A growth apparatus and preparation method for realizing heterostructures of various two-dimensional materials

Abstract

This invention proposes a growth apparatus for realizing heterojunctions of multiple two-dimensional materials, specifically relating to the field of chemical vapor deposition technology. The apparatus includes a sample stage, a driving device, a fixture, and a receiving component. The receiving component includes a first inner tube, a second inner tube, and a third inner tube, and also includes a receiving tube with a receiving cavity inside. The first, second, and third inner tubes are located inside the receiving cavity. The sample stage is located inside the first inner tube. The driving device moves the first, second, and third inner tubes to one side of the sample stage, respectively. Subsequently, the substrate on the sample stage completes two-dimensional material growth in the first, second, and third inner tubes, respectively. Different two-dimensional materials are grown within the first, second, and third inner tubes. This allows for the simultaneous growth of multiple two-dimensional materials within the same apparatus while avoiding contamination and impurity adsorption on the walls of other growth tubes.

Description

Technical Field

[0001] This invention relates to the field of chemical vapor deposition technology, and in particular to a growth apparatus and preparation method for realizing heterojunctions of various two-dimensional materials. Background Technology

[0002] As a representative two-dimensional material, monolayer graphene has a variety of excellent properties such as ultra-high carrier mobility, high thermal conductivity, high mechanical strength and high light transmittance, and has great application prospects in many fields such as optical devices, integrated circuits, and aerospace.

[0003] In the past decade or so, research on two-dimensional materials has grown exponentially. In addition to graphene, many other two-dimensional materials, such as hexagonal boron nitride, transition metal sulfides, and black phosphorus, have been successively prepared, greatly expanding the performance and applications of two-dimensional materials. Besides the study of the properties, growth, and applications of single two-dimensional materials, heterostructures formed by the interaction of multiple two-dimensional materials are also a current research hotspot. For example, graphene / h-BN vertical heterojunctions have played a significant role in increasing the carrier mobility of field-effect transistors, far exceeding the carrier mobility in graphene on silicon.

[0004] Methods for synthesizing two-dimensional materials include mechanical exfoliation, magnetron sputtering, and chemical vapor deposition. Mechanical exfoliation is simple to operate and easily yields high-quality materials, but its small size, difficulty in controlling the number of layers, poor repeatability, and low yield greatly limit its practical application in large-scale production. Magnetron sputtering, on the other hand, has the advantages of growth without substrate catalysis and can be completed at room temperature, resulting in extremely fast preparation speed. However, it suffers from problems such as difficulty in target selection, high growth cost, and poor material crystal quality. Currently, the mainstream method for synthesizing two-dimensional materials is chemical vapor deposition. Its principle is to use gaseous or vaporous substances as precursors, which are transported to the high-temperature growth region at the back end, where a chemical reaction occurs on the substrate surface to generate solid deposits. Chemical vapor deposition has many advantages, such as low cost, strong controllability of the number of layers, and applicability to the preparation of large-area, high-quality continuous thin films.

[0005] The main steps of chemical vapor deposition for heterojunctions of two-dimensional materials using tube furnaces are to grow the first layer of two-dimensional material on the substrate in one growth device, and then place the sample in a second dedicated growth device for heterojunction synthesis. During the transport of the sample from one device to another, impurities may be adsorbed, causing contamination. At the same time, if multiple two-dimensional materials are synthesized continuously in a single device, different precursor sources undergo various chemical reactions in the high-temperature region at the back end, which may cause impurities to be adsorbed on the inner wall of the device, causing serious interference and contamination to subsequent processes. Summary of the Invention

[0006] To address the problem that impurities are easily adsorbed on the substrate or on the inner wall of the equipment during the preparation of heterojunction chemical vapor deposition, this invention proposes a growth device and preparation method for heterojunctions of various two-dimensional materials.

