KR102154242B1 - Multi-layered thin film and manufacturing method thereof - Google Patents

Abstract

A multilayer thin film including high-quality graphene from which the defects of graphene are healed and a method for manufacturing the same are proposed. The multilayer thin film according to the present invention comprises: a graphene layer; a first barrier layer for healing defects in the graphene layer disposed on the graphene layer; A conductive layer positioned on the first barrier layer; And a second barrier layer positioned on the conductive layer.

Description

Multi-layered thin film 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 including high-quality graphene from which defects of graphene are healed, and a method of manufacturing the same.

Barrier film is used in solar cells, displays, various electronic devices, pharmaceuticals, food and beverage packaging fields, etc. When electronic devices (electronic devices), pharmaceuticals, food and beverages are exposed to oxygen and moisture, the performance of the product is reduced. Since there are adverse effects such as deterioration, they are variously applied for the purpose of preventing contact with oxygen or moisture.

Such barrier films have generally been produced by forming a multilayered functional coating layer on a plastic substrate. For example, there is a barrier film having a multilayer structure composed of a combination of an inorganic barrier layer for blocking gas such as oxygen and water vapor, and an organic barrier layer for reducing defects on the surface of a plastic substrate and imparting flatness. However, since the conventional barrier film having such a structure still does not satisfy the high-performance barrier characteristics, efforts to develop a barrier film that meets the high-performance barrier characteristics are continuing.

On the other hand, graphene, a carbon allotrope, is a new material composed of a monoatomic layer having a hexagonal honeycomb shape, and it is known that graphene has very high chemical and thermal stability. Therefore, various studies on barrier materials, heat/chemical resistance materials, etc. are being conducted by applying graphene.

Currently, a variety of methods for preparing graphene are known, and among them, graphene manufactured using chemical vapor deposition (CVD) is known to be the most excellent in characteristics and most suitable for mass production. However, since the graphene fragments grown at various points on the growth substrate were grown and merged to form a single graphene layer, the graphene growth point was randomly selected, so the size of each grown graphene region, that is, the domain of graphene Is not constant, and a defect occurred in a portion overlapping with other graphene domains, and thus a problem occurred in terms of reliability when graphene was applied to a barrier film or other various fields.

The present invention has been conceived to solve the above problems, and an object of the present invention is to provide a multilayer thin film including high-quality graphene from which defects in graphene are healed, and a method for manufacturing the same.

A graphene layer according to an embodiment of the present invention for achieving the above object; A first barrier layer for healing defects in the graphene layer located on the graphene layer; A conductive layer positioned on the first barrier layer; And a second barrier layer positioned on the conductive layer.

The first barrier layer may be formed by arranging atoms in a defect region existing on the graphene layer.

The first barrier layer and the second barrier layer may be layers of atoms of metal or metal oxide.

The conductive layer may include a metal.

The thickness of the graphene layer may be 0.1 nm to 1.0 nm, the thickness of the first barrier layer may be 1.0 nm to 5.0 nm, the thickness of the conductive layer may be 10 to 50 nm, and the thickness of the second barrier layer may be 30 to 50 nm.

According to another aspect of the invention, forming a graphene layer on a metal substrate by a chemical vapor deposition process; Forming a first barrier layer on the graphene layer by an atomic layer deposition process; Forming a conductive layer on the first barrier layer by a sputtering process; And forming a second barrier layer on the conductive layer.

Metal substrates are Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V, Zr, brass, bronze, brass, stainless steel and It may include one or more metals or alloys thereof selected from the group consisting of Ge.

The step of forming the first barrier layer may be an ozone-based atomic layer deposition process.

The graphene layer may include at least one of single-layer graphene and multi-layer graphene.

The step of forming the first barrier layer may be performed at 70 to 100°C.

According to another aspect of the present invention, the step of forming irregularities on a metal substrate; Forming a graphene layer on a metal substrate by a chemical vapor deposition process; Forming a first barrier layer on the graphene layer by an atomic layer deposition process; Forming a conductive layer on the first barrier layer by a sputtering process; And forming a second barrier layer on the conductive layer.

According to another aspect of the present invention, there is provided a multilayer thin film manufactured by a method of manufacturing a multilayer thin film, characterized in that irregularities of a metal substrate are transferred to a surface of a graphene layer.

As described above, according to embodiments of the present invention, defects in the graphene layer are healed by forming a barrier layer on the graphene layer, thereby manufacturing a multilayer thin film having excellent barrier performance and mechanical flexibility.

