High-temperature-resistant nano composite ceramic coating and preparation method thereof

Abstract

The invention relates to the technical field of ceramic coatings, and discloses a high-temperature-resistant nano composite ceramic coating and a preparation method thereof, and the high-temperature-resistant nano composite ceramic coating comprises 15-18 parts of nano, 25-30 parts of nano, 10-12 parts of modified nano, 3-5 parts of nano, 35-40 parts of an acidic silicon solution, 2-3 parts of nano and 1-2 parts of nano SiC. The high-temperature-resistant nano composite ceramic coating has excellent high-temperature resistance, chemical corrosion resistance and thermal shock resistance, the obtained composite ceramic coating is firmly combined with a base material, the preparation method is high in process controllability, and the high-precision requirement of a semiconductor is met.

Description

Technical Field

[0001] This invention relates to the field of ceramic coating technology, and more specifically, to a high-temperature resistant nanocomposite ceramic coating and its preparation method. Background Technology

[0002] Ceramic coatings are a general term for a class of inorganic non-metallic coatings, referring to sprayed coatings whose coating material is ceramic. Their composition includes oxide coatings, non-oxidizing coatings, silicate-based coatings, and composite ceramic coatings. Ceramic coatings possess a variety of properties, such as wear resistance, corrosion resistance, non-stick properties, high-temperature resistance, and good biocompatibility. These properties make ceramic coatings widely used in many fields. For example, in aero-engines, ceramic coatings can improve the high-temperature strength and corrosion resistance of turbine blades, thereby improving engine performance. In the aerospace field, ceramic coatings can be used to protect critical components of spacecraft, improving their reliability and lifespan. Furthermore, ceramic coatings can also be used in automotive manufacturing, machinery manufacturing, and military industries to improve product performance and lifespan.

[0003] During the use of semiconductor manufacturing equipment, the surfaces of structural components such as rack modules need to be coated with ceramic coatings to provide high-strength protection, high-temperature resistance, and chemical corrosion resistance, thereby protecting the equipment, improving its reliability, and enhancing its thermal efficiency. Typically, a single ceramic coating is insufficient to meet the requirements. When the coating substrate expands due to heat during semiconductor manufacturing, a single coating is prone to cracking or even large-scale peeling under thermal stress. Therefore, proposing a method and process for preparing a high-temperature resistant nanocomposite ceramic coating has significant practical implications. Summary of the Invention

[0004] In view of this, the present invention proposes a high-temperature resistant nanocomposite ceramic coating and its preparation method, aiming to solve at least one of the problems in the background art.

[0005] This invention proposes a high-temperature resistant nanocomposite ceramic coating, comprising the following components in parts by weight: 15-18 parts nano 25-30 parts nano 10-12 parts modified nano 3-5 parts nano 35-40 parts acidic silicon solution, 2-3 parts nano And 1-2 parts of nano SiC.

[0006] Preferably, the modified nano-SiO2 is obtained by the following method: Add 2-5 wt.% of nano-sized nanoparticles to a 1 mol / L sodium hydroxide solution. Stir at high speed for 10-15 minutes, then sonicate for 20-30 minutes to obtain a mixed solution; The mixture was then placed in a high-speed centrifuge and centrifuged at 5000 r / min for 10 min. After washing with ethanol and centrifuging again, this process was repeated 2-5 times to obtain activated nanoparticles. ; The activated nano-SiO2 was placed in a hydrochloric acid solution with a pH of 4-5 and mixed to obtain a second mixed solution. The silane coupling agent was placed in the second mixed solution for reaction. After stirring for 3-4 hours, it was thoroughly washed with ethanol, centrifuged 2-5 times, and finally dried in an atmosphere at 105-120℃ for 2 hours to obtain modified nanoparticles. .

[0007] The present invention also provides a method for preparing the high-temperature resistant nanocomposite ceramic coating as described in claim 1, comprising the following steps: Substrate pretreatment: The substrate surface is cleaned, then ultrasonically cleaned and dried, and the substrate is surface activated to obtain the pretreated substrate; Material preparation: Prepare ceramic coating raw material components, mix the ceramic coating raw material components in proportion, and prepare a coating slurry; Coating preparation: In a constant temperature and humidity environment, the coating slurry is sprayed onto the surface of the substrate in a layered gradient spraying manner to obtain a substrate with a coating. Post-coating treatment: After drying the coated substrate, sintering is performed to obtain a sintered high-temperature resistant nanocomposite ceramic coating based on graphite surface. Strengthening treatment: The surface of the sintered graphite-based high-temperature resistant nanocomposite ceramic coating is strengthened by plasma surface treatment to obtain the graphite-based high-temperature resistant nanocomposite ceramic coating.

[0008] Preferably, the substrate is graphite material, and the surface of the substrate is cleaned by mechanical polishing, specifically including the removal of surface oil, impurities and oxides; the parameters of the ultrasonic cleaning are: frequency 20-40kHz, power 150-300W, cleaning time 15-30 minutes, and the cleaning medium for ultrasonic cleaning is anhydrous ethanol or deionized water; the parameters of the drying are: temperature 105-120℃, time 2h.

[0009] Preferably, the activation treatment specifically involves immersing the dried substrate in a 5% dilute nitric acid solution at 60°C for 30 minutes, then removing it for cleaning, vacuum drying at 105°C for 1 hour, and finally transferring it to a sealed container protected by inert gas for storage.

[0010] Preferably, the gradient spraying specifically involves: spraying 1-2 layers of the bottom layer with a low flow rate to form a transition layer with a thickness of 5-10 μm; spraying 2-3 layers of the intermediate layer with a medium flow rate, with a thickness controlled at 10-15 μm; and spraying 1 layer of the top layer with a high flow rate, with a thickness of 5 μm. After each layer is sprayed, infrared pre-baking is performed at a temperature of 80°C for 3 minutes.

