WO2010093069A1

WO2010093069A1 - Method for manufacturing a nanostructure

Info

Publication number: WO2010093069A1
Application number: PCT/KR2009/000645
Authority: WO
Inventors: 강신일; 최준혁
Original assignee: 연세대학교 산학협력단
Priority date: 2009-02-12
Filing date: 2009-02-12
Publication date: 2010-08-19

Abstract

The present invention provides a method for manufacturing a nanostructure, which comprises a first step for applying nanoparticles on a substrate and a second step for binding the nanoparticles on the substrate to create nano-sized unevenness through heat treatment. Particularly, the nanoparticles are metallic. More particularly, the nanoparticles have a diameter of 1-100 nm and the diameter of the nano-sized unevenness is 10-1000 nm. In addition, the present invention provides a method for manufacturing nanopatterns, which comprises: manufacturing the nanostructure by the method for manufacturing the nanostructure; and replicating the manufactured nanostructure.

Description

Nano structure manufacturing method

The present invention relates to a method for manufacturing nanostructures, and more particularly, to a method for manufacturing nanostructures using a combination of nanoparticles.

As NT / IT / BT technology evolves, nanostructures are increasingly growing in applications and demand. In manufacturing nanostructures of various fields, many conventional methods are known. For example, by forming a nanostructure that mimics the moth eye on a substrate to produce an antireflection film required in the display field. Even in the case of a super water-repellent functional film applied to the outer wall of a building, a nanostructure is formed on a substrate and manufactured.

However, the conventional methods for manufacturing nanostructures, such as electron beam lithography, focused ion beam processing, holographic lithography, photolithography, and the like, produce nanostructures in large areas, resulting in high cost, long process time, and process cost. There was this.

For example, in the case of argon fluoride (ArF) photolithography, in order to mass produce nanostructures in large areas, equipment construction and processing costs are very high and it is hard to say that it is economical.

In electron beam lithography, nano / micro diameter structures can be easily created. However, when processing in large areas, not only the cost and processing time are quite high, but also the processing area is limited.

Holographic lithography is a process that utilizes the difference in the interference between beams, which enables high speed and large area, and has been widely applied to the fabrication of periodic nanostructures. Holographic lithography can serve as a breakthrough for the area limitations of electron beam lithography. However, in order to fabricate large-area and ultra-fine nanostructures, expensive equipment is required, and process stability is very important, and large-scale system construction is required.

On the other hand, when manufacturing nanostructures using nano-colloidal coating, it is difficult to overcome the limitations of the nanoparticle size, it is difficult to apply the nano-colloid uniformly in a large area. In particular, the particles should be evenly distributed in a single layer, and for this purpose, optimization of the process conditions such as controlling the density of the particles, the rotational speed of the spin coating, and the like should be made. The optimization is very difficult and the process stability is low.

Recently, attempts have been made to form nanostructures by applying a liquid polymeric material to the intaglio surface of a substrate and heating above the glass transition temperature of the polymeric material to cause dewetting. However, the polymer nanostructures fabricated in this way have a problem in that they are chemically / physically vulnerable, in particular, very vulnerable to dry etching, etc., which acts as a big limitation in the subsequent process.

In addition, there is an attempt to produce a nanostructure by forming a metal thin film by sputtering and heat treatment. However, this has the problem of equipment limitations and large process cost and time in large area applications. In addition, the type of metal thin film material is limited, and due to its structural characteristics, a high temperature heat treatment process of 800 ° C. or higher is required, and thus a special high temperature system is required. In addition, the process stability, such as giving a thermal shock to the substrate is low and the kind of substrate that can be used is limited.

The present invention has been made to solve the above problems, an object of the present invention is to stably provide a nanostructure large area.

In addition, an object of the present invention is to provide a method for manufacturing nanostructures excellent in terms of cost and productivity by simplifying the process and reducing the cost.

In addition, an object of the present invention is to provide a variety of nanostructures suitable for each use by making nanostructures having excellent chemical / physical durability and from another nanostructures therefrom.

In addition, an object of the present invention is to provide a method for manufacturing a nanopattern of low cost and high productivity by using the fabricated nanostructure for pattern replication.

