Growth device for silicon carbide crystals
By adding an annular gas cavity structure inside the crucible body, the problems of thermal stress and uneven distribution of gaseous substances during silicon carbide crystal growth were solved, resulting in a more stable and uniform growth environment, significantly reducing defect density and improving crystal quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-11
- Publication Date
- 2026-04-10
AI Technical Summary
Existing technologies for growing silicon carbide crystals suffer from defects such as microtubes and dislocations, which affect crystal quality and device yield. Traditional crucible structures lead to uneven distribution of thermal stress and gaseous substances, making it difficult to effectively suppress the generation of defects.
An annular gas cavity structure is added inside the crucible body to buffer thermal stress and homogenize the transport of gaseous substances, providing a stable and uniform growth environment. The heat transfer path is adjusted by precisely designing the shape and position of the annular gas cavity, thereby reducing thermoelastic stress and nucleation defects.
It significantly reduces the density of crystal defects such as microtubes and dislocations, improves the quality of silicon carbide crystals, ensures the stability and uniformity of the growth process, and reduces the risk of thermal shock and heterogeneous nucleation.
Smart Images
Figure CN121826897A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of silicon carbide crystal, in particular to a growth device of silicon carbide crystal. BACKGROUND
[0002] Silicon carbide (chemical formula SiC) is a third-generation semiconductor material, which has excellent performance such as wide band gap, high breakdown electric field, and high thermal conductivity. At present, the PVT (full name in English: Physical Vapor Transport, full name in Chinese: Physical Vapor Transport) method is the mainstream technology for growing large-size and high-quality SiC crystals. In the process of growing SiC crystals by using the PVT method, SiC raw materials sublimate at high temperature, and Si, Si2C, SiC2 and other gaseous substances re-crystallize on the surface of the seed crystal at a lower temperature to realize the growth of SiC crystals. However, one of the main challenges faced by this process is the various defects generated during the growth of SiC crystals, such as microtubules, dislocations, polytypes, etc. These defects seriously affect the electrical and optical properties of SiC crystals and reduce the yield and reliability of devices.
[0003] The traditional crucible used for growing SiC crystals is usually a simple closed graphite crucible, which is composed of a crucible body, a crucible cover and a heat preservation layer, etc. During the growth of SiC crystals, there is a significant temperature gradient and thermal stress in the interior of the crucible body. At the same time, the transportation and distribution of gaseous substances are uneven, which can easily cause local oversaturation or deficiency at the crystal growth interface, thereby inducing the formation and proliferation of defects.
[0004] In the prior art, although the crystal quality can be improved to some extent by optimizing the temperature field control and using high-purity materials, the effect of fundamentally regulating the physical and chemical environment near the growth interface and inhibiting the generation of defects is still limited. SUMMARY
[0005] In view of the above problems, the present application provides a growth device of silicon carbide crystal, which effectively buffers thermal stress and homogenizes the transportation of gaseous substances by adding a ring-shaped gas cavity structure in the interior of the crucible body, thereby providing a more stable and uniform growth environment for the growth of silicon carbide crystal and significantly reducing the density of crystal defects such as microtubules and dislocations. The specific scheme is as follows:
[0006] The present application provides a growth device of silicon carbide crystal, which comprises:
[0007] a crucible body;
[0008] a ring-shaped gas cavity structure located in the interior of the crucible body, the ring-shaped gas cavity structure being fixed on the inner side wall of the crucible body;
[0009] a crucible cover located at the opening of the crucible body;
[0010] a seed crystal fixed on the crucible cover;
[0011] wherein, in the direction perpendicular to the plane where the crucible cover is located, the orthographic projection of the annular gas cavity structure covers the edge region of the seed crystal; the inner diameter of the surface of the annular gas cavity structure facing the seed crystal side is D1, and the inner diameter of the surface of the annular gas cavity structure facing the bottom of the crucible body side is D2, D1 < D2.
[0012] Preferably, in the above-mentioned silicon carbide crystal growth device, the diameter of the seed crystal is D3;
[0013] wherein, D1 ≥ 1 / 2 × D3.
