Particle filtering and heating device for SiC crystal growth process

Abstract

The utility model discloses a filtering particle and a heating device for a SiC crystal growth process, the filtering particle comprises a filtering main body, the filtering main body is a metal piece, and a main channel and at least two filtering channels are formed in the filtering main body; the inner end of the filtering channel penetrates into the filtering main body and is communicated with the main channel, and the outer end of the filtering channel penetrates into the outer surface of the filtering main body and forms an outlet; wherein each filter channel is a straight channel, and the extension direction of each filter channel intersects with the extension direction of the main channel, so that the influence of carbon wrapping can be eliminated, and the quality of grown crystals is improved.

Description

Technical Field

[0001] This application relates to the field of materials processing equipment, and in particular to a filter particle and heating device for the SiC crystal growth process. Background Technology

[0002] In related technologies, carbon encapsulation occurs during the PVT growth process. Carbon encapsulation affects the growth rate and weight of silicon carbide crystals. Carbon encapsulation with a size range of 5-500 μm is difficult to suppress through conventional adsorption, filtration, and substrate methods. In the middle and later stages of SiC crystal growth, the severity of carbon encapsulation of the above-mentioned size intensifies. Carbon encapsulation of this size affects the crystal quality and can cause problems such as dislocations, microtubes, and polymorphisms in the grown crystal. Therefore, how to eliminate the influence of carbon encapsulation has become a technical problem that needs to be solved. Utility Model Content

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, one objective of this application is to provide a filter particle for the SiC crystal growth process that can eliminate the influence of carbon encapsulation and improve the quality of the grown crystal.

[0004] According to an embodiment of this application, a filter particle for SiC crystal growth process includes: a filter body, the filter body being a metal part and having a main channel and at least two filter channels formed inside the filter body, the inner end of each filter channel extending into the interior of the filter body and communicating with the main channel, and the outer end of each filter channel extending into the outer surface of the filter body and forming an outlet; wherein each filter channel is constructed as a straight channel, and the extension direction of each filter channel intersects with the extension direction of the main channel.

[0005] According to embodiments of this application, the filter particles used in the SiC crystal growth process have each filter channel extending in a direction that intersects with the main channel. An upward airflow carrying carbon inclusions enters from the outer end of the filter channel. Since the outer end of the filter channel extends to the outer surface of the filter body and the inner end communicates with the main channel, the airflow can smoothly enter the interior of the filter particles. Each filter channel is constructed as a straight channel, and its extending direction intersects with the main channel. This causes the upward airflow to change direction when entering the main channel from the filter channel. The carbon inclusions in the upward airflow are blocked by the main channel wall, preventing them from participating in the crystal growth process. This reduces the negative impact on the crystal growth rate and crystal weight, and improves the quality of the grown crystal.

[0006] According to some embodiments of this application, a filter particle for SiC crystal growth process is provided, wherein the filter body is constructed as a column, the main channel extends along the axis of the filter body and is open at at least one end of the body, and the filter channel extends to the peripheral side of the filter body and forms the outlet.

[0007] According to some embodiments of this application, the filter particles for the SiC crystal growth process have filter channels that are perpendicular to the axis of the filter body. The plurality of filter channels are configured as multiple groups spaced apart on the axis, and each group of filter channels is spaced apart in the circumferential direction of the filter body.

[0008] According to some embodiments of this application, the filter particles used in the SiC crystal growth process have an included angle α between two adjacent filter channels in the circumferential direction in each group of filter channels, and satisfy: 45°≤α≤180°.

[0009] According to some embodiments of this application, the filter particles for the SiC crystal growth process have filter channels that are perpendicular to the axis of the filter body, and the plurality of filter channels are configured to be spaced apart on the axis and arranged parallel to each other.

[0010] According to some embodiments of this application, the filter particles used in the SiC crystal growth process have at least a portion of their outer surface having a straight wall perpendicular to the filter channel.

