Deposition method and system for chemical vapor deposition of silicon carbide

Abstract

The invention provides a deposition method and system for chemical vapor deposition of silicon carbide, and the method comprises the following steps: S1, providing a graphite base material, putting the base material into a reaction module, starting a rotating device, introducing silane gas, controlling the reaction temperature to be 1100-1200 DEG C, and continuously reacting for 5-10 minutes to form silicon carbide grains on the surface of the base material; s2, the temperature of the reaction module is lowered to 400-500 DEG C, annealing treatment is conducted on the base material with the silicon carbide crystal grains formed on the surface, the reaction time is not shorter than 5 min, and the flatness of the silicon carbide crystal grains is improved; and S3, the gas supply module introduces at least three kinds of process gas into the reaction module, the temperature of the reaction module is adjusted to rise to 1300-1500 DEG C, and the silicon carbide film is deposited on the surface of the base material. Through annealing treatment, the flatness of silicon carbide grains is remarkably improved, the deposition efficiency of the silicon carbide thin film is optimized, internal stress generated in the deposition process is effectively reduced, the uniformity and consistency of a deposition layer are ensured through application of the rotating device, and the overall quality of the silicon carbide thin film is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical vapor deposition, and in particular to a deposition method and system for chemically vapor depositing silicon carbide. Background Art

[0002] In the current process for preparing silicon carbide (SiC) thin films, especially in the initial stage of the chemical vapor deposition (CVD) process, the nucleation and growth of SiC grains on the substrate surface face significant challenges. This problem directly restricts the raw material utilization rate of the CVD process, which generally remains at a relatively low level of about 10%. In addition, the stress accumulated inside the silicon carbide thin film during the deposition process is relatively high, which not only increases the risk of film cracking and peeling, but also seriously hinders the improvement of the yield rate of silicon carbide products in the subsequent processing. On the other hand, due to the complexity of the crystal form matching between SiC and the substrate, it is difficult to achieve precise control, resulting in a relatively weak bonding force between the generated silicon carbide thin film and the substrate, affecting the stability and service life of the film. Moreover, the deposition uniformity problem of the silicon carbide thin film has always been a key factor restricting its quality and application performance. Summary of the Invention

[0003] To solve all or part of the above-mentioned prior art problems, the present invention provides a deposition method and system for chemically vapor depositing silicon carbide. After annealing treatment, the flatness of the silicon carbide grains is significantly improved, which not only optimizes the deposition efficiency of the silicon carbide thin film, but also effectively reduces the internal stress generated during the deposition process. The application of the rotating device ensures the uniformity and consistency of the deposition layer, further improving the overall quality of the silicon carbide thin film.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A deposition method for chemically vapor depositing silicon carbide, comprising the following steps:

[0006] S1. Provide a graphite substrate, place the substrate in a reaction module, start the rotating device, and introduce silane gas. Control the reaction temperature at 1100 - 1200 °C and continuously react for 5 - 10 min to form silicon carbide grains on the surface of the substrate;

[0007] S2. Lower the temperature of the reaction module to 400 - 500 °C, and perform annealing treatment on the substrate with silicon carbide grains formed on its surface. The reaction time is not less than 5 min to improve the flatness of the silicon carbide grains;

[0008] S3. The gas supply module introduces at least three process gases into the reaction module, and adjusts the temperature of the reaction module to rise to 1300 - 1500 °C to deposit a silicon carbide thin film on the surface of the substrate.

[0009] The present invention also provides a system for chemical vapor deposition of silicon carbide, specifically including:

[0010] A gas supply module that provides at least three process gases required for the deposition reaction;

[0011] A reaction module in which a substrate is placed and the deposition reaction of silicon carbide is performed on the substrate;

[0012] An exhaust gas treatment module responsible for treating the exhaust gas generated during the reaction;

[0013] The gas supply module includes a vaporization device. At least two process gases are input into the vaporization device in a gaseous form; at least one process gas is in a liquid form and is carried into the vaporization device by another process gas participating in the reaction and serving as a carrier gas, and vaporization is completed in the vaporization device; the output end of the vaporization device is connected to the reaction module, and the output end of the reaction module is connected to the exhaust gas treatment module.

