Corrosion-resistant member

Abstract

The corrosion-resistant member according to the present disclosure is a multilayer body comprising a substrate and a first layer laminated on the substrate. The first layer comprises a rare earth element compound containing a rare earth element as a main metal element component. In the first layer, the crystallinity in a region closer to the substrate is smaller than that in a region farther from the substrate. Alternatively, the corrosion-resistant member according to the present disclosure comprises a substrate, a compound layer laminated on the substrate and comprising a metal element M, and a first layer laminated on the compound layer. The first layer comprises a rare earth element compound containing a rare earth element as a main metal element component. In the compound layer, crystallinity is uniform. In the first layer, the crystallinity in a region closer to the substrate is smaller than that in a region farther from the substrate.

Description

Corrosion-resistant materials

[0001] The present disclosure relates to corrosion-resistant members.

[0002] A known example of a corrosion-resistant member is a component described in Patent Document 1. The component described in Patent Document 1 has a substrate (base) and a composite film provided on the substrate. The composite film is made of amorphous Y. ｘ Al ｙ O ｚ (where 0.24≦x / (x+y)≦0.82, z / (x+y)=1.5) This composite film is produced by vaporizing the raw materials yttrium oxide and aluminum oxide while heating the substrate to a predetermined temperature in the range of 250° C. to 600° C., and then spraying the vaporized raw materials onto the substrate using a carrier gas.

[0003] International Publication No. 2021 / 002339

[0004] The corrosion-resistant member according to the present disclosure is a laminate comprising a substrate and a first layer laminated on the substrate. The first layer is made of a rare earth element compound containing a rare earth element as a main component as a metallic element. The first layer has a region closer to the substrate with lower crystallinity than a region farther from the substrate.

[0005] The corrosion-resistant member according to the present disclosure is a laminate comprising a substrate, a compound layer of a metal element M laminated on the substrate, and a first layer laminated on the compound layer. The first layer is made of a rare earth element compound containing a rare earth element as a main component as the metal element. The compound layer has uniform crystallinity. The first layer has lower crystallinity in a region closer to the substrate than in a region farther from the substrate.

[0006] The corrosion-resistant member according to the present disclosure is a laminate comprising a substrate, a compound layer of a metal element M laminated on the substrate, and a first layer laminated on the compound layer. The first layer is made of a rare earth element compound containing a rare earth element as a main component of the metal element. The atomic number of the metal element M contained in the compound layer is smaller than the atomic number of the rare earth element that is the main component contained in the first layer. The first layer has lower crystallinity in a region closer to the substrate than in a region farther from the substrate.

[0007] FIG. 1 is a cross-sectional view showing a corrosion-resistant member according to a non-limiting embodiment of the present disclosure. FIG. 2 is a cross-sectional view showing a corrosion-resistant member according to a non-limiting embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing a corrosion-resistant member according to a non-limiting embodiment of the present disclosure. FIG. 4 is a cross-sectional view showing a corrosion-resistant member according to a non-limiting embodiment of the present disclosure. FIG. 5 is a cross-sectional view showing a corrosion-resistant member according to a non-limiting embodiment of the present disclosure. FIG. 6 is a schematic diagram showing a sputtering apparatus for obtaining a corrosion-resistant member according to a non-limiting embodiment of the present disclosure. FIG. 7 is a partially enlarged TEM photograph of Example 1. FIG. 8 is a cross-sectional view showing a corrosion-resistant member according to Example 1. ２ O ３ 1 is an electron beam diffraction image of the surface side (NBD1) of the layer. ２ O ３ This is an electron beam diffraction image of the substrate side (NBD2) in the layer.

[0008] The component described in Patent Document 1 has a problem in that the film is made of only amorphous material and therefore has poor corrosion resistance compared to a crystalline film.

[0009] The present disclosure provides a corrosion-resistant member that improves corrosion resistance and improves the bond strength between the substrate and the film.

[0010] The corrosion-resistant member according to the present disclosure has improved corrosion resistance and improved bonding strength between the substrate and the film.

[0011] <Corrosion-Resistant Member> Hereinafter, corrosion-resistant members 1A to 1F according to non-limiting embodiments of the present disclosure will be described in detail with reference to the drawings. However, for the sake of convenience, the drawings referred to below show only the main components necessary for explaining the embodiments in a simplified form. Therefore, the corrosion-resistant members 1A to 1F may include optional components not shown in the drawings referred to. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components, the dimensional ratios of the components, etc.

[0012] As shown in the example of FIG. 1 , the corrosion-resistant member 1A is a laminate 1a made of a substrate 2 and a first layer 3 laminated on the substrate 2. The first layer 3 is made of a rare earth element compound containing a rare earth element as a main component as a metallic element. Furthermore, the crystallinity of the first layer 3 in a region 31 close to the substrate 2 is lower than the crystallinity of a region 32 farther from the substrate 2. In these cases, the corrosion resistance is improved, and the bonding strength between the substrate 2 and the film (first layer 3) is also improved. The following reasons are presumed to be the reasons for this.

