High-purity silicon carbide structural member, method for producing the same, and use thereof

Abstract

The application provides a high-purity silicon carbide structural member and a preparation method and application thereof. The preparation method comprises the following steps: preparing slurry by mixing beta-phase silicon carbide powder with a first particle size and beta-phase silicon carbide powder with a second particle size according to a weight ratio of 10:1-2, wherein the purity of the beta-phase silicon carbide powder with the first particle size is greater than or equal to 99.999%, and the purity of the beta-phase silicon carbide powder with the second particle size is greater than or equal to 99.999%, and the first particle size is greater than the second particle size; ball-milling the slurry, performing suction filtration, and drying to obtain mixed powder; dry-pressing the mixed powder into a blank; cold isostatic pressing the blank to obtain a blank; performing hot isostatic pressing sintering on the blank to obtain a silicon carbide ceramic member; and performing post-processing on the silicon carbide ceramic member to obtain the high-purity silicon carbide structural member. The technical problem to be solved is how to prepare a high-purity silicon carbide structural member, so that the high-purity silicon carbide structural member can simultaneously have high purity and high density, the production efficiency is improved, the manufacturing cost is reduced, and the high-purity silicon carbide structural member is easier to be mass-produced, thereby being more suitable for practical use.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material preparation technology, and in particular to a high-purity silicon carbide structural component, its preparation method, and its application. Background Technology

[0002] The semiconductor industry follows the development pattern of "one generation of technology, one generation of process, one generation of equipment". Semiconductor equipment is the bottleneck and key to continuing "Moore's Law", while precision components are the direct guarantee of the core technology of semiconductor equipment.

[0003] Silicon carbide, as an important wide-bandgap semiconductor material, possesses numerous excellent properties such as high strength, high hardness, high thermal conductivity, low density, low scattering, low expansion, radiation resistance, oxidation resistance, and thermal shock resistance. It also exhibits chemical stability and environmental friendliness, making it a crucial structural material. Silicon carbide precision ceramic components are widely used in core equipment for several critical semiconductor manufacturing processes, including photolithography, etching, thin film deposition, ion implantation, and CMP, such as focusing rings, spray disks, annealing disks, and crystal boats. These components place stringent technical requirements on the density and purity of silicon carbide ceramics.

[0004] Currently, the preparation of high-purity silicon carbide materials faces two major technical challenges: Firstly, as a strongly covalently bonded carbide, the densification and sintering technology for high-purity silicon carbide powder is extremely difficult. Densification is typically achieved by adding sintering aids, such as BC and Al2O3, but these aids contaminate the material itself, failing to meet the current requirements for the development and application of high-purity silicon carbide semiconductors. Secondly, while existing chemical vapor deposition (CVD) methods can prepare high-purity silicon carbide materials, the resulting materials suffer from problems such as long processing time, high cost, high machining difficulty, and low yield, making mass production difficult and severely limiting the development of silicon carbide component manufacturing. Summary of the Invention

[0005] The main objective of this invention is to provide a high-purity silicon carbide structural component, its preparation method, and its application. The technical problem to be solved is how to prepare a high-purity silicon carbide structural component that can simultaneously achieve high purity and high density, while improving production efficiency, reducing manufacturing costs, and making it easier to mass-produce, thus making it more suitable for practical use.

[0006] The objective of this invention and the technical problem it solves are achieved through the following technical solution. A method for preparing a high-purity silicon carbide structural component according to this invention includes the following steps:

[0007] S11. β-phase silicon carbide powder with a purity ≥99.999% and a first particle size of β-phase silicon carbide powder with a purity ≥99.999% is mixed with β-phase silicon carbide powder with a second particle size of ≥99.999% at a weight ratio of 10:1~2 to form a slurry. The slurry is then ball-milled, filtered, and dried to obtain a mixed powder; wherein the first particle size is greater than the second particle size.

[0008] S12 first dry-presses the mixed powder into shape, then cold isostatically presses it to obtain a blank;

[0009] S13 involves hot isostatic pressing of the blank to obtain silicon carbide ceramic parts.

[0010] S14 performs post-processing on silicon carbide ceramic parts to obtain high-purity silicon carbide structural parts.

[0011] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0012] Preferably, in the preparation method, the first particle size is 0.5-1.0 μm and the second particle size is 0.1-0.3 μm; the β-phase silicon carbide powder with the second particle size is synthesized by chemical vapor deposition.

