Silicon carbide epitaxial equipment

Abstract

This application provides a silicon carbide epitaxial device, including a reaction chamber, a casing structure, an annular heat collection chamber, first and second inlet pipes, and first and second delivery pipes. A gas injection device is located at the top of the reaction chamber, and a tail gas discharge port is located at the bottom. A support device is located inside. An annular channel is formed between the outer wall of the support device and the inner wall of the reaction chamber. A reserved cavity is formed between the casing structure and the inner top wall of the reaction chamber. The annular heat collection chamber is suspended in the space between the annular channel and the reaction chamber, and has gaps between it and the support device and the side wall of the reaction chamber. The annular heat collection chamber has an outer annular cavity and an inner annular cavity separated from each other. The first and second inlet pipes connect the outer annular cavity and the inner annular cavity, respectively, and extend to the outside of the reaction chamber. The two ends of the first delivery pipe are connected to the outer annular cavity and the gas injection device, respectively. The two ends of the second delivery pipe are connected to the inner annular cavity and the reserved cavity, respectively. This application's solution can both recover and utilize the heat from process waste gas and alleviate the cold zone effect by utilizing the heat from process waste gas.

Description

Technical Field

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

[0002] Silicon carbide epitaxial growth equipment is a critical piece of equipment in the semiconductor power device manufacturing chain. The growth chamber of this equipment 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, significant cold zones form within the chamber, disrupting the originally uniform thermal boundary layer and causing a cold zone effect at the source gas injection point. Temperature fluctuations occur on the walls of the equipment chamber (e.g., the top wall), resulting in a cold zone effect on the chamber walls. This cold zone effect leads to uneven thickness and doping distribution, affecting the growth rate and uniformity of silicon carbide epitaxy. To mitigate the cold end and cold zone effects, existing solutions often rely on increasing heating power, extending the heating cycle, or introducing complex local thermal insulation structures, leading to increased thermal inertia and shortened maintenance cycles.

[0003] In addition, the top wall of the growth chamber also needs to be maintained at a certain temperature. To avoid pre-reaction of the process gas near the spray surface immediately after it is ejected, which would reduce growth efficiency, and to prevent particle deposition on the spray surface that could affect the gas flow field or even block the spray surface, the temperature of the process gas before it exits the spray surface needs to be lower than the process temperature. During its ejection process, before reaching the substrate, it needs to be heated to the process temperature by the reaction space between the top wall of the growth chamber and the support surface of the support device. It is evident that the temperature of the top wall of the growth chamber is crucial to the growth efficiency and quality of epitaxial growth. Adjusting and maintaining the temperature of the top wall of the growth chamber also increases the complexity of the equipment and energy consumption.

[0004] However, the process exhaust gas after the reaction in the growth chamber carries a large amount of heat and is directly emitted, lacking efficient means of waste heat recovery and resource reuse. Therefore, how to reduce the cold zone effect and how to effectively utilize the waste heat of the process exhaust gas while also improving the quality of epitaxial film formation 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 that can effectively recover and utilize the heat from process waste gas, alleviate the cold zone effect by using the heat from process waste gas, and improve the growth efficiency and quality of epitaxial growth.

[0006] This application provides a silicon carbide epitaxial device, which includes a reaction chamber, a casing structure, an annular heat collection chamber, a first inlet pipe, a second inlet pipe, a first delivery pipe, and a second delivery pipe.

[0007] The reaction chamber has a gas injection device at the top and a tail gas exhaust port at the bottom, with a support device inside. An annular channel is formed between the outer wall of the support device and the inner wall of the reaction chamber. A cover structure is located at the inner top of the reaction chamber, forming a reserved cavity between it and the inner top wall of the reaction chamber. The gas injection device passes through the reserved cavity and faces the top surface of the support device. An annular heat collection chamber is located in the space between the annular channel and the reaction chamber, with gaps between it and the support device and the side wall of the reaction chamber to allow gas passage. The inner cavity of the annular heat collection chamber includes a mutually separated outer annular cavity and an inner annular cavity; the outer annular cavity surrounds the inner annular cavity.

[0008] The first and second inlet pipes connect to the outer annular cavity and the inner annular cavity, respectively, and extend to the outside of the reaction chamber. The first delivery pipe connects to the outer annular cavity and the gas injection device at both ends, and extends within the cavity wall of the reaction chamber, allowing the hot gas from the outer annular cavity to mix with the gas in the gas injection device to increase the gas temperature. The second delivery pipe connects to the inner annular cavity and the reserved cavity at both ends, and extends within the cavity wall of the reaction chamber, allowing the hot gas from the inner annular cavity to enter the reserved cavity, thus promoting temperature uniformity within the reaction space.

[0009] In one feasible embodiment, the first inlet tube is connected to the outer annular cavity from the bottom surface of the outer annular cavity, and the second inlet tube is connected to the inner annular cavity from the bottom surface of the inner annular cavity.

[0010] In one feasible embodiment, the thickness of the bottom wall of the outer annular cavity is greater than the thickness of the bottom wall of the inner annular cavity, such that the height of the inner bottom surface of the outer annular cavity is higher than the height of the inner bottom surface of the inner annular cavity. The second inlet pipe penetrates the bottom wall of the outer annular cavity from the side to communicate with the interior of the inner annular cavity, and the first inlet pipe communicates with the interior of the outer annular cavity from the side.

[0011] In one feasible embodiment, an annular heat collection chamber includes an annular partition plate extending towards the bottom surface of the reaction chamber. The inner annular cavity includes a top-inner wall near the support device to form an inner top structure with the annular partition plate, and the outer annular cavity includes a top-outer wall near the side wall of the reaction chamber to form an outer top structure with the annular partition plate. The top-inner wall, the top-outer wall, and the top of the annular partition plate intersect, and both the top-inner wall and the top-outer wall are inclined relative to the support surface of the support device.

[0012] In one feasible embodiment, the inward-facing top wall and the outward-facing top wall have the same degree of inclination, and the bottom surface of the outward-facing top wall is lower than the bottom surface of the inward-facing top wall.

[0013] In one feasible solution, the top-inner wall, the top-outer wall, and the annular partition plate intersect to form a sharp-angled or chamfered structure.

[0014] In one feasible embodiment, the outer annular cavity further includes an outer bottom structure that is connected to and communicates internally with the outer top structure to increase the volume, and / or the inner annular cavity further includes an inner bottom structure that is connected to and communicates internally with the inner top structure to increase the volume.

[0015] In one feasible embodiment, the outer bottom structure includes a bottom-facing outer wall that is close to the sidewall of the reaction chamber and extends axially along the reaction chamber, and the inner bottom structure includes a bottom-facing inner wall that is close to the side where the support device is located and extends axially along the reaction chamber.

