Method for roll-to-roll deposition of optically transparent and high conductivity metallic thin films

• US 20040001915A1
• Filed: 06/14/2002
• Published: 01/01/2004
• Est. Priority Date: 06/14/2002
• Status: Active Grant

• Current Assignee: Streaming Sales LLC (Intellectual Ventures LLC)
• Original Assignee: Avery Dennison Corporation
• Inventors: Heydarpour, Ramin, He, Xiao-Ming
• Granted Patent: US 6,811,815 B2
• Time in Patent Office: Days
• US Class Current: 427/248.1
• CPC Class Codes: B29D 11/0073 Optical laminates
• CPC Class Codes: C23C 14/022 by means of bombardment with energetic particles or radiation
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/205 by cathodic sputtering
• CPC Class Codes: C23C 14/562 for coating elongated substrates
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: H01B 1/02 mainly consisting of metals or alloys
• CPC Class Codes: H01B 1/08 oxides
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 2201/0338 Layered conductor, e.g. layered metal substrate, layered finish layer or layered thin film adhesion layer
• CPC Class Codes: H05K 2203/095 Plasma, e.g. for treating a substrate to improve adhesion with a conductor or for cleaning holes
• CPC Class Codes: H05K 2203/1545 Continuous processing, i.e. involving rolls moving a band-like or solid carrier along a continuous production path
• CPC Class Codes: H05K 3/381 by special treatment of the substrate
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

Methods for roll-to-roll deposition of optically transparent and high conductivity metallic thin films are disclosed. In general, a method according to the present invention comprises: (1) providing a flexible plastic substrate; (2) depositing a multi-layered conductive metallic film on the flexible plastic substrate by a thin-film deposition technique to form a composite film; and (3) collecting the composite film in continuous rolls. Typically, the thin conductive metallic film is an InCeO—Ag—InCeO film. Typically, the thin-film deposition technique is DC magnetron sputtering. Another aspect of the invention is a composite film produced by a method according to the present invention. Still another aspect of the invention is a composite film comprising InCeO—Ag—InCeO film formed on a flexible plastic substrate, wherein the composite film has a combination of properties including: transmittance of at least 90% throughout the visible region; an electrical resistance of no greater than about 10 Ω/square; a root-mean-square roughness of no greater than about 2.5 nm; and an interlayer adhesion between the InCeO/Ag/InCeO metallic film and the remainder of the composite film that is sufficiently great to survive a 180° peel adhesion test.

Claims

1. A method for forming a composite film comprising:

(a) providing a flexible plastic substrate;

(b) depositing a multi-layered conductive metallic film continuously on the flexible plastic substrate by a thin-film deposition technique; and

(c) collecting the composite film in continuous rolls.

2. The method of claim 1 wherein the thin-film deposition technique is selected from the group consisting of DC magnetron sputtering, ion beam deposition, RF magnetron sputtering, chemical vapor deposition, ion beam enhanced deposition, and laser ablation deposition.

3. The method of claim 2 wherein the thin-film deposition technique is DC magnetron sputtering.

4. The method of claim 2 wherein the thin-film deposition technique is ion beam deposition.

5. The method of claim 2 wherein the thin-film deposition technique is chemical vapor deposition.

6. The method of claim 2 wherein the thin-film deposition technique is ion beam enhanced deposition.

7. The method of claim 2 wherein the thin-film deposition technique is laser ablation deposition.

8. The method of claim 3 wherein the DC magnetron sputtering is performed at a maximum sputter power of from about 300 watts to about 2000 watts.

9. The method of claim 8 wherein the DC magnetron sputtering is performed at a sputter power sequence of from about 500 watts to about 800 watts, followed by from about 50 watts to about 100 watts, followed by from about 500 watts to about 800 watts.

10. The method of claim 9 wherein the DC magnetron sputtering is performed at a sputter power sequence of about 600 watts, followed by about 70 watts, followed by about 600 watts.

11. The method of claim 3 wherein the deposition distance for DC magnetron sputtering is from about 2 inches to about 12 inches.

12. The method of claim 11 wherein the deposition distance for DC magnetron sputtering is from about 9 inches to about 11 inches.

13. The method of claim 3 wherein the DC magnetron sputtering is performed in an atmosphere that contains argon, and, optionally, oxygen.

