Silicon carbide powder decarburization device and decarburization method
By designing a silicon carbide powder decarbonization device for quartz parts, the oxygen flow reaction path is used to remove free carbon in the powder, the problems of impurities in the traditional decarbonization process are solved, the purity and reaction efficiency of the powder are improved, and the quality of crystal growth and device performance are ensured.
Patent Information
- Application Number
- CN202411827333.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-03-21
AI Technical Summary
There are impurities in the decarbonization process of traditional silicon carbide powder, which leads to a decrease in the purity of the powder, affecting the quality of subsequent crystal growth and device performance.
A silicon carbide powder decarbonization device is designed, using quartz piece material, and through the arrangement of ventilation holes, accommodating space, reaction space and vent holes, an oxygen flow reaction path is formed, free carbon in the powder is removed by using oxygen, and the uniformity of the reaction is ensured by the arrangement of multiple material boxes.
The purity and reaction efficiency of the decarbonized silicon carbide powder are improved, and the quality and device performance of the powder in subsequent crystal growth are ensured.
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Figure CN119657059A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of silicon carbide crystal material preparation, and in particular to a silicon carbide powder decarburization device and a decarburization method. Background Art
[0002] As a representative of the third generation of broadband semiconductor materials, silicon carbide (SiC) has an irreplaceable position in high temperature, high pressure, and high frequency applications due to its excellent properties such as high critical breakdown electric field, high thermal conductivity, and high electron saturation mobility. At present, physical vapor transport (PVT) has become the mainstream process for the growth of silicon carbide single crystals. In the PVT growth process, the purity of silicon carbide powder is one of the key factors affecting the quality of the crystal. Impurities in silicon carbide powder will not only cause defects such as micropipes and dislocations in the crystal, but also reduce the electrical performance, breakdown voltage, and reliability of the device.
[0003] In the related art, silicon carbide powder is mainly prepared by an improved self-propagating high temperature synthesis method (SHS). In the self-propagating high temperature synthesis method, silicon powder and carbon powder are mixed in a certain proportion under an inert atmosphere, and the reaction is maintained by the heat released by the reaction after local ignition. However, due to the solid-phase reaction characteristics of the improved self-propagating high temperature synthesis method, the diffusion between the reactants is limited, and the reaction temperature and pressure are difficult to accurately control, resulting in widespread residual free carbon in the synthesized powder. However, the free carbon in the silicon carbide powder will have a serious adverse effect on the subsequent single crystal growth. The traditional treatment process for removing free carbon from silicon carbide powder is a decarburization process, which usually includes multiple steps such as crushing, magnetic separation, rinsing, pickling and screening.
[0004] However, the decarburization process of the conventional silicon carbide powder contains impurities, which results in a decrease in the purity of the silicon carbide powder. This can easily cause defects in the silicon carbide powder during subsequent crystal growth, thus affecting device performance. Summary of the invention
[0005] The embodiments of the present application provide a silicon carbide powder decarbonization device and a decarbonization method to solve the technical problem in the related art that impurities exist in the silicon carbide powder after decarbonization, which easily causes defects in the silicon carbide powder during subsequent crystal growth and affects device performance.
[0006] In a first aspect, an embodiment of the present application provides a silicon carbide powder decarbonization device, comprising: a shell and a material box, wherein the shell and the material box are both configured as quartz parts;
[0007] The shell is formed with a containing cavity, and a vent hole communicating with the containing cavity is provided at the bottom of the shell, and the vent hole is used to introduce oxygen into the containing cavity;
[0008] There are multiple material boxes, which are arranged in parallel and spaced apart along the height direction of the accommodating cavity, and a reaction space is formed between two adjacent material boxes; a partition is arranged in the material box, and the partition separates the material box into multiple material storage spaces;
[0009] An accommodating space is formed between one end of the material box and the first side wall of the accommodating chamber, and the accommodating space is connected to the reaction space and the vent hole respectively; the other end of the material box is closed to the second side wall of the accommodating chamber, and an vent hole connected to the reaction space is formed at the other end of the material box.
[0010] In a feasible implementation, a plurality of partitions are evenly spaced along the extension direction of the material box.
[0011] In a feasible implementation, first protrusions are formed on the side walls of the accommodating cavity located on both sides of the material box, the first protrusions extend along the setting direction of the material box, and track grooves are formed along the extending direction of the first protrusions;
[0012] The bottom wall of the material box is formed with a second protrusion which is matched with the track groove.
