KR20090106948A - A method for manufacturing 2-d phothonic crystal and lumimous elements manufactured by the same using nanosphere - Google Patents

Abstract

PURPOSE: A method for manufacturing a two directional photonic crystal using nano sphere and a light emitting device manufactured by the same are provided to simplify a control variable of a manufacturing process. CONSTITUTION: A nano sphere thin film is stacked on a substrate. A first mask layer(21) and the nano sphere thin film are deposited using ALD(Atomic Layer Deposition) at the same time. A substrate with a nano sphere(20) is exposed to the outside by removing the nano sphere thin film. The substrate exposed to the outside with the nano sphere is etched.

Description

A method for manufacturing a two-dimensional photonic crystal using nanospheres and a light emitting device manufactured by the same {A METHOD FOR MANUFACTURING 2-D PHOTHONIC CRYSTAL AND LUMIMOUS ELEMENTS MANUFACTURED BY THE SAME USING NANOSPHERE}

The present invention relates to a two-dimensional photonic crystal manufacturing method using nanospheres, and more particularly to a two-dimensional photonic crystal manufacturing process that can be easily applied to a large area and simplify the control parameters of the manufacturing process.

In the mid-1990s, the luminous efficiency of green and blue LEDs using nitride semiconductor InGaN exceeded that of incandescent bulbs, which led to the application of LEDs in a wide range of fields, including full-color displays, especially in 1996. The emergence of high-brightness white LEDs made by applying fluorescent materials to blue LEDs has opened the era of semiconductor lighting. Likewise, since the 1990s, OLED display devices applied to displays using organic semiconductors have surpassed the image quality of liquid crystal displays as the next-generation players of total color displays, and OLED display applications have begun in 2004, and active transistors have been introduced in 2006. The OLED used is used as a display for mobile phones and opened a new display market.

In addition, recently known thin film phosphors have not been actually used in spite of various advantages over powder-type phosphors. As will be appreciated by those skilled in the art, thin film phosphors are thermally stable, physically and chemically uniform, have strong adhesion to the substrate, minimize gas evolution, and have a low specific surface area. There is this. However, in spite of these various advantages, the efficiency is lower than that of powder-type phosphors, so it has not been used well in actual displays or LED devices until recently. Recently, it has been proposed that thin film phosphors can be used in place of powder-type phosphors through the development of various techniques for improving the efficiency of thin film phosphors.

Display / lighting including LEDs, OLEDs, thin film electroluminescent displays (TFELs), and thin film phosphors all contain light emitting materials having a thin film structure. 1 is a cross-sectional view of a typical LED device of the prior art. 2 is a cross-sectional view of a typical OLED device of the prior art.

3 illustrates a light emission path generated in the thin film phosphor. Referring to FIG. 3, since most organic and inorganic thin film light emitting materials have a high optical refractive index value, most of the light generated inside the thin film light emitting material is total internal reflection effect or light waveguide effect. ) Is trapped inside the thin film light emitting material and can not escape out. Therefore, the thin film light emitting material is excellent in various properties, but the amount of light actually used is very limited. This limited light makes LEDs, OLEDs, TFELs, and devices using thin-film phosphors limited in efficiency. As shown in Fig. 3, a considerable amount of light is totally reflected from the interface between the fluorescent surface and the air to be confined in the thin film phosphor or disappear in the defect region. To explain this quantitatively, the principle of classical optics can be applied to calculate the amount of light emitted from the thin film emitting material to the front of the device. The emission efficiency of light can be calculated using classical optical calculations proportional to the refractive index. Equation 1 is a formula well known by the classical optical law, which is established when a light emitted from a thin film phosphor is assumed to be Lambertian type light. In Equation 1, it is assumed that light emitted toward the substrate is not reflected.

(Wherein η _{external light} is external light efficiency and n _light emitting material is refractive index of light emitting material)

According to Equation 1, the external light efficiency depends on the refractive index of the thin film light emitting material, and as the refractive index value increases, the light emission efficiency greatly decreases. Most thin film light emitting materials have a value of 1.5 or more, which is a refractive index value of glass. Among the representative sulfide-based light emitting materials, ZnS has a refractive index value of 2.4, a nitride of GaN, which is an LED material, is 2.1, 1.8 is used for Y ₂ O ₃ , which is an oxide, and an organic semiconductor compound, which is an OLED light emitting material, is 1.5 to 1.7. Therefore, since the amount of light emitted to the front surface of the thin film light emitting material is about 4 to 25% depending on the material, it is trapped in most of the remaining thin film or disappears in the thin film.

Due to the classical optical reasons, the light emission efficiency of LEDs, OLEDs, and thin film phosphors is greatly reduced, which is why LEDs, OLEDs, thin film phosphors, etc. are limited in their applicability to real devices despite various excellent characteristics. do.

