Graphite crucible and silicon carbide single crystal growth device

Abstract

The present application discloses a graphite crucible and a silicon carbide single crystal growth device, relating to the field of semiconductor technology. The graphite crucible includes a crucible body, the crucible body is provided with a receiving cavity, the receiving cavity is used to receive silicon material, the receiving cavity has a cavity opening and a cavity bottom relative to each other along a first direction, and a first groove is provided on the side of the cavity bottom facing the inside of the receiving cavity, and the first groove is used to collect polycrystalline particles in the molten silicon material. In this way, when the graphite crucible of the present application is used to generate silicon carbide single crystals, the first groove provided at the bottom of the receiving cavity can disturb the molten silicon material flowing through, thereby forming a local vortex flow, and then can collect polycrystalline particles in the molten silicon material, so that more polycrystalline particles are gathered at the bottom of the receiving cavity, reducing the flow of polycrystalline particles to the growth interface of the silicon carbide single crystal, thereby reducing the influence of polycrystalline particles on the generation of silicon carbide single crystals, thereby improving the quality of silicon carbide single crystal generation.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor technology, and specifically relates to a graphite crucible and a silicon carbide single crystal growth device. Background Art

[0002] As a semiconductor material, silicon carbide (SiC) single crystals are a core foundational material for a new generation of high-temperature, high-performance, and high-power devices due to their wide bandgap, high thermal conductivity, high breakdown electric field, and high electron saturation drift velocity. Currently, the main methods for growing SiC single crystals include physical vapor transport, high-temperature chemical vapor deposition, and liquid phase methods.

[0003] In related technologies, the liquid phase method requires the preparation of silicon carbide single crystals through a graphite crucible, but during the preparation process the graphite crucible will combine with the silicon melt to generate polycrystalline particles. These polycrystalline particles will destroy the integrity of the silicon carbide single crystal and affect the quality of the generated silicon carbide single crystal. Summary of the Invention

[0004] The present application aims to provide a graphite crucible and a silicon carbide single crystal growth device, which can solve the problem in the related art that when preparing silicon carbide single crystals by a liquid phase method, the polycrystalline particles generated by the combination of the graphite crucible and the silicon melt will destroy the integrity of the silicon carbide single crystal and affect the quality of the generated silicon carbide single crystal.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application proposes a graphite crucible, comprising: a crucible body, the crucible body being provided with a accommodating cavity, the accommodating cavity being used to accommodate silicon material, the accommodating cavity having a cavity opening and a cavity bottom opposite to each other along a first direction, the cavity bottom being provided with a first groove on one side facing the interior of the accommodating cavity, the first groove being used to collect polycrystalline particles in the molten silicon material.

[0007] Optionally, along the radial direction of the accommodating cavity, the cross-sectional area of ​​the first groove is S1, and the cross-sectional area of ​​the accommodating cavity is S2, satisfying: 0.12≤S1 / S2≤0.18.

[0008] Optionally, the first groove has a groove wall and a groove bottom connected to each other, and an angle α is formed between the groove wall and the groove, satisfying: 60°≤α≤90°.

[0009] Optionally, the width of the first groove is W1, and the diameter of the accommodating cavity is D, which satisfies: 0.05≤W1 / D≤0.1;

[0010] And / or, the height of the accommodating cavity is H4, the depth of the first groove is H5, and the following condition is satisfied: 0.07≤H5 / H4≤0.13.

[0011] Optionally, the cavity bottom at least partially protrudes toward the cavity opening to form a convex portion, and the accommodating cavity is further provided with a side wall between the cavity opening and the cavity bottom, and there is at least partially a gap between the convex portion and the side wall to form the first groove.

[0012] Optionally, a second groove is provided at the bottom of the first groove, and the second groove is recessed and extends in a direction away from the cavity opening.

[0013] Optionally, the second groove is arranged in an annular shape, and a plurality of the second grooves are provided, and the plurality of second grooves are arranged at intervals along the radial direction of the accommodating cavity.

[0014] Optionally, the protrusion has an outer peripheral surface facing the side wall, a third groove is provided in the outer peripheral surface, and the third groove extends inwardly toward the protrusion.

[0015] Optionally, the third groove is arranged in an annular shape, and a plurality of the third grooves are provided, and the plurality of third grooves are arranged at intervals along the first direction.

[0016] Optionally, an arc transition section is provided between the side wall and the cavity bottom.

[0017] Optionally, the radius of the arc transition section is R, satisfying: 12mm≤R≤18mm.

[0018] Optionally, along the radial direction of the accommodating cavity, the cross-sectional area of ​​the accommodating cavity is S2, and the cross-sectional area of ​​the protruding portion is S3, satisfying: 0.82≤S3 / S2≤0.88.

[0019] Optionally, the cavity bottom is at least partially recessed in a direction away from the cavity opening to form the first groove.

[0020] Optionally, the first groove is arranged around the center of the cavity bottom;

[0021] And / or, a plurality of first grooves are provided, and the plurality of first grooves are arranged at intervals along the radial direction of the accommodating cavity.

[0022] Optionally, the height of the accommodating cavity is H4, and the diameter of the accommodating cavity is D, satisfying: 1<H4 / D≤1.3.

[0023] In a second aspect, an embodiment of the present application provides a silicon carbide single crystal growth device, comprising: a graphite crucible as described in any of the above.

[0024] In an embodiment of the present application, a graphite crucible includes a crucible body, the crucible body is provided with a receiving cavity, the receiving cavity is used to receive silicon material, the receiving cavity has a cavity opening and a cavity bottom relative to each other along a first direction, and a first groove is provided on the side of the cavity bottom facing the inside of the receiving cavity, and the first groove is used to collect polycrystalline particles in the molten silicon material. In this way, when the graphite crucible of the present application is used to generate silicon carbide single crystals, the first groove provided at the bottom of the receiving cavity can disturb the molten silicon material flowing through, thereby forming a local vortex flow, and then can collect polycrystalline particles in the molten silicon material, so that more polycrystalline particles are gathered at the bottom of the receiving cavity, reducing the flow of polycrystalline particles to the growth interface of the silicon carbide single crystal, thereby reducing the influence of polycrystalline particles on the generation of silicon carbide single crystals, thereby improving the quality of silicon carbide single crystal generation.

[0025] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 is a schematic diagram of a first graphite crucible according to an embodiment of the present application;

[0028] Figure 2 is a schematic diagram of the flow of molten silicon material in the containing cavity according to an embodiment of the present application;

[0029] Figure 3 is a schematic diagram of a second graphite crucible according to an embodiment of the present application;

[0030] Figure 4 According to the embodiment of this application Figure 3 An enlarged view of the circled section A;

[0031] Figure 5 is a schematic diagram of a third graphite crucible according to an embodiment of the present application;

[0032] Figure 6 Schematic diagram of a silicon carbide single crystal growth device according to an embodiment of the present application.

[0033] Reference numerals:

[0034] 1: Crucible body; 10: Accommodating cavity; 100: Arc transition section; 101: Cavity mouth; 102: Cavity bottom; 103: First groove; 1031: Groove wall; 1032: Groove bottom; 104: Raised portion; 1041: Peripheral surface; 105: Side wall; 106: Second groove; 107: Third groove; 2: Molten silicon material; 3: Silicon carbide seed crystal; 31: Growth interface; 4: Graphite heater; 5: Side graphite heating element; 6: Seed crystal rod; 7: Support member; 8: Insulation felt; 9: Induction heating coil; 11: Furnace shell; X: First direction. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0036] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly refer to one or more of the features. Throughout the description of this application, unless otherwise specified, "plurality" means two or more. Furthermore, "and / or" in the specification and claims refers to at least one of the connected entities, and the character " / " generally indicates an "or" relationship between the connected entities.

[0037] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present application.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0039] Before explaining the graphite crucible and silicon carbide single crystal growth device provided in the embodiments of the present application, the application scenarios of the graphite crucible and silicon carbide single crystal growth device provided in the embodiments of the present application are specifically described:

[0040] At present, the main methods for growing silicon carbide single crystals include physical vapor transport, high-temperature chemical vapor deposition, and liquid phase methods. The technology for growing silicon carbide crystals using the physical vapor transport method is relatively mature and the principle is simple, but the dislocation density of the grown crystals is high and the diameter expansion technology is difficult. When growing silicon carbide crystals using the high-temperature chemical vapor deposition method, the equipment containers must be frequently replaced due to continuous corrosion by high-temperature gaseous reactants. In addition, the high-purity silane used to grow silicon carbide crystals is expensive and flammable, explosive, and toxic, posing certain safety risks. Since the liquid phase method for growing silicon carbide crystals is closer to thermodynamic equilibrium conditions, it can theoretically reduce the defect density, grow large-sized, high-quality silicon carbide crystals at a lower cost, and the production process is safer.

[0041] refer to Figure 6 , Figure 6 A schematic diagram of a silicon carbide single crystal growth apparatus is shown. In the related art liquid phase method, a graphite crucible (crucible body 1) serves not only as a container but also as a heat and carbon source for molten silicon material 2 (i.e., silicon melt). An induction heating coil 9 and a graphite heater 4 heat the crucible body 1, heating the silicon material within the crucible body 1 into molten silicon material 2. During the heating process, carbon in the bottom or sidewalls of the crucible body 1 dissolves into the molten silicon material 2, serving as a carbon source for growing a silicon carbide single crystal at the bottom of a silicon carbide seed crystal 3. This carbon is transported to the bottom of the silicon carbide seed crystal 3 by convection and diffusion. The temperature near the silicon carbide seed crystal 3 is relatively low, and this area becomes supersaturated with carbon, ultimately resulting in the growth of a silicon carbide single crystal. However, in this process, since different parts of the crucible body 1 are heated to different temperatures, in the high-temperature area of ​​the crucible body 1, the crucible body 1 dissolves in the molten silicon material 2 to provide a carbon source; but in the low-temperature area of ​​the crucible body 1, carbon will react with the molten silicon material 2 to generate polycrystalline particles. These polycrystalline particles will be driven to the growth interface 31 with the flow of the molten silicon material 2, causing large defects in the silicon carbide single crystal grown at the growth interface 31, affecting the generation quality of the silicon carbide single crystal.

