Silicon carbide epitaxial equipment with heat recovery function

Abstract

The present application provides a silicon carbide epitaxial growth device with a heat recovery function, including a reaction chamber, an annular heat collection bin and a delivery pipe. A first gas injection device is provided on the top of the reaction chamber, an exhaust gas discharge port is provided on the bottom, and a supporting device is provided inside, and the supporting top surface of the supporting device is opposite to the first gas injection device. An annular channel is formed between the outer wall of the supporting device and the inner wall of the reaction chamber. The annular heat collection bin is arranged in the space between the annular channel and the bottom surface of the reaction chamber, and is provided with a second gas inlet pipe and an outlet pipe to realize gas transportation, and the second gas inlet pipe extends to the outside of the reaction chamber. The two ends of the delivery pipe are respectively connected to the second gas outlet pipe and the first gas injection device, so as to transport the hot gas in the annular heat collection bin to the first gas injection device to mix with the gas in the first gas injection device to increase the gas temperature. The present application scheme can not only realize the effective recovery and utilization of the heat of the process exhaust gas, but also alleviate the cold zone effect with the help of the heat of the process exhaust gas.

Description

Technical Field

[0001] This application relates to the field of equipment technology for manufacturing or processing semiconductors, and more specifically, to a silicon carbide epitaxial device with heat recovery function. Background Technology

[0002] Silicon carbide epitaxial equipment is a key piece of equipment in the semiconductor power device manufacturing chain. Its main purpose is to grow one or more epitaxial thin films with target conductivity types and doping distributions on silicon carbide substrates.

[0003] The growth chamber of a silicon carbide epitaxial growth apparatus typically needs to be maintained in an ultra-high temperature range, such as 1500-1750°C. However, when room-temperature process gases (including source gases, carrier gases, and purge gases) are injected into the growth chamber, a significant cold zone forms within the chamber, disrupting the originally uniform thermal boundary layer. This cold zone effect leads to uneven thickness and doping distribution, affecting the growth rate and uniformity of silicon carbide epitaxy. To alleviate the cold zone problem, existing solutions often rely on increasing heating power, extending the heating cycle, or introducing complex local insulation structures, resulting in increased thermal inertia and shortened maintenance cycles.

[0004] However, the process exhaust gas after the reaction in the growth chamber carries a large amount of heat and is directly emitted, and there is currently a lack of efficient means for waste heat recovery and resource reuse. Therefore, how to improve the cold zone problem caused by process gas injection, and how to effectively utilize the waste heat of the process exhaust gas, have become urgent problems to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a silicon carbide epitaxial device with heat recovery function, which can not only effectively recover and utilize the heat of process waste gas, but also alleviate the cold zone effect by using the heat of process waste gas.

[0006] This application provides a silicon carbide epitaxial device with heat recovery function, including a reaction chamber, an annular heat collection chamber, and a delivery pipe.

[0007] The reaction chamber includes a first gas injection device at the top and a tail gas outlet at the bottom. An internal support device is located inside, with its top surface facing the first gas injection device. An annular channel is formed between the outer wall of the support device and the inner wall of the reaction chamber. An annular heat collection chamber is situated in the space between the annular channel and the bottom surface of the reaction chamber. It has a second gas inlet pipe and a second gas outlet pipe for gas transport, with the second gas inlet pipe extending outside the reaction chamber. Spacing is maintained between the annular heat collection chamber and the support device, as well as between the annular heat collection chamber and the side wall of the reaction chamber, to allow gas passage. A transport pipe connects at both ends to the second gas outlet pipe and the first gas injection device, extending within the side wall and top wall of the reaction chamber, to transport hot gas from the annular heat collection chamber to the first gas injection device for mixing and increasing the gas temperature.

[0008] In one feasible embodiment, the silicon carbide epitaxial device further includes a current collector with its top surface lower than the bottom surface of the support device. The current collector has an annular current collector cavity, and an annular heat collection chamber is suspended inside the current collector cavity. The top of the current collector cavity communicates with the inside and outside of the reaction chamber, and the bottom communicates with the exhaust port, allowing gas to be discharged from the current collector cavity through the exhaust port. The current collector cavity is fitted or gap-fitted with the side wall of the reaction chamber, and has a gap with the support device to avoid interfering with the movement of the support device. A second gas inlet pipe and a second gas outlet pipe pass through the current collector cavity and communicate with the inside of the annular heat collection chamber.

[0009] In one feasible scheme, both the axial cross-section of the annular heat collection chamber and the axial cross-section of the collection device are axisymmetric structures, and the central axis of the axial cross-section of the annular heat collection chamber coincides with the central axis of the axial cross-section of the collection device.

[0010] In one feasible embodiment, the annular heat collection chamber further includes support feet, and the heat collection device includes a support column located on the bottom surface of the heat collection cavity; the support column has a hollow structure, with its two ends connected to the exhaust port and the heat collection cavity respectively; the support feet are located between the bottom surface of the heat collection cavity and the bottom of the annular heat collection chamber to support the annular heat collection chamber.

[0011] In one feasible scheme, the height of the manifold cavity is H, and the annular heat collection chamber includes a top inner wall near the side where the supporting device is located, and a top outer wall near the side wall of the reaction chamber. The top of the top inner wall and the top of the top outer wall meet and extend towards the inner bottom surface of the reaction chamber to form a top structure. The height of the top structure is h1, and H / 2 ≤ h1 < H.

[0012] In one feasible solution, an isolator is installed inside the annular heat collection chamber to break the connectivity of the annular space inside the annular heat collection chamber. The inlet of the second gas inlet pipe and the outlet of the second gas outlet pipe on the annular heat collection chamber are located in the same half of the annular heat collection chamber and are close to opposite sides of the isolator to connect the same space inside the annular heat collection chamber.

[0013] In one feasible embodiment, a heating device is also included below the supporting device, with the annular heat collection chamber and the heating device being radially opposite each other along the reaction chamber.

[0014] In one feasible embodiment, the annular heat collection chamber includes a top-inner sidewall near the side where the support device is located, and a top-outer sidewall near the sidewall of the reaction chamber. The top ends of the top-inner sidewall and the top ends of the top-outer sidewall converge and extend toward the inner bottom surface of the reaction chamber to form a top structure. The exposed surface of at least one of the top-inner sidewall and the top-outer sidewall is a guide slope that is inclined relative to the top surface of the support device.

[0015] In one feasible embodiment, the annular heat collection chamber also includes a bottom structure that is connected to and internally communicates with the top structure to increase the internal volume of the annular heat collection chamber, and the second gas inlet pipe and the second gas outlet pipe are both located in the bottom structure.

