Mixed thermally sprayed film, component for film forming apparatus, method for manufacturing component for film forming apparatus, and method for manufacturing mixed thermally sprayed film

Abstract

Provided are a mixed thermally sprayed film, a component for a film forming apparatus using a thermally sprayed film, and a method for manufacturing a component for a film forming apparatus, the mixed thermally sprayed film being capable of absorbing a difference in stress from a deposited film deposited on the thermally sprayed film of a component for film forming processing and preventing occurrence of breakage or peeling of the deposited film.　This mixed thermally sprayed film is provided on a surface of a component for film forming processing exposed to a film-forming processing atmosphere for forming a film, is composed of a mixture of Al and AlSi alloy, and has a surface roughness Ra of 9-60 μm.

Description

Mixed thermal sprayed film, film forming device parts, and method for manufacturing film forming device parts and method for manufacturing mixed thermal sprayed film

[0001] The present invention relates to a mixed sprayed film provided on the surface of a film-forming processing part exposed to a film-forming processing atmosphere, a film-forming device part, a manufacturing method for a film-forming device part, and a manufacturing method for a mixed sprayed film.

[0002] There are techniques for forming a film on a substrate in a vacuum chamber by sputtering, CVD, etc. In this case, the film may adhere to film-forming process components (e.g., adhesion prevention plates) other than the substrate that are installed in the vacuum chamber. If such a film peels off from the film-forming process components as particles, the particles may get into the film and cause a decrease in the yield of the film product.

[0003] For these reasons, a thermal spray coating having a predetermined surface roughness is formed on the surface of the coating process component (see, for example, Patent Document 1). By forming such a thermal spray coating on the surface of the coating process component, unwanted peeling of the coating from the coating process component can be effectively suppressed.

[0004] However, if a material with a relatively high film stress is selected as the material for the film to be formed on the substrate, or if film formation is carried out for a long period of time and the thickness of the film formed on the film formation processing part becomes relatively thick, there is a possibility that the sprayed film will peel off from the film formation processing part together with the film if the sprayed film is unable to overcome the stress of the film deposited on it.

[0005] Furthermore, high-melting-point materials (W, Ta, Ti, and their alloys) used in semiconductor manufacturing are also used as film-forming materials. These high-melting-point metals are subject to high (thermal) stress, so further improvement in peel resistance is desired.

[0006] Therefore, conventionally, the spray coating material has been changed to match the coating material. For example, there have been cases where soft materials such as pure aluminum have been sprayed to absorb stress. However, soft materials such as pure aluminum have low material strength and cannot withstand the stress itself, which can cause the spray coating to break. As a result, there has been a tendency for particles to increase as the coating formation progresses.

[0007] On the other hand, attempts have been made to use high-strength materials such as Al alloys, Ni, and Ti, which have the property of being resistant to the stress of the deposited film. In this case, although there is no increase in particles during film formation, there is a problem in that, when film formation is completed, the stress difference due to the difference in thermal expansion coefficient between the base material of the film formation processing parts (e.g., SUS304) and the deposited film cannot be absorbed. As a result, stress is concentrated in the deposited film itself, causing damage and peeling of the deposited film, which is a problem.

[0008] Japanese Patent Application Laid-Open No. 2008-291299

[0009] In view of the above-mentioned circumstances, an object of the present invention is to provide a mixed sprayed film, for example, when using a sputtering target of a high melting point metal, which can absorb the stress difference with the deposited film deposited on the sprayed film of the film-forming processing part and prevent the deposited film itself from being destroyed or peeled off, and a film-forming device part using the mixed sprayed film, a manufacturing method for the film-forming device part, and a manufacturing method for the mixed sprayed film.

