Method for preparing double-layer Y2O3 etching-resistant coating through atmosphere and suspension plasma spraying
By employing a dual-layer coating method combining APS and SPS on semiconductor devices, the problems of coating thickness and bonding strength are solved, achieving high density and corrosion resistance, suitable for semiconductor processes at 7nm and below.
Patent Information
- Application Number
- CN202511628281.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-01-30
AI Technical Summary
Existing technologies struggle to achieve both high-density Y2O3 coating thickness and bonding strength in semiconductor devices, leading to easy corrosion and peeling of the coating during high-energy etching processes, which fails to meet the stringent requirements of 7nm and below nodes.
A two-layer coating method combining atmospheric plasma spraying (APS) and suspension plasma spraying (SPS) is adopted. First, an APS base layer is formed, followed by grinding and annealing, and then an SPS top layer is sprayed to control interlayer thermal stress and improve bonding strength.
This study improved the corrosion resistance and dimensional stability of the highly dense Y2O3 coating while reducing the preparation cost and ensuring the durability and reliability of the coating in high-energy etching processes.
Smart Images
Figure CN121428458A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of coating preparation technology, specifically to a method for preparing a double-layer Y2O3 etching-resistant coating by atmospheric and suspension plasma spraying. Background Technology
[0002] In semiconductor manufacturing, etching is a crucial step in wafer patterning. The fluorine-containing process gases used in this process severely corrode the inner walls of the etching equipment cavity and internal components while etching the wafer. Traditional anodic oxide layers on aluminum alloy substrates, due to their limited corrosion resistance, density, and resistance to plasma impact, can no longer meet the requirements of high-power etching processes and stringent particle control.
[0003] Plasma spraying technology has become the mainstream technology for coating preparation of semiconductor devices due to its advantages of high coating bonding strength and strong performance controllability. Among them, Y2O3 (yttrium trioxide) coating has become the preferred material for corrosion-resistant coatings of semiconductor components due to its excellent high temperature resistance, chemical inertness and mechanical properties. Atmospheric plasma spraying (APS) technology is widely used for the large-scale production of Y2O3 coatings because of its high coating preparation efficiency and easy thickness control.
[0004] However, as semiconductor manufacturing processes advance to 7nm and below, etching processes place higher demands on the plasma impact resistance and density of the inner walls of the equipment cavity. Traditional APS-prepared Y... 2O3 Due to their high porosity (typically 3%-5%), coatings are susceptible to corrosion from fluorine-containing gases under high-energy plasma beams, leading to coating failure. In contrast, suspension plasma spraying (SPS) technology, by injecting nano / submicron-sized Y2O3 powder into a suspension and then into a plasma stream, can produce Y2O3 coatings with extremely low porosity (<1%) and excellent density. These coatings exhibit significantly better corrosion resistance and plasma impact resistance than APS coatings.
[0005] However, SPS technology has inherent drawbacks: during the spraying process, the high-energy plasma jet generates severe thermal stress when it comes into contact with the suspension, making it difficult to exceed 120μm in coating thickness (compared to 200-300μm for traditional APS coatings). When semiconductor equipment components are switched from APS coatings to SPS coatings, the significant reduction in coating thickness can alter the internal dimensions of the cavity, leading to problems such as abnormal plasma beam tip discharge and process parameter drift, thus failing to meet the normal production requirements of the equipment.
[0006] Furthermore, if an SPS coating is directly superimposed on the APS coating surface, the mismatch in thermal expansion coefficients and residual stress caused by differences in the manufacturing processes between the two coatings will lead to a sharp decrease in the interfacial adhesion, ultimately causing the coating to peel off (e.g. Figure 1 , Figure 2(As shown). Therefore, the key to solving the problem of upgrading corrosion-resistant coatings for semiconductor devices lies in combining the cost advantages of APS coatings with the performance advantages of SPS coatings while ensuring that the total coating thickness is comparable to that of traditional APS coatings. Summary of the Invention
[0007] The purpose of this invention is to provide a method for preparing a double-layer Y2O3 etching-resistant coating by atmospheric and suspended plasma spraying, thereby achieving a synergistic improvement in coating corrosion resistance and dimensional stability, while reducing coating preparation costs.