[0011] Preferably, the nozzle flow rate for low-flow spraying is 10 mL / min and the distance is 50 cm; the nozzle flow rate for medium-flow spraying is 15 mL / min and the distance is 40 cm; and the nozzle flow rate for high-flow spraying is 20 mL / min and the distance is 30 cm.

[0012] Preferably, the drying process in the post-coating treatment specifically involves: placing the coated substrate in an oven at 105-120℃ for drying for 2 hours; the sintering process involves: placing the coated substrate in a heating furnace, heating it to 800-1050℃ at a heating rate of 5℃ / min, holding it at that temperature for 2-3 hours, and finally cooling it to room temperature with the furnace.

[0013] Preferably, the plasma surface treatment specifically involves bombarding the coating surface with plasma for 3 minutes in an argon atmosphere, wherein the plasma bombardment power is 500W and the pressure is 10Pa.

[0014] The present invention also provides an application of a high-temperature resistant nanocomposite ceramic coating in semiconductor production, wherein the high-temperature resistant nanocomposite ceramic coating based on a graphite surface is the nanocomposite ceramic coating described in claim 1.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) Excellent high temperature resistance: the coating components contain nano-sized particles. , , All of these materials exhibit excellent high-temperature resistance. When combined with sintering at 800-1050℃ and plasma strengthening treatment, they can maintain structural stability in high-temperature environments (such as the high-temperature conditions in semiconductor manufacturing), without significant cracking, detachment, or weight loss, thus meeting the long-term high-temperature operation requirements of equipment.

[0016] (2) Strong resistance to chemical corrosion: modified nano The coating density is optimized, and plasma treatment further seals the surface pores, enabling the coating to resist corrosive media such as hydrochloric acid, sodium hydroxide, and semiconductor-specific cleaning solutions, preventing corrosive media from penetrating and damaging the substrate, and meeting the chemical protection requirements of semiconductor production.

[0017] (3) The coating is firmly bonded to the substrate: The substrate is activated by dilute nitric acid to generate active groups, which modifies the nano-coating. By acting as an "interface bridge," the layered gradient spraying constructs a transition layer to buffer thermal stress, resulting in a high final coating bonding strength (tensile strength ≥ 8.5 MPa, cross-cut strength grade 0), which can resist external forces and thermal shocks during equipment operation and reduce the risk of coating peeling.

[0018] (4) Outstanding thermal shock resistance: The layered gradient structure balances the difference in thermal expansion coefficients between graphite and coating. Plasma treatment repairs microcracks on the surface. The coating remains crack-free after 50 cycles of “800℃-25℃ cold water”. It can adapt to the heating-cooling cycle of semiconductor equipment and ensure long-term service stability.

[0019] (5) High process controllability, adaptable to the high precision requirements of semiconductors: The parameters of each link (such as ultrasonic cleaning frequency, spraying flow rate, sintering rate) are clearly quantified, and the layered gradient spraying accurately controls the coating thickness (20-30μm) and uniformity, ensuring consistent coating performance in batch production and meeting the stringent requirements of semiconductor equipment for coating precision. Detailed Implementation

[0020] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0021] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0022] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0023] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0024] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0025] This invention provides a high-temperature resistant nanocomposite ceramic coating, comprising the following components in parts by weight: 15-18 parts nano 25-30 parts nano 10-12 parts modified nano 3-5 parts nano 35-40 parts acidic silicon solution, 2-3 parts nano And 1-2 parts of nano SiC.

[0026] Preferably, the component in terms of mass fractions is 15-16 parts nanoparticles. 25-28 parts nano 10-11 parts modified nano 3-4 parts nano 35-36 parts acidic silicon solution, 2 parts nano And 2 parts of nano SiC.

[0027] The present invention does not impose any special limitations on the acidic silica solution, and commercially available acidic silica sol can be used, and it is only necessary to meet the conditions of solid content of 30-40%, SiO2 particle size of 10-20nm, and pH value of 2-4.

[0028] In this invention, the modified nanomaterials The preferred method is to obtain it through the following means: Add 2-5 wt.% of nano-sized nanoparticles to a 1 mol / L sodium hydroxide solution. Stir at high speed for 10-15 minutes, then sonicate for 20-30 minutes to obtain a mixed solution; The mixture was then placed in a high-speed centrifuge and centrifuged at 5000 r / min for 10 min. After washing with ethanol and centrifuging, the process was repeated 2-5 times to obtain activated nanoparticles. ; The activated nano Place it in a hydrochloric acid solution with a pH of 4-5, mix, and obtain a second mixed solution; The silane coupling agent was placed in the second mixed solution for reaction. After stirring for 3-4 hours, it was thoroughly washed with ethanol, centrifuged 2-5 times, and finally dried in an atmosphere at 105-120℃ for 2 hours to obtain modified nanoparticles. .

[0029] The modified nano-SiO2 of this invention has the following effects: This improves the compatibility between nano-SiO2 and the coating system, preventing component separation: Unmodified nano-SiO2 has a large number of hydroxyl groups (-OH) on its surface, which are prone to aggregation due to intermolecular hydrogen bonds, and its hydrophilic surface is incompatible with the acidic silicon solution and nano-SiO2 in the coating. The weak interfacial bonding between components can lead to uneven dispersion of the coating slurry, ultimately causing cracking and peeling. This invention utilizes a process of "sodium hydroxide activation + silane coupling agent modification" (first, alkali treatment increases surface active sites, then organic functional groups are grafted onto the surface using a silane coupling agent). This process transforms the surface of nano-SiO2 from "hydrophilic" to "facultative / hydrophobic," allowing for more uniform dispersion in matrices such as acidic silicon solutions. This reduces agglomeration and ensures a stable overall structure for the coating components, laying the foundation for subsequent high-temperature resistance and crack resistance.

