KR101581533B1 - Photonic crystal and method for fabricating the same - Google Patents

Abstract

A method for forming a photonic crystal using a sacrificial template according to the present invention includes a first step of forming a polymer sacrificial template having a three-dimensional nanostructure in which interconnected pores are formed, a step of peeling a frame material on the pores of the formed sacrificial template filling to form a composite, and
And a third step of removing the polymer sacrificial template from the complex to form a photonic crystal having a three-dimensional reverse nanostructure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a photonic crystal and a photonic crystal,

More particularly, the present invention relates to a method of manufacturing a photonic crystal using prism holographic lithography (PHL) and atomic layer deposition (ALD) .

Zinc oxide (ZnO) is a transparent semiconductor with a direct wide band gap of about 3.37 eV. Zinc oxide has the advantages of good electrical conductivity, high chemical stability, low toxicity, good thermal stability, good biocompatibility and strong piezoelectric and photoluminescent properties. photoluminescence properties).

Due to various nano fabrication techniques, zinc oxide nanostructures have been used in a variety of applications including solar cells, gas sensors, thermoelectric devices, thin film transistors, and piezoelectric nanogenerators.

In particular, photocrystalline research using a three-dimensional zinc oxide nanostructure has been progressing as an application using zinc oxide.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing photonic crystals having improved optical characteristics and mechanical stability.

According to an embodiment of the present invention, a method of forming a photonic crystal using a sacrificial template includes a first step of forming a polymer sacrificial template having a three-dimensional nanostructure in which interconnected pores are formed, a first step of forming a sacrificial template on the pores of the formed sacrificial template A second step of filling the frame material to form a composite, and

And a third step of removing the polymer sacrificial template from the complex to form a photonic crystal having a three-dimensional reverse nanostructure.

At this time, the polymer sacrificial template may be formed using prism holographic lithography (PHL).

The first step may include an applying step of applying a mixed solution containing a polymer template resin and a photoinitiator to a substrate, and irradiating light onto the substrate to which the mixed solution is applied.

At this time, the higher the concentration of the photoinitiator, the larger the lattice constant of the polymer sacrificial template having the three-dimensional nanostructure.

The frame material may be filled using an atomic layer deposition (ALD) method.

Depending on the deposition height of the frame material deposited by the atomic layer deposition method, the degree to which the frame material is peeled into the pores may be varied.

The frame material may be one selected from the group consisting of zinc oxide (Zinc Oxide) and titanium oxide (Titania), or a combination thereof.

Removing the polymeric sacrificial template may include calcining the complex at a predetermined temperature.

At this time, when the composite is sintered, a temperature gradient between 0.1 [deg.] C / min and 1 [deg.] C / min can be used.

By firing the composite, the deposited frame material can be crystallized.

The volume shrinkage of the deposited frame material before and after firing the composite may range from 0 to 50%.

The thickness of the upper surface of the photonic crystal may be thicker than the thickness of the sidewalls inside the photonic crystal.

According to the present invention, the following effects occur.

First, according to the prism light interference etching method applied to an embodiment of the present invention, there is an effect that the beam alignment problem can be solved by a method of splitting a beam using a prism and then irradiating the beams again.

According to an embodiment of the present invention, the lattice constant of the polymer sacrificial template can be easily controlled by adjusting the concentration of the photoinitiator of the mixed solution. By controlling the lattice constant of the polymer sacrificial template, The lattice constant of the photonic crystal produced by the invention can be easily controlled.

Third, according to one embodiment of the present invention, when the atomic layer deposition method is used to deposit a frame material, a frame material can be uniformly deposited on the sidewalls of the sacrificial template.

Fourth, the photonic crystal manufactured according to one embodiment of the present invention has substantially no volume shrinkage before and after the removal of the sacrificial template, and has an effect of greatly improving optical characteristics and mechanical stability.

1 is a schematic view sequentially showing steps of forming photonic crystals using a sacrificial template according to an embodiment of the present invention.
2 is a view showing a top view of a polymer sacrificial template formed by varying the content of the photoinitiator.
Figure 3 shows scanning electron micrographs of a composite of a frame material (ZnO) deposited on a polymeric sacrificial template at different thicknesses.
4 is a cross-sectional view of the photonic crystals manufactured according to an embodiment of the present invention.
5 is a diagram showing reflection peak positions at each step corresponding to the above-mentioned table.