[0016] In one feasible scheme, the total height of the annular heat collection chamber is h, and the height of the lowest of the top-inner sidewall and the top-outer sidewall is h1, where h / 2≤h1≤h.

[0017] In one feasible embodiment, the acute angles of inclination of the top-outer sidewall and the top-inner sidewall relative to the top surface of the bearing device are α1 and α2, respectively, where 45°≤α1<90° and 45°≤α2<90°.

[0018] In one feasible approach, the volume of the outer annular cavity does not exceed the volume of the inner annular cavity.

[0019] In one feasible embodiment, a separator is arranged radially within the annular heat collection chamber to break the connectivity between the annular spaces within the outer and inner annular cavities. A first inlet pipe on the outer annular cavity and a first delivery pipe are positioned near opposite sides of the separator and communicate with the interior of the outer annular cavity, respectively. A second inlet pipe on the inner annular cavity and a second delivery pipe are positioned near opposite sides of the separator and communicate with the interior of the inner annular cavity, respectively.

[0020] In one feasible embodiment, the sidewalls and top wall of the reaction chamber are provided with a heat insulation layer, and the first and second delivery pipes are embedded in the heat insulation layer.

[0021] In one feasible embodiment, the outer contour structure of the axial section of the structure comprising the outer annular cavity and the inner annular cavity is an axisymmetric structure, and / or the outer contour structure of the axial section of the annular heat collection chamber is an axisymmetric structure.

[0022] In one feasible embodiment, a heat collection device is also included, which has an annular heat collection cavity. The top surface of the heat collection device is lower than the bottom surface of the supporting device, and the annular heat collection chamber is suspended in the heat collection cavity of the heat collection device. The top of the heat collection device is connected to the inside and outside of the reaction chamber, and the bottom is connected to the exhaust port, so that the gas can be discharged from the heat collection device through the exhaust port. The heat collection device is fitted or clearance-fitted with the side wall of the reaction chamber, and there is a gap between it and the supporting device so as not to interfere with the movement of the supporting device. The first inlet pipe, the second inlet pipe, the first delivery pipe, and the second delivery pipe all pass through the heat collection device.

[0023] In one feasible scheme, both the axial cross-sectional outer contour structure of the annular heat collection chamber and the axial cross-sectional outer contour structure of the collection device are axisymmetric structures, and the central axis of the axial cross-sectional outer contour structure of the annular heat collection chamber coincides with the central axis of the axial cross-sectional outer contour structure of the collection device.

[0024] 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.

[0025] In one feasible embodiment, the inner annular cavity includes a top-inner wall extending obliquely toward the side where the support device is located, and the outer annular cavity includes a top-outer wall extending obliquely toward the side wall of the reaction chamber; the total height of the internal cavity of the collector is H, the total height of the annular heat collection chamber is h, and the height of the lowest of the top-inner wall and the top-outer wall is h1; wherein, H / 2≤h1<H.

[0026] In one feasible embodiment, the silicon carbide epitaxial apparatus further includes a second gas supply device and a third gas supply device. The second gas supply device, located outside the reaction chamber and connected to the first inlet pipe, provides carrier gas or purge gas; the third gas supply device, located outside the reaction chamber and connected to the second inlet pipe, provides purge gas.

[0027] In one feasible embodiment, the gas injection device is provided with a process gas passage and a purge gas passage, and a second delivery pipe connects to either the process gas passage or the purge gas passage.

[0028] Compared with the prior art, the beneficial effects of this application include at least the following: In the silicon carbide epitaxial equipment of this application, the bottom of the reaction chamber is provided with a tail gas discharge port, the gas injection device is opposite to the bearing top surface of the bearing device, and the annular heat collection chamber is located in the space between the annular channel formed between the outer side wall of the bearing device and the inner side wall of the reaction chamber and the reaction chamber, so that it can be located in the flow path of the high-temperature process waste gas, and can effectively absorb the heat of the high-temperature process waste gas, and increase the temperature of the gas in the outer annular cavity and the inner annular cavity of the annular heat collection chamber.

[0029] Furthermore, the heated gas in the outer annular cavity is transported to the gas injection device through the first delivery pipe and mixed with the gas in the gas injection device to increase the temperature of the gas in the gas injection device, reduce the damage to the originally uniform thermal boundary layer caused by the gas injection into the reaction chamber, reduce the cold zone effect generated when entering the reaction chamber, make the temperature gradient in the reaction chamber more uniform, and help to improve the gas pyrolysis efficiency and improve the epitaxial layer growth efficiency.

[0030] Furthermore, the heated gas in the inner annular cavity is transported by the second delivery pipe to the reserved cavity in the top wall of the reaction chamber to heat the inner top wall of the reaction chamber. This helps to fully utilize the thermal energy of the process waste gas to achieve a reasonable temperature gradient between the top wall of the reaction chamber and the support device, ensuring that the process gas ejected by the gas injection device can be heated to the process temperature range near the substrate and avoiding pre-reaction after being ejected from the spray surface. This is beneficial to improving the growth efficiency and growth quality of epitaxial growth.

[0031] In summary, the silicon carbide epitaxial equipment of this application can effectively recover and utilize the heat of process waste gas by setting up an annular heat collection chamber. With the dual-chamber setting of the annular heat collection chamber, the gas heated by the two chambers is respectively transported to the gas injection device and the reserved cavity at the top wall of the reaction chamber. This can not only alleviate the cold zone effect caused by gas injection of the gas injection device, but also improve the growth efficiency and growth quality of epitaxial growth.

[0032] Furthermore, since the heat from the process exhaust gas is used to improve the cold zone problem and regulate the temperature gradient of the growth space, 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

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Figure 3 for Figure 2 Side view of the central annular solar collector.

[0037] Figure 4 For along Figure 3 Sectional view of AA.

[0038] Figure 5 for Figure 4 A magnified view of a portion of the central isolation component.

[0039] Figure 6This is a three-dimensional structural diagram of the second type of annular heat collection chamber shown in an embodiment of this application.

[0040] Figure 7 for Figure 6 Side view of the central annular solar collector.

[0041] Figure 8 For along Figure 7 A cross-sectional view of BB.

[0042] Figures 9 to 15 The following are axial cross-sectional views of different annular heat collection chambers shown in the embodiments of this application.

[0043] Figure 16 This is a schematic diagram of the structure of a second type of silicon carbide epitaxial device shown in an embodiment of this application.

[0044] Figure 17 for Figure 16 A 3D view of the central heat collection module.

[0045] Figure 18 for Figure 17 Exploded view of the central heat exchanger module.

[0046] Figures 19 to 24 This is an axial cross-sectional view of the heat collection components under different assembly conditions.

[0047] Figure 25 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.