In order to achieve the above object, the present invention comprises a first step of applying nanoparticles on a substrate; And through heat treatment, it provides a nanostructure manufacturing method comprising a second step of bonding the nanoparticles on the substrate with nano irregularities.

Preferably, the nanoparticles are metal nanoparticles.

Preferably, the nanoparticles have a diameter of 1 to 100 nm, and the nano irregularities have a diameter of 10 to 1000 nm.

The nanoparticles may be mixed with a solvent and applied onto the substrate in a solution state.

Preferably, the second step includes the step of sintering the nanoparticles above the sintering temperature of the nanoparticles. In addition, the second step, the heat treatment is started at a temperature lower than the sintering temperature of the nanoparticles.

The substrate may be etched using the nano irregularities as a mask, and a third step of removing the nano irregularities may be included.

The method may include a third step of applying a target material on the substrate on which the nano-evenness is formed, and then performing a lift-off process of removing the nano-evenness.

A third step of selectively applying a target material to a portion of the substrate other than the nano-unevenness using the nano-unevenness as a mask, and removing the nano-unevenness.

It may include a third step of selectively applying a target material on the nano irregularities.

In addition, the present invention, the step of manufacturing the nanostructure by the nanostructure manufacturing method; And it provides a nano-pattern manufacturing method comprising a replication step of replicating the produced nanostructures.

Here, in the replicating step, at least one of electroplating, imprinting, injection molding, and compression molding may be performed at least one time.

According to the above configuration, the present invention has the effect that it is possible to stably provide a nanostructure in a large area.

In addition, the present invention aims to simplify the process and reduce the cost, and there is an effect that a large amount of nanostructures can be manufactured with high mass production and low production cost.

In addition, the present invention has the effect of providing a variety of nanostructures suitable for each purpose by forming a nanostructure having a chemical / physically excellent durability, from which to produce another nanostructure.

In addition, the present invention has the effect of providing a low cost, high productivity nano pattern manufacturing method by using the fabricated nanostructures for pattern replication. In particular, the nanostructure is replicated through electroplating, and the nano-molding using the obtained highly durable nanopattern as a mold has a very excellent advantage in terms of cost and productivity.

1 is a process flowchart showing a method of manufacturing a nanostructure according to a first embodiment of the present invention.

FIG. 2 is a view illustrating a substrate on which a nanostructure manufactured by the method of FIG. 1 is formed.

3 is an enlarged plan view illustrating an arrangement state of nanostructures manufactured by the fabrication method of FIG. 1.

4 is an enlarged perspective view illustrating an arrangement state of the nanostructure of FIG. 3.

5 to 8 are process flowcharts showing a method for manufacturing nanostructures according to the second to fifth embodiments of the present invention.

9 is a process flowchart showing a method of manufacturing a nano pattern according to a sixth embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the present specification, in order to name an array of three-dimensional structures such as nano pillars, nano holes, and the like, they are referred to as nano structures in FIGS. 1 to 8 and nano patterns in FIG. 9. However, it is only named differently for the purpose of distinguishing the subject matter in the claims, the nanostructure and the nanopattern may have the same geometric shape. In addition, although the nanostructure of Figure 1 is referred to in particular as nano irregularities, this is also to clarify the indication in the claims.

As shown, the nanostructure fabrication method of Figure 1 is uniformly applying the nanoparticles on the substrate 10, through the heat treatment, the nanoparticles are bonded to the nano-concave (23) on the substrate 10 ( aggregation).

The substrate 10 includes at least one of silicon, quartz, glass, plastic, oxide, and metal. According to the heat treatment process conditions to be described later, a plastic substrate to be heat treated at a low temperature, a substrate such as glass, quartz, silicon, which can be heat treated at a high temperature is possible.

Oxides, metals, and the like may be formed in the form of a film on the surface of the substrate 10. When the oxide film having an antireflection effect is formed in a single layer or multiple layers on the surface of the substrate 10 and the antireflection nanostructure is formed thereon, the antireflection effect can be doubled. As another example, a metal film may be formed on the surface of the substrate 10 to be used as a seed layer for electroplating described later.