The above objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. It is to be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities.

In the drawings, the thicknesses of the layers and regions are exaggerated for clarity and the element or layer is referred to as being "on" or "on" Included in the scope of the present invention is not only directly above another element or layer but also includes intervening layers or other elements in between. Like reference numerals designate like elements throughout the specification.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. In addition, numerals (e.g., first, second, etc.) used in the description of the present invention are merely an identifier for distinguishing one component from another.

Recently, ZnO-based photonic crystals having three-dimensional nanostructures have attracted attention. In order to fabricate a ZnO photonic crystal having a three-dimensional structure, a sacrificial template for infiltrating ZnO is first made, which is a sacrificial template, mainly composed of inorganic silica or organic polystyrene opal polystyrene opals have been used.

These opal templates form a closed pack system with a full injection ratio (injection ratio) of 74%. Also, the maximum possible injection rate of the frame materials after the inversion process may be 26%, but this maximum possible injection rate is too small to form a complete photonic band gap.

HL (holographic lithography) has the advantage of controlling the injection rate of the polymer sacrificial template simply by diversifying the UV exposure. The result is a reverse structure with a high injection rate of solid materials.

On the other hand, an infiltration method for peeling ZnO in a sacrificial template formed with a three-dimensional structure should be able to provide dense and homogeneous materials having a high refractive index (RI) by filling interconnected submicrometer channels.

Methods employing electrodeposition or sol-gel reactions are simple and advantageous in terms of ease of manufacture. In particular, these methods allow high refractive index materials to penetrate fully into the interconnected porous template and allow the fabrication of 3D photonic crystals with a complete photonic bandgap after removing the polymer template.

Sol-gel processes, however, often lead to structures with voids in the interior, resulting in considerable volume shrinkage and loss of structural long-range structural order at subsequent heat treatment process steps. cause.

Thus, the present inventors disclose a photonic crystal forming method as follows.

A photonic crystal forming method according to an embodiment of the present invention is a photonic crystal forming method using a sacrificial template, comprising: a first step of forming a polymer sacrificial template having a three-dimensional nanostructure in which interconnected pores are formed; A second step of filling the pores of the formed sacrificial template with a frame material to form a complex; And a third step of removing the sacrificial template from the complex to form a photonic crystal having a three-dimensional reverse nanostructure.

At this time, according to one embodiment of the present invention, the polymer sacrificial template having the three-dimensional nanostructure can be formed using prism holographic lithography (PHL). That is, the prism light interference etching method can be used as a method of patterning the sacrificial template before patterning (hereinafter, a patternless sacrificial template) so as to have a three-dimensional nanostructure.

In order to pattern a three-dimensional nanostructure by a general optical interference etching method, it is difficult to accurately align two or more beams having different properties. However, in the prism light interference etching method There is an effect that the beam alignment problem can be solved by a method of splitting a beam using a prism and then irradiating the beam again.

According to an embodiment of the present invention, in order to form the sacrificial template, a patternless sacrificial template must be prepared. The patternless sacrificial template is formed by applying a mixed solution including a polymer template resin and a photoinitiator to a substrate It can be applied and prepared.

At this time, the polymer template resin may be a polymer resin including a monomer and an oligomer, and the photoinitiator may be a material that allows the monomer and oligomers, which are the polymer template material, to be connected to each other. The photoinitiator may decompose upon exposure to light, and the monomer and the oligomer may be linked to each other according to decomposition of the photoinitiator. Thus, the mixed solution can have photo-curability.

At this time, in the mixed solution, when the concentration of the photoinitiator is varied, the lattice constant of the polymer sacrifice template having the three-dimensional nanostructure may be different from each other. More specifically, as the concentration of the photoinitiator increases, the lattice constant becomes larger, and when the concentration of the photoinitiator decreases, the lattice constant may become smaller.

That is, according to one embodiment of the present invention, by controlling the concentration of the photoinitiator of the mixed solution, the size of the lattice constant of the polymer sacrificial template can be easily controlled.

The frame material may be one or a combination of two or more materials selected from the group consisting of Zinc Oxide and Titanium Oxide (Titania), and the frame material may be an atomic layer deposition (ALD, atomic layer deposition) method, the pores of the polymer sacrificial template having the three-dimensional nanostructure can be filled. Using the atomic layer deposition (ALD) technique, the frame materials can be formed into confomal and dense thin films in interconnected pores of the sacrificial template with the three-dimensional nanostructure .

