KR102146448B1 - Multi-layered structure and manufacturing method thereof - Google Patents

Abstract

A multilayer thin film having excellent reliability and a method of manufacturing the same are proposed. The multilayer thin film according to the present invention comprises a conductive oxide layer; A first barrier thin film layer formed on the conductive oxide layer; A conductive layer electrically connected to the conductive oxide layer exposed to the first barrier thin film layer; And a second barrier thin film layer on the conductive layer.

Description

Multi-layered structure and manufacturing method thereof TECHNICAL FIELD

The present invention relates to a multilayer thin film and a method of manufacturing the same, and more particularly, to a multilayer thin film having excellent reliability and a method of manufacturing the same.

Recently, various flexible application devices using flexible substrate materials such as flexible OLED and OPV have been commercialized. As these are applied to next-generation displays, their application range is gradually expanding into foldable information transmission display devices or EC smart curtain modules that can be driven with low power.

However, in terms of reliability, organic photoelectric materials that are vulnerable to moisture and temperature need to be completely blocked from the external environment through encapsulation technology. In addition, since all of these devices satisfy mechanical toughness, high-performance encapsulation film properties, and high-transmission, low-resistance transparent conductive oxide thin films are required, it is very difficult to implement them with existing thin film manufacturing technologies and equipment.

In a large-area device, the thin film encapsulation process has low mass productivity, and the fine glass encapsulation process is easily broken. Currently mass-produced large-area OLEDs are bottom emission type, and since light proceeds in the direction of the glass substrate, metal can be applied as a barrier film to satisfy both mass production and flexible characteristics. When applied to the emission) method, a transparent barrier film must be used.

Therefore, development of a barrier film that is transparent and ultra-thin and can be used in the sealing process of a flexible device is required.

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a multilayer thin film having excellent reliability and a method of manufacturing the same.

A multilayer thin film according to an embodiment of the present invention for achieving the above object is a conductive oxide layer; A first barrier thin film layer formed on the conductive oxide layer; A conductive layer electrically connected to the conductive oxide layer exposed to the first barrier thin film layer; And a second barrier thin film layer on the conductive layer.

The conductive oxide layer is ITO (indium tin oxide), IZO (indium zinc oxide), FTO (F-doped tin oxide), ATO (antimony tin oxide), AZO (ZnO:Al), GZO (ZnO:Ga) and a- It may contain any one of IGZO (In ₂ O ₃ :Ga ₂ O ₃ :ZnO).

The first barrier thin film layer and the second barrier thin film layer may include a metal oxide.

The conductive layer may include at least one of silver (Ag) and copper (Cu).

The thickness of the conductive oxide layer may be 10 nm to 30 nm, the thickness of the first barrier thin layer may be 1.0 nm to 5.0 nm, the thickness of the conductive layer may be 5 to 10 nm, and the thickness of the second barrier thin layer may be 10 to 30 nm.

According to another aspect of the present invention, a first step of forming a conductive oxide layer; A second step of forming a first barrier thin film layer on the conductive oxide layer; A third step of partially removing the first barrier thin film layer so that the conductive oxide layer is exposed; A fourth step of forming a conductive layer on the first barrier thin film layer to contact the exposed conductive oxide layer; And a fifth step of forming a second barrier thin film layer on the conductive layer.

The first and fourth steps may be performed by a sputtering process.

The second step may be performed by an atomic layer deposition process.

The third step may be performed by an etching process in which the etching rate of the conductive oxide layer and the etching rate of the first barrier thin layer are different.

According to another aspect of the present invention, a transparent conductive oxide layer formed by a sputtering process; A metal oxide layer formed by an atomic layer deposition process on the transparent conductive oxide layer, and partially removed to expose the transparent conductive oxide layer; A metal layer formed by a sputtering process; And a metal oxide layer formed on the metal layer.

According to another aspect of the present invention, a sputtering unit for forming a conductive oxide layer and a conductive layer on a substrate by a sputtering process; A buffer area unit for removing residual gas that has moved from the sputtering unit; And an atomic layer deposition unit for forming a first barrier thin film layer and a second barrier thin film layer, respectively, on the conductive oxide layer passing through the buffer region and the atomic layer deposition process on the conductive layer.

