Corrosion-resistant member

Abstract

The corrosion-resistant member according to the present disclosure comprises: a base having a first surface; a first layer which is disposed on at least the first surface of the base and contains mainly a first element and a second element; and a second layer which is disposed on the upper surface of the first layer and contains mainly the first element and the second element, and in which the atomic ratio (second element / first element) of the second element to the first element is different from the atomic ratio in the first layer. The first element is at least one element selected from rare earth elements. The second element is at least one element selected from the group consisting of oxygen, nitrogen, carbon, fluorine, and boron.

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 includes a substrate having a first surface, a first layer located on at least the first surface of the substrate and containing primarily a first element and a second element, and a second layer located on an upper surface of the first layer and containing primarily the first element and the second element, the atomic ratio of the first element to the second element (second element / first element) being different from the atomic ratio in the first layer. The first element is at least one element selected from the rare earth elements. The second element is at least one element selected from the group consisting of oxygen, nitrogen, carbon, fluorine, and boron.

[0005] Fig. 1 is an explanatory view for explaining a corrosion-resistant member according to an embodiment of the present disclosure. Fig. 2 is an explanatory view for explaining a corrosion-resistant member according to another embodiment of the present disclosure. Fig. 3 is an explanatory view for explaining a corrosion-resistant member according to yet another embodiment of the present disclosure. Fig. 4 is an explanatory view for explaining a corrosion-resistant member according to yet another embodiment of the present disclosure. Fig. 5 is an enlarged explanatory view for explaining an example of an interface between a substrate and a first layer. Fig. 6 is a schematic view showing a sputtering apparatus for manufacturing a corrosion-resistant member according to an embodiment of the present disclosure.

[0006] As described above, conventional parts such as those described in Patent Document 1 have poor corrosion resistance because they only have a film formed on a substrate that is composed of Y, Al, and O. Therefore, there is a demand for a corrosion-resistant member that can reduce the amount of particles generated and has excellent corrosion resistance.

[0007] The corrosion-resistant member according to the present disclosure has a configuration as described in the section on means for solving the above problems, thereby reducing the amount of particles generated and providing excellent corrosion resistance.

[0008] A corrosion-resistant member according to an embodiment of the present disclosure will be described with reference to FIG. 1 . FIG. 1 is an explanatory diagram illustrating a corrosion-resistant member 10 according to an embodiment of the present disclosure. The corrosion-resistant member 10 according to an embodiment of the present disclosure includes a substrate 1, a first layer 2, and a second layer 3. For ease of explanation, FIG. 1 shows only the essential components in a simplified manner. Therefore, the corrosion-resistant member 10 shown in FIG. 1 may include optional components not shown. Furthermore, the sizes of the components shown in the drawings are merely examples and do not faithfully represent the actual dimensions of the components and the dimensional ratios of each component. The same applies to FIGS. 2 to 5 .

[0009] 1, the substrate 1 has a first surface 11. The material of the substrate 1 is not limited, and examples thereof include ceramic, single crystal, quartz, glass, metal compound, metal, and silicon. The substrate 1 may contain one of these materials alone or two or more of them.

[0010] When the material of the substrate 1 is ceramic, examples of the ceramic include ceramics containing alumina as a main component, ceramics containing silicon nitride as a main component, ceramics containing silicon carbide as a main component, and ceramics containing zirconia as a main component. In this specification, the term "main component" refers to the component that is contained in the largest amount (mass %) among the components contained. The "main component" may be, for example, a component that is contained in an amount of 80 mass % or more.

[0011] When a ceramic containing alumina as a main component is used, at least one of silicon, magnesium, and calcium may be contained as an oxide. Each component constituting the substrate 1 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.

[0012] When the material of the substrate 1 is a single crystal, examples of the single crystal include sapphire, silicon, and YAG (Y ３ Al ５ O １２ When the material of the substrate 1 is a metal compound, examples of the metal compound include aluminum oxide (Al ２ O ３ ), zirconium oxide (ZrO ２ ), silicon nitride (Si ３ N ４ When the material of the substrate 1 is a metal, examples of the metal include aluminum and stainless steel.

