Tough silicon carbide structures, methods of making and applications thereof

Abstract

This invention proposes a tough silicon carbide structural component, its preparation method, and its application. The preparation method includes: mixing a high aspect ratio reinforcing material, high-purity silicon carbide powder, high-purity tetraethyl orthosilicate, a dispersant, and a binder to obtain a slurry; casting the slurry to obtain a silicon carbide preform; shaping, reinforcing, and high-temperature pretreatment; silicon carbide chemical vapor deposition; cooling and surface grinding until the high aspect ratio reinforcing material is exposed on the surface of the silicon carbide preform; repeating chemical vapor deposition and surface grinding a predetermined number of times; silicon carbide chemical vapor deposition until the silicon carbide thickness deposited on the preform surface is 0.5–2 mm; and post-processing to obtain the tough silicon carbide structural component. The technical problem to be solved is how to prepare a tough silicon carbide structural component with high purity and good toughness, suitable for manufacturing thin-walled, large-size silicon carbide parts; furthermore, this preparation method enables ultra-fast densification, has high preparation efficiency, and is easy to mass-produce.

Description

Technical Field

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

[0002] The semiconductor industry follows a 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. In many key semiconductor manufacturing processes, such as photolithography, etching, thin film deposition, ion implantation, and chemical mechanical polishing (CMP), stable operation relies on core components made of high-performance materials. Silicon carbide, with its high hardness, high thermal conductivity, and high chemical stability, has become an ideal material for core components of semiconductor equipment, possessing irreplaceable application value.

[0003] However, the current application of silicon carbide materials in semiconductor equipment still faces the following core challenges, severely restricting their further promotion and performance: First, the preparation of high-purity silicon carbide is difficult. Powder sintering not only relies on high-purity raw materials but also requires strict control of the entire production process to avoid external contamination. Moreover, high-purity powder itself is difficult to sinter, easily leading to problems such as incomplete sintering and abnormal grain growth. While high-purity chemical vapor deposition of silicon carbide bulk materials can achieve high-purity preparation, the material growth rate is extremely slow, resulting in a long production cycle. Especially for large-sized irregular structural parts, subsequent processing is difficult and time-consuming, making it difficult to guarantee yield and leading to high manufacturing costs, which cannot meet the needs of large-scale semiconductor equipment production. Second, semiconductor equipment uses a large number of thin-walled, large-sized silicon carbide components. During the molding and sintering process, these components are prone to deformation or even cracking due to uneven internal stress distribution. At the same time, during long-term operation of the equipment, frequent temperature changes can cause thermal shock fatigue, further exacerbating the risk of material cracking and seriously affecting the service life of components and the reliability of the equipment. Traditional silicon carbide ceramics are inherently brittle materials with poor toughness. Existing modification technologies struggle to effectively improve their crack resistance and thermal shock resistance, becoming a key bottleneck restricting the application of silicon carbide materials in thin-walled, large-size semiconductor components. Current manufacturing processes are either limited by sintering or deposition efficiency, resulting in long production cycles and low capacity; or they present significant challenges in processing large-size irregularly shaped parts, leading to poor consistency and making it difficult to achieve standardized, large-scale production, thus failing to meet the mass supply demands of the semiconductor equipment industry. Summary of the Invention

[0004] The main objective of this invention is to provide a tough silicon carbide structural component, its preparation method, and its application. The technical problem to be solved is how to prepare a tough silicon carbide structural component with high purity and good toughness, which can be used to prepare thin-walled, large-size silicon carbide parts. Moreover, the preparation method can achieve ultra-fast densification, has high preparation efficiency, and is easy to mass-produce, thus making it more suitable for practical use.

[0005] The objective of this invention and the technical problem it solves are achieved through the following technical solution. A method for preparing a tough silicon carbide structural component according to this invention includes the following steps:

[0006] S11 mixes and disperses a high aspect ratio reinforcing material, high-purity silicon carbide powder, high-purity tetraethyl orthosilicate, dispersant, and binder in a solvent to obtain a mixed slurry; wherein the high aspect ratio reinforcing material is a one-dimensional reinforcing body with an aspect ratio ≥4, and is selected from at least one of silicon-containing ceramic materials and carbonaceous materials;

[0007] S12 grouting molding was used to obtain silicon carbide preforms;

[0008] S13 is used for shaping and reinforcing silicon carbide preforms, and for high-temperature pretreatment.

[0009] S14 performs silicon carbide chemical vapor deposition on the surface and internal pores of a silicon carbide preform.

[0010] S15 cooling, surface grinding, until the high aspect ratio reinforcing material on the surface of the silicon carbide preform is exposed;

[0011] S16 determines whether the number of times steps S14 and S15 have been executed is less than the preset number; if yes, return to step S14; if no, execute step S17.