[0013] Preferably, in the preparation method, the slurry is prepared by dispersing silicon carbide powder in toluene or cyclohexane solvent; wherein the solvent accounts for 10-20% of the weight of the slurry.

[0014] Preferably, in the preparation method, the ball mill container is made of polyurethane or polytetrafluoroethylene, and the ball milling time is 12-24 hours.

[0015] Preferably, in the preparation method, the drying is vacuum drying; the temperature is 80-100℃, the vacuum degree is -0.08--0.1MPa, and the time is 6-12h.

[0016] Preferably, in the preparation method, cold isostatic pressing is carried out in a silicone or polyurethane sleeve, and the pressure of cold isostatic pressing is 250-270 MPa; the pressure of dry pressing is 30-50 MPa.

[0017] Preferably, in the preparation method, during hot isostatic pressing sintering, the billet is placed in a tungsten alloy sheath, and high-purity graphite paper is placed between the billet and the sheath for isolation.

[0018] Preferably, in the preparation method, the hot isostatic pressing sintering temperature is 1800-1900℃, the pressure is 100-150MPa, and the time is 1-2h.

[0019] The objective of this invention and the technical problem it solves are achieved by the following technical solution: A high-purity silicon carbide structural component prepared according to the aforementioned preparation method.

[0020] The objective of this invention and the technical problem it solves are achieved through the following technical solution: An application of a high-purity silicon carbide structural component, as described above, in the fields of semiconductor materials and semiconductor devices, according to this invention.

[0021] By employing the above technical solution, the high-purity silicon carbide structural component, its preparation method, and its application proposed in this invention have at least the following advantages:

[0022] This invention proposes high-purity silicon carbide structural components, their preparation method, and applications. By using β-phase silicon carbide powder with a purity ≥99.999% as raw material, the material achieves high purity and a single crystal phase. Furthermore, the absence of sintering aids in the formulation effectively avoids contamination, thus maintaining a stable purity of over 99.999%. Simultaneously, β-phase silicon carbide exhibits superior mechanical properties and thermal stability, meeting the stringent requirements for material consistency in semiconductor equipment components. The β-phase silicon carbide powder of this invention employs a blend of two particle sizes, wherein the second particle size fine powder can... Filling the gaps between coarse powders of the first particle size allows for tight powder packing, laying the foundation for subsequent densification. Simultaneously, the preparation process of this invention employs a multi-step forming and sintering design. First, dry pressing initially shapes the mixed powder, quickly obtaining a regular green body. Then, cold isostatic pressing further compacts the green body, achieving uniform pressure in all directions, effectively eliminating internal porosity and stress, ultimately significantly improving the density of the green body. Finally, hot isostatic pressing sintering effectively reduces the sintering temperature, increases ceramic density, and effectively achieves densification sintering of high-purity silicon carbide, with a silicon carbide density reaching 98%. As can be seen from the above, the technical solution of the present invention can simultaneously take into account the high purity and high density of the product. Moreover, it directly uses high-purity silicon carbide powder as raw material, eliminating the complex steps of "silicon powder-graphite powder to synthesize silicon carbide" in the traditional process, shortening the production cycle. Furthermore, the multi-step forming and sintering process design of the present invention is not only conducive to the densification of the material, but the hot isostatic pressing process can also reduce the sintering temperature through high pressure compensation, reducing energy consumption and material loss at high temperatures, significantly reducing the preparation cost, and facilitating mass production.

[0023] The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the appendix. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the process flow of the preparation method of the present invention;

[0025] Figure 2 A photograph of the silicon carbide ceramic sample prepared in Example 1 of this invention - spray plate;

[0026] Figure 3The image shows a physical sample of the silicon carbide ceramic prepared in Example 1 of this invention – a reflector. Detailed Implementation

[0027] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the appended tables and preferred embodiments, details the specific implementation methods and effects of a high-purity silicon carbide structural component, its preparation method, and its application according to the present invention. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, the results of one or more embodiments can be combined in any suitable manner. These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​described in these embodiments should be interpreted as merely exemplary and not as limiting.