14. The method of claim 13 wherein the atmosphere contains oxygen in the deposition of InCeO films.

15. The method of claim 14 wherein the flow rate of oxygen is from about 0.2 to about 2.0 standard cubic centimillitor.

16. The method of claim 15 wherein the flow rate of oxygen is from about 0.2 to about 1.0 standard cubic centimillitor.

17. The method of claim 16 wherein the flow rate of oxygen is from about 0.2 to about 0.6 standard cubic centimillitor.

18. The method of claim 14 wherein the flow rate of argon is from about 5.0 to about 20.0 standard cubic centimillitor.

19. The method of claim 18 wherein the flow rate of argon is about 10.0 standard cubic centimillitor.

20. The method of claim 3 wherein line speed during deposition is from about 0.6 to about 4 feet/min.

21. The method of claim 20 wherein the line speed during deposition is about 0.6 to 1.2 feet/min.

22. The method of claim 20 wherein the thin conductive metallic film is an InCeO/Ag/InCeO metallic film and the line speed during deposition is about 0.7 feet/min during deposition of the InCeO layers and is about 0.8 feet/min during deposition of the Ag layers.

23. The method of claim 3 further comprising the step of purging the surface of the flexible plastic substrate prior to film deposition, to enhance the adhesion of the film to the substrate.

24. The method of claim 23 wherein the step of purging the surface of the flexible plastic substrate prior to film deposition is performed with a plasma selected from the group consisting of the group of Ar+O₂, Ar, and Ar+N₂.

25. The method of claim 24 wherein the step of purging the surface of the flexible plastic substrate prior to film deposition is performed with a Ar+O₂ plasma.

26. The method of claim 1 wherein the thin conductive metallic film is an InCeO/Ag/InCeO film.

27. The method of claim 26 wherein the thickness of the InCeO layers is from about 30 nm to about 60 nm and the thickness of the Ag layer is from about 7 nm to about 20 nm.

28. The method of claim 27 wherein the thickness of the InCeO layers is from about 30 nm to about 45 nm and the thickness of the Ag layer is from about 12 nm to about 16 nm.

29. The method of claim 26 wherein the Ag of the InCeO/Ag/InCeO film is doped with about 1 atom percent of Au and about 0.5 atom percent of Cu to enhance the stability of the silver atoms in the silver layer.

30. The method of claim 1 wherein the thin conductive metallic film is selected from the group consisting of silver, gold, and their alloys.

31. The method of claim 1 wherein the flexible plastic substrate is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), polysulfone, a phenolic resin, an epoxy resin, polyester, polyimide, polyetherester, polyetheramide, cellulose acetate, aliphatic polyurethanes, polyacrylonitrile, polytetrafluoroethylenes, polyvinylidene fluorides, poly(methyl α

-methacrylates) and an aliphatic or cyclic polyolefin.

32. The method of claim 31 wherein the flexible plastic substrate is a cyclic polyolefin.

33. The method of claim 32 wherein the cyclic polyolefin is poly(bis(cyclopentadiene)).

34. The method of claim 33 wherein the flexible plastic substrate is a polyester.

35. The method of claim 34 wherein the polyester is an aromatic polyester.

36. The method of claim 31 wherein the flexible plastic substrate is reinforced with a hard coating.

37. The method of claim 36 wherein the hard coating is an acrylic coating.

38. The method of claim 37 wherein the hard coating improved the adhesion and smoothness of the InCeO/Ag/InCeO films to the flexible plastic substrate.

39. The method of claim 1 wherein the method further comprises a post-deposition annealing step at ambient conditions.

40. The method of claim 38 wherein the post-deposition annealing step comprises annealing the film at a temperature of between about 75°

C. and about 250°

C. for from about 0.5 hour to about 2 hours.

41. The method of claim 39 wherein the post-deposition annealing step comprises annealing the film at a temperature of between about 75°

C. and about 145°

C. for from about 1.0 hour to about 2 hours.

42. The method of claim 40 wherein the post-deposition annealing step comprises annealing the film at a temperature of about 140°

C. for about 2 hours.

43. The method of claim 40 wherein the post-deposition annealing step enhances the adhesion and smooth the surface of the InCeO/Ag/InCeO films, and induces the reduction of sheet resistance and the increase of both transmittance and brightness of the films.

