A preheating device and system for silicon tetrachloride

Abstract

This application provides a silicon tetrachloride preheating device and system. The silicon tetrachloride preheating device includes an inlet assembly connected to an external gas supply device; the preheating assembly includes a primary preheating unit, a secondary preheating unit, and a tertiary preheating unit, which are connected sequentially to heat the SiCl4 gas in a stepped manner. The outlet assembly is connected to the tertiary preheating unit. By sequentially setting the multi-stage preheating units, the introduced SiCl4 gas can be heated stably step by step, significantly improving the temperature uniformity of the gas and reducing silicon source waste caused by temperature differences during the deposition process.

Description

Technical Field

[0001] This application relates to the field of vapor deposition technology, and more particularly to a preheating device and system for silicon tetrachloride. Background Technology

[0002] In the preparation of 6.5% Si steel, chemical vapor deposition (CVD) is used to enrich silicon on the surface of a low-carbon steel substrate, thereby obtaining a soft magnetic material with high silicon content, low iron loss, and high magnetic permeability. In this process, silicon tetrachloride (SiCl4) is widely used as the main silicon source precursor gas due to its excellent silicon diffusion performance and high precision. During the CVD silicon infiltration process, SiCl4 reacts with the steel strip substrate at high temperature to form Fe3Si, achieving controlled and uniform diffusion of silicon into the steel substrate and directly affecting the silicon infiltration quality.

[0003] However, SiCl4 faces the following technical bottlenecks under vapor deposition conditions: low decomposition efficiency: SiCl4 reacts slowly at lower temperatures, resulting in low silicon source utilization and reduced deposition efficiency; poor gas uniformity: if SiCl4 gas is not sufficiently preheated before entering the reaction zone, causing it to become liquid below the dew point, the temperature gradient difference leads to uneven flow field distribution, affecting the silicon diffusion effect; existing technologies often use direct heating of the reaction chamber or substrate. In practical applications, SiCl4 gas needs to react at temperatures of 1100℃ or higher. If this temperature needs to be maintained for a long time, high-temperature conditions can easily lead to problems such as equipment and material deformation and excessive energy consumption. Furthermore, the process of heating the furnace from room temperature to the reaction temperature is very slow, seriously affecting production efficiency.

[0004] Therefore, in order to address the above problems, this invention proposes a silicon tetrachloride preheating device and system, which improves the efficiency and effectiveness of the CVD silicon infiltration process by designing a precise gas flow channel and a segmented heating system. Summary of the Invention

[0005] One of the technical problems that this application aims to solve is that the existing heating methods are uneven and consume a lot of energy, causing fluctuations in the SiCl4 gas percolation rate, uneven silicon layer composition, and high energy consumption, which affects production efficiency.

[0006] To address the aforementioned technical problems, embodiments of this application provide a preheating device for silicon tetrachloride, comprising: An air intake assembly, which is connected to an external air supply device; A preheating assembly, comprising a primary preheating unit, a secondary preheating unit, and a tertiary preheating unit, wherein the primary preheating unit is connected to the air intake assembly; An exhaust assembly, which is connected to the three-stage preheating unit; The primary preheating unit includes an external connecting pipe, the secondary preheating unit includes a heating shell, and the tertiary preheating unit includes an insulating shell. The external connecting pipe, heating shell, and insulation shell are connected in sequence to heat the SiCl4 gas in a stepped manner.

[0007] In some embodiments, the aforementioned silicon tetrachloride preheating device further includes an inner connecting pipe in the primary preheating unit, through which SiCl4 gas is supplied to the secondary preheating unit from between the inner connecting pipe and the outer connecting pipe, and the outer connecting pipe is provided with a resistance heating strip.

[0008] In some embodiments, the aforementioned silicon tetrachloride preheating device circulates high-temperature reaction waste gas within its internal connecting pipe.

[0009] In some embodiments, the aforementioned silicon tetrachloride preheating device further includes a heating tube in the secondary preheating unit, the heating tube being located inside the heating shell, SiCl4 gas being transported from inside the heating shell to the tertiary preheating unit, and an infrared heat receiving tube being wound around the outside of the heating shell.

[0010] In some embodiments, the aforementioned silicon tetrachloride preheating device has a gas guide pipe running through the interior of the insulation shell, with SiCl4 gas located inside the gas guide pipe, and an infrared radiation heating element inside the insulation shell to heat the gas guide pipe.

