JP2007204802A - Method of manufacturing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure having an anodized film having micropores with uniform regularity even in a large surface area and a method of manufacturing the same. <P>SOLUTION: The method of manufacturing the structure for obtaining a structure at least partly having an aluminum member provided with an aluminum substrate and the anodized film present on the surface of the aluminum substrate and having the micropores having ≥50% degree of regularity and a S/N ratio of the degree of regularity of ≥20, includes an anodization process for applying the anodization on the surface of the aluminum substrate under a condition that the average flow rate of an electrolyte is 0.5-20.0 m/min. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a structure and a manufacturing method thereof.

  In the technical fields of metal and semiconductor thin films, thin wires, dots, etc., the phenomenon of electrical, optical and chemical peculiarities can be seen by confining the movement of free electrons in a size smaller than a certain characteristic length. It has been known. Such a phenomenon is called “quantum mechanical size effect (quantum size effect)”. Research and development of functional materials applying such a unique phenomenon is being actively conducted. Specifically, a material having a structure finer than several hundred nm is referred to as a “microstructure” or “nanostructure”, and is one of the objects of material development.

  As a method for manufacturing such a fine structure, for example, a method for directly manufacturing a nano structure by a semiconductor processing technique including a fine pattern forming technique such as photolithography, electron beam exposure, and X-ray exposure can be given.

In particular, much research has been conducted on methods for producing nanostructures having a regular microstructure.
For example, as a method for forming a regular structure in a self-regulating manner, an aluminum oxide film (anodized film) obtained by subjecting aluminum to an anodizing treatment in an electrolytic solution can be mentioned. It is known that a plurality of fine pores (micropores) having a diameter of about several nm to several hundred nm are regularly formed in the anodized film. By using this self-ordering of the anodized film and obtaining a perfectly regular arrangement, theoretically, hexagonal prism cells with a regular hexagonal bottom centered around the micropores are formed, and adjacent micropores are formed. It is known that the connecting line forms an equilateral triangle.
For example, Non-Patent Document 1 describes an anodized film in which the pore diameter variation of micropores is 3% or less. Non-Patent Document 2 describes that pores are spontaneously formed in the anodized film as the oxidation proceeds. Non-Patent Document 3 also proposes forming an Au dot array on a Si substrate using a porous oxide film as a mask.

  The greatest feature of the material of the anodic oxide film is that it adopts a honeycomb structure in which a plurality of micropores are formed in a direction substantially perpendicular to the substrate surface and in parallel at substantially equal intervals. In addition to this, the pore diameter, the pore interval, and the pore depth can be controlled relatively freely, which is a feature not found in other materials (see Non-Patent Document 3).

As an application example of the anodized film, various devices such as a nano device, a magnetic device, and a light emitter are known.
For example, in Patent Document 1, Co and Ni, which are magnetic metals, are filled in a micropore as a magnetic device, ZnO, which is a light emitting material, is filled in a micropore, and an enzyme / antibody is used as a biosensor in a micropore. Application examples such as filling inside are described.

  In the method of making anodized film with regularly arranged micropores by using such self-ordering of anodized film, not only the regularity of micropores is improved, but also a structure with a larger area is made uniform. In addition, there is a demand for technology that can be manufactured efficiently.

JP 2000-31462 A H. Masuda et. Al. , Jpn. J. et al. Appl. Phys. , Vol. 37 (1998), pp. L1340-1342, Part 2, No. 1 11A, 1 November 1998 (FIG. 2.) “Surface Technology Handbook”, edited by Surface Technology Association (1998), Nikkan Kogyo Shimbun, p. 490-553 Hideki Masuda, “Highly Ordered Metal Nanohole Array Based on Anodized Alumina”, Solid State Physics, 1996, Vol. 31, No. 5, p. 493-499

  Accordingly, an object of the present invention is to provide a structure having an anodic oxide film having micropores having uniform regularity even in a large area and a method for manufacturing the structure.

  As a result of intensive studies to achieve the above object, the present inventor has controlled the average flow rate of the electrolyte when electrolyzing the anodic oxide film, thereby providing an anodic oxide film having micropores having uniform regularity even in a large area. The present inventors have found that a structure having can be obtained and completed the present invention.

That is, the present invention provides the following (1) and (2).
(1) An aluminum member having an aluminum substrate and an anodized film having micropores present on the surface of the aluminum substrate and having a degree of ordering of 50% or more and an SN ratio of the degree of ordering of 20 or more. A structure manufacturing method for obtaining a structure having at least a part thereof,
The manufacturing method of a structure which comprises the anodizing process process which anodizes on the surface of the said aluminum substrate on the conditions from which the average flow rate of electrolyte solution is 0.5-20.0 m / min.
(2) A structure obtained by the method for producing a structure according to (1) above.