[0012] S17 performs silicon carbide chemical vapor deposition on the surface and internal pores of the silicon carbide preform, until the thickness of silicon carbide deposited on the surface of the silicon carbide preform is 0.5-2 mm;

[0013] S18 post-processing yields tough silicon carbide structural parts.

[0014] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0015] Preferably, in the preparation method, the high aspect ratio reinforcing material is selected from at least one of rod-shaped silicon carbide, silicon carbide whiskers, chopped silicon carbide fibers, silicon nitride whiskers, carbon nanotubes, and chopped carbon fibers.

[0016] Preferably, in the preparation method, the high aspect ratio reinforcing material is purified before the mixed slurry is prepared.

[0017] Preferably, in the preparation method, the mixed slurry comprises, by mass percentage: 30-50% high aspect ratio reinforcing material, 5-10% high-purity silicon carbide powder, 30-55% anhydrous ethanol, 4-5% high-purity tetraethyl orthosilicate, 1-3% dispersant, and 5-10% binder.

[0018] Preferably, in the preparation method, the grouting molding includes: injecting the mixed slurry into a mold, filtration, pressure filtration, demolding, and drying; the grouting pressure is 0.6-1.0 MPa; and / or, the shaping and reinforcement involves transferring the silicon carbide preform onto a graphite tooling, and wrapping, shaping, and reinforcing it with carbon fiber prepreg.

[0019] Preferably, in the preparation method, the high-temperature pretreatment step is as follows: heating to 300°C at a rate of 10°C / min and holding for 30–60 min; heating to 500°C at a rate of 0.5–1°C / min and holding for 60–90 min; heating to 1300–1400°C at a rate of 5°C / min and holding for 30–60 min.

[0020] Preferably, in the preparation method, the silicon carbide chemical vapor deposition step is as follows: a mixed gas of CH4, SiCl4, H2, and Ar is introduced into the working surface of the silicon carbide preform, and the gas is forced through the silicon carbide preform by a pressure difference; wherein, under standard conditions, the SiCl4 unit volume flow rate is 0.2–0.5 L / min / m 3 The CH4 unit volume flow rate is 0.1–0.5 L / min / m³. 3 The flow rate ratio of CH4, SiCl4, H2 and Ar is 1:(1~2):(3~6):(2~4); the temperature is 1300~1400℃, the pressure is 800~25000Pa, the preset number of depositions is 2~3, and the total deposition time is 30~60h.

[0021] The objective of this invention and the technical problem it solves are achieved through the following technical solution. A tough silicon carbide structural component according to this invention comprises:

[0022] A silicon carbide continuous phase matrix, comprising a high aspect ratio reinforcing material; the high aspect ratio reinforcing material is uniformly dispersed in the silicon carbide continuous phase matrix; the high aspect ratio reinforcing material is a one-dimensional reinforcing body with an aspect ratio ≥ 4, and is selected from at least one of silicon-containing ceramic materials and carbonaceous materials;

[0023] The dense silicon carbide surface layer is formed by chemical vapor deposition and has a thickness of 0.5–2 mm. The dense silicon carbide surface layer and the high aspect ratio reinforcement material form an anchoring bonding structure. The anchoring bonding structure is an interlocking structure formed by the ground and exposed high aspect ratio reinforcement and the subsequently deposited silicon carbide.

[0024] The objectives of this invention and the technical problems it addresses can be further achieved by the following technical measures.

[0025] Preferably, the tough silicon carbide structural component is prepared according to the aforementioned preparation method.

[0026] The objective of this invention and the technical problem it solves are achieved by the following technical solution: An application of the aforementioned tough silicon carbide structural component in the fields of semiconductor materials and semiconductor devices, according to this invention.

[0027] By employing the above technical solution, the tough silicon carbide structural component, its preparation method, and its application proposed in this invention have at least the following advantages:

[0028] This invention proposes a tough silicon carbide structural component, its preparation method, and its application. By incorporating a one-dimensional, high aspect ratio reinforcing material with an aspect ratio ≥4 into a slurry, a three-dimensional interwoven reinforcing skeleton is formed within the molded silicon carbide preform. This skeleton can dissipate external impact and thermal shock energy through mechanisms such as crack bridging and reinforcement pull-out. This fundamentally solves the core problem of the brittleness and cracking inherent in traditional unreinforced silicon carbide ceramics, making it suitable for the use of thin-walled, large-size structural components in semiconductor equipment. Furthermore, this invention uses a slurry casting process instead of traditional dry pressing, eliminating the need for high pressure conditions and enabling the integrated molding of thin-walled, irregularly shaped structural components directly through a mold. This fundamentally overcomes the technical bottleneck of difficult molding of complex silicon carbide components, significantly reducing subsequent machining and material waste. Through multiple cycles of chemical vapor deposition (CVI), grinding, and re-deposition, coupled with a process design that ultimately deposits a silicon carbide layer with a thickness of 0.5–2 mm, the process framework ensures that the internal pores of the preform are gradually filled, effectively avoiding surface blockage and internal porosity defects that are prone to occur in single deposition. Furthermore, by precisely controlling the final deposition thickness, a uniform and dense silicon carbide layer is formed on the product surface. This surface layer forms a mechanical interlocking structure with the ground and exposed reinforcing material, further strengthening the bonding strength between the surface layer and the substrate, preventing surface layer detachment during use, and significantly improving the long-term stability of the structural components. Moreover, the mixed slurry uses high-purity silicon carbide powder, high-purity tetraethyl orthosilicate, and other raw materials, without introducing low-purity components, thus initially avoiding the risk of contamination from the source of material selection and basically meeting the basic requirements of semiconductor equipment for material purity. In summary, through the synergistic effect of the aforementioned technical features, this preparation method achieves efficient densification of the preform while significantly improving the toughness and structural stability of silicon carbide ceramics, and simultaneously achieves the goal of high-purity preparation. This provides a feasible basic process solution for the mass production and high-performance preparation of silicon carbide structural components for semiconductor devices.

[0029] 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

[0030] Figure 1 This is a schematic diagram of the process flow of the preparation method of the present invention;

[0031] Figure 2 This is a photograph of the tough silicon carbide ceramic sample prepared in Example 1 of the present invention.

[0032] Figure 3 The image shows the XRD pattern of the tough silicon carbide ceramic prepared in Example 1 of this invention. Detailed Implementation

[0033] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following, in conjunction with the appended tables and preferred embodiments, details the specific implementation methods and effects of a tough 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.

[0034] This invention proposes a method for preparing a tough silicon carbide structural component, as shown in the attached figure. Figure 1 As shown, it includes the following steps:

[0035] The first step is the preparation of raw materials and the preparation of the mixed slurry.

[0036] A high aspect ratio reinforcing material with a one-dimensional morphology and an aspect ratio ≥ 4, high-purity silicon carbide powder, high-purity tetraethyl orthosilicate, dispersant, and binder are mixed and dispersed in a solvent to obtain a slurry. By incorporating the high aspect ratio reinforcing material into the slurry, a three-dimensional interwoven reinforcing skeleton is formed inside the molded silicon carbide preform. This skeleton can dissipate the energy of external force impact and thermal shock through mechanisms such as crack bridging and reinforcement pull-out. This fundamentally solves the core problem of the brittleness of traditional unreinforced silicon carbide ceramics at the process level, making it suitable for the use of thin-walled, large-size structural components in semiconductor equipment.

[0037] In some specific embodiments of the present invention, the high aspect ratio reinforcing material is selected from at least one of silicon-containing ceramic materials and carbonaceous materials; preferably, at least one of rod-shaped silicon carbide, silicon carbide whiskers, chopped silicon carbide fibers, silicon nitride whiskers, carbon nanotubes, and chopped carbon fibers. For example, silicon carbide whiskers with a whisker length of 100-300 μm and a diameter of 12-25 μm, chopped silicon carbide fibers with a diameter of 50 μm and a length of 1 mm, and rod-shaped silicon carbide with a diameter of 10 μm and a length of 50 μm are used. The above materials are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0038] To further improve the purity of the tough silicon carbide structural component of the present invention, it is preferable to purify the high aspect ratio reinforcing material before preparing the mixed slurry. Material purification can be performed using conventional purification methods in the art.

[0039] To better suit the process of this invention, the preferred purification steps are as follows: First, add pure water and concentrated sulfuric acid to the high aspect ratio reinforcing material, stir evenly, heat to 80-90°C, stir for 2-4 hours, and let stand for 18-24 hours; the amount of pure water can be adjusted as needed; the amount of concentrated sulfuric acid added is 5-15% of the mass of the high aspect ratio reinforcing material; generally, concentrated H2SO4 with a mass concentration of 98% is used, at which concentration the oxidizing and acidic properties are sufficient to remove organic impurities and metal oxides from the surface of the material, and the reaction efficiency is highest under the preferred temperature conditions of this invention. Then, a mixture of hydrofluoric acid and hydrochloric acid is added, stirred for 2–4 hours, and allowed to stand for 18–24 hours. The amount of hydrofluoric acid added is 3–5% of the mass of the high aspect ratio reinforcing material; the amount of hydrochloric acid added is 5–10% of the mass of the high aspect ratio reinforcing material. Generally, 40% concentrated HF is used as the hydrofluoric acid, which effectively etches silicon-based oxide impurities on the material surface and, when combined with hydrochloric acid, synergistically removes fluoride precipitates. Generally, 36–38% concentrated HCl is used as the hydrochloric acid, primarily to dissolve metal ion impurities and form a mixed acid system with the hydrofluoric acid to avoid residual fluoride precipitates. Finally, the mixture is filtered, washed with ultrapure water until the pH of the filtrate is 6.5–7, and then vacuum dried to obtain the purified high aspect ratio reinforcing material. The high aspect ratio reinforcing materials used in subsequent embodiments of this invention are all purified using this method. This formulation can efficiently remove metal ions, oxides, and other impurities from the reinforcing material, ensuring the purity of subsequent products.