[0030] Enhancing the bonding strength between the coating and the graphite substrate and reducing interfacial failure: The surface of the graphite substrate is relatively smooth and chemically inert, making it difficult for ordinary nano-SiO2 to form a strong bond with the substrate. The coating is prone to peeling off due to differences in thermal expansion coefficients. Modified nano-SiO2: On the one hand, after alkali activation and pH adjustment with hydrochloric acid, more active groups (such as carboxyl and hydroxyl groups) are formed on the surface, which can chemically bond with oxygen-containing functional groups (such as -COOH and -OH) generated after the graphite substrate activation treatment (immersion in 5% dilute nitric acid). On the other hand, the organic segments of the silane coupling agent can act as a "bridge," connecting nano-SiO2 at one end and binding to active sites on the graphite substrate surface at the other end, significantly improving the interfacial bonding strength between the coating and the substrate, and preventing coating peeling due to thermal stress under high-temperature conditions (such as the heating process in semiconductor manufacturing).

[0031] The microstructure of the coating was optimized to improve its high-temperature resistance and thermal shock resistance: Semiconductor manufacturing equipment needs to withstand high-temperature environments for extended periods and may face temperature fluctuations (thermal shock). Single ceramic coatings are prone to cracking due to mismatched coefficients of thermal expansion. The addition of modified nano-SiO2 can act as a "micro-skeleton": its uniform particle size and good dispersion can fill the tiny pores inside the coating, reducing the increase in porosity caused by gas escape at high temperatures; at the same time, SiO2 itself has good high-temperature resistance, and its synergistic effect with nano-B2O3 and nano-ZrO2 can reduce the overall difference in the coefficient of thermal expansion of the coating, improve the structural stability of the coating at high temperatures, and reduce the risk of cracking caused by thermal shock.

[0032] To enhance the chemical corrosion resistance of the coating and adapt it to the semiconductor manufacturing environment: Semiconductor manufacturing processes may involve contact with corrosive media such as acids and alkalis, requiring the coating to possess a certain degree of chemical resistance to prevent corrosion. Modified nanomaterials... The functional groups (such as amino and epoxy groups) of the silane coupling agent on the surface can interact with other components in the coating (such as nano-coatings). (SiC) forms a cross-linked structure, constructing a denser "chemical barrier" to prevent corrosive media from penetrating into the coating or the substrate surface; simultaneously, It has high chemical stability and does not easily react with acids and alkalis, which can further enhance the coating's resistance to chemical corrosion and extend the service life of semiconductor devices.

[0033] This invention also provides a method for preparing the high-temperature resistant nanocomposite ceramic coating described above, comprising the following steps: Substrate pretreatment: The substrate surface is cleaned, then ultrasonically cleaned and dried, and the substrate is surface activated to obtain the pretreated substrate; Material preparation: Prepare ceramic coating raw material components, mix the ceramic coating raw material components in proportion, and prepare a coating slurry; Coating preparation: In a constant temperature and humidity environment, the coating slurry is sprayed onto the surface of the substrate in a layered gradient spraying manner to obtain a substrate with a coating. Post-coating treatment: After drying the coated substrate, sintering is performed to obtain a sintered high-temperature resistant nanocomposite ceramic coating based on graphite surface. Strengthening treatment: The surface of the sintered graphite-based high-temperature resistant nanocomposite ceramic coating is strengthened by plasma surface treatment to obtain the graphite-based high-temperature resistant nanocomposite ceramic coating.

[0034] Substrate pretreatment: The substrate surface is cleaned, then ultrasonically cleaned and dried, and the substrate is surface activated to obtain the pretreated substrate; Before coating, the substrate is pretreated to clean its surface. During storage and processing, graphite substrates are prone to surface contamination with oil (such as lubricating oil from processing), dust, and oxide layers (graphite exposed to air for a long time is prone to slight oxidation, forming loose carbon oxides). By using a combination of mechanical polishing (to remove oil, impurities, and oxides) and ultrasonic cleaning (20-40kHz frequency, 150-300W power, rinsing with anhydrous ethanol / deionized water for 15-30 minutes), various contaminants on the substrate surface can be thoroughly removed. Mechanical polishing physically removes stubborn oxide layers and large particles, while ultrasonic cleaning uses high-frequency vibration to peel away tiny oil stains and residual impurities, clearing obstacles for the subsequent bonding of the coating to the substrate.

[0035] Furthermore, graphite itself is chemically inert with few surface active sites. If a coating is directly sprayed, the coating components (such as modified nanomaterials) will be affected. Acidic silica solutions are difficult to bond firmly with the substrate, and under high-temperature conditions, thermal stress (the difference in thermal expansion coefficients between graphite and ceramic coatings) can easily cause the coating to crack and peel off. The activation treatment of "5% dilute nitric acid immersion (60℃, 30min) + 105℃ vacuum drying + inert gas storage" can enhance the surface activity of the substrate in the following ways: Introducing active functional groups: The strong oxidizing property of dilute nitric acid can etch tiny pits on the graphite surface (increasing the specific surface area), while simultaneously generating oxygen-containing active groups (such as -COOH, -OH); Enhancing chemical bonding ability: These active groups can interact with modified nanomaterials in the coating. Chemical bonding occurs at active sites on the surface (such as carboxyl groups and silane coupling agent functional groups), forming a strong bond at the "substrate-coating" interface. Secondary contamination / oxidation is avoided: vacuum drying prevents interfacial bubbles caused by residual moisture, while inert gas preservation prevents re-oxidation of the activated substrate surface, ensuring stable retention of active sites and providing a highly active substrate surface for subsequent coating preparation. The substrate pretreatment steps of "mechanical polishing (ensuring surface smoothness) + ultrasonic cleaning (uniformly removing impurities) + drying at 105-120℃ for 2 hours (thoroughly removing moisture)" ensure that the graphite substrate surface reaches a state of "smoothness, cleanliness, dryness, and uniform activity." This ensures that during subsequent layered gradient spraying (bottom layer 5-10μm, intermediate layer 10-15μm, top layer 5μm), the coating slurry adheres uniformly, forming a consistent thickness and stable performance coating after sintering, meeting the high precision requirements of semiconductor manufacturing equipment.

