A gas position control and transfer device and method for CVD equipment

Abstract

This invention discloses a gas positioning and transmission device and method for CVD equipment. The device includes a gas source, pipelines, a mass flow meter, a CVD deposition reaction chamber, and a gas positioning and transmission pipeline. Each gas source is connected to two pipelines, both of which are connected to the pipelines via mass flow meters. The CVD deposition reaction chamber has an inlet and an outlet. The gas positioning and transmission pipeline is located within the CVD deposition reaction chamber and has vent holes. The gas source is collected through one pipeline and connected to the inlet, and collected through the other pipeline and connected to the gas positioning and transmission pipeline. Valves are provided at the inlet, outlet, and gas positioning and transmission pipeline. Using this gas positioning and transmission device for CVD equipment, compared to the mixed gas directly entering the reaction chamber from the inlet, the vent holes in the gas positioning and transmission pipeline can supply gas to a designated location, thereby achieving a specific concentration of a specific gas at a specific location, improving the deposition quality, atmosphere distribution controllability, and richness of the deposited film.

Description

Technical Field

[0001] This invention relates to the field of two-dimensional material thin film technology, and specifically to a gas position control and transmission device and method for CVD equipment. Background Technology

[0002] CVD (Chemical Vapor Deposition) equipment is used to introduce vapors of gaseous or liquid reactants containing the elements constituting the thin film, along with other gases required for the reaction, into a reaction chamber to generate a thin film through a chemical reaction on the substrate surface. In existing technologies, gas supply in CVD equipment typically employs a direct short-pipe method, where a gas source is connected to the CVD equipment via a gas pipeline and directly introduced into the chamber. Quantitative and positional gas input methods are rarely used. When direct gas supply is employed, problems often arise within the CVD equipment, such as uneven gas mixing and the inherent fluidity of the gas at atmospheric pressure. This is particularly problematic in equipment requiring large-scale growth, easily leading to significant differences between different locations within the same batch, or even between different locations on the same cross-section.

[0003] Existing patent CN106756872B discloses a device for high-throughput CVD preparation of silicon-carbon-oxygen thin films. This device, based on high-throughput CVD deposition technology, designs a CVD deposition reaction chamber structure and utilizes different precursor gases (SiH4, C2H4, O2) with N2 as the carrier gas. By controlling their flow distribution within the reaction chamber, a gradient change in the concentration ratio of the precursor gases is created, thereby forming a SiCxOy thin film composite material with varying material composition on a substrate. However, this patent suffers from a limitation: the concentration of the precursor gases inside the CVD equipment can only be simply varied from high to low from the inlet to the outlet, failing to achieve a specific concentration of a specific gas supplied to a specific location. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a gas position control and transmission device and method for CVD equipment, which can achieve the supply of a specific gas at a specific concentration and location.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a gas position control and transmission device and method for CVD equipment, comprising a gas source, pipeline, mass flow meter, CVD deposition reaction chamber and gas position control and transmission pipeline;

[0006] Each of the gas sources is connected to two pipelines and is connected to the pipelines via a mass flow meter. The CVD deposition reaction chamber is provided with an air inlet and an air outlet. The gas positioning and transport pipeline is located inside the CVD deposition reaction chamber and is provided with air vents.

[0007] Multiple gas sources are connected to the air inlet via one pipeline and to the gas control and transport pipeline via another pipeline. The air inlet, air outlet, and gas control and transport pipeline are all equipped with valves.

[0008] The gas flow rate of each gas source is controlled by a mass flow meter, so that the gas enters the CVD deposition reaction chamber through the control valve and the inlet. Then, the gas flow rate of each gas source is controlled by another mass flow meter, so that the gas enters the CVD deposition reaction chamber through the control valve and the gas position control and transport pipeline, and is input at the designated position through the gas hole. Finally, the gas tail gas after deposition is discharged through the exhaust port.

[0009] The beneficial effects of the gas position control and transmission device for CVD equipment are as follows: compared with the mixed gas entering the reaction chamber directly from the inlet, the gas position control and transmission pipeline can input gas at a specified position through the gas vent, thereby achieving a specific concentration of a specific gas at a specific position, improving the deposition quality of the deposited film, the controllability and richness of the atmosphere distribution.

[0010] Furthermore, the CVD deposition reaction chamber is provided with two air inlets, which are respectively located on opposite sides of the CVD deposition reaction chamber.

[0011] Two air inlets can achieve a gradual decrease in concentration in two directions, resulting in films with different gradient changes for moving substrates.

[0012] Furthermore, the gas positioning and transport pipeline has one or more air holes.

[0013] Single-hole or multi-hole structures can be designed as needed to supply gas at specific locations.