[0040] To ensure the purity of the tough silicon carbide structural component of the present invention, in some specific embodiments of the present invention, the high-purity silicon carbide powder is selected as β-phase silicon carbide with a purity of 5N (99.999%).

[0041] In some specific embodiments of the present invention, the mixed slurry, by mass percentage, comprises: 30-50% high aspect ratio reinforcing material, 5-10% high-purity silicon carbide powder, 30-55% anhydrous ethanol, 4-5% high-purity tetraethyl orthosilicate, 1-3% dispersant, and 5-10% binder. The high-purity tetraethyl orthosilicate assists in bonding and subsequent densification; the dispersant prevents particle agglomeration and optimizes slurry dispersibility; and the binder enhances the structural stability of the preform after molding. The synergistic effect of these components lays the foundation for subsequent molding and densification. The present invention does not specifically limit the selection of dispersants and binders; commonly used additives in the silicon carbide processing industry can be employed.

[0042] The second step is the molding of the silicon carbide preform. This invention preferably uses slip casting molding, which does not rely on high pressure conditions and can directly achieve the integrated molding of thin-walled, irregularly shaped structural parts through molds. It breaks through the technical bottleneck of difficult molding of complex silicon carbide components from the basic process design level, and significantly reduces the amount of subsequent cutting and material loss.

[0043] In some specific embodiments of the present invention, slurry injection molding includes: injecting the mixed slurry into a mold, such as a polyurethane sleeve, at a pressure of 0.6–1.0 MPa to ensure that the slurry fills the mold cavity. After injection, the slurry contains a large amount of solvent and is in a flowing state. At this time, the free solvent is first removed by vacuum filtration (using negative pressure) to reduce the moisture content of the preform; then, pressure is applied for pressure filtration to further squeeze out the residual solvent in the pores, while enhancing the bonding force between particles, so that the preform is initially solidified and formed. This step ensures the complete filling of the mold by the slurry and avoids cracking or deformation of the preform due to rapid drying through gradient dehydration. This process can avoid particle agglomeration and uneven orientation, while retaining appropriate porosity to facilitate gas permeation in the subsequent CVI process. After molding, the preform is demolded and dried.

[0044] The third step is to shape and reinforce the silicon carbide preform, and then perform high-temperature pretreatment.

[0045] In some specific embodiments of the present invention, shaping and reinforcement involve transferring the silicon carbide preform onto a graphite fixture, then winding, shaping, and reinforcing it with carbon fiber prepreg. The technical purpose of this step is to provide the preform with rigid shaping and flexible constraint through the support of the graphite fixture and the winding of the carbon fiber prepreg. This allows the preform to resist thermal stress during subsequent high-temperature pretreatment and CVI densification processes, preventing cracking or deformation, ensuring contour accuracy, meeting the stringent dimensional requirements of semiconductor devices, protecting structural integrity, reserving effective porosity, and avoiding contamination. This enables it to adapt to the CVI process and high-purity requirements, laying the foundation for the final product performance. Shaping and reinforcement can be performed using methods conventional in the art, and the present invention does not impose specific limitations.

[0046] Prior to CVI densification, it is preferable to pretreat the preform at high temperature. The core purpose of this high-temperature pretreatment is to remove impurities such as binders and residual solvents from the preform, thereby avoiding contamination during the subsequent CVI process, promoting the initial bonding between the powder and the reinforcing material, improving the strength of the preform, releasing internal stress, and reducing the risk of deformation and cracking during subsequent high-temperature densification.

[0047] In some specific embodiments of the present invention, the parameter settings for the high-temperature pretreatment are precisely designed for the treatment objectives at different stages. The preferred high-temperature pretreatment steps are as follows: Heating to 300°C at a rate of 10°C / min and holding for 30–60 min; this stage involves a rapid heating rate, quickly reaching the evaporation temperature range of the binder and residual solvent (such as anhydrous ethanol), accelerating the evaporation of low-boiling-point components through holding, and avoiding component residue caused by slow heating; then heating to 500°C at a rate of 0.5–1°C / min and holding for 60 min. ~90 min; This stage is the critical range for binder decomposition. Low-speed heating can avoid cracking of the preform due to gas expansion caused by violent decomposition, and long-term heat preservation can ensure the complete decomposition and removal of organic components. Finally, the temperature is increased to 1300~1400℃ at a rate of 5℃ / min and held for 30~60 min. This stage rapidly heats to the initial sintering temperature of the powder and reinforcing material. High-temperature heat preservation promotes diffusion bonding between particles, improves the strength of the preform, and releases accumulated thermal stress, providing a stable substrate for subsequent CVI densification. This invention can achieve the progressive goals of impurity removal, strengthening, and stress release through a combination of fast and slow gradient heating and segmented heat preservation, balancing efficiency and preform stability.

