KR101815679B1 - Method of manufacturing graphene film - Google Patents

Abstract

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a catalyst metal having a graphene formed on a first surface thereof; Patterning the catalytic metal by wet etching; Patterning the graphene by dry etching using the patterned catalyst metal as a mask; Removing the patterned catalytic metal; And transferring the patterned graphene to a target film to obtain a graphene film; And a method for producing the graphene film.

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing graphene film,

The present invention relates to a process for producing a patterned graphene film and a graphene film obtained by the process.

Graphene is a material in which carbon is hexagonally connected to form a honeycomb two-dimensional planar structure. Its thickness is very thin, transparent, and has high electrical conductivity. Many attempts have been made to apply graphene to a touch panel, a transparent display, or a flexible display using such characteristics of graphene. Thus, in order to apply graphene to an electronic device, a pattern must be formed on the graphene.

As a method of forming a pattern on graphene, there is a patterning method using plasma. In this method, a metal mask is placed apart from the graphene, and plasma is applied to pattern the graphene in the pattern of the mask. However, such a method can not realize a fine pattern, has a very large dimensional deviation due to the distance between the mask and the graphene, and has a disadvantage that it is costly to manufacture a mask.

Alternatively, a pattern can be formed on the graphene using a laser. This method involves scanning the laser and patterning by removing unnecessary portions from the graphene. However, such a method requires a long process time when patterning large area graphenes, which increases the process cost and can not be applied to mass production because a large amount of graphene patterning is impossible in a single process.

On the other hand, the following prior art document discloses a method of transferring graphene formed on an imprint stamp onto a substrate, but it is impossible to form a fine graphene pattern.

Korea Patent Publication No. 2011-0054386

The present invention aims to provide a method for producing a graphene film on which a fine pattern is formed and a graphene film obtained by the method.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a catalyst metal having a graphene formed on a first surface thereof; Patterning the catalytic metal by wet etching; Patterning the graphene by dry etching using the patterned catalyst metal as a mask; Removing the patterned catalytic metal; And transferring the patterned graphene to a target film to obtain a graphene film; And a method for producing the graphene film.

Characterized in that the catalytic metal is discontinuously patterned by wet etching a plurality of times.

The catalyst metal is patterned by wet etching using the patterned photoresist as a mask; And patterning the catalyst metal by wet etching using the thickness difference of the patterned catalyst metal; .

The first patterning is to half-etch the entire catalyst metal, and the second patterning is to leave a catalyst metal only on the patterned photoresist portion.

Applying and patterning a photoresist on a second surface of the catalyst metal opposite to the first surface prior to the first patterning; .

Removing the photoresist using a first solution after the first patterning; .

The catalytic metal is wet etched using a second solution, characterized in that the second solution and the first solution are different.

The photoresist film includes a liquid photoresist or a dry film resist.

The dry etching uses plasma.

Forming a carrier film on an outer surface of the graphene without the catalytic metal; .

Forming a protective film for protecting the graphene film on the graphene film; .

And a graphene film obtained by the process for producing the graphene film.

According to the embodiment of the present invention, it is possible to obtain a graphene film on which a fine pattern can be formed and a fine pattern can be formed on the graphene. In addition, it is possible to reduce the damage of the graphene in the patterning process, thereby obtaining a high-quality graphene film.

1 is a perspective view schematically illustrating the graphene referred to herein.
2 is a flowchart schematically showing a method of manufacturing a graphene film according to an embodiment of the present invention.
FIGS. 3 to 17 are schematic cross-sectional side views showing a method of manufacturing a graphene film corresponding to the flow chart of FIG. 2. FIG.
18 is a flowchart schematically showing a method of manufacturing a graphene film according to another embodiment of the present invention.
19 to 23 are schematic cross-sectional side views showing a manufacturing method of a graphene film corresponding to the flow chart of Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terms first, second, etc. used in this specification may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another.

It will be understood that when a layer, film, region, plate, or the like is referred to as being "on" or "on" another portion, do.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to the drawings, substantially identical or corresponding elements are denoted by the same reference numerals, do. In the drawings, the thickness is enlarged to clearly represent the layers and regions. In the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

1 is a perspective view schematically illustrating the graphene referred to herein.

As used herein, the term "graphene" refers to a graft formed in the form of a film in which a plurality of carbon atoms are covalently linked to each other to form a polycyclic aromatic molecule. Graphene is a covalently linked carbon atom which forms a 6-membered ring as a basic repeating unit, but it is also possible to further include a 5-membered ring and / or a 7-membered ring. Thus, graphene forms a single layer of covalently bonded carbon atoms (C) (usually sp2 bonds). The graphene may have a variety of structures, and such a structure may vary depending on the content of the five-membered ring and / or the seven-membered ring which may be contained in the graphene.