[0016] In one feasible embodiment, the bottom structure includes a bottom-inward sidewall and a bottom-outward sidewall. The bottom-inward sidewall is adjacent to the support device, connected to the top-inward sidewall, and extends axially along the reaction chamber; the bottom-outward sidewall is adjacent to the sidewall of the reaction chamber, connected to the top-outward sidewall, and extends axially along the reaction chamber.

[0017] In one feasible scheme, the total height of the annular heat collection chamber is h, and the height occupied by the guide slope is h1, where h / 2≤h1≤h.

[0018] In one feasible solution, the top of the inner sidewall and the top of the outer sidewall meet to form a sharp angle structure or a chamfered structure.

[0019] In one feasible embodiment, the inward-facing top wall and the outward-facing top wall are tilted at the same degree relative to the load-bearing device, with the bottom end of the outward-facing top wall lower than the bottom end of the inward-facing top wall.

[0020] In one feasible embodiment, the acute angles of inclination of the top outer wall and the top inner wall to the top surface of the bearing device are α1 and α2, respectively, wherein 45°≤α1<90° and 45°≤α2<90°.

[0021] In one feasible approach, the axial cross-section of the annular solar collector is axisymmetric.

[0022] In one feasible embodiment, the sidewalls and top wall of the reaction chamber are provided with a heat insulation layer, and the delivery pipe is buried within the heat insulation layer.

[0023] In one feasible embodiment, a second gas supply device located outside the reaction chamber is also included, which is connected to a second gas inlet pipe to provide carrier gas or purge gas.

[0024] In one feasible embodiment, the first gas injection device is provided with a process gas channel and a purge gas channel, and the second gas inlet pipe is connected to either the process gas channel or the purge gas channel.

[0025] Compared with the prior art, the beneficial effects of this application include at least the following: The annular heat collection chamber in the silicon carbide epitaxial equipment with heat recovery function of this application is located in the space between the annular channel formed by the outer wall of the supporting device and the inner wall of the reaction chamber and the bottom surface of the reaction chamber. The supporting top surface of the supporting device is opposite to the first gas injection device located at the top of the reaction chamber, and the bottom of the reaction chamber is provided with a tail gas discharge port, so that the annular heat collection chamber is located in the flow path of the high-temperature process waste gas, which can effectively absorb the heat of the high-temperature process waste gas. By setting a second gas inlet pipe and a second gas outlet pipe to connect the annular heat collection chamber, and setting a conveying pipe to connect the first gas injection device and the second gas outlet pipe, the hot gas in the annular heat collection chamber can be transported to the first gas injection device, mixed with the gas in the first gas injection device, and the gas temperature is increased. This reduces the damage to the originally uniform thermal boundary layer in the reaction chamber caused by the gas injection of the gas injection device, reduces the cold zone effect generated by the gas entering the reaction chamber, makes the temperature gradient in the reaction chamber more uniform, which is conducive to good epitaxial growth quality, and can also make full use of the heat energy of the high-temperature process waste gas and reduce energy consumption.

[0026] In summary, the technical solution of this application can not only effectively recover and utilize the heat of high-temperature process waste gas, but also alleviate the cold zone effect by using the heat of process waste gas. Therefore, it can achieve a win-win result of heat recovery and utilization and improvement of cold zone conditions.

[0027] Furthermore, since the heat from the process exhaust gas is used to improve the cold zone problem, it is no longer necessary to simply rely on increasing heating power, extending the heating cycle, or introducing complex local insulation structures to improve the cold zone problem. This helps to reduce the thermal inertia of the equipment and extend the maintenance cycle, while also reducing energy consumption. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a first type of silicon carbide epitaxial device shown in an embodiment of this application.

[0030] Figure 2 This is a three-dimensional structural diagram of the first type of annular heat collection chamber shown in the embodiments of this application.

[0031] Figure 3 for Figure 2 Side view of the central annular solar collector.

[0032] Figure 4 For along Figure 3 Sectional view of AA.

[0033] Figure 5 for Figure 4 A magnified view of a portion of the central isolation component.

[0034] Figure 6 This is a three-dimensional structural diagram of the second type of annular heat collection chamber shown in an embodiment of this application.

[0035] Figure 7 for Figure 6 Side view of the central annular solar collector.

[0036] Figure 8 For along Figure 7 A cross-sectional view of BB.

[0037] Figures 9 to 14 The following are axial cross-sectional views of different annular heat collection chambers shown in the embodiments of this application.

[0038] Figure 15 This is a schematic diagram of the structure of a second type of silicon carbide epitaxial device shown in an embodiment of this application.

[0039] Figure 16 for Figure 15 A three-dimensional view of the heat collection components of a silicon carbide epitaxial device.

[0040] Figure 17 for Figure 16 Exploded view of the central heat exchanger module.

[0041] Figures 18 to 22 This is an axial cross-sectional view of the heat collection components under different assembly conditions.

[0042] Figure 23 This is a schematic diagram illustrating the composition of a silicon carbide epitaxial device including a gas supply and suction device, as shown in an embodiment of this application.

[0043] In the diagram: 100. Silicon carbide epitaxial equipment with heat recovery function; 1. Reaction chamber; 11. First gas injection device; 12. Tail gas discharge port; 13. Support device; 14. Annular channel; 15. Insulation layer; 16. Intracavity exhaust space; 2. Annular heat collection chamber; 21. Second gas inlet pipe; 22. Second gas outlet pipe; 23. Isolation component; 241. Top inner side wall; 242. Top outer side wall; 243. Bottom inner side wall; 244. Bottom outer side wall; 25. Support foot; 3. Conveying pipe; 4. Collecting device; 41. Collecting inlet; 42. Collecting outlet; 43. Support column; 401. Collecting cavity; 402. Collecting ring; a. First flow channel; b. Second flow channel; 5. First gas supply device; 6. Second gas supply device; 7. Extraction device; 8. Rotary drive device; 9. Heating device; 10. Heat collection assembly. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0046] This application provides a silicon carbide epitaxial device with heat recovery function, including a reaction chamber, an annular heat collection chamber and a delivery pipe.

[0047] The reaction chamber is equipped with a first gas injection device at the top, a tail gas discharge port at the bottom, and a support device inside. The top surface of the support device is positioned opposite to the first gas injection device. An annular channel is formed between the outer wall of the support device and the inner wall of the reaction chamber.

[0048] The annular heat collection chamber is located in the space between the annular channel and the bottom surface of the reaction chamber. It is equipped with a second gas inlet pipe and a second gas outlet pipe to realize gas transportation. The second gas inlet pipe extends to the outside of the reaction chamber. There are gaps between the annular heat collection chamber and the supporting device, as well as between the annular heat collection chamber and the side wall of the reaction chamber, to allow gas to pass through.

[0049] The two ends of the delivery pipe are connected to the second gas outlet pipe and the first gas injection device, respectively, and extend into the side wall and top wall of the reaction chamber to deliver the hot gas in the annular heat collection chamber to the first gas injection device for mixing with the gas in the first gas injection device to increase the gas temperature.