  According to the structure manufacturing method of the present invention, it is possible to obtain a structure having an anodized film having micropores having a uniform regularity even in a large area, and the structure of the structure by high-speed continuous processing using web processing can be obtained. Manufacturing is also possible.

The present invention is described in detail below.
The structure manufacturing method according to the first aspect of the present invention (hereinafter also referred to as “the manufacturing method of the present invention”) is present on an aluminum substrate and the surface of the aluminum substrate, and has a degree of ordering of 50% or more. And an anodized film having micropores having an order of SN ratio of 20 or more, and a method for producing a structure having an aluminum member having at least a part thereof, the surface of the aluminum substrate And an anodizing process in which an anodizing process is performed under the condition that the average flow rate of the electrolytic solution is 0.5 to 20.0 m / min.
Next, an aluminum substrate used in the production method of the present invention and an anodic oxidation treatment applied to the aluminum substrate will be described in detail.

[Aluminum substrate]
The aluminum substrate used in the production method of the present invention is not particularly limited, and specific examples thereof include a commercially available aluminum substrate; an alloy plate containing aluminum as a main component and a trace amount of foreign elements; low purity aluminum (for example, recycled) Examples include a substrate on which high-purity aluminum is deposited on a material); a substrate in which high-purity aluminum is coated on the surface of a silicon wafer, quartz, glass or the like by a method such as vapor deposition or sputtering; a resin substrate on which aluminum is laminated;

  In the present invention, the surface of the aluminum substrate on which the anodized film is provided by an anodic oxidation treatment described later preferably has an aluminum purity of 99.5% by mass or more, more preferably 99.9% by mass or more. Preferably, it is 99.99 mass% or more. When the aluminum purity is within the above range, the regularity of the micropores is further improved.

  In the present invention, the surface of the aluminum substrate on which the anodized film is provided by an anodic oxidation process to be described later is preferably preliminarily degreased and mirror-finished, and particularly obtained by the production method of the present invention. In the case where the structure is used for the purpose of utilizing light transparency, it is preferable to perform heat treatment in advance from the viewpoint of widening the region where the micropores are regularly arranged.

<Heat treatment>
The heat treatment is preferably performed at 200 to 350 ° C. for about 30 seconds to 2 minutes. Specifically, for example, a method of placing an aluminum substrate in a heating oven can be used.
By performing such a heat treatment, a region in which micropores generated by an anodic oxidation process to be described later are regularly arranged becomes wide.
Moreover, it is preferable to cool the aluminum substrate after heat treatment rapidly. As a method for cooling, for example, a method of directly feeding into water can be mentioned.

<Degreasing treatment>
The degreasing treatment uses acid, alkali, organic solvent, etc. to dissolve and remove the organic components such as dust, fat, and resin adhered to the surface of the aluminum substrate, and in each treatment described later due to the organic components. This is done for the purpose of preventing the occurrence of defects.

Specifically, as the degreasing treatment, for example, a method in which an organic solvent such as various alcohols (for example, methanol), various ketones (for example, methyl ethyl ketone), benzine, volatile oil or the like is brought into contact with the aluminum substrate surface at room temperature (organic Solvent method); a method of bringing a liquid containing a surfactant such as soap or neutral detergent into contact with the aluminum substrate surface at a temperature from room temperature to 80 ° C., and then washing with water (surfactant method); concentration of 10 to 200 g A method in which an aqueous solution of sulfuric acid / L is brought into contact with an aluminum substrate surface for 30 to 80 seconds at a temperature from room temperature to 70 ° C. and then washed with water; an aqueous sodium hydroxide solution having a concentration of 5 to 20 g / L is applied to the aluminum substrate surface at room temperature. while contacting about seconds, the aluminum substrate surface and the electrolyte by passing a direct current of a current density of 1 to 10 a / dm ² in the cathode, the , A method of neutralizing by bringing a nitric acid aqueous solution having a concentration of 100 to 500 g / L into contact; while bringing various known anodizing electrolytes into contact with the aluminum substrate surface at room temperature, the aluminum substrate surface is used as a cathode and a current density of 1 to A method in which a 10 A / dm ² direct current is applied or an alternating current is applied for electrolysis; an alkaline aqueous solution having a concentration of 10 to 200 g / L is brought into contact with the aluminum substrate surface at 40 to 50 ° C. for 15 to 60 seconds; A method of neutralizing by bringing a nitric acid aqueous solution having a concentration of 100 to 500 g / L into contact; an emulsion obtained by mixing light oil, kerosene, etc. with a surfactant, water, etc. is brought into contact with the aluminum substrate surface at a temperature from room temperature to 50 ° C. Then, a method of washing with water (emulsification and degreasing method); a mixed solution of sodium carbonate, phosphates, surfactant and the like on the surface of the aluminum substrate at a temperature from room temperature to 50 ° C. Contacting 0-180 seconds, then, a method of washing with water (phosphate method); and the like.