[0013] In a feasible implementation, a card slot is formed on the side wall of the partition, and a buckle that matches the card slot is formed on the side wall of the material box;
[0014] Alternatively, a buckle is formed on the side wall of the partition, and a slot that matches the buckle is formed on the side wall of the material box.
[0015] In a feasible implementation, the height of the partition is the same as the height of the end wall of the material box.
[0016] In a second aspect, an embodiment of the present application provides a method for decarburizing silicon carbide powder, which is applied to the silicon carbide powder decarburization device described in any technical solution of the first aspect, and the method comprises the following steps:
[0017] The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder;
[0018] Spread the silicon carbide powder evenly into the storage space of the material box;
[0019] Oxygen is introduced into the containing cavity through the vent hole, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0020] In a feasible implementation, after the step of introducing oxygen into the containing chamber through the vent hole and heating and heat preservation to obtain the decarbonized silicon carbide powder, the step further includes:
[0021] After the decarburization device is cooled to room temperature, the decarburized silicon carbide powder is taken out and sieved with a sieve to obtain high-purity silicon carbide powder.
[0022] In a feasible implementation, the screen is made of polymer material.
[0023] In a feasible implementation, the thickness of the silicon carbide powder in the material box is not greater than 2 / 3 of the height of the end wall of the material box.
[0024] In a feasible implementation, oxygen is introduced into the containing chamber through the vent hole, and heating and heat preservation are performed to obtain the decarbonized silicon carbide powder, which specifically includes:
[0025] Oxygen with a flow rate of 1000sccm-1500sccm is introduced into the containing chamber through the vent hole;
[0026] The decarbonization device is heated to 600°C to 1000°C and then kept warm for 8H to 10H to obtain decarbonized silicon carbide powder.
[0027] In the first aspect, the embodiment of the present application provides a decarburization device for silicon carbide powder. In the embodiment of the present application, by setting the housing and the material box as quartz parts, the introduction of metal impurities in the decarburization process of silicon carbide powder is avoided, and the purity of silicon carbide powder after decarburization is improved. Further, the embodiment of the present application forms a path for oxygen flow reaction through the setting of vents, accommodating space, reaction space and outlet holes. Through the setting of the accommodating space, it is possible to ensure that the gas fully flows in the accommodating cavity, thereby improving the utilization efficiency of oxygen, so as to effectively remove the free carbon in the silicon carbide powder and ensure the purity of the silicon carbide powder after decarburization. Further, the embodiment of the present application is provided by the setting of multiple material boxes, and each material box is separated by a partition to form a plurality of storage spaces, so that oxygen and silicon carbide powder in each storage space can fully react, ensuring the uniformity of the decarburization effect. And through the setting of multiple material boxes, the charging amount and production efficiency can also be improved. Through the setting of the embodiment of the present application, a decarburization device is provided that makes the silicon carbide powder after decarburization have high purity and high reaction efficiency.
[0028] In the second aspect, the embodiment of the present application also provides a method for decarbonizing silicon carbide powder. Since the method adopts the decarbonization device in the first aspect, the method has all the technical effects of the first aspect and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0030] Figure 1 It is a structural schematic diagram of a silicon carbide powder decarbonization device provided in one embodiment of the present application;
[0031] Figure 2 yes Figure 1 A schematic diagram of the structure of the middle shell;
[0032] Figure 3 yes Figure 1 Schematic diagram of the structure of the material box;
[0033] Figure 4 yes Figure 1 A cross-sectional view of a structure showing a gas flow path;
[0034] Figure 5 This is a method flow chart of a method for decarburizing silicon carbide powder provided in one embodiment of the present application;
[0035] Figure 6 yes Figure 5 Specific method flow chart of S3.
[0036] Description of reference numerals:
[0037] 100-housing; 200-material box;
[0038] 110 - accommodating cavity; 120 - vent hole; 130 - first protrusion; 131 - track groove; 140 - accommodating space;
[0039] 210 - partition; 220 - material storage space; 230 - air outlet; 240 - second protrusion; 250 - operating handle; 260 - reaction space. DETAILED DESCRIPTION
[0040] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.
[0041] It should be noted that many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific implementation methods disclosed below.
[0042] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the present application, unless otherwise expressly specified and limited, a first feature being "up" or "down" a second feature may be the first and second features directly contacting, or the first and second features indirectly contacting through an intermediate medium.