44. The method of claim 1 wherein the composite film has a transmittance of at least about 80%.

45. The method of claim 42 wherein the composite film has a transmittance of at least about 90%.

46. The method of claim 42 wherein the composite film has a brightness of at least about 80%

47. The method of claim 1 wherein the composite film has an electrical resistance of no greater than about 20 Ω

/square.

48. The method of claim 44 wherein the composite film has an electrical resistance of no greater than about 10 Ω

/square.

49. The method of claim 45 wherein the composite film has an electrical resistance of no greater than about 5 Ω

/square.

50. The method of claim 1 wherein the composite film has a root-mean-square roughness of no greater than about 5 nm.

51. The method of claim 47 wherein the composite film has a root-mean-square roughness of no greater than about 2.5 nm.

52. The method of claim 51 further comprising a post-deposition annealing step and wherein the composite film has a root-mean-square roughness of no greater than about 1.5 nm.

53. The method of claim 1 wherein the composite film is stable to a 500-hour exposure at 60°

C. and 90% relative humidity.

54. The method of claim 1 wherein the composite film has interlayer adhesion sufficiently great to survive a 180°

peel adhesion test.

55. The method of claim 1 wherein the composite film is wet and dry etchable.

56. The method of claim 1 wherein the composite film includes a hard coating and is laser etchable.

57. The method of claim 1 wherein the composite film has a brightness L of at least about 80.0%, a red to green shift a of between about 0 and about 7.00 and a blue to yellow shift b of between about 0 and about 7.00.

58. A composite film made by the process of claim 1.

59. The composite film of claim 58 wherein the thin-film deposition technique is selected from the group consisting of DC or RF magnetron sputtering, ion beam deposition, chemical vapor deposition, ion beam enhanced deposition, and laser ablation deposition.

60. The composite film of claim 59 wherein the thin-film deposition technique is DC magnetron sputtering.

61. The composite film of claim 59 wherein the thin-film deposition technique is ion beam deposition.

62. The composite film of claim 59 wherein the thin-film deposition technique is chemical vapor deposition.

63. The composite film of claim 59 wherein the thin-film deposition technique is ion beam enhanced deposition.

64. The composite film of claim 59 wherein the thin-film deposition technique is laser ablation deposition.

65. The composite film of claim 60 wherein the DC magnetron sputtering is performed at a maximum sputter power of from about 300 watts to about 2000 watts.

66. The composite film of claim 65 wherein the DC magnetron sputtering is performed at a sputter power sequence of from about 500 watts to about 800 watts, followed by from about 50 watts to about 100 watts, followed by from about 500 watts to about 800 watts

67. The composite film of claim 66 wherein the DC magnetron sputtering is performed at a sputter power sequence of about 600 watts, followed by about 70 watts, followed by about 600 watts.

68. The composite film of claim 60 wherein the deposition distance for DC magnetron sputtering is from about 2 inches to about 12 inches.

69. The composite film of claim 68 wherein the deposition distance for DC magnetron sputtering is from about 9 inches to about 11 inches.

70. The composite film of claim 58 wherein the DC magnetron sputtering is performed in an atmosphere that contains argon, and optionally, oxygen.

71. The composite film of claim 70 wherein the atmosphere contains oxygen in the deposition of InCeO films.

72. The composite film of claim 71 wherein the flow rate of oxygen is from about 0.2 to about 2.0 standard cubic centimillitor.

73. The composite film of claim 72 wherein the flow rate of oxygen is from about 0.2 to about 1.0 standard cubic centimillitor.

74. The composite film of claim 73 wherein the flow rate of oxygen is from about 0.2 to about 0.6 standard cubic centimillitor.

75. The composite film of claim 71 wherein the flow rate of argon is from about 5.0 to about 20.0 standard cubic centimillitor.

76. The composite film of claim 75 wherein the flow rate of argon is about 10.0 standard cubic centimillitor.

77. The composite film of claim 58 wherein line speed during deposition is from about 0.6 to about 4 feet/min.

78. The composite film of claim 77 wherein the line speed during deposition is about 0.6 to 1.2 feet/min.

79. The composite film of claim 78 wherein the thin conductive metallic film is an InCeO/Ag/InCeO metallic film and the line speed during deposition is about 0.7 feet/min during deposition of the InCeO layers and is about 0.8 feet/min during deposition of the Ag layers.

