JP2000315785A - Manufacture of nano structural member and nano structural member device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nano structural member having fine holes which can be used in wide field as functional material for a light emitting device, an optical device, a magnetic device, a micro device, etc. SOLUTION: In a manufacturing method of a nano structural member where an object to be worked is subjected to anodic oxidation or anodization and fine holes are formed, resist 13 on an object 11 to be worked is interference exposed and developed, part positions 17 penetrating as far as the surface of the object 11 to be worked are formed on the resist 13, and a regular nano structural pattern is formed. After that, the object 11 to be worked is subjected to anodic oxidation or anodization. As a result, a fine whole member having circular fine wholes 20 which are regularly arranged corresponding to the regular nano structural pattern is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a nanostructure in which a nanostructure is ordered by a regular nanostructure pattern on a workpiece using interference exposure, and a regular nanostructure. The present invention relates to a nanostructure device using as a mold or a mask.

[0002]

2. Description of the Related Art Metal and semiconductor thin films, fine lines, dots, and the like are required to have a size smaller than a certain characteristic length.
When the movement of electrons is confined, it may exhibit unique electrical, optical, and chemical properties. From such a viewpoint, there is an increasing interest in a material (nanostructure) having a structure finer than several 100 nm as a functional material. As a method for producing such a nanostructure, for example,
A method of directly manufacturing a nanostructure by a semiconductor processing technique such as a fine pattern forming technique such as photolithography, electron beam exposure, and X-ray exposure is exemplified. In particular, among photolithography, there is a method capable of fabricating a periodic nanostructure in a large area and in a short time by using two-beam interference exposure. This method is characterized in that a periodic nanostructure pattern up to a half cycle of the used wavelength can be formed. The method for forming the fine pattern is described in, for example, (Opti
cal Engineering 1976 Vol.
15 No. 3, J. Vac. Sci. Techno
l. B15 (6), Nov / Dec 1997).

In addition to such a manufacturing method, there has been an attempt to realize a novel nanostructure based on a regular structure formed naturally, that is, a structure formed self-regularly. is there. Many studies have begun on these techniques because there is a possibility that a finer and special structure can be produced more than conventional methods depending on a microstructure used as a base.

[0004] An example of such a self-regular method is anodic oxidation, which allows a nanostructure having nanosized pores to be produced easily and with good control. For example, A
Anodized alumina produced by anodizing 1 and its alloys in an acidic bath is known.

When anodizing an Al plate in an acidic electrolyte,
A porous oxide film is formed (for example, RC Fur)
neaux, W.C. R. Rigby & A. P. David
son NATURE Vol. 337 P147 (1
989)). The feature of this porous oxide film is that it has a unique feature that extremely fine cylindrical pores (nanoholes) having a diameter of several nm to several hundred nm are arranged in parallel at intervals of several nm to several hundred nm (cell size). It has a simple geometric structure. These columnar pores have a high aspect ratio and are excellent in uniformity of cross-sectional diameter. The diameter and spacing of these pores can be controlled to some extent by adjusting the current and voltage during anodic oxidation, and by controlling the thickness of the oxide film and the depth of the pores by controlling the anodic oxidation time. It is possible.

In order to improve the verticality, linearity, and independence of the pores of the porous oxide film, a method of performing two-stage anodic oxidation, that is, a method of temporarily forming a porous oxide film formed by performing anodic oxidation is used. After removal, perform anodization again,
A method for producing a porous oxide film having pores exhibiting better perpendicularity, linearity, and independence has been proposed (Jp.
n. Journal of Applied Physs
ics, Vol. 35, Part 2, No. 1B, p
p. L126-L129,15 January 199
6). Here, this method uses that the depression on the surface of the Al plate formed when the anodic oxide film formed by the first anodic oxidation is removed serves as a starting point of pore formation for the second anodic oxidation.

Further, in order to improve the controllability of the shape, interval and pattern of the pores of the porous oxide film, a method of forming a pore formation starting point using a stamper, that is, a method in which a plurality of projections are provided on the surface. After forming a depression formed by pressing the substrate against the surface of the Al plate as a starting point of pore formation, anodizing is performed to produce a porous oxide film having pores exhibiting better control of shape, spacing and pattern. A method has also been proposed (Japanese Patent Application Laid-Open No. 10-112292).

Various applications have been attempted, focusing on the specific geometric structure of the anodized alumina. The explanation by Masuda is detailed, but the following is a list of application examples.

For example, there is an application as a film utilizing the wear resistance and insulation resistance of the anodic oxide film, and an application to a filter by peeling the film. Furthermore, by using a technique of filling a nanohole with a metal or a semiconductor or a replica technique of the nanohole, coloring, a magnetic recording medium, an EL light emitting element, an electrochromic element, an optical element, a solar cell,
Various applications including gas sensors have been attempted. Further, applications to various fields such as quantum effect devices such as quantum wires and MIM elements, and molecular sensors using nanoholes as chemical reaction fields are expected. (Masuda Solid State Physics 31,493 (1996))

[0010]

The direct fabrication of nanostructures by the above-described semiconductor processing technology has problems such as poor yield and high equipment cost, and is easily produced with good reproducibility by a simple method. A technique that can do this is desired.

