BARRIER LAYER SYSTEM AND METHOD FOR PRODUCING A BARRIER LAYER SYSTEM

Abstract

A layer system includes barrier properties against oxygen and water vapor. There may be an alternating layer system of at least two aluminum oxide layers and at least two titanium oxide layers. The aluminum oxide layers and the titanium oxide layers are deposited alternately on top of one another. The aluminum oxide layers and the titanium oxide layers are deposited by ALD layer deposition with a layer thickness of 5 nm to 20 nm. A first Parylene layer is deposited with a layer thickness of 0.1 μm to 50 μm on a first side of the alternating layer system by CVD.

Claims

1.-31. (canceled)

32. A layer system with barrier properties against oxygen and water vapor, comprising: alternating layers comprising at least two aluminum oxide layers and at least two titanium oxide layers, in which the aluminum oxide layers and the titanium oxide layers are alternately deposited on top of one another, wherein the aluminum oxide layers and the titanium oxide layers each have a layer thickness of 5 nm to 20 nm; and at least one first Parylene layer deposited on a first side of the alternating layers, which has a layer thickness of 0.1 μm to 50 μm.

33. The layer system according to claim 1, further comprising: at least one second Parylene layer with a layer thickness of 0.1 μm to 50 μm is formed on a second side of the alternating layers.

34. The layer system according to claim 2, further comprising: a silicon-containing layer formed between the alternating layers and the at least one second Parylene layer.

35. The layer system according to claim 2, wherein the at least one first Parylene layer and/or the at least one second Parylene layer comprises at least one material from the group of: Parylene C/poly(chloro-p-xylylene); Parylene F/poly(tetrafluoro-p-xylylene); Parylene AF4/poly(CL, α, α′, α′-tetrafluoro-p-xylylene); Parylene N/poly(p-xylylene); or Parylene D/poly(dichloro-p-xylylene).

36. The layer system according to claim 1, wherein the layer system is deposited on a substrate.

37. The layer system according to claim 5, wherein the substrate comprises a plastic film, a glass, or a semiconductor wafer.

38. The layer system according to claim 5, wherein the substrate comprises at least one semiconductor component and/or at least one organic component.

39. A method for producing a layer system which has barrier properties against oxygen and water vapor, the method comprising: forming an alternating layer system comprising at least two aluminum oxide layers and at least two titanium oxide layers, wherein the aluminum oxide layers and the titanium oxide layers bills are deposited on top of one another, wherein the aluminum oxide layers and the titanium oxide layers are deposited by Atomic Layer Deposition (ALD), further wherein each has a layer thickness of 5 nm to 20 nm; and depositing a first Parylene layer with a layer thickness of 0.1 μm to 50 μm on a first side of the alternating layer system by Chemical Vapor Deposition (CVD).

40. The method according to claim 8, further comprising: depositing at least one second Parylene layer with a layer thickness of 0.1 μm to 50 μm on a second side of the alternating layer system.

41. The method according to claim 9, further comprising: forming a silicon-containing layer between the alternating layer system and the at least one second Parylene layer.

42. The method according to claim 8, wherein the ALD layer deposition is carried out at a temperature of at least 60° C.

43. The method according to claim 9, wherein the at least one first Parylene layer and/or the at least one second Parylene layer are deposited at a temperature in a range from 20° C. to 40° C.

44. The method according to claim 8, further comprising: depositing the layer system on a substrate.

45. The method according to claim 13, wherein a plastic film, a glass, or a semiconductor wafer is used as the substrate.

46. The method according to claim 13, further comprising: separating the substrate from the layer system after the layer system has been deposited.

47. The method according to claim 15, further comprising applying a release agent to the substrate; or depositing a sacrificial layer on the substrate before the layer system is deposited on the substrate.

48. The layer system according to claim 1, wherein a silicon-containing layer is formed between the alternating layers and the at least one first Parylene layer.

49. The method according to claim 8, further comprising: forming a silicon-containing layer between the alternating layer system and the at least one first Parylene layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention is explained in more detail below using exemplary embodiments. In the drawings:

[0047] FIG. 1 is a schematic sectional view of a layer system deposited on a substrate;

[0048] FIG. 2 is a schematic sectional view of an alternative layer system deposited on a substrate; and

[0049] FIG. 3a, 3b are schematic sectional representations of a further alternative layer system.

DETAILED DESCRIPTION

[0050] In FIG. 1, a layer system according to the invention deposited on a substrate 11 is shown schematically in a sectional view. The layer system according to the invention initially comprises an alternating layer system consisting of two aluminum oxide layers 12 and two titanium oxide layers 13, which were deposited alternately on top of one another on the substrate 11. The alternating layer system of a barrier layer system according to the invention can comprise up to six aluminum layers 12 and up to six titanium oxide layers 13, which are deposited alternately on top of one another. The individual layers have a layer thickness of 5 nm to 20 nm in each case. For example, a plastic film, a glass, a semiconductor wafer, or an electrical component such as an integrated circuit can be used as the substrate 11.

