Patent Application
20240287700
The present invention relates to an aluminum member for semiconductor manufacturing apparatuses, and to a method of manufacturing the same.
The temperature of component parts of a chamber or the like in a semiconductor manufacturing apparatus, such as a CVD (chemical-vapor deposition) apparatus, a PVD (physical-vapor deposition) apparatus, a dry-etching apparatus, or the like, rises while processes are being performed on semiconductors disposed inside the chamber. In addition, when impurity elements or the like separate from the component parts inside the chamber while a process is being performed on the semiconductors, there is a risk that such will become the cause of semiconductor defects. To curtail the occurrence of these problems, an aluminum alloy that has high heat resistance and from which the separation of impurities is small is used in the component parts of the semiconductor-manufacturing apparatus.
For example, in Patent Document 1, an Al alloy for a semiconductor manufacturing apparatus is described that: contains Mn: 0.3-1.5% (mass %; likewise below), Cu: 0.3-1.5%, and Fe: 0.1-1.0% as alloy components, the remainder being Al and unavoidable impurities; has an average particle size of 50 μm or less; and excels in heat resistance and formability of an Alumite coating that excels in gas-corrosion resistance and plasma-corrosion resistance. After the Al alloy used for the semiconductor manufacturing apparatus described in Patent Document 1 has formed an Alumite coating on a surface, it is used as a material for semiconductor manufacturing apparatuses.
However, the coefficient of thermal expansion of aluminum alloys and the coefficient of thermal expansion of Alumite coatings differ from each other. Consequently, in the situation in which the temperature of the material for semiconductor manufacturing apparatuses, which has an Alumite coating provided on an aluminum alloy, has risen, a crack or cracks sometimes form(s) in the Alumite coating. If the crack(s) advance(s) in the thickness direction of the Alumite coating and reach(es) the interface between the aluminum alloy and the Alumite coating, then there is a risk that the aluminum alloy will be exposed. As a result, there is a risk that it will lead to a decrease in corrosion resistance or an increase in outgassing.
The present invention was conceived considering this background, and an object of the present invention is to provide an aluminum member for semiconductor manufacturing apparatuses and a method of manufacturing the same, in which, even in the situation in which a crack or cracks has/have formed in an anodized coating, it is easy to maintain the state in which the base material is covered by the anodized coating.
One aspect of the present invention is an aluminum member for semiconductor manufacturing apparatuses that comprises:
Another aspect of the present invention is a method of manufacturing the aluminum member for semiconductor manufacturing apparatuses according to the above-mentioned aspect that comprises: an anodizing-process step, in which the anodized coating, which contains the heterogenous particles, is formed on the base material by performing an anodizing process, using an acidic electrolytic solution, on the base material having second-phase particles in the Al parent phase.
The anodized coating is provided on the base material of the above-mentioned aluminum member for semiconductor manufacturing apparatuses (hereinbelow, called “aluminum member”). In addition, the above-mentioned specific heterogenous particles exist in the anodized coating. In the situation in which the temperature of the above-mentioned aluminum member rises and a crack or cracks has/have formed in the anodized coating, such heterogenous particles can guide the crack(s) in a direction or directions that differ(s) from the thickness direction of the anodized coating. For this reason, even in the situation in which a crack has formed in the anodized coating of the above-mentioned aluminum member, owing to the heterogenous particles the crack tends to advance in a direction that differs from the thickness direction of the anodized coating. As a result, the advancement of the crack stops in the interior of the anodized coating and tends not to reach the interface between the anodized coating and the base material.
For this reason, with regard to the above-mentioned aluminum member, even in the situation in which a crack has formed in the anodized coating, the state in which the anodized coating covers the base material tends to be maintained.
In addition, the method of manufacturing the above-mentioned aluminum member has an anodizing-process step in which an anodizing process is performed, using an acidic electrolytic solution, on the base material, which contains second-phase particles. In the anodizing-process step, attendant with the growth of the anodized coating, at least some from among the second-phase particles in the base material are incorporated into the anodized coating. Thereby, an anodized coating having the above-mentioned heterogenous particles can be easily formed on the base material.
