Silicon carbide epitaxy equipment

Abstract

The invention provides silicon carbide epitaxy equipment. The silicon carbide epitaxy equipment comprises a reaction cavity, a housing structure, an annular heat collection bin, a first inlet pipe, a second inlet pipe, a first conveying pipe and a second conveying pipe, a gas injection device is arranged at the top of the reaction cavity, a tail gas discharge port is formed in the bottom and a bearing device is arranged in the reaction cavity. An annular channel is formed between the outer side wall of the bearing device and the inner side wall of the reaction cavity. And a reserved cavity is formed between the housing structure and the inner top wall of the reaction cavity. The annular heat collection bin is suspended in the space between the annular channel and the reaction cavity, and gaps are formed between the annular heat collection bin and the bearing device and between the annular heat collection bin and the side wall of the reaction cavity. The annular heat collection bin is divided into an outer annular cavity and an inner annular cavity. The first inlet pipe and the second inlet pipe are respectively communicated with the outer annular cavity and the inner annular cavity and extend out of the reaction cavity. The two ends of the first conveying pipe communicate with the outer annular cavity and the gas injection device correspondingly. The two ends of the second conveying pipe communicate with the inner annular cavity and the reserved cavity correspondingly. According to the scheme, the heat of the process waste gas can be 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 silicon carbide epitaxial equipment. Background Art

[0002] Silicon carbide epitaxial equipment is a key piece of equipment in the semiconductor power device manufacturing chain. The growth chamber of silicon carbide epitaxial equipment is generally maintained in an ultra-high temperature zone, such as 1500-1750°C. However, after room-temperature process gases (including reaction source gases, carrier gases, purge gases, etc.) are injected into the growth chamber, a distinct cold zone forms within the growth chamber, disrupting the originally uniform thermal boundary layer and causing a cold zone effect at the source gas injection point. The walls within the equipment cavity (such as the top wall) will experience temperature fluctuations, resulting in a cold zone effect on the cavity walls. The cold zone effect leads to uneven distribution of thickness and doping, affecting the growth rate and uniformity of silicon carbide epitaxy. To alleviate the cold end and cold zone effects, 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 the maintenance cycle.

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

[0004] However, the process exhaust gases from the growth chamber, carrying a significant amount of heat, are directly discharged, lacking efficient waste heat recovery and resource reuse. Therefore, how to mitigate the cold zone effect and effectively utilize the waste heat from the process exhaust gases while also improving the quality of epitaxial film formation have become pressing challenges. Summary of the Invention

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

[0006] The present application provides a silicon carbide epitaxial device, which includes a reaction chamber, a cover 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 is equipped with a gas injection device at the top, an exhaust gas outlet at the bottom, and a supporting device inside. An annular channel is formed between the outer wall of the supporting device and the inner wall of the reaction chamber. A housing structure is arranged at the inner top of the reaction chamber, with a reserved cavity formed between it and the inner top wall of the reaction chamber. The gas injection device passes through the reserved cavity and faces the supporting top surface of the supporting device. An annular heat collection chamber is arranged in the space between the annular channel and the reaction chamber, with a gap between it and the supporting device and the side walls 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 separated from each other; the outer annular cavity surrounds the inner annular cavity.

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

[0009] In an implementable solution, the first inlet pipe is connected to the outer annular cavity from the bottom surface of the outer annular cavity, and the second inlet pipe is connected to the inner annular cavity from the bottom surface of the inner annular cavity.

[0010] In one feasible solution, 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, so that the inner bottom surface height of the outer annular cavity is higher than the inner bottom surface height of the inner annular cavity, the second inlet pipe passes through the bottom wall of the outer annular cavity from the side of the outer annular cavity 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 of the outer annular cavity.

[0011] In one feasible solution, an annular partition plate extending toward the inner bottom surface of the reaction chamber is provided within the annular heat collection chamber. The inner annular chamber includes a top-facing inward sidewall proximate to the supporting device, which forms an inner top structure with the annular partition plate. The outer annular chamber includes a top-facing outward sidewall proximate to the sidewall of the reaction chamber, which forms an outer top structure with the annular partition plate. The top-facing inward sidewall, the top-facing outward sidewall, and the top of the annular partition plate intersect, and both the top-facing inward sidewall and the top-facing outward sidewall are inclined relative to the supporting surface of the supporting device.

[0012] In one feasible solution, the top inner sidewall and the top outer sidewall have the same inclination, and the bottom surface of the top outer sidewall is lower than the bottom surface of the top inner sidewall.

[0013] In one feasible solution, the top inner sidewall, the top outer sidewall and the annular partition plate meet to form a pointed angle structure or a chamfered angle structure.

[0014] In one feasible solution, the outer annular cavity further includes an outer bottom structure connected to the outer top structure and communicating with the interior thereof to increase the volume, and / or the inner annular cavity further includes an inner bottom structure connected to the inner top structure and communicating with the interior thereof to increase the volume.

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

[0016] In an implementable solution, the total height of the annular heat collecting 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.

