KR20140033595A - Method of manufacturing surface plasmonic color filter using laser interference lithography - Google Patents

Abstract

A method of manufacturing a surface plasmonic color filter using laser interference lithography comprises the steps of: (a) forming a metal film on a substrate; (b) forming a photosensitive layer on the metal film; (c) forming a nanohole array having periodicity on the photosensitive layer by irradiating the photosensitive layer with a laser interference patterns; (d) forming the nanohole array on the metal film by etching the metal film using the nanohole array of the photosensitive layer; and (e) removing the photosensitive layer having the nanohole array from the metal film having the nanohole array, and forming a dielectric layer on the metal film having the nanohole array.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a surface plasmonic color filter using laser interference lithography,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface plasmonic color filter using a surface plasmon, and more particularly, to a method of manufacturing a surface plasmonic color filter using laser interference lithography.

Recently, interest in information display has increased, and a demand for using portable information media has increased, and a light-weight flat panel display (FPD) that replaces a cathode ray tube (CRT) And research and commercialization are being carried out. Particularly, among such flat panel display devices, a liquid crystal display (LCD) is an apparatus for displaying an image using the optical anisotropy of a liquid crystal, and is excellent in resolution, color display and picture quality and is actively applied to a notebook or a desktop monitor have.

The liquid crystal display may comprise a color filter substrate, an array substrate (thin film transistor (TFT) array substrate), and a liquid crystal layer formed between the color filter substrate and the array substrate . Since a manufacturing process of a liquid crystal display device basically requires a number of mask processes, that is, a photolithography process, a method of reducing the number of masks in terms of productivity is required.

The color filter used in the liquid crystal display device absorbs unnecessary color light using dyes or pigments and extinguishes it. The color filter transmits only light of a desired color to realize a color, so that a white light incident on one sub- By transmitting only one of the RGB three primary colors, the transmittance of the color filter layer may be less than 30 (%). For this reason, the transmission efficiency of the panel (LCD panel) is very low, so that the power consumption by the backlight can be increased. In addition, since the color filter repeats color resist application, exposure, development and curing processes for each primary color, the process may be complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser interference lithography capable of forming a periodic hole array pattern of a nano size in a metal film (metal layer) And a method of manufacturing a surface plasmonic color filter using the same.

According to an aspect of the present invention, there is provided a method of manufacturing a surface plasmonic color filter, including: (a) forming a metal film on a substrate; (b) forming a photosensitive layer on the metal film; (c) forming a nano hole array having a periodicity in the photosensitive layer by irradiating the photosensitive layer with a laser interference pattern; (d) etching the metal film using the nano-hole array of the photosensitive layer to form a nano-hole array in the metal film; And (e) removing the photosensitive layer having the nanohole array from the metal film on which the nanohole array is formed, and forming a dielectric layer on the metal film on which the nanohole array is formed.

According to another aspect of the present invention, there is provided a method of manufacturing a surface plasmonic color filter, including: (a) forming a photosensitive layer on a substrate; (b) irradiating the photosensitive layer with a laser interferogram to form the photosensitive layer into a periodic nano dot array; (c) forming a metal film on the substrate and the photosensitive layer of the nano dot array; (d) removing the metal layer formed on the photosensitive layer of the nano dot array and the photosensitive layer of the nano dot array to form a metal film on which a nano hole array corresponding to the nano dot array is formed; And (e) forming a dielectric layer on the metal film on which the nanohole array is formed.

According to another aspect of the present invention, there is provided a method of fabricating a surface plasmonic color filter, comprising: (a) forming a metal film on a substrate; (b) forming a photosensitive layer on the metal film; (c) irradiating the photosensitive layer with a laser interfering pattern a plurality of times while rotating the substrate on which the photosensitive layer and the metal film are formed through a mask, so that nano holes are arranged in different directions in the photosensitive layer, Forming unit nano hole arrays; (d) forming unit nanohole arrays in the metal film by etching the metal film using unit nanohole arrays of the photosensitive layer; And (e) removing the photosensitive layer having the unit nanohole arrays from the metal film on which the unit nanohole arrays are formed, and forming a dielectric layer on the metal film on which the unit nanohole arrays are formed.

The nano holes included in the unit nanohole array may be periodically arranged on at least two directional axes and at least three of the nanoholes may be disposed on each of the directional axes.

According to another aspect of the present invention, there is provided a method of manufacturing a surface plasmonic color filter, including: (a) forming a photosensitive layer on a substrate; (b) irradiating the photosensitive layer with a laser interferogram pattern a plurality of times while rotating the substrate on which the photosensitive layer is formed through a mask so that the photosensitive layers have different nano dots array directions and periodicity Forming unit nano dot arrays; (c) forming a metal film on the substrate and the photosensitive layer of the unit nano dot arrays; (d) removing the metal layer formed on the photosensitive layer of the unit nano dot arrays and the photosensitive layer of the unit nano dot arrays to form a unit nanohole array corresponding to the unit nano dot arrays, forming a metal film on which nano hole arrays are formed; And (e) forming a dielectric layer on the metal film on which the unit nanohole arrays are formed.

The nano holes included in the unit nanohole array may be periodically arranged on at least two directional axes and at least three of the nanoholes may be disposed on each of the directional axes.