[0014] By using a vaporization device to replace the traditional mixing tank, the present invention significantly improves the vaporization efficiency of methyltrichlorosilane (MTS), greatly increases the utilization efficiency of the raw material MTS, and effectively reduces the consumption of hydrogen. This improvement not only reduces the production cost but also makes the control of process conditions easier and more precise, further improving the purity of the silicon carbide product.

[0015] The reaction module includes a deposition chamber, at least one intake pipe, and at least one exhaust unit. The intake pipe and the exhaust unit are connected to the side wall of the deposition chamber. A deposition area is provided in the deposition chamber, at least one group of reaction substrates is provided in the deposition area, a rotating device connected to each group of the reaction substrates is provided below the deposition chamber, and the rotating device drives the reaction substrates to rotate.

[0016] The deposition area includes multiple groups of the reaction substrates arranged horizontally, and multiple groups of the rotating devices are correspondingly provided below the deposition chamber for driving multiple groups of the reaction substrates to rotate.

[0017] The reaction module includes a deposition chamber, at least one intake pipe, and at least one exhaust unit. The intake pipe and the exhaust unit are connected to the side wall of the deposition chamber. A deposition area is provided in the deposition chamber, at least one reaction substrate is provided in the deposition area, and the exhaust unit is provided at the top of the deposition chamber and directly above the reaction substrate.

[0018] A first filtering device is connected between the reaction module and the tail gas treatment module; the first filtering device includes a body and a filter core. The interior of the body is a hollow chamber, and the filter core is arranged in the hollow chamber, dividing the interior of the body into an unfiltered area and a filtered area; an air inlet and an air outlet are arranged on the body, the air inlet is communicated with the unfiltered area, and the air outlet is communicated with the filtered area; a cooling device is further included, and the cooling device is arranged on the periphery of the body to cool the body.

[0019] The gas supply module further includes a gas output part and a liquid output part. The gas output part includes at least two types of gas supply devices, and the liquid output part includes a gas supply device and a liquid supply device connected in sequence. A second filtering device is sequentially arranged on the connecting pipeline between the gas supply device and the liquid supply device.

[0020] The gas output part includes a first gas supply device and a second gas supply device; the liquid output part includes a second gas supply device and a liquid supply device; the first gas supply device supplies argon, the second gas supply device supplies hydrogen, and the liquid supply device supplies methyltrichlorosilane.

[0021] A purification device is arranged at the outlet of the second gas supply device, and the purification device is made of one of a palladium tube, a palladium membrane, a cellulose membrane or a hydrogen membrane separator.

[0022] An air inlet pipe and a liquid outlet pipe are arranged at the outlet of the liquid supply device. The end of the liquid outlet pipe is located below the liquid level, and the end position of the air inlet pipe is higher than the end position of the liquid outlet pipe; a pressure detection device is further arranged inside the liquid supply device and is located above the liquid level.

[0023] The present invention has at least the following beneficial effects:

[0024] 1) First, silicon carbide grains are formed on the surface of the substrate. After annealing treatment to change the shape of the silicon carbide grains, deposition of a silicon carbide thin film is carried out. After the annealing treatment, the flatness of the silicon carbide grains is significantly improved, which can effectively improve the deposition efficiency of the silicon carbide thin film, reduce the internal stress of the deposited silicon carbide thin film, and improve the utilization rate of raw materials during the deposition process of the silicon carbide thin film; moreover, the silicon carbide grains on the surface of the substrate contribute to a more firm bonding between the silicon carbide thin film and the substrate.

[0025] 2) By adopting a vaporization device to replace the traditional mixing tank and optimizing the design of the methyltrichlorosilane liquid supply device, the efficient vaporization and precise supply of raw materials such as methyltrichlorosilane are achieved. This not only significantly improves the utilization efficiency of the gas supply raw materials but also reduces the consumption of hydrogen, thereby effectively reducing the production cost. At the same time, the precise metering device ensures the precise control of the gas flow rate, further improving the accuracy and stability of the deposition reaction. The design of the rotating device ensures higher uniformity of the silicon carbide film deposited on each substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 It is a time-temperature relationship diagram of a chemical vapor deposition silicon carbide deposition method according to an embodiment of the present invention.

[0028] Figure 2 It is a process schematic diagram of a chemical vapor deposition silicon carbide deposition method according to an embodiment of the present invention.

