A silicon carbide crystal growth furnace and a silicon carbide crystal growth method

Abstract

This invention provides a silicon carbide crystal growth furnace and a silicon carbide crystal growth method. The silicon carbide crystal growth method is applied to the silicon carbide crystal growth furnace and relates to the field of silicon carbide crystal growth technology. The silicon carbide crystal growth furnace includes a crucible, a first flow guide hood, a second flow guide hood, and a filter. The growth atmosphere inside the crucible flows upward along the crucible wall and the external cavity formed by the second flow guide hood. After reaching the top, the growth atmosphere flows downward along the inner wall of the second flow guide hood and the outer wall of the first flow guide hood, finally entering the crystal growth cavity formed by the first and second flow guide hoods. A filter is placed between the first and second flow guide hoods. This ensures a relatively uniform growth atmosphere velocity and increases the concentration of the growth atmosphere, thereby improving the growth quality of the silicon carbide crystal.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide crystal growth technology, and more specifically, to a silicon carbide crystal growth furnace and a silicon carbide crystal growth method. Background Technology

[0002] Silicon carbide (SiC), as an emerging core material for third-generation semiconductors, possesses excellent properties such as a wide bandgap, high critical breakdown electric field strength, high electron mobility, and good radiation resistance and chemical stability. This makes it an important substrate wafer material with wide applications and shows promising application prospects in fields such as aerospace devices, new energy vehicles, rail transportation, and home appliances.

[0003] In the existing PVT method for growing silicon carbide crystals, the growth atmosphere near the inner wall of the crucible rises faster than that in the center of the crucible during the growth process, which affects the quality and consistency of crystal growth. Summary of the Invention

[0004] The present invention aims to provide a silicon carbide crystal growth furnace and a silicon carbide crystal growth method, which can improve the quality of silicon carbide crystal growth.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a silicon carbide crystal growth furnace, comprising:

[0007] The crucible has a seed crystal on its top.

[0008] The first flow guide shroud is disposed on the top of the crucible, the seed crystal is located inside the first flow guide shroud, and the end of the first flow guide shroud away from the top of the crucible has a first opening;

[0009] The second flow guide is installed inside the crucible and located below the first flow guide. The second flow guide has a second opening facing the top wall of the crucible. The radial dimension of the second opening is larger than the radial dimension of the first opening. The orthographic projection of the first opening in the axial direction falls into the second flow guide. A first flow channel is defined between the outer wall of the second flow guide and the inner wall of the crucible. A second flow channel is defined between the inner wall of the second flow guide and the outer wall of the first flow guide. The first flow channel and the second flow channel are in communication.

[0010] The filter element is installed inside the second flow channel;

[0011] The growth atmosphere inside the crucible flows into the crystal growth cavity after passing through the first and second flow channels in sequence.

[0012] In an optional embodiment, the distance between the first opening and the top wall of the crucible is greater than the distance between the second opening and the top wall of the crucible, and the filter element is located between the inner wall of the second guide shroud and the outer wall of the first guide shroud.

[0013] In an optional embodiment, the second flow guide is placed above the crystal growth material inside the crucible.

[0014] In an optional embodiment, the bottom of the second flow guide is further provided with a partition column extending toward the bottom wall of the crucible, and the partition column is coaxial with the crucible.

[0015] In an optional implementation, the separator column is a hollow column.

[0016] In an optional implementation, the second flow guide does not come into contact with the crystal growth material.

[0017] In an optional embodiment, a temperature regulating plate is slidably disposed between the first flow guide shroud and the inner wall of the crucible.

[0018] In an optional embodiment, the seed crystal, the second flow guide, the first flow guide, and the crucible are arranged coaxially.

[0019] In an optional embodiment, the first flow guide shroud has an inner flow guide wall and an outer flow guide wall, the seed crystal is located inside the inner flow guide wall, the radial dimension of the inner flow guide wall gradually decreases in the direction close to the top wall of the crucible, and the outer flow guide wall and the inner wall of the second flow guide shroud define a second flow channel.