[0007] This invention is achieved through the following technical solution:

[0008] This invention proposes a growth apparatus for realizing various two-dimensional material heterostructures, comprising a sample stage, a driving device, a fixing frame, and a housing assembly, wherein:

[0009] The receiving assembly includes a first inner tube, a second inner tube, and a third inner tube. The first inner tube is located inside the second inner tube, and the third inner tube is located outside the second inner tube. One side of the first inner tube, the second inner tube, and the third inner tube are respectively fixedly connected to the driving device. The receiving assembly also includes a receiving tube with a receiving cavity inside. The first inner tube, the second inner tube, and the third inner tube are located inside the receiving cavity. The receiving tube is fixed to one side of the top of the fixing frame.

[0010] The sample stage is located inside the first inner tube and is used to accommodate the substrate. The sample stage is supported and fixed by a robotic arm. The driving device drives the first inner tube, the second inner tube, and the third inner tube to move to one side of the sample stage. Subsequently, the substrate on the sample stage completes two-dimensional material growth in the first inner tube, the second inner tube, and the third inner tube.

[0011] Furthermore, it also includes a vacuum device, which includes a vacuum pump and an exhaust pipe. The vacuum pump is located on the side of the housing assembly away from the drive device, and the vacuum pump is connected to the internal space of the sample stage through the exhaust pipe.

[0012] Furthermore, a pressure gauge is provided on the vent pipe, which is used to detect the pressure value inside the accommodating cavity.

[0013] Furthermore, the device also includes a gas supply device, which includes a mixing chamber and a gas supply pipe. One end of the gas supply pipe is connected to one side of the receiving pipe and communicates with the receiving cavity, and the other end is connected to the mixing chamber. The mixing chamber is located at the bottom of the fixing frame on the side away from the receiving component.

[0014] Furthermore, the gas pipe is also equipped with an air inlet valve, which is used to control the opening and closing of the gas pipe.

[0015] Furthermore, the gas pipe is equipped with a flow meter, which is used to detect the gas flow rate.

[0016] Furthermore, it also includes a gas control system, which is integrated with the mixing chamber.

[0017] Furthermore, it also includes a heating box, which is located on one side of the bottom of the receiving tube and is fixedly connected to the fixing frame.

[0018] Furthermore, the driving device includes a gear transmission device, the transmission device includes a telescopic rod and a transmission mechanism, and multiple telescopic rods are provided. One end of each telescopic rod is fixedly connected to the first inner tube, the second inner tube and the third inner tube respectively, and the other end is connected to the transmission mechanism.

[0019] Furthermore, a method for fabricating a growth device for multiple two-dimensional material heterostructures includes the following steps:

[0020] S1. Place the substrate in the sample stage and perform vacuum and air purging treatments on the cavity in sequence.

[0021] S2. Set up the mixing chamber to introduce different gas sources, and set up the heating program required for the growth of different gas sources in the heating chamber respectively;

[0022] S3. Different two-dimensional materials are grown in the first inner tube, the second inner tube, and the third inner tube, respectively.

[0023] S4. Stop the gas supply, close the mixing chamber and heating chamber, and obtain the finished product after cooling.

[0024] The beneficial effects of this invention are:

[0025] The proposed device for growing heterostructures of multiple two-dimensional materials uses a movable arrangement of a first inner tube, a second inner tube, and a third inner tube. A receiving tube accommodates the first, second, and third inner tubes, and a sample stage is located inside the third inner tube. A driving device then moves the three inner tubes, allowing the sample stage to grow different two-dimensional materials on different inner tubes. This allows for the growth of multiple two-dimensional materials within a single device, while preventing impurities formed during the growth of different two-dimensional materials from adsorbing onto the same inner wall and causing serious interference and contamination to subsequent reactions. Attached Figure Description

[0026] Figure 1 This is an overall structural diagram of the growth device for realizing heterojunctions of various two-dimensional materials according to the present invention;

[0027] Figure 2 A cross-sectional view of the housing component of the growth apparatus for realizing various two-dimensional material heterostructures according to the present invention;

[0028] In the figure: 1. Container assembly, 11. Container tube, 12. First inner tube, 13. Second inner tube, 14. Third inner tube, 2. Drive device, 21. Transmission mechanism, 22. Telescopic rod, 3. Gas supply device, 31. Mixing box, 32. Vacuum device, 41. Vacuum pump, 42. Gas outlet pipe, 5. Heating box, 6. Fixture, 7. Sample stage.