According to another aspect of the present invention, there is provided a method of fabricating a surface plasmonic color filter, comprising: (a) forming a metal film on a substrate; (b) forming a photosensitive layer on the metal film; (c) forming a first laser interferogram pattern on the photosensitive layer through a mask for forming a red sub-pixel, a mask for forming a green sub-pixel, and a mask for forming a blue sub-pixel, A laser interferogram pattern, and a third laser interferogram pattern, respectively, to form a first nanohole array having a first nanohole period corresponding to the red sub-pixel, the green sub-pixel, and the blue sub-pixel, respectively nano hole array, a second nano hole array having a second nano hole period, and a third nano hole array having a third nano hole period; (d) etching the metal film using the first nanohole array, the second nanohole array and the third nanohole array of the photosensitive layer to form a first nanohole array and a second nanohole array And forming a third nano-hole array; And (e) forming a photosensitive layer having the first nanohole array, the second nanohole array, and the third nanohole array from a metal film on which the first nanohole array and the second nanohole array and the third nanohole array are formed And forming a dielectric layer on the metal film on which the first nanohole array and the second nanohole array and the third nanohole array are formed.

According to another aspect of the present invention, there is provided a method of manufacturing a surface plasmonic color filter, including: (a) forming a photosensitive layer on a substrate; (b) forming a first laser interferogram pattern on the photosensitive layer through a mask for forming a red sub-pixel, a mask for forming a green sub-pixel, and a mask for forming a blue sub-pixel, Laser interference fringe, and third laser interference fringe, respectively, so that the photosensitive layer is divided into a first nano dot array having a first nano dot period corresponding to the red sub-pixel, the green sub-pixel, and the blue sub- a nano dot array, a second nano dot array having a second nano dot period, and a third nano dot array having a third nano dot period; (c) forming a metal film on the substrate, the photosensitive layer of the first nano dot array, the second nano dot array, and the third nano dot array; (d) a photosensitive layer of the first nano dot array, the second nano dot array and the third nano dot array, and a metal layer formed on the photosensitive layer of the first nano dot array and the second nano dot array and the third nano dot array, The metal film on which the first nano dot array and the second nano dot array and the third nano dot array corresponding to the first nano hole array and the second nano hole array and the third nano hole array are formed is removed, ; And (e) forming a dielectric layer on the metal film on which the first nanohole array, the second nanohole array, and the third nanohole array are formed.

The method of manufacturing a surface plasmonic color filter using laser interference lithography according to the present invention excludes the use of pigments or dyes when manufacturing a color filter and uses the surface plasmon resonance phenomenon through laser interference lithography, It is possible to fabricate a surface plasmonic color filter structure capable of improving light transmission efficiency. The color filter of the present invention, which improves the transmission efficiency of light and filters the light of a white light source by plasmon resonance, can reduce power consumption in a white light source, and can be used for flat panel displays such as LCDs and organic light emitting diodes display device or the like.

The present invention relates to a manufacturing method of a surface plasmonic color filter using laser interference lithography, which is a technique for forming a nano-sized periodic hole array pattern on a metal film. In particular, laser exposure can form a nano-sized pattern with a large area. Therefore, the present invention can simplify the process procedure (or the entire process procedure) including the fabrication process of the color filter and reduce the process cost. As a result, the present invention can be applied to a display device that is large-sized and commercialized at low cost.

The present invention can improve the characteristics of the surface plasmonic color filter by solving the problem of color change according to a viewing angle by partially forming a hole array pattern having a constant period using laser interference lithography.

Further, the present invention can simplify the process and reduce the process cost by implementing red, green, and blue subpixels at once using laser interference lithography.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the drawings used in the detailed description of the present invention, a brief description of each drawing is provided.
1 is a view illustrating a method of manufacturing a surface plasmonic color filter using laser interference lithography according to an embodiment of the present invention.
2 is a view illustrating a method of manufacturing a surface plasmonic color filter using laser interference lithography according to another embodiment of the present invention.
3 is a view for explaining a method of manufacturing a surface plasmonic color filter capable of solving a color change according to a viewing angle by using laser interference lithography according to another embodiment of the present invention.
FIG. 4 is a graph showing a transmittance change of light according to an incident angle of light in a surface plasmonic color filter structure in which a metal nanohole array pattern having a constant period is formed.
5 is a graph showing a transmittance change of light according to an incident angle of light in a surface plasmonic color filter using a metal film on which a polycrystalline periodic pattern according to the present invention shown in FIG. 3 is formed .
6 is a view illustrating a method of manufacturing a surface plasmonic color filter using laser interference lithography according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, and the objects attained by the practice of the invention, reference should be made to the accompanying drawings, which illustrate embodiments of the invention, and to the description in the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

Color filters are one of the major components that constitute and drive display devices for color implementation in flat panel displays. The color filter has a principle of selectively transmitting red, green or blue light from a white light source to implement color. The color filter technique applied to a commercialized flat panel display uses a material characteristic of a pigment or a dye, The transmittance is not more than 30 (%) because it absorbs light of unnecessary color and transmits only the target color light, and there is a drawback that the power consumption by the backlight is increased in order to generate high luminance. In addition, a photolithography process is required in the fabrication process of the color filter, and a large number of mask processes are required for the color filter, thereby increasing the process cost.

On the other hand, a hole array pattern having a plurality of nano-sized holes having a periodicity in the metal thin film layer is formed so that the plasmon effect (surface plasmon resonance phenomenon) occurring in this structure (hole array pattern) And a color filter is used as a color filter. Surface plasmon resonance can be a phenomenon that increases the transmission (transmission efficiency) of light passing through a nano-sized hole.