[0043] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. However, if it is indicated as a direct connection, it means that the two connected entities are not connected through an intermediate structure, but are only connected to form a whole through a connecting structure. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0044] In this application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.
[0045] As a representative of the third generation of broadband semiconductor materials, silicon carbide (SiC) has an irreplaceable position in high temperature, high voltage and high frequency applications due to its excellent properties such as high critical breakdown electric field, high thermal conductivity and high electron saturation mobility. Especially in core components such as DC-DC converters, on-board chargers (OBCs) and motor controllers in new energy vehicle drive systems, as well as strategic emerging industries such as photovoltaic inverters, 5G base station RF devices, and aerospace equipment, the application demand for silicon carbide devices is showing explosive growth. At present, physical vapor transport (PVT) has become the mainstream process for the growth of silicon carbide single crystals. In the PVT growth process, the purity of silicon carbide powder is one of the key factors affecting the quality of the crystal. Impurities in silicon carbide powder will not only cause defects such as micropipes and dislocations in the crystal, but also reduce the electrical properties, breakdown voltage and reliability of the device.
[0046] In the related art, silicon carbide powder is mainly prepared by an improved self-propagating high temperature synthesis method (SHS). In the self-propagating high temperature synthesis method, silicon powder and carbon powder are mixed in a certain proportion under an inert atmosphere, and the reaction is maintained by the heat released by the reaction after local ignition. However, due to the solid-phase reaction characteristics of the improved self-propagating high temperature synthesis method, the diffusion between the reactants is limited, and the reaction temperature and pressure are difficult to accurately control, resulting in widespread residual free carbon in the synthesized powder. However, the free carbon in the silicon carbide powder will have a serious adverse effect on the subsequent single crystal growth. The traditional treatment process for removing free carbon from silicon carbide powder is a decarburization process, which usually includes multiple steps such as crushing, magnetic separation, rinsing, pickling and screening.
[0047] However, the decarburization process of the conventional silicon carbide powder contains impurities in the decarburized silicon carbide powder, which results in a decrease in the purity of the silicon carbide powder and easily causes defects in the subsequent crystal growth of the silicon carbide powder, thus affecting the device performance.
[0048] Therefore, the embodiments of the present application provide a silicon carbide powder decarbonization device and a decarbonization method to solve the technical problem in the related art that impurities exist in the silicon carbide powder after decarbonization, which easily causes defects in the silicon carbide powder during subsequent crystal growth and affects device performance.
[0049] Figure 1 It is a structural schematic diagram of a silicon carbide powder decarbonization device provided in one embodiment of the present application; Figure 2 yes Figure 1 A schematic diagram of the structure of the middle shell; Figure 3 yes Figure 1 Schematic diagram of the structure of the material box.
[0050] First, refer to Figures 1 to 3 , the embodiment of the present application provides a decarbonization device for silicon carbide powder, comprising: a shell 100 and a material box 200, wherein the shell 100 and the material box 200 are both configured as quartz parts;
[0051] The housing 100 is formed with a receiving chamber 110, and a vent hole 120 communicating with the receiving chamber 110 is provided at the bottom of the housing 100, and the vent hole 120 is used to introduce oxygen into the receiving chamber 110;
[0052] A plurality of material boxes 200 are provided, and the plurality of material boxes 200 are arranged in parallel and spaced apart along the height direction of the accommodating chamber 110, and a reaction space 260 is formed between two adjacent material boxes 200; a partition 210 is provided in the material box 200, and the partition 210 divides the material box 200 into a plurality of material storage spaces 220;
[0053] A accommodating space 140 is formed between one end of the material box 200 and the first side wall of the accommodating chamber 110, and the accommodating space 140 is respectively connected to the reaction space 260 and the vent 120; the other end of the material box 200 is closed to the second side wall of the accommodating chamber 110, and the other end of the material box 200 is formed with an outlet hole 230 connected to the reaction space 260.
[0054] It should be noted that the housing 100 and the material box 200 are both made of high-purity quartz material to prevent the silicon carbide powder from introducing metal impurities into the silicon carbide powder during the decarburization process. Of course, the partition 210 is a part of the material box 200 and is also made of high-purity quartz.
[0055] For example, the material box 200 can be divided into material storage spaces 220 of different shapes and sizes by using partitions 210 as needed.