In the case of interference exposure, since the interference wave is a sine wave, a high aspect ratio pattern cannot be carved on the resist. Further, a mesh-shaped opening is produced by changing the crossing angle and performing the second interference exposure. In this case, it was difficult to make the shape of the opening portion a perfect circle.

From this point of view, the self-regular method, particularly the anodic oxidation method, can easily produce a nanostructure with good control, and can produce a large-area nanostructure. It is desired because there is.

However, in the case of a porous body produced only by ordinary anodic oxidation, although many techniques for controlling the shape and pattern of the pores have been developed, the control is limited. It is known that the control of the anodized alumina can be controlled to some extent by the anodizing voltage, the pore depth by time, and the pore diameter by pore widening.

Further, as an example of controlling the arrangement of pores, Masuda et al. Produced an ordered nanohole in which round holes were arranged in a honeycomb shape by performing anodic oxidation under appropriate anodic oxidation conditions. Examples have been reported. However, in the ordered nanoholes, there are problems such as a limitation on a pore interval of a pore body that can be produced and a necessity of long-time anodic oxidation.

In the two-stage anodic oxidation method, the verticality, straightness, and independence of the pores of the porous oxide film are improved, but the pore pattern is disturbed. There is a problem that the shape and the interval of are not constant and their controllability is not good.

Further, in the method of forming the starting point of pore formation using a stamper, the controllability of the shape, spacing and pattern of the pores of the porous oxide film is improved, but there are the following problems. Was. (1) Since a stamper is used, it is difficult to uniformly form a starting point for forming pores on a workpiece having an uneven surface. (2) Since it is necessary to apply pressure to the workpiece when the stamper is used, it is difficult to apply to a workpiece having low mechanical strength because there is a risk that the workpiece is broken. (3) Since compression using a stamper is used, Al
Since it is difficult to expose Al on the surface of a workpiece having a film formed on the surface, it is difficult to use the stamp position as the starting point of pore formation. (4) When using a stamper, a hydraulic press must be used, and it is not easy to perform pattern positioning with high accuracy. (5) The stamper must be manufactured using a complicated fine processing technique such as electron beam lithography, and it is easy to manufacture a stamper having uniform and high-density projections without defects in a short time. is not.

An object of the present invention is to solve these problems. That is, an object of the present invention is to produce, in a nanostructure having pores produced by anodization or anodization, circular holes arranged in an arbitrary cycle over a large area at low cost, easily, and in a short time. To provide possible technologies.

Further, an object of the present invention is based on a nanostructure having pores produced by applying this manufacturing technique,
An object of the present invention is to provide novel nanostructures and nanostructure devices that can be applied in various directions.

[0019]

The configuration of the present invention which has been made to achieve the above object is as follows.

That is, a first aspect of the present invention is to provide a method for producing a nanostructure in which pores are formed by anodizing or anodizing a workpiece, by exposing and developing a resist on the workpiece. Step 1 of forming a part penetrating to the surface of the workpiece in the resist to form a regular nanostructure pattern, and subsequently, corresponding to the regular nanostructure pattern by anodizing or anodizing the workpiece. Forming porous body having regularly arranged fine pores
And a method for producing a nanostructure.

As a further feature, the first manufacturing method of the present invention has a further feature that "the step 1 comprises at least a step of forming a resist on a workpiece, a step of subjecting the resist to interference exposure, and a step of developing. "Step 1 has two or more interference exposure steps, and the interference fringe direction in the second interference exposure step is the interference fringe direction in the first interference exposure step." By different from the direction, it is a step of forming a regular nanostructure pattern in which each intersection point of the interference fringes is regularly arranged. ”“ In the step 2, up to the surface of the workpiece of the regular nanostructure pattern by the resist. "A perfect circular pore is formed in the penetrating part", "The regular nanostructure pattern by the resist has a penetrating part width of 500 nm or less", The regular nanostructure pattern formed by the resist has an interval between the penetrating portions of 30 to 1000 nm, "and" penetrates to the workpiece surface of the regular nanostructure pattern formed by the resist, which is a starting point of pore formation. "The site is a repetition of the same interval and pattern", "The pore formation start point is a repetition of a regular hexagonal pattern", "The pore formation start point is a quadrangular shape "The pattern is a repetition", "the workpiece is a bulk mainly composed of Al",
"The workpiece is formed on a substrate with a film mainly composed of Al", "The workpiece is a bulk mainly composed of Si", and "The workpiece is bulk." Is a film made of Si as a main component formed on a substrate. ''
That is, including.

The second aspect of the present invention relates to a nanostructure manufactured by the first method of the present invention.

A third aspect of the present invention relates to a method for manufacturing a nanostructure using the above-described second nanostructure of the present invention as a mold or a mask.

A fourth aspect of the present invention relates to a nanostructure produced by the third method of the present invention.

A fifth aspect of the present invention relates to an electron-emitting device having an electron-emitting portion in pores of a substrate having a regular nanostructure in the fourth nanostructure of the present invention. .

A sixth aspect of the present invention has a structure in which a substance having a different dielectric constant from that of the substrate is embedded in pores of the substrate having a regular nanostructure in the fourth nanostructure of the present invention, The present invention relates to a photonic device characterized in that light dispersion characteristics and light propagation direction can be controlled.

