System for chemical vapor deposition of silicon carbide

Abstract

The utility model provides a system for chemical vapor deposition of silicon carbide, which comprises a gas supply module for providing required gas for deposition reaction; the reaction module comprises a chemical vapor deposition chamber and is used for executing a deposition reaction process of silicon carbide; the tail gas treatment module is responsible for treating tail gas generated in the reaction process; the gas supply module comprises a gas output part, a liquid output part and a vaporization device, the gas output part and the liquid output part are both connected with the input end of the vaporization device, and the output end of the vaporization device is connected with the reaction module; the output end of the reaction module is connected with the tail gas treatment module, and a first filtering device is connected between the reaction module and the tail gas treatment module. The vaporization device is adopted to replace a traditional mixing tank, so that the vaporization efficiency of methyl trichlorosilane (MTS) is remarkably improved, the utilization efficiency of the raw material MTS is greatly improved, and meanwhile, the use amount of hydrogen is effectively reduced. Not only is the production cost reduced, but also the control of process conditions becomes more accurate, and the purity of the silicon carbide product is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to chemical vapor deposition technical field especially relates to a system of chemical vapor deposition silicon carbide. BACKGROUND

[0002] In the existing chemical vapor deposition silicon carbide system, the system is mainly composed of three core parts of gas supply system, reaction cavity and tail gas and vacuum treatment system. In the gas supply system, hydrogen (H2) is used as a carrier gas to bring methyltrichlorosilane (MTS) vapor into the mixing tank. Specifically, the traditional technical scheme needs to heat the entire storage tank to form MTS vapor in the upper part of the storage tank. Then, H2 as a carrier gas carries these vapors out of the storage tank and mixes with additional H2 and inert gas (such as argon Ar) in the mixing tank to achieve the specific ratio required by the process. This mixed gas is then input into the reaction cavity for chemical vapor deposition process.

[0003] However, the prior art has several significant problems. First, the flow of MTS is closely related to the MTS vapor pressure, and since the flow is relatively small, a large amount of H2 is needed to effectively carry the MTS vapor out of the storage tank. However, the ratio of H2 to MTS has a crucial impact on the properties of the final SiC material, so this dependence on a large amount of H2 is not conducive to the precise adjustment of the entire process. Second, although high-purity H2 is used, impurities may exist in the storage tank itself, which will enter the MTS storage tank with H2 and even eventually deposit on the SiC product, thereby adversely affecting the quality and performance of the product. These problems not only increase the difficulty of process control, but also may pose potential risks to the final quality of the product. SUMMARY

[0004] To solve all or part of the problems of the prior art, the utility model provides a system for chemical vapor deposition of silicon carbide, which uses a vaporization device to replace the traditional mixing tank. MTS liquid is vaporized in the vaporizer, which not only significantly improves the vaporization efficiency of MTS, but also makes it easier and more accurate to adjust the ratio of each gas in the system.

[0005] To achieve the above purpose, the utility model provides the following technical scheme:

[0006] A system for chemical vapor deposition of silicon carbide, comprising:

[0007] A gas supply module provides the required gas for the deposition reaction;

[0008] A reaction module includes a chemical vapor deposition chamber for performing the deposition reaction process of silicon carbide;

[0009] A tail gas treatment module is responsible for treating the tail gas generated in the reaction process.

[0010] The gas supply module comprises a gas output part, a liquid output part and a vaporization device, the gas output part and the liquid output part are connected with the input end of the vaporization device, and the output end of the vaporization device is connected with the reaction module; the output end of the reaction module is connected with the tail gas treatment module, and a first filter device is connected between the two.

[0011] The utility model discloses a vaporization device replaces the traditional mixing tank, and the vaporization efficiency of methyltrichlorosilane (MTS) is improved significantly, so that the utilization efficiency of raw material MTS is improved greatly, and the hydrogen consumption is reduced effectively.

[0012] The gas output part of the gas supply module comprises at least two types of gas supply devices; the liquid output part comprises a gas supply device and a liquid supply device connected in sequence, the liquid in the liquid supply device is carried into the vaporization device by the gas supply device, and a second filter device is arranged on the connecting pipeline of the gas supply device and the liquid supply device.

[0013] The gas output part comprises a first gas supply device and a second gas supply device; the liquid output part comprises a third gas supply device and a liquid supply device.

