Graphene thin film flat plate vapor deposition device and preparation method

Abstract

This application provides a planar plasma-enhanced chemical vapor deposition (PECVD) apparatus and a method for preparing graphene films. The planar PCVD apparatus, used for preparing graphene films, includes an unwinding chamber, a winding chamber, an inner sleeve, an outer sleeve, a first radio frequency (RF) plate, and a second RF plate. The unwinding chamber contains an unwinding roller, and the winding chamber contains a winding roller. The inner sleeve seals and connects the unwinding chamber and the winding chamber. The outer sleeve is located outside the inner sleeve. The first and second RF plates are arranged parallel to each other between the inner and outer sleeves. This design enables coupling between the plasma excitation and heating regions, effectively improving plasma utilization efficiency and reducing the impact of contaminants on the substrate.

Description

Technical Field

[0001] This application relates to an apparatus and method for preparing graphene films, and more specifically, to a planar plasma-enhanced chemical vapor deposition apparatus and method for preparing graphene films. Background Technology

[0002] Graphene is a novel carbon material with a two-dimensional honeycomb crystal structure composed of a single layer of tightly packed carbon atoms. It has many excellent properties in terms of electrical conductivity, thermal conductivity, mechanics, and optics, and also has some unique properties, such as high-performance sensor function, catalyst function, hydrogen absorption function, bipolar semiconductor, non-scattering transmission, and stress sensor function. Graphene has obvious application advantages in touch screens.

[0003] Plasma-enhanced chemical vapor deposition (PECVD) is a method for preparing graphene using radio frequency plasma-assisted chemical vapor deposition. This method utilizes plasma to effectively break down precursor molecules, lowering the chemical reaction barrier and enabling film formation at lower temperatures. Common plasma sources include microwave, radio frequency, and DC discharge. Depending on the plasma source, these are called WPCVD, RF-PECVD, and DC-PECVD, respectively. RF-PECVD technology reduces the cost of graphene film preparation by achieving low-temperature growth and offers advantages such as high film quality, large growth area, and high transparency. It also significantly increases the possibility of large-area preparation of high-quality graphene on high-temperature-sensitive substrates, facilitating the industrial production and practical scientific applications of graphene. Specifically, methane and hydrogen are introduced. Under the influence of a radio frequency electric field, the hydrogen ionizes into plasma, enhancing plasma activity and accelerating the reaction. The kinetic energy of electrons accelerated by the radio frequency electric field exceeds 10 eV, which can break most of the carbon-hydrogen bonds of methane molecules, causing carbon atoms to deposit on the substrate, thus preparing a graphene film.

[0004] In PECVD graphene film preparation systems, the plasma excitation coil is positioned at the front end of the heating zone, meaning the RF coil and heating zone are sequentially distributed and do not overlap. Since the strongest plasma is generated inside the coil, the plasma density in the heating zone decreases, resulting in low film preparation efficiency. The plasma generation region is separated from the high-temperature heating growth region; only by partially overflowing the coil region can graphene films be effectively prepared in the high-temperature heating zone. Furthermore, the presence of plasma at the front end of the heating zone causes some of the plasma generated in the colder region at the front of the high-temperature heating zone to polymerize at low temperatures, generating side reactions and contaminants. Because these side reactions and contaminants are all located at the front end of the high-temperature heating zone, the contaminants generated by the side reactions will deposit on the substrate, causing surface contamination and hindering graphene film preparation. Summary of the Invention

[0005] A primary objective of this application is to overcome at least one of the deficiencies of the prior art and to provide a planar plasma-enhanced chemical vapor deposition apparatus capable of improving the efficiency of graphene film preparation.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] According to one aspect of this application, a planar plasma-enhanced chemical vapor deposition apparatus for preparing graphene films is provided, comprising an unwinding chamber, a winding chamber, an inner sleeve, an outer sleeve, a first radio frequency (RF) plate, and a second RF plate. The unwinding chamber is provided with an unwinding wheel, and the winding chamber is provided with a winding wheel. The inner sleeve sealably connects the unwinding chamber and the winding chamber. The outer sleeve is disposed outside the inner sleeve. The first RF plate and the second RF plate are parallel to each other and disposed between the inner sleeve and the outer sleeve.