[0020] In an optional embodiment, the inclination direction of the outer wall of the first deflector is the same as the inclination direction of the inner wall of the second deflector.

[0021] In an optional embodiment, the silicon carbide crystal growth furnace further includes a flow equalization plate, which is installed inside a first flow guide shroud or a second flow guide shroud.

[0022] In a second aspect, the present invention provides a silicon carbide crystal growth method, applied to the silicon carbide crystal growth furnace of any of the foregoing embodiments, the method comprising:

[0023] The crystal growth material is loaded into the crucible;

[0024] The crucible is evacuated.

[0025] Inert gas is introduced into the crucible;

[0026] The crucible is heated to sublimate the crystal growth material;

[0027] The growth atmosphere formed by the sublimation of the crystal growth raw material can flow into the crystal growth cavity through the first flow channel and the second flow channel in sequence, and then through the filter element, thereby growing silicon carbide crystals on the seed crystal.

[0028] The beneficial effects provided by the embodiments of the present invention include: the embodiments of the present invention provide a silicon carbide crystal growth furnace and a silicon carbide crystal growth method. The silicon carbide crystal growth method is applied to the silicon carbide crystal growth furnace, which includes a crucible, a first flow guide hood, a second flow guide hood, and a filter element. A seed crystal is placed on the top of the crucible. A first flow guide hood is located on the top of the crucible, with the seed crystal inside the first flow guide hood. The end of the first flow guide hood furthest from the top of the crucible has a first opening. A second flow guide hood is installed inside the crucible and below the first flow guide hood. The first flow guide hood has a ring-shaped structure, and the second flow guide hood has a second opening facing the top wall of the crucible. The radial dimension of the second opening is larger than the radial dimension of the first opening. The orthogonal projection of the first opening in the axial direction falls within the second flow guide hood. The first and second flow guide hoods together define a crystal growth cavity. A first flow channel is defined between the outer wall of the second flow guide hood and the inner wall of the crucible, and a second flow channel is defined between the inner wall of the second flow guide hood and the outer wall of the first flow guide hood. The first and second flow channels are connected, and a filter element is installed within the second flow channel. The growth atmosphere inside the crucible can flow into the crystal growth cavity sequentially through the first and second flow channels. It can slow down the flow rate of the growth atmosphere, allowing the growth atmosphere to enter the first guide hood relatively evenly. This can make the growth atmosphere flow rate relatively uniform and increase the concentration of the growth atmosphere entering the first guide hood, thereby effectively improving the growth quality of silicon carbide crystals. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, 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 the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the silicon carbide crystal growth furnace provided in this embodiment;

[0031] Figure 2 One of the schematic diagrams of a silicon carbide crystal growth furnace provided in an optional embodiment;

[0032] Figure 3 This is a second schematic diagram of the silicon carbide crystal growth furnace provided as an optional embodiment.

[0033] Icons: 1-Silicon carbide crystal growth furnace; 100-Crucible; 110-Temperature control plate; 101-Crystal growth cavity; 200-First flow guide shroud; 210-Inner flow guide wall; 211-First opening; 220-Outer flow guide wall; 300-Second flow guide shroud; 310-End plate; 320-Third flow guide enclosure plate; 321-Second opening; 330-Separator column; 400-First flow channel; 500-Second flow channel; 600-Filter element; 800-Seed crystal; 2-Crystal growth raw material. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0037] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0038] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0039] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0040] The following describes in detail, with reference to the accompanying drawings, the specific structure of a silicon carbide crystal growth furnace provided by an embodiment of the present invention and the corresponding technical effects it brings.

