Adhesive structure and method for manufacturing adhesive structure

Abstract

Provided is an adhesive structure in which a fiber structure layer configured from a plurality of fiber bodies composed of an inorganic material is formed on at least a portion of the surface of a base material composed of an inorganic material, the equivalent circle diameter D of a cross-section orthogonal to the extension direction of a fiber body (21) constituting the fiber structure layer is within the range of 15-400 nm, an aspect ratio H / D calculated from the height H and the equivalent circle diameter D of the fiber body (21) is 3 or greater, and the adhesive structure can be stably used even in a high-temperature environment and a clean environment and can achieve sufficient adhesive force.

Description

Bonded structure and method for manufacturing the bonded structure

[0001] The present invention relates to a bonded structure and a method for manufacturing a bonded structure. This application claims priority to Japanese Patent Application No. 2023-149145, filed on September 14, 2023, the contents of which are incorporated herein by reference.

[0002] For example, in semiconductor manufacturing equipment, if particles or the like are present on the holding surface of a semiconductor wafer, the flatness of the holding surface is impaired, causing manufacturing defects and reducing yield. Conventionally, as a method for removing particles, as shown in Patent Documents 1 and 2, for example, a substrate to which an adhesive substance is adhered is used as a cleaning wafer, and this cleaning wafer is transported empty to remove particles from the transport system and processing unit.

[0003] Furthermore, in gripping members that grip an object and transport members that transport an object, adhesive structures having adhesive properties are disposed in the portions that come into contact with the object in order to stably fix the object, as shown in Patent Documents 2 and 3, for example. Furthermore, when handling an object, adhesive structures are used to temporarily fix the object and prevent it from shifting position, as shown in Patent Document 4, for example. Here, the adhesive structures are required to have sufficient frictional force between them and the object, and therefore are usually made of an organic material such as rubber, which is a viscoelastic body.

[0004] Japanese Patent Publication No. 2009-117440 (A) Japanese Patent Publication No. 2018-094704 (A) International Publication No. WO2009 / 005027 (A) Japanese Patent Publication No. 2009-168860 (A)

[0005] However, the method disclosed in Patent Document 1 requires temporarily halting the operation of semiconductor manufacturing equipment or lowering the environmental temperature to 400°C or below when removing particles, resulting in a decrease in productivity due to downtime. Furthermore, organic materials such as rubber have insufficient heat resistance, making them unable to be used stably in high-temperature environments. Furthermore, there is a problem that they cannot be used in clean environments due to the risk of contamination by the organic materials. Therefore, adhesive structures made of organic materials could not be applied to, for example, semiconductor manufacturing process applications, aerospace applications, and robot applications.

[0006] Here, industrial materials that constitute various components can be broadly divided into organic materials such as resins and rubber, and inorganic materials such as ceramics and metals. As mentioned above, organic materials have excellent flexibility but poor heat resistance. In contrast, inorganic materials have excellent heat resistance but poor flexibility. Thus, when it comes to industrial materials, a trade-off in properties occurs depending on the material selected.

[0007] Therefore, when the adhesive structure is made of inorganic materials, it has excellent heat resistance and reduces contamination problems, but there is a risk that it will not be possible to obtain sufficient adhesive strength, and it will not be possible to adequately fix the object or to adsorb and remove particles.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an adhesive structure that can be used stably even in high-temperature environments and clean environments, and that can obtain sufficient adhesive strength.

[0009] In order to solve this problem, the inventors conducted extensive research and discovered that by forming a special structure on the surface of a substrate made of an inorganic material such as ceramic or metal, sufficient adhesive strength can be imparted to the surface, making it possible to use the substrate as an adhesive structure.

[0010] The present invention has been made based on the above-mentioned findings, and the adhesive structure of aspect 1 of the present invention is characterized in that a fiber structure layer composed of a plurality of fiber bodies made of an inorganic material is formed on at least a part of the surface of a substrate made of an inorganic material, and the circular equivalent diameter D of a cross section perpendicular to the extension direction of the fiber bodies constituting the fiber structure layer is in the range of 15 nm to 400 nm, and the aspect ratio H / D calculated from the circular equivalent diameter D and height H of the fiber bodies is 3 or more.