In order to realize a nano-sized hole array pattern having the predetermined period, studies using e-beam lithography (electron beam lithography) or ion milling (ion etching) have been reported, Is expensive and requires a lot of time, so it is inevitable to obstruct the large-scale and the fair price lowering for commercialization.

1 is a view illustrating a method of manufacturing a surface plasmonic color filter using laser interference lithography according to an embodiment of the present invention.

Referring to FIG. 1, a metal film 105 is formed on a glass substrate 100. Thereafter, a photoresist layer (a photoresist layer, a PR layer) 110 is formed on the metal film 105. The photosensitive layer 110 may be a positive photosensitive layer 110 or a negative photosensitive layer 110. In another embodiment of the present invention, a plastic substrate may be used in place of the transparent glass substrate 100. The plastic substrate may be a transparent flexible substrate including PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or ITO (Indium Tin Oxide). The metal film 105 may include, for example, aluminum (Al), gold (Au), silver (Ag), or copper (Cu). The metal film 105 may have a thickness of, for example, 10 (nm) to 400 (nm).

The photosensitive layer 110 is then used for laser interference lithography to form a nano-sized periodic hole array pattern (nano hole array pattern) in the photosensitive layer 110 The interference fringes of the lasers are exposed (irradiated) onto the photosensitive layer 110. The laser interferometric lithography uses a two-dimensional (1-D) line array pattern to form interference fringes when two lights (lasers) are used, and a first direction and a second direction (Or the difference in degree of energy experienced by the photosensitive layer depending on the thickness of the photosensitive layer), and the type of the photosensitive layer, that is, the negative photosensitive layer < RTI ID = Depending on whether the photosensitive layer is a positive or a photosensitive layer, the shape of the pattern can be formed into a hole or a dot shape through development. For example, in the case of using a photographic sensitive layer, a portion exposed (exposed) to light twice during development using a photosensitive material developing solution (PR development) after exposure in first and second directions The hole pattern (nanohole array pattern) can be formed. Alternatively, a dot pattern (nano dot array pattern) may be formed after development if the exposure energy is adjusted so that a portion exposed to light at least once is removed. In the case of the negative photosensitive layer, after the exposure in the first and second directions, the unexposed portion may be removed during development to form a hole pattern. That is, it is possible to form a nano-sized periodic hole array (periodic nanohole array) in the photosensitive layer 110 by irradiating the photosensitive layer 110 with laser interference fringes.

Laser interference lithography is a technique of engraving a pattern using a light interference pattern, in which two or more coherence light patterns are patterned to produce an interference pattern having a uniform periodicity, exposed to a photoresist coated on a substrate It can be very effective in making periodic nanostructures by forming nanopattern through a development process. The laser interference lithography can be easily used in a large-area process, can realize a large area pattern, and does not require masking in particular, so that the process can be simplified and the process cost can be reduced. Therefore, the present invention can manufacture a surface plasmonic color filter having improved transmission efficiency characteristics compared to conventional color filters while simplifying the process procedure and reducing the process cost by applying laser interference lithography.

Next, when the metal film 105 is etched using a nano-hole array of the photosensitive layer 110 (by injecting the etching solution through the nano-hole array of the photosensitive layer 110) A nano-patterned metal layer is formed. The metal film 105 may be etched by a dry etching method or a wet etching method. Thereafter, plasma etching is performed from the metal film 105 on which the nano-hole array is formed with the photosensitive layer 110 having the nano-hole array using oxygen plasma, or a PR striping process using a stripping solvent or may be stripped and removed by a photoresist stripping process. The nanohole array has holes or nano holes each having a nano-size (for example, a sub-wavelength size of incident light (for example, red light)) in a first direction (Arranged) periodically in a first direction (e.g., a lateral direction) and a second direction (e.g., a longitudinal direction). When small holes of wavelengths or less are periodically arranged in the metal film 105, the transmittance of light to the excitation of the surface plasmon can be greatly amplified. The shape of each of the holes may be circular, elliptical, rectangular, or triangular with a diameter of sub-wavelength diameter of incident light, for example white light. For example, each of the holes has a size (diameter) of 50 (nm) or more and 1 (μm) or less, and the interval (pattern period, or pitch) May be 50 (nm) or more and 1 (占 퐉) or less.

Next, when the dielectric layer 115 is formed (or deposited) on the metal film 105 on which the nanohole array is formed, the dielectric layer 115 is formed by the nanohole array of the metal film 105 A surface plasmonic color filter using the surface plasmon resonance phenomenon of the present invention capable of selectively transmitting light in a wavelength band (surface plasmon resonance wavelength band) can be manufactured (formed). The dielectric material of the dielectric layer 115 can fill the inside of the holes of the metal thin film 105. [ The surface plasmonic color filter of the present invention extracts three colors of red, green, or blue on a pixel-by-pixel basis in white light emitted from a back light that can be disposed on the dielectric layer 115, Which is a thin film type optical component which can realize a light emitting device. The thickness of the dielectric layer 115 may be, for example, 10 (nm) or more and 1000 (nm) or less. Conductive oxides such as dielectric layer 115, for example, include a general dielectric material (dielectric material), such as LiF, or SiO _2, or Al ₂ O _3, MgO, ZnO, ZnS, or ITO (Indium Tin Oxide) (transparent conductive Oxide). ≪ / RTI >

In the surface plasmonic color filter, plasmon resonance can occur at the interface between the metal (metal film 105) and the dielectric (dielectric layer 115 or substrate 100). In another embodiment of the present invention, the plasmon resonance mode at the interface between the metal (the interface between the substrate 100 and the metal film 105 and the interface between the dielectric layer 115 and the metal film 105) The substrate 100 and the dielectric layer 115 may each include a dielectric material having the same refractive index so as to enhance the transmission improvement effect. The dielectric layer 115 formed on the uppermost layer may serve to prevent corrosion and oxidation of the metal film 105.

