Le, Qui T.
• Primary Examiner(s): Nhu, David
• Application Number:
  US10/841,100
• Publication Number:
  US 20050032362A1
• Time in Patent Office: 865 Days
• Field of Search: 438/697, 438/692, 438/680, 438/706, 438/712, 438/745
• US Class Current: 438/697
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: C23C 18/1605 by masking
• 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: H01L 21/288 from a liquid, e.g. electrolytic deposition
• CPC Class Codes: H01L 21/311 Etching the insulating layers by chemical or physical means H01L21/31058 takes precedence
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288

Abstract

A method of fabricating three-dimensional structures from a plurality of adhered layers of at least a first and a second material wherein the first material is a conductive material and wherein each of a plurality of layers includes treating a surface of a first material prior to deposition of the second material. The treatment of the surface of the first material either (1) decreases the susceptibility of deposition of the second material onto the surface of the first material or (2) eases or quickens the removal of any second material deposited on the treated surface of the first material. In some embodiments the treatment of the first surface includes forming a dielectric coating over the surface and the second material is electrodeposited (e.g. using an electroplating or electrophoretic process). In other embodiments the first material is coated with a conductive material that doesn'"'"'t readily accept deposits of electroplated or electroless deposited materials.

Claims

1. A method for forming at least a portion of a three-dimensional structure from a plurality of stacked and adhered layers, comprising:

(a) depositing and patterning a first conductive material on a substrate or previous layer to obtain a desired pattern having at least one protrusion of the first conductive material having a surface and at least one opening extending from the surface through a thickness of the first conductive material to the substrate or previously formed layer;

(b) treating the surface of the first conductive material to decrease susceptibility of the surface to receive a second conductive material which is to be deposited;

(c) depositing the second conductive material, such that deposition occurs with a higher selectivity to one or more regions defined by the at least one opening, wherein the higher selectivity results, at least in part, from the treating of the surface of the first conductive material;

(d) removing an effect of the treating of the surface of the first conductive material;

(e) repeating elements (a)–

(d) such that a plurality of stacked layers are adhered to successively formed layers to form the at least portion of the three-dimensional structure.

2. The method of claim 1 wherein the depositing and patterning of the first conductive material comprises electroplating the first conductive material onto the substrate or previously formed layer using a contact mask.

3. The method of claim 1 wherein the depositing and patterning of the first conductive material comprises electroplating the first conductive material onto the substrate or previously formed layer using a patterned dielectric adhered to the substrate or previously formed layer.

4. The method of claim 1 wherein the depositing and patterning of the first conductive material comprises blanket depositing the first conductive material onto the substrate or previously formed layer and then patterning the deposited first conductive material.

5. The method of claim 4 wherein the patterning of the first conductive material comprises selectively etching the first conductive material wherein selectivity of the etching is obtained using a contact mask.

6. The method of claim 4 wherein the patterning of the first conductive material comprises selectively etching the first conductive material wherein selectivity of the etching is obtained using a patterned dielectric adhered to the substrate or previously formed layer.

7. The method of claim 6 wherein the etching comprises wet etching.

8. The method of claim 7 wherein the etching comprises chemical etching.

9. The method of claim 7 wherein the etching comprises electrochemical etching.

10. The method of claim 6 wherein the etching comprises dry etching.

11. The method of claim 6 wherein the etching comprises at least one of reactive ion etching, sputter etching, or vapor phase etching.

12. The method of claim 4 wherein the patterning of the first conductive material comprises ablating selected portions of the first conductive material.

13. The method of claim 1 wherein the treating of the surface comprises stamping a solidifiable material against the surface to transfer the material to the surface and then solidifying the solidifiable material on the surface to form a dielectric coating.

14. The method of claim 1 wherein the treating of the surface comprises applying at least one of a solidifiable material or powder material to the surface using a roller to transfer the solidifiable material and then solidifying and adhering the transferred solidifiable material on the surface to form a dielectric coating.

15. The method of claim 1 wherein the treating of the surface comprises:

(a) applying and adhering a sheet of photoresist to the surface of the first conductive material;

(b) patterning the photoresist to leave at least one opening through the photoresist in at least one location where the second conductive material is to be deposited.