[0028] This invention proposes a method for preparing high-purity silicon carbide structural components, as shown in the attached figure. Figure 1 As shown, it includes the following steps:

[0029] First, there is the raw material preparation. This invention directly uses two types of high-purity silicon carbide powder with different particle sizes as raw materials for slurry preparation. This avoids the numerous steps involved in traditional processes, such as synthesis reactions, decarburization, and purification using carbon and silicon powder. This improves production efficiency and avoids the risk of process contamination from impurities introduced during preparation. Furthermore, during slurry preparation, only the two types of high-purity silicon carbide powder with different particle sizes need to be dispersed in a suitable solvent for subsequent ball milling. No other materials need to be added; that is, no sintering aids are added to the raw materials. Densification is achieved entirely through the close packing of the powder itself and high temperature and pressure, fundamentally avoiding contamination of material purity by additives and meeting the requirements of semiconductor equipment for high-purity materials (purity ≥ 99.999%).

[0030] To improve the density of the material, this invention preferably uses a blend of two high-purity silicon carbide powders with different particle sizes. The finer powder fills the gaps between the coarser powders, achieving close packing and laying the foundation for subsequent densification. In some specific embodiments of this invention, the particle size of the coarse powder (i.e., the first particle size) is preferably 0.5–1.0 μm, and the particle size of the fine powder (i.e., the second particle size) is preferably 0.1–0.3 μm. For optimal packing of the two powders, this invention preferably uses a coarse powder to fine powder weight ratio of 10:1–2.

[0031] To ensure the high purity of the product, this invention preferably uses two types of silicon carbide powders that are both high-purity raw materials, with a strict purity requirement of ≥99.999%. At the same time, the crystal phase of both powders is strictly limited to β-phase silicon carbide powder. Since β-phase silicon carbide has superior mechanical properties and thermal stability, the product prepared by this invention can meet the stringent requirements for material consistency in semiconductor equipment components.

[0032] In some specific embodiments of the present invention, it is further preferred that the fine powder (β-phase silicon carbide powder of the second particle size) is synthesized by chemical vapor deposition to ensure the high purity and low impurity characteristics of the fine powder.

[0033] The second step is mixing and drying. The weighed high-purity silicon carbide powders of two different particle sizes are dispersed in a solvent to facilitate subsequent ball milling.

[0034] In some specific embodiments of the present invention, silicon carbide powder is dispersed in toluene or cyclohexane solvent, preferably the solvent weight accounts for 10-20% of the total weight of the slurry.

[0035] The prepared slurry is ball-milled. In some specific embodiments of the present invention, it is preferable to add the slurry to a ball milling container made of polyurethane or polytetrafluoroethylene and ball-mill for 12-24 hours to achieve thorough mixing. The present invention chooses a ball milling container made of polyurethane or polytetrafluoroethylene for ball milling because, on the one hand, polyurethane or polytetrafluoroethylene is a polymer material with extremely low impurity content and extremely strong chemical stability. During ball milling, it will not generate debris due to friction, nor will it react chemically with silicon carbide powder or solvents (toluene / cyclohexane), fundamentally eliminating the introduction of impurities, thereby avoiding or reducing the introduction of impurities into the powder during ball milling. On the other hand, organic solvents are used in the ball milling slurry, which may pose a risk of swelling or dissolution to some polymer materials. The ball milling container made of polyurethane or polytetrafluoroethylene preferred in the present invention is well compatible with organic solvents. To prevent the powder from swelling or contaminating due to solvents, the present invention employs a synergistic ratio of two powder sizes. The core principle is to improve the density of the green body by filling the gaps between coarse powders with fine powder. Therefore, the optimal design of the technical solution should avoid excessive crushing of coarse powder or agglomeration of fine powder during ball milling. Since the hardness of polyurethane and polytetrafluoroethylene is lower than that of silicon carbide, powder mixing is primarily achieved through the impact of the grinding media during ball milling. The container itself will not cause excessive grinding of silicon carbide particles, thus preventing excessive crushing of coarse powder during ball milling. Furthermore, the moderate smoothness of the inner walls of polyurethane and polytetrafluoroethylene ensures sufficient contact and mixing between the powder and solvent, while preventing fine powder adsorption and agglomeration due to rough inner walls. This allows for precise control of the powder particle size distribution, ensuring the synergistic effect of the two particle sizes and guaranteeing the uniformity of the green body in subsequent molding stages.

