KR101577991B1 - Method for preparing graphene using overlapping and method for fabricating electronics comprising the graphene - Google Patents

Abstract

The present invention relates to a method of manufacturing a semiconductor device, comprising: stacking a thin film containing a metal catalyst layer to form a superimposed body (step a); And chemical vapor deposition to produce graphene on the metal catalyst layer (step b). According to this, the movement of the metal catalyst molecules in the chemical vapor deposition apparatus is promoted, and the vapor phase of the metal catalyst is prevented by the influence of the overlapped substrate, so that the grain boundary size of the micro catalyst unit surface The transparency can be improved. In addition, it is possible to synthesize a graphene sheet that grows at various concentrations of a gas of a carbon source, and efficiently mass-produce it in a limited space in a chemical vapor deposition apparatus.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing graphene using a superposition method, and a method of manufacturing an electronic device including the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a method of producing graphene and a method of manufacturing an electronic device including the graphene, and more particularly, to a method of forming graphene using a superposition method and a chemical vapor deposition method, To a method of manufacturing an electronic device.

Graphene is a layer of a thin film of carbon atoms bonded in a sp2 hybrid orbital to form a planar honeycomb structure. It is not only excellent in conductivity, but also has flexible properties, making it easily seen as a substitute for semiconductors and semiconductors that are easily broken or broken.

Methods for synthesizing graphene include mechanical or chemical peeling, chemical vapor deposition, epitaxial synthesis, and organic synthesis. Among them, the chemical vapor deposition method is excellent in quality and is the most suitable method for mass production of a large-area graphene layer.

In the chemical vapor deposition method, graphene growth occurs at a high temperature. At this time, the grain growth of the metal catalyst is performed, and as the grain boundary grows, the graining may occur in the grain boundary. In such a grain boundary, a multi-layered graphene is likely to be formed, and a multi-layered graphene can act as a cause for lowering the light transmittance of the finally formed graphene sheet. In other words, when the size of the metal catalyst grains is small and the number of the grain boundaries is large, the area of the formed graphene in multiple layers is likely to increase, and as a result, the light transmittance of graphene may be lowered. Conventionally, in the production of graphene by chemical vapor deposition, the grain size of the metal catalyst is small and grain boundaries are formed in a large amount. Therefore, there is a demand for a graphene synthesis method capable of increasing the light transmittance by increasing the grain size of the metal catalyst and reducing the grain boundary to suppress the growth of graphene in the multi-layer.

Conventionally, graphene was synthesized with a metal (for example, Cu) catalyst useful for synthesizing a graphene monolayer in the graphene synthesis while the surface of the graphene layer was directly exposed in the evaporator. At this time, there is a problem that the surface of the catalyst melts when the chemical vapor deposition which maintains a high temperature at a melting point (1,040 ° C in the case of copper) of the catalyst.

Further, conventionally, when the graphene is grown using the chemical vapor deposition method, the metal catalyst for graphene growth is exposed to the gas stream, and the chamber size of the vapor deposition apparatus is limited, thereby limiting the amount of graphene that can be synthesized at one time . Therefore, from the viewpoints of energy saving and mass production, a new method capable of synthesizing a larger amount of graphene in a single process is required.

It is an object of the present invention to provide a method of manufacturing a graphene sheet, which can increase the production efficiency, reduce the production cost and make uniform graphene even under various gas composition conditions in the production of graphene by chemical vapor deposition, Graphene with excellent light transmittance and electrical characteristics by suppressing the growth of multi-layer graphenes, which are likely to be formed at grain boundaries through reduction in grain boundary size, increase in grain size and decrease in number of grains.

Another object of the present invention is to provide a new method capable of producing a larger amount of graphene in a single process in terms of energy saving and mass production.

According to an aspect of the present invention, there is provided a method for fabricating a semiconductor device, comprising: stacking a thin film including a metal catalyst layer to form a superimposed structure (step a); And performing chemical vapor deposition to produce graphene on the metal catalyst layer (step b).

The thin film may further include a substrate on the metal catalyst layer.

The superimposed material may be stacked in a direction perpendicular to the surface of the plurality of thin films.

The superimposition may be such that the thin film is rolled up into a rolled form.

The substrate may include at least one selected from the group consisting of an inorganic substance, a metal, and an oxide thereof.

The inorganic material may include at least one selected from the group consisting of silicon, ceramics, and quartz.

The metal may include at least one selected from the group consisting of aluminum, tin, copper, iron, nickel, cobalt, and stainless steel.

The metal catalyst layer may include at least one selected from the group consisting of nickel, iron, copper, platinum, palladium, ruthenium, and cobalt.