[0042] To this end, the embodiments of the present application provide a graphite crucible and a silicon carbide single crystal growth device. The graphite crucible and the silicon carbide single crystal growth device provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0043] like Figures 1 to 5 As shown, the graphite crucible according to some embodiments of the present application includes a crucible body 1, the crucible body 1 is provided with a accommodating cavity 10, the accommodating cavity 10 is used to accommodate silicon material, the accommodating cavity 10 has a cavity mouth 101 and a cavity bottom 102 arranged relatively along a first direction X, and the cavity bottom 102 is provided with a first groove 103 on the side facing the accommodating cavity 10, and the first groove 103 is used to collect polycrystalline particles in the molten silicon material 2.

[0044] In an embodiment of the present application, by setting a first groove 103 facing the accommodating cavity 10 at the bottom 102 of the accommodating cavity 10 of the crucible body 1, the molten silicon material 2 flowing through the first groove 103 can be disturbed during the process of generating a silicon carbide single crystal from the molten silicon material 2 and the carbon source provided by the crucible body 1, thereby forming a local vortex flow, and then the carbon dissolved in the crucible body 1 and the polycrystalline particles generated by the molten silicon material 2 can be gathered, so that more polycrystalline particles are gathered at the bottom of the accommodating cavity 10, reducing the flow of polycrystalline particles to the growth interface 31 of the silicon carbide single crystal, thereby reducing the influence of polycrystalline particles on the generation of silicon carbide single crystals, thereby improving the quality of silicon carbide single crystal generation.

[0045] It should be noted that the graphite crucible provided in this application is used to grow silicon carbide single crystals through a top seed solution growth method (liquid phase method), wherein the graphite crucible serves as a carbon source for the silicon carbide single crystals. Upon heating, the carbon atoms in the graphite crucible dissolve in the silicon material, forming a Si-C solution, which then precipitates silicon carbide crystals. Specifically, the silicon material is high-purity silicon, which is contained in the accommodating cavity 10 of the crucible body 1. After being heated, it becomes molten silicon material 2, that is, a silicon melt. The carbon atoms in the crucible body 1 dissolve in the molten silicon material 2, forming a Si-C solution, which then precipitates silicon carbide crystals. At the same time, in the event of insufficient carbon diffusion, a low-temperature contact zone on the wall of the accommodating cavity 10, or the presence of impurities, the carbon source and the molten silicon material 2 form incompletely converted intermediate products, impurity phases, or SiC aggregates of non-target crystalline form, that is, polycrystalline particles.

[0046] In the actual production process, the crucible body 1 includes a cavity opening 101 and a cavity bottom 102 relative to each other, and a side wall 105 therebetween. The carbon ash in the cavity bottom 102 or the side wall 105 is dissolved in the molten silicon material 2 at a high temperature. When the graphite crucible is used to generate silicon carbide single crystals by a liquid phase method, the graphite crucible has two temperature field configurations: in the first temperature field configuration, the side wall temperature of the graphite crucible is high and the bottom temperature is low, as shown in FIG. Figure 5As shown, the temperature at the side wall 105 of the crucible body 1 is higher. The side wall 105 serves as a carbon source. The carbon atoms in the side wall 105 can dissolve in the molten silicon material 2. The temperature at the bottom 102 of the cavity is lower. The carbon atoms easily form polycrystalline particles with the molten silicon material 2 at the bottom 102 of the cavity. In the second temperature field configuration, the bottom temperature of the graphite crucible is high and the side wall temperature is low. Figure 1 and Figure 3 As shown, the temperature at the bottom 102 of the crucible body 1 is higher. The bottom 102 of the cavity serves as a carbon source, and the carbon atoms in the bottom 102 can be dissolved in the molten silicon material 2. The temperature at the side wall 105 is lower, and the carbon atoms can easily generate polycrystalline particles with the molten silicon material 2 at the side wall 105. Under both temperature field configurations, polycrystalline particles may be generated to affect the formation of silicon carbide single crystals. Therefore, the present application sets a first groove 103 facing the accommodating cavity 10 at the bottom 102 of the cavity to collect the polycrystalline particles and reduce the influence of the polycrystalline particles on the formation of silicon carbide single crystals.

[0047] It needs to be explained that, Figure 2 As shown, the silicon carbide seed crystal 3 is arranged at the cavity opening 101 of the accommodating cavity 10, and a silicon carbide single crystal can be generated on the side of the silicon carbide seed crystal 3 facing the accommodating cavity 10, that is, the bottom of the silicon carbide seed crystal 3, that is, the bottom of the silicon carbide seed crystal 3 is specifically the growth interface 31 of the silicon carbide single crystal. In actual use, the molten silicon material 2 is as follows Figure 2 The flow direction is shown by the arrow in the middle, forming a symmetrical flow field, thereby ensuring that the growth interface is uniform, ensuring uniform solute transportation, and improving the growth rate and crystallization quality of silicon carbide single crystals; Figure 2 During the flow shown, the polycrystalline particles generated in the low temperature region of the crucible body 1 will flow to the growth interface 31 along with the molten silicon material 2, resulting in the following defects:

[0048] 1. Polycrystalline particles will destroy the continuity of silicon carbide single crystals, resulting in defects such as lattice dislocation;

[0049] Second, the polycrystalline particles will interfere with the stability of the growth interface 31, resulting in inconsistent growth rates of the silicon carbide single crystal at the growth interface 31 and affecting the lattice uniformity of the silicon carbide single crystal;

[0050] Third, the thermal expansion coefficients of the polycrystalline particles and the silicon carbide single crystal are different, which will generate stress at the growth interface 31, resulting in defects such as cracks or fractures in the silicon carbide single crystal;

[0051] 4. Polycrystalline particles may carry impurities, which can easily contaminate silicon carbide single crystals and affect the electrical and chemical properties of silicon carbide single crystals.

[0052] Since polycrystalline particles may bring the above-mentioned defects to the silicon carbide single crystal, the present application sets a first groove 103 at the bottom of the cavity 102 to gather the polycrystalline particles flowing with the molten silicon material 2, so as to reduce the influence of the polycrystalline particles on the growth of the silicon carbide single crystal at the growth interface 31, thereby improving the growth rate and crystallization quality of the silicon carbide single crystal.

[0053] In a specific application, the first groove 103 can be a protrusion of the cavity bottom 102 toward the cavity opening 101, and the gap between the protrusion and the side wall 105 forms the first groove 103, such as Figure 1 and Figure 3 As shown; the first groove 103 can also be formed by the cavity bottom 102 being recessed away from the cavity opening 101, as shown Figure 5 As shown; of course, the first groove 103 can also be formed by other structures, as long as it can collect polycrystalline particles. Those skilled in the art can set it according to actual needs, and this application does not limit it.

[0054] Understandably, if Figure 2 As shown, when the molten silicon material 2 drives the polycrystalline particles to flow to the first groove 103 at the bottom of the cavity 102, the polycrystalline particles will be blocked by the groove wall of the first groove 103 and then settle in the first groove 103, and will not continue to flow with the molten silicon material 2 to the growth interface 31, thereby reducing the influence of the polycrystalline particles on the growth of the silicon carbide single crystal at the growth interface 31.

[0055] It should be noted that the accommodating cavity 10 of the crucible body 1 is specifically a cylindrical cavity having relative radial and axial directions; the first direction X is specifically the axial direction of the accommodating cavity 10. In actual use, the first direction X is the height direction of the crucible body 1. The first groove 103 can be a "complete annular" groove surrounding the cavity bottom 102 of the accommodating cavity 10, or a "discontinuous annular" groove partially surrounding the cavity bottom 102 of the accommodating cavity 10. Of course, grooves of other shapes are also possible, as long as they can collect polycrystalline particles. Those skilled in the art can configure the grooves according to actual needs, and this application does not impose any restrictions on this.

[0056] Optionally, the first groove 103 is arranged around the cavity bottom 102, that is, the first groove 103 forms a "complete annular" groove, so that polycrystalline particles can be collected from multiple directions, thereby improving the collection ability and further reducing the impact of polycrystalline particles on the growth of silicon carbide single crystals.

[0057] like Figure 1 As shown, in some embodiments of the present application, along the radial direction of the accommodating cavity 10 , the cross-sectional area of ​​the first groove 103 is S1 , and the cross-sectional area of ​​the accommodating cavity 10 is S2 , satisfying: 0.12≤S1 / S2≤0.18.

[0058] In the embodiment of the present application, by setting the ratio S1 / S2 between the radial cross-sectional area S1 of the first groove 103 and the radial cross-sectional area S2 of the accommodating chamber 10 within a reasonable range, while ensuring that the cavity bottom 102 can normally provide a carbon source, the collection effect of polycrystalline particles can also be guaranteed.

[0059] It needs to be explained that when the molten silicon material 2 flows in the accommodating cavity 10, the flow state is laminar. When the molten silicon material 2 drives the polycrystalline particles to flow to the first groove 103, the groove wall at the first groove 103 can destroy the flow state of the molten silicon material 2, so that the molten silicon material 2 is in a local vortex flow or other flow form to disrupt the flow state of the molten silicon material 2. In this way, the flow velocity of the molten silicon material 2 in the first groove 103 will be reduced, which is convenient for the polycrystalline particles to settle in the first groove 103.