[0029] Figure 3 It is a structural schematic diagram of a chemical vapor deposition silicon carbide system according to an embodiment of the present invention.

[0030] Figure 4 It is a first perspective structural schematic diagram of a rotating device provided below the deposition chamber of the reaction module according to an embodiment of the present invention.

[0031] Figure 5 It is a second perspective structural schematic diagram of a rotating device provided below the deposition chamber of the reaction module according to an embodiment of the present invention.

[0032] Figure 6 It is a first perspective structural schematic diagram of the exhaust unit of the reaction module provided at the top of the deposition chamber according to an embodiment of the present invention.

[0033] Figure 7 It is a second perspective structural schematic diagram of the exhaust unit of the reaction module provided at the top of the deposition chamber according to an embodiment of the present invention.

[0034] Figure 8 It is a structural schematic diagram of the first filtering device according to an embodiment of the present invention.

[0035] Figure 9 It is a structural schematic diagram of the liquid supply device according to an embodiment of the present invention.

[0036] Reference numerals: 1 - gas supply module; 101 - first gas supply device; 102 - second gas supply device; 103 - liquid supply device; 1031 - intake pipeline; 1032 - liquid outlet pipeline; 1033 - switching valve; 1034 - pressure detection device; 104 - vaporization device; 105 - second filtration device; 106 - purification device; 2 - reaction module; 201 - deposition chamber; 2011 - deposition area; 2012 - reaction substrate; 2013 - support; 202 - intake pipeline; 2021 - gas outlet end; 2022 - opening; 203 - exhaust unit; 204 - rotating device; 2041 - transmission member; 2042 - first power source; 3 - tail gas treatment module; 301 - vacuum device; 302 - tail gas treatment device; 4 - first filtration device; 401 - body; 4011 - unfiltered area; 4012 - filtered area; 402 - filter element; 403 - cooling device; 404 - collection chamber. Detailed implementation manners

[0037] The technical solutions in the specific embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] The implementation of the present invention will be described in detail below in conjunction with specific embodiments.

[0039] In the embodiment of the present invention, with reference to Figures 1 to 9 as shown, a method for depositing silicon carbide by chemical vapor deposition is provided, which specifically includes the following steps:

[0040] S1. Provide a graphite substrate, place the substrate in the reaction module 2, start the rotating device 204, and introduce silane gas. Control the reaction temperature at 1100 - 1200 °C and continuously react for 5 - 10 min to form silicon carbide grains on the surface of the substrate.

[0041] S2. Lower the temperature of the reaction module 2 to 400 - 500 °C, and perform annealing treatment on the substrate with silicon carbide grains formed on the surface. The reaction time is not less than 5 min to improve the flatness of the silicon carbide grains.

[0042] S3. The gas supply module 1 introduces at least three process gases into the reaction module 2, and adjusts the temperature of the reaction module 2 to rise to 1300 - 1500 °C to deposit a silicon carbide thin film on the surface of the substrate.

[0043] In step S1, at a temperature of 1100 - 1200 °C, silane reacts with the graphite substrate to form silicon carbide grains on the surface of the graphite substrate. As Figure 1As shown, the time for forming silicon carbide grains in step S1 is 5-10 minutes. Specifically, the reaction gas is silane, which decomposes under heating conditions to release silicon atoms, and these silicon atoms combine with carbon atoms from the graphite substrate to form silicon carbide; for the formation of silicon carbide, 1100-1200°C is a relatively ideal temperature range. Within this temperature range, the decomposition of silane and the chemical reaction between silicon and carbon can be effectively promoted, thereby forming a stable silicon carbide crystal structure. There is good lattice matching between the graphite substrate and the silicon carbide formed on the surface of the graphite substrate, which helps to reduce stress problems caused by lattice mismatch and ensure better bonding between the graphite substrate and the silicon carbide grains; and the silicon carbide grains formed on the surface of the graphite substrate help the silicon carbide film to be more firmly bonded to the substrate.