The graphene may be composed of a single layer of graphene as shown, but they may be stacked to form a plurality of layers, and usually the side ends of the graphene may be saturated with hydrogen atoms (H) .

As used herein, "graphene" means a graphene film in the form of a single layer or a plurality of layers, and "graphene film" means that graphene is transferred to a target film.

Fig. 2 is a flow chart schematically showing a manufacturing method of a graphene film referred to in the present specification. 3 to 17 are schematic cross-sectional side views of a laminate including graphene 110 corresponding to the flow chart of Fig.

As used herein, the term "laminate" refers to a plurality of layers including graphene 110, and according to each step of the method of manufacturing a graphene film according to an embodiment of the present invention, At least one layer of the catalytic metal 101, the carrier film 120, the target film 130, the photoresist film 150, and the protective film 140 may be further included in addition to the graphene 110.

Although not shown in the drawing, the catalyst metal to be graphene is pretreated. (S11)

The catalyst metal may be a catalyst for graphene growth, such as a sheet type, a substrate type or a roll film type. The catalytic metal may be selected from the group consisting of copper, nickel, cobalt, iron, platinum, gold, silver, aluminum, chromium, Mg, Mn, Mo, Rh, Si, Ta, Ti, W, U, V, At least one metal or alloy selected from the group consisting of Pd, Y, Zr, Ge, Brass, Bronze, White Brass and Stainless Steel, But are not limited thereto.

The catalytic metal may be a single layer, and one of the multilayer substrates of at least two layers may be a catalytic metal. In this case, the catalyst metal is disposed at the outermost portion of the multilayer substrate.

A pretreatment process is carried out to clean the surface of the catalyst metal before graphene is formed. The pretreatment process is for removing impurities existing on the surface of the catalyst metal, and hydrogen gas can be used. Further, by cleaning the surface of the catalyst metal using an acid or an alkali solution or the like, defects can be reduced in the subsequent process, that is, graphene formation. This step of cleaning the surface of the catalytic metal may be omitted if necessary.

Next, referring to FIG. 3, the process of forming the graphene 110 proceeds. (S12)

When the catalytic metal 101 is transferred to the chamber, the gaseous carbon source is introduced into the chamber and heat-treated. The heat treatment consists of heating and cooling. The graphene 110 may be formed by a chemical vapor deposition (CVD) method, a thermal chemical vapor deposition (TCVD) method, a rapid thermal chemical vapor deposition (PTCVD) method, an inductively coupled plasma Various processes such as inductively coupled plasma chemical vapor deposition (ICP-CVD) and atomic layer deposition (ATLD) may be used.

A carbon source of the vapor is methane (CH _4), carbon monoxide (CO), ethane (C ₂ H _6), ethylene (CH _2), ethanol (C ₂ H _5), acetylene (C ₂ H _2), propane (CH ₃ CH ₂ CH _3), propylene (C ₃ H _6), butane (C ₄ H _10), pentane _{(CH 3 (CH 2) 3} CH 3), pentene (C ₅ H _10), dicyclopentadiene (C ₅ H ₆ carbon atoms such as hexane (C ₆ H ₁₄ ), cyclohexane (C ₆ H ₁₂ ), benzene (C ₆ H ₆ ), and toluene (C ₇ H ₈ ). Such a gaseous carbon source is separated into carbon atoms and hydrogen atoms at high temperatures. The separated carbon atoms are deposited on the heated catalyst metal 101 and the graphene 110 is formed as the catalyst metal 101 is cooled.

The graphene 110 may be formed on at least one side of the catalyst metal 101. 3, the graphene 110 may be formed on both surfaces of the catalytic metal 101, but the present invention is not limited thereto. The graphene 110 may be formed on only one side of the catalytic metal 101, (110) may be formed.

Next, referring to FIG. 4, a carrier film 120 is formed on the graphene 110. (S13)

The carrier film 120 supports the layered body 300 of FIG. 3 to facilitate transport, and maintains the shape of the graphene 110 and prevents damage. The carrier film 120 may be a thermal release tape or a polymeric support. The heat peeling tape has a property that one side has adhesive property at room temperature but loses adhesiveness when heated to a predetermined peeling temperature or more. The polymer support includes an organic polymer such as polymethylmethacrylate (PMMA), and is formed by drop-coating an organic polymer into a liquid phase on one side of the graphene 110 and then solidifying it to form a polymer support , And then may be removed with an organic solvent.

