KR20100040649A - Photonic crystal type optical filter, reflective type color filter and display device using the same - Google Patents

Abstract

A photonic crystal optical filter, a reflective color filter and a display device using the same are disclosed. The disclosed reflective color filter includes a transparent substrate; A barrier layer formed on the transparent substrate and having a plurality of pixel regions; A first material having a relatively high refractive index and a second material having a relatively low refractive index are periodically arranged to reflect light in a wavelength band corresponding to the photonic band gap, and are formed in the plurality of pixel regions. And a plurality of photonic crystal units having a structure in which a light cutoff layer is formed on the material.

Description

Photonic crystal type optical filter, reflective type color filter and display device using the same}

The disclosed embodiments relate to a photonic crystal type optical filter, a reflective color filter implementing high color purity using the same, a display device, and a method of manufacturing the same.

As a method of manufacturing a color filter, a pigment dispersion method is mainly used in which a solution obtained by dispersing a pigment in a photoresist is applied onto a substrate and patterned to form pixels of each color. Since the pigment dispersion method uses a photolithography process, it is possible to realize a large area, to be thermally and chemically stable, and to secure color uniformity. However, such pigment type color filters are determined by the absorption spectrum inherent in the pigments in which their color characteristics are dispersed, and the light transmittance decreases as the thickness of the color filters becomes thicker, so that the color filter of high color purity is obtained. There is a problem in that the brightness is lowered when manufacturing.

Recently, photonic crystal type color filters based on structural colors have been studied. Photonic crystal color filters use nanostructures smaller than the wavelength of light to control the reflection or absorption of light incident from the outside, thereby reflecting (or transmitting) light of a desired color and transmitting (or reflecting) light of other colors. Let's do it. The photonic crystal color filter has a structure in which nano-sized unit blocks are periodically arranged at regular intervals. The photonic crystal color filter has an advantage of excellent wavelength selectivity and easy color bandwidth adjustment by fabricating a structure suitable for a specific wavelength because its optical properties are determined by the size and period of the nanostructure. And, due to such characteristics, the photonic crystal color filter may be more usefully applied to a reflective liquid crystal display device using external light having a very wide spectrum distribution.

Embodiments of the present invention provide a photonic crystal type optical filter, a reflective color filter that implements high color purity using the same, a display device, and a method of manufacturing the same.

Optical filter according to an embodiment of the present invention is a transparent substrate; A barrier layer formed on the transparent substrate; A first material having a relatively high refractive index and a second material having a relatively low refractive index, which are formed on the barrier layer to reflect light in a wavelength band corresponding to a photonic bandgap, and the first material being periodically arranged And a photonic crystal layer having a light cut-off layer formed thereon.

The first material is configured to form island shaped patterns.

The difference between the real part component of the refractive index of the first material and the second material may be two or more, and the imaginary part component of the refractive index of the first material and the second material may be 0.1 or less in the visible light wavelength band. .

An absorbing layer may be further formed below the transparent substrate.

The first material may form an island pattern, and the second material may form a supporting layer supporting an island pattern formed of the first material.

The barrier layer may be made of the same material as the second material.

Reflective color filter according to an embodiment of the present invention is a transparent substrate; A barrier layer formed on the transparent substrate and having a plurality of pixel regions; A first material having a relatively high refractive index and a second material having a relatively low refractive index, which are formed in the plurality of pixel regions and reflect light in a wavelength band corresponding to a photonic band gap, And a plurality of photonic crystal units having a structure in which a light cut-off layer is formed on the first material.

The plurality of photonic crystal units may include a plurality of red photonic crystal units for reflecting red light; A plurality of green photonic crystal units for reflecting green light; It includes; a plurality of blue photonic crystal unit for reflecting blue light.

The plurality of red photonic crystal units, green photonic crystal units, and blue photonic crystal units may be arranged in a stripe shape, a mosaic shape, or a delta shape.

The first material is configured to form island shaped patterns.

The difference between the real part component of the refractive index of the first material and the second material may be two or more, and the imaginary part component of the refractive index of the first material and the second material may be 0.1 or less in the visible light wavelength band. .

An absorbing layer may be further formed below the transparent substrate.

The first material may form an island pattern, and the second material may form a supporting layer supporting an island pattern formed of the first material.

The barrier layer may be made of the same material as the second material.

Reflective display device according to an embodiment of the present invention comprises a liquid crystal layer in which the transmittance of the incident light is electrically controlled; A reflection type color filter reflecting light having a wavelength band corresponding to a photonic band gap among the light incident through the liquid crystal layer, according to an embodiment of the present invention; An absorbing layer provided on a lower surface of the transparent substrate; And a TFT-array layer including a plurality of thin film transistors for driving the liquid crystal layer according to image information.