[0014] Furthermore, the gas positioning and transport pipeline with multiple vents can be a straight pipe or a non-straight pipe structure. In the straight pipe structure, the vents of the gas positioning and transport pipeline are spaced at the same distance from the substrate, while in the non-straight pipe structure, the vents of the gas positioning and transport pipeline are spaced at different distances from the substrate.

[0015] By varying the spacing between different pores and the substrate, it is possible to more precisely supply gas at specific locations with specific concentrations.

[0016] Furthermore, the gas positioning and transport pipeline is made of catalytic or non-catalytic materials;

[0017] When the gas positioning and transport pipeline is made of a non-catalytic material, the substrate in the CVD deposition reaction chamber is a catalytic substrate;

[0018] When the gas positioning and transport pipeline uses a catalytic material, the substrate in the CVD deposition reaction chamber is either a catalytic substrate or a non-catalytic substrate.

[0019] By using pipelines with catalytic growth gas properties, the gas can undergo a chemical reaction inside the pipeline before entering the reaction chamber and then be deposited directly. This can greatly improve the diversity of substrate selection and is no longer limited to substrates with catalytic activity.

[0020] Furthermore, the catalytic substrate includes copper foil and nickel foil, and the non-catalytic substrate includes glass and SiO2 / Si.

[0021] Furthermore, the gas source includes CH4, H2, O2 and Ar, wherein CH4, H2 and O2 are reaction gases, Ar is a carrier gas, the substrate in the CVD deposition reaction chamber is copper foil, and the gas positioning and transport pipeline is one of nickel pipe, copper pipe or stainless steel pipe.

[0022] A method of using a gas position control transmission device for a CVD equipment, wherein when preparing a thin film, valves for the inlet and outlet are used, and the valves of the gas position control transport pipeline are closed.

[0023] When growing multilayer graphene films under normal pressure, using valves for the air inlet and outlet can produce a large amount of activated carbon in the early stages of graphene film growth, which is beneficial to the growth of multilayer graphene films.

[0024] Furthermore, during the preparation of the thin film, valves are used at the exhaust port and the gas control and transport pipeline, while the valve at the inlet is closed.

[0025] When growing standard monolayer graphene films, a quantitative supply of activated carbon gas can be achieved using only a gas-controlled transport pipeline.

[0026] Furthermore, valves are used in the air inlet, air outlet, and gas positioning and transport pipeline during the thin film preparation process.

[0027] By using an air inlet and a gas positioning and transport pipeline, both uniform atmosphere within the chamber and rapid growth can be achieved. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0029] Figure 1 This is a schematic diagram of a gas position control and transmission device for a CVD equipment according to an embodiment of the present invention;

[0030] Figure 2 for Figure 1The diagram shows a gas control transport pipeline for a gas control transport device used in a CVD equipment. Figure 1 ;

[0031] Figure 3 for Figure 1 The diagram shows a gas control transport pipeline for a gas control transport device used in a CVD equipment. Figure 2 ;

[0032] Figure 4 Optical photographs and Raman spectra of monolayer graphene obtained using a gas position control and transmission device for CVD equipment provided by the present invention;

[0033] Figure 5 Optical photographs and Raman spectra of multilayer graphene obtained using a gas position control transmission device for CVD equipment provided by the present invention. Detailed Implementation

[0034] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0035] Please see Figure 1 The present invention provides a gas position control and transmission device for CVD equipment, including a gas source, pipeline, mass flow meter, CVD deposition reaction chamber and gas position control and transmission pipeline.

[0036] Multiple gas sources are connected to two pipelines, and each is connected to the pipeline via a mass flow meter. The CVD deposition reaction chamber is equipped with an inlet and an outlet. The gas control and transport pipeline is located inside the CVD deposition reaction chamber and has vent holes. Multiple gas sources are combined through one pipeline and connected to the inlet, and combined through the other pipeline and connected to the gas control and transport pipeline. Valves are provided at the inlet, outlet, and gas control and transport pipeline.

[0037] The gas flow rate of each gas source is controlled by a mass flow meter, allowing gas to enter the CVD deposition chamber through the inlet via a valve. Another mass flow meter controls the gas flow rate of each gas source, allowing gas to enter the CVD deposition chamber through a gas-controlled delivery pipeline via a valve. Gas is then introduced at designated locations via vents. Finally, the gas exhaust gas after deposition is discharged through the exhaust port. The vents in the gas-controlled delivery pipeline allow for the introduction of gas at specific locations, achieving a specific concentration of a specific gas at a specific location, thus improving the deposition quality, atmosphere distribution controllability, and richness of the deposited film.