16. The method of claim 1 wherein the treating of the surface comprises:

(a) applying a coating of photoresist to the surface of the first conductive material;

(b) solidifying, patterning, and adhering the photoresist to leave at least one opening through the photoresist in at least one location were the second conductive material is to be deposited.

17. The method of claim 1 wherein the treating of the surface comprises:

(a) applying a sheet of dielectric material to the surface of the first conductive material;

(b) bonding the sheet of dielectric material to the surface; and

(c) applying at least one of gas pressure, liquid conveyed pressure or particulate conveyed pressure to the sheet to cause separation between those portions of the sheet supported by the first conductive material and those portions that are not supported.

18. The method of claim 1 wherein the treating of the surface comprises:

(a) applying a solidifiable material, supported by a support structure, to the first conductive material;

(b) solidifying solidifiable material on the first conductive material to form a dielectric coating; and

(c) lifting off or peeling back the support structure to leave the surface of the first conductive material covered by the dielectric coating whereby portions of the coating not in contact with the first conductive material remain adhered to the support structure during lifting off or peeling back.

19. The method of claim 1 wherein the treating of the surface comprises:

(a) adhering a patterned dielectric material to the surface of the first conductive material, wherein the patterned dielectric is supported by a support structure; and

(b) separating the support structure from the patterned dielectric.

20. The method of claim 1 wherein the treating of the surface comprises:

(a) applying a solidifiable material to the surface of the first conductive material and to the substrate or previously formed layer exposed by the at least one opening;

(b) solidifying the solidifiable material to form a first solidified material; and

(c) planarizing the solidified material to expose the first conductive material;

(d) selectively depositing a second solid ifiable material onto the exposed first conductive material and then solidifying the second solidifiable material to form a second solidified material; and

(e) removing the first solidified material to expose the substrate or previously formed layer through the at least one opening in the first conductive material.

21. The method of claim 1 wherein the treating of the surface comprises applying a selected conductive material to the exposed surface of the first conductive material, wherein the selective conductive material has the property that is does not readily accept at least one of electrodeposits or electroless deposits of at least some other conductive materials.

22. The method of claim 21 wherein the selected conductive material comprises chromium.

23. The method of claim 1 wherein the treating of the surface comprises a chemical treatment of the surface that converts the surface to a dielectric material.

24. The method of claim 23 wherein the chemical treatment oxidizes the exposed surface of the first conductive material.

25. The method of claim 1 wherein the patterning of the first conductive material comprises:

(a) contacting or adhering a mask to the substrate or previously formed layer, wherein the mask has at least one opening through which the first conductive material may be deposited onto the substrate or previously formed layer; and

(b) electrodepositing the first conductive material onto the substrate or previously formed layer through the at least one opening.

26. The method of claim 25, wherein a height of the at least one opening through the mask is greater than a thickness of deposit of the first conductive material, such that at least a portion of the opening remains unfilled by the first conductive material, and wherein the treating of the surface of the first conductive material, comprises:

(a) electrophoretically depositing a dielectric material into the unfilled portion of the at least one opening.

27. The method of claim 26, additionally comprising:

(a) treating the electrophoretically deposited dielectric material to transform the electrophoretically deposited material into at least one cohesive insulative coating.

28. The method of claim 27 wherein the treating of the electrophoretically deposited dielectric material comprises at least one of:

(a) applying pressure to the electrophoretically deposited dielectric material;

(b) heating the electrophoretically deposited dielectric material;

or

(c) applying a selected radiation to the electrophoretically deposited dielectric material.

29. The method of claim 25, wherein a height of the at least one opening through the mask is greater than a thickness of deposit of the first conductive material, such that at least a portion of the opening remains unfilled by the first conductive material, and wherein the treating of the surface of the first conductive material, comprises spraying or spreading a material into the unfilled portion of the at least one opening.

30. The method of claim 29, additionally comprising treating the sprayed or spread material to form at least one cohesive insulative coating within the at least one opening.

31. The method of claim 30 wherein the treating of the sprayed or spread dielectric material comprises at least one of:

(a) applying pressure to the sprayed or spread material;

(b) heating the sprayed or spread material;

(c) applying a selected radiation to the sprayed or spread material;

or

(d) removing oxygen from the sprayed or spread material.