[0036] After ball milling, the mixed slurry is filtered to remove excess solvent. The filtration step can be performed according to conventional procedures in the art, and this invention does not specifically limit its application. Then, the obtained filter cake is dried to obtain a uniformly dried mixed powder.

[0037] In some specific embodiments of the present invention, drying is preferably vacuum drying, with a preferred temperature of 80–100°C, a preferred vacuum degree of -0.08–-0.1 MPa, and a preferred time of 6–12 hours. The purpose of setting these drying parameters is to achieve a balance between efficient dehydration of the slurry and uniform drying of the powder while ensuring the high purity of the silicon carbide powder, and to avoid damage to the powder properties, thus laying the foundation for subsequent molding and sintering processes. Specifically, designing drying in a vacuum environment avoids contact between impurities such as dust, moisture, and oxygen in the air and the filter cake. This prevents dust from directly mixing into the silicon carbide powder to ensure its high purity, and also avoids the introduction of impurities through a slight oxidation reaction between oxygen and the powder at high temperatures. Simultaneously, vacuum drying significantly lowers the boiling point of the solvent, allowing it to quickly vaporize and detach from the slurry at lower temperatures, greatly shortening the drying time and reducing the impact of high temperatures on the powder properties. The present invention preferably uses a drying temperature of 80–100°C to balance drying efficiency and powder stability. This temperature range satisfies the requirement for rapid vaporization of toluene / cyclohexane under vacuum conditions, avoiding solvent residue due to excessively low temperatures. Simultaneously, it avoids slight agglomeration of silicon carbide powder particles due to excessively high temperatures, which could disrupt the synergistic particle size distribution between fine and coarse powders and affect the packing density of the subsequent green body. The vacuum degree is preferably -0.08–-0.1 MPa. If the vacuum degree is too low, the solvent boiling point will decrease only slightly, requiring higher temperatures for vaporization. This can easily lead to excessively high local temperatures in the slurry and rapid boiling of the solvent, causing the powder to form porous agglomerates. Conversely, if the vacuum degree is too high, although it can further lower the boiling point, the solvent vaporization rate is too fast, potentially causing the slurry surface to dry rapidly, forming a hard shell. The internal solvent cannot be easily removed, resulting in a powder that is dry on the outside and wet on the inside. During subsequent molding, residual moisture can easily lead to defects such as cracking of the green body. Under the above-mentioned vacuum and temperature settings, the preferred drying time is 6 to 12 hours. This ensures that the residual amount of toluene / cyclohexane in the slurry is reduced to below 0.1%, avoiding the formation of internal pores due to solvent vaporization during subsequent hot isostatic pressing sintering, which would affect the density of the product. At the same time, it also avoids the agglomeration of particles due to excessive drying of the powder, which would increase the surface activity of the particles.

[0038] The third step is the forming process. In this step, the mixed powder is first dry-pressed into shape, and then cold isostatically pressed to obtain the billet. This step-by-step forming process can quickly shape the billet and initially remove air through dry pressing, and then make the billet uniform and dense, eliminate gradients, and ultimately achieve a balance between high-efficiency production and high-quality billets through cold isostatic pressing.

[0039] In some specific embodiments of the present invention, the pressure for dry pressing is preferably set to 30-50 MPa. The lower limit of the pressure is set to 30 MPa to ensure that the powder can be formed smoothly without the occurrence of loose blanks, thus initially obtaining a well-shaped blank, while also allowing the gas in the blank to be discharged smoothly to meet the basic requirements of subsequent processes. The upper limit of the pressure is set to 50 MPa to avoid the blank from becoming too dense during dry pressing, making it difficult to discharge gas, thereby better adapting to the secondary densification of subsequent cold isostatic pressing.

[0040] In some specific embodiments of the present invention, cold isostatic pressing preferably involves placing the pre-shaped billet into a silicone or polyurethane sleeve for cold isostatic pressing. Cold isostatic pressing enables uniform pressure on the billet in all directions, thereby eliminating internal porosity and stress unevenness, ultimately significantly improving the density of the billet and obtaining a high-density billet. The present invention uses a silicone or polyurethane sleeve for cold isostatic pressing to prevent contamination of the billet during the molding process. Furthermore, the sleeve's flexibility and elasticity allow for uniform pressure application while protecting the billet during molding and accommodating complex shapes.