[0011] According to some embodiments of this application, the filter particles used in the SiC crystal growth process have a plurality of straight wall surfaces formed on the outer surface of the filter body. The plurality of straight wall surfaces are evenly spaced in the circumferential direction of the filter body, and two adjacent straight wall surfaces are connected by a curved surface.

[0012] According to some embodiments of this application, the filter particles used in the SiC crystal growth process have a main channel diameter of R and each filter channel diameter of r, satisfying: r≤R≤5r.

[0013] The heating device according to an embodiment of this application is briefly described below.

[0014] The heating device according to an embodiment of this application includes an outer crucible, an inner crucible, and filter particles. A first heating chamber is formed inside the outer crucible, and a second heating chamber is formed inside the inner crucible, housed within the first heating chamber. The filter particles are housed within the second heating chamber and are configured as filter particles as described in any of the above embodiments. Because the heating device according to this embodiment is equipped with filter particles from any of the above embodiments, the heating device according to this application has better production quality. The filter particles purify the growth environment within the second heating chamber, reducing the interference of carbon encapsulation on the SiC crystal growth process, ensuring the stability of the heating environment, allowing the crystal to grow in a purer atmosphere, and improving crystal quality. The presence of carbon encapsulation affects the flow state of airflow within the heating chamber, thereby interfering with heat transfer. When the filter particles block the carbon encapsulation, the airflow within the second heating chamber becomes smoother and more stable. Stable airflow helps to distribute heat more evenly in the crystal growth area, avoiding localized temperature anomalies caused by airflow turbulence, thereby improving heating efficiency and heating uniformity, providing more suitable temperature conditions for SiC crystal growth, and promoting crystal growth.

[0015] According to some embodiments of the heating apparatus of this application, the inner crucible includes: an inner crucible bottom; an inner crucible wall, the inner crucible wall being disposed on the outer periphery of the inner crucible bottom and forming a second heating cavity; and an inner crucible cover, the inner crucible cover being disposed on the top of the inner crucible wall and having a plurality of flow guide holes forming therethrough in the thickness direction, each of the flow guide holes having a gradually increasing cross-sectional area in the direction toward the top.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a schematic diagram of the structure of filter particles used in the SiC crystal growth process according to an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the AA cross-sectional structure of filter particles used in the SiC crystal growth process according to an embodiment of this application;

[0020] Figure 3 This is a schematic diagram of the BB cross-sectional structure of filter particles used in the SiC crystal growth process according to an embodiment of this application;

[0021] Figure 4This is a schematic diagram of a filter particle with a single straight wall surface used in the SiC crystal growth process according to an embodiment of this application.

[0022] Figure 5 This is a schematic cross-sectional view of a filter particle with a single straight wall surface used in the SiC crystal growth process according to an embodiment of this application.

[0023] Figure 6 This is a schematic diagram of a filter particle with multiple straight walls used in the SiC crystal growth process according to an embodiment of this application.

[0024] Figure 7 This is a schematic cross-sectional view of the main channel opening on one side of a filter particle used in the SiC crystal growth process according to an embodiment of this application.

[0025] Figure 8 This is a schematic diagram of the structure of a heating device according to an embodiment of this application;

[0026] Figure 9 This is a top view of the second heating chamber after the filter particles are filled.

[0027] Figure 10 yes Figure 9 Schematic diagram of the CC cross-section structure.

[0028] Figure label:

[0029] 100. Filter particles;

[0030] 1. Filter body; 11. Main channel; 12. Filter channel; 13. Straight wall; 14. Curved surface;

[0031] 200. Heating device;

[0032] 2. Outer crucible; 21. First heating chamber;

[0033] 3. Inner crucible; 31. Second heating chamber; 32. Bottom of inner crucible; 33. Inner crucible wall; 34. Inner crucible lid; 341. Flow guide hole;

[0034] 4. Adhesive layer. Detailed Implementation

[0035] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0036] The following is for reference. Figures 1-10This application describes a filter particle 100 and a heating device 200 for a SiC crystal growth process according to an embodiment of the present application.