In addition, it is possible to obtain a multilayer thin film with irregularities formed on the graphene layer, so when used in an optical device, the multilayer thin film exhibits excellent conductivity while exhibiting flexibility and at the same time inducing light scattering from the surface, thereby increasing the optical efficiency of the device I can.

1 is a cross-sectional view of a multilayer thin film according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing that a first barrier layer heals defects formed on a graphene layer.
3 is an optical surface image of a multilayer thin film produced by an ozone-based atomic layer deposition process, FIG. 4 is an optical surface image of a multilayer thin film produced by an oxygen-based atomic layer deposition process, and FIG. 5 is an H ₂ O This is an optical surface image of a multilayer thin film manufactured by the atomic layer deposition process.
6 is a Raman spectrum measurement result and plan images after the deposition process is performed by an ozone-based atomic layer deposition process, an oxygen-based atomic layer deposition process, and an H ₂ O-based atomic layer deposition process, respectively.
7 to 10 are views provided to explain a method of manufacturing a multilayer thin film according to another embodiment of the present invention.

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 components having a specific unevenness or a predetermined thickness, but this is for convenience of explanation or distinction, so even if they have a specific unevenness and a predetermined thickness, the features of the components illustrated in the present invention It is not limited to only.

1 is a cross-sectional view of a multilayer thin film according to an embodiment of the present invention, and FIG. 2 is a schematic view showing that a first barrier layer heals defects formed on a graphene layer. The multilayer thin film 100 according to the present embodiment includes a graphene layer 120; A first barrier layer 130 for healing defects in the graphene layer 120 positioned on the graphene layer 120; A conductive layer 140 positioned on the first barrier layer 130; And a second barrier layer 150 positioned on the conductive layer 140.

The multilayer thin film 100 of the present invention includes a graphene layer 120. In graphene, a plurality of carbon atoms are covalently linked to each other to form a polycyclic aromatic molecule to form a layer or sheet form. Graphene has very high chemical and thermal stability and high conductivity and heat dissipation due to its layered structure. Therefore, the multilayer thin film 100 of the present invention can be manufactured in an ultra-thin film including graphene and exhibiting excellent barrier properties.

Graphene can be manufactured by various methods, and if a chemical vapor deposition (CVD) process is used, graphene properties are excellent and mass production is possible. Chemical vapor deposition methods include high temperature chemical vapor deposition (RTCVD), inductively coupled plasma chemical vapor deposition (ICP-CVD), low pressure chemical vapor deposition (LPCVD), atmospheric pressure chemical vapor deposition (APCVD), metal organic chemical vapor deposition (MOCVD), or chemical vapor deposition. It can be subdivided into vapor deposition (PECVD) and the like.

Carbon atoms connected by covalent bonds constituting graphene grown at any point on the growth substrate form a 6-membered ring as a basic repeating unit, but may further include a 5-membered ring or a 7-membered ring. In particular, when the growth direction of graphene is different at the domain boundary of graphene, each domain collides to form a 5-membered ring or a 7-membered ring, and this irregular crystal arrangement causes deterioration of graphene's quality.

The domain of graphene refers to a region where crystals increase as graphene grows from a certain point and horizontal expansion occurs. That is, the graphene within the boundary formed at the point where the region of graphene formed at one point and the region of graphene formed at another point meet is called a domain. At the interface of graphene domains, when contacting the domains due to the difference in growth directions of different domains, irregular crystal arrangement occurs as described above, and such irregularities may act as defects of graphene.

Graphene is a single layer of carbon atoms (usually sp ² bonds) covalently bonded to each other. Graphene may have various structures, and such a structure may vary depending on the content of 5-membered rings and/or 7-membered rings that may be included in graphene. In addition, graphene may form a multi-layered graphene having a plurality of layers by stacking a plurality of single-layered graphene.

In order for the excellent properties of graphene to be expressed in the barrier film, it is necessary to minimize the aforementioned defects of graphene. In the present invention, defects in the graphene layer 120 are cured by forming the first barrier layer 130 on the graphene layer 120. 2, a part of the multilayer thin film 100 is shown. When a defect is formed in the central part of the graphene layer 120, when only the graphene layer 120 is used as a barrier film, the defect is Infiltration of moisture or impurities becomes possible. Accordingly, the barrier performance of the barrier film varies according to the degree of defects in the graphene layer 120.