[0041] In some specific embodiments of the present invention, cold isostatic pressing is preferably performed at a pressure of 250–270 MPa. In the prior art, the pressure of cold isostatic pressing is generally 100–200 MPa. The present invention, by appropriately increasing the pressure of cold isostatic pressing, can appropriately increase the density of the green body, thereby reducing the shrinkage rate in subsequent sintering processes, thus reducing the risk of product deformation and improving the mechanical properties of the product. Simultaneously, appropriately increasing the pressure of cold isostatic pressing can break up powder agglomerates and strengthen particle bonding, thereby reducing micropores and increasing product density. Furthermore, excessively high pressure during cold isostatic pressing may increase equipment costs and pose a risk of sleeve breakage. Through extensive experimental verification, the present invention preferably uses a cold isostatic pressing pressure of 250–270 MPa, thereby achieving a better balance between performance, cost, and efficiency.

[0042] The fourth step is hot isostatic pressing sintering, also known as high-temperature densification, to obtain silicon carbide ceramic parts.

[0043] In some specific embodiments of the present invention, during hot isostatic pressing (HIP), the billet is placed inside a tungsten alloy sheath, and high-purity graphite paper is placed between the billet and the sheath for isolation. The sheath is then vacuum degassed and sealed by welding. The technical purpose of this arrangement is that the tungsten alloy sheath is resistant to high temperature and high pressure, making it suitable for the HIP sintering environment and preventing deformation / cracking of the sheath. Simultaneously, the tungsten alloy sheath has strong chemical stability, preventing reactions between the sheath and the billet under high temperature and high pressure, ensuring high product purity. The high-purity graphite paper between the billet and the sheath prevents high-temperature adhesion or interdiffusion of elements, further blocking impurity migration from the sheath and ensuring billet purity. It also facilitates subsequent demolding. Vacuum degassed and sealing by welding remove air and impurity gases from the sheath, preventing defects such as bubbles and pinholes in the billet during sintering, thereby improving product density and performance.

[0044] In some specific embodiments of the present invention, the packaged blank is placed in a hot isostatic pressing furnace and sintered for 1 to 2 hours at a temperature of 1800 to 1900°C and a pressure of 100 to 150 MPa to complete the densification of the blank and obtain silicon carbide pillar ceramic parts.

[0045] Silicon carbide is a typical difficult-to-sinter ceramic due to its high covalent bond ratio, extremely high melting point, and extremely low atomic diffusion coefficient at high temperatures. Even with conventional high-pressure sintering methods, temperatures approaching 2000℃ are insufficient to allow for sufficient particle bonding, resulting in a large number of pores remaining in the green body. This invention creatively introduces high-temperature isostatic pressing (HSP) technology into the green body sintering process. The preferred sintering temperature is 1800–1900℃, which, while avoiding over-burning (such as abnormal grain growth), provides sufficient energy to the silicon carbide atoms, enabling them to break through covalent bonds and undergo surface and volume diffusion, promoting the formation of strong sintering necks between particles. The preferred sintering pressure is 100–150 MPa, which further compresses the green body pores, forcing particles closer together and increasing the contact area, while simultaneously accelerating the atomic diffusion rate. This significantly reduces the sintering difficulty of silicon carbide, allowing the originally difficult-to-densify green body to efficiently form a continuous and dense ceramic structure. This invention directly compresses residual pores in the billet (including the original pores of the pre-pressed billet and the micropores generated during sintering) using a pressure of 100-150 MPa, and promotes particle fusion with a temperature of 1800-1900℃, ensuring that the final part meets the density requirements and avoiding a decrease in strength, hardness, and wear resistance due to porosity. Under these temperature and pressure conditions, if the holding time is too short (<1h), atomic diffusion will be insufficient, the particles will not be firmly bonded, and unsintered areas will easily remain. If the time is too long (>2h), the silicon carbide grains will grow excessively, from the micrometer level to the sub-millimeter level, which may lead to increased brittleness and fluctuations in mechanical properties of the part. This invention preferably sintersects for 1-2 hours, which can ensure sufficient particle bonding while controlling the grain size within a suitable range, ensuring that the part has both high density and good strength and toughness.

[0046] Finally, according to the size requirements of semiconductor equipment components, the silicon carbide ceramic parts are post-processed, including but not limited to dimensional precision machining such as cutting, grinding, and polishing, to finally obtain high-purity silicon carbide components for semiconductor equipment that meet the usage standards.