 Each of the plurality of thin film transistors may be provided adjacent to each of the plurality of photonic crystal units for each pixel area, and the plurality of the thin film transistors and the plurality of photonic crystal units may be provided on the same substrate.

Reflective color filter manufacturing method according to an embodiment of the present invention comprises the steps of forming a barrier layer on a transparent substrate; On the barrier layer, a first material having a high refractive index and a second material having a relatively low refractive index are periodically arranged, the first material forms island-shaped patterns, and an optical cutoff layer is formed on the first material. It includes; forming a photonic crystal layer of the structure.

The optical filter according to the embodiment of the present invention can easily determine the reflection wavelength band by the shape and period of the high refractive patterns, and excellent filtering performance.

The reflective color filter according to the embodiment of the present invention has excellent color characteristics, and unlike the photolithography process in which the same process is repeated three times in order to implement R, G, and B, R, G, B can be implemented to reduce the number of processes.

The reflective display device according to an embodiment of the present invention provides a display of excellent quality, and also can form a reflective color filter and a TFT array on the same substrate, so that manufacturing steps or process errors can be reduced and cost can be reduced. It is possible.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of description.

 1 is a perspective view showing a schematic structure of an optical filter according to an embodiment of the present invention, Figure 2 is a cross-sectional view of the optical filter of FIG. Referring to the drawings, the optical filter 100 includes a transparent substrate 130, a barrier layer 150 formed on the transparent substrate 130, and a photonic crystal layer 160 formed on the barrier layer 150. An absorbing layer 110 may be further provided below the transparent substrate 130.

The photonic crystal layer 160 is provided to reflect light in a wavelength band corresponding to the photonic bandgap by periodic refractive index distribution. The photonic crystal layer 160 has a structure in which a first material 162 having a relatively high refractive index and a second material 166 having a relatively low refractive index are periodically arranged, and an optical cutoff is formed on the first material 162. Layer 164 is formed.

The first material 162 forms island-shaped patterns. Although shown in the shape of a rectangular parallelepiped, a circle or polygonal pillar shape is possible and may have various other shapes. The first material 162 has a larger refractive index than the second material 166. For example, the difference between the real part component of the refractive index of the first material 162 and the refractive index of the second material 166 is two or more. Can be. In addition, the imaginary component of the refractive index of the first material 162 and the refractive index of the second material 166 may be 0.1 or less in the visible light wavelength band. It is intended to use materials with small minor component values. As the first material 162, any one of single crystal silicon, poly silicon, AlSb, AlAs, AlGaAs, AlGaInP, BP, and ZnGeP ₂ may be employed, and as the second material 166, Air, PC, PS , PMMA, Si ₃ N ₄ , SiO ₂ may be employed.

The second material 166 may form a supporting layer for supporting an island-shaped pattern made of the first material 162. As shown in the drawing, the second material 166 may include a region between the patterns formed by the first material 162. It may be formed to cover the upper portion of the first material 162 as a whole. Such a structure may be selected, for example, to form a pattern using the first material 162 as amorphous silicon, and then to protect the pattern shape without damaging the pattern shape in the step of crystallizing with single crystal silicon or polysilicon. .

The light cutoff layer 164 serves to improve cut-off characteristics of the optical filter 100. The light cutoff layer 164 may be formed of a silicon oxide film (SiO 2) or a silicon nitride film (Si 3 N 4).

The transparent substrate 130 is provided to serve as a waveguide. Only the light having a specific wavelength is reflected by the crystal structure of the photonic crystal layer 160, and the remaining light is transmitted and trapped in the transparent substrate 130. A glass substrate may be used as the transparent substrate 130.

The barrier layer 150 is provided between the transparent substrate 130 and the photonic crystal layer 160. The barrier layer 150 may include, for example, impurities in the glass substrate used as the transparent substrate 130 during the crystallization process, and are incorporated into the silicon material used as the first material 162 of the photonic crystal layer 160. It is for preventing the fall of purity. The barrier layer 150 may be formed of a material having a refractive index similar to that of the transparent substrate 130. As the material of the barrier layer 150, the same material as the material selected as the second material 166 constituting the supporting layer may be used.

An absorbing layer 110 may be further provided below the transparent substrate 130. The absorbing layer 110 may improve reflectance characteristics of the optical filter 100 by absorbing light trapped in the transparent substrate 130.

The optical filter 100 having the structure described above reflects light of a specific wavelength band by a photonic cystal structure that forms a periodic refractive index distribution. At this time, since the band band and width are determined by the shape and period of the patterns formed by the first material 162, it is easy to select them appropriately and the filtering performance is excellent and thus may be applied to various technical fields. For example, it can be applied to solar cells, QD-LEDs, OLEDs, and can also be applied to color filters of display devices, as described below.