[0048] In the diagram: 100. Silicon carbide epitaxial equipment; 1. Reaction chamber; 11. Gas injection device; 12. Exhaust port; 13. Supporting device; 14. Annular channel; 15. Insulation layer; 16. Exhaust space inside the chamber; 2. Cover structure; 21. Reserved cavity; 3. Annular heat collection chamber; 31. Annular partition plate; 32. Isolation component; 301. Outer annular cavity; 3011. Top facing the outer side wall; 3012. Bottom facing the outer side wall; 302. Inner annular cavity; 3021. Top facing the inner side wall; 3022. Bottom facing the inner side wall; A1. First inlet; A 2. First outlet; B1. Second inlet; B2. Second outlet; 33. Support foot; 41. First inlet pipe; 42. Second inlet pipe; 43. First conveying pipe; 44. Second conveying pipe; 5. Collecting device; 51. Collecting air inlet; 52. Collecting air outlet; 53. Support column; 501. Collecting cavity; 502. Collecting ring; a. First flow channel; b. Second flow channel; 61. First air supply device; 62. Second air supply device; 63. Third air supply device; 7. Air extraction device; 8. Rotary drive device; 9. Heating device; 10. Heat collection assembly. Detailed Implementation

[0049] 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.

[0050] 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.

[0051] This application provides a silicon carbide epitaxial device, including a reaction chamber, a casing structure, an annular heat collection chamber, a first inlet pipe, a second inlet pipe, a first delivery pipe, and a second delivery pipe.

[0052] The reaction chamber has a gas injection device at the top and a tail gas discharge port at the bottom, and a support device inside. An annular channel is formed between the outer wall of the support device and the inner wall of the reaction chamber. A cover structure is located at the inner top of the reaction chamber, forming a reserved cavity between it and the inner top wall of the reaction chamber. The gas injection device passes through the reserved cavity and is opposite to the top surface of the support device.

[0053] The annular heat collection chamber is located in the space between the annular channel and the reaction chamber, with gaps between it and the supporting device and between it and the sidewall of the reaction chamber to allow gas to pass through. The inner cavity of the annular heat collection chamber includes an outer annular cavity and an inner annular cavity that are separated from each other; the outer annular cavity surrounds the inner annular cavity. The first inlet pipe and the second inlet pipe are respectively connected to the outer annular cavity and the inner annular cavity, and extend to the outside of the reaction chamber.

[0054] The first delivery pipe connects to the outer annular cavity and the gas injection device at both ends, and extends within the wall of the reaction chamber, allowing the hot gas in the outer annular cavity to mix with the gas in the gas injection device to increase the gas temperature. The second delivery pipe connects to the inner annular cavity and the reserved cavity at both ends, and extends within the wall of the reaction chamber, allowing the hot gas in the inner annular cavity to enter the reserved cavity to improve the temperature uniformity of the reaction space within the reaction chamber.

[0055] The gas injected into the gas injection device is either the reaction source gas or the purge gas; the gas injected into the outer annular cavity is either the carrier gas or the purge gas; and the gas injected into the inner annular cavity is the purge gas.

[0056] The annular heat collection chamber in the silicon carbide epitaxial equipment of this application 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 and increase the temperature of the gas in the outer annular cavity and the inner annular cavity of the annular heat collection chamber.

[0057] On the one hand, the heated gas in the outer annular cavity is transported to the gas injection device through the first delivery pipe and mixed with the gas in the gas injection device to increase the temperature of the gas in the gas injection device, increase the temperature of the reaction source gas, reduce the damage to the originally uniform thermal boundary layer caused by the injection of the reaction source gas into the reaction cavity, reduce the cold zone effect generated when the reaction source gas enters the reaction cavity, make the temperature gradient in the reaction cavity more uniform, and help improve the gas cracking efficiency and increase the epitaxial layer growth efficiency.

[0058] On the other hand, the heated gas in the inner annular cavity is transported by the second delivery pipe to the reserved cavity in the top wall of the reaction chamber to heat the top of the reaction chamber. This helps to make full use of the heat energy of the process waste gas to achieve a reasonable temperature gradient between the top wall of the reaction chamber and the support device, ensuring that the process gas sprayed by the gas injection device can be heated to the process temperature range near the top of the substrate and avoiding pre-reaction after spraying. This helps to improve the growth efficiency and growth quality of epitaxial growth.

[0059] In summary, the silicon carbide epitaxial equipment of this application can effectively recover and utilize the heat of process waste gas by setting up an annular heat collection chamber. With the dual-chamber setting of the annular heat collection chamber, the gas heated by the two chambers is respectively delivered to the gas injection device and the reserved cavity at the top wall of the reaction chamber. This can not only alleviate the cold zone effect caused by gas injection of the gas injection device, but also improve the cold zone effect at the top wall of the reaction chamber, thereby improving the growth efficiency and growth quality of epitaxial growth.

[0060] Furthermore, since the heat from the process exhaust gas is used to improve the cold zone problem and regulate the temperature gradient of the growth space, 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.

[0061] To provide a more detailed explanation of the structure and working principle of the silicon carbide epitaxial device of this application, the following embodiments are provided. It should be noted that, without conflict, the technical features and solutions in each embodiment can be used in combination.

[0062] Example 1

[0063] like Figures 1 to 5 As shown, this embodiment first provides a silicon carbide epitaxial device 100, including a reaction chamber 1, a cover structure 2, an annular heat collection chamber 3, a first inlet pipe 41, a second inlet pipe 42, a first delivery pipe 43, and a second delivery pipe 44.

[0064] The reaction chamber 1 has a gas injection device 11 at the top, a tail gas discharge port 12 at the bottom, and a support device 13 inside. An annular channel 14 is formed between the outer wall of the support device 13 and the inner wall of the reaction chamber 1. The cover structure 2 is located at the inner top of the reaction chamber 1, and a reserved cavity 21 is formed between it and the inner top wall of the reaction chamber 1. The gas injection device 11 passes through the reserved cavity 21 and is opposite to the top support surface of the support device 13.

[0065] The annular heat collection chamber 3 is located in the space between the annular channel 14 and the reaction chamber 1, and has gaps between itself and the supporting device 13 and between itself and the side wall of the reaction chamber 1 to allow gas to pass through; the inner cavity of the annular heat collection chamber 3 includes an outer annular cavity 301 and an inner annular cavity 302 that are separated from each other; the outer annular cavity 301 surrounds the inner annular cavity 302.

[0066] The first inlet pipe 41 and the second inlet pipe 42 are respectively connected to the outer annular cavity 301 and the inner annular cavity 302, and extend to the outside of the reaction chamber 1. The first delivery pipe 43 is connected at both ends to the outer annular cavity 301 and the gas injection device 11, and extends within the cavity wall of the reaction chamber 1, so that the hot gas in the outer annular cavity 301 mixes with the gas in the gas injection device 11 to increase the gas temperature. The second delivery pipe 44 is connected at both ends to the inner annular cavity 302 and the reserved cavity 21, and extends within the cavity wall of the reaction chamber 1, so that the hot gas in the inner annular cavity 302 enters the reserved cavity 21 to facilitate the uniformity of the temperature field in the reaction space within the reaction chamber 1.