Hereinafter, one embodiment of the present invention will be described in more detail with reference to the drawings.

1 is a schematic view sequentially showing steps of forming photonic crystals using a sacrificial template according to an embodiment of the present invention.

Referring to FIG. 1, a polymer sacrificial template 10 having a three-dimensional nanostructure may be formed on a substrate, as shown in FIG. 1 (a). At this time, the polymer sacrificial template 10 may have pores 15 connected to each other.

As shown in FIG. 1 (b), a frame material may be deposited on the polymer sacrificial template 10 having the three-dimensional nanostructure. The frame material may be deposited inside the pores 15 of the polymer sacrificial template 10 and may completely fill the inside of the pores 15 depending on the degree of deposition of the frame material. 1 (c), after the sacrificial template 10 is removed, the material of the photonic crystal according to an embodiment of the present invention is removed from the pores of the frame material 15 can be controlled by controlling the volumetric filling fractions of the photonic crystals formed by the present invention.

1 (c) is a cross-sectional view of a photonic crystal 20 according to an exemplary embodiment of the present invention, after filling the frame material 15 in the pores 15, . The photonic crystal 20 according to an embodiment of the present invention is filled in the pores 15 formed in the polymer sacrificial template 10 so that the lattice constant of the sacrificial template 10 constant and the lattice constant of the photonic crystal 20 are equal to each other.

Hereinafter, each step will be described in more detail.

First, a method of forming the polymer sacrificial template 10 will be described in detail.

First, a photocurable resin solution is prepared. The photo-curable resin solution may include a polymer resin including a monomer and an oligomer, a solvent, and a photoinitiator. In preparing the photo-curable resin solution, the present inventors have found that when GBL (gamma-butyrolactone) is used as a solvent, 150 wt% of SU-8 resin is used as the polymer resin, 0.17 wt SU-8 photoresist (negative type) was prepared using 1.3% by weight to 1.3% by weight of triarylsulfonium hexafluorophosphate as a cationic photoacid generator (PAG).

Subsequently, the photocurable resin solution is applied to a predetermined substrate. There is no particular limitation on the method of applying the photocurable resin solution to the substrate. However, the inventors of the present invention coated the resin solution on the substrate by spin-casting to a thickness of 10 탆.

In addition, the solvent contained in the photocurable resin solution applied to the substrate can be removed. For example, the present inventors soft-baked the applied resin solution at 95 캜 for evaporation of the solvent. Thereby, a patternless sacrificial template can be formed on the substrate.

The patternless sacrificial template may then be patterned such that the patternless sacrificial template has a three-dimensional nanostructure. According to an embodiment of the present invention, prism holographic lithography (PHL) may be used to pattern the three-dimensional nanostructure.

In order to apply the prism light interference etching method to the patternless sacrificial template, a laser beam is irradiated onto the patternless sacrificial template, the laser beam can pass through a prism, and the laser beam is passed through the prism Beam expander.

The present inventors used a 325 nm, 50 mW HeCd laser as the laser beam to apply the prism optical interference etching method, and the radius of the laser beam was 1 mm. In addition, the present inventors used a top-cut fused silica prism having a top surface cut out. In addition, a post-exposure bake performed by irradiation of the laser beam proceeded at a temperature of 55 ° C.

In order to apply the prism light interference etching method according to the present invention, it is not necessary to use the prism of the type used in the experiments by the present inventors. In addition, in order to apply the prism light interference etching method according to the present invention, it is not necessary to use the laser beam of the specification used in the experiments by the present inventors. However, since the shape of the prism and the specification of the laser beam affect the interference pattern of the laser beam, the overall shape of the polymer sacrificial template 10 can be controlled by adjusting the shape of the prism or the specifications of the laser beam . For example, when the shape of the prism is changed, the shape of the pores formed in the polymer sacrificial template 10 may be changed.

On the other hand, the post exposure bake for irradiating the laser beam does not necessarily have to be performed at 55 [deg.] C, but in order to reduce the thermal stress accumulated in the patternless sacrificial template by processes proceeding for forming the patternless sacrificial template It is preferable to be performed at a relatively low temperature.