[0013] The base 2 is made of any one of ceramics, single crystals, glass, and metals. When the base 2 is made of ceramics, the main component may be alumina, silicon nitride, silicon carbide, zirconia, etc. When the base 2 is made of single crystals, the main component may be sapphire, silicon, YAG (YAG), etc. ３ Al ５ O １２ In the case of glass, quartz glass may be used. In the case of metal, Al, stainless steel, etc. may be used.

[0014] Taking the case where the base 2 is made of ceramic as an example, the ceramic (base 2) is made of a polycrystalline sintered body. Crystals in the ceramic are bonded to the low-crystalline portion of the first layer 3. Bonding to the low-crystalline portion of the first layer 3 reduces lattice defects that occur at the bonded portion between the crystals in the ceramic and the low-crystalline portion of the first layer 3. This improves the bonding strength between the base 2 and the first layer 3.

[0015] Also, Y ２ O ３ These rare earth element compounds 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 far from the substrate 2 has high crystallinity and therefore has 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] The corrosion resistance means, for example, excellent corrosion resistance against corrosive gas plasma and little particle detachment from the surface. Furthermore, the "major component" may refer to the component with the largest mass % value compared to other components. The major component may be, for example, 80 mass % or more.

[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 simply referred to as the rare earth compound. The first layer 3 may be simply referred to as the film.

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

[0019] The measurement (confirmation) that the main component contained in the first layer 3 is a rare earth element may be performed using an energy dispersive X-ray analyzer (EDS) attached to a transmission electron microscope (TEM). Furthermore, the measurement that the crystallinity of the region 31 close to the substrate 2 in the first layer 3 is lower than the crystallinity of the region 32 far from the substrate 2 may be performed by electron beam diffraction using a TEM.

[0020] Here, crystallinity will be described using specific examples. Figures 8 to 10 show the measurement results of Example 1, which will be described later. As shown in Figures 8 and 10, in the region close to the substrate (NBD2), the number of concentric Debye-Scherrer rings observed by electron beam diffraction is small, and the contours of each concentric circle are relatively unclear, resulting in low crystallinity. On the other hand, as shown in Figures 8 and 9, in the region farther from the substrate (NBD1), the number of concentric Debye-Scherrer rings observed by electron beam diffraction is large, and the contours of each concentric circle are clear, compared to the region close to the substrate (NBD2), resulting in higher crystallinity than the region close to the substrate (NBD2).

[0021] The higher the crystallinity, the more clearly the contours of the concentric circles of the Debye-Scherrer rings formed in a concentric pattern can be distinguished when observed by electron beam diffraction. The lower the crystallinity, the less clear the contours of the concentric circles of the Debye-Scherrer rings formed in a concentric pattern can be observed by electron beam diffraction, making them difficult to distinguish. When the crystallinity is uniform, the arrangement and clarity of the contours of the Debye-Scherrer rings observed by electron beam diffraction are comparable between regions close to the substrate and regions far from the substrate.

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

[0023] The first layer 3 may be exposed on the surface of the corrosion-resistant member 1A. ２ O ３ Rare earth element compounds such as these have excellent corrosion resistance. The higher the crystallinity of a rare earth element compound, the better the corrosion resistance. The region 32 of the first layer 3 far from the substrate 2 has high crystallinity and therefore excellent corrosion resistance. Therefore, when the first layer 3 is exposed to the surface, the corrosion-resistant member 1A has excellent corrosion resistance.

[0024] The rare earth element compound may be an oxide. ２ O ３ , Y ３ Al ５ O １２ The term "oxide" includes "complex oxides."

[0025] The substrate 2 is made of alumina (Al ２ O ３ ) as a main component. The first layer 3 may also contain an oxide of Y as a main component and a composite oxide of Y and Al. The "oxide of Y" may be either crystalline or amorphous, or may contain both crystalline and amorphous oxides.

[0026] When the base 2 is mainly composed of alumina, the chemical bonding strength with a compound containing Y as a metal element is high. This improves the bonding strength between the base 2 and the first layer 3, which is mainly composed of an oxide of Y. Furthermore, when the first layer 3 is mainly composed of an oxide of Y, the corrosion resistance of the film is improved. When the first layer 3 further contains a composite oxide of Y and Al, the composite oxide of Y and Al contained in the first layer 3 is intimately bonded to the main component (Al) of the base 2. ２ O ３ ) and is chemically bonded firmly to the substrate 2. Therefore, the bonding strength between the substrate 2 and the first layer 3 is improved.

[0027] Examples of composite oxides of Y and Al include YAlO ３ (Y ２ O ３ :Al ２ O ３ =1:1(YAM)), Y ４ Al ２ O ９ (Y ２ O ３ :Al ２ O ３ =2:1(YAP)), Y ３ Al ５ O １２ (Y ２ O ３ :Al ２ O ３ = 3:5 (YAG)).

[0028] The fact that the first layer 3 is mainly composed of an oxide of Y and the fact that the first layer 3 further contains a composite oxide of Y and Al may be measured using an EDS attached to a TEM, or may be measured by electron beam diffraction using a TEM.

[0029] When the main component of the base 2 is alumina, it may contain at least one of silicon, magnesium, and calcium as an oxide. Each component constituting the base 2 may be identified by an X-ray diffraction apparatus using CuKα radiation. The content of each identified component may be determined, for example, by an ICP (Inductively Coupled Plasma) emission spectrometer or an X-ray fluorescence analyzer.

