Silicon carbide epitaxy equipment with heat recovery function

Abstract

The invention provides silicon carbide epitaxy equipment with a heat recovery function. The silicon carbide epitaxy equipment comprises a reaction cavity, an annular heat collection bin and a conveying pipe. A first gas injection device is arranged at the top of the reaction cavity, a tail gas discharge port is formed in the bottom, a bearing device is arranged in the reaction cavity, and the bearing top surface of the bearing device is opposite to the first gas injection device. And an annular channel is formed between the outer side wall of the bearing device and the inner side wall of the reaction cavity. The annular heat collection bin is arranged in the space between the annular channel and the inner bottom face of the reaction cavity and provided with a second gas inlet pipe and a second gas outlet pipe to achieve gas conveying, and the second gas inlet pipe extends out of the reaction cavity. The two ends of the conveying pipe communicate with the second gas outlet pipe and the first gas injection device correspondingly, and the conveying pipe is used for conveying hot gas in the annular heat collection bin into the first gas injection device so that the hot gas can be mixed with gas in the first gas injection device to increase the gas temperature. According to the scheme, the heat of the process waste gas can be effectively recycled, and the cold zone effect can be relieved by means of the heat of the process waste gas.

Description

Technical Field

[0001] The present application relates to the technical field of equipment used in manufacturing or processing semiconductors, and in particular to a silicon carbide epitaxial growth device with a heat recovery function. Background Art

[0002] Silicon carbide epitaxial growth equipment is a key component in the semiconductor power device manufacturing chain. Its primary purpose is to grow one or more epitaxial thin films with the target conductivity type and doping profile on a silicon carbide substrate.

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

[0004] However, the process exhaust gases from the growth chamber, carrying a significant amount of heat, are directly discharged. Currently, there is a lack of efficient waste heat recovery and resource reuse methods. Therefore, how to improve the cold zone caused by process gas injection and effectively utilize the waste heat from the process exhaust gases have become urgent challenges. Summary of the Invention

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

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

[0007] The reaction chamber is provided with a first gas injection device at the top, an exhaust gas outlet at the bottom, and a supporting device inside. The supporting top surface of the supporting device is arranged opposite 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. An annular heat collection chamber is located in the space between the annular channel and the bottom surface of the reaction chamber. It is provided 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 is a gap between the annular heat collection chamber and the supporting device, as well as between the annular heat collection chamber and the side walls of the reaction chamber to allow gas to pass through. The two ends of the delivery pipe are respectively connected to the second gas outlet pipe and the first gas injection device, and extend within the side walls and top wall of the reaction chamber to transport the hot gas in the annular heat collection chamber to the first gas injection device, where it mixes with the gas in the first gas injection device to increase the gas temperature.

[0008] In an implementable scheme, the silicon carbide epitaxial equipment also includes a collecting device whose top surface is lower than the bottom surface of the supporting device, the collecting device has an annular collecting cavity, and the annular heat collecting bin is suspended in the collecting cavity of the collecting device; the top of the collecting cavity is communicated with the inside and outside of the reaction chamber, and the bottom is communicated with the exhaust gas exhaust port, so that the gas can be discharged from the collecting cavity through the exhaust gas exhaust port; the collecting cavity is in contact with the side wall of the reaction chamber or has a gap fit, and there is a distance between it and the supporting device so as not to interfere with the movement of the supporting device; the second gas inlet pipe and the second gas outlet pipe pass through the collecting cavity and communicate with the inside of the annular heat collecting bin.

[0009] In one feasible solution, the axial cross-section of the annular heat collecting bin and the axial cross-section of the current collecting device are both axisymmetric structures, and the central axis of the axial cross-section of the annular heat collecting bin coincides with the central axis of the axial cross-section of the current collecting device.

[0010] In an implementable solution, the annular heat collection bin also includes support feet, and the flow collecting device includes a support column arranged on the outer bottom surface of the flow collecting cavity; the support column is a hollow structure, and its two ends are respectively connected to the exhaust gas discharge port and the flow collecting cavity; the support feet are arranged between the inner bottom surface of the flow collecting cavity and the bottom of the annular heat collection bin to support the annular heat collection bin.

[0011] In an implementable solution, the height of the collecting cavity is H, and the annular heat collecting chamber includes a top inner wall close to the side where the supporting device is located, and a top outer wall close to the side wall of the reaction chamber. The top ends of the top inner wall and the top ends of the top outer wall intersect and extend toward 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 isolation piece is provided in the annular solar collection bin to break the connectivity of the annular space in the annular solar collection bin. The inlet of the second gas inlet pipe on the annular solar collection bin and the outlet of the second gas outlet pipe on the annular solar collection bin are located in the same half of the annular solar collection bin and are respectively close to the opposite sides of the isolation piece to connect the same space in the annular solar collection bin.

[0013] In an practicable solution, a heating device is further included below the supporting device, and the annular heat collecting bin is radially opposite to the heating device in the reaction chamber.

