A two-dimensional material preparation apparatus and process

Abstract

This invention proposes a two-dimensional material preparation device, specifically relating to the field of semiconductor equipment technology. The two-dimensional material preparation device includes a supply device and a heating device, wherein: the supply device includes a receiving plate, the receiving plate has multiple reaction chambers inside, and an inner nested tube is provided inside the reaction chamber. The inner nested tube is fixedly connected to the receiving plate, and the top and bottom of the inner nested tube are provided with conduits, which communicate with the inner nested tube; the heating device includes two first heating modules, which are respectively located at the top and bottom of the receiving plate. This invention uses external gas to introduce into the inner nested tube to carry out metal oxidation and metal sulfidation reactions. The entire reaction takes place inside the receiving plate, which is more controllable and less prone to the risk of blockage.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and more particularly to a two-dimensional material preparation apparatus. Background Technology

[0002] Novel two-dimensional materials, especially transition metal disulfide compounds such as molybdenum disulfide with semiconductor properties, have a series of excellent characteristics such as atomic layer thickness, adjustable band gap and mechanical flexibility. They are expected to replace traditional silicon-based semiconductors, break the limitations of Moore's Law, and realize the application of a new generation of high-performance integrated circuits. At present, the mainstream growth equipment adopts horizontal quartz tube chemical vapor deposition furnace. The horizontal supply of source materials on the substrate will inevitably lead to the problem of poor uniformity of two-dimensional materials.

[0003] To improve the uniformity of large-size two-dimensional material preparation, some reports have used the currently mainstream vertical MOCVD equipment, with solid molybdenum hexacarbonyl at room temperature and hydrogen sulfide as the metal and sulfur source, respectively, for the growth of two-dimensional materials. However, since the supply of solid molybdenum hexacarbonyl requires the pipeline and gas supply system to be maintained above the melting point of 150°C, it poses a great challenge to the stability and safety of equipment operation. In addition, for the spray head inside MOCVD, the vaporization temperature of molybdenum hexacarbonyl is high and it is easy to condense, which leads to the blockage of the pores of the spray head and is not conducive to the long-term stable operation of the equipment.

[0004] From the perspective of the chemical reaction process inside the MOCVD chamber, molybdenum hexacarbonyl and hydrogen sulfide are introduced to the substrate surface through different pores on the spray head to carry out chemical reactions. This source supply method makes the chemical reaction process on the substrate surface quite complex, including the decomposition of molybdenum hexacarbonyl and hydrogen sulfide, atomic bonding reactions, molecular adsorption and desorption reactions, surface migration, etc., which are difficult to control effectively. In addition, the dispersion of the two sources inside the chamber means that the chemical reaction cannot be immediately terminated when the source supply is turned off, which is not conducive to the controllable growth of two-dimensional materials. Summary of the Invention

[0005] To address the problems of uncontrollable and unstoppable growth of two-dimensional materials and the tendency for source material to clog the supply conduit, this invention proposes a two-dimensional material preparation device and process.

[0006] This invention is achieved through the following technical solution: This invention proposes a two-dimensional material preparation apparatus comprising a supply device and a heating device, wherein: The supply device includes a receiving tray, which has multiple reaction chambers inside. Each reaction chamber has an inner nested tube inside. The inner nested tube is fixedly connected to the receiving tray. The top and bottom of the inner nested tube are provided with conduits, which communicate with the inner nested tube. The heating device includes a first heating module, and there are two first heating modules, which are respectively located at the top and bottom of the receiving plate.

[0007] Furthermore, the heating device also includes a second heating module, which is located on one side of the bottom of the supply device.

[0008] Furthermore, a graphite disk is provided on one side of the top of the second heating module, and the graphite disk is fixedly connected to the second heating module.

[0009] Furthermore, the inner nested tube is made of a transition metal material.