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

[0031] Next, a non-limiting embodiment of the corrosion-resistant member 1B of the present disclosure will be described. Below, differences between the corrosion-resistant member 1B and the corrosion-resistant member 1A will be mainly described, and detailed descriptions of the same configurations as the corrosion-resistant member 1A may be omitted. Therefore, the description of the corrosion-resistant member 1A may be used to understand the configuration of the corrosion-resistant member 1B. These points also apply to the corrosion-resistant members 1C to 1F described below.

[0032] As shown in an example in FIG. 2 , the corrosion-resistant member 1B is a laminate 1b comprising a substrate 2, a compound layer 4 of a metal element M laminated on the substrate 2, and a first layer 3 laminated on the compound layer 4. The first layer 3 is made of a rare earth element compound containing a rare earth element as a main component as a metal element. The compound layer 4 has uniform crystallinity. The first layer 3 has a region 31 closer to the substrate 2 with lower crystallinity than a region 32 farther from the substrate 2. In these cases, the corrosion resistance is improved, and the bonding strength between the substrate 2 and the film (first layer 3) is improved. The following reasons are presumed to be the reasons for this.

[0033] The material of the base 2 may be the same as that exemplified for the corrosion-resistant member 1A. Taking the case where the base 2 is made of ceramic as an example, the ceramic (base 2) is made of a polycrystalline sintered body. The M compound (e.g., SiO ２ ) may be crystalline or amorphous. The compound layer 4 (M compound) with uniform crystallinity is bonded to the low-crystallinity portion of the first layer 3. Bonding to the low-crystallinity portion of the first layer 3 reduces lattice defects that occur at the bonded portion between the M compound and the low-crystallinity portion of the first layer 3. This improves the bonding strength between the base 2 and the first layer 3 bonded via the M compound.

[0034] Also, Y ２ O ３ These rare earth element compounds 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 far from the substrate 2 has high crystallinity and therefore has excellent corrosion resistance. Therefore, the surface side of the first layer 3 (rare earth oxide) of the corrosion-resistant member 1B has excellent corrosion resistance.

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

[0036] The content of the metal element M contained in the compound layer 4 may be measured using an EDS attached to a TEM. Furthermore, whether the crystallinity of the compound layer 4 is uniform may be measured by electron beam diffraction using a TEM.

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

[0038] In the junction region between the first layer 3 and the compound layer 4, cations of the rare earth element constituting the first layer 3 and cations of the metal element M constituting the compound layer 4 are substituted or form a solid solution. In this case, lattice defects in the junction region are reduced. This is because when the atomic number is small, the ionic radius of the metal element M constituting the compound layer 4 tends to be small, and therefore the residual stress generated in the first layer 3 is alleviated.

[0039] Examples of the rare earth element contained in the first layer 3 as a main component include the same rare earth elements as those 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 main rare earth element contained in the first layer 3 may be Y. The main component of the metal element M contained in the compound layer 4 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, since the first layer 3 and the compound layer 4 contain a rare earth element, the chemical affinity between the first layer 3 and the compound layer 4 is improved. As a result, 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 is large, the effect of improving the mechanical strength of the compound layer 4 is not significant. Since the rare earth element content of the compound layer 4 is smaller than the rare earth element content of the first layer 3, a decrease in the mechanical strength of the compound layer 4 can be suppressed. As a result, the risk of a decrease in the overall mechanical strength of the corrosion-resistant member 1B can be suppressed.

[0043] The first layer 3 may be exposed on the surface of the corrosion-resistant member 1B. ２ O ３ Rare earth element compounds such as these have excellent corrosion resistance. The higher the crystallinity of a rare earth element compound, the better the corrosion resistance. The region 32 of the first layer 3 far from the substrate 2 has high crystallinity and therefore excellent corrosion resistance. Therefore, when the first layer 3 is exposed to the surface, the corrosion-resistant member 1B has excellent corrosion resistance.

[0044] The compound layer 4 may be amorphous. A region 31 of the first layer 3 that is close to the substrate 2 has low 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 is bonded to the amorphous compound layer 4, the crystallinity of both is low, and therefore, lattice defects that occur between them are reduced. As a result, the bonding strength between the low crystallinity region of the first layer 3 and the amorphous compound layer 4 is improved.

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

[0046] The rare earth element contained in the first layer 3 may be selected from at least one of Y, La, Nd, Sm, Eu, Gd, Dy, and Ho. The metal element M contained in the compound layer 4 may be selected from at least one 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 have relatively excellent corrosion resistance against corrosive gas plasma. Except when the rare earth elements contained in the first layer 3 and the compound layer 4 are 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 cation of the metal element M contained in the compound layer 4 is smaller than the ionic radius of the cation of the rare earth element contained in the first layer 3. This reduces lattice defects in the junction region between the first layer 3 and the compound layer 4. This improves the bonding strength between the first layer 3 and the compound layer 4.

[0048] The rare earth element may be Y. Among the rare earth elements, an oxide of Y (Y ２ O ３ ) has excellent corrosion resistance, particularly against corrosive gas plasma.

