Method of forming a reactive material and article formed thereby

• US 20030138656A1
• Filed: 01/07/2003
• Published: 07/24/2003
• Est. Priority Date: 01/07/2002
• Status: Active Grant

• Current Assignee: Materion Corporation
• Original Assignee: Integrated Sensing Systems Incorporated
• Inventors: Sparks, Douglas Ray
• Granted Patent: US 6,923,625 B2
• Time in Patent Office: Days
• US Class Current: 428/615
• CPC Class Codes: B32B 9/00 Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
• CPC Class Codes: B81C 1/00285 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: Y10T 428/12493 Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
• CPC Class Codes: Y10T 428/12806 Refractory [Group IVB, VB, or VIB] metal-base component
• CPC Class Codes: Y10T 428/12847 Cr-base component
• CPC Class Codes: Y10T 428/12889 Au-base component
• CPC Class Codes: Y10T 428/12993 Surface feature [e.g., rough, mirror]

Abstract

A method for preventing contamination, oxidation and gas absorption of reactive materials, and articles formed thereby. The method generally entails depositing a first layer of a reactive material and a second layer of a substantially nonreactive material so that the second layer protects the first layer from a surrounding atmosphere. For example, the first and second layers may be deposited to form a film on a surface within a chamber that is desired to be maintained in a vacuum during use of the article. The second layer is sufficiently thin such that appropriately heating the first and second layers causes the reactive material of the first layer to become interdiffused with the nonreactive material of the second layer, to the extent that at least a portion of the reactive material is able to react and getter gases from the surrounding atmosphere.

Claims

1. An article comprising a first layer of a reactive material and a second layer of a substantially nonreactive material, the second layer protecting the first layer from a surrounding atmosphere of the article, the reactive material of the first layer being interdiffused with the second layer so that some of the reactive material is exposed to the surrounding atmosphere.

2. An article according to claim 1, wherein the first and second layers are disposed within a chamber of the article.

3. An article according to claim 2, wherein the chamber is evacuated and the first and second layers constitute a getter material within the chamber.

4. An article according to claim 3, wherein the getter material is on a plate secured within the chamber.

5. An article according to claim 4, wherein the plate comprises an uneven surface and the getter material is a deposit on the uneven surface of the plate such that the getter material has an outer uneven surface exposed to the surrounding atmosphere.

6. An article according to claim 3, wherein the getter material is a deposit on a surface within the chamber.

7. An article according to claim 6, wherein the surface is uneven such that the getter material has an outer uneven surface exposed to the surrounding atmosphere within the chamber.

8. An article according to claim 3, wherein the getter material defines a film.

9. An article according to claim 3, further comprising means enclosed with the first and second layers within the chamber for heating the getter material.

10. An article according to claim 3, wherein the article is an electronic device.

11. An article according to claim 1, wherein the first and second layers are on a plate.

12. An article according to claim 11, wherein the plate comprises an uneven surface and the first and second layers are on the uneven surface of the plate such that the second layer defines an outer uneven surface exposed to the surrounding atmosphere.

13. An article according to claim 1, wherein the first and second layers are on a surface of the article.

14. An article according to claim 13, wherein the surface is uneven such that the second layer defines an outer uneven surface exposed to the atmosphere.

15. An article according to claim 1, wherein the first and second layers define a freestanding metal foil.

16. An article according to claim 1, further comprising means for heating the first and second layers.

17. An article according to claim 1, wherein the reactive material of the first layer is chosen from the group consisting of metals and metal alloys that are absorb and/or react with oxygen, hydrogen, nitrogen, water, carbon monoxide, carbon dioxide, or hydrocarbons.

18. An article according to claim 1, wherein the reactive material of the first layer is chosen from the group consisting of Al, C, carbon compounds, Si, Ge, and all Group IA, 2A, 3A, 4A, 5A, 6A and 7A elements.

19. An article according to claim 1, wherein the reactive material of the first layer is chosen from the group consisting of Al, Ba, C, carbon compounds, Ca, Ce, Cr, Co, Fe, Hf, Mg, Mn, Mo, Nb, Ni, Si, Ta, Ti, Th, V, W, and Zr.