  Among these, the organic solvent method, the surfactant method, the emulsion degreasing method, and the phosphate method are preferable from the viewpoint that the fat content on the aluminum surface can be removed while the aluminum hardly dissolves.

  Moreover, a conventionally well-known degreasing agent can be used for a degreasing process. Specifically, for example, various commercially available degreasing agents can be used by a predetermined method.

<Mirror finish processing>
The mirror finishing process is performed in order to eliminate unevenness on the surface of the aluminum substrate, for example, rolling streaks generated during the rolling of the aluminum substrate, and improve the uniformity and reproducibility of the sealing process by an electrodeposition method or the like.
In the present invention, the mirror finish is not particularly limited, and a conventionally known method can be used. Examples thereof include mechanical polishing, chemical polishing, and electrolytic polishing.

  Examples of the mechanical polishing include a method of polishing with various commercially available polishing cloths, a method of combining various commercially available abrasives (for example, diamond, alumina) and a buff. Specifically, when an abrasive is used, a method in which the abrasive used is changed from coarse particles to fine particles over time is preferably exemplified. In this case, the final polishing agent is preferably # 1500. Thereby, the glossiness can be 50% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 50% or more).

As chemical polishing, for example, “Aluminum Handbook”, 6th edition, edited by Japan Aluminum Association, 2001, p. Examples thereof include various methods described in 164 to 165.
Further, phosphoric acid - nitric acid method, Alupol I, Alupol V, Alcoa R5, H 3 PO 4 -CH 3 COOH-Cu _{method, H 3 PO 4 -HNO 3 -CH} 3 COOH method are preferably exemplified. Among these, the phosphoric acid-nitric acid method, the H ₃ PO ₄ —CH ₃ COOH—Cu method, and the H ₃ PO ₄ —HNO ₃ —CH ₃ COOH method are preferable.
By chemical polishing, the glossiness can be made 70% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 70% or more).

As electrolytic polishing, for example, “Aluminum Handbook”, 6th edition, edited by Japan Aluminum Association, 2001, p. 164-165; various methods described in US Pat. No. 2,708,655; “Practical Surface Technology”, vol. 33, no. 3, 1986, p. The method described in 32-38;
By electropolishing, the gloss can be 70% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 70% or more).

  These methods can be used in appropriate combination. Specifically, for example, a method of performing mechanical polishing in which the abrasive is changed from coarse particles to fine particles with time, and then performing electrolytic polishing is preferable.

By mirror finishing, for example, a surface having an average surface roughness R _{a of} 0.1 μm or less and a glossiness of 50% or more can be obtained. The average surface roughness _Ra is preferably 0.03 μm or less, and more preferably 0.02 μm or less. Further, the glossiness is preferably 70% or more, and more preferably 80% or more.
The glossiness is a regular reflectance obtained in accordance with JIS Z8741-1997 “Method 3 60 ° Specular Gloss” in the direction perpendicular to the rolling direction. Specifically, using a variable angle gloss meter (for example, VG-1D, manufactured by Nippon Denshoku Industries Co., Ltd.), when the regular reflectance is 70% or less, the incident reflection angle is 60 degrees and the regular reflectance is 70%. In the case of exceeding, the incident / reflection angle is 20 degrees.

[Anodic oxidation treatment]
The anodizing treatment is a treatment for forming an anodized film on the surface of the aluminum substrate.
In the present invention, as the method for anodizing the surface of the aluminum substrate, the micro-layer of the present anodizing treatment is performed before the anodizing treatment for forming micropores (hereinafter also referred to as “the present anodizing treatment”). It is preferable to form a depression that is a starting point for pore generation.

<Formation of depression>
The method for forming the depression is not particularly limited, and examples thereof include a self-ordering method using the self-ordering property of the anodized film.

The self-ordering method is a method of improving the regularity by utilizing the property that the micropores of the anodized film are regularly arranged and removing the factors that disturb the regular arrangement. Specifically, high-purity aluminum is used, and an anodized film is formed at a low speed over a long period of time (for example, several hours to several tens of hours) at a voltage corresponding to the type of electrolyte, and then removed. Perform membrane treatment.
In this method, since the pore diameter depends on the voltage, a desired pore diameter can be obtained to some extent by controlling the voltage.