[0041] Please refer to Figure 1 This embodiment provides a silicon carbide crystal growth furnace 1, including a crucible 100, a first flow guide hood 200, a second flow guide hood 300, and a filter element 600. A seed crystal 800 is disposed on the top of the crucible 100. The first flow guide hood 200 is disposed on the top of the crucible 100, with the seed crystal 800 located inside the first flow guide hood 200. The end of the first flow guide hood 200 away from the top of the crucible 100 has a first opening 211. The second flow guide hood 300 is installed inside the crucible 100 and located below the first flow guide hood 200. The first flow guide hood 200 has an annular structure. The second flow guide hood 300 has a second opening 321 facing the top wall of the crucible 100. The radial dimension of the second opening 321 is larger than the radial dimension of the first opening 211. The orthogonal projection of the port 211 in the axial direction falls into the second flow guide shroud 300. The first flow guide shroud 200 and the second flow guide shroud 300 together define the crystal growth cavity 101. The outer wall of the second flow guide shroud 300 and the inner wall of the crucible 100 define the first flow channel 400. The inner wall of the second flow guide shroud 300 and the outer wall of the first flow guide shroud 200 define the second flow channel 500. The first flow channel 400 and the second flow channel 500 are connected. The filter element 600 is installed in the second flow channel 500. Specifically, the two sides of the filter element 600 are connected to the first flow guide shroud 200 and the second flow guide shroud 300, respectively.

[0042] Please refer to Figures 1-3 The growth atmosphere in the crucible 100 can flow into the crystal growth cavity 101 through the first flow channel 400 and the second flow channel 500 in sequence.

[0043] Since the radial dimension of the second opening 321 in this application is larger than the radial dimension of the first opening 211, and the orthogonal projection of the first opening 211 in the axial direction falls into the second guide shroud 300, at this time, during the upward movement of the growth atmosphere in the crucible 100, the growth atmosphere in the middle will be blocked by the bottom of the second guide shroud 300, and then guided by the outer peripheral wall of the second guide shroud 300, and thus move upward. The growth atmosphere near the inner peripheral wall in the crucible 100 will be guided by the outer peripheral wall of the second guide shroud 300, and thus achieve upward movement.

[0044] Some existing silicon carbide crystal growth furnaces only include a first flow guide shroud 200. The first flow guide shroud 200 has two main purposes: first, to force growth and fix the shape of the silicon carbide crystal; second, to fix the direction of the growth atmosphere flow and increase the utilization rate of the growth atmosphere.

[0045] In this embodiment, a second flow guide 300 is added. Based on the flow field characteristics within the crucible 100, the rising velocity of the growth atmosphere near the inner wall of the crucible 100 is faster, while the rising velocity of the growth atmosphere in the center of the crucible 100 is slower. By adding the second flow guide 300, the original situation where the growth atmosphere entering the first flow guide 200 has a faster rising velocity near the edge and a slower rising velocity near the center is changed.

[0046] With the setting of the second flow guide shroud 300, the growth atmosphere in the crucible 100 can move upward under the guidance of the outer wall of the second flow guide shroud 300 and the inner wall of the crucible 100. After the upward movement of the growth atmosphere is obstructed, it moves downward and finally flows into the crystal growth cavity 101 through the filter 600.

[0047] Therefore, the growth atmosphere can enter the crystal growth cavity 101 after passing through the first flow channel 400 and the second flow channel 500 in sequence. This can prevent the growth atmosphere from flowing directly upward into the first flow guide hood 200 and directly contacting the seed crystal 800. This can make the growth atmosphere speed relatively uniform and increase the concentration of the growth atmosphere entering the first flow guide hood 200, which can effectively improve the growth quality of silicon carbide crystals.

[0048] Under the guidance of the second flow guide shroud 300, and with the gravity of the growth atmosphere and the top barrier effect inside the crucible 100, the growth atmosphere is guided into the first flow guide shroud 200. This avoids the disadvantage that when there is only the first flow guide shroud 200 in the traditional crystal growth furnace, the growth atmosphere near the edge of the first flow guide shroud 200 rises at a high speed and the growth atmosphere near the middle rises at a low speed. It also avoids the scouring of the wall surface by the fast-moving growth atmosphere, and can also improve the concentration and uniformity of the growth atmosphere in the space formed by the first flow guide shroud 200 and the second flow guide shroud 300, thereby improving the growth quality of silicon carbide crystals.

