Surface-treated aluminum material, method for producing same, and member for semiconductor production device

Abstract

A surface-treated aluminum material (1) comprising: a base material (2) comprising an aluminum alloy in which the content of aluminum or Cu is 0-1.8 mass%; and a protective film (3) formed on the base material (2). The protective film (3) has: an oxide layer (31) that contains an aluminum oxide and covers the base material (2); and a hydrated oxide layer (32) that contains a hydrated oxide of aluminum and covers the oxide layer (31). When the surface-treated aluminum material (1) is subjected to cathodic polarization measurement of the base material (2) using a specific measurement solution and heated at a temperature of 200 DEG C for 4 hours, the ratio (J1 / J2) of the current density (J1) of the surface-treated aluminum material (1) at a specific potential to the current density (J2) of the base material (2) is 150 * 10-5 or less.

Description

Technical Field

[0001] This invention relates to surface-treated aluminum materials and their manufacturing methods, as well as components for semiconductor manufacturing apparatus. Background Technology

[0002] Aluminum materials, including aluminum or aluminum alloys, are used for a variety of applications. Sometimes, an anodized coating is applied to the surface of these aluminum materials for purposes such as surface protection.

[0003] For example, Patent Document 1 describes a component for a substrate processing apparatus, characterized in that the component for plasma processing of a substrate includes a coating film, which is formed on the surface of the component by connecting the component to the anode of a DC power supply and performing anodizing treatment by immersing it in a solution mainly composed of organic acids, and the coating film is subjected to a semi-sealing treatment using boiling water.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2008-81815 Summary of the Invention The technical problem that the invention aims to solve However, regarding the component in Patent Document 1, since the pores of the anodized coating are not completely sealed, there is a problem of low durability against corrosive gases and plasmas.

[0005] On the other hand, in the component of Patent Document 1, a method is considered to completely seal the pores of the anodized coating in order to improve durability against corrosive gases and plasmas. However, in this case, when the temperature has risen, it may become easy for cracks to form in the anodized coating, resulting in foreign matter containing small pieces of the anodized coating. In order to suppress the formation of such foreign matter, it is desirable to further improve the heat resistance of the aluminum material with anodized coating on the surface.

[0006] The present invention was made in view of the following background, and its object is to provide a surface-treated aluminum material with excellent corrosion resistance to corrosive gases and plasmas, and which can suppress the formation of cracks even when the temperature rises, as well as a method for manufacturing the same, and a component for a semiconductor manufacturing apparatus.

[0007] Technical solutions for solving technical problems The first aspect of the present invention is a surface-treated aluminum material comprising: a base material comprising an aluminum alloy having an aluminum or Cu (copper) content of 0% by mass or more and 1.8% by mass or less; and a protective coating formed on the base material. The protective coating comprises: an oxide layer containing aluminum oxide and covering the base material; and A hydrated oxide layer comprising a hydrated oxide of aluminum, and covering the oxide layer. The cathodic polarization of the substrate and the surface-treated aluminum material heated at 200°C for 4 hours was measured using a test solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution at a volume ratio of NaCl solution:acetic acid = 1000:1. The current density at the center of the potential region exhibiting the limiting diffusion current of hydrogen ions in the substrate was measured, and the ratio J1 of the current density J1 of the surface-treated aluminum material to the current density J2 of the substrate was obtained. / J2 is 150×10 -5 the following.

[0008] A second aspect of the present invention is a surface-treated aluminum material comprising: a base material containing an aluminum alloy having an aluminum or Cu content of 0% by mass or more and 1.8% by mass or less; and a protective coating formed on the base material. The protective coating comprises: an oxide layer containing aluminum oxide and covering the base material; and A hydrated oxide layer comprising a hydrated oxide of aluminum, and covering the oxide layer. A specimen made from the surface-treated aluminum material, having the protective coating on one side of the base material, and with a strain gauge mounted on the reverse side of the side with the protective coating, measures the strain of the specimen at a temperature of 200°C. e 1. Strain of the base material at 200°C e difference of 2 e 1- e 2 is 100×10 -6 the following.

[0009] A third aspect of the present invention is a component for a semiconductor manufacturing apparatus, wherein, The component for the semiconductor manufacturing apparatus includes surface-treated aluminum material in the manner described above.

[0010] The fourth aspect of the present invention is a method for manufacturing a surface-treated aluminum material, which is the method for manufacturing a surface-treated aluminum material according to the aforementioned aspect. The oxide layer with pores is formed on the base material by anodizing. Then, the base material and the oxide layer are heated at a temperature above 50°C and below 350°C. Then, the oxide layer is brought into contact with a sealing agent to form a hydrated oxide layer on the oxide layer while sealing the pores.

[0011] Invention Effects The surface-treated aluminum material (hereinafter referred to as "aluminum material") of the first embodiment has a protective coating on the surface of the base material, the protective coating comprising the oxide layer and the hydrated oxide layer. Furthermore, in the case of measuring the cathodic polarization of the surface-treated aluminum material and the base material after heating at 200°C for 4 hours using the specific method, the ratio J1 of the current density J1 of the surface-treated aluminum material to the current density J2 of the base material is... / J2 is 150×10 -5 The following describes the properties of aluminum materials. These materials exhibit excellent resistance to corrosive gases and plasmas, as well as superior heat resistance, which inhibits crack formation even at elevated temperatures.

