Method for electrochemical fabrication

• US 6,475,369 B1
• Filed: 01/18/2000
• Issued: 11/05/2002
• Est. Priority Date: 04/04/1997
• Status: Expired due to Term

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Cohen, Adam L.
• Primary Examiner(s): Nguyen, Nam
• Assistant Examiner(s): SMITH HICKS, ERICA D
• Application Number:
  US09/487,408
• Time in Patent Office: 1,022 Days
• Field of Search: 205/118, 205/135, 205/78
• US Class Current: 205/135
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B81C 1/00126 Static structures not provided for in groups B81C1/00031 - B81C1/00119
• CPC Class Codes: B81C 2201/0181 Physical Vapour Deposition [PVD], i.e. evaporation, sputtering, ion plating or plasma assisted deposition, ion cluster beam technology
• CPC Class Codes: B81C 2201/0197 Processes for making multi-layered devices not provided for in groups B81C2201/0176 - B81C2201/0192
• CPC Class Codes: B81C 2201/032 LIGA process
• CPC Class Codes: C25D 1/00 Electroforming
• CPC Class Codes: C25D 1/003 3D structures, e.g. superposed patterned layers
• CPC Class Codes: C25D 17/06 Suspending or supporting devices for articles to be coated
• 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 5/12 at least one layer being of nickel or chromium
• CPC Class Codes: C25D 5/22 Electroplating combined with mechanical treatment during the deposition
• CPC Class Codes: C25D 5/611 Smooth layers
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H05K 3/241 characterised by the electroplating method; means therefor, e.g. baths or apparatus
• CPC Class Codes: Y10T 428/12486 Laterally noncoextensive components [e.g., embedded, etc.]
• CPC Class Codes: Y10T 428/239 Complete cover or casing

Abstract

An electroplating method includes forming a layer, the forming of the layer includes: a) contacting a substrate with a first article, the first article includes a support and a conformable mask disposed in a pattern on the support; b) electroplating a first metal from a source of metal ions onto the substrate in a first pattern, the first pattern corresponding to the complement of the conformable mask pattern; and c) removing the first article from the substrate. The method may further involve one or more of (1) selectively depositing or non-selectively depositing one or more additional materials to complete formation of the layer, (2) planarizing deposited material after each deposition or after all depositions for a layer, and/or (3) forming layers adjacent previously formed layers to build up a structure from a plurality of adhered layers. Electroplating articles and electroplating apparatus are also disclosed.

Claims

1. An electroplating method comprising:

forming a layer comprising;

a) contacting a substrate with a first article, the first article comprising a support and a first conformable mask disposed in a pattern on said support;

b) electroplating a first metal from a source of metal ions onto said substrate in a first pattern, said first pattern substantially corresponding to the complement of said first conformable mask pattern; and

c) removing said first article from said substrate; and

(ii) building additional layers adjacent to and adhered to previously formed layers, using one or more articles that may be identical to or different from the first article.

2. The method of claim 1, further comprising electroplating a second metal from a second metal ion source onto said substrate.

3. The method of claim 2, wherein said step of electroplating said second metal comprises:

a) contacting said substrate with a second article, said second article comprising a second support, and a second conformable mask disposed in a pattern on said second support;

b) electroplating said second metal onto said substrate in a second pattern, said second pattern corresponding substantially to thecomplement of said second conformable mask pattern of said second article; and

c) removing said second article from said substrate.

4. An electroplating method comprising:

a) contacting a substrate with a patterned conformable mask;

b) electroplating a metal from a source of metal ions onto said substrate in a pattern, said pattern corresponding to the complement of said conformable mask pattern;

c) removing said mask from said substrate; and

d) repeating said contacting, said electroplating, and said removing operations a plurality of times such that a plurality of successively formed layers of metal are formed adjacent to and adhered to previously formed layers of metal.

23. The method of claim 4 wherein the patterns of the conformable masks used in formation of at least two layers are different.

24. The method of claim 23 wherein the formation of each of a plurality of layers includes a blanket deposition of a second metal and at least one planarization operation that planarizes at least one of the first metal or the second metal.

25. The method of claim 23 wherein one conformable mask is used in the formation of at least two layers.

5. A method for manufacturing an element comprising:

a) forming a multi-layer structure by repeatedly forming layers, said step of forming said layers comprising;

i) contacting a substrate with an article, the article comprising a support and a conformable mask disposed in a pattern on said support;

ii) electroplating a first metal from a first metal ion source in a deposition pattern onto said substrate, said deposition pattern substantially corresponding to the complement of said conformable mask pattern;

iii) removing said article from said substrate; and

iv) electroplating a second metal from a second metal ion source onto said substrate; and

b) removing at least a portion of at least one of said metals from said multi-layer structure to form the element.