[0049] It should be noted that in this embodiment, the second opening 321 of the second flow guide shroud 300 and the first opening 211 of the first flow guide shroud 200 have gaps in both the axial and radial directions. That is, the growth atmosphere can flow into the first flow guide shroud 200 through the gap between the first flow guide shroud 200 and the second flow guide shroud 300. In order to improve the growth quality of the crystal, this embodiment provides a filter element 600 in the gap between the first flow guide shroud 200 and the second flow guide shroud 300 to reduce the formation of carbon inclusions in the grown crystal.

[0050] Please refer to Figures 1-2Specifically, in some embodiments, the distance between the first opening 211 and the top wall of the crucible 100 is greater than the distance between the second opening 321 and the top wall of the crucible 100. That is, axially, a portion of the first flow guide 200 is located within the second flow guide 300. In other words, the outer wall of the first flow guide 200 and the inner wall of the second flow guide 300 can define channels for guiding the growth atmosphere into the crystal growth cavity 101.

[0051] Please refer to Figure 3 Of course, in some other alternative embodiments, the distance between the first opening 211 and the top wall of the crucible 100 can also be equal to the distance between the second opening 321 and the top wall of the crucible 100.

[0052] The filter element 600 is located between the inner wall of the second guide shroud 300 and the outer wall of the first guide shroud 200. That is, the two sides of the filter element 600 are respectively connected to the inner wall of the second guide shroud 300 and the outer wall of the first guide shroud 200.

[0053] Optionally, in some embodiments, the first flow guide hood 200 has a flow guide inner wall 210 and a flow guide outer wall 220, and the seed crystal 800 is located inside the flow guide inner wall 210. The radial dimension of the flow guide inner wall gradually decreases in the direction close to the top wall of the crucible 100, which can effectively guide the growth atmosphere located inside the first flow guide hood 200 towards the center, so as to improve the quality of silicon carbide crystal growth on the seed crystal 800.

[0054] In detail, the outer wall 220 and the inner wall of the second flow guide shroud 300 define the second flow channel 500 so as to guide the growth atmosphere into the crystal growth cavity 101.

[0055] Please refer to Figures 1-2 In some embodiments, the inclination direction of the outer wall of the first flow guide 200 is the same as the inclination direction of the inner wall of the second flow guide 300. That is, the inclination direction of the outer wall 220 of the flow guide is the same as the inclination direction of the inner wall of the second flow guide 300, so as to ensure that the radial dimension of the second flow channel 500 itself remains relatively unchanged in its own extension direction, thereby ensuring that the growth atmosphere flow rate and distribution in the second flow channel 500 are relatively uniform.

[0056] Please refer to Figure 3 In some other embodiments, the tilting direction of the outer wall 220 of the flow guide can also be at an angle to the tilting direction of the inner wall of the second flow guide shroud 300.

[0057] Optionally, in this embodiment, the second flow guide shroud 300 includes an end plate 310 and a third flow guide surrounding plate 320. The third flow guide surrounding plate 320 surrounds the end plate 310 and extends towards the top wall of the crucible 100. The second opening 321 is located at the end of the third flow guide surrounding plate 320 away from the end plate 310. The end plate 310 is opposite to the top wall and bottom wall of the crucible 100. The third flow guide surrounding plate 320 and the inner peripheral wall of the crucible 100 define a first flow channel 400. The third flow guide surrounding plate 320 and the outer peripheral wall of the first flow guide shroud 200 define a second flow channel 500. The first flow channel 400 and the second flow channel 500 are in communication. The filter element 600 is located in the second flow channel 500.

[0058] In other words, the outer side of the third flow guide plate 320 and the inner peripheral wall of the crucible 100 together define the first flow channel 400, and the inner side of the third flow guide plate 320 and the outer flow guide wall 220 define the second flow channel 500.

[0059] The growth atmosphere inside the crucible 100 can move upward under the guidance of the outer wall of the second flow guide shroud 300. After encountering the obstruction of the outer flow guide 220 or the inner wall of the crucible 100, the growth atmosphere moves downward and finally flows into the crystal growth cavity 101 through the filter 600.