[0017] In an implementable solution, the acute inclination angles of the top outer sidewall and the top inner sidewall relative to the top surface of the supporting device are α1 and α2 respectively, wherein 45°≤α1<90°, and 45°≤α2<90°.

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

[0019] In one feasible solution, an isolation member is radially arranged in the annular heat collection chamber to break the connectivity of the internal annular spaces of the outer annular cavity and the inner annular cavity; the first inlet of the first inlet pipe on the outer annular cavity and the first delivery pipe for connecting to the first outlet of the outer annular cavity are respectively close to the opposite sides of the isolation member and communicate with the interior of the outer annular cavity; the second inlet of the second inlet pipe on the inner annular cavity and the second delivery pipe for connecting to the second outlet of the inner annular cavity are respectively close to the opposite sides of the isolation member and communicate with the inner annular cavity.

[0020] In one feasible solution, a heat insulation layer is provided on the side wall and the top wall of the reaction chamber, and the first delivery pipe and the second delivery pipe are buried in the heat insulation layer.

[0021] In one feasible solution, the outer contour structure of the axial cross section of the structure composed of the outer annular cavity and the inner annular cavity is an axisymmetric structure, and / or the outer contour structure of the axial cross section of the annular heat collecting bin is an axisymmetric structure.

[0022] In an implementable scheme, it also includes a collecting device, which has an annular collecting cavity, the top surface of the collecting device is lower than the bottom surface of the carrying device, and the annular heat collection bin is suspended in the collecting cavity of the collecting device; the top of the collecting device is communicated with the inside and outside of the reaction chamber, and the bottom is connected with the exhaust gas discharge port, so that the gas can be discharged from the collecting device through the exhaust gas discharge port; the collecting device 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 carrying device so as not to interfere with the movement of the carrying device; the first inlet pipe, the second inlet pipe, the first delivery pipe, and the second delivery pipe all pass through the collecting device.

[0023] In one feasible solution, the axial cross-sectional outer contour structure of the annular heat collecting bin and the axial cross-sectional outer contour structure of the current collecting device are both axially symmetrical structures, and the central axis of the axial cross-sectional outer contour structure of the annular heat collecting bin coincides with the central axis of the axial cross-sectional outer contour structure of the current collecting device.

[0024] 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.

[0025] In an implementable solution, the inner annular cavity includes a top inner wall that extends obliquely close to and toward the side where the supporting device is located, and the outer annular cavity includes a top outer wall that extends obliquely close to and toward the side wall of the reaction chamber; the total height of the internal cavity of the collecting device is H, the total height of the annular heat collection bin 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 embodiment, the silicon carbide epitaxial growth apparatus further includes a second gas supply device and a third gas supply device. The second gas supply device is located outside the reaction chamber and communicates with the first inlet pipe to provide carrier gas or purge gas. The third gas supply device is located outside the reaction chamber and communicates with the second inlet pipe to provide purge gas.

[0027] In an implementable solution, a process gas channel and a purge gas channel are provided in the gas injection device, and the second delivery pipe is connected to either the process gas channel or the purge gas channel.

[0028] Compared with the prior art, the beneficial effects of the present application include at least: in the silicon carbide epitaxial equipment of the present application, an exhaust gas discharge port is provided at the bottom of the reaction chamber, the gas injection device is opposite to the supporting top surface of the supporting device, and the annular heat collection bin is arranged 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 reaction chamber, so that it can be located on the flow path of the high-temperature process exhaust gas, can effectively absorb the heat of the high-temperature process exhaust gas, and increase the temperature of the gas in the outer annular cavity and the inner annular cavity in the annular heat collection bin.

[0029] Furthermore, the heated gas in the outer annular cavity is transported to the gas injection device by 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, and make the temperature gradient in the reaction chamber more uniform, which helps to improve the gas cracking 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, which is conducive to making full use of the thermal energy of the process exhaust gas to achieve a reasonable temperature gradient in the growth space between the top wall of the reaction chamber and the supporting device, ensuring that the process gas ejected by the gas injection device can be heated to the process temperature range near the top of the substrate, and avoiding pre-reaction after being ejected from the spray surface, which is conducive to improving the growth efficiency and growth quality of epitaxial growth.

[0031] In summary, the silicon carbide epitaxial equipment of the present application can achieve effective recovery and utilization of the heat of process exhaust gas by setting up an annular heat collection chamber, cooperate with the dual-cavity setting of the annular heat collection chamber, and transport the heated gas in the dual cavities to the gas injection device and the reserved cavity at the top wall of the reaction chamber respectively, which can not only alleviate the cold zone effect caused by the gas injection of the gas injection device, but also improve the growth efficiency and growth quality of epitaxial growth.

[0032] In addition, since the heat of process exhaust gas is used to improve the cold zone problem and adjust the temperature gradient in 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 reduce the thermal inertia of the equipment and extend the maintenance cycle, while also reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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.

[0034] Figure 1 This is a schematic structural diagram of the first silicon carbide epitaxial device shown in an embodiment of the present application.