[0049] The compound layer 4 may contain an oxide of Al as a main component, or a composite oxide of Y and Al as a main component. The first layer 3 may have an amorphous region 33 made of Y, Al, and O (oxygen) in a region in contact with the compound layer 4. In this case, the bonding strength between the first layer 3 and the compound layer 4 is further improved. The following reason is presumed to be the reason for this.

[0050] The compound layer 4 is mainly composed of an oxide of Al or a composite oxide of Y and Al. The first layer 3 is mainly composed of an oxide of Y (Y ２ O ３ ) as its main component. The first layer 3 has an amorphous region 33 made of Y, Al, and O in a region in contact with the compound layer 4. This particularly reduces lattice defects between the first layer 3 and the compound layer 4. As a result, the bonding strength between the first layer 3 and the compound layer 4 is further improved. The compound layer 4 is preferably amorphous and contains either an oxide of Al as its main component or a composite oxide of Y and Al as its main component. When the compound layer 4 is amorphous and contains an oxide of Al as its main component or when the compound layer 4 contains a composite oxide of Y and Al as its main component, the lattice defects between the compound layer 4 and the first layer 3 are further reduced, thereby particularly improving the bonding strength between the first layer 3 and the compound layer 4.

[0051] The fact that the compound layer 4 is mainly composed of an oxide of Al or a composite oxide of Y and Al may be measured by using an EDS attached to a TEM or by electron diffraction using a TEM. The fact that the first layer 3 has an amorphous region 33 may be measured by electron diffraction using a TEM.

[0052] The oxide of Al that is the main component of the compound layer 4 is, for example, Al ２ O ３ Examples of the composite oxide of Al and Y that is the main component of the compound layer 4 include YAlO ３ , Y ２ Al ４ O ９ , Y ３ Al ５ O １２ etc. may be mentioned.

[0053] In the amorphous region 33, the O content may be the highest in terms of atomic ratio. In addition, in the amorphous region 33, the Al content may be higher in terms of atomic ratio than the Y content. Note that the Y content may be 5 atomic % or more and 30 atomic % or less. The Al content may be 10 atomic % or more and 40 atomic % or less. The O content may be 40 atomic % or more and 80 atomic % or less.

[0054] The average thickness of the amorphous region 33 may be 1 nm or more and 15 nm or less. The average thickness of the amorphous region 33 may be measured by the same method as that for the average thickness of the first layer 3.

[0055] The average thickness of the compound layer 4 may be 1 nm or more and 300 nm or less. When the lower limit is 1 nm, lattice defects occurring in the bonding region between the first layer 3 and the compound layer 4 are reduced. This improves the bonding strength between the first layer 3 and the compound layer 4. When the upper limit is 300 nm, particles generated during exposure to corrosive gas plasma can be reduced. The average thickness of the compound layer 4 may be measured using the same method as that for measuring the average thickness of the first layer 3.

[0056] Next, a corrosion-resistant member 1C according to a non-limiting embodiment of the present disclosure will be described. As shown in an example in FIG. 3 , the corrosion-resistant member 1C includes a laminate 1a, a compound layer 4 of a metal element M, and a first layer 3 alternately stacked above the laminate 1a. The compound layer 4 has uniform crystallinity. The corrosion-resistant member 1C includes a surface layer 5 made of the first layer 3 in a region farthest from the substrate 2.

[0057] In the corrosion-resistant member 1C, the compound layers 4 and the first layers 3 formed on the laminate 1a are alternately laminated (bonded) together. In the bonding region where the compound layers 4 and the first layers 3 are laminated in this order, the compound layers 4 are bonded to the low-crystalline portions of the first layers 3 closer to the substrate 2. Lattice defects are reduced in this bonding region. This improves the bonding strength between the compound layers 4 and the first layers 3.

[0058] Furthermore, in the bonding region where the first layer 3 and the compound layer 4 are laminated in this order, a highly crystalline portion of the first layer 3 farther from the base 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. When the first layer 3 has a highly crystalline region, the mechanical strength of the first layer 3 is improved compared to when the entire first layer 3 has low crystallinity. Therefore, it is possible to improve the bonding strength between the first layer 3 and the compound layer 4 while suppressing the occurrence of cracks in the first layer 3.

[0059] The metal element M contained in at least the compound layer 4 closest to the surface layer 5 may be Al. Rare earth elements and Al have a strong chemical bonding force. When the surface layer 5 is the first layer 3, if the metal element M of the compound layer 4 closest to the surface layer 5 is Al, the bonding strength with the surface layer 5 is improved. Therefore, even when exposed to corrosive gas plasma, particles are unlikely 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 stacked multiple times, can maintain a high bonding strength. The reason for this is presumed to be as follows.

[0061] Any region 31 of the first layer 3 that is close to the substrate 2 has low 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 is bonded to the amorphous compound layer 4, the lattice defects that occur between them are reduced because both have low crystallinity. As a result, the bonding 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 effect, in the region 32 of any first layer 3 far from the base 2, i.e., in the region with high crystallinity, residual stress caused by bonding with the compound layer 4 is reduced. Therefore, even if the region 32 of any first layer 3 far from the base 2 has high crystallinity, 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, which are laminated multiple times, can maintain a high bonding strength.