[0012] The aluminum material of the second type has a protective coating on the surface of the base material, the protective coating comprising the oxide layer and the hydrated oxide layer. Additionally, the strain of the sample at 200°C, measured by the specific method... e 1. Strain of the base material at 200°C e difference of 2 e 1- e 2 is 100×10 -6 The following describes the properties of aluminum materials. These materials exhibit excellent resistance to corrosive gases and plasmas, as well as superior heat resistance, which inhibits crack formation even at elevated temperatures.

[0013] The components of the third-party semiconductor manufacturing apparatus are made of the aluminum material, thus exhibiting excellent corrosion resistance to corrosive gases and plasmas, and excellent heat resistance, which can suppress the formation of cracks even when the temperature rises.

[0014] Furthermore, in the fourth method for manufacturing aluminum, after anodizing the base material, the oxide layer formed by the anodizing process is heated at a temperature within the specified range. This allows for the mitigation of internal stress generated during oxide layer formation by heating the oxide layer before sealing the pores. After mitigating the internal stress, the oxide layer is brought into contact with a sealing agent, forming a hydrated oxide layer on the oxide layer while simultaneously sealing the pores. This improves resistance to corrosive gases and plasmas, enhances heat resistance, and suppresses crack formation even at elevated temperatures.

[0015] As described above, according to the aforementioned method, it is possible to provide a surface-treated aluminum material, a method for manufacturing the same, and a component for a semiconductor manufacturing apparatus that exhibits excellent corrosion resistance to corrosive gases and plasmas, as well as excellent heat resistance and can suppress crack formation even at elevated temperatures. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the surface-treated aluminum material in Example 1.

[0017] Figure 2 This is a cross-sectional view of the base material with an oxide layer formed during the manufacturing process of the surface-treated aluminum material in Example 1.

[0018] Figure 3 This is an explanatory diagram showing the cathodic polarization curve of the base material in Example 1.

[0019] Figure 4 This is an enlarged view of the stepped portion in the cathodic polarization curve of the base material.

[0020] Figure 5 This is an explanatory diagram illustrating the method for measuring the strain of the surface-treated aluminum material in Example 3.

[0021] Figure 6 This is an explanatory graph showing the measurement results of the strain of the surface-treated aluminum material in Example 3. Detailed Implementation

[0022] (Aluminum) The base material of the aluminum material is composed of an aluminum alloy with an aluminum or Cu content of 0% by mass or more and 1.8% by mass or less. The shape of the base material is not particularly limited and can be varied depending on the intended use of the aluminum material.

[0023] The material of the base material in the aluminum material can be appropriately selected from the group of aluminum alloys containing 0% by mass and 1.8% by mass of aluminum and Cu, depending on the application of the aluminum material. For example, if it is desired to reduce the exhaust gases from the aluminum material, the base material is preferably composed of 1000 series aluminum or 3000 series aluminum alloy.

[0024] As the base material constituting the aluminum material, 1000 series aluminum can be used, for example, aluminum with the chemical composition shown in alloy numbers AA1100, AA1100A, AA1200, AA1230, AA1230A, AA1235, AA1145, AA1345, AA1350, AA1199, AA1050, AA1060, AA1085, AA1060EC, or AA1070.

[0025] In addition, the 3000 series aluminum alloys that form the base material of the aluminum material can, for example, be aluminum alloys with the following chemical composition: containing Mn (manganese): 1.0% by mass and 1.5% by mass, and containing one or more elements selected from Si (silicon), Fe (iron), Cu (copper), Mg, Cr (chromium), Zn (zinc) and Ti (titanium) as arbitrary components, with the remainder containing Al and unavoidable impurities.

[0026] More specifically, as a 3000 series aluminum alloy, for example, aluminum alloys with chemical compositions indicated by alloy numbers AA3003, AA3203, AA3004, AA3104, AA3005, AA3105, or AA3021 can be used.

[0027] Furthermore, when it is desired to improve the strength of the aluminum material, the base material is preferably composed of 5000 series aluminum alloy or 6000 series aluminum alloy. As a 5000 series aluminum alloy, for example, an aluminum alloy having the following chemical composition can be used: containing Mg (magnesium): 0.5% by mass or more and 5.0% by mass or less, and containing one or more elements selected from Si, Fe, Cu, Mn, Cr, Zn and Ti as arbitrary components, with the remainder containing Al and unavoidable impurities.

[0028] More specifically, as a 5000 series aluminum alloy, for example, aluminum alloys with chemical compositions shown in alloy numbers AA5182, AA5005, AA5110A, AA5021, AA5041, AA5042, AA5050, AA5151, AA5251, AA5052, AA5252, AA5154, AA5154C, AA5254, AA5454, AA5554, AA5654, AA5754, AA5356, AA5456, AA5556, AA5657, AA5082, AA5083, AA5183, AA5086, AA5457, AA5006, AA5652, or AA5056 can be used.

[0029] In addition, the 6000 series aluminum alloys that form the base material of the aluminum material can, for example, be aluminum alloys with the following chemical composition: containing Mg: 0.3% by mass or more and 1.5% by mass or less, Si: 0.2% by mass or more and 1.2% by mass or less, and containing one or more elements selected from Fe, Cu, Mn, Cr, Zn and Ti as arbitrary components, with the remainder containing Al and unavoidable impurities.

