Conductive material patterning methods

• US 20030219991A1
• Filed: 06/16/2003
• Published: 11/27/2003
• Est. Priority Date: 08/25/2000
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Geusic, Joseph E., Reinberg, Alan R.
• Granted Patent: US 6,972,257 B2
• Time in Patent Office: Days
• US Class Current: 438/742
• CPC Class Codes: H01L 21/288 from a liquid, e.g. electrolytic deposition
• CPC Class Codes: H01L 21/321 After treatment
• CPC Class Codes: H01L 21/32135 by vapour etching only
• CPC Class Codes: H01L 21/76823 transforming an insulating layer into a conductive layer
• CPC Class Codes: H01L 21/76825 by exposing the layer to particle radiation, e.g. ion implantation, irradiation with UV light or electrons etc. plasma treatment H01L21/76826
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76841 Barrier, adhesion or liner layers
• CPC Class Codes: H01L 21/76852 the layer also covering the sidewalls of the conductive structure
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76874 for electroless plating
• CPC Class Codes: H01L 21/76885 By forming conductive members before deposition of protective insulating material, e.g. pillars, studs
• CPC Class Codes: H01L 21/76888 By rendering at least a portion of the conductor non conductive, e.g. oxidation
• CPC Class Codes: H05K 2201/0175 Inorganic, non-metallic layer, e.g. resist or dielectric for printed capacitor
• CPC Class Codes: H05K 2203/0315 Oxidising metal
• CPC Class Codes: H05K 2203/1142 Conversion of conductive material into insulating material or into dissolvable compound
• CPC Class Codes: H05K 2203/1157 Using means for chemical reduction
• CPC Class Codes: H05K 3/02 in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
• CPC Class Codes: H05K 3/105 by conversion of non-conductive material on or in the support into conductive material, e.g. by using an energy beam
• CPC Class Codes: H05K 3/108 by semi-additive methods; masks therefor characterised by metallic etch mask H05K3/062; electroplating methods or apparatus H05K3/241

Abstract

A patterning method includes providing a first material (e.g., copper) and transforming at a least a surface region of the first material to a second material (e.g., copper oxide). One or more portions of the second material (e.g., copper oxide) are converted to one or more converted portions of first material (e.g., copper) while one or more portions of the second material (e.g., copper oxide) remain. One or more portions of the remaining second material (e.g., copper oxide) are removed selectively relative to converted portions of first material (e.g., copper). Further, a thickness of the converted portions may be increased. Yet further, a diffusion barrier layer may be used for certain applications.

Claims

1. A patterning method comprising:

providing a first material;

transforming at a least a surface region of the first material to a second material;

converting one or more portions of the second material to one or more converted portions of first material while one or more portions of the second material remain; and

removing one or more portions of the remaining second material selectively relative to converted portions of first material.

2. The method of claim 1, wherein providing the first material comprises forming a first material comprising copper or an alloy thereof, and further wherein transforming at least a surface region of the first material to a second material comprises transforming at least a surface region of the copper or copper alloy to a copper oxide material.

3. The method of claim 1, wherein transforming at least a surface region of a first material to a second material includes oxidizing the first material comprising metal to the second material comprising a metal oxide.

4. The method of claim 3, wherein converting the one or more portions of the second material comprises exposing the one or more portions of the second material to radiation.

5. The method of claim 4, wherein exposing the one or more portions of the second material to radiation includes using a broadband radiation source and a photo mask to expose the one or more portions of the second material to the radiation.

6. The method of claim 4, wherein exposing the one or more portions of the second material to radiation comprises using a scanning laser to expose the one or more portions of the second material to radiation.

7. The method of claim 1, wherein the method further comprises increasing a layer thickness of the one or more converted portions of first material.

8. The method of claim 7, wherein increasing the thickness of the one or more converted portions comprises electroplating material on the one or more converted portions of first material.

9. The method of claim 7, wherein increasing the thickness of one or more converted portions of first material comprises electroless depositing of material on the one or more converted portions of first material.

10. The method of claim 7, wherein increasing the thickness of one or more converted portions of first material includes increasing the thickness of one or more converted portions of first material prior to removing the one or more portions of the remaining second material selectively relative to converted portions of first material.