[0044] In step S2, the silicon carbide grains formed on the surface of the substrate in step S1 are annealed by an annealing process. The annealing time should be no less than 5 minutes. After the annealing process, the shape of the silicon carbide grains can become smooth, such as Figure 2 As shown, the flatness of silicon carbide grains is effectively improved, which helps silicon carbide film to be better deposited. Specifically, the temperature of the reaction module 2 is lowered to 400-500°C for low-temperature annealing or medium-temperature annealing. Although it is not enough to trigger large-scale atomic migration and lattice reconstruction, it is enough to activate the diffusion behavior of surface atoms, which enables surface atoms to move in a smaller range, fill tiny pits or remove protrusions, so that the grain boundaries are smoother and the overall surface becomes flatter; and low-temperature annealing helps to reduce some surface defects, such as steps, kinks and point defects, etc. The presence of these defects often increases the surface roughness, and these defects can be partially healed by annealing, thereby improving the surface quality; although 400-500°C is relatively low compared to high-temperature annealing, it is still enough to release some residual stress accumulated inside the material to a certain extent, and the release of stress also helps to prevent the deformation of silicon carbide grains and promote a more uniform silicon carbide grain morphology. In addition, a suitable annealing gas can be selected according to specific needs. For example, under the protection of an inert gas, additional oxidation reactions can be avoided during the annealing process.

[0045] In step S3, argon is provided as a diluent gas through the first gas supply device 101, hydrogen is provided through the second gas supply device 102, and methyltrichlorosilane is provided as a key reaction gas raw material in the chemical vapor deposition reaction by the liquid supply device 103. These gases and liquid raw materials are vaporized in the vaporization device 104 to form a mixed gas. Then, the mixed gas is input into the reaction module 2 to complete the deposition of the silicon carbide film on the surface of the substrate after annealing, wherein the reaction time is positively correlated with the thickness of the silicon carbide film.

[0046] This method first forms silicon carbide grains on the surface of the substrate, changes the shape of the silicon carbide grains through annealing treatment, and then deposits the silicon carbide thin film. After annealing treatment, the flatness of the silicon carbide grains is significantly improved, which can effectively improve the deposition efficiency of the silicon carbide thin film, reduce the internal stress of the deposited silicon carbide thin film, and improve the utilization rate of raw materials during the deposition process of the silicon carbide thin film; moreover, the silicon carbide grains on the surface of the substrate contribute to a more firm bonding between the silicon carbide thin film and the substrate.

[0047] The present invention also provides a system for chemical vapor deposition of silicon carbide. Referring to Figures 2 to 9 as shown, the system mainly consists of three core modules: a gas supply module 1, a reaction module 2, and a tail gas treatment module 3. Specifically, the gas supply module 1 is designed to provide all the necessary gas components for the subsequent deposition reaction. The reaction module 2, as the core of the system, is equipped with a chemical vapor deposition chamber and a substrate is placed therein. This chamber not only provides an ideal deposition environment but also ensures that the silicon carbide deposition reaction can proceed smoothly according to the predetermined process parameters, thereby achieving the expected material properties and structural characteristics. The tail gas treatment module 3 is responsible for safely and effectively treating the tail gas generated during the deposition reaction. To ensure the environmental protection and safety of the system operation, a first filtering device 4 is specially provided between the output end of the reaction module 2 and the tail gas treatment module 3. This filtering device can effectively capture and remove harmful particles and unreacted gases in the tail gas, thereby ensuring that the tail gas emission meets the relevant environmental protection standards.

[0048] The gas supply module 1 includes a vaporization device 104, and at least two process gases are input into the vaporization device 104 in a gaseous form; at least one process gas is carried into the vaporization device 104 in a liquid form by another process gas participating in the reaction and serving as a carrier gas, and is vaporized in the vaporization device 104. The gas supply module 1 specifically includes a gas output part and a liquid output part. Among them, both the gas output part and the liquid output part are connected to the input end of the vaporization device 104 through their respective connecting pipes, and the output end of the vaporization device 104 is connected to the reaction module 2 to ensure the stable supply and efficient utilization of gas. The gas output part, as the starting point of the gas supply module 1, is responsible for providing various gas components required for the deposition reaction. At least two types of gas supply devices can be designed, and a metering device is installed on the connecting pipe between each gas supply device and the vaporization device 104 to facilitate the accurate monitoring and adjustment of the gas flow rate. In this embodiment, the gas output part includes a first gas supply device 101 and a second gas supply device 102. The first gas supply device 101 is specifically used to supply the inert gas - argon, and its main function is to dilute the gas mixture participating in the subsequent reaction; while the second gas supply device 102 is responsible for supplying the active gas - hydrogen. Hydrogen not only directly participates in the chemical vapor deposition as a reaction gas during the process, but also has the function of a carrier gas. It should be noted that a purification device 106 is specially configured at the outlet position of the second gas supply device 102. The purification device 106 is made of one of a palladium tube, a palladium membrane, a cellulose membrane, or a hydrogen membrane separator to ensure that the hydrogen supplied to the reaction module 2 has extremely high purity and stability.