[0067] It should be noted that the annular heat collection chamber 3 is composed of a thermally conductive material. The thermally conductive material can be graphite or silicon carbide.

[0068] 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.

[0069] In some embodiments, the disk may be made of materials such as graphite, graphite-plated silicon carbide, or graphite-plated tantalum carbide.

[0070] In some embodiments, the small disk may be made of materials such as graphite, graphite-plated tantalum carbide, or graphite-plated silicon carbide.

[0071] 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.

[0072] In some embodiments, the small disk is structured as a recess on the top surface of the large disk to support the substrate.

[0073] In this embodiment, the gas injection device 11 extends toward the support device 13 to a point near the middle surface of the support device 13, allowing the gas to exit 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.

[0074] In this embodiment, the gas provided by the 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).

[0075] In this embodiment, the gas provided by the gas injection device 11 may also include purge gas.

[0076] In this embodiment, the gas injection device 11 may be provided with a process gas channel and a purge gas channel, and the first delivery pipe 43 connects to either the process gas channel or the purge gas channel.

[0077] In this embodiment, the gas input into the outer annular cavity 301 is either a carrier gas or a purge gas, and the gas input into the inner annular cavity 302 is a purge gas. The main function of the carrier gas is to transport the reaction source gas into the reaction cavity 1, 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 cavity, 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).

[0078] In this embodiment, as Figure 25 As shown, the silicon carbide epitaxial equipment also includes a first gas supply device 61, a second gas supply device 62, a third gas supply device 63, and a vacuum device 7. The first gas supply device 61 is connected to the gas injection device 11 and is used to supply reaction source gas or purge gas to the gas injection device 11. The second gas supply device 62 is located outside the reaction chamber 1 and is connected to the first inlet pipe 41 to provide carrier gas or purge gas. The third gas supply device 63 is located outside the reaction chamber 1 and is connected to the second inlet pipe 42 to provide purge gas. The vacuum 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.

[0079] Specifically, in the silicon carbide epitaxial apparatus of this embodiment, the reaction source gas entering the reaction chamber 1 via the gas injection device 11 flows through the top surface of the support device 13 and the exposed surfaces of each substrate. After a portion of the reaction 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 support device 13 and the inner wall of the reaction chamber 1. The gas flows through the annular heat collection chamber 3 located below the annular channel 14 to fully contact its surface, thereby heating the gas in the outer annular cavity 301 and the inner annular cavity 302 within the annular heat collection chamber 3. The heated gas in the outer annular cavity 301 is transported to the gas injection device 11 via the first delivery pipe 43, and the heated gas in the inner annular cavity 302 is transported to the reserved cavity 21 on the top wall of the reaction chamber 1 via the second delivery pipe 44.

[0080] In some embodiments, the bottom surface of the annular heat collection chamber 3 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 3. 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.

[0081] In this embodiment, the annular heat collection chamber 3 and the heating device 9 are radially opposite to each other in the reaction chamber 1. Therefore, the heating device 9 can also effectively transfer heat to the annular heat collection chamber 3, which is also conducive to the rapid heating of the gas in the annular heat collection chamber 3.

[0082] 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.

[0083] Since the gas supplied by the 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 need to 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 is also beneficial 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 gas injection device 11, and the suction of the gas extraction device 7 need to work together to ensure the stability of the gas flow field.

[0084] 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.

[0085] Therefore, the annular heat collection chamber 3 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 3, thereby facilitating the effective heating of the gas within the annular heat collection chamber 3. Specifically, the top of the annular heat collection chamber 3 is not higher than the bottom surface of the supporting device 13.

[0086] The annular heat collection chamber 3 in the silicon carbide epitaxial equipment of this embodiment is located on the flow path of the high-temperature process waste gas, which can effectively absorb the heat of the high-temperature process waste gas and increase the temperature of the gas in the outer annular cavity 301 and the inner annular cavity 302 of the annular heat collection chamber 3.

[0087] On the one hand, the heated gas in the outer annular cavity 301 is transported to the gas injection device 11 by the first delivery pipe 43 and mixed with the gas in the gas injection device 11 to increase the temperature of the gas in the gas injection device 11, reduce the damage to the originally uniform thermal boundary layer caused by the gas injection into the reaction chamber 1, reduce the cold zone effect generated when entering the reaction chamber 1, make the temperature gradient in the reaction chamber 1 more uniform, and help to improve the gas cracking efficiency and improve the epitaxial layer growth efficiency.

[0088] While preheating the purge gas in the input 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. The hot purge gas provided by the outer annular cavity 301, when mixed with the existing purge gas in the gas injection device 11, can raise the temperature of the purge gas in the gas injection device 11. By controlling the flow rates of the hot purge gas in the outer annular cavity 301 and the purge gas in the gas injection device 11, combined with the temperature achievable through the heating control of the carrier device 13, the mixed purge gas can reach the target temperature. Similarly, the hot carrier gas in the outer annular cavity 301, when mixed with the reaction source gas carried by the carrier gas in the gas injection device 11, can raise the temperature of the mixed gas. By rationally designing the flow rates of the hot carrier gas in the outer annular cavity 301, the flow rates of the carrier gas and the reaction source gas in the gas injection device 11, combined with the temperature achievable through the heating control of the carrier device 13, the mixed reaction source gas containing the carrier gas can also reach the target temperature.

[0089] On the other hand, the heated gas in the inner annular cavity 302 is transported by the second delivery pipe 44 to the reserved cavity 21 in the inner top wall of the reaction chamber 1 to heat the inner top of the reaction chamber 1. This helps to make full use of the thermal energy of the process waste gas to achieve a reasonable temperature gradient between the inner top wall of the reaction chamber 1 and the support device 13, ensuring that the process gas sprayed by the gas injection device 11 can be heated to the process temperature range near the top of the substrate and avoiding pre-reaction after spraying. This helps to improve the growth efficiency and growth quality of epitaxial growth.

[0090] In summary, the silicon carbide epitaxial equipment 100 of this embodiment can effectively recover and utilize the heat of process waste gas by setting up an annular heat collection chamber 3. With the dual-chamber setting of the annular heat collection chamber 3, the gas heated by the two chambers is respectively transported to the gas injection device 11 and the reserved cavity 21 at the top wall of the reaction chamber 1. This can not only alleviate the cold zone effect caused by the gas injection of the gas injection device 11, but also participate in the temperature gradient regulation of the growth space at the top wall of the reaction chamber 1, thereby effectively improving the growth efficiency and growth quality of epitaxial growth, and effectively reducing energy consumption.