[0037] According to an embodiment of this application, a filter particle 100 for SiC crystal growth includes: a filter body 1, which is a metal part and has a main channel 11 and at least two filter channels 12 formed inside the filter body 1. The inner end of the filter channel 12 extends into the interior of the filter body 1 and communicates with the main channel 11, and the outer end of the filter channel 12 extends into the outer surface of the filter body 1 and forms an outlet. Each filter channel 12 is constructed as a straight channel, and the extension direction of each filter channel 12 intersects with the extension direction of the main channel 11.

[0038] During SiC crystal growth, the formation of carbon inclusions can severely affect crystal quality. Carbon inclusions typically originate from the uneven flow of gaseous substances in the growth environment, causing carbon particles to aberrate at the crystal growth interface and become encapsulated within the crystal, thus creating defects.

[0039] The filter body 1 is made of metal, which has good thermal conductivity and chemical stability. The metal filter body 1 remains stable under the high-temperature environment required for SiC crystal growth.

[0040] During SiC crystal growth, the rising airflow carries carbon inclusions. When the airflow carrying carbon inclusions enters the filter channel 12, the airflow can move relatively smoothly in a straight line because the filter channel 12 is constructed as a straight channel. However, the extension direction of each filter channel 12 intersects the extension direction of the main channel 11. When the rising airflow enters the main channel 11 from the filter channel 12, the airflow direction needs to change. According to the principles of fluid dynamics, gas has inertia. When the airflow direction changes, the gas can relatively flexibly change its trajectory to adapt to the direction of the main channel 11. However, carbon inclusions have a certain mass and greater inertia. When the airflow direction changes abruptly, carbon inclusions cannot change their direction of movement like gas. Therefore, they will directly collide with the wall of the main channel 11 due to inertia. The carbon inclusions that collide with the wall of the main channel 11 will gradually deposit in the main channel 11 under the action of gravity and subsequent airflow, thus separating from the continuing airflow. The content of carbon inclusions in the airflow flowing out of the main channel 11 is greatly reduced.

[0041] The presence of carbon inclusions during SiC crystal growth can severely impact the process. If carbon inclusions are present in the growth environment, they can become embedded in the crystal, leading to defects and impurities, which in turn affect the crystal's physical and chemical properties and reduce its quality. However, after filtration through 100-mesh filtration particles, the influence of carbon inclusions is eliminated, allowing SiC crystals to grow in a relatively pure environment. This results in a more stable growth process, reduces lattice defects caused by impurities, and ultimately improves the quality of the grown crystal.

[0042] In short, the upward airflow carrying carbon inclusions enters from the outer end of the filter channel 12 through the intersection of the extension direction of each filter channel 12 and the extension direction of the main channel 11. Since the outer end of the filter channel 12 extends to the outer surface of the filter body 1 and the inner end is connected to the main channel 11, the airflow can smoothly enter the interior of the filter particles 100. Each filter channel 12 is constructed as a straight channel, and its extension direction intersects with the extension direction of the main channel 11. This causes the upward airflow to change direction when it enters the main channel 11 from the filter channel 12. The carbon inclusions in the upward airflow are blocked by the wall of the main channel 11. The blocked carbon inclusions cannot participate in the crystal growth process, reducing the negative impact on the crystal growth rate and crystal weight, and improving the quality of the grown crystal.

[0043] According to some embodiments of this application, a filter particle 100 for SiC crystal growth process has a filter body 1 constructed as a column, a main channel 11 extending along the axis of the filter body 1 and open at least one end of the body, and a filter channel 12 extending to the peripheral side of the filter body 1 and forming an outlet.