11. The method of claim 1, wherein the method further includes forming a barrier material on the substrate prior to providing the first material.

12. The method of claim 11, wherein the method further comprises removing barrier material exposed upon removal of the one or more portions of the remaining second material selectively relative to the first material.

13. The method of claim 1, wherein transforming at least a surface region of the first material to the second material comprises transforming substantially all of the first material to the second material.

14. The method of claim 1, wherein providing a first material comprises providing copper, wherein transforming at least a surface region of the first material to a second material comprises transforming at least a surface region of the copper to copper oxide, and further wherein removing one or more portions of the remaining second material selectively relative to the converted portions of first material comprises removing the copper oxide by exposure to a etchant.

15. A patterning method comprising:

providing a layer on a substrate, the layer comprising a first chemical composition;

treating the layer comprising the first chemical composition to transform at least a region of the layer to a second chemical composition;

patterning the layer, wherein patterning the layer comprises;

converting one or more portions of the transformed region comprising the second chemical composition to one or more converted portions comprising the first chemical compositions with one or more portions comprising the second chemical composition remaining, and

removing the one or more remaining portions comprising the second chemical composition selectively relative to the one or more converted portions comprising the first chemical composition.

16. The patterning method of claim 15, wherein treating the layer comprising the first composition to transform at least a region of the layer to a second chemical composition comprises transforming at least a region of the layer comprising the first chemical composition to a metal oxide.

17. The patterning method of claim 16, wherein converting one or more portions of the transformed region comprising the second chemical composition to one or more converted portions comprising the first chemical composition comprises exposing the one or more portions of the transformed region comprising the second chemical composition to radiation.

18. The patterning method of claim 17, wherein exposing the one or more portions comprising the second chemical composition to radiation comprises using a broadband source and a photo mask to expose the one or more portions of the second chemical composition.

19. The patterning method of claim 17, wherein exposing the one or more portions comprising the second chemical composition to radiation comprises using a scanning laser to expose the one or more portions of the second chemical composition to radiation.

20. The patterning method of claim 15, wherein providing a layer on a substrate comprises providing a first chemical composition comprising an elemental metal on the substrate, and further wherein treating the layer comprising the first chemical composition to transform at least a region of the layer comprises oxidizing the first chemical composition comprising an elemental metal to transform the at least a region of the layer to a second chemical composition comprising a metal oxide.

21. The patterning method of claim 15, wherein the method further comprises increasing a thickness of one or more converted portions comprising the first chemical composition.

22. The patterning method of claim 15, wherein the first chemical composition comprises copper and the second chemical composition comprises copper oxide;

and further wherein removing the one or more remaining portions comprising the second chemical composition selectively relative to the one or more converted portions comprising the first chemical composition comprises exposing the one or more portions comprising the second chemical composition to hexafluoroacetylacetone.

23. A patterning method comprising:

providing metal oxide comprising material on a substrate;

transforming one or more regions of the metal oxide comprising material to one or more regions of an elemental metal comprising material while leaving one or more remaining regions of the metal oxide comprising material; and

removing one or more of the remaining regions of the metal oxide comprising material selectively relative to the one or more regions of the elemental metal comprising material to form conductors on the substrate.

24. The method of claim 23, wherein providing the metal oxide comprising material on a substrate comprises:

forming an elemental metal comprising material on the substrate; and

oxidizing substantially all of the elemental metal comprising material to form the metal oxide comprising material.

25. The method of claim 24, wherein the elemental metal comprising material is one of copper and a copper alloy, and further wherein the metal oxide comprising material comprises copper oxide.

26. The method of claim 25, wherein the elemental metal comprising material consists essentially of copper and further wherein the metal oxide comprising material consists essentially of copper oxide.

27. The method of claim 23, wherein transforming the one or more regions of the metal oxide comprising material comprises exposing the metal oxide comprising material to radiation.

28. The method of claim 23, wherein removing the one or more of the remaining regions of the metal oxide comprising material comprises etching one or more of the remaining regions of the metal oxide comprising material with a gaseous etchant.

29. The method of claim 28, wherein the metal oxide comprising material comprises copper oxide, and further wherein the gaseous etchant comprises hexafluoroacetylacetone.