  As a representative example of the self-ordering method, J.A. Electrochem. Soc. Vol. 144, no. 5, May 1997, p. L128 (Non-Patent Document 4), Jpn. J. et al. Appl. Phys. Vol. 35 (1996) Pt. 2, no. 1B, L126 (Non-patent Document 5), Appl. Phys. Lett, Vol. 71, no. 19, 10 Nov 1997, p. 2771 (Non-Patent Document 6) and Non-Patent Document 1 are known. Specifically, the self-ordering method is performed under the conditions shown below.

0.3 mol / L sulfuric acid, 0 ° C., 27 V, 450 minutes (non-patent document 4)
0.3 mol / L sulfuric acid, 10 ° C., 25 V, 750 minutes (Non-patent Document 4)
0.3 mol / L oxalic acid, 17 ° C., 40 V, 600 minutes; then pore-wide treatment (liquid containing 6 wt% phosphoric acid and 1.8 wt% chromic acid, 60 ° C., 840 minutes) (Non-patent Document 5)
0.3 mol / L oxalic acid, 17 ° C., 40-60 V, 36 minutes; then pore-wide treatment (5 wt% phosphoric acid, 30 ° C., 70 minutes) (Non-patent Document 6)
0.04 mol / L oxalic acid, 3 ° C., 80 V, film thickness 3 μm; then pore-wide treatment (5 wt% phosphoric acid, 30 ° C., 70 minutes) (Non-patent Document 6)
0.3 mol / L phosphoric acid, 0 ° C., 195 V, 960 minutes; then pore wide treatment (10 wt% phosphoric acid, 240 minutes) (Non-patent Document 1)

  The formation of the anodized film by the self-ordering method (hereinafter referred to as “self-ordered anodizing treatment”) is performed, for example, in a solution having an acid concentration of 1 to 10% by mass with an aluminum substrate as an anode. Can do. Examples of the solution used for the self-ordering anodizing treatment include sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid and the like, and these may be used alone. More than one species may be used in combination. Of these, phosphoric acid and oxalic acid are preferably used.

The average flow rate of the electrolytic solution in the self-ordering anodizing treatment is preferably 0.5 to 20.0 m / min, more preferably 1.0 to 15.0 m / min, and 2.0 to 10 Particularly preferred is 0.0 m / min. When the average flow rate of the electrolytic solution is within the above range, the regularity of the micropores can be further improved in the main anodizing treatment to be described later. It can also be outside the range of 5 to 20.0 m / min.
In addition, the method of flowing the electrolytic solution under the above-mentioned conditions in the self-ordering anodizing treatment is not particularly limited, but specific examples thereof include a method using a general stirring device such as a stirrer. In particular, it is preferable to use a stirrer that can control the stirring speed by digital display because the average flow velocity can be controlled. Examples of such a stirring apparatus include “Magnetic Stirrer HS-50D (manufactured by AS ONE)” and the like.

Further, the conditions of the self-ordering anodizing treatment cannot be determined unconditionally because they vary depending on the electrolytic solution used. In general, however, the electrolytic solution concentration is 0.1 to 20% by mass, and the liquid temperature is −10. ˜30 ° C., current density 0.01˜20 A / dm ² , voltage 3˜300 V, electrolysis time 0.5˜30 hours are preferable, electrolyte concentration 0.5˜15 mass%, liquid temperature −5˜5 More preferably, the temperature is 25 ° C., the current density is 0.05 to 15 A / dm ² , the voltage is 5 to 250 V, and the electrolysis time is 1 to 25 hours. The electrolyte concentration is 1 to 10% by mass, the liquid temperature is 0 to 20 ° C. Particularly preferred are 0.1 to 10 A / dm ² , a voltage of 10 to 200 V, and an electrolysis time of 2 to 20 hours.

  The film thickness of the anodized film formed by such a self-ordering method is preferably 1 to 300 μm, more preferably 5 to 150 μm, and particularly preferably 10 to 100 μm.

Since the anodic oxide film formed by the self-ordering method becomes more regular as it gets closer to the aluminum part, the film is removed once, and the bottom part of the anodic oxide film remaining in the aluminum part is put on the surface, Regular depressions can be obtained.
Therefore, in the film removal process, aluminum is not dissolved, but only the anodic oxide film that is aluminum oxide is dissolved.
Specifically, it is preferable to take 3 hours or more using a mixed aqueous solution of chromic acid and phosphoric acid at about 50 ° C., similarly to the methods described in Non-Patent Documents 1 and 4 to 7 described above. More preferably, the time is more than 10 hours. In addition, since the starting point of ordering will be destroyed and disturb | disturbed if it processes using the boiled aqueous solution, it uses without boiling.

  In this way, after forming the anodized film by the self-ordering method, this is dissolved and removed, and when the anodizing process described later is performed again under the same conditions, a substantially straight micropore is obtained. It is formed substantially perpendicular to the film surface.