[0014] Preferably, in the above-mentioned silicon carbide crystal growth device, 1.2 × D1 ≤ D2 ≤ 2 × D1.
[0015] Preferably, in the above-mentioned silicon carbide crystal growth device, the height of the annular gas cavity structure is H1;
[0016] wherein, 10 mm ≤ H1 ≤ 40 mm.
[0017] Preferably, in the above-mentioned silicon carbide crystal growth device, the annular gas cavity structure comprises a first part, a second part and a third part;
[0018] The first part and the second part are oppositely arranged in the direction perpendicular to the plane where the crucible cover is located;
[0019] One side of the first part and one side of the second part are both fixed on the inner side wall of the crucible body;
[0020] The other side of the first part and the other side of the second part are both connected with the third part.
[0021] Preferably, in the above-mentioned silicon carbide crystal growth device, the thickness of the first part, the second part and the third part is the same, and the thickness ranges from 2 mm to 5 mm.
[0022] Preferably, in the above-mentioned silicon carbide crystal growth device, the distance between the annular gas cavity structure and the seed crystal is L1;
[0023] wherein, 30 mm ≤ L1 ≤ 150 mm.
[0024] Preferably, in the above-mentioned silicon carbide crystal growth device, when the silicon carbide raw material is placed at the bottom of the crucible body, the distance between the annular gas cavity structure and the silicon carbide raw material is L2;
[0025] Wherein, 0 < L2 ≤ 50mm.
[0026] Preferably, in the above-mentioned silicon carbide crystal growth device, the inner side wall of the crucible body has a stepped structure;
[0027] The annular gas cavity structure is fixed on the stepped structure.
[0028] Preferably, in the above-mentioned silicon carbide crystal growth device, the annular gas cavity structure is fixed on the inner side wall of the crucible body through a latch structure.
[0029] By the above technical solution, the application provides a silicon carbide crystal growth device, which comprises a crucible body, an annular gas cavity structure located inside the crucible body and fixed on the inner side wall of the crucible body, a crucible cover located at the opening of the crucible body, and a seed crystal fixed on the crucible cover; wherein, in the direction perpendicular to the plane where the crucible cover is located, the orthographic projection of the annular gas cavity structure covers the edge region of the seed crystal; the inner diameter of the surface of the annular gas cavity structure facing the seed crystal is D1, and the inner diameter of the surface of the annular gas cavity structure facing the bottom of the crucible body is D2, D1 < D2.
[0030] By adding an annular gas cavity structure inside the crucible body, the thermal stress is effectively buffered, and the gas phase material transport is homogenized, thereby providing a more stable and uniform growth environment for the growth of silicon carbide crystals, significantly reducing the density of crystal defects such as microtubules and dislocations, i.e. fundamentally regulating the physical and chemical environment near the growth interface, thereby inhibiting the generation of defects.
[0031] The silicon carbide crystal growth device provided by the technical solution of the application mainly has the following effects:
[0032] Effect one, thermal field optimization and homogenization effect;
[0033] Specifically, the annular gas cavity structure is equivalent to introducing a controllable "thermal resistance layer" above the growth interface. By accurately designing the shape, size and position of the annular gas cavity structure, the heat transfer path from the thermal field to the growth interface can be actively adjusted, effectively reducing the radial temperature gradient between the center and the edge of the growth interface, and making the growth interface tend to be flat. A flat growth interface is the key to reducing thermal elastic stress and thereby reducing dislocation defects, especially basal plane dislocations.
[0034] Effect two, gas flow field stabilization effect;
[0035] Specifically, the gaseous phase matter sublimated from the area where the silicon carbide raw material is located will enter the annular air cavity structure during transportation to the seed crystal. The annular air cavity structure, as a fixed physical boundary, can change the flow field pattern below the crucible cover, inhibit the direct and violent impact of the hot gas flow rising from the inner sidewall of the crucible main body on the growth interface, make the gaseous phase matter flowing to the growth interface more gentle and uniform, and reduce the nucleation defects and polytype inclusions caused by the violent fluctuation of local supersaturation.