[0047] This invention uses two types of β-phase silicon carbide powder with a purity ≥99.999% as raw materials for compounding. Through a step-by-step molding process, first dry pressing, then cold isostatic pressing, and finally hot isostatic pressing sintering, structural parts with high purity and high density are obtained. At the same time, this invention directly uses high-purity silicon carbide powder as raw material, eliminating the complicated step of "silicon powder-graphite powder to synthesize silicon carbide" in the traditional process, shortening the production cycle. The hot isostatic pressing process reduces the sintering temperature through high pressure compensation, reducing energy consumption and material loss at high temperatures, significantly reducing the preparation cost and facilitating mass production. Through the optimal control of process parameters in each step, and by selecting consumables such as cladding and ball mill barrels with excellent chemical stability, the impact of process fluctuations on product quality can be effectively avoided, ensuring the consistency of product performance between batches.

[0048] The present invention also proposes a high-purity silicon carbide structural component prepared according to the aforementioned preparation method, which has both high purity and high density, with a purity of over 99.999% and a relative density of 99.1%.

[0049] The present invention also proposes an application of the aforementioned high-purity silicon carbide structural component in the fields of semiconductor materials and semiconductor equipment. It is applicable to the preparation of precision components such as focusing rings, spray disks, annealing disks, crystal boats, and reflectors in core equipment of key semiconductor manufacturing processes such as photolithography, etching, thin film deposition, ion implantation, and chemical mechanical polishing.

[0050] The present invention will be further described below with reference to specific embodiments, but this should not be construed as a limitation on the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention still fall within the scope of protection of the present invention.

[0051] Unless otherwise specified, all materials and reagents mentioned below are commercially available products well known to those skilled in the art; unless otherwise specified, all methods described are methods known in the art. Unless otherwise defined, the technical or scientific terms used should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0052] Example 1

[0053] This embodiment prepares a high-purity silicon carbide structural component for semiconductor devices, specifically including the following steps:

[0054] (1) Material selection: β-phase silicon carbide with a purity of 5N (99.999%) or higher is selected. The particle size of coarse powder is d50 = 0.9 μm, and the particle size of fine powder (synthesized by CVD method) is d50 = 0.2 μm.

[0055] (2) Mixing: Cyclohexane was selected as the solvent, and high-purity silicon carbide powder with particle sizes of 0.2um and 0.9um was mixed at a weight ratio of 1:10 to prepare a slurry, wherein the weight of cyclohexane was 15% of the total weight of the slurry; the prepared slurry was added to a ball mill made of polyurethane material and the ball milling time was 12h.

[0056] (3) Drying: The ball-milled slurry is filtered, and the filter cake is placed in a vacuum oven and dried at 90°C and -0.08MPa vacuum for 7 hours to obtain the mixed powder.

[0057] (4) Molding: The dried mixed powder is pressed into shape using dry pressing molds and equipment at a pressing pressure of 35MPa. The pressed blank is then placed into a polyurethane sleeve for cold isostatic pressing to obtain a blank at a pressure of 251MPa.

[0058] (5) Encasing: The blank is encased in a tungsten alloy encasing, and high-purity graphite paper is laid between the blank and the encasing for isolation. The encasing is then vacuum degassed and welded.

[0059] (6) Sintering: The cladding blank is placed in a hot isostatic pressing furnace and hot isostatic pressing sintering is performed at a temperature of 1870℃, a sintering pressure of 110MPa, and a sintering time of 2h to obtain silicon carbide ceramic parts.

[0060] (7) Finishing: Cutting and polishing to obtain high-purity silicon carbide structural parts.

[0061] Appendix Figure 2 The image shown is a physical picture of the spray disc prepared using the materials in this embodiment. Figure 3 The image shown is a physical picture of the reflector made of the material in this embodiment. As can be seen from the picture, the structure has a regular appearance and is free of cracks and defects. When a USB flash drive is placed in front of the reflector, the image of the USB flash drive can be clearly displayed in the reflector.

[0062] Testing revealed that the high-purity silicon carbide structural component prepared in this embodiment has a purity of 99.9998% and a density of 99.10%.