[0050] The annular heat collection chamber in the silicon carbide epitaxial equipment with heat recovery function of this application is located in the space between the annular channel formed by the outer wall of the supporting device and the inner wall of the reaction chamber and the bottom surface of the reaction chamber. The top surface of the supporting device is opposite to the first gas injection device located at the top of the reaction chamber, and the bottom of the reaction chamber is provided with a tail gas discharge port, so that the annular heat collection chamber is located in the flow path of the high-temperature process waste gas, which can effectively absorb the heat of the high-temperature process waste gas. By setting a second gas inlet pipe and a second gas outlet pipe to connect the annular heat collection chamber, and setting a delivery pipe to connect the first gas injection device and the second gas outlet pipe, the hot gas in the annular heat collection chamber can be transported to the first gas injection device, mixed with the gas in the first gas injection device, and the gas temperature is increased. This reduces the damage to the originally uniform thermal boundary layer in the reaction chamber caused by the gas injection of the gas injection device, reduces the cold zone effect caused by the gas entering the reaction chamber, makes the temperature gradient in the reaction chamber more uniform, which is conducive to good epitaxial growth quality, and can also make full use of the heat energy of the high-temperature process waste gas, reducing energy consumption.

[0051] In summary, the technical solution of this application can not only effectively recover and utilize the heat of high-temperature process waste gas, but also alleviate the cold zone effect by using the heat of process waste gas. Therefore, it can achieve a win-win result of heat recovery and utilization and improvement of cold zone conditions.

[0052] Furthermore, since the heat from the process exhaust gas is used to improve the cold zone problem, it is no longer necessary to simply rely on increasing heating power, extending the heating cycle, or introducing complex local insulation structures to improve the cold zone problem. This helps to reduce the thermal inertia of the equipment and extend the maintenance cycle, while also reducing energy consumption.

[0053] To provide a more detailed explanation of the structure and working principle of the silicon carbide epitaxial device with heat recovery function, this application provides the following embodiments. It should be noted that, without conflict, the technical features and solutions in each embodiment can be used in combination.

[0054] Example 1

[0055] like Figure 1 and Figure 2 As shown, this embodiment first provides a silicon carbide epitaxial device 100 with heat recovery function, including a reaction chamber 1, an annular heat collection chamber 2 and a conveying pipe 3.

[0056] The reaction chamber 1 is provided with a first gas injection device 11 at the top, a tail gas discharge port 12 at the bottom, and a support device 13 inside. The support top surface of the support device 13 is arranged opposite to the first gas injection device 11. An annular channel 14 is formed between the outer wall of the support device 13 and the inner wall of the reaction chamber 1.

[0057] The annular heat collection chamber 2 is located in the space between the annular channel 14 and the bottom surface of the reaction chamber 1. It is equipped with a second gas inlet pipe 21 and a second gas outlet pipe 22 to realize gas transportation. The second gas inlet pipe 21 extends to the outside of the reaction chamber 1. There are gaps between the annular heat collection chamber 2 and the supporting device 13, as well as between the annular heat collection chamber 2 and the side wall of the reaction chamber 1, to allow gas to pass through.

[0058] The two ends of the conveying pipe 3 are connected to the second gas outlet pipe 22 and the first gas injection device 11, respectively, and extend into the side wall and top wall of the reaction chamber 1 to convey the hot gas in the annular heat collection chamber 2 to the first gas injection device 11 for mixing with the gas in the first gas injection device 11 to increase the gas temperature.

[0059] It should be noted that the annular heat collection chamber 2 is made of a thermally conductive material. This material can be graphite or silicon carbide.

[0060] The supporting device 13 in this embodiment includes a rotatable large disk and a rotatable small disk disposed on the large disk. The large disk can be made of... Figure 1 The rotary drive device 8 shown, such as a magnetohydrodynamic rotary assembly, is dynamically sealed on the bottom surface of the reaction chamber 1 and rotatably connected to the center of the bottom surface of the support device 13 to drive its rotation. The small disk can be configured with air flotation rotation to support the substrate; the specific implementation method is a conventional technique in the art and will not be described in detail here.

[0061] In some embodiments, the disk may be made of materials such as graphite, graphite-plated silicon carbide, or graphite-plated tantalum carbide.

[0062] In some embodiments, the small disk may be made of materials such as graphite, graphite-plated tantalum carbide, or graphite-plated silicon carbide.

[0063] In some embodiments, the top surface of the large disk has a recess for supporting the small disk, and the top surface of the small disk has a recess for supporting the substrate.

[0064] In some embodiments, the small disk is structured as a recess on the top surface of the large disk to support the substrate.

[0065] In this embodiment, the first gas injection device 11 extends toward the support device 13 to near the middle surface of the support device 13, so that the gas is discharged in a near-horizontal lateral flow to grow an epitaxial layer on the substrate surface. The specific implementation method is a conventional technique in the art and will not be described in detail here.

[0066] In this embodiment, the first gas provided by the first gas injection device 11 includes a reaction source gas. The reaction source gas includes a silicon-containing gas carried by a carrier gas and a carbon-containing gas carried by a carrier gas. Silicon-containing gases include silanes (SiH4), trichlorosilanes (SiHCl3, TCS), and dichlorosilanes (SiH2Cl2, DCS), while carbon-containing gases include hydrocarbons such as propane (C3H8) and ethylene (C2H4).

[0067] In this embodiment, the first gas provided by the first gas injection device 11 may also include purge gas.

[0068] In this embodiment, the first gas injection device 11 may be provided with a process gas channel and a purge gas channel, and the second gas inlet pipe 21 is connected to either the process gas channel or the purge gas channel.

[0069] In this embodiment, the second gas can be a carrier gas or a purge gas. The main function of the carrier gas is to deliver the reaction source gas into the reaction chamber, while simultaneously diluting the concentration of the reaction source gas, controlling the reaction rate and deposition uniformity. Hydrogen (H2) is commonly used as a carrier gas in SiC epitaxy, but argon (Ar) or a mixture of hydrogen (H2) and argon (Ar) can also be used. The purge gas is used between process steps or after the process to quickly remove residual reaction source gas, byproducts, or impurities from the reaction chamber, preventing cross-contamination and particle deposition that affects film quality. The purge gas is typically hydrogen (H2) or an inert gas (such as nitrogen N2 or argon Ar).

[0070] In this embodiment, as Figure 23 As shown, the silicon carbide epitaxial equipment also includes a first gas supply device 5, a second gas supply device 6, and a gas extraction device 7. The first gas supply device 5 is connected to the first gas injection device 11 and is used to supply reaction source gas to the first gas injection device 11. The second gas supply device 6 is connected to the second gas inlet pipe 21 of the annular heat collection chamber 2 and is used to supply carrier gas or purge gas into the annular heat collection chamber 2. The gas extraction device 7 is connected to the exhaust port 12 of the reaction chamber 1 and is used to extract process waste gas from the reaction chamber 1.