A first barrier layer 130 is formed on the graphene layer 120, and the first barrier layer 130 may be formed by arranging atoms in a defect region existing on the graphene layer 120. When atoms are arranged on the graphene layer 120, the atoms are first arranged and stacked in the defect region of the graphene layer 120. Accordingly, the graphene layer 120 is filled with the defective region by the first barrier layer 130, thereby increasing the barrier performance.

Since the first barrier layer 130 must be deposited in atomic units, it may be formed by an atomic layer deposition process unlike the graphene layer 120 formed by a chemical vapor deposition process. The atomic layer deposition (ALD) process is an atomic-level deposition process, in which a precursor gas of an atom to be deposited is injected and a reaction gas is injected together to form a thin film by laminating atoms in layers on a substrate to be deposited. to be. In the atomic layer deposition process, one atomic layer thin film layer 130 is formed on the graphene layer 120 through a plurality of (about 5 times) atomic layer deposition processes. Therefore, when a thin film layer is formed on the graphene layer 120 according to the atomic layer deposition process, defects formed in the graphene layer 120 can be healed. Since the first barrier layer 130 is formed on the graphene layer 120 and fills the voids or channels generated on the surface of the graphene layer 120, it is impossible to penetrate moisture from the outside, thus exhibiting the optimum effect as a barrier film. I can.

The first barrier layer 130 may be a layer of atoms of metal or metal oxide. Metal oxides that may be used for the first barrier layer 130 include silicon oxide, silicon nitride, silicon nitride oxide, aluminum oxide, aluminum nitride or aluminum nitride oxide.

A conductive layer 140 is positioned on the first barrier layer 130. The conductive layer 140 includes a metal. When the conductive layer 140 including a metal is included in the multilayer thin film 100, there is an effect of increasing the flexibility of the multilayer thin film 100 and improving the conductivity performance, and the conductive layer 140 acts as a buffer layer in a subsequent process. When a high energy process such as a plasma process or an ion beam process is applied, the graphene layer 120 can be performed without damage.

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.

It is formed on the second barrier layer 150 on the conductive layer 140. The second barrier layer 150 is for improving the barrier performance of the multilayer thin film 100, and may be a layer of metal or metal oxide atoms like the first barrier layer 130. Metal oxides that may be used for the second barrier layer 150 include silicon oxide, silicon nitride, silicon nitride oxide, aluminum oxide, aluminum nitride or aluminum nitride oxide.

In the multilayer thin film 100 according to the present invention, the thickness of the graphene layer 120 is 0.1 nm to 1.0 nm, the thickness of the first barrier layer 130 is 1.0 nm to 5.0 nm, and the conductive layer 140 The thickness may be 10 to 50 nm, and the thickness of the second barrier layer 150 may be 30 to 50 nm.

The multilayer thin film 100 according to the present invention comprises the steps of forming a graphene layer 120 on a metal substrate 110 by a chemical vapor deposition process; Forming a first barrier layer 130 on the graphene layer 120 by an atomic layer deposition process; Forming a conductive layer 140 on the first barrier layer 130 by a sputtering process; And forming the second barrier layer 150 on the conductive layer 140.

The metal substrate 110 is Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V, Zr, brass, bronze, brass, It may include one or more metals or alloys thereof selected from the group consisting of stainless steel and Ge. When the metal substrate 110 is used, the properties of the graphene layer 120 to be formed are excellent, but due to the properties of the metal, the metal substrate 110 may be affected in a later process.

Therefore, it is preferable not to adversely affect the metal substrate 110 in the process of forming the first barrier layer 130, the conductive layer 140, and the second barrier layer 150. When forming the thin film layers of the first barrier layer 130 and the second barrier layer 150, an atomic layer deposition process may be used, and the atomic layer deposition process is an ozone-based atomic layer deposition process, an oxygen-based atomic layer deposition process, or H It can be subdivided into ₂ O-based atomic layer deposition process.

3 is an optical surface image of a multilayer thin film produced by an ozone-based atomic layer deposition process, FIG. 4 is an optical surface image of a multilayer thin film produced by an oxygen-based atomic layer deposition process, and FIG. 5 is an H ₂ O This is an optical surface image of a multilayer thin film manufactured by the atomic layer deposition process.