[0030] More specifically, as 6000 series aluminum alloys, for example, aluminum alloys with chemical compositions shown in alloy numbers AA6101, AA6201, AA6003, AA6005, AA6005A, AA6005C, AA6105, AA6110, AA6111, AA6016, AA6151, AA6351, AA6951, AA6053, AA6060, AA6061, AA6162, AA6262, AA6063, AA6463, AA6066, AA6070, AA6181, AA6082, or AA6253 can be used.

[0031] In addition, as the base material for the aluminum material, 8000 series aluminum alloys, for example, aluminum alloys with chemical compositions shown in alloy numbers AA8021, AA8079, AA8017, AA8030 or AA8176 can be used.

[0032] A protective coating is formed on the base material, comprising: an oxide layer containing aluminum oxide and laminated on the base material; and a hydrated oxide layer containing hydrated aluminum oxide and laminated on the oxide layer. More specifically, the hydrated oxide layer may also be composed of hydrated aluminum oxide. Additionally, the hydrated oxide layer may also contain hydrated oxide and metal salt. The protective coating can be obtained, for example, by anodizing the base material to form a porous oxide layer on its surface, followed by a sealing process, using the hydrated oxide layer to seal the pores of the oxide layer. Such a protective coating exhibits excellent corrosion resistance to corrosive gases, plasma, etc. Therefore, by forming the protective coating on the base material, the corrosion resistance of the aluminum material can be improved.

[0033] The thickness of the protective coating is preferably 2. m The thickness of the protective coating is above 5 μm. This further improves the corrosion resistance of the aluminum. From a corrosion resistance perspective, there is no specific upper limit to the thickness of the protective coating; the thicker the protective coating, the better the corrosion resistance of the aluminum. From this perspective, a thickness of 5 μm is more preferably preferred for the protective coating. m m or more, further preferably 10 m m or more. It should be noted that the manufacturing upper limit for the thickness of the protective coating is, for example, 200. m From the viewpoint of suppressing crack formation at the protective coating, the thickness of the protective coating is preferably 100 μm. m Below m.

[0034] When the sealing degree test is performed according to the method specified in JIS H8683-2:2013, the preferred mass reduction per unit area of ​​the aluminum material is 0.3g. / dm2 The corrosion resistance of the aluminum material can be improved more reliably because the pores of the oxide layer are fully sealed by the hydrated oxide layer.

[0035] It should be noted that the specific method for the sealing porosity test is as follows. First, dissolve 35 mL of phosphoric acid and 20 g of chromic anhydride in water to prepare 1 L of test solution. Next, collect a test piece containing the protective coating from the aluminum material and measure the area of ​​the protective coating on the test piece. After removing stains from the surface of the test piece, measure the mass of the test piece. Then, immerse the test piece in the test solution maintained at a temperature of 38℃±1℃ for 15 minutes±5 seconds.

[0036] After the test piece is immersed in the test solution, it is rinsed with running water, and then further rinsed with deionized water or distilled water. After the rinsed test piece is thoroughly dried, its mass is measured.

[0037] The area A (unit: dm) of the protective coating on the test piece obtained above. 2 The mass m1 (in g) of the test piece before immersion in the test solution and the mass m2 (in g) of the test piece after immersion in the test solution can be used to calculate the mass reduction per unit area based on the following formula (1). d A (unit: g) / dm 2 ).

[0038] d A = (m1 - m2) / A (1) The surface-treated aluminum material involved in the first method has the following characteristics: After heating the surface-treated aluminum material at 200°C for 4 hours using a test solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid at a volume ratio of NaCl solution:acetic acid = 1000:1, the cathodic polarization of the surface-treated aluminum material is measured, and the current density at the center of the potential region exhibiting the limiting diffusion current of hydrogen ions in the base material is measured. The ratio J1 of the current density J1 of the surface-treated aluminum material to the current density J2 of the base material is also measured. / J2 is 150×10 -5 The following is the ratio of current density J1 to J1. / J2 aluminum materials within the specified range have the property of being difficult to crack when the temperature rises. Therefore, the ratio of the protective coating to the current density of J1 is... / J2, within the specified range, exhibits excellent corrosion resistance and heat resistance. From the viewpoint of improving the heat resistance of the aluminum material, the current density ratio J1... / J2 has no lower limit, but the current density ratio of J1 / J2 is defined as a value greater than 0.

[0039] Furthermore, the surface-treated aluminum material involved in the second method has the following characteristics: a specimen with the protective coating on one side of the base material is made from the surface-treated aluminum material, and the strain of the specimen at a temperature of 200°C is measured with a strain gauge mounted on the reverse side of the side with the protective coating. e 1. Strain of the base material at 200°C e difference of 2 e 1- e 2 is 100×10 -6 The following is the difference in the dependent variable. e 1- e 2. Aluminum materials within the specified range exhibit properties that make them less prone to cracking when temperatures rise. Therefore, aluminum materials with the protective coating and a strain difference within the specified range exhibit excellent corrosion resistance and heat resistance. It should be noted that the strain difference of the specimens made from the aluminum material... e 1- e The lower limit of 2 is usually -100 × 10 -6 above.

[0040] There are no particular limitations on the method for preparing test specimens from surface-treated aluminum materials; various methods can be used as long as they do not affect the strain of the specimen. For example, when the surface-treated aluminum material is a sheet with a protective coating on only one side of the base material, small pieces cut into appropriately sized pieces can be used as test specimens. Alternatively, when the surface-treated aluminum material is a sheet with a protective coating on both sides of the base material, a test specimen can be obtained by cutting the surface-treated aluminum material into appropriately sized pieces, removing one of the two protective coatings from the small pieces, and then removing the protective coating. Methods for removing the protective coating include, for example, dissolving the protective coating using an acid or alkali.