[0060] This avoids the growth atmosphere flowing directly upwards into the first guide shroud 200 and directly contacting the seed crystal 800. Instead, it passes through the first flow channel 400 and the second flow channel 500 in sequence, and finally enters the crystal growth cavity 101 through the filter element 600.

[0061] It should be noted that, in some optional embodiments, in order to facilitate the installation of the first flow guide 200 described above, the first flow guide 200 can be installed on the top wall of the crucible 100, that is, the first flow guide 200 can be installed on the lid of the crucible 100.

[0062] Optionally, a temperature regulating plate 110 is slidably disposed between the first flow guide hood 200 and the inner wall of the crucible 100. Specifically, this can regulate the thermal field inside the crucible 100, which can reduce the crystallization of the growth atmosphere on the top wall of the crucible 100. Since the temperature regulating plate 110 can also block the growth atmosphere flowing upward in the first flow channel 400, the growth atmosphere is redirected and flows downward to the second flow channel 500.

[0063] It should be noted that the sliding temperature adjustment plate 110 can be understood as allowing the user to adjust the axial position of the temperature adjustment plate 110 within the crucible 100 before crystal growth in the crucible 100.

[0064] Please continue to refer to this. Figure 1Optionally, in this embodiment, the second flow guide 300 can be placed directly on the surface of the crystal growth raw material 2 inside the crucible 100. During crystal growth, the second flow guide 300 can effectively prevent the growth atmosphere from flowing directly upward into the first flow guide 200, and also avoids the need to set up other support structures, thus saving the manufacturing cost of the support structure.

[0065] Please refer to Figure 2 Of course, in some other alternative embodiments, the second flow guide 300 can be installed in the crucible 100 in other ways. For example, a partition column 330 can be provided at the bottom of the second flow guide 300, and the partition column 330 abuts against the bottom wall of the crucible 100. That is, the second flow guide 300 is supported in the crucible 100 by the partition column 330.

[0066] In detail, the separator column 330 can be set coaxially with the crucible 100. Understandably, the raw material in the middle of the crucible 100 does not participate in crystal growth, and during crystal growth, the raw material in the middle of the crucible 100 is prone to crystallization and waste. However, by setting the separator column 330, the raw material can be prevented from being in the middle of the crucible 100, thereby reducing the waste of raw material in the crucible 100 and improving the utilization rate of raw material in the crucible 100.

[0067] It should be noted that by setting the separator column 330, heat can be transferred to the outer wall of the second flow guide shroud 300 through the separator column 330, avoiding the possibility of crystallization at the bottom of the second flow guide shroud 300.

[0068] To facilitate heat conduction from the bottom of the crucible 100 to the bottom of the second flow guide 300, and to further prevent the growth atmosphere from crystallizing at the bottom of the second flow guide 300, in some embodiments, the separator column 330 may be a hollow column.

[0069] It should be noted that when the second flow guide shroud 300 is installed inside the crucible 100 via the partition column 330, the bottom of the second flow guide shroud 300 does not need to contact the crystal growth material 2 inside the crucible 100; that is, there is a gap between the bottom of the second flow guide shroud 300 and the crystal growth material 2 inside the crucible 100. This allows the crystal growth material directly below the second flow guide shroud 300 to sublimate smoothly and form a crystal growth atmosphere.

[0070] It should be noted that whether the separator column 330 abuts against the bottom wall of the crucible 100 depends on the thermal field conditions. By setting the separator column 330, the amount of material loaded into the crucible 100 can be reduced, avoiding waste of raw material in the middle of the crucible 100 and preventing crystallization of the raw material at the bottom of the crucible 100. Therefore, the separator column 330 may not abut against the bottom wall of the crucible 100, depending on the thermal field conditions. After adding raw material into the crucible 100, it can be placed on the silicon carbide crystal growth raw material 2.

[0071] Alternatively, in some other embodiments, the second flow guide shroud 300 can also be installed inside the crucible 100 in other ways. For example, the inner wall of the crucible 100 can also be provided with a second protrusion, and the third flow guide plate 320 can cooperate with the second protrusion. That is, the outer wall of the third flow guide plate 320 can be locked onto the second protrusion.