The substrate may move the sputtering portion, the buffer region portion, and the atomic layer deposition portion in a roll-to-roll manner.

As described above, the multilayer thin film according to the embodiments of the present invention is applied in various ways as a highly reliable barrier film or transparent electrode showing excellent quality by simultaneously applying a high-speed sputtering process and an atomic layer deposition process capable of improving surface roughness. There is a possible effect.

1 to 7 are views provided to explain a method of manufacturing a multilayer thin film according to an embodiment of the present invention.
8A is a surface image of a multilayer thin film film having an AZO layer by an atomic layer deposition process and an Al ₂ O ₃ layer by an atomic layer deposition process on a PEN substrate, and FIG. 8B is an AZO layer and an AZO layer by a sputtering process on a PEN substrate. Surface image of a multilayer thin film film with an Al ₂ O ₃ layer formed by sputtering process, FIG. 8C is the surface of a multilayer thin film film formed with an AZO layer by sputtering process and an Al ₂ O ₃ layer by atomic layer deposition process on a PEN substrate It is a diagram showing an image.
9 is a view showing the WVTR results of a multilayer thin film formed only by a sputtering process, and FIG. 10 is a view showing the WVTR results of a multilayer thin film formed only by a sputtering process / atomic layer deposition process and an atomic layer deposition process. .

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art. In the accompanying drawings, there may be elements having a specific pattern or having a predetermined thickness, but this is for convenience of description or distinction, so even if they have a specific pattern and a predetermined thickness, the present invention is characterized by the illustrated elements. It is not limited to only.

1 to 7 are views provided to explain a method of manufacturing a multilayer thin film according to an embodiment of the present invention. The method for manufacturing a multilayer thin film according to the present embodiment comprises: a first step of forming a conductive oxide layer; A second step of forming a first barrier thin film layer on the conductive oxide layer; And a third step of partially removing the first barrier thin film layer so that the conductive oxide layer is exposed. A fourth step of forming a conductive layer on the first barrier thin film layer to contact the exposed conductive oxide layer; And a fifth step of forming a second barrier thin film layer on the conductive layer.

In the method of manufacturing a multilayer thin film according to the present invention, first, a first step of forming the conductive oxide layer 110 is performed (FIG. 1). The multilayer thin film 100 according to the present invention may exhibit conductivity by including the conductive oxide layer 110. The conductive oxide layer 110 is ITO (indium tin oxide), IZO (indium zinc oxide), FTO (F-doped tin oxide), ATO (antimony tin oxide), AZO (ZnO:Al), GZO (ZnO:Ga) And a-IGZO (In2O3:Ga2O3:ZnO).

In the first step, the conductive oxide layer 110 may be formed by a sputtering process. The sputtering process refers to a process in which high-energy particles collide with a target made of a material homogeneous to a desired thin film, and atoms and molecules are separated from the target to form a thin film. In the case of the sputtering process, the stability of the equipment is high, it is advantageous in terms of maintenance, and has the advantage of being able to easily control the thickness and components of the thin film. In addition, there is an advantage in that the thin film deposition time is short compared to the atomic layer deposition process to be performed later.

However, the thin film layer formed by the sputtering process may have defects such as voids, grain boundaries, and channels on the surface as shown in FIG. 2. Since a number of defects exist in the conductive oxide layer 120 formed by the sputtering process, when the conductive oxide layer 120 formed by the sputtering process is used as a barrier film, for example, moisture penetration into the defective part is easy, and the device to be barrier May cause problems with the reliability of the product. In addition, even when the conductive oxide layer 110 is used as an electrode, the current flow is unstable, and reliability may be adversely affected.