The surface plasmon resonance phenomenon is a nano-sized metal structure. When light is incident, the free electrons (surface plasmon) on the surface of the metal thin film and the light of a specific wavelength resonate to form a specific wavelength In the metal thin film structure in which periodic patterns are formed, the resonance wavelength band can be set by changing the pattern period and appropriately combining the dielectric constants of the metal and the dielectric material. In the plasmonic structure having the holes, only light of a specific wavelength capable of forming a surface plasmon by the incident light can transmit the structure (structure), and all the remaining light is transmitted through the metal film (metal thin film) Reflection or absorption is performed.

In the wavelength band where the surface plasmon resonance occurs, the electric field of the incident light and the plasmon are coupled to each other to maximize the amount of light passing through the hole (nano hole), and the amount of the hole becomes the aperture ratio Thereby increasing the transmittance.

As described above, according to the present invention, a laser beam is irradiated onto a metal film (nano-sized hole array) formed by using a laser interference lithography capable of forming a pattern having a constant period using an interference fringe of two or more lights. 105). ≪ / RTI >

2 is a view illustrating a method of manufacturing a surface plasmonic color filter using laser interference lithography according to another embodiment of the present invention.

Referring to FIG. 2, a photosensitive layer (photosensitive layer) 205 is formed (applied) on a glass substrate 200. The photosensitive layer 205 may be a negative photosensitive layer 205 or a positive photosensitive layer 205. [ In another embodiment of the present invention, a plastic substrate may be used instead of the glass substrate 200. The plastic substrate may be a transparent flexible substrate including PET, ITO, or PEN.

The photosensitive layer 205 is then used for laser interference lithography to form a nano-sized periodic dot array pattern (nano dot array pattern) on the photosensitive layer 205 The interference fringes of lasers are exposed on the photosensitive layer 205. The laser interferometric lithography can form a pattern having a predetermined period on the photosensitive layer 205 using the interference fringes of at least two lights (lasers), and the method of laser interference lithography mentioned in the description of Fig. 1 is applied . Thereafter, the photosensitive layer 205 having a nano dot array may be formed according to the degree of change of the medium exposed to the laser interferogram using the photosensitive material developer (PR development). That is, the photosensitive layer 205 can be formed into a nano-sized periodic dot array (a periodic nano dot array) by irradiating the photosensitive layer 205 with laser interference fringes. In the case of using the nano dot array, the metal etching process is omitted in the manufacturing method of the present invention, so that the process can be simplified and the process cost can be further reduced as compared with the manufacturing method of FIG. The nano dot arrays are formed on a substrate 200 having a nano-sized array (for example, a sub-wavelength size of incident light (e.g., red light) May refer to a structure that is periodically arranged in one direction (e.g., transverse direction) and in a second direction (e.g., longitudinal direction). The present invention can manufacture a surface plasmonic color filter having improved transmission efficiency characteristics compared to conventional color filters while simplifying the process procedure and reducing the process cost by applying the laser interference lithography described above.

Next, a metal film 210 is formed (or deposited) on the substrate 200 (or on the substrate 200) and on the photosensitive layer 205 of the nano dot array.

Next, the metal layer 210 formed on the nano dot array photosensitive layer 205 and the nano dot array photosensitive layer 205 is removed by a lift-off method (a solvent for dissolving the photoresist PR) ) To remove the nano-patterned metal layer 210 to form a nano-patterned metal layer 210 corresponding to the nano dot array. The metal film 210 may include, for example, aluminum (Al), gold (Au), silver (Ag), or copper (Cu). The metal film 210 may have a thickness of, for example, 10 (nm) to 400 (nm). The shape of each of the holes included in the nanohole array may be circular, elliptical, rectangular, or triangular having a sub-wavelength diameter of incident light, for example, white light. If a small hole having a wavelength or less is periodically arranged in the metal film 210, the transmittance of light to the excitation of the surface plasmon can be greatly amplified. For example, each of the holes has a size (diameter) of 50 (nm) or more and 1 (μm) or less, and the interval (period or pitch) between the holes is 50 (nm) or more and 1 (μm) or less. A developer (for example, SU-8 photoresist solvent) is removed to remove the metal layer 210 formed on the photosensitive layer 205 of the nano dot array and the nano dot array photosensitive layer 205 in the PR-lift off process Can be used.