[0041] As described above, the aluminum material exhibits excellent corrosion resistance to corrosive gases, plasmas, etc., and can suppress the formation of cracks at the protective coating even at elevated temperatures. Therefore, the aluminum material is suitable for applications such as shrouds around fans in heating and cooking appliances, and components for semiconductor manufacturing apparatuses. More specifically, the aluminum material is suitable, for example, for chambers and components disposed within chambers in semiconductor manufacturing apparatuses such as film deposition apparatuses and etching apparatuses. Examples of film deposition apparatuses include PVD (Physical Vapor Deposition) apparatuses and CVD (Chemical Vapor Deposition) apparatuses. Examples of etching apparatuses include dry etching apparatuses.

[0042] (Manufacturing methods for aluminum materials) In manufacturing the surface-treated aluminum material, firstly, a base material of an aluminum alloy containing 0% by mass or more and 1.8% by mass or less of aluminum or Cu is prepared. The manufacturing method of the base material is not particularly limited, and known methods can be used. For example, the base material can also be manufactured by a suitable combination of casting, rolling, and heat treatment. Furthermore, during the period after manufacturing the base material and before anodizing, pretreatments such as degreasing, acid cleaning, and grinding for anodizing can be performed as needed. Next, the base material is anodized to form a porous oxide layer. During the anodizing process, with the base material and the counter electrode immersed in an electrolyte, a direct current can be passed between the base material and the counter electrode to form an oxide layer on the surface of the base material. The oxide layer thus formed is composed of aluminum oxides such as aluminum oxide and has multiple pores.

[0043] The electrolyte used in the anodizing process can be, for example, an acidic electrolyte containing electrolytes such as sulfuric acid or phosphoric acid, or an alkaline electrolyte containing electrolytes such as sodium metaborate. Preferably, the electrolyte used in the anodizing process contains an inorganic electrolyte, which includes inorganic cations and one or more anions selected from sulfate ions, phosphate ions, ammonium ions, and borate ions. By using an electrolyte containing an inorganic electrolyte for anodizing, it is easier to form an oxide layer with the desired structure.

[0044] The current density of the direct current in the anodizing process, for example, can be determined based on 1 mA. / cm 2 Above and 100mA / cm 2 The following ranges should be set appropriately. Additionally, the temperature of the electrolyte in the anodizing process can be appropriately set, for example, within a range of 0°C to 40°C.

[0045] The thickness of the oxide layer formed during the anodizing process is preferably 2. m m or more. By making the oxide layer thickness 2 m A thickness of m or more ensures that the protective coating obtained after sealing is thick enough, making it easier to obtain aluminum materials with excellent corrosion resistance and heat resistance.

[0046] In the manufacturing method described above, after anodizing, the base material and the oxide layer are heated at a temperature between 50°C and 350°C. By heating the oxide layer at this specific temperature range before sealing the pores in the oxide layer after anodizing, the internal stress of the oxide layer can be mitigated. Furthermore, by sealing the pores after mitigating the internal stress of the oxide layer, the internal stress in the protective coating after sealing is reduced. As a result, the generation of cracks at the protective coating during heating can be suppressed, and aluminum with excellent heat resistance can be obtained.

[0047] When the heating temperature of the oxide layer is below 50°C, the internal stress of the oxide layer is not adequately relieved, and the protective coating may easily crack as the temperature of the aluminum material rises. On the other hand, when the heating temperature of the oxide layer exceeds 350°C, the oxide layer cannot keep up with the thermal expansion of the base material, and the oxide coating may crack. During the heating of the oxide layer, heating can be stopped shortly after the desired temperature is reached, or the desired temperature can be maintained for a certain period of time after reaching it. From the viewpoint of adequately relieving the internal stress of the oxide layer and more reliably improving the heat resistance of the aluminum material, the heating time from the start to the end of heating the oxide layer is preferably 1 minute or more and less than 12 hours.

[0048] The oxide layer is heated, and then brought into contact with a sealing agent. This forms a hydrated oxide layer on the oxide layer, sealing the pores. As a sealing agent, for example, a substance that can react with aluminum oxide to form a hydrated oxide, such as warm water, can be used. When using warm water for sealing, a hydrated oxide layer containing aluminum hydrates can be formed on the oxide layer.

[0049] Alternatively, as sealing agents, substances capable of reacting with aluminum oxides to form hydrated oxides and metal salts, such as aqueous solutions of nickel acetate, cobalt acetate, chromate, and silicate, can be used. When sealing pores using such sealing agents, a hydrated oxide layer containing aluminum hydrates and metal salts can be formed on the oxide layer.

[0050] From the viewpoint of more easily obtaining aluminum materials with excellent corrosion resistance and heat resistance, warm water is preferred as the sealing agent. Furthermore, by using warm water to seal the pores in the oxide layer, a hydrated oxide layer free of metal salts can be formed on the oxide layer. Metal salts in the hydrated oxide layer, for example, can become a cause of internal contamination when the aluminum material is used as a component in a semiconductor manufacturing apparatus. Therefore, by using warm water as the sealing agent to form a hydrated oxide layer free of metal salts, it is possible to easily obtain aluminum materials suitable for use as components in semiconductor manufacturing apparatuses. When using warm water as the sealing agent, it is more preferable to seal the pores in the oxide layer by contacting the oxide layer with warm water at 95°C or higher for 10 minutes to less than 120 minutes.

