Thermal spray member, semiconductor manufacturing equipment component equipped with thermal spray member, method for manufacturing thermal spray member, and method for manufacturing semiconductor manufacturing equipment component equipped with thermal spray member

Abstract

To provide a thermal spray member capable of exhibiting sufficient adhesion force and insulation function even when the thickness of a zirconia thermal spray film is relatively thin compared with the surface roughness of the surface to be thermally sprayed of an aluminum base material.SOLUTION: A thermal spray member 1 includes an aluminum base material 10 and of yttrium containing zirconia spray film 12. In the cross section of the surface of the base material 10 orthogonal to an interface between a surface 100 to be thermally sprayed and the spray film 12, a distance between two parallel straight lines sandwiching the interface is 0.2 μm over a length of 10 μm or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sprayed member, a semiconductor manufacturing apparatus component including the sprayed member, a method for manufacturing the sprayed member, and a method for manufacturing a semiconductor manufacturing apparatus component including the sprayed member.

Background Art

[0002] Patent Document 1 discloses a sprayed composite coating formed on a metal substrate or a non-metal substrate. The sprayed composite coating described in Patent Document 1 has a first ceramic material phase and a second ceramic material phase. The first ceramic material phase includes a zirconia-based coating selected from zirconia, partially stabilized zirconia, and fully stabilized zirconia, and is present in an amount sufficient to provide corrosion resistance to the ceramic composite coating. The second ceramic material phase is present in an amount sufficient to provide plasma erosion resistance to the ceramic composite coating.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the thermal spray composite coating described in Patent Document 1, when forming a thermal spray composite coating on a metal substrate, the surface of the metal substrate to be thermal sprayed was roughened, and a zirconia-based coating was formed on it. Generally, to form a ceramic thermal spray film such as a zirconia thermal spray film on a metal substrate, it is necessary to increase the surface roughness of the surface of the metal substrate to be thermal sprayed. This is because molten particles are allowed to penetrate into narrow spaces corresponding to the surface roughness of the metal substrate, and the thermal spray film is fixed to the thermal sprayed surface by the anchoring effect caused by the solidification of the molten particles that have entered into these narrow spaces. When the surface roughness of the thermal sprayed surface of the metal substrate is small (for example, when the surface roughness Ra is 0.001 μm to 0.2 μm), the influence of the above-mentioned anchoring effect becomes small, making it very difficult to directly form a zirconia thermal spray film on the thermal sprayed surface of the metal substrate. Furthermore, when the thickness of the thermal spray film is relatively small compared to the surface roughness of the thermal sprayed surface of the metal substrate, the influence of the above-mentioned anchoring effect becomes small, and it was anticipated that it would be difficult to make the thermal spray film perform its function.

[0005] The present invention has been made in view of these circumstances, and aims to provide a thermal spray member and a method for manufacturing the same, which includes a zirconia thermal spray film provided on the thermal spray surface of an aluminum or aluminum alloy substrate, and which can exhibit sufficient adhesion and insulating function even when the thickness of the zirconia thermal spray film is relatively thin compared to the surface roughness of the thermal spray surface of the aluminum substrate. [Means for solving the problem]

[0006] According to aspects of the present invention, a base material of aluminum or an aluminum alloy, The thermal spray coating covering the surface to be thermal sprayed of the substrate comprises a thermal spray coating of yttrium-containing zirconia, which is zirconium oxide containing yttrium, In a cross-section of the substrate covered with the thermal spray film, on a surface perpendicular to the interface between the thermal sprayed surface of the substrate and the thermal spray film, Parallel to the surface to be sprayed, The distance between two parallel lines that straddle the interface is the flatness of the interface. H In that case, The interface has a flatness of 0.2 μm or less over a length of 10 μm or more.H to have death, The peel strength of the thermal spray coating is 100 MPa or more. A thermal spray member characterized by the above is provided.

[0007] In the above configuration, the thermal spray member comprises an aluminum or aluminum alloy substrate and a yttrium-containing zirconia thermal spray coating. In the cross-section of the substrate perpendicular to the interface between the surface to be thermal sprayed and the thermal spray coating, the distance between two parallel lines across the interface (flatness H) is 0.2 μm or less over a length of 10 μm or more. In the thermal spray member with the above configuration, the interface between the surface to be thermal sprayed and the thermal spray coating is smooth, and there is no need to provide an intermediate layer between the surface to be thermal sprayed and the thermal spray coating. Furthermore, even if the thickness of the thermal spray coating is relatively thin compared to the surface roughness of the surface to be thermal sprayed on the substrate, sufficient adhesion and insulating function can be achieved.