[0036] In this invention, the substrate is preferably graphite material, and the surface of the substrate is preferably cleaned by mechanical polishing, specifically including the removal of surface oil, impurities, and oxides; the ultrasonic cleaning parameters are preferably: frequency 20-40kHz, power 150-300W, cleaning time 15-30 minutes, and the ultrasonic cleaning medium is anhydrous ethanol or deionized water; the drying parameters are preferably: temperature 105-120℃, time 2h.

[0037] In this invention, the activation treatment is preferably performed by immersing the dried substrate in a 5% dilute nitric acid solution at 60°C for 30 minutes, then removing it for cleaning, vacuum drying at 105°C for 1 hour, and finally transferring it to a sealed container protected by inert gas for storage.

[0038] Material preparation: Prepare ceramic coating raw material components, mix the ceramic coating raw material components in proportion, and prepare a coating slurry; This invention does not impose any special restrictions on the mixing method of the ceramic coating raw material components. A single mixing method can be used, or a multi-stage mixing method can be used as needed.

[0039] Coating preparation: In a constant temperature and humidity environment, the coating slurry is sprayed onto the surface of the substrate in a layered gradient spraying manner to obtain a substrate with a coating. This invention constructs a gradient structure of "transition layer-intermediate layer-surface layer" during coating preparation to mitigate the difference in thermal expansion coefficients and reduce coating cracking. The thermal expansion coefficients of graphite substrates and ceramic coatings differ significantly (graphite's thermal expansion coefficient is approximately 4~6 × 10⁻⁶). -6 At / ℃, the coefficient of thermal expansion of components such as B4C and ZrO2 in the ceramic coating is approximately 5~10×10⁻⁶℃. -6 If a single thickness / flow rate is used for spraying, the coating is prone to cracking and peeling due to thermal stress concentration under high-temperature conditions (such as the heating process in semiconductor production and coating sintering at 800-1050℃). Layered gradient spraying achieves a smooth transition between the graphite substrate and the coating by forming a 5-10μm transition layer with a low flow rate (10mL / min, 50cm distance) at the bottom layer. The transition layer is thin and has low spraying pressure, which can form a tight bond with the activated graphite substrate (treated with 5% dilute nitric acid). At the same time, its components can fully react with the active groups on the substrate surface through slow penetration, reducing the thermal stress at the interface. The middle layer (15mL / min, 40cm distance, 10-15μm) acts as a buffer layer, which can further balance the thermal expansion difference between the substrate and the surface layer. The surface layer (20mL / min, 30cm distance, 5μm) focuses on performance enhancement. The synergistic effect of the three layers structurally avoids the risk of cracking caused by the thermal expansion mismatch of a single coating.

[0040] Layered gradient spraying can also optimize the microstructure and density of the coating, reduce porosity and defects, and improve high temperature and corrosion resistance. Semiconductor manufacturing equipment needs to withstand high temperatures (above 800°C for extended periods) and chemical corrosion (such as acidic and alkaline media). If there are pores in the coating, high-temperature gases can penetrate and corrosive media can infiltrate, ultimately leading to coating failure or substrate damage. Layered gradient spraying, through a combination of "flow rate + distance + infrared pre-baking," can precisely control the density of the coating: The bottom layer uses low flow rate + long distance: the slurry atomizes more finely during spraying, resulting in uniform particle deposition. The resulting transition layer fills the tiny pits on the graphite substrate surface, reducing porosity at the substrate-coating interface. The middle layer uses medium flow rate + medium distance: 2-3 layers are stacked on top of the transition layer, gradually increasing the spraying amount to further fill any potential tiny pores in the bottom layer, constructing a continuous "barrier layer." The top layer uses high flow rate + short distance: the spraying pressure is greater, resulting in denser accumulation of slurry particles on the substrate surface. Simultaneously, infrared pre-baking at 80℃ for 3 minutes after each layer removes solvents (such as moisture in acidic silicon solutions) from the slurry, preventing solvent vaporization and the formation of air bubbles and pores during high-temperature sintering.

[0041] The final coating exhibits progressively improved density from the inside out, effectively blocking the penetration of high-temperature gases and corrosive media, making it suitable for the harsh environment of semiconductor manufacturing.

[0042] Achieve layered performance adaptation of "bonding force-strength-protection" to meet multi-dimensional needs. The core requirements for ceramic coatings in semiconductor manufacturing are "strong adhesion (no peeling), high temperature resistance (resistant to high-temperature deformation), and excellent protection (corrosion resistance)." A single coating cannot simultaneously meet these multi-dimensional performance requirements. Layered gradient spraying can achieve targeted performance optimization through layered design: Bottom layer (transition layer): Focusing on "strong adhesion," low-flow spraying ensures full contact between the coating and the substrate, and in conjunction with activating the active sites of the substrate, maximizes interfacial adhesion, solving the core problem of "coating peeling"; Intermediate layer (buffer layer): Focusing on "structural strength and high-temperature resistance," 2-3 layers are stacked to increase the overall thickness of the coating. At the same time, the synergistic effect of nano-B2O3 (forming a glass phase to fill gaps) and nano-Al2O3 (enhancing strength) provides the coating with "structural support" for high-temperature resistance and deformation resistance; Top layer: Focusing on "protective performance," the dense surface layer formed by high-flow spraying can directly resist external chemical corrosion and high-temperature erosion. At the same time, the concentrated effect of nano-SiC (wear-resistant) and nano-ZrO2 (thermal shock resistant) further strengthens the protective ability of the surface layer, achieving a layered performance adaptation of "bottom layer ensuring adhesion, intermediate layer ensuring strength, and top layer ensuring protection."

