KR101294362B1 - Method for graphene hybrid film comprising hexagonal boron nitride - Google Patents

Abstract

A graphene composite film manufacturing method including a hexagonal boron nitride layer is disclosed. Graphene composite film manufacturing method according to an embodiment of the present invention comprises a first step of forming a hexagonal boron nitride layer on the catalyst-free substrate; A second step of forming a metal catalyst layer on the hexagonal boron nitride layer; Supplying carbon to the metal catalyst layer to form at least one or more lower graphene layers below the metal catalyst layer, and forming at least one or more upper graphene layers above the metal catalyst layer; And a fourth step of removing the metal catalyst layer and the upper graphene layer.

Description

Graphene composite film manufacturing method comprising a hexagonal boron nitride layer {METHOD FOR GRAPHENE HYBRID FILM COMPRISING HEXAGONAL BORON NITRIDE}

The present invention relates to a graphene composite film manufacturing method, and more particularly to a graphene composite film manufacturing method comprising a hexagonal boron nitride layer.

Graphene (Graphene), which is in the spotlight recently, is flexible, has a very high electrical conductivity, and is transparent. Therefore, studies are being actively conducted to use it as a transparent and curved electrode or as an electron transport material such as an electron transport layer in an electronic device.

However, due to the constraints on the graphene formation process, there is a problem in that the quality of the electronic device to which the graphene is applied is practically low. Such a problem may be due to various causes, but typically includes the characteristics of an insulator (substrate) to which graphene is attached.

More specifically, as an insulator to which graphene is attached, a SiO ₂ substrate is typically used. Since the SiO ₂ substrate has a lattice mismatch with graphene, the graphene is deposited on the SiO ₂ substrate. When put up, electrons were trapped in a part of SiO ₂ and there was a problem that the electrical characteristics of the graphene were changed, which resulted in the degradation of the electronic device to which graphene was applied.

In order to solve the above problems, studies have been made to use hexagonal boron nitride (h-BN, Hexagonal Boron Nitride) as an insulator to which graphene is attached. Since the hexagonal boron nitride has a lattice mismatch with graphene of 1.7% and the interface structure between the substrate and the substrate is stable and has a property of a complete insulator, the graphene may be electrically and structurally insulated. In this regard, recent studies have shown that when the hexagonal boron nitride is used as a substrate material for graphene, electron mobility of graphene can be greatly improved.

In order to form such a hexagonal boron nitride layer, a conventional chemical vapor deposition (CVD) method has been used, which deposits a metal catalyst on a silicon oxide substrate and contains nitrogen bubbles containing borazine (H ₃ B ₃ N ₃ H ₃ ). It is a method of injecting gas and forming a hexagonal boron nitride layer through an additional high temperature annealing process.

However, in the above-described conventional method, there is a problem in that the surface roughness of the hexagonal boron nitride layer is increased, and since the growth is based on a metal catalyst, an etching and a transfer process are additionally required, resulting in a complicated process.

On the other hand, the method for synthesizing the graphene on the formed hexagonal boron nitride layer may be various, typically, a method of growing the graphene directly on the peeling method (also known as Scotch Tetch) or a metal catalyst is used.

By the way, in the case of exfolidation, the graphene and the graphite pieces are randomly mixed on the substrate while graphene and multiple layers of graphite are easily broken in the process of depositing on the substrate with Scotch tape in a process that is expected by chance. There was a problem. In addition, in the method of directly growing graphene on the metal catalyst, since the metal catalyst is also a conductor, there is a problem in that it affects the characteristics of the graphene formed on the metal catalyst, and even when etching the metal catalyst, A further problem arises that it is difficult to completely remove the contaminants present in the formed graphene.

Therefore, the inventors of the present invention to prepare a graphene composite film, to prevent the problem of surface roughness when forming the hexagonal boron nitride layer, and to devise a way to more effectively synthesize the graphene on the hexagonal boron nitride layer Was done.

Embodiments of the present invention to form a hexagonal boron nitride layer without a separate catalyst, to provide a graphene composite film manufacturing method capable of preventing the surface roughness increase problem of the hexagonal boron nitride layer.

In addition, by forming a graphene on the upper and lower metal catalyst and using only the graphene layer formed under the metal catalyst of the above, to provide a graphene composite film manufacturing method that can form a higher quality graphene.

According to an aspect of the invention, the first step of forming a hexagonal boron nitride layer (H-BN, Hexagonal Boron Nitride) on the catalyst-free substrate; A second step of forming a metal catalyst layer on the hexagonal boron nitride layer; Supplying carbon to the metal catalyst layer to form at least one or more lower graphene layers below the metal catalyst layer, and forming at least one or more upper graphene layers above the metal catalyst layer; And a graphene composite film manufacturing method comprising a fourth step of removing the metal catalyst layer and the upper graphene layer may be provided.

