A growth apparatus and method for reducing edge stress in silicon carbide crystals.

Abstract

This invention provides a growth apparatus and method for reducing edge stress in silicon carbide crystals, relating to the field of silicon carbide crystal growth technology. It includes a crucible body covered by a crucible lid, the lid and body defining a connected raw material region and a growth region. The raw material region contains silicon carbide powder, and a guide tube is disposed within the growth region. The guide tube includes a first containing surface and a second containing surface. The second containing surface contains a seed crystal, and multiple growth grooves are formed on the second containing surface. These grooves allow edge growth of silicon carbide crystals to enter and form edge crystals within them. By providing growth grooves, this invention enables the crystal entering the growth grooves to apply locally concentrated high stress to the guide tube, causing the guide tube to crack and break, thereby releasing crystal stress and reducing the generation of basis plane dislocations.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon carbide crystal growth, in particular to a growth device and method for reducing edge stress of silicon carbide crystal. BACKGROUND

[0002] In the physical vapor transport method of silicon carbide crystal, in order to optimize the transmission path of the vapor raw material in the crucible, a graphite flow guide cylinder is usually selected to be arranged in the crucible, and the flow guide cylinder is arranged around the seed crystal to guide the vapor raw material from the edge of the crucible to the middle region, and finally to the surface of the seed crystal.

[0003] When the crystal growth process is over and enters the cooling process, due to the different thermal expansion coefficients of the silicon carbide crystal and the graphite flow guide cylinder, the graphite flow guide cylinder has a relatively larger shrinkage and a relatively faster shrinkage speed, thereby causing the crystal edge to be extruded by the flow guide cylinder during the cooling process to generate more basal plane dislocations, and further affecting the crystal quality. SUMMARY

[0004] The purpose of the present application includes providing a growth device and method for reducing the edge stress of silicon carbide crystal to improve the technical problem that the flow guide cylinder extrudes the crystal edge during the cooling process of the silicon carbide crystal, thereby causing the crystal to generate more basal plane dislocations and affecting the crystal quality.

[0005] Embodiments of the present application can be implemented as follows:

[0006] In a first aspect, the present application provides a growth device for reducing the edge stress of silicon carbide crystal, comprising:

[0007] a crucible body;

[0008] a crucible cover arranged on the crucible body, the crucible cover and the crucible body together defining a raw material area and a growth area in communication;

[0009] The raw material area is filled with silicon carbide powder, and the growth area is provided with a flow guide cylinder; the flow guide cylinder comprises a first containing surface and a second containing surface, and the second containing surface contains a seed crystal, so that the outer edge of the seed crystal abuts against the second containing surface;

[0010] A plurality of growth grooves are arranged in a ring array on the second containing surface, and the growth grooves extend from one end to the other end of the flow guide cylinder in the axial direction and are used for the edge of the silicon carbide crystal to grow into and form an edge crystal in the growth grooves;

[0011] The growth groove comprises a first sharp portion;

[0012] Under the condition that the edge crystal is formed in the growth groove, the first sharp portion generates concentrated stress;

[0013] The first containing surface is provided with a plurality of breaking grooves, and each pair of the breaking grooves is symmetrically arranged on both sides of the corresponding growth groove in the circumferential direction.

[0014] The breaking groove comprises a second sharp portion, and a cracking path is formed between the second sharp portion and the first sharp portion.

[0015] In an optional embodiment, the first sharp portion is provided in a plurality of numbers, and a thrust portion is formed between adjacent first sharp portions.

[0016] In an optional embodiment, the growth groove further comprises a transition portion, one end of the transition portion is connected with the second containing surface, and the other end is connected with the thrust portion and defines the first sharp portion with the thrust portion.

[0017] In an optional embodiment, the transition portion is a plane or a curved surface.

[0018] In the case where the transition portion is a curved surface, one end of the transition portion close to the second containing surface is tangent to the second containing surface.

[0019] In an optional embodiment, the thrust portion comprises a first thrust surface and a second thrust surface connected with each other.

