Corrosion resistant material

Abstract

The corrosion-resistant component disclosed herein is a laminate consisting of a substrate and a first layer deposited on the substrate. The first layer is composed of a rare earth element compound, with a rare earth element as the main component and a rare earth element as the metallic element. In the first layer, the crystallinity of the region closer to the substrate is lower than that of the region farther from the substrate. Furthermore, the corrosion-resistant component disclosed herein is a laminate consisting of a substrate, a compound layer deposited on the substrate and being a metallic element M, and a first layer deposited on the compound layer. The first layer is composed of a rare earth element compound, with a rare earth element as the main component and a rare earth element as the metallic element. The crystallinity of the compound layer is uniform. In the first layer, the crystallinity of the region closer to the substrate is lower than that of the region farther from the substrate.

Description

Technical Field

[0001] This disclosure relates to a corrosion-resistant member. Prior Art

[0002] As a corrosion-resistant member, for example, the parts described in Patent Document 1 are known. The parts described in Patent Document 1 have a base material (substrate) and a composite film provided on the base material. The composite film has amorphous YxAlyOz (where 0.24 x / (x + y) 0.82, z / (x + y) = 1.5). This composite film is manufactured by vaporizing each raw material of yttrium oxide and aluminum oxide in a state where the base material is heated to a predetermined temperature in the range of 250°C or more and 600°C or less, and then spraying the vaporized raw materials toward the base material by a carrier gas. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2021 / 002339 Summary of the Invention Problems to be Solved by the Invention

[0004] In the parts described in Patent Document 1, the film is composed only of amorphous, so there is a problem that the corrosion resistance is worse than that of a crystalline film.

[0005] <> The problem of this disclosure is to provide a corrosion-resistant member that improves the corrosion resistance and the bonding strength between the substrate and the film. Means for Solving the Problems

[0006] The corrosion-resistant member of this disclosure is a laminate composed of a substrate and a first layer laminated on the substrate. The first layer is composed of a rare earth element compound containing a rare earth element as a main component of a metal element. In the first layer, the crystallinity in the region close to the substrate is lower than the crystallinity in the region far from the substrate.

[0007] The corrosion-resistant member of this disclosure is a laminate composed of a substrate, a compound layer that is a compound of a metal element M laminated on the substrate, and a first layer laminated on the compound layer. The first layer is composed of a rare earth element compound containing a rare earth element as a main component of a metal element. The crystallinity of the compound layer is uniform. In the first layer, the crystallinity in the region close to the substrate is lower than the crystallinity in the region far from the substrate.

[0008] The corrosion-resistant member of the present disclosure is a laminate composed of a substrate, a compound layer laminated on the substrate and composed of a metal element M, and a first layer laminated on the compound layer. The first layer is composed of a rare earth element compound, and the rare earth element compound contains a rare earth element as a metal element as a main component. The atomic number of the metal element M contained in the compound layer is smaller than the atomic number of the rare earth element which is the main component contained in the first layer. In the first layer, the crystallinity of the region close to the substrate is lower than the crystallinity of the region far from the substrate. Effect of the Invention

[0009] According to the corrosion-resistant member of the present disclosure, the corrosion resistance is improved and the bonding strength between the substrate and the film is improved. Brief Explanation of Drawings

[0010] FIG. 1 is a cross-sectional view showing a corrosion-resistant member of a non-limiting embodiment of the present disclosure. FIG. 2 is a cross-sectional view showing a corrosion-resistant member of a non-limiting embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing a corrosion-resistant member of a non-limiting embodiment of the present disclosure. FIG. 4 is a cross-sectional view showing a corrosion-resistant member of a non-limiting embodiment of the present disclosure. FIG. 5 is a cross-sectional view showing a corrosion-resistant member of a non-limiting embodiment of the present disclosure. FIG. 6 is a cross-sectional view showing a corrosion-resistant member of a non-limiting embodiment of the present disclosure. FIG. 7 is a schematic view showing a sputtering apparatus for obtaining a corrosion-resistant member of a non-limiting embodiment of the present disclosure. FIG. 8 is a partially enlarged image of the TEM in Example 1. FIG. 9 is an electron beam diffraction image of the surface side (NBD1) in the Y2O3 layer in Example 1. FIG. 10 is an electron beam diffraction image of the substrate side (NBD2) in the Y2O3 layer in Example 1. Embodiment

[0011] <Corrosion-resistant member> The following will use the drawings to detail the corrosion-resistant members 1A to 1F of the non-limiting embodiments of the present disclosure. Among them, in each of the following drawings referred to, for convenience of explanation, simplification is carried out, and only the main members required for explaining the embodiments are shown. Therefore, the corrosion-resistant members 1A to 1F may include any constituent members not shown in the respective drawings referred to. Also, the sizes of the members in each drawing do not truly represent the actual sizes of the constituent members and the size ratios of the respective members, etc.

[0012] As shown in Figure 1, a corrosion-resistant member 1A is a laminate 1a comprising a substrate 2 and a first layer 3 laminated on the substrate 2. The first layer 3 is composed of a rare earth element compound containing a rare earth element as a metal element as its main component. Furthermore, in the first layer 3, the crystallinity of a region 31 close to the substrate 2 is lower than that of a region 32 farther from the substrate 2. This improves corrosion resistance and enhances the bonding strength between the substrate 2 and the film (first layer 3). The reasons for this are presumably as follows.

[0013] The material of the substrate 2 is any one of ceramics, single crystals, glass, and metal. Examples of ceramic materials for the substrate 2 include those whose main component is aluminum oxide, silicon nitride, silicon carbide, and zirconium dioxide. Examples of single crystal materials include sapphire, silicon, and YAG (Y3Al5O12). Examples of glass materials include quartz glass. Examples of metals include aluminum and stainless steel.

[0014] Taking the example of a substrate 2 made of ceramic, the ceramic (substrate 2) is composed of a polycrystalline sintered body. The crystals in the ceramic bond with the low-crystalline portion of the first layer 3. Bonding with the low-crystalline portion of the first layer 3 reduces lattice defects in the bond between the crystals in the ceramic and the low-crystalline portion of the first layer 3. Consequently, the bond strength between the substrate 2 and the first layer 3 is improved.