According to the above-mentioned aspect as described above, it is possible to provide an aluminum member for semiconductor manufacturing apparatuses and a method of manufacturing of the same, wherein, even in the situation in which a crack or cracks has/have formed in the anodized coating, the state in which the base material is covered by the anodized coating tends to be maintained.
The material of the base material of the above-mentioned aluminum member can be selected as appropriate from among the group consisting of aluminum and aluminum alloys in accordance with the application of the aluminum member. For example, in the situation in which one endeavors to reduce outgassing from the aluminum member, it is preferable that the base material is constituted from a 1000-series aluminum or a 3000-series aluminum alloy. For example, an aluminum alloy having a chemical composition that contains Mn (manganese): 1.0 mass % or more and 1.5 mass % or less and contains, as optional components, one or two or more elements selected from the group consisting of Si (silicon), Fe (iron), Cu (copper), Mg, Cr (chrome), Zn (zinc), and Ti (titanium), the remainder being Al and unavoidable impurities, can be used as the 3000-series aluminum alloy.
In addition, in the situation in which one endeavors to increase the strength of the aluminum member, it is preferable that the base material is constituted from a 5000-series aluminum alloy or a 6000-series aluminum alloy. For example, an aluminum alloy having a chemical composition that contains Mg (magnesium): 0.5 mass % or more and 5.0 mass % or less and contains, as optional components, one or two or more elements selected from the group consisting of Si, Fe, Cu, Mn, Cr, Zn, and Ti, the remainder being Al and unavoidable impurities, can be used as the 5000-series aluminum alloy. In addition, for example, an aluminum alloy having a chemical composition that contains Mg: 0.3 mass % or more and 1.5 mass % or less and Si: 0.2 mass % or more and 1.2 mass % or less and contains, as optional components, one or two or more elements selected from the group consisting of Fe, Cu, Mn, Cr, Zn, and Ti, the remainder being Al and unavoidable impurities, can be used as the 6000-series aluminum alloy.
The base material of the above-mentioned aluminum member may contain second-phase particles. As described below, in the situation in which an anodizing process has been performed on a base material that contains second-phase particles, at least some of the second-phase particles are incorporated into the anodized coating to become heterogenous particles. As a result, the above-mentioned aluminum member can be manufactured easily.
The second-phase particles contained in the base material have a variety of compositions in accordance with the material of the base material. For example, a base material composed of a 1000-series aluminum contains second-phase particles such as Al—Fe—series intermetallic compounds, Al—Fe—Si-series intermetallic compounds, and the like. A base material composed of a 3000-series aluminum alloy contains second-phase particles such as Al—Mn-series intermetallic compounds, Al—Mn—Si-series intermetallic compounds, Al—Fe—Si-series intermetallic compounds, Al—Mn—Fe—Si-series intermetallic compounds, and the like. A base material composed of a 5000-series aluminum alloy contains second-phase particles such as Al—Mg-series intermetallic compounds. A base material composed of a 6000-series aluminum alloy contains second-phase particles such as Al—Mg-series intermetallic compounds, Al—Mg—Si-series intermetallic compounds, Si, Mg2Si, and the like.
The anodized coating is provided on the above-mentioned base material. The anodized coating is mainly constituted from oxides of aluminum. The anodized coating may be, for example, a porous-type anodized coating having numerous small holes or may be a barrier-type anodized coating that does not have small holes. The thickness of the anodized coating is not particularly limited and, for example, can be set as appropriate within the range of 0.1 μm or more and 100 μm or less.