[0008] According to one embodiment of this application, both the inner sleeve and the outer sleeve are made of high-temperature resistant rigid material.

[0009] According to one embodiment of this application, both the first radio frequency board and the second radio frequency board are elongated strip-shaped and have the same size.

[0010] According to one embodiment of this application, the inner diameter of the outer sleeve is D, the outer diameter of the inner sleeve is d, the thickness of the first RF board is t1, and the thickness of the second RF board is t2, where D>d+t1+t2.

[0011] According to one embodiment of this application, the width of the first radio frequency board and the width of the second radio frequency board are both smaller than the inner diameter of the inner sleeve.

[0012] According to one embodiment of this application, the width of the first radio frequency board and the width of the second radio frequency board are both 3-4 cm, and the inner diameter of the inner sleeve is 6.5-8.5 cm.

[0013] According to one embodiment of this application, the inner wall of the outer sleeve is provided with protrusions for fixing the first radio frequency board and the second radio frequency board.

[0014] According to one embodiment of this application, the planar plasma-enhanced chemical vapor deposition apparatus further includes a heating furnace disposed between the unwinding chamber and the rewinding chamber, the heating furnace accommodating the outer sleeve, the first radio frequency board and the second radio frequency board, and the inner sleeve penetrating through the heating furnace.

[0015] According to one embodiment of this application, the lengths of the first radio frequency board and the second radio frequency board are both less than the length of the heating cavity of the heating furnace, and the distance between the ends of the first radio frequency board and the second radio frequency board and the inner wall of the corresponding ends of the heating cavity is 4-6 cm.

[0016] According to one embodiment of this application, the inner sleeve is provided with plugs at both ends, and a slit is provided in the middle of the plug, the slit being used for the substrate to pass through.

[0017] According to another aspect of this application, a method for preparing graphene thin films is provided, employing the aforementioned planar plasma-enhanced chemical vapor deposition apparatus, with the specific steps as follows:

[0018] Step 1: Place the substrate on the unwinding roller inside the unwinding chamber;

[0019] Step 2: Pass the substrate through the inner sleeve and connect it to the winding wheel in the winding chamber, with the substrate parallel to the first RF board or the second RF board;

[0020] Step 3: Introduce protective gas, turn on heating and introduce carbon source atmosphere. When the temperature inside the inner sleeve reaches the preparation temperature, turn on the radio frequency board.

[0021] Step 4: Prepare a graphene film. During the preparation process, the winding wheel winds up the substrate and the graphene film deposited on the substrate.

[0022] As can be seen from the above technical solutions, the advantages and positive effects of the planar plasma-enhanced chemical vapor deposition device and preparation method for graphene films proposed in this application are as follows:

[0023] This application proposes a planar plasma-enhanced chemical vapor deposition (PECVD) apparatus for graphene films, comprising an unwinding chamber, a winding chamber, an inner sleeve, an outer sleeve, a first radio frequency (RF) plate, and a second RF plate. The unwinding chamber contains an unwinding roller for mounting the substrate, providing the necessary attachment carrier for the continuous preparation of the graphene film. The winding chamber contains a winding roller for winding the substrate with the attached graphene film, completing the orderly collection of the prepared product and providing sufficient and suitable conditions for subsequent processes. The inner sleeve seals and connects the unwinding chamber and the winding chamber, ensuring the preparation environment for the graphene film, preventing contamination during the preparation process, and guaranteeing the quality of the graphene film. The outer sleeve is located outside the inner sleeve, and the first and second RF plates are arranged parallel between the inner and outer sleeves. This achieves coupling between the RF excitation region and the high-temperature heating region, ensuring that the plasma and high-temperature environment required for graphene film preparation are in the same area. The RF-generated plasma does not need to diffuse into the heating region as in traditional preparation equipment; instead, it is generated directly in the heating region, increasing the plasma concentration in the high-temperature heating region and improving plasma utilization efficiency. Simultaneously, due to the coupling between the radio frequency (RF) region and the heating region, plasma generation is prevented at the front end of the heating region. This avoids the possibility of plasma generated in the cold region at the front end of the high-temperature heating zone undergoing polymerization at low temperatures, resulting in side reactions and contaminants that could contaminate the deposited substrate. This application couples the RF excitation region of the plasma with the high-temperature heating region, improving plasma utilization efficiency and preventing contaminants from affecting the substrate, thus effectively improving the quality of the graphene film. Attached Figure Description