[0048] The fourth step is densification. This step involves depositing silicon carbide on the surface and within the pores of the preform through a gas reaction to achieve densification while ensuring purity and toughness. It includes a collaborative process unit consisting of deposition, grinding, and cycle judgment composed of S14 to S16. The core purpose is to solve the common problems of easy surface blockage and difficulty in filling internal pores in a single CVI deposition. Specifically, the process includes: Step S14, performing silicon carbide chemical vapor deposition on the surface and internal pores of the silicon carbide preform; initially generating a silicon carbide layer on the surface and internal pores of the preform, filling some of the pores; however, a single deposition is prone to problems such as surface blockage and inability of internal gas to permeate, therefore, after cooling in Step S15, surface grinding is required to remove the dense surface layer and expose the high aspect ratio reinforcing material inside, i.e., surface grinding until the high aspect ratio reinforcing material on the surface of the silicon carbide preform is exposed; in this way, the gas permeation channel for subsequent deposition is opened, and an intercalation anchoring point is provided for the newly deposited silicon carbide; then, based on the cycle number determination in Step S16, the above deposition and grinding process is repeated. The present invention preferably presets the number of repetitions to 2 to 3 times, gradually filling the deep internal pores to avoid the uneven densification caused by a single deposition, laying the foundation for the final deposition to form a uniform surface layer in Step S17.

[0049] In some specific embodiments of the present invention, the silicon carbide chemical vapor deposition step is as follows: a mixed gas of CH4, SiCl4, H2, and Ar is introduced into the working surface of the silicon carbide preform, and the gas is forced through the interior of the silicon carbide preform by a pressure difference to improve the penetration efficiency. For example, a deposition furnace with a diameter of 1 meter and a height of 1.8 meters is used for chemical vapor deposition. The carbon source gas CH4 and the silicon source gas SiCl4 react under the action of hydrogen at the deposition temperature, and the generated silicon carbide adheres to the surface of the high aspect ratio reinforcing material and the high-purity silicon carbide powder, gradually filling the pores inside the preform. In this step, although H2 is not a raw material for SiC, it is a key auxiliary gas to ensure the smooth progress of the reaction. On the one hand, at high temperatures, H2 can reduce some of the Cl element in SiCl4 to generate HCl, and at the same time promote the dissociation of SiCl4 and CH4 into more reactive Si and C intermediates, such as SiH2 and CH3, providing reactive species for SiC formation. On the other hand, the presence of H2 can inhibit the decomposition of SiCl4 itself to generate free silicon or silicon low chlorides, avoiding these impurities from adhering to the pores of the preform and affecting the purity and compactness of the final material. At the same time, H2 also has a certain carrier gas function, which can carry SiCl4 and CH4 to diffuse evenly into the interior of the preform, improving the uniformity of gas permeation. Ar is a chemically stable inert gas that does not participate in the SiC formation reaction. Its main function is to optimize the reaction environment and permeation efficiency. By adjusting the Ar flow rate, the concentrations of SiCl4 and CH4 in the mixed gas can be controlled, avoiding excessively high raw material concentrations that could lead to rapid SiC deposition on the preform surface and cause pore blockage, thus clogging internal pores and affecting subsequent permeation. It can also avoid excessively low concentrations that could lead to a significant decrease in deposition efficiency. At the same time, as an inert gas, Ar can work synergistically with H2 to regulate the overall pressure in the deposition furnace, promoting more efficient permeation of the mixed gas into the deep pores of the preform, ensuring uniform SiC filling and reducing core porosity defects. Furthermore, Ar can slightly dilute the H2 concentration in the reaction system, preventing excessive reduction due to excessively high local H2 concentrations, and creating an inert atmosphere in the deposition furnace to prevent the reinforcing material in the preform from being oxidized or reacting with other impurities at high temperatures.

[0050] In some specific embodiments of the present invention, when performing chemical vapor deposition using the above-described deposition furnace, under standard conditions, it is preferable to control the SiCl4 flow rate to be 5-10 L / min and the CH4 flow rate to be 2.5-10 L / min; the flow rate ratio of CH4, SiCl4, H2 and Ar to be 1:(1-2):(3-6):(2-4); the preferred temperature is 1300-1400℃ and the pressure is 800-25000 Pa.