During the post exposure baking step, due to the interference phenomenon of the laser beam, a specific region of the patternless sacrificial template is exposed to the laser beam, and the other region is not exposed to the laser beam. The non-patterned sacrificial template is formed using a photocurable resin solution, and chemical / physical properties of the specific region (exposed region) and the other region (non-exposed region) may be different from each other by post exposure baking .

Then, one of the exposed region or the non-exposed region of the unpatterned sacrificial template processed by the post exposure beam process is removed to form a polymer sacrificial template having a three-dimensional nanostructure.

The present inventors removed the area not exposed to the laser beam using propylene glycol methyl ether acetate (PGMEA).

Then, if necessary, the polymer sacrificial template having the three-dimensional nanostructure can be cleaned. The present inventors washed the polymer sacrificial template sample with the 3-dimensional patterning completed using 2-propanol.

As described above, the lattice constant of the photonic crystal formed by the photonic crystal forming method using the sacrificial template according to the present invention is equal to the lattice constant of the sacrificial template. On the other hand, the lattice constant of the photonic crystal is a very important factor that determines the optical characteristics of the photonic crystal. Therefore, in order to control the optical characteristics of the photonic crystal, precise control of the lattice constant is required. According to the photonic crystal forming method of the present invention, the lattice constant of the photonic crystal can be controlled by controlling the lattice constant of the sacrificial template.

The present inventors have made various attempts to control the lattice constant of the sacrificial template and have found that by controlling the concentration of the photoinitiator contained in the photocurable resin solution used to form the sacrificial template, .

Table 1 below shows the results of experiments on the relationship between the concentration of the photoinitiator and the lattice constant of the polymer sacrificial template.

Content of photoinitiator (wt%) Lattice constant (nm) 0.17 650 0.33 670 1.33 730

2 is a view showing a top view of a polymer sacrificial template formed by varying the content of the photoinitiator. 2 (a) shows the case where the content of the photoinitiator is 0.17 wt%, FIG. 2 (b) shows the case where the content of the photoinitiator is 0.33 wt%, and FIG. 2 Is 1.33 wt%. ≪ tb > < TABLE >

As can be seen from the above table and FIG. 2, it can be seen that the lattice constant of the sacrificial template varies depending on the content of the photoinitiator. In particular, it can be seen that as the content of photoinitiator increases, the lattice constant of the sacrificial template increases.

Therefore, according to the present invention, the lattice constant of the sacrificial template can be easily controlled by appropriately controlling the content of the photoinitiator, and ultimately, the lattice constant of the photonic crystal can be easily controlled .

Next, a method of forming a photonic crystal using a polymer sacrificial template having a three-dimensional nanostructure will be described.

First, a method of forming a complex by injecting a frame material into a polymer sacrificial template will be described.

According to one embodiment of the present invention, as described above, filling the frame material in the pores of the polymer sacrificial template formed with the three-dimensional nanostructure is performed by an atomic layer deposition (ALD) method.

Specifically, the penetration of a frame material through an atomic layer deposition (ALD) process is explained by taking ZnO as an example.

The present inventors deposited a ZnO film at 100 DEG C using an ALD system (Lucida M100, NCD). Diethyl zinc (DEZ, Zn (C2H5) 2) and desalted water vapor were used as the zinc precursor and oxygen source, respectively. The temperature of the diethylzinc source (DEZ source) was maintained at 10 ° C using a cooler. During the deposition process, argon gas was allowed to flow continuously through the reaction chamber at a rate of 100 sccm. The thickness of the ZnO layer deposited during each ALD cycle is 1.39 A. The number of ALD cycles was appropriately adjusted to form a ZnO thin film to a predetermined thickness.

As described above, it was confirmed that when the frame material was deposited on the polymer sacrificial template through the atomic layer deposition technique, the frame material was uniformly deposited on the sidewalls of the pores of the polymer sacrificial template.

This results in the formation of a composite in which the pores of the polymer sacrificial template are filled with the frame material.

Figure 3 shows scanning electron micrographs of a composite of a frame material (ZnO) deposited on a polymeric sacrificial template at different thicknesses. 3 (a) and 3 (b) are photographs taken at an angle of 45 degrees after deposition of ZnO to a thickness of 200 nm, and FIGS. 3 (c) and 3 This is a picture taken at an angle of 45 degrees.