[0020] The included angle between the first thrust surface and the second thrust surface is gamma , 10°≤ gamma ≤180°.

[0021] In an optional embodiment, the arc of each adjacent growth groove connected with the center of the draft tube is α , and the arc of each pair of breaking grooves connected with the center of the draft tube is β ; wherein, .

[0022] In an optional embodiment, .

[0023] In an optional embodiment, the thickness of the draft tube is H , the depth of the breaking groove is h 1, and the depth of the growth groove is h 2.

[0024] wherein, , .

[0025] In an optional embodiment, , .

[0026] In a second aspect, the present application provides a method for reducing the edge stress of a silicon carbide crystal, based on the growth device for reducing the edge stress of a silicon carbide crystal according to any one of the preceding embodiments, comprising:

[0027] mounting the draft tube and the seed crystal in the crucible, and filling the silicon carbide powder;

[0028] starting the heating structure to heat the crucible body to start the crystal growth, and the edge of the silicon carbide crystal grows into the growth groove and forms the edge crystal in the growth groove;

[0029] cooling the crucible body, and cooling the crucible body until room temperature, and the draft tube cracks and breaks under the action of the edge crystal;

[0030] separating the crucible body from the draft tube, and taking out the draft tube and the silicon carbide crystal;

[0031] separating the draft tube from the silicon carbide crystal, and completing the taking out of the silicon carbide crystal.

[0032] The method for growing and taking out the silicon carbide crystal and the growth device for reducing the edge stress of the silicon carbide crystal provided by the embodiments of the present application have the following beneficial effects:

[0033] The growth device for reducing the edge stress of the silicon carbide crystal provided by the present application has the following beneficial effects: a plurality of growth grooves are arranged in a ring array on the second containing surface of the draft tube, so that the edge of the silicon carbide crystal can grow into the growth groove during the growth process, and the crystal in the growth groove can exert local high concentrated stress on the draft tube during the cooling and shrinking process of the draft tube, so that the draft tube cracks and breaks, and the stress of the crystal is released, and the generation of the basal plane dislocation is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0035] Figure 1 Front view of the growth device for reducing the edge stress of the silicon carbide crystal provided by the first embodiment of the present application Figure 1 ;

[0036] Figure 2 Front view of the growth device for reducing the edge stress of the silicon carbide crystal provided by the first embodiment of the present application Figure 2 ;

[0037] Figure 3A top view of the flow guide cylinder and the seed crystal in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One;

[0038] Figure 4 A partial enlarged view of the P portion Figure 3 ;

[0039] Figure 5 A structure diagram of the growth groove in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One Figure 1 ;

[0040] Figure 6 A structure diagram of the growth groove in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One Figure 2 ;

[0041] Figure 7 A structure diagram of the growth groove in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One Figure 3 ;

[0042] Figure 8 A front view of the flow guide cylinder in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One Figure 1 ;

[0043] Figure 9 A front view of the flow guide cylinder in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One Figure 1 ;

[0044] Figure 10 A front view of the flow guide cylinder in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One Figure 2 ;

[0045] Figure 11 A front view of the flow guide cylinder in the growth device for reducing the edge stress of silicon carbide crystal provided in Embodiment One Figure 2 ;

[0046] Figure 12 A flow chart of the method for reducing the edge stress of silicon carbide crystal provided in Embodiment One.

[0047] Figure legend: 100-crucible body; 110-raw material zone; 120-growth zone; 130-silicon carbide powder; 140-seed crystal;

[0048] 200-crucible cover;

[0049] 300 - flow conductor; 310 - first containment surface; 311 - breakage groove; 3111 - second sharp portion; 320 - second containment surface; 321 - growth groove; 3211 - first sharp portion; 3212 - thrust portion; 3212a - first thrust surface; 3212b - second thrust surface; 3213 - transition portion; 330 - support member;

[0050] A1 - cracking path. DETAILED DESCRIPTION

[0051] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0052] 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 claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0053] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0054] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is used, only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0055] In addition, if the terms "first", "second" and the like appear, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0056] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0057] The detailed steps, implementation principles, and technical effects of the growth device and method for reducing the edge stress of a silicon carbide crystal provided by the present application, as well as the overall structure, working principle, and technical effects of the matching growth device for reducing the edge stress of a silicon carbide crystal, are described in detail below through examples and in conjunction with the accompanying drawings.

