Silicon carbide crystal growth furnace and silicon carbide crystal growth method

Abstract

The embodiment of the 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 technical field of silicon carbide crystal growth. The silicon carbide crystal growth furnace comprises a crucible, a first flow guide cover, a second flow guide cover and a filtering piece, the growth atmosphere in the crucible can flow upwards along an external cavity formed by the wall surface of the crucible and the second flow guide cover, and after reaching the top, the growth atmosphere flows downwards along the inner wall of the second flow guide cover and the outer wall of the first flow guide cover and finally enters a crystal growth cavity formed by the first flow guide cover and the second flow guide cover; and a filtering piece is arranged between the first flow guide cover and the second flow guide cover. Therefore, the speed of the growth atmosphere can be ensured to be relatively uniform, the concentration of the growth atmosphere is improved, and the growth quality of silicon carbide crystals is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon carbide crystal growth, and in particular, to a silicon carbide crystal growth furnace and a method for growing silicon carbide crystals. Background Art

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

[0003] When growing silicon carbide crystals by the existing PVT method, during the crystal growth process, the growth atmosphere near the inner wall of the crucible in the raw material chamber rises faster than that in the middle of the crucible, which will affect the quality and consistency of crystal growth. Summary of the Invention

[0004] The objectives of the present invention include providing a silicon carbide crystal growth furnace and a method for growing silicon carbide crystals, which can improve the quality of silicon carbide crystal growth.

[0005] Embodiments of the present invention may be implemented as follows:

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

[0007] A crucible with a seed crystal provided at the top of the crucible;

[0008] A first flow guide cover provided at the top of the crucible, the seed crystal being located inside the first flow guide cover, and the first flow guide cover having a first opening at one end away from the top of the crucible;

[0009] A second flow guide cover installed inside the crucible and below the first flow guide cover, the second flow guide cover having a second opening facing the top wall of the crucible, the radial dimension of the second opening being larger than that of the first opening, the positive projection of the first opening in the axial direction falling inside the second flow guide cover, a first flow channel being defined between the outer wall of the second flow guide cover and the inner wall of the crucible, and a second flow channel being defined between the inner wall of the second flow guide cover and the outer wall of the first flow guide cover, the first flow channel communicating with the second flow channel;

[0010] A filter member installed in the second flow channel;

[0011] Wherein, the growth atmosphere inside the crucible can flow into the crystal growth cavity after passing through the first flow channel and the second flow channel in sequence.

[0012] In an alternative 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 is located between the inner wall of the second flow guide cover and the outer wall of the first flow guide cover.

[0013] In an alternative embodiment, the second flow guide cover is placed above the crystal growth raw material in the crucible.

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

[0015] In an alternative embodiment, the partition column is a hollow column.

[0016] In an alternative embodiment, the second flow guide cover does not contact the crystal growth raw material.

[0017] In an alternative embodiment, a temperature regulating plate is slidably arranged between the outer wall of the first flow guide cover and the inner wall of the crucible.

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

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

[0020] In an alternative embodiment, the inclination direction of the outer wall of the first flow guide cover is the same as the inclination direction of the inner wall of the second flow guide cover.

[0021] In an alternative embodiment, the silicon carbide crystal growth furnace further includes a flow equalizing plate, and the flow equalizing plate is installed in the first flow guide cover or the second flow guide cover.

[0022] In a second aspect, the present invention provides a method for growing silicon carbide crystals, which is applied to the silicon carbide crystal growth furnace according to any one of the foregoing embodiments. The method includes:

[0023] Loading the crystal growth raw material into the crucible;

[0024] Performing a pumping treatment on the crucible;

[0025] Filling the crucible with an inert gas;

[0026] Heating the crucible to sublimate the crystal growth raw material;