[0008] According to another aspect of the present invention, a method for manufacturing a thermal spray member, The thermal spray member comprises an aluminum or aluminum alloy substrate and a thermal spray film covering the thermal spray surface of the substrate, which is a yttrium-containing zirconia thermal spray film containing yttrium. The aforementioned manufacturing method is The substrate having a surface roughness Ra of 0.001 μm to 0.2 μm is subjected to an activation treatment. The method comprises plasma spraying a slurry (zirconia slurry) prepared from yttrium-containing zirconia raw material powder with a median diameter in the range of 0.5 μm to 6 μm and an aqueous solvent onto the surface of the substrate to be thermally sprayed, thereby forming a thermal spray film with a thickness of 3 μm to 350 μm. The aforementioned activation treatment is The surface to be sprayed Non Irradiating with an oxidizing gas plasma That is A method for manufacturing a thermal spray member is provided, characterized by the following features.

[0009] In the above configuration, the thermal spray member comprises an aluminum or aluminum alloy substrate and a thermal spray film of yttrium-containing zirconia. The thermal spray member has a first step of heating the substrate, in which the surface roughness Ra of the surface to be sprayed is in the range of 0.001 μm to 0.2 μm, thereby making the surface to be sprayed smooth. The thermal spray member also has a second step of plasma spraying a slurry prepared from yttrium-containing zirconia raw material powder with a particle size D50 (median diameter) in the range of 0.5 μm to 6 μm and an aqueous solvent onto the thermal spray surface of the substrate to be sprayed, thereby forming a thermal spray film with a thickness of 3 μm to 350 μm. This makes it possible to form a thermal spray film of yttrium-containing zirconia on an aluminum substrate and to make the interface of the thermal spray surface smooth.

[0010] In this process, the water contained in the slurry reacts with the aluminum contained in the substrate during the first and second steps to form Al- or Al-O- bonds. Yttrium (Y) contained in the yttrium-containing zirconia then chemically bonds to these bonds, and O and Zr further bond to these bonds, resulting in the formation of a yttrium-containing zirconia thermal spray film. Therefore, a yttrium-containing zirconia thermal spray film can be formed even on a smooth substrate, such as one with a surface roughness Ra of 0.001 μm to 0.2 μm. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic diagram illustrating the thermal spray member 1. [Figure 2] Figure 2 is a schematic diagram illustrating the flatness H of the interface between the sprayed surface 100 and the sprayed film 12 of the sprayed member 1. [Figure 3] Figure 3 is a flowchart showing the method for manufacturing the thermal spray component 1. [Figure 4] Figure 4 is a schematic diagram illustrating the first step. [Figure 5] Figure 5 is a schematic diagram illustrating the second process. [Figure 6]FIG. 6 is an explanatory diagram for explaining an electrostatic chuck 300 as an example of a semiconductor manufacturing apparatus component.

Embodiments for Carrying Out the Invention

[0012] As an example of a thermal spraying member according to an embodiment of the present invention, the thermal spraying member 1 will be described. As shown in FIG. 1, the thermal spraying member 1 includes a plate-shaped base material 10 and a thermal spray film 12 of zirconium oxide containing yttrium provided on a sprayed surface 100 which is one of the peripheral surfaces of the base material 10. In the following description, zirconium oxide containing yttrium is referred to as yttrium-containing zirconia or simply zirconia. In the present embodiment, the base material 10 is a plate-shaped member formed of aluminum or an aluminum alloy (Al alloy). Examples of the Al alloy include those in the 1000 series, 2000 series, 5000 series, and 6000 series. The surface roughness Ra of the sprayed surface 100 is preferably 0.001 μm to 0.2 μm. Further preferably, the surface roughness Ra of the sprayed surface 100 is 0.001 μm to 0.1 μm. The thickness of the thermal spray film 12 is preferably 5 μm to 350 μm.