[0051] Example (Example 1) Reference Figure 1 ～ Figure 2 Examples of the surface-treated aluminum material and its manufacturing method are described below. Figure 1 As shown, the surface-treated aluminum material 1 in this example comprises: a base material 2, which contains an aluminum alloy with an aluminum or Cu content of 0% by mass or more and 1.8% by mass or less; and a protective coating 3, which is formed on the base material. The protective coating 3 comprises: an oxide layer 31, which contains an aluminum oxide and covers the base material 2; and a hydrated oxide layer 32, which contains a hydrated aluminum oxide and covers the oxide layer 31. Using a test solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution at a volume ratio of NaCl solution:acetic acid = 1000:1, the cathodic polarization of the base material 2 and the surface-treated aluminum material 1, which has been heated at 200°C for 4 hours, is measured. The current density at the center of the potential region exhibiting the limiting diffusion current of hydrogen ions in the base material 2 is measured, and the ratio J1 of the current density J1 of the surface-treated aluminum material 1 to the current density J2 of the base material 2 is obtained. / J2 is 150×10 -5 the following.

[0052] In making aluminum material 1 in this example, firstly, as follows: Figure 2 As shown, by anodizing the base material 2, an oxide layer 31 with pores 311 is formed on the base material 2. Then, the base material 2 and the oxide layer 31 are heated at a temperature of 50°C or higher and 350°C or lower to alleviate the internal stress of the oxide layer 31. Then, the oxide layer 31 is brought into contact with a sealing agent to form a hydrated oxide layer 32 on the oxide layer 31, and the pores 311 are sealed, thereby obtaining the aluminum material 1.

[0053] Specific examples of aluminum material 1 (test materials A1 to A16) are shown in Table 1. Test material A1～ The manufacturing method of A16 is as follows, for example. First, as the base material 2, an aluminum plate with a chemical composition indicated by any of the alloy numbers shown in Table 1 and a thickness of 1.1 mm is prepared. The base material 2 is then subjected to a pretreatment of anodizing. Specifically, as a pretreatment, the base material 2 is first subjected to an alkaline etching treatment by immersing it in a sodium hydroxide aqueous solution with a concentration of 5% by mass and a temperature of 55°C. Then, the base material 2 is immersed in nitric acid with a concentration of 30% by mass and subjected to a decontamination treatment. Next, the base material 2 is immersed in a mixed solution of phosphoric acid and sulfuric acid at a volume ratio of phosphoric acid:sulfuric acid = 7:3 and a temperature of 85°C for chemical polishing. After the chemical polishing treatment, a decontamination treatment is performed again under the same conditions as described above.

[0054] After pretreating the base material 2 as described above, the base material 2 is subjected to anodizing treatment to form an oxide layer 31 on the surface of the base material 2. The electrolyte used in the anodizing treatment is a 15% by mass sulfuric acid aqueous solution, and the electrolyte temperature is set to 5°C. Furthermore, the current density in the anodizing treatment is set to 10 mA. / cm 2 The processing time is set to 60 minutes. For example... Figure 2 As shown, the oxide layer 31 thus formed is a so-called porous alumite coating, which has multiple pores 311. It should be noted that the thickness of the oxide layer 31 formed by anodizing under the above conditions is approximately 15 μm. m m.

[0055] After anodizing, the base material 2 is heated in a heating furnace to alleviate the internal stress of the oxide layer 31. The set temperature of the heating furnace is the value shown in the "Heating Temperature" column of Table 1, and the residence time of the base material in the furnace, i.e., the time from the start of heating to the end of heating, is the value shown in the "Heating Time" column of Table 1.

[0056] Then, by immersing the base material 2 having the oxide layer 31 in warm water at 100°C (as a sealing agent) for 60 minutes, a hydrated oxide layer 32 containing hydrated aluminum oxide is formed on the oxide layer 31, and the hydrated oxide layer 32 is used to seal the pores 311 of the oxide layer 31. Through the above, the experimental material A1 shown in Table 1 can be obtained. ～ A16. It should be noted that, under these conditions, when the holes 311 of the oxide layer 31 are sealed, and the sealing degree test is performed according to the method specified in JISH 8683-2:2013, the mass reduction per unit area of ​​the aluminum material 1 is 0.3 g / dm². 2 the following.

[0057] It should be noted that the test material B1 shown in Table 1 ～B7 is used in conjunction with test material A1. ～ A16 is the material used for comparison. Test material B1 ～ The manufacturing method of B6 involves forming an oxide layer 31 on the base material 2, then contacting the oxide layer 31 with the sealing agent without heating it. Otherwise, it is similar to the test material A1. ～ The manufacturing method for A16 is the same. Additionally, the manufacturing method for test material B7 is shown in Table 1, except that the heating conditions in the furnace are changed; otherwise, it is the same as the manufacturing method for test material A1.

[0058] Next, the test material A1 ～ A16 and test material B1 ～ The method for measuring the cathodic polarization of B7 is explained.

[0059] [Cathode Polarization Measurement] The cathodic polarization of the base material and the test material heated at 200°C for 4 hours was measured using the following method. Based on these cathodic polarization curves, the ratio J1 of the current density J1 of the surface-treated aluminum material to the current density J2 of the base material was calculated. / J2. First, the test material was heated in an oven set to 200°C for 4 hours. After the test material was removed from the oven and cooled to room temperature, an evaluation area was marked on the protective film, and the portion of the test material's surface outside the evaluation area was coated with silicone resin.