In order to solve this problem, it is known that a method of optically extracting light trapped in a thin film without affecting the film quality of the thin film light emitting material has a two-dimensional nanostructure such as a two-dimensional photonic crystal (photonic crystal) It is possible to manufacture LEDs, OLEDs, TFELs, and thin film phosphor structures having high efficiency by manufacturing composite structures that combine nanostructures with thin film light emitting materials and attaching or inserting them in the front direction of LEDs, OLEDs, TFELs, and thin film phosphor devices. Since this solves the problem of the thin film light emitting material using the two-dimensional photonic crystal nanostructure it has been proposed that the efficiency of the device using the LED, OLED, TFEL, thin film phosphor can be greatly improved.

4 is a cross-sectional view of an LED device in which a two-dimensional photonic crystal is inserted. 5 is a cross-sectional view of an OLED device in which a two-dimensional photonic crystal is inserted. A typical two-dimensional photonic crystal fabrication process that has been conventionally used to make a structure into which the two-dimensional photonic crystal structure is inserted is laser holographic lithography.

6 is a manufacturing flowchart of a two-dimensional photonic crystal nanostructure by a laser holographic lithography process. Referring to FIG. 6, the manufacturing process of the two-dimensional photonic crystal nanostructure includes preparing a substrate; Coating a dielectric onto the substrate; Depositing the dielectric chromium thin film; Photoresist (PR) coating on the chromium thin film; A two-dimensional photonic crystal nanostructure PR fabrication step by exposure method using a laser hologram; The chrome mask dry etching step; Dry etching the dielectric; Removing the chrome mask.

In more detail, a SiO ₂ or SiN _x layer is deposited on a device substrate on which a photonic crystal is to be deposited by plasma enhanced chemical vapor deposition (PECVD), and a chromium thin film to be used as a mask is deposited by thermal evaporation. The deposition thickness is between about 20 and 100 nm. Thereafter, the photoresist is coated on the chromium thin film by spin coating or the like. When the photoresist is exposed twice by rotating 90 degrees by a laser interference exposure method, a pattern of two-dimensional nanostructures is formed, and the pattern is developed with a solvent to remove unnecessary portions of the photoresist and dry etched to form a chrome mask. . After that, chromium is used as a mask to fabricate two-dimensional photonic crystal nanostructures of the dielectric / element substrate by dry etching.

This method has been a problem that when the two-dimensional photonic crystal nanostructures are made, the change width of the structural variables such as the height, period, and size of the nanostructures is limited, and an expensive exposure apparatus is required to make a large area. Lithography processes using nanospheres described below have emerged to address the problem.

7 is a manufacturing flowchart of the two-dimensional photonic crystal nanostructure by the nanosphere lithography process. Referring to FIG. 7, the manufacturing process of the two-dimensional photonic crystal nanostructure includes preparing a substrate; Coating a dielectric onto the substrate; Coating a polystyrene or SiO ₂ nanosphere monolayer on the dielectric; Coating a chromium thin film on the nanosphere monolayer and the dielectric; Dry etching the chrome mask on the exposed dielectric; Dry etching the dielectric; Removing the chrome mask.

In more detail, a dielectric photonic crystal is formed by depositing a SiO ₂ or SiN _x layer on a device substrate on which a photonic crystal is to be deposited by plasma enhanced chemical vapor deposition (PECVD), and coating a polystyrene or SiO ₂ nanosphere monolayer film by a self-assembly method. Used as primary mask for fabrication. After that, a chromium thin film to be used as a mask is deposited by thermal evaporation.

This method is superior to laser holographic lithography in terms of structural parameters such as height, period, and size of nanostructures when making two-dimensional photonic crystal nanostructures, but nanospheres are not formed in a single layer but in multiple layers. If the pattern is formed on the substrate, it causes deformation of the pattern in the subsequent process and there is a problem that misalignment occurs due to the torsion of the structure because the exposed dielectric layer is different, so patterning the nanospheres into a single layer is a very important technical factor. to be.

In particular, it is difficult to make a large area because it is not easy to make nanosphere monolayer film. In other words, in order to use nanospheres as a mask, a single layer film should be made, and the self-assembly process used to make such a single layer film has not only the surface properties of the nanospheres but also a process constraint for preventing the multilayer film. Conventional techniques for patterning nanospheres as a single layer on a substrate include spin coating, which is applied by spin coating after the nanospheres are dispersed, or Langmuir-Blodgett, which is a lamination method by dip coating. The law is being used.