[0060] It should be noted that, along the radial direction of the accommodating cavity 10, that is, perpendicular to the first direction X. When the ratio S1 / S2 between the cross-sectional area S1 of the first groove 103 along the radial direction of the accommodating cavity 10 and the cross-sectional area S2 of the accommodating cavity 10 along the radial direction of the accommodating cavity 10 is less than 0.12, that is, the cross-sectional area S1 of the first groove 103 is too small, the capacity of the first groove 103 will be small, and in a long production process, the polycrystalline particles will easily fill the first groove 103, thereby making it impossible to continue to precipitate the polycrystalline particles. At the same time, the cross-sectional area S1 of the first groove 103 is too small, which has a poor effect on the flow disturbance of the molten silicon material 2, and there is no The method is to reduce the flow velocity of the molten silicon material 2 in the first groove 103, so that the polycrystalline particles cannot be well precipitated; and when the ratio S1 / S2 of the radial cross-sectional area S1 of the first groove 103 to the radial cross-sectional area S2 of the accommodating cavity 10 is greater than 0.18, that is, the cross-sectional area S1 of the first groove 103 is too large, the cavity bottom 102 cannot provide carbon well when serving as a carbon source. In addition, the flow velocity of the molten silicon material 2 cannot be effectively reduced, so that the polycrystalline particles cannot be precipitated in time.

[0061] In specific applications, the ratio S1 / S2 between the radial cross-sectional area S1 of the first groove 103 and the radial cross-sectional area S2 of the accommodating cavity 10 can be set to any value such as 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, or a range between any two values.

[0062] It can be understood that when performing specific design or measurement, the cross-section of the first groove 103 can be a complete circular ring or a combination of multiple partial circular rings, and the cross-sectional area S1 can be calculated according to the area calculation formula of the circular ring, which will not be repeated here; the cross-section of the accommodating cavity 10 along the first direction X is specifically circular, and its cross-sectional area S1 is calculated according to the circular calculation formula, which will not be repeated here.

[0063] In some embodiments of the present application, two experimental methods are proposed to judge the growth quality of silicon carbide single crystals:

[0064] 1. Observation method of surface roughness (RN) of silicon carbide single crystal:

[0065] The surface of the silicon carbide single crystal grown by the liquid phase method was observed. Concave and convex particles were present on the surface of the silicon carbide single crystal. The diameter of the concave and convex particles was measured, and the quality of the silicon carbide single crystal was divided into four grades according to the diameter of the concave and convex particles. The different grades indicate the quality of the surface roughness of the silicon carbide single crystal, thereby indicating the growth quality of the silicon carbide single crystal. It should be noted that the lower the grade, the smaller the diameter of the concave and convex particles on the surface of the silicon carbide single crystal, that is, the better the growth quality of the silicon carbide single crystal:

[0066] Level 1: The diameter of the uneven particles on the surface of the silicon carbide single crystal is between 1mm and 2mm; Level 2: The diameter of the uneven particles on the surface of the silicon carbide single crystal is less than 2mm; Level 3: The diameter of the uneven particles on the surface of the silicon carbide single crystal is between 2mm and 5mm; Level 4: The diameter of the uneven particles on the surface of the silicon carbide single crystal is greater than 5mm. That is, the surface roughness (RN) of silicon carbide single crystal has the above four levels.

[0067] 2. Carbon Effective Utilization Rate Measurement Method:

[0068] The mass of the silicon carbide single crystal produced by the liquid phase method is measured. At the same time, the polycrystalline particles precipitated in the crucible body 1 are collected and the total mass of the precipitated polycrystalline particles is measured according to the following formula:

[0069] X=M1 / (M1+M2), where: X refers to the effective carbon utilization rate; M1 refers to the mass of the silicon carbide single crystal, in g; M2 refers to the total mass of the collected polycrystalline particles, in g; the above formula can be used to calculate the ratio of the mass of the carbon source dissolved in the crucible body 1 used to generate the silicon carbide single crystal to the total mass of the dissolved carbon source, that is, the effective utilization rate of the carbon source.

[0070] The following describes the effect of the specific selection of the ratio S1 / S2 between the radial cross-sectional area S1 of the first groove 103 and the radial cross-sectional area S2 of the accommodating cavity 10 on the growth quality of silicon carbide using specific examples and comparative examples.

[0071] The experiment specifically adopts a liquid phase method (top seed solution growth method), and heats the crucible body 1 through a graphite heater and / or an induction heating coil, so that the crucible body 1 is in a second temperature field configuration, that is, the bottom temperature of the graphite crucible is high and the side wall temperature is low; at this time, the cavity bottom 102 serves as a carbon source, and the carbon atoms in the cavity bottom 102 can dissolve in the molten silicon material 2 in the containing cavity 10, and the temperature at the side wall 105 is relatively low, so the carbon atoms can easily form polycrystalline particles with the molten silicon material 2 at the side wall 105; the molten silicon material 2 is as follows Figure 2 Flow in the direction indicated by the arrow. Using multiple crucible bodies 1 with identical conditions except for the S1 / S2 settings, silicon carbide single crystals were prepared under identical external conditions (specifically, heating temperature, silicon material content, etc.), with each preparation time being 100 hours. The test results shown in Table 1 below were obtained:

[0072] Table 1:

[0073]

[0074] From Table 1 we can see that:

[0075] Compared with comparative example 1, embodiment 1 can reduce the roughness of silicon carbide single crystal by setting the first groove 103, that is, improve the growth quality of silicon carbide single crystal; and can improve the effective utilization rate of carbon, so that the carbon source provided by the crucible body 1 is more used for the growth of silicon carbide single crystal.

[0076] When the ratio S1 / S2 between the radial cross-sectional area S1 of the first groove 103 along the accommodating cavity 10 and the radial cross-sectional area S2 of the accommodating cavity 10 is set within a reasonable range, as shown in Example 1, when 0.12≤S1 / S2≤0.18, the surface roughness of the silicon carbide single crystal can be reduced, the growth quality of the silicon carbide single crystal can be improved, and the effective utilization rate of carbon can be improved, that is, more carbon can be used to grow the silicon carbide single crystal; and when S1 / S2<0.12, as shown in Comparative Example 2, compared with Example 1, the carbon source cannot be effectively utilized, and the surface roughness of the silicon carbide single crystal cannot reach the optimal level. In a longer test process, the polycrystalline particles will fill the first groove 103, making it impossible to continue to collect and precipitate the polycrystalline particles; and when S1 / S2>0.18, as shown in Comparative Example 3, compared with Example 1, the effective utilization rate of carbon is lower, and more polycrystalline particles are generated, which in turn affects the growth quality of the silicon carbide single crystal.

[0077] It can be inferred from the above results that, under the condition that other conditions are the same, setting the ratio S1 / S2 between the radial cross-sectional area S1 of the first groove 103 along the accommodating cavity 10 and the radial cross-sectional area S2 of the accommodating cavity 10 within the selected value range of the present application can improve the generation quality of silicon carbide single crystals and effectively utilize the carbon source.

[0078] It should be noted that the above test can also be performed by placing the crucible body 1 under the first temperature field configuration. The first temperature field configuration has been described in detail above and will not be repeated here.

[0079] like Figure 1 As shown, in some embodiments of the present application, the first groove 103 has a groove wall 1031 and a groove bottom 1032 connected to each other, and an angle α is formed between the groove wall 1031 and the groove bottom 1032, which satisfies: 60°≤α≤90°.

[0080] In the embodiment of the present application, by setting the angle α between the groove wall 1031 and the groove bottom 1032 of the first groove 103 within a reasonable range, it is possible to ensure that the polycrystalline particles are effectively collected while facilitating processing.

[0081] It should be explained that when the angle α between the groove wall 1031 and the groove bottom 1032 is less than 60°, the processing difficulty of the first groove 103 will increase and the cost will increase; when the angle α between the groove wall 1031 and the groove bottom 1032 is greater than 90°, the groove wall 1031 cannot effectively block the molten silicon material 2 flowing therein, and cannot effectively reduce the flow rate of the molten silicon material 2, so that the polycrystalline particles cannot stay and precipitate in the first groove 103.

[0082] In specific applications, the angle α between the groove wall 1031 and the groove bottom 1032 of the first groove 103 can be set to any value such as 60°, 65°, 70°, 75°, 80°, 85°, 90°, or a range between any two values.

[0083] It can be understood that when the angle α between the groove wall 1031 and the groove bottom 1032 of the first groove 103 is in the range of 60°~90°, that is, the cross-section of the first groove 103 along the first direction X is in a "small at the top and large at the bottom" shape, when the molten silicon material 2 flows into the first groove 103, its flow rate can be reduced, and a good barrier is formed for the polycrystalline particles in the molten silicon material 2, thereby improving the precipitation effect of the polycrystalline particles.

[0084] The following describes the effect of the specific selection of the angle α between the groove wall 1031 and the groove bottom 1032 of the first groove 103 on the growth quality of silicon carbide using specific examples and comparative examples:

[0085] The experiment specifically adopts a liquid phase method (top seed solution growth method), and heats the crucible body 1 through a graphite heater and / or an induction heating coil, so that the crucible body 1 is in a second temperature field configuration, that is, the bottom temperature of the graphite crucible is high and the side wall temperature is low; at this time, the cavity bottom 102 serves as a carbon source, and the carbon atoms in the cavity bottom 102 can dissolve in the molten silicon material 2 in the containing cavity 10, and the temperature at the side wall 105 is relatively low, so the carbon atoms can easily form polycrystalline particles with the molten silicon material 2 at the side wall 105; the molten silicon material 2 is as follows Figure 2 Flow in the direction indicated by the arrow. Using multiple crucible bodies 1 with identical conditions except for the angle α, silicon carbide single crystals were prepared under identical external conditions (specifically, heating temperature, silicon material content, etc.), with each preparation time being 100 hours. The test results shown in Table 2 below were obtained:

[0086] Table 2:

[0087]

[0088] From Table 2 we can see that:

[0089] When the angle α between the groove wall 1031 and the groove bottom 1032 of the first groove 103 is set within a reasonable range, as shown in Example 2, the surface roughness of the silicon carbide single crystal can be reduced, the generation quality of the silicon carbide single crystal can be improved, the carbon source can be effectively utilized, and the processing is easy; when the angle α is less than 60°, as shown in Comparative Example 4, compared with Example 2, the effective utilization rate of carbon is reduced, and the processing difficulty is higher, which is not conducive to cost control; when the angle α is greater than 90°, as shown in Comparative Example 5, the carbon source cannot be effectively utilized, and the surface roughness of the silicon carbide single crystal cannot reach the optimal level.