[0064] The first layers 3 in the corrosion-resistant member 1C may have the same or different compositions, etc. The same applies to the compound layers 4. That is, the compound layers 4 in the corrosion-resistant member 1C may have the same or different compositions, etc.

[0065] For example, the atomic number of the metal element M contained in at least one of the 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 compound layers 4 may contain a rare earth element, and the content of the rare earth element in this compound layer 4 may be smaller than the content of the rare earth element in the first layer 3. At least one of the 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 may be set to 20 or more and 5,000 or less. The number of first layers 3 may be set to 20 or more and 5,000 or less.

[0067] Next, a non-limiting embodiment of the corrosion-resistant member 1D of the present disclosure will be described. As shown in the example of FIG. 4 , the corrosion-resistant member 1D includes a laminate 1b, a compound layer 4 of metal element M, and a first layer 3 alternately stacked above the laminate 1b. The compound layer 4 has uniform crystallinity. The corrosion-resistant member 1D includes a surface layer 5 made of the first layer 3 in a region farthest from the substrate 2. In these cases, it is possible to improve the bonding strength between the first layer 3 and the compound layer 4 while suppressing cracks from occurring in the first layer 3. The reasons for this are the same as those described for the corrosion-resistant member 1C.

[0068] The number of compound layers 4 and the number of first layers 3 alternately stacked on the laminate 1b are not limited to a specific value. For example, the number of compound layers 4 may be set to 20 or more and 5,000 or less. The number of first layers 3 may be set to 20 or more and 5,000 or less.

[0069] Next, a non-limiting embodiment of the corrosion-resistant member 1E of the present disclosure will be described. As shown in FIG. 5 , the corrosion-resistant member 1E is a laminate 1c including a substrate 2, a compound layer 4 of a metal element M laminated on the substrate 2, and a first layer 3 laminated on the compound layer 4. The first layer 3 is made of a rare earth element compound containing a rare earth element as the main component of the metal element. The atomic number of the metal element M contained in the compound layer 4 is smaller than the atomic number of the main component rare earth element contained in the first layer 3. The first layer 3 has a region 31 closer to the substrate 2 with lower crystallinity than a region 32 farther from the substrate 2. In these cases, corrosion resistance is improved, and the bonding strength between the substrate 2 and the film (first layer 3) is improved. The reasons for this are the same as those described for the corrosion-resistant members 1A and 1B. The laminate 1c may also be referred to as a third laminate 1c.

[0070] Next, a non-limiting embodiment of the corrosion-resistant member 1F of the present disclosure will be described. As shown in FIG. 6 , the corrosion-resistant member 1F includes a laminate 1c, a compound layer 4 of a metal element M, and a first layer 3, which are alternately stacked on top of 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 contained in the first layer 3 as the main component. The corrosion-resistant member 1F includes a surface layer 5 made of the first layer 3 in a region farthest from the substrate 2. In these cases, the bonding strength between the first layer 3 and the compound layer 4 can be improved while cracks can be prevented from occurring 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 above the laminate 1c is not limited to a specific value. For example, the number of compound layers 4 may be set to 20 or more and 5,000 or less. The number of first layers 3 may be set to 20 or more and 5,000 or less.

[0072] The corrosion-resistant members 1A to 1F described above can be used, for example, as members exposed to corrosive gases containing F, Cl, and Br or plasma of these gases, and as members exposed to corrosive substances such as HF. In particular, members used at high temperatures of about 300 to 700°C in these gases and substances can be used. Corrosive gases include CF ４ Gases and the like may be mentioned.

[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 substrate 2 may be prepared. A method for manufacturing the substrate 2 made of ceramics containing alumina as the main component will be described as an example.

[0075] Alumina (Al) having an average particle size of 0.4 μm to 0.6 μm ２ O ３ ) powder A and alumina powder B having an average particle size of about 1.2 μm to 1.8 μm are prepared. In addition, silicon oxide (SiO ２ ) powder, calcium carbonate (CaCO ) as a Ca source ３) powder is prepared. The silicon oxide powder is prepared as a fine powder with an average particle size of 0.5 μm or less. To obtain an alumina ceramic containing Mg, magnesium hydroxide powder is used. In the following description, powders other than alumina A powder and alumina B powder are collectively referred to as the first minor component powder.

[0076] Next, the mass ratio of the alumina A powder and the alumina B powder is set to 40:60 to 60:40, and Al is mixed with Al in 100 mass % of the components constituting the obtained ceramic. ２ O ３ The alumina powder is weighed so that the converted content is 99.4 mass % or more, and the alumina powder is obtained. In addition, for the first subcomponent powder, the Na content in the alumina powder is first determined, and the Na content in the alumina powder is calculated from the Na content in the ceramics. ２ The powder is converted into O, and the components (in this example, Si, Ca, etc.) constituting the first subcomponent powder are weighed so that the ratio of this converted value to the converted value of the oxide of the component is 1.1 or less.

[0077] Then, 100 parts by mass of the alumina blend powder and the first subcomponent powder combined are mixed and stirred in a stirring device with 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 to obtain a slurry.