[0011] The bonded structure of aspect 1 of the present invention is composed of an inorganic material such as ceramics or metal, and therefore has excellent heat resistance and can sufficiently suppress contamination problems. Furthermore, a fiber structure layer composed of a plurality of fibers is formed on at least a portion of the surface of a substrate, and the equivalent circle diameter D of the cross section perpendicular to the extension direction of the fibers is in the range of 15 nm to 400 nm. The aspect ratio H / D calculated from the equivalent circle diameter D and height H of the cross section of the fibers is 3 or greater, thereby imparting sufficient adhesive strength to the surface of the substrate. Therefore, the bonded structure of aspect 1 of the present invention can be used stably even in high-temperature and clean environments, and can obtain sufficient adhesive strength. In other words, the bonded structure of aspect 1 of the present invention can be used as an anti-slip member or a foreign matter adsorption member that can be used stably even in high-temperature and clean environments.

[0012] The bonded structure of Aspect 2 of the present invention is characterized in that the fibrous bodies constituting the fiber structure layer are made of a metal oxide in the bonded structure of Aspect 1. According to the bonded structure of Aspect 2 of the present invention, since the fibrous bodies constituting the fiber structure layer are made of a metal oxide, the fiber structure layer can be reliably formed in the above-mentioned shape, and sufficient adhesive strength can be obtained, while excellent heat resistance and contamination problems can be sufficiently suppressed.

[0013] The bonded structure of Aspect 3 of the present invention is characterized in that, in the bonded structure of Aspect 2, the metal oxide is aluminum oxide. According to the bonded structure of Aspect 3 of the present invention, the fibrous bodies constituting the fiber structure layer are made of aluminum oxide, so that sufficient adhesive strength can be obtained, heat resistance is excellent, and contamination problems can be sufficiently suppressed.

[0014] The bonded structure of Aspect 4 of the present invention is characterized in that the fiber structure layer occupies 20% or more of the surface area of ​​the bonded structure of any one of Aspects 1 to 3. According to the bonded structure of Aspect 4 of the present invention, since the fiber structure layer occupies 20% or more of the surface area, sufficient adhesive strength can be reliably obtained and particles can be reliably removed.

[0015] The bonded structure of Aspect 5 of the present invention is characterized in that the adsorption rate of particles having a particle diameter of 1 μm or more and 30 μm or less is 5% or more in the bonded structure of any one of Aspects 1 to 4. According to the bonded structure of Aspect 5 of the present invention, the adsorption rate of particles having a particle diameter of 1 μm or more and 30 μm or less is 5% or more, so that particles can be reliably removed by adhesion.

[0016] The bonded structure of Aspect 6 of the present invention is the bonded structure of any one of Aspects 1 to 5, characterized in that the static friction coefficient of the surface of the substrate with respect to silicon is 0.30 or more. According to the bonded structure of Aspect 6 of the present invention, since the static friction coefficient of the surface of the substrate with respect to silicon is 0.30 or more, the target member can be reliably fixed.

[0017] The bonded structure of aspect 7 of the present invention is a method for manufacturing a bonded structure according to any one of claims 1 to 6, and is characterized by comprising a pretreatment step of forming a mirror-finished metal surface on the surface of the base material, an anodizing step of anodizing the metal surface, and an etching step of dissolving and removing a portion of the resulting anodized layer, wherein the anodizing step and the etching step are repeated multiple times.

[0018] According to the bonded structure of the seventh aspect of the present invention, the mirror-finished metal surface is repeatedly anodized and etched, so that the above-described fiber structure layer can be formed on the surface of the substrate, thereby producing a bonded structure that can be used stably even in high-temperature and clean environments and that can obtain sufficient adhesive strength.

[0019] According to the present invention, it is possible to provide an adhesive structure that can be stably used even in high-temperature environments and clean environments and that can obtain sufficient adhesive strength, and a method for manufacturing the adhesive structure.

[0020] FIG. 1 is a schematic explanatory diagram of a bonded structure according to an embodiment of the present invention. FIG. 2 is an SEM observation photograph of a fiber structure layer in a bonded structure according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a fiber structure layer in a bonded structure according to an embodiment of the present invention. FIG. 4 is an SEM observation photograph of a fiber structure layer in a bonded structure according to an embodiment of the present invention. FIG. 5 is a schematic diagram of a fiber structure layer in a bonded structure according to an embodiment of the present invention. FIG. 6 is an explanatory diagram of a fibrous body in a bonded structure according to an embodiment of the present invention. FIG. 7 is an explanatory diagram showing a method for measuring a particle adsorption rate. FIG. 8 is an explanatory diagram showing a method for measuring a static friction coefficient. FIG. 9 is a flow chart showing a method for manufacturing a bonded structure according to an embodiment of the present invention.