[0035] 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.

[0036] Figure 3 for Figure 2 Side view of the middle ring solar collector.

[0037] Figure 4 For the Figure 3 Cross-sectional view of AA in the figure.

[0038] Figure 5 for Figure 4 A partial enlarged view of the middle separator.

[0039] Figure 6This is a schematic diagram of the three-dimensional structure of the second annular solar collector shown in an embodiment of the present application.

[0040] Figure 7 for Figure 6 Side view of the middle ring solar collector.

[0041] Figure 8 For the Figure 7 Cross-sectional view of the BB.

[0042] Figures 9 to 15 This is an axial cross-sectional view of different annular heat collection bins shown in the embodiments of the present application.

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

[0044] Figure 17 for Figure 16 A three-dimensional diagram of the solar collector assembly.

[0045] Figure 18 for Figure 17 Exploded structure diagram of the solar collector assembly.

[0046] Figures 19 to 24 Axial cross-sectional views of different solar collector components in assembly status.

[0047] Figure 25 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.

[0048] In the figure: 100, silicon carbide epitaxial growth equipment; 1, reaction chamber; 11, gas injection device; 12, exhaust gas outlet; 13, carrying device; 14, annular channel; 15, thermal insulation layer; 16, exhaust space in the chamber; 2, cover structure; 21, reserved cavity; 3, annular heat collection chamber; 31, annular partition plate; 32, spacer; 301, outer annular cavity; 3011, top facing outer wall; 3012, bottom facing outer wall; 302, inner annular cavity; 3021, top facing inner wall; 3022, bottom facing inner 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 delivery pipe; 44. Second delivery 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. Exhaust device; 8. Rotation drive device; 9. Heating device; 10. Heat collection assembly. DETAILED DESCRIPTION

[0049] 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.

[0050] 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 making any creative efforts shall fall within the scope of protection of the present application.

[0051] The present application provides a silicon carbide epitaxial growth device, comprising a reaction chamber, a cover 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 features a gas injection device at the top, an exhaust outlet at the bottom, and a support mechanism within. An annular channel is formed between the outer wall of the support mechanism and the inner wall of the reaction chamber. A housing structure is positioned at the inner top of the reaction chamber, creating a reserved cavity between the housing and the inner top wall. The gas injection device passes through the reserved cavity and faces the top surface of the support mechanism.

[0053] The annular heat collection chamber is located in the space between the annular channel and the reaction chamber, with a gap between it and the supporting device and the sidewalls of the reaction chamber to allow gas to pass through. The inner chamber of the annular heat collection chamber includes an outer annular chamber and an inner annular chamber separated from each other, with the outer annular chamber surrounding the inner annular chamber. A first inlet pipe and a second inlet pipe respectively connect the outer annular chamber and the inner annular chamber and extend to the outside of the reaction chamber.

[0054] The first delivery pipe, with its two ends connected to the outer annular chamber and the gas injection device, extends within the reaction chamber wall, allowing the hot gas from the outer annular chamber to mix with the gas in the gas injection device to increase the gas temperature. The second delivery pipe, with its two ends connected to the inner annular chamber and the reserved cavity, extends within the reaction chamber wall, allowing the hot gas from the inner annular chamber to enter the reserved cavity, thereby promoting temperature uniformity within the reaction space.

[0055] The gas inputted by the gas injection device is reaction source gas or purge gas, the gas inputted into the outer annular cavity is carrier gas or purge gas, and the gas inputted into the inner annular cavity is purge gas.

[0056] The annular heat collection chamber provided in the silicon carbide epitaxial equipment of the present application 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 and increase the temperature of the gas in the outer annular cavity and the inner annular cavity in 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 by 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 reaction source gas injected into the reaction chamber, reduce the cold zone effect generated when the reaction source gas enters the reaction chamber, make the temperature gradient in the reaction chamber more uniform, help to improve the gas cracking efficiency, and improve 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 on the top wall of the reaction chamber to heat the top of the reaction chamber, which is conducive to making full use of the thermal energy of the process exhaust gas to achieve a reasonable temperature gradient in the growth space between the top wall of the reaction chamber and the supporting device, ensuring that the process gas ejected by the gas injection device can be heated to the process temperature range near the top of the substrate, and avoiding pre-reaction after being ejected from the spray surface, which is conducive to improving the growth efficiency and growth quality of epitaxial growth.

[0059] In summary, the silicon carbide epitaxial equipment of the present application can achieve effective recovery and utilization of the heat of process exhaust gas by setting up an annular heat collection chamber, cooperate with the dual-cavity setting of the annular heat collection chamber, and transport the heated gas in the dual cavities to the gas injection device and the reserved cavity at the top wall of the reaction chamber respectively. It can not only alleviate the cold zone effect caused by the 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] In addition, since the heat of process exhaust gas is used to improve the cold zone problem and adjust the temperature gradient in 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 reduce the thermal inertia of the equipment and extend the maintenance cycle, while also reducing energy consumption.