A seventh aspect of the present invention relates to a magnetic device characterized in that a magnetic substance is embedded in pores of a substrate having a regular nanostructure in the fourth nanostructure of the present invention.

An eighth aspect of the present invention relates to a light emitting device characterized in that a luminous body is embedded in pores of a substrate having a regular nanostructure in the fourth nanostructure of the present invention.

[0029]

According to the method for producing a nanostructure of the present invention, in a nanostructure having pores produced by anodization or anodization, a regular nanostructure pattern of a resist formed on a workpiece and a self-structure can be obtained. By combining the characteristics of ordering, regular perfect circular pores can be formed over a large area.

In other words, the interference exposure itself preferably used in the present invention cannot form a high aspect ratio pattern on the resist because the interference wave is a sine wave. I do. Further, by performing the interference exposure of the resist twice, the regular nanostructure pattern and the ordered pore arrangement of the anodized alumina can be matched (matched). Therefore, if a regular nanostructure pattern formed by resist interference exposure is used as an anodic oxidation mask, a high aspect nanostructure can be produced even if the shape of the penetrating part of the regular nanostructure pattern is not a perfect circle. Can be.

In the method for producing a nanostructure according to the present invention, since a regular nanostructure pattern of a resist is used as a mask for a workpiece, it is not necessary to form a starting point for forming pores on the surface of the workpiece, and the resist is used. Anodization or anodic oxidation can be performed without peeling.

The method for producing a nanostructure of the present invention does not require the use of two times of anodic oxidation and the use of a stamper, as compared with the conventional method of forming anodized ordered nanoholes. Therefore, the thickness of the workpiece can be accurately determined, and it is not necessary to apply pressure to the workpiece when forming the starting point for forming pores. It is possible.

The method for producing a nanostructure of the present invention uses a semiconductor processing technique such as electron beam lithography to form a large area in a much shorter time than forming each pore formation starting point on the surface of a workpiece. It is practical in that it can produce a periodic nanostructure at low cost and without damaging the workpiece surface.

In the method for producing a nanostructure of the present invention, a regular nanostructure pattern is used for forming the starting point of pore formation, so that a workpiece having a film formed on the Al surface can be used. Since it is possible to expose Al on the surface within the thickness (difference in height) of the nanostructure pattern, it is possible to form a pore formation starting point.

According to the method for manufacturing a nanostructure of the present invention, since a regular nanostructure pattern of a resist formed on a workpiece is used as an anodic oxidation mask, there is no need to position the pattern, and the area can be increased. And it is easy to regularize.

Further, the method for producing a nanostructure of the present invention comprises:
Since the regular nanostructure pattern of the resist formed on the workpiece is used as an anodic oxidation mask, the starting point of pore formation depends only on the penetrating part of this regular nanostructure pattern, and the arbitrary arrangement of pores Is possible.

The nanostructure of the present invention can be used as a functional material by itself, but can be used as a base material, a template, and the like for further novel nanostructures. Specifically, by embedding a functional material such as a metal and a semiconductor in the pores of the nanostructure of the present invention, it can be applied to a new electronic device.

Further, the nanostructure of the present invention comprises a quantum wire,
MIM element, molecular sensor, coloring, magnetic recording medium, EL
Light-emitting devices, electrochromic devices, optical devices including photonic bands, electron-emitting devices, solar cells,
It can be applied in various forms including gas sensors, wear-resistant and insulation-resistant films, filters, and has the effect of significantly expanding the range of application.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for producing a nanostructure according to the present invention will be described below with reference to FIGS. The following steps (a) to (f) correspond to (a) to (f) in FIGS. 1 and 2, respectively.

(A) Workpiece preparation A workpiece is prepared. Examples of the material of the workpiece of the present invention include those containing Al as a main component, but are not particularly limited as long as the material can form pores by anodic oxidation.

As an example of the first embodiment of the workpiece of the present invention, a bulk 1 mainly composed of Al shown in FIG.
0. In addition, in the bulk containing Al as a main component, it is not always necessary to perform mirror polishing in order to impart smoothness to the surface. However, since a periodic nanostructure is formed on the workpiece, there is no surface unevenness. Is more preferred.

Next, as an example of the second embodiment of the workpiece of the present invention, there is a workpiece in which a film 11 mainly composed of Al is formed on a substrate 12 shown in FIG. 1 (a-2). At this time, examples of the substrate 12 include substrates such as an insulator substrate such as quartz glass, a semiconductor substrate such as silicon and gallium arsenide, and a substrate having one or more layers formed on these substrates. If there is no problem in forming pores by anodic oxidation of the film 11 containing Al as a main component,
The material, thickness, mechanical strength, and the like of are not particularly limited. For example, by using a substrate 12 on which a film of a pore formation end point member such as Ti or Nb is formed on a substrate, the uniformity of the depth of the pores can be improved.

As a method of forming the film 11 containing Al as a main component, any film forming method including resistance heating evaporation, EB evaporation, sputtering, CVD, and plating can be applied. A
In the film 11 containing l as a main component, a film forming method in which surface irregularities due to the presence of grains or the like are not generated as much as possible is preferable.