[0024] The above and other features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the flat-plate plasma-enhanced chemical vapor deposition apparatus of this application.

[0026] Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure at point AA.

[0027] Figure 3 This is a schematic diagram of the second configuration method of the radio frequency board in this application.

[0028] Figure 4 This is a schematic diagram of the third configuration method of the radio frequency board in this application.

[0029] The reference numerals in the attached figures are explained as follows:

[0030] 100-Planet-type plasma-enhanced chemical vapor deposition apparatus;

[0031] 101 - Unwinding bin;

[0032] 102 - Unwinding reel;

[0033] 103 - Rewinding Warehouse;

[0034] 104 - Take-up reel;

[0035] 105 - Inner sleeve;

[0036] 106 - Outer tube;

[0037] 107 - First RF board;

[0038] 108 - Second RF board;

[0039] 109-substrate;

[0040] 110 - Intake pipe;

[0041] 111 - Extraction pipe;

[0042] 112 - Heating furnace;

[0043] 113 - Pipe plug;

[0044] d - Outer diameter of the inner sleeve;

[0045] D - Inner diameter of the outer sleeve;

[0046] t1 - The thickness of the first RF board;

[0047] t2 - Thickness of the second RF board. Detailed Implementation

[0048] Typical embodiments embodying the features and advantages of this application will be described in detail in the following description. It should be understood that this application can have various variations in different embodiments, all of which do not depart from the scope of this application, and the descriptions and drawings therein are for illustrative purposes only and not intended to limit this application.

[0049] In the following description of various exemplary embodiments of this application, reference is made to the accompanying drawings, which form part of this application, and which illustrate by way of example different exemplary structures, systems, and steps that can implement various aspects of this application. It should be understood that other specific solutions to components, structures, exemplary devices, systems, and steps may be used, and structural and functional modifications may be made without departing from the scope of this application. Furthermore, while the terms “upper,” “middle,” “inner,” etc., may be used in this specification to describe different exemplary features and elements of this application, these terms are used herein only for convenience, such as the orientation according to the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of this application.

[0050] To make the above-mentioned objectives, features and advantages of this application readily apparent, specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0051] like Figure 1 As shown, the planar plasma-enhanced chemical vapor deposition apparatus 100 of this application includes an unwinding chamber 101, a winding chamber 103, an inner sleeve 105, an outer sleeve 106, a first radio frequency (RF) plate 107, and a second RF plate 108. The unwinding chamber 101 is equipped with an unwinding roller 102 for mounting a substrate 109; the winding chamber 103 is equipped with a winding roller 104 for winding the substrate 109 with the graphene film attached; the inner sleeve 105 seals and connects the unwinding chamber 101 and the winding chamber 103, ensuring the preparation environment for the graphene film; the outer sleeve 106 is disposed outside the inner sleeve 105 and does not require sealing; the first RF plate 107 and the second RF plate 108 are arranged parallel between the inner sleeve 105 and the outer sleeve 106. Using parallel RF plates ensures a more uniform plasma distribution and increases plasma intensity, thereby guaranteeing the preparation quality and efficiency of the graphene film. Using parallel RF plates also enables the fabrication of large-size graphene films. Using an inner sleeve and placing the parallel RF board on the outer periphery of the inner sleeve effectively solves the support problem of the RF parallel board and prevents short circuits caused by contact between the substrate and the parallel RF board. The outer sleeve serves to fix the parallel RF board and effectively protect it.