[0014] In an implementable solution, the annular heat collection bin 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 ends of the top inner wall and the top outer wall intersect 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 wall and the top outer wall is a guide slope inclined relative to the top surface of the supporting device.

[0015] In an implementable solution, the annular heat collection chamber further includes a bottom structure connected to the top structure and internally communicated 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 arranged on the bottom structure.

[0016] In one feasible solution, the bottom structure includes a bottom inner sidewall and a bottom outer sidewall. The bottom inner sidewall is adjacent to the supporting device, connected to the top inner sidewall, and extends axially along the reaction chamber; the bottom outer sidewall is adjacent to the sidewall of the reaction chamber, connected to the top outer sidewall, and extends axially along the reaction chamber.

[0017] In an implementable solution, the total height of the annular heat collecting chamber is h, and the height occupied by the guide slope is h1, wherein h / 2≤h1≤h.

[0018] In an implementable solution, the top of the inner side wall and the top of the outer side wall meet to form a pointed angle structure or a chamfered angle structure.

[0019] In an implementable solution, the top inner sidewall and the top outer sidewall have the same inclination relative to the supporting device, and the bottom end of the top outer sidewall is lower than the bottom end of the top inner sidewall.

[0020] In an implementable solution, the acute inclination angles of the top outer sidewall and the top inner sidewall to the top surface of the carrying device are α1 and α2 respectively, wherein 45°≤α1<90°, and 45°≤α2<90°.

[0021] In one feasible solution, the axial cross-section of the annular heat collecting chamber is an axisymmetric structure.

[0022] In one feasible solution, the side walls and top wall of the reaction chamber are provided with a heat insulation layer, and the delivery pipe is buried in the heat insulation layer.

[0023] In an practicable solution, a second gas supply device is further included outside the reaction chamber, and the second gas supply device is connected to the second gas inlet pipe to provide carrier gas or purge gas.

[0024] In one feasible solution, a process gas channel and a purge gas channel are provided in the first gas injection device, 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 the present application include at least the following: the annular heat collection chamber provided in the silicon carbide epitaxial growth apparatus with heat recovery function of the present application is provided in the space between the annular channel formed between 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 arranged opposite to the first gas injection device provided at the top of the reaction chamber, and the bottom of the reaction chamber is provided with an exhaust gas discharge port, so that the annular heat collection chamber is located in the flow path of the high-temperature process exhaust gas, which can effectively absorb the heat of the high-temperature process exhaust gas. By providing a second gas inlet pipe and a second gas outlet pipe to connect the annular heat collection chamber, and providing 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, thereby reducing the damage to the originally uniform thermal boundary layer in the reaction chamber caused by the gas injection of the gas injection device, reducing the cold zone effect caused by the gas entering the reaction chamber, making the temperature gradient in the reaction chamber more uniform, which is conducive to good epitaxial growth quality, and fully utilizing the thermal energy of the high-temperature process exhaust gas, thereby reducing energy consumption.

[0026] In summary, the technical solution of the present application can not only realize the effective recovery and utilization of the heat of high-temperature process exhaust gas, but also alleviate the cold zone effect with the help of the heat of the process exhaust gas, thus at least achieving a win-win result of heat recovery and utilization and improvement of the cold zone condition.

[0027] In addition, since the heat of 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 reduce equipment thermal inertia and extend maintenance cycles, while also reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

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

[0030] Figure 2 This is a schematic diagram of the three-dimensional structure of the first annular heat collection bin shown in an embodiment of the present application.

[0031] Figure 3 for Figure 2 Side view of the middle ring solar collector.

[0032] Figure 4 For the Figure 3 Cross-sectional view of AA in the figure.

[0033] Figure 5 for Figure 4 A partial enlarged view of the middle separator.

[0034] Figure 6 This is a schematic diagram of the three-dimensional structure of the second annular solar collector shown in an embodiment of the present application.

[0035] Figure 7 for Figure 6 Side view of the middle ring solar collector.

[0036] Figure 8 For the Figure 7 Cross-sectional view of the BB.

[0037] Figures 9 to 14 This is an axial cross-sectional view of different annular heat collection bins shown in the embodiments of the present application.

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

[0039] Figure 16 for Figure 15 A three-dimensional image of the heat collection component of the silicon carbide epitaxial equipment.

[0040] Figure 17 for Figure 16 Exploded structure diagram of the solar collector assembly.

[0041] Figures 18 to 22 Axial cross-sectional views of different solar collector components in assembly status.

[0042] Figure 23 This is a schematic diagram of the composition of a silicon carbide epitaxial apparatus including a gas supply and suction device according to an embodiment of the present application.