[0044] The filter body 1 is cylindrical, providing a stable and symmetrical spatial environment for internal fluid movement. The cylindrical structure makes the internal channel layout more regular, which helps control the movement path of airflow and impurities. The main channel 11 extends along the axis of the filter body 1, ensuring that the airflow maintains a relatively stable velocity and direction along the central axis when flowing in the main channel 11, reducing unnecessary turbulence. At the same time, the main channel 11 is open at at least one end of the body, providing a channel for airflow to enter and exit, and facilitating the subsequent cleaning of impurities deposited in the main channel 11, avoiding blockage that affects the filtration effect. The filter channel 12 extends to the peripheral side of the filter body 1 and forms an outlet, allowing the rising airflow to enter the interior of the filter particles 100 from multiple directions on the side of the column, increasing the contact area between the filter particles 100 and the airflow, and improving the filtration efficiency.

[0045] According to some embodiments of this application, the filter particles 100 for the SiC crystal growth process have filter channels 12 that are perpendicular to the axis of the filter body 1. The plurality of filter channels 12 are configured as a plurality of groups spaced apart on the axis, and each group of filter channels 12 is spaced apart in the circumferential direction of the filter body 1.

[0046] The filter channels 12 are perpendicular to the axis of the filter body 1, so that the direction of the rising airflow entering the filter channel 12 is perpendicular to the axis of the main channel 11. When the airflow flows from the filter channel 12 into the main channel 11, the airflow direction needs to change by 90°, which creates a more significant condition for separation by utilizing the inertial difference between the airflow and the carbon coating. The multiple filter channels 12 are constructed as multiple groups arranged at intervals on the axis, which increases the processing capacity of the filter particles 100 for rising airflow at different positions. This allows the airflow carrying carbon coating at different positions in the SiC crystal growth space to be effectively filtered, avoiding the occurrence of filtration blind spots. Each group of filter channels 12 is arranged at intervals in the circumferential direction of the filter body 1. This ensures that the filter particles 100 can receive rising airflow from different directions in all directions on the same cross-section at the same height, avoiding insufficient filtration in some areas due to a single airflow direction, and improving the comprehensiveness and uniformity of filtration.

[0047] According to some embodiments of this application, the filter particles 100 used in the SiC crystal growth process have an included angle α between two adjacent filter channels 12 in the circumferential direction in each group of filter channels 12, and satisfy: 45°≤α≤180°.

[0048] When the included angle between two adjacent filter channels 12 in each group of filter channels 12 in the circumferential direction satisfies 45°≤α≤180°, the filter channels 12 can be distributed at a reasonable angle on the cross-section of the filter body 1. When the angle is close to 45°, the filter channels 12 are relatively densely distributed, which can capture the rising airflow in different directions more precisely and avoid airflow convergence and blockage caused by too small an angle. When the angle is close to 180°, it can ensure that there is enough space for the airflow to diffuse after entering the filter particles 100, prevent the local airflow from being too concentrated, and ensure that the airflow in the entire circumferential direction can enter the filter channel 12 evenly, creating good initial conditions for subsequent carbon encapsulation separation. When the airflow turns, the gas and carbon encapsulation separate due to inertial differences. If the angle is too small, the carbon encapsulation may not be able to fully impact the wall and continue to move with the airflow. If the angle is too large, the carbon encapsulation may bounce back into the airflow after impact. Within the range of 45°≤α≤180°, the carbon encapsulation can impact the wall of the main channel 11 in the best way, improve the interception efficiency, and make the carbon encapsulation easier to deposit in the main channel 11.

[0049] According to some embodiments of this application, the filter particles 100 for the SiC crystal growth process have filter channels 12 that are perpendicular to the axis of the filter body 1, and the plurality of filter channels 12 are configured to be spaced apart on the axis and arranged parallel to each other.

[0050] Multiple filter channels 12 are spaced apart on the axis, enabling stratified filtration of rising airflow at different locations. The filter channels 12 are arranged parallel to each other, ensuring a relatively consistent flow state of airflow within each filter channel 12, reducing airflow turbulence caused by differences in channel layout. The parallel filter channels 12 allow the airflow to flow towards the main channel 11 at a stable and uniform speed and direction after entering the filter particles 100, which is beneficial to improving the consistency and stability of carbon encapsulation separation. Furthermore, the parallel filter channels 12 are relatively simple to manufacture, easy to process and assemble, and reduce production difficulty and cost.