However, since the spin coating method physically rotates the substrate, physical damage to the substrate may be performed, and the morphology of the stacked nanolayers may not be uniform. In addition, the spin coating method may simply stack the nanospheres by centrifugal force. Since the layer is planarized, there is a problem in that the nanospheres of the fine units are patterned in the form of multiple layers instead of a single layer.

In addition, the Langmuir-Blodgett method using a state in which organic molecules having a hydrophilic part and a hydrophobic part are arranged in water also has a limitation in forming a uniform nanosphere monolayer on a large surface area.

As described above, the related art has a problem in that the nanospheres cannot be patterned to a satisfactory level in a single layer. As mentioned above, although the two-dimensional photonic crystal structure is useful for all light emitting devices using the thin film type light emitting material, the two-dimensional photonic crystal manufacturing process known to date has a large area and difficulty in easily adjusting the structure. The efficiency improvement method using is not well utilized.

Accordingly, the first object of the present invention is to provide a method for producing a two-dimensional photonic crystal which is very economical and large in area.

In addition, a second object of the present invention is to provide a light emitting device comprising a two-dimensional photonic crystal produced by the above-described method for producing a two-dimensional photonic crystal.

In order to solve the first problem, the present invention comprises the steps of laminating a nanosphere thin film on a substrate; Simultaneously depositing a first mask layer on the nanosphere thin film and the substrate using atomic layer deposition (ALD); Removing the nanosphere thin film to expose a nanosphere-shaped substrate to the outside; And it provides a method for producing a two-dimensional photonic crystal comprising the step of etching the substrate exposed to the outside in the nanosphere shape.

In addition, the manufacturing method of the present invention provides a method for manufacturing a two-dimensional photonic crystal further comprising the step of stacking the nanosphere thin film on the substrate, the nanosphere particle size of the nanosphere thin film.

In addition, the substrate is a base substrate; A fluorescent layer laminated on the base substrate; Provided is a method for manufacturing a two-dimensional photonic crystal comprising a photonic crystal layer laminated on the fluorescent layer and a second mask layer laminated on the photonic crystal layer, the etching process by etching the second mask layer and the photonic crystal layer, It is possible to provide a method for manufacturing a two-dimensional photonic crystal comprising selectively exposing the fluorescent layer in which the photonic crystal layer is laminated.

In addition, the stacking of the fluorescent layer is a step of applying a fluorescent material constituting the fluorescent layer on the base substrate in a sol state; And it may provide a method for producing a two-dimensional photonic crystal which is performed by a process comprising the step of spin coating the applied sol phosphor, wherein the deposition of the photonic crystal layer is deposited by a plasma enhanced chemical vapor deposition (PECVD) method A method for producing a two-dimensional photonic crystal can be provided.

In addition, the base substrate may provide a method for producing a two-dimensional photonic crystal comprising one selected from the group consisting of glass, sapphire, and quartz substrate, wherein the fluorescent layer is prepared of a two-dimensional photonic crystal comprising an organic or inorganic phosphor It may provide a method.

In addition, the fluorescent layer may provide a method for producing a two-dimensional photonic crystal including Y ₂ O ₃ : Eu, the photonic crystal layer may provide a method for producing a two-dimensional photonic crystal containing SiO ₂ or SiN _x .

In addition, the second mask layer may provide a method of manufacturing a two-dimensional photonic crystal including chromium, and the nanosphere thin film may provide a method of manufacturing a two-dimensional photonic crystal including polystyrene or SiO ₂ .

In addition, the nanosphere particle size used in the nanosphere thin film may provide a method for producing a two-dimensional photonic crystal of 150 to 2000nm, the particle size adjusting step of the nanospheres after the nanosphere thin film laminated O ₂ It is possible to provide a method for producing a two-dimensional photonic crystal that is performed by a process comprising the step of ashing.

In addition, the first mask layer by the atomic layer deposition may provide a method for producing a two-dimensional photonic crystal is 0.5 to 20nm, the first mask layer by the atomic layer deposition to produce a two-dimensional photonic crystal containing a metal or oxide It may provide a method.

In addition, the removing of the nanosphere thin film may provide a method for producing a two-dimensional photonic crystal comprising the step of removing the nanosphere thin film in a chloroform solution by ultrasonication, the step of etching the second mask layer is It is possible to provide a method for manufacturing a two-dimensional photonic crystal comprising the step of dry etching the second mask layer.

In addition, the etching of the photonic crystal layer under the second mask may provide a method for manufacturing a two-dimensional photonic crystal comprising the step of dry etching the photonic crystal layer.

In addition, to solve the second problem, the present invention provides a light emitting device comprising a two-dimensional photonic crystal produced by the above-described method.