[0090] It can be inferred from the above results that, under the same other conditions, setting the angle α between the groove wall 1031 and the groove bottom 1032 of the first groove 103 within the selected value range of this application can improve the production quality of silicon carbide single crystals and effectively utilize carbon sources.

[0091] It should be noted that the above test can also be performed by placing the crucible body 1 under the first temperature field configuration. The first temperature field configuration has been described in detail above and will not be repeated here.

[0092] like Figure 1 As shown, in some embodiments of the present application, the width of the first groove 103 is W1, and the diameter of the accommodating cavity 10 is D, which satisfies: 0.05≤W1 / D≤0.07.

[0093] In the embodiment of the present application, by setting the ratio W1 / D between the groove width W1 of the first groove 103 and the diameter D of the accommodating cavity 10 within a reasonable range, it is possible to ensure that the cavity bottom 102 can normally provide a carbon source while also ensuring the collection effect of polycrystalline particles.

[0094] It should be explained that when the ratio W1 / D between the groove width W1 of the first groove 103 and the diameter D of the accommodating cavity 10 is less than 0.05, that is, the groove width W1 of the first groove 103 is too small, the capacity of the first groove 103 will be small. During a long production process, the polycrystalline particles will easily fill the first groove 103, and the polycrystalline particles cannot continue to be precipitated. At the same time, the groove width W1 of the first groove 103 is too small, and the flow velocity disturbance effect of the molten silicon material 2 is not good, and the flow velocity of the molten silicon material 2 in the first groove 103 cannot be reduced, so that the polycrystalline particles cannot be well precipitated; and when the ratio W1 / D between the groove width W1 of the first groove 103 and the diameter D of the accommodating cavity 10 is greater than 0.1, that is, the groove width W1 of the first groove 103 is too large, the cavity bottom 102 cannot provide carbon well when used as a carbon source. In addition, the flow velocity of the molten silicon material 2 cannot be effectively reduced, so that the polycrystalline particles cannot be precipitated in time.

[0095] In a specific application, the ratio W1 / D between the width W1 of the first groove 103 and the diameter D of the accommodating cavity 10 can be set to any value such as 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, or a range between any two values.

[0096] It should be explained that when the first groove 103 is formed by the gap between the protrusion 104 and the side wall 105, the groove width W1 of the first groove 103 can be calculated by measuring the width of the gap, or by subtracting the radial dimension of the protrusion 104 along the accommodating cavity 10 from the diameter D of the accommodating cavity 10; and when the first groove 103 is formed by the cavity bottom 102 being recessed in the direction away from the cavity mouth 101, the spacing between the two groove walls of the first groove 103 can be measured.

[0097] The following describes the effect of the specific selection of the ratio W1 / D between the width W1 of the first groove 103 and the diameter D of the accommodating cavity 10 on the growth quality of silicon carbide using specific examples and comparative examples.

[0098] The experiment specifically adopts a liquid phase method (top seed solution growth method), and heats the crucible body 1 through a graphite heater and / or an induction heating coil, so that the crucible body 1 is in a second temperature field configuration, that is, the bottom temperature of the graphite crucible is high and the side wall temperature is low; at this time, the cavity bottom 102 serves as a carbon source, and the carbon atoms in the cavity bottom 102 can dissolve in the molten silicon material 2 in the containing cavity 10, and the temperature at the side wall 105 is relatively low, so the carbon atoms can easily form polycrystalline particles with the molten silicon material 2 at the side wall 105; the molten silicon material 2 is as follows Figure 2 Flow in the direction indicated by the arrow. Using multiple crucible bodies 1 with identical conditions except for the W1 / D setting, silicon carbide single crystals were prepared under identical external conditions (specifically, heating temperature, silicon material content, etc.), with each preparation time being 100 hours. The test results shown in Table 3 below were obtained:

[0099] Table 3:

[0100]

[0101] From Table 3 we can see that:

[0102] When the ratio W1 / D between the groove width W1 of the first groove 103 and the diameter D of the accommodating cavity 10 is set within a reasonable range, as shown in Example 3, the surface roughness of the silicon carbide single crystal can be reduced, the generation quality of the silicon carbide single crystal can be improved, and the carbon source can be effectively utilized; when W1 / D is less than 0.05, as shown in Comparative Example 6, the carbon source cannot be effectively utilized, and the surface roughness of the silicon carbide single crystal cannot reach the optimal level. In addition, during a longer test process, the polycrystalline particles will fill the first groove 103, making it impossible to continue to collect and precipitate the polycrystalline particles. After filling the first groove 103, the polycrystalline particles will also affect the dissolution of carbon atoms in the cavity bottom 102 into the molten silicon material 2, affecting the provision of the carbon source; when W1 / D is greater than 0.1, as shown in Comparative Example 7, compared with Example 3, the carbon source utilization rate and the surface roughness of the silicon carbide single crystal cannot reach the optimal level.

[0103] It can be inferred from the above results that, under the same other conditions, setting the ratio W1 / D between the groove width W1 of the first groove 103 and the diameter D of the accommodating cavity 10 within the selected value range of the present application can improve the production quality of silicon carbide single crystals and effectively utilize carbon sources.

[0104] It should be noted that the above test can also be performed by placing the crucible body 1 under the first temperature field configuration. The first temperature field configuration has been described in detail above and will not be repeated here.

[0105] like Figure 1 and Figure 5As shown, in some embodiments of the present application, the height of the accommodating cavity 10 is H4, and the depth of the first groove 103 is H5, satisfying: 0.07≤H5 / H4≤0.13.

[0106] In the embodiment of the present application, by setting the ratio H5 / H4 between the groove depth H5 of the first groove 103 and the height H4 of the accommodating cavity 10 within a reasonable range, it is possible to form a sufficiently large disturbance to the molten silicon material 2 and form a local vortex flow to facilitate the collection and precipitation of polycrystalline particles, while also reducing the possibility of polycrystalline particles filling the first groove 103 and affecting the collection of polycrystalline particles.

[0107] It should be explained that when the ratio H5 / H4 between the depth H5 of the first groove 103 and the height H4 of the accommodating cavity 10 is less than 0.07, that is, the depth H5 of the first groove 103 is too small, the capacity of the first groove 103 will be small. During a long production process, the polycrystalline particles will easily fill the first groove 103, making it impossible to continue to precipitate the polycrystalline particles. At the same time, the depth H5 of the first groove 103 is too small, which has a poor effect on the flow velocity disturbance of the molten silicon material 2 and cannot reduce the flow velocity of the molten silicon material 2 in the first groove 103, so that the polycrystalline particles cannot be well precipitated. When the ratio H5 / H4 between the depth H5 of the first groove 103 and the height H4 of the accommodating cavity 10 is greater than 0.13, that is, the depth H5 of the first groove 103 is too large, as shown in FIG. Figure 1 、 Figure 2 、 Figure 3 and Figure 4 When the first groove 103 is shown, the surface of the protrusion 104 facing the cavity opening 101 is too far away from the cavity bottom 102, which will reduce the efficiency of heat transfer from the cavity bottom 102 to the cavity opening 101. In this way, the efficiency of the protrusion 104 in dissolving carbon atoms in the molten silicon material 2 when heated will be reduced, thereby reducing the carbon saturation in the molten silicon material 2, which is not conducive to the growth of silicon carbide single crystals; and Figure 5 In the case of the first groove 103 shown, the groove depth H5 of the first groove 103 is too large, which will cause the groove bottom of the first groove 103 to be too close to the edge of the cavity bottom 102, and there is a risk of burning through the cavity bottom 102 of the crucible body 1, which reduces the reliability of the crucible body 1.

[0108] In a specific application, the ratio H5 / H4 between the groove depth H5 of the first groove 103 and the height H4 of the accommodating cavity 10 can be set to any value such as 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, or a range between any two values.

[0109] It is understandable that during specific design or measurement, the groove depth H5 of the first groove 103 may be as follows: Figure 1 The height H1 of the middle raised portion 104, or Figure 5 The depth of the depression of the cavity bottom 102 is measured by a caliper, etc., and will not be repeated here; the height H4 of the accommodating cavity 10 specifically refers to the height of the cavity mouth 101 to the cavity bottom 102, that is, the depth of the actual volume of the accommodating cavity 10, which can be measured by a caliper, etc., and will not be repeated here.