[0052] In this embodiment, the substrate 109 is a metal foil, generally copper foil, but in some other embodiments it can be a lighter metal such as aluminum foil, or nickel foil.

[0053] In this embodiment, the planar plasma-enhanced chemical vapor deposition apparatus 100 further includes a heating furnace 112, which is disposed between the unwinding chamber 101 and the winding chamber 103. The heating furnace 112 contains an outer sleeve 106, a first radio frequency (RF) plate 107, and a second RF plate 108. The outer sleeve 106 secures the first RF plate 107 and the second RF plate 108. An inner sleeve 105 penetrates the heating furnace 112 and connects to the unwinding chamber 101 and the winding chamber 103. A substrate 109 is disposed within the inner sleeve 105, extending from the unwinding chamber 101 along the axial direction of the inner sleeve 105 to the winding chamber 103. The heating furnace housing the first and second RF plates allows the plasma generation region and the high-temperature heating region to overlap and couple into a single region, increasing the plasma concentration in the high-temperature heating region and improving plasma utilization efficiency. This avoids the plasma generated in the cold front zone of the high-temperature heating region from partially polymerizing at low temperatures, producing side reactions and contaminants that could contaminate the deposited substrate, thus further facilitating the preparation of graphene films.

[0054] In this embodiment, both the inner sleeve 105 and the outer sleeve 106 are made of high-temperature resistant rigid materials, such as quartz, graphite, ceramic, or high-temperature resistant alloys. Since the inner sleeve 105 and the outer sleeve 106 need to be heated during the graphene film preparation process, using high-temperature resistant rigid materials can prevent the inner sleeve and the outer sleeve from deforming during high-temperature heating, thereby preventing them from effectively supporting the radio frequency parallel plate.

[0055] In this embodiment, both the first RF board 107 and the second RF board 108 are elongated strips, which can be rectangular or elongated strips with curved short sides. This allows the first and second RF boards to generate a higher plasma density, which is beneficial for improving plasma utilization efficiency. Furthermore, the first and second RF boards are the same size, which facilitates processing and reduces costs; the material can be copper plate or silver-plated copper plate, and the materials of the first and second RF boards can be the same or different.

[0056] In this embodiment, the lengths of the first radio frequency board 107 and the second radio frequency board 108 are both less than the length of the heating cavity of the heating furnace 112, and the distance between the ends of the first radio frequency board 107 and the second radio frequency board 108 and the inner wall of the corresponding ends of the heating cavity is 4-6 cm, preferably 5 cm, so as to reduce the plasma excited by the first radio frequency board and the second radio frequency board from overflowing to both ends of the heating zone and causing contamination.

[0057] In this embodiment, the planar plasma-enhanced chemical vapor deposition apparatus 100 further includes an inlet pipe 110 and an exhaust pipe 111. The inlet pipe 110 is connected to the unwinding chamber 101 and to an external air source. The exhaust pipe 111 is connected to the winding chamber 103 and to an external exhaust device, which may be a vacuum pump, an air extractor, etc.

[0058] In this embodiment, cooling water flanges (not shown in the figure) are provided at both ends of the heating furnace 112. Cylindrical pipe plugs 113 are provided at the connection between the inner sleeve 105 and the unwinding chamber 101 and the connection between the inner sleeve 105 and the winding chamber 103. A slit for the substrate 109 to pass through is opened in the middle of the pipe plug 113. The diameter of the pipe plug 113 is slightly smaller than the diameter of the inner sleeve 105, so as to achieve sandwich protection of the substrate by the upper and lower cover plates, ensure that the plasma is concentrated in the heating area, and further reduce the contamination of the substrate by the low-temperature polymer.

[0059] In this embodiment, the end of the outer sleeve 106 needs to be properly insulated and sealed to reduce heat loss. This can be achieved by filling with quartz wool or sealing with quartz welding to reduce heat dissipation and ensure the stability of the heating environment temperature.

[0060] In this embodiment, a winding correction device (not shown in the figure) can also be provided inside the winding chamber 103 to ensure flat winding. A horizontal support frame (not shown in the figure) can also be provided below the substrate 109 in the heating area to support the substrate 109 and ensure that it is centered in the inner sleeve 105.