[0014] The first gas supply device supplies argon, and the second gas supply device supplies hydrogen; the third gas supply device supplies hydrogen, and the liquid supply device supplies methyltrichlorosilane.

[0015] 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 film, a cellulose film or a hydrogen film separator.

[0016] An air inlet pipeline and a liquid outlet pipeline are arranged at the outlet of the liquid supply device, the end of the liquid outlet pipeline is below the liquid level, and the end of the air inlet pipeline is higher than the end of the liquid outlet pipeline.

[0017] Switch valves are arranged on the air inlet pipeline and the liquid outlet pipeline outside the outlet of the liquid supply device.

[0018] A pressure detection device is further arranged in the liquid supply device and located above the liquid level.

[0019] The tail gas treatment module comprises a vacuum device and a tail gas treatment device, the vacuum device is connected with the first filtering device, and the tail gas treatment device is connected with the vacuum device.

[0020] The vaporization device is connected with the reaction module.

[0021] The utility model has at least the following beneficial effects:

[0022] 1) By adopting the vaporization device to replace the traditional mixing tank, and optimizing the design of the liquid supply device of methyltrichlorosilane, efficient vaporization and accurate supply of raw materials such as methyltrichlorosilane are realized. This not only significantly improves the utilization efficiency of the gas supply raw materials, but also reduces the amount of hydrogen, thereby effectively reducing the production cost. At the same time, the precise metering device ensures the accurate control of the gas flow, further improving the precision and stability of the deposition reaction.

[0023] 2) By optimizing the gas supply module, the reaction module and the tail gas treatment module, the utility model ensures the stability and controllability of the deposition reaction process. The efficient vaporization device and the accurate metering mechanism provide reliable technical support for the preparation of high-quality silicon carbide thin film materials, significantly enhancing the overall performance and practicality of the system. The liquid supply device is also provided with a pressure detection device, which can further integrate the alarm and emergency treatment mechanism to monitor and prevent potential safety hazards in real time. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, obviously, the drawings described below are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating labor.

[0025] Figure 1 It is a structure schematic view of the system for chemical vapor deposition of silicon carbide of the embodiment of the utility model.

[0026] Figure 2 It is a structure schematic view of the liquid supply device provided by the embodiment of the utility model. Figure 1

[0027] Mark: 1-gas supply module; 101-first gas supply device; 102-second gas supply device; 103-liquid supply device; 1031-gas inlet pipeline; 1032-liquid outlet pipeline; 1033-switching valve; 1034-pressure detection device; 104-vaporization device; 105-second filtering device; 106-purification device; 2-reaction module; 3-tail gas treatment module; 301-vacuum device; 302-tail gas treatment device; 4-first filtering device.​ DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0029] The implementation of the present application will be described in detail below in combination with specific embodiments.

[0030] In the embodiments of the present application, as shown in combination with reference Figure 1 , Figure 2 , a system for chemical vapor deposition of silicon carbide is provided. The system is mainly composed of three core modules: gas supply module 1, reaction module 2 and tail gas treatment module 3. Specifically, the gas supply module 1 aims to provide all the necessary gas components for the subsequent deposition reaction. The reaction module 2, as the core of the system, is built-in with a chemical vapor deposition chamber. 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 performance and structural characteristics. The tail gas treatment module 3 is responsible for safely and effectively treating the tail gas generated during the deposition reaction. In order to ensure the environmental protection and safety of the system operation, a first filter device 4 is specially arranged between the output end of the reaction module 2 and the tail gas treatment module 3. The filter device can effectively capture and remove harmful particles and unreacted gas in the tail gas, thereby ensuring that the tail gas emission meets the relevant environmental protection standards.

[0031] The gas supply module 1 specifically comprises a gas output part, a liquid output part and a vaporization device 104, wherein the gas output part and the liquid output part are both in communication with the input end of the vaporization device 104 through respective connecting pipelines, and the output end of the vaporization device 104 is connected with the reaction module 2 to ensure stable supply and efficient use of the gas. The gas output part as the starting point of the gas supply module 1 is responsible for providing various gas components required for deposition reaction, and at least two types of gas supply devices can be designed, and a metering device is installed on the connecting pipeline between each gas supply device and the vaporization device 104 to facilitate accurate monitoring and adjustment of the flow of the gas. In this embodiment, the gas output part comprises a first gas supply device 101 and a second gas supply device 102. The first gas supply device 101 is specially used for supplying inert gas, argon, which plays an important protective role in semiconductor manufacturing and other processes. The second gas supply device 102 is responsible for supplying active gas, hydrogen, which plays an indispensable role in various chemical reactions. It is worth noting that the outlet position of the second gas supply device 102 is also specially configured with a purification device 106 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.

