KR20130130336A - Silica nano structure, method of fabricating the same and etching mask using the same - Google Patents

Abstract

The present invention provides a silica nanostructure and a manufacturing method thereof. The silica nanostructure comprises silica nanopatterns and at least one silica bridge between the silica nanopatterns. Accordingly, the nanosize silica structure can be precisely controlled by using etching and inverse reaction.

Description

Silica nanostructure, method of manufacturing the same, and etching mask using same

The present invention relates to a silica nanostructure, a method for producing the same, and an etching mask using the same. More particularly, the present invention relates to a silica nanostructure using etching and reverse reaction, a method for producing the same, and an etching mask using the same.

The sol-gel process in the silica production technology is a hydrolysis reaction in which a compound of a molecular unit having a size of 1 nanometer or less dissolved in a solvent reacts with water to form a hydroxyl group (-OH) Is a process in which the reactants are connected to each other through a condensation reaction in which a water molecule is released from the reaction mixture to form a bond with oxygen.

As an example using a sol-gel process, Korean Patent Registration No. 10-0824291 (Apr. 16, 2008) discloses a method of dissolving a one-dimensional structure forming material having a one-dimensional structure forming ability such as a block copolymer or TEOS in a solution containing silica nanoparticles And adjusting the pH by a pH adjusting agent.

However, the sol-gel process has a problem in that the material used for the reaction is relatively expensive and the final product is small in size. In addition, low pH and high temperature are generally required, and cracks or non-uniform compositions are present. Therefore, it is difficult to make it into an elaborate shape, and there are also serious problems of deformation due to drying or heat.

In the case of other silica production techniques, such as firing and vapor deposition, it is difficult to control the shape and has a disadvantage in that a high temperature is required.

Therefore, there is a need to develop a method for fabricating a nanoscale sophisticated silica structure.

A problem to be solved by the present invention is to provide a silica nanostructure produced by controlling the silica structure using etching and reverse reaction.

Another object of the present invention is to provide a method for manufacturing a silica nanostructure that controls a silica structure using etching and reverse reaction.

Another object of the present invention is to provide an etch mask using a silica nanostructure produced by controlling a silica structure using an etching and a reverse reaction.

According to an aspect of the present invention, there is provided a silica nanostructure including at least one silica bridge formed between a silica nanopattern and a silica nanopattern.

To a mixed solution comprising the another side step and the fixed substrate on which the silica nano pattern hydrofluoric acid (HF) and ammonium fluoride (NH ₄ F) for fixing the silica nano pattern on the substrate of the present invention to achieve the above objective, And immersing the silica nanoparticles in a solvent to form a silica bridge between the silica nanopatterns by etching and reverse reaction.

According to another aspect of the present invention, there is provided an etch mask comprising a silica nanostructure formed of a silica nanopattern and at least one silica bridge connecting the silica nanopattern.

According to the present invention, a silica nanostructure can be prepared at a pH close to normal temperature, normal pressure and neutral.

In addition, nano-sized sophisticated silica structures can be produced.

The technical effects of the present invention are not limited to those mentioned above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 is a schematic view of a silica nanostructure according to an embodiment of the present invention.
2 is a flowchart illustrating a method of manufacturing a silica nanostructure according to an embodiment of the present invention.
FIG. 3 is a schematic view showing a process of forming a silica bridge between silica nanospheres by etching and reverse reaction with time.
Figs. 4 and 5 are images of the silica nanostructure according to Production Example 1. Fig.
6 is an image and table of energy spectroscopic analysis measured at the centers of silica nanospheres and silica bridges.
FIG. 7 shows images of the silica structure produced by the manufacturing method according to Comparative Example 1. FIG.
FIG. 8 shows images of the silica structure produced by the manufacturing method according to Comparative Example 2. FIG.
FIG. 9 shows images of the silica structure produced by the manufacturing method according to Comparative Example 3. FIG.
10 are images of the silica nanostructures prepared by the production method of the silica nanostructure according to Production Examples 2 to 5. FIG.
11 is a photonic bandgap diagram of a two-dimensional crystalline silica nanostructure according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms.