3A to 3C are optical images after deposition of an Al ₂ O ₃ layer on the graphene layer 5 times, 20 times and 100 times by an ozone-based atomic layer deposition process, respectively. In the image in which the ozone-based atomic layer deposition process was performed 5 times, defects in the graphene layer were confirmed, but in FIG. 3B performed 20 times, the defects in graphene began to be cured, and in FIG. 3C performed 100 times, the defects in graphene. It can be seen that this is almost healed.

4A to 4C are optical images after deposition of an Al ₂ O ₃ layer on the graphene layer 5 times, 20 times and 100 times by an oxygen-based atomic layer deposition process, respectively. In FIG. 4, the oxygen-based atomic layer deposition process was performed, and it was confirmed that the defects in graphene were cured from FIG. 4C after 100 times deposition as in the ozone-based atomic layer deposition process.

5A to 5C are optical images after deposition of an Al ₂ O ₃ layer on a graphene layer 5 times, 20 times and 100 times by an H ₂ O based atomic layer deposition process, respectively. In FIG. 5, the H ₂ O-based atomic layer deposition process was performed, but unlike the ozone-based atomic layer deposition process or the oxygen-based atomic layer deposition process, a region in which the defects of graphene are not healed remains as shown in FIG. I could confirm that. In the case of the region in which the graphene defects of FIG. 5C are not healed, the multilayer graphene as a multilayer graphene region has a problem of wettability of H ₂ O, and thus it is impossible to perform an H ₂ O-based atomic layer deposition process.

Therefore, when the graphene layer includes multilayer graphene, it is preferable to form the first barrier layer using an ozone-based atomic layer deposition process or an oxygen-based atomic layer deposition process.

6 is a Raman spectrum measurement result and plane images after the deposition process is performed by an ozone-based atomic layer deposition process, an oxygen-based atomic layer deposition process, and an H ₂ O-based atomic layer deposition process, respectively. The ozone-based atomic layer deposition process is performed at about 80°C, the oxygen-based atomic layer deposition process is performed at about 100°C, and the H ₂ O-based atomic layer deposition process is performed at about 120°C.

In the image of the ozone-based atomic layer deposition process, it was confirmed that the metal substrate was not affected. However, in the image in which the oxygen-based atomic layer deposition process is performed, there is a problem that defects are additionally formed on the graphene surface and the boundary due to the effect of plasma radical by-products during oxidation of the metal substrate and formation of oxygen plasma. In addition, in the case of FIG. 6C in which the H ₂ O-based atomic layer deposition process is performed, it must be performed at about 120° C., so that the substrate may be damaged by heating.

Therefore, it is preferable to form the first barrier layer by an ozone-based atomic layer deposition process capable of forming a first barrier layer even on multilayer graphene without affecting the metal substrate and the graphene layer. In addition, a functional group including oxygen is added to the surface of the first barrier layer 130 by ozone (O ₃ ) used in the ozone-based atomic layer deposition process, thereby activating the surface of the first barrier layer 130. Accordingly, there is an advantage in that the chemical vapor deposition process can be effectively performed when the conductive layer 140 is formed later.

In the method of manufacturing a multilayer thin film according to the present invention, the first barrier layer forming step is performed at 70 to 100° C. (ozone-based atomic layer deposition process), so that the influence on the metal substrate can be minimized.

7 to 10 are views provided to explain a method of manufacturing a multilayer thin film according to another embodiment of the present invention. According to this embodiment, forming the uneven 111 on the metal substrate 110; Forming a graphene layer 120 on the metal substrate 110 by a chemical vapor deposition process; Forming a first barrier layer 130 on the graphene layer 120 by an atomic layer deposition process; Forming a conductive layer 140 on the first barrier layer 130 by a sputtering process; And forming the second barrier layer 150 on the conductive layer 140 is provided. According to the method for manufacturing a multilayer thin film according to the present embodiment, the irregularities 111 of the metal substrate 110 are transferred to the surface of the graphene layer 120, and the surface of the graphene layer of the finally formed multilayer thin film 100 is irregular. Will be formed.

Unevenness 111 is formed on the surface of the metal substrate 110 (FIG. 7). It is preferable that the shape of the irregularities 111 corresponds to the shape of the irregularities to be formed on the graphene layer 120. Since the thickness of the graphene layer 120 is thin, if the height difference between the peaks and valleys of the irregularities 111 is too large, the formed graphene layer 120 may be difficult to be uniformly formed on the surface of the metal substrate 110 with high quality. In addition, defects may occur in the graphene layer 120 formed in the valley of the irregularities 111 due to surface characteristics.