[0091] Furthermore, since the heat from the process exhaust gas is used to improve the cold zone problem and regulate the temperature gradient of the growth space, 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.

[0092] To avoid pre-reaction of the process gas near the spray surface immediately after ejection, which would reduce growth efficiency and potentially cause particle deposition on the spray surface, affecting the gas flow field or even clogging the spray surface, the inlet temperature of the reaction source gas needs to be lower than the process temperature inside the reaction chamber 1. The reaction source gas is heated by the reaction space after ejection and before reaching the top surface of the support device 13, thereby reaching the process temperature. This process is greatly affected by the temperature field between the top wall of the reaction chamber 1 and the support device 13. Moreover, the temperatures of the top wall of the reaction chamber 1 and the support device 13 can be monitored. Because the inner annular cavity 302 is closer to the support device 13 and the side where the heating device 9 is located, its temperature can be considered to be closer to the temperature of the support device 13 than that of the outer annular cavity 301, or even comparable to the temperature of the support device 13. Therefore, by controlling the temperature of the top wall of the reaction chamber 1 through the heating gas in the inner annular cavity 302, combined with the temperature control of the support device 13 by the heating device 9, a reasonable temperature gradient between the top wall of the reaction chamber 1 and the support device 13 can be achieved, effectively improving the growth efficiency and quality of epitaxial growth.

[0093] In this embodiment, as Figure 1 and Figure 2As shown, the first inlet pipe 41 can be connected to the outer annular cavity 301 from the bottom surface of the outer annular cavity 301, and the second inlet pipe 42 can be connected to the inner annular cavity 302 from the bottom surface of the inner annular cavity 302.

[0094] Alternatively, if the bottom space of reaction chamber 1 is underutilized, to avoid interference with other components that would be detrimental to the process, such as... Figure 15 As shown, the thickness of the bottom wall of the outer annular cavity 301 can be greater than the thickness of the bottom wall of the inner annular cavity 302, so that the height of the inner bottom surface of the outer annular cavity 301 is higher than the height of the inner bottom surface of the inner annular cavity 302. The second inlet pipe 42 can penetrate the bottom wall of the outer annular cavity 301 from the side to communicate with the interior of the inner annular cavity 302. The first inlet pipe 41 can communicate with the interior of the outer annular cavity 301 from the side.

[0095] In this embodiment, as Figure 4 and Figure 8 As shown, the annular heat collection chamber 3 is provided with an annular partition plate 31 extending toward the bottom surface of the reaction chamber 1. The annular partition plate 31 divides the inner cavity of the annular heat collection chamber 3 into an outer annular cavity 301 and an inner annular cavity 302.

[0096] In some embodiments, such as Figures 2 to 5 As shown, a separator 32 can be radially arranged inside the annular heat collection chamber 3 to break the communication between the annular spaces inside the outer annular cavity 301 and the inner annular cavity 302. The first inlet A1 of the first inlet pipe 41 on the outer annular cavity 301 and the first delivery pipe 43 are used to connect the first outlet A2 of the outer annular cavity 301, respectively located near the opposite sides of the separator 32 and communicating with the interior of the outer annular cavity 301. The second inlet B1 of the second inlet pipe 42 on the inner annular cavity 302 and the second delivery pipe 44 are used to connect the second outlet B2 of the inner annular cavity 302, respectively located near the opposite sides of the separator 32 and communicating with the inner annular cavity 302.

[0097] Therefore, when the gas flows through the outer annular cavity 301 and the inner annular cavity 302, its gas path flows along the circumference of the annular heat collection chamber 3 through most of the space of the outer annular cavity 301 and the inner annular cavity 302 before flowing out, so as to maximize the gas path length, 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.

[0098] Alternatively, in some embodiments, the first inlet A1 and the first outlet A2 are located in different half-regions of the annular heat collection chamber 3, and the second inlet B1 and the second outlet B2 are located in different half-regions of the annular heat collection chamber 3. For example, as Figure 6 , Figure 7 and Figure 8As shown, the first inlet A1 and the first outlet A2 are opposite each other along the radial direction of the reaction chamber 1, and the second inlet B1 and the second outlet B2 are opposite each other along the radial direction of the reaction chamber 1. The gas path length can also be increased to improve the heat exchange and heating effect accordingly.

[0099] In some embodiments, such as Figure 1 As shown, the sidewalls and topwalls of the reaction chamber 1 are provided with a heat insulation layer 15, and the first delivery pipe 43 and the second delivery pipe 44 are embedded in the heat insulation layer 15. The heat insulation layer 15 can be made of graphite hard felt coated with silicon carbide, and is installed on at least the inner sidewalls and inner topwalls of the reaction chamber 1 to keep the chamber warm, and also to keep the first delivery pipe 43 and the second delivery pipe 44 warm.

[0100] In some embodiments, such as Figures 9 to 12 As shown, the outer contour shape of the axial cross-section of the structure formed by the outer annular cavity 301 and the inner annular cavity 302 can be an axisymmetric structure. Alternatively, as... Figures 9 to 13 As shown, the axial cross-sectional outer contour structure of the annular heat collection chamber 3 can be an axisymmetric structure. This is beneficial for improving the consistency of the flow resistance of the gas channels on both sides of the annular heat collection chamber 3, avoiding 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 uniformity of film formation.

[0101] For example, such as Figure 9 As shown, the outer contour shape of the axial section of the annular heat collection chamber 3 can be rectangular.

[0102] 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.

[0103] Therefore, in some embodiments, such as Figures 10 to 13 As shown, the inner annular cavity 302 includes a top-inner sidewall 3021 near the support device 13 to form an inner top structure with the annular partition plate 31, and the outer annular cavity 301 includes a top-outer sidewall 3011 near the sidewall of the reaction chamber 1 to form an outer top structure with the annular partition plate 31. The top-inner sidewall 3021, the top-outer sidewall 3011, and the top of the annular partition plate 31 intersect, and both the top-inner sidewall 3021 and the top-outer sidewall 3011 are inclined relative to the support surface of the support device 13.

[0104] The top is inclined towards the inner side wall 3021 and the top is inclined towards the outer side wall 3011, which can guide the downward airflow, significantly reduce the obstruction of the airflow, reduce the generation of turbulence, facilitate the smooth discharge of process waste gas, and reduce the interference of the airflow at the edge of the bearing device 13.

[0105] In this embodiment, as Figures 10 to 13 As shown, the top inner sidewall 3021, the top outer sidewall 3011 and the annular partition plate 31 intersect to form a sharp corner structure or a chamfered structure, which can reduce the area of ​​the process waste gas colliding with the upper surface of the annular heat collection chamber 3, thereby reducing turbulence and reducing the impact on the airflow at the edge of the bearing device 13.