[0051] According to some embodiments of this application, the filter particles 100 for the SiC crystal growth process have at least a portion of the outer surface of the filter body 1 having a straight wall surface 13 perpendicular to the filter channel 12.

[0052] The straight wall surface 13 allows the filter particles 100 to be stably laid out during placement. In the actual production process of SiC crystal growth, multiple filter particles 100 are usually required to ensure sufficient filtration of the airflow. The straight wall surface 13 ensures that the filter particles 100 can be laid out flat and are not prone to rolling, avoiding the problem of unstable placement caused by irregular surfaces. Stable flat placement helps to optimize the internal spatial layout of the filtration equipment, allowing the airflow to pass evenly through each filter particle 100, fully utilizing the efficiency of each filter particle 100, and also facilitating the installation, commissioning, and maintenance of the equipment.

[0053] According to some embodiments of this application, the filter particles 100 for SiC crystal growth process have a plurality of straight wall surfaces 13 formed on the outer surface of the filter body 1. The plurality of straight wall surfaces 13 are evenly spaced in the circumferential direction of the filter body 1, and two adjacent straight wall surfaces 13 are connected by a curved surface 14.

[0054] Two adjacent straight wall surfaces 13 are connected by a curved surface 14, reducing airflow resistance and turbulence at the junction of the straight wall surfaces 13. When the airflow transitions from one straight wall surface 13 to another, the curved surface 14 guides the airflow to smoothly change direction, avoiding vortices caused by right-angle turns. Multiple evenly spaced straight wall surfaces 13 provide multiple stable support surfaces for the filter particles 100 during placement. In actual production, whether it is a single-layer flat laying or multi-layer stacking, the straight wall surfaces 13 can ensure that the filter particles 100 are tightly attached and not easily slipped. When placed horizontally, the straight wall surfaces 13 can form surface contact with the placement plane, providing greater friction and preventing the filter particles 100 from shifting. When stacked in multiple layers, the straight wall surfaces 13 of the upper layer of filter particles 100 can be accurately embedded in the grooves formed by the lower layer of straight wall surfaces 13, achieving stable stacking. This optimizes the internal spatial layout of the filtration equipment while ensuring that the airflow passes evenly through each filter particle 100, maximizing filtration efficiency.

[0055] The filtering particle 100 for the SiC crystal growth process according to some embodiments of the present application, the diameter of the main channel 11 is R, the diameter of each filtering channel 12 is r, and it satisfies: r ≤ R ≤ 5r.

[0056] When r ≤ R ≤ 5r is satisfied, it can ensure that the air flow smoothly flows from the filtering channel 12 into the main channel 11. If R < r, when the air flow enters the main channel 11 from the filtering channel 12, a large local resistance will be generated due to the sudden contraction of the channel, resulting in a sharp change in the air flow velocity, forming a turbulent flow, and destroying the inertial separation condition of the carbon coating and the gas; if R > 5r, after the air flow enters the main channel 11, the flow velocity will rapidly decrease due to the sudden expansion of the space, and even an air flow reflux phenomenon will occur, which is also not conducive to the effective separation of the carbon coating. Within the range of r ≤ R ≤ 5r, the air flow can turn from the filtering channel 12 to the main channel 11 at a relatively stable speed and direction, creating a good flow environment for the inertial separation of the carbon coating.

[0057] The heating device 200 according to the embodiments of the present application will be briefly described below.