[0021] Hereinafter, a bonded structure 10 according to one embodiment of the present invention will be described with reference to the accompanying drawings. The bonded structure 10 according to this embodiment is used to temporarily fix an object or to adsorb and remove particles present on the surface of a substrate or the like in gripping devices, conveying devices, manufacturing devices, and the like used in high-temperature or clean environments in the aerospace, semiconductor manufacturing process, medical, and other fields.

[0022] The adhesive structure 10 of this embodiment has a substrate 11 made of an inorganic material such as ceramics or metal, and a fiber structure layer 20 made of a plurality of fiber bodies 21 is formed on at least a portion of the surface of the substrate 11. There are no particular restrictions on the shape or size of the substrate 11, but in this embodiment, as shown in Fig. 1, the substrate 11 is plate-shaped and has a thickness in the range of, for example, 10 µm to 10 cm.

[0023] Here, examples of inorganic materials constituting the substrate 11 include metal, ceramics, silicon, and glass. The inorganic material constituting the substrate 11 preferably has a melting point of 100°C or higher and a decomposition temperature of 100°C or higher, more preferably a melting point of 300°C or higher and a decomposition temperature of 300°C or higher, and even more preferably a melting point of 500°C or higher and a decomposition temperature of 500°C or higher.

[0024] The metal constituting the substrate 11 may be a simple metal or an alloy. Alloys include those composed of multiple metal elements and those composed of a metal element and a non-metal element. Examples of simple metals include aluminum, nickel, iron, copper, titanium, tungsten, and magnesium. Examples of alloys include aluminum alloys, NiP, stainless steel, and copper alloys.

[0025] The ceramics constituting the substrate 11 may be oxides, nitrides, or carbides. Examples of ceramics include aluminum oxide (alumina), titanium oxide, and quartz. The inorganic material constituting the substrate 11 is preferably a metal, and more preferably contains any of copper, a copper alloy, aluminum, an aluminum alloy, and a NiP alloy.

[0026] The fiber structure layer 20 formed on the surface of the substrate 11 has a structure in which a plurality of fiber bodies 21 are arranged upright, as shown in Figures 2A and 2B or 3A and 3B. ２ The number of fibrous bodies 21 per ３ It may be 10 or more. ４ It may be 10 or more. ５ Although not particularly limited, the number of fibers per 1 mm ２ The number of fibrous bodies 21 per ２０ It may be 10 or less, １７ It may be 10 or less, １４The number of adjacent fibrous bodies 21 may be 1 or less. Furthermore, although not particularly limited, the distance between the nearest fibrous bodies 21 may be 1 nm or more, 10 nm or more, or 50 nm or more. Furthermore, although not particularly limited, the distance between the nearest fibrous bodies 21 may be 1 μm or less, 500 nm or less, or 200 nm or less. Here, the metal oxide constituting the fibrous bodies 21 is preferably aluminum oxide. In this embodiment, the substrate 11 is made of aluminum, and the fibrous bodies 21 are made of aluminum oxide.

[0027] The fibrous body 21 has an average circle-equivalent diameter D of 15 nm to 400 nm in a cross section perpendicular to its extension direction. The circle-equivalent diameter D of the fibrous body 21 can be measured from a cross-sectional SEM photograph of the fiber structure layer 20 taken with an SEM (scanning electron microscope). In this embodiment, as shown in FIG. 4 , the fibrous body 21 has a roughly conical shape, and the circle-equivalent diameter D is the circle-equivalent diameter at the cross section of the bottom of the conical shape. Here, the lower limit of the average circle-equivalent diameter D of the cross section of the fibrous body 21 is more preferably 30 nm or more, and even more preferably 50 nm or more. On the other hand, the average circle-equivalent diameter D of the cross section of the fibrous body 21 is preferably 300 nm or less, and even more preferably 200 nm or less.