[0036] Effect three, thermal shock buffering effect;
[0037] Specifically, during the heating and cooling process, the annular air cavity structure can act as an effective thermal buffer layer to slow down the thermal shock of the seed crystal and the newly born silicon carbide crystal caused by the sharp change of temperature, which helps to prevent the silicon carbide crystal from cracking.
[0038] Effect four, inhibiting heterogeneous nucleation effect;
[0039] Specifically, the annular air cavity structure makes the sidewall temperature of the crucible main body different from the main growth area, reduces the risk of condensation and heterogeneous nucleation of the gaseous phase matter on the sidewall of the crucible main body, and ensures that the growth process only occurs on the seed crystal. BRIEF DESCRIPTION OF DRAWINGS
[0040] The above and other features, advantages, and aspects of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the proportions of the elements and the like are not necessarily drawn to scale.
[0041] Figure 1 Part of the structure schematic diagram of a silicon carbide crystal growth device provided by the embodiment of the present application;
[0042] Figure 2 Part of the structure schematic diagram of a silicon carbide crystal growth device provided by the embodiment of the present application;
[0043] Figure 3 The surface type test diagram of the silicon carbide crystal grown by the comparative example scheme provided by the embodiment of the present application;
[0044] Figure 4 The surface type test diagram of the silicon carbide crystal grown by the comparative example scheme provided by the embodiment of the present application;
[0045] Figure 5 The EPD schematic diagram of the silicon carbide crystal grown by the comparative example scheme provided by the embodiment of the present application;
[0046] Figure 6TSD schematic diagram of a silicon carbide crystal grown according to a comparative example provided in an embodiment of the present application;
[0047] Figure 7 TED schematic diagram of a silicon carbide crystal grown according to a comparative example provided in an embodiment of the present application;
[0048] Figure 8 BPD schematic diagram of a silicon carbide crystal grown according to a comparative example provided in an embodiment of the present application;
[0049] Figure 9 EPD schematic diagram of a silicon carbide crystal grown according to an example provided in an embodiment of the present application;
[0050] Figure 10 TSD schematic diagram of a silicon carbide crystal grown according to an example provided in an embodiment of the present application;
[0051] Figure 11 TED schematic diagram of a silicon carbide crystal grown according to an example provided in an embodiment of the present application;
[0052] Figure 12 BPD schematic diagram of a silicon carbide crystal grown according to an example provided in an embodiment of the present application. DETAILED DESCRIPTION
[0053] The embodiments of the present application are described below in conjunction with the drawings of the embodiments of the present application. The terms used in the embodiment part of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. It is known to those skilled in the art that, as technology develops and new scenarios appear, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.
[0054] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the present application is further described in detail below in conjunction with the drawings and specific embodiments.
[0055] It should be noted that the positional words appearing in the present application are based on the relative positional relationship shown in the drawings, and cannot be used as an absolute limitation on the present application.
[0056] Various modifications and changes can be made to the present application without departing from the spirit or scope thereof, which will be apparent to one of ordinary skill in the art. Thus, the present application is intended to cover the modifications and variations of this application that come within the scope of the corresponding claims (the technical solutions claimed to be protected) and their equivalents. It should be noted that the embodiments provided in the embodiments of the present application can be combined with each other without contradiction.
[0057] Reference Figure 1 ,Figure 1 This is a partial structural schematic diagram of a silicon carbide crystal growth apparatus provided in an embodiment of the present invention, with reference to... Figure 2 , Figure 2 This is a partial structural diagram of a silicon carbide crystal growth apparatus provided in an embodiment of the present invention, showing the process of growing silicon carbide crystals. The silicon carbide crystal growth apparatus provided in this embodiment of the present invention includes: a crucible body 11.
[0058] An annular gas cavity structure 12 is located inside the crucible body 11, and the annular gas cavity structure 12 is fixed on the inner wall of the crucible body 11.
[0059] The crucible cover 13 is located at the opening of the crucible body 11.
[0060] Seed crystal 14 fixed on the crucible lid 13.
[0061] Wherein, in the direction perpendicular to the plane where the crucible cover 13 is located, the orthographic projection of the annular air cavity structure 12 covers the edge region of the seed crystal 14; the inner diameter of the surface of the annular air cavity structure 12 facing the seed crystal 14 is D1, and the inner diameter of the surface of the annular air cavity structure 12 facing the bottom of the crucible body 11 is D2, where D1 < D2.