[0043] In the figure: 100, silicon carbide epitaxial growth equipment with heat recovery function; 1, reaction chamber; 11, first gas injection device; 12, exhaust gas outlet; 13, supporting device; 14, annular channel; 15, thermal insulation layer; 16, exhaust space in the cavity; 2, annular heat collection chamber; 21, second gas inlet pipe; 22, second gas outlet pipe; 23, isolation member; 241, top toward the inner wall; 242, top toward the outer wall; 243, bottom toward the inner wall; 244, bottom toward the outer wall; 25, supporting foot; 3, delivery pipe; 4, collecting device; 41, collecting air inlet; 42, collecting air outlet; 43, supporting 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, exhaust device; 8, rotary drive device; 9, heating device; 10, heat collection assembly. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

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

[0047] Among them, a first gas injection device is provided on the top of the reaction chamber, an exhaust gas discharge port is provided at the bottom, and a supporting device is provided inside. The supporting top surface of the supporting device is arranged 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.

[0048] The annular heat collection bin is arranged in the space between the annular channel and the bottom surface of the reaction chamber. It is provided 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 is a distance between the annular heat collection bin and the supporting device, as well as between the annular heat collection bin and the side wall of the reaction chamber to allow gas to pass through.

[0049] The two ends of the delivery pipe are respectively connected to the second gas outlet pipe and the first gas injection device, and extend inside the side wall and top wall of the reaction chamber 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.

[0050] The annular heat collection bin provided in the silicon carbide epitaxial device with heat recovery function of the present application is provided in the space between the annular channel formed between 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 arranged opposite to the first gas injection device provided at the top of the reaction chamber. The bottom of the reaction chamber is provided with an exhaust gas discharge port, so that the annular heat collection bin is located on the flow path of the high-temperature process exhaust gas and can effectively absorb the heat of the high-temperature process exhaust gas. By providing a second gas inlet pipe and a second gas outlet pipe to connect the annular heat collection bin, and providing a delivery pipe to connect the first gas injection device and the second gas outlet pipe, the hot gas in the annular heat collection bin 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, so as to reduce the damage to the originally uniform thermal boundary layer in the reaction chamber caused by the gas injection of the gas injection device, reduce the cold zone effect caused by the gas entering the reaction chamber, make the temperature gradient in the reaction chamber more uniform, which is conducive to good epitaxial growth quality, and can also fully utilize the thermal energy of the high-temperature process exhaust gas and reduce energy consumption.

[0051] In summary, the technical solution of the present application can not only realize the effective recovery and utilization of the heat of high-temperature process exhaust gas, but also alleviate the cold zone effect with the help of the heat of the process exhaust gas, thus at least achieving a win-win result of heat recovery and utilization and improvement of the cold zone condition.

[0052] In addition, since the heat of 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 reduce equipment thermal inertia and extend maintenance cycles, while also reducing energy consumption.

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

[0054] Example 1

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

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

[0057] The annular heat collection bin 2 is arranged in the space between the annular channel 14 and the inner 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 is a distance between the annular heat collection bin 2 and the supporting device 13, as well as between the annular heat collection bin 2 and the side wall of the reaction chamber 1 to allow gas to pass through.

[0058] The two ends of the delivery pipe 3 are respectively connected to the second gas outlet pipe 22 and the first gas injection device 11, and extend inside the side wall and top wall of the reaction chamber 1, so as to transport the hot gas in the annular heat collection bin 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.

[0059] It should be noted that the annular heat collecting chamber 2 is made of a heat conducting material, which may be graphite or silicon carbide.

[0060] The carrier device 13 of this embodiment includes a rotatable large plate and a rotatable small plate arranged on the large plate. Figure 1 The illustrated rotation drive device 8, such as a magnetic fluid rotating assembly, is dynamically sealed to the bottom surface of the reaction chamber 1 and rotatably connected to the center of the bottom surface of the carrier 13 to drive the rotation. The small plate can be configured to rotate with air flotation to support the substrate. The specific implementation method is conventional in the art and will not be detailed here.

[0061] In some embodiments, the large disk may be made of materials such as graphite, graphite coated with silicon carbide, and graphite coated with tantalum carbide.

[0062] In some embodiments, the small disk can be made of graphite, graphite coated with tantalum carbide, graphite coated with silicon carbide, and the like.

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

[0064] In some embodiments, the structure of the small disk is a recess opened on the top surface of the large disk for supporting the substrate.

[0065] In this embodiment, the first gas injection device 11 extends toward the carrier 13 to a position near the center surface of the carrier 13, so that the gas is discharged in a nearly horizontal lateral flow to grow an epitaxial layer on the substrate surface. The specific implementation method is conventional in the art and will not be detailed 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 silane (SiH4), trichlorosilane (SiHCl3, TCS), and dichlorosilane (SiH2Cl2, DCS); 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 further include a purge gas.

[0068] In this embodiment, a process gas channel and a purge gas channel may be provided in the first gas injection device 11 , 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 transport the reaction source gas into the reaction chamber, while diluting the reaction source gas concentration and controlling the reaction rate and deposition uniformity. Hydrogen (H2) is a commonly used carrier gas in SiC epitaxy. 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 is completed to quickly remove residual reaction source gas, byproducts, or impurities in the reaction chamber to prevent 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, if Figure 23 As shown, the silicon carbide epitaxial growth 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 deliver the 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 deliver 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 the process waste gas in the reaction chamber 1.