[0060] Next, prepare a 5% (w / w) NaCl aqueous solution and a 99.7% acetic acid solution. The test solution is prepared by adding acetic acid to the NaCl aqueous solution, making the volume ratio of NaCl aqueous solution to acetic acid 1000:1. The test piece, counter electrode, and reference electrode, which are electrically connected to the potentiostat, are immersed in this test solution and allowed to stand for 30 minutes to stabilize the potential of the measuring section. It should be noted that the test solution is not degassed. Furthermore, Ag can be used as the reference electrode, for example. / AgCl electrode.

[0061] After the potential of the measuring section stabilizes, a voltage is applied between the test piece and the counter electrode using a potentiostat. Before the potential of the measuring section reaches -2000mV relative to the reference electrode, a voltage of 20mV is applied. / The potential of the measuring section is scanned at a scanning speed of minutes. The cathodic polarization curve of the heated test material is obtained by measuring the current density flowing through the measuring section at this time. Furthermore, the same measurement is performed using a pretreated base material that has undergone anodizing treatment using the above method to obtain the cathodic polarization curve of the base material. It should be noted that the cathodic polarization measurements of both the test material and the base material are performed in an atmospheric atmosphere while maintaining the temperature of the measuring solution at 25°C. Additionally, the cathodic polarization measurements of both the test material and the base material are performed without stirring the measuring solution, and are conducted in a substantially non-flowing state.

[0062] Figure 3 An example showing the cathodic polarization curve of the base material. It should be noted that... Figure 3 The vertical axis represents the potential of the measuring unit (unit: V), and the horizontal axis represents the current density (unit: ...). m A / cm 2 ).in addition, Figure 3 The horizontal axis is a logarithmic scale. For example... Figure 3 As shown, the cathodic polarization curve of the substrate has a stepped shape. In cathodic polarization measurement, if the current approaches a state limited by the diffusion rate of hydrogen ions, the change in current relative to the change in potential at the measuring section becomes smaller. Therefore, as... Figure 3 As shown, in the cathodic polarization curve where the vertical axis represents potential and the horizontal axis represents current density, the potential region exhibiting the limiting diffusion current of hydrogen ions is contained in the steeply sloped part of the stepped section of the cathodic polarization curve.

[0063] Figure 4 express Figure 3 An enlarged view of the stepped portion of the cathodic polarization curve. The method for determining the potential region representing the limiting diffusion current of hydrogen ions in the cathodic polarization curve of the substrate is as follows. First, as... Figure 4 As shown, a tangent line L with the largest absolute value of the slope is drawn from the stepped portion of the cathodic polarization curve. Furthermore, the region R where this tangent line L overlaps with the cathodic polarization curve is defined as the potential region exhibiting the limiting diffusion current of hydrogen ions. The current density J2 at the potential at the center of this defined region R is calculated. Additionally, in the cathodic polarization curve of the heated test material, the current density J1 at the potential at the same center of the aforementioned potential region as in the cathodic polarization curve of the parent material is calculated.

[0064] The current density J1 calculated based on the cathodic polarization curve of the heated test material can be used as an indicator of the contact area between the base material and the test solution in the heated test material, showing that the larger the current density value, the larger the contact area between the base material and the test solution. Therefore, the ratio J1 of the current density J1 calculated using the heated test piece to the current density J2 calculated using the base material can be used. / J2 is used as an indicator of the rate of increase in the exposed area of ​​the base material due to heating. More specifically, for example, in cases where the protective coating in the heated test material has defects such as cracks, the base material may sometimes be exposed due to these cracks. Therefore, in this case, the current density is higher than J1. / J2 increases. The current density ratio of each test material to J1 is adjusted. / J2 is shown in Table 1.

[0065] [Table 1] As shown in Table 1, in the preparation of experimental material A1 ～ In A16, after an oxide layer is formed on the base material, the oxide layer is heated within the specified temperature range before sealing the pores in the oxide layer. Therefore, these test materials have a current density ratio within the specified range compared to J1. / J2, even at elevated temperatures, can suppress the formation of cracks in the protective coating. Furthermore, the oxide layer of the protective coating in these test materials is sealed by a hydrated oxide layer, thus exhibiting excellent resistance to corrosive gases, plasmas, and the like.

[0066] On the other hand, in the preparation of experimental material B1 ～ At B6, after an oxide layer is formed on the base material, the pores are sealed without heating the oxide layer. Therefore, the current density of these test materials is higher than that of J1. / J2 is above the specified range, and is prone to cracking when the temperature rises.

[0067] The heating temperature during the heating of the oxide layer in the preparation of test material B7 was too high. Therefore, the current density ratio J1 / J2 of test material B7 was higher than the specified range, making it prone to cracking under rising temperatures.

[0068] (Example 2) In this example, an example of heating the oxide layer at a higher temperature during the manufacturing process of aluminum is described. Although not shown in the figure, the aluminum material in this example comprises: a base material containing an aluminum alloy with an aluminum or Cu content of 0% by mass or more and 1.8% by mass or less; and a protective coating formed on the base material. The protective coating comprises: an oxide layer containing aluminum oxide and covering the base material; and a hydrated oxide layer containing hydrated aluminum oxide and covering the oxide layer. Specific examples of the aluminum material in this example (test material A17 and test material A18) are shown in Table 2. The manufacturing methods of test materials A17 and A18 are the same as those of test material A1 in Example 1, except that the set temperature of the heating furnace and the residence time of the base material in the furnace when heating the oxide layer are changed as shown in Table 2. ～The manufacturing method for A16 is the same.