When a layer is referred to herein as being "on" another layer or substrate, it may be formed directly on another layer or substrate, or a third layer may be interposed therebetween. In addition, in the present specification, the directional expression of the upper portion, the upper portion, and the upper surface may be understood as the meaning of the lower portion, the lower portion, the lower surface, and the like. That is, the expression of the spatial direction should be understood in a relative direction, and it should not be construed as definitively as an absolute direction.

In the present embodiments, "first "," second ", or "third" is not intended to impose any limitation on the elements, but merely as terms for distinguishing the elements.

Further, in the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout.

The term "atmospheric pressure" used in the present invention refers to a pressure at which the pressure is not reduced or increased, and usually refers to a pressure of about one atmosphere such as atmospheric pressure.

The term "normal temperature" used in the present invention means 15 deg. C to 25 deg.

Example  One

The silica nanostructure according to one embodiment of the present invention will be described.

The silica nanostructure comprises a silica nanopattern and at least one silica bridge formed between the silica nanopatterns.

The silica nanopattern may include nanospheres, nanorods, nano-hemispheres, nano cylinders, or nanopahedral prisms.

Hereinafter, the silica nano pattern will be described as an example of a silica nanosphere.

1 is a schematic view of a part of a silica nanostructure according to an embodiment of the present invention.

Referring to FIG. 1, the silica nanostructure includes a plurality of silica nanocrystals 200 and at least one silica bridge 400 formed between the silica nanospheres 200.

The diameter of the silica nanosphere 200 may be several hundred nanometers. For example, from 500 nm to 700 nm. However, the present invention is not limited thereto, and the diameter of the silica nanosphere 200 may be in the order of micrometers or several tens of nanometers.

The silica bridge 400 serves as a bridge connecting the nanoscale spheres 200. The diameter of the silica bridge 400 may be smaller than the diameter of the silica nanosphere 200. Here, the diameter of the silica bridge 400 means the length of the vertical cross-sectional area of the bridge in the longitudinal direction. For example, when the diameter of the silica nanosphere 200 is about 600 nm, the diameter of the silica bridge 400 may be 150 nm to 200 nm.

In the silica nanostructure, the arrangement of the silica nanospheres 200 may be in various forms. For example, one silica nanosphere 200 is surrounded by six silica nanospheres 200 spaced apart from each other, and the silica nanospheres 200 can be connected to each other by a silica bridge 400. In another example, the silica nanostructure may be a honeycomb structure.

The above-mentioned silica nanostructure can be used as a mask for etching other materials such as silicon and graphene.

In addition, the above-mentioned silica nanostructure can be used for application of photonic crystals.

Example  2

A method for producing a silica nanostructure according to an embodiment of the present invention will be described.

The method for manufacturing a silica nanostructure includes the steps of fixing a silica nanoparticle on a substrate and forming a silica bridge between the silica nanopatterns.

The silica nanopattern may include nanospheres, nanorods, nano-hemispheres, nano cylinders, or nanopahedral prisms.

Hereinafter, the silica nano pattern will be described as an example of a silica nanosphere.

2 is a flowchart illustrating a method of manufacturing a silica nanostructure according to an embodiment of the present invention.

Referring to FIG. 2, a method of manufacturing a silica nanostructure includes a step (S1) of fixing a silica nanosphere on a substrate and a step (S2) of forming a silica bridge.

More specifically, step (S1) of immobilizing a silica nanosphere on a substrate may comprise the step of forming a silica nanosphere on the substrate and a step of heat treating the silica nanosphere on the substrate have.

The step of forming the silica nanospheres on the substrate may be performed by a Langmuir-blodgett assembly or the like. In addition, the silica nanospheres may be formed as a single layer. For example, a silica nanosphere can be formed as a single layer on a substrate by a Langmuir blowing assembly.

In addition, the silica nanospheres can be deposited on the substrate in such a manner that the silica nanospheres are closely adhered to each other. For example, a closed paked silica nanosphere can be formed on a substrate. For example, a hexagonally colsed packed (HCP) silica nanosphere can be arranged. However, the present invention is not limited thereto, and the silica nanospheres may be arranged at a predetermined interval to such an extent that etching and adverse reactions as described below may occur.

The substrate is not particularly limited, and various types of substrates can be used. For example, the substrate may be a SiO ₂ / Si substrate.

The substrate may comprise a PMMA layer. The PMMA layer can be formed on a substrate by spin coating or the like. However, the present invention is not limited thereto, and the substrate may include any material layer that can fix the silica nanosphere. Also, the substrate itself may be made of PMMA.