[0071] Specifically, in the silicon carbide epitaxial equipment with heat recovery function in this embodiment, the reaction source gas entering the reaction chamber 1 through the first gas injection device 11 flows through the top surface of the support device 13 and the exposed surfaces of each substrate. After part of the reaction source gas undergoes epitaxial reaction, the remaining gas and reaction byproducts, as process waste gas, enter the annular channel 14 between the outer wall of the support device 13 and the inner wall of the reaction chamber 1, and flow through the annular heat collection chamber 2 located below the annular channel 14 to fully contact its surface, thereby heating the second gas (carrier gas or purge gas) in the annular heat collection chamber 2. After heating, the second gas is introduced into the first gas injection device 11 through the delivery pipe 3, mixes with the first gas (reaction source gas) introduced into the first gas injection device 11, and then enters the reaction chamber 1 together.

[0072] In some embodiments, the bottom surface of the annular heat collection chamber 2 is provided with at least one support structure, which is in contact with or located on the inner bottom surface of the reaction chamber 1, so as to achieve a stable support for the annular heat collection chamber 2. For example, the number of support structures is at least two and they are evenly arranged around the circumference, or they are fixedly located on the inner bottom surface of the reaction chamber 1.

[0073] In this embodiment, the annular heat collection chamber 2 and the heating device 9 are radially opposite to each other in the reaction chamber 1. Therefore, the effective heat transfer of the heating device 9 to the annular heat collection chamber 2 is also conducive to the rapid heating of the gas in the annular heat collection chamber 2.

[0074] like Figure 1 As shown, the exhaust space 16 formed by the inner wall and bottom surface of the reaction chamber 1 and the bottom of the support device 13 is connected to the annular channel 14. The heating device 9 is located in the exhaust space 16 and below the support device 13. The heating device 9 heats the support device 13, and the heating effect on the substrate is achieved through the heat transfer from the support device 13 to the substrate.

[0075] Since the gas supplied by the first gas injection device 11 has a certain flow rate, and the gas extraction device 7 has a certain suction effect on the gas in the exhaust space 16, both work together to ensure the stability of the flow field on and near the top surface of the support device 13. A stable gas flow field also contributes to the uniformity of substrate surface temperature, thereby ensuring good epitaxial wafer quality. In addition, when the rotation drive device 8 is needed to assist in the gas mixing on the top surface of the support device 13 to further improve the quality of the epitaxial wafer, the rotation of the support device 13, the flow rate of the gas supplied by the first gas injection device 11, and the suction of the gas extraction device 7 together ensure the stability of the gas flow field.

[0076] Since the annular channel 14 is closer to the top surface of the support device 13 and the channel is relatively narrow, once the exhaust gas becomes turbulent as it flows through the annular channel 14, the turbulent airflow can easily affect the stable gas flow field in the reaction space above the support device 13, which is detrimental to the film formation quality of the epitaxial wafer.

[0077] Therefore, the annular heat collection chamber 2 is positioned within the exhaust space 16 of the cavity, specifically below the annular channel 14, and radially opposite the heating device 9 to the reaction chamber 1. The heating device 9 can more effectively transfer heat to the annular heat collection chamber 2, thereby facilitating the effective heating of the gas within the annular heat collection chamber 2. Specifically, the top of the annular heat collection chamber 2 is not higher than the bottom surface of the supporting device 13.

[0078] In this embodiment, the annular heat collection chamber 2, located in the flow path of the high-temperature process waste gas, can effectively absorb the heat of the high-temperature process waste gas, increase the temperature of the second gas (carrier gas or purge gas) in the annular heat collection chamber 2, and transport it to the first gas injection device 11 to mix with the first gas, thereby increasing the temperature of the first gas (reaction source gas), reducing the damage of the originally uniform thermal boundary layer caused by the injection of the first gas, reducing the cold zone effect generated by the first gas entering the reaction chamber 1, making the temperature gradient in the reaction chamber 1 more uniform, which is conducive to good epitaxial growth quality, and can also make full use of the thermal energy of the high-temperature process waste gas, reducing energy consumption.

[0079] While preheating the purge gas into the first gas injection device 11 before introducing it can solve the problem of cold zones in the reaction chamber 1, the additional preheating structure complicates the external device both structurally and functionally, and generates additional energy consumption. Mixing the hot purge gas provided by the annular heat collection chamber 2 with the existing purge gas in the first gas injection device 11 increases the temperature of the purge gas in the first gas injection device 11. By controlling the flow rates of the hot purge gas in the annular heat collection chamber 2 and the purge gas in the first gas injection device 11, combined with the achievable temperature through the heating control of the carrying device 13, the mixed purge gas can reach the target temperature. Similarly, after the hot carrier gas in the annular heat collection chamber 2 is mixed with the reaction source gas carried by the carrier gas in the first gas injection device 11, the temperature of the mixed gas can be increased. By reasonably designing the flow rate of the hot carrier gas in the annular heat collection chamber 2, the flow rate of the carrier gas and the reaction source gas in the first gas injection device 11, combined with the heating control of the bearing device 13, can achieve the target temperature of the mixed reaction source gas containing the carrier gas.

[0080] In summary, the technical solution of this embodiment can not only effectively recover and utilize the heat of high-temperature process waste gas, but also alleviate the cold zone effect by using the heat of process waste gas. Therefore, it can at least achieve a win-win result of heat recovery and utilization and improvement of the cold zone condition.

[0081] Furthermore, since the heat from the process exhaust gas is used to improve the cold zone problem, it is no longer necessary to simply rely on increasing heating power, extending the heating cycle, or introducing complex local insulation structures to improve the cold zone problem. This helps to reduce the thermal inertia of the equipment and extend the maintenance cycle, while also reducing energy consumption.

[0082] In some embodiments, such as Figure 3 , Figure 4 and Figure 5 As shown, an isolating element 23 can be installed inside the annular solar collector 2 to block the internal space and disrupt the connectivity of the annular space within the annular solar collector 2. The second gas inlet pipe 21, located at the inlet of the annular solar collector 2, and the second gas outlet pipe 22, located at the outlet of the annular solar collector 2, are respectively located on opposite sides of the isolating element 23, specifically, on opposite sides along the circumference of the annular solar collector 2. The inlet of the second gas inlet pipe 21 and the outlet of the second gas outlet pipe 22 are located in the same half of the annular solar collector 2 and connect to the same space within the annular solar collector 2.

[0083] Therefore, after the second gas enters the annular heat collection chamber 2 through the second gas inlet pipe 21, its gas path flows through most of the space inside the annular heat collection chamber 2 along the circumference before flowing out from the second gas outlet pipe 22, so as to maximize the path length of the second gas, thereby improving the heat exchange and heating effect. In addition, the longer gas path can also improve the uniformity of the gas temperature after heating.