[0051] The alternating deposition of the aluminum oxide layers 12 and the titanium oxide layers 13 took place in a first working chamber using known ALD deposition processes. During layer deposition, temperatures above 60° C. are set in the first working chamber. In a second working chamber, a Parylene layer 14 is then deposited on the alternating layer system, consisting of the aluminum oxide layers 12 and the titanium oxide layers 13, with a layer thickness of 0.1 μm to 50 μm using a known CVD deposition process. Alternatively, a layer system according to the invention can also have a plurality of Parylene layers 14 deposited directly on top of one another.

[0052] Both aluminum oxide and titanium oxide layers deposited by means of ALD and Parylene layers deposited by means of CVD are distinguished by the fact that they can also be deposited area-wide on structured surfaces and three-dimensional objects. A further advantage of a layer system according to the invention is that a Parylene layer deposited by means of CVD also covers the side edges of underlying layers and, if necessary, even the entire substrate, including its rear side. A layer system according to the invention therefore has very good barrier properties with respect to oxygen and water vapor and is therefore also particularly well suited for encapsulating electrical components which usually have a structured surface. Such an electrical component can, for example, comprise at least one semiconductor component and/or at least one organic component. In this case, in one embodiment, a layer system according to the invention can be deposited directly on the electrical component. In relation to the exemplary embodiment described with reference to FIG. 1, the substrate 11 is then designed as an electrical component. Alternatively, in such an application, the substrate 11 can also be provided in the form of a plastic film, in which case the plastic film coated with the layer system according to the invention is then used as an encapsulation film for an electrical component.

[0053] In a further alternative embodiment, an electrical component can also be produced on a substrate, the substrate being formed as a barrier layer system according to the invention and the substrate with the electrical component located thereon then being encapsulated by means of a further barrier layer system according to the invention.

[0054] An alternative layer system according to the invention, which is deposited on a substrate 21, is shown schematically in a sectional view in FIG. 2. In this exemplary embodiment, the substrate 21 is designed as a plastic film consisting of the material polyethylene naphthalate (abbreviation “PEN”). The alternative layer system according to the invention from FIG. 2 initially comprises an alternating layer system consisting of four aluminum oxide layers 22 and four titanium oxide layers 23, which were deposited alternately on top of one another on the substrate 21 with a layer thickness of 5 nm each. According to the invention, the aluminum oxide and titanium oxide layers were deposited using ALD within a first working chamber. An adhesion promoter layer 25 was then produced on the alternating layer system, which ensures better adhesion to a Parylene layer 24 that is subsequently deposited and is 2 μm thick. The Parylene layer 24, consisting of Parylene C, is preferably deposited in a second working chamber by means of CVD. A silicon-containing layer in the form of a silane layer was produced as the adhesion promoter layer 25 by introducing a silane as a precursor into the second working chamber before the Parylene layer 24 was deposited. In the layer stack described for FIG. 2, consisting of the PEN substrate 21, the alternating layer system of aluminum oxide layers 22 and titanium oxide layers 23, the adhesion promoter layer 25, and the Parylene layer 24, a barrier with regard to WVTR of <6.6*10−6 g/(m2d) can be determined at ambient conditions of 38° C. and 90% humidity. Very good barrier properties could thus be demonstrated in a layer system according to the invention.

[0055] A further alternative layer system according to the invention with barrier properties with regard to oxygen and water vapor is shown schematically in a sectional view in FIGS. 3a and 3b. The layer system according to FIGS. 3a and 3b initially comprises an alternating layer system consisting of three aluminum oxide layers 32 and three titanium oxide layers 33, which are arranged alternately on top of one another. A first Parylene layer 34a is formed on one side of the alternating layer system and a second Parylene layer 34b is formed on the other side of the alternating layer system, with a first adhesion promoter layer 35a being deposited between the first Parylene layer 34a and the alternating layer system and a second adhesion promoter layer 35b being deposited between the second Parylene layer 34b and the alternating layer system. Such a layer system according to the invention can be used as a flexible substrate and at the same time has barrier properties with regard to oxygen and water vapor.

[0056] When producing the layer system shown in FIGS. 3a and 3b, the Parylene layer 34a is first deposited on a substrate 31 within a working chamber by means of CVD. The optional adhesion promoter layer 35a can also be deposited in the same working chamber, for example by introducing a silane into the working chamber. The aluminum oxide layers 32 and the titanium oxide layers 33 are then produced alternately by means of ALD in a second working chamber. In a further method step, the adhesion promoter layer 35b and the Parylene layer 34b are then deposited again in the working chamber suitable for CVD processes. To form the adhesion-promoting layer 35b, the same method steps are preferably used as for forming the adhesion-promoting layer 35a. Finally, the substrate 31 is separated from the rest of the layer stack by the layer stack for example being pulled off the substrate 31. A semiconductor wafer or a glass, for example, can be used as the substrate 31.

[0057] The separation of the substrate 31 from the remaining layer stack can be simplified if a release agent is applied to the substrate 31 or a sacrificial layer is deposited on the substrate 31 before the Parylene layer 34a is deposited. A solution containing surfactants, for example, can be applied to the substrate 31 as a release agent.