[0027] The growth atmosphere formed by the sublimation of the crystal growth raw material can flow through the first flow channel and the second flow channel in sequence and then flow into the crystal growth cavity through the filter, and then grow 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, and the silicon carbide crystal growth furnace includes a crucible, a first flow guide cover, a second flow guide cover, and a filter element. A seed crystal is arranged at the top of the crucible, the first flow guide cover is arranged at the top of the crucible, the seed crystal is located inside the first flow guide cover, one end of the first flow guide cover away from the top of the crucible has a first opening, the second flow guide cover is installed inside the crucible and below the first flow guide cover, the first flow guide cover is of an annular structure, the second flow guide cover has a second opening, the second opening faces the top wall of the crucible, the radial dimension of the second opening is larger than the radial dimension of the first opening, the positive projection of the first opening in the axial direction falls inside the second flow guide cover, the first flow guide cover and the second flow guide cover jointly define a crystal growth cavity, a first flow channel is defined between the outer wall of the second flow guide cover and the inner wall of the crucible, a second flow channel is defined between the inner wall of the second flow guide cover and the outer wall of the first flow guide cover, the first flow channel is communicated with the second flow channel, and the filter element is installed inside the second flow channel. The growth atmosphere inside the crucible can flow into the crystal growth cavity through the first flow channel and the second flow channel in sequence. The flow rate of the growth atmosphere can be slowed down, so that the growth atmosphere can enter the first flow guide cover relatively uniformly, the speed of the growth atmosphere can be relatively uniform, and the concentration of the growth atmosphere entering the first flow guide cover can also be increased, which can effectively improve the growth quality of the silicon carbide crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be 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 therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

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

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

[0032] Figure 3 Another structural schematic diagram of the silicon carbide crystal growth furnace provided in an alternative embodiment.

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

[0034] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and illustrated herein generally may be arranged and designed in a variety of different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but is merely representative of selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0036] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

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

[0038] In addition, terms such as "first" and "second" are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0039] It should be noted that the features in the embodiments of the present invention may be combined with each other without conflict.

[0040] The following details the specific structure of a silicon carbide crystal growth furnace provided by the embodiments of the present invention with reference to the patent drawings and the corresponding technical effects brought thereby.

[0041] Please refer toFigure 1 In this embodiment, a silicon carbide crystal growth furnace 1 includes a crucible 100, a first flow guide cover 200, a second flow guide cover 300, and a filter element 600. A seed crystal 800 is provided at the top of the crucible 100. The first flow guide cover 200 is arranged at the top of the crucible 100, and the seed crystal 800 is located inside the first flow guide cover 200. One end of the first flow guide cover 200 away from the top of the crucible 100 has a first opening 211. The second flow guide cover 300 is installed inside the crucible 100 and below the first flow guide cover 200. The first flow guide cover 200 is of a ring structure. The second flow guide cover 300 has a second opening 321, and the second opening 321 faces 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 positive projection of the first opening 211 in the axial direction falls inside the second flow guide cover 300. The first flow guide cover 200 and the second flow guide cover 300 jointly define a crystal growth cavity 101. A first flow channel 400 is defined between the outer wall of the second flow guide cover 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 cover 300 and the outer wall of the first flow guide cover 200. The first flow channel 400 is communicated with the second flow channel 500. The filter element 600 is installed inside the second flow channel 500. Specifically, both sides of the filter element 600 are respectively connected to the first flow guide cover 200 and the second flow guide cover 300.

[0042] Please refer to Figures 1 - 3 , and the growth atmosphere inside 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 positive projection of the first opening 211 in the axial direction falls inside the second flow guide cover 300. At this time, during the upward movement of the growth atmosphere inside the crucible 100, the growth atmosphere in the middle will be blocked by the bottom of the second flow guide cover 300, and then will be guided by the outer peripheral wall of the second flow guide cover 300 and move upward. The growth atmosphere near the inner peripheral wall of the crucible 100 will be guided by the outer peripheral wall of the second flow guide cover 300 and then move upward.

[0044] Some existing silicon carbide crystal growth furnaces only include the first flow guide cover 200. The first flow guide cover 200 has two main purposes. First, for forced growth to fix the shape of the silicon carbide crystal. Second, to fix the flow direction of the growth atmosphere and increase the utilization rate of the growth atmosphere.

[0045] In the embodiment of the present application, a second flow guide cover 300 is added. According to the flow field characteristics in the crucible 100, the rising speed of the growth atmosphere near the inner wall of the crucible 100 is fast, while the rising speed of the growth atmosphere in the middle of the crucible 100 is slow. By adding the second flow guide cover 300, the situation that the original growth atmosphere enters the first flow guide cover 200 with a fast speed near the edge and a slow rising speed near the middle is changed.

[0046] Through the setting of the second flow guide cover 300, since the growth atmosphere in the crucible 100 can move upward under the guidance of the outer wall of the second flow guide cover 300 and the inner wall of the crucible 100, after the growth atmosphere encounters an obstacle when moving upward, it then moves downward and finally flows into the crystal growth cavity 101 through the filter element 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, which can avoid the growth atmosphere directly flowing upward into the first flow guide cover 200 and directly contacting the seed crystal 800. It can make the speed of the growth atmosphere relatively uniform, and can also increase the concentration of the growth atmosphere entering the first flow guide cover 200, effectively improving the growth quality of the silicon carbide crystal.