[0029] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] To more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0031] Please refer to Figures 1-2 This invention proposes a growth apparatus for realizing heterostructures of various two-dimensional materials, comprising a sample stage 7, a driving device 2, a fixing frame 6, and a housing assembly 1, wherein:

[0032] The receiving assembly 1 includes a first inner tube 12, a second inner tube 13, and a third inner tube 14. The first inner tube 12 is located inside the second inner tube 13, and the third inner tube 14 is located outside the second inner tube 13. One side of the first inner tube 12, the second inner tube 13, and the third inner tube 14 are respectively fixedly connected to the driving device 2. The receiving assembly 1 also includes a receiving tube 11. The receiving tube 11 has a receiving cavity inside. The first inner tube 12, the second inner tube 13, and the third inner tube 14 are located inside the receiving cavity. The receiving tube 11 is fixed to one side of the top of the fixing frame 6.

[0033] The sample stage 7 is located inside the first inner tube 12. The sample stage 7 is used to accommodate the substrate. The sample stage 7 is supported and fixed by a robotic arm. The driving device 2 drives the first inner tube 12, the second inner tube 13 and the third inner tube 14 to move to one side of the sample stage 7. Then, the substrate on the sample stage 7 completes two-dimensional material growth in the first inner tube 12, the second inner tube 13 and the third inner tube 14 respectively.

[0034] In this embodiment:

[0035] Sample stage 7 is used to place the substrate;

[0036] The drive device 2 is used to drive the first inner tube 12, the second inner tube 13 and the third inner tube 14 to move;

[0037] The receiving tube 11 is used to provide a receiving structure;

[0038] The first inner tube 12, the second inner tube 13 and the third inner tube 14 are used to provide a containment structure for different two-dimensional materials;

[0039] Specifically, the receiving tube 11 and the sample stage 7 are made of quartz. The fixing frame 6 has a support for supporting the receiving assembly 1, which supports the receiving tube 11. Sealing flanges are provided on both sides of the receiving tube 11. The right side of the receiving tube 11 is a high-temperature area. The first inner tube 12, the second inner tube 13, and the third inner tube 14 are respectively connected to the driving device 2. The sample stage 7 is set inside the third inner tube 14 by a mechanical support arm. The sample stage 7 remains stationary and is not affected by external factors. A substrate is placed on the sample stage 7. The third inner tube 14, the second inner tube 13, and the first inner tube 12 are arranged sequentially on the outside of the sample stage 7. When multiple two-dimensional materials need to be continuously synthesized, the second inner tube 13 and the third inner tube 14 are first moved to one side of the receiving cavity. Then, the substrate on the sample stage 7 first grows two-dimensional materials in the closed space formed inside the first inner tube 12. After the growth of a two-dimensional material is completed, the driving device 2 moves the first inner tube 12 laterally and detaches it from the sample stage 7. Then, the second inner tube 13 is moved until the sample stage 7 is completely inside the second inner tube 13. The substrate sample stage 7 completes the growth of another two-dimensional material in the sealed space formed inside the second inner tube 13. Similarly, when the growth of a third two-dimensional material is required, the second inner tube 13 can be moved to one side, and the third inner tube 14 can be moved until the sample stage 7 is inside the third inner tube 14, so that the sample stage 7 and the substrate form a sealed space inside the third inner tube 14. By using the first inner tube 12, the second inner tube 13 and the third inner tube 14 to move one of them to the outside of the sample stage 7 to complete the growth of two-dimensional materials, it is possible to achieve the continuous synthesis of multiple two-dimensional materials and it is not easy to cause contamination to subsequent reactions.