6. The method of claim 5, wherein said electroplating said second metal comprises:

a) contacting said substrate with a different article comprising a support and a conformable mask deposited in a pattern on said support of said different article;

b) electrodepositing said second metal from a second metal ion source onto said substrate in a pattern corresponding substantially to the complement of said conformable mask pattern of said different article; and

c) removing said different article from said substrate.

26. The method of claim 5 wherein the conformable mask patterns used in the formation of at least two layers are different.

27. The method of claim 26 wherein the formation of each of a plurality of layers includes a blanket deposition of a second metal and at least one planarization operation that planarizes at least one of the first metal or the second metal.

28. The method of claim 26 wherein one conformable mask is used in the formation of at least two layers.

29. The method of claim 5 wherein the patterns used in the formation of at least two layers are different.

30. The method of claim 29 wherein the formation of each of a plurality of layers includes a blanket deposition of a second metal and at least one planarization operation that planarizes at least one of the first metal or the second metal.

31. The method of claim 29 wherein one conformable mask is used in the formation of at least two layers.

7. A method of forming a structure comprising:

obtaining a preformed patterned mask;

bringing said mask into contact with a substrate;

applying an electrical current across a conductive bath in the presence of said substrate, said conductive bath having a property to pattern said substrate in the presence of said electrical current where patterned portions of said mask are not in contact with said substrate;

removing said mask from contact with said substrate; and

repeating said bringing, said applying, and said removing, to form a structure from a plurality of at least partially overlaid layers of patterning.

8. The method of claim 7, wherein said patterning of said substrate comprises electrodepositing material in a plurality of layers to form a multilayer structure, wherein patterned electrodeposition of successive layers occurs via a mask placed in contact with a previously deposited layer that forms, at least in part, part of the structure and thus part of the substrate for any successive depositions.

9. The method of claim 8, further comprising depositing a second material into spaces between deposits of the first material.

10. The method of claim 9, wherein one of said materials is a sacrificial material and the other of said materials is a structural material.

11. The method of claim 10, further comprising removing at least a portion of said sacrificial material.

12. The method of claim 10, further comprising encapsulating at least a portion of the sacrificial material with the structural material.

13. The method of claim 7, wherein said mask has a patterning surface which contacts said substrate, said patterning surface being conformable to said substrate to prevent said conductive bath from conducting electricity in regions intended to be covered by said patterning surface.

14. The method of claim 8, further comprising smoothing deposited material to form a smoother surface.

15. The method of claim 8, wherein said bringing, said applying, and said removing is repeated multiple times with the same mask, or a mask of identical patterning, re-mated in the precise position that it was mated previously, so as to increase a thickness of the deposit of the first material.

16. The method of claim 10, further comprising:

stopping said repeating;

removing at least some of the sacrificial material;

replacing said removed sacrificial material with another material; and

then

continuing said repeating, to form additional layers.

17. The method of claim 9, wherein said second material is applied by blanket deposition, followed by removing a portion of at least one of the materials.

18. The method of claim 17, further comprising using a mask to prevent blanket deposited material from being deposited near edges of said substrate.

19. The method of claim 7, further comprising:

determining a current cross section to be processed for a given level of the multilayer structure;

comparing said current cross section to previously-generated mask cross sections; and

if the current cross section is similar enough, within a predetermined tolerance, then assigning said previously-generated mask to the given level.

20. The method of claim 10, wherein said sacrificial material is copper.

21. The method of claim 8, further comprising processing said materials so that no material remains overlying any other material deposited since said last bringing.

22. The method of claim 8, wherein there are a plurality of deposited materials, one of which is applied by blanket depositing, followed by removing a portion of at least one of the materials.

32. A method for fabricating a multi-layer 3-dimensional (3-D) structure according to a 3-D description, comprising:

processing said 3-D description to obtain a plurality of 2-dimensional (2-D) descriptions of cross sections of said 3-D structure;

fabricating one or more selective electrodesposition masks each corresponding to at least one of said 2-D descriptions;

using said selective electrodeposition masks; and

electrodepositing one or more materials to form structures corresponding to said 2-D descriptions in succession over a substrate.