[0071] Specifically, in the silicon carbide epitaxial growth apparatus with heat recovery function of this embodiment, the source gas enters the reaction chamber 1 through the first gas injection device 11, flows through the top surface of the carrier device 13 and the exposed surfaces of each substrate. After a portion of the source gas undergoes the epitaxial reaction, the remaining gas and reaction byproducts, as process waste gas, enter the annular channel 14 between the outer wall of the carrier device 13 and the inner wall of the reaction chamber 1. It then flows 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. The heated second gas is then introduced into the first gas injection device 11 through the delivery pipe 3, mixed with the first gas (source gas) introduced from 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 bin 2 is provided with at least one support structure that contacts or is provided on the inner bottom surface of the reaction chamber 1 to provide stable support for the annular heat collection bin 2. For example, there are at least two support structures that are evenly arranged around the circumference, or are fixedly provided on the inner bottom surface of the reaction chamber 1.

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

[0074] like Figure 1 As shown, the inner sidewall and inner bottom of the reaction chamber 1, as well as the bottom of the carrier 13, define an exhaust space 16 that communicates with the annular channel 14. The heating device 9 is located within the exhaust space 16 and below the carrier 13. The heating device 9 heats the carrier 13, and the substrate is heated by heat transfer from the carrier 13 to the substrate.

[0075] Since the gas provided by the first gas injection device 11 has a certain flow rate, the exhaust device 7 has a certain suction effect on the gas in the exhaust space 16 in the cavity. The two together ensure the stability of the flow field on the top surface of the carrier device 13 and near the top surface. A stable gas flow field is also beneficial to the uniformity of the substrate surface temperature, thereby ensuring good epitaxial wafer quality. In addition, when it is necessary to rotate the drive device 8 to assist the mixing of the gas on the top surface of the carrier device 13 to further benefit the quality of the epitaxial wafer, the rotation of the carrier device 13, the flow rate of the gas provided by the first gas injection device 11, and the suction of the exhaust 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 carrier device 13 and the channel is relatively narrow, once the exhaust gas flows through the annular channel 14 and the airflow is turbulent, the turbulent airflow will easily affect the stable gas flow field of the reaction space above the carrier device 13, which is not conducive to the film formation quality of the epitaxial wafer.

[0077] Therefore, the annular heat collection bin 2 is disposed within the intracavity exhaust space 16, specifically below the annular channel 14 and radially opposite the heating device 9 of the reaction chamber 1. The heating device 9 can more effectively transfer heat to the annular heat collection bin 2, thereby facilitating effective heating of the gas within the annular heat collection bin 2. Specifically, the top of the annular heat collection bin 2 is no higher than the bottom surface of the supporting device 13.

[0078] The annular heat collection bin 2 provided in this embodiment is located on the flow path of the high-temperature process exhaust gas, so it can effectively absorb the heat of the high-temperature process exhaust gas, increase the temperature of the second gas (carrier gas or purge gas) in the annular heat collection bin 2, and transport it to the first gas injection device 11 to mix with the first gas to increase the temperature of the first gas (reaction source gas), so as to reduce the damage to the originally uniform thermal boundary layer caused by the injection of the first gas, reduce the cold zone effect generated by the first gas entering the reaction chamber 1, make 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 exhaust gas to reduce energy consumption.

[0079] Considering that although the problem of cold zones in the reaction chamber 1 can be solved by preheating the purge gas input to the first gas injection device 11 before introduction, the additional corresponding preheating structure complicates the epitaxial apparatus in terms of both structure and functional control, and generates additional energy consumption. The hot purge gas provided by the annular heat collection chamber 2 is mixed with the original purge gas in the first gas injection device 11, which can increase the temperature of the purge gas in the first gas injection device 11. By controlling the flow rate of the hot purge gas in the annular heat collection chamber 2 and the flow rate of the purge gas in the first gas injection device 11, combined with the temperature that can be achieved by the heating control of the carrier 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 hot carrier gas flow rate in the annular heat collection chamber 2, the temperature that can be reached by the carrier gas and reaction source gas flow rates in the first gas injection device 11 combined with the heating control of the carrying device 13, the mixed reaction source gas containing the carrier gas can also reach the target temperature.

[0080] In summary, the technical solution of this embodiment can not only effectively recover and utilize the heat of high-temperature process exhaust gas, but also alleviate the cold zone effect with the help of the heat of the process exhaust gas, thus at least achieving a win-win result of heat recovery and improvement of the cold zone condition.

[0081] In addition, since the heat of 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 reduce equipment thermal inertia and extend maintenance cycles, while also reducing energy consumption.