Next, when a dielectric layer 215 is formed on the metal film 210 on which the nano-hole array is formed, as shown in the lower left part of FIG. 2, the nano- A surface plasmonic color filter using the surface plasmon resonance phenomenon of the present invention capable of selectively transmitting light can be manufactured (formed). The dielectric material of the dielectric layer 215 can fill the inside of the holes of the metal foil 210. [ The surface plasmonic color filter of the present invention extracts three colors of red, green, or blue on a pixel-by-pixel basis in white light emitted from a back light, which can be disposed on the dielectric layer 215, Which is a thin film type optical component which can realize a light emitting device. The thickness of the dielectric layer 215 may be, for example, 10 (nm) or more and 1000 (nm) or less. Conductive oxides such as dielectric layer 215, for example, include a general dielectric material (dielectric material), such as LiF, or SiO _2, or Al ₂ O _3, MgO, ZnO, ZnS, or ITO (Indium Tin Oxide) (transparent conductive Oxide). ≪ / RTI >

Plasmon resonance in a surface plasmonic color filter can occur at the interface between the metal (metal film 210) and the dielectric (dielectric layer 215 or substrate 200). In another embodiment of the present invention, the plasmon resonance mode at the interface between the metal film (the interface between the substrate 200 and the metal film 210 and the interface between the dielectric film 215 and the metal film 210) The substrate 200 and the dielectric layer 215 may each include a dielectric material having the same refractive index.

As described above, according to the present invention, a laser beam is irradiated onto a metal film (nano-sized hole array) formed by using a laser interference lithography capable of forming a pattern having a constant period using an interference fringe of two or more lights. 210). ≪ / RTI >

3 is a view for explaining a method of manufacturing a surface plasmonic color filter capable of solving a color change according to a viewing angle by using laser interference lithography according to another embodiment of the present invention.

Referring to FIG. 3, a laser interference pattern (laser) is irradiated to the photosensitive layer (110 in FIG. 1 or 205 in FIG. 2) through a mask (region indicated by black in FIG. 3) The substrate 100 on which the metal film 105 and the photosensitive layer 110 are formed or the substrate 200 on which the photosensitive layer 205 of FIG. 2 is formed is irradiated with laser every time the laser is irradiated, ) Is rotated so that a unit nanohole array pattern or a unit nano dot array pattern which is a partially periodic unit cell (a portion indicated by an arrow in Fig. 3) is formed as a polycrystal (polycrystalline type) The distributed pattern can be made entirely in the photosensitive layer (110 in FIG. 1 or 205 in FIG. 2). That is, in the embodiment described with reference to FIG. 3, the laser irradiation conditions (laser irradiation environment) are kept constant, and the unit patterns (the periods of the holes) Unit cell) may be randomly scattered (dispersed).

In order to utilize it as a color filter, it is necessary to derive the selective transmittance through plasmon resonance in a specific wavelength band by using a periodic pattern (periodic hole pattern). In order to make a matching condition for plasmon resonance using a periodic pattern The hole pattern may require a minimum of three or more in the first and second periodic directions (i.e., in the case of a two-dimensional array pattern having two periodic directions, in order to transmit light in a specific wavelength band through surface plasmon resonance , At least nine holes may be necessary), and the larger the area in which the repeated directionality is uniform, the larger the effect becomes. Therefore, the unit cells that are separated through the mask must secure an area where three or more patterns can be repeated. Since the area of the unit cell to be secured is about a few micrometers, although the refractive index of the metal and the dielectric material included in the plasmonic color filter is different, the present invention including the unit cell has a problem in that, It can be fully applied.

In other words, the holes (nano holes) included in the unit nanohole array pattern (unit nanohole array) are aligned in the orthogonal direction or the hexagonal direction (the first direction forming an angle of 120 degrees with respect to each other, Direction, and the third direction), as shown in FIG.

The holes may be repeated a plurality of times at least three times along a repeated direction with a constant period. More specifically, the holes included in the metal film (105 in FIG. 1 or 210 in FIG. 2) are periodically arranged on at least two direction axes and at least three can be disposed in each of the direction axes. For example, in the case of three direction axes, in order to transmit light of a specific wavelength band through surface plasmon resonance, a first direction axis, a second direction axis, and a third direction At least three holes in each of the shafts may be disposed in the plane of the metal film 105 or 210. If there are four or more directional axes, holes may be arranged in each of the directional axes which are at the same angle with each other, as in the case of three directional axes described above.

On the other hand, in the case of forming an array repeated in mutually orthogonal first and second directions, the number of holes arranged in the first direction and the second direction is such that light of a specific wavelength band is transmitted through surface plasmon resonance For example, at least nine.

An embodiment of the method of manufacturing the surface plasmonic color filter shown in Fig. 3 can be described as follows.

First, the embodiment of FIG. 3 may be combined with the embodiment of FIG. 3 includes a step of forming a metal film 105 on a substrate 100 (FIG. 1), a step of forming a photosensitive layer 110 on the metal film 105, The laser interference pattern is irradiated a plurality of times (at least twice) while rotating the substrate 100 on which the photosensitive layer 110 and the metal film 105 are formed through a mask (a portion indicated by black in Fig. 3) The unit nanohole array patterns generated in the photosensitive layer 110 are developed through a development process to form unit nano holes having different nano holes array direction in the photosensitive layer 110, Forming unit nano hole arrays and etching the metal film 105 using unit nanohole arrays of the photosensitive layer 110 to form unit nanohole arrays in the metal film 105 A step of forming a photosensitive layer 110 having unit nanohole arrays in a unit nanohole array It may include the step of forming the dielectric layer 115 over to the metal film 105 is removed from the metal film 105 is formed and provided to the unit nanohole array. The nano holes included in the unit nanohole array may be periodically arranged on at least two directional axes and at least three of the nanoholes may be disposed on each of the directional axes.