[0043] Layered gradient spraying also improves process stability through "layered quantitative control": Precise parameters: The flow rate (10 / 15 / 20mL / min), distance (50 / 40 / 30cm), number of layers (1-2 / 2-3 / 1 layer), and thickness (5-10 / 10-15 / 5μm) of the bottom / middle / top layers are clearly quantified and can be precisely adjusted according to needs, avoiding human error. Infrared pre-baking assistance: 80℃ pre-baking after each layer of spraying can quickly fix the coating shape, prevent the underlying slurry from being washed away and deformed during subsequent spraying, and ensure that the thickness of each layer is controllable; Ultimately, the coating can achieve a uniform overall thickness (20-30μm) and stable performance of each layer, meeting the requirements of semiconductor devices for high precision and high consistency of coatings.

[0044] In this invention, the gradient spraying is preferably performed as follows: 1-2 layers of the bottom layer are sprayed with a low flow rate to form a transition layer with a thickness of 5-10 μm; 2-3 layers of the intermediate layer are sprayed with a medium flow rate, with a thickness controlled at 10-15 μm; and 1 layer of the top layer is sprayed with a high flow rate, with a thickness of 5 μm. Each layer is pre-baked with infrared light after spraying, and the infrared pre-baking temperature is 80°C for 3 minutes.

[0045] In this invention, the nozzle flow rate for low-flow spraying is 10 mL / min and the distance is 50 cm; the nozzle flow rate for medium-flow spraying is 15 mL / min and the distance is 40 cm; and the nozzle flow rate for high-flow spraying is 20 mL / min and the distance is 30 cm.

[0046] Post-coating treatment: After drying the coated substrate, sintering is performed to obtain a sintered high-temperature resistant nanocomposite ceramic coating based on graphite surface. In this invention, the drying process in the post-coating treatment is preferably: the coated substrate is placed in an oven at 105-120℃ for drying for 2 hours; the sintering process is preferably: the coated substrate is placed in a heating furnace and heated to 800-1050℃ at a heating rate of 5℃ / min, held at that temperature for 2-3 hours, and finally cooled to room temperature with the furnace.

[0047] Strengthening treatment: The surface of the sintered graphite-based high-temperature resistant nanocomposite ceramic coating is strengthened by plasma surface treatment to obtain the graphite-based high-temperature resistant nanocomposite ceramic coating.

[0048] Finally, the coating surface of this invention is further strengthened, and the strengthening treatment has the following effects: Densified coating surface blocks the penetration channels of corrosive media and high-temperature gases: After the coating is sintered at 800-1050℃, although it has formed an integral structure, there may be tiny pores on the surface (due to solvent evaporation and slight shrinkage of components during the sintering process). These pores can become channels for the penetration of "acidic and alkaline corrosive media" (such as chemical reagents in the semiconductor cleaning process) and "high-temperature gases" (such as gases generated by equipment heating) in semiconductor production, leading to internal deterioration of the coating or corrosion of the substrate.

[0049] Plasma surface treatment achieves surface densification through the following method: Argon plasma, under a low-pressure environment of 500W power and 10Pa, generates a high-energy ion flow (such as Ar...). + When the surface of the coating is bombarded, the tiny pores on the surface can be filled with ceramic components (such as SiO2 and B2O3 glass phases) in a molten / plastic state. At the same time, high-energy ions can promote the secondary diffusion and bonding of surface particles, reduce porosity, and ultimately form a dense barrier on the coating surface, completely blocking the penetration path of external harmful media and enhancing the coating's resistance to chemical corrosion and high-temperature sealing.

[0050] Improve the surface hardness and wear resistance of the coating to resist mechanical damage during semiconductor manufacturing: During the assembly, maintenance, or operation of semiconductor manufacturing equipment (such as rack modules), the coated surface may face slight friction (such as component mating or dust washing). If the surface hardness of the coating is insufficient, scratches and wear are likely to occur, damaging the integrity of the coating.

[0051] The "high-energy effect" of plasma bombardment can significantly improve the surface hardness of coatings: on the one hand, high-energy ions cause "lattice distortion" in the crystal structure of the coating surface, forming a more compact crystal arrangement (such as nano-SiC, ...). On the one hand, the surface crystallinity of the particles is increased; on the other hand, plasma energy can promote the reconstruction of chemical bonds in the surface components (such as the formation of a more stable composite phase between SiO2 and ZrO2), enhancing the bonding force between surface particles. Ultimately, this increases the surface hardness of the coating, improves its wear resistance, and enables it to resist minor mechanical damage during semiconductor production, thus extending the coating's service life.

[0052] Repairing surface microcracks in the sintered coating to prevent defect propagation and coating failure: During the sintering and cooling process, slight differences in the coefficients of thermal expansion of the components may cause invisible "microcracks" to form on the surface of the coating (especially since the surface layer is only 5μm thick and its structure is relatively fragile). If these microcracks are not addressed, they will gradually expand into macrocracks under the long-term high-temperature cycling (thermal shock) conditions of semiconductor equipment, eventually leading to coating cracking and peeling.

[0053] Plasma surface treatment can repair microcracks: When high-energy argon plasma bombards the coating surface, it transfers heat and energy to the surface, raising the local temperature to a "semi-molten state" (before reaching the overall sintering temperature, thus avoiding damage to the coating structure). At this point, the ceramic components on the surface (such as low-melting-point...) It exhibits a certain degree of fluidity, which can fill the gaps in microcracks; at the same time, plasma energy can promote the recombination of particles at the crack edge, realizing the "healing" of microcracks, preventing the expansion of defects from the source, ensuring that the coating maintains structural integrity under high-temperature thermal shock environments (such as the heating-cooling cycle of semiconductor equipment), and avoiding coating failure.

[0054] In this invention, the plasma surface treatment specifically involves bombarding the coating surface with plasma for 3 minutes in an argon atmosphere, wherein the plasma bombardment power is 500W and the pressure is 10Pa.