The non-catalyst substrate may be at least one selected from a Si substrate, a Si / Si0 ₂ substrate, a sapphire substrate, a quartz substrate, and a glass substrate.

Meanwhile, the first step may include a solid source including ammonia borane (H ₃ BNH ₃ ) or boron trioxide (B ₂ O ₃ ) and B ₃ N ₃ H ₆ on the non-catalyst substrate. The method may include forming a hexagonal boron nitride layer by thermally decomposing a gas including B ₃ H ₃ Cl ₃ , B ₃ N ₃ Cl ₆ , BF _3, or BCL ₃ .

In addition, the metal catalyst layer is silicon, Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V, Zr, brass, bronze, At least one metal or alloy selected from the group consisting of copper, stainless steel and Ge.

In addition, the thickness of the metal catalyst layer may be 10nm to 100㎛.

On the other hand, the second step, the step of patterning the metal catalyst layer; And depositing the metal catalyst layer on the hexagonal boron nitride layer.

The patterning of the metal catalyst layer may include patterning a source region and a drain region at both sides of the metal catalyst layer, and patterning a channel region connecting the source region and the drain region at the center of the metal catalyst layer.

According to another aspect of the present invention, a graphene composite film manufactured by the graphene composite film manufacturing method according to an aspect of the present invention may be provided.

Embodiments of the present invention by using a catalyst having a very low surface roughness to form a hexagonal boron nitride layer, it is possible to maintain a low surface roughness of the hexagonal boron nitride layer.

In addition, after forming the graphene on the upper and lower metal catalyst layer, it is possible to form a higher quality graphene on the hexagonal boron nitride layer by using only the graphene layer formed under the metal catalyst layer of the.

1 is a perspective view showing a state before removing the metal catalyst layer and the upper graphene layer in the graphene composite film prepared by the graphene composite film manufacturing method according to an embodiment of the present invention.
2a to 2f is a process chart of the graphene composite film manufacturing method according to an embodiment of the present invention.
3 is a view showing a state of the metal catalyst layer in the graphene composite film manufacturing method according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a state before removing the metal catalyst layer and the upper graphene layer in the graphene composite film prepared by the graphene composite film manufacturing method according to an embodiment of the present invention.

1, the graphene composite film 100 manufactured by the graphene composite film manufacturing method according to an embodiment of the present invention is a non-catalyst substrate 110, a hexagon formed on the non-catalytic substrate 110 Formed on top of the boron nitride layer 130, the metal catalyst layer 150 formed on the hexagonal boron nitride layer 130, the lower graphene layer 170 formed below the metal catalyst layer 150 and the metal catalyst layer 150 The upper graphene layer 190 may be formed in a form in which the metal catalyst layer 150 and the upper graphene layer 190 are removed. However, FIG. 1 shows the state before removing the metal catalyst layer 150 and the upper graphene layer 190 for convenience of description.

In the graphene composite film 100 manufactured by the graphene composite film manufacturing method according to an embodiment of the present invention, by forming a hexagonal boron nitride layer 130 using the non-catalyst substrate 110, the conventional CVD ( The problem of surface roughness increase caused by the Chemical Vapor Deposition method can be prevented. In addition, by using only the lower graphene layer 170 formed under the metal catalyst layer 150, higher quality graphene may be formed on the hexagonal boron nitride layer 130.

Hereinafter, the graphene composite film manufacturing method according to an embodiment of the present invention will be described sequentially.

2a to 2f is a process chart of the graphene composite film manufacturing method according to an embodiment of the present invention.

Referring to FIG. 2A, first, a noncatalytic substrate 110 is prepared. The noncatalytic substrate 110 is not limited to a particular kind. For example, the non-catalytic substrate 110 may use at least one selected from a Si substrate, a Si / Si0 ₂ substrate, a sapphire substrate, a quartz substrate, and a glass substrate. On the other hand, the shape of the non-catalyst substrate 110 is not limited. For example, the noncatalytic substrate 110 may have a sheet, rod, or wire form. However, for convenience of description, the following description will focus on the case where the non-catalyst substrate 110 is formed in a sheet shape.