80. The composite film of claim 58 wherein the method further comprises the step of purging the surface of the flexible plastic substrate prior to film deposition.

81. The composite film of claim 80 wherein the step of purging the surface of the flexible plastic substrate prior to film deposition is performed with a plasma selected from the group consisting of the group of Ar+O₂, Ar, and Ar+N₂.

82. The composite film of claim 81 wherein the step of purging the surface of the flexible plastic substrate prior to film deposition is performed with a Ar+O₂ plasma.

83. The composite film of claim 58 wherein the thin conductive metallic film is an InCeO/Ag/InCeO film.

84. The composite film of claim 83 wherein the thickness of the InCeO layers is from about 10 nm to about 100 nm and the thickness of the Ag layer is from about 7 nm to about 20 nm.

85. The composite film of claim 84 wherein the thickness of the InCeO layers is from about 30 nm to about 45 nm and the thickness of the Ag layer is from about 12 nm to about 16 nm.

86. The composite film of claim 83 wherein the Ag of the InCeO/Ag/InCeO film is doped with about 1 atom percent of Au and about 0.5 atom percent of Cu to enhance the stability of the silver atoms in the silver layer.

87. The composite film of claim 58 wherein the conductive metallic film is selected from the group consisting of silver, gold, and their alloys.

88. The composite film of claim 58 wherein the flexible plastic substrate is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), polysulfone, a phenolic resin, an epoxy resin, polyester, polyimide, polyetherester, polyetheramide, cellulose acetate, aliphatic polyurethanes, polyacrylonitrile, polytetrafluoroethylenes, polyvinylidene fluorides, poly(methyl α

-methacrylates) and an aliphatic or cyclic polyolefin.

89. The composite film of claim 88 wherein the flexible plastic substrate is a cyclic polyolefin.

90. The composite film of claim 89 wherein the cyclic polyolefin is poly(bis(cyclopentadiene)).

91. The composite film of claim 90 wherein the flexible plastic substrate is a polyester.

92. The composite film of claim 91 wherein the polyester is an aromatic polyester.

93. The composite film of claim 88 wherein the flexible plastic substrate is reinforced with a hard coating.

94. The composite film of claim 93 wherein the hard coating is an acrylic coating.

95. The composite film of claim 58 wherein the process for producing the composite film further comprises a post-deposition annealing step at ambient conditions.

96. The composite film of claim 95 wherein the post-deposition annealing step comprises annealing the film at a temperature of between about 75°

C. and about 250°

C. for from about 0.5 hour to about 2 hours.

97. The composite film of claim 96 wherein the post-deposition annealing step comprises annealing the film at a temperature of between about 75°

C. and about 145°

C. for from about 1.0 hour to about 2 hours.

98. The composite film of claim 97 wherein the post-deposition annealing step comprises annealing the film at a temperature of about 140°

C. for about 2 hours.

99. The composite film of claim 58 wherein the composite film has a transmittance of at least about 80%.

100. The composite film of claim 99 wherein the composite film has a transmittance of at least about 90%.

101. The composite film of claim 58 wherein the composite film has an electrical resistance of no greater than about 20 Ω

/square.

102. The composite film of claim 101 wherein the composite film has an electrical resistance of no greater than about 10 Ω

/square.

103. The composite film of claim 102 wherein the composite film has an electrical resistance of no greater than about 5 Ω

/square.

104. The composite film of claim 58 wherein the composite film has a root-mean-square roughness of no greater than about 5 nm.

105. The composite film of claim 104 wherein the composite film has a root-mean-square roughness of no greater than about 2.5 nm.

106. The composite film of claim 105 wherein the process for producing the composite film further comprises a post-deposition annealing step and wherein the composite film has a root-mean-square roughness of no greater than about 1.5 nm.

107. The composite film of claim 58 wherein the composite film is stable to a 500 hour exposure at 60°

C. in 90% relative humidity.

108. The composite film of claim 58 wherein the composite film has interlayer adhesion sufficiently great to survive a 180°

peel adhesion test.