The chemical vapor deposition may be performed with a mixture comprising hydrogen, argon and hydrocarbon gases.

The hydrocarbon gas may include at least one selected from the group consisting of methane, ethane, and propane.

The method of manufacturing graphene may further comprise, after step b, forming a polymeric support layer on the graphene of the result of step b) (step c).

The method for producing graphene may further comprise, after step c, removing the thin film layer to obtain graphene having a polymer support layer formed thereon (step e).

The method of producing graphene may further comprise removing graphene layer after step b to obtain graphene (step d).

The metal catalyst layer may be formed by any one method selected from the group consisting of sputtering, thermal deposition, and electron beam deposition.

The metal catalyst layer may be formed on the substrate to a thickness of 50 to 1,000 nm.

The chemical vapor deposition may be performed at a temperature of 400 to 1,300 ° C.

The chemical vapor deposition may be performed by a low pressure chemical vapor deposition method, an atmospheric pressure chemical vapor deposition method, a plasma-enhanced chemical vapor deposition method, a joule-heating method, Chemical vapor deposition, and microwave chemical vapor deposition.

According to another aspect of the present invention, there is provided a method of fabricating a semiconductor device, comprising: stacking a thin film containing a metal catalyst layer to form a superimposed structure (step 1); Performing chemical vapor deposition to produce graphene on the metal catalyst layer (step 2); (Step 3) of removing the thin film layer from the result of step 2 to obtain graphene, and a step (step 4) of producing an electronic device including the graphene of step 3 (step 4). .

The electronic device may be any one selected from the group consisting of an electrode, a touch panel, an electroluminescent display, a backlight, a radio frequency identification (RFID) tag, a solar cell module, an electronic paper, a TFT for a flat display, and a TFT array.

It is possible to increase the production efficiency and reduce the production cost in the production of graphene by chemical vapor deposition and to make uniform graphene even under various gas composition conditions and to provide a grain boundary size The increase of the grain size and the decrease of the number of grains can suppress the growth of the multi-layer graphene, which is likely to be formed at the grain boundary, so that the light transmittance and ductility of the graphene can be improved.

1 is a flowchart sequentially illustrating a method of manufacturing graphene according to the present invention.
2 (a) schematically shows a state in which a superimposed body (b) in which a plurality of substrates having metal catalyst layers formed thereon are stacked in a chemical vapor deposition process using a superimposed type superimposed body.
Fig. 3 is a photograph showing the rolled-type superimposer (a) of Example 3 and the appearance (b) of the graphene produced thereby.
Fig. 4 is an optical microscope image of a graphene layer produced according to Comparative Examples 3 to 6. Fig.
5 is an optical microscope image of the graphene layer produced according to Example 1 for each sample.
6 is an optical microscope image of the graphene layer produced according to Example 2 for each sample.
7 is an optical microscope image of the graphene layer produced according to Example 3 for each sample.
Fig. 8 shows Raman spectra of the graphene layers prepared according to Comparative Examples 3 to 6. Fig.
FIG. 9 shows a Raman spectrum of the graphene layer produced according to Example 1. FIG.
10 shows a Raman spectrum of the graphene layer produced according to Example 2. Fig.
11 shows Raman spectrum of the graphene layer produced according to Example 3. Fig.
12 is a graph showing the sheet resistance and transmittance of the graphene layer produced according to Example 1 at a wavelength of 550 nm.
13 is a graph showing the sheet resistance and transmittance of the graphene layer produced according to Example 2 at a wavelength of 550 nm.
14 shows the transmittance of the graphene layer produced according to Comparative Examples 3 to 6 at a wavelength of 550 nm.
Fig. 15 shows the sheet resistance of the graphene layer produced according to Comparative Examples 3 to 6. Fig.

Hereinafter, a method of manufacturing graphene according to the present invention will be described with reference to FIG.

A thin film comprising a metal catalyst layer is stacked and superposed to produce a superimposed body (step a).

The thin film includes a metal catalyst layer, and may further include a substrate on the metal catalyst layer.

The stack may be a stacked stack that can be manufactured by stacking a plurality of the thin films in a direction perpendicular to the surface. Accordingly, one metal catalyst layer can contact with another metal catalyst layer, or in the case of a thin film including a substrate, the metal catalyst layer can be in contact with the substrate.

The superimposed body may be a roll-shaped superimposed body rolled up into a rolled shape. Accordingly, one metal catalyst layer can be in contact with the metal catalyst layer, or in the case of a thin film including a substrate, the metal catalyst layer can be in contact with the substrate.