[0058] Example 1

[0059] Referring to Figure 1 , the present embodiment provides a growth device for reducing the edge stress of a silicon carbide crystal, which is used for the growth of a silicon carbide crystal and the formation of a crystal ingot, and includes a crucible body 100 and a crucible cover 200 arranged on the crucible body 100; the crucible cover 200 and the crucible body 100 define a raw material area 110 and a growth area 120 in communication; the raw material area 110 contains silicon carbide powder 130, and the growth area 120 is provided with a flow guide cylinder 300; the flow guide cylinder 300 is detachably arranged in the growth area 120 through a support 330, and the support 330 is a graphite support. The flow guide cylinder 300 includes a first containing surface 310 and a second containing surface 320, and a gap is formed between the first containing surface 310 and the inner wall of the crucible body 100, which provides a space for stress release of the flow guide cylinder 300; the second containing surface 320 contains a seed crystal 140, so that the outer edge of the seed crystal 140 abuts against the second containing surface 320; a plurality of growth grooves 321 are arranged in an annular array on the second containing surface 320, extend along the axial direction from one end of the flow guide cylinder 300 to the other end, and are used for the edge of a silicon carbide crystal to grow into and form an edge crystal in the growth grooves 321.

[0060] In the present embodiment, the silicon carbide powder 130 is heated and sublimated in the raw material area 110 to form a gas-phase raw material, which enters the growth area 120 and finally reaches the surface of the seed crystal 140 under the action of the flow guide cylinder 300, and starts to grow.

[0061] Referring to Figure 1 and Figure 2 , further, the flow guide cylinder 300 is a cylindrical structure made of graphite, is arranged at one end of the crucible body 100 away from the silicon carbide powder 130 and is fixed through the support 330, has opposite outer and inner sidewalls; specifically, the first containing surface 310 is the outer sidewall, the second containing surface 320 is the inner sidewall, and the outer sidewall and the inner sidewall are a dense graphite structure. During the growth of the silicon carbide crystal, the purpose of arranging the flow guide cylinder is mainly to accurately control the temperature gradient and gas-phase transport by guiding the airflow, so as to suppress the growth of foreign crystals, reduce defects, and finally achieve the efficient growth of high-quality single crystals; therefore, in some embodiments, as shown in Figure 1 , the first containing surface 310 and the second containing surface 320 are arranged vertically and form a vertical sidewall of the flow guide cylinder 300; in other embodiments, as shown in Figure 2As shown, the first containing surface 310 and the second containing surface 320 can be arranged obliquely and form an oblique draft tube 300 sidewall to further guide the gas phase raw material to the seed crystal 140; the draft tube 300 is mainly to realize the optimization of the gas phase raw material path, which is not limited here.

[0062] In this embodiment, because the plurality of growth grooves 321 are arranged on the inner sidewall of the ring-shaped array, when the crystal is in a growth state, the growth grooves 321 can allow the crystal edge to grow in, form edge crystals in the growth grooves 321 while consuming the unstable gas flow of the crystal edge, reducing the polymorphic probability of the crystal edge, and reducing the poly-crystal quality and the number of dislocations; when the crystal growth process ends and enters the cooling process, the draft tube 300 shrinks as the temperature decreases, at this time, the edge crystals in the growth grooves 321 can exert a local stress on the draft tube 300, so that the draft tube 300 cracks and breaks under the action of the edge crystals; at this time, because the draft tube 300 does not continue to press the crystal, the stress of the crystal is released, thereby reducing the generation of the basal plane dislocation, and further ensuring the crystal quality.