[0013] In the following description, the interface between the sprayed surface 100 and the thermal spray film 12 is simply referred to as the interface. Note that, in a portion where a space is generated between the sprayed surface 100 and the thermal spray film 12, both the surfaces of the sprayed surface 100 and the thermal spray film 12 are regarded as the interface. In this specification, the flatness of the interface is defined as the distance between two parallel straight lines sandwiching the interface in a cross section of a surface of the base material 10 that is orthogonal to the interface. Here, "orthogonal" means that when the sprayed surface is a flat surface or a curved surface, the normal direction of the sprayed surface 100 and the normal direction of the cross section intersect at 90° ± 10°. In the thermal spraying member 1 of the present embodiment, the flatness H of the interface (see FIG. 2) is 0.2 μm or less over a length of 10 μm or more.

[0014] Next, a method for manufacturing the spraying member 1 will be described while referring to FIGS. 3 to 5. As shown in FIG. 3, a plate-shaped base material 10 made of aluminum (Al) or an aluminum alloy is prepared (S11). As described above, as the Al alloy, 1000 series, 2000 series, 5000 series, or 6000 series Al alloys can be used. At least one main surface of the plate-shaped base material 10 is the sprayed surface 100. The surface roughness Ra of the sprayed surface 100 is 0.001 μm to 0.2 μm. Note that the surface of the sprayed surface 100 may be subjected to surface treatment so that the surface roughness Ra of the sprayed surface 100 becomes 0.001 μm to 0.2 μm. As the surface treatment, roughening treatment such as sandblasting is not necessary, and grinding and subsequent polishing are preferable.

[0015] Next, as the first step, an activation treatment is performed on the sprayed surface 100 of the base material 10 (S12). In the activation treatment, first, the base material 10 is heated. Specifically, as shown in FIG. 4, a first non-oxidizing gas is supplied from the first non-oxidizing gas supply device 211 to the first plasma spraying device 210, and the plasma P1 of the first non-oxidizing gas is irradiated onto the sprayed surface 100 of the base material 10 from the first plasma spraying device 210 or the nozzle constituting the same. As the first non-oxidizing gas, for example, Ar gas, H2 gas, or N2 gas can be used. Alternatively, as the first non-oxidizing gas, a mixed gas of an arbitrary combination of Ar gas, H2 gas, and N2 gas can be used.

[0016] By performing the activation treatment, the sprayed surface 100 of the base material 10 is activated. Activating the sprayed surface 100 includes forming an oxide layer on the sprayed surface 100. Note that in the activation treatment, instead of irradiating the first non-oxidizing plasma gas P1, the base material 10 may be heated using a heating device such as a hot plate in an air atmosphere or a non-oxidizing atmosphere.

[0017] Next, as the second step, a yttrium-containing zirconia thermal spray film 12 is formed on the thermal spray surface of the substrate 10 (S13). Specifically, first, a zirconia slurry (hereinafter simply referred to as slurry) is prepared by preparing a raw material powder of zirconia (yttrium-containing zirconia) containing yttrium and having a particle size D50 (median diameter) of 0.5 μm to 6 μm, and an aqueous solvent. As shown in Figure 5, the prepared slurry is supplied from the slurry supply device 222 to the second plasma spray device 220 or the nozzles constituting it. The second non-oxidizing gas is supplied from the second non-oxidizing gas supply device 221 to the second plasma irradiation device 220, and the slurry is plasma sprayed onto the surface 100 of the substrate 10 from the second plasma spray device 220 or the nozzles constituting it using the second non-oxidizing gas or its plasma P2. Furthermore, it is preferable that the yttrium content in yttrium-containing zirconia is 2 mol% to 8 mol% in terms of Y2O3.

[0018] The second non-oxidizing gas may be the same as or different from the first non-oxidizing gas. When a common plasma spraying apparatus is used as the first plasma spraying apparatus 210 and the second plasma spraying apparatus 220, the first and second steps can be carried out continuously in the common plasma spraying apparatus without the need to transport the substrate 10. In this case, the manufacturing cost of the sprayed member 1 can be reduced. The first plasma spraying apparatus 210 and the second plasma spraying apparatus 220 may be separate plasma spraying apparatuses.

[0019] As a result, as shown in Figure 1, a yttrium-containing zirconia thermal spray film 12 is formed to cover the thermal spray surface 100 of the substrate 10. The thickness of the thermal spray film 12 is preferably adjusted to 5 μm to 350 μm. If the thickness of the thermal spray film 12 is less than 3 μm, the insulating properties of the thermal spray film 12 may decrease. Also, if the thickness of the thermal spray film 12 exceeds 350 μm, the internal stress of the thermal spray film 12 will increase, which may lead to a decrease in adhesion or delamination. The porosity of the thermal spray film 12 is preferably adjusted to 0.1 to 5%.