[0110] The following describes the effect of the specific selection of the ratio H5 / H4 between the depth H5 of the first groove 103 and the height H4 of the accommodating cavity 10 on the growth quality of silicon carbide using specific examples and comparative examples:

[0111] The experiment specifically adopts a liquid phase method (top seed solution growth method), and heats the crucible body 1 through a graphite heater and / or an induction heating coil, so that the crucible body 1 is in a second temperature field configuration, that is, the bottom temperature of the graphite crucible is high and the side wall temperature is low; at this time, the cavity bottom 102 serves as a carbon source, and the carbon atoms in the cavity bottom 102 can dissolve in the molten silicon material 2 in the containing cavity 10, and the temperature at the side wall 105 is relatively low, so the carbon atoms can easily form polycrystalline particles with the molten silicon material 2 at the side wall 105; the molten silicon material 2 is as follows Figure 2 Flow in the direction indicated by the arrow. Using multiple crucible bodies 1 with identical conditions except for the H5 / H4 settings, silicon carbide single crystals were prepared under identical external conditions (specifically, heating temperature, silicon material content, etc.), with each preparation time being 100 hours. The test results shown in Table 4 below were obtained:

[0112] Table 4:

[0113]

[0114] From Table 4 we can see that:

[0115] When the ratio H5 / H4 between the groove depth H5 of the first groove 103 and the height H4 of the accommodating cavity 10 is set within a reasonable range, as shown in Example 4, the surface roughness of the silicon carbide single crystal can be reduced, the generation quality of the silicon carbide single crystal can be improved, and the carbon source can be effectively utilized, so that more carbon atoms are used for the growth of the silicon carbide single crystal; when H5 / H4 is less than 0.07, as shown in Comparative Example 8, compared with Example 4, the carbon source cannot be effectively utilized, and the surface roughness of the silicon carbide single crystal cannot reach the optimal level. In addition, during a longer test process, the polycrystalline particles will fill the first groove 103, making it impossible to continue to collect and precipitate the polycrystalline particles. After filling the first groove 103, the polycrystalline particles will also affect the dissolution of carbon atoms in the cavity bottom 102 into the molten silicon material 2, affecting the provision of the carbon source; when H5 / H4 is greater than 0.13, as shown in Comparative Example 9, compared with Example 4, the carbon source utilization rate and the surface roughness of the silicon carbide single crystal cannot reach the optimal level.

[0116] It can be inferred from the above results that, under the condition that other conditions are the same, when the ratio H5 / H4 between the groove depth H5 of the first groove 103 and the height H4 of the accommodating cavity 10 is set within the range proposed in this application, the surface roughness of the silicon carbide single crystal can be reduced, the generation quality of the silicon carbide single crystal can be improved, and the carbon source can be effectively utilized so that more carbon atoms are used for the growth of the silicon carbide single crystal.

[0117] It should be noted that the above test can also be performed by placing the crucible body 1 under the first temperature field configuration. The first temperature field configuration has been described in detail above and will not be repeated here.

[0118] like Figure 1 、 Figure 2 and Figure 3 As shown, in some embodiments of the present application, the cavity bottom 102 at least partially protrudes toward the cavity opening 101 to form a protrusion 104, and the accommodating cavity 10 is also provided with a side wall 105 between the cavity opening 101 and the cavity bottom 102, and there is at least partially a gap between the protrusion 104 and the side wall 105 to form a first groove 103.

[0119] In an embodiment of the present application, the cavity bottom 102 at least partially protrudes toward the cavity mouth 101 to form a protrusion 104, and there is at least partially a gap between the protrusion 104 and the side wall 105 to form a first groove 103, so that the carbon atoms in the protrusion 104 can be dissolved in the molten silicon material 2 as a carbon source, and the first groove 103 formed by the gap can collect the polycrystalline particles driven by the flow of the molten silicon material 2, thereby reducing the influence of the polycrystalline particles on the growth of the silicon carbide single crystal and improving the growth quality of the silicon carbide single crystal.

[0120] It should be explained that when the cavity bottom 102 at least partially protrudes toward the cavity mouth 101 to form the protrusion 104, the crucible body 1 is in the second temperature field configuration, that is, the temperature of the side wall 105 of the crucible body 1 is low, and the temperature of the cavity bottom 102 is high; in this way, the carbon atoms in the protrusion 104 can be dissolved in the molten silicon material 2 at high temperature, and serve as a carbon source for the growth of silicon carbide single crystals. The protrusion 104 is closer to the growth interface 31, which can improve the carbon saturation of the growth interface 31; at the same time, there can naturally be a gap between the protrusion 104 and the side wall 105, and the gap forms a first groove 103, which can collect polycrystalline particles.

[0121] It can be understood that the raised portion 104 can form a circular cross-section, a rectangular cross-section, a polygonal cross-section or an irregular cross-section along the radial direction of the accommodating cavity 10, so that the raised portion 104 has a variety of shapes. Those skilled in the art can set it according to needs, and the applicant does not impose any restrictions on this.

[0122] Preferably, the cross section of the protrusion 104 along the radial direction of the accommodating cavity 10 is a circular cross section, which is convenient for processing and can form a relatively regular first groove 103 to facilitate the collection of polycrystalline particles from multiple directions.

[0123] It should be explained that there is at least a partial gap between the raised portion 104 and the side wall 105. The gap may be present all around the raised portion 104, or there may be a gap partially around the raised portion 104, thereby forming a "complete circular ring" first groove 103 or an "interrupted circular ring" first groove 103. Those skilled in the art can make settings according to actual needs, and this application does not impose any restrictions on this.

[0124] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, a second groove 106 is provided at the bottom 1032 of the first groove 103 , and the second groove 106 is recessed and extends in a direction away from the cavity opening 101 .

[0125] In the embodiment of the present application, by providing the second groove 106 at the groove bottom 1032 of the first groove 103 , the flow rate of the molten silicon material 2 can be further disturbed, while the accommodation space of the first groove 103 is increased, and more polycrystalline particles can be collected.

[0126] In a specific application, the second groove 106 can be a regular rectangular groove or an irregular shaped groove. Those skilled in the art can set it according to actual needs, and this application does not limit it. Preferably, the second groove 106 is set as a rectangular groove for easy processing.

[0127] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the second groove 106 is arranged in an annular shape, and there are multiple second grooves 106 , and the multiple second grooves 106 are arranged at intervals along the radial direction of the accommodating cavity 10 .

[0128] In the embodiment of the present application, a plurality of second grooves 106 are arranged at intervals along the radial direction of the accommodating cavity 10 , thereby further enhancing the effect of disrupting the flow rate of the molten silicon material 2 and, at the same time, further increasing the accommodating space for accommodating polycrystalline particles.

[0129] It should be explained that the multiple second grooves 106 can form multiple local vortex flows of the molten silicon material 2 flowing through. Each time a local vortex flow is formed, the flow rate of the molten silicon material 2 will change. At the same time, the groove wall of each second groove 106 can form a barrier to the polycrystalline particles.

[0130] In a specific application, the number of the second grooves 106 can be set to any value such as 1, 2, 3, or 4. The number of the second grooves 106 is determined by the groove width of the second groove 106 and the groove width of the first groove 103 .

[0131] Preferably, the number of the second grooves 106 is set to three.

[0132] It can be understood that the second groove 106 is arranged in an annular shape, specifically a "complete circular ring" or an "interrupted circular ring" or other annular settings. Those skilled in the art can set it according to actual needs, and this application does not limit this.

[0133] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the groove depth of the second groove 106 is H2, which satisfies: 1mm≤H2≤3mm.

[0134] In the embodiment of the present application, by setting the groove depth H2 of the second groove 106 within a reasonable range, the flow rate of the molten silicon material 2 is disturbed to form a local vortex flow, while the volume capable of accommodating polycrystalline particles is increased.

[0135] It should be explained that when the groove depth H2 of the second groove 106 is less than 1 mm, that is, the groove depth H2 of the second groove 106 is too shallow, so that the volume of the second groove 106 that can accommodate polycrystalline particles is too small. During a long production process, the polycrystalline particles will fill the second groove 106, making it impossible to continue to collect polycrystalline particles; when the groove depth H2 of the second groove 106 is greater than 3 mm, that is, the groove depth H2 of the second groove 106 is too deep, after the molten silicon material 2 flows into the second groove 106, the molten silicon material 2 at the bottom of the second groove 106 may not be able to flow out, thereby causing poor disturbance to the flow rate of the molten silicon material 2.

[0136] In a specific application, the groove depth H2 of the second groove 106 can be set to any value such as 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a range between two arbitrary values.

[0137] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the width of the second groove 106 is W2, which satisfies: 1 mm ≤ W2 ≤ 3 mm.

[0138] In the embodiment of the present application, by setting the groove width W2 of the second groove 106 within a reasonable range, it is possible to ensure that the flow rate of the molten silicon material 2 is disturbed and a local vortex flow is formed to facilitate the precipitation of polycrystalline particles while increasing the volume that can accommodate polycrystalline particles.

[0139] It needs to be explained that when the groove width W2 of the second groove 106 is less than 1 mm, that is, the groove width W2 of the second groove 106 is too small, so that the volume of the second groove 106 that can accommodate polycrystalline particles is too small. During a long production process, the polycrystalline particles will fill the second groove 106, making it impossible to continue to collect polycrystalline particles; when the groove width W2 of the second groove 106 is greater than 3 mm, that is, the groove width W2 of the second groove 106 is too large, after the molten silicon material 2 flows into the second groove 106, a local vortex flow cannot be formed, thereby causing a poor disturbance effect on the flow rate of the molten silicon material 2.

[0140] In a specific application, the groove width W2 of the second groove 106 can be set to any value such as 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a range between two arbitrary values.

[0141] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the protrusion 104 has an outer peripheral surface 1041 facing the side wall 105 , and a third groove 107 is provided in the outer peripheral surface 1041 . The third groove 107 extends inwardly toward the protrusion 104 .

[0142] In the embodiment of the present application, by providing a third groove 107 on the outer peripheral surface 1041 of the protrusion 104 facing the side wall 105 , the flow rate of the molten silicon material 2 can be further disrupted, while the accommodation space of the first groove 103 is increased, so that more polycrystalline particles can be collected.

[0143] In a specific application, the third groove 107 can be a regular rectangular groove or an irregular shaped groove. Those skilled in the art can set it according to actual needs, and this application does not limit it. Preferably, the third groove 107 is set as a rectangular groove to facilitate processing and reduce the cost of the graphite crucible.