[0011] In some embodiments, the aforementioned silicon tetrachloride preheating device includes infrared radiation heating elements arranged in a ring or U-shape outside the gas duct.

[0012] In some embodiments, the aforementioned silicon tetrachloride preheating device has a heating temperature of 200-500°C for the primary preheating unit, 500-700°C for the secondary preheating unit, and 700-1000°C for the tertiary preheating unit.

[0013] In some embodiments, the aforementioned silicon tetrachloride preheating device includes a gas homogenizing device between the three-stage preheating unit and the gas outlet assembly to eliminate temperature and concentration gradients in the gas flow; wherein the gas homogenizing device is honeycomb-shaped.

[0014] A second aspect of this application provides a silicon tetrachloride preheating system, which includes the aforementioned silicon tetrachloride preheating device.

[0015] Through the above technical solution, the silicon tetrachloride preheating device and system provided in this application can stably heat the introduced SiCl4 gas step by step by setting up multi-stage preheating units in sequence. This will prevent the SiCl4 gas from becoming unstable due to large temperature changes during transportation, significantly improve the temperature uniformity of the gas, reduce the waste of silicon source caused by temperature difference during the deposition process, and slow down the overall heating time of the SiCl4 gas, thereby improving work efficiency and reducing energy consumption. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the silicon tetrachloride preheating device and system disclosed in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the primary preheating unit of the silicon tetrachloride preheating device and system disclosed in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the secondary preheating unit of the silicon tetrachloride preheating device and system disclosed in the embodiments of this application; Figure 4 This is a schematic diagram of the three-stage preheating unit of the silicon tetrachloride preheating device and system disclosed in the embodiments of this application; Figure 5 This is a schematic diagram of the gas homogenization device structure of the silicon tetrachloride preheating device and system disclosed in the embodiments of this application.

[0018] Explanation of reference numerals in the attached figures: 1. Inlet assembly; 2. Preheating assembly; 21. Primary preheating unit; 211. Inner connecting pipe; 212. Outer connecting pipe; 22. Secondary preheating unit; 221. Heating tube; 222. Heating shell; 23. Tertiary preheating unit; 231. Insulation shell; 3. Outlet assembly; 4. Resistance heating strip; 5. Infrared heat exchanger tube; 6. Air guide pipe; 7. Infrared radiation heating element; 8. Gas homogenization device. Detailed Implementation

[0019] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application. This application can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0020] These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​illustrated in these embodiments should be interpreted as merely exemplary and not as limiting.

[0021] It should be noted that, in the description of this application, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] Furthermore, the terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well.

[0023] It should also be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0024] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0025] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0026] Example 1 Reference Appendix Figure 1 This embodiment discloses a silicon tetrachloride preheating device, which includes an air inlet assembly 1, a preheating assembly 2, and an air outlet assembly 3. The air inlet assembly 1 is connected to an external air supply device. The preheating assembly 2 includes a primary preheating unit 21, a secondary preheating unit 22, and a tertiary preheating unit 23, which are connected in sequence to heat SiCl4 gas in a stepped manner. The primary preheating unit 21 is connected to the air inlet assembly 1, and the air outlet assembly 3 is connected to the tertiary preheating unit 23.

[0027] Specifically, to address the problems of uneven heating and high energy consumption in existing methods, which cause fluctuations in the SiCl4 gas silicon diffusion rate, uneven silicon layer composition, and high energy consumption affecting production efficiency, the silicon tetrachloride preheating device provided in this embodiment adopts a stepped heating method consisting of a primary preheating unit 21, a secondary preheating unit 22, and a tertiary preheating unit 23. This eliminates the need for a single high-temperature furnace heating method, greatly improving the heating rate of SiCl4 gas and thus increasing the overall heating efficiency. In addition, the stepped heating avoids the condensation of SiCl4 gas, which would affect the deposition quality and silicon diffusion rate. At the same time, the heating scheme is optimized, reducing the thermal interference effects before and after a single heating method.