[0013] The first layer 2 is located on the first surface 11 of the substrate 1. The first layer 2 mainly contains a first element and a second element. In this specification, "mainly containing" is synonymous with the above-mentioned "main component" and means that the total content (number of atoms) of the first element and the second element is the highest. For example, the total content (number of atoms) of the first element and the second element may be 80 atomic % or more. The first element is at least one element selected from rare earth elements. Examples of rare earth elements include Y, La, Nd, Sm, Eu, Gd, Dy, and Ho. The second element is at least one element selected from the group consisting of oxygen, nitrogen, carbon, fluorine, and boron.

[0014] The first element may be yttrium (Y). When the first element is yttrium, the corrosion-resistant member 10 exhibits excellent corrosion resistance even when exposed to a corrosive atmosphere. Specifically, the first layer 2 and the second layer 3 described below are less likely to be worn away.

[0015] The thickness of the first layer 2 is not limited. The first layer 2 may have a thickness of, for example, 1 nm or more and 100 nm or less. When the first layer 2 has a thickness of 1 nm or more and 100 nm or less, the strength of the layer can be further increased. Therefore, the size of particles can be made relatively small, and the amount of particles generated can be reduced. Small particles are less likely to adversely affect the surrounding area when the corrosion-resistant member 10 is in use. Furthermore, high layer strength reduces the amount of layer wear, resulting in improved corrosion resistance. The thickness of the first layer 2 is measured using, for example, a transmission electron microscope (TEM) or a scanning electron microscope (SEM).

[0016] For example, if the corrosion-resistant member 10 is used in an apparatus for manufacturing semiconductor wafers with wiring widths of 50 nm, the particle size must be equal to or less than twice the wiring width to prevent adverse effects on the wiring. In such a case, if the thickness of the first layer 2 is equal to or less than 100 nm, the particle size can also be equal to or less than 100 nm.

[0017] The second layer 3 is located on the upper surface of the first layer 2. The second layer 3 mainly contains a first element and a second element. Although the first layer 2 and the second layer 3 mainly contain the first element and the second element, the atomic ratio of the first element to the second element (second element / first element) is different between the first layer 2 and the second layer 3. The ratios of the first element and the second element contained in the first layer 2 and the second layer 3 are measured, for example, using an energy dispersive X-ray analyzer (EDS) attached to a TEM.

[0018] The difference between the atomic ratio in the first layer 2 and the atomic ratio in the second layer 3 is not limited. The absolute value of the difference between the atomic ratio in the first layer 2 and the atomic ratio in the second layer 3 may be, for example, 0.02 or more and 1.7 or less, or may be 0.2 or more and 1.25 or less. When this absolute value is 0.02 or more and 1.7 or less, the corrosion-resistant member 10 can reduce particles from being detached together from the first layer 2 and the second layer 3. As a result, the particles become smaller.

[0019] The thickness of the second layer 3 is not limited. The second layer 3 may have a thickness of, for example, 1 nm or more and 100 nm or less. When the second layer 3 has a thickness of 1 nm or more and 100 nm or less, the strength of the layer can be further increased and the size of particles can be relatively small. The thickness of the second layer 3 is measured using, for example, a TEM or a SEM.

[0020] For example, if the corrosion-resistant member 10 is used in an apparatus for manufacturing semiconductor wafers with wiring widths of 50 nm, the particle size must be equal to or less than twice the wiring width to prevent adverse effects on the wiring. In such a case, if the thickness of the second layer 3 is equal to or less than 100 nm, the particle size can also be equal to or less than 100 nm.

[0021] Generally, Y ２ O ３ is a highly corrosion-resistant material, and polycrystalline Y is deposited on the substrate. ２ O ３ Corrosion-resistant members having a layer are known in the art. ２ O ３ In order to further improve the corrosion resistance of the corrosion-resistant member having the layer, ２ O ３ If you try to make the layer thicker, Y ２ O ３ In this case, the crystal grains grow, increasing the average crystal grain size and decreasing the density. As a result, particles tend to become larger. In contrast, the corrosion-resistant member according to one embodiment of the present disclosure has a structure in which relatively thin first layers 2 and relatively thin second layers 3 are alternately laminated. Therefore, the total thickness of the first layers 2 and the second layers 3 is increased while maintaining a small average crystal grain size and a high density in the first layers 2 and the second layers 3.