(B) Application of resist on workpiece The resist 13 is applied to the workpiece (see FIG.
1)). The surface to be processed is previously subjected to ultrasonic cleaning with acetone and IPA for 10 minutes each, and then dried in a clean oven at 120 ° C. for 20 minutes or more.

As the resist to be used, both a high resolution positive resist for i-line and a high resolution negative resist for i-line can be used. At that time, a developer corresponding to each of a positive type and a negative type is used. This time is Clariant Japan
An AZ5214E positive resist manufactured by AN was diluted with a resist thinner solution and used.

Before the application of the resist, either the HMDS application or the antireflection film 15 is applied (FIG. 1B-2).
The HMDS used this time was manufactured by Chisso, and the anti-reflection film 15 was AZBARL manufactured by Clariant JAPAN.
i100 was used. When applying HMDS,
It chemically improves resist wetting on an object to be coated. The anti-reflection film 15 is effective for increasing the reflectance of the workpiece and reducing the unevenness of exposure by suppressing interference in the film. However, when the antireflection film 15 is used as a base of the resist, it is necessary to perform dry etching in order to deposit the surface of the workpiece after exposure and development of the resist.

The HMDS coating, the antireflection coating and the resist coating are performed by a spin coater method. After the workpiece is placed on the stage and the surface is cleaned by nitrogen blowing, the coating is performed while changing the rotation speed stepwise such as initial speed, main speed, final speed, and slope. By applying in this manner, the coating unevenness can be reduced even a little. After that, a drying process is performed using a hot plate or a clean oven.

(C) First Interference Exposure By performing the first interference exposure, the resist 13 is exposed in the form of a stripe having a period of 14 to form a photosensitive portion 16. FIG. 1) and FIG. 1 of the substrate surface view
(See (c-2)).

The interference exposure apparatus used this time is AOIS
ANSHO CO. And FX4010 manufactured by Ltd. were used. Laser is He-Cd laser (wavelength 325n)
m, TEM00 mode). In principle, the interference exposure can cut a pattern up to a half-wave period of the wavelength, so that the type of laser used is not particularly limited. But,
Stable output and laser quality of TEM00 mode are preferred.

Further, since exposure is performed using light interference, it is necessary to cover the apparatus with an acrylic case or stop air conditioning to minimize air fluctuations. In addition, a vibration isolating table structure is used to eliminate shaking of the apparatus itself. In experiments, in order to keep the interference intensity constant, it is necessary to adjust each optical path using a power meter, a photosensitive plate, or the like, and confirm interference fringes.

As described above, interference exposure requires precise adjustment, and reproducibility during exposure and development is not very good.
Therefore, uneven resist coating, uneven exposure, sample difference,
Due to the development temperature difference, some fluctuations are mixed in the exposure and development conditions.

(D) Development after Second Interference Exposure The second interference exposure is caused to intersect with the first interference fringe direction (for example, at 60 ° and 90 °), thereby obtaining the image shown in FIG.
As shown in 2), an intersection portion 1 due to interference fringes in different directions.
7 is formed. The strongly exposed portion 17 is developed so as to form a concave portion. The interval 18 indicates the interval of the formed concave portion.

At this time, in the formation of pores by anodic oxidation, the pattern of the pores tends to be a repetition of a substantially regular hexagonal pattern due to self-organization, so that a regular nanostructure pattern (Al film 11) used as an anodic oxidation mask is used. It is reasonable to form the pattern so that the pattern of the concave portion 17 penetrating through to the shape of a regular hexagonal pattern is repeated. This is particularly desirable when trying to form nanostructures with deep pores. However, if the pores are shallow, the above self-organization does not yet occur,
It also makes sense to form the regular nanostructure pattern having the concave portion 17 so as to be a repetition of an arbitrary pattern such as a substantially square shape. This is particularly significant when the workpiece is formed by forming a film containing Al as a main component on the substrate, since the depth of the pores is inevitably shallow.

In the formation of pores by anodic oxidation, the spacing between the pores is controlled to some extent by the process conditions such as the type, concentration and temperature of the electrolytic solution used for anodic oxidation, the method of applying anodizing voltage, voltage value, and time. it can. Therefore, it is reasonable to form a regular nanostructure pattern having a concave portion 17 in advance at the intervals of the pores expected from various process conditions.

(E) Anodization Using the regular nanostructure pattern made of the resist 13 having the concave portions 17 as a mask, the workpiece is subjected to anodizing treatment, whereby the workpiece is formed into a thin circular shape. A nanostructure having holes 19 is produced.

Examples of the electrolytic solution used for the anodic oxidation include oxalic acid, phosphoric acid, sulfuric acid, and chromic acid solution, but are not particularly limited as long as there is no problem in forming pores by the anodic oxidation. Various conditions such as anodizing voltage and temperature depending on each electrolytic solution can be appropriately set according to the nanostructure to be manufactured.

(F) Stripping of resist After the resist 13 having the regular nano-structure pattern is stripped with a resist stripping solution, the resist 13 is not immersed in an acid solution (in the case of anodized alumina, for example, a phosphoric acid solution). The pore diameter can be appropriately increased. Acid concentration,
A nanostructure having pores 20 of a desired diameter can be obtained depending on the processing time, temperature, and the like. Finally, running water washing is performed with ultrapure water.