[0028] In this embodiment, a silicon tetrachloride preheating device is mainly used in the preparation of 6.5% high-Si steel. The inlet assembly 1 is a general term for devices used to transport SiCl4 gas, and it is equipped with a flow monitoring device to monitor the volume of the incoming gas flow in real time and adjust the transported volume as needed to ensure the heating effect of the flowing gas. The preheating unit heats the SiCl4 gas in stages: the first-stage preheating unit 21 has a heating temperature of 200-500℃, the second-stage preheating unit 22 has a heating temperature of 500-700℃, and the third-stage preheating unit 23 has a heating temperature of 700-1000℃. Each preheating unit is equipped with a temperature sensor to monitor the heating effect of each unit and connect to an external closed-loop control system for precise control, ensuring the stability of gas heating. In addition, the SiCl4 gas is preheated in a spiral heat exchanger before entering the first-stage preheating unit 21. The spiral heat exchanger is heated by circulating waste gas from the reaction chamber, which greatly reduces the overall reaction energy consumption of the equipment. A gas homogenization device 8 is also provided between the gas outlet assembly 3 and the third-stage preheating unit 23. The gas homogenization device 8 has a honeycomb structure, which can transport the SiCl4 gas through a fixed pipeline to reduce temperature fluctuations.

[0029] In some embodiments, refer to the appendix Figure 2 The silicon tetrachloride preheating device provided in this embodiment includes an inner connecting pipe 211 and an outer connecting pipe 212. SiCl4 gas is transported from the inner connecting pipe 211 and the outer connecting pipe 212 to the secondary preheating unit 22. The outer connecting pipe 212 is provided with a resistance heating strip 4.

[0030] Specifically, to achieve steady heating of SiCl4 gas, the primary preheating unit 21 in this embodiment adopts a sleeve design, that is, heating is achieved through the combined action of an inner connecting pipe 211 and an outer connecting pipe 212. The inner connecting pipe 211 is connected to the exhaust gas in the external reaction chamber, utilizing the residual heat in the exhaust gas for preheating, eliminating the need for additional energy consumption. Furthermore, the inner connecting pipe 211 serves as an external circulation pipe, ensuring effective heating of the SiCl4 gas. The outer connecting pipe 212 is heated externally using a resistance heating band 4; alternatively, an infrared ceramic heating band could also be used. The ceramic heater heats the SiCl4 gas without direct contact with it. Both the inner connecting pipe 211 and the outer connecting pipe 212 are ceramic pipes. Since the SiCl4 gas at room temperature is not stable and is prone to corrosion, the SiCl4 gas only exists in the area between the outside of the inner connecting pipe 211 and the inside of the outer connecting pipe 212. This isolation heating method avoids corrosion of the SiCl4 gas. Therefore, this setup can smoothly raise the temperature of the SiCl4 gas to a stable level and maximize energy utilization.

[0031] In some embodiments, refer to the appendix Figure 3 The silicon tetrachloride preheating device provided in this embodiment includes a secondary preheating unit 22 comprising a heating tube 221 and a heating shell 222. The heating tube 221 is located inside the heating shell 222. SiCl4 gas is transported from inside the heating shell 222 to the tertiary preheating unit. An infrared heat receiving tube 5 is wound around the outside of the heating shell 222.

[0032] Specifically, in order to further stabilize and enhance the SiCl4 gas, a heating tube 221 is provided inside the heating shell 222 in this embodiment. The heating tube 221 is located at the central axis of the heating shell 222. The SiCl4 gas is stable at this temperature, so it can directly receive radiation heating from the heating tube 221 from its outer periphery for rapid temperature rise. An infrared heating tube 221 is wound around the outside of the heating shell 222 to stabilize the internal environment of the heating shell 222 and reduce heat loss from the heating tube 221. Through the combined effect of the inside and outside, the temperature of the SiCl4 gas is further enhanced at this location.

[0033] In some embodiments, refer to the appendix Figures 4 to 5 The silicon tetrachloride preheating device provided in this embodiment includes a three-stage preheating unit comprising an insulating shell 231, a gas guide pipe 6 passing through the interior of the insulating shell 231, SiCl4 gas being located inside the gas guide pipe 6, and an infrared radiation heating element 7 being provided inside the insulating shell 231 to heat the gas guide pipe 6.