[0063] It should be noted that after the silicon carbide crystal growth is completed and the draft tube 300 is separated from the crystal ingot, the edge crystals will remain on the outer edge of the crystal ingot and be removed in the subsequent rounding process of the crystal ingot, without affecting the quality of the crystal ingot.

[0064] It can be understood that the shape of the edge crystal matches the shape of the growth groove 321, and in the cooling process, in order to make the edge crystal effectively cause the draft tube 300 to crack and break, the growth groove 321 includes a first sharp portion 3211; when the edge crystal is formed in the growth groove 321, the first sharp portion 3211 generates a concentrated stress to cause the draft tube 300 to crack and break at the stress concentration position of the first sharp portion 3211.

[0065] Further, the number of the first sharp portion 3211 can be multiple to cause the draft tube 300 to crack and break; at the same time, a thrust portion 3212 for increasing the acting area of the edge crystal on the draft tube 300 is formed between adjacent first sharp portions 3211; after the silicon carbide crystal growth is completed and the crucible body 100 enters the cooling process, because the draft tube 300 has a relatively larger shrinkage amount and a relatively faster shrinkage speed, the edge crystal can form a radial thrust acting on the draft tube 300 at the thrust portion 3212 to cause the draft tube 300 to crack and break at the stress concentration position of the first sharp portion 3211.

[0066] Specifically, the number of the first sharp portion 3211 can be 2, 4, etc.

[0067] Furthermore, the thrust unit 3212 includes a first thrust surface 3212a and a second thrust surface 3212b connected together, and the included angle between the first thrust surface 3212a and the second thrust surface 3212b is . gamma ,10°≤ gamma ≤180°.

[0068] Please see Figure 5 and Figure 7 , Figure 5 The included angle between the first thrust surface 3212a and the second thrust surface 3212b is shown. gamma This is a schematic diagram of the structure at 90° (for ease of description and understanding). Figures 5 to 7 Only a portion of the seed crystal 140 structure is shown in the figure. At this time, a thrust part 3212 with an inverted triangular structure is formed between the first thrust surface 3212a and the second thrust surface 3212b. This allows the edge crystal and the guide tube 300 to have a sufficient working area, while the guide tube 300 can also generate sufficient stress at the position of the first sharp part 3211, so that the guide tube 300 can crack and break under the action of the edge crystal.

[0069] It is understandable that the angle between the first thrust surface 3212a and the second thrust surface 3212b... gamma When the angle is between 0° and 90°, a similar shape is formed between the first thrust surface 3212a and the second thrust surface 3212b. gamma The thrust section 3212, which forms an inverted triangle at 90°, differs only in that the interaction area between the edge crystal and the guide tube 300 is changed. Operators can select the included angle according to actual working needs. gamma Specific angles within the range of 10° to 90°.

[0070] In some embodiments, a chamfer is provided at the connection between the first thrust surface 3212a and the second thrust surface 3212b to further increase the interaction area between the edge crystal and the guide tube 300.

[0071] Figure 7 The included angle between the first thrust surface 3212a and the second thrust surface 3212b is shown. gamma The diagram shows a 180° view of the structure. At this point, the first thrust surface 3212a and the second thrust surface 3212b are connected flush, so that there is a larger working area between the edge crystal and the guide tube 300, thereby increasing the thrust of the edge crystal on the guide tube 300 during the cooling process.

[0072] In this embodiment, the growth groove 321 further includes a transition portion 3213, one end of which is connected to the second containment surface 320, and the other end is connected to the thrust portion 3212 and defines the first sharp portion 3211.

[0073] Similar to the thrust section 3212, after the crucible body 100 enters the cooling process, the edge crystals can form a thrust acting on the guide tube 300 in the transition section 3213, so as to cause the guide tube 300 to crack and break at the stress concentration point of the first sharp section 3211.

[0074] For further details, please refer to Figure 5 and Figure 6 The transition section 3213 is a plane or a curved surface; wherein, Figure 5 This shows a schematic diagram of the structure of the fracture groove 311 when the transition section 3213 is a plane. Figure 6 A schematic diagram of the structure of the fracture groove 311 when the transition part 3213 is a curved surface is shown.