[0048] Under the guidance of the second flow guide cover 300, as well as the gravity of the growth atmosphere and the blocking effect at the top in the crucible 100, the growth atmosphere is guided into the first flow guide cover 200, which can avoid the disadvantages that when there is only the first flow guide cover 200 in the traditional crystal growth furnace, the rising speed of the growth atmosphere near the edge of the first flow guide cover 200 is high and the rising speed of the growth atmosphere near the middle is low. It also avoids the erosion of the wall surface by the faster-growing atmosphere, and can also increase the concentration and uniformity of the growth atmosphere in the space formed by the first flow guide cover 200 and the second flow guide cover 300, thereby improving the growth quality of the silicon carbide crystal.

[0049] It should be noted that in this embodiment, the second opening 321 of the second flow guide cover 300 and the first opening 211 of the first flow guide cover 200 have gaps both axially and radially. That is to say, the growth atmosphere can flow into the first flow guide cover 200 through the gap between the first flow guide cover 200 and the second flow guide cover 300. In order to improve the growth quality of the crystal, a filter element 600 is provided in the gap between the first flow guide cover 200 and the second flow guide cover 300 in this embodiment, thereby reducing the formation of carbon inclusions in the grown crystal.

[0050] Please refer to Figures 1 - 2, Specifically, 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 to say, axially, a part of the first flow guiding cover 200 is located within the second flow guiding cover 300. Namely, the outer wall of the first flow guiding cover 200 and the inner wall of the second flow guiding cover 300 can define a channel for guiding the growth atmosphere, so as to facilitate 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 may 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 flow guiding cover 300 and the outer wall of the first flow guiding cover 200. That is to say, both sides of the filter element 600 are respectively connected to the inner wall of the second flow guiding cover 300 and the outer wall of the first flow guiding cover 200.

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

[0054] , Specifically, the flow guiding outer wall 220 and the inner wall of the second flow guiding cover 300 define a second flow channel 500, so as to facilitate guiding 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 guiding cover 200 is the same as the inclination direction of the inner wall of the second flow guiding cover 300. That is to say, the inclination direction of the flow guiding outer wall 220 is the same as the inclination direction of the inner wall of the second flow guiding cover 300, so as to ensure that the radial dimension of the second flow channel 500 itself remains relatively unchanged in its own extending direction, thereby ensuring that the flow rate and distribution of the growth atmosphere within the second flow channel 500 are relatively uniform.

[0056] Please refer to Figure 3 , In some other embodiments, the inclination direction of the flow guiding outer wall 220 and the inclination direction of the inner wall of the second flow guiding cover 300 may also form an included angle.

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

[0058] That is to say, the first flow channel 400 is jointly defined by the outer side of the third deflector shroud 320 and the inner peripheral wall of the crucible 100, and the second flow channel 500 is defined between the inner side of the third deflector shroud 320 and the deflector outer wall 220.

[0059] The growth atmosphere in the crucible 100 can move upward under the guidance of the outer wall of the second deflector 300. After the growth atmosphere moves upward and encounters the obstruction of the deflector outer wall 220 or the inner wall of the crucible 100, it then moves downward and finally flows into the crystal growth chamber 101 through the filter element 600.

[0060] It can be avoided that the growth atmosphere directly flows upward into the first deflector 200 and directly contacts 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 chamber 101 through the filter element 600.

[0061] It should be noted that in some alternative embodiments, for the convenience of installing the above-mentioned first deflector 200, the first deflector 200 can be installed on the top wall of the crucible 100, that is, the first deflector 200 can be installed on the lid of the crucible 100.

[0062] Optionally, a temperature adjustment plate 110 is slidably disposed between the first deflector 200 and the inner wall of the crucible 100. Specifically, the thermal field in the crucible 100 can be adjusted thereby, and the crystallization of the growth atmosphere on the top wall of the crucible 100 can be reduced. Since the temperature adjustment plate 110 can also block the growth atmosphere flowing upward in the first flow channel 400, the growth atmosphere then changes direction and flows downward to the second flow channel 500.

[0063] It should be noted that the slidably disposed temperature adjustment plate 110 can be understood as that before crystal growth in the crucible 100, the user can adjust the position of the temperature adjustment plate 110 in the axial direction of the crucible 100 according to the situation.