Heterogenous particles, which contain a metal atom or metal atoms other than Al atoms and the major-axis diameters of which are 0.1 μm or more and 15 μm or less, exist in the anodized coating. In the situation in which a crack or cracks has/have formed in the anodized coating, the heterogenous particles, the major-axis diameters of which are within the above-mentioned specific range, can guide the advancement direction of the crack(s) in a direction or directions that is/are tilted relative to the thickness direction of the anodized coating. For this reason, in the situation in which a crack or cracks has/have formed in the above-mentioned anodized coating, the crack(s) tend(s) to advance in a direction or directions that is/are tilted relative to the thickness direction of the anodized coating. Even if a crack that has advanced in a direction that is tilted relative to the thickness direction of the anodized coating and the crack that has advanced along the thickness direction of the anodized coating are the same length, the depth of the crack tip from the surface of the anodized coating can be shallower. In addition, by causing a crack to advance in a direction that is tilted relative to the thickness direction of the anodized coating, the length of the crack can be longer, and stress that arises within the anodized coating due to a thermal-expansion differential can be reduced. As a result, the tip of the crack tends to remain in the interior of the anodized coating, and thereby the crack tends not to reach the interface between the anodized coating and the base material.
The major-axis diameters of the heterogenous particles existing in the anodized coating are values measured by the following method. First, the aluminum member is cut at an arbitrary cross section, and a sample is taken. After this sample has been embedded in a resin, mirror polishing is performed on a cross section of the sample to expose the cross section of the anodized coating. Next, the cross section of the anodized coating is observed using an electron microscope, and an electron micrograph that includes the heterogenous particles is acquired. Oblong shapes, which respectively circumscribe the heterogenous particles existing in this electron micrograph, are drawn, and the length of the long side of each oblong shape is taken as the major-axis diameter of the corresponding heterogenous particle.
It is noted that heterogenous particles having a major-axis diameter of less than 0.1 μm and heterogenous particles having a major-axis diameter that is greater than 15 μm may exist in the anodized coating. However, the effect of guiding the advancement direction of a crack is lower for heterogenous particles having a major-axis diameter of less than 0.1 μm than for particles having a major-axis diameter within the above-mentioned specific range. In addition, if the number of the heterogenous particles having a major-axis diameter of greater than 15 μm becomes excessive large, then the number of the heterogenous particles contained in the anodized coating will become small, and there is a risk that this will lead to a decrease in the effect of guiding the advancement direction of the crack.
From the viewpoint of more effectively curtailing the advancement of a crack or cracks in the thickness direction of the anodized coating, the average value of the major-axis diameters of the heterogenous particles contained in the anodized coating preferably is 0.1 μm or more and 15 μm or less, more preferably is 0.5 μm or more and 10 μm or less, and yet more preferably is 1.0 μm or more and 5.0 μm or less. In the situation in which the average value of the major-axis diameters of the heterogenous particles is excessively small, the proportion of heterogenous particles contained in the anodized coating and having a major-axis diameter of less than 0.1 μm becomes large, and there is a risk that this will lead to a decrease in the effect of guiding the advancement direction of the crack. In addition, in the situation in which the average value of the major-axis diameters of the heterogenous particles is excessively large, the proportion of the heterogenous particles contained in the anodized coating and having a major-axis diameter greater than 15 μm becomes large, and there is a risk that this will lead to a decrease in the number of the heterogenous particles contained in the anodized coating.
The number of heterogenous particles, per 1 mm2 of surface area of the anodized coating, that have major-axis diameters of 0.1 μm or more and 15 μm or less preferably is 1,600 or more. In this situation, the spacing between the heterogenous particles within the anodized coating can be made sufficiently short. Consequently, even in the situation in which a crack has formed in any portion of the anodized coating, the possibility that heterogenous particles having major-axis diameters in the above-mentioned specific range exist in the vicinity of the crack can be increased. Accordingly, by setting the number of the above-mentioned heterogenous particles per 1 mm2 of surface area of the anodized coating to within the above-mentioned specific range, the effect of curtailing the exposure of the base material can be further increased, and thereby it is possible to more easily maintain the state in which the base material is covered by the anodized coating.