Next, the embodiment of FIG. 3 may be combined with the embodiment of FIG. 3 includes a step of forming a photosensitive layer 205 on a substrate 200 (FIG. 2) and a step of forming a photosensitive layer 205 on a substrate (a portion indicated by black in FIG. 3) The laser interferogram is irradiated a plurality of times (at least twice) while rotating the substrate 200 on which the photosensitive layer 205 is formed, and the unit nano dot array patterns generated in the photosensitive layer 205 by the irradiation are developed forming the photosensitive layer 205 into unit nano dot arrays having different nano dots and arranging directions of the nano dots and developing the substrate 200 (the substrate 200) Forming a metal layer 210 on the photosensitive layer 205 of the unit nano dot arrays and forming a metal layer 210 on the photosensitive layer 205 of the unit nano dot arrays and on the photosensitive layer 205 of the unit nano dot arrays The metal film 210 is removed to form a unit nanohole array (na) corresponding to the unit nano dot arrays. forming a metal layer 210 on which the unit nanohole arrays are formed, and forming a dielectric layer 215 on the metal layer 210 on which the unit nanohole arrays are formed. The nano holes included in the unit nanohole array may be periodically arranged on at least two directional axes and at least three of the nanoholes may be disposed on each of the directional axes.

As described above, the embodiment of the present invention described with reference to FIG. 3 provides a method of forming a polycrystalline periodic pattern in a photosensitive layer using laser interference lithography combined with a mask process . That is, the present invention can be a process for partially forming a periodic pattern by adding a masking process to a process of irradiating light in laser interference lithography.

The surface plasmon resonance phenomenon in a structure having a certain periodic pattern is influenced by the directionality of light incident for plasmon excitation in determining the wavelength band where resonance occurs. This phenomenon is caused by the wavelength of light transmitted through the viewing angle The band changes and the color changes. The resonance condition changes according to the change of momentum of light along the in-plane direction of the metal thin film (metal film), and the position of the transmission peak value is shifted. Changing the incident angle of vertically incident light changes the in-plane component of the light, changing the resonance condition and changing the transmission color. The change in momentum of light also correlates with the degree to which the in-plane component matches the directionality of the periodic pattern.

When a color filter having a polycrystalline periodic pattern is implemented using the manufacturing method (process method) according to the present invention shown in FIG. 3, the change of the light momentum according to the direction of the pattern is reduced, The phenomenon can be reduced. That is, when a plasma-based color filter is formed by forming a polycrystalline periodic pattern by the mask process and the rotation of the substrate, the periodic structure of the plasmonic color filter using the periodic pattern on the entire area It is possible to alleviate or eliminate the problem (for example, a color change problem depending on the viewing angle).

FIG. 4 is a graph showing a transmittance change of light according to an incident angle of light in a surface plasmonic color filter structure in which a metal nanohole array pattern having a constant period is formed.

Referring to FIG. 4, it can be seen that the transmission wavelength band of light moves according to the incident angle (degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 25 degrees) of light. As the transmission wavelength band of light moves, a problem of color change of light according to the above-mentioned viewing angle may occur. That is, from the viewpoint of the observer who views the display device equipped with the surface plasmonic color filter structure in which the metal nanohole array pattern of a certain period is formed, the color changes depending on the position of the observer. The incident angle of light means an angle formed by the vertical line (normal line) of the upper surface of the dielectric layer (115 in FIG. 1 or 215 in FIG. 1 or 100 or 200 in FIG. do. In FIG. 4, the first line above indicates the transmittance when the incident angle of light is 0 degrees.

5 is a graph showing a transmittance change of light according to an incident angle of light in a surface plasmonic color filter using a metal film on which a polycrystalline periodic pattern according to the present invention shown in FIG. 3 is formed .

Referring to FIG. 5, it can be seen that the transmission wavelength band of light does not move according to the incident angle (degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 25 degrees) of light. The incident angle of the light is perpendicular to the vertical line (normal line) with reference to the top surface of the dielectric layer (115 in FIG. 1 or 215 in FIG. 1) (or substrate (100 in FIG. 1 or 200 in FIG. 2) It means the angle formed by the direction of light propagation. In FIG. 5, the first line above indicates the transmittance when the incident angle of light is 0 degrees. When the incident angle of light is 0 degree, the transmittance of the incident light becomes maximum and the transmittance decreases as the incident angle increases.

As shown in FIG. 5, the light transmittance is decreased according to the viewing angle (or the incident angle), but the peak value of the light transmittance as shown in FIG. 4 does not move. Therefore, the present invention may not cause a color change according to the viewing angle.

6 is a view illustrating a method of manufacturing a surface plasmonic color filter using laser interference lithography according to another embodiment of the present invention. The method of manufacturing the surface plasmonic color filter may be a method of separately manufacturing the sub pixels of the surface plasmonic color filter.

The embodiment described with reference to FIG. 3 may have a pattern in which unit patterns having the same period are randomly scattered (dispersed) by keeping the laser irradiation conditions constant and using the masking process and the rotation of the substrate.

Referring to FIG. 6, unlike the embodiment of FIG. 3, a pattern having different cycles may be implemented in one panel (for example, an LCD panel) at a time by changing laser irradiation conditions in the masking process. When a color filter is implemented using a periodic hole array pattern of a metal film (105 in FIG. 1 or 210 in FIG. 2), the transmission band of light is directly affected by the period of the pattern (hole pattern) The color wavelength band to be transmitted can be adjusted. Therefore, in order to distinguish red, green, and blue sub-pixels, a hole array pattern having different periods should be formed in each pixel. Masking and laser setting (or setting of the laser beam angle (angle of incidence for the sample of the laser beam)) as shown in FIG. 6 are repeated three times to obtain different periods The laser interference pattern of the laser interference pattern is irradiated to a photoresist (110 in FIG. 1 or 205 in FIG. 2) and development is performed at a time to form a red interference pattern corresponding to red, green, The pattern may be formed separately in the metal film (105 in FIG. 1 or 210 in FIG. 2).