In the present invention, the self-ordering anodizing treatment is preferably 0.5 to 30 hours, more preferably 1 to 25 hours, and further preferably 2 to 20 hours.
The film removal treatment is preferably 0.5 to 10 hours, more preferably 2 to 10 hours, and further preferably 4 to 10 hours.

  The depth of the depression formed is preferably about 10 nm or more. The width is preferably equal to or less than the desired pore diameter.

<This anodizing treatment>
In the present invention, an anodization having micropores having a degree of ordering of 50% or more and an SN ratio of the ordering degree of 20 or more is formed by the present anodizing treatment after forming a recess on the aluminum substrate surface as desired. A film is formed.
This anodizing treatment is performed except that the average flow rate of the electrolytic solution is 0.5 to 20.0 m / min, preferably 1.0 to 15.0 m / min, and more preferably 2.0 to 10.0 m / min. A conventionally known method can be used, and it is preferable to carry out under the same conditions as the above-described self-ordering anodizing treatment. As described above, when the average flow rate of the electrolytic solution in the self-ordering anodizing treatment is set within the range of 0.5 to 20.0 m / min, the average flow rate of the electrolytic solution in the present anodizing treatment is 0. It may be outside the range of 5 to 20.0 m / min.

In particular, in the present anodizing treatment, a method of repeatedly turning on and off the current intermittently while keeping the DC voltage constant; a method of repeatedly turning on and off the current while intermittently changing the DC voltage; Is exemplified. These methods are preferable because the degree of ordering of the micropores formed on the anodized film is further improved.
In the above-described method of intermittently changing the voltage, it is preferable to decrease the voltage sequentially. This is preferable because the resistance of the anodized film can be lowered.

By setting the average flow rate of the electrolyte in one or both of the self-ordering anodizing treatment and the main anodizing treatment within the above range, the degree of ordering is 50% or more and the SN ratio of the ordering degree is 20 or more. A structure having an anodic oxide film having micropores having a uniform regularity even in a large area can be obtained.
This is considered to be because the electrolyte solution can penetrate into the pores widely and uniformly permeate during the micropore growth process.
Here, the degree of ordering is an index of micropore regularity, and is defined by the following formula (1).

Order degree (%) = B ÷ A × 100 (1)
Here, in the above formula (1), A represents the total number of micropores in the measurement range (1 to 5 μm ² ). B is a micropore that is centered on one micropore and in which the circumference of another micropore closest to the one micropore is inscribed. This represents the number of micropores that will have six (including the micropores whose center is inside the circle).

FIG. 1 is a schematic diagram of the anodized film surface for explaining the degree of ordering of micropores. Hereinafter, B in the above formula (1) will be described in detail with reference to FIG.
As shown in FIG. 1 (a), one micropore 1 is centered on the one micropore 1, and the circumference of another micropore 2 closest to the one micropore 1 is inscribed therein. When the circle 3 is drawn, it becomes a micropore that has six micropores inside the circle 3, and is counted as B. Note that the micropore 4 has a portion protruding from the circle 3, but since the center is inside the circle 3, the micropore 4 is counted as the number of micropores inside the circle 3.
On the other hand, as shown in FIG. 1B, one micropore 5 is centered on the one micropore 5 and the circumference of another micropore 6 that is the closest to the one micropore 5 is When an inscribed circle 7 is drawn, it becomes a micropore that has five micropores inside the circle 7, and therefore cannot be counted as B. Note that the micropores 8 are not counted as the number of micropores inside the circle 7 because the center of the micropores 8 protrudes from the circle 7. Further, when one micropore 9 draws a circle 11 centered on the one micropore 9 and inscribed by the circumference of another micropore 10 at the closest distance to the one micropore 9, Since it is a micropore that has seven micropores inside the circle 11, it cannot be counted as B.

In the present invention, the SN ratio of the degree of ordering is 20 or more. The larger the S / N ratio value, the smaller the variation in the degree of ordering depending on the location. When the S / N ratio is 20 or more, the degree of ordering variation is within about 3%.
Here, the SN ratio is arbitrarily selected from at least 10 measurement ranges in which the degree of ordering defined by the above formula (1) is measured, the degree of ordering at each point is obtained, and the degree of ordering at each point is represented by X ₁ , X ₂ ,..., X _n are calculated by the following formula (2).

SN ratio = 10 × log (m ² / σ ² ) (2)
Here, in the above formula (2), m is an average value of the degree of ordering at each point, and is represented by m ² = ((X ₁ + X ₂ +... + X _n ) / n) ² , It is error variance and is represented by ((X ₁ −m) ² + (X ₂ −m) ² +... + (X _n −m) ² ) / (n−1).