[0051] In some specific embodiments of the present invention, chemical vapor deposition is performed according to the above-described process conditions. After a certain deposition time in a single cycle, the substrate is cooled, removed, and its surface is ground to remove the sealing layer before the next silicon carbide deposition is performed. Preferably, the total deposition time for the cycle deposition is 30–60 hours; the deposition time for a single cycle can be adjusted appropriately according to the process.

[0052] After a preset number of cyclic depositions, preferably 2-3 times, silicon carbide chemical vapor deposition is performed on the surface and internal pores of the silicon carbide preform until the silicon carbide thickness deposited on the surface of the silicon carbide preform is 0.5-2 mm. The deposition conditions in this step are basically the same as those in the aforementioned cyclic deposition, and can be adjusted appropriately according to actual conditions. In this step, the surface SiC deposition thickness is controlled at 0.5-2 mm. The technical purpose is to form a dense barrier structurally to solve the surface porosity problem, to balance strength and toughness in terms of performance to adapt to various application scenarios, to optimize deposition efficiency and control costs in terms of process, and to leave a margin in processing to ensure the precision of the final product. This layer thickness setting is the optimal range derived from the physicochemical properties of SiC material, CVD process rules, and industrial application requirements. If the thickness is less than 0.5 mm, the surface layer may not be able to play its barrier and strengthening role, directly leading to substandard preform performance and reduced application reliability. If the thickness exceeds 2 mm, internal stress accumulation and reduced process efficiency may occur, damaging the overall performance and economy of the material.

[0053] Finally, the densified product is dimensionally processed to meet the technical specifications required for semiconductor devices, resulting in a tough silicon carbide structural component.

[0054] This invention also proposes a tough silicon carbide structural component, prepared according to the aforementioned method, comprising a continuous silicon carbide matrix and a densified silicon carbide surface layer. The continuous silicon carbide matrix includes a high aspect ratio reinforcing material uniformly dispersed within it. The high aspect ratio reinforcing material is a one-dimensional reinforcement with an aspect ratio ≥ 4, and is selected from at least one of silicon-containing ceramic materials and carbonaceous materials. The densified silicon carbide surface layer is formed by chemical vapor deposition, with a thickness of 0.5–2 mm. This densified silicon carbide surface layer and the high aspect ratio reinforcing material form an anchoring bond structure. This anchoring bond structure is an interlocking structure formed by the ground and exposed high aspect ratio reinforcing material and subsequently deposited silicon carbide. The tough silicon carbide structural component of this invention exhibits good toughness, high strength, and a fracture toughness reaching 1.5 Pa·m. 1 / 2 The bending strength can reach over 470 MPa; with further optimization of process parameters, its fracture toughness can reach 2.1 Pa·m. 1 / 2 The bending strength can reach over 530 MPa.

[0055] The present invention also proposes an application of the aforementioned tough silicon carbide structural component in the fields of semiconductor materials and semiconductor devices.

[0056] 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.

[0057] 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.

[0058] Example 1

[0059] This embodiment describes the fabrication of a tough silicon carbide structural component for semiconductor devices, comprising the following steps:

[0060] (1) Material selection and purification:

[0061] High aspect ratio reinforcing materials were synthesized using a vapor-phase method with silicon carbide whiskers. The whisker length was 100–300 μm and the diameter was 12–25 μm. The material was purified by acid washing and drying according to the following method: Purification steps: Pure water and concentrated sulfuric acid were added to the whiskers, stirred evenly, heated to 85°C, stirred for 3 hours, and then kept at this temperature for 20 hours. The amount of concentrated sulfuric acid added was 10% of the whisker mass. Then, a mixture of hydrofluoric acid and hydrochloric acid was added, stirred for 3 hours, and then kept at this temperature for 20 hours. The amount of hydrofluoric acid added was 4% of the whisker mass, and the amount of hydrochloric acid added was 8% of the whisker mass. Finally, the mixture was filtered, washed with ultrapure water until the pH of the filtrate was 6.5–7, and then vacuum dried to obtain purified whiskers.

[0062] The high-purity silicon carbide powder is selected from β-phase silicon carbide with a purity of 5N (99.999%) or higher and a particle size of d50 = 0.9 μm.

[0063] Anhydrous ethanol was of analytical grade, tetraethyl orthosilicate conformed to the standard of "GB / T 43965-2024 Electronic Grade Tetraethyl Orthosilicate", dispersant was AD8085, and binder was IOTA R31000.

[0064] (2) Mixing:

[0065] Purified whiskers were mixed with high-purity silicon carbide powder using anhydrous ethanol as a solvent. The mass fractions of purified whiskers, high-purity silicon carbide powder, anhydrous ethanol, tetraethyl orthosilicate, dispersant, and binder were 30 wt%, 10 wt%, 50 wt%, 4 wt%, 1 wt%, and 5 wt%, respectively. The mixture was then added to a polyurethane ball mill and milled for 12 hours.