[0040] In one embodiment, more inner tubes, such as a fourth inner tube, a fifth inner tube, a sixth inner tube, etc., can be set to complete the continuous synthesis of more types of two-dimensional materials. The materials of the receiving tube 11 and the sample stage 7 can also be selected from other materials according to the actual situation. The substrate can be selected from copper foil, copper-nickel alloy, sapphire and Si / SiO2, etc.

[0041] Furthermore, it also includes a vacuum device 4, which includes a vacuum pump 41 and an outlet pipe 42. The vacuum pump 41 is located on the side of the housing component 1 away from the drive device 2, and the vacuum pump 41 is connected to the internal space of the sample stage 7 through the outlet pipe 42.

[0042] A pressure gauge is installed on the vent pipe 42, which is used to detect the pressure value inside the containment cavity;

[0043] It also includes a gas supply device 3, which includes a gas mixing box 31 and a gas supply pipe 32. One end of the gas supply pipe 32 is connected to one side of the receiving pipe 11 and communicates with the receiving cavity, and the other end is connected to the gas mixing box 31. The gas mixing box 31 is located at the bottom of the fixed frame 6 on the side away from the receiving component 1.

[0044] It also includes a pneumatic control system, which is integrated with the mixing chamber 31;

[0045] A flow meter is installed on the gas pipe 32, which is used to detect the gas flow rate;

[0046] The gas pipe 32 is also equipped with an air inlet valve, which is used to control the opening and closing of the gas pipe 32;

[0047] It also includes a heating box 5, which is located on one side of the bottom of the receiving tube 11 and is fixedly connected to the fixing frame 6.

[0048] In this embodiment:

[0049] Vacuum pump 41 is used to provide a vacuum environment for air intake;

[0050] Mixing box 31 is used to supply multiple gases;

[0051] Heating chamber 5 is used to heat the interior of housing component 1;

[0052] Specifically, the vacuum pump 41 is connected to the interior of the container assembly 1 through the gas outlet pipe 42. The vacuum pump 41 can extract gas to make the sealed space where the sample stage 7 is located in a vacuum state. The gas mixing box 31 is equipped with a gas control system, which can set various gas supply rates. The gas inlet pipe 32 is equipped with an inlet valve. After the inlet valve is opened, since the vacuum pump 41 makes the space where the sample stage 7 is located in a sealed state, the gas will be transported to the interior of the container assembly 1 through the gas inlet pipe 32. Finally, the heating box 5 heats the container assembly 1 to the reaction temperature required for the growth of two-dimensional materials and completes the growth of two-dimensional materials.

[0053] In one embodiment, the actual number of gas tubes 32 can be selected according to the actual situation. There can be one or multiple tubes. When multiple tubes are set, the reaction gas and the inert gas used for transport can be separated. The heating box 5 is equipped with a heat exhaust fan, which can facilitate rapid cooling after the two-dimensional material growth is completed and reduce the temperature overshoot phenomenon that may occur during the heating process.

[0054] Furthermore, the drive device 2 includes a gear transmission device, which includes a telescopic rod 22 and a transmission mechanism 21. Multiple telescopic rods 22 are provided, with one end of each telescopic rod 22 fixedly connected to the first inner tube 12, the second inner tube 13 and the third inner tube 14 respectively, and the other end connected to the transmission mechanism 21.

[0055] In this embodiment:

[0056] The transmission mechanism 21 and the telescopic rod 22 are used to drive the receiving assembly 1 to move laterally;

[0057] Specifically, there are three telescopic rods 22, which are fixedly connected to the first inner tube 12, the second inner tube 13, and the third inner tube 14, respectively. The telescopic rods 22 can extend and retract. When the telescopic rods 22 are shortened, they will drive the first inner tube 12, the second inner tube 13, or the third inner tube 14 connected to them to move laterally, thereby detaching from the sample stage 7. Under the action of the driving device 2, the sample stage 7 performs two-dimensional material growth inside the first inner tube 12, the second inner tube 13, and the third inner tube 14, respectively.