Next, referring to FIG. 5, the graphene 110 on one surface of the catalyst metal 101 is removed. (S14)

3, when the graphene 110 is formed on both surfaces of the catalyst metal 101, the process of FIG. 5 is performed. However, in the case where the graphene 110 is formed only on one side of the catalytic metal 101, the process of FIG. 5 may be omitted.

The graphene 110 on one surface of the catalytic metal 101 can be removed by dry etching. In detail, since the graphene 110 is chemically stable, it is difficult to remove chemical bonds by wet etching, and the graphene 110 can be removed by dry etching using a plasma. Specifically, the oxygen plasma ion is chemically combined with the carbon atoms constituting the graphene 110 to generate carbon monoxide or carbon dioxide, thereby removing the graphene 110.

When the process of patterning the catalytic metal 101 without removing the graphene 110 on one side of the catalytic metal 101 is performed, the grains 110 of the graphene 110, There is a problem that the quality and characteristics of the finally obtained graphene film (1600 in Fig. 16) are deteriorated by being physically bonded to the graphene 110 bonded to the stamper 120. Therefore, a step of removing the graphene 110 and exposing the catalyst metal 101 as shown in FIG. 5 is necessary.

Referring next to FIG. 6, a photoresist layer 150 is formed on the surface of the exposed catalytic metal 101. (S15)

The photoresist film 150 is formed on the exposed catalytic metal 101 by removing the graphene 110 in the process of FIG. The photosensitive film 150 is a film containing a photosensitive material whose resistance is changed by light. A liquid photoresist is a liquid photoresist and the liquid photoresist is applied to the catalytic metal by spin, bar, spray, roll coating or the like and then pre-baked or soft baked baking to remove the solvent to form a photoresist layer 150. The photosensitive material in the form of a film is dry film resist (DFR), and the dry film resist forms a photoresist film 150 on the catalytic metal by roll-to-roll lamination or vacuum pressing.

 The photoresist film 150 has a negative type which is insoluble by chemicals when exposed to light, and a positive type which becomes soluble as opposed to a negative type which is insoluble by chemicals. In the present embodiment, a positive type will be described as an example, but the present invention is not limited thereto.

Next, referring to FIGS. 7 and 8, the photoresist layer 150 is patterned using a photolithography process. (S16)

The photosensitive film 150 performs patterning using a frame mask M on which a predetermined pattern is drawn. Of course, patterning may be performed using a halftone mask or a diffraction mask. FIG. 7 shows a method of patterning using a conventional frame mask.

The frame mask used in one embodiment of the present invention includes a light transmitting portion M1 and a light blocking portion M2. The light transmitting portion M1 transmits light of a predetermined wavelength band, and the light blocking portion M2 blocks light. The frame mask M shown in Fig. 7 is a conceptual view for conceptually explaining the function of each part of the frame mask. Actually, the frame mask M is formed in a predetermined pattern on a transparent substrate such as quartz Qz . At this time, the light shielding portion (M2) are formed by patterning a material such as Cr or CrO ₂ on the quartz substrate.

The frame mask M on which the pattern is drawn is aligned to expose the photosensitive film 150 with light of a predetermined wavelength band to perform exposure.

Referring to FIG. 8, a remaining photoresist pattern 151 is schematically shown after a development process of removing a photoresist layer of an exposed portion. In this embodiment, a positive type in which the exposed portion is removed is shown, but the present invention is not limited to this, and a negative type may be used.

Referring to FIG. 8, the photoresist pattern corresponding to the light transmitting portion M1 of the frame mask M is removed, and the photoresist pattern 151 corresponding to the light intercepting portion M2 remains.

Next, referring to FIG. 9, the catalytic metal 101 is primarily etched using the photoresist pattern 151 as a mask. (S17)

The catalytic metal 101 may be etched by wet etching using the photoresist pattern 151 as a mask. At this time, the primary etching does not completely remove the catalyst metal 101 in the portion where the photoresist pattern 151 is not formed by performing half etching. Therefore, the thickness d1 of the catalyst metal corresponding to the photoresist pattern 151 as a result of the first etching is larger than the thickness d2 of the catalyst metal corresponding to the portion not in the photoresist pattern. At this time, the thickness d1 of the catalyst metal corresponding to the photoresist pattern 151 is the same as the thickness of the initial catalyst metal (d1 in Fig. 3).