[0056] Exemplarily, guide rails are provided on the side walls of the accommodating chamber 110 on both sides of the material box 200 , and rollers adapted to the guide rails are provided on the side walls of the material box 200 to enable the material box 200 to be installed in or removed from the accommodating chamber 110 .
[0057] Exemplarily, the height of the accommodating cavity 110 can be set to 400 mm to 800 mm, that is, the height of the accommodating cavity 110 can be set to 400 mm, 450 mm, 485.5 mm, 800 mm, etc. The height of the end wall of the material box 200 can be set to 60 mm to 80 mm, that is, the height of the end wall of the material box 200 can be set to 60 mm, 70 mm, 75.5 mm, 80 mm, etc.
[0058] For example, the vent hole 120 may be disposed in the middle area of the bottom of the accommodating cavity 110. The diameter of the vent hole 120 is set to 20 mm to 50 mm, that is, the diameter of the vent hole 120 may be set to 20 mm, 30 mm, 45 mm, 50 mm, etc.
[0059] Furthermore, the length of the accommodating space 140 along the extending direction of the material box 200 is set to 40 mm to 50 mm. That is, the length of the accommodating space 140 along the extending direction of the material box 200 can be set to 40 mm, 42 mm, 45 mm, 50 mm, etc.
[0060] Figure 4 yes Figure 1 A cross-sectional view of the structure showing the gas flow path.
[0061] In specific implementation, refer to Figure 4After the silicon carbide powder is spread in the storage space 220 of each material box 200, oxygen is introduced into the vent hole 120, and the oxygen enters the bottom of the accommodating chamber 110 through the vent hole 120, diffuses from the bottom of the accommodating chamber 110 to the accommodating space 140, and then diffuses from the accommodating space 140 to the reaction space 260 of the material box 200. The oxygen reacts with the free carbon in the reaction space 260, and the carbon monoxide, carbon dioxide and unreacted oxygen produced after the reaction flow out through the outlet hole 230 of the material box 200 ( Figure 4 The arrow in the middle shows the flow path of oxygen).
[0062] From the above description, it can be seen that this solution achieves the following technical effects:
[0063] The embodiment of the present application provides a decarburization device for silicon carbide powder. In the embodiment of the present application, by setting the housing 100 and the material box 200 as quartz parts, the introduction of metal impurities in the decarburization process of the silicon carbide powder is avoided, and the purity of the silicon carbide powder after decarburization is improved. Further, the embodiment of the present application forms a path for oxygen flow reaction through the arrangement of the vent 120, the accommodating space 140, the reaction space 260 and the outlet 230. Through the arrangement of the accommodating space 140, it is possible to ensure that the gas fully flows in the accommodating chamber 110, thereby improving the utilization efficiency of oxygen, so as to effectively remove the free carbon in the silicon carbide powder and ensure the purity of the silicon carbide powder after decarburization. Further, the embodiment of the present application is through the arrangement of multiple material boxes 200, and each material box 200 is separated by a partition 210 to form a plurality of storage spaces 220, so that oxygen and the silicon carbide powder in each storage space 220 can fully react, ensuring the uniformity of the decarburization effect. Furthermore, the charging amount and production efficiency can be increased by providing multiple material boxes 200. Through the configuration of the embodiment of the present application, a decarburization device is provided, which can make the silicon carbide powder material with high purity and high reaction efficiency after decarburization.
[0064] Exemplarily, a plurality of partitions 210 are evenly spaced apart along the extension direction of the material box 200 .
[0065] For example, the spacing between adjacent partitions 210 can be set to 40 mm to 50 mm, that is, the distance between adjacent partitions 210 can be set to 40 mm, 43 mm, 45.5 mm, 50 mm, etc.
[0066] In specific implementation, when the length of the material box 200 remains unchanged, as the number of partitions 210 increases, the reaction between the silicon carbide powder and oxygen becomes more complete, but the silicon carbide powder contained in the material box 200 becomes less, and the cost of the decarburization device increases with the increase in the number of partitions 210. When the spacing between adjacent partitions 210 is set to 40mm to 50mm, not only can the silicon carbide powder and oxygen fully react, but also the amount of reacted materials can be guaranteed, and the cost can also be controlled.
[0067] In the embodiment of the present application, a plurality of partitions 210 are evenly spaced along the extension direction of the material box 200, so that the storage space 220 can be distributed along the flow direction of oxygen, so that the silicon carbide powder in the storage space 220 can react better with oxygen.