From the same viewpoint, in an arbitrary cross section of the above-mentioned aluminum member, the spacing between the above-mentioned heterogenous particle and the heterogenous particle closest to that heterogenous particle preferably is 25 μm or less, more preferably is 20 μm or less, and yet more preferably is 15 μm or less.
The composition of the above-mentioned heterogenous particles is not particularly limited; the heterogenous particles may contain Si atoms. For example, elementary Si, Mg2Si, Al—Mn—Fe—Si-series intermetallic compounds, and the like can be given as examples of such heterogenous particles. In the situation in which the aluminum member is to be manufactured by the manufacturing method according to the above-mentioned aspect, from among the second-phase particles in the base material, the second-phase particles that were not dissolved during the anodizing process are incorporated into the anodized coating to become heterogenous particles. Accordingly, it is often the case that the heterogenous particles have a composition the same as that of the second-phase particles contained in the base material or a composition derived from the second-phase particles. For example, with regard to the Mg2Si in the base material, because the Mg atoms elute during the anodizing process and the Si atoms are incorporated into the coating, the fine heterogenous particles, which contain Si atoms in abundance, can be dispersed into the coating.
The thickness of the above-mentioned aluminum member for semiconductor manufacturing apparatuses is not particularly limited. For example, the aluminum member for semiconductor manufacturing apparatuses may be a thick plate having a thickness of 6 mm or more. It is conceivable that the formation of a crack or cracks extending to the anodized coating occurs owing to the difference between the thermal expansion of the anodized coating and the thermal expansion of the base material. When the thickness of the base material becomes thick, stresses arising due to the thermal-expansion differential become high, and consequently cracks tend to form in the anodized coating. In contrast, because heterogenous particles having major-axis diameters in the above-mentioned specific range are contained in the anodized coating of the above-mentioned aluminum member, as described above, even in the situation in which a crack or cracks has/have formed in the anodized coating, the advancement direction of the crack(s) can be guided in a direction or directions that differ(s) from the thickness direction of the anodized coating. For this reason, even in the situation in which the thickness of the above-mentioned aluminum member for semiconductor manufacturing apparatuses is thick, the state in which the base material is covered by the anodized coating can be easily maintained owing to the effect of the heterogenous particles.
The above-mentioned aluminum member is used in component parts of semiconductor manufacturing apparatuses. More specifically, the above-mentioned aluminum member is used in, for example, the chambers of film-forming apparatuses, such as CVD apparatuses and PVD apparatuses, and etching apparatuses, such as dry-etching apparatuses, as well as components disposed inside such chambers.
A method of manufacturing the aluminum member for semiconductor manufacturing apparatuses comprises:
In the anodizing-process step, an anodizing process is performed on the base material, which has second-phase particles, using an acidic electrolytic solution. In the situation in which an acidic electrolytic solution is used as the electrolytic solution in the anodizing process, the dissolution reaction of the base material and the aluminum oxides and the growth reaction of the aluminum oxide during the anodizing process proceed in parallel. Thereby, a porous-type anodized coating having numerous small holes can be formed on the base material. In addition, attendant with the growth of the anodized coating, the second-phase particles, from among the second-phase particles in the base material, that did not dissolve in the electrolytic solution are incorporated into the anodized coating to become heterogenous particles. Accordingly, by performing the above-mentioned anodizing process on the base material, an anodized coating that contains heterogenous particles can be formed on the base material.
For example, the electrolytic solution used in the anodizing-process step may contain one or two or more acids selected from the group consisting of organic acids, such as oxalic acid, malonic acid, tartaric acid, or the like, and inorganic acids, such as sulfuric acid, phosphoric acid, and the like. From the viewpoint of further improving the heat resistance of the anodized coating, the electrolytic solution preferably contains one or two acids from among oxalic acid and sulfuric acid.