[0022] In the corrosion-resistant member 10 according to one embodiment, both the first layer 2 and the second layer 3 contain a first element (a rare earth element). Therefore, the corrosion-resistant member 10 has excellent corrosion resistance. Furthermore, the first layer 2 and the second layer 3 have different atomic ratios of the first element to the second element (second element / first element). Therefore, integration between the first layer 2 and the second layer 3 is less likely to progress. Even if particles from the surface layer are detached, they are less likely to be detached together with particles from the underlying layer. In other words, the particles from the underlying layer are maintained without detachment, and the size of the detached particles is reduced.

[0023] At least one of the first layer 2 and the second layer 3 may be amorphous. When at least one of the first layer 2 and the second layer 3 is amorphous, the particles become smaller. Whether the first layer 2 and the second layer 3 are amorphous or not can be confirmed, for example, by an electron beam diffraction image obtained by TEM.

[0024] The first element contained in the first layer 2 and the first element contained in the second layer 3 may be the same element or different elements. Furthermore, the second element contained in the first layer 2 and the second element contained in the second layer 3 may be the same element or different elements. In terms of facilitating the formation of the first layer 2 and the second layer 3 and preventing cracks and the like, the first element contained in the first layer 2 and the second element contained in the second layer 3 may be the same, and the second element contained in the first layer 2 and the second element contained in the second layer 3 may be the same.

[0025] The first layer 2 and the second layer 3 may be crystalline. When the first layer 2 and the second layer 3 are crystalline, the second element contained in the first layer 2 and the second layer 3 may include oxygen, and the content of oxygen vacancies contained in the first layer 2 may be different from the content of oxygen vacancies contained in the second layer 3. With such a configuration, the corrosion-resistant member 10 can reduce the possibility of particles detaching together from the first layer 2 and the second layer 3. As a result, particles become smaller. When at least one of the first layer 2 and the second layer 3 is crystalline, the average crystal grain size may be 0.1 nm or more and 100 nm or less, or may be 30 nm or less, from the viewpoint of reducing particle size. The crystal grain size can be measured by crystal grain size measurement using a TEM.

[0026] Oxygen defects refer to a state in which some oxygen ions that should constitute the crystalline lattice are missing in a crystal containing oxygen ions, resulting in lattice defects, and these lattice defects exist as oxygen defects. Oxygen defects form oxygen vacancies. For example, in the case of yttrium oxide (Y ２ O ３ ) in the case of oxygen vacancy yttrium oxide Y ２ O ３－ｘ (0<x<3). The difference in the content of oxygen vacancies is expressed by the following formula: In the case of yttrium oxide, Y ２ O ３－ｘ (0<x<3) means that the value of x is different. ２ O ３－ｘ The value of x (0<x<3) and the amount of Y contained in the second layer 3 ２ O ３－ｘ This means that the value of x is different from the value of x in the formula (0<x<3). The content of oxygen defects can be measured, for example, using an EDS attached to a TEM. The fact that the first layer 2 and the second layer 3 are crystalline can be confirmed using X-ray diffraction and electron beam diffraction.

[0027] Next, a corrosion-resistant member according to another embodiment of the present disclosure will be described with reference to Fig. 2. Fig. 2 is an explanatory diagram for describing a corrosion-resistant member 20 according to another embodiment of the present disclosure. Like the corrosion-resistant member 10, the corrosion-resistant member 20 shown in Fig. 2 also includes a base 1, a first layer 2, and a second layer 3. In the corrosion-resistant member 20, the same components as those in the corrosion-resistant member 10 are designated by the same reference numerals, and detailed description thereof will be omitted as has been described above.

[0028] As described above, the corrosion-resistant member 10 has a structure in which the first layer 2 is laminated on the first surface 11 of the base 1, and the second layer 3 is laminated on the upper surface of the first layer 2, i.e., a structure in which one first layer 2 and one second layer 3 are laminated. On the other hand, the corrosion-resistant member 20 has a structure in which the first layer 2 and the second layer 3 are further laminated alternately on the upper surface of the second layer 3 of the corrosion-resistant member 10. In other words, at least two first layers 2 and at least two second layers 3 may be alternately laminated on the first surface 11 of the base 1. This structure reduces particle size. The laminated structure can be confirmed using, for example, a TEM or SEM.