[0058] In one embodiment, the transmission mechanism 21 can adopt a gear-type mechanical transmission structure or other structures, and the structure of the telescopic rod 22 can also be selected according to the actual situation.

[0059] Furthermore, the method for fabricating a growth device for various two-dimensional material heterostructures includes the following steps:

[0060] S1. Place the substrate in the sample stage 7, and perform vacuuming and ventilation cleaning in the receiving tube 11 in sequence.

[0061] S2. Set up the mixing chamber 31 to introduce different gas sources, and set up the heating program required for the growth of different gas sources in the heating chamber 5 respectively;

[0062] S3. Different two-dimensional materials are grown in the first inner tube 12, the second inner tube 13, and the third inner tube 14 respectively;

[0063] S4. Stop the gas supply, close the mixing box 31 and the heating box 5, and obtain the finished product after cooling.

[0064] Specifically, taking the preparation of h-BN / Gra heterojunction on a metal substrate as an example, open the sealing flanges on the right side of both sides of the receiving tube 11 and place the growth substrate on the sample stage 7, wherein the substrate is a 5cm*5cm copper foil.

[0065] Close the sealing flange on the right side, and use the robotic arm to send the sample stage 7 to the center of the receiving tube 11 (at this time, since the first inner tube 12, the second inner tube 13 and the third inner tube 14 are on the same side, the sample stage 7 is also in the center of the third inner tube 14). Turn on the vacuum pump 41 to perform vacuum evacuation.

[0066] Once the pressure inside the cavity has decreased to the set value, turn off the vacuum pump 41, open the inlet valve on the mixing chamber 31 and the mixer tube, introduce high-purity argon gas, and set the gas rate through the gas control system on the mixing chamber 31.

[0067] When the pressure in the containment chamber rises to atmospheric pressure, close the inlet valves on the mixing chamber 31 and the gas pipe 32, set the argon gas rate to 0 through the gas control system on the mixing chamber 31, and restart the vacuum pump 41.

[0068] Repeat the process of evacuating to a certain pressure and introducing argon gas to atmospheric pressure three or more times to achieve high-flow-rate, high-purity argon gas to clean the internal cavity of the equipment.

[0069] The heating program is set in heating chamber 5 to heat the containment cavity to the reaction temperature required for the growth of the first two-dimensional material;

[0070] By pulling the corresponding telescopic rod 22 through the transmission mechanism 21, the second inner tube 13 and the third inner tube 14 are pulled to the front end of the main cavity. The supply rates of methane, high-purity argon and high-purity hydrogen are set by the gas control system on the mixing box 31, the gas inlet valves on the mixing box 31 and the gas pipe 32 are opened, the gas is introduced and the graphene growth in the first inner tube 12 begins.

[0071] After the first layer of two-dimensional material graphene is grown, the air inlet valves on the mixing chamber 31 and the gas pipe 32 are closed. The gas control system on the mixing chamber 31 is used to set all gas rates to 0. The heating program in the heating chamber 5 is adjusted so that the cavity reaches the temperature required for the growth of the second two-dimensional material.

[0072] By adjusting the corresponding telescopic rod 22 through the transmission mechanism 21, the first inner tube 12 is pulled to one end of the receiving cavity, and the second inner tube 13 is pushed into the outside of the sample stage 7.

[0073] Once the cavity reaches the temperature required for the second two-dimensional material, hexagonal boron nitride, the supply rates of cycloborane gas, high-purity argon gas, and high-purity hydrogen gas are set by the control system on the mixing chamber 31, and the inlet valves on the mixing chamber and the gas pipe 32 are opened to start the growth of hexagonal boron nitride.

[0074] After growth is complete, close the air inlet valves on the gas mixing chamber 31 and the gas pipe 32, set all gas rates to 0 through the gas control system on the gas mixing chamber 31, wait for the equipment to cool down, and then take out the sample.

[0075] In one embodiment, the present invention can also be applied to the preparation of two-dimensional materials such as graphene, hexagonal boron nitride, and transition metal sulfides that can be grown using gaseous precursors, and related vertical heterostructures.