[0061] In order to explain the structure and working principle of the silicon carbide epitaxial device of the present application in more detail, 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.

[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 is equipped with a gas injection device 11 at the top, an exhaust outlet 12 at the bottom, and a support device 13 within. An annular channel 14 is formed between the outer wall of the support device 13 and the inner wall of the reaction chamber 1. A housing structure 2 is disposed at the inner top of the reaction chamber 1, forming a reserved cavity 21 between the housing structure 2 and the inner top wall of the reaction chamber 1. The gas injection device 11 passes through the reserved cavity 21 and faces the top surface of the support device 13.

[0065] The annular heat collection chamber 3 is arranged in the space between the annular channel 14 and the reaction chamber 1, and has a distance between it and the supporting device 13 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 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 respectively connect 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 connects the outer annular cavity 301 and the gas injection device 11 at both ends and extends within the wall of the reaction chamber 1, allowing the hot gas from the outer annular cavity 301 to mix with the gas within the gas injection device 11 to increase the gas temperature. The second delivery pipe 44 connects the inner annular cavity 302 and the reserved cavity 21 at both ends and extends within the wall of the reaction chamber 1, allowing the hot gas from the inner annular cavity 302 to enter the reserved cavity 21, thereby promoting temperature uniformity in the reaction space within the reaction chamber 1.

[0067] It should be noted that the annular heat collecting chamber 3 is made of a heat conducting material, which may be graphite or silicon carbide.

[0068] 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.

[0069] 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.

[0070] In some embodiments, the small disk can be made of graphite, graphite coated with tantalum carbide, graphite coated with silicon carbide, and the like.

[0071] 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.

[0072] 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.

[0073] In this embodiment, the 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.

[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 silane (SiH4), trichlorosilane (SiHCl3, TCS), and dichlorosilane (SiH2Cl2, DCS); 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 a purge gas.

[0076] In this embodiment, a process gas channel and a purge gas channel may be provided in the gas injection device 11 , and the first delivery pipe 43 is connected 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 a carrier gas or 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 source gas into the reaction chamber 1, while also diluting the concentration of the source gas to control the reaction rate and deposition uniformity. Hydrogen (H2) is a commonly used 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 is completed to quickly remove residual 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).

[0078] In this embodiment, if Figure 25 As shown, the silicon carbide epitaxial growth equipment also includes a first gas supply device 61, a second gas supply device 62, a third gas supply device 63 and a gas extraction device 7. The first gas supply device 61 is connected to the gas injection device 11 and is used to deliver 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 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.

[0079] Specifically, in the silicon carbide epitaxial growth equipment of this embodiment, the reaction source gas entering the reaction chamber 1 through the gas injection device 11 flows through the top surface of the carrier device 13 and the exposed surface of each substrate. After part of the reaction source gas undergoes epitaxial reaction, the remaining gas and reaction by-products enter the annular channel 14 between the outer wall of the carrier device 13 and the inner wall of the reaction chamber 1 as process waste gas, and flows through the annular heat collection bin 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 in the annular heat collection bin 3. The heated gas in the outer annular cavity 301 is transported to the gas injection device 11 by the first delivery pipe 43, and the heated gas in the inner annular cavity 302 is transported to the reserved cavity 21 on the inner top wall of the reaction chamber 1 by the second delivery pipe 44.

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

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

[0082] 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.

[0083] Since the gas provided by the 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 need to work together to 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 gas injection device 11, and the suction of the exhaust 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 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.

[0085] Therefore, the annular heat collection bin 3 is disposed within the intra-cavity 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 3, thereby facilitating effective heating of the gas within the annular heat collection bin 3. Specifically, the top of the annular heat collection bin 3 is no higher than the bottom surface of the supporting device 13.

[0086] The annular heat collection chamber 3 provided in the silicon carbide epitaxial equipment of 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 and increase the temperature of the gas in the outer annular cavity 301 and the inner annular cavity 302 in 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, and make the temperature gradient in the reaction chamber 1 more uniform, which helps to improve the gas cracking efficiency and improve the epitaxial layer growth efficiency.

[0088] Considering that although the problem of cold zone in the reaction chamber 1 can be solved by preheating the purge gas input to the gas injection device 11 before introducing it, the additional corresponding preheating structure makes the epitaxial device complicated in terms of both structure and function control, and generates additional energy consumption. After the hot purge gas provided by the outer annular cavity 301 is mixed with the original purge gas in the gas injection device 11, the temperature of the purge gas in the gas injection device 11 can be increased. By controlling the flow rate of the hot purge gas in the outer annular cavity 301 and the flow rate of the purge gas in the 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 outer annular cavity 301 is mixed with the reaction source gas carried by the carrier gas in the gas injection device 11, the temperature of the mixed gas can be increased. By reasonably designing the flow rate of the hot carrier gas in the outer annular cavity 301, the temperature that can be achieved by the flow rate of the carrier gas and the reaction source gas in the gas injection device 11 and 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 on the inner top wall of the reaction chamber 1 to heat the inner top of the reaction chamber 1, which is conducive to making full use of the thermal energy of the process exhaust gas to achieve a reasonable temperature gradient in the growth space between the inner top wall of the reaction chamber 1 and the supporting device 13, ensuring that the process gas ejected 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 being ejected from the spray surface, which is conducive to improving the growth efficiency and growth quality of epitaxial growth.