6, the angle of the laser beam for generating the first laser interferogram for red sub-pixel formation is? 1, and the second laser interferogram for green sub-pixel formation is generated And the angle of the laser beam for generating the third laser interferogram for blue sub-pixel formation may be? 3. The pitch of the nanohole array pattern of the metal film formed on the metal film (105 in FIG. 1 or 210 in FIG. 2) by θ1 is pitch1, and the metal film (105 in FIG. 1 or 2 The nanohole period of the hole array pattern of the metal film formed on the metal film (105 in FIG. 1 or 210 in FIG. 2) by pitch? 3 is pitch3 have. In the period size, the size of pitch1 may be larger than the size of pitch2, and the size of pitch2 may be larger than the size of pitch3. That is, pitch1> pitch2> pitch3. Figure 6 shows a mask for red sub-pixel formation consisting of, for example, four unit masks, four unit masks for the implementation of red, green and blue surface plasmonic filters in one panel A mask for green sub-pixel formation, and a mask for blue sub-pixel formation consisting of four unit masks.

An embodiment of the method of manufacturing the surface plasmonic color filter shown in Fig. 6 can be described as follows.

First, the embodiment of FIG. 6 may be combined with the embodiment of FIG. 6 includes a step of forming a metal film 105 on a substrate 100 (FIG. 1), a step of forming a photosensitive layer 110 on the metal film 105, A first laser interferogram pattern is formed through a mask for forming a red sub-pixel, a mask for forming a green sub-pixel, and a mask for forming a blue sub-pixel, And the third laser interference fringe are respectively irradiated and the first nanohole array pattern, the second nanohole array pattern, and the third nanohole array pattern generated in the photosensitive layer 110 by the irradiation are developed a first nano hole array having a first nano hole period (pitch 1) corresponding to the red sub-pixel, the green sub-pixel, and the blue sub-pixel in the photosensitive layer 110, A second nanohole array having a 2 nanohole period (pitch 2), and a second nanohole array having a third nanohole period (pitch 3) To form a third nanohole array having a second nanohole array.

6, the metal film 105 is etched using the first nanohole array, the second nanohole array, and the third nanohole array of the photosensitive layer 110 to form a metal film Forming a first nanohole array, a second nanohole array and a third nanohole array on the first nanohole array, a second nanohole array and a third nanohole array, ) Is removed from the metal film 105 on which the first nanohole array and the second nanohole array and the third nanohole array are formed and the metal film 105 on which the first nanohole array and the second nanohole array and the third nanohole array are formed And forming a dielectric layer 115 on the dielectric layer 105.

Next, the embodiment of FIG. 6 may be combined with the embodiment of FIG. 6 includes a step of forming a photosensitive layer 205 on a substrate 200 and a step of forming a mask for forming a red sub-pixel on the photosensitive layer 205 ), A mask for forming a green sub-pixel, and a mask for forming a blue sub-pixel, the first laser interferogram, the second laser interferogram, and the third laser interferogram, respectively, The first nano dot array pattern, the second nano dot array pattern, and the third nano dot array pattern generated in the light emitting layer 205 are developed through a developing process so that the photosensitive layer 205 is divided into a red sub- A second nano dot array having a second nano dot period (pitch 2), and a second nano dot array having a first nano dot period (pitch 1) corresponding to blue sub- Forming a third nano dot array having a third nano dot cycle (pitch3) It can be included.

6 includes a substrate 200 (on the substrate 200), a metal film (not shown) on the photosensitive layer 205 of the first nano dot array and the second nano dot array and the third nano dot array, Forming a first nano dot array, a second nano dot array, and a third nano dot array; forming a first nano dot array, a second nano dot array, and a third nano dot array; The metal film 210 formed on the photosensitive layer 205 of the array is removed to form a first nano-dot array and a second nano-dot array and a second nano-hole array and a second nano-hole array and a second nano- Forming a metal film 210 on which a 3-nano-hole array is formed, and forming a dielectric layer 215 on the metal film 210 on which the first nano-hole array and the second nano-hole array and the third nano-hole array are formed As shown in FIG.

In the case of color filters using dyes or pigments, the application and development processes must be repeated to produce color resist or color photoresist corresponding to red, green, and blue, respectively. When the color filter is manufactured by the laser lithography process in which the masking process of the present invention is added, the process can be simplified and waste of materials such as pigment can be reduced.

In more detail, photolithography processes are used to implement existing color filters based on dyes or pigments, which require multiple masks to implement complex structures and process difficulties due to mask alignment . The method of manufacturing a color filter according to the present invention described with reference to FIG. 6 reduces the number of process steps of implementing sub-color pixels by separating red, green, and blue using three masks in a laser interferometric lithography process, Can be greatly reduced.

As described above, embodiments of the invention described with reference to FIG. 6 provide a method of easily forming red, green, and blue color subpixels using laser interference lithography that incorporates a mask process.