[0082] In some embodiments, as Figure 3 、 Figure 4 and Figure 5 As shown, an isolation piece 23 that forms a barrier to the space inside the annular heat collecting bin 2 can be provided inside the annular heat collecting bin 2 to break the connectivity of the annular space inside the annular heat collecting bin 2. The inlet of the second gas inlet pipe 21 located in the annular heat collecting bin 2 and the outlet of the second gas outlet pipe 22 located in the annular heat collecting bin 2 are respectively close to the opposite sides of the isolation piece 23, specifically, they can be the opposite sides along the circumference of the annular heat collecting bin 2. The inlet of the second gas inlet pipe 21 located in the annular heat collecting bin 2 and the outlet of the second gas outlet pipe 22 located in the annular heat collecting bin 2 are located in the same half of the annular heat collecting bin 2 and are connected to the same space inside the annular heat collecting bin 2.

[0083] Therefore, after the second gas enters the annular heat collecting bin 2 through the second gas inlet pipe 21, its gas path flows along the circumference of the annular heat collecting bin 2 through most of the space inside the annular heat collecting bin 2 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 effects, and a longer gas path can also improve the balance of the gas temperature after heating.

[0084] In some embodiments, without providing the isolating member 23, the second gas inlet pipe 21 and the second gas outlet pipe 22 are located in different half areas of the annular heat collecting chamber 2. In some more specific embodiments, as Figure 6 、 Figure 7 and Figure 8 As shown, the second gas inlet pipe 21 and the second gas outlet pipe 22 are opposite to each other along the radial direction of the reaction chamber 1, and the gas path length can be relatively increased to correspondingly improve the heat exchange and heating effects.

[0085] In some embodiments, as Figure 1 As shown, the side walls and top wall of the reaction chamber 1 are provided with a heat insulation layer 15 , and the delivery pipe 3 extends toward the side wall of the reaction chamber 1 into the heat insulation layer 15 and extends therein.

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

[0087] In this embodiment, if Figures 9 to 12As shown, the axial cross-section of the annular heat collection chamber 2 is an axisymmetric structure, which helps improve the consistency of the flow resistance of the gas flow channels on both sides of the annular heat collection chamber 2, avoid local strong turbulence and its potential adverse effects on the process flow field near the top of the carrier device 13. If the process flow field near the top of the carrier device 13 is significantly disturbed, it will affect the growth quality of the epitaxial wafer, such as affecting the uniformity of film formation. In some specific embodiments, the inner sidewall of the reaction chamber 1 and the side of the outer sidewall of the carrier device 13 (specifically, the virtual extension surface of the outer sidewall of the carrier device 13 extending vertically toward the inner bottom surface of the reaction chamber 1) are respectively at the same radial distance 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 of the axial cross section of the annular heat collecting chamber 2 can be a rectangle.

[0089] Considering the rectangular top, when receiving the incoming flow, it will generate obvious turbulence, which will hinder the smooth discharge of high-temperature process exhaust gas, and may cause the air flow at the edge of the carrier 13 to be turbulent, affecting the growth quality of the edge of the epitaxial wafer.

[0090] Therefore, preferably, in this embodiment, Figure 10 、 Figure 11 and Figure 12 As shown, at the top of the annular heat collecting bin 2, at least part of the inner and outer side walls of the axial section can be provided with guide slopes, which are configured to guide the downward-moving airflow.

[0091] For example, Figure 10 As shown, the entire area of ​​the inner side wall and the outer side wall of the annular heat collecting chamber 2 can be set as a flow guide slope to significantly reduce the obstruction effect on the airflow.

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

[0093] Furthermore, in this embodiment, Figure 11 and Figure 12As shown, the annular heat collecting chamber 2 further includes a bottom structure connected to the top structure and communicated with the interior thereof to increase the internal volume of the annular heat collecting chamber 2, and the second gas inlet pipe 21 and the second gas outlet pipe 22 are both provided at the bottom structure.

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

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

[0096] Furthermore, in some embodiments, Figure 12 As shown, the top of the annular heat collection chamber 2's top structure (i.e., the intersection of the top of the inner wall 241 and the top of the outer wall 242) is chamfered. This helps prevent airflow turbulence caused by changes in gas flow direction and velocity when process wastewater flows into the annular heat collection chamber 2.

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

[0098] In some embodiments, as Figure 11 As shown, Figure 11 In the axial cross section of the annular heat collecting chamber 2 shown, the guide slopes of the inner wall and the outer wall are symmetrically structured, 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 collection bin 2 becomes flat, increasing the area where the process exhaust gas collides with the top of the annular heat collection bin 2 and causing turbulence. Increasing the angle α increases the length of the guide slope and the heat exchange area of ​​the two side walls, which more effectively utilizes the heat of the process exhaust gas. Decreasing the angle α reduces the two side walls 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 growth device with a heat recovery function. The difference from the first embodiment is that the axial cross-section of the annular heat collection chamber 2 of this embodiment is not an axisymmetric structure.

[0102] Specifically, in this embodiment, Figure 13 As shown, the annular heat collection chamber 2 includes a top inner wall 241 close to the side where the supporting device 13 is located, and a top outer wall 242 close to the side wall of the reaction chamber 1. The top ends of the top inner wall 241 and the top outer wall 242 intersect and extend toward 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 inclined relative to the top surface of the supporting device 13.