[0034] Specifically, to ensure that the SiCl4 gas reaches the specified temperature, in this embodiment, the gas guide pipe 6 is directly connected to the heating shell 222, and the SiCl4 gas, which has undergone secondary heating, is transported into the gas guide pipe 6. An infrared radiation heating element 7 is provided on the outside of the gas guide pipe 6 inside the insulation shell 231. The infrared radiation heating element 7 can emit infrared waves to heat the gas inside the gas guide pipe 6, and the infrared radiation heating element 7 is distributed in a ring or U-shape on the outside of the gas guide pipe 6. The multi-layer heating method can ensure the heating effect of the gas guide pipe 6 and achieve temperature stability. In addition, the insulation shell 231 is covered with ceramic insulation material, which effectively reduces the heat loss inside the insulation shell 231 and stabilizes the ambient temperature. Finally, the SiCl4 gas is heated to 700-1000℃ and then output to the gas outlet assembly 3 for discharge. A temperature sensor is also provided on the insulation shell 231 to detect the heat of the gas guide pipe 6 and transmit it to the air inlet assembly 1 to control the air inlet flow rate, so as to ensure the heating effect of the SiCl4 gas.

[0035] In addition, when the SiCl4 gas is output from the gas outlet assembly 3, it first passes through the gas homogenization device 8 to reduce temperature loss. The gas homogenization device 8 is honeycomb-shaped, which can maximize the contact between the SiCl4 gas and the steel plate, further improving the silicon infiltration rate.

[0036] Example 2 This embodiment provides a silicon tetrachloride preheating system, which includes at least one silicon tetrachloride preheating device. Specifically, the glass processing apparatus is the glass processing apparatus of Embodiment 1. For the specific structure and working principle, please refer to the description of Embodiment 1, which will not be elaborated further here.

[0037] The embodiments of this application have now been described in detail. To avoid obscuring the concept of this application, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0038] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

Claims

1. A preheating device for silicon tetrachloride, characterized by, include: An air intake assembly (1) is connected to an external air supply device; The preheating assembly (2) includes a primary preheating unit (21), a secondary preheating unit (22) and a tertiary preheating unit (23), wherein the primary preheating unit (21) is connected to the air intake assembly (1); An exhaust assembly (3) is connected to the three-stage preheating unit (23); The primary preheating unit (21) includes an external connecting pipe (212), the secondary preheating unit (22) includes a heating shell (222), and the tertiary preheating unit (23) includes an insulating shell (231). The external connecting pipe (212), heating shell (222) and insulation shell (231) are connected in sequence to heat SiCl4 gas in a stepped manner.

2. The silicon tetrachloride preheating device according to claim 1, characterized in that, The primary preheating unit (21) also includes an inner connecting pipe (211), through which the SiCl4 gas is transported to the secondary preheating unit (22) between the inner connecting pipe (211) and the outer connecting pipe (212), and the outer connecting pipe (212) is provided with a resistance heating strip (4).

3. The silicon tetrachloride preheating device according to claim 2, characterized in that, The internal connecting pipe (211) circulates high-temperature reaction waste gas.

4. The silicon tetrachloride preheating device according to claim 1, characterized in that, The secondary preheating unit (22) also includes a heating tube (221), which is located inside the heating shell (222). The SiCl4 gas is transported from inside the heating shell (222) to the tertiary preheating unit (23). An infrared heat exchanger tube (5) is wound around the outside of the heating shell (222).

5. The silicon tetrachloride preheating device according to claim 1, characterized in that, The heat insulation shell (231) is provided with a gas guide pipe (6) inside, and the SiCl4 gas is located inside the gas guide pipe (6). The heat insulation shell (231) is provided with an infrared radiation heating element (7) to heat the gas guide pipe (6).

6. The silicon tetrachloride preheating device according to claim 5, characterized in that, The infrared radiation heating element (7) is distributed in a ring or U-shape outside the air duct (6).

7. The silicon tetrachloride preheating device according to claim 1, characterized in that, The heating temperature of the first-stage preheating unit (21) is 200-500℃, the heating temperature of the second-stage preheating unit (22) is 500-700℃, and the heating temperature of the third-stage preheating unit (23) is 700-1000℃.

8. The silicon tetrachloride preheating device according to claim 1, characterized in that, A gas homogenization device (8) is provided between the three-stage preheating unit (23) and the gas outlet assembly (3) to eliminate temperature and concentration gradients in the airflow; The gas homogenizing device (8) is honeycomb-shaped.

9. A preheating system for silicon tetrachloride, characterized by It includes: A preheating device for silicon tetrachloride comprising at least the features of any one of claims 1-8.

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