[0029] Next, a corrosion-resistant member according to yet another embodiment of the present disclosure will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram for describing a corrosion-resistant member 30 according to yet another embodiment of the present disclosure. Like the corrosion-resistant member 10, the corrosion-resistant member 30 shown in Fig. 3 also includes a base 1, a first layer 2, and a second layer 3. In the corrosion-resistant member 30, the same components as those in the corrosion-resistant member 10 are designated by the same reference numerals, and detailed description thereof will be omitted as has been described above.

[0030] As described above, the corrosion-resistant member 10 has a structure in which the first layer 2 is laminated on the first surface 11 of the substrate 1, and the second layer 3 is laminated on the upper surface of the first layer 2. On the other hand, the corrosion-resistant member 30 further includes a third layer 4 between the first layer 2 and the second layer 3, the third layer 4 containing the first element, the second element, and an aluminum element. The third layer 4 has a structure in which the first element, the second element, and the aluminum element are firmly bonded. Therefore, when the third layer 4 is included between the first layer 2 and the second layer 3, it is possible to reduce the possibility of particles detaching together from the first layer 2 and the second layer 3. As a result, the particles become smaller.

[0031] Next, a corrosion-resistant member according to yet another embodiment of the present disclosure will be described with reference to Fig. 4. Fig. 4 is an explanatory diagram for describing a corrosion-resistant member 40 according to yet another embodiment of the present disclosure. Like the corrosion-resistant member 10, the corrosion-resistant member 40 shown in Fig. 4 also includes a base 1, a first layer 2, and a second layer 3. In the corrosion-resistant member 40, the same components as those in the corrosion-resistant member 10 are designated by the same reference numerals, and detailed description thereof will be omitted as has been described above.

[0032] As described above, the corrosion-resistant member 10 has a structure in which the first layer 2 is laminated on the first surface 11 of the base 1, and the second layer 3 is laminated on the upper surface of the first layer 2. On the other hand, in the corrosion-resistant member 40, the base 1 contains aluminum elements. As described above, examples of materials containing aluminum elements include ceramics containing alumina as a main component, sapphire, YAG, and aluminum.

[0033] The corrosion-resistant member 40 further includes a fourth layer 5 containing the first element, the second element, and aluminum between the base 1 containing aluminum and the first layer 2. The inclusion of such a fourth layer 5 further improves the adhesive strength between the base 1 and the first layer 2. This reduces the likelihood of particles detaching together from the first layer 2 and the second layer 3. As a result, the particles become smaller.

[0034] The second layer 3 is located at the outermost layer, and the atomic ratio in the second layer 3 may be greater than the atomic ratio in the first layer 2. With such a structure, crystallization is promoted in the second layer 3 located at the outermost layer more than in the first layer 2. As a result, excellent corrosion resistance is exhibited.

[0035] The second layer 3 is located at the outermost layer, and the atomic ratio in the second layer 3 may be smaller than the atomic ratio in the first layer 2. With such a structure, the second layer 3 located at the outermost layer is more likely to become amorphous than the first layer 2. As a result, the particles become smaller.

[0036] The first surface 11 of the substrate 1 may have a recess 12 as shown in Fig. 5. Fig. 5 is an enlarged explanatory view illustrating an example of the boundary surface between the substrate 1 and the first layer 2. If the first surface 11 has the recess 12, for example, when forming the first layer 2, the recess 12 may not be completely filled with the first layer 2. As a result, a void 13 is formed inside the first layer 2 facing at least a part of the recess 12.

[0037] By having such voids 13 located inside the first layer 2, even if a crack occurs in the base 1, it is possible to reduce the progression of the crack to the first layer 2 and the second layer 3. As shown in Figure 4, when the fourth layer 5 is located between the base 1 and the first layer 2, the voids 13 are formed inside the fourth layer 5.

[0038] The corrosion-resistant member of the present disclosure is used for members exposed to, for example, corrosive gases containing F, Cl, or Br or plasma of such gases, members exposed to corrosive substances such as HF, and members exposed to high-temperature environments of 300° C. or higher and 700° C. or lower. Examples of corrosive substances include CF ４ Gas, etc.