[0008] To achieve the above objectives, the technical solution of this application is: a method for preparing a double-layer Y2O3 etching-resistant coating by atmospheric and suspended liquid plasma spraying, comprising: Step 1: Sandblast the aluminum-based sample. After sandblasting, remove the sand particles and impurities remaining on the sample surface by high-pressure water washing. Then, dry the sample surface with compressed air and place the dried sample in an oven to dry. Step 2: High-purity Y2O3 powder is sprayed onto the surface of the treated aluminum-based sample using atmospheric plasma spraying technology to form an APS underlayer with a preset thickness. Step 3: After the APS substrate has cooled, grind the surface of the APS substrate. Step 4: Place the ground aluminum-based sample into an annealing furnace for annealing treatment to release the residual stress generated by spraying and grinding in the APS underlayer and inside the aluminum-based sample. Step 5: After the annealed aluminum-based sample is cooled to the preset temperature, the Y2O3 suspension is injected into a high-energy plasma flame through a plasma spraying device, causing the Y2O3 suspension to melt in the plasma flame. The molten Y2O3 is then impacted at high speed by the plasma stream onto the surface of the APS bottom layer. After cooling, it forms the SPS top layer, ultimately resulting in a double-layer high-density Y2O3 corrosion-resistant coating composed of the APS bottom layer and the SPS top layer.
[0009] In another implementation of the present invention, the sandblasting treatment in step one uses white corundum sand, the sandblasting pressure is 0.2-0.4 MPa, and the surface roughness of the aluminum-based sample after treatment is Ra3-3.5 μm.
[0010] In another implementation of the present invention, the high-pressure water washing pressure in step one is 1900-2100 psi; the compressed air pressure is 0.8-0.9 MPa; the drying temperature is 115-125°C, and the drying time is 1.5-3 hours.
[0011] In another implementation of the present invention, the atmospheric plasma spraying technology in step two adopts the F4BM-XL spraying system, with the following spraying parameters: argon 30-35 NLPM, hydrogen 3-6 NLPM, power 35-38 KW, and auxiliary gas pressure 2-3 Bar.
[0012] In another implementation of the present invention, the thickness of the APS substrate is 150-250 μm and the coating roughness is Ra5-7 μm.
[0013] In another implementation of the present invention, in step three, diamond sandpaper is used to grind the surface of the APS substrate. The mesh size of the diamond sandpaper is 800 mesh, 1200 mesh, and 3000 mesh respectively. After grinding, the surface roughness of the APS substrate is reduced to Ra3-4μm.
[0014] In another implementation of the present invention, the annealing parameters in step four are: annealing temperature 400-500℃, heating rate 10-12℃ / min, holding time 0.8-1.2 hours, cooling rate 3-5℃ / min, and the sample is taken out and directly clamped when the temperature drops to 78-82℃.
[0015] In another embodiment of the present invention, the Y2O3 suspension is prepared by mixing Y2O3 powder with a particle size of 2-4 μm and a purity of >99.9% with ultrapure water with a conductivity of >18.2 MΩ, and stirring thoroughly to form a suspension with a mass fraction of 32-36%.
[0016] In another embodiment of the present invention, the plasma spraying equipment is a 100HE type plasma spraying equipment, and the spraying process parameters are: argon flow rate 145-155 SLPM, nitrogen flow rate 66-70 SLPM, hydrogen flow rate 60-65 SLPM, spray gun power 100-102KW, spray gun moving speed 6-30mm / s, turntable speed 120-150RPM, spraying distance 65-70mm, Y2O3 suspension injection flow rate 30-34mL / min, and cooling gas pressure 2-3Bar.
[0017] In another embodiment of the present invention, the total thickness of the double-layer high-density Y2O3 etching-resistant coating is 200-350 μm, the surface roughness Ra is 2-3 μm, the porosity of the SPS top layer is 0.6%-0.8%, the porosity of the APS bottom layer is 2.5%-3%, the coating bonding strength is 22-25 MPa, the hardness Hv0.2=550-600, and the breakdown voltage is >6 kV.
[0018] By adopting the above technical solution, the present invention can achieve the following technical effects: 1. This invention adopts a composite coating structure of "APS base layer + SPS functional layer". The top SPS coating is dense and provides the best corrosion resistance, which can completely resist the strong corrosion of fluorine-containing gases in the etching process; while the bottom APS coating is not only inexpensive, but also serves as an additional protective barrier, forming a "double insurance" mechanism with the SPS layer, which effectively controls manufacturing costs while ensuring performance.
[0019] 2. This invention effectively eliminates residual thermal stress within the coating and between the coating and the substrate by introducing key grinding and annealing post-treatment processes after APS spraying, thus avoiding coating cracking or peeling caused by stress concentration (as shown in the attached figure). Figure 1 , 2 (As shown). In addition, by controlling the substrate temperature before SPS spraying (maintaining a certain temperature during spraying instead of dropping to room temperature), interlayer thermal mismatch was further reduced, ensuring the successful preparation and strong bonding of the thick SPS coating.