[0015] Furthermore, rare earth element compounds such as Y2O3 have excellent corrosion resistance. The higher the crystallinity of the rare earth element compound, the better the corrosion resistance. The region 32 of the first layer 3, which is remote from the substrate 2, has high crystallinity and therefore excellent corrosion resistance. Therefore, the surface side of the first layer 3 (rare earth oxide) of the corrosion-resistant member 1A has excellent corrosion resistance.

[0016] Corrosion resistance refers to, for example, excellent resistance to corrosive gas plasma and minimal particle detachment from the surface. Furthermore, the term "main component" may refer to the component with the highest mass percentage compared to other components. For example, the main component may comprise 80% or more by mass.

[0017] The laminate 1a may be referred to as the first laminate 1a. The first layer 3 may be referred to as the rare earth element compound layer. The rare earth element compound may be referred to simply as the rare earth compound. Furthermore, the first layer 3 may be referred to simply as a film.

[0018] Examples of the rare earth elements contained as main components in the first layer 3 include Y, La, Nd, Sm, Eu, Gd, Dy, and Ho.

[0019] An energy dispersive X-ray analyzer (EDS) attached to a transmission electron microscope (TEM) can also be used to determine (confirm) whether the main component of the first layer 3 is a rare earth element. Furthermore, electron beam diffraction analysis using a TEM can be used to determine whether the crystallinity of the region 31 of the first layer 3 close to the substrate 2 is lower than that of the region 32 farther from the substrate 2.

[0020] Here, a specific example is given to illustrate crystallinity. Figures 8 to 10 show the measurement results of Example 1, described later. As shown in Figures 8 and 10, the region close to the substrate (NBD2) has fewer concentric Debye-Scherrer rings observed by electron beam diffraction, and the contours of each concentric ring are less clear, indicating low crystallinity. On the other hand, as shown in Figures 8 and 9, the region far from the substrate (NBD1) has more concentric Debye-Scherrer rings observed by electron beam diffraction, and the contours of each concentric ring are clearer, compared to the region close to the substrate (NBD2). Therefore, the crystallinity is higher than that of the region close to the substrate (NBD2).

[0021] The higher the crystallinity, the more clearly the contours of the concentric circles forming the Debye-Scherrer rings observed by electron beam diffraction can be discerned. The lower the crystallinity, the less clearly the contours of the concentric circles forming the Debye-Scherrer rings observed by electron beam diffraction become, making them difficult to discern. When the crystallinity is uniform, the arrangement and contours of the Debye-Scherrer rings observed by electron beam diffraction are equally clear in regions close to the matrix and those far from the matrix.

[0022] The region 31 close to the substrate 2 may be closer to the substrate 2 than the center 3a in the thickness direction of the first layer 3. Furthermore, the region 32 far from the substrate 2 may be further from the substrate 2 than the center 3a in the thickness direction of the first layer 3. Furthermore, the region 31 close to the substrate 2 may be referred to as the first region 31, and the region 32 far from the substrate 2 may be referred to as the second region 32.

[0023] The first layer 3 can be exposed on the surface of the corrosion-resistant member 1A. Rare earth element compounds such as Y2O3 exhibit excellent corrosion resistance. The higher the crystallinity of the rare earth element compound, the better the corrosion resistance. The region 32 of the first layer 3 that is remote from the substrate 2 exhibits high crystallinity, resulting in excellent corrosion resistance. Therefore, if the first layer 3 is exposed on the surface, the corrosion-resistant member 1A exhibits excellent corrosion resistance.

[0024] Rare earth element compounds can be oxides. Oxides (such as Y2O3 and Y3Al5O12) offer excellent corrosion resistance to corrosive gas plasmas. Therefore, they maintain corrosion resistance for extended periods. "Oxides" include "complex oxides."

[0025] The matrix 2 can be composed primarily of aluminum oxide (Al2O3). Furthermore, the first layer 3 can be composed primarily of a Y oxide and further include a composite oxide of Y and Al. The "Y oxide" can be crystalline or amorphous, or both.

[0026] When the substrate 2 is primarily composed of aluminum oxide, it forms a strong chemical bond with compounds containing Y as a metal element. Consequently, the bonding strength between the substrate 2 and the first layer 3, which is primarily composed of Y oxide, is enhanced. Furthermore, since the first layer 3 is primarily composed of Y oxide, the corrosion resistance of the film is improved. When the first layer 3 further comprises a composite oxide of Y and Al, the composite oxide of Y and Al contained in the first layer 3 forms a strong chemical bond with the primary component of the substrate 2 (Al2O3). Consequently, the bonding strength between the substrate 2 and the first layer 3 is enhanced.

[0027] Examples of composite oxides of Y and Al include YAlO3 (Y2O3:Al2O3=1:1 (YAM)), Y4Al2O9 (Y2O3:Al2O3=2:1 (YAP)), and Y3Al5O12 (Y2O3:Al2O3=3:5 (YAG)).

[0028] EDS with TEM or electron beam diffraction using TEM can be used to determine whether the first layer 3 contains Y oxide as a main component and whether the first layer 3 further contains a composite oxide of Y and Al.

[0029] When the main component of the matrix 2 is aluminum oxide, it may also contain at least one of silicon, magnesium, and calcium as an oxide. The components constituting the matrix 2 can be identified using an X-ray diffraction device utilizing CuKα radiation. The content of each identified component can be determined, for example, using an inductively coupled plasma (ICP) emission spectrometer or a fluorescent X-ray analyzer.

[0030] The average thickness of the first layer 3 can be between 1 nm and 1100 nm. The thickness of the first layer 3 can also be measured by cross-sectional observation using an electron microscope. For example, the thickness can be measured at five or more measurement points at any position on the first layer 3, and the average value calculated. Examples of electron microscopes include scanning electron microscopes (SEMs) and TEMs.

[0031] Next, a non-limiting embodiment of the present disclosure, a corrosion-resistant member 1B, will be described. The following primarily describes the differences between corrosion-resistant member 1B and corrosion-resistant member 1A. Details of the same components as corrosion-resistant member 1A may be omitted. Therefore, the structure of corrosion-resistant member 1B can be understood by referring to the description of corrosion-resistant member 1A. These same points also apply to corrosion-resistant members 1C to 1F, described later.