[0061] In this embodiment, grounded copper foil (not shown in the figure) is provided to cover both the unwinding end of the unwinding chamber and the winding end of the winding chamber to reduce plasma overflow. When the unwinding and winding ends are insulated, it is found that some plasma overflows along the substrate 109, resulting in some low-temperature polymer contamination on the product surface. However, when both ends are adequately grounded, the plasma overflow in the unwinding and winding chamber is greatly reduced.

[0062] like Figure 2 As shown, the inner diameter of the outer sleeve 106 of the planar plasma-enhanced chemical vapor deposition apparatus 100 of this application is D, the outer diameter of the inner sleeve 105 is d, the thickness of the first RF plate 107 is t1, and the thickness of the second RF plate 108 is t2, wherein D > d + t1 + t2 is required. This allows the first RF plate 107 and the second RF plate 108 to be positioned between the inner sleeve 105 and the outer sleeve 106, and the diameters of the inner sleeve 105 and the outer sleeve 106 should not differ too much; they only need to be positioned in parallel. This is because if the diameters of the inner sleeve 105 and the outer sleeve 106 differ too much, it will result in greater heat loss, which is detrimental to energy conservation and leads to waste.

[0063] In this embodiment, the widths of the first RF plate 107 and the second RF plate 108 are both smaller than the inner diameter of the inner sleeve 105. Since the first RF plate 107 and the second RF plate 108 are elongated, this width refers to the distance between the two long sides of the elongated shape. The width of the substrate 109 is smaller than the inner diameter of the inner sleeve 105; therefore, the inner diameter of the inner sleeve cannot be too small. Furthermore, since the diameters of the inner sleeve 105 and the outer sleeve 106 cannot differ too much, it is necessary that the widths of the first RF plate 107 and the second RF plate 108 are both smaller than the inner diameter of the inner sleeve 105. This avoids affecting the width of the graphene film while ensuring coupling between the RF region and the heating region.

[0064] In this embodiment, the width of the first RF plate 107 and the width of the second RF plate 108 are both 3-4 cm, the inner diameter of the inner sleeve 105 is 6.5-8.5 cm, preferably 7.5 cm, and the inner diameter of the outer sleeve is selected to be about 10 cm. The selection of the above data affects each other and, when used in combination, can achieve coupling between the RF region and the heating region, and can also make the produced graphene film have a wider width.

[0065] In this embodiment, the first RF plate 107 and the second RF plate 108 are arranged vertically parallel to each other outside the inner sleeve 105, and both are parallel to the substrate 109. A protrusion (not shown in the figure) is also provided on the inner wall of the outer sleeve 106 to fix the positions of the first RF plate 107 and the second RF plate 108. This is used to reduce deformation of the RF plates due to high temperature during heating, and to control the parallelism between the first and second RF plates, maintaining a stable plasma intensity during the fabrication process.

[0066] Figure 3 This paper illustrates a second arrangement of the first radio frequency (RF) plate 107 and the second RF plate 108 of the planar plasma-enhanced chemical vapor deposition (PECVD) apparatus 100 of this application. The first RF plate 107 and the second RF plate 108 are arranged horizontally parallel to each other outside the inner sleeve 105 and are both parallel to the substrate 109. A protrusion (not shown) is also provided on the inner wall of the outer sleeve 106 to fix the positions of the first RF plate 107 and the second RF plate 108. Other requirements, such as the inner diameter of the outer sleeve 106, the outer diameter of the inner sleeve 105, the thickness of the first RF plate 107, and the thickness of the second RF plate 108, are all consistent with... Figure 2 The implementation shown is the same. Furthermore, the width of the first RF board 107 and the width of the second RF board 108 are both smaller than the inner diameter of the inner sleeve 105. Alternatively, the width of the first RF board 107 and the width of the second RF board 108 can both be 3-4 cm, the inner diameter of the inner sleeve 105 can be 6.5-8.5 cm, preferably 7.5 cm, and the inner diameter of the outer sleeve can be around 10 cm.