[0010] A first aspect of the present invention that solves the above-mentioned problems is a mixed sprayed coating provided on the surface of a coating treatment component exposed to a coating treatment atmosphere in which a coating is formed, the mixed sprayed coating consisting of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm. A second aspect of the present invention is the mixed sprayed coating of the first aspect, having a thickness of 300 to 500 μm. A third aspect of the present invention is the mixed sprayed coating of the first or second aspect, in which the Si content of the AlSi is 0.5 to 12 mass%. A fourth aspect of the present invention is a coating apparatus component in which a sprayed coating is formed on the surface of a component substrate exposed to a coating treatment atmosphere in which a coating is formed, the sprayed coating being a mixed sprayed coating consisting of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm. A fifth aspect of the present invention is the film formation apparatus component of the fourth aspect, which is an adhesion prevention plate surrounding the film formation atmosphere or a shield member surrounding the sputtering target serving as the film formation source. A sixth aspect of the present invention is the film formation apparatus component of the fourth or fifth aspect, in which the surface roughness Ra of the component substrate on which the mixed sprayed film is formed is 3 to 5 μm. A seventh aspect of the present invention is a method for manufacturing a film formation apparatus component having a sprayed film formed on the surface of a component substrate exposed to a film formation atmosphere, the method comprising the step of forming a mixed sprayed film made of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm on the surface of the component substrate. An eighth aspect of the present invention is the method for manufacturing a film formation apparatus component of the seventh aspect, in which the film formation apparatus component is an adhesion prevention plate surrounding the film formation atmosphere or a shield member surrounding the sputtering target serving as the film formation source. A ninth aspect of the present invention is the method for manufacturing a coating apparatus part according to the seventh or eighth aspect, wherein the surface of the component substrate on which the mixed sprayed coating is formed has a surface roughness Ra of 3 to 5 μm. A tenth aspect of the present invention is the method for manufacturing a mixed sprayed coating, which comprises feeding two spray wires consisting of an Al spray wire and an AlSi alloy spray wire at a constant speed, generating an arc at the intersection of the two spray wires, spraying the respective molten materials, and forming a mixed sprayed coating consisting of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm on the surface of a coating treatment part exposed to a coating treatment atmosphere in which a coating is formed.

[0011] The mixed sprayed film of the present invention has the effect of absorbing the stress difference with the deposited film deposited on the sprayed film of the film forming processing part, even when the film is formed to the end of the sputtering target using, for example, a high-melting point metal sputtering target, thereby preventing the deposited film itself from being destroyed or peeled off.By using this mixed sprayed film, it is possible to realize a film forming apparatus part and a method for manufacturing a film forming apparatus part that have the above-mentioned effects.

[0012] FIG. 1 is a schematic diagram of an example of a sputtering apparatus equipped with a coating treatment component on which a mixed sprayed coating of the present invention is provided. FIG. 2 is a schematic diagram illustrating an arc spraying method. FIG. 3 is a micrograph of a cross section of a mixed sprayed coating of Example 1. FIG. 4 is a micrograph of a cross section of a sprayed coating of Comparative Example 1. FIG. 5 is a micrograph of a cross section of a sprayed coating of Comparative Example 2. FIG. 6 is a diagram showing the results of tensile strength measurement. FIG. 7 is a diagram showing the results of tensile strength measurement. FIG. 8 is a diagram showing the results of tensile strength measurement. FIG. 9 is a diagram showing the results of measurement of particles on the surface of a sprayed coating. FIG. 10 is a diagram showing how hardness is measured. FIG. 11 is a diagram showing the results of hardness measurement.

[0013] The present invention will be described in detail below. The mixed sprayed coating of the present invention is a mixed sprayed coating provided on the surface of a coating process part exposed to a coating process atmosphere, and is made of a mixture of Al and an AlSi alloy. The Al is preferably aluminum (4NAl) with a purity of 99.99% or more.

[0014] The AlSi alloy is an alloy of aluminum and silicon, and the Si content is 0.5 to 12 mass %, preferably 1 to 5 mass %, because if the Si content is too high, the AlSi alloy becomes too hard and its stress relaxation ability is reduced.

[0015] The mixed sprayed coating of the present invention is formed by arc spraying or plasma spraying using Al and an AlSi alloy, with arc spraying being more preferred. Plasma spraying requires mixing of powders, and the melting method varies depending on the difference in the melting points of the powders, making adjustment difficult. Furthermore, plasma spraying does not allow for control of surface roughness, so a final blasting treatment or the like is required. Therefore, arc spraying is preferred.

[0016] The mixing ratio of Al to the AlSi alloy is about 1:1 by volume, but a range of 90:100 to 100:90 is acceptable.

[0017] Specifically, the mixed sprayed film of the present invention is produced, for example, by using an arc spraying device capable of simultaneously spraying two types of spray wires to form a film, feeding two spray wires consisting of an Al spray wire and an AlSi alloy spray wire at a constant speed, generating an arc at the intersection of the two spray wires, and spraying the molten materials of each wire with gas to form a mixed sprayed film. In arc spraying, the desired mixed sprayed film can be obtained by adjusting the current, voltage, air cap, gas type, and gas pressure.

[0018] The mixed sprayed film is a mixture of Al and an AlSi alloy, and is also called a pseudo-alloy sprayed film, although it is not an alloy. The thickness of the mixed sprayed film is preferably 300 to 500 nm.