109. The composite film of claim 58 wherein the composite film is wet and dry etchable.

110. The composite film of claim 58 wherein the composite film includes a hard coating and is laser etchable.

111. The composite film of claim 58 wherein the composite film has a brightness L of at least about 80.0, a red to green shift a between about 0 and about 7.00, and a blue to yellow shift b between about 0 and about 7.00.

112. A multilayered electrode/substrate structure comprising the composite film of claim 58.

113. The multilayered electrode/substrate structure of claim 112 wherein the multilayered electrode/substrate structure is an OLED.

114. The multilayered electrode/substrate structure of claim 112 wherein the multilayered electrode/substrate structure is a PLED.

115. The multilayered electrode/substrate structure of claim 112 wherein the multilayered electrode/substrate structure has surface roughness of less than about 8 nm.

116. The multilayered electrode/substrate structure of claim 112 wherein the multilayered electrode/substrate structure has a driving voltage of less than about 20 volts.

117. The multilayered electrode/substrate structure of claim 112 wherein the multilayered electrode/substrate structure includes a conductive material that is a light-emitting polymer.

118. The multilayered electrode/substrate structure of claim 117 wherein the light-emitting polymer is selected from the group consisting of poly(p-phenylenevinylene) (PPV), poly(dialkoxyphenylenevinylene), poly(thiophene), poly(fluorene), poly(phenylene), poly(phenylacetylene), poly(aniline), poly(3-alkylthiophene), poly(3-octylthiophene), and poly(N-vinylcarbazole).

119. The multilayered electrode/substrate structure of claim 118 wherein the light-emitting polymer is poly(p-phenylenevinylene) (PPV).

120. The multilayered electrode/substrate structure of claim 118 wherein the light-emitting polymer is poly(fluorene).

121. The multilayered electrode/substrate structure of claim 112 wherein the multilayered electrode/substrate structure includes a conductive material that is a luminescent organic or organometallic material.

122. The multilayered electrode/substrate structure of claim 121 wherein the luminescent organic or organometallic material is selected from the group consisting of metal ion salts of 8-hydroxyquinolate, trivalent metal quinolate complexes, trivalent metal bridged quinolate complexes, Schiff base divalent metal complexes, tin (IV) metal complexes, metal acetylacetonate complexes, metal bidentate ligand complexes incorporating an organic ligand selected from the group consisting of 2-picolylketones, 2-quinaldylketones, and 2-(o-phenoxy) pyridine ketones, bisphosphonates, divalent metal maleonitriledithiolate complexes, molecular charge transfer complexes, rare earth mixed chelates, (5-hydroxy) quinoxaline metal complexes, and aluminum tris-quinolates.

123. A composite film comprising an InCeO/Ag/InCeO metallic film coated or deposited on a flexible plastic substrate, wherein the composite film:

(1) has a transmittance of at least 80% in the visible region;

(2) has an electrical resistance of no greater than about 20 Ω

/square;

(3) has a root-mean-square roughness of no greater than about 5 nm; and

(4) has an interlayer adhesion between the InCeO/Ag/InCeO metallic film and other elements of the composite film that is sufficiently great to survive a 180°

peel adhesion test.

124. The composite film of claim 123 wherein the transmittance is at least 90% in the visible region, the electrical resistance is no greater than about 10 Ω

/square, and the root-mean-square roughness is no greater than about 2.5 nm.

125. The composite film of claim 123 wherein the composite film further comprises a reinforcing hard coating located between the InCeO/Ag/InCeO metallic film and the flexible plastic substrate.

126. The composite film of claim 125 wherein the reinforcing hard coating is an acrylic coating.

127. The composite film of claim 126 wherein the flexible plastic substrate is selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), polysulfone, a phenolic resin, an epoxy resin, polyester, polyimide, polyetherester, polyetheramide, cellulose acetate, aliphatic polyurethanes, polyacrylonitrile, polytetrafluoroethylenes, polyvinylidene fluorides, poly(methyl α

-methacrylates) and an aliphatic or cyclic polyolefin.

128. The composite film of claim 127 wherein the flexible plastic substrate is a cyclic polyolefin.

129. The composite film of claim 128 wherein the cyclic polyolefin is poly(bis(cyclopentadiene)).

130. The composite film of claim 127 wherein the flexible plastic substrate is a polyester.

131. The composite film of claim 130 wherein the polyester is an aromatic polyester.