[0078] The slurry is then sprayed and granulated to obtain granules, which are then molded into a predetermined shape using a powder press molding device, an isostatic press molding device, or the like, and optionally cut to obtain a molded body.

[0079] Next, the sintered body is sintered at a temperature of 1500°C to 1700°C for a holding time of 4 to 6 hours to obtain a sintered body. The surface of the sintered body on which the film is to be formed is then ground to obtain a ground surface, and the ground surface is then roughly polished using diamond abrasive grains with an average particle size of 4 μm or more and a cast iron polishing disc. Rough polishing may be performed using diamond abrasive grains with a large average particle size, followed by diamond abrasive grains with a small average particle size. The substrate 2 can then be obtained by finish polishing using diamond abrasive grains with an average particle size of 1 μm to 5 μm and a tin polishing disc. After finish polishing, polishing may be performed using colloidal silica, ceria, or alumina abrasive grains and a polishing pad made of a nonwoven fabric formed from polyester fibers impregnated with polyurethane. The average particle size of the colloidal abrasive grains is, for example, 20 μm to 50 μm.

[0080] Next, regarding the film forming method, the first layer 3 is formed by Y ２ O ３ The case of forming a layer will be described as an example.

[0081] A sputtering apparatus 101 may be used to form the film, as shown in an example in Fig. 7. The sputtering apparatus 101 includes a chamber 102, a gas supply source 103 connected to the inside of the chamber 102, an anode 104 and a cathode 105 located in the chamber 102, and a target 106 connected to the cathode 105 side.

[0082] First, the substrate 2 is placed on the anode 104 side in the chamber 102. A target 106 containing a rare earth element, in this case metallic yttrium as its main component, is placed on the cathode 105 side. In this state, the pressure inside the chamber 102 is reduced by an exhaust pump, and argon is supplied as gas G from the gas supply source 103. Here, the pressure of the argon gas supplied is set to 0.1 Pa or more and 2 Pa or less. The temperature inside the chamber 102 is set to 50°C or more and 400°C or less.

[0083] Then, an electric field is applied between the anode 104 and the cathode 105 by the power supply, generating plasma P1, and sputtering is performed to form a metal yttrium film on the surface of the substrate 2. The power supplied from the power supply may be either high-frequency power or DC power. The thickness of the film formed in one step is on the order of sub-nanometers.

[0084] Next, plasma P2 is generated to oxidize the metal yttrium film. Then, the metal yttrium film is formed by alternately depositing the film and the oxidation process so that the total average thickness of the film is 1 nm or more and 1000 nm or less. ２ O ３ 7, the symbol P denotes plasma P1 or plasma P2.

[0085] The plasma P1 has a first spectrum, which has the highest intensity, located at wavelengths of 390 nm to 430 nm, and the other spectrums (second spectrum, third spectrum, and fourth spectrum, in order of decreasing intensity) located at wavelengths of 300 nm to 700 nm.

[0086] The plasma P2 has a spectrum in which the first spectrum, which has the highest intensity, is located at a wavelength of 500 nm to 550 nm, and the other spectrums (the second spectrum, third spectrum, and fourth spectrum, in order of decreasing intensity) are located at a wavelength of 380 nm to 820 nm.

[0087] Low crystallinity Y ２ O ３ To form the layer, the temperature in the chamber 102 should be lowered. ２ O ３ To deposit a layer, the temperature within the chamber 102 may be increased.

[0088] Other films such as the compound layer 4 are ２ O ３ For example, the compound layer 4 may be formed in the same manner as the Al layer. ２ O ３When depositing a layer, a target 106 containing Al as a main component may be used. To deposit an amorphous compound layer 4, the temperature inside the chamber 102 may be lowered. To form the amorphous region 33, after the compound layer 4 is formed, when depositing the first layer 3 on the compound layer 4, the temperature inside the chamber 102 may be initially lowered and then gradually increased.

[0089] Although the embodiments of the present disclosure have been exemplified above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can be any embodiment as long as it does not deviate from the gist of the present disclosure.