[0062] Optionally, 1.2×D1≤D2≤2×D1.
[0063] Optionally, the annular air cavity structure 12 is an annular air cavity structure 12 that is symmetrically distributed along the central axis.
[0064] Specifically, in the embodiments of the present invention, the crucible body 11 includes, but is not limited to, being made of high-purity graphite or other high-temperature resistant materials, and is the main part forming the growth chamber.
[0065] The crucible lid 13 is located at the top opening of the crucible body 11 and is used to fix the seed crystal 14. After the crucible lid 13 is fixed to the crucible body 11, a closed growth chamber is formed, at which time the seed crystal 14 is located inside the growth chamber.
[0066] The annular gas cavity structure 12 is located inside the crucible body 11 and between the seed crystal 14 and the silicon carbide raw material 15. In the direction perpendicular to the plane of the crucible cover 13, the orthographic projection of the annular gas cavity structure 12 covers the edge region of the seed crystal 14. The inner diameter of the surface of the annular gas cavity structure 12 facing the seed crystal 14 is D1, and the inner diameter of the surface of the annular gas cavity structure 12 facing the bottom of the crucible body 11 is D2, where D1 < D2. This effectively buffers thermal stress and homogenizes the transport of gaseous substances, thereby providing a more stable and uniform growth environment for the growth of silicon carbide crystal 16, significantly reducing the density of crystal defects such as microtubes and dislocations. In other words, it fundamentally regulates the physicochemical environment near the growth interface, thereby suppressing the generation of defects.
[0067] Optionally, the annular air cavity structure 12 may include, but is not limited to, being made of high-temperature resistant materials such as high-purity graphite.
[0068] It should be noted that, Figure 2 The single solid arrow in the image represents the transport path of a portion of the gaseous substances after the silicon carbide raw material 15 has been sublimated.
[0069] The silicon carbide crystal growth apparatus provided in this application mainly includes the following functions:
[0070] Function 1: Thermal field optimization and homogenization;
[0071] Specifically, the annular gas cavity structure 12 is equivalent to introducing a controllable "thermal resistance layer" above the growth interface. This is achieved through precise design of the shape, size, and position of the annular gas cavity structure 12, such as... Figure 2 As shown, the heat transfer path from the thermal field to the growth interface can be actively adjusted, effectively reducing the radial temperature gradient between the center and edge of the growth interface, making the growth interface tend to be flat. A flat growth interface is key to reducing thermoelastic stress, thereby reducing dislocation defects, especially basal plane dislocations.
[0072] Function 2: Stabilizing the airflow field;
[0073] Specifically, during the transport of sublimated gaseous material from the region where silicon carbide raw material 15 is located to the seed crystal 14, some of it enters the annular gas cavity structure 12. For example... Figure 2 As shown, the annular gas cavity structure 12, as a fixed physical boundary, can change the flow field morphology below the crucible lid 13. It can suppress the direct and violent impact of the hot gas flow rising from the inner wall of the crucible body 11 on the growth interface, making the gas phase material flowing to the growth interface more gentle and uniform, and reducing nucleation defects and polymorphic inclusions caused by violent fluctuations in local supersaturation.
[0074] Third function: thermal shock buffering;
[0075] Specifically, during the heating and cooling process, the annular air cavity structure 12 can act as an effective heat buffer layer to slow down the thermal shock of the seed crystal 14 and the newly born silicon carbide crystal 16 caused by the sharp change of temperature, which helps to prevent the silicon carbide crystal 16 from cracking.
[0076] Action four, inhibiting heterogeneous nucleation;
[0077] Specifically, the annular air cavity structure 12 makes the sidewall temperature of the crucible main body 11 different from the main growth zone, which reduces the risk of condensation and heterogeneous nucleation of gas phase substances on the sidewall of the crucible main body 11, and ensures that the growth process only occurs on the seed crystal 14.
[0078] In an optional embodiment of the present application, as shown in Figure 1 and Figure 2 The annular air cavity structure 12 includes a first part 121, a second part 122, and a third part 123.