[0049] The liquid output section is used to deliver the liquid raw material of the reaction gas necessary for the deposition reaction to the vaporization device 104. This section is formed by sequentially connecting a gas supply device and a liquid supply device 103 to ensure the purity and precise metering of the liquid raw material. On the connecting pipeline between the gas supply device and the liquid supply device 103, a second filtering device 105 is configured to further filter out potential impurity particles, and a metering device is also configured to achieve precise control and monitoring of the flow rate of the liquid raw material. In this embodiment, the liquid output section specifically includes a second gas supply device 102 and a liquid supply device 103 connected in series in sequence. Among them, the second gas supply device 102 is specifically used to supply hydrogen, and its function is to provide the necessary carrier gas or protective atmosphere for the liquid raw material to enhance the stability and safety of the liquid raw material during transportation. The liquid supply device 103 is responsible for supplying the key liquid raw material of the reaction gas, methyltrichlorosilane. Methyltrichlorosilane is often used as a precursor in the deposition reaction and is crucial for forming high-quality thin film materials. In other specific embodiments, according to the specific requirements of the actual application scenario, the hydrogen supply device can be designed as independent individuals, each equipped with an independent gas source, and hydrogen is input into the vaporization device 104 and the liquid supply device 103 respectively. In this embodiment, in order to simplify the system structure and improve the operation convenience, a hydrogen supply device (i.e., the second gas supply device 102) is used to supply gas uniformly.

[0050] The vaporization device 104 is the core of the gas supply module 1 and is used to mix and vaporize the raw materials provided by the gas output section and the liquid output section. The vaporization device 104 is internally designed with efficient heating elements and a mixing chamber, which can heat the liquid raw material to the vaporization point within a short time and fully mix it with the gas raw material to form a uniform gas-phase mixture. This mixture is then transported to the reaction module 2 through the output end of the vaporization device 104 in the form of a stable gas flow to provide the necessary raw materials for the subsequent deposition reaction. In addition, in order to precisely control the gas-phase raw material supply required by the reaction module 2, a metering device is installed on the connecting pipeline between the vaporization device 104 and the reaction module 2. This metering device can real-time monitor the flow rate of the gas-phase mixture output by the vaporization device 104 and automatically adjust it to the optimal feeding rate according to the preset reaction conditions, providing strong technical support for the precise control of the deposition reaction, while also improving the utilization rate of raw materials and reducing production costs.

[0051] The reaction module 2 includes a deposition chamber 201, at least one intake pipe 202, and at least one exhaust unit 203. The intake pipe 202 and the exhaust unit 203 are connected to the side wall of the deposition chamber 201. A deposition area 2011 is provided in the deposition chamber 201, and at least one reaction substrate 2012 is provided in the deposition area 2011. A rotating device 204 is provided below the deposition chamber 201, and the rotating device 204 drives the reaction substrate 2012 in the deposition chamber 201 to rotate. In the existing deposition chamber design, in the place far from the air inlet, the gas flow rate is large and easy to form turbulence, and the uneven deposition of silicon carbide occurs at this place because the air flow is difficult to control. In the present invention, by adding a rotating device 204 below the deposition chamber 201 to drive the reaction substrate 2012 in the deposition chamber 201 to rotate, the difference in air flow in different directions of the reaction substrate 2012 can be reduced, and the uniformity of the silicon carbide thin film deposition can be ensured. Specifically, as Figure 4 and Figure 5 shown, one intake pipe 202 and one exhaust unit 203 are connected to the side wall of the deposition chamber 201. The intake pipe 202 is connected to the deposition chamber 201, and its opening is located above the reaction substrate 2012. A control valve is provided on the intake pipe 202. The control valve realizes the individual adjustment of the flow rate and flow velocity of the reaction gas in each intake pipe 202. A reaction substrate 2012 and a support member 2013 are provided in the deposition area. The support member 2013 is located in the round hole of the reaction substrate 2012 and is fixed to the reaction substrate 2012, ensuring that each layer of the reaction substrate 2012 is arranged below the opening of the corresponding intake pipe 2021, so that each layer of the reaction substrate 2012 can contact the reaction gas. The deposition area 2011 includes multiple groups of reaction substrates 2012 arranged horizontally. The rotating device 204 is connected below a group of reaction substrates 2012 for driving the corresponding reaction substrates 2012 to rotate.