[0032] The liquid output section is dedicated to delivering the liquid feedstock of the reaction gas necessary for the deposition reaction to the vaporization device 104, and is sequentially connected by a gas supply device and a liquid supply device 103, with the liquid in the liquid supply device 103 being carried into the vaporization device 104 by the gas supply device. On the connecting pipeline between the gas supply device and the liquid supply device 103, a second filter device 105 is arranged to further filter out potential impurity particles, and a metering device is also arranged to achieve accurate control and monitoring of the flow of the liquid feedstock. In this embodiment, the specific composition of the liquid output section includes a third gas supply device and a liquid supply device 103 connected in series. Among them, the third gas supply device is specifically used to supply hydrogen, which serves to provide the necessary carrier gas or protective atmosphere for the liquid feedstock, so as to improve the stability and safety of the liquid feedstock during transportation. While the liquid supply device 103 is responsible for supplying methyltrichlorosilane, a key reaction gas liquid feedstock, which is often used as a precursor in the deposition reaction and is essential for the formation of high-quality thin film materials. In this embodiment, an efficient and economical design scheme is adopted, in which the third gas supply device and the second gas supply device 102 are integrated into the same supply device. This design not only simplifies the structure of the system and reduces the manufacturing cost, but also effectively improves the resource utilization rate and the flexibility of system operation by sharing the same gas source. The integrated supply device can simultaneously meet the needs of providing hydrogen as a carrier gas or protective atmosphere for the vaporization device 104 (in the role of the liquid output section) and directly supplying hydrogen as a reaction gas for the reaction module 2 (in the role of the gas output section). Although the third gas supply device and the second gas supply device 102 are integrated into one in this embodiment, in other specific embodiments, according to different actual application scenarios, the third gas supply device and the second gas supply device 102 can be designed as independent individuals, each equipped with an independent gas source and control system, to better adapt to the specific requirements of different reaction conditions for gas types, flow rates, and purity.

[0033] The vaporization device 104 is the core of the gas supply module 1, which is used to mix and vaporize the raw materials provided by the gas output part and the liquid output part. The vaporization device 104 is designed with high-efficiency heating elements and mixing chambers inside, which can heat the liquid raw materials to the vaporization point in a short time and fully mix with the gas raw materials to form a uniform gas-phase mixture. This mixture is then delivered through the output end of the vaporization device 104 in the form of a stable gas flow to the reaction module 2, providing the necessary raw materials for the subsequent deposition reaction. In addition, in order to accurately 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. The metering device can monitor the flow of the gas-phase mixture output by the vaporization device 104 in real time and automatically adjust to the optimal supply 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.

[0034] During the deposition reaction process, the tail gas generated is extracted and treated through 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. The vacuum device 301 is connected to the first filter device 4, which effectively removes residual gas and impurities in the pipeline during and after the reaction by vacuum extraction, ensuring the cleanliness of the system and the pure environment of the reaction. The tail gas treatment device 302 is connected to the vacuum device 301, which uses advanced catalytic oxidation, adsorption or other chemical treatment technologies to deeply purify the reaction-generated tail gas, to ensure that the content of all harmful substances is below the emission standard, achieving environmentally friendly waste gas treatment.

[0035] In this embodiment, an innovative liquid supply device 103 design is proposed, which is significantly different from the prior art and is 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 dedicated vaporizer. In this process, hydrogen gas acts as a carrier gas, taking on the critical task of safely and efficiently transporting methyltrichlorosilane in liquid form to the vaporizer. For this specific need, the liquid supply device 103 is designed accordingly. Specifically, at the outlet area of the liquid supply device 103, an inlet gas pipe 1031 and a liquid outlet pipe 1032 are provided. The end of the liquid outlet pipe 1032 is positioned below the liquid level to ensure that methyltrichlorosilane liquid can be smoothly discharged; while the end of the inlet gas 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 gas as a carrier gas is introduced, as the internal pressure of the device gradually increases, an upward airflow effect will be generated, which can effectively lift and guide the methyltrichlorosilane liquid to flow smoothly along the pipe. The inlet gas pipe 1031 and the liquid outlet pipe 1032 outside the outlet of the liquid supply device 103 are both equipped with on-off valves 1033. These on-off valves 1033 can accurately control the on-off and flow of gas as needed, thereby achieving fine adjustment of the liquid delivery process.