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

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

[0066] Specifically, the separating column 330 can be coaxially arranged with the crucible 100. It can be understood that the raw materials in the middle of the crucible 100 basically do not participate in crystal growth, and during crystal growth, the raw materials in the middle of the crucible 100 are prone to crystallization waste. By providing the separating column 330, the raw materials can be prevented from being in the middle of the crucible 100, thereby reducing the waste of raw materials in the crucible 100 and improving the utilization rate of the raw materials in the crucible 100.

[0067] It should be noted that by providing the separating column 330, heat can be transferred to the outer wall of the second deflector 300 through the separating column 330, avoiding the possibility of crystallization at the bottom of the second deflector 300.

[0068] In order to make the heat at the bottom of the crucible 100 more easily conducted to the bottom of the second deflector 300, further avoiding the possibility of crystallization of the growth atmosphere at the bottom of the second deflector 300. In some embodiments, the separating column 330 can be a hollow column.

[0069] It should be noted that when the second deflector 300 is installed in the crucible 100 through the separating column 330, the bottom of the second deflector 300 may not be in contact with the crystal growth raw material 2 in the crucible 100, that is, there is a gap between the bottom of the second deflector 300 and the crystal growth raw material 2 in the crucible 100. So that the crystal growth raw material directly below the second deflector 300 can be sublimated smoothly to form a crystal growth atmosphere.

[0070] It should be noted that whether the separating column 330 abuts against the bottom wall of the crucible 100 depends on the thermal field situation. By providing the separating column 330, the loading amount of the crucible 100 can be reduced, avoiding the waste of raw materials in the middle of the crucible 100, and also avoiding the crystallization of the raw materials at the bottom and middle of the crucible 100. Therefore, the separating column 330 may not abut against the bottom wall of the crucible 100, which can be determined according to the thermal field situation. After adding raw materials in the crucible 100, it can be placed on the silicon carbide crystal growth raw material 2.

[0071] Optionally, in some other embodiments, the second deflector 300 can also be installed in the crucible 100 in other ways. For example, a second boss can be provided on the inner wall of the crucible 100, and the third deflector shroud 320 can cooperate with the second boss, that is, the outer wall of the third deflector shroud 320 can be clamped on the second boss.

[0072] It can be understood that in order to facilitate the upward flow of the growth atmosphere without being blocked by the second boss, ventilation holes can be provided on the second boss, and the ventilation holes are evenly spaced circumferentially around the second boss.

[0073] Please refer to Figure 3 , the second deflector 300 can also be arranged differently from the above, that is, the second deflector 300 may not be composed of the end plate 310 and the third deflector shroud 320. The second deflector 300 can be generally bowl-shaped, and in order to guide the growth atmosphere in the first flow channel 400, in the direction close to the top wall of the crucible 100, the distance between the outer peripheral wall of the second deflector 300 and the inner wall of the crucible 100 gradually decreases.

[0074] Optionally, in some embodiments, the silicon carbide crystal growth furnace 1 further includes a flow equalizing plate, and the flow equalizing plate is installed in the first deflector 200. It can be understood that through the arrangement of the flow equalizing plate, the growth atmosphere can enter the first deflector 200 more evenly during the rising process after entering the crystal growth cavity 101, so as to improve the quality of the silicon carbide crystal grown on the seed crystal 800.

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

[0076] In order to ensure that after the growth atmosphere enters the crystal growth cavity 101 through the first flow channel 400 and the second flow channel 500, it can enter the first deflector 200 relatively evenly. In some alternative embodiments, the seed crystal 800, the second deflector 300, the first deflector 200 and the crucible 100 are coaxially arranged.

[0077] It should be noted that the coaxial arrangement in this application is not limited to the strict sense of coaxial, and it only needs to be generally coaxial.

[0078] The embodiment of the present invention also provides a method for growing a silicon carbide crystal, which is applied to the above-mentioned silicon carbide crystal growth furnace 1. The method includes loading the crystal growth raw material 2 into the crucible 100, performing a pumping process on the crucible 100, and then flushing an inert gas into the crucible 100.

[0079] Furthermore, the crucible 100 can be heated to sublime the crystal growth raw material 2 in the crucible 100. The growth atmosphere formed by the sublimation of the crystal growth raw material 2 can flow into the crystal growth chamber 101 through the first flow channel 400 and the second flow channel 500 in sequence, and then a silicon carbide crystal can grow on the seed crystal 800.