Since the present invention provides a combination of nanosphere lithography and atomic layer deposition technology, it is not necessary to stack a single layer of nanospheres, thus making it easier to apply a larger area than a process using a conventional nanosphere single layer. It can simplify the adjustment of In addition, the present invention enables the formation of a two-dimensional photonic crystal structure that can easily control the size of the nanosphere, and has a large ability to control structural variables such as the height, period, and size of the nanostructure, and easy to manufacture a two-dimensional photonic crystal structure. can do. Furthermore, since the luminous efficiency of the thin film phosphor coated with the two-dimensional photonic crystal structure according to the present invention is increased by about six times compared with the conventional thin film phosphor, the two-dimensional photonic crystal produced by the present invention greatly increases the efficiency of the device to be used for the thin film phosphor. Improve.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings and examples. However, the following drawings and examples are only intended to illustrate the invention, the invention is not limited or limited thereto.

As described above, the present invention provides the following atomic layer deposition (Atomic Layer) for the preparation of the first mask layer in the two-dimensional photonic crystal nanostructure manufacturing process by the nanosphere lithography described above in order to obtain a two-dimensional photonic crystal pattern with greatly improved light efficiency A process using Deposition (ALD) is applied, which will be described in detail with reference to FIG. 8.

FIG. 8 is a schematic view showing that a first mask layer is simultaneously coated on a surface of a nanosphere and a substrate not in contact with the nanosphere by the principle of conformal growth of atomic layer deposition. Referring to FIG. 8, the first mask layer 21 is coated on the top layer 22 of the substrate on which the nanospheres 20 are deposited by atomic layer deposition.

As a general chemical vapor deposition method, it is difficult to form a film having a desired composition and physical properties because the raw materials required for film formation are simultaneously supplied. In the case of various reaction raw materials used for forming a film in a gaseous state, it may be difficult to form a film. There is a problem that particles can be generated and cause contamination.

The atomic layer deposition method is a surface controlled process that separates each of the reactants forming the atomic layer and supplies them to the chamber in a pulse form. Chemical adsorption by a saturated surface reaction of. At this time, since the atomic layer forming the film grows uniformly in the vertical and horizontal directions surrounding the surface material, the reaction raw materials exhibit the property of reacting only on the surface. Therefore, the surface where the nanospheres are in contact with the substrate is not formed in the atomic layer film, only the other surface is formed in the atomic layer film is formed to form a first mask layer of the array shape of nanospheres in contact with the substrate. That is, since the first mask layer is deposited by conformal growth, even if the nanospheres have a multilayer structure, the first mask layer having a pattern in which the nanospheres are in contact with the substrate is deposited. Therefore, the novel two-dimensional photonic crystal manufacturing process using the atomic layer deposition layer as a mask does not need to be a single layer film, as opposed to the conventional technology, and there is a big problem in manufacturing an atomic layer deposition mask even if a single layer or a multilayer film is mixed. In addition, regardless of the interlayer structure of the nano-film, it is possible to obtain a nanostructure photonic crystal of a certain pattern.

The two-dimensional photonic crystal manufacturing process applying atomic layer deposition to the nanosphere process of the present invention comprises the steps of laminating a nanosphere thin film on a substrate; Simultaneously depositing a first mask layer on the nanosphere thin film and the substrate using atomic layer deposition (ALD); Removing the nanosphere thin film to expose a nanosphere-shaped substrate to the outside; And etching the substrate exposed to the outside in the nanosphere shape. Here, the substrate on which the nanosphere thin film is laminated is a base substrate; A fluorescent layer laminated on the base substrate; It includes a photonic crystal layer laminated on the fluorescent layer and a second mask layer laminated on the photonic crystal layer.

Hereinafter, the two-dimensional photonic crystal manufacturing process according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

9 is a view of the substrate stacked up to the nanospheres before forming the first mask layer using atomic layer deposition. On the substrate 25, a phosphor 24, which is a phosphor used for display, is stacked. On the phosphor, a photonic crystal 23 used to increase the illumination efficiency of the phosphor is stacked. On the photonic crystal, a second mask layer 22 for providing a two-dimensional nanostructure to the photonic crystal is stacked. The nanospheres 20 thin film is stacked on the second mask layer, which is a nanosphere for determining the actual two-dimensional nanostructure of the lower photonic crystal.

FIG. 10 is a flowchart of a two-dimensional photonic crystal manufacturing by a novel nanosphere lithography process using a nanosphere thin film and an atomic layer deposited film mask.