The silica nanospheres may be heat-treated on the substrate to fix the silica nanospheres. For example, silica nanospheres may be deposited on a substrate containing a PMMA layer, and then the PMMA layer may be softened through heat treatment to fix the nanoparticles of silica. For example, the heat treatment may be performed at a temperature of 150 ° C to 200 ° C. Preferably, the silica nanospheres can be immobilized by heat treatment at 180 DEG C for 4 minutes or more.

The step (S2) of forming the silica bridge can form a silica bridge between the silica spheres by etching and reverse reaction. In addition, the step (S2) of forming the silica bridge may further include a washing step.

In the etching reaction, a silica spherical body is etched, and the reverse reaction means that a silica bridge is formed between silica spheres.

The step of forming the silica bridge may include immersing the substrate on which the silica nanospheres are immobilized in a mixed solution containing hydrofluoric acid (HF) and ammonium fluoride (NH ₄ F), and performing etching and reverse reaction between the silica nanospheres Silica bridge can be formed.

The pH of the mixed solution may be close to neutrality. For example, the pH of the mixed solution may be 6.7 to 6.8.

The mixed solution may further include water (H ₂ O). The rate of formation of the silica bridge can be controlled according to the ratio of water in the mixed solution.

When the substrate on which the silica nanospheres are immersed is immersed in a mixed solution containing hydrofluoric acid (HF) and ammonium fluoride (NH ₄ F), a silica bridge is formed in the early stage. However, the silica bridge formed is etched The reaction should be terminated before the silica bridge is etched. Therefore, after the silica bridge is formed, the substrate is washed to terminate the reaction before the silica bridge is etched. For example, the substrate may be washed with deionized water.

FIG. 3 is a schematic diagram showing a process in which a silica bridge 400 is formed between silica nanocrystals 200 by etching and reverse reaction.

Referring to FIG. 3, the principle of forming the silica bridge 400 is as follows. First, a silica nanosphere 200 is densely arrayed and fixed on a substrate 100, and then the substrate 100 is immersed in a mixed solution containing hydrofluoric acid (HF) and ammonium fluoride (NH ₄ F) So that the reaction proceeds.

 Referring to FIG. 3 (a), initially, a silica nanosphere 200 is densely arranged on a substrate 100 in a hexagonal manner.

Referring to FIG. 3 (b), hydrogen hexafluorosilicate (H ₂ SiF ₆ ) is produced by silica etching the silica nanospheres 200 with hydrofluoric acid as shown in Formula 1 below.

[Formula 1]

SiO ₂ + 6HF ↔ H ₂ SiF ₆ + 2H ₂ O

The produced hydrogen hexafluorosilicate reacts with water to be changed into a silicate acid salt (Si (OH) ₄ ) as shown in the following Chemical Formula 2.

(2)

H ₂ SiF ₆ + 4H ₂ O ↔ Si (OH) ₄ + 6HF

On the other hand, ammonium fluoride is combined with silica and hydrofluoric acid to form ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ) (AHFS) as shown in the following chemical formula 3.

(3)

SiO ₂ + 4HF + 2NH ₄ F ↔ (NH ₄ ) ₂ SiF ₆ + 2H ₂ O

The prepared ammonium hexafluorosilicate becomes extremely high in concentration instantaneously and has a very low solubility in hydrofluoric acid, so that the ammonium hexafluorosilicate maintains a supersaturated state without being completely dissolved.

For this reason, the mixed solution is divided into a high concentration ammonium hexafluorosilicate region 300 and a low concentration ammonium hexafluorosilicate region. That is, phase seperation occurs.

In particular, the resulting ammonium hexafluorosilicate can be divided into an ammonia group and a hexafluorosilicate. Since the ammonia group has a very high affinity for water, the ammonia group is located on the surface of the coagulated ammonium hexafluorosilicate, Phase.

Referring to FIG. 3 (c), since the ammonia group is electrically positive and the surface of the silica is electronegative, the phase formed by the electrostatic interaction forms three centers of the silica nanosphere 200 Lt; / RTI > That is, the high-concentration ammonium hexafluorosilicate region 300 is located at the center of three silica nanospheres 200, and the other region is the low-concentration ammonium hexafluorosilicate region.