[0058] The heating device 200 according to the embodiments of the present application includes an outer crucible 2, an inner crucible 3 and a filtering particle 100. A first heating cavity 21 is formed inside the outer crucible 2. The inner crucible 3 is received in the first heating cavity 21 and a second heating cavity 31 is formed inside the inner crucible 3. The filtering particle 100 is received in the second heating cavity 31 and is configured as the filtering particle 100 in any one of the above. Since the heating device 200 according to this embodiment is provided with the filtering particle 100 in any one of the above embodiments, therefore, the heating device 200 according to the present application has better production quality. The growth environment in the second heating cavity 31 is purified by the filtering particle 100, reducing the interference of the carbon coating on the SiC crystal growth process, ensuring the stability of the heating environment, allowing the crystal to grow in a purer atmosphere, and improving the crystal quality. The presence of the carbon coating will affect the flow state of the air flow in the heating cavity, and further interfere with the heat transfer. When the filtering particle 100 blocks the carbon coating, the air flow in the second heating cavity 31 flows more smoothly and stably. The stable air flow helps the heat to be more evenly distributed in the crystal growth area, avoiding local temperature anomalies caused by air flow disorders, thereby improving the heating efficiency and heating uniformity, providing more suitable temperature conditions for the growth of SiC crystals, and promoting the growth of crystals.

[0059] According to some embodiments of the present application, the heating device 200 includes an inner crucible 3 comprising an inner crucible bottom 32, an inner crucible wall 33, and an inner crucible cover 34. The inner crucible wall 33 is disposed on the outer periphery of the inner crucible bottom 32 and forms a second heating cavity 31. The inner crucible cover 34 is disposed on the top of the inner crucible wall 33 and a plurality of flow guide holes 341 extending in the thickness direction are formed on the inner crucible cover 34. The cross-sectional area of ​​each flow guide hole 341 gradually increases in the direction toward the top.

[0060] The inner crucible 3 consists of an inner crucible bottom 32, an inner crucible wall 33, and an inner crucible lid 34. The inner crucible wall 33 encloses the inner crucible bottom 32 to form a second heating chamber 31, providing a stable heating space for SiC crystal growth. The enclosed structure can effectively concentrate heat, reduce heat loss, maintain the stability of the temperature inside the chamber, and create a suitable thermal environment for crystal growth. The flow guide hole 341 on the inner crucible lid 34 gradually increases in cross-sectional area towards the top. When gas flows from the bottom to the top of the flow guide hole 341, as the cross-sectional area of ​​the channel increases, The gas flow rate gradually decreases, and the gradually increasing cross-sectional area of ​​the guide hole 341 allows the gas entering the second heating chamber 31 to diffuse evenly. When the gas flows in at high speed from the bottom of the guide hole 341, the gas flow rate decreases as the cross-sectional area of ​​the channel increases, and it flows out at a lower speed and a larger area at the top outlet. This avoids the gas entering the chamber in a high-speed concentrated jet manner, preventing drastic disturbance to the original airflow field in the chamber, and ensuring that the gas can be evenly distributed throughout the second heating chamber 31, which is beneficial to the stability of the temperature field and flow field during crystal growth.

[0061] In some embodiments of this application, the filter particles 100 are constructed as titanium particles. First, graphite paper is placed at the bottom of the second heating chamber 31, and a layer of titanium oxide powder is spread on the surface of the graphite paper. The amount of the first layer is 1 / 3 of the total amount of TiO2 powder to be spread, calculated by the mass multiple of the metallic titanium particles. Then, multiple filter particles 100 are placed at the bottom of the second heating chamber 31 and the filter particles 100 are vibrated to compact them. Then, the remaining 2 / 3 of the titanium oxide powder is spread on the filter particles 100 and compacted with a tool. After compaction, the filter particles 100 and titanium oxide powder are sintered at high temperature. Under high temperature conditions, titanium oxide melts, and oxygen atoms are released. The molten titanium element precipitates downward to form a titanium element adhesive layer 4, which connects the filter particles 100 spread at the bottom of the second heating chamber 31 into a whole to form a filter plate structure. The filter particles connected as a whole are not easy to rotate, which affects the filtration effect.