Referring to Figures 3 (a) and 3 (b), when ZnO is deposited to 200 nm, as the ZnO is deposited on the sacrificial template, the composite will have an open pore that is smaller than the pore size of the sacrificial template, You can see what you have. In addition, it can be seen that the inner pores of the sacrificial template are not completely filled with ZnO. As a result of the confirmation, it was confirmed that the pore size in the uppermost layer of the composite having ZnO deposited at 200 nm was about 100 nm, and the top layer pore size of the polymer sacrificial template before deposition of ZnO was 500 nm.

3 (c) and 3 (d), when the ZnO is deposited to a thickness of 400 nm, the upper surface of the composite is completely closed, and furthermore, the inner pores of the sacrificial template are filled with the ZnO . However, in the case of a gas phase reaction such as occurs in atomic layer deposition, the deposition is terminated by closing the upper forer channel, and before the upper forer channel is closed, the inner pores of the sacrificial template are not completely filled with ZnO The channel may be closed.

In order to ensure the optical properties and mechanical integrity of the photonic crystal, it is very important to uniformly penetrate the frame material, such as ZnO, into the sacrificial template, which enables this high level of penetration. Therefore, the photonic crystal of the present invention, which is manufactured by applying the primer deposition method, has high optical characteristics and mechanical stability.

Next, a method for finally forming the photonic crystal according to the present invention by removing the polymer sacrificial template from the formed complex will be described.

There are various methods for removing the polymer sacrificial template, and a method of controlling the polymer sacrificial template is selected in consideration of the kind of material of the polymer sacrificial template and the kind of the frame material among the various methods It will be possible.

The present inventors selected a heat treatment method to remove the SU-8 polymer sacrificial template from a composite composed of a SU-8 polymer sacrificial template and a ZnO frame material. More specifically, the present inventors calcined the composite at 450 DEG C for 1 hour. By the above baking treatment, the SU-8 polymer sacrificial template is decomposed, and amorphous ZnO can be converted into a polycrystalline phase.

On the other hand, low temperature gradients are important to maintain structural integrity before removing the polymer template to prevent film from collapsing. For this purpose, the present inventors selected a low temperature gradient of 1 [deg.] C / min in the sintering step.

4 is a cross-sectional view of photonic crystals manufactured according to an embodiment of the present invention.

4 (a) and 4 (b) are cross-sectional views showing a cross section of a photonic crystal in which a polymer sacrificial template is removed by firing after formation of 200 nm thick ZnO. As shown in the figure, the structure of the photonic crystal fabricated according to one embodiment of the present invention is formed to be very uniform. On the other hand, although ZnO was deposited to a thickness of 200 nm, it was confirmed that the thickness of ZnO formed on the sidewalls of the pores of the polymer sacrificial template was 170 nm, which is slightly thinner than 200 nm.

4 (c) and 4 (d) are cross-sectional views showing a cross section of the photonic crystal in which the polymer sacrificial template is removed by firing after formation of 400 nm thick ZnO. As shown in the figure, even when 400 nm of ZnO is stacked, it can be seen that the inner structure of the photonic crystal is formed very uniformly. It can be seen that the thickness of ZnO formed on the sidewalls of the pore is slightly thinner than 400 nm even when ZnO is deposited to a thickness of 400 nm similarly to the case of depositing ZnO to a thickness of 200 nm. However, it can be seen that the difference in the thickness when deposited at 200 nm (the difference between the thickness of ZnO deposited on the top surface and the thickness of ZnO deposited on the sidewalls in the pore) This is because the rate at which ZnO is deposited on the sidewalls in the pores gradually decreases because the inlet channel of the gas to be deposited on the inner wall of the pores gradually becomes narrower as the forer channel is gradually closed.

4 (a) to 4 (d), it can be confirmed that there is no volume contraction after firing because the atomic layer deposition method is used to deposit the frame material (ZnO) This is because the frame material is deposited.

The following Table 2 and FIG. 5 illustrate that the volume shrinkage of the frame material is substantially unlikely to occur.

Table 2 below shows measured values for several optical characteristic data in each step of forming a photonic crystal using Su-8 and ZnO, according to an embodiment of the present invention.