[0068] Exemplarily, the side walls of the accommodating cavity 110 located on both sides of the material box 200 are formed with first protrusions 130, the first protrusions 130 extend along the setting direction of the material box 200, and a track groove 131 is formed along the extending direction of the first protrusions 130;
[0069] The bottom wall of the material box 200 is formed with a second protrusion 240 that fits with the track groove 131 .
[0070] For example, an operating handle 250 is further provided on the outer side wall of the material box 200 to facilitate taking and placing the material box 200 .
[0071] The embodiment of the present application realizes the disassembly and installation of the material box 200 and the accommodating chamber 110 by setting the track groove 131 and the second protrusion 240. When a material box 200 is damaged, it can be replaced individually, avoiding the waste of resources caused by the overall replacement of the decarbonization device.
[0072] Exemplarily, a slot is formed on the side wall of the partition 210, and a buckle that matches the slot is formed on the side wall of the material box 200;
[0073] Alternatively, a buckle is formed on the side wall of the partition 210, and a slot that matches the buckle is formed on the side wall of the material box 200.
[0074] The embodiment of the present application facilitates the assembly and disassembly of the partition 210 and the material box 200 by providing the buckle and the slot, and the partition 210 and the material box 200 can be assembled or disassembled according to actual production needs.
[0075] In some other examples, the height of the partition 210 is the same as the height of the end wall of the material box 200 .
[0076] For example, the height of the partition 210 may be set to 60 mm to 80 mm, that is, the height of the partition 210 may be a suitable height such as 60 mm, 70 mm, 75 mm, or 80 mm.
[0077] Figure 5 This is a method flow chart of a method for decarburizing silicon carbide powder provided in one embodiment of the present application.
[0078] Second, refer to Figure 5 The embodiment of the present application also provides a method for decarbonizing silicon carbide powder, and the decarbonization method adopts the decarbonization device in any technical solution disclosed in the first aspect.
[0079] The decarbonization method comprises the following steps:
[0080] S1: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder.
[0081] For example, the jaw crusher may be a ceramic jaw crusher.
[0082] In the process of crushing the silicon carbide block powder in the embodiment of the present application, a jaw crusher made of silicon carbide material is used to avoid the introduction of metal impurities into the silicon carbide powder, so as to improve the purity of the silicon carbide powder after decarburization.
[0083] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0084] For example, in order to ensure uniform reaction of the silicon carbide powder in the decarburization device, when the silicon carbide powder is spread into the storage space 220 of the material box 200 , the thickness of the silicon carbide powder in each storage space 220 needs to be consistent.
[0085] Exemplarily, the thickness of the silicon carbide powder in the material box 200 is not greater than 2 / 3 of the height of the end wall of the material box 200. When the thickness of the silicon carbide powder in the material box 200 is greater than 2 / 3 of the height of the end wall of the material box 200, due to the large thickness of the silicon carbide powder, the silicon carbide powder at the bottom of the material box 200 cannot fully react with oxygen, which easily leads to poor decarburization effect of the silicon carbide powder after decarburization.
[0086] Of course, the thickness of the silicon carbide powder in the material box 200 should not be less than 1 / 6 of the height of the end wall of the material box 200. When the thickness of the silicon carbide powder in the material box 200 is less than 1 / 6 of the height of the end wall of the material box 200, the capacity of the decarburization device will be reduced, thereby reducing the decarburization output of the silicon carbide powder.
[0087] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0088] Figure 6 yes Figure 5 Specific method flow chart of S3.
[0089] Among them, refer to Figure 6 , S3 specifically includes:
[0090] S301 : introducing oxygen gas with a flow rate of 1000 sccm to 1500 sccm into the containing chamber 110 through the vent hole 120 .
[0091] For example, the vent 120 allows 1000 sccm of oxygen to flow into the containment chamber 110 , or the vent 120 allows 1200 sccm of oxygen to flow into the containment chamber 110 , or the vent 120 allows 1350 sccm of oxygen to flow into the containment chamber 110 , or the vent 120 allows 1500 sccm of oxygen to flow into the containment chamber 110 .
[0092] As another example, the purity of oxygen is 99.999%.
[0093] S302: After heating the decarbonization device to 600°C to 1000°C, the temperature is kept at this temperature for 8 hours to 10 hours to obtain decarbonized silicon carbide powder.