[0067] Figure 4 This paper illustrates a third arrangement of the first radio frequency (RF) plate 107 and the second RF plate 108 of the planar plasma-enhanced chemical vapor deposition (PECVD) apparatus 100 of this application. In this arrangement, the first RF plate 107 and the second RF plate 108 are parallel to each other and obliquely disposed outside the inner sleeve 105, and both are parallel to the substrate 109. A protrusion (not shown) for fixing the positions of the first RF plate 107 and the second RF plate 108 is also provided on the inner wall of the outer sleeve 106. Other requirements, such as the inner diameter of the outer sleeve 106, the outer diameter of the inner sleeve 105, the thickness of the first RF plate 107, and the thickness of the second RF plate 108, are all consistent with... Figure 2 The implementation shown is the same. Furthermore, the width of the first RF board 107 and the width of the second RF board 108 are both smaller than the inner diameter of the inner sleeve 105. Alternatively, the width of the first RF board 107 and the width of the second RF board 108 can both be 3-4 cm, the inner diameter of the inner sleeve 105 can be 6.5-8.5 cm, preferably 7.5 cm, and the inner diameter of the outer sleeve can be around 10 cm.

[0068] It should be noted that the planar plasma-enhanced chemical vapor deposition apparatus shown in the accompanying drawings and described in this specification are merely a few examples among many planar plasma-enhanced chemical vapor deposition apparatuses capable of employing the principles of this application. It should be clearly understood that the principles of this application are by no means limited to any details of the planar plasma-enhanced chemical vapor deposition apparatus shown in the accompanying drawings or described in this specification, or to any component of the planar plasma-enhanced chemical vapor deposition apparatus.

[0069] The above is a detailed description of several exemplary embodiments of the planar plasma-enhanced chemical vapor deposition apparatus proposed in this application. The following will provide an exemplary description of the method for preparing graphene films proposed in this application.

[0070] Combined with appendix Figures 1 to 4 The method for preparing graphene films proposed in this application uses the aforementioned planar plasma-enhanced chemical vapor deposition apparatus, and the specific steps are as follows:

[0071] Step 1: Place the substrate 109 on the unwinding roller 102 inside the unwinding chamber 101;

[0072] Step 2: Pass the substrate 109 through the inner sleeve 105 and connect it to the winding wheel 104 in the winding chamber 103. The substrate 109 is parallel to the first RF board 107 or the second RF board 108.

[0073] Step 3: Introduce protective gas, turn on heating and introduce carbon source atmosphere. When the temperature inside the inner sleeve 105 reaches the preparation temperature, turn on the first radio frequency board 107 and the second radio frequency board 108.

[0074] Step 4: Prepare graphene film. During the preparation process, the winding wheel 106 winds up the substrate 109 and the graphene film deposited on the substrate 109.

[0075] In this embodiment, the preparation of graphene film in step 4 can be carried out according to conventional steps in the prior art, or it can be carried out by other steps, as long as it is to prepare graphene film.

[0076] In this embodiment, the first RF board 107 is connected to the transmitter of the RF power supply, and the second RF board 108 is connected to the ground of the RF power supply. After heating, the temperature inside the inner sleeve is typically 600 degrees Celsius. The protective gas can be hydrogen or argon, and the carbon source atmosphere can be methane, ethane, etc. The substrate 109 can be selected from 8 to 10 transition metals (such as Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Au) and alloys (such as Co-Ni, Au-Ni, Ni-Mo, stainless steel). The main criteria for selection include the melting point of the metal, the amount of carbon dissolved, and whether there are stable metal carbides. These factors determine the growth temperature, growth mechanism, and type of carrier gas used for graphene. In addition, the crystal type and crystal orientation of the metal also affect the growth quality of graphene.