[0020] Furthermore, the second step may be repeated multiple times. For example, after the first second step forms a first thermal spray film that covers the thermal spray surface 100 of the substrate 10, the second second step may form a second thermal spray film that further covers the first thermal spray film. [Examples]

[0021] The present invention will be further described below using Examples 1 to 6. However, the present invention is not limited to the examples described below. Tables 1 and 2 below summarize the results of Examples 1 to 6 and Comparative Examples 1 to 5.

[0022] [Example 1] <1st process> As the substrate 10, a rectangular aluminum plate substrate with dimensions of 20 mm × 30 mm and a thickness of 3 mm was prepared, with a surface roughness Ra of 0.2 μm on the surface to be sprayed 100. The surface to be sprayed 100 was prepared by grinding and then polishing. Using the first plasma spraying apparatus 210 (high-speed plasma spraying apparatus), plasma P1 of the first non-oxidizing gas was irradiated onto the surface to be sprayed 100 of the substrate 10 (see Figure 3). A mixed gas of Ar gas, N2 gas, and H2 gas was used as the first non-oxidizing gas. The supply amount of Ar gas to the nozzles constituting the spraying apparatus was controlled to 100 l / min, the supply amount of N2 gas was controlled to 70 l / min, and the supply amount of H2 gas was controlled to 60 l / min.

[0023] The current applied to the nozzle constituting the first plasma spraying apparatus 210 was controlled to 250A, thereby adjusting the power supplied to the nozzle to 65kW. The distance between the nozzle tip and the sprayed surface 100 of the substrate 10 was adjusted to 75mm. The scanning speed or displacement speed of the nozzle relative to the substrate 10 was adjusted to 850mm / s. Then, a plasma P1 of a mixed gas of Ar gas, N2 gas, and H2 gas was generated, and this plasma P1 was irradiated or sprayed from the nozzle tip onto the sprayed surface 100 of the substrate 10. As a result, the sprayed surface 100 of the substrate 10 was activated (see Figure 4).

[0024] <Second process> The first plasma spraying apparatus 210 was used as the second plasma spraying apparatus 220. A slurry containing zirconia was plasma sprayed onto the surface 100 of the substrate 10 using plasma P2, a second non-oxidizing gas (see Figure 5). The slurry was prepared by mixing 300 g of zirconia raw material powder with a purity of 99.9% or higher, containing 3 mol% yttrium (calculated as Y2O3) and having a particle size D50 (median diameter) of 3 μm, with 700 g of water. A mixed gas of Ar gas, N2 gas, and H2 gas was used as the second non-oxidizing gas. The supply of Ar gas to the nozzles constituting the second plasma spraying apparatus 220 was controlled to 100 l / min, the supply of N2 gas to 70 l / min, and the supply of H2 gas to 60 l / min. This controlled the spraying speed to 600-700 mm / s.

[0025] The current applied to the nozzle constituting the second plasma spraying apparatus 220 was controlled to 250A, thereby adjusting the power supplied to the nozzle to 65kW. The distance between the nozzle tip and the sprayed surface 100 of the substrate 10 was adjusted to 75mm. The scanning speed or displacement speed of the nozzle relative to the substrate 10 was adjusted to 850mm / s. Then, a plasma P2 of a mixed gas of Ar gas, N2 gas, and H2 gas was generated, and the raw material powder melted by the plasma P2 was sprayed from the nozzle tip onto the sprayed surface 100 of the substrate 10. As a result, a sprayed film 12 with a thickness of 150μm was formed on the sprayed surface 10 of the substrate 10 (see Figure 1). Thus, the sprayed member 1 of Example 1 was manufactured. The thickness of the sprayed film 12 was measured using an eddy current film thickness gauge.

[0026] <Example 2> The thermal spray member 1 of Example 2 was manufactured according to the same conditions as in Example 1, except that a substrate 10 with a surface roughness Ra of 0.005 μm of the surface to be thermal sprayed 100 was prepared.

[0027] <Example 3> In the first step (see Figure 3, S12), the sprayed member of Example 3 was manufactured under the same conditions as in Example 1, except that the base material 10 was heated on a hot plate instead of being sprayed with a non-oxidizing gas plasma, thereby activating the sprayed surface 100 of the base material 10.