[0094] Exemplarily, a heating cavity is formed between the side wall of the accommodating cavity 110 and the housing 100, and a resistance wire is arranged in the heating cavity to heat the decarburization device. Of course, a microwave heating device can also be arranged in the heating cavity.
[0095] In specific implementation, the decarburization heating device can heat to temperatures such as 600°C, 700°C, 750°C and 1000°C.
[0096] In specific implementation, the insulation time can be 8H, 8.5H, 9H, 10H or other suitable time.
[0097] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0098] Exemplarily, the screen can be made of a polymer material, for example, the screen can be made of a polymer material such as polyurethane or polytetrafluoroethylene to avoid the introduction of metal impurities.
[0099] In order to further illustrate the present invention, a method for decarbonizing silicon carbide powder provided by the present invention is described in detail below in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.
[0100] Embodiment 1
[0101] S1: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder.
[0102] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0103] In this step, the specific dimensions of the decarbonization device used are: the height of the accommodating chamber 110 is set to 400 mm, the end wall height of the material box 200 is set to 50 mm, the number of material boxes 200 is set to 4, the number of partitions 210 is set to 4 layers, the diameter of the vent 120 is set to 30 mm, the length of the accommodating space 140 along the extension direction of the material box 200 is set to 30 mm, and the thickness of the silicon carbide powder spread flat in the material box 200 is 25 mm.
[0104] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0105] Among them, S3 specifically includes:
[0106] S301 : introducing oxygen gas at a flow rate of 1000 sccm into the containing chamber 110 through the vent hole 120 .
[0107] S302: After heating the decarbonization device to 600°C, keep it warm for 8 hours to obtain decarbonized silicon carbide powder.
[0108] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0109] The content of metal impurities (Al, Fe, Mn, V, Ti) in the high-purity silicon carbide powder prepared by Example 1 is lower than 0.01PPM, and the content of free carbon is 0.3wt% to 0.5wt%. In Example 1, not only the content of metal impurities and the content of free carbon in the high-purity silicon carbide powder are effectively guaranteed, but also the reaction yield and reaction efficiency of the high-purity silicon carbide powder are greatly improved.
[0110] Embodiment 2
[0111] S1: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder.
[0112] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0113] In this step, the specific dimensions of the decarbonization device used are: the height of the accommodating chamber 110 is set to 400 mm, the end wall height of the material box 200 is set to 50 mm, the number of material boxes 200 is set to 3, the number of partitions 210 is set to 4 layers, the diameter of the vent 120 is set to 30 mm, the length of the accommodating space 140 along the extension direction of the material box 200 is set to 30 mm, and the thickness of the silicon carbide powder spread flat in the material box 200 is 25 mm.
[0114] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0115] Among them, S3 specifically includes:
[0116] S301 : introducing oxygen gas at a flow rate of 1000 sccm into the containing chamber 110 through the vent hole 120 .
[0117] S302: After heating the decarbonization device to 600°C, keep it warm for 8 hours to obtain decarbonized silicon carbide powder.
[0118] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0119] The contents of metal impurities (Al, Fe, Mn, V, Ti) in the high-purity silicon carbide powder prepared in Example 2 are all lower than 0.01 PPM, and the content of free carbon is less than 0.3 wt%.
[0120] Embodiment 3
[0121] S1: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder.
[0122] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0123] In this step, the specific dimensions of the decarbonization device used are: the height of the accommodating chamber 110 is set to 400 mm, the end wall height of the material box 200 is set to 50 mm, the number of material boxes 200 is set to 4, the number of partitions 210 is set to 5 layers, the diameter of the vent 120 is set to 30 mm, the length of the accommodating space 140 along the extension direction of the material box 200 is set to 30 mm, and the thickness of the silicon carbide powder spread flat in the material box 200 is 25 mm.
[0124] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0125] Among them, S3 specifically includes:
[0126] S301 : introducing oxygen gas at a flow rate of 1000 sccm into the containing chamber 110 through the vent hole 120 .
[0127] S302: After heating the decarbonization device to 600°C, keep it warm for 8 hours to obtain decarbonized silicon carbide powder.
[0128] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0129] The contents of metal impurities (Al, Fe, Mn, V, Ti) in the high-purity silicon carbide powder prepared in Example 3 are all lower than 0.01 PPM, and the content of free carbon is 0.5 wt% to 1 wt%.