[0069] The ratio J1 of the current density of test material A17 and test material A18, measured based on cathode polarization. / J2 is shown in Table 2. It should be noted that the method for determining cathodic polarization in this example is the same as that for the cathodic polarization determination in Example 1, except that the heating temperature of the test material used in the determination is changed to 250°C.

[0070] [Table 2] As shown in Table 2, the current density ratio J1 of test material A17 and test material A18 is... / J2 also falls within the specified range when heated to 250°C. Generally, higher heating temperatures increase the likelihood of cracks forming at the protective coating; therefore, the current density at 200°C is considered to be higher than that of J1. / J2 is the current density ratio of J1 when heated at 250℃. / J2 and below. Therefore, it is believed that test materials A17 and A18, even when heated at a temperature of 200°C, have a current density ratio J1 within the aforementioned specific range. / J2 can suppress the formation of cracks in the protective coating even when the temperature rises.

[0071] (Example 3) In this example, an example of strain measurement for aluminum material with a protective coating on the base material is described. It should be noted that, unless otherwise specified, reference numerals used in this example that are identical to those used in existing examples indicate the same constituent elements as those in existing examples.

[0072] like Figure 5 As shown, when measuring the strain of the aluminum material 1 with the protective coating 3, the base material 2 is exposed on the reverse side of the aluminum material 1 with the protective coating 3. A strain gauge 4 is then mounted on the exposed base material 2. The strain caused by the thermal expansion of the base material 2 and the protective coating 3 can be measured by heating the aluminum material 1 with the strain gauge 4 mounted thereon. It should be noted that... Figure 5 For convenience, the structure of the protective coating 3 is simplified in the description.

[0073] Figure 6 This indicates the change in strain when test materials A4, A6, and B1 in Example 1 are heated for 30 minutes in a heating furnace set to 200°C. Figure 6 The vertical axis represents the dependent variable, and the horizontal axis represents the elapsed time since heating began. It should be noted that in... Figure 6 For comparison, the change in strain is shown when a base material 2 without the protective coating 3 is heated for 30 minutes in a heating furnace set to 200°C. Although not shown, when measuring the strain of the base material 2 without the protective coating 3, the base material 2 can be heated after mounting a strain gauge on one side of the base material 2 in the thickness direction.

[0074] Shortly after heating begins, the test material and the base material thermally expand as the temperature rises; therefore, as... Figure 6 As shown, the strain increases sharply from the start of the test until several minutes later. Then, if the temperature of the test material and the base material reaches a substantially constant temperature, the strain of the test material and the base material becomes a substantially constant value.

[0075] The maximum values ​​of strain during heating of the test material and the base material are shown in Table 3. Additionally, the maximum values ​​of strain from the test material are also shown in Table 3. e 1 minus the maximum value of the strain of the parent material e The value obtained from 2 e 1- e 2. Strain of the test materials is shown in Table 3. e 1. Strain of the base material e difference of 2 e 1- e 2 represents the magnitude of the internal stress of the protective coating released by heating during the test, and the difference in strain. e 1- e The smaller the value of 2, the lower the internal stress of the protective coating.

[0076] [Table 3] As shown in Table 3, during the manufacturing process of the test materials, the strain of test materials A4 and A6, which underwent heating of the oxide layer to form a hydrated oxide layer, was smaller compared to the strain of test material B1, which formed a hydrated oxide layer without heating the oxide layer. Therefore, these results indicate that during the manufacturing process of aluminum, forming a hydrated oxide layer after heating the oxide layer can alleviate the internal stress of the protective coating.

[0077] Furthermore, based on the comparison between test materials A4 and A6 and test material B1, it can be seen that the strain of the specimen measured at 200°C with a strain gauge mounted on the reverse side of the protective coating in the test materials is... e 1. Strain of the base material at 200℃ e difference of 2 e 1- e 2 is 100×10 -6The protective coating on the following aluminum materials has low internal stress and excellent heat resistance.

[0078] The above description illustrates the surface-treated aluminum material and its manufacturing method according to the present invention based on the embodiments. However, the specific methods of surface-treated aluminum material and its manufacturing method according to the present invention are not limited to the embodiments, and appropriate modifications can be made without prejudice to the spirit of the present invention.

[0079] For example, the surface-treated aluminum material involved in this invention can be adopted in the manner described in [1] to [3].

[0080] [1] A surface-treated aluminum material comprising: a base material comprising an aluminum alloy having an aluminum or Cu content of 0% by mass or more and 1.8% by mass or less; and a protective coating formed on the base material. The protective coating has the following characteristics: An oxide layer comprising an aluminum oxide and covering the substrate; and Hydrated oxide layer: which comprises hydrated oxide of aluminum and covers the oxide layer. The cathodic polarization of the substrate and the surface-treated aluminum material, after being heated at 200°C for 4 hours, was measured using a test solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution at a volume ratio of NaCl solution:acetic acid = 1000:1. The ratio J1 of the current density J1 of the surface-treated aluminum material to the current density J2 of the substrate was measured. / J2 is 150×10 -5 the following.