As shown, the substrate 10 may be a two-dimensional flat surface, or may be a three-dimensional solid surface on which an optical lens, a flow channel, and the like are formed.

In the present invention, nanoparticles are applied to these substrates 10, where the present invention may be distinguished from the prior art described above.

First, the nanostructures formed by dewetting have a disadvantage in that they are very vulnerable to dry etching, etc., thereby limiting subsequent processes. However, the nanostructures of the present invention have excellent chemical / physical durability and can be applied to various subsequent processes. Has an advantage.

On the other hand, when forming a metal thin film on the substrate in the form of a thin film rather than particles, a large amount of thermal energy is required to break the metal bonds closely bonded to each other to cause recombination. In order to apply high thermal energy to the metal thin film, a sintering furnace should be used. In order to make the temperature distribution uniform, many difficulties are required and the process cost is very high. Proper gaps between the crystals are necessary in order to fabricate the metal crystals that are densely packed with each other into uniform and independent circular nano irregularities using heat treatment. If the gap between the crystals is too small, the gap increases the irregularities of the obtained nano irregularities. Therefore, uniform application of the metal material in the form of particles rather than in the form of thin films is advantageous for obtaining uniform nano irregularities at low temperatures.

As nanoparticles, metal nanoparticles are preferably used. Here, the metal nanoparticles include at least one of silver, aluminum, copper, iron, platinum, lead, gold, and mercury. Nanoparticles may comprise a single or two or more materials. In addition, silica (SiO ₂ ) nanoparticles, and the like may also be used.

Preferably, the nanoparticles are 1-100 nm in diameter.

The nanoparticles may be mixed with an organic solvent or a polymer resin solvent and applied to the substrate 10 in a solution state. That is, the solution 21 in which the nanoparticles are mixed may be applied to the substrate 10. However, the nanoparticle solution 21 is already dried at the time when the heat treatment starts, the heat treatment can be started in a solid state.

Spin coating, bar coating, spray coating, deep coating, or the like may be used for the application of the solution 21. With these coating methods, nanoparticles can be uniformly applied to a large area, which has the advantage of low process cost.

Specifically, the nanoparticles are applied according to the conditions such as the rotation speed and rotation time of the spin coating (when using spin coating), the temperature, the size of the nanoparticles, the concentration of the solution 21, the type of the solution 21, and the like. Uniformity is determined, which affects the size and distribution of the nano irregularities 23 formed after the heat treatment.

After the nanoparticles are thinly coated on the substrate 10 and then heat treated, the nanoparticles are combined by thermal energy to form nanoconvex and convexities 23. At this time, the size of the nano-concave-convex 23 is determined according to the process conditions, such as the heat treatment temperature, the type of nanoparticles, the surrounding environment. Preferably, the diameter of the nano irregularities 23 is 10 to 1000 nm.

The heat treatment includes sintering the nanoparticles above the sintering temperature of the nanoparticles. Here, the heat treatment is preferably started at a temperature lower than the sintering temperature of the nanoparticles.

The mechanism by which nanoparticles are aggregated is as follows. If the heat treatment is started at a temperature lower than the sintering temperature, the isolation phenomenon is started. Subsequently, when the temperature is increased to a sintering temperature or higher, the isolated particles are sintered to form nano irregularities.

For example, assuming that the sintering temperature is 250 ° C, the heat treatment is started at 200 ° C to raise the temperature to 250 ° C, the heat treatment is started at 180 ° C and the temperature is increased to 250 ° C, and the heat treatment is started at 150 ° C. In the case of raising the temperature to 250 ° C., the size of the nano irregularities obtained is different. Starting the heat treatment at a lower temperature will result in a larger nano bumps. Because enough time is given for isolation. These characteristics can be used to control the size of the nano irregularities.

The heat treatment may be performed at an extremely low temperature as compared to the heat treatment of the metal thin film described above. For example, the 20-30 nm Ag nanoparticles may be heat-treated at 250 ° C. for 10 minutes to obtain nano irregularities 23 as illustrated in FIG. 1B. Although the melting point of Ag is 961 ° C., by using Ag in a fine particle state, the Ag can be produced at a temperature much lower than the melting point, thereby producing the nanoconcave-convex (23).