[0103] Moreover, the extension length of the top-facing outer sidewall 242 (i.e., the length thereof extending from the top toward the inner bottom surface of the reaction chamber 1) is greater than the extension length of the top-facing inner sidewall 241 (i.e., the length thereof extending from the top toward the inner bottom surface of the reaction chamber 1), that is, the surface area of ​​the guide slope of the top-facing outer sidewall 242 is greater than the surface area of ​​the guide slope of the top-facing inner sidewall 241, so that the heating area of ​​the top-facing outer sidewall 242 is larger than that of the top-facing inner sidewall 241.

[0104] Since the heating device 9 is provided below the supporting device 13, the heating and temperature-raising effect of the portion of the annular heat collecting bin 2 close to the supporting device 13 is better. Therefore, by configuring the extension length of the top toward the outer side wall 242 to be greater than the extension length of the top toward the inner side wall 241, the flow resistance of the flow channel on the side of the top toward the outer side wall 242 is made smaller, so as to guide a larger proportion of process exhaust gas to pass through the flow channel on the side of the top toward the outer side wall 242. Moreover, since the length of the guide slope of the top toward the outer side wall 242 is greater than the length of the guide slope of the top toward the inner side wall 241, the heating area of ​​the top toward the outer side wall 242 is larger, which can also improve the heating and heating effect, thereby balancing the heating uniformity of the inner and outer walls of the annular heat collecting bin 2.

[0105] In some embodiments, such as Figure 13As shown, the top-facing outer wall 242 and the top-facing inner wall 241 have the same degree of inclination relative to the support device 13, with the bottom end of the top-facing outer wall 242 lower than the bottom end of the top-facing inner wall 241. The inclination of the top-facing outer wall 242 is indicated by α1, with the extended dashed line at its bottom end representing the position to which the auxiliary line of the top surface of the support device 13 has been moved. Similarly, the inclination of the top-facing inner wall 241 is indicated by α2. When α1 = α2, the bottom surface of the top-facing outer wall 242 is lower than the bottom surface of the top-facing inner wall 241. This indicates that the surface area of ​​the top-facing outer wall 242 is increased, and the flow resistance of the process waste flow passage on its side is lower than that on the side of the top-facing inner wall 241.

[0106] Furthermore, in this embodiment, the inclination angles of the top-facing outer sidewall 242 and the top-facing inner sidewall 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 sizes of α1 and α2, the process exhaust gas can exhibit different flow resistance differences between the flow channels on the top-facing outer sidewall 242 and the top-facing inner sidewall 241. The above configuration of α1 and α2 can ensure that even if the flow resistance of the process exhaust flow channel on the side of the top-facing outer sidewall 242 is different from that on the side of the top-facing inner sidewall 241, strong turbulence that may affect the process gas flow field near the top of the carrier device 13 is avoided.

[0107] In one embodiment, α1>α2 can be configured so that the flow resistance at the top facing the outer sidewall 242 is smaller than the flow resistance at the top facing the inner sidewall 241 .

[0108] Example 3

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

[0110] Specifically, if Figure 14 As shown, the annular heat collection chamber 2 includes a top inner wall 241 close to the supporting device 13, and a top outer wall 242 close to the side wall of the reaction chamber 1. The top end of the top inner wall 241 and the top end of the top outer wall 242 intersect and extend toward the inner bottom surface of the reaction chamber 1 to form a top structure, and only the exposed surface of the top outer wall 242 is set as a guide slope inclined relative to the top surface of the supporting device 13.

[0111] Example 4

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

[0113] Specifically, the silicon carbide epitaxial device includes a current collecting device 4 whose top surface is lower than the bottom surface of the supporting device 13. The current collecting device 4 has an annular current collecting cavity 401, and the annular heat collecting bin 2 is suspended in the current collecting cavity 401 of the current collecting device 4. The top of the current collecting cavity 401 is in communication with the inside and outside of the reaction chamber 1, and the bottom is in communication with the exhaust gas discharge port 12, so that the gas can be discharged from the current collecting cavity 401 through the exhaust gas discharge port 12. The current collecting cavity 401 is in contact with the side wall of the reaction chamber 1 or has a gap fit, and there is a distance between it and the supporting device 13 so as not to interfere with the movement of the supporting device 13 (such as rotational movement). The second gas inlet pipe 21 and the second gas outlet pipe 22 pass through the current collecting cavity 401 and communicate with the inside of the annular heat collecting bin 2. The annular heat collecting bin 2 and the current collecting device 4 together constitute the heat collecting assembly 10.

[0114] Among them, the inner and outer side walls of the collecting device 4 are respectively close to the side walls of the supporting device 13 and the inner wall of the reaction chamber 1, which is equivalent to the collecting device 4 filling the annular channel 14. This is beneficial for the high-temperature process exhaust gas to flow through the annular channel 14. Most of the gas will flow through the collecting device 4, and then it can be more fully contacted with the annular heat collection bin 2 in the collecting device 4 to achieve a better heating effect.