[0081] [2] A surface-treated aluminum material comprising: a base material comprising an aluminum alloy having an aluminum or Cu content of 0% by mass or more and 1.8% by mass or less; and a protective coating formed on the base material. The protective coating has the following characteristics: An oxide layer comprising an aluminum oxide and covering the substrate; and Hydrated oxide layer: which comprises hydrated oxide of aluminum and covers the oxide layer. A specimen with the protective coating on one side of the base material was prepared from the surface-treated aluminum material. The strain of the specimen was measured at 200°C with a strain gauge mounted on the reverse side of the protective coating. e 1. Strain of the base material at 200°C e difference of 2 e 1- e 2 is 100×10-6 the following.

[0082] [3] The surface-treated aluminum material according to [1] or [2], wherein the mass reduction per unit area is 0.3g when the sealing degree test is performed by the method specified in JIS H8683-2:2013. / dm 2 the following.

[0083] Furthermore, the semiconductor manufacturing apparatus component involved in this invention can be adopted in the manner described in [4].

[0084] [4] A component for a semiconductor manufacturing apparatus comprising the surface-treated aluminum material described in [1] or [2].

[0085] In addition, the manufacturing method of the surface-treated aluminum material involved in this invention can be carried out in the manner shown in [5] to [9].

[0086] [5] A method for manufacturing a surface-treated aluminum material, wherein the method is the same as described in any one of [1] to [3]. The oxide layer with pores is formed on the base material by anodizing. Then, the base material and the oxide layer are heated at a temperature above 50°C and below 350°C. Then, the oxide layer is brought into contact with a sealing agent to form a hydrated oxide layer on the oxide layer while sealing the pores.

[0087] [6] In the method for manufacturing surface-treated aluminum material according to [5], the heating time from the start of heating the oxide layer to the end of heating is more than 1 minute and less than 12 hours.

[0088] [7] The manufacturing method of surface-treated aluminum material according to [5] or [6], wherein the sealing agent is warm water.

[0089] [8] A method for manufacturing surface-treated aluminum material according to any one of [5] to [7], wherein, in the sealing process, the oxide layer is contacted with warm water at 95°C or higher as the sealing agent for 10 minutes or more and less than 120 minutes.

[0090] [9] The method for manufacturing surface-treated aluminum material according to any one of [5] to [8], wherein the electrolyte used in the anodizing process comprises an inorganic electrolyte, the inorganic electrolyte comprising: inorganic cations, and one or more anions selected from sulfate ions, phosphate ions, ammonium ions and borate ions.

Claims

1. A surface-treated aluminum material, characterized in that, have: The base material, comprising aluminum alloys containing 0% by mass or more and 1.8% by mass or less aluminum or Cu; and A protective coating is formed on the base material. The protective coating has the following characteristics: An oxide layer comprising an aluminum oxide and covering the substrate; and A hydrated oxide layer comprising a hydrated oxide of aluminum, and covering the oxide layer. The cathodic polarization of the substrate and the surface-treated aluminum material heated at 200°C for 4 hours was measured using a test solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution at a volume ratio of NaCl solution:acetic acid = 1000:

1. The current density at the center of the potential region exhibiting the limiting diffusion current of hydrogen ions in the substrate was measured, and the ratio J1 of the current density J1 of the surface-treated aluminum material to the current density J2 of the substrate was obtained. / J2 is 150×10 -5 the following.

2. A surface-treated aluminum material, characterized in that, have: The base material, comprising aluminum alloys containing 0% by mass or more and 1.8% by mass or less aluminum or Cu; and A protective coating is formed on the base material. The protective coating has the following characteristics: An oxide layer comprising an aluminum oxide and covering the substrate; and A hydrated oxide layer comprising a hydrated oxide of aluminum, and covering the oxide layer. A specimen made from the surface-treated aluminum material, having the protective coating on one side of the base material, and strain measured at 200°C with a strain gauge mounted on the reverse side of the protective coating. ε 1. Strain of the base material at 200°C ε difference of 2 ε 1- ε 2 is 100×10 -6 the following.

3. The surface-treated aluminum material according to claim 1 or 2, wherein, The mass reduction per unit area is 0.3g when the porosity test is performed according to the method specified in JIS H8683-2:2013. / dm 2 the following.

4. A component for a semiconductor manufacturing apparatus, characterized in that, Includes claim 1 ～ The surface-treated aluminum material as described in any one of the 3.

5. Claim 1 ～ The method for manufacturing the surface-treated aluminum material as described in any one of the 3 methodes is characterized in that, Anodizing the base material creates a porous oxide layer on it. Then, the base material and the oxide layer are heated at a temperature above 50°C and below 350°C. Then, the oxide layer is brought into contact with a sealing agent to form a hydrated oxide layer on the oxide layer while sealing the pores.

6. The method for manufacturing surface-treated aluminum material according to claim 5, wherein, The heating time from the start of heating the oxide layer to the end of heating is more than 1 minute and less than 12 hours.

7. The method for manufacturing surface-treated aluminum material according to claim 5 or 6, wherein, The sealing agent is warm water.

8. According to claim 5 ～ The method for manufacturing the surface-treated aluminum material as described in any one of the 7, wherein, In the sealing process, the oxide layer is brought into contact with warm water at 95°C or higher as the sealing agent for 10 minutes or more but less than 120 minutes.

9. According to claim 5 ～ The method for manufacturing the surface-treated aluminum material as described in any one of the 8, wherein, The electrolyte used in the anodic oxidation process contains an inorganic electrolyte, which includes inorganic cations and one or more anions selected from sulfate ions, phosphate ions, ammonium ions and borate ions.

Images