[0020] 3. In the initial stage of SPS spraying, the high-energy plasma beam provides secondary heating to the underlying APS coating. This process further optimizes the bonding interface between the APS layer and the aluminum alloy substrate, thereby dynamically and continuously improving the bonding strength of the underlying layer. This "self-reinforcing" effect makes the overall anti-detachment performance and adhesion of the composite coating of this invention significantly superior to a simple APS / SPS dual-layer structure, resulting in higher reliability and service life. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0022] Figure 1 This is a diagram illustrating the coating peeling caused by applying SPS directly after APS layer spraying; Figure 2 Microscopic cross-section of a coating that peels off when SPS is applied directly after APS layer spraying. Figure 3 Image of a sample of a double-layer, highly dense, corrosion-resistant Y2O3 coating prepared using the method of this invention; Figure 4 Microscopic image of the cross-section of the double-layer high-density Y2O3 corrosion-resistant coating prepared using the method of the present invention. Detailed Implementation
[0023] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0026] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.
[0027] This embodiment provides a method for preparing a double-layer Y2O3 etching-resistant coating by atmospheric and suspended liquid plasma spraying, including: Step 1: Sandblast the aluminum-based sample to enhance the adhesion between the sample surface and the subsequent coating. After sandblasting, remove the residual sand particles and impurities on the sample surface by high-pressure water washing, then dry the sample surface with compressed air, and finally put the dried sample into an oven to dry it, removing the moisture adsorbed inside the sample and avoiding the formation of pores during the subsequent spraying process. In this embodiment, the aluminum-based sample was sandblasted with WA#80 white corundum sand at a pressure of 0.3 MPa to achieve a surface roughness of Ra 3-3.5 μm. Then, it was subjected to high-pressure water washing at a pressure of 2000 psi, followed by air drying with compressed air at a pressure of 0.8-0.9 MPa. Finally, it was placed in an oven to dry at a temperature of 120°C for 2 hours.
[0028] Step 2: High-purity Y2O3 powder is sprayed onto the surface of the aluminum-based sample after the pretreatment in Step 1 using atmospheric plasma spraying technology to form an atmospheric plasma spraying (APS) underlayer with a preset thickness, which provides a supporting substrate for the subsequent suspension plasma spraying (SPS) top layer. In this embodiment, high-purity Y2O3 powder was sprayed using the OERLIKON F4BM-XL spraying system. The spraying parameters used were: argon 32 NLPM, hydrogen 3 NLPM, power 35-38 KW, auxiliary gas 2 Bar, coating thickness 200 μm, and coating roughness Ra 5.9 μm.
[0029] Step 3: After the APS base layer formed in Step 2 has cooled, use diamond sandpaper to grind the surface of the APS base layer to reduce the surface roughness, eliminate surface protrusions and defects, and improve the interface bonding with the subsequent SPS top layer. In this embodiment, the surface of the APS coating was polished using diamond sandpaper of 800 mesh, 1200 mesh and 3000 mesh respectively, and the roughness was reduced to Ra3.5μm after the treatment.
[0030] Step 4: Place the sample after grinding in step 3 into an annealing furnace for annealing treatment to release the residual stress generated by spraying and grinding in the APS underlayer and aluminum base sample, and avoid coating peeling due to stress difference during subsequent SPS spraying. In this embodiment, the sample is placed in an annealing furnace for annealing at a temperature of 450°C, a heating rate of 10°C / min, a holding time of 1 hour, a cooling rate of 5°C / min, and is taken out when the temperature drops to about 80°C and directly clamped for SPS spraying.
[0031] Step 5: After the sample annealed in Step 4 has cooled to the preset temperature, the self-made Y2O3 suspension is injected into a high-energy plasma flame through a specific plasma spraying device, so that the Y2O3 suspension melts in the plasma flame. The molten Y2O3 is then impacted at high speed by the plasma stream onto the surface of the annealed APS bottom layer. After cooling, a suspension plasma spraying (SPS) top layer is formed, and finally a double-layer high-density Y2O3 corrosion-resistant coating composed of the APS bottom layer and the SPS top layer is obtained.
[0032] In this embodiment, after cooling, a 35%wt Y2O3 suspension was injected into a ProgressiveSurface 100HE plasma spraying equipment. The spraying process parameters used were: argon flow rate 150 SLPM; nitrogen flow rate 68 SLPM; hydrogen flow rate 62 SLPM; spray gun power 100 kW; spray gun moving speed 25 mm / s; turntable speed 120 RPM; spraying distance 69 mm; Y2O3 suspension injection flow rate 30 mL / min; cooling gas pressure 2 Bar.
[0033] The prepared double-layer coating has a total thickness of 200-350μm, which matches the thickness of traditional APS coatings. It can directly replace the coating of existing equipment without modifying the equipment cavity, and is suitable for the stringent requirements of advanced semiconductor processes below 7nm.