[0032] As shown in Figure 2, a corrosion-resistant member 1B is a laminate 1b comprising a substrate 2, a compound layer 4 of a metal element M deposited on the substrate 2, and a first layer 3 deposited on the compound layer 4. The first layer 3 is composed of a rare earth element compound containing a rare earth element as a main component. Furthermore, the compound layer 4 has uniform crystallinity. In the first layer 3, the crystallinity of a region 31 close to the substrate 2 is lower than that of a region 32 farther from the substrate 2. This improves corrosion resistance and enhances the bonding strength between the substrate 2 and the film (first layer 3). The reasons for this are presumably as follows.

[0033] The material of the substrate 2 can be the same as that exemplified for the corrosion-resistant member 1A. For example, the substrate 2 is made of ceramic. The ceramic (substrate 2) is composed of a polycrystalline sintered body. The M compound (e.g., SiO2), which is a compound of the metal element M, can be either crystalline or amorphous. The compound layer 4 (M compound) with uniform crystallinity is bonded to the low-crystalline portion of the first layer 3. When bonded to the low-crystalline portion of the first layer 3, lattice defects generated in the bond between the M compound and the low-crystalline portion of the first layer 3 are reduced. Consequently, the bond strength between the substrate 2 and the first layer 3, bonded via the M compound, is improved.

[0034] Furthermore, rare earth element compounds such as Y2O3 exhibit excellent corrosion resistance. The higher the crystallinity of the rare earth element compound, the better the corrosion resistance. The region 32 of the first layer 3, which is remote from the substrate 2, exhibits excellent corrosion resistance due to its high crystallinity. Therefore, the surface side of the first layer 3 (rare earth oxide) of the corrosion-resistant member 1B exhibits excellent corrosion resistance.

[0035] The crystallinity of the compound layer 4 can be more uniform than that of the first layer 3. The compound layer 4 can be referred to as the second layer 4. The compound layer 4 can be referred to simply as a film. The laminate 1b can be referred to as the second laminate 1b.

[0036] The content of the metal element M contained in the compound layer 4 can also be measured using EDS attached to a TEM. Furthermore, the uniformity of the crystallinity of the compound layer 4 can also be measured using electron beam diffraction performed using a TEM.

[0037] The atomic number of the metal element M included in the compound layer 4 may be smaller than the atomic number of the rare earth element as the main component included in the first layer 3 .

[0038] In the junction region between the first layer 3 and the compound layer 4, the cations of the rare earth element constituting the first layer 3 substitute for or form a solid solution with the cations of the metal element M constituting the compound layer 4. This reduces lattice defects in the junction region. This is because the smaller the atomic number, the smaller the ionic radius of the metal element M constituting the compound layer 4, thus alleviating the residual stress generated in the first layer 3.

[0039] Examples of the rare earth element as a main component contained in the first layer 3 include the same rare earth elements as exemplified in the corrosion-resistant member 1A. Examples of the metal element M contained in the compound layer 4 include Mg, Al, Si, Cr, Ni, Cu, Ga, Sr, Y, Ru, Pd, Sn, Hf, Ta, and W.

[0040] The rare earth element contained in the first layer 3 as a main component may be Y. Furthermore, the metal element M contained in the compound layer 4 as a main component may be Al.

[0041] The compound layer 4 may contain a rare earth element. The content of the rare earth element in the compound layer 4 may be less than the content of the rare earth element in the first layer 3 .

[0042] In the above case, because the first layer 3 and the compound layer 4 contain rare earth elements, the chemical affinity between the first layer 3 and the compound layer 4 is enhanced. Consequently, the bonding strength between the first layer 3 and the compound layer 4 is improved. On the other hand, if the rare earth element content of the compound layer 4 increases, the effect of improving the mechanical strength of the compound layer 4 becomes less pronounced. Since the rare earth element content of the compound layer 4 is lower than that of the first layer 3, a decrease in the mechanical strength of the compound layer 4 can be suppressed. Consequently, the concern that the overall mechanical strength of the corrosion-resistant member 1B may be reduced can be suppressed.

[0043] The first layer 3 can be exposed on the surface of the corrosion-resistant member 1B. Rare earth element compounds such as Y2O3 have excellent corrosion resistance. The higher the crystallinity of the rare earth element compound, the better the corrosion resistance. The region 32 of the first layer 3 that is remote from the substrate 2 has high crystallinity, resulting in excellent corrosion resistance. Therefore, if the first layer 3 is exposed on the surface, the corrosion-resistant member 1B has excellent corrosion resistance.

[0044] The compound layer 4 can be amorphous. The region 31 of the first layer 3 that is close to the substrate 2 has low crystallinity. The amorphous compound layer 4 is bonded to the low-crystalline region of the first layer 3. Therefore, when the amorphous compound layer 4 and the low-crystalline region of the first layer 3 are bonded together, both have low crystallinity, reducing the amount of lattice defects generated between them. As a result, the bond strength between the low-crystalline region of the first layer 3 and the amorphous compound layer 4 is improved.

[0045] Whether the compound layer 4 is amorphous can also be determined by electron beam diffraction using a TEM.

[0046] The rare earth element contained in the first layer 3 may be at least one selected from the group consisting of Y, La, Nd, Sm, Eu, Gd, Dy, and Ho. Furthermore, the metal element M contained in the compound layer 4 may be at least one selected from the group consisting of Mg, Al, Si, Cr, Ni, Cu, Ga, Sr, Y, Ru, Pd, Sn, Hf, Ta, and W.

[0047] Among rare earth elements, compounds of Y, La, Nd, Sm, Eu, Gd, Dy, and Ho exhibit excellent corrosion resistance against corrosive gas plasma. Excluding cases where the rare earth element contained in the first layer 3 and the compound layer 4 is the same, when the metal element M is Mg, Al, Si, Cr, Ni, Cu, Ga, Sr, Y, Ru, Pd, Sn, Hf, Ta, or W, the ionic radius of the cations of the metal element M contained in the compound layer 4 is smaller than the ionic radius of the cations of the rare earth element contained in the first layer 3. This reduces lattice defects in the bonding region between the first layer 3 and the compound layer 4. Consequently, the bonding strength between the first layer 3 and the compound layer 4 is enhanced.

[0048] The rare earth element may be Y. Among rare earth elements, Y oxide (Y2O3) has excellent corrosion resistance to corrosive gas plasma.