32. The method of claim 25, wherein a height of the at least one opening through the mask is greater than a thickness of deposit of the first conductive material, such that at least a portion of the opening remains unfilled by the first conductive material, and wherein the treating of the surface of the first conductive material, comprises electrostatically directing a powdered dielectric material to a desired location, or away from a desired location, using repulsive or attractive force or causing adhesion between a powdered dielectric and the first conductive material located in an unfilled portion of the at least one opening.

33. The method of claim 32, additionally comprising removing powdered dielectric material from undesired locations using at least one of gravity, a magnetic brush, or gas flow.

34. The method of claim 32, additionally comprising treating the powdered dielectric material to form at least one cohesive insulative coating within the at least one opening.

35. The method of claim 34 wherein the treating of the powdered dielectric material comprises at least one of:

(a) applying pressure to powdered dielectric material;

(b) heating the powdered dielectric material;

or

(c) applying a selected radiation to the powdered dielectric.

36. The method of claim 25 wherein mask is a first mask and wherein the treating of the surface of the first conductive material comprises:

(a) applying a coating of solidifiable dielectric material on the first mask and on the surface of the first conductive material; and

(b) solidifying at least a portion of the solidifiable dielectric material to form at least a partial insulative coating; and

(c) etching away those portions of the coating of solid ifiable dielectric material or of the insulative coating that do not overlay the first conductive material.

37. The method of claim 25 wherein mask is a first mask and wherein the treating of the surface of the first conductive material comprises:

(a) applying a sheet or coating of photoresist on the first mask and on the surface of the first conductive material; and

(b) patterning the photoresist to form an insulative coating on the first conductive material.

38. The method of claim 1 wherein formation of a layer comprises deposition of at least one additional conductive material.

39. The method of claim 38 wherein a surface of the second conductive material, or of one of the at least one additional conductive materials, is treated to decrease susceptibility of the surface of the second conductive material, or of one of the at least one additional conductive materials, to receive a deposition of a subsequently deposited conductive material.

40. The method of claim 39 wherein the treatment of the second conductive material, or of one of the at least one additional conductive materials, treats a surface of the first conductive material to decrease susceptibility of the surface of the first conductive material to receive a deposition of the subsequently deposited conductive material.

41. The method of claim 39 wherein the treatment of the second conductive material, or of one of the at least one additional conductive materials, is removed separately form the removal of the treatment of the first conductive material.

42. The method of claim 39 wherein the treatment of the second conductive material, or of one of the at least one additional conductive materials, is removed along with the removal of the treatment of the first conductive material.

43. The method of claim 1 additional comprising:

(a) planarizing the first conductive material and the second conductive material to a common level during the formation of at least some layers.

44. The method of claim 1 wherein one of the first or second conductive materials is a structural material while the other of the first or second conductive materials is a sacrificial material, and wherein the method additional comprises separating the sacrificial material from the structural material to release the at least portion of the three-dimensional structure.

45. The method of claim 1 wherein the first conductive material comprises a plurality of materials one deposited on another.

46. The method of claim 1 wherein the first conductive material comprises a material on one layer and a different material on a different layer.

47. The method of claim 1 wherein the second conductive material comprises a plurality of materials one deposited on another.

48. The method of claim 1 wherein the second conductive material comprises a material on one layer and a different material on a different layer.

49. A method for forming at least a portion of a three-dimensional structure from a plurality of stacked and adhered layers, comprising:

(a) depositing and patterning a first conductive material on a substrate or previous layer to obtain a desired pattern having at least one protrusion of the first conductive material having a surface and at least one opening extending from the surface through a thickness of the first conductive material to the substrate or previously formed layer;

(b) treating the surface of the first conductive material to form a coating on the first conductive material;

(c) depositing the second conductive material at least into the at least one opening;

(d) removing the coating from the surface of the first conductive material along with any second conductive material deposited thereon;

(e) repeating elements (a)–

(d) such that a plurality of stacked layers are adhered to successively formed layers to form the at least portion of the three-dimensional structure.

50. The method of claim 49 wherein formation of a layer comprises deposition of at least one additional conductive material.

51. The method of claim 50 wherein a surface of the second conductive material, or of one of the at least one additional conductive materials, is treated to decrease susceptibility of the surface of the second conductive material, or of one of the at least one additional conductive materials, to receive a deposition of a subsequently deposited conductive material.

52. The method of claim 51 wherein the treatment of the second conductive material, or of one of the at least one additional conductive materials, treats a surface of the first conductive material to decrease susceptibility of the surface of the first conductive material to receive a deposition of the subsequently deposited conductive material.