In the anodizing-process step, the anodized coating can be formed on the surface of the base material by supplying a direct current between the base material and a counter electrode in the state in which the base material and the counter electrode are immersed in the electrolytic solution. The electric current density of the direct current in the anodizing process preferably is 100 A/m2 or more and 600 A/m2 or less. By setting the electric current density of the direct current in the anodizing process to 100 A/m2 or more and more preferably to 200 A/m2 or more, the growth rate of the anodized coating can be increased, and thereby the productivity of the aluminum member can be increased. In addition, by setting the electric-current density of the direct current in the anodizing process to 600 A/m2 or less and more preferably to 500 A/m2 or less, the anodized coating can be grown evenly on the base material, and thereby scorching of the base material and the formation of nonuniformity in the anodized coating can be avoided.
The temperature of the electrolytic solution in the anodizing-process step preferably is 263 K or higher and 303 K or lower. By setting the temperature of the electrolytic solution to 263 K or higher and more preferably to 273 K or higher, the solubility of the electrolyte can be suitably increased, and the concentration of the electrolyte in the electrolytic solution can be sufficiently increased. In addition, by setting the temperature of the electrolytic solution to 303 K or lower and more preferably to 293 K or lower, an excessive increase in the dissolving power of the electrolytic solution can be avoided, and thereby the growth rate of the anodized coating can be increased.
The base material used in the anodizing-process step may be manufactured by any method.
For example, the method of manufacturing the aluminum member for semiconductor manufacturing apparatuses may further comprise:
For example, DC casting can be used as the casting method in the casting step. The thickness of the ingot obtained in the casting step is not particularly limited, and the ingot may have a thickness of, for example, 600 mm or more.
In the homogenizing-process step, a homogenizing process is performed in which the ingot obtained in the casting step is held for 5 hours or more and 10 hours or less at a temperature of 500° C. or higher and 560° C. or lower. By setting the hold temperature and the hold time in the homogenizing process to the above-mentioned specific ranges, respectively, the structure of the ingot can be sufficiently homogenized. Furthermore, by performing hot rolling on such an ingot, a base material that contains the desired second-phase particles can be obtained.
In the hot-rolling step, hot rolling is performed on the ingot, on which the homogenizing process has been performed, in the state in which the temperature thereof is 500° C. or higher and 560° C. or lower. Thereby, the base material can be obtained. In the situation in which the start temperature in the hot rolling is too low, there is a risk that the deformation resistance of the ingot will become high and cracks will form in the ingot during rolling, which will lead to degradation in productivity. On the other hand, in the situation in which the start temperature in the hot rolling is too high, there is a risk that the ingot will melt locally owing to the manufacturing-induced heat generation during hot rolling.
In the above-mentioned manufacturing method, the base material obtained as described above may be subject to the anodizing-process step as is. In addition, the above-mentioned manufacturing method may have a heat-treatment step in which, after the hot-rolling step has been performed and before the anodizing-process step is performed, a heat treatment, such as annealing, is performed on the base material as needed.
Furthermore, the above-mentioned manufacturing method may have a preprocessing step in which, after the hot-rolling step has been performed and before the anodizing-process step is performed, a preprocess is performed on the base material. For example, a degreasing process, such as an alkali-degreasing process, or the like, a polishing process, such as mechanical polishing, chemical polishing, electrolytic polishing, or the like, can be given as examples of preprocess(es) of the base material. In the preprocessing step(s), one singular preprocess from among the preprocesses described above may be performed or two or more preprocesses may be performed as appropriate in combination in accordance with the desired characteristics of the aluminum member.
In the situation in which an alkali-degreasing process is performed in the preprocessing step(s), the luster of the anodized coating obtained after the anodizing process is reduced, and thereby an aluminum member having a non-glossy external appearance can be obtained. In addition, in the situation in which a polishing process is performed in the preprocessing step(s), the luster of the anodized coating obtained after the anodizing process can be increased, and thereby an aluminum member having a glossy external appearance can be obtained. From the viewpoint of further increasing the luster of the aluminum member, it is preferable to perform an electrolytic-polishing process on the base material in the preprocessing step(s).