Accordingly, in the present invention, the first barrier thin film layer 120 is formed on the conductive oxide layer 110. Since the barrier film is required to be thin, in order to keep the thickness as thin as possible, it is preferable that the thickness of the additional layer formed to heal the defects of the conductive oxide layer 110 is also thin. The atomic layer deposition (ALD) process is an atomic-level deposition process. Although the deposition rate is slower than that of the sputtering process, a thin film can be formed because a layer at the atomic level can be formed.

The first barrier thin film layer 120 may include a metal oxide. Examples of the metal oxide include silicon oxide, silicon nitride, silicon nitride oxide, aluminum oxide, aluminum nitride, or aluminum nitride oxide. For example, metal oxides that can be used in the present invention include ZnO, BaO, Bi ₂ O ₃ , SiO ₂ , SiCOx and Al ₂ O ₃ .

In addition, due to the characteristics of the deposition process, the surface of the conductive oxide layer 110 may not be flat and may have irregularities as shown in FIG. 4. At this time, there is a high possibility that defects 111 such as cracks may occur in the valleys of the irregularities. Therefore, when the second step of forming the first barrier thin film layer 120 on the conductive oxide layer 110 is performed, voids, grain boundaries, channels or cracks existing in the conductive oxide layer 110 can be healed. do.

When the first barrier thin layer 120 is formed, the first barrier thin layer 120 is partially removed so that the conductive oxide layer 110 is exposed (3rd step, FIG. 6). The exposed area 112 of the conductive oxide layer 110 is in contact with the conductive layer 130 to be formed later (FIG. 7).

In order to remove a part of the first barrier thin film layer 120 so that a part of the conductive oxide layer 110 is exposed to the outside, a dry method so that the etching rate of the conductive oxide layer 110 and the etching rate of the first barrier thin film layer 120 are different. An etching process using an etching process (RIE, ALE) may be performed. That is, in FIG. 5, there are irregularities on the surface of the first barrier thin film layer 120, but when a part of the conductive oxide layer 110 is removed, the surface can be smoothed by controlling the etching rate. Accordingly, the surfaces of the conductive layer 130 and the second barrier thin film layer 140 stacked thereon are also smoothed, thereby improving the quality of the entire multilayer thin film 100.

The conductive layer 130 is formed on the first barrier thin film layer 120 to contact the exposed conductive oxide layer 110 (step 4, FIG. 7). The metal that may be used for the conductive layer 140 is a metal having high electrical conductivity, and may be, for example, any one of Ag, Cu, Al, Ir, In, Ni, Mg, Pt, and Pd. The conductive layer 140 may be any process as long as it is a metal thin film forming process. For example, the conductive layer 140 may be formed through a sputtering process.

A second barrier thin film layer 140 may be formed on the conductive layer 130 again (step 5). The second barrier thin film layer 140 may include a metal oxide, like the first barrier thin film layer 120, and is a layer for improving the barrier characteristics of the entire multilayer thin film 100. Like the first barrier thin film layer 120, the second barrier thin film layer 140 may be formed by an atomic layer deposition process, or alternatively, may be formed by a sputtering process. Since the first barrier thin film layer 120 is a layer for healing defects in the conductive oxide layer 110, it is preferable to form it by an atomic layer deposition process, but the second barrier thin film layer 140 formed on the conductive layer 130 Silver need not be formed by an atomic layer deposition process.

In the multilayer thin film 100 according to the present invention, the thickness of the conductive oxide layer 110 is 10 nm to 30 nm, the thickness of the first barrier thin film layer 120 is 1.0 nm to 5.0 nm, and the thickness of the conductive layer 130 Is 5 to 10 nm, and the thickness of the second barrier thin film layer 140 may be 10 to 30 nm.

8A is a surface image of a multilayer thin film film in which an AZO layer by an atomic layer deposition process and an Al2O3 layer by an atomic layer deposition process are formed on a PEN substrate. A surface image of a multilayer thin film film with an Al2O3 layer formed thereon, FIG. 8C is a view showing a surface image of a multilayer thin film film having an AZO layer by a sputtering process and an Al2O3 layer by an atomic layer deposition process on a PEN substrate. In this specification, the sputtering process was performed using Sukwon's in-line sputter, the atomic layer deposition process was performed using CN1_TALD_Classic, and the WVTR value was measured using MOCON AQUATRON MODEL 2.