Referring to FIG. 3 (d), on the other hand, the seed in the silica matrix is mainly present in the region between two silica nanospheres 200. That is, the region between the silica nanocrystals 200 exists in the region between the two silica nanospheres 200, not the high-concentration ammonium hexafluorosilicate region 300. At this time, due to the catalytic action of the ammonia group of the ammonium hexafluorosilicate seeded in the silylation, the silica bridge 400 connecting the silica nanospheres 200 is formed while being polymerized and precipitated.

Referring to Figure 3 (e), the separation of the phase by the concentration difference of ammonium hexafluorosilicate depends on the transient non-equilibrium state. Thus, diffusion back through time, and coprecipitation at the time of silica formation, return to one phase. That is, the high concentration ammonium hexafluorosilicate region 300 is annihilated.

 Referring to FIG. 3 (f), after a further period of time, the silica bridge 400 that has been formed is etched away.

Therefore, if the reaction is terminated before the ammonium hexafluorosilicate returns to one phase, that is, before the silica bridge 400 is etched away, the silica nanospheres 200 are connected to each other through the silica bridge 400 A nanostructure can be formed.

Meanwhile, the step of forming the silica bridge 400 between the silica nanospheres 200 may be repeated a plurality of times. For example, a new shape structure can be produced by forming a silica bridge 400 by first etching and reverse reaction, washing it with deionized water to terminate the reaction, and then conducting a second etching and reverse reaction .

Further, when the step of forming the silica bridge 400 between the silica nanospheres 200 is repeated a plurality of times, each component of the mixed solution used in the reaction may be controlled.

Manufacturing example  One

Thereby preparing a silica nanostructure according to an embodiment of the present invention.

First, a 200 nm-thick PMMA layer was formed by spin coating on an Si substrate having a SiO ₂ layer of 300 nm thickness, and an oxygen plasma process (30 W, 3 seconds) was performed. A hexagonally close-packed (HCP) silica nanocrystalline monolayer was deposited on the PMMA layer by a Langmuir-blodgett assembly. Then, the substrate was heated at 180 캜 for 4 minutes to 10 minutes to soften the PMMA, and the silica spheres were fixed to the PMMA layer to prepare samples.

A mixed solution having a volume ratio of 1:30 (v / v) of 49% HF acid and 40% NH ₄ F, which is nearly neutral (pH 6.7 to 6.8), was prepared and the samples were immersed in the mixed solution. After 5 seconds, 10 seconds and 15 seconds of reaction, the substrate was washed with deionized water and then dried with N ₂ to remove the silica nanosphere-sieve-bridge network (SB-NW) .

The reaction was carried out at room temperature without stirring.

Manufacturing example  2

After the formation of the SB-NW, the substrate on which the SB-NW was formed was immersed again in the same solution as the mixed solution to carry out the second reaction. After a second reaction for 5 seconds, the substrate was washed with deionized water and then dried with N ₂ .

Manufacturing example  3

The procedure of Preparation Example 1 was repeated except that the step of forming a silica bridge was repeated three times under the same conditions.

Manufacturing example  4

The procedure of Preparation Example 1 was repeated except that the step of forming the silica bridge was repeated four times under the same conditions.

Manufacturing example  5

The SB-NW structure formed in the same manner as in Preparation Example 1 was immersed in a diluted HF solution (mixed solution of 49% HF and 1:30 (v / v) water) for 5 seconds, washed, and dried in N _2, and then on to.

Comparative Example  One

The 49% HF solution was diluted with DI water to form a mixed solution having a volume ratio of HF and deionized water of 1: 100 (v / v).

Samples having HCP silica spheres fixed in the same PMMA layer as the sample of Preparation Example 1 were immersed in the mixed solution for 5 seconds, 10 seconds, and 15 seconds, respectively. After the reaction, the samples were immediately washed with deionized water and then dried with N ₂ .

Comparative Example  2

Samples having HCP silica spheres fixed to the PMMA layer as in the sample of Preparation Example 1 were prepared. The sizes of the spherical silica spheres were reduced by reactive ion etching (RIE) with CF ₄ . Etching at 140 W for 90 seconds reduced the diameter of the spheroids from about 650 nm to about 600 nm.