[0106] In this embodiment, as Figure 11 As shown, the inclination of the top inner wall 3021 and the top outer wall 3011 is the same, and the bottom surface of the top outer wall 3011 is lower than the bottom surface of the top inner wall. The acute angle of inclination of the top inner wall 3021 and the top outer wall 3011 relative to the top surface of the bearing device 13 is α, wherein, preferably, 45°≤α<90° is provided.

[0107] If the angle α is too small, the top of the annular heat collection chamber 3 tends to be flat, resulting in a larger area where the heat exchanger collides with the process waste gas at the top of the annular heat collection chamber 3, 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 in utilizing the heat of 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.

[0108] In this embodiment, as Figure 11 , Figure 12 and Figure 13 As shown, the outer annular cavity 301 also includes an outer bottom structure that is connected to and communicates with the outer top structure to increase the volume, and / or the inner annular cavity 302 also includes an inner bottom structure that is connected to and communicates with the inner top structure to increase the volume.

[0109] Specifically, the outer bottom structure includes a bottom-facing outer wall 3012 that is close to the side wall of the reaction chamber 1 and extends along the axial direction of the reaction chamber 1, and the inner bottom structure includes a bottom-facing inner wall 3022 that is close to the side where the support device 13 is located and extends along the axial direction of the reaction chamber 1.

[0110] In some embodiments, such as Figure 14 As shown, the structure composed of the outer annular cavity 301 and the inner annular cavity 302 can be a non-axisymmetric structure, and the outer contour structure of the annular heat collection chamber 3 can also be a non-axisymmetric structure.

[0111] For example, the inclination of the top inner wall 3021 and the top outer wall 3011 is not the same. The acute angles of inclination of the top outer wall 3011 and the top inner wall 3021 relative to the top surface of the bearing device 13 are α1 and α2, respectively, where 45°≤α1<90° and 45°≤α2<90°.

[0112] Specifically, the extension length of the top outward sidewall 3011 (i.e., the length extending from the top towards the bottom surface of the reaction chamber 1) can be set to be greater than the extension length of the top inward sidewall 3021 (i.e., the length extending from the top towards the bottom surface of the reaction chamber 1), so that the heated area of ​​the top outward sidewall 3011 is larger.

[0113] Because the heating device 9 is installed below the support device 13, the heating and temperature rise effect of the annular heat collection chamber 3 near the inner wall of the support device 13 is better. Therefore, by configuring the extension length of the top outward wall 3011 to be greater than the extension length of the top inward wall 3021, the flow resistance of the flow channel on the top outward wall 3011 side is smaller, so as to guide the process waste gas with a larger proportion to pass through the flow channel on the top outward wall 3011 side. In addition, since the length of the top outward wall 3011 is greater than the length of the top inward wall 3021, the heating area of ​​the top outward wall 3011 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 3.

[0114] In some embodiments, such as Figure 14 As shown, the top outer wall 3011 and the top inner wall 3021 have the same degree of inclination relative to the supporting device 13, and the bottom end of the top outer wall 3011 is lower than the bottom end of the top inner wall 3021. The degree of inclination of the top outer wall 3011 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 3021 is represented by α2 in the figure. When α1=α2, the bottom surface of the top outer wall 3011 is lower than the bottom surface of the top inner wall 3021. It can be seen that the surface area of ​​the top outer wall 3011 increases, and the flow resistance of the process waste gas passage on its side is lower than that on the side where the top outer wall 3011 is located.

[0115] Furthermore, the inclination angles of the top outer wall 3011 and the top inner wall 3021 are α1 and α2, respectively. α1 and α2 can be equal or unequal. By configuring the values ​​of α1 and α2, the process exhaust gas can exhibit different flow resistance differences in the flow channels on both sides of the top outer wall 3011 and the top inner wall 3021. This configuration of α1 and α2 ensures that even when there is a difference in flow resistance between the process exhaust gas flow channel on the side of the top outer wall 3011 and the side of the top inner wall 3021, strong turbulence that would affect the process gas flow field near the top of the supporting device 13 can be avoided.

[0116] In one embodiment, α1 > α2 can be configured such that the flow resistance at the top outer sidewall 3011 is less than the flow resistance at the top inner sidewall 3021.

[0117] In some embodiments, such as Figure 11 As shown, the total height of the annular heat collection chamber 3 is h, and the height of the lowest of the top inner side wall 3021 and the top outer side wall 3011 is h1, wherein 1 / 2h≤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 3.

[0118] In some embodiments, such as Figure 13 and Figure 14 As shown, the volumes of the outer annular cavity 301 and the inner annular cavity 302 can be configured to be unequal.

[0119] For example, the volume of the outer annular cavity 301 can be configured not to exceed the volume of the inner annular cavity 302, that is, the volume of the inner annular cavity 302 is larger, which means that the gas flow rate delivered by the inner annular cavity 302 at one time is larger, and the gas heated by the inner annular cavity 302 has a more obvious effect on the temperature increase at the top wall of the reaction chamber 1.

[0120] As mentioned above, the reaction source gas is heated by the reaction space after being ejected and before reaching the top surface of the support device 13, thereby reaching the process temperature. This process, as well as the growth rate and growth quality, are greatly affected by the temperature field between the top wall of the reaction chamber 1 and the support device 13. By increasing the volume of the inner annular cavity 302, the control effect and flexibility of the temperature at the top wall of the reaction chamber 1 can be improved, and the reasonable temperature gradient between the top wall of the reaction chamber 1 and the support device 13 can be further enhanced, which is conducive to achieving better film quality.

[0121] Example 2

[0122] like Figure 16 , Figure 17 and Figure 18 As shown, this embodiment also provides a silicon carbide epitaxial device 100. The difference from the first embodiment is that this embodiment also includes a current collector 5.

[0123] Specifically, the silicon carbide epitaxial equipment includes a collector 5 with its top surface lower than the bottom surface of the support device 13. The collector 5 has an annular collecting cavity 501, and an annular heat collection chamber 3 is suspended within the collecting cavity 501 of the collector 5. The top of the collector 5 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 5 through the exhaust port 12. The collector 5 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 of the support device 13. The first inlet pipe 41, the second inlet pipe 42, the first delivery pipe 43, and the second delivery pipe 44 all pass through the collector 5. The annular heat collection chamber 3 and the collector 5 together constitute the heat collection assembly 10.

[0124] The inner and outer walls of the collecting device 5 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 5 fills the lower part of 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 5, and thus can make more full contact with the annular heat collection chamber 3 inside the collecting device 5, so as to achieve a better heating effect.