The multilayer thin film of FIG. 8A shows excellent conformality as both layers are formed by an atomic layer deposition process. However, the multilayer thin film of FIG. 8B is formed by a sputtering process and exhibits undesirable adhesion. The surface conformality of the multilayer thin film of FIG. 8C, in which an AZO layer was formed by a sputtering process and an Al ₂ O ₃ layer was formed by an atomic layer deposition process, was the most excellent. Both the multilayer thin film of FIGS. 8A and 8C had excellent surface adhesion. However, in the case of the sputtering process, a thin film of several nm per second can be formed, but in the case of the atomic layer deposition process, a thin film of 0.1Å or less per second is possible. Since the multilayer thin film has a side that is not suitable for mass production because the process time is too long, it is most preferable that the layer produced by the atomic layer deposition process is formed on the layer produced by the sputtering process as shown in FIG. 8C.

9 is a view showing the WVTR results of a multilayer thin film formed only by a sputtering process, and FIG. 10 is a view showing the WVTR results of a multilayer thin film formed only by a sputtering process / atomic layer deposition process and an atomic layer deposition process. . WVTR (Water Vapor Transmission Rate, g/m ² day) indicates the degree of penetration of water per unit area per day. LCD requires a WVTR of 10 ^-2 or less, but it is sensitive to moisture and oxygen. In the case of an OLED, a high WVTR of 10 ^-4 or less is generally required. When OLED displays are exposed to moisture and oxygen, problems such as pixel shrinkage, dark spots, and electrode oxidation occur, so the encapsulation process of forming a barrier film to satisfy the WVTR requirements is required. need.

Referring to FIG. 9, when all the layers of the multilayer thin film were formed by a sputtering process, all of them exhibited WVTR values of 10 ^-1 to 10 ^-2 . However, as shown in FIG. 10, in the case of a multilayer thin film formed by using a sputtering process and an atomic layer deposition process together, a WVTR value of 10 ^-4 was displayed, and thus excellent moisture barrier results were obtained. In addition, it was confirmed that all layers exhibited a WVTR value of 10 ^-4 even in the case of sample d formed by the atomic layer deposition process.

According to another aspect of the present invention, a transparent conductive oxide layer formed by a sputtering process; A metal oxide layer formed by an atomic layer deposition process on the transparent conductive oxide layer, and partially removed to expose the transparent conductive oxide layer; A metal layer formed by a sputtering process; And a metal oxide layer formed on the metal layer. The transparent electrode according to the present invention is a metal oxide layer formed by an atomic layer deposition process that heals defects in a transparent conductive oxide layer, a metal layer that guarantees excellent quality by improving the conductivity of the transparent electrode, and the barrier properties of the entire transparent electrode. It includes an outer metal oxide layer. Accordingly, it is a multilayer thin film that exhibits excellent conductivity and is highly reliable even at external moisture or high temperatures, and can be applied as a transparent electrode with excellent performance.

According to another aspect of the present invention, a sputtering unit for forming a conductive oxide layer and a conductive layer on a substrate by a sputtering process; A buffer area unit for removing residual gas that has moved from the sputtering unit; And an atomic layer deposition unit for forming a first barrier thin film layer and a second barrier thin film layer, respectively, on the conductive oxide layer and the conductive layer passing through the buffer region by an atomic layer deposition process (not shown). Is provided.

The substrate may move the sputtering portion, the buffer region portion, and the atomic layer deposition portion in a roll-to-roll manner. The substrate may form a multilayer thin film by stacking a conductive oxide layer and a first barrier thin film layer in a continuous process while moving the sputtering part, the buffer region part, and the atomic layer deposition part in a roll-to-roll method. The buffer area portion is a region for removing the influence of the first barrier thin film layer in the atomic layer deposition portion by the residual gas from the sputtering portion because the gas used for the sputtering portion and the atomic layer deposition portion are different. In the substrate, a conductive oxide layer is formed in a sputtering portion, a first barrier thin film layer is formed in an atomic layer deposition portion, and a conductive layer is formed through a buffer region. Thereafter, when the second barrier thin film layer is formed in the atomic layer deposition part through the buffer region part, a multilayer thin film film may be manufactured.