On the other hand, 1 liter of hydrogen hexafluorosilicate (H ₂ SiF ₆ , 35%) and fumed silica (SiO ₂ ) powder were mixed and stirred at 400 rpm. After stirring overnight, the silica material not dissolved in the solution was removed using a vacuum filter system. Next, 2 liters of DI water was added to the solution, which allowed the silicic acid to be supersaturated in the solution. Immediately after preparing the solution, samples with the reduced size spherical silica particles were immersed in the solution for 10 seconds, 30 minutes, 1 hour, 2 hours, and 3 hours, respectively.

Comparative Example  3

The reaction was carried out under the same conditions as in Preparation Example 1 except that the mixed solution was stirred at 500 rpm for the immersion time (reaction time).

Experimental Example  One

Figs. 4 and 5 are images of the silica nanostructure according to Production Example 1. Fig.

4A and 4B are top and cross-sectional SEM images of SB-NW structures (scale bars: 500 nm). 4C is a TEM image (scale bars: 500 nm) of the SB-NW structure, and FIGS. 4D and 4E are high magnification TEM images (scale bars: 200 nm). Referring to FIGS. 4A to 4D, it can be seen that cylindrical bridges are formed at positions nearest the distance between the spherical spherical bodies of silica between the spherical spherical bodies.

Figure 4f is the EDS spectra measured on silica spheres and silica bridges. Referring to FIG. 4F, the presence of Si and O elements in the silica nanospheres and silica bridges can be confirmed. Further, the atomic ratio of Si: O in the silica bridge is evaluated as 1: 1.61. This is quite similar to the atomic ratio of Si: O in the spheres (1: 1.66) and is close to the stoichiometric composition of SiO ₂ . Therefore, it can be confirmed that the material of the silica bridge is silica.

5 is images of the silica nanostructure formed according to immersion time. Referring to FIG. 5, when immersed for 5 seconds, 10 seconds, and 15 seconds, the dense silica spheres are initially etched isotropically, and the reverse reaction (silica bridge formation) occurs almost simultaneously. Since the silica growth is dominant over the etching process, the diameter of the silica bridge increases from 150 to 200 nm for the first 10 seconds. However, as the etching reaction becomes more dominant as time elapses, the silica bridge begins to etch from the center. Thereafter, the silica bridge becomes elongated and narrower in 15 seconds.

6 is an image and table of energy dispersive X-ray spectrometry (EDS) measured at the centers of silica nanospheres and silica bridges.

Referring to FIG. 6, the presence of Si and O elements in the silica nanospheres and silica bridges can be confirmed. Further, it can be seen that the concentration of nitrogen on the silica bridge surface is higher than that on the surface of the silica nanosphere. It can be seen that amine moieties in ammonium hexafluorosilicate are involved in bridge growth.

Experimental Example  2

The images of the silica structures formed according to the immersion time were analyzed by the manufacturing method according to Comparative Examples 1 to 3.

FIG. 7 shows images of the silica structure produced by the manufacturing method according to Comparative Example 1. FIG. Referring to FIG. 7, it can be seen that the silica spheres are etched when they are immersed for 5 seconds, 10 seconds, and 15 seconds. However, it can be seen that no bridge is formed between the spherical bodies. This is because the phase separation is not generated because NH ₄ F is not contained in the mixed solution.

FIG. 8 shows images of the silica structure produced by the manufacturing method according to Comparative Example 2. FIG. Referring to FIG. 8, it can be seen that as the immersion time is increased, the diameter of the silica spheres increases by homogeneous precipitation of silica on the surface of the spheres of silica. However, it can be seen that no silica bridge is formed between the silica spheres. It is considered that silica is formed on the entire surface of the spherical silica spheres because phase separation is not generated because NH ₄ F is not contained in the mixed solution.

FIG. 9 shows images of the silica structure produced by the manufacturing method according to Comparative Example 3. FIG. Referring to FIG. 9, it can be seen that no bridge is formed between nanospheres when immersed for 5 seconds, 10 seconds, and 15 seconds. Therefore, as compared with the above-mentioned production example, it can be seen that the formation of the bridge is restricted by stirring.

Experimental Example  3

10 are images of the silica nanostructures prepared by the production method of the silica nanostructure according to Production Examples 2 to 5. FIG. Referring to FIG. 10, the number of times of the step of forming the silica bridge using the sample and the shape of the silica nanostructures changed according to the adjustment of each component of the mixed solution were shown.