[0039] The method for manufacturing the corrosion-resistant member of the present disclosure is not limited. Hereinafter, a method for manufacturing the corrosion-resistant member 10 according to one embodiment will be described with reference to Fig. 6. Fig. 6 is a schematic diagram showing a sputtering apparatus 101 for manufacturing the corrosion-resistant member 10 according to one embodiment of the present disclosure.

[0040] First, prepare the substrate 1. A method for manufacturing the substrate 1 containing ceramics containing alumina as the main component will be described as an example.

[0041] Alumina (Al) having an average particle size of 0.4 μm or more and 0.6 μm or less ２ O ３ A powder A and an alumina powder B having an average particle size of 1.2 μm or more and 1.8 μm or less are prepared. Silicon oxide (SiO ２ ) powder, calcium carbonate (CaCO ) having an average particle size of 1 μm or less as a Ca source; ３) powder is prepared. Magnesium hydroxide powder may be used to obtain an alumina ceramic containing Mg. Hereinafter, powders other than the alumina A powder and the alumina B powder will be collectively referred to as the first minor component powder.

[0042] Next, a predetermined amount of each of the first subcomponent powders is weighed. The mass ratio of the alumina A powder to the alumina B powder is set to 40:60 to 60:40. Of the 100 mass % of the components constituting the resulting ceramic, Al is ２ O ３ The alumina powder is weighed so that the converted content is 99.4 mass % or more, and an alumina blend powder is obtained. For the first subcomponent powder, the Na content in the alumina blend powder is first determined. The Na content in the alumina blend powder is calculated from the Na content in the case of the ceramic. ２ The components constituting the first subcomponent powder (in this example, Si, Ca, etc.) are weighed so that the ratio of this converted value to the converted value of the oxide thereof is 1.1 or less.

[0043] Next, 100 parts by weight of the alumina blend powder and the first subcomponent powder combined were mixed with 1 to 1.5 parts by weight of a binder such as PVA (polyvinyl alcohol), 100 parts by weight of a solvent, and 0.1 to 0.55 parts by weight of a dispersant in a stirring device. The resulting mixture was then mixed and stirred to obtain a slurry. The resulting slurry was spray-granulated to obtain granules, which were then molded into a desired shape using a powder press molding device or an isostatic press molding device, and optionally machined to obtain a compact.

[0044] 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 (the surface corresponding to the first surface 11) is then ground to obtain a ground surface, which 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. Subsequently, the substrate 1 is 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.

[0045] Next, a first layer 2 and a second layer 3 are formed on one surface (first surface 11) of the obtained substrate 1. The first layer 2 and the second layer 3 will be described using an example in which the first element is Y and the second element is O.

[0046] 6 may be used to form the first layer 2 and the second layer 3. 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 within the chamber 102, and a target 106 connected to the cathode 105 side.

[0047] First, the substrate 1 is placed on the anode 104 side in the chamber 102, and the target 106, which is mainly composed of metallic yttrium, 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.

[0048] Next, an electric field is applied between the anode 104 and the cathode 105 by the power supply, generating plasma P (plasma P1), and sputtering is performed to form a metal yttrium film on the surface of the substrate 1. 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 sub-nanometer.

[0049] Next, a plasma P (plasma P2) of oxygen gas is generated to oxidize the metal yttrium film. The deposition of the metal yttrium film and the oxidation process are alternately repeated until the desired thickness (for example, 1 nm or more and 100 nm or less) is achieved. ２ O ３ A first layer 2 including the plasma P1 or P2 is formed. The symbol P shown in FIG.

[0050] The plasma P1 has a first spectrum with the highest intensity located in the wavelength range of 390 nm to 430 nm, and the other spectra (second, third, and fourth spectra in descending order of intensity) located in the wavelength range of 300 nm to 700 nm.

[0051] The plasma P2 has a first spectrum with the highest intensity located in the wavelength range of 500 nm to 550 nm, and the other spectra (second, third, and fourth spectra in descending order of intensity) located in the wavelength range of 380 nm to 820 nm.

[0052] After the first layer 2 is formed, the second layer 3 is formed on the upper surface of the first layer 2 to a desired thickness (e.g., 1 nm or more and 100 nm or less) using the same procedure as the method for forming the first layer 2, except that, for example, the power applied to the target 106 containing metallic yttrium as the main component, the flow rate of the oxygen gas, or the voltage applied when converting the oxygen gas into plasma is changed.