[0066] (3) Molding:

[0067] The molding process employs high-pressure grouting, where the slurry is injected into a polyurethane sleeve at a pressure of 0.8 MPa; followed by filtration, pressure filtration, and dehydration before molding.

[0068] (4) Drying and shaping:

[0069] The formed preform is dried and transferred to a graphite support fixture, where it is wrapped, shaped, and reinforced with carbon fiber prepreg.

[0070] (5) High-temperature pretreatment:

[0071] The preform is placed in a deposition furnace with a diameter of 1m and a height of 1.8m. The temperature is increased to 300℃ at 10℃ / min and held for 30-60min. Then the temperature is increased to 500℃ at 0.5-1℃ / min and held for 60-90min. Finally, the temperature is increased to 1300-1400℃ at 5℃ / min and held for 30-60min.

[0072] (6) Densification:

[0073] A mixed gas of CH4, SiCl4, H2, and Ar was introduced into the deposition furnace, with a SiCl4 flow rate of 5 L / min and a CH4:SiCl4:H2:Ar flow rate ratio of 1:2:6:3. The deposition temperature was 1300℃, the deposition pressure was 800 Pa, and the single deposition time was 10 h. The initially densified product with a certain rigidity was cooled and removed for shaping, removal of carbon fiber cloth and graphite tooling, and surface grinding of the preform.

[0074] Adjust the gas permeation direction to densify again from the inside out, and use the same deposition process conditions as above. Grind the surface of the preform; repeat this step 3 times.

[0075] (7) Densification is carried out again under the same process conditions as above, until the surface silicon carbide thickness is 1 mm. The product is then processed to precise dimensions to obtain a high-purity, tough silicon carbide structural component.

[0076] A physical image of the tough silicon carbide structural component prepared in this embodiment is attached. Figure 2 As shown in the figure, the large-sized, thin-walled structural component has a regular appearance and is free of cracks and defects.

[0077] A physical image of the tough silicon carbide structural component prepared in this embodiment is attached. Figure 3 As shown in the figure, only the characteristic peaks of β-phase silicon carbide appear in the spectrum, proving that the material has a single crystal form and high purity.

[0078] Its fracture toughness was measured to be 1.67 MPa·m. 1 / 2 Flexural strength 517.8 MPa.

[0079] Example 2

[0080] This embodiment prepares a tough silicon carbide structural component for semiconductor devices. The difference between this embodiment and Example 1 is that: in step (1), the high aspect ratio reinforcing material is short-cut silicon carbide fiber with a diameter of 50 μm and a length of 1 mm. The high-purity silicon carbide powder is β-phase silicon carbide powder with a purity of 5N (99.999%) or higher and a particle size of 10 μm. In step (2), the mass fractions of the high aspect ratio reinforcing material, high-purity silicon carbide powder, anhydrous ethanol, tetraethyl orthosilicate, dispersant, and binder are 50 wt%, 5 wt%, 30 wt%, 4 wt%, 1 wt%, and 10 wt%, respectively. The remaining steps are consistent with those in Example 1.

[0081] The fracture toughness was measured to be 2.12 MPa·m. 1 / 2 Flexural strength 532.3 MPa.

[0082] Example 3

[0083] This embodiment prepares a tough silicon carbide structural component for semiconductor devices. The difference between this embodiment and Example 1 is that in step (2), the mass fractions of the high aspect ratio reinforcing material, high-purity silicon carbide powder, anhydrous ethanol, tetraethyl orthosilicate, dispersant, and binder are 40 wt%, 7 wt%, 40 wt%, 5 wt%, 3 wt%, and 5 wt%, respectively. In step (6), densification is achieved with a flow ratio of CH4, SiCl4, H2, and Ar of 2:3:10:2, a deposition temperature of 1350℃, a deposition pressure of 10000 Pa, and a single deposition time of 15 h. All other steps are consistent with those in Example 1.

[0084] The fracture toughness was measured to be 2.01 MPa·m. 1 / 2 Flexural strength 501.5 MPa.

[0085] Example 4

[0086] This embodiment prepares a tough silicon carbide structural component for semiconductor devices. The difference between this embodiment and Embodiment 1 is that: in step (1), the high aspect ratio reinforcing material is rod-shaped silicon carbide with a diameter of 10 μm and a length of 50 μm. The high-purity silicon carbide powder is β-phase silicon carbide powder B with a purity of 5N (99.999%) or higher and a particle size of 2.5 μm. In step (2), the mass fractions of the high aspect ratio reinforcing material, high-purity silicon carbide powder, anhydrous ethanol, tetraethyl orthosilicate, dispersant, and binder are 30 wt%, 5 wt%, 55 wt%, 4 wt%, 1 wt%, and 5 wt%, respectively. The remaining steps are consistent with those in Embodiment 1.