[0028] Furthermore, the aspect ratio H / D of the fibrous body 21, calculated from the average value of the equivalent circle diameter D and the average height H of the fibrous body 21, is preferably 3 or more. The aspect ratio of the fibrous body 21 can be measured from a cross-sectional SEM photograph of the fiber structure layer 20 taken with an SEM (scanning electron microscope). The aspect ratio H / D of the fibrous body 21 is preferably 4 or more, and more preferably 5 or more. On the other hand, the aspect ratio H / D of the fibrous body 21 is preferably 50 or less, and more preferably 30 or less.

[0029] The average height H of the fibrous body 21 is preferably in the range of 50 nm to 3000 nm. The height of the fibrous body 21 can be measured from a cross-sectional SEM photograph of the fiber structure layer 20 taken with an SEM (scanning electron microscope). The average height H of the fibrous body 21 is more preferably 300 nm or more, and even more preferably 500 nm or more. On the other hand, the average height H of the fibrous body 21 is preferably 3000 nm or less, and even more preferably 2000 nm or less.

[0030] In the adhesive structure 10 of this embodiment, the area ratio (occupancy ratio) of the fiber structure layer 20 on the surface (adhesion surface) is preferably 20% or more. In the adhesive structure 10 shown in FIG. 1 , the fiber structure layer 20 is formed on approximately 70% of the surface of the substrate 11. The area ratio of the fiber structure layer 20 on the surface of the substrate 11 is preferably 25% or more, and more preferably 50% or more. Furthermore, the area ratio of the fiber structure layer 20 on the surface of the substrate 11 is 100% or less.

[0031] In the adhesive structure 10 of this embodiment, the adsorption rate of particles having a particle diameter of 1 μm to 30 μm is set to 5% or higher. While not particularly limited, the adsorption rate of particles having a particle diameter of 1 μm to 30 μm may be 7% or higher, or 10% or higher. Furthermore, the adsorption rate of particles having a particle diameter of 1 μm to 30 μm may be 100% or lower, 70% or lower, or 50% or lower. The particle adsorption rate can be calculated using the procedure shown in FIG. 5 . Specifically, a liquid L containing particles P (PSL particles: polystyrene latex particles) having a particle diameter of 1 μm to 30 μm is dropped onto the surface of an object O (e.g., a wafer) to disperse the particles P. The surface of the adhesive structure 10 on which the fiber structure layer 20 is formed is brought into contact with the object O to adsorb the particles P. The number of particles in the contact area of ​​the adhesive structure 10 on the surface of the object O before and after contact is counted, and the adsorption rate of the particles P is calculated.

[0032] Furthermore, in the adhesive structure 10 of this embodiment, the static friction coefficient μ on the surface of the substrate 11 on which the fiber structure layer 20 is formed is set to 0.30 or more. The static friction coefficient μ on the surface of the substrate 11 is preferably 0.35 or more, and more preferably 0.40 or more. There is no particular upper limit to the static friction coefficient μ, but in reality, the static friction coefficient μ is 10 or less. Here, the static friction coefficient μ on the surface of the substrate 11 can be calculated using the following formulas (1) to (4) and FIG. 6. Formula (1) is the formula for the maximum static friction coefficient. In FIG. 6, m is the mass of the object, g is the gravitational acceleration, F ０ is the maximum static friction force, and N is the normal force. Specifically, when the angle at which an object starts to slide is θ, the coefficient of static friction is expressed as μ = tan θ. Therefore, the coefficient of static friction μ can be obtained by substituting the angle θ at which an object starts to slide into equation (4).

[0033] Next, an example of a method for manufacturing the bonded structure 10 of this embodiment will be described. In the bonded structure 10 of this embodiment, as described above, the substrate 11 is made of aluminum, and the fibrous body 21 is made of aluminum oxide. As shown in the flow diagram of Fig. 7, this embodiment includes a pretreatment step S01, an anodizing step S02, and an etching step S03.

[0034] In the pretreatment step S01, a mirror-finished metal surface is formed on the surface of the substrate 11. In this embodiment, since the substrate 11 is made of aluminum, the surface of the substrate 11 is electropolished to a mirror finish, thereby forming a mirror-finished metal surface. In this embodiment, the substrate 11 is electropolished with an electropolishing solution (e.g., HClO ４ / EtOH), at a temperature of 0°C to 5°C, for a retention time of 4 minutes to 5 minutes, and at a current density of 0.20 A / cm ２ 0.25A / cm or more ２ Electrolytic polishing is carried out under the following conditions.