[0028] <Example 4> In the second step (see Figure 3, S13), the thermal spray component of Example 4 was manufactured under the same conditions as in Example 1, except that a slurry was prepared using zirconia raw material powder with a particle size D50 of 0.5 μm.

[0029] <Example 5> In the second step (see Figure 3, S13), the thermal spray component of Example 5 was manufactured under the same conditions as in Example 1, except that a slurry was prepared using zirconia raw material powder with a particle size D50 of 6 μm.

[0030] <Example 6> In the second step (see Figure 3, S12), a 3 μm thick thermal spray film 12 was formed on the sprayed surface 100 of the substrate 10. Except for this, the thermal spray member of Example 6 was manufactured according to the same conditions as in Example 1.

[0031] <Example 7> In the first step (see Figure 3, S12), the sprayed surface 100 of the base material 10 was polished to prepare a base material 10 with a surface roughness Ra of 0.2 μm, and the sprayed surface 100 was adjusted by grinding, but the sprayed member of Example 7 was manufactured under the same conditions as Example 1.

[0032] <Comparative Example 1> The thermal spray member of Comparative Example 1 was manufactured under the same conditions as in Example 1, except that in the first step (see Figure 3, S12), the thermal spray surface 100 of the base material 10 was sandblasted to prepare a base material 10 with a surface roughness Ra of 2 μm on the thermal spray surface 100.

[0033] <Comparative Example 2> In the second step (see Figure 3, S13), dry thermal spraying was employed instead of wet thermal spraying. Granules made from zirconia raw material with a particle size D50 of 30 μm were used, and a mixed gas of Ar gas, N2 gas, and H2 gas was used as the carrier gas. The supply of Ar gas to the nozzles constituting the second plasma spraying apparatus 220 was controlled to 100 l / min, the supply of N2 gas was controlled to 70 l / min, and the supply of H2 gas was controlled to 70 l / min. As a result, the spraying speed was controlled to 600-700 mm / s.

[0034] The current applied to the nozzle constituting the second plasma spraying apparatus 220 was controlled within the range of 100 to 110 A, thereby adjusting the power supplied to the nozzle to 50 to 60 kW. The distance between the nozzle tip and the sprayed surface 10 of the substrate 1 was adjusted to 80 mm. The scanning speed or displacement speed of the nozzle relative to the substrate 1 was adjusted to fall within the range of 100 to 1000 mm / s.

[0035] Aside from these conditions, the thermal spray member of Comparative Example 2 was manufactured according to the same conditions as in Example 1.

[0036] <Comparative Example 3> In the second step (see Figure 3, S13), the slurry was prepared using ethanol as the solvent instead of water. Otherwise, the thermal spray component of Comparative Example 3 was manufactured under the same conditions as in Example 1.

[0037] <Comparative Example 4> In the second step (see Figure 3, S13), a thermal spray film 12 with a thickness of 400 μm was formed on the sprayed surface 100 of the substrate 10. Except for this, the thermal spray member of Comparative Example 4 was manufactured according to the same conditions as in Example 1.

[0038] <Comparative Example 5> The thermal spray component of Comparative Example 5 was manufactured under the same conditions as in Example 1, except that in the second step (see Figure 3, S13), zirconia raw material powder with a particle size D50 of 9 μm was used to prepare the slurry.

[0039] In Table 1 below, in the column for the substrate heating method, "1" means plasma irradiation and "2" means heating by a hot plate.

[0040] [Table 1]

[0041] <Evaluation of whether or not peeling occurs> In the thermal spray members of Examples 1-7 and Comparative Examples 1-5, the presence or absence of delamination of the thermal spray film 12 from the substrate 10 (and the presence or absence of thermal spray film 12 formation) was visually confirmed. As shown in Table 2, no delamination of the thermal spray film 12 was confirmed in the thermal spray members 1 of Examples 1-7. In addition, in the thermal spray members 1 of Comparative Examples 1-5, it was confirmed that the thermal spray film 12 had partially delaminated from the substrate 10, or that cracks had formed in the thermal spray film 12.