[0075] Please continue reading. Figure 5 When the transition section 3213 is planar, it connects the second containment surface 320 and the thrust section 3212. The transition section 3213 and the guide tube 300 form a variable angle radially. This variable angle can be adjusted according to actual arrangement needs. For example, when the angle between the first thrust surface 3212a and the second thrust surface 3212b... gamma When the angle is 90°, the variable included angle is relatively small; when the angle between the first thrust surface 3212a and the second thrust surface 3212b is 90°, the variable included angle is relatively small. gamma When the angle is greater than 90°, the variable included angle can be increased at any time.

[0076] During the crystal growth process, edge crystals that connect to silicon carbide crystals can be generated in the growth groove 321. In order to reduce the disturbance of the silicon carbide crystal edge caused by opening the growth groove 321, the growth groove 321 should be connected to the guide tube 300 (i.e. the second containment surface 320) relatively smoothly, so as to reduce the influence of the corners caused by opening the growth groove 321 on the edge gas phase of silicon carbide crystal.

[0077] For example, while the transition portion 3213 is a curved surface, one end of the transition portion 3213 near the second containing surface 320 is tangent to the second containing surface 320. Figure 6 The dashed line in the middle shows the tangent position where the transition section 3213 is tangent to the second containment surface 320, so that the growth groove 321 and the guide tube 300 are connected relatively smoothly, thereby reducing the influence of the corners generated by opening the growth groove 321 on the edge gas phase of the silicon carbide crystal.

[0078] Please see Figure 3 and Figure 4In order to facilitate the separation of the guide tube 300 and the crystal ingot, in this embodiment, a plurality of fracture grooves 311 are arranged in an annular array on the first enclosing surface 310. The plurality of fracture grooves 311 are arranged in pairs, and each pair of fracture grooves 311 is symmetrically opened on both sides of the corresponding growth groove 321 in the circumferential direction. The fracture groove 311 includes a second sharp part 3111, and a cracking path A1 is formed between the second sharp part 3111 and the first sharp part 3211.

[0079] The correspondence here means that each growth groove 321 corresponds to two (i.e. a pair) cracking grooves 311. The pair of cracking grooves 311 are symmetrically opened on both sides of the corresponding growth groove 321 in the circumferential direction, and cracking paths A1 are generated between them and the growth groove 321 respectively.

[0080] It should be noted that the cracking groove 311 on the first containment surface 310 and the growth groove 321 on the second containment surface 320 should be arranged to be staggered in the radial direction in order to avoid excessively weakening the strength of the guide tube 300, which could lead to cracking or damage of the guide tube 300 during crystal growth.

[0081] In this embodiment, the growth groove 321 has two first sharp parts 3211. It is understood that in a pair of crack grooves 311, a cracking path A1 is generated between the second sharp part 3111 of a single crack groove 311 and the adjacent first sharp part 3211 in the corresponding growth groove 321.

[0082] Specifically, in a pair of fracture grooves 311, the arc connecting the center of adjacent growth grooves 321 and the center of the guide tube 300 is... α The arc of the connection between each pair of rupture grooves 311 and the center of the guide tube 300 is... β , .

[0083] Understandable, radian α With radians β The relationship is related to the formation of crack path A1, when At that time, due to the short distance between the second sharp part 3111 and the first sharp part 3211, the structural strength of the guide tube 300 is excessively weakened, causing the cracking path A1 to appear prematurely during the crystal growth stage, resulting in cracking and breakage of the guide tube 300, thus affecting crystal growth; when At that time, because there is a long distance between the second sharp part 3111 and the first sharp part 3211, the guide tube 300 has excessive structural strength, which makes it impossible to form a cracking path A1 between the second sharp part 3111 and the first sharp part 3211 during the cooling stage of the crucible body 100, affecting the subsequent separation of the guide tube 300 and the crystal.

[0084] For example, .