[0058]

Embodiments of the present invention will be described below.

Embodiment 1 This embodiment is directed to a method for manufacturing a nanostructure in which pores are formed by anodizing an Al film deposited on a substrate. A regular nanostructure pattern was formed by performing interference exposure twice, and this was used as an anodization mask. Less than,
A method for manufacturing a nanostructure of this example will be described with reference to FIGS.

(1) An Al film 11 on an n-Si substrate 12
(Thickness: 500 nm) was formed (FIG. 3A).

(2) Next, washing with acetone and IPA,
After drying, a resist film 13 (thickness: 200 nm) was applied by spin coating and dried (90 ° C. for 20 minutes) (FIG. 3B).

(3) Next, a regular nanostructure pattern made of a resist having a stripe-shaped periodic structure (interval 14 is 230 nm) is formed using interference exposure. In this embodiment, a He-Cd laser (λ = 325 nm, interference fringe 2
Exposure was performed at an irradiation dose of 29.5 mJ / cm ² using an interval of 30 nm. Then, the developer was diluted one-to-one with pure water and developed for 90 seconds and 30 seconds to form a regular nanostructure pattern having a stripe-shaped recess 17 penetrating to the surface of the Al film 11 (FIG. 3 (c)). FIG.
It is a top view of this regular nanostructure pattern.

(4) Next, a phosphoric acid 0.3M solution, 100
By performing anodic oxidation with V, pores 19 periodically arranged in the Al film 11 (alumina film 11 ') were formed (FIG. 3D).

(5) Finally, using a resist stripper,
The resist 13 was peeled off from the substrate to be processed, immersed in 5 wt% phosphoric acid for 30 minutes, and a hole opening process (pore widening process) was performed (FIG. 3E).

<Evaluation> The nanostructure produced by the above method was observed by FESEM. As a result, as shown in FIG. 5, it was confirmed that the circular pores 20 having an interval of about 230 nm and a hole diameter of about 100 nm were arranged corresponding to the concave portions 17 of the interference fringes at intervals of 230 nm.

Embodiment 2 This embodiment is directed to a method of manufacturing a nanostructure in which pores are formed by anodizing an Al film deposited on a substrate. By performing interference exposure twice, a regular nanostructure pattern having a hexagonal lattice array was formed, and this was used as an anodization mask. Hereinafter, a method for manufacturing a nanostructure of this example will be described with reference to FIGS.

(1) First, an Al film 31 (500 nm thick) was formed on an n-Si substrate 32 (FIG. 6A).

(2) After cleaning and drying with acetone and IPA, the resist film 33 (film thickness 20
0 nm) and dried (90 degrees 20 minutes) (FIG. 6).
(B)).

(3) Next, using interference exposure, a regular nanostructure pattern is formed using a resist having a hexagonal lattice arrangement periodically. In this embodiment, a He-Cd laser (λ
= 325 nm, interference fringes at 230 nm intervals), and the first exposure was performed at an irradiation amount of 14.75 mJ / cm ² , and the resist 33 was exposed in a stripe shape as shown in FIG. Subsequently, the exposure was performed at an irradiation dose of 14.75 mJ / cm ² by shifting the interference fringe direction by 60 degrees from the interference fringe direction in the first interference exposure step. Thereafter, the developer was diluted one-to-one with pure water and developed for about 30 seconds, so that only the exposure intersection became concave, and a regular nanostructure pattern having a concave portion 35 penetrating to the substrate surface was formed ( FIG. 6 (c)). In this embodiment, the periodic interval of the stripe is 230 nm, and as shown in FIG. 8, the periodic interval 34 at the exposure intersection is (2/２3) × 230 ≒ 266 nm.

(4) Next, a 0.3 M phosphoric acid solution, 130
Anodization was performed at V (FIG. 6D).

(5) Finally, using a resist stripper,
The resist 31 was peeled off from the substrate to be processed, immersed in 5 wt% phosphoric acid for 30 minutes, and subjected to a hole opening process (pore widening process) to form pores 42 periodically arranged in a hexagonal lattice (FIG. 6).
(E)).

<Evaluation> The nanostructure produced by the above method was observed by FESEM. As a result, as shown in FIG. 9, it was confirmed that the perfect circular pores 42 having an interval of about 266 nm and a hole diameter of about 100 nm were arranged corresponding to the exposure intersection points.

(Embodiment 3) This embodiment is directed to a method for manufacturing a nanostructure in which pores are formed by anodizing an Al film deposited on a substrate. By performing interference exposure twice, a regular nanostructure pattern arranged in four directions was formed, and this was used as an anodization mask. Hereinafter, a method for fabricating the nanostructure of this example is shown in FIG.
This will be described with reference to FIG.

(1) First, an Al film 51 (thickness: 500 nm) was formed on an n-Si substrate 52 (FIG. 10A).

(2) After washing and drying with acetone and IPA, the resist film 53 (film thickness 20
0 nm) and dried (90 ° C. for 20 minutes) (FIG. 10).
(B)).