[0144] It should be explained that the outer peripheral surface 1041 is the end surface of the protrusion 104 facing the side wall 105. When the protrusion 104 is a columnar structure, the outer peripheral surface 1041 is specifically a columnar outer surface, that is, the outer peripheral surface 1041 is a circular arc surface. The third groove 107 is arranged around the outer peripheral surface 1041 of the protrusion 104, so that the polycrystalline particles can be collected in multiple directions, thereby improving the collection efficiency.

[0145] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the third groove 107 is arranged in a ring shape, and a plurality of third grooves 107 are provided, and the plurality of third grooves 107 are arranged at intervals along the first direction X.

[0146] In the embodiment of the present application, a plurality of third grooves 107 are arranged at intervals on the outer peripheral surface 1041 along the first direction X, which can further enhance the effect of disrupting the flow rate of the molten silicon material 2 and further increase the accommodating space for polycrystalline particles.

[0147] It should be explained that the multiple third grooves 107 can form multiple local vortex flows of the molten silicon material 2 flowing through. Each time a local vortex flow is formed, the flow rate of the molten silicon material 2 will change. At the same time, the groove wall of each third groove 107 can form a barrier to the polycrystalline particles.

[0148] In specific applications, the number of the third grooves 107 can be set to any value such as 1, 2, 3, or 4. The number of the third grooves 107 is determined by the groove width of the third groove 107 and the groove depth of the first groove 103 .

[0149] Preferably, the number of the third grooves 107 is set to three.

[0150] It can be understood that the third groove 107 is arranged in an annular shape, which can be a "complete circular ring" or an "interrupted circular ring" or other annular settings. Those skilled in the art can set it according to actual needs, and this application does not limit this.

[0151] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the groove depth of the third groove 107 is H3, which satisfies: 1mm≤H3≤3mm.

[0152] In the embodiment of the present application, by setting the groove depth H3 of the third groove 107 within a reasonable range, the flow rate of the molten silicon material 2 is disturbed to form a local vortex flow, while the volume capable of accommodating polycrystalline particles is increased.

[0153] It should be explained that when the groove depth H3 of the third groove 107 is less than 1 mm, that is, the groove depth H3 of the third groove 107 is too shallow, so that the volume of the third groove 107 that can accommodate polycrystalline particles is too small. During a long production process, the polycrystalline particles will fill the third groove 107, making it impossible to continue to collect polycrystalline particles; when the groove depth H3 of the third groove 107 is greater than 3 mm, that is, the groove depth H3 of the third groove 107 is too deep, after the molten silicon material 2 flows into the third groove 107, the molten silicon material 2 at the bottom of the third groove 107 may not be able to flow out, thereby causing a poor disturbance effect on the flow rate of the molten silicon material 2.

[0154] In a specific application, the groove depth H3 of the third groove 107 can be set to any value such as 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a range between two arbitrary values.

[0155] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the width of the third groove 107 is W3, which satisfies: 1 mm ≤ W3 ≤ 3 mm.

[0156] In the embodiment of the present application, by setting the groove width W3 of the third groove 107 within a reasonable range, it is possible to ensure that the flow rate of the molten silicon material 2 is disturbed and a local vortex flow is formed to facilitate the precipitation of polycrystalline particles while increasing the volume that can accommodate polycrystalline particles.

[0157] It needs to be explained that when the groove width W3 of the third groove 107 is less than 1 mm, that is, the groove width W3 of the third groove 107 is too small, so that the volume of the third groove 107 that can accommodate polycrystalline particles is too small. During a long production process, the polycrystalline particles will fill the third groove 107, making it impossible to continue to collect polycrystalline particles; when the groove width W3 of the third groove 107 is greater than 3 mm, that is, the groove width W3 of the third groove 107 is too large, after the molten silicon material 2 flows into the third groove 107, a local vortex flow cannot be formed, thereby causing a poor disturbance effect on the flow rate of the molten silicon material 2.

[0158] In a specific application, the groove width W3 of the third groove 107 can be set to any value such as 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, or a range between two arbitrary values.

[0159] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, an arc transition section 100 is provided between the side wall 105 and the cavity bottom 102 .

[0160] In the embodiment of the present application, by providing an arc transition section 100 between the side wall 105 and the cavity bottom 102, the flow rate of the molten silicon material 2 from the side wall 105 toward the cavity bottom 102 can be increased, so that the polycrystalline particles can flow to the cavity bottom as quickly as possible and gather in the first groove 103, the second groove 106 and the third groove 107; at the same time, the flow rate of the molten silicon material 2 in the accommodating cavity 10 is improved, so that the regional flow and carbon concentration distribution of the molten silicon material 2 reach the optimal state, and ultimately the quality of the grown silicon carbide single crystal is the highest, and the amount of crystal precipitation is large, thereby improving the growth efficiency and crystal quality of the silicon carbide single crystal.

[0161] It can be understood that when the first groove 103 is formed in the gap between the protrusion 104 and the side wall 105, the arc transition section 100 is actually located between the groove wall 1031 on one side of the first groove 103 and the groove bottom 1032. In this way, the flow rate of the molten silicon material 2 in this area can be increased. After flowing into the first groove 103, the flow rate of the molten silicon material 2 is reduced to form a local vortex flow, which can improve the precipitation efficiency of the polycrystalline particles.

[0162] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the radius of the arc transition section 100 is R, which satisfies: 12 mm ≤ R ≤ 18 mm.

[0163] In the embodiment of the present application, by setting the radius R of the arc transition section 100 within a reasonable range, the volume of the first groove 103 is guaranteed while ensuring the increase in the flow rate of the molten silicon material 2 .

[0164] It needs to be explained that when the radius R of the arc transition section 100 is less than 12 mm, the arc transition section 100 is too small, so that the effect on the flow rate of the molten silicon material 2 is too small, and the local vortex cannot be formed well, which affects the precipitation of polycrystalline particles; and when the radius R of the arc transition section 100 is greater than 18 mm, the arc transition section 100 is too large, and thus it will occupy more space in the first groove 103, making the volume of the first groove 103 too small, and it is easy to be filled with polycrystalline particles in the process of collecting polycrystalline particles.

[0165] In a specific application, the radius R of the arc transition section 100 can be set to any value such as 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, or a range between two arbitrary values.

[0166] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, along the radial direction of the accommodating cavity 10 , the cross-sectional area of ​​the accommodating cavity 10 is S2, and the cross-sectional area of ​​the protrusion 104 is S3, satisfying: 0.82≤S3 / S2≤0.88.

[0167] In the embodiment of the present application, by setting the ratio S3 / S2 between the cross-sectional area S3 of the protrusion 104 and the cross-sectional area S2 of the accommodating cavity 10 within a reasonable range, it is possible to ensure that a sufficient carbon source is provided to the silicon carbide single crystal, ensure the growth rate of the silicon carbide single crystal, meet the collection efficiency of the polycrystalline particles, and reduce the influence of the polycrystalline particles on the growth of the silicon carbide single crystal.

[0168] It should be explained that when the ratio S3 / S2 between the cross-sectional area S3 of the protrusion 104 and the cross-sectional area S2 of the accommodating cavity 10 is less than 0.82, that is, the cross-sectional area S3 of the protrusion 104 is too small. Since the protrusion 104 acts as a carbon source at this time, the carbon source in the molten silicon material 2 will be insufficient, affecting the growth rate of the silicon carbide single crystal; when the ratio S3 / S2 between the cross-sectional area S3 of the protrusion 104 and the cross-sectional area S2 of the accommodating cavity 10 is greater than 0.88, that is, the cross-sectional area S3 of the protrusion 104 is too large, the cross-sectional area S1 of the first groove 103 will be too small, the flow velocity disturbance effect on the molten silicon material 2 is poor, and the flow velocity of the molten silicon material 2 in the first groove 103 cannot be reduced, so that the polycrystalline particles cannot be well precipitated, and the polycrystalline particles can still have an adverse effect on the growth of the silicon carbide single crystal.

[0169] In a specific application, the ratio S3 / S2 between the cross-sectional area S3 of the protrusion 104 and the cross-sectional area S2 of the accommodating cavity 10 can be set to any value such as 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, or a range between two arbitrary values.

[0170] It is understandable that, when performing specific design or measurement, the cross-sectional area S3 of the protrusion 104 can be calculated by a circle area calculation formula, a rectangle area calculation formula, or an integral method, for example, Figure 1 As shown, when the protrusion 104 is a columnar structure, the diameter of the protrusion 104 is L, and the cross-sectional area of ​​the protrusion 104 is S3=πL 2 / 4; the cross section of the accommodating cavity 10 along the first direction X is specifically circular, and its cross-sectional area S1 is calculated according to the circular calculation formula, which will not be repeated here.