[0049] The compound layer 4 may be primarily composed of an Al oxide or a composite oxide of Y and Al. Furthermore, the region where the first layer 3 and the compound layer 4 contact each other may include an amorphous region 33 composed of Y, Al, and O (oxygen). In this case, the bonding strength between the first layer 3 and the compound layer 4 is further enhanced. The reason for this is presumably as follows.

[0050] The compound layer 4 is primarily composed of an Al oxide or a composite oxide of Y and Al. The first layer 3 is primarily composed of an Y oxide (Y2O3). The region of the first layer 3 in contact with the compound layer 4 includes an amorphous region 33 composed of Y, Al, and O. Therefore, lattice defects between the first layer 3 and the compound layer 4 are particularly reduced. As a result, the bonding strength between the first layer 3 and the compound layer 4 is further enhanced. The compound layer 4 is preferably amorphous and primarily composed of an Al oxide or a composite oxide of Y and Al. When the compound layer 4 is amorphous and primarily composed of an Al oxide or a composite oxide of Y and Al, lattice defects between the compound layer 4 and the first layer 3 are further reduced, thereby significantly enhancing the bonding strength between the first layer 3 and the compound layer 4.

[0051] It is also possible to use EDS with a TEM or electron beam diffraction with a TEM to determine whether the compound layer 4 is primarily composed of an Al oxide or a Y and Al composite oxide. Furthermore, it is also possible to determine whether the first layer 3 has an amorphous region 33 by electron beam diffraction with a TEM.

[0052] Examples of the oxide of Al as the main component in the compound layer 4 include Al2O3, etc. Examples of the composite oxide of Al and Y as the main components in the compound layer 4 include YAlO3, Y2Al4O9, and Y3Al5O12.

[0053] In the amorphous region 33, the content ratio of O can be the highest in terms of atomic ratio. Furthermore, in the amorphous region 33, the content ratio of Al can be higher than the content ratio of Y in terms of atomic ratio. Furthermore, the content of Y can be from 5 atomic % to 30 atomic %. The content of Al can be from 10 atomic % to 40 atomic %. The content of O can be from 40 atomic % to 80 atomic %.

[0054] The average thickness of the amorphous region 33 can be not less than 1 nm and not more than 15 nm. The average thickness of the amorphous region 33 can be measured by the same method as the average thickness of the first layer 3 .

[0055] The average thickness of the compound layer 4 can be between 1 nm and 300 nm. A lower limit of 1 nm reduces lattice defects in the bonding region between the first layer 3 and the compound layer 4. Consequently, the bonding strength between the first layer 3 and the compound layer 4 is improved. Furthermore, an upper limit of 300 nm reduces the size of particles generated during exposure to corrosive gas plasma. The average thickness of the compound layer 4 can be measured using the same method as the average thickness of the first layer 3.

[0056] Next, a corrosion-resistant component 1C according to a non-limiting embodiment of the present disclosure will be described. As shown in FIG3 , a corrosion-resistant member 1C comprises a laminate 1a, and compound layers 4 of a metal element M and first layers 3 alternately stacked on the laminate 1a. The compound layers 4 have uniform crystallinity. The corrosion-resistant member 1C has a surface layer 5 composed of the first layer 3 in the region farthest from the substrate 2.

[0057] In the corrosion-resistant member 1C, compound layers 4 and first layers 3 are alternately laminated (bonded) on the laminate 1a. In the bonded region formed by sequentially laminating the compound layers 4 and first layers 3, the low-crystalline portion of the first layer 3 near the substrate 2 is bonded to the compound layers 4. Lattice defects are reduced in this bonded region, thereby enhancing the bond strength between the compound layers 4 and first layers 3.

[0058] Furthermore, in the bonded region formed by sequentially laminating the first layer 3 and the compound layer 4, the highly crystalline portion of the first layer 3, located away from the substrate 2, is bonded to the compound layer 4. The highly crystalline region of the first layer 3 has higher mechanical strength than the low-crystalline region. Compared to a case where the entire first layer 3 has low crystallinity, the presence of the highly crystalline region in the first layer 3 improves the mechanical strength of the first layer 3. This improves the bond strength between the first layer 3 and the compound layer 4 and suppresses the generation of cracks in the first layer 3.

[0059] At least the metal element M contained in the compound layer 4 closest to the surface layer 5 can be Al. Rare earth elements and Al have a strong chemical bonding strength. When the surface layer 5 is the first layer 3, if the metal element M in the compound layer 4 closest to the surface layer 5 is Al, the bonding strength with the surface layer 5 is enhanced. Therefore, even when exposed to corrosive gas plasma, particles are less likely to be generated from the surface layer 5.

[0060] The compound layer 4 may be amorphous. In this case, the first layer 3 and the compound layer 4, which are formed by multiple layers, can maintain a high bonding strength. The reason for this is presumably as follows.

[0061] In any first layer 3, the region 31 near the substrate 2 is low in crystallinity. The low-crystallinity region of the first layer 3 is bonded to the amorphous compound layer 4. Therefore, when the low-crystallinity region of the first layer 3 and the amorphous compound layer 4 are bonded together, both have low crystallinity, reducing the number of lattice defects generated between them. As a result, the bond strength between the low-crystallinity region of the first layer 3 and the amorphous compound layer 4 is improved.

[0062] Due to the above-described effects, the residual stress generated by the bonding with the compound layer 4 in the region 32 of any first layer 3 that is remote from the substrate 2, i.e., the highly crystalline region, is reduced. Therefore, even if the crystallinity of the region 32 of any first layer 3 that is remote from the substrate 2 increases, the bonding strength between the highly crystalline region of the first layer 3 and the amorphous compound layer 4 is improved.

[0063] Due to the above-mentioned effects, the first layer 3 and the compound layer 4 formed by multiple laminations can maintain a high bonding strength.

[0064] The compositions of the plurality of first layers 3 in the corrosion-resistant member 1C may be the same or different. This also applies to the compound layer 4. In other words, the compositions of the plurality of compound layers 4 in the corrosion-resistant member 1C may be the same or different.

[0065] For example, the atomic number of the metal element M contained in at least one of the plurality of compound layers 4 may be smaller than the atomic number of the rare earth element that is the main component contained in the first layer 3. Furthermore, at least one of the plurality of compound layers 4 may contain a rare earth element, and the content of the rare earth element in this compound layer 4 may be less than the content of the rare earth element in the first layer 3. At least one of the plurality of compound layers 4 may be amorphous.