Working examples of the above-mentioned aluminum member for semiconductor manufacturing apparatuses and the method of manufacturing of the same will be explained below. As shown in
The aluminum member 1 according to the present example can be obtained by, for example, the following method. First, an ingot having a chemical composition indicated by any of alloy symbols A5052, A5083, and A6063 is manufactured by DC casting (casting step). The thickness of the ingot is set to, for example, 600 mm. A homogenizing process is performed on this ingot by holding the ingot for 5 hours or more and 10 hours or less at a temperature of 500° C. or higher and 560° C. or lower (homogenizing-process step). After the homogenizing-process step has been performed, hot rolling is performed while the temperature of the ingot is 500° C. or higher and 560° C. or lower, and thereby a plate material having a thickness of 300 mm is manufactured (hot-rolling step).
The plate material after hot rolling is used, as is, as the base material 2 for the plate material having the chemical composition indicated by alloy symbol A5052. It is noted that this plate material is refined to the grade indicated by grade symbol H112. With regard to a plate material having the chemical composition indicated by alloy symbol A5083, the plate material is refined to the grade indicated by grade symbol O by heating the plate material after hot rolling to anneal it. Furthermore, the plate material after annealing is used as the base material 2. With regard to the plate material having the chemical composition indicated by alloy symbol A6063, the plate material is refined to the grade indicated by grade symbol T6 by performing a heat-solution treatment on the plate material after hot rolling and subsequently performing an artificial-aging process. Furthermore, the plate material after the artificial-aging process is used as the base material 2.
By performing the anodizing process, under the conditions indicated in Table 1, on these three base materials 2, the anodized coatings 3 are formed on the base materials 2. Based on the above, Test Materials S1-S6 listed in Table 1 can be obtained. It is noted that Test Material R1 listed in Table 1 is a test material for comparison with Test Materials S1-S6. The method of manufacturing Test Material R1 is the same as the method of manufacturing Test Materials S1-S6 other than that the hold temperature in the homogenizing-process step is set to 480° C., the hold time is set to 4 hours, and the rolling-start temperature in the hot-rolling step is set to 450° C.
Next, the structure and a heat-resistance evaluating method of the anodized coating 3 for Test Materials S1-S6 and Test Material R1 will be explained.
For example, each test material is cut at a surface that is orthogonal to the rolling direction to expose a cross section of the anodized coating 3. The cross section of the anodized coating 3 is observed using a field-emission scanning secondary electron microscope (i.e., FE-SEM) equipped with an energy-dispersive X-ray spectrometer (i.e., EDX), a secondary electron image is acquired, and an element-mapping image of a visual field the same as the secondary electron image is acquired. Furthermore, based on the secondary electron image and the element-mapping image, the locations and sizes of the heterogenous particles 31 existing within the anodized coating 3 are specified. It is noted that, for example, the “SU-8230” made by Hitachi High Technologies Corporation can be used as the FE-SEM. In addition, for example, the “QUANTAX FlatQUAD” or the like made by Bruker Corporation can be used as the EDX.
Next, an oblong shape that circumscribes each of the heterogenous particles 31 is determined for each individual heterogenous particle 31 appearing in the secondary electron image. The length of the long side of each oblong shape is taken as the major-axis diameter of the corresponding heterogenous particle 31. In Table 1, the maximum value of the major-axis diameter of the heterogenous particle 31 is listed for each of the test materials. In addition, the spacing between each individual heterogenous particle 31 appearing in the secondary electron image and the heterogenous particle 31 that is closest to that heterogenous particle 31 is measured. The maximum value of the spacings between the heterogenous particles 31 is listed in Table 1.
A heat-resistance evaluation is performed based on the results of polarization measurements of the test materials. Specifically, first, multiple test pieces for polarization measurement are manufactured by masking the surface of each test material such that a portion of the anodized coating 3 of each test material is exposed. The surface area of the measurement portion of each test piece, that is, the portion in which the anodized coating 3 is exposed, is set to 1 cm2. Then, some of the test pieces of the multiple test pieces are heated for 8 hours at a temperature of 200° C. in the atmosphere.