[0036] In addition, a pressure detection device 1034 is also specially provided inside the liquid supply device 103, and the device is located above the liquid level. This design can monitor the pressure changes inside the liquid supply device 103 in real time, prevent the risk of outlet pipe blockage by impurities that may exist inside the device, and avoid the problem of abnormal increase in internal gas pressure caused thereby. 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 an accurate alarm signal. Further, this pressure detection device 1034 can be integrated into the entire system, and once an abnormal pressure is detected, not only can it automatically trigger an alarm mechanism, but it can also quickly interact with other parts of the system to take necessary emergency measures, such as closing the gas inlet valve, starting the backup exhaust device, etc., to ensure the safe and stable operation of the entire system.

[0037] The utility model integrates the optimized gas supply module 1, reaction module 2 and tail gas treatment module 3, especially the innovative liquid supply device 103 and vaporization device 104, which ensures the safe and efficient vaporization and accurate control of liquid raw materials such as methyltrichlorosilane. At the same time, the built-in precision metering, filtering and pressure detection mechanism of the system not only improves the raw material utilization rate and deposition reaction accuracy, but also effectively guarantees 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.

[0038] It should be noted that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A system for chemical vapor deposition of silicon carbide, characterized in that, include: Gas supply module (1) provides the gas required for the deposition reaction; The reaction module (2) includes a chemical vapor deposition chamber for performing the silicon carbide deposition reaction process; The exhaust gas treatment module (3) is responsible for treating the exhaust gas generated during the reaction process; The gas supply module (1) includes a gas output section, a liquid output section and a vaporization device (104). The gas output section and the liquid output section are both connected to the input end of the vaporization device (104). The output end of the vaporization device (104) is connected to the reaction module (2). The output end of the reaction module (2) is connected to the exhaust gas treatment module (3), and a first filter device (4) is connected between the two.

2. The system according to claim 1, characterized in that, The gas output section of the gas supply module (1) includes at least two types of gas supply devices; the liquid output section includes a gas supply device and a liquid supply device (103) connected in sequence, and the gas supply device carries the liquid in the liquid supply device (103) into the vaporization device (104); a second filter device (105) is provided on the connecting pipe of the gas supply device and the liquid supply device (103).

3. The system according to claim 2, characterized in that, The gas output section includes a first gas supply device (101) and a second gas supply device (102); the liquid output section includes a third gas supply device and a liquid supply device (103).

4. The system according to claim 3, characterized in that, The first gas supply device (101) supplies argon, the second gas supply device (102) supplies hydrogen, the third gas supply device supplies hydrogen, and the liquid supply device (103) supplies methyltrichlorosilane.

5. The system according to claim 4, characterized in that, A purification device (106) is provided at the outlet of the second gas supply device (102), the purification device (106) being made of one of a palladium tube, a palladium membrane, a cellulose membrane, or a hydrogen membrane separator.

6. The system according to claim 2, characterized in that, The liquid supply device (103) is provided with an air inlet pipe (1031) and a liquid outlet pipe (1032) at its outlet. The end of the liquid outlet pipe (1032) is below the liquid surface, and the end of the air inlet pipe (1031) is higher than the end of the liquid outlet pipe (1032).

7. The system according to claim 6, characterized in that, A switch valve (1033) is provided on both the air inlet pipe (1031) and the liquid outlet pipe (1032) outside the outlet of the liquid supply device (103).

8. The system according to claim 6, characterized in that, The liquid supply device (103) is also equipped with a pressure detection device (1034), which is located above the liquid surface.

9. The system according to claim 1, characterized in that, The exhaust gas treatment module (3) includes a vacuum device (301) and an exhaust gas treatment device (302). The vacuum device (301) is connected to the first filter device (4), and the exhaust gas treatment device (302) is connected to the vacuum device (301).

10. The system according to claim 1, characterized in that, A metering device is connected between the vaporization device (104) and the reaction module (2).

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