[0066] The number of compound layers 4 and first layers 3 alternately stacked on the laminate 1a is not limited to a specific value. For example, the number of compound layers 4 can be set to 20 or more and 5000 or less. The number of first layers 3 can also be set to 20 or more and 5000 or less.

[0067] Next, a corrosion-resistant member 1D according to a non-limiting embodiment of the present disclosure will be described. As shown in Figure 4, a corrosion-resistant member 1D comprises a laminate 1b, compound layers 4 of a metal element M, and first layers 3 alternately laminated on the laminate 1b. The compound layers 4 have uniform crystallinity. The corrosion-resistant member 1D has a surface layer 5 composed of the first layer 3 in the region farthest from the substrate 2. This improves the bonding strength between the first layer 3 and the compound layer 4, and suppresses cracks originating from the first layer 3. The reasons for this are similar to those described for the corrosion-resistant member 1C.

[0068] The number of compound layers 4 and first layers 3 alternately stacked on the laminate 1b is not limited to a specific value. For example, the number of compound layers 4 can be set to 20 or more and 5000 or less. The number of first layers 3 can also be set to 20 or more and 5000 or less.

[0069] Next, a corrosion-resistant component 1E according to a non-limiting embodiment of the present disclosure will be described. As shown in Figure 5, a corrosion-resistant member 1E is a laminate 1c comprising a substrate 2, a compound layer 4 of a metal element M deposited on the substrate 2, and a first layer 3 deposited on the compound layer 4. The first layer 3 is composed of a rare earth element compound containing a rare earth element as a main component. Furthermore, the atomic number of the metal element M contained in the compound layer 4 is smaller than the atomic number of the rare earth element as the main component contained in the first layer 3. In the first layer 3, the crystallinity of a region 31 close to the substrate 2 is lower than that of a region 32 farther from the substrate 2. This improves corrosion resistance and the bonding strength between the substrate 2 and the film (first layer 3). The reasons for this are the same as those described for the corrosion-resistant members 1A and 1B. The laminate 1c can be referred to as a third laminate 1c.

[0070] Next, a corrosion-resistant member 1F according to a non-limiting embodiment of the present disclosure will be described. As shown in FIG6 , a corrosion-resistant member 1F comprises a laminate 1c, compound layers 4 of a metal element M, and first layers 3 alternately laminated on the laminate 1c. The atomic number of the metal element M contained in the compound layer 4 is smaller than the atomic number of the rare earth element as the main component contained in the first layer 3. The corrosion-resistant member 1F has a surface layer 5 composed of the first layer 3 in the region farthest from the substrate 2. This improves the bonding strength between the first layer 3 and the compound layer 4, and suppresses cracking in the first layer 3. The reasons for this are the same as those described for the corrosion-resistant members 1A to 1C.

[0071] The number of compound layers 4 and first layers 3 alternately stacked on the laminate 1c is not limited to a specific value. For example, the number of compound layers 4 can be set to 20 or more and 5000 or less. The number of first layers 3 can also be set to 20 or more and 5000 or less.

[0072] Examples of applications for the corrosion-resistant components 1A to 1F include components exposed to corrosive gases containing F, Cl, or Br, or plasma derived from these gases, and components exposed to corrosive substances such as HF. In particular, components used in these gases and substances at high temperatures of approximately 300 to 700°C are particularly suitable. Examples of corrosive gases include CF4 gas.

[0073] <Method for Manufacturing Corrosion-Resistant Member> Next, a method for manufacturing a corrosion-resistant member according to a non-limiting embodiment of the present disclosure will be described.

[0074] First, the base 2 is prepared. The following description will take as an example a method for manufacturing the base 2 made of ceramics having alumina as a main component.

[0075] Alumina (Al2O3) powder A with an average particle size of 0.4 to 0.6 μm and aluminum oxide (B) powder with an average particle size of approximately 1.2 to 1.8 μm are prepared. Silicon oxide (SiO2) powder is prepared as a silicon source, and calcium carbonate (CaCO3) powder is prepared as a calcium source. The silicon oxide powder is a fine powder with an average particle size of 0.5 μm or less. Furthermore, magnesium hydroxide powder is used to produce an alumina ceramic containing magnesium. In the following description, all powders other than aluminum oxide (A) powder and aluminum oxide (B) powder are collectively referred to as the first auxiliary component powder.

[0076] Next, a predetermined amount of the first auxiliary component powder is weighed. The alumina blended powder is then weighed as follows: the mass ratio of alumina A powder to alumina B powder is 40:60 to 60:40, and the Al content, calculated as Al₂O₃, is 99.4% or greater out of 100% by mass of the components constituting the resulting ceramic. Furthermore, the first auxiliary component powder is weighed as follows: the amount of Na in the alumina blended powder is determined, converted from the Na content in the ceramic to Na₂O, and the ratio of this converted value to the value of the components constituting the first auxiliary component powder (in this example, Si or Ca, etc.) converted to oxides is maintained at a ratio of 1.1 or less.

[0077] Then, 1 to 1.5 parts by mass of a binder such as PVA (polyvinyl alcohol), 100 parts by mass of a solvent, and 0.1 to 0.55 parts by mass of a dispersant are placed in a stirring device and mixed and stirred to obtain a slurry based on 100 parts by mass of the alumina mixed powder and the first auxiliary component powder.

[0078] After that, the slurry is spray-granulated to obtain granules, which are then formed into a predetermined shape using a powder compacting device, a hydrostatic compacting device, etc., and cut as needed to obtain a compact.

[0079] The substrate 2 is then calcined at a calcination temperature of 1500°C to 1700°C, and held for 4 to 6 hours to obtain a sintered body. The surface of the sintered body on the side where the film is formed is then ground to obtain a ground surface. This surface is then coarsely polished using a grinding wheel composed of diamond abrasive grains with an average particle size of 4 μm or greater and cast iron. Rough polishing can be performed using diamond abrasive grains with a large average particle size, followed by diamond abrasive grains with a small average particle size. Finish polishing is then performed using a grinding wheel composed of diamond abrasive grains with an average particle size of 1 μm to 5 μm and tin to obtain the substrate 2. After finish polishing, polishing can be performed using abrasive grains of colloidal silica, cerium oxide, or aluminum oxide and a polishing pad made of a polyester fiber nonwoven fabric impregnated with polyurethane. The average particle size of the colloidal abrasive grains is, for example, 20 μm to 50 μm.