[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A method for producing a dual layer Y2O3 etch resistant coating by atmospheric and suspension plasma spraying, characterized in that, The application relates to a method for preparing a double-layer high-density Y2O3 corrosion-resistant coating. Step one: sandblasting treatment is carried out on an aluminum base sample; after sandblasting, residual sand and impurities on the surface of the sample are removed through high-pressure water washing; compressed air is used to dry the surface of the sample; and the dried sample is placed into an oven for drying; Step two: high-purity Y2O3 powder is sprayed on the surface of the treated aluminum base sample by using atmospheric plasma spraying technology to form an APS bottom layer with a preset thickness; Step three: after the APS bottom layer cools down, the surface of the APS bottom layer is ground; Step four: the ground aluminum base sample is placed into an annealing furnace for annealing treatment to release the residual stress generated in the APS bottom layer and the aluminum base sample due to spraying and grinding; Step five: after the annealed aluminum base sample cools down to a preset temperature, Y2O3 suspension liquid is injected into a high-energy plasma flame by using plasma spraying, so that the Y2O3 suspension liquid is melted in the plasma flame; the melted Y2O3 impacts the surface of the APS bottom layer at a high speed along with the plasma flow; and after cooling, an SPS top layer is formed, and finally a double-layer high-density Y2O3 corrosion-resistant coating composed of the APS bottom layer and the SPS top layer is obtained.
2. The method of claim 1, wherein the method of producing a dual layer Y203 etch resistant coating by atmospheric and suspension plasma spraying is characterized by, The sandblasting treatment in step one adopts white corundum sand, and the sandblasting pressure is 0.2-0.4 Mpa; the surface roughness of the aluminum base sample after treatment is Ra 3-3.5 mu m.
3. The method of claim 1, wherein the method of atmospheric and suspension plasma spraying of bi-layer Y203 etch resistant coating is characterized by, The high-pressure water washing pressure in step one is 1900-2100 psi; the air pressure of the compressed air is 0.8-0.9 Mpa; the drying temperature is 115-125 DEG C; and the drying time is 1.5-3 hours.
4. The method of claim 1, wherein the method of atmospheric and suspension plasma spraying of dual layer Y203 etch resistant coating is characterized by, The atmospheric plasma spraying technology in step two adopts an F4BM-XL spraying system, and the spraying parameters are as follows: argon 30-35 NLPM, hydrogen 3-6 NLPM, power 35-38 KW, and auxiliary gas pressure 2-3 Bar.
5. The method of claim 1, wherein the method of atmospheric and suspension plasma spraying of dual layer Y203 etch resistant coating is characterized by, The thickness of the APS bottom layer is 150-250 mu m, and the coating roughness is Ra 5-7 mu m.
6. The method of claim 1, wherein the method of atmospheric and suspension plasma spraying of dual layer Y203 etch resistant coating is characterized by, In step three, diamond sandpaper is used to grind the surface of the APS bottom layer; the mesh number of the diamond sandpaper is 800 mesh, 1200 mesh and 3000 mesh in sequence; and after grinding, the surface roughness of the APS bottom layer is reduced to Ra 3-4 mu m.
7. The method of claim 1 wherein the method of atmospheric and suspension plasma spraying of dual layer Y203 etch resistant coating is characterized by, The annealing treatment parameters in step four are as follows: annealing temperature 400-500 DEG C, heating rate 10-12 DEG C / min, holding time 0.8-1.2 hours, cooling rate 3-5 DEG C / min, and the sample is taken out and directly clamped when the temperature is lowered to 78-82 DEG C.
8. The method of claim 1 wherein the method of atmospheric and suspension plasma spraying of dual layer Y203 etch resistant coating is characterized by, The preparation method of the Y2O3 suspension liquid is as follows: Y2O3 powder with a particle size of 2-4 mu m and a purity of >99.9% is mixed with ultrapure water with an electric conductivity of >18.2 M omega; after sufficient stirring, a suspension liquid with a mass fraction of 32-36% is formed.
9. The method of claim 1 wherein the dual layer Y203 etch resistant coating is produced by atmospheric and suspension plasma spraying, and wherein The plasma spraying equipment is a 100HE type plasma spraying equipment, and the spraying process parameters are as follows: argon flow rate 145-155 SLPM, nitrogen flow rate 66-70 SLPM, hydrogen flow rate 60-65 SLPM, spraying gun power 100-102 KW, spraying gun moving speed 6-30 mm / s, rotating disc rotating speed 120-150 RPM, spraying distance 65-70 mm, Y2O3 suspension liquid injection flow rate 30-34 mL / min, and cooling gas pressure 2-3 Bar.
10. The method of claim 1 wherein the dual layer Y203 etch resistant coating is produced by atmospheric and suspension plasma spraying, and wherein The total thickness of the double-layer high-density Y2O3 etching-resistant coating is 200-350 μm, the surface roughness Ra is 2-3 μm, the porosity of the SPS top layer is 0.6%-0.8%, the porosity of the APS bottom layer is 2.5%-3%, the coating bonding strength is 22-25 MPa, the hardness Hv0.2 is 550-600, and the breakdown voltage resistance is >6 Kv.