[0085] In this embodiment, the thickness of the flow guide cylinder 300 is H , the opening depth of the breakage groove 311 is h 1, and the opening depth of the growth groove 321 is h 2; wherein, , .

[0086] It can be understood that the opening depth h 1 of the breakage groove 311 and the opening depth h 2 of the growth groove 321 are related to the structural strength of the flow guide cylinder 300 and the difficulty of the flow guide cylinder 300 cracking under the action of the edge crystal, and the operator can adaptively adjust according to the actual work needs.

[0087] Exemplarily, , .

[0088] Please refer to Figure 8 and Figure 9 , in some embodiments, the breakage groove 311 is continuously opened along the axial direction of the first containing surface 310, so that the flow guide cylinder 300 can be smoothly broken during the crystal cooling process.

[0089] Please refer to Figure 10 and Figure 11 , in other embodiments, in order to avoid that the continuously opened breakage groove 311 excessively weakens the structural strength of the flow guide cylinder 300, the breakage groove 311 can also be intermittently opened along the axial direction of the first containing surface 310, avoiding the flow guide cylinder 300 cracking during the crystal growth stage.

[0090] The growth device for reducing the edge stress of silicon carbide crystal provided by the application can at least produce the following technical effects:

[0091] On the one hand, by opening the growth groove 321 on the second containing surface 320 of the flow guide cylinder 300, when the crystal is in a growth state, the growth groove 321 can allow the edge of the crystal to grow into, consume the unstable airflow of the edge of the crystal, reduce the polymorph probability of the edge of the crystal, and reduce the polycrystal quality and the dislocation number, while forming the edge crystal in the growth groove 321, so that when the crystal growth process ends and enters the cooling process, the local stress is generated in the growth groove 321 under the action of the edge crystal, since the flow guide cylinder 300 is made of graphite material, which is a brittle material, and then the flow guide cylinder 300 can crack and break under the action of the edge crystal; at this time, since the flow guide cylinder 300 no longer continues to press the crystal, the stress of the crystal is released, thereby reducing the generation of the basal plane dislocation, and further ensuring the crystal quality.

[0092] On the other hand, since the flow guide cylinder 300 can be cracked and broken under the action of the edge crystal during the crystal cooling process, it is convenient for the operator to subsequently separate the flow guide cylinder 300 and the silicon carbide crystal, thereby reducing the risk of crystal cracking, edge collapse or even personnel injury due to improper operation of the operator when separating the flow guide cylinder 300 when taking out the crystal.

[0093] Embodiment two:

[0094] The embodiment provides a method for reducing the edge stress of a silicon carbide crystal, based on the growth device for reducing the edge stress of a silicon carbide crystal provided in embodiment one, by reducing the extrusion of the flow guide cylinder 300 on the edge of the silicon carbide crystal, thereby reducing the generation of the basal plane dislocation of the crystal, and further ensuring the crystal quality.

[0095] Please refer to Figure 12 In the embodiment, the method for reducing the edge stress of a silicon carbide crystal comprises:

[0096] S1, installing the flow guide cylinder 300 and the seed crystal 140 in the crucible, and filling the silicon carbide powder 130;

[0097] Similar to the prior art, in the embodiment, the crucible body 100 provides a growth space for the silicon carbide crystal, the flow guide cylinder 300 and the seed crystal 140 are arranged in the crucible body 100, the flow guide cylinder 300 is made of graphite, and is used for optimizing the transmission path of the gas phase raw material in the crucible, so as to guide the gas phase raw material from the edge of the crucible body 100 to the middle region, and finally to the surface of the seed crystal 140.

[0098] S2, starting the heating structure to heat the crucible body 100 to start crystal growth, and the edge of the silicon carbide crystal grows into the growth groove 321 and forms an edge crystal in the growth groove 321.

[0099] In the embodiment, the heating structure is used to heat the crucible body 100, so that the silicon carbide powder 130 sublimates to form a gas phase raw material. Under the condition of a temperature gradient, the gas phase raw material migrates to the surface of the seed crystal 140. Finally, the gas phase raw material is orderly deposited and grown on the surface of the seed crystal 140 in a single crystal structure, and a large-size silicon carbide single crystal ingot, i.e. a crystal ingot, is finally formed.