30. The method of claim 23, wherein the method further comprises increasing a thickness of the conductors on the substrate.

31. The method of claim 23, wherein the substrate includes a silicon region and further wherein the method comprises the step of forming a diffusion barrier material prior to providing the metal oxide comprising material on the substrate.

32. The method of claim 23, wherein the substrate comprises an elemental metal.

33. The method of claim 32, wherein the method further comprises removing at least some of the elemental metal that was beneath the removed metal oxide comprising material to extend the pattern into the substrate.

34. A patterning method comprising:

providing a metal oxide comprising material on a substrate;

exposing one or more regions of the metal oxide comprising material to radiation to transform the exposed regions to one or more regions of elemental metal comprising material while leaving one or more remaining regions of metal oxide comprising material; and

removing one or more of the remaining regions of metal oxide comprising material selectively relative to the one or more regions of elemental metal comprising material.

35. The method of claim 34, wherein providing metal oxide comprising material on a substrate comprises:

forming a layer of elemental metal comprising material on a substrate; and

oxidizing substantially all of the elemental metal comprising material to form the metal oxide comprising material.

36. The method of claim 34, wherein the elemental metal comprising material is one of copper and a copper alloy, and further wherein the metal oxide comprising material comprises copper oxide.

37. The method of claim 36, wherein the elemental metal comprising material consists essentially of copper and the metal oxide comprising material consists essentially of copper oxide.

38. The method of claim 37, wherein removing one or more of the remaining regions of metal oxide comprising material selectively relative to the one or more regions of elemental metal comprising material comprises exposing the one or more of the remaining regions of the metal oxide comprising material to an etchant.

39. The method of claim 34, wherein the method further comprises increasing a thickness of the one or more regions of elemental metal comprising material.

40. A metal conductor patterning method comprising:

providing a layer of copper on a substrate;

transforming at least a surface region of the copper to a copper oxide;

converting one or more portions of the copper oxide to one or more converted portions of copper while at least other portions of the copper oxide remain; and

removing substantially all of the portions of the copper oxide remaining relative to the copper resulting in copper conductors on the substrate.

41. The method of claim 40, wherein converting the one or more portions of the copper oxide to one or more converted portions of copper comprises photoreducing the one or more portions of copper oxide to copper.

42. The method of claim 41, wherein photoreducing the one or more portions of copper oxide to copper comprises exposing the one or more portions of copper oxide to radiation from a broad area source using a photo mask.

43. The method of claim 41, wherein photoreducing the one or more portions of copper oxide to copper comprises scanning a laser to expose the one or more portions of copper oxide to radiation.

44. The method of claim 41, wherein the method further comprises increasing a thickness of the copper conductors.

45. The method of claim 44, wherein increasing the thickness of the copper conductors includes electroplating material on the one or more converted portions of copper.

46. The method of claim 44, wherein increasing the thickness of the copper conductors comprises electroless depositing of material on the one or more converted portions of copper.

47. The method of claim 40, wherein transforming at least a surface region of the copper to copper oxide comprises transforming all of the copper to copper oxide.

48. A patterning method comprising:

forming diffusion barrier material on a substrate;

forming a first material on at least a portion of the diffusion barrier material;

transforming at least a surface region of the first material to a second material;

converting one or more portions of the second material to one or more converted portions of first material while at least one or more portions of the second material overlying diffusion barrier material remain;

removing one or more of the remaining portions of second material selectively relative to the one or more converted portions of first material exposing diffusion barrier material thereunder; and

removing the exposed diffusion barrier material selectively relative to the one or more converted portions of first material.

49. The method of claim 48, wherein transforming at least a surface region of the first material to a second material comprises oxidizing the first material.

50. The method of claim 48, wherein converting one or more portions of the second material to one or more converted portions of first material comprises exposing the one or more portions of second material to radiation.

51. The method of claim 48, wherein forming the diffusion barrier material comprises depositing the diffusion barrier material on the substrate by chemical vapor deposition.

52. The method of claim 48, wherein forming the diffusion barrier material comprises forming the diffusion barrier material on the substrate by electroless deposition.

53. The method of claim 48, wherein the method further comprises increasing a thickness of the one or more converted portions of first material.