20. An article according to claim 1, wherein the nonreactive material of the second layer is chosen from the group consisting of Pb, Sn, In, and all Group 8A, 1B, 2B, and 3B metals except Al.

21. An article according to claim 1, wherein the nonreactive material of the second layer is chosen from the group consisting of Ag, Au, Cu, Ir, Os, Pd, and Pt.

22. An electronic device comprising an evacuated chamber and a getter material within the chamber, the getter material comprising a first layer of a reactive material on a substrate region within the chamber of the device, and a second layer of a substantially nonreactive material on the first layer, the second layer protecting the first layer from an atmosphere within the chamber, the reactive material of the first layer being interdiffused with the second layer so that some of the reactive material is exposed to the atmosphere.

23. An electronic device according to claim 22, wherein the getter material is on an uneven surface such that the getter material has an outer uneven surface exposed to the atmosphere.

24. An electronic device according to claim 22, wherein the uneven surface is a surface of the chamber.

25. An electronic device according to claim 22, further comprising means within the chamber for heating the getter material.

26. An electronic device according to claim 25, wherein the heating means comprises the getter material and means for passing a current through the getter material for resistively heating the getter material.

27. An electronic device according to claim 22, wherein the reactive material of the first layer is chosen from the group consisting of metals and metal alloys that are absorb and/or react with oxygen, hydrogen, nitrogen, water, carbon monoxide, carbon dioxide, or hydrocarbons.

28. An electronic device according to claim 22, wherein the reactive material of the first layer is chosen from the group consisting of Al, C, carbon compounds, Si, Ge, and all Group IA, 2A, 3A, 4A, 5A, 6A and 7A elements.

29. An electronic device according to claim 22, wherein the reactive material of the first layer is chosen from the group consisting of Al, Ba, C, carbon compounds, Ca, Ce, Cr, Co, Fe, Hf, Mg, Mn, Mo, Nb, Ni, Si, Ta, Ti, Th, V, W, and Zr.

30. An electronic device according to claim 22, wherein the nonreactive material of the second layer is chosen from the group consisting of Pb, Sn, In, and all Group 8A, 1B, 2B, and 3B metals except Al.

31. An electronic device according to claim 22, wherein the nonreactive material of the second layer is chosen from the group consisting of Ag, Au, Cu, Ir, Os, Pd, and Pt.

32. A method of providing a reactive material for an article, the method comprising the steps of:

depositing a first layer of a reactive material and a second layer of a substantially nonreactive material so that the second layer protects the first layer from a surrounding atmosphere of the article; and

then heating the first and second layers so that the reactive material of the first layer becomes interdiffused with the nonreactive material of the second layer, wherein at least a portion of the reactive material of the first layer is sufficiently close to the surface of the second layer as to be able to react with the surrounding atmosphere.

33. A method according to claim 32, wherein the first and second layers are deposited on a surface within a chamber of the article.

34. A method according to claim 33, further comprising the step of evacuating the chamber prior to the heating step, and then utilizing the first and second layers to getter gases from the evacuated chamber.

35. A method according to claim 34, wherein the first and second layers are deposited on a plate and the plate is secured within the chamber prior to the heating step.

36. A method according to claim 35, wherein the first and second layers are deposited on an uneven surface of the plate such that the second layer defines an outer uneven surface exposed to the surrounding atmosphere within the chamber.

37. A method according to claim 34, wherein the first and second layers are directly deposited on a surface of the chamber.

38. A method according to claim 37, wherein the surface is uneven such that the second layer has an outer uneven surface exposed to the surrounding atmosphere within the chamber.

39. A method according to claim 34, wherein the first and second layers are deposited on a substrate, the method further comprising the steps of removing the substrate to yield a freestanding foil, and then placing the foil in the chamber.

40. A method according to claim 34, wherein the heating step is performed with heating means enclosed with the first and second layers within the chamber.