(3) Next, using interference exposure, a regular nanostructure pattern is formed by a resist that is periodically arranged in a square pattern. In this embodiment, a He-Cd laser (λ = 3
25 nm, interference fringes at 230 nm intervals) and an irradiation dose of 1
The first exposure was performed at 4.75 mJ / cm ² , and the resist 53 was exposed in a stripe shape as shown in FIG. Subsequently, exposure was performed at an irradiation dose of 14.75 mJ / cm ² by shifting the interference fringe direction by 90 degrees from the interference fringe direction in the first interference exposure step. Thereafter, the developer was diluted one-to-one with pure water and developed for about 30 seconds, so that only the exposure intersections became concave, and a regular nanostructure pattern having the concave portion 55 penetrating to the substrate surface was formed ( FIG. 10 (c)). The periodic interval of the stripes in this embodiment is 230 nm, and the periodic interval 54 at the exposure intersection is 230 nm as shown in FIG.

(4) Next, a 0.3 M phosphoric acid solution, 130
Anodization was performed at V (FIG. 10D).

(5) Finally, using a resist stripper,
The resist 53 was peeled off from the substrate to be processed, immersed in 5 wt% phosphoric acid for 30 minutes, and subjected to an opening process (pore wide process) to form periodically arranged pores 62 (FIG. 10).
(E)).

<Evaluation> The nanostructure produced by the above method was observed by FESEM. As a result, as shown in FIG. 13, it was confirmed that circular holes 62 having an interval of about 230 nm and a hole diameter of about 100 nm were arranged corresponding to the exposure intersection points.

(Embodiment 4) In this embodiment, after forming a regular nanostructure pattern in which a hexagonal lattice array is formed on a resist by using interference exposure, ion milling irradiation is performed on the entire surface to form an antireflection film under the resist regularly. Peeled according to the nanostructure pattern, followed by anodic oxidation, and produced a regular nanostructure pattern with a hexagonal lattice array on the workpiece (aluminum plate). Is.). Hereinafter, a method for manufacturing a nanostructure of this example will be described with reference to FIGS.

(1) An antireflection film 72 and a resist film 73 are laminated on an aluminum plate 71, and interference exposure is performed on the film.
In the same manner as in Example 2, a regular nanostructure pattern was formed using a resist in which the concave portions 74 were periodically arranged in a hexagonal lattice (FIG. 14A).

(2) The entire surface of the sample was subjected to ion milling irradiation, and the antireflection film 72 under the resist was peeled off in accordance with the regular nanostructure pattern (FIG. 14B).

(3) After anodic oxidation, the resist 73 is peeled off with a resist stripper, and the antireflection film 7 is stripped with an antireflection film stripper.
2 was peeled off and immersed in 5 wt% phosphoric acid for 30 minutes to perform a hole opening treatment (FIG. 14C).

<Evaluation> The nanostructure produced by the above method was observed by FESEM. As a result, it was confirmed that circular holes 75 having a hole interval of about 266 nm and a hole diameter of about 100 nm periodically arranged in a hexagonal lattice were formed.

(Embodiment 5) In this embodiment, anodization is performed after forming a regular nanostructure pattern in a square array using interference exposure on a resist formed on a Si substrate.
A regular nanostructure pattern arranged in a square on a Si substrate was fabricated (a nanostructure pattern arranged in a hexagonal lattice can also be fabricated). Hereinafter, a method for manufacturing a nanostructure of this example will be described with reference to FIGS.

(1) A resist film 82 is formed on a Si substrate 81, and a regular nanostructure pattern of a resist in which concave portions 83 are periodically arranged in a square pattern is formed on the resist film 82 by using interference exposure as in the third embodiment. It was produced (FIG. 15A).

(2) Anodizing in HF acid solution
A nanostructure pattern was formed on the i-substrate 81 using a resist that was periodically arranged on all sides (FIG. 15B).

(3) Finally, the resist 82 was stripped with a resist stripper (FIG. 15C).

<Evaluation> The nanostructure produced by the above method was observed by FESEM. As a result, it was confirmed that circular holes 84 having a hole interval of about 230 nm, which were periodically arranged in a square lattice, were formed.

Example 6 In this example, a magnetic material was embedded in a nanostructure having periodic pores to produce a magnetic device. Hereinafter, a method for manufacturing the magnetic device of this example will be described with reference to FIGS.

(1) First, Pt is placed on the n-Si substrate 91.
A film 92 (film thickness 50 nm) was formed (FIG. 16A).

(2) Next, on this Pt / n-Si,
An Al film 93 (500 nm thick) was formed (FIG. 16).
(B)).

(3) Next, after the resist film 94 is formed, a concave portion 95 is formed in the resist film 94 by the same interference exposure as in the second embodiment, and the regular nanostructure is formed by the resist film 94 having a periodic structure. A pattern was prepared (FIG. 16
(C)). In addition, the formation of this regular nanostructure pattern
It can be performed in the same manner as in the first embodiment and the third to fifth embodiments.

(4) Next, a 0.3 M phosphoric acid solution and a voltage of 1
Anodization was performed at 30 V (FIG. 16D). At this time, the anodic oxidation was terminated when the current value in the current profile decreased.