[0080] Next, the method of forming a film is described by taking as an example the case where a Y2O3 layer is formed as the first layer 3.

[0081] As shown in FIG7 , a film can be formed using a sputtering apparatus 101. The sputtering apparatus 101 includes a chamber 102, a gas supply source 103 connected to the chamber 102, an anode 104 and a cathode 105 located within the chamber 102, and a target 106 connected to the cathode 105.

[0082] First, the substrate 2 is placed on the anode 104 side of the chamber 102. A target 106 composed primarily of a rare earth element, in this case, metallic yttrium, is placed on the cathode 105 side. In this state, the chamber 102 is decompressed using an exhaust pump, and argon is supplied from the gas supply source 103 as gas G. The pressure of the supplied argon gas is maintained at a range of 0.1 Pa to 2 Pa. The temperature within the chamber 102 is maintained at a range of 50°C to 400°C.

[0083] Then, a power supply applies an electric field between anode 104 and cathode 105, generating plasma P1 for sputtering, thereby forming a metal yttrium film on the surface of substrate 2. The power input from the power supply can be either high-frequency or direct current. Furthermore, the thickness of the film formed in one step is on the sub-nanometer level.

[0084] Next, plasma P2 is generated to oxidize the metal yttrium film. Subsequently, the metal yttrium film formation and oxidation steps are alternately performed to achieve a total average film thickness of 1 nm to 1000 nm, thereby forming a Y2O3 layer as the first layer 3. The symbol P in FIG7 represents plasma P1 or plasma P2.

[0085] Plasma P1, among the spectral spectra of plasma P1, the first spectrum with the highest intensity is located at a wavelength of 390nm to 430nm, and the other spectral spectra (the second spectrum, the third spectrum and the fourth spectrum in descending order of intensity) are located at a wavelength of 300nm to 700nm.

[0086] Plasma P2, among the spectral spectra of plasma P2, the first spectrum with the highest intensity is located at a wavelength of 500nm to 550nm, and the other spectral spectra (the second spectrum, the third spectrum and the fourth spectrum in descending order of intensity) are located at a wavelength of 380nm to 820nm.

[0087] To form a Y2O3 layer with low crystallinity, the temperature in the chamber 102 can be lowered. To form a Y2O3 layer with high crystallinity, the temperature in the chamber 102 can be increased.

[0088] Other films, such as the compound layer 4, can be formed in the same manner as the Y2O3 layer. For example, when forming an Al2O3 layer as the compound layer 4, a target material 106 containing Al as its main component can be used. To form an amorphous compound layer 4, the temperature within the chamber 102 can be lowered. To form the amorphous region 33, after forming the compound layer 4, when forming the first layer 3 on the compound layer 4, the temperature within the chamber 102 can be initially lowered and then gradually increased to form the film.

[0089] Although the embodiments of the present disclosure are exemplified above, the present disclosure is not limited to the above embodiments and can be implemented in any form without departing from the gist of the present disclosure.

[0090] For example, the corrosion-resistant member may have the following configuration. (1) A corrosion-resistant component comprising a laminate consisting of a substrate and a first layer laminated on the substrate, wherein the first layer is composed of a rare earth element compound containing a rare earth element as a metal element as a main component, and in the first layer, the crystallinity of a region close to the substrate is lower than the crystallinity of a region away from the substrate. (2) A corrosion-resistant component comprising a substrate, a compound layer of a metal element M deposited on the substrate, and a first layer deposited on the compound layer, wherein the first layer is composed of a rare earth element compound containing a rare earth element as a metal element as a main component, the compound layer has uniform crystallinity, and in the first layer, the crystallinity of a region close to the substrate is lower than the crystallinity of a region away from the substrate. (3) A corrosion-resistant component as described in (1) or (2) above, comprising the aforementioned layered body and compound layers of the metal element M alternately layered on top of the aforementioned layered body and the aforementioned first layer, wherein the aforementioned compound layers have uniform crystallinity and may have a surface layer composed of the aforementioned first layer in the region farthest from the aforementioned substrate. (4) A corrosion-resistant component as described in (2) or (3) above, wherein the atomic number of the metal element M contained in the aforementioned compound layer may be smaller than the atomic number of the aforementioned rare earth element as the main component contained in the aforementioned first layer. (5) A corrosion-resistant component comprising a substrate, a compound layer of a metal element M deposited on the substrate, and a first layer deposited on the compound layer, wherein the first layer is composed of a rare earth element compound containing a rare earth element as a metal element as a main component, the atomic number of the metal element M contained in the compound layer is smaller than the atomic number of the rare earth element as the main component contained in the first layer, and the crystallinity of the region near the substrate in the first layer is lower than the crystallinity of the region away from the substrate. (6) A corrosion-resistant component as described in (1) or (5) above, which comprises the aforementioned layered body and compound layers of the metal element M alternately layered on top of the aforementioned layered body and the aforementioned first layer, wherein the atomic number of the metal element M contained in the aforementioned compound layer is smaller than the atomic number of the aforementioned rare earth element as the main component contained in the aforementioned first layer, and may have a surface layer composed of the aforementioned first layer in the area farthest from the aforementioned substrate. (7) In the corrosion-resistant component according to (3) or (6) above, the metal element M contained in at least the compound layer closest to the surface layer may be Al. (8) A corrosion-resistant component as described in any one of (2) to (7) above, wherein the compound layer contains a rare earth element, and the content of the rare earth element in the compound layer may be less than the content of the rare earth element in the first layer. (9) The corrosion-resistant component according to any one of (1) to (8) above, wherein the first layer is exposed on the surface. (10) The corrosion-resistant component according to any one of (2) to (9) above, wherein the compound layer may be amorphous. (11) The corrosion-resistant component according to any one of (1) to (10) above, wherein the rare earth element compound may be an oxide. (12) A corrosion-resistant component as described in any one of (2) to (11) above, wherein the rare earth element contained in the aforementioned first layer can be selected from at least one of Y, La, Nd, Sm, Eu, Gd, Dy and Ho, and the metal element M contained in the aforementioned compound layer can be selected from at least one of Mg, Al, Si, Cr, Ni, Cu, Ga, Sr, Y, Ru, Pd, Sn, Hf, Ta and W. (13) The corrosion-resistant component as described in (12) above, wherein the rare earth element may be Y. (14) The corrosion-resistant component according to any one of (1) to (13) above, wherein the substrate is made of ceramic. (15) A corrosion-resistant component as described in any one of (1) to (14) above, wherein the matrix comprises aluminum oxide as a main component, the first layer comprises Y oxide as a main component, and may further comprise a composite oxide of Y and Al. (16) A corrosion-resistant component as described in any one of (2) to (15) above, wherein the compound layer has an oxide of Al as its main component or a composite oxide of Y and Al as its main component, and the first layer may have an amorphous region composed of Y, Al, and O in the region in contact with the compound layer. (17) The corrosion-resistant component according to any one of (2) to (16) above, wherein the average thickness of the compound layer may be greater than 1 nm and less than 300 nm.