[0090] For example, the corrosion-resistant member may have the following configuration: (1) The corrosion-resistant member is a laminate comprising a base and a first layer laminated on the base, the first layer being made of a rare earth element compound containing a rare earth element as a main component as a metallic element, and the first layer having lower crystallinity in a region closer to the base than in a region farther from the base. (2) The corrosion-resistant member is a laminate comprising a base, a compound layer of a metallic element M laminated on the base, and a first layer laminated on the compound layer, the first layer being made of a rare earth element compound containing a rare earth element as a main component as a metallic element, the compound layer having uniform crystallinity, and the first layer having lower crystallinity in a region closer to the base than in a region farther from the base. (3) The corrosion-resistant member of (1) or (2) above may have the laminate, and a compound layer of metal element M and the first layer alternately stacked on the laminate, the compound layer having uniform crystallinity and having a surface layer made of the first layer in a region farthest from the substrate. (4) The corrosion-resistant member of (2) or (3) above may have an atomic number of the metal element M contained in the compound layer smaller than the atomic number of the rare earth element contained as a main component in the first layer. (5) A corrosion-resistant member is a laminate comprising a substrate, a compound layer of a metal element M laminated on the substrate, and a first layer laminated on the compound layer, wherein the first layer is made 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 that is the main component contained in the first layer, and the first layer has a region closer to the substrate and a lower crystallinity than a region farther from the substrate. (6) The corrosion-resistant member of (1) or (5) above may have the laminate, and compound layers of a metal element M and the first layer laminated alternately above the laminate, wherein the atomic number of the metal element M contained in the compound layer is smaller than the atomic number of the rare earth element that is the main component contained in the first layer, and a surface layer made of the first layer in a region farthest from the substrate. (7) In the corrosion-resistant member of (3) or (6) above, the metal element M contained in at least the compound layer closest to the surface layer may be Al.(8) In the corrosion-resistant member of any one of (2) to (7) above, the compound layer may contain 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) In the corrosion-resistant member of any one of (1) to (8) above, the first layer may be exposed on the surface. (10) In the corrosion-resistant member of any one of (2) to (9) above, the compound layer may be amorphous. (11) In the corrosion-resistant member of any one of (1) to (10) above, the rare earth element compound may be an oxide. (12) In the corrosion-resistant member of any one of (2) to (11) above, the rare earth element contained in the first layer may be selected from at least one of Y, La, Nd, Sm, Eu, Gd, Dy, and Ho, and the metal element M contained in the compound layer may be selected from at least one of Mg, Al, Si, Cr, Ni, Cu, Ga, Sr, Y, Ru, Pd, Sn, Hf, Ta, and W. (13) In the corrosion-resistant member of (12) above, the rare earth element may be Y. (14) In the corrosion-resistant member of any one of (1) to (13) above, the substrate may be made of ceramics. (15) In the corrosion-resistant member of any one of (1) to (14) above, the substrate may be primarily composed of alumina, and the first layer may be primarily composed of an oxide of Y and further contain a composite oxide of Y and Al. (16) In the corrosion-resistant member of any one of (2) to (15) above, the compound layer may be mainly composed of an oxide of Al or a composite oxide of Y and Al, and the first layer may have, in a region in contact with the compound layer, an amorphous region composed of Y, Al, and O. (17) In the corrosion-resistant member of any one of (2) to (16) above, the compound layer may have an average thickness of 1 nm or more and 300 nm or less.

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

[0092] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0093] (Example 1) According to the above-mentioned manufacturing method, Al ２ O ３ On the substrate consisting of ２ O ３layers (50 layers in total) and Al as a compound layer ２ O ３ The surface layer is made of Y ２ O ３ The first layer (Y ２ O ３ The average thickness of the compound layer (Al ２ O ３ The average thickness of the layer was 11 nm.

[0094] In the enlarged TEM photograph of the obtained corrosion-resistant member, ２ O ３ The lattice pattern of the layer was confirmed (see Figure 8). ２ O ３ It was confirmed that the layer contained crystalline regions.

[0095] Y with an average thickness of 11 nm ２ O ３ The electron diffraction patterns were different between the surface side and the substrate side within the layer (see FIGS. 9 and 10). ２ O ３ It was confirmed that within the layer, the region close to the substrate (NBD2) had low crystallinity, while the region far from the substrate (NBD1) had high crystallinity.

[0096] As a result of electron beam diffraction using a TEM, the first layer had an amorphous region consisting of Y, Al, and O in a region in contact with the compound layer. The average thickness of the amorphous region was 4 nm. In the amorphous region, O was 60.28 atomic %, Al was 24.72 atomic %, and Y was 15.00 atomic %. Furthermore, as a result of electron beam diffraction using a TEM, the compound layer had uniform crystallinity.

[0097] (Example 2) According to the above-mentioned manufacturing method, a plurality of each of the following Samples No. 1 and No. 2 was obtained. Sample No. 1: Al ２ O ３ On the substrate consisting of ２ O ３ A corrosion-resistant member on which a layer (average thickness 1.1 μm) was formed.

[0098] Sample No. 2: Al ２ O ３On the substrate consisting of ２ O ３ layer (average thickness 11 nm) and Al as a compound layer ２ O ３ The surface layer is made of Y ２ O ３ A corrosion-resistant member with layers. ２ O ３ There are 50 layers in total, Al ２ O ３ The total number of layers is 49. The average overall thickness of the film is 1.1 μm.

[0099] As a result of measuring Samples No. 1 and 2 in the same manner as in Example 1, Y ２ O ３ It was confirmed that the region closer to the substrate in the layer had low crystallinity, while the region farther from the substrate had high crystallinity. The compound layer also had uniform crystallinity.

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

[0101] (Method for Evaluating Adhesion Strength) Scratch tests were performed three times for each sample using a Revetest Scratch Tester (Serial No. 27-486) ​​manufactured by CSM Instruments, Inc. A diamond indenter (N2-5168) with a tip curvature radius of 200 μm was used.