The two-dimensional photonic crystal manufacturing process of the present invention includes steps (a) to (f) as shown in FIG. Step (a) is a step of depositing a nanosphere thin film on the substrate, as described above consisting of the base substrate 25, the fluorescent layer 24, the photonic crystal layer 23, and the second mask layer 22 A step of stacking nanospheres to determine the two-dimensional nanostructure on the substrate. Step (b) is a step of simultaneously depositing the first mask layer 21 on the nanosphere thin film and the substrate using atomic layer deposition. The reaction materials react only on the surface and the thickness of the film growing in one raw material supply cycle is time. Regardless, the first mask layer 21 is almost simultaneously deposited on the nanosphere thin film and the second mask layer, which is the uppermost layer of the substrate. Step (c) is a step of removing the nanosphere thin film to expose the nanosphere-shaped substrate to the outside. As described above, adsorption having a very excellent step coverage by the atomic layer deposition method is always a surface motion region. When the nanosphere thin film is removed because it is in a surface controlled process, regardless of whether the nanosphere thin film laminated on the second mask layer is a single layer or a multilayer, except that the nanosphere thin film is in contact with the second mask layer. Only the atomic layer deposition film (first mask layer) on the second mask layer remains. Therefore, the deposited layer by atomic layer deposition may be patterned into a nanohole structure regardless of whether the nanosphere thin film is a single layer or a multilayer. Steps (d) to (f) etch the substrate exposed to the outside in the nanosphere shape, which will be described in detail below.

The etching may include etching the second mask layer and the photonic crystal layer to selectively expose the fluorescent layer stacked with the photonic crystal layer. . Referring to FIG. 10 (d), in order to obtain a fluorescent layer laminated with a two-dimensional photonic crystal with a greatly improved light efficiency, the second mask layer is formed according to the pattern of the first mask layer formed after removing the nanosphere thin film. Etch first. Subsequently, as shown in FIG. 10E, the fluorescent layer under the second mask layer is etched to maintain the same pattern as the second mask layer. Subsequently, as shown in FIG. 10F, when the first mask layer is peeled off, the second mask layer is exposed, and finally, the second mask layer is removed to be laminated with the two-dimensional nanohole photonic crystal layer to form a hole ( The fluorescent layer is exposed from the hole.

The present invention provides a method for manufacturing a two-dimensional photonic crystal which may further include the step of laminating the nanosphere thin film on the substrate, and adjusting the nanosphere particle diameter of the nanosphere thin film in the step of adjusting the nanosphere particle diameter It may be included after the spear thin film is laminated on the second mask layer and before the first mask layer is laminated, which facilitates the adjustment of the nanosphere particle diameter, such as the height, period, size, etc. of the nanostructure in forming the two-dimensional photonic crystal structure. Increase the ability to control structural variables. In one embodiment, the particle size adjusting step of the nanospheres is O ₂ after the nanosphere thin film is laminated. This can be done by ashing, because it is easy to adjust the ashing time and the nanosphere size can be easily adjusted, thereby facilitating the patterning of the photonic crystal structure. However, it is not limited by this method.

The stacking of the fluorescent layer is a step of applying a fluorescent material constituting the fluorescent layer on the base substrate in a sol state; And spin coating the coated sol phosphor and depositing the photonic crystal layer is deposited by a plasma enhanced chemical vapor deposition (PECVD) method suitable for miniaturization and lowering of a process in the surface treatment of a metal or a polymer. do.

The base substrate is a base wafer used to manufacture a light emitting diode (LED) and uses a glass, sapphire, or quartz substrate suitable as a source material of the LED. Since the Sapphire substrate has a high degree of orientation and no scratches or marks due to precise polishing, it is suitable for forming two-dimensional photonic crystal nanostructure patterns using atomic layer deposition because it is used as a deposition substrate for nitrides or compound semiconductors for LEDs. The phosphor layer may include an organic or inorganic phosphor, which is a two-dimensional photonic crystal prepared in a conventional manner when the two-dimensional photonic crystal prepared by the above-described manufacturing method is deposited on the organic or inorganic phosphor to the general phosphor This is because the luminous efficiency is improved by about six times than when deposited. In addition, the phosphor layer may include Y ₂ O ₃ : Eu, which is often used as a cathode ray emitting phosphor, which is thermally stable, physicochemically uniform, has high adhesion to a substrate, and minimizes gas generation. It is a material that can be suitably used for the two-dimensional photonic crystal nanostructure of the present invention. However, it is not necessarily limited thereto.

The photonic crystal layer has a SiO ₂ or SiN _x layer, and compared with conventional OLEDs, the extraction efficiency is increased by about 50% in the gaze angle of 90 ° ± 40 °, and thus shows excellent light efficiency. The second mask layer has excellent durability and opacity, so that the two-dimensional photonic crystal may be manufactured using chromium suitable for using atomic layer deposition. When the second mask layer is a chromium thin film, the second mask layer is deposited by thermal evaporation.