[0084] In some embodiments, without the isolation element 23, the second gas inlet pipe 21 and the second gas outlet pipe 22 are located in different halves of the annular heat collection chamber 2. In some more specific embodiments, such as Figure 6 , Figure 7 and Figure 8 As shown, the second gas inlet pipe 21 and the second gas outlet pipe 22 are radially opposite each other in the reaction chamber 1, which can also increase the gas path length to improve the heat exchange and heating effect accordingly.

[0085] In some embodiments, such as Figure 1 As shown, the sidewalls and topwalls of the reaction chamber 1 are provided with heat insulation layers 15, and the delivery pipe 3 extends toward the sidewalls of the reaction chamber 1 into the heat insulation layers 15 and extends therein.

[0086] In some embodiments, the heat insulation layer 15 can be made of graphite hard felt coated with silicon carbide, and is installed on the side wall and top wall of the reaction chamber 1 to keep the chamber warm, and also to keep the delivery pipe 3 warm.

[0087] In this embodiment, as Figures 9 to 12As shown, the axial cross-section of the annular heat collection chamber 2 is axisymmetric, which helps to improve the consistency of the gas flow resistance on both sides of the annular heat collection chamber 2, and avoids local strong turbulence and its potential adverse effects on the process flow field near the top of the support device 13. If the process flow field near the top of the support device 13 is significantly disturbed, it will affect the growth quality of the epitaxial wafer, such as affecting the film uniformity. In some specific embodiments, the inner sidewall of the reaction chamber 1 and the outer sidewall of the support device 13 (specifically, the virtual extension surface of the outer sidewall of the support device 13 extending vertically toward the inner bottom surface of the reaction chamber 1) are respectively radially distanced from the central axis of the cross-section of the annular heat collection chamber 2.

[0088] In some embodiments, such as Figure 9 As shown, the outer contour shape of the axial section of the annular heat collection chamber 2 can be rectangular.

[0089] Considering the top of the rectangle, when receiving the incoming flow, significant turbulence will be generated, which will hinder the smooth discharge of high-temperature process waste gas and may cause airflow turbulence at the edge of the bearing device 13, affecting the growth quality of the epitaxial wafer edge.

[0090] Therefore, preferably, in this embodiment, such as Figure 10 , Figure 11 and Figure 12 As shown, at least a portion of the inner and outer walls of the annular heat collection chamber 2 at the top of its axial cross-section can be provided with guide slopes, which are configured to guide the downward-moving airflow.

[0091] For example, such as Figure 10 As shown, the entire area of ​​the inner and outer sidewalls of the annular heat collection chamber 2 can be set as flow-guiding slopes to significantly reduce the obstruction of airflow.

[0092] For example, such as Figure 11 and Figure 12 As shown, the annular heat collection chamber 2 includes a top-inner sidewall 241 near the support device 13 and a top-outer sidewall 242 near the sidewall of the reaction chamber 1. The top ends of the top-inner sidewall 241 and the top ends of the top-outer sidewall 242 converge and extend towards the inner bottom surface of the reaction chamber 1 to form a top structure. The exposed surfaces of the top-inner sidewall 241 and the top-outer sidewall 242 are guide slopes inclined relative to the top surface of the support device 13. The guide slopes can significantly reduce the obstruction of airflow, reduce the generation of turbulence, facilitate the smooth discharge of process waste gas, and reduce interference with the airflow at the edge of the support device 13.

[0093] Furthermore, in this embodiment, as Figure 11 and Figure 12As shown, the annular heat collection chamber 2 also includes a bottom structure that is connected to and internally communicates with the top structure to increase the internal volume of the annular heat collection chamber 2. The second gas inlet pipe 21 and the second gas outlet pipe 22 are both located in the bottom structure.

[0094] In some embodiments, such as Figure 11 and Figure 12 As shown, the bottom structure of the annular heat collection chamber 2 includes an inner bottom wall 243 and an outer bottom wall 244. The inner bottom wall 243 is close to the supporting device 13, connected to the inner top wall 241, and extends axially along the reaction chamber 1. The outer bottom wall 244 is close to the side wall of the reaction chamber 1 and connected to the outer top wall 242, extending axially along the reaction chamber 1. By controlling both the inner bottom wall 243 and the outer bottom wall 244 to extend axially along the reaction chamber 1, it is possible to ensure the largest possible volume within the annular heat collection chamber 2 while also ensuring that the flow channels for process waste gas on both sides of the annular heat collection chamber 2 are as wide as possible, reducing the flow resistance of the process waste gas and avoiding localized strong turbulence.

[0095] In this embodiment, as Figure 10 and Figure 11 As shown, the top of the top structure of the annular heat collection chamber 2 (i.e., the intersection of the top of the top facing the inner side wall 241 and the top of the top facing the outer side wall 242) forms a sharp corner structure, which can reduce the area of ​​the process waste gas colliding with the upper surface of the annular heat collection chamber 2, thereby reducing turbulence and reducing or avoiding adverse effects on the process airflow field near the top of the supporting device 13.

[0096] Furthermore, in some embodiments, such as Figure 12 As shown, the top of the annular heat collection chamber 2 has a chamfered structure at its apex (i.e., the intersection of the top of the inner sidewall 241 and the top of the outer sidewall 242). This rounded corner structure can further mitigate airflow turbulence caused by changes in gas flow direction and velocity when process waste gas flows into the annular heat collection chamber 2.

[0097] In some embodiments, such as Figure 11 As shown, the total height of the annular heat collection chamber 2 is h, and the height occupied by the guide slope is h1, where h / 2≤h1≤h. This is to further reduce the gas flow resistance in the process waste gas flow channel near the guide slope to avoid local strong turbulence, and also to increase the heating efficiency and heating effect of the gas in the chamber by increasing the contact area between the hot process waste gas and the annular heat collection chamber 2.

[0098] In some embodiments, such as Figure 11 As shown, Figure 11 In the axial section of the annular heat collection chamber 2 shown, the guide slopes of the inner and outer walls have a symmetrical structure, and the inclination angle of the guide slope is α, wherein it is preferably set to 45°≤α<90°.

[0099] If the angle α is too small, the top of the annular heat collector 2 tends to be flat, resulting in a larger area where the heat exchanger collides with the process waste gas at the top, which easily generates turbulence. Increasing the angle α increases the length of the guide slope and the heat exchange area of ​​the side walls, making it more effective at utilizing the heat from the process waste gas. Decreasing the angle α reduces the side wall area and the heat exchange area. Within the range of 45° ≤ α < 90°, sufficient heat exchange area is ensured while minimizing turbulence.