[0053] For example, the amount of oxygen radicals in the plasma P2 can be increased by increasing the flow rate of oxygen gas. As a result, the atomic ratio in the second layer 3 becomes larger than the atomic ratio in the first layer 2. On the other hand, the amount of oxygen radicals in the plasma P2 can be decreased by decreasing the flow rate of oxygen gas. As a result, the atomic ratio in the second layer 3 becomes smaller than the atomic ratio in the first layer 2.

[0054] Amorphous Y ２ O ３ To form the layer, at least one of the following methods may be used: a method of lowering the temperature inside the chamber 102; and a method of reducing the flow rate of oxygen gas. ２ O ３ To form the layer, at least one of the following methods may be used: increasing the temperature inside the chamber 102; or increasing the flow rate of oxygen gas.

[0055] The third layer 4 and the fourth layer 5 containing the first element, the second element, and the aluminum element are also formed in accordance with the first layer 2 and the second layer 3. Specifically, when forming the third layer 4 and the fourth layer 5, a target 106 containing aluminum as a main component may be used in addition to a target 106 containing a rare earth metal such as metallic yttrium as a main component. For example, when forming the fourth layer 5 on the first surface 11 of the substrate 1, the plasma P2 may be generated by applying a voltage of about 9 kW.

[0056] When the second element is N, nitrogen gas may be used instead of oxygen gas to generate plasma P of nitrogen gas (plasma P2). When the second element is C, carbon monoxide gas may be used instead of oxygen gas to generate plasma P of carbon monoxide gas (plasma P2). When the second element is F, fluorine gas may be used instead of oxygen gas to generate plasma P of fluorine gas (plasma P2). When the second element is B, boron may be used instead of oxygen gas to generate plasma P of boron (plasma P2).

[0057] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0058] Example 1 In accordance with the above-described manufacturing method, a Y-type ceramic was applied to the first surface of a substrate containing a ceramic mainly composed of alumina under the conditions shown in Table 1. ２ O ３ A corrosion-resistant member was obtained by alternately laminating a Y layer (first layer) and a Y O layer (second layer). ２ O ３ Layers are stacked, and Y ２ O ３ A YO(1) layer is laminated on the top surface of the layer, and a Y ２ O ３ Layers are stacked, and Y ２ O ３ A YO(2) layer is laminated on the top surface of the layer, and a Y ２ O ３ Layers are stacked, and Y ２ O ３ A YO(3) layer is laminated on the top surface of the layer, and a Y ２ O ３ Layers are stacked, and Y ２ O ３ A YO(4) layer was laminated on the top surface of the layer to obtain a corrosion-resistant member. ２ O ３ The Y layer had a thickness of about 10 nm, and the Y O layer had a thickness of about 1 μm. Y O indicates that the yttrium oxide film was formed under conditions different from the standard conditions (yttrium oxide film containing oxygen defects), and the atomic ratio of Y to O is not necessarily 1:1.

[0059] Example 1 is Y ２ O ３ This is to evaluate the YO layer located between the layers. That is, on one substrate, multiple Y layers are placed via YO(1) layer to YO(4) layer with different conditions. ２ O ３ A layer is formed, and each YO layer and Y ２ O ３ When used as a corrosion-resistant member for semiconductor manufacturing equipment, etc., it is necessary to separate the YO layer through various YO layers as in Example 1. ２ O ３ A laminate of layers may be used, such as a layer of YO and a layer of Y ２ O ３Alternatively, layers may be laminated alternately.

[0060]

[0061] When the cross section of the corrosion-resistant member obtained in Example 1 was examined by SEM, ２ O ３ The Y layer (first layer) and the Y O layer (second layer) were clearly separated, as shown in Table 1 as "Fair." ２ O ３ It was found that the amount of wear of both the YO layer and the YO layer was small. As a result, it was found that the corrosion-resistant member obtained in Example 1 had excellent corrosion resistance.