The nanosphere thin film is characterized in that the polystyrene or SiO _{2 It} is easy to control the structure of the two-dimensional photonic crystal, the two-dimensional photonic crystal structure is smoothly applied to the light emitting device containing a variety of thin film emitters, sedimentation method, spin coating method, printing This is because the conventionally known nanosphere thin film coating method can be used. The nanosphere particle size used in the nanosphere thin film may be 150-2000 nm to manufacture a two-dimensional photonic crystal, because if the nanosphere particle size is less than 150nm or more than 2000nm is laminated to the thin film phosphor to give sufficient light efficiency.

The first mask layer by atomic layer deposition may include a metal or an oxide. In the case of using atomic layer deposition, a metal or an oxide having excellent deposition degree between the nanospheres and the second mask layer is used. The first mask layer by atomic layer deposition is characterized in that 0.5 to 20nm. In this case, if the thickness of the atomic layer is less than 0.5 nm, it cannot act as a mask, and if the thickness becomes too thick, the nanosphere layer and the bottom thereof may be simultaneously coated to remove the atomic layer thin film when the nanosphere is removed.

The removing of the nanosphere thin film may include removing the nanosphere thin film by ultrasonication in a chloroform solution. This is because when the ultrasonic sphere is used to remove the nanosphere thin film and chloroform is used as the solvent, the desired photonic crystal and the phosphor can be stably obtained by not chemically changing the photonic crystal and the phosphor.

Etching the second mask layer may include dry etching the second mask layer, and etching the photonic crystal layer under the second mask may be performed by dry etching the photonic crystal layer and removing the second mask. It can proceed by ashing with Cl ₂ gas. When etching the second mask layer by dry etching using O ₂ / Cl ₂ gas and dry etching the photonic crystal layer with CF ₄ gas, the etching time can be shortened and cost is advantageous. When the second mask is removed after etching, ashing with Cl ₂ gas causes no physical damage to the photonic crystal layer and the fluorescent layer under the second mask, and does not cause chemical change.

In another aspect, the present invention provides a thin film display including a two-dimensional photonic crystal, wherein the two-dimensional crystal is a step of depositing a mask layer on the nanosphere thin film and the substrate using atomic layer deposition (ALD); It is possible to provide a thin film display, which is manufactured by a process comprising the step of exposing a nanosphere-shaped substrate to the outside. The light efficiency of a display including a two-dimensional photonic crystal manufactured according to the present invention is manufactured in a conventional manner. This is because the experimental difference is six times higher than the display including the two-dimensional photonic crystal. This will be described in more detail in Experimental Example 1 below.

Example 1

Example  1-1

Substrate Manufacturing

A Y ₂ O ₃ : Eu thin film was prepared on a sapphire substrate by a sol-gel method and subsequent spin coating. 95% Y (NO ₃ ) ₃ and 5% Eu (NO ₃ ) ₃ are dissolved in 2-methoxyhexanol, citric acid is added, and a sol is formed to spin sapphire by spin coating. The substrate was coated. After coating was dried for 5 minutes at 100 ℃ and pyrolyzed at 600 ℃ for 5 minutes to remove unnecessary carbon compounds and UV / ozone irradiation to coat a second sol. The thickness of the thin film phosphor was controlled by repeating the coating process. In this embodiment, five thin film phosphors were coated, and the coated thin film was prepared by calcination of 1000 ° C. time and Y ₂ O ₃ : Eu thin film phosphor. Subsequently, a two-dimensional SiNx photonic crystal nanostructure was prepared on a Y ₂ O ₃ : Eu thin film phosphor. A SiN _x thin film to be used as a two-dimensional photonic crystal on a Y ₂ O ₃ : Eu thin film phosphor-coated sapphire substrate was prepared by depositing at about 200 nm by a plasma enhanced chemical vapor deposition (PECVD) method. On it, chromium to be used as a mask was thermally deposited to a thickness of 50 nm.

Example  1-2

Nanospheres  deposition

The polystyrene nanosphere thin film was spin-coated about 1 to 5 layers on the chromium mask prepared in Example 1-1 to prepare a pattern of two-dimensional nanostructure.

Example 1 -3

O ₂ Ashing

The polystyrene nanospheres were ashed with O ₂ gas for 10 minutes to reduce the polystyrene nanosphere size.