[0035] In the anodization step S02, the metal surface formed in the pretreatment step S01 is anodized. An anodization film is formed by the anodization. In this embodiment, a treatment liquid (e.g., H ３ P.O.４ Anodizing is performed using a solution of 1,000 ppm or more of ammonium hydroxide (aqueous solution) at a temperature of 0° C. to 5° C., a holding time of 60 minutes to 70 minutes, and a voltage of 160 V to 170 V.

[0036] In the etching step S03, a part of the anodized layer obtained in the anodizing step S02 is dissolved and removed. ２ CrO ４ / HPO ４ Aqueous solution or H ３ P.O. ４ The etching treatment is carried out using a solution of 1,000 ppm or more of acetic acid and 1,000 ppm or more of acetic acid at a temperature of 70° C. to 75° C. for a retention time of 120 minutes to 130 minutes.

[0037] Here, by repeatedly performing the above-described anodizing step S02 and etching step S03, a fiber structure layer 20 having a plurality of fibrous bodies 21 standing upright is formed. Note that by adjusting the number of times the anodizing step S02 and etching step S03 are repeated, it is possible to manufacture a fiber structure layer 20 having the structure shown in FIGS. 2A and 2B or the structure shown in FIGS. 3A and 3B. Although not particularly limited, the number of times the anodizing step S02 and etching step S03 are repeated may be two or more, three or more, or five or more. Furthermore, the number of times the anodizing step S02 and etching step S03 are repeated may be 50 or less, 30 or less, or 10 or less.

[0038] The bonded structure 10 of this embodiment is manufactured by the above-described steps.

[0039] The adhesive structure 10 of this embodiment, configured as described above, is made of an inorganic material such as ceramic or metal, and therefore has excellent heat resistance and can sufficiently suppress contamination problems. Furthermore, a fiber structure layer 20 composed of a plurality of fiber bodies 21 is formed on at least a portion of the surface of the substrate 11. The fiber bodies 21 constituting the fiber structure layer 20 have a cross-sectional circle-equivalent diameter D of 15 nm to 400 nm inclusive, perpendicular to the extension direction, and the aspect ratio H / D calculated from the circle-equivalent diameter D and height H of the fiber bodies 21 is 3 or greater. This allows for sufficient adhesive strength to be imparted to the surface of the substrate 11. Therefore, the adhesive structure 10 can be used stably even in high-temperature and clean environments, and sufficient adhesive strength can be obtained.

[0040] In the adhesive structure 10 of this embodiment, when the fiber body 21 constituting the fiber structure layer 20 is composed of a metal oxide, the fiber structure layer 20 composed of the fiber body 21 of the above-mentioned configuration can be reliably formed, and sufficient adhesive strength can be obtained, while also having excellent heat resistance and being able to sufficiently suppress contamination problems.

[0041] In the adhesive structure 10 of this embodiment, when the metal oxide constituting the fibrous body 21 is composed of aluminum oxide, an appropriate fiber structure layer 20 can be formed to obtain sufficient adhesive strength.

[0042] In the bonded structure 10 of this embodiment, when the area ratio of the fiber structure layer 20 on the surface of the substrate 11 is 20% or more, the fiber structure layer 20 can reliably obtain sufficient adhesive strength.

[0043] In the adhesive structure 10 of this embodiment, when the adsorption rate of particles having a particle diameter of 1 μm or more and 30 μm or less is 5% or more, particles present on the surface of the object can be reliably adhered and removed.

[0044] In the bonded structure 10 of this embodiment, if the static friction coefficient of the surface of the substrate 11 against silicon is 0.30 or more, the bonded structure 10 can be used to reliably fix the target member.

[0045] In the manufacturing method of the bonded structure 10 of this embodiment, a mirror-finished metal surface is formed on the surface of the substrate 11, and this metal surface is repeatedly subjected to anodizing and etching, so that the above-mentioned fiber structure layer 20 can be formed on the surface of the substrate 11. This makes it possible to manufacture a bonded structure 10 that can be used stably even in high-temperature and clean environments and that can obtain sufficient adhesive strength.

[0046] The adhesive structure according to the embodiment of the present invention has been described above, but the present invention is not limited thereto and can be modified as appropriate within the scope of the technical concept of the invention. For example, in the present embodiment, the substrate is made of aluminum and the fibrous body constituting the fiber structure layer is formed of aluminum oxide, but the present invention is not limited thereto and the substrate and the fibrous body may be made of other inorganic materials.