33. The method of claim 32, further comprising, for each selective electrodeposition mask, aligning said selective electrodeposition mask with a structure on said substrate.

34. An electroplating method comprising:

a) contacting a substrate with a first article, the first article comprising a support and a comformable mask disposed in a pattern on the support;

b) electroplating a first metal from a source of metal ions onto the substrate in a first pattern;

c) removing the first article from the substrate; and

d) building at least one additional layer by re-contacting the substrate with the first article and electroplating the first metal onto the substrate in the first pattern.

35. The method of claim 34, wherein the first pattern substantially corresponds to a complement of the conformable mask pattern.

36. The method of claim 34, wherein after the removal of the first article from the substrate, the support and the conformable mask are in substantially the same state as before the first article was brought into contact with the substrate.

37. The method of claim 34, wherein building at least one additional layer further includes contacting a second article with the substrate, the second article comprising a support and a conformable mask disposed in a second pattern on the second article support.

38. The method of claim 37, wherein building at least one additional layer further includes electroplating a second metal from a second metal ion source onto the substrate.

39. A method of fabricating a three-dimensional element from at least one structural material, wherein the at least one structural material comprises one of a first electrodeposition material or a second electrodeposition material, wherein a sacrificial material comprises the other of the first electrodeposition material or the second electrodeposition material, and wherein the three dimensional element is formed from a plurality of electrodeposited layers, the method comprising:

(a) providing a substrate which may include one or more previously deposited layers of a solidified material;

(b) providing an electrodeposition source of the first electrodeposition material;

(c) providing an electrodeposition source of the second electrodeposition material;

(d) providing a plurality of preformed masks with negative features and with non-conductive positive features, wherein either the positive or negative features on each mask represents at least a portion of at least one cross-section of the three-dimensional element to be formed;

(e) contacting a selected one of said preformed masks to a surface of said substrate thereby forming a non-conductive barrier over a portion of the surface of the substrate;

(f) while the mask and the surface of the substrate are in contact with the first electrodeposition source, providing electric power to the electrodeposition source in a manner to cause deposition of the first electrodeposition material onto the surface of the substrate, in a pattern corresponding to the negative features of the selected mask, to form a portion of an electrodeposited layer;

(g) separating the selected mask from said substrate;

(h) performing at least one additional electrodeposition operation to complete formation of a electrodeposited layer wherein the at least one additional electrodeposition operation comprises deposition of the second electrodeposition material;

(i) repeating (e) through (h) a plurality of times to form additional layers adjacent to and adhered to previously formed layers layers of the three-dimensional element wherein at least one selected mask is used in the formation of each layer, and wherein at least a portion of the selected masks are different for at least a portion of the layers;

(j) separating the structural material from at least a portion of the sacrificial material to yield the three-dimensional element.

40. The method of claim 39 wherein the structural material comprises the first electrodeposition material and the sacrificial material comprises the second electrodeposition material.

41. The method of claim 40 wherein the deposition of the second electrodeposition material comprises a blanket deposition.

42. The method of claim 40 wherein the deposition of the second electrodeposition material comprises a selective deposition using at least one of the preformed masks.

43. The method of claim 40 wherein the first electrodeposition material comprises nickel.

44. The method of claim 43 wherein the second electrodeposition material comprises copper.

45. The method of claim 39 wherein the structural material comprises the second electrodeposition material and the sacrificial material comprises the first electrodeposition material.

46. The method of claim 45 wherein the deposition of the second electrodeposition material comprises a blanket deposition.

47. The method of claim 45 wherein the deposition of the second electrodeposition material comprises a selective deposition using at least one of the preformed masks.

48. The method of claim 45 wherein the second electrodeposition material comprises nickel.

49. The method of claim 48 wherein the first electrodeposition material comprises copper.

50. The method of claim 39 wherein the first and second electrodeposition materials are selected from the group containing (1) metals, (2) semiconductor materials, (3) ceramics, and (4) polymers.

51. The method of claim 39 wherein the performance of at least one additional electrodeposition operation to complete formation of the electrodeposited layer additionally comprises planarizing the first and second electrodeposited materials.

52. The method of claim 39 wherein the performance of at least one additional electrodeposition operation to complete formation of the electrodeposited layer additionally comprises reversing the polarity of the electric power to cause etching.

53. The method of claim 39 wherein the separating of the mask occurs in a manner that allows a plurality of deposition processes to be performed using the selected mask.