[0171] The following describes the effect of the specific selection of the ratio S3 / S2 between the cross-sectional area S3 of the protrusion 104 and the cross-sectional area S2 of the accommodating cavity 10 on the growth quality of silicon carbide using specific examples and comparative examples:

[0172] The experiment specifically adopts a liquid phase method (top seed solution growth method), and heats the crucible body 1 through a graphite heater and / or an induction heating coil, so that the crucible body 1 is in a second temperature field configuration, that is, the bottom temperature of the graphite crucible is high and the side wall temperature is low; at this time, the cavity bottom 102 serves as a carbon source, and the carbon atoms in the cavity bottom 102 can dissolve in the molten silicon material 2 in the containing cavity 10, and the temperature at the side wall 105 is relatively low, so the carbon atoms can easily form polycrystalline particles with the molten silicon material 2 at the side wall 105; the molten silicon material 2 is as follows Figure 2Flowing in the direction indicated by the arrow. Using multiple crucible bodies 1, all conditions were identical except for the S3 / S2 settings. Silicon carbide single crystals were prepared under the same external conditions (specifically, heating temperature, silicon material content, etc.), with each preparation time being 100 hours. The test results shown in Table 5 below were obtained:

[0173] Table 5:

[0174]

[0175] From Table 5 we can see that:

[0176] When the ratio S3 / S2 between the cross-sectional area S3 of the protrusion 104 and the cross-sectional area S2 of the accommodating cavity 10 is set within a reasonable range, as shown in Example 5, when 0.82≤S3 / S2≤0.88, the surface roughness of the silicon carbide single crystal can be reduced, the growth quality of the silicon carbide single crystal can be improved, and the effective utilization rate of carbon can be improved, that is, more carbon can be used to grow the silicon carbide single crystal; and when S3 / S2<0.82, as shown in Comparative Example 10, compared with Example 5, the carbon source cannot be effectively utilized, and the surface roughness of the silicon carbide single crystal cannot reach the optimal level; and when S3 / S2>0.88, as shown in Comparative Example 11, compared with Example 5, the effective utilization rate of carbon is lower, and more polycrystalline particles are generated, which in turn affects the growth quality of the silicon carbide single crystal.

[0177] It can be inferred from the above results that, under the same other conditions, setting the ratio S3 / S2 between the cross-sectional area S3 of the protrusion 104 and the cross-sectional area S2 of the accommodating cavity 10 within the selected value range of this application can improve the production quality of silicon carbide single crystals and effectively utilize carbon sources.

[0178] like Figure 1 As shown, in some embodiments of the present application, along the first direction X, the height of the protrusion 104 is H1, which satisfies: 12 mm ≤ H1 ≤ 18 mm.

[0179] In the embodiment of the present application, by setting the height H1 of the protrusion 104 along the first direction X within a reasonable range, it is ensured that the first groove 103 has sufficient volume to accommodate polycrystalline particles, while at the same time ensuring the temperature of the protrusion 104 and ensuring that the carbon atoms in the protrusion 104 can be dissolved in the molten silicon material 2.

[0180] It should be explained that when the height H1 of the protrusion 104 along the first direction X is less than 12 mm, since the groove depth of the first groove 103 is equal to the height H1 of the protrusion 104 along the first direction X, that is, the groove depth of the first groove 103 is too small, the volume of the first groove 103 is too small. During a long production process, the polycrystalline particles easily fill the first groove 103, and then the polycrystalline particles cannot be well collected. When the height H1 of the protrusion 104 along the first direction X is greater than 18 mm, that is, the protrusion 104 protrudes too high from the cavity bottom 102, the side surface of the protrusion 104 facing the cavity port 101 is too far away from the bottom of the crucible body 1, the thermal conductivity is reduced, and the temperature of the side surface of the protrusion 104 facing the cavity port 101 may be too low, so that the carbon atoms in the protrusion 104 cannot be well dissolved in the molten silicon material 2, thereby affecting the carbon saturation in the molten silicon material 2, and then affecting the growth rate of the silicon carbide single crystal.

[0181] In a specific application, the height H1 of the protrusion 104 along the first direction X can be set to any value such as 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, or a range between two arbitrary values.

[0182] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the height H1 of the protrusion 104 along the first direction X, the radius R of the arc transition section, and the groove width W1 of the first groove 103 satisfy: H1=R=W1 / 2, thereby facilitating the processing of the crucible body 1 while ensuring the collection effect of polycrystalline particles, and reducing the cost of the crucible body 1.

[0183] like Figure 5 As shown, in some embodiments of the present application, the cavity bottom 102 is at least partially recessed in a direction away from the cavity opening 101 to form a first groove 103 .

[0184] In an embodiment of the present application, the cavity bottom 102 is at least partially recessed in a direction away from the cavity opening 101 to form a first groove 103. In this way, the first groove 103 can be formed by the recess without affecting the provision of a carbon source by the crucible body 1, so as to collect the polycrystalline particles driven by the flow of the molten silicon material 2, reduce the influence of the polycrystalline particles on the growth of the silicon carbide single crystal, and improve the growth quality of the silicon carbide single crystal.

[0185] It should be explained that when the cavity bottom 102 is at least partially recessed in a direction away from the cavity mouth 101 to form the first groove 103, the crucible body 1 is in a first temperature field configuration, that is, the temperature of the side wall 105 of the crucible body 1 is high and the temperature of the cavity bottom 102 is low; in this way, the carbon atoms in the side wall 105 can be dissolved in the molten silicon material 2 at high temperature and serve as a carbon source for the growth of silicon carbide single crystals; at the same time, the cavity bottom 102 is recessed to form the first groove 103, which can collect polycrystalline particles; compared with the first groove 103 formed by the protrusion 104, the first groove 103 formed by the recess can increase the volume of the accommodating cavity 10 without affecting the provision of the carbon source by the crucible body 1, thereby being able to accommodate more silicon material.

[0186] In a specific application, the cavity bottom 102 is at least partially recessed in a direction away from the cavity opening 101 to form a first groove 103, so that the first groove 103 can form a "complete circular ring" first groove 103 or an "interrupted circular ring" first groove 103. Those skilled in the art can set it according to actual needs, and this application does not impose any restrictions on this.

[0187] Preferably, the first groove 103 is specifically in the shape of a "complete circular ring" so as to be able to collect the polycrystalline particles in multiple directions, thereby improving the collection efficiency.

[0188] like Figure 5 As shown, in some embodiments of the present application, the first groove 103 is arranged in an annular shape and surrounds the center of the cavity bottom 102 .

[0189] In an embodiment of the present application, by setting the first groove 103 in a ring shape and surrounding the center of the cavity bottom 102, the first groove 103 can cover the entire cavity bottom 102, collect polycrystalline particles from multiple directions, improve the collection efficiency of polycrystalline particles, and thereby reduce the impact of polycrystalline particles on the growth of silicon carbide single crystals.

[0190] like Figure 5 As shown, in some embodiments of the present application, a plurality of first grooves 103 are provided, and the plurality of first grooves 103 are arranged at intervals along the radial direction of the accommodating cavity 10 .

[0191] In an embodiment of the present application, a plurality of first grooves 103 are arranged at radial intervals along the accommodating cavity 10, thereby being able to cause multiple disturbances in the flow rate of the molten silicon material 2 flowing through the cavity bottom 102, and forming a local vortex flow at each first groove 103, thereby being able to precipitate polycrystalline particles at each first groove 103, and further improving the aggregation effect of the polycrystalline particles.

[0192] In a specific application, the number of the first grooves 103 can be set to any value such as 2, 3, 4, or 5.

[0193] Preferably, the number of the first grooves 103 is set to 4, so as to ensure that the flow rate of the molten silicon material 2 is disturbed and a local vortex flow is generated, while not affecting the overall laminar state of the molten silicon material 2 and reducing the generation of more polycrystalline particles.

[0194] like Figure 5 As shown, in some embodiments of the present application, the height of the accommodating cavity 10 is H4, and the diameter of the accommodating cavity 10 is D, satisfying: 1<H4 / D≤1.3.

[0195] In the embodiment of the present application, by setting the ratio H4 / D between the height H4 of the accommodating cavity 10 and the diameter D of the accommodating cavity 10 within a reasonable range, when the silicon material is heated and becomes molten silicon material 2 and flows, the flow rate of the molten silicon material 2 at the bottom of the accommodating cavity 10 is slowed down, which is more conducive to the collection of polycrystalline particles carried in the molten silicon material 2, while ensuring the sufficiency of the silicon material.

[0196] It should be explained that when the ratio H4 / D between the height H4 of the accommodating cavity 10 and the diameter D of the accommodating cavity 10 is ≤1, that is, when the accommodating cavity 10 is "short and fat" as a whole, when the molten silicon material 2 flows when heated, the flow rate of the molten silicon material 2 at the bottom of the accommodating cavity 10 is faster, which is not conducive to the collection of polycrystalline particles carried in the molten silicon material 2; and when the ratio H4 / D between the height H4 of the accommodating cavity 10 and the diameter D of the accommodating cavity 10 is H4 / D>1.3, that is, the accommodating cavity 10 is too deep as a whole, the molten silicon material 2 may be heated unevenly, and more polycrystalline particles are easily generated, which is not conducive to the growth of silicon carbide single crystals.

[0197] In a specific application, the ratio H4 / D between the height H4 of the accommodating cavity 10 and the diameter D of the accommodating cavity 10 can be set to any value such as 1.1, 1.15, 1.2, 1.25, 1.3, or a range between two arbitrary values.

[0198] The following describes the effect of the specific selection of the ratio H4 / D between the height H4 of the accommodating cavity 10 and the diameter D of the accommodating cavity 10 on the growth quality of silicon carbide using specific examples and comparative examples:

[0199] The experiment specifically adopts a liquid phase method (top seed solution growth method), and heats the crucible body 1 through a graphite heater and / or an induction heating coil, so that the crucible body 1 is in a first temperature field configuration, that is, the side wall temperature of the graphite crucible is high and the bottom temperature is low; at this time, the side wall 105 serves as a carbon source, and the carbon atoms in the side wall 105 can be dissolved in the molten silicon material 2 in the receiving chamber 10. The temperature at the bottom 102 of the chamber is relatively low, and the carbon atoms are easy to form polycrystalline particles with the molten silicon material 2 at the side wall 105; the molten silicon material 2 is as follows Figure 2Flowing in the direction indicated by the arrow. Using multiple crucible bodies 1, all conditions were identical except for the H4 / D settings, and silicon carbide single crystals were prepared under the same external conditions (specifically, heating temperature, silicon material content, etc.), with each preparation time being 100 hours. The test results shown in Table 6 below were obtained:

[0200] Table 6:

[0201]

[0202] From Table 6 we can see that:

[0203] When the ratio H4 / D between the height H4 of the accommodating cavity 10 and the diameter D of the accommodating cavity 10 is set within a reasonable range, as shown in Example 6, when 1<H4 / D≤1.3, the surface roughness of the silicon carbide single crystal can be reduced, the growth quality of the silicon carbide single crystal can be improved, and the effective utilization rate of carbon can be improved, that is, more carbon can be used to grow the silicon carbide single crystal; and when H4 / D≤1, as shown in Comparative Example 12, the surface roughness of the silicon carbide single crystal is relatively high, and the first groove 103 cannot collect the polycrystalline particles well, affecting the growth quality of the silicon carbide single crystal; and when H4 / D>1.3, as shown in Comparative Example 13, the effective utilization rate of carbon is relatively low, and more polycrystalline particles are generated, which in turn affects the growth of the silicon carbide single crystal.