[0042] <Evaluation of electrical insulation properties> In the dielectric strength test, a 15 × 10 mm Ag electrode was formed on the thermal spray coating 12, and with the thermal spray member 1 immersed in insulating oil, an AC 60 Hz voltage (1000 V / mm) was applied between the Ag electrode and the substrate 10, and the presence or absence of breakdown was evaluated. In Table 2, ○ indicates that a voltage of 1000 V / mm or higher was maintained, and × indicates that breakdown occurred at less than 1000 V / mm. As shown in Table 2, no breakdown occurred in the thermal spray member 1 of Examples 1 to 7. In contrast, breakdown was observed in the thermal spray member 1 of Comparative Examples 1 to 5.

[0043] <Measurement of peel strength> In the thermal spray members of Examples 1-7 and Comparative Examples 1-5, the peel strength of the thermal spray film 12 relative to the substrate 10 was measured. In the peel strength test, a 15 mm diameter disc-shaped metal plate was bonded to the thermal spray film 12 with an organic adhesive, and after fixing the periphery of the thermal spray member, the bonded metal plate was pulled vertically and peeled off, and the strength was measured. As shown in Table 2, it was found that the peel strength of the thermal spray members 1 of Examples 1-7 was 100 MPa or higher. In contrast, it was found that the peel strength of the thermal spray members 1 of Comparative Examples 1-5 was less than 100 MPa (peel strength of 65 MPa or lower).

[0044] <Measurement of flatness H> In the thermal spray members of Examples 1-7 and Comparative Examples 1-5, the flatness H of the interface between the substrate 10 and the thermal spray film 12 was measured. In the 5000x SEM cross-sectional image, a distance of 0.2 μm or less over a length of 10 μm or more between two parallel lines across the interface was marked with ○, and a distance exceeding 0.2 μm over a length of 10 μm or more was marked with ×. As shown in Table 2, in all thermal spray members 1 of Examples 1-6, the flatness H was found to be 0.2 μm or less over a length of 10 μm or more. In contrast, in the thermal spray members 1 of Comparative Examples 1-5, the flatness H was found to exceed 0.2 μm over a length of 10 μm or more.

[0045] [Table 2]

[0046] From the above results, it was found that the thermal spray films 12 of Examples 1 to 7 have superior adhesion to the substrate 10 compared to the thermal spray films 12 of Comparative Examples 1 to 5. It was found that the thermal spray films 12 of Examples 1 to 7 have superior dielectric strength compared to the thermal spray films 12 of Comparative Examples 1 to 5. It was found that the thermal spray films 12 of Examples 1 to 7 have superior peel resistance compared to the thermal spray films 12 of Comparative Examples 1 to 5. It was found that the interface between the substrate 10 and the thermal spray film 12 in Examples 1 to 7 has less unevenness and a lower flatness H than the interface between the substrate 10 and the thermal spray film 12 in Comparative Examples 1 to 5. As shown in Examples 1 to 7, it was confirmed that the present invention can produce thermal spray members with good adhesion and insulation even if the surface roughness of the substrate is small. In particular, in Example 2, it was found that a thermal spray member with high flatness can be produced even if the surface roughness of the substrate is very small, and that it can be applied to thermal spray members with high surface accuracy. Furthermore, in Example 6, it was confirmed that even with a very thin thermal spray coating of 3 μm, due to the low surface roughness of the substrate, a thermal spray component with good adhesion and insulation properties can be produced.

[0047] In Comparative Example 1, the surface roughness Ra of the thermal sprayed surface 100 of the substrate 10 was excessively large in light of the zirconia particle size. Therefore, it is presumed that the anchoring effect of the thermal spray film 12 on the substrate 10 due to the penetration of molten zirconia particles into narrow spaces in the microstructure of the surface of the thermal sprayed surface 100 was not sufficiently realized. Furthermore, it is presumed that the flatness H became greater than 0.2 μm due to the excessively large surface roughness Ra of the thermal sprayed surface 100.

[0048] In Comparative Example 2, the particle size of the zirconia was excessively large compared to the surface roughness Ra of the sprayed surface 100 of the substrate 10. Therefore, it is presumed that the anchoring effect of the sprayed film 12 on the substrate 10 was not sufficiently realized due to the penetration of molten zirconia particles into the narrow spaces in the microstructure of the surface 100. Furthermore, it is presumed that because the molten zirconia particles could not penetrate into the narrow spaces in the microstructure of the surface 100, some delamination occurred at the interface, resulting in a flatness H greater than 0.2 μm.

[0049] In Comparative Example 3, it is presumed that the ethanol solvent in the slurry had poor reactivity with the aluminum substrate, preventing the formation of the chemical bonds described later, and thus preventing adhesion between the substrate 10 and the thermal spray film 12. As a result, partial delamination occurred at the interface, and the flatness H became greater than 0.2 μm.