PCs Reflectance peak position
(탆) Interlayer spacing along [111] direction (nm) Reflectance
(%) Filling fraction of skeleton material (%) SU-8 / air 1.99 750 29 44 SU-8 / ZnO / air composite 2.60 750 28 SU-8 = 44, ZnO = 46 ZnO (200 nm) / air 2.20 750 47 42 ZnO (400 nm) / air 2.23 750 41 44

From the above table, it is possible to calculate the Filling fraction of SU-8 and ZnO. In this case, the following two equations are used.

[Equation 1]

In this case, λ ₀ is the position of the reflection peak position, n _eff is the effective refractive index of the three-dimensional structure, and n _eff is obtained from the equation (2).

[Equation 2]

n _frame is the refractive index of frame material of the frame or skeleton, f is the filling fraction of the skeletal material, n _m is the refractive index of the medium other than the skeleton, index of medium.

As can be seen from the above table, when there is only a sacrificial template, SU-8 occupies 44% by volume and air is 56%.

At this time, when ZnO is deposited by atomic vapor deposition, it can be seen that about 56% of the ZnO is not completely filled, but about 46% is filled.

At this time, when the SU-8 is removed through the above-described baking process or the like, the volume ratio of ZnO is calculated to be 42%. That is, the volume ratio of ZnO calculated in the SU-8 / ZnO composite was 46%, but the reduction in the volume ratio of ZnO after removal of SU-8 to 42% is considered as a calculation error because the volume shrinkage of ZnO during the firing process , The volume fraction of air due to volume shrinkage will decrease, and the volume ratio of ZnO should therefore increase further than 46%. The most obvious evidence of no volume contraction is that the grating constant in the Z-axis direction is equal to 750 nm, as shown in the table. Generally, when volume shrinkage occurs, the lattice constant of the ZnO photonic crystal becomes smaller than the lattice constant of the sacrificial template (SU-8).

5 shows the reflection peak positions at the respective steps corresponding to the above-mentioned table. Referring to FIG. 5, it can be seen that the optical characteristics of ZnO of 200 nm and ZnO of 400 nm are greatly improved If the volume shrinkage of ZnO occurs, the optical characteristics of ZnO may be greatly reduced. However, the fact that the optical characteristics of ZnO is greatly improved may be indirect evidence that the volume shrinkage of ZnO hardly occurs .

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, The present invention is not limited to the drawings. In addition, the embodiments described in this document can be applied to not only the present invention, but also all or some of the embodiments may be selectively combined so that various modifications can be made. Further, the steps constituting each embodiment can be used separately or in combination with the steps constituting the other embodiments.

Claims (12)

A first step of forming a polymer sacrifice template having a three-dimensional nanostructure in which interconnected pores are formed;
A second step of filling the pores of the formed polymer sacrificial template with a frame material to form a complex; And
And a third step of calcining the complex at a predetermined temperature to remove the polymer sacrificial template from the complex to form a photonic crystal having a three-dimensional reverse nanostructure,
The polymer sacrificial template is formed using prism holographic lithography (PHL)
The frame material is filled using an atomic layer deposition (ALD) method,
The filled frame material is crystallized without volume contraction to form the photonic crystal,
Wherein the lattice constant of the polymer sacrificial template and the lattice constant of the photonic crystal are equal to each other
Method for forming photonic crystal using sacrificial template.
delete 2. The method according to claim 1,
A coating step of applying a mixed solution including a polymer template resin and a photoinitiator to a substrate; And
And irradiating light onto the substrate to which the mixed solution is applied
Method for forming photonic crystal using sacrificial template.
The method of claim 3,
And the lattice constant of the polymer sacrificial template having the three-dimensional nanostructure is increased as the concentration of the photoinitiator increases.
Method for forming photonic crystal using sacrificial template.
delete The method according to claim 1,
Wherein the degree of filling of the frame material with the pores varies depending on the deposition height of the frame material deposited by the atomic layer deposition method.
The method according to claim 1,
Wherein the frame material is one selected from the group consisting of zinc oxide (Zinc Oxide) and titanium oxide (Titania), or a combination thereof.
delete The method according to claim 1,
Wherein a temperature gradient between 0.1 [deg.] C / min and 1 [deg.] C / min is used for baking the composite.
delete delete The method according to claim 1,
Wherein the thickness of the upper surface of the photonic crystal is thicker than the thickness of the sidewall inside the photonic crystal.

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