[0130] Embodiment 4
[0131] S1: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder.
[0132] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0133] In this step, the specific dimensions of the decarbonization device used are: the height of the accommodating chamber 110 is set to 400 mm, the end wall height of the material box 200 is set to 50 mm, the number of material boxes 200 is set to 4, the number of partitions 210 is set to 5 layers, the diameter of the vent 120 is set to 30 mm, the length of the accommodating space 140 along the extension direction of the material box 200 is set to 30 mm, and the thickness of the silicon carbide powder spread flat in the material box 200 is 25 mm.
[0134] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0135] Among them, S3 specifically includes:
[0136] S301 : introducing oxygen gas at a flow rate of 1000 sccm into the containing chamber 110 through the vent hole 120 .
[0137] S302: After heating the decarbonization device to 800°C, keep it warm for 6 hours to obtain decarbonized silicon carbide powder.
[0138] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0139] The contents of metal impurities (Al, Fe, Mn, V, Ti) in the high-purity silicon carbide powder prepared in Example 4 are all lower than 0.01 PPM, and the content of free carbon is 1 wt% to 1.5 wt%.
[0140] Embodiment 5
[0141] S1: The silicon carbide block material is crushed using a manganese steel jaw crusher to obtain silicon carbide powder.
[0142] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0143] In this step, the specific dimensions of the decarbonization device used are: the height of the accommodating chamber 110 is set to 400 mm, the end wall height of the material box 200 is set to 50 mm, the number of material boxes 200 is set to 4, the number of partitions 210 is set to 4 layers, the diameter of the vent 120 is set to 30 mm, the length of the accommodating space 140 along the extension direction of the material box 200 is set to 30 mm, and the thickness of the silicon carbide powder spread flat in the material box 200 is 25 mm.
[0144] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0145] Among them, S3 specifically includes:
[0146] S301 : introducing oxygen gas at a flow rate of 1000 sccm into the containing chamber 110 through the vent hole 120 .
[0147] S302: After heating the decarbonization device to 600°C, keep it warm for 8 hours to obtain decarbonized silicon carbide powder.
[0148] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0149] The content of metal impurities (Al, Fe, Mn, V, Ti) in the high-purity silicon carbide powder prepared by Example 5 is less than 1PPM, and the content of free carbon is 0.3wt% to 0.5wt%. Due to the high content of metal impurities in the high-purity silicon carbide powder, the high-purity silicon carbide powder obtained by Example 5 cannot be used for semiconductor-grade silicon carbide single crystal growth.
[0150] Embodiment 6
[0151] S1: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder.
[0152] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0153] In this step, the specific dimensions of the decarbonization device used are: the height of the accommodating chamber 110 is set to 400 mm, the end wall height of the material box 200 is set to 50 mm, the number of material boxes 200 is set to 4, the number of partitions 210 is set to 4 layers, the diameter of the vent 120 is set to 30 mm, the length of the accommodating space 140 along the extension direction of the material box 200 is set to 0 mm, and the thickness of the silicon carbide powder spread flat in the material box 200 is 25 mm.
[0154] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0155] Among them, S3 specifically includes:
[0156] S301 : introducing oxygen gas at a flow rate of 1000 sccm into the containing chamber 110 through the vent hole 120 .
[0157] S302: After heating the decarbonization device to 600°C, keep it warm for 8 hours to obtain decarbonized silicon carbide powder.
[0158] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0159] The contents of metal impurities (Al, Fe, Mn, V, Ti) in the high-purity silicon carbide powder prepared in Example 6 are all lower than 0.1 PPM, and the content of free carbon is 0.3 wt% to 0.5 wt%.
[0160] Embodiment 7
[0161] S1: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder.
[0162] S2: Spreading the silicon carbide powder into the material storage space 220 of the material box 200 .
[0163] In this step, the specific dimensions of the decarbonization device used are: the height of the accommodating chamber 110 is set to 400 mm, the end wall height of the material box 200 is set to 50 mm, the number of material boxes 200 is set to 4, the number of partitions 210 is set to 0 layers, the diameter of the vent 120 is set to 30 mm, the length of the accommodating space 140 along the extension direction of the material box 200 is set to 0 mm, and the thickness of the silicon carbide powder spread flat in the material box 200 is 25 mm.
[0164] S3: introducing oxygen into the containing chamber 110 through the vent hole 120, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
[0165] Among them, S3 specifically includes:
[0166] S301 : introducing oxygen gas at a flow rate of 1000 sccm into the containing chamber 110 through the vent hole 120 .