The apparatus for manufacturing a multilayer thin film according to the present exemplary embodiment may further include an etching part to expose the conductive oxide layer by removing a part of the first barrier thin film layer.

In the above, embodiments of the present invention have been described, but those of ordinary skill in the relevant technical field add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. Various modifications and changes can be made to the present invention by means of the like, and it will be said that this is also included within the scope of the present invention.

100: multilayer thin film
10: substrate
110: conductive oxide layer
111: defect
112: exposure area
120: first barrier thin film layer
130: conductive layer
140: second barrier thin film layer

Claims (12)

A conductive oxide layer;
A first barrier thin film layer formed on the conductive oxide layer;
A conductive layer electrically connected to the exposed conductive oxide layer by removing a portion of the first barrier thin film; And
A multilayer thin film film comprising; a second barrier thin film layer formed over the entire conductive layer in order to improve the barrier properties of the multilayer thin film film on the conductive layer. The method according to claim 1,
The conductive oxide layer is ITO (indium tin oxide), IZO (indium zinc oxide), FTO (F-doped tin oxide), ATO (antimony tin oxide), AZO (ZnO:Al), GZO (ZnO:Ga) and a- Multilayer thin film comprising any one of IGZO (In ₂ O ₃ :Ga ₂ O ₃ :ZnO). The method according to claim 1,
The first barrier thin film layer and the second barrier thin film layer are multilayer thin film, characterized in that it contains a metal oxide. The method according to claim 1,
The conductive layer is a multilayer thin film comprising at least one of silver (Ag) and copper (Cu). The method according to claim 1,
The thickness of the conductive oxide layer is 10 nm to 30 nm,
The thickness of the first barrier thin film layer is 1.0 nm to 5.0 nm,
The thickness of the conductive layer is 5 to 10 nm,
The second barrier thin film layer has a thickness of 10 to 30 nm. A first step of forming a conductive oxide layer;
A second step of forming a first barrier thin film layer on the conductive oxide layer;
A third step of partially removing the first barrier thin film layer so that the conductive oxide layer is exposed;
A fourth step of forming a conductive layer on the first barrier thin film layer to contact the exposed conductive oxide layer; And
A method for manufacturing a multilayer thin film comprising; a fifth step of forming a second barrier thin film layer on the entire upper part of the conductive layer to improve the barrier properties of the multilayer thin film film. The method of claim 6,
The first step and the fourth step are multilayer thin film manufacturing method, characterized in that performed by a sputtering process. The method of claim 6,
The second step is a method of manufacturing a multilayer thin film, characterized in that it is performed by an atomic layer deposition process. The method of claim 6,
The third step is a method of manufacturing a multilayer thin film, characterized in that the etching rate of the conductive oxide layer and the etching rate of the first barrier thin layer are performed by different etching processes. A transparent conductive oxide layer formed by a sputtering process;
A metal oxide layer formed by an atomic layer deposition process on the transparent conductive oxide layer, and partially removed to expose the transparent conductive oxide layer;
A metal layer formed by a sputtering process; And
A transparent electrode comprising a; a metal oxide layer formed over the entire metal layer to improve the barrier property of the transparent electrode on the metal layer. A sputtering unit for forming a conductive oxide layer and a conductive layer on a substrate by a sputtering process;
A buffer area unit for removing residual gas that has moved from the sputtering unit; And
A multilayer thin film manufacturing apparatus comprising: an atomic layer deposition unit for forming a first barrier thin film layer and a second barrier thin film layer, respectively, on the conductive oxide layer passing through the buffer region and the atomic layer deposition process on the conductive layer. The method of claim 11,
The substrate is a multilayer thin film manufacturing apparatus, characterized in that moving the sputtering portion, the buffer region portion and the atomic layer deposition portion in a roll-to-roll method.

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