[0100] The growth method of the silicon carbide crystal provided in the embodiment can make the edge of the silicon carbide crystal grow into the growth groove 321 formed on the flow guide cylinder 300 during the growth process of the silicon carbide crystal, can consume the unstable airflow of the crystal edge, and reduce the polymorphic probability of the crystal edge, thereby reducing the polycrystal quality and the number of dislocations.

[0101] S3, cooling the crucible body 100, so that the crucible body 100 is cooled to room temperature, and the flow guide cylinder 300 is cracked and broken under the action of the edge crystal.

[0102] It should be noted that, in order to avoid the problem of thermal stress of the crystal due to the large temperature difference between the inside and the outside, and further cause the quality defect of the crystal, the crucible body 100 and the crystal gradient should be cooled to room temperature, and a slow, controllable and uniform temperature drop rate is achieved.

[0103] In the present embodiment, during the cooling and shrinking process of the flow guide cylinder 300, the crystal entering the growth groove 321 can exert local high concentrated stress on the flow guide cylinder 300, and further cause the flow guide cylinder 300 to crack and break, thereby realizing the release of the crystal stress and reducing the generation of the base vector surface dislocation.

[0104] S4, separate the crucible body 100 from the flow guide cylinder 300, and take out the flow guide cylinder 300 and the silicon carbide crystal.

[0105] Similar to the prior art, the crucible body 100 and the flow guide cylinder 300 are separably connected, and the flow guide cylinder 300 is arranged in the crucible body 100 through the support 330; therefore, the operator can take out the flow guide cylinder 300 from the crucible by artificial or mechanical device.

[0106] S5, separate the flow guide cylinder 300 from the silicon carbide crystal, take out the silicon carbide crystal, and complete the taking out of the silicon carbide crystal.

[0107] In the method for reducing the edge stress of the silicon carbide crystal provided in the present embodiment, the flow guide cylinder 300 can be smoothly cracked and broken under the action of the edge crystal, so that the method of manually knocking the flow guide cylinder 300 is not needed, and further the risk of cracking, edge collapse and even personnel injury of the crystal due to improper operation of separating the flow guide cylinder 300 when the operator takes out the crystal is reduced.

[0108] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application.

Claims

1. A growth apparatus for reducing edge stress in silicon carbide crystals, comprising: The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device.

2. The growth apparatus of claim 1, wherein, The application relates to a silicon carbide crystal growth device. An angle between the first thrust surface (3212a) and the second thrust surface (3212b) is The application relates to a silicon carbide crystal growth device. , 10°≤ The application relates to a silicon carbide crystal growth device. ≤180°.

3. The growth apparatus of claim 1, wherein, The arc of the growth groove (321) connected with the center of the flow guide cylinder (300) adjacent to the growth groove (321) is α The arc of each pair of the breakage groove (311) connected with the center of the flow guide cylinder (300) is β ; wherein .

4. The growth apparatus of claim 3, wherein the apparatus further comprises a means for reducing edge stress in the silicon carbide crystal. 。 5. The growth apparatus of claim 1, wherein, The thickness of the guiding cylinder (300) is H , the opening depth of the breaking groove (311) is h 1, and the opening depth of the growth groove (321) is h 2. wherein , .

6. The growth apparatus of claim 5, wherein the apparatus further comprises a means for reducing edge stress in the silicon carbide crystal. , 。 7. A method of reducing edge stress in a silicon carbide crystal, comprising: The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. 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The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide crystal growth device. The application relates to a silicon carbide Cooling the crucible body (100), cooling the crucible body (100) until room temperature, the draft tube (300) cracking, crushing under the action of edge crystal; Separate the crucible body (100) from the draft tube (300), and take out the draft tube (300) and the silicon carbide crystal; Separate the draft tube (300) from the silicon carbide crystal, and complete the taking out of the silicon carbide crystal.

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