[0072] Understandably, in order to facilitate the upward flow of the growth atmosphere without being blocked by the second protrusion, ventilation holes can be started on the second protrusion, and the ventilation holes are evenly spaced around the circumference of the second protrusion.

[0073] Please refer to Figure 3 The second flow guide 300 may not be configured as described above. That is, the second flow guide 300 may not be composed of the end plate 310 and the third flow guide plate 320. The second flow guide 300 may be roughly bowl-shaped. In order to guide the growth atmosphere in the first flow channel 400, the distance between the outer peripheral wall of the second flow guide 300 and the inner wall of the crucible 100 gradually decreases in the direction close to the top wall of the crucible 100.

[0074] Optionally, in some embodiments, the silicon carbide crystal growth furnace 1 further includes a flow equalization plate, which is installed inside the first flow guide shroud 200. It is understood that by setting the flow equalization plate, the growth atmosphere can enter the first flow guide shroud 200 more uniformly during its ascent after entering the crystal growth cavity 101, thereby improving the quality of the silicon carbide crystal grown on the seed crystal 800.

[0075] Optionally, in some embodiments, to achieve a slightly convex center on the silicon carbide crystal grown on the seed crystal 800, the distance between the flow equalization plate and the top wall of the crucible 100 gradually increases in the direction close to the inner wall of the crucible 100. Of course, in other embodiments, the flow equalization plate is simply a flat plate, and only flow equalization holes are provided on it.

[0076] In order to ensure that the growth atmosphere can enter the first flow guide shroud 200 relatively uniformly after passing through the first flow channel 400 and the second flow channel 500 into the crystal growth cavity 101, in some optional embodiments, the seed crystal 800, the second flow guide shroud 300, the first flow guide shroud 200 and the crucible 100 are arranged coaxially.

[0077] It should be noted that the coaxial setting in this application is not limited to coaxial in the strict sense; it is sufficient that it is approximately coaxial.

[0078] This invention also provides a silicon carbide crystal growth method, applied to the silicon carbide crystal growth furnace 1 described above. The method includes loading the crystal growth raw material 2 into a crucible 100, evacuating the crucible 100, and then injecting an inert gas into the crucible 100.

[0079] The crucible 100 can then be heated to sublimate the crystal growth material 2 inside the crucible 100. The growth atmosphere formed by the sublimation of the crystal growth material 2 can flow into the crystal growth cavity 101 through the first flow channel 400 and the second flow channel 500 in sequence, thereby growing silicon carbide crystals on the seed crystal 800.

[0080] In summary, this invention provides a silicon carbide crystal growth furnace 1 and a silicon carbide crystal growth method. The silicon carbide crystal growth method is applied to the silicon carbide crystal growth furnace 1, which includes a crucible 100, a first flow guide hood 200, a second flow guide hood 300, and a filter element 600. A seed crystal 800 is disposed on the top of the crucible 100. The first flow guide hood 200 is disposed on the top of the crucible 100, and the seed crystal 800 is located inside the first flow guide hood 200. The end of the first flow guide hood 200 away from the top of the crucible 100 has a first opening 211. The second flow guide hood 300 is installed inside the crucible 100 and located below the first flow guide hood 200. The first flow guide hood 200 has an annular structure, and the second flow guide hood 300 has a second opening 321 facing the top wall of the crucible 100. The diameter of the second opening 321 is... The diameter of the first opening 211 is larger than its radial dimension. The orthogonal projection of the first opening 211 in the axial direction falls within the second flow guide shroud 300. The first flow guide shroud 200 and the second flow guide shroud 300 together define the crystal growth cavity 101. A first flow channel 400 is defined between the outer wall of the second flow guide shroud 300 and the inner wall of the crucible 100. A second flow channel 500 is defined between the inner wall of the second flow guide shroud 300 and the outer wall of the first flow guide shroud 200. The first and second flow channels are connected, and a filter element 600 is installed within the second flow channel 500. The growth atmosphere in the crucible 100 can flow into the crystal growth cavity 101 sequentially through the first flow channel 400 and the second flow channel 500. This can slow down the flow rate of the growth atmosphere, allowing it to enter the first flow guide shroud 200 relatively uniformly. This also increases the concentration of the growth atmosphere entering the first flow guide shroud 200, effectively improving the growth quality of the silicon carbide crystal.