[0091] In the corrosion-resistant member 1F, the layered body 1a may be used instead of the layered body 1c.

[0092] Hereinafter, the present disclosure will be described in detail with reference to the following embodiments, but the present disclosure is not limited to the following embodiments. [Example]

[0093] (Example 1) Using this manufacturing method, a corrosion-resistant component with a Y2O3 surface layer was obtained by alternately laminating 50 Y2O3 layers (a total of 50 layers) as the first layer and 49 Al2O3 layers (a total of 49 layers) as the compound layer on an Al2O3 substrate. The average thickness of the first layer (Y2O3 layer) was 11 nm, and the average thickness of the compound layer (Al2O3 layer) was 11 nm.

[0094] In the magnified TEM image of the corrosion-resistant component obtained, lattice fringes of the Y2O3 layer can be confirmed (see Figure 8). This confirms the presence of crystalline regions in the Y2O3 layer.

[0095] Electron beam diffraction patterns differ between the surface and substrate sides of the Y2O3 layer with an average thickness of 11 nm (see Figures 9 and 10). These results confirm that within the Y2O3 layer, the region close to the substrate (NBD2) has low crystallinity, while the region farther from the substrate (NBD1) has high crystallinity.

[0096] Electron beam diffraction analysis using a TEM revealed that the first layer, in contact with the compound layer, contained an amorphous region composed of Y, Al, and O. The average thickness of the amorphous region was 4 nm. Within the amorphous region, O accounted for 60.28 atomic %, Al for 24.72 atomic %, and Y for 15.00 atomic %. Furthermore, electron beam diffraction analysis using a TEM revealed uniform crystallinity in the compound layer.

[0097] (Example 2) By the above-mentioned manufacturing method, a plurality of the following samples No. 1 to 2 were obtained. Sample No. 1: A corrosion-resistant component in which a Y2O3 layer (average thickness 1.1 μm) is formed as the first layer on a substrate composed of Al2O3.

[0098] Sample No. 2: A corrosion-resistant component constructed by alternating layers of Y2O3 (average thickness 11 nm) as the first layer and Al2O3 (average thickness 11 nm) as the compound layer on an Al2O3 substrate, with the surface layer being the Y2O3 layer. There are 50 Y2O3 layers and 49 Al2O3 layers. The average thickness of the entire film is 1.1 μm.

[0099] Samples No. 1 and 2 were measured in the same manner as in Example 1. The results confirmed that within the Y2O3 layer, the crystallinity was low in the region close to the substrate, while the crystallinity was high in the region farther from the substrate. Furthermore, the crystallinity of the compound layer was uniform.

[0100] Adhesion strength and plasma resistance were evaluated for Samples No. 1 and 2. The evaluation methods are as follows.

[0101] (Evaluation method of adhesion strength) Each sample was subjected to three scratch tests using a Revetest Scratch Tester (S / N: 27-486) ​​manufactured by CSM Instruments. A diamond indenter (N2-5168) with a tip curvature radius of 200 μm was used.

[0102] The test conditions are as follows. Begin load: 0.9N Loading rate: 100N / min Scratch speed: 10mm / min AE sensitivity: 9 The adhesion strength (N) of each sample is the average of three measurements.

[0103] (Evaluation method of plasma resistance) Apply masking tape to a portion of the surface layer to mask it. Measure the step difference before and after exposure to plasma using an optical surface texture analyzer. Step difference refers to the reduction in film thickness due to plasma exposure. The step difference measurement method is as follows. First, apply masking tape to a portion of the film surface and expose it to plasma. After exposure to plasma, remove the masking tape. A step difference is formed between the surface after the masking tape is removed (unexposed surface) and the surface exposed to plasma (after exposure). Measure the size of this step difference. The smaller the step difference, the better the plasma resistance.

[0104] The plasma exposure conditions are as follows. Partial pressure of CF4 gas (Pa): 9Pa CF4 gas flow rate (L / min): 100 sccm Exposure time to CF4 gas: 4 hours Output: 900W Material of paper tape: Kapton tape In addition, the plasma exposure is performed using a reactive ion etching (RIE) device.

[0105] The measurement results are as follows. (Seal strength) Sample No. 1: 24.2N Sample No. 2: 34.2N (Plasma resistance) Sample No. 1: 0.0792 μm Sample No. 2: 0.0902 μm

[0106] The samples No. 1 and 2 of the present disclosure have excellent adhesion strength and plasma resistance. From these results, it can be said that the corrosion resistance and the bonding strength between the substrate and the film are improved according to the samples No. 1 and 2.

[0107] In the comparative example, a sample composed of a sintered body of yttrium oxide (Y2O3) was used to evaluate plasma resistance under the same conditions as in Example 2. The results showed that the step difference of the sintered body of yttrium oxide was as large as 0.11 μm, indicating poor corrosion resistance.