[0090] In summary, the silicon carbide epitaxial equipment 100 of this embodiment can achieve effective recovery and utilization of the heat of process exhaust gas by setting up the annular heat collection chamber 3, cooperate with the dual-cavity setting of the annular heat collection chamber 3, and transport the heated gas in the dual cavities to the gas injection device 11 and the reserved cavity 21 at the top wall of the reaction chamber 1 respectively. It 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 adjustment of the growth space at the top wall of the reaction chamber 1, thereby effectively improving the growth efficiency and growth quality of the epitaxial growth, and effectively reducing energy consumption.

[0091] In addition, since the heat of process exhaust gas is used to improve the cold zone problem and adjust the temperature gradient in 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 reduce the thermal inertia of the equipment and extend the maintenance cycle, while also reducing energy consumption.

[0092] To prevent the process gas from pre-reacting near the spray surface immediately after being ejected, thereby reducing growth efficiency, and to prevent particle deposition on the spray surface that could affect the gas flow field or even clog the spray surface, the inlet temperature of the source gas needs to be lower than the process temperature within the reaction chamber 1. The source gas is heated by the reaction space after being ejected and before reaching the top surface of the carrier 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 carrier device 13. Moreover, the temperature of the top wall of the reaction chamber 1 and the temperature of the carrier device 13 can be monitored. Because the inner annular cavity 302 is closer to the carrier 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 carrier device 13 than that of the outer annular cavity 301, and may even be equivalent to the temperature of the carrier device 13. Therefore, the temperature control of the top wall of the reaction chamber 1 by the heated gas in the inner annular cavity 302, combined with the temperature control of the carrier device 13 by the heating device 9, can jointly achieve a reasonable temperature gradient between the top wall of the reaction chamber 1 and the carrier device 13, effectively improving the growth efficiency and growth quality of epitaxial growth.

[0093] In this embodiment, if 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, in the case where the utilization rate of the bottom space in the reaction chamber 1 is low, in order to avoid interference with other components that is detrimental to the process, 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 inner bottom surface height of the outer annular cavity 301 is higher than the inner bottom surface height of the inner annular cavity 302. The second inlet pipe 42 can pass through the bottom wall of the outer annular cavity 301 from the side of the outer annular cavity 301 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 of the outer annular cavity 301.

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

[0096] In some embodiments, as Figures 2 to 5 As shown, an isolation member 32 can be radially arranged in the annular heat collection chamber 3 to disrupt the connectivity of the annular spaces within 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 close to 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, respectively close to opposite sides of the isolation member 32 and communicate 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 path length of the 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.

[0098] Alternatively, in some embodiments, the first inlet A1 and the first outlet A2 are located in different halves of the annular heat collecting chamber 3, and the second inlet B1 and the second outlet B2 are located in different halves of the annular heat collecting chamber 3. Figure 6 、 Figure 7 and Figure 8As shown, the first inlet A1 and the first outlet A2 are opposite to each other along the radial direction of the reaction chamber 1, and the second inlet B1 and the second outlet B2 are opposite to each other along the radial direction of the reaction chamber 1, which can also relatively increase the gas path length to correspondingly improve the heat exchange and heating effects.

[0099] In some embodiments, as Figure 1 As shown, the sidewalls and top wall of the reaction chamber 1 are provided with a thermal insulation layer 15, and the first and second delivery pipes 43 and 44 are embedded in the thermal insulation layer 15. The thermal 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 top wall of the reaction chamber 1 to insulate the chamber and also the first and second delivery pipes 43 and 44.

[0100] In some embodiments, as Figures 9 to 12 As shown, the outer contour of the axial section of the structure composed of the outer annular cavity 301 and the inner annular cavity 302 can be an axisymmetric structure. Figures 9 to 13 As shown, the outer contour structure of the axial cross-section of the annular heat collection chamber 3 can be an axisymmetric structure. This helps to improve the consistency of the flow resistance of the gas flow channels on both sides of the annular heat collection chamber 3, 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.

[0101] For example, Figure 9 As shown, the outer contour of the axial cross section of the annular heat collecting chamber 3 can be a rectangle.

[0102] 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.

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

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

[0105] In this embodiment, if Figures 10 to 13 As shown, the top inner wall 3021, the top outer wall 3011 and the annular partition plate 31 intersect to form a pointed structure or a chamfered structure, which can reduce the area where the process exhaust gas collides with the upper surface of the annular heat collection bin 3, thereby reducing turbulence and reducing the impact on the airflow at the edge of the carrier device 13.