The catalytic metal 101 is wet-etched with a catalytic metal removing liquid. (NH ₄ ) ₂ S ₂ O ₈ ), hydrogen fluoride (HF), buffered oxide etch (BOE), ferric chloride (FeCl 3), and the like. ₃ ), iron nitrate (Fe (No ₃ ) ₃ ), copper chloride (CuCl ₂ ), hydrogen peroxide (H ₂ O ₂ ), sulfuric acid (H ₂ SO ₄ ), and sodium persulfate (Na ₂ S ₂ O ₈ ) Can be used. However, the present invention is not limited to this, and a solution of perhydrous sulfuric acid, which is a composition containing hydrogen peroxide (H ₂ O ₂ ), sulfuric acid (H ₂ SO ₄ ) and water (H ₂ O)

Next, referring to FIG. 10, the remaining photoresist pattern 151 is removed. (S18)

The remaining photoresist pattern 151 in FIG. 9 is removed with a solvent different from the catalyst metal removing solution. For example, as the solvent for removing the photoresist pattern 151, a solvent such as a basic amine selected from the group consisting mainly of hydroxyamine, diglycolamine, and methylethanolamine is used. However, unlike the catalyst metal removing solution, when such a solvent is brought into contact with the graphene 110, the physical properties such as the sheet resistance of the graphene 110 and the adhesive force between the target film and the graphene 110 are lowered.

According to an embodiment of the present invention, the catalytic metal 101 is discontinuously etched a plurality of times, and the photoresist pattern 151 is removed between the primary etching and the secondary etching of the catalytic metal. That is, the photoresist pattern 151 is removed before the graphene 110 is exposed by removing the catalyst metal 101. Therefore, when the photoresist pattern 151 is removed, the graphene 110 is covered with the catalyst metal 101, and the solvent for removing the photoresponsive film does not directly contact the graphene 110, Can be solved.

Next, referring to FIG. 11, the catalytic metal 101 is secondarily etched using the difference in thickness of the remaining catalytic metal 101. (S19)

11 is a step of forming the catalyst metal 101 as a mask for patterning the graphene 110 to pattern the graphene 110. [ In FIG. 11, the catalytic metal 101 is etched so that the catalytic metal 101 corresponding to a portion not in the photoresist pattern 151 as a result of the primary etching shown in FIG. 9 is removed and the catalytic metal pattern 102 is left. That is, as a result of the secondary etching, the thickness of the thick catalytic metal portion 101 of FIG. 9 becomes thinner and the thinner portion of the catalytic metal 101 of FIG. 9 is removed to form the catalytic metal pattern 102. The thickness d3 of the catalyst metal pattern is set to a value obtained by subtracting the thickness of the catalyst metal (d2 in Fig. 9) corresponding to the portion not in the photoresist pattern in the thickness of the catalyst metal (d1 in Fig. 9) corresponding to the photoresist pattern 151 Respectively.

In the second etching, the catalytic metal 101 is removed by wet etching using a catalytic metal removing liquid as in the first etching.

12 and 13, the graphene 110 is patterned using the catalyst metal pattern 102 as a mask (S20)

The graphene 110 may be patterned by dry etching using a plasma. In detail, when oxygen plasma ions are applied to the laminate 1100 of FIG. 11, the graphene 110 of the portion covered with the catalytic metal pattern 102 is preserved, but the exposed graphene (110) is removed by being converted into carbon monoxide or carbon dioxide in combination with oxygen plasma ions.

Fig. 13 shows a graphene pattern 111 patterned by such a mechanism.

In the case of patterning the graphene using the frame metal mask, there is a gap between the graphene and the frame metal mask, so that a patterning error occurs. However, according to the embodiment of the present invention, since the graphene 110 is patterned using the catalyst metal pattern 102 as a mask, there is no gap between the graphene 110 and the mask, There is also a feature that a fine pattern can be realized. On the other hand, the production cost of the frame metal mask is high, and it is difficult to realize a fine pattern on the frame metal mask. In detail, the pattern capable of implementing the frame metal mask should have a pitch of at least about 300 mu m or more, but the required pitch of the graphene pattern 111 may be about 100 mu m or less. However, according to one embodiment of the present invention, a graphene film having a fine pattern can be manufactured by applying a photolithography process capable of realizing a fine pattern to a catalyst metal. Also, by patterning the graphene 110 by a dry etching process using plasma using the catalytic metal pattern 102 as a mask, it is possible to pattern the large area graphene 110 at the same time, There is an advantage that mass production of the graphene film can be mass-produced.

Next, referring to Fig. 14, the catalyst metal pattern (102 in Fig. 13) is completely removed. (S21)

The catalytic metal pattern (102 in FIG. 13) is removed by a wet etching method using a catalyst metal removing liquid. After removing the catalytic metal pattern (102 in Fig. 13), the step may further include a step of cleaning the remaining catalytic metal removal liquid and a step of drying.