[0010] Furthermore, a vertical two-dimensional material growth and preparation process with highly controllable source supply includes the following steps: S1. Vacuum treatment is applied to the reaction chamber, and the container is heated to the first preset temperature; S2. Introduce a certain flow rate of oxygen into the inner nested tube and continue for a first preset time to oxidize the inner wall of the inner nested tube to form molybdenum oxide. Then disconnect the oxygen supply and introduce a certain flow rate of hydrogen sulfide gas for a second preset time to obtain molybdenum disulfide material. S3. The second heating module heats the sapphire inside the graphite disk to a second preset temperature; S4. The oxygen and hydrogen sulfide gases are alternately introduced in a pulsed manner to control the ejection of molybdenum disulfide material through the conduit, so that the molybdenum disulfide material reaches the surface of the sapphire substrate.

[0011] Furthermore, in step S1, the pressure in the reaction chamber after vacuum treatment is 1×10⁻⁶. -4 Pa.

[0012] Furthermore, the first preset temperature is 800°C.

[0013] Furthermore, in step S2, the first preset time is 30 seconds and the second preset time is 20 seconds.

[0014] Furthermore, the oxygen flow rate in step S2 is 1 cm. 3 The flow rate of hydrogen sulfide introduced is 0.5 cm. 3 .

[0015] Furthermore, the second preset temperature in step S3 is 1000℃.

[0016] The beneficial effects of this invention are: The two-dimensional material preparation device proposed in this invention employs a two-step chemical reaction process. The metal is first oxidized, and then the metal oxide is sulfided. The entire process takes place inside the container, and the two reaction processes are pulsed and alternated. This allows for precise control of the generation of two-dimensional materials by adjusting the gas supply, temperature, and time. This invention enables better control of the flow of two-dimensional growth materials, reduces the risk of gas supply duct blockage, and allows two-dimensional material molecules to reach the substrate surface in gaseous form via the supply device for adsorption and direct bonding reactions. Parasitic reaction processes are relatively few, which has a significant advantage for the controllable growth of two-dimensional materials. Attached Figure Description

[0017] Figure 1 This is an overall view of the two-dimensional material preparation apparatus of the present invention; Figure 2 This is a structural diagram of the supply device of the two-dimensional material preparation apparatus of the present invention; Figure 3 This is a schematic diagram of the conduit distribution of the two-dimensional material preparation device of the present invention; In the figure: supply device 1, receiving plate 11, conduit 12, inner nested tube 13, first heating module 2, second heating module 3, graphite plate 4; 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

[0018] To more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings.

[0019] Please refer to Figures 1-2 This invention proposes a two-dimensional material preparation apparatus comprising a supply device and a heating device, wherein: The supply device 1 includes a receiving tray 11, which has multiple reaction chambers inside. The reaction chambers are provided with inner nested tubes 13, which are fixedly connected to the receiving tray 11. The top and bottom of the inner nested tubes 13 are provided with conduits 12, which are connected to the inner nested tubes 13. The heating device includes a first heating module 2, and there are two first heating modules 2, which are located at the top and bottom of the receiving plate 11, respectively.

[0020] In this embodiment: The first heating module 2 is used to heat the receiving tray 11; The receiving tray 11 is used to hold the reactants; The inner nested tube 13 is used to form molybdenum sulfide; The conduit 12 is used to introduce gas into the inner nested tube 13 and to eject gas. Specifically, the inner nested tube 13 is made of molybdenum metal. The inner nested tube 13 is placed inside the receiving tray 11 and connected to the conduit 12 in a quick-connect manner to facilitate the disassembly and replacement of the inner nested tube 13. Oxygen is introduced into the inner nested tube 13 through the top conduit 12. The inner nested tube 13 reacts with oxygen to generate molybdenum oxide. Subsequently, the oxygen supply is cut off externally, and hydrogen sulfide gas is introduced. The hydrogen sulfide gas reacts with molybdenum oxide to generate molybdenum disulfide material. In the reaction chamber, the metal is oxidized first, and then the metal oxide is sulfided. The two reaction processes are carried out alternately in a pulsed manner. Two-dimensional materials are generated directly on the inner wall of the inner nested tube 13, and all of this is achieved within the supply device 1. Compared with the prior art, this application can achieve immediate termination of the chemical reaction at the moment the gas supply is turned off, and can better control the growth of two-dimensional materials.