As the heat treatment, a method using an oven, a method using a hot plate, a method using a sintering furnace, a method using an infrared heater, and the like can be used.

Depending on the heat treatment conditions, a vacuum atmosphere, a nitrogen atmosphere, an argon atmosphere, a general atmospheric atmosphere, or the like can be used as the process atmosphere.

Depending on the process conditions, the heat treatment may improve the bonding properties of the nanoparticles through multiple conditions, rather than a single condition to form a uniform nano irregularities (23).

FIG. 2 is a diagram illustrating a state in which nanostructures are formed by the fabrication method of FIG. 1 on the substrate 10, and FIG. 3 is an enlarged plan view illustrating an arrangement state of the nanostructures fabricated by the fabrication method of FIG. 1. 4 is an enlarged perspective view illustrating an arrangement state of the nanostructure of FIG. 3.

As shown, uniform nano irregularities 23 can be obtained by the nanostructure fabrication method of the present invention.

Various nanostructures may be obtained by using the nano-concave-convex 23 manufactured in FIG. 1 in a subsequent process.

5 is a process flowchart showing a method of manufacturing a nanostructure according to a second embodiment of the present invention.

As shown in FIG. 1, the nanostructures 23 may be etched using the nanoconcave-convex 23 manufactured as shown in FIG. 1 as a mask, and the nanoconcave-convex 23 may be removed. Dry etching, wet etching, and the like can be used.

In order to etch the substrate 10, a chemical substance that reacts only with the substrate 10 without reacting with the nano irregularities 23 or a chemical substance having a difference in reaction speed between the nano irregularities 23 and the substrate 10 is used. Can be etched.

Using nano-concave-convex (23) and etching can be produced a variety of nanostructures, such as nanostructures, triangular nanostructures of high-grade equipment.

6 is a process flowchart showing a method of manufacturing a nanostructure according to a third embodiment of the present invention.

After applying the target material 25 on the substrate 10 having the nano-concave-convex 23 of FIG. 1, the nano-structure may be manufactured through a lift-off process of removing the nano-concave-convex 23. .

The target material is coated with a material different from the nano-concave-convex (23) such as oxide, metal, polymer, etc., and then the nano-convex (23) is melted to manufacture a nano-hole.

The manufacturing method of FIG. 6 is used to make the nanostructure having the lower end or the upper end of the flat surface by removing the upper end of the nano-concave-convex 23.

7 is a process flowchart showing a method of manufacturing a nanostructure according to a fourth embodiment of the present invention, Figure 8 is a process flowchart showing a method of manufacturing a nanostructure according to a fifth embodiment of the present invention.

The target material may be selectively coated on the nano-convexities 23 or the substrate 10 of FIG. 1 to impart a special effect.

In the embodiment of FIG. 7, the nano unevenness 23 functions as a mask to selectively apply the target material 26 to substrate portions other than the nano unevenness 23 and remove the nano unevenness 23.

Nanostructures coated with TiO ₂ on silver nano irregularities absorb ultraviolet rays and can be applied to keypads of mobile phones. As such, the metal nano bumps may be coated with metals, oxides, polymers, and the like having different dielectric constants to impart desired optical properties.

Biochips require nanostructures to attach / grow cells. Depending on the size, cycle, height, material, etc. of the nanostructures, various applications are possible by changing the attachment and growth mechanisms of the cells. The nanostructures may be selectively coated on the nano-concave-convex 23 to manufacture nanostructures, and may be used as filters by inducing a selective reaction by the fabricated nanostructures. As such, the

target materials

26 and 27 may be selectively coated on the nano irregularities 23 or the substrate 10 by using the surface energy difference, and then the secondary reaction may be induced using the

target materials

26 and 27.

The self-assembled monolayer may be selectively coated on the substrate 10 or the nano unevenness 23. For example, thiol-based materials are coated on materials such as gold, platinum, nickel, copper, etc., but not coated on silicon, glass, quartz, and polymer materials, and have reactive nano irregularities 23 such as gold or platinum. In this case, the thiol-based organic material may be coated and applied to a bio device. In addition, the substrate 10 may be selectively reacted with the target material 26 which does not react with the nano unevenness 23, and the nano unevenness 23 may be removed to form nano holes at a portion thereof.