When such a superposed body is formed, one thin film can serve to cover the metal catalyst layer of another thin film in contact therewith. Thus, the surface of the metal catalyst layer can be prevented from being directly exposed to the outside.

However, the scope of the present invention is not limited thereto, and the method of forming a superimposed body may be all of the forms in which the laminate can be laminated into a plurality of layers. As a result, the maximum area of the metal catalyst layer capable of forming graphene within a limited space can be secured.

Thereafter, chemical vapor deposition is performed to produce graphene on the metal catalyst layer (step b).

The chemical vapor deposition may be performed with a gas mixture comprising hydrogen, argon, and hydrocarbon gas.

The hydrocarbon gas is preferably methane, ethane or propane.

The chemical vapor deposition may be performed using low pressure chemical vapor deposition, atmospheric pressure chemical vapor deposition, plasma-enhanced chemical vapor deposition, joule-heating, A chemical vapor deposition method, a microwave chemical vapor deposition method, and the like. In addition to the chemical vapor deposition described above, a method of growing a graphene layer on the metal catalyst layer is also possible.

The chemical vapor deposition can be performed at a temperature of 400 to 1300 DEG C, preferably at a temperature of 800 to 1000 DEG C. [

Optionally, after step b, a polymeric support layer may be formed on the graphene in step b) (step c).

Further, after step c, the thin film layer may be removed to obtain graphene having a polymer support layer (step e).

A chemical vapor deposition method using a laminate type superposed body made of a substrate having a metal catalyst layer formed thereon is schematically shown in Fig.

The graphene produced according to the above production method can be applied to various electronic devices and can be applied to electronic devices required by transferring a graphene layer to a target substrate as described below. It does not.

In detail, in the laminated structure including the thin film (substrate / metal catalyst layer) / graphene / polymer support layer prepared according to steps a to c, the thin film layer (substrate and metal catalyst layer) is removed to form a graphen / Can only leave. At this time, the polymer scaffold may be a commercially available polymer material such as polymethylmethacrylate (PMMA), a silicon polymer, or the like.

The graphene / polymeric support layer can be used to transfer the graphene to the desired substrate. After the transferring step, the polymer supporting layer may be removed. Herein, an organic solvent such as chloroform, toluene, acetone, or the like or a possible inorganic solvent may be used as the solvent for removing the polymer supporting layer.

As described above, the graphene sheet transferred onto a target substrate can be applied to a flexible electronic device, a transparent electronic device, and the like, and more specifically, to an electrode, a touch panel, an electroluminescent display, a backlight, , A solar cell module, an electronic paper, a TFT for a flat display, a TFT array, and the like.

[Example]

Hereinafter, preferred embodiments of the present invention will be described. However, this is for illustrative purposes only, and thus the scope of the present invention is not limited thereto.

Example  One: Laminated type Overlay  Used Chemical vapor deposition

400 nm of nickel was thermally deposited on a silicon wafer substrate coated with a 300 nm silicon oxide layer in the form of a film. Then, six substrates on which the nickel layer was formed were stacked in order to form a laminate, which was then placed in a chemical vapor deposition apparatus. After raising the furnace temperature of the chemical vapor deposition apparatus to 900 DEG C, the movable tube containing the laminate was rapidly transferred and placed in a furnace. The graphene was grown while flowing a reaction gas mixture (hydrogen = 100 sccm, argon = 500 sccm, and methane gas = 2 sccm), and then hydrogen gas was only flowed at a rate of 10 ° C / min.

Next, a polymethylmethacrylate solution was coated with a graphene support layer, and then a silicon oxide layer was dissolved with a 5 wt% solution of hydrofluoric acid, and a nickel layer / a graphene layer / a polymer support layer was coated with a FeCl ₃ solution to form a nickel layer It dissolved. The floating graphene layer / polymer support layer in the solution was transferred to the target substrate, and the polymer support layer was removed with chloroform to leave only graphene on the target substrate.

Then, the five graphene-formed substrates were separated from each other, and a sample 2-1 (1 ^st layer), a sample 2-2 (2 ^nd layer), a sample 2-3 (3rd layer) , A sample 2-4 (4th layer), and a sample 2-5 (5th layer).

Example  2: Laminated type Overlay  Used Chemical vapor deposition

Except that graphene was grown while flowing a gas mixture (hydrogen = 100 sccm, argon = 500 sccm, and methane gas = 10 sccm) instead of the reaction gas mixture (hydrogen = 100 sccm, argon = 500 sccm, methane gas = 2 sccm) The chemical vapor deposition was carried out in the same manner as in Example 1.