41. A method according to claim 34, wherein the article is an electronic device.

42. A method according to claim 32, wherein the first and second layers are deposited on a plate and the plate is placed on the article prior to the heating step.

43. A method according to claim 42, wherein the first and second layers are on an uneven surface of the plate such that the second layer defines an outer uneven surface exposed to the surrounding atmosphere.

44. A method according to claim 32, wherein the first and second layers are directly deposited on a surface of the article.

45. A method according to claim 44, wherein the surface is uneven such that the second layer defines an outer uneven surface exposed to the atmosphere.

46. A method according to claim 32, wherein the first and second layers are deposited on a substrate, the method further comprising the steps of removing the substrate to yield a freestanding foil, and then placing the foil on the article.

47. A method according to claim 32, wherein the heating step is performed by passing a current through the first and second layers.

48. A method according to claim 32, wherein the reactive material of the first layer is chosen from the group consisting of metals and metal alloys that are absorb and/or react with oxygen, hydrogen, nitrogen, water, carbon monoxide, carbon dioxide, or hydrocarbons.

49. A method according to claim 32, wherein the reactive material of the first layer is chosen from the group consisting of Al, C, carbon compounds, Si, Ge, and all Group IA, 2A, 3A, 4A, 5A, 6A and 7A elements.

50. A method according to claim 32, wherein the reactive material of the first layer is chosen from the group consisting of Al, Ba, C, carbon compounds, Ca, Ce, Cr, Co, Fe, Hf, Mg, Mn, Mo, Nb, Ni, Si, Ta, Ti, Th, V, W, and Zr.

51. A method according to claim 32, wherein the nonreactive material of the second layer is chosen from the group consisting of Pb, Sn, In, and all Group 8A, 1B, 2B, and 3B metals except Al.

52. A method according to claim 32, wherein the nonreactive material of the second layer is chosen from the group consisting of Ag, Au, Cu, Ir, Os, Pd, and Pt.

53. A method of providing a getter material for an evacuated chamber of an electronic device, the method comprising the steps of:

depositing a first layer of a reactive material on a substrate region within the chamber of the device, and then depositing a second layer of a substantially nonreactive material so that the second layer protects the first layer from an atmosphere within the chamber;

evacuating the chamber; and

then

heating the first and second layers so that the reactive material of the first layer becomes interdiffused with the nonreactive material of the second layer, wherein at least a portion of the reactive material of the first layer becomes exposed to the surrounding atmosphere and getters gases from the chamber.

54. A method according to claim 53, wherein the heating step is a wafer-to-wafer bonding process performed in a vacuum during which the substrate is bonded to a micromachined device wafer.

55. A method according to claim 54, wherein the wafer-to-wafer bonding process is selected from the group consisting of glass frit, solder, eutectic, fusion, anodic and reactive bonding techniques.

56. A method according to claim 53, wherein the first and second layers are deposited on an uneven surface such that the second layer has an outer uneven surface exposed to the atmosphere.

57. A method according to claim 56, wherein the uneven surface is a surface of the chamber.

58. A method according to claim 53, wherein the heating step is performed by passing a current through the first and second layers.

59. A method according to claim 53, wherein the reactive material of the first layer is chosen from the group consisting of Al, C, carbon compounds, Si, Ge, and all Group IA, 2A, 3A, 4A, 5A, 6A and 7A elements.

60. A method according to claim 53, wherein the reactive material of the first layer is chosen from the group consisting of Al, Ba, C, carbon compounds, Ca, Ce, Cr, Co, Fe, Hf, Mg, Mn, Mo, Nb, Ni, Si, Ta, Ti, Th, V, W, and Zr.

61. A method according to claim 53, wherein the nonreactive material of the second layer is chosen from the group consisting of Pb, Sn, In, and all Group 8A, 1B, 2B, and 3B metals except Al.

62. A method according to claim 53, wherein the nonreactive material of the second layer is chosen from the group consisting of Ag, Au, Cu, Ir, Os, Pd, and Pt.