[0052] Specifically, the rotating device 204 includes a transmission member 2041 and a first power source 2042. One end of the transmission member 2041 and the bottom end of the support member 2013 are a gear structure for mutual cooperation. The first power source 2042 drives the support member 2013 to rotate through the transmission member 2041. The transmission member 2041 and the support member 2013 are provided for cooperation. The first power source 2042 drives the support member 2013 to rotate, so that the reaction substrate 2012 on the support member 2013 makes a rotational motion, reducing the difference in air flow in different directions of the reaction substrate 2012 and ensuring the uniformity of the thin film deposition. The sawteeth of the gear structure are any one of rectangular, triangular, or chevron-shaped.

[0053] In other specific embodiments, the exhaust unit 203 in the reaction module 2 can also be arranged at the top of the deposition chamber 201 and directly above the reaction substrate 2012. In the existing reaction chamber design, in the place far from the inlet, the gas flow rate is relatively large and turbulence is likely to form, and the deposition of silicon carbide is uneven due to the difficult control of the air flow. By modifying the exhaust unit 203 from the side wall of the deposition chamber 201 to the top of the deposition chamber 201 and arranging it directly above the deposition area, even if there is air flow disturbance at the exhaust unit 203, the air flow will only exist in the middle of the deposited silicon carbide ring, and deposition is not required in the middle of the silicon carbide ring, so it will not affect the overall uniformity of the silicon carbide ring, and there is no need to increase the deposition film thickness to improve the deposition uniformity, thus saving the production cost. Specifically, as Figure 6 and Figure 7 shown, an intake pipe 202 is arranged on the side wall of the deposition chamber 201. The outlet end 2021 of the intake pipe 202 extends into the deposition chamber 201. Two openings 2022 are arranged at the outlet end 2021. Nozzles (not shown in the figure) are arranged at the openings 2022. The air flow of the reaction gas in the nozzles flows along the horizontal direction parallel to the reaction substrate 2012. The openings 2022 are arranged above the reaction substrate 2012 so that the reaction gas can cover the surface of the reaction substrate 2012. A circular reaction substrate 2012 is horizontally arranged in the deposition area 2011. The silicon carbide ring is deposited on the reaction substrate 2012. The shape of the reaction substrate 2012 is adapted to the shape of the silicon carbide ring to be deposited. The number of openings at the outlet end of the intake pipe 2021 can be flexibly adjusted and can be symmetrically arranged along the side wall of the deposition chamber 201 to ensure uniform distribution of the reaction gas. Multiple intake pipes 202 can also be arranged. By separately adjusting the gas flow rate of the intake pipe 2021 in each intake pipe 202, the uniform distribution of the reaction gas in the deposition chamber 201 is realized, and the deposition uniformity of the deposited silicon carbide ring is ensured. The outlet end of each intake pipe 2021 can have only one opening or multiple openings.

[0054] During the deposition reaction process, the generated tail gas is extracted and processed by the tail gas treatment module 3. The tail gas treatment module 3 specifically includes a vacuum device 301 and a tail gas treatment device 302. Among them, the vacuum device 301 is connected to the first filtering device 4. By means of vacuum pumping, the residual gas and impurities in the pipeline are effectively removed during and after the reaction process, ensuring the cleanliness inside the system and the pure reaction environment. The tail gas treatment device 302 is connected to the vacuum device 301 and adopts advanced catalytic oxidation, adsorption or other chemical treatment technologies to deeply purify the tail gas generated by the reaction to ensure that the content of all harmful substances is lower than the emission standard, realizing environmentally friendly waste gas treatment. Among them, as Figure 8As shown, the first filtering device 4 includes a body 401 and a filter element 402. The interior of the body 401 is a hollow chamber, and the filter element 402 is disposed in the hollow chamber, dividing the interior of the body 401 into an unfiltered area 4011 and a filtered area 4012; an air inlet and an air outlet are provided on the body 401, the air inlet is communicated with the unfiltered area 4011, and the air outlet is communicated with the filtered area 4012; a cooling device 403 is further included, and the cooling device 403 is disposed on the periphery of the body 401 to cool the body 401. A collection chamber 404 is further provided inside the body 401. The collection chamber 404 is located below the hollow chamber and is communicated with the hollow chamber. An external interface is provided at the bottom of the collection chamber 404 for facilitating connection with an external collection container. In order to monitor the temperature condition in the collection chamber 404 in real time, a temperature controller is further disposed in the collection chamber and is connected to an external display through a signal line so that an operator can grasp the temperature change in the collection chamber 404 at any time.