(5) Next, the resist film 94 was stripped with a resist stripping solution, and immersed in 5 wt% phosphoric acid for 30 minutes to form a hole (FIG. 16E).

(6) Next, electrodeposition was performed by immersing in a Co electrodeposition solution (FIG. 16 (f)).

(7) Finally, the surface was polished and flattened using a diamond paste having a particle size of 500 ° (FIG. 16).
(G)).

<Evaluation> The nanostructure produced by the above method was observed by FESEM. As a result, it was confirmed that Co was uniformly electrodeposited on the circular holes 96 having a hole interval of about 266 nm and a hole diameter of about 100 nm periodically arranged in a hexagonal lattice.

[0099]

As described above, the present invention has the following effects.

(1) The method for producing a nanostructure of the present invention comprises:
By forming a regular nanostructure pattern on the workpiece using interference exposure, and by anodizing the workpiece, regular perfect circular pores can be formed over a large area. It is possible to produce a nanostructure (alumina pores) in which perfect circular holes having excellent linearity are regularly arranged over the entire region. Further, a nanostructure having a high aspect ratio can be manufactured by performing anodization or anodic oxidation using a regular nanostructure pattern formed by interference exposure as a mask of a workpiece. In particular, since interference exposure uses a sine wave component interference wave, it is possible to overcome the problem that a high aspect ratio pattern cannot be carved on the resist itself.

(2) In the method for producing a nanostructure of the present invention, since a regular nanostructure pattern is used for forming the pore formation starting point, the workpiece is formed when the pore formation starting point is formed. There is no need to apply pressure to the stamper or to position the stamper, and the present invention can be applied to a workpiece having low mechanical strength.

(3) Further, in the method for producing a nanostructure according to the present invention, since a regular nanostructure pattern is used for forming the pore formation starting point, a workpiece having a film formed on the Al surface is used. Also the thickness of the nanostructure pattern (height difference)
Within this range, it is possible to expose Al on the surface, so that it is possible to form a pore formation starting point.

(4) Further, since the method for producing a nanostructure of the present invention uses a regular nanostructure pattern, the starting point of pore formation depends only on the concave position of the nanostructure, and arbitrary arrangement of pores is possible. Is possible. Further, in the anodization, since the pores grow in a perfect circle, the penetrating portion of the periodic nanostructure may not be a perfect circle.

(5) A periodic nanostructure can be produced at a much larger area and at a lower cost than using semiconductor processing techniques such as X-ray exposure and electron beam exposure. This is practical in that it does not require direct patterning on the workpiece surface and does not damage the workpiece.

(6) The present invention also makes it possible to apply the porous body of anodized alumina in various forms, and greatly expands its application range. Further, the nanostructure of the present invention can be used as a functional material by itself, but can also be used as a base material, a template, and the like of a novel nanostructure.

[Brief description of the drawings]

FIG. 1 is a view for explaining one embodiment of a method for producing a nanostructure of the present invention.

FIG. 2 is a view for explaining one embodiment of a method for producing a nanostructure of the present invention.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing a nanostructure according to Example 1 of the present invention.

FIG. 4 is a plan view showing a regular nanostructure pattern according to Example 1 of the present invention.

FIG. 5 is a plan view showing a nanostructure manufactured in Example 1 of the present invention.

FIG. 6 is a cross-sectional view for explaining a method for manufacturing a nanostructure according to Example 2 of the present invention.

FIG. 7 is a plan view showing a first interference exposure pattern in a method for manufacturing a nanostructure according to Example 2 of the present invention.

FIG. 8 is a plan view showing a regular nanostructure pattern according to a second embodiment of the present invention.

FIG. 9 is a plan view showing a nanostructure manufactured in Example 2 of the present invention.

FIG. 10 is a cross-sectional view illustrating a method for manufacturing a nanostructure according to Example 3 of the present invention.

FIG. 11 is a plan view showing a first interference exposure pattern in a method for manufacturing a nanostructure according to Example 3 of the present invention.

FIG. 12 is a plan view showing a regular nanostructure pattern according to Example 3 of the present invention.

FIG. 13 is a plan view showing a nanostructure manufactured in Example 3 of the present invention.

14A and 14B are a plan view and a cross-sectional view illustrating a method for manufacturing a nanostructure according to Example 4 of the present invention.

15A and 15B are a plan view and a cross-sectional view illustrating a method for manufacturing a nanostructure according to Example 5 of the present invention.