[0079] The first part 121 and the second part 122 are oppositely arranged in a direction perpendicular to the plane on which the crucible cover 13 is located.
[0080] One side of the first part 121 and one side of the second part 122 are fixed on the inner sidewall of the crucible main body 11.
[0081] The other side of the first part 121 and the other side of the second part 122 are connected with the third part 123.
[0082] Specifically, in the embodiment of the present application, the first part 121, the second part 122, the third part 123, and the inner sidewall of the crucible main body 11 between the first part 121 and the second part 122 constitute a gas cavity. It should be noted that the first part 121, the second part 122, and the third part 123 can be integrally formed, or they can be independent and form the annular air cavity structure 12 by splicing.
[0083] In the case where the first part 121, the second part 122, and the third part 123 are independent, the first part 121, the second part 122, and the third part 123 of different sizes and other parameters can be flexibly used to flexibly adjust the shape, size, and other parameters of the annular air cavity structure 12, thereby meeting the actual application requirements.
[0084] In addition, the first part 121, the second part 122, and the third part 123 can also be replaced individually to achieve the purpose of reducing cost.
[0085] Optionally, the first portion 121, the second portion 122 and the third portion 123 have the same thickness, and the thickness ranges from 2mm to 5mm.
[0086] For example, the thickness of the first portion 121, the second portion 122 and the third portion 123 is 2mm, 2.8mm, 3.5mm or 5mm, etc.
[0087] In an optional embodiment of the present application, as shown in Figure 1 and Figure 2 The diameter of the seed crystal 14 is D3; wherein D1≥1 / 2×D3.
[0088] Specifically, in the embodiment of the present application, the design of D1≥1 / 2×D3 is to ensure that the orthographic projection of the annular air cavity structure 12 can effectively cover the edge region of the seed crystal 14 and expose the part of the seed crystal 14 in the main growth region in the direction perpendicular to the plane where the crucible cover 13 is located.
[0089] In an optional embodiment of the present application, as shown in Figure 1 and Figure 2 The height of the annular air cavity structure 12 is H1; wherein 10mm≤H1≤40mm.
[0090] Specifically, in the embodiment of the present application, the height H1 of the annular air cavity structure 12 can be 10mm, 15.5mm, 32.6mm or 40mm, etc.
[0091] In an optional embodiment of the present application, as shown in Figure 1 and Figure 2 The distance between the annular air cavity structure 12 and the seed crystal 14 is L1; wherein 30mm≤L1≤150mm.
[0092] When the silicon carbide raw material 15 is placed at the bottom of the crucible body 11, the distance between the annular air cavity structure 12 and the silicon carbide raw material 15 is L2; wherein 0<L2≤50mm.
[0093] Specifically, in the embodiment of the present application, the position of the annular air cavity structure 12 inside the crucible body 11 is mainly determined according to the weight and height of the silicon carbide raw material 15 loaded in the crucible body 11. The weight of the silicon carbide raw material 15 will affect the weight and size of the grown crystal, and the higher the loading height, the closer the annular air cavity structure 12 to the surface of the silicon carbide raw material 15, and the space for airflow flow needs to be left with the seed crystal 14. The change of the distance will affect the impact degree of the hot airflow, thereby facilitating the control of the facet shape of the grown silicon carbide crystal 16.
[0094] Therefore, in the embodiments of the present application, L1 and L2 can be flexibly adjusted according to different growth requirements based on the settings of 30mm≤L1≤150mm and 0<L2≤50mm to achieve the required requirements.
[0095] In an optional embodiment of the present application, as shown in Figure 1 and Figure 2 , the inner side wall of the crucible body 11 has a step structure.
[0096] The annular air cavity structure 12 is fixed on the step structure.
[0097] Alternatively, the annular air cavity structure 12 is fixed on the inner side wall of the crucible body 11 through a latch structure.
[0098] Specifically, in the embodiments of the present application, only two implementation modes of the annular air cavity structure 12 fixed on the inner side wall of the crucible body 11 are shown, i.e., the mode of the annular air cavity structure 12 fixed on the step structure and the mode of the annular air cavity structure 12 fixed on the inner side wall of the crucible body 11 through a latch structure, which can achieve the purpose of flexibly adjusting the position of the annular air cavity structure 12.