As described above, the embodiments have been disclosed in the drawings and specification. Although specific terms are used herein, they are used for the purpose of describing the present invention only and are not used to limit the scope of the present invention described in the claims or the claims. It is therefore to be understood by those skilled in the art that various modifications and equivalent embodiments are possible in light of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: substrate
105: metal film
110: Photosensitive layer
115: dielectric layer
200: substrate
205: Photosensitive layer
210: metal film
215: dielectric layer

Claims (8)

A method of manufacturing a surface plasmonic color filter,
(a) forming a metal film on a substrate;
(b) forming a photosensitive layer on the metal film;
(c) irradiating a laser interference pattern on the photosensitive layer to form a nano hole array having a periodicity in the photosensitive layer;
(d) etching the metal film using the nano hole array of the photosensitive layer to form a nano hole array in the metal film; And
(e) removing the photosensitive layer having the nano hole array from the metal film on which the nano hole array is formed, and forming a dielectric layer on the metal film on which the nano hole array is formed. A method of manufacturing a surface plasmonic color filter,
(a) forming a photosensitive layer on a substrate;
(b) irradiating the photosensitive layer with a laser interferogram to form the photosensitive layer into a periodic nano dot array;
(c) forming a metal film on the substrate and the photosensitive layer of the nano dot array;
(d) removing the metal layer formed on the photosensitive layer of the nano dot array and the photosensitive layer of the nano dot array to form a metal film on which a nano hole array corresponding to the nano dot array is formed; And
(e) forming a dielectric layer on the metal film on which the nanohole array is formed. A method of manufacturing a surface plasmonic color filter,
(a) forming a metal film on a substrate;
(b) forming a photosensitive layer on the metal film;
(c) Irradiating a laser interference pattern a plurality of times while rotating the substrate on which the photosensitive layer and the metal film are formed through a mask on the photosensitive layer, and thus the arrangement direction of the nano holes in the photosensitive layer is different from each other. Forming branched nano hole arrays;
(d) forming unit nanohole arrays in the metal film by etching the metal film using unit nanohole arrays of the photosensitive layer; And
(e) removing the photosensitive layer having the unit nanohole arrays from the metal film on which the unit nanohole arrays are formed, and forming a dielectric layer on the metal film on which the unit nanohole arrays are formed. Way. The method of claim 3,
Wherein the nanoholes included in the unit nanohole array are periodically disposed on at least two directional axes and at least three of the nanoholes are disposed in each of the directional axes. A method of manufacturing a surface plasmonic color filter,
(a) forming a photosensitive layer on a substrate;
(b) irradiating the photosensitive layer with a laser interfering pattern repeatedly while rotating the substrate on which the photosensitive layer is formed through a mask so that the photosensitive layer is irradiated with a unit having nano dots arranged in different directions and having a periodicity Forming nano dot arrays;
(c) forming a metal film on the substrate and the photosensitive layer of the unit nano dot arrays;
(d) removing the metal layer formed on the photosensitive layer of the unit nano dot arrays and the photosensitive layer of the unit nano dot arrays to form a unit nanohole array corresponding to the unit nano dot arrays, forming a metal film on which nano hole arrays are formed; And
(e) forming a dielectric layer on the metal film on which the unit nanohole arrays are formed. 6. The method of claim 5,
Wherein the nanoholes included in the unit nanohole array are periodically disposed on at least two directional axes and at least three of the nanoholes are disposed in each of the directional axes. A method of manufacturing a surface plasmonic color filter,
(a) forming a metal film on a substrate;
(b) forming a photosensitive layer on the metal film;
(c) a first laser interference fringe, and a second laser interference fringe through a mask for forming a red sub-pixel, a mask for forming a green sub-pixel, and a mask for forming a blue sub-pixel in the photosensitive layer; A first nano hole array having a first nano hole period corresponding to a red sub-pixel, a green sub-pixel, and a blue sub-pixel on the photosensitive layer by irradiating a laser interference fringe and a third laser interference fringe, respectively. nano hole array), a second nano hole array having a second nano hole period, and a third nano hole array having a third nano hole period;
(d) etching the metal film using the first nanohole array, the second nanohole array and the third nanohole array of the photosensitive layer to form a first nanohole array and a second nanohole array And forming a third nano-hole array; And
(e) removing the photosensitive layer having the first nanohole array, the second nanohole array and the third nanohole array from the metal film on which the first nanohole array and the second nanohole array and the third nanohole array are formed And forming a dielectric layer on the metal film on which the first nanohole array, the second nanohole array, and the third nanohole array are formed. A method of manufacturing a surface plasmonic color filter,
(a) forming a photosensitive layer on a substrate;
(b) forming a first laser interferogram pattern on the photosensitive layer through a mask for forming a red sub-pixel, a mask for forming a green sub-pixel, and a mask for forming a blue sub-pixel, Laser interference fringe, and third laser interference fringe, respectively, so that the photosensitive layer is divided into a first nano dot array having a first nano dot period corresponding to the red sub-pixel, the green sub-pixel, and the blue sub- nano dot array, a second nano dot array having a second nano dot period, and a third nano dot array having a third nano dot period;
(c) forming a metal film on the substrate, the photosensitive layer of the first nano dot array, the second nano dot array, and the third nano dot array;
(d) a photosensitive layer of the first nano dot array, the second nano dot array and the third nano dot array, and a metal layer formed on the photosensitive layer of the first nano dot array and the second nano dot array and the third nano dot array, The metal film on which the first nano dot array and the second nano dot array and the third nano dot array corresponding to the first nano hole array and the second nano hole array and the third nano hole array are formed is removed, ; And
(e) forming a dielectric layer on the metal film on which the first nanohole array, the second nanohole array, and the third nanohole array are formed.

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