[0062] That is, Y ２ O ３ When the Y layer and the YO layer are clearly separated, ２ O ３ The layer is made of a dense, highly corrosion-resistant polycrystalline Y alloy with an average crystal grain size of 10 nm or less. ２ O ３ Therefore, the Y layer can be clearly separated in this way. ２ O ３ By further alternately stacking the Y layer and the YO layer, ２ O ３ The average crystal grain size of the layer is kept small and the density is kept high. ２ O ３ The total thickness of the Y layer and the YO layer can be increased. As a result, the particles become smaller. ２ O ３ When the Y layer and the YO layer are not clearly separated, ２ O ３ The Y layer and the YO layer are integrated to form a single layer. ２ O ３ Therefore, if you try to increase the total thickness, the Y ２ O ３ The thickness of the layer increases, the average crystal grain size increases, and the density decreases. As a result, the particles become larger than those with clearly separated layers.

[0063] In Example 1, Y２ O ３ is a crystalline material, YO(1) is a crystalline material having the crystal structure of Y, and YO(2) is a crystalline material having the crystal structure of Y. ２ O ３ YO(3) and YO(4) were amorphous. The crystallinity was determined by checking the clear peaks in X-ray diffraction, the spot pattern in TEM electron diffraction, and the lattice fringes in TEM cross-sectional images. This confirmed that the YO layer was either crystalline or amorphous, and Y ２ O ３ It can be said that the Y layer and the Y O layer are clearly separated. ２ O ３ has higher corrosion resistance than Y. Therefore, the order of the YO layer is YO(2)>YO(3)>YO(4)>YO(1), with Y being the most ２ O ３ The closer the composition is to this, the higher the corrosion resistance is.

[0064] In this specification, the term "upper surface" is used merely for convenience of explanation. In actual use of the corrosion-resistant member according to the present disclosure, the upper and lower surfaces may be reversed. Therefore, even if a structure such as that of the above-described embodiment is located on the lower surface, the lower surface can be considered the upper surface if the upper and lower surfaces are reversed. Furthermore, the above-described embodiment describes a case in which the first layer 2, the second layer 3, etc. are laminated only on the first surface 11 of the base 1. However, the corrosion-resistant member according to the present disclosure also includes an embodiment in which the first layer 2, the second layer 3, etc. are laminated on the surface opposite the first surface of the base.

[0065] The embodiments of the present disclosure have been described above. However, the invention according to the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the present disclosure as shown in (1) to (15) below.

[0066] (1) A corrosion-resistant member according to the present disclosure includes a substrate having a first surface, a first layer located on at least the first surface of the substrate and containing primarily a first element and a second element, and a second layer located on an upper surface of the first layer and containing primarily the first element and the second element, the atomic ratio of the first element to the second element (second element / first element) being different from the atomic ratio in the first layer. The first element is at least one element selected from rare earth elements. The second element is at least one element selected from the group consisting of oxygen, nitrogen, carbon, fluorine, and boron. (2) In the corrosion-resistant member described in (1) above, the first element contained in the first layer and the first element contained in the second layer are the same element, and the second element contained in the first layer and the second element contained in the second layer are the same element. (3) The corrosion-resistant member according to (1) or (2) above, wherein the first surface has a structure in which at least two first layers and at least two second layers are alternately laminated. (4) The corrosion-resistant member according to any one of (1) to (3) above, wherein the second layer is located at the outermost layer, and the atomic ratio in the second layer is greater than the atomic ratio in the first layer. (5) The corrosion-resistant member according to any one of (1) to (3) above, wherein the second layer is located at the outermost layer, and the atomic ratio in the second layer is smaller than the atomic ratio in the first layer. (6) The corrosion-resistant member according to any one of (1) to (5) above, wherein at least one of the first layer and the second layer is amorphous. (7) The corrosion-resistant member according to any one of (1) to (6) above, wherein the first element is yttrium. (8) The corrosion-resistant member according to any one of (1) to (7) above, wherein the absolute value of the difference between the atomic ratio in the first layer and the atomic ratio in the second layer is 0.02 or more and 1.7 or less. (9) The corrosion-resistant member according to any one of (1) to (8) above, further comprising a third layer between the first layer and the second layer, the third layer containing the first element, the second element, and aluminum. (10) The corrosion-resistant member according to any one of (1) to (9) above, wherein the first layer and the second layer each have a thickness of 1 nm or more and 100 nm or less.(11) The corrosion-resistant member according to any one of (1) to (10) above, wherein the first layer and the second layer are crystalline, the second element contained in the first layer and the second layer includes oxygen, and the content of oxygen vacancies contained in the first layer is different from the content of oxygen vacancies contained in the second layer. (12) The corrosion-resistant member according to any one of (1) to (11) above, wherein the substrate includes at least one material selected from the group consisting of ceramic, single crystal, quartz, glass, metal compound, metal, and silicon. (13) The corrosion-resistant member according to any one of (1) to (12) above, wherein the first surface has recesses, and voids are located within the first layer facing at least some of the recesses. (14) The corrosion-resistant member according to any one of (1) to (12) above, wherein the substrate is formed of an aluminum-containing substrate, and further includes a fourth layer between the substrate and the first layer, the fourth layer containing the first element, the second element, and aluminum. (15) In the corrosion-resistant member described in (14) above, the first surface has a recess, and a void is located inside the fourth layer facing at least a part of the recess.