Next, referring to FIG. 2B, a hexagonal boron nitride layer (h-BN) 130 is formed on the noncatalytic substrate 110. Specifically, the non-catalyst substrate 110 is placed in a furnace, and a solid source including ammonia borane (H ₃ BNH ₃ ) or boron trioxide (B ₂ O ₃ ) and B ₃ N Hexagonal boron nitride layer 130 by supplying a gas containing ₃ H ₆ , B ₃ H ₃ Cl ₃ , B ₃ N ₃ Cl ₆ , BF ₃ or BCL ₃ and heat treatment at normal pressure (400 ℃ to 1000 ℃) ) Can be formed. Meanwhile, reaction conditions such as reaction temperature, gas pressure, and reaction time may vary depending on the type of gas used.

Next, referring to FIG. 2C, a metal catalyst layer 150 is formed on the hexagonal boron nitride layer 130. The metal catalyst layer 150 is for forming graphene, and includes silicon, Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, One or more metals or alloys selected from the group consisting of V, Zr, brass, bronze, cupronickel, stainless steel and Ge.

The method of forming the metal catalyst layer 150 is not limited. For example, it is possible to use conventional coating methods or application methods such as spin coating, dip coating and spray coating.

On the other hand, the thickness of the metal catalyst layer 150 may be 10nm to 100㎛. If the thickness of the metal catalyst layer 150 is less than 10nm, there is a problem that it is difficult to manufacture a plate-shaped graphene composite film, if the thickness of the metal catalyst layer 150 exceeds 100㎛ lower graphene layer 170 when forming the graphene ) Has a problem that not only the growth rate is lowered but also the quality is lowered.

Next, referring to FIG. 2D, carbon is supplied to the metal catalyst layer 150 to form at least one or more lower graphene layers 170 below the metal catalyst layer 150, and at least one or more layers above the metal catalyst layer 150. An upper graphene layer 190 is formed.

The lower graphene layer 170 and the upper graphene layer 190 are graphenes in which a plurality of carbon atoms are covalently connected to each other to form polycyclic aromatic molecules to form a layer or sheet.

The covalently linked carbon atoms form a 6-membered ring as shown in FIG. 1 as a basic repeating unit, but is not limited thereto. That is, the carbon atoms may be formed of five-membered rings, seven-membered rings, and the like.

The lower graphene layer 170 and the upper graphene layer 190 may be formed as a single layer, but are not limited thereto. For example, at least one of the lower graphene layer 170 or the upper graphene layer 190 may be formed of 50 layers.

In addition, the lower graphene layer 170 or the upper graphene layer 190 may be formed in a large area. For example, the lower graphene layer 170 or the upper graphene layer 190 may be formed to have a length of about 1 mm or more and about 1000 m in a horizontal or longitudinal direction.

First, a conventional chemical vapor deposition method may be used as a method for forming the upper graphene layer 190 on the metal catalyst layer 150. Examples of chemical vapor deposition 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), and metal organic chemical vapor deposition (MOCVD). ) Or chemical vapor deposition (PECVD).

For example, it is possible to grow the upper graphene layer 190 by placing the metal catalyst layer 150 in a furnace, supplying a reaction gas containing a carbon source, and heat-treating at atmospheric pressure (300 to 2000 ° C.). .

Examples of the carbon source may be carbon monoxide, carbon dioxide, methane, ethane, ethylene, ethanol, acetylene, propane, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, benzene, toluene and the like.

Next, when the reaction gas including the carbon source is supplied and the metal catalyst layer 150 is heated under an appropriate pressure condition and a temperature condition, carbon atoms diffuse into the metal catalyst layer 150. In this state, when cooling while lowering the temperature, one or more carbon layers may be additionally formed as the carbon dissolved in the metal catalyst layer 150 is agglomerated under the metal catalyst layer 150 to form the lower graphene layer 170. . At this time, the cooling rate is not limited and may be, for example, 20 ° C / min to 100 ° C / min.

2E and 2F, the graphene composite film 100 is completed by removing the metal catalyst layer 150 and the upper graphene layer 190. This is a problem that the characteristics of the upper graphene layer 190 is affected by the metal catalyst layer 150, which is a conductor deteriorated, even in the case of removing only the metal catalyst layer 150 is present in the graphene layer 190 This is because complete removal of possible contaminants is difficult.

Since graphene can be easily removed using oxygen (O ₂ ) or hydrogen (H ₂ ) gas, the upper graphene layer 190 can be removed using a conventional method. In the case of the metal catalyst layer 150, the metal catalyst layer 150 may be removed using an etching solution capable of selectively etching the metal catalyst layer 150. That is, the etching solution may be selected correspondingly according to the type of the metal catalyst layer 150.

Hereinafter, a graphene composite film manufacturing method according to another embodiment of the present invention will be described.