[0062] After sintering, the filter plate is placed back at the bottom of the second heating chamber, and carbon powder is added into the second heating chamber. The amount of carbon powder added is controlled by the filling height. The added carbon powder is filled to half the height of the inner crucible wall. The crucible is sealed, and the second sintering begins to carbonize the titanium particles and the titanium elemental bonding layer 4 to form titanium carbide, thus forming a filter plate with titanium carbide to avoid the titanium element affecting the crystallization of SiC. The filter plate is then removed, the residual carbon powder is removed, and the filter is thoroughly soaked in pure water and then ultrasonically cleaned to remove excess impurities, powder, and loosely bonded residues. It is then dried for later use. After preparation, conventional production is carried out to achieve the filtering of carbon-encapsulated particles.

[0063] In some other embodiments of this application, the material of the filter particles 100 may be a refractory metal with good ductility and processability, and the corresponding sintering mixture may be selected as pure metal powder or oxide of the corresponding metal particles.

[0064] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0065] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0066] In the description of this application, "multiple" means two or more.

[0067] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them.

[0068] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0069] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A filter particle for use in the SiC crystal growth process, characterized in that, include: A filter body (1) is a metal part and a main channel (11) and at least two filter channels (12) are formed inside the filter body (1). The inner end of the filter channel (12) extends into the interior of the filter body (1) and communicates with the main channel (11). The outer end of the filter channel (12) extends into the outer surface of the filter body (1) and forms an outlet. in Each of the filter channels (12) is constructed as a straight channel, and the extension direction of each filter channel (12) intersects the extension direction of the main channel (11).

2. The filter particles for SiC crystal growth process according to claim 1, characterized in that, The filter body (1) is constructed as a column, the main channel (11) extends along the axis of the filter body (1) and is open at at least one end of the body, and the filter channel (12) extends to the peripheral side of the filter body (1) and forms the outlet.

3. The filter particles for SiC crystal growth process according to claim 2, characterized in that, The filter channels (12) are perpendicular to the axis of the filter body (1). The plurality of filter channels (12) are configured as multiple groups spaced apart on the axis, and each group of filter channels (12) is arranged at intervals in the circumferential direction of the filter body (1).

4. The filter particles for SiC crystal growth process according to claim 3, characterized in that, The included angle between two adjacent filter channels (12) in each group of filter channels (12) in the circumferential direction is α, and satisfies: 45°≤α≤180°.

5. The filter particles for SiC crystal growth process according to claim 2, characterized in that, The filter channels (12) are perpendicular to the axis of the filter body (1), and the plurality of filter channels (12) are configured to be spaced apart on the axis and arranged parallel to each other.

6. The filter particles for SiC crystal growth process according to claim 2, characterized in that, At least a portion of the outer surface of the filter body (1) is formed with a straight wall surface (13) perpendicular to the filter channel (12).

7. The filter particles for SiC crystal growth process according to claim 6, characterized in that, The outer surface of the filter body (1) has a plurality of straight wall surfaces (13), which are evenly spaced in the circumferential direction of the filter body (1), and two adjacent straight wall surfaces (13) are connected by a curved surface (14).

8. The filter particles for SiC crystal growth process according to claim 2, characterized in that, The diameter of the main channel (11) is R, and the diameter of each filter channel (12) is r, and the following conditions are met: r≤R≤5r.

9. A heating device, characterized in that, include: An outer crucible (2) has a first heating chamber (21) formed inside it; An inner crucible (3) is housed in the first heating chamber (21) and a second heating chamber (31) is formed inside the inner crucible (3); Filter particles (100) are housed in the second heating chamber (31) and are configured as filter particles (100) as described in any one of claims 1-8.

10. The heating device according to claim 9, characterized in that, The inner crucible (3) includes: Inner crucible bottom (32); The inner crucible wall (33) is disposed on the outer periphery of the inner crucible bottom (32) and surrounds the second heating cavity (31); An inner crucible cover (34) is disposed on the top of the inner crucible wall (33) and a plurality of flow guide holes (341) are formed on the inner crucible cover (34) in the thickness direction, and the cross-sectional area of ​​each flow guide hole (341) gradually increases in the direction toward the top.

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