  In the present invention, when the anodizing treatment is performed at a low temperature, the regularity of the micropores can be further improved and the pore diameter can be made uniform.

The film thickness of the anodized film formed by this anodizing treatment is preferably 0.5 to 10 times the pore diameter, more preferably 1 to 8 times, and further preferably 1 to 5 times. preferable.
The average pore density of the micropores is preferably 50-1500 / μm ² .
Further, the area ratio occupied by the micropores is preferably 20 to 50%.
The area ratio occupied by the micropore is a ratio of the total area of the opening of the micropore to the area of the aluminum surface. In the calculation of the area ratio occupied by the micropores, the micropores include those that are not filled with metal and those that are not filled with metal. Specifically, it is obtained by measuring the surface porosity before the sealing treatment.

<Pore wide processing>
In the present invention, after this anodizing treatment, if necessary, the aluminum member is immersed in an aqueous acid solution or an aqueous alkaline solution to dissolve the anodized film and perform pore-wide treatment for expanding the pore diameter of the micropore. Is preferred.
As a result, the regularity of the micropores can be further improved, and the pore diameter variation can be easily controlled. Further, by dissolving the barrier film at the bottom of the micropores of the anodized film, it is possible to selectively deposit the inside of the micropores and to slightly increase the pore diameter variation.

When an aqueous acid solution is used for the pore wide treatment, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, or a mixture thereof. The concentration of the acid aqueous solution is preferably 1 to 10% by mass. The temperature of the acid aqueous solution is preferably 25 to 40 ° C.
When an alkaline aqueous solution is used for the pore-wide treatment, it is preferable to use an aqueous solution of at least one alkali selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1 to 5% by mass. The temperature of the alkaline aqueous solution is preferably 20 to 35 ° C.
Specifically, for example, 50 g / L, 40 ° C. phosphoric acid aqueous solution, 0.5 g / L, 30 ° C. sodium hydroxide aqueous solution or 0.5 g / L, 30 ° C. potassium hydroxide aqueous solution is preferably used. .
The immersion time in the acid aqueous solution or the alkali aqueous solution is preferably 8 to 60 minutes, more preferably 10 to 50 minutes, and further preferably 15 to 30 minutes.

<Other processing>
Further, other processes can be performed as necessary.
For example, when the structure obtained by the production method of the present invention is used as a sample stage and it is desired to form a film by hanging an aqueous solution, a hydrophilization treatment may be performed in order to reduce the contact angle with water. . The hydrophilic treatment can be performed by a conventionally known method.
In addition, when the structure obtained by the production method of the present invention is used as a sample stage and targeted for a protein that is denatured with acid or decomposed, it is used for anodizing treatment and remains on the aluminum surface. In order to neutralize the acid, neutralization treatment may be performed. The neutralization treatment can be performed by a conventionally known method.

The structure according to the second aspect of the present invention (hereinafter also referred to as “the structure of the present invention”) is a structure obtained by the production method of the present invention described above, and has a degree of ordering of 50% or more. The structure having at least a part of an aluminum member having an anodized film having micropores with an S / N ratio of 20 or more.
Since such a structure has micropores having uniform regularity even in a large area, it can be applied to various applications.
For example, it can be used as a sample table for Raman spectroscopic analysis by filling a plurality of depressions or micropores with metal by a sealing treatment.
It can also be used as a nanoprint mold.

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.
(Examples 1-31 and Comparative Examples 1-4)
1. Production of Structure As shown in Table 1, each structure was obtained by subjecting the substrate to a mirror finishing process, formation of a dent, this anodizing process and a pore-wide process in order. In Table 1, “-” indicates that the corresponding processing is not performed.

  Hereinafter, the substrate and each process will be described.

(1) Substrate The substrates used for manufacturing the structure are as follows. These were cut and used so that they could be anodized in an area of 10 cm square.
-Substrate 1: High-purity aluminum, manufactured by Wako Pure Chemical Industries, Ltd., purity 99.99 mass%, thickness 0.4 mm
-Substrate 2: Aluminum JIS A1050 material provided with surface layer A, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.24 mm
-Substrate 3: Aluminum JIS A1050 material provided with surface layer B, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.24 mm
-Substrate 4: Aluminum JIS A1050 material, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.30 mm
-Substrate 5: Aluminum JIS A1050 material provided with a surface layer C, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.30 mm
-Substrate 6: Aluminum JIS A1050 material provided with a surface layer D, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.30 mm