[0100] Example 2

[0101] This embodiment also provides a silicon carbide epitaxial device with heat recovery function. The difference from Embodiment 1 is that the axial cross section of the annular heat collection chamber 2 in this embodiment is not an axisymmetric structure.

[0102] Specifically, in this embodiment, such as Figure 13 As shown, the annular heat collection chamber 2 includes a top inner wall 241 near the side where the supporting device 13 is located, and a top outer wall 242 near the side wall of the reaction chamber 1. The top ends of the top inner wall 241 and the top ends of the top outer wall 242 converge and extend towards the inner bottom surface of the reaction chamber 1 to form a top structure. The exposed surfaces of the top inner wall 241 and the top outer wall 242 are guide slopes that are inclined relative to the top surface of the supporting device 13.

[0103] Furthermore, the extension length of the top outer wall 242 (i.e., the length extending from the top towards the bottom surface of the reaction chamber 1) is greater than the extension length of the top inner wall 241 (i.e., the length extending from the top towards the bottom surface of the reaction chamber 1). In other words, the surface area of ​​the flow guiding slope of the top outer wall 242 is greater than the surface area of ​​the flow guiding slope of the top inner wall 241, making the heated area of ​​the top outer wall 242 larger than that of the top inner wall 241.

[0104] Because the heating device 9 is installed below the support device 13, the heating and temperature rise effect of the part of the annular heat collection chamber 2 near the support device 13 is better. Therefore, by configuring the extension length of the top outward wall 242 to be greater than the extension length of the top inward wall 241, the flow resistance of the flow channel on the top outward wall 242 side is smaller, so that more process waste gas is attracted to pass through the flow channel on the top outward wall 242 side. Furthermore, since the length of the guide slope of the top outward wall 242 is greater than the length of the guide slope of the top inward wall 241, the heat-receiving area of ​​the top outward wall 242 is larger, which can also improve the heating effect. This can balance the heating uniformity of the inner and outer walls of the annular heat collection chamber 2.

[0105] In some embodiments, such as Figure 13As shown, the top outer wall 242 and the top inner wall 241 have the same degree of inclination relative to the supporting device 13, and the bottom end of the top outer wall 242 is lower than the bottom end of the top inner wall 241. The degree of inclination of the top outer wall 242 is represented by α1 in the figure, and the extended dashed line at its bottom end represents the movement of the auxiliary line on the top surface of the supporting device 13 to that point; similarly, the degree of inclination of the top inner wall 241 is represented by α2 in the figure. When α1=α2, the bottom surface of the top outer wall 242 is lower than the bottom surface of the top inner wall 241. It can be seen that the surface area of ​​the top outer wall 242 increases, and the flow resistance of the process waste gas passage on its side is lower than that on the side of the top inner wall 241.

[0106] Furthermore, in this embodiment, the inclination angles of the top outer wall 242 and the top inner wall 241 are α1 and α2, respectively, where 45°≤α1<90° and 45°≤α2<90°. α1 and α2 can be equal or unequal. By configuring the values ​​of α1 and α2, the process waste gas can exhibit different flow resistance differences in the flow channels on both sides of the top outer wall 242 and the top inner wall 241. With the above configuration of α1 and α2, even when there is a difference in flow resistance between the process waste gas flow channel on the side where the top outer wall 242 is located and the process waste gas flow channel on the side where the top inner wall 241 is located, it is possible to ensure that strong turbulence that would affect the process gas flow field near the top of the supporting device 13 is avoided.

[0107] In one embodiment, α1 > α2 can be configured such that the flow resistance at the top outward sidewall 242 is less than the flow resistance at the top inward sidewall 241.

[0108] Example 3

[0109] This embodiment also provides a silicon carbide epitaxial device with heat recovery function. The difference from the first embodiment is that the annular heat collection chamber 2 in this embodiment is provided with a guide slope on only one side wall.

[0110] Specifically, such as Figure 14 As shown, the annular heat collection chamber 2 includes a top inner sidewall 241 near the support device 13 and a top outer sidewall 242 near the sidewall of the reaction chamber 1. The top ends of the top inner sidewall 241 and the top ends of the top outer sidewall 242 converge and extend towards the inner bottom surface of the reaction chamber 1 to form a top structure. Only the exposed surface of the top outer sidewall 242 is set as a guide slope that is inclined relative to the top surface of the support device 13.

[0111] Example 4

[0112] like Figure 15 , Figure 16 and Figure 17As shown, this embodiment also provides a silicon carbide epitaxial device 100 with heat recovery function. The difference from any of the previous embodiments is that this embodiment also includes a current collector 4.

[0113] Specifically, the silicon carbide epitaxial equipment includes a collector 4 whose top surface is lower than the bottom surface of the support device 13. The collector 4 has an annular collector cavity 401, and an annular heat collection chamber 2 is suspended inside the collector cavity 401. The top of the collector cavity 401 communicates with the inside and outside of the reaction chamber 1, and the bottom communicates with the exhaust port 12, allowing gas to be discharged from the collector cavity 401 through the exhaust port 12. The collector cavity 401 is fitted or clearance-fitted with the side wall of the reaction chamber 1, and has a gap between it and the support device 13 to avoid interfering with the movement (e.g., rotational movement) of the support device 13. The second gas inlet pipe 21 and the second gas outlet pipe 22 pass through the collector cavity 401 and communicate with the inside of the annular heat collection chamber 2. The annular heat collection chamber 2 and the collector 4 together constitute the heat collection assembly 10.

[0114] The inner and outer walls of the collecting device 4 are close to the side wall of the bearing device 13 and the inner wall of the reaction chamber 1, respectively. This means that the collecting device 4 fills the annular channel 14. This is beneficial because when the high-temperature process waste gas flows through the annular channel 14, most of the gas will flow through the collecting device 4, and thus can come into more full contact with the annular heat collection chamber 2 inside the collecting device 4, so as to achieve a better heating effect.

[0115] In some embodiments, such as Figure 17 As shown, the annular heat collection chamber 2 also includes support feet 25, and the flow collection device 4 includes a support column 43 located on the outer bottom surface of the flow collection cavity 401. The support column 43 has a hollow structure, with both ends connected to the exhaust port 12 and the flow collection cavity 401, respectively. The hollow support column 43 can serve to transport gas and provide support, or a solid support column can be used to support the flow collection device 4. The support feet 25 are located between the inner bottom surface of the flow collection cavity 401 and the bottom of the annular heat collection chamber 2 to support the annular heat collection chamber 2, thereby preventing the annular heat collection chamber 2 from blocking the flow collection outlet 42 and ensuring the smooth flow of process waste gas.