10 (a) is an SEM image of the silica nanostructure according to Production Example 2. FIG. Referring to FIG. 10 (a), the silica structure has double layer bridges as a result of performing the step of forming the silica bridge twice.

10 (b) is an SEM image of the silica nanostructure according to Production Example 3, and FIG. 10 (c) is an SEM image of the silica nanostructure according to Production Example 4. FIG. 10 (d) is a schematic view of the silica nanostructure of the honeycomb structure. Referring to FIGS. 10 (b) and 10 (c), as a result of performing the steps 3 and 4 of forming the silica bridge, the silica nano-bridges become wider and the holes between the silica nanostructures become more rounded . Further, as the step of forming the silica bridge is repeated, it can be seen that the silica nanospheres and the silica bridges are etched more and the silica nanospheres become more planar. Referring to FIG. 10 (d), when the step of forming the silica bridge is repeated a plurality of times, the upper surface becomes more flat like a honeycomb lattice, and gradually changes into a structure having more round holes .

10 (e) and 10 (f) are SEM images of the silica nanostructure according to Production Example 5, and FIG. 10 (g) is a schematic view thereof. 10 (e) to 10 (g), after performing the step of forming a silica bridge, the SB-NW structure is further diluted with diluted HF solution (49% HF and water at 1:30 / v) for 5 seconds, a hexagonal saucer-shaped silica nanostructure is formed.

Experimental Example  4

11 is a photonic band diagram of a two-dimensional crystalline silica nanostructure according to an embodiment of the present invention.

Referring to FIG. 11, a two-dimensional photonic band structure of a silica nanostructure was calculated using a finite difference time-domain (FDTD) simulation method. Was simplified to a dielectric slab with a two-dimensional array of holes with a radius of 125 nm in a crystal lattice of the honeycomb structure (lattice constant of 650 nm). As a result, it can be seen that, in the visible light region, the silica nanostructure according to one embodiment of the present invention can be used as a two-dimensional photonic crystal slab.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, This is possible.

100: substrate 200: silica nanospheres
300: high concentration ammonium hexafluorosilicate region
400: silica bridge

Claims (14)

Silica nanopatterns; And
And at least one silica bridge formed between the silica nanopatterns. The method of claim 1,
Wherein the silica nanopattern comprises a nanospherical body, a nanorod, a nanoparticle, a nanocrystal, or a nanocrystal. The method of claim 1,
Wherein the silica nanostructure is a honeycomb structure. Fixing the silica nanopattern on the substrate; And
Immersing the substrate on which the silica nano pattern is immersed in a mixed solution containing hydrofluoric acid (HF) and ammonium fluoride (NH ₄ F), and forming a silica bridge between the silica nano patterns by etching and reverse reaction Wherein the method comprises the steps of: 5. The method of claim 4,
Wherein the silica nanopattern comprises the shape of a nanospheres, a nanorod, a nanoparticle, a nanoparticle, or a nanopahedral prism. 5. The method of claim 4,
The step of fixing the silica nanopattern on the substrate includes:
Wherein the silica nanopattern is fixed in a hexagonal close-packed structure of a single layer. 5. The method of claim 4,
Wherein the substrate comprises a PMMA layer. The method of claim 7, wherein
The step of fixing the silica nanopattern on the substrate includes:
Depositing a silica nanopattern on the PMMA layer, and heat treating the PMMA layer to fix the silica nanopattern. 5. The method of claim 4,
Wherein the mixed solution has a pH of 6.7 to 6.8. 5. The method of claim 4,
Wherein the mixed solution further comprises water. 5. The method of claim 4,
Forming a silica bridge between the silica nanopatterns,
Further comprising the step of terminating the reaction before the silica bridge is formed and then etching the substrate, and washing the substrate with deionized water. 12. The method of claim 11,
The method of manufacturing a nanostructure, characterized in that to repeat the step of forming a silica bridge between the silica nanopattern a plurality of times. 5. The method of claim 4,
Forming a silica bridge between the silica nanopattern is nanostructure manufacturing method, characterized in that performed at room temperature. An etching mask comprising a silica nanostructure composed of a silica nanopattern and at least one silica bridge connecting the silica nanopattern.

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