[0019] The mixed sprayed coating of the present invention has a surface roughness Ra, which is the arithmetic mean roughness, of 9 to 60 μm, preferably 20 to 40 μm, and more preferably 25 to 35 μm. The surface roughness of the mixed sprayed coating formed by thermal spraying can be adjusted to a desired surface roughness by appropriately adjusting the spraying conditions, but the surface roughness Ra may also be adjusted by performing a blasting treatment after thermal spraying.

[0020] The mixed sprayed film of the present invention is suitable for application to the surface of a film-forming processing part of a sputtering device. For example, even if a high-melting point metal sputtering target is used and film formation is completed to the end of the sputtering target, the stress difference between the mixed sprayed film on the film-forming processing part and the deposited film can be absorbed, preventing damage or peeling of the deposited film itself.

[0021] Fig. 1 is a schematic diagram of an example of a sputtering apparatus equipped with a film-forming processing component for forming a mixed sprayed film of the present invention. In Fig. 1, the equipment for forming a vacuum space and various equipment for film formation are omitted.

[0022] As shown in FIG. 1 , a sputtering target 12 mounted on a backing plate 11 and a deposition substrate 14 fixed by an electrostatic chuck (ESC) 13 are disposed facing each other within a vacuum deposition chamber 10. The space between the sputtering target 12 and the deposition substrate 14 is surrounded by deposition process components. Specifically, in this example, the deposition processing apparatus includes a cylindrical first shield member 21, a donut-shaped second shield member 22 surrounding the deposition substrate 14, and a third shield member 23 connecting these. These deposition process components prevent the deposition material emitted from the sputtering target 12 from diffusing, and the deposition material adheres to form a film. Therefore, a mixed sprayed film of the present invention is formed on the surfaces of the first shield member 21, the second shield member 22, and the third shield member 23.

[0023] Films of the film-forming materials are formed on the mixed sprayed film on the surfaces of the first shield member 21, the second shield member 22, and the third shield member 23, and are successively deposited to form a deposited film, but when a deposited film is formed on the mixed sprayed film of the present invention, the stress difference between the newly formed film on this deposited film and the deposited film is absorbed, preventing the deposited film itself from being damaged or peeled off. This prevents the generation of particles due to damage or peeling of the deposited film, and prevents poor film formation due to particles even when the sputtering target 12 is used to the end.

[0024] In particular, in recent years, sputtering targets 12 made of high-melting-point materials (W, Ta, Ti, and alloys thereof) used in semiconductor manufacturing have been used, and the target size has also increased to 12 inches or more. Therefore, if the film formation process is continued until the sputtering target 12 is used up, the amount of the high-melting-point material deposited on the sprayed film of the shield member increases, increasing the area and thickness of the deposited film and increasing stress on the sprayed film. Therefore, the sprayed film on the surface of the shield member must have even greater stress resistance. However, even in this case, it is possible to prevent the generation of particles and the like until the large sputtering target 12 is used up. Specific examples of high-melting-point film formation materials include W, WN, WSi, SiN, TiW, Ta / TaN, and Ti / TiN.

[0025] Furthermore, for example, if the sputtering target 12 is 12 inches in size, the first shield member 21 has an outer diameter of about 600 mm and a height of, for example, about 60 mm to 250 mm. The second shield member 22 and the third shield member 23 have dimensions corresponding to these.

[0026] As explained above, the mixed sprayed coating of the present invention is formed by a spraying method on the surfaces of the coating apparatus components such as the first shield member 21, the second shield member 22 and the third shield member 23.

[0027] Although arc spraying, flame spraying, plasma spraying, etc. can be used as the thermal spraying method, arc spraying is preferred for realizing the present invention. Arc spraying makes it relatively easy to adjust the surface roughness, makes it relatively easy to form a mixed sprayed film having the desired properties described above, and even if a high-melting-point coating material is deposited and the coating material is also deposited on the mixed sprayed film, particle generation can be suppressed to the end.

[0028] 2 is a schematic diagram illustrating the arc spraying method. Arc spraying is a technique in which a predetermined voltage / current 33 is applied between two spray material rods 31, 32 continuously fed in the direction of the arrows, generating arcing 34 near the tips of the two spray material rods. At the same time, the metal melted by the arcing 34 is atomized into spray particles 36 using a blowing gas 35. The atomized spray particles 36 are then blown onto a target substrate 38 through an opening 37a in an air cap 37, where they are deposited on the target substrate 38 to form a desired sprayed film 39.

[0029] In the present invention, two spray materials are used: one made of Al and the other made of an AlSi alloy. The spray gas is preferably air, nitrogen gas, or argon gas.