[0050] In Comparative Example 4, the thermal spray coating 12 was excessively thick, preventing the film stress from being relieved. It is presumed that the thermal stress, stemming from the difference in thermal expansion coefficients between the thermal spray coating 12 and the substrate 10, concentrated at the interface between the thermal spray coating 12 and the substrate 10 (the sprayed surface 100), causing delamination. As a result, partial delamination occurred at the interface, and the flatness H became greater than 0.2 μm.

[0051] In Comparative Example 5, it is presumed that a fluid slurry could not be prepared because the particle size of the yttrium oxide raw material powder was too large. As a result, the thermal spray film was not sufficiently formed on the surface of the surface to be thermally sprayed 100, resulting in a structure in which molten zirconia particles could not penetrate into narrow parts of the microstructure, causing partial delamination at the interface and resulting in a flatness H greater than 0.2 μm.

[0052] <Effects of the Embodiment>

[0053] The thermal spray member 1 of Examples 1 to 7 comprises an aluminum substrate 10 and a yttrium-containing zirconia thermal spray film 12. The thermal spray member 1 has a first step of heating the substrate 10, in which the surface roughness Ra of the surface to be sprayed 100 is in the range of 0.001 μm to 0.2 μm, thereby making the surface to be sprayed 100 of the thermal spray member 1 smooth. The thermal spray member 1 also has a second step of plasma spraying a slurry prepared from yttrium-containing zirconia raw material powder with a particle size D50 (median diameter) in the range of 0.5 μm to 6 μm and an aqueous solvent onto the surface to be sprayed 100 of the substrate 10 to form a thermal spray film with a thickness of 3 μm to 350 μm. This makes it possible to form a yttrium-containing zirconia thermal spray film on the aluminum substrate 10 and to make the interface of the thermal spray surface smooth.

[0054] Here, it is thought that in the first and second steps, the water contained in the slurry reacts with the aluminum substrate 10 to form Al- or Al-O- bonds, which are then chemically bonded to by yttrium (Y) contained in zirconia, and further bonded by O and Zr, thereby forming a zirconia thermal spray film. Therefore, it is presumed that a zirconia thermal spray film could be formed even on a smooth aluminum substrate 10, for example, with a surface roughness Ra of 0.001 μm to 0.2 μm.

[0055] In conventional methods for depositing zirconia thermal spray films, as described above, the mechanism utilized was that molten particles penetrated into narrow areas corresponding to the surface roughness of the substrate, and the deposition occurred due to an anchoring effect caused by the solidification of these penetrated molten particles. In contrast, in the present invention, the surface 100 to be thermal sprayed of the substrate 10 is heated and activated by irradiating it with a non-oxidizing gas plasma or by heating the substrate 10 with a hot plate. Subsequently, a slurry containing an aqueous solvent is plasma sprayed, and it is presumed that a chemical reaction occurs at the boundary (interface) between the aluminum substrate 10 and the zirconia thermal spray film 12, causing the zirconia thermal spray film to bond firmly to the aluminum surface and form the film. It is presumed that yttrium contained in zirconia contributes to this chemical reaction. Furthermore, even when the boundary is magnified, for example, to 100,000 times and observed with an SEM, it cannot be clearly distinguished. For this reason, it is presumed that this type of chemical bonding is the main film formation mechanism.

[0056] As described above, the thermal spray member 1 of Examples 1 to 7 comprises an aluminum base material 10 and a yttrium-containing zirconia thermal spray film 12. In the cross-section of the base material 10 perpendicular to the interface between the thermal spray surface 100 and the thermal spray film 12, the distance between two parallel lines across the interface is 0.2 μm or less over a length of 10 μm or more. Thus, in the thermal spray member 1, the interface between the thermal spray surface 100 and the thermal spray film 12 is smooth, and there is no need to provide an intermediate layer between the thermal spray surface 100 and the thermal spray film 12. Furthermore, even if the thickness of the thermal spray film 12 is relatively thin compared to the surface roughness of the thermal spray surface 100 of the base material 10, sufficient adhesion and insulating function can be achieved.