[0077] The preparation reaction process is described in detail below, using copper foil as a substrate and methane as a carbon source atmosphere:

[0078] CH4 molecules adsorb onto the surface of a copper foil substrate. At high temperatures, the CH bonds break, producing various carbon fragments (CHx). After the methane molecules are dehydrogenated, the carbon species on the copper foil surface aggregate to form new C-C bonds and clusters, which begin to nucleate and form graphene islands. As the number of graphene nuclei on the copper foil surface increases, the carbon atoms or clusters that are subsequently generated continuously attach to the nucleation sites, causing the graphene nuclei to gradually grow until they suture together. Suturing refers to the connection that occurs between the graphene nuclei as they grow, forming larger graphene sheets, which eventually connect to form a continuous graphene film.

[0079] Through the above-described process of using the planar plasma-enhanced chemical vapor deposition device and the method for preparing graphene films, it can be concluded that the planar plasma-enhanced chemical vapor deposition device of this application is equipped with inner and outer sleeves, and a planar radio frequency plate is sandwiched in the inner and outer sleeves. During the preparation process, the radio frequency plate is set inside the heating area, realizing the overlapping coupling of the heating area and the plasma excitation area. It can be made to be of equal length, so that the heating area and the plasma can be fully utilized, which can save energy, improve efficiency, and reduce costs.

[0080] Furthermore, the planar plasma-enhanced chemical vapor deposition apparatus of this application can simultaneously avoid low-temperature polymerization contaminants generated by plasma at the front end of the heating zone, allowing the plasma generated by excitation to fully exert its effect in the high-temperature heating zone, thereby improving the production quality of graphene films. The planar plasma-enhanced chemical vapor deposition apparatus of this application has a simple structural design, low processing precision requirements, a wide range of material choices, flexible and convenient operation, and low cost, making it conducive to widespread adoption.

[0081] In summary, the planar plasma-enhanced chemical vapor deposition apparatus proposed in this application includes an unwinding chamber, a winding chamber, an inner sleeve, an outer sleeve, a first radio frequency (RF) plate, and a second RF plate. The unwinding chamber contains an unwinding wheel for mounting the substrate; the winding chamber contains a winding wheel for winding the substrate with the graphene film attached. The inner sleeve seals and connects the unwinding and winding chambers, ensuring the optimal environment for graphene film fabrication. The outer sleeve is positioned outside the inner sleeve, and the first and second RF plates are arranged parallel between the inner and outer sleeves. This achieves coupling between the RF excitation region and the high-temperature heating region, allowing the plasma and high-temperature environment required for graphene film fabrication to overlap. The RF-generated plasma is directly generated in the heating region, increasing the plasma concentration and utilization efficiency in the high-temperature heating region. Furthermore, due to the coupling between the RF and heating regions, plasma is not generated at the front end of the heating region, thus preventing some of the plasma generated in the cold region at the front end of the high-temperature heating region from polymerizing at low temperatures, producing side reactions and contaminants that could contaminate the deposited substrate.

[0082] The graphene film preparation method proposed in this application employs the aforementioned planar plasma-enhanced chemical vapor deposition (PECVD) apparatus. The substrate is placed on an unwinding roller within the unwinding chamber and connected to a winding roller within the winding chamber via an inner sleeve, ultimately ensuring the substrate is parallel to either the first or second radio frequency (RF) plate. A protective gas is then introduced, heating is activated, and a carbon source atmosphere is introduced. Once the temperature within the inner sleeve reaches the preparation temperature, the first and second RF plates are activated. The graphene film is then prepared, with the winding roller winding up the substrate and the graphene film deposited on it. This method, due to the coupling between the plasma excited by the RF plate and the high-temperature heating required for preparation, allows for efficient utilization of both plasma and heat. This approach improves the quality of the graphene film, saves energy, reduces costs, and increases production efficiency.

[0083] The foregoing describes and / or illustrates exemplary embodiments of the planar plasma-enhanced chemical vapor deposition apparatus and the method for preparing graphene films according to this application. However, the embodiments of this application are not limited to the specific embodiments described herein; rather, components and / or steps of each embodiment may be used independently and separately from other components and / or steps described herein. Each component and / or step of one embodiment may also be used in combination with other components and / or steps of other embodiments. In describing the elements / components / etc. described and / or illustrated herein, the terms “a,” “first,” “second,” and “the above” are used to indicate the presence of one or more elements / components / etc. The terms “comprising,” “including,” and “having” are used to indicate an open-ended inclusion and mean that additional elements / components / etc. may exist in addition to those listed.