[0021] In one embodiment, the first heating module 2 is also equipped with a circulating water cooling and temperature measurement and control device. The maximum temperature of the first heating module 2 can reach 1200℃. Each conduit 12 is externally configured to form a branch, which can be connected to two or more gases. A gas mass flow controller is provided between the gas source bottle connections, and the controller's response time is less than 50ms. The first heating module 2 adopts a ring resistance wire heating method, which provides the heat required for chemical reaction to the gas source supply conduit 12 and the inner nested tube 13 through heat conduction and heat radiation.

[0022] In one embodiment, the inner nested tube 13 is consistent with the conduit 12, and is usually a 1 / 4 steel pipe. The distribution position and density of the inner nested tube 13 on the disk can be adjusted according to demand to further optimize the source supply flow field.

[0023] Furthermore, the heating device also includes a second heating module 3, which is located on one side of the bottom of the supply device 1; A graphite disk 4 is also provided on one side of the top of the second heating module 3, and the graphite disk 4 is fixedly connected to the second heating module 3.

[0024] In this embodiment: The second heating module 3 is used for heating the substrate layer; Specifically, the molybdenum disulfide growth substrate is a single-sided polished sapphire. There is a placement groove on the surface of the graphite disk 4, and the sapphire is placed inside the graphite disk 4. The depth of the placement groove of the graphite disk 4 is consistent with the thickness of the sapphire. The second heating module 3 heats the substrate, and the sapphire substrate reaches a certain temperature through heat conduction, so as to be used for the epitaxial growth of molybdenum disulfide. The highest temperature that the substrate can reach is 1200℃. The diameter of the sapphire is 2 inches and the thickness is 500 μm.

[0025] Furthermore, the inner nested tube 13 is made of a transition metal material, such as molybdenum and tungsten.

[0026] Specifically, the inner nested tube 13 is made of molybdenum metal, which can facilitate the formation of the inner wall of molybdenum disulfide and subsequent reactions. By carrying the gas medium through the inner nested tube 13, the supply of molybdenum disulfide material can be effectively controlled by the gas, and the on / off control of the source can also be effectively realized.

[0027] In a real-time example, other transition metal materials can also be used to prepare two-dimensional materials according to actual needs. For example, tungsten can be selected as the transition metal material, and oxygen and hydrogen sulfide are introduced to generate a tungsten disulfide film.

[0028] Furthermore, a fabrication process for a two-dimensional material preparation device is characterized by comprising the following steps: S1. Vacuum treatment is performed inside the reaction chamber, and the container 11 is heated to the first preset temperature; S2. A certain flow rate of oxygen is introduced into the inner nested tube 13 and continued for a first preset time, so that the inner wall of the inner nested tube 13 is oxidized to form molybdenum oxide. The oxygen is then turned off, and then a certain flow rate of hydrogen sulfide gas is introduced and continued for a second preset time to obtain molybdenum disulfide material. S3. The second heating module 3 heats the sapphire inside the graphite disk 4 to a second preset temperature; S4. The oxygen and hydrogen sulfide gases are alternately introduced in a pulsed manner to control the ejection of molybdenum disulfide material through the conduit 12, so that the molybdenum disulfide material reaches the surface of the sapphire substrate.

[0029] Furthermore, the pressure in the reaction chamber after vacuum treatment in step S1 is 1×10⁻⁶. -4 Pa.

[0030] Furthermore, the first preset temperature is 800℃.

[0031] Furthermore, in step S2, the first preset time is 30 seconds and the second preset time is 20 seconds.