-Substrate 7: Aluminum vapor deposition film, Trefan AT80, manufactured by Toray Industries, Inc., purity 99.9% by mass, thickness 0.02 mm
-Substrate 8: Aluminum XL untreated material provided with surface layer A, manufactured by Sumitomo Light Metal Industries, Ltd., purity 99.3 mass%, thickness 0.30 mm
-Substrate 9: Glass provided with surface layer E, manufactured by AS ONE, purity 99.9% by mass, thickness 5 mm
-Substrate 10: Silicon wafer provided with surface layer E, manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99% by mass or more-Substrate 11: Synthetic quartz provided with surface layer E, VIOSIL-SG-2B, manufactured by Shin-Etsu Chemical Co., Ltd. Purity 99.99% by mass or more, thickness 0.6mm
-Substrate 12: A copper-clad laminate (RAS33S42, manufactured by Shin-Etsu Chemical Co., Ltd., purity unknown, thickness 0.08 mm) provided with a surface layer E provided with an Al-Cu alloy film by sputtering.

The aluminum JIS A1050 material has a regular reflectance of 40% in the vertical direction (standard deviation of 10%), a regular reflectance of 15% in the lateral direction (standard deviation of 10%), and a purity of 99.5% by mass (standard deviation of 0.1%). 1% by mass).
Further, the above-mentioned aluminum XL non-treated material has a vertical regular reflectance of 85% (standard deviation of 5%), a horizontal regular reflectance of 83% (standard deviation of 5%), and a purity of 99.3% by mass (standard deviation of 0). .1% by mass).

The surface layers A to E were provided as follows.
Surface layer A is a vacuum deposition method under the conditions of ultimate pressure: 4 × 10 ⁻⁶ Pa, deposition current: 40 A, substrate: 150 ° C. heating, deposition material: aluminum wire with purity of 99.9% by mass (manufactured by Niraco) Was formed on the substrate. The thickness of the surface layer A was 0.2 μm.
The surface layer B was formed by the same method as the surface layer A, except that an aluminum wire (manufactured by Nilaco) having a purity of 99.99% by mass was used as the vapor deposition material. The thickness of the surface layer B was 0.2 μm.
Surface layer C has ultimate pressure: 4 × 10 ⁻⁶ Pa, sputtering pressure: 10 ⁻² Pa, argon flow rate: 20 sccm, substrate: 150 ° C. control (with cooling), bias: none, sputtering power source: RC, sputtering power: RF400W, sputtering material: It was formed on the substrate by a sputtering method under the condition of a 3N backing plate (manufactured by Kyodo International Co., Ltd.) having a purity of 99.9% by mass. The thickness of the surface layer C was 0.5 μm.
The surface layer D was formed by the same method as the surface layer C except that a 4N backing plate (manufactured by Kyodo International Co., Ltd.) having a purity of 99.99% by mass was used as the sputtering material. The thickness of the surface layer D was 0.5 μm.
The surface layer E was formed by the same method as the surface layer A, except that the thickness was 1 μm.

The thickness of the surface layer is determined by masking the PET substrate, performing the vacuum deposition method and the sputtering method while changing the time under the same conditions as described above, and using an atomic force microscope (AFM). It adjusted by adjusting time using the correlation calibration curve of the time and film thickness obtained by measuring each film thickness.
In addition, the purity of the surface layer was determined using a scanning X-ray photoelectron spectrometer (Quantum 2000, manufactured by ULVAC-PHI) to perform a full quantitative analysis while digging in the depth direction with an ion gun for etching. The content of was quantified by a calibration curve method. As a result, all the surface layers had substantially the same purity as the vapor deposition material or the sputtering material.

(2) Mirror surface finishing process About the board | substrates 1-6 among the said substrates 1-12, the following mirror surface finishing processes were performed.
<Mirror finish processing>
By performing polishing using a polishing cloth, buffing and electrolytic polishing in this order, a mirror finish was applied. After buffing, it was washed with water.
Polishing using a polishing cloth uses a polishing disk (Struers Abramin, manufactured by Marumoto Kogyo Co., Ltd.) and a water-resistant polishing cloth (commercially available), and the number of the water-resistant polishing cloth is # 200, # 500, # 800, # 1000 and # The change was made in the order of 1500.
The buffing was performed using a slurry-like abrasive (FM No. 3 (average particle size 1 μm) and FM No. 4 (average particle size 0.3 μm), both manufactured by Fujimi Incorporated).
The electrolytic polishing was performed for 2 minutes using an electrolytic solution (temperature: 70 ° C.) having the following composition, using the anode as a substrate and the cathode as a carbon electrode at a constant current of 130 mA / cm ² . As a power source, GP0110-30R (manufactured by Takasago Seisakusho) was used.