[0099] Based on the above-mentioned embodiments of the present application, in another embodiment of the present application, a method for growing silicon carbide crystals based on the silicon carbide crystal growth device as shown in Figure 1 is provided, which comprises the following steps:
[0100] Step one, fill the silicon carbide raw material 15 into the bottom of the crucible body 11.
[0101] Step two, design the annular air cavity structure 12 according to design requirements, such as shape, size, etc., and then fix the annular air cavity structure 12 on the target position of the inner side wall of the crucible body 11.
[0102] Step three, fix the seed crystal 14 on the crucible cover 13, and assemble the crucible cover 13 with the crucible body 11 to form a closed growth chamber, and place it in a PVT single crystal growth furnace.
[0103] Step four, vacuumize the growth single crystal furnace, and then fill in inert gas argon / helium as a protective atmosphere; fill in nitrogen as a growth atmosphere.
[0104] Step five, heat to make the temperature in the growth chamber reach the growth temperature, so that the silicon carbide raw material 15 sublimates and transmits to the seed crystal 14, and the growth of the silicon carbide crystal 16 on the seed crystal 14 begins.
[0105] During the growth of the silicon carbide crystal 16, the annular air cavity structure 12 in the crucible body 11 plays a role of heat buffering and physical adjustment, optimizing the growth process.
[0106] The technical scheme of the present application is further described below in a comparative manner.
[0107] Embodiment scheme:
[0108] The silicon carbide crystal growth device shown in the embodiment is used to grow the silicon carbide crystal. Figure 1 The silicon carbide crystal growth device shown in the embodiment is used to grow the silicon carbide crystal.
[0109] Comparative scheme:
[0110] The only difference between the silicon carbide crystal growth device used in the comparative scheme and the silicon carbide crystal growth device used in the embodiment scheme is that the comparative scheme does not include the annular air cavity structure 12.
[0111] The process conditions of the embodiment scheme and the comparative scheme are completely the same.
[0112] Based on the embodiment scheme, in the process of growing the silicon carbide crystal based on the PVT method, the heat of the sidewall of the crucible main body 11 is buffered by the annular air cavity structure 12, so that the lateral heating of the silicon carbide crystal 16 is reduced, and the radial temperature gradient becomes gentle. A part of the gaseous substances sublimed from the silicon carbide raw material 15 is directly transported upward along the axial direction, and the other part enters the annular air cavity structure 12, and then diffuses to the growth interface after buffering and homogenization. This structure effectively stabilizes the growth process of the silicon carbide crystal 16, and finally the silicon carbide crystal 16 obtained by the test shows that the surface of the silicon carbide crystal 16 is more flat, the dislocation density is significantly reduced, and the crystal quality is greatly improved.
[0113] Reference Figure 3 , Figure 3 The surface test diagram of the silicon carbide crystal grown by the comparative scheme provided by the embodiment of the present application is shown in FIG. 2. Figure 4 , Figure 4 The surface test diagram of the silicon carbide crystal grown by the embodiment scheme provided by the embodiment of the present application is shown in FIG. 1. Figure 3 and Figure 4 As shown in FIG. 1 and FIG. 2, the isotherm of the growth interface of the crucible main body in the silicon carbide crystal growth device used in the embodiment scheme is obviously flatter than the isotherm of the growth interface of the crucible main body in the silicon carbide crystal growth device used in the comparative scheme, and the surface of the grown silicon carbide crystal is more flat.
[0114] After the grown silicon carbide crystal is cut, polished and etched by molten KOH, the dislocation etch pit density (English full name: Etch Pit Density, abbreviated as EPD) is counted.
[0115] Reference Figure 5 , Figure 5 The EPD schematic diagram of the silicon carbide crystal grown by the comparative scheme provided by the embodiment of the present application is shown in FIG. 2.Figure 6 , Figure 6 TSD diagram of the silicon carbide crystal grown by the example scheme provided by the embodiment of the present application, refer to Figure 7 , Figure 7 TED diagram of the silicon carbide crystal grown by the example scheme provided by the embodiment of the present application, refer to Figure 8 , Figure 8 BPD diagram of the silicon carbide crystal grown by the example scheme provided by the embodiment of the present application.