[0080] In summary, the embodiment of the present 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. The silicon carbide crystal growth furnace 1 includes a crucible 100, a first flow guiding cover 200, a second flow guiding cover 300, and a filter element 600. A seed crystal 800 is arranged at the top of the crucible 100. The first flow guiding cover 200 is arranged at the top of the crucible 100, and the seed crystal 800 is located inside the first flow guiding cover 200. One end of the first flow guiding cover 200 away from the top of the crucible 100 has a first opening 211. The second flow guiding cover 300 is installed in the crucible 100 and is located below the first flow guiding cover 200. The first flow guiding cover 200 is of an annular structure. The second flow guiding cover 300 has a second opening 321, and the second opening 321 faces 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 positive projection of the first opening 211 in the axial direction falls inside the second flow guiding cover 300. The first flow guiding cover 200 and the second flow guiding cover 300 jointly define a crystal growth chamber 101. A first flow channel 400 is defined between the outer wall of the second flow guiding cover 300 and the inner wall of the crucible 100. A second flow channel 500 is defined between the inner wall of the second flow guiding cover 300 and the outer wall of the first flow guiding cover 200. The first flow channel is communicated with the second flow channel. The filter element 600 is installed in the second flow channel 500. The growth atmosphere in the crucible 100 can flow into the crystal growth chamber 101 through the first flow channel 400 and the second flow channel 500 in sequence. The flow rate of the growth atmosphere can be slowed down, so that the growth atmosphere can enter the first flow guiding cover 200 relatively uniformly, the speed of the growth atmosphere can be relatively uniform, and the concentration of the growth atmosphere entering the first flow guiding cover 200 can also be increased, which can effectively improve the growth quality of the silicon carbide crystal.

[0081] The above is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A silicon carbide crystal growth furnace, characterized in that, Comprising: A crucible (100), with a seed crystal (800) provided at the top of the crucible (100); A first flow guide cover (200), the first flow guide cover (200) is provided at the top of the crucible (100), the seed crystal (800) is located within the first flow guide cover (200), and one end of the first flow guide cover (200) away from the top of the crucible (100) has a first opening (211); A second flow guide cover (300), the second flow guide cover (300) is installed within the crucible (100) and below the first flow guide cover (200), the second flow guide cover (300) has a second opening (321), the second opening (321) faces the top wall of the crucible (100), the radial dimension of the second opening (321) is greater than the radial dimension of the first opening (211), the positive projection of the first opening (211) in the axial direction falls within the second flow guide cover (300), the first flow guide cover (200) and the second flow guide cover (300) jointly define a crystal growth cavity (101), a first flow channel (400) is defined between the outer wall of the second flow guide cover (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 cover (300) and the outer wall of the first flow guide cover (200), and the first flow channel (400) communicates with the second flow channel (500); A filter element (600), the filter element (600) is installed within the second flow channel (500); Wherein, the growth atmosphere within the crucible (100) can successively pass through the first flow channel (400) and the second flow channel (500) and flow into the crystal growth cavity (101).

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

3. The silicon carbide crystal growth furnace according to claim 1, characterized in that: The bottom of the second flow guide cover (300) is further provided with a partition column (330) extending towards 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, characterized in that: The partition column (330) is a hollow column.

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

6. The silicon carbide crystal growth furnace according to claim 1, characterized in that: A temperature adjustment plate (110) is slidably provided 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, characterized in that: 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, characterized in that: The first deflector (200) has a deflector inner wall (210) and a deflector outer wall (220). The seed crystal (800) is located within the deflector inner wall (210). The radial dimension of the deflector inner wall gradually decreases in the direction close to the top wall of the crucible (100). The deflector outer wall (220) and the inner wall of the second deflector (300) define the second flow channel (500).

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

10. A method for growing a silicon carbide crystal, which is applied to the silicon carbide crystal growth furnace according to any one of claims 1-9, and is characterized in that, The method includes: Loading the crystal growth raw material (2) into the crucible (100); Performing a pumping process on the crucible (100); Filling the crucible (100) with an inert gas; Heating the crucible (100) to sublime the crystal growth raw material (2); The growth atmosphere formed by sublimation of the crystal growth raw material (2) can flow into the crystal growth cavity (101) after passing through the first flow channel (400) and the second flow channel (500) in sequence, and then grow silicon carbide crystals on the seed crystal (800).

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