[0106] In this embodiment, if Figure 11 As shown, the top inward-facing sidewall 3021 and the top outward-facing sidewall 3011 have the same inclination, and the bottom surface of the top outward-facing sidewall 3011 is lower than the bottom surface of the top inward-facing sidewall. The top inward-facing sidewall 3021 and the top outward-facing sidewall 3011 are both inclined at an acute angle α relative to the top surface of the support device 13, preferably 45°≤α<90°.

[0107] If the angle α is too small, the top of the annular heat collection bin 3 becomes flat, increasing the area where the process exhaust gas collides with the top of the annular heat collection bin 3 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.

[0108] In this embodiment, if Figure 11 、 Figure 12 and Figure 13 As shown, the outer annular cavity 301 further includes an outer bottom structure connected to the outer top structure and communicating with the interior to increase the volume, and / or the inner annular cavity 302 further includes an inner bottom structure connected to the inner top structure and communicating with the interior to increase the volume.

[0109] Specifically, the outer bottom structure includes a bottom-facing outer sidewall 3012 close to the side wall of the reaction chamber 1 and extending axially along the reaction chamber 1, and the inner bottom structure includes a bottom-facing inner sidewall 3022 close to the side where the supporting device 13 is located and extending axially along the reaction chamber 1.

[0110] In some embodiments, 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 collecting chamber 3 can also be a non-axisymmetric structure.

[0111] For example, the inclination degrees of the top inner wall 3021 and the top outer wall 3011 are inconsistent, and the acute inclination angles of the top outer wall 3011 and the top inner wall 3021 relative to the top surface of the supporting device 13 are α1 and α2 respectively, wherein 45°≤α1<90°, 45°≤α2<90°.

[0112] Specifically, the extension length of the top toward the outer side wall 3011 (i.e., the length extending from the top toward the inner bottom surface of the reaction chamber 1) can be set to be greater than the extension length of the top toward the inner side wall 3021 (i.e., the length extending from the top toward the inner bottom surface of the reaction chamber 1), so that the heating area of ​​the top toward the outer side wall 3011 is larger.

[0113] Because the heating device 9 is disposed below the carrier device 13, the inner sidewall of the annular heat collection bin 3 near the carrier device 13 is heated and heated more effectively. Therefore, by configuring the extension length of the top-facing outer sidewall 3011 to be greater than the extension length of the top-facing inner sidewall 3021, the flow resistance of the flow channel on the side of the top-facing outer sidewall 3011 is reduced, thereby guiding the process exhaust gas, which accounts for a larger proportion, to pass through the flow channel on the side of the top-facing outer sidewall 3011. Furthermore, because the length of the top-facing outer sidewall 3011 is greater than the length of the top-facing inner sidewall 3021, the heated area of ​​the top-facing outer sidewall 3011 is larger, which can also improve the heating effect and balance the heating uniformity of the inner and outer walls of the annular heat collection bin 3.

[0114] In some embodiments, such as Figure 14 As shown, the top-facing outer wall 3011 and the top-facing inner wall 3021 have the same degree of inclination relative to the support device 13, with the bottom end of the top-facing outer wall 3011 being lower than the bottom end of the top-facing inner wall 3021. The degree of inclination of the top-facing outer wall 3011 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 degree of inclination of the top-facing inner wall 3021 is indicated by α2. When α1 = α2, the bottom surface of the top-facing outer wall 3011 is lower than the bottom surface of the top-facing inner wall 3021. This indicates that the surface area of ​​the top-facing outer wall 3011 is increased, and the flow resistance of the process waste flow path on its side is lower than that on the side of the top-facing outer wall 3011.

[0115] Furthermore, the inclination angles of the top-facing outer sidewall 3011 and the top-facing inner sidewall 3021 are α1 and α2, respectively. α1 and α2 can be equal or unequal. By adjusting the values ​​of α1 and α2, the process exhaust gas can exhibit different flow resistances along the top-facing outer sidewall 3011 and the top-facing inner sidewall 3021. This configuration of α1 and α2 ensures that even if there is a difference in flow resistance between the process exhaust gas flow path on the top-facing outer sidewall 3011 and the top-facing inner sidewall 3021, strong turbulence that could affect the process gas flow field near the top of the carrier device 13 is avoided.

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

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

[0118] In some embodiments, as Figure 13 and Figure 14 As shown, the volumes of the outer annular cavity 301 and the inner annular cavity 302 may 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 single gas flow rate delivered by the inner annular cavity 302 is larger, and the gas heated in the inner annular cavity 302 has a more obvious effect on increasing the temperature 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 carrier device 13, thereby reaching the process temperature. This process, as well as the growth rate and quality, are significantly affected by the temperature field between the top wall of the reaction chamber 1 and the carrier 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 gradient of the temperature field between the top wall of the reaction chamber 1 and the carrier device 13 can be further improved, which is conducive to achieving better film formation quality.

[0121] Example 2

[0122] like Figure 16 、 Figure 17 and Figure 18 As shown, this embodiment also provides a silicon carbide epitaxial growth device 100 , which is different from the first embodiment in that this embodiment further includes a current collecting device 5 .