[0125] In some embodiments, such as Figure 18 As shown, the annular heat collection chamber 3 also includes support feet 33, and the flow collection device 5 includes a support column 53 located on the outer bottom surface of the flow collection cavity 501. The support column 53 has a hollow structure, with both ends connected to the exhaust port 12 and the flow collection cavity 501, respectively. The hollow support column 53 can serve to transport gas and provide support, or a solid support column can be used to support the flow collection device 5. The support feet 33 are located between the inner bottom surface of the flow collection cavity 501 and the bottom of the annular heat collection chamber 3 to support the annular heat collection chamber 3, thereby preventing the annular heat collection chamber 3 from blocking the flow collection outlet 52 and ensuring the smooth flow of process waste gas.

[0126] In some embodiments, such as Figure 17 and Figure 18 As shown, the flow collecting device 5 may further include a flow collecting ring 502. The flow collecting cavity 501 is provided with an upward-facing annular opening, and its bottom surface is provided with several flow collecting outlets 52 that communicate with the hollow support columns 53. The flow collecting ring 502 covers the annular opening of the flow collecting cavity 501, and the flow collecting ring 502 is provided with several circumferentially evenly distributed flow collecting inlets 51. The shape of the flow collecting inlets 51 may be a circular hole, an oblong hole, etc.

[0127] In some embodiments, such as Figures 19 to 22 As shown, the outer contour structure of the annular heat collection chamber 3 and the flow collection device 5 are both axisymmetric structures, and the central axis of the annular heat collection chamber 3 coincides with the central axis of the flow collection device 5.

[0128] In some embodiments, such as Figure 23 As shown, the outer contour structure of the annular heat collection chamber 3 can be a non-axisymmetric structure, while the axial section of the flow collection device 5 can be an axisymmetric structure. The centerline of the axial section of the annular heat collection chamber 3 coincides with the center axis of the axial section of the flow collection device 5, which is beneficial to the consistency of flow resistance of the process waste gas channels on both sides of the annular heat collection chamber 3 and avoids the generation of strong turbulence.

[0129] In this embodiment, as Figure 19As shown, the axial cross-sectional shape of the annular heat collection chamber 3 can be rectangular. When gas flows in through the gas collection inlet 51 of the gas collection device 5, considering the top of the rectangle and the inner wall structure of the gas collection cavity 501, 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.

[0130] Therefore, in some embodiments, such as Figures 20 to 23 As shown, at least a portion of the inner and outer walls of the annular heat collection chamber 3 are provided with guide slopes, which are configured to guide the downward-moving airflow.

[0131] For example, such as Figure 20 As shown, the entire area of ​​the inner and outer sidewalls of the annular heat collection chamber 3 can be set as flow guiding slopes to significantly reduce the obstruction of airflow.

[0132] For example, such as Figure 21 , Figure 22 and Figure 23 As shown, the inner annular cavity 302 includes a top inner wall 3021 that extends obliquely towards the side where the support device 13 is located, and the outer annular cavity 301 includes a top outer wall 3011 that extends obliquely towards the side wall of the reaction chamber 1. The oblique arrangement can significantly reduce the obstruction of airflow, reduce the generation of turbulence, facilitate the smooth discharge of process waste gas, and reduce the interference of airflow at the edge of the support device 13.

[0133] In this embodiment, the volume of the annular heat collection chamber 3 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 3 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 3 to be larger than the cross-section of the top, that is, the annular heat collection chamber 3 includes both a top structure and a bottom structure.

[0134] Among them, such as Figure 21 As shown, the channel formed by the top inner wall 3021 and the top outer wall 3011 with the inner wall of the flow collecting device 5 can be called the first flow channel a, and the channel formed by the lower part of the guide slope with the inner wall of the flow collecting device 5 can be called the second flow channel b.

[0135] like Figure 24As shown, if the height h1 of the inclined plane is less than half of the total height h of the annular heat collection chamber 3, the inclination angle of the guide inclined plane will also be relatively small. When the high-temperature process waste gas enters through the collection inlet 51 of the collection device 5, it passes through the space of the first flow channel a and collides with the top of the annular heat collection chamber 3. In the narrow space, it rebounds 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 3 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.

[0136] In this embodiment, as Figure 21 As shown, the height of the collecting cavity 501 of the collecting device 5 is H, and the height of the lowest of the inner sidewall 3021 and the outer sidewall 3011 of the annular heat collection chamber 3 is h1, where H / 2 ≤ h1 < H. Within this limitation, when the process waste gas enters through the collecting inlet 51 of the collecting device 5, 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 51 of the collecting device 5, thereby reducing the impact of turbulence on the growth of the epitaxial wafer edge.

[0137] Furthermore, in this embodiment, since h1≥H / 2 is set, it is ensured that the height of the top inner sidewall 3021 and the top outer sidewall 3011 occupies at least half of the internal height of the flow collection device 5, so that the space of the first flow channel a forms as large a space as possible, and the airflow can be effectively diffused and buffered.

[0138] 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, characterized in that, include: The reaction chamber (1) is provided with a gas injection device (11) at the top and a tail gas discharge port (12) at the bottom, and a support device (13) inside; an annular channel (14) is formed between the outer wall of the support device (13) and the inner wall of the reaction chamber (1). The cover structure (2) is located at the top of the inner side of the reaction chamber (1), and a reserved cavity (21) is formed between it and the inner top wall of the reaction chamber (1). The gas injection device (11) passes through the reserved cavity (21) and is opposite to the top surface of the bearing device (13). An annular heat collection chamber (3) is located in the space between the annular channel (14) and the reaction chamber (1), and has gaps between itself and the support device (13) and between itself and the side wall of the reaction chamber (1) to allow gas to pass through; the inner cavity of the annular heat collection chamber (3) includes an outer annular cavity (301) and an inner annular cavity (302) that are separated from each other; the outer annular cavity (301) surrounds the inner annular cavity (302). The first inlet pipe (41) and the second inlet pipe (42) are respectively connected to the outer annular cavity (301) and the inner annular cavity (302), and extend to the outside of the reaction chamber (1); The first delivery pipe (43) is connected at both ends to the outer annular cavity (301) and the gas injection device (11) respectively, and extends within the cavity wall of the reaction chamber (1) to mix the hot gas in the outer annular cavity (301) with the gas in the gas injection device (11) to increase the gas temperature; The second delivery pipe (44) is connected to the inner annular cavity (302) and the reserved cavity (21) at both ends, and extends into the cavity wall of the reaction chamber (1) so that the hot gas in the inner annular cavity (302) enters the reserved cavity (21) to facilitate the uniformity of the temperature field in the reaction space of the reaction chamber (1).

2. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, The first inlet pipe (41) is connected to the outer annular cavity (301) from the bottom surface of the outer annular cavity (301), and the second inlet pipe (42) is connected to the inner annular cavity (302) from the bottom surface of the inner annular cavity (302).

3. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, The thickness of the bottom wall of the outer annular cavity (301) is greater than the thickness of the bottom wall of the inner annular cavity (302), so that the height of the inner bottom surface of the outer annular cavity (301) is higher than the height of the inner bottom surface of the inner annular cavity (302). The second inlet pipe (42) penetrates the bottom wall of the outer annular cavity (301) from the side to communicate with the interior of the inner annular cavity (302). The first inlet pipe (41) communicates with the interior of the outer annular cavity (301) from the side.

4. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, The annular heat collection chamber (3) is provided with an annular partition plate (31) extending toward the bottom surface of the reaction chamber (1). The inner annular cavity (302) includes a top inner sidewall (3021) near the support device (13) to form an inner top structure with the annular partition plate (31). The outer annular cavity (301) includes a top outer sidewall (3011) near the sidewall of the reaction chamber (1) to form an outer top structure with the annular partition plate (31). The top inner sidewall (3021), the top outer sidewall (3011) and the top of the annular partition plate (31) intersect, and the top inner sidewall (3021) and the top outer sidewall (3011) are both inclined relative to the bearing surface of the bearing device (13).

5. The silicon carbide epitaxial apparatus according to claim 4, characterized in that, The inclination of the top inner sidewall (3021) is the same as that of the top outer sidewall (3011), and the bottom surface of the top outer sidewall (3011) is lower than the bottom surface of the top inner sidewall.

6. The silicon carbide epitaxial apparatus according to claim 4, characterized in that, The top inner sidewall (3021), the top outer sidewall (3011), and the annular partition plate (31) intersect to form a sharp corner structure or a chamfered structure.

7. The silicon carbide epitaxial apparatus according to claim 4, characterized in that, The outer annular cavity (301) further includes an outer bottom structure that is connected to and communicates with the outer top structure to increase the volume, and / or the inner annular cavity (302) further includes an inner bottom structure that is connected to and communicates with the inner top structure to increase the volume.

8. The silicon carbide epitaxial apparatus according to claim 7, characterized in that, The outer bottom structure includes a bottom outer sidewall (3012) that is close to the sidewall of the reaction chamber (1) and extends along the axial direction of the reaction chamber (1), and the inner bottom structure includes a bottom inner sidewall (3022) that is close to the side where the support device (13) is located and extends along the axial direction of the reaction chamber (1).

9. The silicon carbide epitaxial apparatus according to claim 4, characterized in that, The total height of the annular heat collection chamber (3) is h, and the height of the lowest of the top inner side wall (3021) and the top outer side wall (3011) is h1, wherein h / 2≤h1≤h.

10. The silicon carbide epitaxial apparatus according to claim 4, characterized in that, The acute angles of inclination of the top outer sidewall (3011) and the top inner sidewall (3021) relative to the top surface of the bearing device (13) are α1 and α2, respectively, where 45°≤α1<90° and 45°≤α2<90°.

11. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, The volume of the outer annular cavity (301) does not exceed the volume of the inner annular cavity (302).

12. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, An isolation element (32) is arranged radially inside the annular heat collection chamber (3) to break the communication between the annular spaces inside the outer annular cavity (301) and the inner annular cavity (302); The first inlet (A1) of the first inlet pipe (41) on the outer annular cavity (301) and the first delivery pipe (43) are used to connect the first outlet (A2) of the outer annular cavity (301) to the opposite sides of the isolation member (32) and communicate with the interior of the outer annular cavity (301); The second inlet (B1) of the second inlet pipe (42) on the inner annular cavity (302) and the second delivery pipe (44) are used to connect the second outlet (B2) of the inner annular cavity (302) to the opposite sides of the isolation member (32) and communicate with the inner annular cavity (302).

13. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, The reaction chamber (1) has a heat insulation layer (15) on its side wall and top wall, and the first delivery pipe (43) and the second delivery pipe (44) are embedded in the heat insulation layer (15).

14. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, The outer contour structure of the axial section of the structure composed of the outer annular cavity (301) and the inner annular cavity (302) is an axisymmetric structure, and / or the outer contour structure of the axial section of the annular heat collection chamber (3) is an axisymmetric structure.

15. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, It also includes a heat collection device (5) having an annular heat collection cavity (501), the top surface of the heat collection device (5) being lower than the bottom surface of the supporting device (13), and the annular heat collection chamber (3) being suspended in the heat collection cavity (501) of the heat collection device (5). The top of the collecting device (5) is connected to the inside and outside of the reaction chamber (1), and the bottom is connected to the exhaust port (12), so that the gas can be discharged from the collecting device (5) through the exhaust port (12). The flow collection device (5) 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 first inlet pipe (41), the second inlet pipe (42), the first delivery pipe (43), and the second delivery pipe (44) all pass through the collector (5).

16. The silicon carbide epitaxial apparatus according to claim 15, characterized in that, The axial cross-sectional outer contour structure of the annular heat collection chamber (3) and the axial cross-sectional outer contour structure of the collection device (5) are both axisymmetric structures. The central axis of the axial cross-sectional outer contour structure of the annular heat collection chamber (3) coincides with the central axis of the axial cross-sectional outer contour structure of the collection device (5).

17. The silicon carbide epitaxial apparatus according to claim 15, characterized in that, The annular heat collection chamber (3) also includes a support foot (33), and the flow collection device (5) includes a support column (53) disposed on the bottom surface of the flow collection cavity (501). The support column (53) has a hollow structure, and its two ends are connected to the exhaust port (12) and the manifold cavity (501) respectively. The support foot (33) is located between the bottom surface of the manifold cavity (501) and the bottom of the annular heat collection chamber (3) to support the annular heat collection chamber (3).

18. The silicon carbide epitaxial apparatus according to claim 15, characterized in that, The inner annular cavity (302) includes a top-inner sidewall (3021) that extends obliquely toward the side where the support device (13) is located, and the outer annular cavity (301) includes a top-outer sidewall (3011) that extends obliquely toward the sidewall of the reaction chamber (1). The total height of the internal cavity of the heat collection device (5) is H, the total height of the annular heat collection chamber (3) is h, and the height of the lowest of the top inner side wall (3021) and the top outer side wall (3011) is h1; Where H / 2 ≤ h1 < H.

19. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, Also includes: The second gas supply device (62) is located outside the reaction chamber (1) and is connected to the first inlet pipe (41) to provide carrier gas or purge gas; The third gas supply device (63) is located outside the reaction chamber (1) and is connected to the second inlet pipe (42) to provide purge gas.

20. The silicon carbide epitaxial apparatus according to claim 1, characterized in that, The gas injection device (11) is provided with a process gas channel and a purge gas channel, and the second delivery pipe (44) is connected to either the process gas channel or the purge gas channel.

Images