[0167] S302: After heating the decarbonization device to 600°C, keep it warm for 8 hours to obtain decarbonized silicon carbide powder.
[0168] S4: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out, and the decarbonized silicon carbide powder is sieved with a sieve to obtain high-purity silicon carbide powder.
[0169] The contents of metal impurities (Al, Fe, Mn, V, Ti) in the high-purity silicon carbide powder prepared by Example 7 are all lower than 0.1 PPM, and the content of free carbon is greater than 0.5 wt%. Due to the high content of free carbon in the high-purity silicon carbide powder, the high-purity silicon carbide powder obtained by Example 7 cannot be used for semiconductor-grade silicon carbide single crystal growth.
[0170] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments based on the several embodiments provided in the present application, and these embodiments do not exceed the protection scope of the present application.
[0171] The above specific implementation methods further explain in detail the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above are only specific implementation methods of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.
Claims
1. A silicon carbide powder decarbonization device, characterized in that: include: A shell and a material box, wherein the shell and the material box are both configured as quartz pieces; The shell is formed with a containing cavity, and the bottom of the shell is provided with a vent hole communicating with the containing cavity, and the vent hole is used to let oxygen into the containing cavity; There are multiple material boxes, which are arranged in parallel and spaced apart along the height direction of the accommodating cavity, and a reaction space is formed between two adjacent material boxes; a partition is arranged in the material box, and the partition divides the material box into multiple material storage spaces; An accommodating space is formed between one end of the material box and the first side wall of the accommodating chamber, and the accommodating space is respectively connected to the reaction space and the vent hole; the other end of the material box is closed to the second side wall of the accommodating chamber, and the other end of the material box is formed with an vent hole connected to the reaction space.
2. The decarbonization device for silicon carbide powder according to claim 1, characterized in that: A plurality of partitions are evenly spaced along the extending direction of the material box.
3. The decarbonization device for silicon carbide powder according to claim 1, characterized in that: The side walls of the accommodating cavity located on both sides of the material box are formed with first protrusions, the first protrusions extend along the setting direction of the material box, and a track groove is formed along the extending direction of the first protrusions; The bottom wall of the material box is formed with a second protrusion which is matched with the track groove.
4. The decarbonization device for silicon carbide powder according to claim 1, characterized in that: The partition side wall is formed with a card slot, and the material box side wall is formed with a buckle that matches the card slot; Alternatively, a buckle is formed on the side wall of the partition, and a slot adapted to fit the buckle is formed on the side wall of the material box.
5. A silicon carbide powder decarbonization device according to any one of claims 1 to 4, characterized in that: The height of the partition is the same as the height of the end wall of the material box.
6. A method for decarburizing silicon carbide powder, characterized in that: Applicable to the silicon carbide powder decarbonization device according to any one of claims 1 to 5, the method comprises the following steps: The silicon carbide block material is crushed using a silicon carbide jaw crusher to obtain silicon carbide powder; Spread the silicon carbide powder evenly into the storage space of the material box; Oxygen is introduced into the containing cavity through the vent hole, and heating and heat preservation are performed to obtain decarbonized silicon carbide powder.
7. A method for decarburizing silicon carbide powder according to claim 6, characterized in that: After the step of introducing oxygen into the containing cavity through the vent hole and heating and heat preservation to obtain the decarbonized silicon carbide powder, the method further includes: After the decarbonization device is cooled to room temperature, the decarbonized silicon carbide powder is taken out and sieved with a sieve to obtain high-purity silicon carbide powder.
8. The method for decarburizing silicon carbide powder according to claim 7, characterized in that: The screen is made of polymer material.
9. The method for decarburizing silicon carbide powder according to claim 6, characterized in that: The thickness of the silicon carbide powder in the material box is not greater than 2 / 3 of the height of the end wall of the material box.
10. The method for decarburizing silicon carbide powder according to claim 6, characterized in that: The step of introducing oxygen into the containing cavity through the vent hole and heating and heat preservation to obtain the decarbonized silicon carbide powder specifically includes: Oxygen with a flow rate of 1000sccm-1500sccm is introduced into the containing chamber through the vent hole; The decarbonization device is heated to 600°C to 1000°C and then kept warm for 8H to 10H to obtain decarbonized silicon carbide powder.