Example 1 -4

Mask layer  deposition

Subsequently, 1 to 10 nm of Al ₂ O ₃ is deposited using trimethyl aluminum and water as precursors by atomic layer deposition. Thereafter, the polystyrene nanosphere thin film is removed by sonication in a chloroform solution to obtain a chromium mask layer laminated with Al ₂ O ₃ except for the nanohole region. The chromium mask layer was dry-etched (O ₂ / Cl ₂ gas) to remove unnecessary portions by using the Al ₂ O ₃ pattern to form a chromium mask having a two-dimensional nanostructure having a period of 580 nm. Next, through etching again, the SiN _x thin film was etched with CF ₄ gas and the upper chromium mask was removed (ashing with Cl ₂ gas) to give a period of 580 nm, a height of about 200 nm, and a diameter on the thin film phosphor substrate. A 350 nm two-dimensional nanohole photonic crystal structure was formed. 11 (a) shows a thin film phosphor coated with a two-dimensional photonic crystal nanostructure having a period of 580 nm, a height of 200 nm, and a diameter of 350 nm (area ratio of 0.53) on the Y ₂ O ₃ : Eu thin film phosphor prepared in Example 1 Electron microscope (SEM) plane photo.

Example  2

A two-dimensional photonic crystal structure was manufactured in the same manner as in Example 1, except that the time for ashing the polystyrene nanospheres with O ₂ gas of Examples 1-3 was 20 minutes.

11 (b) is a thin film coated with a two-dimensional photonic crystal nanostructure having a period of 580 nm, a height of 200 nm, and a diameter of 250 nm (area ratio 0.35) on the Y ₂ O ₃ : Eu thin film phosphor prepared by the method of Example 2 An electron microscope (SEM) planar photo of the phosphor. Referring to FIG. 11 (b), when the polystyrene nanospheres were ashed with O ₂ gas for 20 minutes, the size of the two-dimensional nano holes was reduced compared to FIG. 11 (a).

Example  3

A two-dimensional photonic crystal structure was manufactured in the same manner as in Example 1, except that the time for ashing the polystyrene nanospheres was 30 minutes with the O ₂ gas of Examples 1-3.

FIG. 11 (c) shows a two-dimensional photonic crystal nanostructure having a period of 580 nm, a height of 200 nm, and a diameter of 150 nm (area ratio 0.18) on the Y ₂ O ₃ : Eu thin film phosphor prepared by the method of Example 3. An electron microscope (SEM) planar photograph of a thin film phosphor. Referring to FIG. 11 (c), when the polystyrene nanospheres were ashed with O ₂ gas for 30 minutes, the size of the two-dimensional nano holes was reduced compared to FIG. 11 (b).

Therefore, the size of the nanoholes is changed according to the time of ashing the polystyrene nanospheres with O ₂ gas, thereby controlling the ashing time to prepare nanoholes having a desired size.

Experimental Example  One

Comparison of Luminous Efficiency of Emission Spectrum of Thin Film Phosphors

12 shows the luminous efficiency of the emission spectrum of the conventional Y ₂ O ₃ : Eu thin film phosphor and the Y ₂ O ₃ : Eu thin film phosphor coated with a two-dimensional photonic crystal structure, in area ratio (area ratio = air area / dielectric area). Relative comparison graph. The emission spectrum was measured using ultraviolet (254 nm) as an excitation light source for the substrate having the phosphor thin films prepared in Examples 1 to 3, and the area of the emission spectrum was relatively determined based on Example 1-1. The luminous efficiency was measured and measured, and the value was measured relative to the luminous amount of Example 1-1 as 1.0. Referring to FIG. 12, when the area ratio is 0.1 to 0.7, the luminous efficiency of the thin film phosphor coated with the two-dimensional photonic crystal structure according to the present invention is at least three times higher and up to six times higher than that of the conventional thin film phosphor. . Therefore, it was confirmed that the two-dimensional photonic crystal prepared according to the present invention greatly improved the efficiency of the device to be used in the thin film phosphor.

1 is a cross-sectional view of a conventional LED device.

2 is a cross-sectional view of a conventional OLED device.

3 is a schematic diagram showing a structure coated with a conventional thin film phosphor and an emission path of emitted light generated in the phosphor.

4 is a cross-sectional view of a structure in which a two-dimensional photonic crystal nanostructure is inserted into a conventional LED.

5 is a cross-sectional view of a structure in which a two-dimensional photonic crystal nanostructure is inserted into a conventional OLED.

6 is a manufacturing flowchart of a two-dimensional photonic crystal nanostructure by a conventional laser holographic lithography process.

7 is a manufacturing flowchart of the two-dimensional photonic crystal nanostructure by the nanosphere lithography process.

FIG. 8 is a schematic view showing that a first mask layer is simultaneously coated on a surface of a nanosphere and a substrate not in contact with the nanosphere by the principle of conformal growth of atomic layer deposition.

9 is a view of the substrate stacked up to the nanospheres before forming the first mask layer using atomic layer deposition.

FIG. 10 is a manufacturing flowchart of a two-dimensional photonic crystal nanostructure by a novel nanosphere lithography process using a nanosphere thin film and an atomic layer deposited film mask.