Next, referring to FIG. 15, the process of transferring the graphene pattern 111 to the target film 130 and the carrier film 120 are removed. (S22)

The target film 130 refers to a substrate that finally forms the graphene film 1600 with the graphene pattern 111 formed thereon. As the target film 130, at least one of polyethylene terephthalate (PET), polyimide (PI), polydimethylsiloxane (PDMS), plastic, glass, and metal may be used, It is not. The target film 130 coated with the graphene pattern may be used as a transparent electrode film such as a flexible display, an organic light emitting device, or a solar cell as a graphene film.

When the carrier film 120 is a heat peeling tape, heat is applied at a temperature equal to or higher than the peeling temperature to weaken the adhesive strength of the peeling tape, and a predetermined force is applied to peel off the peeling tape from the graphene pattern 111. When the carrier film 120 is a polymer support, an organic solvent such as acetone may be added to dissolve and remove the polymer support.

Next, although not shown, the doping process of the graphene film 1600 proceeds.

Doping may be performed to improve the electrical characteristics of the graphene pattern 111, which may be performed by a dry doping method or a wet doping method.

16, a protective film 140 is formed on the graphene film 110. (S23)

The protective film 140 is formed on the graphene pattern to protect the graphene pattern 111 from the outside.

The analysis process for analyzing the graphene film 1600 with no electrical damage or the like may be further performed. The manufacturing process of the graphene film 1600 described above is not limited to the description, and some of the steps may be changed, or some steps may be omitted or added.

18 is a flowchart schematically showing a method of manufacturing a graphene film according to another embodiment of the present invention. 19 to 23 are schematic cross-sectional side views showing a manufacturing method of a graphene film corresponding to the flow chart of Fig.

The method of manufacturing a graphene film according to another embodiment of the present invention shown in FIG. 18 is different from the method of manufacturing a graphene film according to an embodiment of the present invention shown in FIG. 2, It differs in that the catalytic metal is patterned at a single time instead of patterning a plurality of times.

Therefore, the method of manufacturing a graphene film according to another embodiment of the present invention is the same as that shown in Figs. 3 to 7 after the contents of Figs. 19 to 23, 17 is performed.

In FIGS. 19 to 23, the components corresponding to the components in the first embodiment of the present invention described with reference to FIGS. 3 to 17 perform the same or similar functions as those described in the first embodiment, A more detailed description will be omitted.

Referring to FIG. 19, the catalyst metal is patterned using the photoresist pattern 151 as a mask. (S17)

The catalytic metal may be etched by a wet etching method using a catalytic metal removing liquid using the photoresist pattern 151 as a mask. At this time, the catalyst metal pattern 102 is formed by completely removing the catalyst metal in the portion where the photoresist pattern 151 is not formed, instead of performing half-etching as shown in FIG. Therefore, the thickness d1 of the catalyst metal pattern 102 remaining in Fig. 19 is substantially equal to the thickness (d1 in Fig. 3) of the initial catalyst metal pattern.

Next, referring to FIG. 20, the photoresist pattern 151 is removed. (S18)

Next, referring to FIGS. 21 and 22, the graphene 110 is patterned using the catalyst metal pattern 102 as a mask. Here, the graphene 110 is patterned by a dry etching method using plasma to form a graphene pattern 111. (S20)

Next, referring to FIG. 23, the catalyst metal pattern 102 is removed using a catalyst metal removing liquid. (S21)

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

101: catalyst metal
110: graphene
120: carrier film
130: target film
140: Protective film

Claims (9)

Preparing a catalytic metal in which graphene is disposed;
Forming a photoresist on a surface of the catalyst metal where the graphene is not disposed;
Forming a photoresist pattern by patterning the photoresist;
Etching the catalytic metal by a half etching using the photoresist pattern as a mask so as not to expose the graphene;
Removing the photoresist pattern with a solvent that removes the photoresist pattern so that the graphene does not come into contact with the solvent that removes the photoresist pattern by a portion of the catalytic metal remaining after the first etching step;
Forming a catalytic metal pattern that exposes the graphene by secondary etching the catalytic metal using the difference in thickness of the primary catalytic metal after removing the photoresist pattern;
Patterning the graphen using the catalyst metal pattern as a mask;
Removing the catalyst metal pattern after patterning the graphene; And
And transferring the patterned graphene to a target film. delete The method according to claim 1,
Wherein the first etching of the catalyst metal and the second etching of the catalyst metal are performed by wet etching. The method according to claim 1,
Wherein the patterning of the graphenes is performed by dry etching. delete delete delete delete delete

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