Graphene composite film manufacturing method according to another embodiment of the present invention further comprises the step of patterning the metal catalyst layer 150 in the above-described embodiment. That is, the hexagonal boron nitride layer 130 is formed on the non-catalyst substrate 110, and the metal catalyst layer 150 is formed on the hexagonal boron nitride layer 130, wherein the metal catalyst layer 150 is patterned. It may further comprise the step.

In the graphene composite film manufacturing method according to another embodiment of the present invention, the remaining processes except for patterning the metal catalyst layer 150 are the same as or similar to the above-described embodiment will be omitted.

The method for patterning the metal catalyst layer 150 may use a conventional photo lithohraphy process or the like. For example, it is possible to coat the photoresist composition on the surface of the metal catalyst layer 150 and to use an exposure process and a printing process. The photoresist composition may be removed after patterning the metal catalyst layer 150.

On the other hand, the patterning shape of the metal catalyst layer 150 is not limited, it is possible to pattern corresponding to the electronic device to be implemented.

In this regard, Figure 3 is a view showing the appearance of the metal catalyst layer 150 in the graphene composite film manufacturing method according to another embodiment of the present invention.

Referring to FIG. 3, the patterning shape of the metal catalyst layer 150 patterns the source region S and the drain region D on both sides of the metal catalyst layer 150, and the source region S at the center of the metal catalyst layer 150. And the channel region C connecting the drain region D. FIG. In this case, the source region S and the drain region D may be in the form of a pad, and the channel region C may be formed in the form of a narrow line.

As described above, when the metal catalyst layer 150 is patterned, the graphene layers may be formed in a desired shape, so that the lower graphene layer 170 may be used for various purposes such as electrodes, inductors, wirings, and sensors in electronic devices. It is possible to use.

Meanwhile, according to another aspect of the present invention, a graphene composite film manufactured according to the graphene composite film manufacturing method according to the above embodiments may be provided.

The graphene composite film may be used in the manufacture of electrodes (especially transparent electrodes) of various electronic and electronic devices such as next-generation field effect transistors or diodes requiring flexibility and / or stretchability, or in photovoltaics, touch sensors, and related flexible electronic technologies. It is possible to be used as graphene transparent electrode for miracle applications.

As described above, the embodiments of the present invention form a hexagonal boron nitride layer by using a catalyst having a very low surface roughness, thereby maintaining a low surface roughness of the hexagonal boron nitride layer, and the upper and lower metal catalyst layers. After the graphene layer is formed on, by using only the graphene layer formed below the metal catalyst layer of the higher quality it can be formed on the hexagonal boron nitride layer upper graphene.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, many modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. The present invention can be variously modified and changed by those skilled in the art, and it is also within the scope of the present invention.

100: graphene composite film
110: noncatalytic substrate
130: hexagonal boron nitride layer
150: metal catalyst layer
170: lower graphene layer
190: upper graphene layer

Claims (8)

A first step of forming a hexagonal boron nitride layer (H-BN, Hexagonal Boron Nitride) on the non-catalyst substrate;
A second step of forming a metal catalyst layer on the hexagonal boron nitride layer;
Supplying carbon to the metal catalyst layer to form at least one or more lower graphene layers below the metal catalyst layer, and forming at least one or more upper graphene layers above the metal catalyst layer; And
Graphene composite film manufacturing method comprising a fourth step of removing the metal catalyst layer and the upper graphene layer. The method of claim 1,
The catalyst-free substrate is a graphene composite film manufacturing method of at least one selected from Si substrate, Si / SiO ₂ substrate, sapphire substrate, quartz (Quartz) substrate and glass substrate. The method of claim 1,
In the first step,
A solid source comprising ammonia borane (H ₃ BNH ₃ ) or boron trioxide (B ₂ O ₃ ) and B ₃ N ₃ H ₆ , B ₃ H ₃ Cl ₃ , B ₃ N ₃ Cl ₆ , BF ₃ or BCL _{3 A} method for producing a graphene composite film which is a step of forming a hexagonal boron nitride layer by pyrolysis. The method of claim 1,
The metal catalyst layer is silicon, Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V, Zr, brass, bronze, cupronickel, Graphene composite film manufacturing method of at least one metal or alloy selected from the group consisting of stainless steel and Ge. The method of claim 1,
The thickness of the metal catalyst layer is a graphene composite film manufacturing method of 10nm to 100㎛. The method of claim 1,
The second step comprises:
Patterning the metal catalyst layer; And
Graphene composite film manufacturing method comprising the step of depositing the metal catalyst layer on the hexagonal boron nitride layer. The method according to claim 6,
Patterning the metal catalyst layer,
And patterning a source region and a drain region on both sides of the metal catalyst layer, and patterning a channel region connecting the source region and the drain region to a central portion of the metal catalyst layer. delete

Images