[0087] The fracture toughness was measured to be 1.55 MPa·m. 1 / 2 Flexural strength 473.8 MPa.

[0088] 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.

[0089] 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 tough silicon carbide structural component, characterized in that, It includes the following steps: S11 mixes and disperses a high aspect ratio reinforcing material, high-purity silicon carbide powder, high-purity tetraethyl orthosilicate, dispersant, and binder in a solvent to obtain a mixed slurry; wherein the high aspect ratio reinforcing material is a one-dimensional reinforcing body with an aspect ratio ≥4, and is selected from at least one of silicon-containing ceramic materials and carbonaceous materials; S12 grouting molding was used to obtain silicon carbide preforms; S13 is used for shaping and reinforcing silicon carbide preforms, and for high-temperature pretreatment. S14 performs silicon carbide chemical vapor deposition on the surface and internal pores of a silicon carbide preform. S15 cooling, surface grinding, until the high aspect ratio reinforcing material on the surface of the silicon carbide preform is exposed; S16 determines whether the number of times steps S14 and S15 have been executed is less than the preset number; if yes, return to step S14; if no, execute step S17. S17 involves performing silicon carbide chemical vapor deposition on the surface and internal pores of the silicon carbide preform until the silicon carbide thickness deposited on the surface of the silicon carbide preform is 0.5~2mm, forming a dense silicon carbide surface layer; the dense silicon carbide surface layer forms an anchoring bond structure with the high aspect ratio reinforcement material; the anchoring bond structure is an interlocking structure formed by the ground and exposed high aspect ratio reinforcement and the subsequently deposited silicon carbide. S18 post-processing yields tough silicon carbide structural parts.

2. The production method according to claim 1, characterized by, The high aspect ratio reinforcing material is selected from at least one of rod-shaped silicon carbide, silicon carbide whiskers, chopped silicon carbide fibers, silicon nitride whiskers, carbon nanotubes, and chopped carbon fibers.

3. The production method according to claim 1 or 2, characterized by, Before the mixed slurry is prepared, the high aspect ratio reinforcing material is purified.

4. The method of claim 1, wherein, The slurry comprises, by mass percentage: 30-50% high aspect ratio reinforcing material, 5-10% high-purity silicon carbide powder, 30-55% anhydrous ethanol, 4-5% high-purity tetraethyl orthosilicate, 1-3% dispersant, and 5-10% binder.

5. The preparation method according to claim 1, characterized in that, The grouting molding process includes: injecting the mixed slurry into the mold, filtration, pressure filtration, demolding, and drying; the grouting pressure is 0.6~1.0MPa; and / or, the shaping and reinforcement involves transferring the silicon carbide preform onto a graphite fixture, wrapping it with carbon fiber prepreg, shaping it, and reinforcing it.

6. The method of claim 1, wherein, The high-temperature pretreatment steps are as follows: heat to 300℃ at a rate of 10℃ / min and hold for 30~60min; heat to 500℃ at a rate of 0.5~1℃ / min and hold for 60~90min; heat to 1300~1400℃ at a rate of 5℃ / min and hold for 30~60min.

7. The preparation method according to claim 1, characterized in that, The silicon carbide chemical vapor deposition steps are as follows: a mixed gas of CH4, SiCl4, H2, and Ar is introduced into the working surface of the silicon carbide preform, and the gas is forced through the silicon carbide preform by a pressure difference; wherein, under standard conditions, the SiCl4 unit volume flow rate is 0.2~0.5 L / min / m 3 The CH4 unit volume flow rate is 0.1~0.5 L / min / m³. 3 The flow rate ratio of CH4, SiCl4, H2 and Ar is 1:(1~2):(3~6):(2~4); the temperature is 1300~1400℃, the pressure is 800~25000Pa, the preset number of depositions is 2~3, and the total deposition time is 30~60h.

8. A tough silicon carbide structural component prepared by the preparation method according to any one of claims 1 to 7, characterized in that, It includes: Silicon carbide continuous phase matrix, including high aspect ratio reinforcing materials; The high aspect ratio reinforcing material is uniformly dispersed in the silicon carbide continuous phase matrix; The high aspect ratio reinforcing material is a one-dimensional reinforcing body with an aspect ratio ≥ 4, and is selected from at least one of silicon-containing ceramic materials and carbonaceous materials. The dense silicon carbide surface layer is formed by chemical vapor deposition and has a thickness of 0.5–2 mm. The dense silicon carbide surface layer and the high aspect ratio reinforcement material form an anchoring bonding structure. The anchoring bonding structure is an interlocking structure formed by the ground and exposed high aspect ratio reinforcement and the subsequently deposited silicon carbide.

9. Use of a toughened silicon carbide structure according to claim 8 in the field of semiconductor materials and semiconductor devices.

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