[0123] Specifically, the silicon carbide epitaxial device includes a current collecting device 5 whose top surface is lower than the bottom surface of the supporting device 13. The current collecting device 5 has an annular current collecting cavity 501, and the annular heat collecting bin 3 is suspended in the current collecting cavity 501 of the current collecting device 5. The top of the current collecting device 5 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 device 5 through the exhaust gas discharge port 12. The current collecting device 5 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. 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 current collecting device 5. The annular heat collecting bin 3 and the current collecting device 5 together constitute the heat collecting assembly 10.

[0124] Among them, the inner and outer side walls of the collecting device 5 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 5 filling the lower part of 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 5, and then it can be more fully contacted with the annular heat collection bin 3 in the collecting device 5 to achieve a better heating effect.

[0125] In some embodiments, as Figure 18 As shown, the annular heat collection bin 3 also includes support legs 33, and the flow collecting device 5 includes support columns 53 provided on the outer bottom surface of the flow collecting cavity 501. The support columns 53 are hollow structures, with their ends respectively connected to the exhaust outlet 12 and the flow collecting cavity 501. The hollow support columns 53 can serve as gas conveyance and support, or a solid support column can be separately provided to support the flow collecting device 5. The support legs 33 are provided between the inner bottom surface of the flow collecting cavity 501 and the bottom of the annular heat collection bin 3 to support the annular heat collection bin 3, thereby preventing the annular heat collection bin 3 from blocking the flow collecting gas outlet 52 and ensuring smooth flow of process exhaust gas.

[0126] In some embodiments, as Figure 17 and Figure 18 As shown, the flow collecting device 5 may further include a collecting ring 502. The collecting cavity 501 is provided with an upward annular opening, and its bottom surface is provided with a plurality of collecting outlets 52 connected to the hollow support columns 53. The collecting ring 502 covers the annular opening of the collecting cavity 501 and is provided with a plurality of collecting inlets 51 evenly distributed around the circumference. The shapes of the collecting inlets 51 can be circular holes, waist-shaped holes, etc.

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

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

[0129] In this embodiment, if Figure 19As shown, the axial cross-section of the annular heat collection chamber 3 can be rectangular. When gas flows in through the collecting inlet 51 of the collecting device 5, considering the rectangular top and the inner wall structure of the collecting cavity 501, significant turbulence will be generated when receiving the incoming flow, hindering the smooth discharge of high-temperature process exhaust gas. This may cause turbulence in the airflow at the edge of the carrier device 13, affecting the growth quality of the epitaxial wafer edge.

[0130] Therefore, in some embodiments, Figures 20 to 23 As shown, at least part of the inner and outer walls of the annular heat collecting chamber 3 are provided with flow guiding slopes, which are configured to guide the downwardly moving airflow.

[0131] 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 3 can be set as a flow guide slope to significantly reduce the obstruction effect on the airflow.

[0132] For example, Figure 21 、 Figure 22 and Figure 23 As shown, the inner annular cavity 302 includes a top inner wall 3021 that is close to and extends obliquely toward the side where the carrier device 13 is located, and the outer annular cavity 301 includes a top outer wall 3011 that is close to and extends obliquely toward the side wall of the reaction chamber 1. The inclined setting can significantly reduce the obstruction effect on 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.

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

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

[0135] like Figure 24As shown, if the height h1 occupied by the inclined surface is less than half of the total height h of the annular heat collection bin 3, the inclination angle of the guide inclined surface will also be relatively small. When the high-temperature process exhaust gas enters through the collecting inlet 51 of the collecting device 5, 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 3. 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 3 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 device 13, affecting the growth quality of the edge of the epitaxial wafer.

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

[0137] Furthermore, in this embodiment, since h1≥H / 2 is set, it is ensured that the height of the top inner wall 3021 and the top outer wall 3011 occupy at least more than half of the internal height of the collecting device 5, 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.

[0138] 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, characterized in that: include: A reaction chamber (1) is provided with a gas injection device (11) at the top, an exhaust gas discharge port (12) at the bottom, and a supporting device (13) inside; an annular channel (14) is formed between the outer wall of the supporting device (13) and the inner wall of the reaction chamber (1); A cover structure (2) is arranged at the inner top of the reaction chamber (1), and a reserved cavity (21) is formed between the cover structure and the inner top wall of the reaction chamber (1); the gas injection device (11) passes through the reserved cavity (21) and faces the bearing top surface of the bearing device (13); An annular heat collection bin (3) is provided in the space between the annular channel (14) and the reaction chamber (1), and has a spacing between the annular heat collection bin (3) and the supporting device (13) and the side wall of the reaction chamber (1) to allow gas to pass through; the inner cavity of the annular heat collection bin (3) includes an outer annular cavity (301) and an inner annular cavity (302) separated from each other; the outer annular cavity (301) surrounds the inner annular cavity (302); A first inlet pipe (41) and a second inlet pipe (42) are connected to the outer annular cavity (301) and the inner annular cavity (302), respectively, and extend to the outside of the reaction cavity (1); a first delivery pipe (43), the two ends of which are respectively connected to the outer annular cavity (301) and the gas injection device (11), and extending inside the cavity wall of the reaction cavity (1), so that the hot gas in the outer annular cavity (301) is mixed with the gas in the gas injection device (11) to increase the gas temperature; The second delivery pipe (44) has two ends respectively connected 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 temperature uniformity of the reaction space in the reaction chamber (1).