[0030] Example 1 In Example 1, a SUS304 substrate with planar dimensions of 80 mm x 100 mm and a thickness of 2 mm was used. A mixed sprayed film consisting of a mixture of aluminum (4NAl) with a purity of 99.99% or higher and an AlSi alloy was formed on the surface of the substrate using an arc spraying method. The thickness was 350 μm, and the surface roughness Ra was 29 μm. The AlSi alloy used had a Si content of 5% by mass. The surface roughness was measured using a surface roughness measuring instrument in accordance with JIS B0601 (1994), and the arithmetic mean roughness (Ra) was calculated. Close observation of the surface and cross section of the produced mixed sprayed film revealed no cracks or peeling.

[0031] Figure 3 shows a micrograph of the cross section of the mixed sprayed film. No large pores were found in the cross section of the mixed sprayed film, and the adhesion to the substrate was good. As shown in the enlarged photograph of Figure 3(b), the mixed state of 4N-Al and AlSi was found to be almost uniform. In the enlarged photograph, the light-colored areas are 4N-Al, and the dark areas are Al-5%Si.

[0032] <Comparative Example 1> In Comparative Example 1, a thermal sprayed film made of 4NAl alone was formed by arc spraying on the surface of the same substrate as in Example 1, so as to have the same thickness. The thickness was 320 μm. Figure 4 shows a micrograph of the cross section of the thermal sprayed film.

[0033] In Comparative Example 2, a thermal sprayed film made of an AlSi alloy alone was formed by arc spraying on the surface of the same substrate as in Example 1. The thickness was 300 μm. Figure 5 shows a micrograph of the cross section of the thermal sprayed film.

[0034] Comparative Example 3 In Comparative Example 3, a mixed sprayed film made of 4NAl and a CuAl alloy (Cu-3.5% Al) was formed to the same thickness on the surface of the same substrate as in Example 1 by arc spraying.

[0035] Comparative Example 4 In Comparative Example 4, a mixed sprayed film made of 4NAl and Ti was formed on the surface of the same substrate as in Example 1 by arc spraying to the same thickness.

[0036] Comparative Example 5 In Comparative Example 5, a mixed sprayed film made of Ti (two types) and a CuAl alloy (Cu-3.5% Al) was formed on the surface of the same substrate as in Example 1 by arc spraying to the same thickness.

[0037] <Film-forming apparatus component> A film-forming apparatus component, which is an adhesion prevention plate corresponding to the second shield member 22 in Fig. 1, was formed with the mixed sprayed film of Example 1 and the sprayed films of Comparative Examples 1 and 2. Using this film-forming apparatus component, a WSi film was formed to a thickness of 1.5 mm on a substrate using a WSi sputtering target, and then the chamber was cooled down, after which the film-forming apparatus component was observed.

[0038] In the case of the Al / AlSi mixed sprayed film of Example 1, no peeling of the WSi deposited film deposited on the mixed sprayed film was observed. On the other hand, in the case of the Al sprayed film of Comparative Example 1, peeling of the WSi deposited film was observed, and cracks occurred on the deposition surface. Furthermore, in the case of the AlSi sprayed film of Comparative Example 2, peeling of the WSi deposited film was observed, and fractures occurred within the deposited film.

[0039] <Tensile Strength Measurement> The tensile strength of the thermal sprayed coatings of Example 1 and Comparative Examples 1 to 5 was measured using a tensile tester according to the 5-7 pull-off method of JIS K5600. The results are shown in Figures 6 and 7. As a result, the 4NAl / AlSi mixed thermal sprayed coating of Example 1 had the highest tensile strength, equivalent to that of an AlSi alloy sprayed coating. Furthermore, as shown in Figure 8, the mixed thermal sprayed coating of Example 1 was found to have a 23% increase in tensile strength compared to the 4NAl thermal sprayed coating of Comparative Example 1.

[0040] <Surface Particle Measurement> Using an air-born particle counter equipped with a 0.4 MPa particle counter with a 0.1 μm filter, clean air was sprayed at 28.3 L / min for 30 seconds onto the sprayed coating surfaces of the mixed sprayed coatings of Example 1 and Comparative Examples 1, 3, 4, and 5, and the generated particles were measured. Measurements were performed three times, and the results are shown in FIGS. 9 and 10 . As a result, it was found that the mixed sprayed coating of Example 1 had fewer surface particles than the comparative examples. The Al / CuAl mixed sprayed coating of Comparative Example 3 also had fewer surface particles, but as described above, it had low tensile strength and poor adhesion, making it difficult to use.