Accordingly, after forming the graphene layer 120 by the chemical vapor deposition process on the metal substrate 110 (FIG. 8), the first barrier layer 130 is formed on the graphene layer 120 by the atomic layer deposition process. Do (Fig. 9). The atomic layer deposition process is an atomic-level deposition process, and since it is a process of forming a thin film by layering atoms on a deposition target, defects in the graphene layer 120 on the metal substrate 110 on which the irregularities 111 are formed can be cured. I can.

A conductive layer 140 is formed on the first barrier layer 130 by a sputtering process. The conductive layer 140 is a layer serving as a barrier layer of the graphene layer 120 while improving the conductivity of the multilayer thin film 100 by supplementing the conductivity of the graphene layer 120. A second barrier layer 150 is formed on the conductive layer 140 to finally form all of the barrier layers of the graphene layer 120.

Referring to FIG. 9, due to the shape of the irregularities 111 of the metal substrate 110, the graphene layer 120, which is thinner than other layers, exhibits the shape of the irregularities 111, but the first barrier layer 130, conduction The layer 140 and the second barrier layer 150 are stacked to smooth the peaks and valleys of the irregularities 111. Therefore, after the multilayer thin film 100 is formed, when the metal substrate 110 is removed (FIG. 10), a graphene layer 120 with irregularities formed on the surface of the multilayer thin film 100 is located, and a smoothed surface is located at the lower side. The second barrier layer 150 is positioned.

In the multilayer thin film 100 manufactured according to the present embodiment, a pattern or irregularities having a desired shape may be formed on the surface of the graphene layer 120, so that various functions may be provided. For example, when the multilayer thin film 100 is used as a transparent electrode of a solar cell, light scattering effect due to surface irregularities can be obtained to obtain a light collecting function, so that the light efficiency of the solar cell is increased. In addition, patterns or irregularities are formed on the surface of the multilayer thin film 100 to increase surface activity and increase effective specific surface area, so that it can be applied to various types of devices.

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
110: metal substrate
120: graphene layer
130: first barrier layer
140: conductive layer
150: second barrier layer

Claims (12)

Forming a graphene layer on a metal substrate by a chemical vapor deposition process;
Forming a first barrier layer on a graphene layer formed by a chemical vapor deposition process by an atomic layer deposition process to form a first barrier layer formed by arranging atoms in the defect regions existing on the graphene layer;
Forming a conductive layer on the first barrier layer by a sputtering process; And
Forming a second barrier layer on the conductive layer; a multilayer thin film manufacturing method comprising a. delete The method according to claim 1,
The first barrier layer and the second barrier layer is a method of manufacturing a multilayer thin film, characterized in that the layer of atoms of a metal or metal oxide. The method according to claim 1,
A method for manufacturing a multilayer thin film, characterized in that the conductive layer contains a metal. The method according to claim 1,
The thickness of the graphene layer is 0.1nm to 1.0nm,
The thickness of the first barrier layer is 1.0 nm to 5.0 nm,
The thickness of the conductive layer is 10 to 50 nm,
The thickness of the second barrier layer is a multilayer thin film manufacturing method, characterized in that 30 to 50nm. delete The method according to claim 1,
Metal substrates are Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V, Zr, brass, bronze, brass, stainless steel and A method for producing a multilayer thin film comprising at least one metal selected from the group consisting of Ge or an alloy thereof. The method according to claim 1,
The step of forming the first barrier layer is an ozone-based atomic layer deposition process, characterized in that the multilayer thin film manufacturing method. The method of claim 8,
The graphene layer is a multilayer thin film manufacturing method, characterized in that it comprises single-layer graphene and multi-layer graphene. The method according to claim 1,
The step of forming the first barrier layer is a multilayer thin film manufacturing method, characterized in that performed at 70 to 100 ℃. Forming irregularities on the metal substrate;
Forming a graphene layer on a metal substrate by a chemical vapor deposition process;
Forming a first barrier layer on the graphene layer by an atomic layer deposition process;
Forming a conductive layer on the first barrier layer by a sputtering process; And
Forming a second barrier layer on the conductive layer; a multilayer thin film manufacturing method comprising a. As a multilayer thin film manufactured by the multilayer thin film manufacturing method of claim 11,
Multilayer thin film, characterized in that the unevenness of the metal substrate is transferred to the surface of the graphene layer.

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