Thereafter, the five graphene-formed substrates were separated from each other, and a sample 2-1 (1 ^st layer), a sample 2-2 (2 ^nd layer), a sample 2-3 (3rd layer), a sample 2-4 layer, and Sample 2-5 (5th layer).

Example  3: Roll Overlay  Used Chemical vapor deposition

Nickel 400 nm thick was thermally fired on a flexible stainless steel substrate (SUS) having 500 nm of SiO ₂ deposited by PECVD, and the substrate having a substrate width of 2 cm and a length of 15 cm was rolled four times to prepare a roll having a diameter of 1 cm.

The prepared rolls were subjected to chemical vapor deposition under the same conditions and in the same manner as in Example 2 to prepare graphene.

Thereafter, samples 2-1 (1st turn), 2-2 (2nd turn), 2-3 (3rd turn) and 2-4 (4th turn) were prepared according to the number of turns of the roll.

The roll (a) and the graphene-forming photograph (b) of each sample are shown in Fig.

Comparative Example  1: metal The catalyst layer  Exposed Chemical vapor deposition

Chemical vapor deposition was performed to form a graphene layer in the same manner as in Example 1, except that the surface of the nickel film was exposed without making the nickel-deposited substrate into a laminate.

Comparative Example  2 to 6

Chemical vapor deposition was carried out in the same manner as in Comparative Example 1, except that the mixing ratio of the reaction gas mixture flow rate was set as shown in Table 1 below.

division Hydrogen (sccm) argon
(sccm) Methane (sccm) Methane concentration ratio (volume%) Direct exposure of nickel surface
(Non-exposure: X, exposure: O) Stacking order
(Laminated type) Number of turns
(Rolled) Whether graphene is formed
(Formation: O,
Nonformed: X) Example Sample Example 1 1-1 100 500 2 0.33 X One - O 1-2 100 500 2 0.33 X 2 - O 1-3 100 500 2 0.33 X 3 - O 1-4 100 500 2 0.33 X 4 - O 1-5 100 500 2 0.33 X 5 - O Example 2 2-1 100 500 10 1.64 X One - O 2-2 100 500 10 1.64 X 2 - O 2-3 100 500 10 1.64 X 3 - O 2-4 100 500 10 1.64 X 4 - O 2-5 100 500 10 1.64 X 5 - O Example 3 3-1 100 500 10 1.64 X - One O 3-2 100 500 10 1.64 X - 2 O 3-3 100 500 10 1.64 X - 3 O 3-4 100 500 10 1.64 X - 4 O Comparative Example 1 100 500 2 0.33 O - - X Comparative Example 2 100 500 10 1.64 O - - X Comparative Example 3 100 500 15 2.44 O - - O Comparative Example 4 100 500 20 3.23 O - - O Comparative Example 5 100 500 50 7.69 O - - O Comparative Example 6 100 500 70 10.45 O - - O

[Test Example]

Hereinafter, the measurement method in the test example of the present invention is as follows.

The morphology of graphene was observed with an optical microscope (Axioplan, Zeiss), and Raman analysis was performed with a Raman spectrometer (WITec, Micro Raman) at 532 nm. The transmittance of graphene was determined by UV-vis analysis in a transparent mode and the sheet resistance was measured by a four-probe resistance meter. In the tapping mode of the nickel catalyst surface, an atomic force microscope (Digital Instruments Multimode Nanoscope III) was used and the normal mode XRD measurement was measured at 9 C beamline (wavelength 1.08 Å).

Test Example  One: Graphene  Optical microscope image and Raman spectrum analysis

An optical microscope image of the graphene layer produced according to Comparative Examples 1 to 6 is shown in Fig. 4, and an optical microscope image of each sample of the graphene layer produced according to Examples 1, 2 and 3 is shown in Figs. 5, 6 and 7 Respectively.

Raman spectra of the graphene layers produced according to Comparative Examples 3 to 6 are shown in Fig. 8, and Raman spectra of the graphene layers prepared according to Examples 1 and 2 are shown in Figs. 9 and 10 for each sample, 11 shows the Raman spectrum of the graphene layer (1 ^st turn to 4 ^th turn continuous) prepared according to the method of Fig.

Referring to FIGS. 4 and 8, in the comparative examples 1 to 6, the graphene layer was not generated under conditions where the concentration of methane was low (Comparative Examples 1 and 2).

These results indicate that when chemical vapor deposition is performed with the metal catalyst layer exposed, it is difficult to grow the graphene layer under a relatively low concentration of methane.

5 to 7 and 9 to 11, when graphene is produced according to Examples 1 to 3 of the present invention, although the concentration of methane is the same as that of Comparative Example 1 or 2, Were well formed.