[0115] In some embodiments, as Figure 17 As shown, the annular heat collection bin 2 also includes support legs 25, and the flow collecting device 4 includes support columns 43 provided on the outer bottom surface of the flow collecting cavity 401. The support columns 43 are hollow structures, with their ends respectively connected to the exhaust outlet 12 and the flow collecting cavity 401. The hollow support columns 43 can serve as gas conveyance and support, or a solid support column can be separately provided to support the flow collecting device 4. The support legs 25 are provided between the inner bottom surface of the flow collecting cavity 401 and the bottom of the annular heat collection bin 2 to support the annular heat collection bin 2, thereby preventing the annular heat collection bin 2 from blocking the flow collecting gas outlet 42 and ensuring smooth flow of process exhaust gas.

[0116] In some embodiments, as Figure 16 and Figure 17 As shown, the manifold device 4 may further include a manifold ring 402. The manifold cavity 401 is provided with an upward annular opening, and its bottom surface is provided with a plurality of manifold outlets 42 connected to the hollow support columns 43. The manifold ring 402 covers the annular opening of the manifold cavity 401 and is provided with a plurality of manifold inlets 41 evenly distributed around the circumference. The manifold inlets 41 may be in the shape of a circular hole, a waist-shaped hole, or the like.

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

[0118] In some embodiments, as Figure 21 As shown, the axial cross-section of the annular heat collecting bin 2 can be a non-axisymmetric structure, the axial cross-section of the current collecting device 4 can be an axisymmetric structure, and the center line of the axial cross-section of the annular heat collecting bin 2 coincides with the center axis of the axial cross-section of the current collecting device 4.

[0119] In this embodiment, if Figure 18 As shown, the axial cross-section of the annular heat collection chamber 2 can be rectangular. When gas flows in through the collecting inlet 41 of the collecting device 4, the rectangular top and the inner wall structure of the collecting cavity 401 will generate significant turbulence when receiving the incoming flow. This will hinder the smooth discharge of high-temperature process exhaust gas, potentially causing turbulent airflow at the edge of the carrier 13 and affecting the growth quality of the epitaxial wafer edge.

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

[0121] For example, Figure 20 As shown, the entire area of ​​the inner side wall and the outer side wall of the annular heat collecting chamber 2 can be set as a flow guide slope to significantly reduce the obstruction effect on the airflow.

[0122] For example, Figure 19 、 Figure 21 and Figure 22 As shown, the annular heat collection chamber 2 includes a top-facing inner sidewall 241 near the side where the carrier device 13 is located, and a top-facing outer sidewall 242 near the sidewall of the reaction chamber 1. The top ends of the top-facing inner sidewall 241 and the top ends of the top-facing outer sidewall 242 intersect and extend toward the inner bottom surface of the reaction chamber 1 to form a roof structure. The exposed surface of at least one of the top-facing inner sidewall 241 and the top-facing outer sidewall 242 is a flow-guiding slope that is inclined relative to the top surface of the carrier device 13. The flow-guiding slope can significantly reduce the obstruction to the airflow, reduce the generation of turbulence, facilitate the smooth discharge of process exhaust gas, and reduce interference with the airflow at the edge of the carrier device 13.

[0123] Furthermore, in this embodiment, the annular heat collecting chamber 2 also includes a bottom structure connected to the top structure and communicated with the interior to increase the internal volume of the annular heat collecting chamber 2, and the second gas inlet pipe 21 and the second gas outlet pipe 22 are both provided in the bottom structure.

[0124] Specifically, if Figure 19 、 Figure 21 and Figure 22 As shown, the bottom structure of the annular heat collection chamber 2 includes a bottom inner sidewall 243 and a bottom outer sidewall 244. The bottom inner sidewall 243 is adjacent to the supporting device 13, connected to the top inner sidewall 241, and extends axially along the reaction chamber 1. The bottom outer sidewall 244 is adjacent to the sidewall of the reaction chamber 1, connected to the top outer sidewall 242, and extends axially along the reaction chamber 1.

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

[0126] In this embodiment, if Figures 10 to 20 、 Figure 22 As shown, the guide slopes of the inner and outer walls of the annular heat collecting bin 2 are symmetrical structures, and the center of the top of the annular heat collecting bin 2 is opposite to the center of the collecting air inlet 41 of the collecting device 4. That is, in the axial cross-section of the annular heat collecting bin 2 and the collecting device 4, the cross-sectional center axis of the annular heat collecting bin 2 is consistent with the cross-sectional center axis of the collecting device 4. In this way, the process exhaust gas can be in contact with the annular heat collecting bin 2 as evenly as possible, thereby improving the heat transfer effect. In addition, the annular heat collecting bin 2 is set in the middle of the collecting device 4, which can keep the channels on both sides completely symmetrical, avoid deviation caused by different flow resistance at both ends, and induce local strong turbulence.