[0038] Furthermore, the CVD deposition chamber has two air inlets, located on opposite sides of the chamber. These two inlets allow for a gradual decrease in CH4 concentration in two directions: one from left to right and the other from right to left. This effect is minimal for static substrates but is particularly important for moving substrates, such as roll-to-roll growth of graphene films. Since the winding direction is fixed, these two directions determine whether a high or low concentration of CH4 will be encountered first.

[0039] Furthermore, such as Figure 2 and Figure 3 As shown, the gas-controlled positioning transport pipeline has one or more vents. Gas-controlled positioning transport pipelines with multiple vents can be straight or non-straight pipe structures. In straight pipe structures, the vents are spaced equidistant from the substrate, while in non-straight pipe structures, the vents are spaced differently from the substrate. Single-hole or multi-hole structures can be designed as needed to achieve gas supply at specific locations. Furthermore, the different vent spacings between non-straight pipes and the substrate allow for more precise supply of specific gas concentrations at specific locations.

[0040] Furthermore, the gas-controlled transport pipeline is made of either catalytic or non-catalytic materials. When using pipelines without catalytic growth gas properties, the gas transported into the reaction chamber remains the original growth gas, and the substrate in the CVD deposition reaction chamber must be a catalytic substrate, such as copper foil or nickel foil. However, using pipelines with catalytic growth gas properties allows the gas to undergo a chemical reaction beforehand inside the pipeline, and then directly deposit upon entering the reaction chamber. This greatly increases the diversity of substrate selection, no longer limiting it to catalytically active substrates, but also allowing the use of non-catalytic substrates, such as glass and SiO2 / Si.

[0041] Taking CH4, used in graphene preparation, as an example, when using a quartz tube (which lacks catalytic growth gas properties), CH4 still enters the reaction chamber. However, when using pipes with catalytic growth gas properties, such as nickel, copper, or stainless steel pipes, CH4 is pre-decomposed into activated carbon within the catalytic pipe (CH4 → C + 4H). The material entering the reaction chamber is no longer CH4 gas, but rather the decomposed activated carbon, which can be directly deposited without further decomposition. Therefore, when using such pipes with catalytic growth gas properties, the substrates for graphene growth are no longer limited to catalytically active substrates such as copper foil; non-catalytically active glass and SiO2 / Si substrates can also be directly deposited, greatly expanding the diversity of substrates.

[0042] The above-mentioned gas position control and transfer device for CVD equipment will be used, specifically, as an example of graphene film preparation: For example... Figure 1As shown, the gas source includes CH4, H2, O2, and Ar, where CH4, H2, and O2 are the reactant gases, and Ar is the carrier gas. There are eight mass flow meters in total, namely MFC1-MFC8. MFC1 and MFC2 control the CH4 flow rate, MFC3 and MFC4 control the H2 flow rate, MFC5 and MFC6 control the O2 flow rate, and MFC7 and MFC8 control the Ar flow rate. MFC1, MFC3, MFC5, and MFC7 are combined and connected to the gas inlet of the CVD deposition reaction chamber, with valve 1 controlling the left inlet and valve 2 controlling the right inlet. MFC2, MFC4, MFC6, and MFC8 are combined and connected to the gas positioning and transport pipeline, with valve 4 controlling its opening and closing. Valve 3 controls the opening and closing of the exhaust port.

[0043] The substrate in the CVD deposition chamber is copper foil, and the gas positioning and transport pipeline is made of nickel, copper, or stainless steel, specifically nickel. Since the growth temperature of graphene is around 1000℃, and nickel, copper, and stainless steel tubes soften and deform at this temperature, a quartz tube is used as an external support to ensure that the catalyst tube can function normally after deformation and softening, without affecting gas transport.

[0044] The flow rates of each gas are controlled by MFC1, MFC3, MFC5, and MFC7. Opening valve 1 allows gas to be input from the left end of the CVD deposition chamber, resulting in a gradual decrease in gas concentration on the substrate from left to right. Alternatively, opening valve 2 allows gas to be input from the right end of the CVD deposition chamber, resulting in a gradual decrease in gas concentration on the substrate from right to left. Simultaneously, opening valve 4, in conjunction with MFC2, MFC4, MFC6, and MFC8, allows gas to be input to a designated location through the vents of the gas positioning transport pipeline, achieving a specific concentration of a specific gas at a specific location. Gases such as CH4 can react prematurely during transport in the gas positioning transport pipeline, allowing them to be directly deposited on the substrate after entering the CVD deposition chamber.