[0055] The present invention also provides an application of a high-temperature resistant nanocomposite ceramic coating in semiconductor production, wherein the high-temperature resistant nanocomposite ceramic coating based on a graphite surface is the nanocomposite ceramic coating described in claim 1.

[0056] Example 1 I. Coating Components 15 nano 25 nanoparticles 10 parts modified nano 3 nano 35 parts acidic silicon solution, 2 parts nano 1 part of nano SiC.

[0057] II. Modified Nano preparation Add 2 wt.% nano-sized particles to a 1 mol / L sodium hydroxide solution The mixture was stirred at high speed for 10 minutes, followed by ultrasonic treatment for 20 minutes to obtain a mixed solution. The mixed solution was placed in a high-speed centrifuge and centrifuged at 5000 r / min for 10 min. It was then washed with ethanol and centrifuged again, repeated twice, to obtain activated nanoparticles. ; Activated nano The solution was placed in a hydrochloric acid solution with a pH of 4 and mixed to obtain a second mixed solution. Add a silane coupling agent to the second mixed solution, stir for 3 hours, wash thoroughly with ethanol, centrifuge twice, and finally dry at 105°C for 2 hours to obtain the modified nanoparticles. .

[0058] III. Coating Preparation Methods Substrate pretreatment: Graphite was selected as the substrate, and mechanical polishing was used to remove surface oil, impurities and oxides; then ultrasonic cleaning was performed with parameters of frequency 20kHz, power 150W, cleaning time 15 minutes, and anhydrous ethanol as the cleaning medium; after cleaning, it was dried at 105℃ for 2 hours; the dried substrate was immersed in 5% dilute nitric acid solution at 60℃ for 30 minutes, then removed and cleaned, and vacuum dried at 105℃ for 1 hour, and then transferred to a sealed container under inert gas protection for storage to obtain the pretreated substrate.

[0059] Material preparation: Mix the raw materials according to the above coating component ratio to prepare the coating slurry.

[0060] Coating preparation: In a constant temperature and humidity environment, a layered gradient spraying method was adopted: a base layer was sprayed with a low flow rate (nozzle flow rate 10 mL / min, distance 50 cm) to form a transition layer with a thickness of 5 μm; two intermediate layers were sprayed with a medium flow rate (nozzle flow rate 15 mL / min, distance 40 cm) with a thickness controlled at 10 μm; a top layer was sprayed with a high flow rate (nozzle flow rate 20 mL / min, distance 30 cm) with a thickness of 5 μm; after each layer was sprayed, it was pre-baked with infrared at 80℃ for 3 min to obtain a substrate with a coating.

[0061] Post-coating treatment: The coated substrate is placed in an oven at 105℃ and dried for 2 hours; then it is placed in a heating furnace and heated to 800℃ at a heating rate of 5℃ / min, held for 2 hours, and cooled to room temperature with the furnace to obtain the sintered coating.

[0062] Enhancement treatment: The sintered coating surface was subjected to plasma bombardment for 3 minutes in an argon atmosphere with a power of 500W and a pressure of 10Pa to obtain a high-temperature resistant nanocomposite ceramic coating.

[0063] Example 2 I. Coating Components 16.5 parts nano 27.5 parts nano 11 parts of modified nano 4 nano 37.5 parts acidic silicon solution, 2.5 parts nano 1.5 parts nano SiC.

[0064] II. Modified Nano preparation Add 3.5 wt.% nano-sized particles to a 1 mol / L sodium hydroxide solution. The mixture was stirred at high speed for 12 minutes, followed by sonication for 25 minutes to obtain a mixed solution. The mixed solution was placed in a high-speed centrifuge and centrifuged at 5000 r / min for 10 min. It was then washed with ethanol and centrifuged again, repeated three times to obtain activated nanoparticles. ; Activated nano The solution was placed in a hydrochloric acid solution with a pH of 4.5 and mixed to obtain a second mixed solution; A silane coupling agent was added to the second mixed solution, and after stirring for 3.5 hours, the solution was thoroughly washed with ethanol, centrifuged three times, and finally dried at 110°C for 2 hours to obtain the modified nanomaterials. .

[0065] III. Coating Preparation Methods Substrate pretreatment: Graphite was selected as the substrate, and mechanical polishing was used to remove surface oil, impurities and oxides; ultrasonic cleaning parameters were 30kHz frequency, 225W power, and 22 minutes cleaning time, with deionized water as the cleaning medium; after cleaning, the substrate was dried at 110℃ for 2 hours; the dried substrate was immersed in 5% dilute nitric acid solution at 60℃ for 30 minutes, then removed and cleaned, and vacuum dried at 105℃ for 1 hour, and then stored in a sealed container under inert gas protection to obtain the pretreated substrate.

[0066] Material preparation: Mix the raw materials according to the above coating component ratio to prepare the coating slurry.

[0067] Coating preparation: In a constant temperature and humidity environment, layered gradient spraying was performed: 1.5 layers of the bottom layer were sprayed at a low flow rate (nozzle flow rate 10 mL / min, distance 50 cm) to form a transition layer with a thickness of 7.5 μm; 2.5 layers of the middle layer were sprayed at a medium flow rate (nozzle flow rate 15 mL / min, distance 40 cm) with a thickness controlled at 12.5 μm; and 1 layer of the top layer was sprayed at a high flow rate (nozzle flow rate 20 mL / min, distance 30 cm) with a thickness of 5 μm. After each layer was sprayed, it was pre-baked at 80℃ for 3 min using infrared technology to obtain the coated substrate.

[0068] Post-coating treatment: The coated substrate is placed in an oven at 110℃ and dried for 2 hours; then placed in a heating furnace and heated to 925℃ at a heating rate of 5℃ / min, held for 2.5 hours, and cooled to room temperature with the furnace to obtain the sintered coating.