[0047] The results of confirmation experiments conducted to confirm the effects of the present invention will be described below.

[0048] (Example 1 of the present invention) First, a substrate (length: 7 mm, width: 7 mm, thickness: 1 mm) made of an inorganic material shown in Table 1 was prepared. An electrolytic polishing solution (20 vol% HClO ４ / 80 vol% EtOH) at a current density of 0.2 A / cm ２ The surface of the substrate was subjected to electrolytic polishing under the conditions of a temperature of 0° C. and a treatment time of 4 minutes to give a mirror finish to the surface of the substrate.

[0049] The obtained sample was anodized for 120 minutes in a 0.2 M malic acid aqueous solution containing 3 mM phosphoric acid at a bath temperature of 16°C and a constant voltage of 350 V. After anodization, the sample was immersed in an aqueous solution containing 1.8 mass% chromic acid and 6 mass% phosphoric acid at a bath temperature of 70°C for 2 hours to selectively dissolve and remove only the anodized layer, thereby obtaining an aluminum plate with a recessed pattern corresponding to the pore arrangement on the back surface of the anodized film.

[0050] The aluminum plate with the recessed pattern was anodized again for 35 seconds under the same conditions as the previous anodization. The resulting sample was etched for 16 minutes in a 10 mass% aqueous phosphoric acid solution at a bath temperature of 30°C. Five sets of anodization and etching were repeated to obtain a pillar array structure with a diameter of 15 nm and a height of 50 nm.

[0051] (Example 2 of the present invention) A substrate (length: 7 mm, width: 7 mm, thickness: 1 mm) made of the inorganic material shown in Table 1 was prepared. An electropolishing solution (20 vol% HClO ４ / 80 vol% EtOH) at a current density of 0.2 A / cm ２ The surface of the substrate was subjected to electrolytic polishing under the conditions of a temperature of 0° C. and a treatment time of 4 minutes to give a mirror finish to the surface of the substrate.

[0052] For the electropolished sample, 0.1 mol H ３ P.O. ４ Anodization was carried out using an aqueous solution under conditions of a voltage of 160 V, a temperature of 0° C., and a treatment time of 60 minutes. ２ CrO ４ / 6,0mass%HPO ４ The anodized film was partially removed by etching using an aqueous solution at 70°C for 120 minutes, yielding an aluminum plate with a recess pattern corresponding to the arrangement of pores on the back surface of the anodized film.

[0053] Using an aluminum plate with a recessed pattern, 0.1 mol H ３ P.O. ４ Anodization was carried out using an aqueous solution under conditions of a voltage of 160 V, a temperature of 0°C, and a treatment time of 60 minutes, and then immersed in a 10 mass% H ３ P.O. ４ An alumina pillar array structure was formed by etching using an aqueous solution at a temperature of 30° C. for a treatment time of 160 minutes.

[0054] (Invention Example 3) The same procedure as in Invention Example 2 was carried out on the electrolytically polished sample, except that the anodization voltage was set to 250 V, to obtain a pillar array structure having a diameter of 200 nm and a height of 1000 nm.

[0055] (Invention Example 4) The same procedure as in Invention Example 2 was carried out on the electrolytically polished sample, except that the anodization voltage was set to 350 V, to obtain a pillar array structure having a diameter of 300 nm and a height of 1200 nm.

[0056] Invention Example 5 The same procedure as in Invention Example 2 was carried out on the electrolytically polished sample, except that the anodization voltage was set to 130 V, to obtain a pillar array structure with a diameter of 72 nm and a height of 611 nm.

[0057] (Invention Example 6) The same procedure as in Invention Example 2 was carried out on the electrolytically polished sample, except that the anodization voltage was set to 100 V, to obtain a pillar array structure having a diameter of 91 nm and a height of 23,300 nm.

[0058] Comparative Example 1 First, a substrate (length: 7 mm, width: 7 mm, thickness: 1 mm) made of an inorganic material shown in Table 1 was prepared. An electrolytic polishing solution (20 vol% HClO ４ / 80 vol% EtOH) at a current density of 0.2 A / cm ２ Electrolytic polishing was carried out under the conditions of a temperature of 0° C. and a treatment time of 4 minutes to obtain an aluminum mirror surface.