[0063] Example 2

[0064] This embodiment provides a method for preparing high-purity silicon carbide ceramic materials for semiconductor devices. The difference between this method and Example 1 is that the powder 1 in step (1) is selected as high-purity silicon carbide powder with a particle size of D50 = 0.5 μm, and the sintering temperature in step (6) is 1820 °C. All other steps are consistent with those in Example 1. Testing showed that the purity of the high-purity silicon carbide structural component prepared in this embodiment is 99.9997%, and the density is 99.06%.

[0065] Example 3

[0066] This embodiment provides a method for preparing high-purity silicon carbide ceramic materials for semiconductor devices. The difference between this method and Example 1 is that the sintering temperature in step (6) is 1850℃ and the sintering pressure is 140MPa; the remaining steps are consistent with those in Example 1. Testing showed that the high-purity silicon carbide structural component prepared in this embodiment has a purity of 99.9995% and a density of 99.07%.

[0067] Example 4

[0068] This embodiment provides a method for preparing high-purity silicon carbide ceramic materials for semiconductor devices. The difference from Embodiment 1 is that in step (2), toluene is used as the solvent. A slurry is prepared by mixing high-purity silicon carbide powder with particle sizes of 0.2 μm and 0.9 μm at a weight ratio of 2:10, with toluene accounting for 20% of the slurry weight. The slurry is then added to a polyurethane ball mill, and the milling time is 12 hours. The remaining steps are consistent with those in Embodiment 1. Testing shows that the high-purity silicon carbide structural component prepared in this embodiment has a purity of 99.9993% and a density of 99.03%.

[0069] Example 5

[0070] This embodiment provides a method for preparing high-purity silicon carbide ceramic materials for semiconductor devices. The difference between this method and Example 1 is that the particle size D50 of powder 2 in step (1) is 0.1 μm, the cold isostatic pressing pressure in step (4) is 260 MPa, the sintering temperature in step (6) is 1830 °C, and the sintering pressure is 120 MPa. All other steps are consistent with those in Example 1. Testing showed that the purity of the high-purity silicon carbide structural component prepared in this embodiment is 99.9996%, and the density is 98.93%.

[0071] The technical features in the claims and / or specification of this invention can be combined, and the combination is not limited to the combinations obtained through reference in the claims. Technical solutions obtained by combining the technical features in the claims and / or specification are also within the scope of protection of this invention.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a high-purity silicon carbide structural component, characterized in that, It includes the following steps: S11. β-phase silicon carbide powder with a purity ≥99.999% and a first particle size of ≥99.999% and a second particle size of ≥99.999% are mixed at a weight ratio of 10:1~2 to form a slurry. This slurry is then ball-milled and mixed in a ball mill container made of polyurethane or polytetrafluoroethylene, filtered, and dried to obtain a mixed powder. The first particle size is greater than the second particle size; the first particle size is 0.5~1.0 μm, and the second particle size is 0.1~0.3 μm. S12 first dry-presses the mixed powder into shape, then puts it into a silicone or polyurethane sleeve for cold isostatic pressing to obtain a blank. S13 places the blank in a tungsten alloy cladding and sets high-purity graphite paper between the blank and the cladding for isolation, and then performs hot isostatic pressing sintering to obtain silicon carbide ceramic parts. S14 performs post-processing on silicon carbide ceramic parts to obtain high-purity silicon carbide structural parts.

2. The preparation method according to claim 1, characterized in that, The second-sized β-phase silicon carbide powder was synthesized by chemical vapor deposition.

3. The preparation method according to claim 1, characterized in that, The slurry is prepared by dispersing silicon carbide powder in toluene or cyclohexane solvent; wherein the solvent accounts for 10-20% of the weight of the slurry.

4. The preparation method according to claim 1, characterized in that, The ball milling time is 12~24 hours.

5. The preparation method according to claim 1, characterized in that, The drying process is vacuum drying; the temperature is 80~100℃, the vacuum degree is -0.08~-0.1MPa, and the time is 6~12h.

6. The preparation method according to claim 1, characterized in that, The pressure for cold isostatic pressing is 250~270MPa; the pressure for dry pressing is 30~50MPa.

7. The preparation method according to claim 1, characterized in that, The hot isostatic pressing sintering temperature is 1800~1900℃, the pressure is 100~150MPa, and the time is 1~2h.

8. A high-purity silicon carbide structural component prepared by the preparation method according to any one of claims 1 to 7.

9. The application of a high-purity silicon carbide structural component according to claim 8 in the field of semiconductor materials and semiconductor devices.

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