[0045] Specifically, the methods of using the gas position control and transmission device for CVD equipment mentioned above when preparing graphene films include the following:

[0046] (1) When growing multilayer graphene films under normal pressure, only valves 1 and 3 at the air inlet and exhaust outlet are used. A large amount of activated carbon can be obtained in the early stage of graphene film growth, which is beneficial to the growth of multilayer graphene films.

[0047] (2) When rapidly growing a thin film, valves 1, 2 and 3 of the air inlet and exhaust port can be used to ensure that there is a large amount of activated carbon in the chamber during the early and late stages of graphene growth. When the copper foil is pulled rapidly, it can still meet the requirement of full coverage of the graphene film, thereby achieving rapid growth of graphene film.

[0048] (3) When growing standard monolayer graphene, the gas can be quantitatively supplied by using only the gas position control transport pipeline and the valves 4 and 3 of the exhaust port.

[0049] (4) When rapidly growing standard monolayer graphene films, valves 1, 2, 3 and 4 can be used to ensure the uniformity of the atmosphere in the chamber and to achieve rapid growth of graphene films.

[0050] like Figure 4 As shown, the left image is an optical photograph of the transfer of graphene film from copper foil to a SiO2 / Si substrate using nickel tube catalysis via controlled-position transfer of the required CVD atmosphere. The right image is a Raman spectrum obtained by measuring the cross region, with a monolayer ratio >95%, used to characterize the defect rate. D / I G <3%, significantly improving the deposition quality and uniformity of the deposited film.

[0051] Controlled-position transport of the atmosphere required for CVD and the use of catalytically charged pipeline transport gases can significantly improve the utilization rate of growth gases. Typically, the C / H ratio during graphene growth is approximately 1:1000. Figure 4 The C / H ratio of monolayer graphene films catalyzed by nickel-plated tubes can reach 1:50,000. Furthermore, it increases the diversity of deposition substrates; the substrate no longer necessarily needs to possess catalytic properties, and non-catalytic substrates such as glass and SiO2 / Si can also be selected. When using catalytically-integrated tubes, the catalytic limitations of the substrate are no longer a concern. For example, when growing graphene films on copper foil, the self-limiting growth characteristics of copper foil make it difficult to achieve the growth of multilayer graphene films. However, using catalytically-integrated tubes allows for easy multilayer graphene growth. Optical and Raman spectra of multilayer graphene films are shown below. Figure 5 As shown.

[0052] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A gas position control and transmission device for CVD equipment, characterized in that: This includes the gas source, pipelines, mass flow meter, CVD deposition reaction chamber, and gas positioning and transport pipeline; Each of the gas sources is connected to two pipelines and is connected to the pipelines via a mass flow meter. The CVD deposition reaction chamber is provided with an air inlet and an air outlet. The gas positioning and transport pipeline is located inside the CVD deposition reaction chamber and is provided with air vents. Multiple gas sources are connected to the air inlet through one pipeline and to the gas control and transportation pipeline through another pipeline. The air inlet, air outlet and gas control and transportation pipeline are all equipped with valves. The gas positioning and transport pipeline is made of catalytic material, and the substrate in the CVD deposition reaction chamber is either a catalytic substrate or a non-catalytic substrate. The catalytic substrate includes copper foil and nickel foil, and the non-catalytic substrate includes glass and SiO2 / Si; The gas positioning and transport pipeline is provided with one or more air holes; The gas positioning and transport pipeline with multiple vents can be a straight pipe or a non-straight pipe structure. In the straight pipe structure, the vents of the gas positioning and transport pipeline are spaced at the same distance from the substrate, while in the non-straight pipe structure, the vents of the gas positioning and transport pipeline are spaced at different distances from the substrate.

2. The gas position control and transmission device for CVD equipment according to claim 1, characterized in that: The CVD deposition reaction chamber is provided with two air inlets, which are respectively located on opposite sides of the CVD deposition reaction chamber.

3. A gas position control and transmission device for CVD equipment according to any one of claims 1-2, characterized in that: The gas source includes CH4, H2, O2 and Ar, wherein CH4, H2 and O2 are reaction gases, Ar is a carrier gas, the substrate in the CVD deposition reaction chamber is copper foil, and the gas positioning and transport pipeline is one of nickel pipe, copper pipe or stainless steel pipe.

4. A method of using a gas position control and transfer device for a CVD equipment, employing the gas position control and transfer device for a CVD equipment as described in claim 3, characterized in that: When preparing the thin film, use valves for the inlet and outlet of the gas and close the valves of the gas control and transport pipeline; Alternatively, use the valves at the exhaust port and the gas control and transport pipeline to close the valve at the inlet. Alternatively, valves can be used for air inlets, exhaust outlets, and gas positioning and transport pipelines.

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