[0055] In this embodiment, an innovative design of a liquid supply device 103 is proposed, as Figure 9As shown, the design is significantly different from the prior art, and is particularly optimized for the vaporization process of methyltrichlorosilane. Methyltrichlorosilane is not directly vaporized in a conventional supply device, but the vaporization process is completed in a special vaporizer. In this process, hydrogen, as a carrier gas, undertakes the key task of safely and efficiently transporting the liquid form of methyltrichlorosilane to the vaporizer. In response to this special demand, the present invention has specifically designed the liquid supply device 103. Specifically, in the outlet area of ​​the liquid supply device 103, an air inlet pipe 1031 and a liquid outlet pipe 1032 are provided. Among them, the end of the liquid outlet pipe 1032 is positioned below the liquid surface to ensure that the methyltrichlorosilane liquid can be discharged smoothly; and the end of the air inlet pipe 1031 is set at a position higher than the end of the liquid outlet pipe 1032. The purpose of this design is that when hydrogen is introduced as a carrier gas, as the pressure inside the device gradually increases, a bottom-up airflow effect will be generated, and this airflow can effectively lift and guide the methyltrichlorosilane liquid to flow out smoothly along the pipe. Switch valves 1033 are installed on the air inlet pipe 1031 and the liquid outlet pipe 1032 outside the outlet of the liquid supply device 103. These switch valves 1033 can accurately control the on-off and flow rate of the gas as needed, thereby realizing fine adjustment of the liquid delivery process. In addition, a pressure detection device 1034 is specially set inside the liquid supply device 103, and the device is located above the liquid surface. This design can monitor the pressure changes inside the liquid supply device 103 in real time, prevent the risk of the outlet pipe being blocked by impurities that may exist inside the device, and avoid the problem of abnormal increase in gas pressure inside the device caused by this. Once the outlet pipe is unfortunately blocked, causing the internal pressure of the device to rise rapidly, the pressure detection device 1034 can immediately capture this change and send out an accurate alarm signal. Furthermore, the pressure detection device 1034 can be integrated into the entire system. Once abnormal pressure is detected, it can not only automatically trigger the alarm mechanism, but also quickly link with other parts of the system to take necessary emergency measures, such as closing the intake valve, starting the backup exhaust device, etc., to ensure the safe and stable operation of the entire system.

[0056] This system integrates optimized gas supply module 1, reaction module 2 and tail gas treatment module 3, especially the innovatively designed liquid supply device 103 and vaporization device 104, which ensures the safe, efficient vaporization and precise control supply of liquid raw materials such as methyltrichlorosilane. At the same time, the system's built-in precision metering, filtration and pressure detection mechanisms not only improve the raw material utilization rate and deposition reaction accuracy, but also effectively ensure the cleanliness, environmental protection and safety of the system, providing reliable technical support for the preparation of high-quality silicon carbide thin film materials, and significantly enhancing the overall performance and practicality of the system.

[0057] It should be noted that, for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A deposition method for chemical vapor deposition of silicon carbide, characterized in that, It includes the following steps: S1. Provide a graphite substrate, place the substrate into the reaction module (2), start the rotating device (204), and introduce silane gas. Control the reaction temperature at 1100 - 1200 °C and continuously react for 5 - 10 min to form silicon carbide grains on the surface of the substrate. S2. Lower the temperature of the reaction module (2) to 400 - 500 °C, and perform annealing treatment on the substrate with silicon carbide grains formed on its surface. The reaction time is not less than 5 min to improve the flatness of the silicon carbide grains. S3. The gas supply module (1) introduces at least three process gases into the reaction module (2), and adjusts the temperature of the reaction module (2) to rise to 1300 - 1500 °C to deposit a silicon carbide film on the surface of the substrate.