[0116] In some embodiments, such as Figure 16 and Figure 17 As shown, the flow collecting device 4 may further include a flow collecting ring 402. The flow collecting cavity 401 is provided with an upward-facing annular opening, and its bottom surface is provided with several flow collecting outlets 42 that communicate with the hollow support column 43. The flow collecting ring 402 covers the annular opening of the flow collecting cavity 401, and the flow collecting ring 402 is provided with several circumferentially evenly distributed flow collecting inlets 41. The shape of the flow collecting inlets 41 can be a circular hole, an oblong hole, etc.

[0117] In some embodiments, such as Figures 18 to 20As shown, the axial cross-sections of the annular heat collection chamber 2 and the flow collection device 4 can both be axisymmetric structures. The central axis of the axial cross-section of the annular heat collection chamber 2 coincides with the central axis of the axial cross-section of the flow collection device 4, which is beneficial to the consistency of flow resistance in the process waste gas channels on both sides of the annular heat collection chamber 2 and avoids the generation of strong turbulence.

[0118] In some embodiments, such as Figure 21 As shown, the axial section of the annular heat collection chamber 2 can be a non-axisymmetric structure, while the axial section of the heat collection device 4 can be an axisymmetric structure. The centerline of the axial section of the annular heat collection chamber 2 coincides with the center axis of the axial section of the heat collection device 4.

[0119] In this embodiment, as Figure 18 As shown, the axial cross-sectional shape of the annular heat collection chamber 2 can be rectangular. When gas flows in through the gas collection inlet 41 of the gas collection device 4, considering the top of the rectangle and the inner wall structure of the gas collection cavity 401, significant turbulence will be generated when receiving the incoming flow, which will hinder the smooth discharge of high-temperature process waste gas and may cause airflow turbulence at the edge of the bearing device 13, affecting the growth quality of the epitaxial wafer edge.

[0120] Therefore, in some embodiments, such as Figures 19 to 22 As shown, at least a portion of the inner and outer walls of the annular heat collection chamber 2 are provided with guide slopes, which are configured to guide the downward-moving airflow.

[0121] For example, such as Figure 20 As shown, the entire area of ​​the inner and outer sidewalls of the annular heat collection chamber 2 can be set as flow-guiding slopes to significantly reduce the obstruction of airflow.

[0122] For example, such as Figure 19 , Figure 21 and Figure 22 As shown, the annular heat collection chamber 2 includes an inner-top wall 241 near the side where the supporting device 13 is located, and an outer-top wall 242 near the side wall of the reaction chamber 1. The top ends of the inner-top wall 241 and the outer-top wall 242 converge and extend towards the inner bottom surface of the reaction chamber 1 to form a top structure. At least one of the inner-top wall 241 and the outer-top wall 242 has an exposed surface that is a guide slope inclined relative to the top surface of the supporting device 13. The guide slope can significantly reduce the obstruction of airflow, reduce the generation of turbulence, facilitate the smooth discharge of process waste gas, and reduce interference with the airflow at the edge of the supporting device 13.

[0123] Furthermore, in this embodiment, the annular heat collection chamber 2 also includes a bottom structure that is connected to and internally communicates with the top structure to increase the internal volume of the annular heat collection chamber 2. The second gas inlet pipe 21 and the second gas outlet pipe 22 are both located in the bottom structure.

[0124] Specifically, such as Figure 19 , Figure 21 and Figure 22 As shown, the bottom structure of the annular heat collection chamber 2 includes a bottom inner wall 243 and a bottom outer wall 244. The bottom inner wall 243 is close to the support device 13, connected to the top inner wall 241, and extends axially along the reaction chamber 1. The bottom outer wall 244 is close to the side wall of the reaction chamber 1, connected to the top outer wall 242, and extends axially along the reaction chamber 1.

[0125] In this embodiment, the volume of the annular heat collection chamber 2 is as large as possible to ensure that the heat exchange area between the high-temperature process waste gas and the annular heat collection chamber 2 is as large as possible, so as to maximize the utilization of the heat of the process waste gas. Therefore, it is preferable to design the cross-section of the bottom of the annular heat collection chamber 2 to be larger than the cross-section of the top, that is, the annular heat collection chamber 2 includes both a top structure and a bottom structure.

[0126] In this embodiment, as Figures 10 to 20 , Figure 22 As shown, the guide slopes of the inner and outer walls of the annular heat collection chamber 2 have a symmetrical structure, and the center of the top of the annular heat collection chamber 2 is opposite to the center of the air inlet 41 of the collecting device 4. That is, in the axial cross-section of the annular heat collection chamber 2 and the collecting device 4, the central axis of the cross-section of the annular heat collection chamber 2 is consistent with the central axis of the cross-section of the collecting device 4. This allows the process waste gas to contact the annular heat collection chamber 2 as evenly as possible, improving the heat transfer effect. In addition, the annular heat collection chamber 2 is located in the exact center of the collecting device 4, which can maintain the complete symmetry of the channels on both sides and avoid the flow deviation caused by different flow resistance at both ends, thus preventing the induction of local strong turbulence.

[0127] The channel formed by the guide slope and the inner wall of the collecting device 4 can be called the first flow channel a, and the channel formed by the lower part of the guide slope and the inner wall of the collecting device 4 can be called the second flow channel b.

[0128] like Figure 22 As shown, if the height h1 of the guide slope is less than half of the total height h of the annular heat collection chamber 2, the inclination angle of the guide slope will also be relatively small. When the high-temperature process waste gas enters through the collection inlet 41 of the collection device 4, it passes through the space of the first flow channel a and collides with the top of the annular heat collection chamber 2. In the narrow space, it bounces rapidly and collides with each other, forming a relatively obvious and chaotic turbulent state. A large number of vortices are generated rapidly, which may affect the growth of the epitaxial wafer edge. The process waste gas continues to enter the space of the second flow channel b. Since the bottom size of the annular heat collection chamber 2 is relatively large, the space of the second flow channel b will be smaller than that of the first flow channel a, and the flow resistance will increase, causing the airflow to change for the second time. This change will further cause turbulence in the space of the first flow channel a above, which will further affect the airflow turbulence at the edge of the bearing device 13 and affect the growth quality of the epitaxial wafer edge.

[0129] In this embodiment, as Figure 19 As shown, the height of the collecting cavity 401 of the collecting device 4 is H, and the height of the top structure of the annular heat collection chamber 2 is h1, where H / 2 ≤ h1 < H. Within this limitation, when the process waste gas enters through the collecting inlet 41 of the collecting device 4, the turbulence in the space of the first flow channel a can be significantly reduced. Furthermore, due to the significant downward shift of the position of the second flow channel b, the area where turbulence occurs also shifts significantly downward, relatively away from the collecting inlet 41 of the collecting device 4, thereby reducing the impact of turbulence on the growth of the epitaxial wafer edge.

[0130] Furthermore, in this embodiment, since h1≥H / 2 is set, it is ensured that the height of the guide slope occupies at least half of the internal height of the flow collection device 4, so that the space of the first flow channel a is as large as possible, and the airflow can be effectively diffused and buffered.