Next, a measurement solution is prepared by adding acetic acid to a 5% aqueous solution of NaCl such that the acetic acid concentration becomes 1 mL/L. The test piece, the counter electrode, and the reference electrode, which are electrically connected to a potentiostat, are immersed in that solution and held stationary for a while to stabilize the electric potential of the measurement portion. It is noted that, for example, an Ag/AgCl electrode can be used as the reference electrode.
After the electric potential of the measurement portion has stabilized, a voltage is applied between the test piece and the counter electrode using the potentiostat, and the density of the electric current flowing to the measurement portion is measured while sweeping the electric potential of the measurement portion at a sweep rate of 20 mV/min. Furthermore, at the point in time at which the electric potential of the measurement portion has reached −2,000 mV with respect to the reference electrode, the sweeping of the electric potential is ended. Based on the above, a polarization curve is acquired.
Next, in the polarization curve, the center of the electric-potential region, which indicates the diffusion limiting current of hydrogen, is determined. Furthermore, the electric-current density at the center of that electric-potential region is calculated. The electric-current density obtained in this manner can be used as an indicator of defects in the anodized coating in the test piece, wherein the greater the value of the electric-current density, the greater the number of defects that exist in the anodized coating 3, and the larger the contact-surface area between the base material 2 and the measurement solution.
Accordingly, the ratio of the value of the electric-current density calculated using the test piece after heating to the value of the electric-current density calculated using the test piece before heating indicates the rate of increase of defects due to heating. The rate of increase of defects due to heating is indicated for each test material.
As shown in Table 1, the heterogenous particles 31 having major-axis diameters in the above-mentioned specific range exist in the anodized coating 3 of each of Test Materials S1-S6. Consequently, in the situation in which the temperature of the test material rises and a crack or cracks has/have formed in the anodized coating 3, the crack(s) tend(s) to advance in a direction or directions that differ(s) from the thickness direction of the anodized coating 3 owing to the heterogenous particles 31.
The secondary electron image of a cross section of Test Material S3 after heating for 8 hours at a temperature of 200° C. is shown as one example. In Test Material S3, a crack 4 formed at the surface of the anodized coating 3 is guided, owing to the existence of the heterogenous particles 31, in a direction that is tilted relative to the thickness direction of the anodized coating 3. Furthermore, by the crack 4 advancing in a direction that is tilted relative to the thickness direction of the anodized coating 3, the tip of the crack 4 stops in the interior of the anodized coating 3. Although not shown in the drawings, with regard to Test Materials S1-S2 and Test Materials S4-S6 as well, the same as Test Material S3, a crack 4 formed at the surface of the anodized coating 3 tends to be guided, owing to the existence of the heterogenous particles 31, in a direction that is tilted relative to the thickness direction of the anodized coating 3.
As a result of the above, the advance of the crack 4 stops in the interior of the anodized coating 3 and tends not to reach the interface between the anodized coating 3 and the base material 2.
On the other hand, the heterogenous particles 31 having major-axis diameters in the above-mentioned specific range do not exist in the anodized coating 3 of Test Material R1. Consequently, as shown in
According to the results above, it can be understood that the aluminum member 1, which has the heterogenous particles 31 having major-axis diameters in the above-mentioned specific range in the interior of the anodized coating 3, excels in heat resistance and tends to maintain the state in which the base material 2 is covered by the anodized coating 3, even in the situation in which a crack 4 has formed in the anodized coating 3.
It is noted that specific aspects of the aluminum member for semiconductor manufacturing apparatuses and the method of manufacturing of the same according to the present invention are not limited to the aspects described in the working examples, and the appropriate configuration can be modified within a range that does not compromise the gist of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-144535 | Sep 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/033012 | 9/1/2022 | WO |