The result is that when the substrate on which the metal catalyst layer is formed is stacked in layers or rolled so that the metal catalyst layer is not directly exposed, the influence of the concentration of the reactive gas is minimized by controlling the behavior of the gas flow, Lt; / RTI >

Test Example  2: Graphene  Transmittance and Sheet resistance  analysis

The transmittance and sheet resistance of the graphene prepared according to Examples 1 and 2 at 550 nm wavelength light are shown in FIGS. 12 and 13. Table 2 below shows the sheet resistance and permeability under the same conditions as in Example 3 using the rolled laminate.

The transmittance and sheet resistance of the graphene layer prepared according to Comparative Examples 1 to 6 at 550 nm wavelength light are shown in Figs. 14 and 15, respectively.

12 to 15 and Table 2, when the graphene layer is formed without exposing the metal catalyst layer by stacking the laminate (substrate on which the metal catalyst layer is formed) in a stacked or rolled shape according to the present invention, the metal catalyst layer is exposed , The light transmittance was relatively higher and the sheet resistance was somewhat higher than that of the case where it was applied. This means that the graphene layer is thinner than when the surface is exposed by the formation of the laminate.

Example Sample Permeability (%) Sheet resistance (k? / Sq) Nickel surface exposed Number of turns
(Rolled) Example 3 3-1 90.7 7.76 X 1st turn 3-2 91.2 8.47 X 2nd turn 3-3 90.8 7.86 X 3rd turn 3-4 91.1 8.25 X 4th turn

Claims (19)

Stacking the thin films including the metal catalyst layer to form a superimposed layer (step a); And
And performing chemical vapor deposition to produce graphene on the metal catalyst layer (step b).
Method of manufacturing graphene. The method according to claim 1,
Wherein the thin film further comprises a substrate on the metal catalyst layer. The method according to claim 1,
Wherein the plurality of thin films are stacked in a direction perpendicular to the surface of the stack. The method according to claim 1,
Wherein the superimposed material is formed by rolling the thin film in a roll form. 3. The method of claim 2,
Wherein the substrate comprises at least one selected from the group consisting of an inorganic substance, a metal, and an oxide thereof. 6. The method of claim 5,
Wherein the inorganic material comprises at least one selected from the group consisting of silicon, ceramics and quartz. 6. The method of claim 5,
Wherein the metal comprises at least one selected from the group consisting of aluminum, tin, copper, iron, nickel, cobalt and stainless steel. The method according to claim 1,
Wherein the metal catalyst layer comprises at least one selected from the group consisting of nickel, iron, copper, platinum, palladium, ruthenium and cobalt. The method according to claim 1,
Characterized in that the chemical vapor deposition is carried out with a mixture comprising hydrogen, argon and hydrocarbon gases. 10. The method of claim 9,
Wherein the hydrocarbon gas comprises at least one selected from the group consisting of methane, ethane and propane. The method according to claim 1,
Wherein the method for producing graphene further comprises, after step b, forming a polymer support layer on the graphene of the resultant product of step b) (step c). 12. The method of claim 11,
Wherein the method for producing graphene further comprises the step of removing the thin film after step c to obtain graphene having a polymer support layer formed thereon (step e). The method according to claim 1,
Wherein the method for producing graphene further comprises a step (d) of obtaining graphene by removing the thin film after step b. The method according to claim 1,
Wherein the metal catalyst layer is formed by any one method selected from the group consisting of sputtering, thermal evaporation, and electron beam evaporation. 3. The method of claim 2,
Characterized in that the metal catalyst layer is formed on the substrate to a thickness of 50 to 1,000 nm The method according to claim 1,
Wherein the chemical vapor deposition is performed at a temperature of 400 to 1,300 ° C. The method according to claim 1,
The chemical vapor deposition may be performed by a low pressure chemical vapor deposition method, an atmospheric pressure chemical vapor deposition method, a plasma-enhanced chemical vapor deposition method, a joule heating method, Wherein the graphene is formed by any one method selected from the group consisting of chemical vapor deposition and microwave chemical vapor deposition. Stacking the thin films including the metal catalyst layer to form a superimposed body (step 1);
Performing chemical vapor deposition to produce graphene on the metal catalyst layer (step 2);
Removing the thin film from the result of step 2 to obtain graphene (step 3): and
(Step 4) of producing an electronic device including the graphene of step 3:
Wherein the method comprises the steps of: 19. The method of claim 18,
Wherein the electronic device is any one selected from the group consisting of an electrode, a touch panel, an electroluminescent display, a backlight, an RFID tag, a solar cell module, an electronic paper, ≪ / RTI >

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