[0076] Of course, the present invention may have many other embodiments. Based on this embodiment, other embodiments obtained by those skilled in the art without any creative effort are all within the scope of protection of the present invention.

Claims

1. A growth apparatus for realizing heterostructures of various two-dimensional materials, characterized in that, Includes a sample stage, drive unit, fixture, and housing assembly, wherein: The receiving assembly includes a first inner tube, a second inner tube, and a third inner tube. The first inner tube is located inside the second inner tube, and the third inner tube is located outside the second inner tube. One side of the first inner tube, the second inner tube, and the third inner tube are respectively fixedly connected to the driving device. The receiving assembly also includes a receiving tube with a receiving cavity inside. The first inner tube, the second inner tube, and the third inner tube are located inside the receiving cavity. The receiving tube is fixed to one side of the top of the fixing frame. The sample stage is located inside the first inner tube and is used to accommodate the substrate. The sample stage is supported and fixed by a robotic arm. The driving device moves the first inner tube, the second inner tube, and the third inner tube to one side of the sample stage. Subsequently, the substrate on the sample stage grows different two-dimensional materials in the sealed space formed by the first inner tube, the second inner tube, and the third inner tube. When multiple two-dimensional materials need to be synthesized continuously, the second inner tube and the third inner tube are first moved to one side of the accommodating cavity. Then, the substrate on the sample stage grows two-dimensional materials in the sealed space formed by the first inner tube. After the growth of one two-dimensional material is completed, the driving device moves the first inner tube laterally and detaches it from the sample stage. Then, the second inner tube is moved until the sample stage is completely inside the second inner tube. The substrate sample stage grows another two-dimensional material in the sealed space formed by the second inner tube. When the growth of a third two-dimensional material is required, the second inner tube is moved to one side until the sample stage is inside the third inner tube, so that the sample stage and the substrate form a sealed space inside the third inner tube.

2. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 1, characterized in that, It also includes a vacuum device, which includes a vacuum pump and an outlet pipe. The vacuum pump is located on the side of the housing assembly away from the drive device, and the vacuum pump is connected to the internal space of the sample stage through the outlet pipe.

3. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 2, characterized in that, A pressure gauge is installed on the vent pipe, and the pressure gauge is used to detect the pressure value inside the accommodating cavity.

4. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 1, characterized in that, It also includes a gas supply device, which includes a gas mixing box and a gas supply pipe. One end of the gas supply pipe is connected to one side of the receiving pipe and communicates with the receiving cavity, and the other end is connected to the gas mixing box. The gas mixing box is located at the bottom of the fixing frame on the side away from the receiving component.

5. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 4, characterized in that, The gas pipe is also equipped with an air inlet valve, which is used to control the opening and closing of the gas pipe.

6. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 5, characterized in that, The gas pipe is equipped with a flow meter, which is used to detect the gas flow rate.

7. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 6, characterized in that, It also includes a gas control system, which is integrated with the gas mixing chamber.

8. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 1, characterized in that, It also includes a heating box, which is located on one side of the bottom of the receiving tube and is fixedly connected to the fixing frame.

9. The growth apparatus for realizing heterostructures of various two-dimensional materials according to claim 1, characterized in that, The driving device includes a gear transmission device, and the transmission device includes a telescopic rod and a transmission mechanism. There are multiple telescopic rods, one end of which is fixedly connected to the first inner tube, the second inner tube and the third inner tube respectively, and the other end is connected to the transmission mechanism.

10. A method for preparing various two-dimensional material heterostructures using the growth apparatus according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Place the substrate in the sample stage, and sequentially perform vacuuming and air purging in the receiving tube; S2. Set up the mixing chamber to introduce different gas sources, and set up the heating program required for the growth of different gas sources in the heating chamber respectively; S3. Different two-dimensional materials are grown in the sealed spaces formed by the first inner tube, the second inner tube, and the third inner tube, respectively. S4. Stop the gas supply, close the mixing chamber and heating chamber, and obtain the finished product after cooling.

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