[0084] The embodiments of this application are not limited to the specific embodiments described herein. Rather, components of each embodiment can be used independently and separately from other components described herein. Each component of one embodiment can also be used in combination with other components of other embodiments. In the description of this specification, the terms "one embodiment," "some embodiments," "other embodiments," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the embodiments. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0085] The above are merely preferred embodiments of the application examples and are not intended to limit the application examples. For those skilled in the art, the application examples can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the application examples should be included within the protection scope of the application examples.

Claims

1. A flat plate type plasma enhanced chemical vapor deposition apparatus for preparing a graphene thin film, characterized by comprising: include: An unwinding bin, wherein an unwinding reel is provided inside the unwinding bin; A winding bin, wherein a winding reel is provided inside the winding bin; Inner sleeve, the inner sleeve sealingly connecting the unwinding chamber and the winding chamber; An outer sleeve is disposed outside the inner sleeve; A first radio frequency board and a second radio frequency board are disposed between the inner sleeve and the outer sleeve, and the first radio frequency board and the second radio frequency board are parallel to each other. A heating furnace is disposed between the unwinding bin and the rewinding bin. The heating furnace accommodates the outer sleeve, the first radio frequency board, and the second radio frequency board. The inner sleeve passes through the heating furnace. The lengths of the first radio frequency board and the second radio frequency board are both less than the length of the heating cavity of the heating furnace.

2. The planar plasma enhanced chemical vapor deposition apparatus of claim 1, wherein: Both the inner sleeve and the outer sleeve are made of high-temperature resistant rigid materials.

3. The planar plasma enhanced chemical vapor deposition apparatus of claim 1, wherein: Both the first RF board and the second RF board are elongated and have the same size.

4. The planar plasma enhanced chemical vapor deposition apparatus of claim 1, wherein: The inner diameter of the outer sleeve is D, the outer diameter of the inner sleeve is d, the thickness of the first RF board is t1, and the thickness of the second RF board is t2, where D > d + t1 + t2.

5. The planar plasma enhanced chemical vapor deposition apparatus of claim 1, wherein: The width of the first RF board and the width of the second RF board are both smaller than the inner diameter of the inner sleeve.

6. The planar plasma enhanced chemical vapor deposition apparatus of claim 5, wherein: The width of the first RF board and the width of the second RF board are both 3-4 cm, and the inner diameter of the inner sleeve is 6.5-8.5 cm.

7. The planar plasma enhanced chemical vapor deposition apparatus of claim 1, wherein: The inner wall of the outer sleeve is provided with protrusions for fixing the first radio frequency board and the second radio frequency board.

8. The planar plasma-enhanced chemical vapor deposition apparatus as described in claim 1, characterized in that: The distance between the ends of the first and second radio frequency boards and the inner wall of the corresponding ends of the heating cavity is 4-6 cm.

9. The planar plasma enhanced chemical vapor deposition apparatus of claim 1, wherein: The inner sleeve is provided with plugs at both ends, and a slit is provided in the middle of the plug for the substrate to pass through.

10. A method of producing a graphene film, characterized by: The specific steps of using the planar plasma-enhanced chemical vapor deposition apparatus as described in any one of claims 1-9 are as follows: Step 1: Place the substrate on the unwinding roller inside the unwinding chamber; Step 2: Pass the substrate through the inner sleeve and connect it to the winding wheel in the winding chamber. The substrate is parallel to the first RF board or the second RF board. Step 3: Introduce protective gas, turn on heating and introduce carbon source atmosphere. When the temperature inside the inner sleeve reaches the preparation temperature, turn on the radio frequency board. Step 4: Prepare a graphene film. During the preparation process, the winding wheel winds up the substrate and the graphene film deposited on the substrate.

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