[0041] <Hardness Measurement> The cross-sectional hardness of the sprayed coatings of Example 1, Comparative Example 1 (FIG. 12), and Comparative Examples 3 to 5 (FIG. 13) was measured using a micro-Vickers hardness tester. FIG. 11 shows the hardness measurement of the cross-section of the sprayed coating. As shown in FIG. 11, the hardness was measured at 10 locations. The results are shown in FIGS. 12 and 13. As a result, it was found that the average strength of the sprayed coating of Example 1 was increased by 51% compared to Comparative Example 1. Furthermore, the hardness range expanded from 15.1 in Comparative Example 1 to 36.7 in Example 1. This indicates that the sprayed coating of Example 1 has both hardness and flexibility due to the uniform mixture of Al and AlSi, resulting in a mixture of the hardness range from the soft Al sprayed coating to the relatively high Al-Si sprayed coating. Furthermore, the mixed sprayed coatings of Al / CuAl in Comparative Example 3, Al / Ti in Comparative Example 4, and CuAl / Ti in Comparative Example 5 had high average hardness, but did not have a low hardness range, and as mentioned above, had many surface particles, making them difficult to use.

[0042] In the present invention, a mixed sprayed film of Al and an AlSi alloy is used, which absorbs the stress difference with the deposited film deposited on the sprayed film of the coating processing part, thereby realizing a sprayed film that can prevent the deposition film itself from being damaged or peeled off. The reason for using an AlSi alloy as the Al alloy to be mixed and sprayed with Al is that it was possible to select a practical and optimal blend of mechanical properties in controlling mechanical properties such as hardness and tensile strength by using added elements while avoiding problems such as impurity contamination in the coating process. However, if there is an Al alloy such as another Al-based binary or ternary Al alloy that can have mechanical properties equivalent to those of the above-mentioned AlSi sprayed film, it is thought that a mixed sprayed film with the same effects as the present invention can be obtained.

[0043] REFERENCE SIGNS LIST 10 Vacuum film formation chamber 11 Backing plate 12 Sputtering target 13 Electrostatic chuck (ESC) 14 Film formation substrate 21 First shield member 22 Second shield member 23 Third shield member 31, 32 Thermal spray material 33 Current 34 Arcing 35 Gas 36 Sprayed particles 37 Air cap 37a Opening 38 Target substrate 39 Thermal spray film

Claims

1. A mixed sprayed film provided on the surface of a film-forming processing part that is exposed to a film-forming processing atmosphere, the mixed sprayed film being made of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm.

2. The mixed sprayed coating according to claim 1, having a thickness of 300 to 500 μm.

3. A mixed sprayed coating according to claim 1 or 2, wherein the Si content of the AlSi alloy is 0.5 to 12 mass %.

4. A part for a coating device, in which a thermal spray coating is formed on the surface of a component substrate exposed to a coating treatment atmosphere in which a coating is formed, the thermal spray coating being a mixed thermal spray coating made of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm.

5. A part for a film forming apparatus according to claim 4, which is an adhesion prevention plate surrounding the film forming processing atmosphere, or a shielding member surrounding a sputtering target serving as a film forming source for the film formation.

6. A part for a film forming apparatus according to claim 4 or 5, wherein the surface roughness Ra of the surface of the part substrate on which the mixed sprayed film is formed is 3 to 5 μm.

7. A method for manufacturing a film-forming device part in which a thermal spray coating is formed on the surface of a component substrate exposed to a film-forming treatment atmosphere, the method comprising the step of forming a mixed thermal spray coating on the surface of the component substrate, the mixed thermal spray coating being made of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm.

8. The method for producing a film forming apparatus part according to claim 7, wherein the film forming apparatus part is an adhesion prevention plate surrounding the film forming processing atmosphere, or a shielding member surrounding a sputtering target serving as a film forming source.

9. The method for manufacturing a film-forming device part according to claim 7 or 8, wherein the surface of the part substrate on which the mixed sprayed film is formed has a surface roughness Ra of 3 to 5 μm.

10. A method for manufacturing a mixed sprayed film, comprising: feeding two spray wires, one made of an Al spray wire and the other made of an AlSi alloy, at a constant speed while generating an arc at the intersection of the two spray wires; spraying the molten material of each; and forming a mixed sprayed film, made of a mixture of Al and an AlSi alloy and having a surface roughness Ra of 9 to 60 μm, on the surface of a coating processing part exposed to a coating processing atmosphere in which coating is formed.

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