1 and the nanostructures may be manufactured by duplicating the nanostructures manufactured by the method of FIGS. 5 to 8. Here, as the replication method, various replication methods such as electroplating, imprinting, injection molding, compression molding, and the like may be used, and one or more replication may be performed. For example, the nanostructures having the opposite shape as the nanostructures may be manufactured by imprinting the fabricated nanostructures, or the nanostructures having the same shape as the nanostructures may be manufactured by two imprinting, or the nanostructures may be formed by preplating and imprinting. It can be applied to various applications, such as manufacturing a nano pattern of the same shape.

In particular, when performing roll imprinting using the fabricated nanostructures or nanopatterns, the process speed may be greatly improved.

By continuously replicating the nanopattern using the fabricated nanostructure, the nanopattern can be mass produced at low cost.

9 shows an embodiment in which electroplating is performed as a subsequent process of the manufacturing method of FIG. 5. However, of course, the electroplating may be performed as a subsequent process of the other manufacturing method.

In detail, first, the seed layer 31 is formed on the nanostructure, and then electroplating is performed.

Nano pattern 33 produced by electroplating is very excellent in durability, it is suitable for use as a mold for manufacturing other nano patterns. In this case, it brings the advantage of mass-producing nanopatterns at even lower cost.

Based on the fabrication method of the present invention, nanostructures or nanopatterns can be manufactured at low cost in large areas such as biochips, optical filters for display devices, optical devices for solar cells, and the like.

Claims

Applying a nanoparticle to a substrate;

Through the heat treatment, the nanostructure fabrication method comprising the step of bonding the nanoparticles on the substrate with nano irregularities.
The method of claim 1,

The nanoparticles are nanostructures manufacturing method characterized in that the metal nanoparticles.
The method of claim 2,

The metal nanoparticles, nanostructure manufacturing method comprising at least one of silver, aluminum, copper, iron, platinum, lead, gold and mercury.
The method of claim 1,

The nanoparticles are nanostructures manufacturing method characterized in that the diameter of 1 ~ 100nm.
The method of claim 1,

The nano irregularities are nanostructures manufacturing method characterized in that the diameter of 10 ~ 1000nm.
The method of claim 1,

The nanoparticles are mixed in a solvent and nanostructures manufacturing method characterized in that the coating on the substrate in a solution state.
The method of claim 1,

The solvent is a nano-structure manufacturing method characterized in that the organic solvent or polymer resin solvent.
The method of claim 1,

The substrate has a two-dimensional flat surface or three-dimensional solid surface manufacturing method characterized in that it has a three-dimensional solid surface.
The method of claim 1,

The second step, the nanostructure fabrication method comprising the step of sintering the nanoparticles at the sintering temperature of the nanoparticles.
The method of claim 9,

The second step, the nanostructure fabrication method characterized in that the heat treatment is started at a temperature lower than the sintering temperature of the nanoparticles.
The method of claim 1,

The substrate is a nanostructure manufacturing method comprising at least one of silicon, glass, quartz, plastic, oxide and metal.
The method of claim 11,

The oxide and metal is a nanostructure manufacturing method characterized in that formed by forming a film on the surface of the substrate.
The method of claim 1,

And etching the substrate using the nano irregularities as a mask and removing the nano irregularities.
The method of claim 1,

And applying a target material on the substrate on which the nano-evenness is formed, and then performing a lift-off process of removing the nano-evenness.
The method of claim 1,

And a third step of selectively applying a target material to a portion of the substrate other than the nano irregularities using the nano irregularities as a mask, and removing the nano irregularities.
The method of claim 1,

And a third step of selectively applying a target material on the nano-unevenness.
The method according to any one of claims 14 to 16,

The target material is a nanostructure manufacturing method, characterized in that the oxide, metal or polymer.
17. A method for manufacturing a nanostructure according to any one of claims 1 to 16; And

Nano pattern fabrication method comprising the step of replicating the nanostructures produced.
The method of claim 18,

In the replicating step, a nano-pattern manufacturing method comprising performing at least one of electroplating, imprinting, injection molding and compression molding at least one time.