[0108] 1A: Corrosion-resistant components 1B: Corrosion-resistant components 1C: Corrosion-resistant components 1D: Corrosion-resistant components 1E: Corrosion-resistant components 1F: Corrosion-resistant components 1a: Laminated body (first laminate) 1b: Laminated body (second laminate) 1c: Laminated body (third laminate) 2: Matrix 3: Layer 1 31: Area close to the substrate 32: Area away from the substrate 33: Amorphous region 3a: Center 4: Compound layer (2nd layer) 5: Surface 101: Sputtering device 102: Chamber 103: Gas supply source 104: Anode 105: cathode 106: Target P: Plasma

Claims

1. A corrosion-resistant component, comprising a laminate consisting of a substrate and a first layer deposited on the substrate, wherein, The aforementioned first layer is composed of rare earth element compounds containing rare earth elements as metallic elements as the main components. In the aforementioned first layer, the crystallinity of the region near the aforementioned matrix is ​​lower than that of the region far from the aforementioned matrix. In the aforementioned first layer, both the region near the aforementioned matrix and the region far from the aforementioned matrix are crystalline. The aforementioned matrix is ​​composed of any one of ceramics, single crystals, glass, and metals. The aforementioned ceramics are composed of any one of alumina, silicon nitride, silicon carbide, and zirconium dioxide as the main components. The aforementioned single crystals are any one of sapphire, silicon, and YAG (Y3Al5O12). The aforementioned glass is quartz glass. The aforementioned metals are Al or stainless steel.

2. A corrosion-resistant component, which is a laminate, the laminate system comprising a substrate, a compound layer of metallic element M laminated on the substrate, and a first layer laminated on the compound layer, wherein, The aforementioned first layer is composed of rare earth element compounds containing rare earth elements as metallic elements as the main components. The crystallinity of the aforementioned compound layer is uniform. In the aforementioned first layer, the crystallinity of the region near the aforementioned substrate is lower than that of the region far from the aforementioned substrate. In the aforementioned first layer, both the region near the aforementioned substrate and the region far from the aforementioned substrate are crystalline. The aforementioned substrate is composed of any one of ceramics, single crystals, glass, and metals. The aforementioned ceramics are composed of any one of alumina, silicon nitride, silicon carbide, and zirconium dioxide as the main components. The aforementioned single crystals are any one of sapphire, silicon, and YAG (Y3Al5O12). The aforementioned glass is quartz glass. The aforementioned metals are Al or stainless steel.

3. The corrosion-resistant component as claimed in claim 1 or 2, comprising: the aforementioned laminate; and a compound layer of metallic element M and the aforementioned first layer alternately laminated on top of the aforementioned laminate, wherein the aforementioned compound layer is uniformly crystalline, and the region furthest from the aforementioned substrate has a surface layer composed of the aforementioned first layer.

4. The corrosion-resistant component as described in claim 2, wherein, The atomic number of the metal element M contained in the aforementioned compound layer is lower than the atomic number of the rare earth element, which is the main component contained in the aforementioned first layer.

5. A corrosion-resistant component, which is a laminate, the laminate system comprising a substrate, a compound layer of metallic element M laminated on the substrate, and a first layer laminated on the compound layer, wherein, The aforementioned first layer is composed of rare earth element compounds containing rare earth elements as metal elements as the main components. The atomic number of the metal element M contained in the aforementioned compound layer is lower than the atomic number of the aforementioned rare earth elements as the main components contained in the aforementioned first layer. In the aforementioned first layer, the crystallinity of the region near the aforementioned matrix is ​​lower than that of the region far from the aforementioned matrix. In the aforementioned first layer, both the region near the aforementioned matrix and the region far from the aforementioned matrix are crystalline. The aforementioned matrix is ​​composed of any one of ceramics, single crystals, glass, and metals. The aforementioned ceramics are composed of any one of alumina, silicon nitride, silicon carbide, and zirconium dioxide as the main components. The aforementioned single crystals are any one of sapphire, silicon, and YAG (Y3Al5O12). The aforementioned glass is quartz glass. The aforementioned metals are Al or stainless steel.

6. The corrosion-resistant component as claimed in claim 1 or 5, comprising: the aforementioned laminate; and a compound layer of metal element M and the aforementioned first layer alternately laminated on top of the aforementioned laminate, wherein the atomic number of the metal element M contained in the aforementioned compound layer is lower than the atomic number of the aforementioned rare earth element, which is the main component contained in the aforementioned first layer, and the region furthest from the aforementioned substrate has a surface layer composed of the aforementioned first layer.

7. The corrosion-resistant component as described in claim 3, wherein, At least the metal element M contained in the aforementioned compound layer closest to the aforementioned surface layer is Al.

8. The corrosion-resistant component as described in any one of claims 2, 4, and 5, wherein, The aforementioned compound layer contains rare earth elements, and the content of rare earth elements in the aforementioned compound layer is less than the content of rare earth elements in the aforementioned first layer.

9. A corrosion-resistant component as described in any one of claims 1, 2, 4, and 5, wherein, The aforementioned first layer is exposed on the surface.

10. A corrosion-resistant component as described in any one of claims 2, 4, and 5, wherein, The aforementioned compound layer is amorphous.

11. The corrosion-resistant component as described in any one of claims 1, 2, 4, and 5, wherein, The aforementioned rare earth element compounds are oxides.

12. The corrosion-resistant component as described in any one of claims 2, 4, and 5, wherein, The rare earth elements contained in the first layer are selected from at least one of Y, La, Nd, Sm, Eu, Gd, Dy and Ho. The metal element M contained in the compound layer is selected from at least one of Mg, Al, Si, Cr, Ni, Cu, Ga, Sr, Y, Ru, Pd, Sn, Hf, Ta and W.

13. The corrosion-resistant component as described in claim 12, wherein, The aforementioned rare earth element is Y.

14. The corrosion-resistant component as described in any one of claims 1, 2, 4, and 5, wherein, The aforementioned base system is composed of ceramics.

15. The corrosion-resistant component as described in any one of claims 1, 2, 4, and 5, wherein, The aforementioned base system uses alumina as the main component, and the aforementioned first layer system uses oxides of Y as the main component, and further includes composite oxides of Y and Al.

16. The corrosion-resistant component as described in any one of claims 2, 4, and 5, wherein, The aforementioned compound layer system uses Al oxide as the main component or a composite oxide of Y and Al as the main component. In the aforementioned first layer, there is an amorphous region composed of Y, Al and O in the region in contact with the aforementioned compound layer.

17. The corrosion-resistant component as described in any one of claims 2, 4, and 5, wherein, The average thickness of the aforementioned compound layer is between 1 nm and 300 nm.

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