[0069] Enhancement treatment: The sintered coating surface was subjected to plasma bombardment for 3 minutes in an argon atmosphere with a power of 500W and a pressure of 10Pa to obtain a high-temperature resistant nanocomposite ceramic coating.

[0070] Example 3 I. Coating Components 18 parts nano 30 nano 12 parts of modified nano 5 nano 40 parts acidic silicon solution, 3 parts nano 2 parts of nano SiC.

[0071] II. Modified Nano preparation Add 5 wt.% nano-sized particles to a 1 mol / L sodium hydroxide solution The mixture was stirred at high speed for 15 minutes, followed by ultrasonic treatment for 30 minutes to obtain a mixed solution. The mixed solution was placed in a high-speed centrifuge and centrifuged at 5000 r / min for 10 min. It was then washed with ethanol and centrifuged again, repeated 5 times to obtain activated nanoparticles. ; Activated nano The solution was placed in a hydrochloric acid solution with a pH of 5 and mixed to obtain a second mixed solution; Add a silane coupling agent to the second mixed solution, stir for 4 hours, wash thoroughly with ethanol, centrifuge 5 times, and finally dry at 120°C for 2 hours to obtain the modified nanoparticles. .

[0072] III. Coating Preparation Methods Substrate pretreatment: Graphite was selected as the substrate, and mechanical polishing was used to remove surface oil, impurities and oxides; ultrasonic cleaning parameters were 40kHz frequency, 300W power, and 30 minutes cleaning time, with anhydrous ethanol as the cleaning medium; after cleaning, the substrate was dried at 120℃ for 2 hours; the dried substrate was immersed in 5% dilute nitric acid solution at 60℃ for 30 minutes, then removed and cleaned, and vacuum dried at 105℃ for 1 hour, and then transferred to a sealed container under inert gas protection for storage to obtain the pretreated substrate.

[0073] Material preparation: Mix the raw materials according to the above coating component ratio to prepare the coating slurry.

[0074] Coating preparation: In a constant temperature and humidity environment, layered gradient spraying was performed: two layers of the bottom layer were sprayed at a low flow rate (nozzle flow rate 10 mL / min, distance 50 cm) to form a transition layer with a thickness of 10 μm; three layers of the middle layer were sprayed at a medium flow rate (nozzle flow rate 15 mL / min, distance 40 cm) with a thickness controlled at 15 μm; and one layer of the top layer was sprayed at a high flow rate (nozzle flow rate 20 mL / min, distance 30 cm) with a thickness of 5 μm. After each layer was sprayed, it was pre-baked at 80℃ for 3 min to obtain the substrate with the coating.

[0075] Post-coating treatment: The coated substrate is placed in an oven at 120℃ and dried for 2 hours; then placed in a heating furnace and heated to 1050℃ at a heating rate of 5℃ / min, held for 3 hours, and cooled to room temperature with the furnace to obtain the sintered coating.

[0076] Enhancement treatment: The sintered coating surface was subjected to plasma bombardment for 3 minutes in an argon atmosphere with a power of 500W and a pressure of 10Pa to obtain a high-temperature resistant nanocomposite ceramic coating.

[0077] Test Example 1: High Temperature Resistance Test 1. Test Sample The “graphite substrate + composite ceramic coating” samples prepared in Examples 1, 2 and 3 were all 50mm×50mm×5mm in size, and three parallel samples were prepared for each group.

[0078] 2. Test equipment and parameters Equipment: Box-type resistance furnace (temperature control accuracy ±5℃), electronic analytical balance (accuracy 0.1mg), optical microscope (magnification 200x) Test conditions: The sample was placed in a resistance furnace and heated to 1000℃ (above the upper limit of sintering temperature, simulating extreme high temperature) at a heating rate of 5℃ / min, held at that temperature for 48 hours, and then cooled to room temperature with the furnace.

[0079] The test results are shown in Table 1. Table 1. Results of High Temperature Resistance Test

[0080] As shown in Table 1, after the coatings of the three sets of embodiments were kept at 1000℃ for 48 hours, the weight loss rate, appearance and thickness changes all met the performance targets. The weight loss rate was small, the appearance change was slight, and the high temperature resistance was excellent, which can be adapted to the high temperature conditions in semiconductor production.

[0081] Test Example 2: Chemical Corrosion Resistance Test 1. Test Sample Similar to test example 1, each group of samples had 3 parallel samples. Before the test, the coating surface was cleaned with anhydrous ethanol and dried.

[0082] 2. Test equipment and parameters Equipment: Constant temperature immersion bath (temperature control accuracy ±1℃), electronic analytical balance, scanning electron microscope (SEM) Test media and conditions: ① 10 wt.% hydrochloric acid solution (25℃, soaking for 24h); ② 5 wt.% sodium hydroxide solution (25℃, soaking for 24h); ③ Commonly used cleaning solution in semiconductor production (ammonia-hydrogen peroxide mixture, volume ratio 1:1:5, 25℃, soaking for 24h).

[0083] The test results are shown in Table 2. Table 2 Results of Chemical Corrosion Resistance Test

[0084] As shown in Table 2, after immersion in three typical corrosive media for 24 hours, the coatings of the three sets of embodiments showed low weight loss and no obvious corrosion defects on the surface, and their chemical corrosion resistance met the protection requirements of coatings for semiconductor production.

[0085] Test Example 3: Bond Strength and Thermal Shock Resistance Test 1. Test Sample Combined strength test samples: Coating samples from Examples 1-3 (size 50mm×50mm×5mm); Thermal shock resistance test samples: Same as test example 1, with 3 parallel samples in each group.

[0086] 2. Test equipment and parameters (1) Combined strength test Cross-cut test: Use a cross-cut knife (1mm spacing) to cut a 10×10 grid on the coating surface, stick it with 3M tape and then quickly peel it off, observe the coating peeling; Pull-off method: According to GB / T 5210-2006 "Paints and Varnishes - Pull-off Adhesion Test", the pull-off adhesion tester is used to test the interfacial pull-off strength between the coating and the graphite substrate.