[0067] REFERENCE SIGNS LIST 1 substrate 11 first surface 12 recess 13 gap 2 first layer 3 second layer 4 third layer 5 fourth layer 10, 20, 30, 40 corrosion-resistant member 101 sputtering apparatus 102 chamber 103 gas supply source 104 anode 105 cathode 106 target

Claims

1. A corrosion-resistant member comprising: a substrate having a first surface; a first layer located at least on the first surface of the substrate and mainly containing a first element and a second element; and a second layer located on the upper surface of the first layer, mainly containing the first element and the second element, and having an atomic number ratio (second element / first element) of the first element to the second element different from that in the first layer, wherein the first element is at least one element selected from rare earth elements, and the second element is at least one element selected from the group consisting of oxygen, nitrogen, carbon, fluorine, and boron.

2. The corrosion-resistant member according to claim 1, wherein the first element contained in the first layer and the first element contained in the second layer are the same element, and the second element contained in the first layer and the second element contained in the second layer are the same element.

3. The corrosion-resistant member according to claim 1 or 2, wherein at least two layers of the first layer and at least two layers of the second layer are alternately laminated on the first surface.

4. The corrosion-resistant member according to any one of claims 1 to 3, wherein the second layer is located on the outermost surface, and the atomic number ratio in the second layer is larger than the atomic number ratio in the first layer.

5. The corrosion-resistant member according to any one of claims 1 to 3, wherein the second layer is located on the outermost surface, and the atomic number ratio in the second layer is smaller than the atomic number ratio in the first layer.

6. The corrosion-resistant member according to any one of claims 1 to 5, wherein at least one of the first layer and the second layer is amorphous.

7. The corrosion-resistant member according to any one of claims 1 to 6, wherein the first element is yttrium.

8. The corrosion-resistant member according to any one of claims 1 to 7, wherein the absolute value of the difference between the atomic number ratio in the first layer and the atomic number ratio in the second layer is 0.02 or more and 1.7 or less.

9. The corrosion-resistant member according to any one of claims 1 to 8, further comprising a third layer containing the first element, the second element, and an aluminum element between the first layer and the second layer.

10. The corrosion-resistant member according to any one of claims 1 to 9, wherein the first layer and the second layer each have a thickness of 1 nm or more and 100 nm or less.

11. The corrosion-resistant member according to any one of claims 1 to 10, wherein the first layer and the second layer are crystalline, the second element contained in the first layer and the second layer contains oxygen, and the content of oxygen defects contained in the first layer is different from the content of oxygen defects contained in the second layer.

12. The corrosion-resistant member according to any one of claims 1 to 11, wherein the substrate includes at least one selected from the group consisting of ceramics, single crystals, quartz, glass, metal compounds, metals, and silicon.

13. The corrosion-resistant member according to any one of claims 1 to 12, wherein the first surface has a recess, and voids are located inside the first layer facing at least a part of the recess.

14. The corrosion-resistant member according to any one of claims 1 to 12, wherein the substrate is formed of a substrate containing an aluminum element, and further includes a fourth layer containing the first element, the second element, and an aluminum element between the substrate and the first layer.

15. The corrosion-resistant member according to claim 14, wherein the first surface has a recess, and voids are located inside the fourth layer facing at least a part of the recess.

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