[0057] <Change form> The embodiments and Examples 1-7 described above are merely illustrative and can be modified as appropriate. For example, the shape and dimensions of the substrate 10 are not limited to those of Examples 1-7 and can be modified as appropriate. In addition, in the first step of Examples 1, 2, 4, 6, and 7, a plasma P1 of a first non-oxidizing gas and a plasma P2 of a second non-oxidizing gas were irradiated onto the sprayed surface 100 of the substrate 10. The present invention is not limited to such embodiments, and the gas used to generate the plasma can be changed as appropriate.

[0058] In the above embodiments and Examples 1 to 7, the thermal spray member 1 was described using as an example a member in which a thermal spray film 12 of yttrium-containing zirconium was formed on the thermal spray surface 100 of a plate-shaped base material 10. However, the thermal spray member of the present invention is not limited to such a member. For example, the thermal spray member of the present invention may be used in a thermal spray member included in a semiconductor manufacturing equipment component. For example, the thermal spray member of the present invention may be used in an electrostatic chuck as a semiconductor manufacturing equipment component. As shown in Figure 6, the electrostatic chuck 300 comprises a base material 10 formed of an aluminum alloy as the thermal spray member 1, and a thermal spray film 12 with a thickness of 30 μm that is thermal sprayed on the thermal spray surface of the base material 10. In this electrostatic chuck 300, the base material 10 is used as an electrode for high-frequency power or as a DC electrode. As a result, the electrostatic chuck 300 can generate a potential difference between itself and a substrate such as a silicon wafer placed on the thermal spray film 12, thereby electrostatically adsorbing the substrate such as a silicon wafer. When manufacturing the electrostatic chuck 300, the thermal spray member 1 can be manufactured by the above manufacturing method.

[0059] Although embodiments and modified versions of the invention have been described above, the technical scope of the present invention is not limited to the scope described above. It will be obvious to those skilled in the art that various modifications or improvements can be made to the above embodiments. It is also clear from the claims that such modified or improved forms may be included in the technical scope of the present invention.

[0060] The order in which each process in the manufacturing method shown in the specification and drawings is executed is not specifically defined, and unless the output of a previous process is used in a later process, the processes can be executed in any order. Even if phrases such as "first," and "next," are used for convenience, this does not mean that the processes must be performed in that order. [Explanation of Symbols]

[0061] 1. Thermal spray member 10 Base material 12 Thermal spray coating 100 Surface to be sprayed 210 Plasma spraying device No. 1 211 First non-oxidizing gas supply device 220 Second Plasma Spraying Apparatus 221 Second non-oxidizing gas supply device 222 Slurry supply device 300 Electrostatic Chuck

Claims

1. A base material made of aluminum or an aluminum alloy, The thermal spray coating covering the surface to be thermal sprayed of the substrate comprises a thermal spray coating of yttrium-containing zirconia, which is zirconium oxide containing yttrium, In a cross-section of the substrate covered with the thermal spray film, on a plane perpendicular to the interface between the thermal sprayed surface of the substrate and the thermal spray film, when the distance between two parallel lines parallel to the thermal sprayed surface and enclosing the interface is defined as the flatness H of the interface, The interface has a flatness H of 0.2 μm or less over a length of 10 μm or more. A thermal spray member characterized in that the peel strength of the thermal spray film is 100 MPa or more.

2. A semiconductor manufacturing apparatus component characterized by comprising the thermal spray member described in claim 1.

3. A method for manufacturing a thermal spray member, The thermal spray member comprises an aluminum or aluminum alloy substrate and a thermal spray film covering the thermal spray surface of the substrate, which is a yttrium-containing zirconia thermal spray film containing yttrium. The aforementioned manufacturing method is The substrate having a surface roughness Ra of 0.001 μm to 0.2 μm is subjected to an activation treatment. The method comprises plasma spraying a slurry prepared from the yttrium-containing zirconia raw material powder, which has a median diameter in the range of 0.5 μm to 6 μm, and an aqueous solvent onto the surface of the substrate to be thermally sprayed, thereby forming a thermal spray film with a thickness of 3 μm to 350 μm. The aforementioned activation treatment is A method for manufacturing a thermal spray member, characterized by irradiating the surface to be thermal sprayed with a plasma of a non-oxidizing gas.

4. A method for manufacturing semiconductor manufacturing equipment components equipped with a base plate, The base plate is a thermal spray member, The manufacturing method for semiconductor manufacturing apparatus parts comprises manufacturing the thermal spray member as a base plate by the manufacturing method for the thermal spray member described in claim 3.

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