FIG. 16 is a cross-sectional view for explaining the method for manufacturing the magnetic device according to the sixth embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 aluminum plate 11 aluminum film 11 ′ alumina film 12 n-Si substrate 13 resist 14 stripe-shaped periodic interval in first interference exposure 15 antireflection film 16 resist portion exposed in stripe form 17 After developing the exposure intersection,
Part penetrating concavely to the workpiece (aluminum film) 18 Spacing between pores arranged in hexagonal lattice 19 Regular pores formed in Al film by anodic oxidation 20 Regular pores subjected to aperture treatment 31 Al film 31 'Alumina film 32 n-Si substrate 33 Resist film 34 Interval of pores arranged in hexagonal lattice 35 After developing exposure intersection points of interference exposure over 2 degrees,
A portion penetrating in a concave shape up to the workpiece 41 A resist exposed in a stripe shape 42 A hole formed in a hexagonal lattice array of pores formed in an Al film by anodic oxidation 51 Al film 51 ′ Alumina film 52 n-Si substrate 53 resist film 54 interval of periodically arranged fine pores 55 55 after developing the exposure intersection part of interference exposure over 2 degrees,
A portion penetrating to the workpiece in a concave shape 61 A resist portion exposed in a stripe shape 62 A hole formed by periodically opening pores formed in an Al film by anodic oxidation 71 Aluminum plate 72 Antireflection film 73 Resist 74 A resist pattern periodically formed in a hexagonal lattice formed by interference exposure twice 75 A pore 81 formed on a workpiece (aluminum plate) by anodic oxidation 81 Si substrate 82 Resist 83 formed by interference exposure twice In addition, a resist pattern that is periodically arranged in four directions 84 Pores of a workpiece (Si) formed by anodization 91 Si substrate 92 Pt film 93 Al film 93 ′ Alumina film 94 Resist 95 Exposure intersection points of interference exposure over two degrees After developing the part,
A part penetrating in a concave shape to the workpiece 96 A hexagonal lattice arranged pores formed in the Al film by anodic oxidation Opening treatment 97 Co electrodeposited in the pores

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01J 1/304 H01J 9/02 B 9/02 G11B 5/62 // G11B 5/62 5/84 Z 5 / 84 H01L 43/08 Z H01L 43/08 H01J 1/30 F (72) Inventor Tohru 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (Reference) 2H096 AA27 BA10 CA14 EA04 EA12 GA08 HA30 5D006 BB01 BB06 BB07 CA01 CB04 CB08 DA03 FA09 5D112 AA02 AA03 AA05 AA18 AA24 BA02 BB05 BB10 BD03 GA19 GA29

Claims (20)

[Claims] In a method for producing a nanostructure in which pores are formed by anodizing or anodizing a workpiece, a resist on the workpiece is exposed and developed to form a resist on the surface of the workpiece. Step 1 of forming a regular nano-structure pattern by forming a portion penetrating to the order, and then anodizing or anodizing the workpiece so as to form a regular array corresponding to the regular nano-structure pattern. A method for producing a nanostructure, comprising a step 2 of forming a porous body having pores. 2. The method according to claim 1, wherein the step 1 is a step of forming a regular nanostructure pattern by at least a step of forming a resist on a workpiece, a step of subjecting the resist to interference exposure, and a step of developing. The method for producing a nanostructure according to claim 1. 3. The step 1 includes two or more interference exposure steps, and the interference fringe direction in the second interference exposure step is one.
3. A step of forming a regular nanostructure pattern in which intersections of interference fringes are regularly arranged by being different from an interference fringe direction in a second interference exposure step.
3. The method for producing a nanostructure according to 1.). 4. The process according to claim 1, wherein in the step (2), a circular hole is formed in a portion of the regular nanostructure pattern formed of the resist penetrating to the surface of the workpiece. A method for producing a nanostructure according to any one of the above. 5. The method for manufacturing a nanostructure according to claim 1, wherein the regular nanostructure pattern made of the resist has a width of a penetrating portion of 500 nm or less. 6. The method for manufacturing a nanostructure according to claim 1, wherein the regular nanostructure pattern made of the resist has an interval between each penetrating portion of 30 to 1000 nm. 7. A portion of the regular nanostructure pattern formed of the resist, which is a starting point of pore formation, penetrating to the surface of the workpiece, has a same interval and a repetition of the pattern. 7. The method for producing a nanostructure according to any one of 1 to 6. 8. The method according to claim 7, wherein the pore formation start point is a repetition of a regular hexagonal pattern. 9. The method according to claim 7, wherein the pore formation start point is a repetition of a quadrangular pattern. 10. The method of manufacturing a nanostructure according to claim 1, wherein the workpiece is a bulk containing Al as a main component. 11. The method for producing a nanostructure according to claim 1, wherein the workpiece is formed by forming a film containing Al as a main component on a substrate. . 12. The method of manufacturing a nanostructure according to claim 1, wherein the workpiece is a bulk containing Si as a main component. 13. The method of manufacturing a nanostructure according to claim 1, wherein the workpiece is formed by forming a film containing Si as a main component on a substrate. . 14. A nanostructure produced by the method according to claim 1. 15. A method for manufacturing a nanostructure using the nanostructure according to claim 14 as a mold or a mask. 16. A nanostructure produced by the method according to claim 15. 17. An electron-emitting device, comprising an electron-emitting portion in a pore of a substrate having a regular nanostructure in the nanostructure according to claim 16. 18. The nanostructure according to claim 16, which has a structure in which a substance having a different dielectric constant from that of the substrate is embedded in pores of the substrate having a regular nanostructure.
A photonic device capable of controlling a light propagation direction. 19. A magnetic device, wherein a magnetic material is embedded in pores of a substrate having a regular nanostructure in the nanostructure according to claim 16. 20. A light emitting device comprising a nanostructure according to claim 16, wherein a light emitter is embedded in pores of a substrate having a regular nanostructure.