54. The method of claim 53, wherein increasing the thickness of the one or more converted portions of first material comprises electroplating material on the one or more converted portions of first material.

55. The method of claim 53, wherein increasing the thickness of the one or more converted portions of first material comprises electroless deposition of material on the one or more converted portions of first material.

56. The method of claim 53, further comprising forming an additional diffusion barrier layer over the one or more converted portions of first material having an increased thickness.

57. The method of claim 56, wherein forming the additional diffusion barrier layer comprises electroless depositing diffusion barrier material over the one or more converted portions of first material having an increased thickness.

58. The method of claim 48, wherein transforming at least a surface region of the first material to a second material comprises transforming at least a surface region of the first material to a second material comprising metal oxide.

59. The method of claim 58, wherein forming a first material on the diffusion barrier material comprises forming a first material comprising an elemental metal on the substrate.

60. The method of claim 48, wherein forming the diffusion barrier material on the substrate includes forming a diffusion barrier material comprising cobalt, tungsten, and phosphorous on the substrate, wherein forming the first material on the diffusion barrier material comprises forming a first material comprising copper on the diffusion barrier material, and further wherein transforming at least a surface region of the first material to a second material includes transforming at least a surface region of the first material comprising copper to a second material comprising copper oxide.

61. A conductor patterning method comprising:

forming a diffusion barrier material comprising cobalt, tungsten, and phosphorous on a silicon-containing region of a substrate;

forming a first material comprising copper on the diffusion barrier material;

oxidizing at least a surface region of the first material comprising copper to a second material comprising copper oxide;

converting one or more portions of the second material comprising copper oxide to one or more converted portions of first material comprising copper while leaving at least one or more portions of the second material comprising copper oxide remaining over underlying portions of the diffusion barrier material;

removing one or more of the remaining portions of second material comprising copper oxide selectively relative to the first material comprising copper exposing underlying diffusion barrier material; and

removing the exposed diffusion barrier material.

62. The method of claim 61, wherein converting the one or more portions of the second material comprising copper oxide to the one or more converted portions of the first material comprising copper comprises photoreducing one or more portions of the second material comprising copper oxide to copper.

63. The method of claim 61, wherein forming the diffusion barrier material comprises depositing a barrier material comprising cobalt, tungsten, and phosphorous by chemical vapor deposition.

64. The method of claim 61, wherein forming the diffusion barrier material comprises depositing a diffusion barrier material comprising cobalt, tungsten, and phosphorous by electroless deposition.

65. The method of claim 61, wherein forming the diffusion barrier material comprising cobalt, tungsten, and phosphorous includes forming the diffusion barrier material by electroless deposition.

66. The method of claim 61, wherein the method further comprises increasing a thickness of one or more converted portions of the first material comprising copper.

67. The method of claim 66, wherein increasing the thickness comprises electroplating material on the one or more converted portions comprising copper.

68. The method of claim 66, wherein increasing the thickness comprises depositing material on the one or more converted portions of first material comprising copper by electroless deposition.

69. The method of claim 61, wherein the method further comprises forming additional diffusion barrier material over the one or more converted portions of the first material comprising copper having an increased thickness to provide a barrier completely about the converted portions.

70. The method of claim 69, wherein forming an additional diffusion barrier material comprises forming diffusion barrier material comprising cobalt, tungsten, and phosphorous.

71. The method of claim 69, wherein forming an additional diffusion barrier material over the one or more converted portions of the first material comprises forming additional diffusion barrier material by selective deposition over the one or more converted portions.

72. The method of claim 61, wherein the method further comprises forming additional diffusion barrier material on the one or more converted portions of first material comprising copper.

73. The method of claim 61, wherein removing one or more of the remaining portions of second material comprising copper oxide selectively relative to the first material comprising copper comprises exposing the one or more remaining portions of second material comprising copper oxide to a gaseous etchant.

74. The method of claim 73, wherein removing one or more of the remaining portions of second material comprising copper oxide selectively relative to the first material comprising copper comprises exposing the one or more remaining portions of second material comprising copper oxide to hexafluoroacetylacetone.

75. The method of claim 61, wherein removing the exposed diffusion barrier material comprises one of removing the exposed diffusion barrier material by at least one of ion milling or sputter etching.