2. The silicon carbide epitaxial device 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 device 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 of the outer annular cavity (301) 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 of the outer annular cavity (301).

4. The silicon carbide epitaxial device according to claim 1, characterized in that: An annular partition plate (31) extending toward the inner bottom surface of the reaction chamber (1) is provided in the annular heat collecting chamber (3); the inner annular chamber (302) includes an inner sidewall (3021) near the top of the supporting device (13) to form an inner top structure with the annular partition plate (31); and the outer annular chamber (301) includes an outer sidewall (3011) near the top of 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 device according to claim 4, characterized in that: The top inner sidewall (3021) and the top outer sidewall (3011) have the same degree of inclination, 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 device according to claim 4, characterized in that: The top inner sidewall (3021), the top outer sidewall (3011) and the annular partition plate (31) converge to form a pointed angle structure or a chamfered angle structure.

7. The silicon carbide epitaxial device according to claim 4, characterized in that: The outer annular cavity (301) further comprises an outer bottom structure connected to and internally communicated with the outer top structure to increase the volume, and / or the inner annular cavity (302) further comprises an inner bottom structure connected to and internally communicated with the inner top structure to increase the volume.

8. The silicon carbide epitaxial device according to claim 7, characterized in that: The outer bottom structure comprises a bottom-facing outer side wall (3012) close to the side wall of the reaction chamber (1) and extending axially along the reaction chamber (1), and the inner bottom structure comprises a bottom-facing inner side wall (3022) close to the side where the supporting device (13) is located and extending axially along the reaction chamber (1).

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

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

11. The silicon carbide epitaxial device 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 device according to claim 1, characterized in that: An isolation piece (32) is radially arranged in the annular heat collecting chamber (3) to break the connectivity between the respective inner annular spaces of 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 communicate with the first outlet (A2) of the outer annular cavity (301), respectively close to 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) for communicating with the second outlet (B2) of the inner annular cavity (302) are respectively close to opposite sides of the isolation member (32) and communicate with the inner annular cavity (302).

13. The silicon carbide epitaxial growth equipment 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 first delivery pipe (43) and the second delivery pipe (44) are buried in the heat insulation layer (15).

14. The silicon carbide epitaxial device according to claim 1, characterized in that: The outer contour structure of the axial cross-section of the structure formed by the outer annular cavity (301) and the inner annular cavity (302) is an axisymmetric structure, and / or the outer contour structure of the axial cross-section of the annular heat collecting bin (3) is an axisymmetric structure.

15. The silicon carbide epitaxial device according to claim 1, characterized in that: It also includes a current collecting device (5) having an annular current collecting cavity (501), the top surface of the current collecting device (5) being lower than the bottom surface of the supporting device (13), and the annular heat collecting bin (3) being suspended in the current collecting cavity (501) of the current collecting device (5); The top of the flow collecting device (5) 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 flow collecting device (5) through the tail gas discharge port (12); The current collecting device (5) is fitted with or gap-fitted to 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 first inlet pipe (41), the second inlet pipe (42), the first delivery pipe (43), and the second delivery pipe (44) all pass through the flow collecting device (5).

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

17. The silicon carbide epitaxial device according to claim 15, characterized in that: The annular heat collection chamber (3) further includes a support foot (33), and the current collecting device (5) includes a support column (53) provided on the outer bottom surface of the current collecting cavity (501); The support column (53) is a hollow structure, with two ends respectively connected to the exhaust gas discharge port (12) and the manifold cavity (501); The support foot (33) is provided between the inner bottom surface of the manifold cavity (501) and the bottom of the annular heat collection bin (3) to support the annular heat collection bin (3).

18. The silicon carbide epitaxial device according to claim 15, characterized in that: The inner annular cavity (302) comprises a top inner sidewall (3021) extending obliquely close to and toward the side where the carrier device (13) is located, and the outer annular cavity (301) comprises a top outer sidewall (3011) extending obliquely close to and toward the sidewall of the reaction chamber (1); The total height of the internal cavity of the current collecting device (5) is H, the total height of the annular heat collecting chamber (3) is h, and the height of the lowest of the top inner wall (3021) and the top outer wall (3011) is h1; Among them, H / 2≤h1<H.

19. The silicon carbide epitaxial device according to claim 1, characterized in that: Also includes: a second gas supply device (62), located outside the reaction chamber (1) and connected to the first inlet pipe (41) to provide carrier gas or purge gas; A 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 device according to claim 1, characterized in that: A process gas channel and a purge gas channel are provided in the gas injection device (11), and the second delivery pipe (44) is connected to either the process gas channel or the purge gas channel.

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