[0032] Furthermore, the oxygen flow rate in step S2 is 1 cm. 3 The flow rate of hydrogen sulfide introduced is 0.5 cm. 3 .

[0033] Furthermore, the second preset temperature in step S3 is 1000℃.

[0034] Specifically, taking metallic molybdenum as an example, the receiving tray 11 is heated by the upper and lower first heating modules 2, and a 1cm diameter tube is introduced through the conduit 12. 3 The oxygen caused the inner wall of the inner molybdenum tube 13 to oxidize, forming molybdenum oxide. After the oxygen flow continued for 30 seconds, the oxygen channel was closed, and hydrogen sulfide gas was introduced at a flow rate and time of 0.5 cm³ / s. 3The reaction proceeds for 20 seconds to form molybdenum disulfide material. Molybdenum disulfide material is synthesized through a two-step chemical reaction, with the two reaction processes alternating in a pulsed manner. The molybdenum disulfide material is synthesized entirely within the reaction chamber of the receiving plate 11. The inner nested tube 13 serves as the intermediate carrier medium, which can effectively control the on / off flow of molybdenum disulfide and regulate the supply of molybdenum disulfide material. Finally, the molybdenum disulfide material is desorbed from the inner wall of the inner nested tube 13 by heating, and is carried by the carrier gas through the gas source to the conduit 12, and sprayed onto the surface of the sapphire substrate. Through molecular adsorption and chemical bonding, a continuous two-dimensional molybdenum disulfide film is formed.

[0035] 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 two-dimensional material preparation apparatus, characterized in that, Includes a supply device and a heating device, wherein: The supply device includes a receiving tray, which has multiple reaction chambers inside. Each reaction chamber has an inner nested tube inside. The inner nested tube is fixedly connected to the receiving tray. The top and bottom of the inner nested tube are provided with conduits, which communicate with the inner nested tube. The heating device includes a first heating module, and there are two first heating modules, which are respectively located at the top and bottom of the receiving plate. The inner nested tube is made of molybdenum or tungsten.

2. The two-dimensional material preparation apparatus according to claim 1, characterized in that, The heating device also includes a second heating module, which is located on one side of the bottom of the supply device.

3. The two-dimensional material preparation apparatus according to claim 2, characterized in that, The second heating module is also provided with a graphite disk on one side of its top, and the graphite disk is fixedly connected to the second heating module.

4. The two-dimensional material preparation apparatus according to claim 1, characterized in that, The inner nested tube is made of transition metal.

5. A fabrication process for a two-dimensional material preparation apparatus according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Vacuum treatment is applied to the reaction chamber, and the container is heated to the first preset temperature; S2. Introduce a certain flow rate of oxygen into the inner nested tube and continue for a first preset time to oxidize the inner wall of the inner nested tube to form molybdenum oxide. Then disconnect the oxygen supply and introduce a certain flow rate of hydrogen sulfide gas for a second preset time to obtain molybdenum disulfide material. S3. The second heating module heats the sapphire inside the graphite disk to a second preset temperature; S4. The oxygen and hydrogen sulfide gases are alternately introduced in a pulsed manner to control the ejection of molybdenum disulfide material through the conduit, so that the molybdenum disulfide material reaches the surface of the sapphire substrate.

6. The preparation process according to claim 5, characterized in that, In step S1, the pressure of the reaction chamber after vacuum treatment is 1×10⁻⁶. -4 Pa.

7. The preparation process according to claim 5, characterized in that, The first preset temperature is 800℃.

8. The preparation process according to claim 5, characterized in that, In step S2, the first preset time is 30 seconds and the second preset time is 20 seconds.

9. The preparation process according to claim 5, characterized in that, In step S2, the oxygen flow rate is 1 cm. 3 The flow rate of hydrogen sulfide introduced is 0.5 cm. 3 .

10. The preparation process according to claim 5, characterized in that, The second preset temperature in step S3 is 1000℃.

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