<Electrolyte composition>
-660 mL of 85% by mass phosphoric acid (reagent manufactured by Wako Pure Chemical Industries, Ltd.)
・ Pure water 160mL
・ Sulfuric acid 150mL
・ Ethylene glycol 30mL

(3) Formation of a depression A depression serving as a starting point for forming micropores was formed on the surfaces of the substrates 1 to 6 subjected to mirror finishing and the surfaces of the substrates 7 to 12 not subjected to mirror finishing by the following method.

  First, self-ordered anodizing treatment was performed at the electrolytic solution type, concentration, electrolytic solution flow rate, temperature, voltage, current density, and processing time shown in Table 2, and the film thickness shown in Table 2 was obtained. An oxide film was formed. In the self-ordering anodizing treatment, NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) is used as a cooling device, Pear Stirrer PS-100 (manufactured by EYELA) is used as a stirring and heating device, and GP0650-2R (manufactured by Takasago Seisakusho) is used as a power source. It was. The flow rate of the electrolyte was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE).

  In Table 2, for phosphoric acid, oxalic acid, and sulfuric acid, all reagents manufactured by Kanto Chemical Co., Ltd. were used. The current density showed a stable value.

  Next, film removal treatment was performed by immersing the substrate on which the anodized film was formed in the treatment liquid under the conditions shown in Table 3 to dissolve the anodized film.

  In Table 3, as for 85 mass% phosphoric acid and chromic anhydride, reagents manufactured by Kanto Chemical Co., Inc. were used. In addition, the process liquid used for conditions 53 and 56 is a composition prescribed | regulated to JISH8688 (1998) -H8688.

(4) Main anodizing treatment The main anodizing treatment was applied to the substrate on which the depressions were formed. In this anodizing treatment, the substrate is immersed in the electrolytic solution, and any one of conditions (71 to 80) selected from the conditions (71 to 80) of the type, concentration and temperature of the electrolytic solution and the first voltage shown in Table 4 Then, the electrolytic treatment was performed once or a plurality of times.
When the electrolytic treatment is performed a plurality of times, the electrolysis is interrupted when the initial value V ₀ of the constant voltage is reached for the first time, and the initial set value 0.9 × V ₀ [V] of the constant voltage is reached the second time. Then, the electrolysis is interrupted, and the third time, the electrolysis is interrupted when the constant voltage initial setting value 0.8 × V ₀ [V] is reached. The nth time, the constant voltage initial setting value {1-0 .1 × (n−1)} × V ₀ was repeated several times to stop electrolysis.
Further, the thickness of the anodized film was measured by the same method as described above, and the increment was shown in Table 4.

(5) Pore-wide treatment The pore-wide treatment was performed by immersing the substrate in a treatment solution of the type, concentration and temperature shown in Table 5 for the time shown in Table 1.

2. Properties of Structure (1) Degree of Ordering About the structure obtained above, a surface photograph was taken by FE-SEM, and the degree of ordering of micropores was measured according to the above formula (1). The results are shown in Table 6. In the examples, the degree of ordering (%) was calculated in the measurement range of 1 μm ² .

(2) SN ratio The SN ratio of the degree of ordering of micropores was calculated for the structure obtained above. The S / N ratio was calculated according to the above formula (2) by selecting a measurement range of 10 points randomly from the surface of the 10 cm square structure, measuring the degree of ordering at each point, obtaining m as an average value thereof. . The results are shown in Table 6.

3. Large-area treatment The structures obtained by the same method as in Example 1 and Comparative Example 1 except that the size of the support to be treated was 50 cm square were evaluated as Example 31 and Comparative Example 4 respectively. The results are shown in Table 6.

  As is apparent from Table 6, the anodizing treatment was performed under the condition that the average flow rate of the electrolytic solution was 0.5 to 20.0 m / min, and the SN ratio of the degree of ordering was 50% or more. The structure of the present invention obtained by a manufacturing method comprising an anodizing treatment step for forming an anodic oxide film having micropores of 20 or more has an anodic oxide film having micropores having uniform regularity even in a large area. It turned out that it becomes a structure which has.

FIG. 1 is a schematic view of the anodized film surface for explaining the degree of ordering of micropores.

Explanation of symbols

1, 5, 9 One micropore 2, 6, 10 Other micropore 3, 7, 11 yen 4,8 Micropore

Claims (2)

At least a part of an aluminum member having an aluminum substrate and an anodized film having micropores present on the surface of the aluminum substrate and having a degree of ordering of 50% or more and an SN ratio of the ordering degree of 20 or more A structure manufacturing method for obtaining a structure having
The manufacturing method of a structure which comprises the anodizing process process which anodizes on the conditions which the average flow velocity of electrolyte solution will be 0.5-20.0 m / min on the surface of the said aluminum substrate.   A structure obtained by the method for producing a structure according to claim 1.

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