[0116] Based on Figure 9 , Figure 9 EPD diagram of the silicon carbide crystal grown by the example scheme provided by the embodiment of the present application, refer to Figure 10 , Figure 10 TSD diagram of the silicon carbide crystal grown by the example scheme provided by the embodiment of the present application, refer to Figure 11 , Figure 11 TED diagram of the silicon carbide crystal grown by the example scheme provided by the embodiment of the present application, refer to Figure 12 , Figure 12 BPD diagram of the silicon carbide crystal grown by the example scheme provided by the embodiment of the present application.
[0117] Based on Figures 5-12 the results shown, the threading screw dislocation (English full name: Threading Screw Dislocation, abbreviated as TSD) and base plane dislocation (English full name: Base Plane Dislocation, abbreviated as BPD) density of the silicon carbide crystal grown by the example scheme is on average one order of magnitude lower than that of the silicon carbide crystal grown by the comparison scheme, and the threading edge dislocation (English full name: Threading Edge Dislocation, abbreviated as TED) is also improved.
[0118] As can be seen from the above description, the present application provides a growth device for silicon carbide crystal, by additionally arranging a ring-shaped gas cavity structure 12 in the inside of the crucible main body 11, effectively buffering thermal stress and homogenizing gas phase material transport, thereby providing a more stable and more uniform growth environment for the growth of silicon carbide crystal 16, significantly reducing the density of crystal defects such as microtubules and dislocations.
[0119] The above describes in detail the silicon carbide crystal growth device provided by the present application, and the principles and implementation manners of the present application are described by using specific examples. The above description of the examples is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range can be changed, and the above description of the present application should not be understood as a limitation of the present application.
[0120] It should be noted that each embodiment in the present specification mainly explains the difference from other embodiments, and the same or similar parts between the embodiments can be understood by referring to each other.
[0121] It should also be noted that, in the present specification, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements, or the elements inherent in the process, method, article or device, or further includes the elements inherent in the process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.
[0122] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A silicon carbide crystal growth apparatus, characterized in that, The silicon carbide crystal growth apparatus includes: Crucible body; An annular gas cavity structure is located inside the crucible body, and the annular gas cavity structure is fixed on the inner wall of the crucible body; The crucible lid is located at the opening of the crucible body; Seed crystals fixed on the crucible lid; Wherein, in the direction perpendicular to the plane where the crucible lid is located, the orthographic projection of the annular air cavity structure covers the edge region of the seed crystal; the inner diameter of the surface of the annular air cavity structure facing the seed crystal is D1, and the inner diameter of the surface of the annular air cavity structure facing the bottom of the crucible body is D2, where D1 < D2.
2. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The diameter of the seed crystal is D3; Where D1 ≥ 1 / 2 × D3.
3. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, 1.2×D1≤D2≤2×D1.
4. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The height of the annular air cavity structure is H1; Where 10mm≤H1≤40mm.
5. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The annular air cavity structure includes a first part, a second part, and a third part; The first part and the second part are arranged opposite each other in a direction perpendicular to the plane where the crucible lid is located; One side of the first part and one side of the second part are both fixed to the inner wall of the crucible body; The other side of the first part, and the other side of the second part, are both connected to the third part.
6. The silicon carbide crystal growth apparatus according to claim 5, characterized in that, The first part, the second part, and the third part have the same thickness, ranging from 2mm to 5mm.
7. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The distance between the annular air cavity structure and the seed crystal is L1; Where 30mm≤L1≤150mm.
8. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, When silicon carbide raw material is placed at the bottom of the crucible body, the distance between the annular gas cavity structure and the silicon carbide raw material is L2; Where 0 < L2 ≤ 50 mm.
9. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The inner wall of the crucible body has a stepped structure; The annular air cavity structure is mounted and fixed on the stepped structure.
10. The silicon carbide crystal growth apparatus according to claim 1, characterized in that, The annular air cavity structure is fixed to the inner wall of the crucible body by a pin structure.