[0081] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A silicon carbide crystal growth furnace, characterized in that, The application relates to a silicon carbide crystal growth furnace, comprising: a crucible (100) provided with a seed crystal (800) at the top of the crucible (100); a first flow guide cover (200) arranged at the top of the crucible (100), wherein the seed crystal (800) is arranged in the first flow guide cover (200), and the first flow guide cover (200) is provided with a first opening (211) at the end away from the top of the crucible (100); a second flow guide cover (300) arranged in the crucible (100) and below the first flow guide cover (200), wherein the second flow guide cover (300) is provided with a second opening (321) facing the top wall of the crucible (100), the radial dimension of the second opening (321) is larger than that of the first opening (211), the first opening (211) is projected in the axial direction and falls in the second flow guide cover (300), and the first flow guide cover (200) and the second flow guide cover (300) jointly define a crystal growth cavity (101), the outer wall of the second flow guide cover (300) and the inner wall of the crucible (100) define a first flow channel (400), and the inner wall of the second flow guide cover (300) and the outer wall of the first flow guide cover (200) define a second flow channel (500), wherein the first flow channel (400) and the second flow channel (500) are communicated; a filter (600) arranged in the second flow channel (500); wherein the growth atmosphere in the crucible (100) can flow into the crystal growth cavity (101) through the first flow channel (400) and the second flow channel (500) in sequence.

2. The silicon carbide crystal growth furnace according to claim 1, wherein: the second flow guide cover (300) is arranged above the crystal growth raw material (2) in the crucible (100).

3. The silicon carbide crystal growth furnace according to claim 1, wherein: the bottom of the second flow guide cover (300) is further provided with a partition column (330) extending to the bottom wall of the crucible (100), and the partition column (330) is coaxial with the crucible (100).

4. The silicon carbide crystal growth furnace according to claim 3, wherein: the partition column (330) is a hollow column.

5. The silicon carbide crystal growth furnace according to claim 4, wherein: the second flow guide cover (300) is not in contact with the crystal growth raw material (2).

6. The silicon carbide crystal growth furnace according to claim 1, wherein: a temperature adjusting plate (110) is arranged in sliding mode between the first flow guide cover (200) and the inner wall of the crucible (100).

7. The silicon carbide crystal growth furnace according to claim 1, wherein: the seed crystal (800), the second flow guide cover (300), the first flow guide cover (200) and the crucible (100) are coaxially arranged.

8. The silicon carbide crystal growth furnace according to claim 1, wherein: The first flow guide cover (200) has a flow guide inner wall (210) and a flow guide outer wall (220), the seed crystal (800) is located in the flow guide inner wall (210), the radial dimension of the flow guide inner wall gradually decreases in the direction close to the top wall of the crucible (100), and the flow guide outer wall (220) and the inner wall of the second flow guide cover (300) define the second flow channel (500).

9. The silicon carbide single crystal growth furnace of claim 1, wherein: The inclination direction of the outer wall of the first flow guide cover (200) is the same as the inclination direction of the inner wall of the second flow guide cover (300).

10. A method for growing a silicon carbide crystal, applied to the silicon carbide crystal growing furnace according to any one of claims 1 to 9, characterized by, The method comprises: loading a growth raw material (2) into the crucible (100); performing a vacuum treatment on the crucible (100); filling the crucible (100) with inert gas; heating the crucible (100) to sublimate the growth raw material (2); the growth atmosphere formed by the sublimation of the growth raw material (2) can flow into the growth chamber (101) through the first flow channel (400) and the second flow channel (500) in turn, and then grow silicon carbide crystals on the seed crystal (800).

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