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

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

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

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

[0131] The foregoing description is merely a partial embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A silicon carbide epitaxial device with heat recovery function, characterized in that: include: A reaction chamber (1) is provided with a first gas injection device (11) at the top, an exhaust gas discharge port (12) at the bottom, and a supporting device (13) is provided inside, wherein the supporting top surface of the supporting device (13) is arranged opposite to the first gas injection device (11); an annular channel (14) is formed between the outer side wall of the supporting device (13) and the inner side wall of the reaction chamber (1); An annular heat collecting bin (2) is provided in the space between the annular channel (14) and the inner bottom surface of the reaction chamber (1), and is provided with a second gas inlet pipe (21) and a second gas outlet pipe (22) for transporting gas, wherein the second gas inlet pipe (21) extends to the outside of the reaction chamber (1); a spacing is provided between the annular heat collecting bin (2) and the supporting device (13), as well as between the annular heat collecting bin (2) and the side wall of the reaction chamber (1), to allow gas to pass through; A delivery pipe (3) has two ends connected to the second gas outlet pipe (22) and the first gas injection device (11) respectively, and extends inside the side wall and top wall of the reaction chamber (1), for delivering the hot gas in the annular heat collection bin (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 device further comprises a current collecting device (4) whose top surface is lower than the bottom surface of the carrying device (13), the current collecting device (4) having an annular current collecting cavity (401), and the annular heat collecting chamber (2) is suspended in the current collecting cavity (401) of the current collecting device (4); The top of the manifold cavity (401) is in communication with the inside and outside of the reaction chamber (1), and the bottom is in communication with the tail gas discharge port (12), so that gas can be discharged from the manifold cavity (401) through the tail gas discharge port (12); The manifold cavity (401) is fitted or gap-fitted with the side wall of the reaction chamber (1), and has a distance with the carrying device (13) so as not to interfere with the movement of the carrying 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 collecting bin (2) and the axial cross-section of the current collecting device (4) are both axisymmetric structures, and the central axis of the axial cross-section of the annular heat collecting bin (2) coincides with the central axis of the axial cross-section of the current collecting 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) further comprises a support foot (25), and the current collecting device (4) comprises a support column (43) provided on the outer bottom surface of the current collecting cavity (401); The support column (43) is a hollow structure, with two ends respectively connected to the exhaust gas discharge port (12) and the manifold cavity (401); The support foot (25) is provided between the inner bottom surface of the manifold cavity (401) and the bottom of the annular heat collection bin (2) to support the annular heat collection bin (2).

5. The silicon carbide epitaxial device with heat recovery function according to claim 2, characterized in that: The height of the collecting cavity (401) is H, and the annular heat collecting chamber (2) includes a top inner wall (241) close to the side where the supporting device (13) is located, and a top outer wall (242) close to 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) 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 in the annular heat collecting bin (2) to break the connectivity of the annular space in the annular heat collecting bin (2); the inlet of the second gas inlet pipe (21) on the annular heat collecting bin (2) and the outlet of the second gas outlet pipe (22) on the annular heat collecting bin (2) are located in the same half of the annular heat collecting bin (2) and are respectively close to opposite sides of the isolator (23) to connect the same space in the annular heat collecting bin (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) disposed below the carrying device (13), and the annular heat collection bin (2) and the heating device (9) are opposite to each other along the radial direction of the reaction chamber (1).

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

9. The silicon carbide epitaxial device with heat recovery function according to claim 8, characterized in that: The annular heat collection bin (2) further comprises a bottom structure connected to and internally communicated with the top structure to increase the internal volume of the annular heat collection bin (2); the second gas inlet pipe (21) and the second gas outlet pipe (22) are both provided on the bottom structure.

10. The silicon carbide epitaxial device with heat recovery function according to claim 9, characterized in that: The bottom structure comprises: The bottom portion faces the inner side wall (243), is close to the carrying device (13), is connected to the top portion faces the inner side wall (241), and extends axially along the reaction chamber (1); The bottom sidewall (244) is close to the sidewall of the reaction chamber (1), is connected to the top sidewall (242), and extends 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 collecting bin (2) is h, and the height occupied by the diversion 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 top inner sidewall (241) and the top of the top outer sidewall (242) meet to form a pointed angle structure or a chamfered angle structure.

13. The silicon carbide epitaxial device with heat recovery function according to claim 8, characterized in that: The top inner sidewall (241) and the top outer sidewall (242) have the same degree of inclination relative to the carrying device (13), 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 inclination angles of the top outer side wall (242) and the top inner side wall (241) relative to the top surface of the carrying device (13) are α1 and α2, respectively, wherein 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 cross-section of the annular heat collecting bin (2) is an axisymmetric structure.

16. The silicon carbide epitaxial device with heat recovery function according to claim 1, characterized in that: The side walls and top wall 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) arranged outside the reaction chamber (1), and the second gas supply device (6) 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: A process gas channel and a purge gas channel are provided in the first gas injection device (11), and the second gas inlet pipe (21) is connected to either the process gas channel or the purge gas channel.

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