11 (a) shows an electron microscope (SEM) plane of a thin film phosphor coated with a two-dimensional photonic crystal nanostructure having a period of 580 nm, a height of 200 nm, and a diameter of 350 nm (area ratio of 0.53) on a Y ₂ O ₃ : Eu thin film phosphor. It is a photograph.

11 (b) shows an electron microscope (SEM) plane of a thin film phosphor coated with a two-dimensional photonic crystal nanostructure having a period of 580 nm, a height of 200 nm, and a diameter of 250 nm (area ratio of 0.35) on a Y ₂ O ₃ : Eu thin film phosphor. It is a photograph.

11 (c) shows an electron microscope (SEM) plane of a thin film phosphor coated with a two-dimensional photonic crystal nanostructure having a period of 580 nm, a height of 200 nm, and a diameter of 150 nm (area ratio of 0.18) on a Y ₂ O ₃ : Eu thin film phosphor. It is a photograph.

12 shows the luminous efficiency of the emission spectrum of the conventional Y ₂ O ₃ : Eu thin film phosphor and the Y ₂ O ₃ : Eu thin film phosphor coated with a two-dimensional photonic crystal structure, area ratio (area ratio = air area / dielectric area). Relative comparison graph.

<Description of the symbols for the main parts of the drawings>

1 electrode 2 inorganic semiconductor light emitting layer

3 ... Substrate 4 ... ITO Transparent Electrode

5 ... organic semiconductor light emitting layer 6 ... Al electrode

7 ... Thin Film Phosphor 8 ... Emission Mode

9 ... substrate mode 10 ... thin film phosphor mode

11 ... 2D photonic crystal thin film layer 12 ... transparent dielectric layer

13 ... chrome thin film 14 ... photoresist thin film

15 ... Exposed Photoresist Thin Film

16 ... 2D nanostructured photoresist thin film

17 ... 2D nanostructured chromium thin film

18. Transparent dielectric two-dimensional photonic crystal nanostructure

19 ... nanosphere monolayer 20 ... nanosphere monolayer or multilayer

21 ... first mask layer deposited thin film 22 ... second mask layer

23 ... photonic crystal layer 24 ... fluorescent layer

25 ... Base Board

Claims (20)

Depositing a nanosphere thin film on a substrate; Simultaneously depositing a first mask layer on the nanosphere thin film and the substrate using atomic layer deposition (ALD); Removing the nanosphere thin film to expose a nanosphere-shaped substrate to the outside; And And etching the substrate exposed to the outside in the nanosphere shape. The method of claim 1, further comprising adjusting a nanosphere particle size of the nanosphere thin film after laminating the nanosphere thin film on the substrate. The substrate of claim 1, wherein the substrate comprises: a base substrate; A fluorescent layer laminated on the base substrate; And a second mask layer stacked on the photonic crystal layer. The method of claim 3, wherein the etching comprises etching the second mask layer and the photonic crystal layer to selectively expose a fluorescent layer in which the photonic crystal layer is stacked. The method of claim 3, wherein the stacking of the fluorescent layer comprises: applying a phosphor forming the fluorescent layer on the base substrate in a sol state; And spin coating the phosphor in the sol state. The method of claim 3, wherein the stacking of the photonic crystal layer comprises depositing by plasma enhanced chemical vapor deposition (PECVD). 4. The method of claim 3, wherein the base substrate is any one selected from the group consisting of glass, sapphire, and quartz substrates. The method of claim 3, wherein the phosphor layer comprises an organic or inorganic phosphor. The method of claim 8, wherein the fluorescent layer comprises Y ₂ O ₃ : Eu. The method of claim 3, wherein the photonic crystal layer comprises SiO ₂ or SiN _x . The method of claim 3, wherein the second mask layer comprises chromium. The method of claim 1, wherein the nanosphere thin film comprises polystyrene or SiO ₂ . The method of manufacturing a two-dimensional photonic crystal according to claim 1, wherein the nanosphere particle diameter used in the nanosphere thin film is 150 to 2000 nm. The particle size adjusting step of the nanospheres according to claim 2, wherein the nanospheres are laminated after the thin film of O _2. A method for producing a two-dimensional photonic crystal which is carried out by a process comprising the step of ashing. The method of claim 1, wherein the first mask layer by atomic layer deposition is 0.5 to 20 nm. The method of claim 1, wherein the first mask layer by atomic layer deposition includes a metal or an oxide. The method of claim 1, wherein the removing of the nanosphere thin film comprises ultrasonically removing the nanosphere thin film in a chloroform solution. The method of claim 4, wherein etching the second mask layer comprises dry etching the second mask layer. The method of claim 4, wherein etching the photonic crystal layer under the second mask comprises dry etching the photonic crystal layer. 20. A light emitting device comprising the two-dimensional photonic crystal produced by any one of claims 1 to 19.

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