[0087] (2) Thermal shock resistance test Equipment: Box-type resistance furnace, cold water tank (25℃) Cyclic conditions: Place the sample in the furnace, heat it to 800℃ at a rate of 5℃ / min, hold it at that temperature for 30min, then quickly remove it and cool it in 25℃ cold water for 5min. This completes one cycle. A total of 50 cycles are performed, and the changes in the appearance of the coating are observed.

[0088] The test results are shown in Table 3. Table 3. Test results of bond strength and thermal shock resistance

[0089] As shown in Table 3, the coating bonding strength (cross-cut grade 0, tensile strength ≥ 8.5 MPa) and thermal shock resistance (no defects after 50 cycles) of the three sets of embodiments all meet the performance targets, effectively resisting the external forces and thermal shock effects during the operation of semiconductor equipment, and ensuring long-term stable adhesion of the coating.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high-temperature resistant nanocomposite ceramic coating, characterized in that, The components include the following parts by mass: 15-18 parts nano 25-30 parts nano 10-12 parts modified nano 3-5 parts nano 35-40 parts acidic silicon solution, 2-3 parts nano And 1-2 parts of nano SiC.

2. The high-temperature resistant nanocomposite ceramic coating according to claim 1, characterized in that, The modified nano Obtained through the following methods: Add 2-5 wt.% of nano-sized nanoparticles to a 1 mol / L sodium hydroxide solution. Stir at high speed for 10-15 minutes, then sonicate for 20-30 minutes to obtain a mixed solution; The mixture was then placed in a high-speed centrifuge and centrifuged at 5000 r / min for 10 min. After washing with ethanol and centrifuging again, this process was repeated 2-5 times to obtain activated nanoparticles. ; The activated nano Place it in a hydrochloric acid solution with a pH of 4-5, mix, and obtain a second mixed solution; The silane coupling agent was placed in the second mixed solution for reaction. After stirring for 3-4 hours, it was thoroughly washed with ethanol, centrifuged 2-5 times, and finally dried in an atmosphere at 105-120℃ for 2 hours to obtain modified nanoparticles. .

3. A method for preparing the high-temperature resistant nanocomposite ceramic coating according to claim 1, characterized in that, Includes the following steps: Substrate pretreatment: The substrate surface is cleaned, then ultrasonically cleaned and dried, and the substrate is surface activated to obtain the pretreated substrate; Material preparation: Prepare ceramic coating raw material components, mix the ceramic coating raw material components in proportion, and prepare a coating slurry; Coating preparation: In a constant temperature and humidity environment, the coating slurry is sprayed onto the surface of the substrate in a layered gradient spraying manner to obtain a substrate with a coating. Post-coating treatment: After drying the coated substrate, sintering is performed to obtain a sintered high-temperature resistant nanocomposite ceramic coating based on graphite surface. Strengthening treatment: The surface of the sintered graphite-based high-temperature resistant nanocomposite ceramic coating is strengthened by plasma surface treatment to obtain the graphite-based high-temperature resistant nanocomposite ceramic coating.

4. The method for preparing the high-temperature resistant nanocomposite ceramic coating according to claim 3, characterized in that, The substrate is graphite material. The surface of the substrate is cleaned by mechanical polishing, specifically removing oil, impurities and oxides from the surface. The ultrasonic cleaning parameters are: frequency 20-40kHz, power 150-300W, cleaning time 15-30 minutes, and the ultrasonic cleaning medium is anhydrous ethanol or deionized water. The drying parameters are: temperature 105-120℃, time 2 hours.

5. The method for preparing the high-temperature resistant nanocomposite ceramic coating according to claim 2, characterized in that, The activation treatment specifically involves immersing the dried substrate in a 5% dilute nitric acid solution at 60°C for 30 minutes, then removing it for cleaning, vacuum drying at 105°C for 1 hour, and finally transferring it to a sealed container protected by inert gas for storage.

6. The method for preparing the high-temperature resistant nanocomposite ceramic coating according to claim 3, characterized in that, The layered gradient spraying process specifically involves: applying 1-2 layers of the bottom layer with a low flow rate to form a transition layer with a thickness of 5-10 μm; applying 2-3 layers of the intermediate layer with a medium flow rate, with a thickness controlled at 10-15 μm; and applying 1 layer of the top layer with a high flow rate, with a thickness of 5 μm. Each layer is pre-baked with infrared light after spraying, and the infrared pre-baking temperature is 80℃ for 3 minutes.

7. The method for preparing the high-temperature resistant nanocomposite ceramic coating according to claim 6, characterized in that, The low-flow spraying nozzle has a flow rate of 10 mL / min and a distance of 50 cm; the medium-flow spraying nozzle has a flow rate of 15 mL / min and a distance of 40 cm; and the high-flow spraying nozzle has a flow rate of 20 mL / min and a distance of 30 cm.

8. The method for preparing the high-temperature resistant nanocomposite ceramic coating according to claim 3, characterized in that, The drying process in the post-coating treatment is as follows: the coated substrate is placed in an oven at 105-120℃ for drying for 2 hours; the sintering process is as follows: the coated substrate is placed in a heating furnace and heated to 800-1050℃ at a heating rate of 5℃ / min, held at that temperature for 2-3 hours, and finally cooled to room temperature with the furnace.

9. The method for preparing the high-temperature resistant nanocomposite ceramic coating according to claim 3, characterized in that, The plasma surface treatment specifically involves bombarding the coating surface with plasma for 3 minutes in an argon atmosphere. The plasma bombardment power is 500W and the pressure is 10Pa.

10. The application of a high-temperature resistant nanocomposite ceramic coating in semiconductor manufacturing, characterized in that, The high-temperature resistant nanocomposite ceramic coating is the nanocomposite ceramic coating as described in claim 1.

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