53. The method of claim 51 wherein the treatment of the second conductive material or of one of the at least one additional conductive materials is removed separately form the removal of the treatment of the first conductive material.

54. The method of claim 51 wherein the treatment of the second conductive material, or of one of the at least one additional conductive materials, is removed along with the removal of the treatment of the first conductive material.

55. The method of claim 49 additional comprising planarizing the first conductive material and the second conductive material to a common level during the formation of at least some layers.

56. The method of claim 49 wherein one of the first or second conductive materials is a structural material while the other of the first or second conductive materials is a sacrificial material, and wherein the method additional additionally comprises separating the sacrificial material from the structural material to release the at least portion of the three-dimensional structure.

57. A method for forming at least a portion of a three-dimensional structure from a plurality of stacked and adhered layers, comprising:

(a) depositing and patterning a first conductive material on a substrate or previous layer to obtain a desired pattern having at least one protrusion of the first conductive material having a surface and at least one opening extending from the surface through a thickness of the first conductive material to the substrate or previously formed layer;

(b) forming a dielectric coating on the surface of the first conductive material to decrease susceptibility of the surface to receive a second conductive material which is to be deposited;

(c) depositing the second conductive material, such that deposition occurs with a higher selectivity to one or more regions defined by the at least one opening, wherein the higher selectivity results, at least in part, from the treating of the surface of the first conductive material;

(d) removing an effect of the treating of the surface of the first conductive material;

(e) repeating elements (a)–

(d) such that a plurality of stacked layers are adhered to successively formed layers to form the at least portion of the three-dimensional structure.

58. The method of claim 57 additional comprising planarizing the first conductive material and the second conductive material to a common level during the formation of at least some layers.

59. The method of claim 57 wherein one of the first or second conductive materials is a structural material while the other of the first or second conductive materials is a sacrificial material, and wherein the method additionally comprises separating the sacrificial material from the structural material to release the at least portion of the three-dimensional structure.

60. A method for forming at least a portion of a three-dimensional structure from a plurality of stacked and adhered layers, comprising:

(a) depositing and patterning a first conductive material on a substrate or previous layer to obtain a desired pattern having at least one protrusion of the first conductive material having a surface and at least one opening extending from the surface through a thickness of the first conductive material to the substrate or previously formed layer;

(b) treating the surface of the first conductive material to decrease susceptibility of the surface to receive a second material which is to be deposited;

(c) depositing the second material, such that deposition occurs with a higher selectivity to one or more regions defined by the at least one opening, wherein the higher selectivity results, at least in part, from the treating of the surface of the first conductive material;

(d) removing an effect of the treating of the surface of the first conductive material;

(e) repeating elements (a)–

(d) such that a plurality of stacked layers are adhered to successively formed layers to form the at least portion of the three-dimensional structure.

61. The method of claim 60 wherein the first conductive material comprises a plurality of materials one deposited on another.

62. The method of claim 60 wherein the first conductive material comprises a material on one layer and a different material on a different layer.

63. The method of claim 60 wherein the second material comprises a plurality of materials one deposited on another.

64. The method of claim 60 wherein the second material comprises a material on one layer and a different material on a different layer.

65. A method for forming at least a portion of a three-dimensional structure from a plurality of stacked and adhered layers, comprising:

(a) depositing and patterning a first conductive material on a substrate or previous layer to obtain a desired pattern having at least one protrusion of the first conductive material having a surface and at least one opening extending from the surface through a thickness of the first conductive material to the substrate or previously formed layer;

(b) treating the surface of the first conductive material to form a coating on the first conductive material;

(c) depositing the second material at least into the at least one opening;

(d) removing the coating from the surface of the first conductive material along with any second material deposited thereon;

(e) repeating elements (a)–

(d) such that a plurality of stacked layers are adhered to successively formed layers to form the at least portion of the three-dimensional structure.

66. The method of claim 65 wherein the first conductive material comprises a plurality of materials one deposited on another.

67. The method of claim 65 wherein the first conductive material comprises a material on one layer and a different material on a different layer.

68. The method of claim 65 wherein the second material comprises a plurality of materials one deposited on another.

69. The method of claim 65 wherein the second material comprises a material on one layer and a different material on a different layer.