[0059] Comparative Example 2 The same procedure as in Invention Example 1 was carried out except that etching using an aluminum plate having a recess pattern was carried out for 25 minutes, thereby obtaining a pillar array structure having a diameter of 10 nm and a height of 35 nm.

[0060] Comparative Example 3 The same procedure as in Invention Example 1 was carried out except that etching using an aluminum plate having a recess pattern was carried out for 9 minutes, and a pillar array structure having a diameter of 25 nm and a height of 30 nm was obtained.

[0061] Comparative Example 4 The same procedure as in Invention Example 1 was carried out except that etching using an aluminum plate having a recess pattern was carried out for 5 minutes, thereby obtaining a pillar array structure having a diameter of 50 nm and a height of 100 nm.

[0062] The particle adsorption rate of the bonded structure obtained as described above was measured by the following procedure.

[0063] A 300 mm disk-shaped silicon wafer S was prepared. A liquid containing standard particles with an average particle diameter of 30 μm was dropped onto the surface of this silicon wafer to disperse the standard particles. In this state, the number of particles present in the area on the surface of the silicon wafer where the adhesive structure was to be laminated was measured using a particle counter. Next, the adhesive structure and the silicon wafer were laminated so that the surface of the adhesive structure on which the tube array structure was formed came into contact with the surface of the silicon wafer S on which the standard particles (polystyrene latex particles: 30 μm) were dispersed. After allowing them to contact for 30 seconds, the adhesive structure was removed.

[0064] The number of particles present on the surface of the silicon wafer in the region where the adhesive structure was laminated was measured using a particle counter. The particle adsorption rate was calculated from the number of particles before and after laminating the adhesive structure. The results are shown in Table 1.

[0065]

[0066] In Comparative Example 1, in which a fiber structure layer was not formed, and Comparative Examples 2 to 4, in which the circular equivalent diameter D of the cross section of the fiber body and the aspect ratio H / D of the circular equivalent diameter D to the height H were outside the range of the present invention, the particle adsorption rate was 0.0%, and no effect of removing particles was observed.

[0067] In contrast, in Examples 1 to 6 of the present invention, a fiber structure layer was formed in which the circular equivalent diameter D of the cross section of the fiber body and the aspect ratio H / D of the height H and the circular equivalent diameter D were within the range of the present invention, and it was confirmed that the particle adsorption rate was 5% or more and that particles present on the surface of the target object could be removed.

[0068] From the above, it was confirmed that the present invention can provide an adhesive structure that can be used stably even in high-temperature environments and clean environments and that can obtain sufficient adhesive strength.

[0069] According to the present invention, it is possible to provide an adhesive structure that can be used stably even in high-temperature environments and clean environments and that can obtain sufficient adhesive strength.

[0070] REFERENCE SIGNS LIST 10 Bonded structure 11 Substrate 20 Fiber structure layer 21 Fiber body L Liquid containing particles with a particle diameter of 1 μm or more and 30 μm or less O Object P Particles

Claims

1. An adhesive structure, characterized in that a fiber structure layer composed of a plurality of fibers made of an inorganic material is formed on at least a portion of the surface of a substrate made of an inorganic material, the fiber structures constituting the fiber structure layer have a cross-sectional area perpendicular to the extension direction of the fibers, the circular equivalent diameter D of the cross-section perpendicular to the extension direction of the fibers is within a range of 15 nm to 400 nm, and the aspect ratio H / D calculated from the circular equivalent diameter D and height H of the fibers is 3 or more.

2. The adhesive structure according to claim 1, characterized in that the fibrous body constituting the fiber structure layer is composed of a metal oxide.

3. The bonded structure according to claim 2, wherein the metal oxide is aluminum oxide.

4. The adhesive structure according to claim 1, characterized in that the occupancy rate of the fiber structure layer on the surface is 20% or more.

5. The bonded structure according to claim 1, characterized in that the adsorption rate of particles having a particle diameter of 1 μm or more and 30 μm or less is 5% or more.

6. The bonded structure according to claim 1, characterized in that the static friction coefficient against silicon is 0.30 or more.

7. A method for manufacturing an adhesive structure for producing the adhesive structure described in any one of claims 1 to 6, comprising a pretreatment step of forming a mirror-finished metal surface on the surface of the base material, an anodizing step of anodizing the metal surface, and an etching step of dissolving and removing a portion of the resulting anodized layer, characterized in that the anodizing step and the etching step are repeated multiple times.

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