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

[0103] (Method for evaluating plasma resistance) Masking tape is applied to a portion of the surface layer to mask it. The difference in level before and after exposure to plasma is measured using an optical surface texture measuring device. The difference in level is the thickness of the film reduced by exposure to plasma. The method for measuring the difference in level is as follows: First, masking tape is applied to a portion of the film surface, and then the film is exposed to plasma. After exposure to plasma, the masking tape is peeled off. A difference in level is formed between the surface from which the masking tape has been peeled off (unexposed surface) and the surface exposed to plasma (after exposure). The dimensions of this difference in level are measured. The smaller the difference in level, the better the plasma resistance.

[0104] The plasma exposure conditions were as follows: CF ４ Gas partial pressure (Pa): 9 Pa CF ４ Gas flow rate (L / min): 100 sccm CF ４ Gas exposure time: 4 hours Output: 900 W Masking tape material: Kapton tape A reactive ion etching (RIE) device was used for the plasma exposure.

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

[0106] Samples Nos. 1 and 2 of the present disclosure were excellent in adhesion strength and plasma resistance. From these results, it can be said that Samples Nos. 1 and 2 have improved corrosion resistance and improved bonding strength between the substrate and the film.

[0107] As a comparative example, yttrium oxide (Y ２ O ３ The plasma resistance of the yttrium oxide sintered body was evaluated under the same conditions as in Example 2. As a result, the step height was as large as 0.11 μm, and the corrosion resistance was poor in the case of the yttrium oxide sintered body.

[0108] DESCRIPTION OF SYMBOLS 1A... Corrosion-resistant member 1B... Corrosion-resistant member 1C... Corrosion-resistant member 1D... Corrosion-resistant member 1E... Corrosion-resistant member 1F... Corrosion-resistant member 1a... Laminate (first laminate) 1b... Laminate (second laminate) 1c... Laminate (third laminate) 2... Substrate 3... First layer 31... Region close to substrate 32... Region far from substrate 33... Amorphous region 3a... Center 4... Compound layer (second layer) 5... Surface layer 101... Sputtering apparatus 102... Chamber 103... Gas supply source 104... Anode 105... Cathode 106... Target

Claims

1. A substrate; A laminate comprising a first layer laminated on the substrate, the first layer is made of a rare earth element compound containing a rare earth element as a main component as a metallic element, The first layer has a region closer to the substrate that has lower crystallinity than a region farther from the substrate.

2. A substrate; a compound layer of a metal element M laminated on the substrate; a first layer laminated on the compound layer, the first layer is made of a rare earth element compound containing a rare earth element as a main component as a metallic element, The compound layer has uniform crystallinity, The first layer has a region closer to the substrate that has lower crystallinity than a region farther from the substrate.

3. The laminate; a compound layer of a metal element M and the first layer alternately stacked on the upper side of the stack; The compound layer has uniform crystallinity, 3. The corrosion-resistant member according to claim 1, further comprising a surface layer made of said first layer in a region farthest from said base body.

4. 3. The corrosion-resistant member according to claim 2, wherein the atomic number of the metal element M contained in the compound layer is smaller than the atomic number of the rare earth element contained in the first layer as a main component.

5. A substrate; a compound layer of a metal element M laminated on the substrate; a first layer laminated on the compound layer, the first layer is made of a rare earth element compound containing a rare earth element as a main component as a metallic element, the atomic number of the metal element M contained in the compound layer is smaller than the atomic number of the rare earth element contained in the first layer as a main component, The first layer has a region closer to the substrate that has lower crystallinity than a region farther from the substrate.

6. The laminate; a compound layer of a metal element M and the first layer alternately stacked on the upper side of the stack; the atomic number of the metal element M contained in the compound layer is smaller than the atomic number of the rare earth element contained in the first layer as a main component, 6. The corrosion-resistant member according to claim 1, further comprising a surface layer made of said first layer in a region farthest from said base body.

7. 4. The corrosion-resistant member according to claim 3, wherein the metal element M contained in at least the compound layer closest to the surface layer is Al.

8. the compound layer contains a rare earth element, 6. The corrosion resistant member according to claim 2 or 5, wherein the compound layer has a rare earth element content lower than a rare earth element content of the first layer.

9. 6. The corrosion resistant component according to claim 2 or 5, wherein the first layer is exposed at a surface.

10. The corrosion-resistant member according to claim 2 or 5, wherein the compound layer is amorphous.

11. 6. The corrosion resistant member according to claim 1, 2 or 5, wherein the rare earth compound is an oxide.

12. The rare earth element contained in the first layer is selected from at least one of Y, La, Nd, Sm, Eu, Gd, Dy, and Ho; 6. The corrosion-resistant member according to claim 2, wherein 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 member according to claim 12 , wherein the rare earth element is Y.

14. 6. The corrosion-resistant member according to claim 1, 2 or 5, wherein said substrate is made of a ceramic material.

15. The substrate is mainly composed of alumina, The corrosion-resistant member according to claim 1 , wherein the first layer contains an oxide of Y as a main component and further contains a composite oxide of Y and Al.

16. the compound layer is mainly composed of an oxide of Al or a composite oxide of Y and Al, 6. The corrosion-resistant member according to claim 2, wherein the first layer has an amorphous region made of Y, Al, and O in a region in contact with the compound layer.

17. The corrosion-resistant member according to claim 2 or 5, wherein the compound layer has an average thickness of 1 nm or more and 300 nm or less.