[0131] The above description is only a partial embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A silicon carbide epitaxial device with heat recovery function, characterized in that, include: The reaction chamber (1) is provided with a first gas injection device (11) at the top and a tail gas discharge port (12) at the bottom. The interior is provided with a support device (13). The top surface of the support device (13) is opposite to the first gas injection device (11). An annular channel (14) is formed between the outer wall of the support device (13) and the inner wall of the reaction chamber (1). An annular heat collection chamber (2) is located in the space between the annular channel (14) and the bottom surface of the reaction chamber (1). It is provided with a second gas inlet pipe (21) and a second gas outlet pipe (22) to realize gas transportation. The second gas inlet pipe (21) extends to the outside of the reaction chamber (1). There are gaps between the annular heat collection chamber (2) and the supporting device (13), as well as between the annular heat collection chamber (2) and the side wall of the reaction chamber (1) to allow gas to pass through. The delivery pipe (3) is connected at both ends to the second gas outlet pipe (22) and the first gas injection device (11) respectively, and extends in the side wall and top wall of the reaction chamber (1) to deliver the hot gas in the annular heat collection chamber (2) to the first gas injection device (11) to mix with the gas in the first gas injection device (11) to increase the gas temperature.

2. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, The silicon carbide epitaxial equipment also includes a current collection device (4) with its top surface lower than the bottom surface of the support device (13). The current collection device (4) has an annular current collection cavity (401), and the annular heat collection chamber (2) is suspended in the current collection cavity (401) of the current collection device (4). The top of the manifold cavity (401) is connected to the inside and outside of the reaction chamber (1), and the bottom is connected to the exhaust port (12), so that gas can be discharged from the manifold cavity (401) through the exhaust port (12). The manifold cavity (401) is fitted or gap-fitted with the side wall of the reaction chamber (1), and has a gap with the support device (13) so as not to interfere with the movement of the support device (13); The second gas inlet pipe (21) and the second gas outlet pipe (22) pass through the manifold cavity (401) and communicate with the interior of the annular heat collection chamber (2).

3. The silicon carbide epitaxial device with heat recovery function according to claim 2, characterized in that, The axial cross-section of the annular heat collection chamber (2) and the axial cross-section of the flow collection device (4) are both axisymmetric structures, and the central axis of the axial cross-section of the annular heat collection chamber (2) coincides with the central axis of the axial cross-section of the flow collection device (4).

4. The silicon carbide epitaxial device with heat recovery function according to claim 2, characterized in that, The annular heat collection chamber (2) also includes a support foot (25), and the flow collection device (4) includes a support column (43) disposed on the bottom surface of the flow collection cavity (401). The support column (43) has a hollow structure, and its two ends are connected to the exhaust port (12) and the manifold cavity (401) respectively. The support foot (25) is located between the bottom surface of the manifold cavity (401) and the bottom of the annular heat collection chamber (2) to support the annular heat collection chamber (2).

5. The silicon carbide epitaxial device with heat recovery function according to claim 2, characterized in that, The height of the manifold cavity (401) is H. The annular heat collection chamber (2) includes a top inner wall (241) near the side where the supporting device (13) is located, and a top outer wall (242) near the side wall of the reaction chamber (1). The top of the top inner wall (241) and the top of the top outer wall (242) meet and extend toward the inner bottom surface of the reaction chamber (1) to form a top structure. The height of the top structure is h1, and H / 2≤h1<H.

6. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, An isolator (23) is provided inside the annular heat collection chamber (2) to break the connectivity of the annular space inside the annular heat collection chamber (2). The inlet of the second gas inlet pipe (21) on the annular heat collection chamber (2) and the outlet of the second gas outlet pipe (22) on the annular heat collection chamber (2) are located in the same half of the annular heat collection chamber (2) and are respectively close to the opposite sides of the isolator (23) to connect the same space inside the annular heat collection chamber (2).

7. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, It also includes a heating device (9) located below the bearing device (13), with the annular heat collection chamber (2) and the heating device (9) being radially opposite each other along the reaction chamber (1).

8. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, The annular heat collection chamber (2) includes a top inner wall (241) near the side where the support device (13) is located, and a top outer wall (242) near the side wall of the reaction chamber (1). The top ends of the top inner wall (241) and the top ends of the top outer wall (242) converge and extend toward the inner bottom surface of the reaction chamber (1) to form a top structure. The exposed surface of at least one of the top inner wall (241) and the top outer wall (242) is a guide slope inclined relative to the top surface of the support device (13).

9. The silicon carbide epitaxial device with heat recovery function according to claim 8, characterized in that, The annular heat collection chamber (2) also includes a bottom structure that is connected to and internally communicates with the top structure to increase the internal volume of the annular heat collection chamber (2). The second gas inlet pipe (21) and the second gas outlet pipe (22) are both located in the bottom structure.

10. The silicon carbide epitaxial device with heat recovery function according to claim 9, characterized in that, The bottom structure includes: The bottom inner sidewall (243) is close to the support device (13) and connected to the top inner sidewall (241), extending axially along the reaction chamber (1); The bottom sidewall (244) is close to the sidewall of the reaction chamber (1) and is connected to the top sidewall (242), extending along the axial direction of the reaction chamber (1).

11. The silicon carbide epitaxial device with heat recovery function according to claim 8, characterized in that, The total height of the annular heat collection chamber (2) is h, and the height occupied by the guide slope is h1, wherein h / 2≤h1≤h.

12. The silicon carbide epitaxial device with heat recovery function according to claim 8, characterized in that, The top of the inner sidewall (241) and the top of the outer sidewall (242) meet to form a sharp corner structure or a chamfered structure.

13. The silicon carbide epitaxial device with heat recovery function according to claim 8, characterized in that, The inclination of the top inner sidewall (241) and the top outer sidewall (242) relative to the support device (13) is the same, and the bottom end of the top outer sidewall (242) is lower than the bottom end of the top inner sidewall (241).

14. The silicon carbide epitaxial device with heat recovery function according to claim 8, characterized in that, The acute angles of inclination of the top outer sidewall (242) and the top inner sidewall (241) relative to the top surface of the bearing device (13) are α1 and α2, respectively, where 45°≤α1<90° and 45°≤α2<90°.

15. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, The axial section of the annular heat collection chamber (2) is an axisymmetric structure.

16. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, The sidewalls and topwalls of the reaction chamber (1) are provided with a heat insulation layer (15), and the delivery pipe (3) is buried in the heat insulation layer (15).

17. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, It also includes a second gas supply device (6) located outside the reaction chamber (1), which is connected to the second gas inlet pipe (21) to provide carrier gas or purge gas.

18. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that, The first gas injection device (11) is provided with a process gas channel and a purge gas channel, and the second gas inlet pipe (21) is connected to either the process gas channel or the purge gas channel.

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