2. A chemical vapor deposition silicon carbide system, characterized in that, For implementing the deposition method described in claim 1, it specifically includes: A gas supply module (1) that provides at least three process gases required for the deposition reaction; A reaction module (2) where a substrate is placed to perform the deposition reaction of silicon carbide; An exhaust gas treatment module (3) responsible for treating the exhaust gas generated during the reaction process; The gas supply module (1) includes a vaporization device (104). At least two process gases are input into the vaporization device (104) in a gaseous form, and at least one process gas is carried into the vaporization device (104) in a liquid form through another process gas participating in the reaction and acting as a carrier gas to complete vaporization in the vaporization device (104). The output end of the vaporization device (104) is connected to the reaction module (2), and the output end of the reaction module (2) is connected to the exhaust gas treatment module (3).

3. The system according to claim 2, wherein The reaction module (2) includes a deposition chamber (201), at least one intake pipe (202), and at least one exhaust unit (203). The intake pipe (202) and the exhaust unit (203) are connected to the side wall of the deposition chamber (201). A deposition area (2011) is provided in the deposition chamber (201), and at least one set of reaction substrates (2012) is provided in the deposition area (2011). A rotating device (204) connected to each set of reaction substrates (2012) is provided below the deposition chamber (201), and the rotating device (204) drives the reaction substrates (2012) to rotate.

4. The system according to claim 3, characterized in that, The deposition area (2011) includes multiple sets of reaction substrates (2012) arranged horizontally, and multiple sets of rotating devices (204) are correspondingly provided below the deposition chamber (201) to drive the multiple sets of reaction substrates (2012) to rotate.

5. The system according to claim 2, wherein The reaction module (2) includes a deposition chamber (201), at least one intake pipe (202), and at least one exhaust unit (203). The intake pipe (202) and the exhaust unit (203) are in communication with the side wall of the deposition chamber (201). A deposition area (2011) is provided inside the deposition chamber (201), and at least one reaction substrate (2012) is provided in the deposition area (2011). The exhaust unit (203) is provided at the top of the deposition chamber (201) and directly above the reaction substrate (2012).

6. The system according to claim 2, wherein A first filtration device (4) is connected between the reaction module (2) and the tail gas treatment module (3); the first filtration device (4) includes a body (401) and a filter core (402). The interior of the body (401) is a hollow chamber, and the filter core (402) is provided in the hollow chamber, dividing the interior of the body (401) into an unfiltered area (4011) and a filtered area (4012); an intake port and an outlet port are provided on the body (401). The intake port is in communication with the unfiltered area (4011), and the outlet port is in communication with the filtered area (4012); a cooling device (403) is further included. The cooling device (403) is provided on the periphery of the body (401) to cool the body (401).

7. The system according to claim 2, wherein The gas supply module (1) further includes a gas output part and a liquid output part. The gas output part includes at least two types of gas supply devices. The liquid output part includes a gas supply device and a liquid supply device (103) connected in sequence. A second filtration device (105) is provided on the connecting pipe of the gas supply device and the liquid supply device (103).

8. The system according to claim 7, wherein The gas output part includes a first gas supply device (101) and a second gas supply device (102); the liquid output part includes a second gas supply device (102) and a liquid supply device (103); the first gas supply device (101) supplies argon, the second gas supply device (102) supplies hydrogen, and the liquid supply device (103) supplies methyltrichlorosilane.

9. The system according to claim 8, wherein A purification device (106) is provided at the outlet of the second gas supply device (102). The purification device (106) is made of one of a palladium tube, a palladium membrane, a cellulose membrane, or a hydrogen membrane separator.

10. The system according to claim 7, wherein An intake pipe (1031) and a liquid outlet pipe (1032) are provided at the outlet of the liquid supply device (103). The end of the liquid outlet pipe (1032) is located below the liquid level, and the end position of the intake pipe (1031) is higher than the end position of the liquid outlet pipe (1032); a pressure detection device (1034) is further provided inside the liquid supply device (103) and above the liquid level.

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