[0204] It can be inferred from the above results that, under the same other conditions, setting the ratio H4 / D between the height H4 of the accommodating cavity 10 and the diameter D of the accommodating cavity 10 within the selected value range of this application can improve the production quality of silicon carbide single crystals and effectively utilize carbon sources.

[0205] like Figure 5 As shown, in some embodiments of the present application, the groove depth of the first groove 103 is H5, which satisfies: 10 mm ≤ H5 ≤ 15 mm.

[0206] In the embodiment of the present application, by setting the groove depth H5 of the first groove 103 within a reasonable range, sufficient disturbance can be caused to the flow of the molten silicon material 2 to form a local vortex flow, which is convenient for collecting polycrystalline particles while also providing sufficient accommodation space for collecting polycrystalline particles.

[0207] It should be explained that when the groove depth H5 of the first groove 103 is less than 10 mm, that is, the groove depth H5 of the first groove 103 is too small, the capacity of the first groove 103 will be small. During a long production process, the polycrystalline particles will easily fill the first groove 103, making it impossible to continue to precipitate the polycrystalline particles. At the same time, the groove depth H5 of the first groove 103 is too small, and the flow velocity disturbance effect of the molten silicon material 2 cannot be reduced. The flow velocity of the molten silicon material 2 in the first groove 103 cannot be reduced, so that the polycrystalline particles cannot be well precipitated; and when the groove depth H5 of the first groove 103 is greater than 15 mm, that is, the groove depth H5 of the first groove 103 is too large, the cavity bottom 102 will be too thin, and there is a risk of burning through, which reduces the reliability of the graphite crucible.

[0208] In a specific application, the groove depth H5 of the first groove 103 can be set to any value such as 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, or a range between any two values.

[0209] like Figure 5 As shown, in some embodiments of the present application, the groove width of the first groove 103 is W1, which satisfies: 8mm≤W1≤12mm.

[0210] In the embodiment of the present application, by setting the groove width W1 of the first groove 103 within a reasonable range, sufficient disturbance can be caused to the flow of the molten silicon material 2 to form a local vortex flow, which is convenient for collecting polycrystalline particles while also providing sufficient accommodation space for collecting polycrystalline particles.

[0211] It should be explained that when the groove width W1 of the first groove 103 is less than 8 mm, that is, the groove width W1 of the first groove 103 is too small, the capacity of the first groove 103 will be small. During a long production process, the polycrystalline particles will easily fill the first groove 103, making it impossible to continue to precipitate the polycrystalline particles. At the same time, the groove width W1 of the first groove 103 is too small, and the flow velocity disturbance effect of the molten silicon material 2 is not good, and the flow velocity of the molten silicon material 2 in the first groove 103 cannot be reduced, so that the polycrystalline particles cannot be well precipitated; and when the groove width W1 of the first groove 103 is greater than 12 mm, that is, the groove width W1 of the first groove 103 is too large, the molten silicon material 2 will not be able to form a local vortex flow when flowing through the first groove 103, so that the polycrystalline particles cannot be well precipitated.

[0212] In a specific application, the groove width W1 of the first groove 103 can be set to any value such as 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, or a range between any two values.

[0213] like Figure 6As shown, in some embodiments of the present application, a silicon carbide single crystal growth device is also proposed, including the graphite crucible as described in any of the above embodiments.

[0214] In an embodiment of the present application, a graphite crucible includes a crucible body 1, which is provided with a receiving chamber 10 for receiving silicon material. The receiving chamber 10 has a chamber opening 101 and a chamber bottom 102 arranged opposite to each other along a first direction X. The chamber bottom 102 is provided with a first groove 103 on a side facing the interior of the receiving chamber 10. The first groove 103 is used to collect polycrystalline particles in the molten silicon material 2. In this way, by providing the first groove 103 facing the interior of the receiving chamber 10 on the chamber bottom 102 of the receiving chamber 10 of the crucible body 1, the carbon dissolved in the crucible body 1 and the polycrystalline particles generated by the molten silicon material 2 can be collected during the process of generating a silicon carbide single crystal from the molten silicon material 2 and the carbon source provided by the crucible body 1. This allows more polycrystalline particles to be collected at the bottom of the receiving chamber 10 and not to flow to the growth interface 31 of the silicon carbide single crystal. This can reduce the impact of the polycrystalline particles on the growth of the silicon carbide single crystal, thereby improving the quality of the generated silicon carbide single crystal.

[0215] In specific applications, other components of the silicon carbide single crystal growth device according to the embodiment of the present application, such as the silicon carbide seed crystal 3, the growth interface 31, the graphite heater 4, the side graphite heating element 5, the seed crystal rod 6, the support 7, the thermal insulation felt 8, the induction heating coil 9 and the furnace shell 11, as well as when the silicon carbide single crystal is grown by the liquid phase method, the corresponding operations of the silicon carbide single crystal growth device are known to ordinary technicians in this field and will not be described in detail here.

[0216] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0217] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A graphite crucible, characterized in that: include: A crucible body (1), the crucible body (1) being provided with a receiving cavity (10), the receiving cavity (10) being used to receive silicon material, the receiving cavity (10) having a cavity opening (101) and a cavity bottom (102) which are opposite to each other along a first direction (X), the cavity bottom (102) being provided with a first groove (103) on a side facing the inside of the receiving cavity (10), the first groove (103) being used to collect polycrystalline particles in the molten silicon material (2); Along the radial direction of the accommodating cavity (10), the cross-sectional area of ​​the first groove (103) is S1, and the cross-sectional area of ​​the accommodating cavity (10) is S2, satisfying the following: 0.12≤S1 / S2≤0.

18.

2. The graphite crucible according to claim 1, characterized in that The first groove (103) comprises a groove wall (1031) and a groove bottom (1032) connected to each other, and an angle α is formed between the groove wall (1031) and the groove bottom (1032), satisfying the following: 60°≤α≤90°.

3. The graphite crucible according to claim 1, characterized in that The width of the first groove (103) is W1, and the diameter of the accommodating cavity (10) is D, which satisfies the following relationship: 0.05≤W1 / D≤0.1; And / or, the height of the accommodating cavity (10) is H4, and the depth of the first groove (103) is H5, satisfying: 0.07≤H5 / H4≤0.

13.

4. The graphite crucible according to any one of claims 1 to 3, characterized in that: The cavity bottom (102) at least partially protrudes toward the cavity opening (101) to form a raised portion (104); the accommodating cavity (10) is further provided with a side wall (105) between the cavity opening (101) and the cavity bottom (102); and a gap at least partially exists between the raised portion (104) and the side wall (105) to form the first groove (103).

5. The graphite crucible according to claim 4, characterized in that A second groove (106) is provided at the groove bottom (1032) of the first groove (103), and the second groove (106) is recessed and extends in a direction away from the cavity opening (101).

6. The graphite crucible according to claim 5, characterized in that The second groove (106) is arranged in an annular shape, and a plurality of the second grooves (106) are provided. The plurality of second grooves (106) are arranged at intervals along the radial direction of the accommodating cavity (10).

7. The graphite crucible according to claim 5, characterized in that The raised portion (104) has an outer peripheral surface (1041) facing the side wall (105), and a third groove (107) is provided in the outer peripheral surface (1041). The third groove (107) extends inwardly toward the raised portion (104).

8. The graphite crucible according to claim 7, characterized in that The third groove (107) is arranged in an annular shape, and a plurality of the third grooves (107) are provided, and the plurality of third grooves (107) are arranged at intervals along the first direction (X).

9. The graphite crucible according to claim 4, characterized in that A circular arc transition section (100) is provided between the side wall (105) and the cavity bottom (102).

10. The graphite crucible according to claim 9, characterized in that The radius of the arc transition section (100) is R, which satisfies: 12 mm ≤ R ≤ 18 mm.

11. The graphite crucible according to claim 4, characterized in that Along the radial direction of the accommodating cavity (10), the cross-sectional area of ​​the accommodating cavity (10) is S2, and the cross-sectional area of ​​the protruding portion (104) is S3, satisfying: 0.82≤S3 / S2≤0.

88.

12. The graphite crucible according to any one of claims 1 to 3, characterized in that: The cavity bottom (102) is at least partially recessed in a direction away from the cavity opening (101) to form the first groove (103).

13. The graphite crucible according to claim 12, characterized in that The first groove (103) is arranged around the center of the cavity bottom (102); And / or, a plurality of the first grooves (103) are provided, and the plurality of the first grooves (103) are arranged at intervals along the radial direction of the accommodating cavity (10).

14. The graphite crucible according to claim 12, characterized in that The height of the accommodating cavity (10) is H4, and the diameter of the accommodating cavity (10) is D, satisfying the following relationship: 1<H4 / D≤1.

3.

15. A silicon carbide single crystal growth device, characterized in that: The invention comprises the graphite crucible according to any one of claims 1 to 14.

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