3 is a cross-sectional view showing a schematic structure of a reflective color filter according to an embodiment of the present invention. Referring to the drawings, the reflective color filter 200 includes a plurality of photonic crystals that reflect light of a predetermined wavelength band formed on the transparent substrate 230, the barrier layer 250 formed on the transparent substrate 230, and the barrier layer 250. Units 270, 280, and 290.

The region on the barrier layer 250 includes a plurality of pixel regions PA1, PA2, and PA3. For example, a red photonic crystal that reflects the red light L _R of the incident light L in the pixel region PA1. unit 270, a pixel area (PA2), the green light (L _G) to which a green optical crystal unit 280 for reflecting the reflection of the pixel region (PA3), the blue light (L _B), the blue optical crystal unit 290 is provided do. The red photonic crystal unit 270, the green photonic crystal unit 280, and the blue photonic crystal unit 290 each have a first material 272, 282, 292 having a relatively high refractive index, and a second material having a relatively low refractive index. (276) (286) and (296) are arranged periodically, and a light cutoff layer (274) (284) (294) is formed on the first materials (272) (282) (292). The first materials 272, 282 and 292 form island shaped patterns.

In the red photonic crystal unit 270, the green photonic crystal unit 280, and the blue photonic crystal unit 290, the first materials 272, 282, 292, the second materials 276, 286, 296, and an optical cutoff layer The materials of (274) (284) and (294) may be selected from various materials employed in the first material 162, the second material 166, and the optical cutoff layer 164 of the optical filter 100 of FIG. have. In addition, different photonic materials may be selected from different photonic crystal units or the same material, and photonic patterns in which the pattern shape and the period formed by the first materials 272, 282, and 292 correspond to red, green, and blue, respectively. Differently defined to have a band gap. For example, the pattern size formed by the first material 272 of the red photonic crystal unit 270 may be a pattern formed by the first material 282 of the green photonic crystal unit 280 or the first pattern of the blue photonic crystal unit 290. The size and period are larger than the pattern formed by the material 292. In addition, the pattern formed by the first material 282 of the green photonic crystal unit 280 is larger than the pattern formed by the first material 292 of the blue photonic crystal unit 290.

An absorbing layer 210 may be further provided below the transparent substrate 230. The absorbing layer 210 absorbs light trapped in the transparent substrate 230. That is, since light of color not reflected by each of the red photonic crystal unit 270, the green photonic crystal unit 280, and the blue photonic crystal unit 290 is trapped in the transparent substrate 230 and absorbed by the absorbing layer 210, the color filter ( 200) color purity is increased.

Although only three photonic crystal units 270, 280, and 290 forming the basic pixel are illustrated in the drawing, the reflective color filter 200 has a structure in which a plurality of photonic crystal units 270, 280, and 290 forming the basic pixel are repeatedly arranged.

4A to 4C illustrate various embodiments of the arrangement of the plurality of photonic crystal units 270, 280, and 290 of the reflective color filter 200 of FIG. 3. 4A illustrates a plurality of red photonic crystal units 270 arranged in a line, and a plurality of green photonic crystal units 280 and a plurality of blue photonic crystal units 290 are arranged in a line, respectively. 4B shows a mosaic arrangement in which a plurality of red photonic crystal units 270, a green photonic crystal unit 280, and a blue photonic crystal unit 290 are arranged such that photonic crystal units of different colors are adjacent to each other. 4C illustrates a plurality of red, green, and blue photonic crystal units 270 such that the centers of the red photonic crystal unit 270, the green photonic crystal unit 280, and the blue photonic crystal unit 290 are connected to each other in a delta (Δ) form. 280, 290 shows a delta-like arrangement. Although not shown in detail in the drawings, the size and the period of the pattern formed by the red photonic crystal unit 270, the green photonic crystal unit 280, and the blue photonic crystal unit 290 may correspond to photonic band gaps corresponding to red, green, and blue, respectively. It is set differently to have. For example, the size and period of the red photonic crystal unit 270 pattern is the largest, and the size and period of the blue photonic crystal unit 290 pattern is the smallest.

5 is a cross-sectional view illustrating a schematic structure of a display device according to an embodiment of the present invention. Referring to the drawing, the display apparatus 300 reflects light of a wavelength band corresponding to a photonic bandgap among light incident through the liquid crystal layer 330 and the liquid crystal layer 330 whose transmittance with respect to incident light is electrically controlled. And a TFT-array layer 310 including a plurality of thin film transistors 312 for driving the reflective color filter 200 and the liquid crystal layer 330 according to image information.

Since the reflective color filter 200 has substantially the same structure as the reflective color filter 200 described with reference to FIG. 3, a detailed description thereof will be omitted.

The TFT-array layer 310 includes a plurality of thin film transistors 312 and a plurality of pixel electrodes 314. In the present exemplary embodiment, the plurality of thin film transistors 312 driving the liquid crystal layer 330 in correspondence with individual pixels may include a plurality of photonic crystal units 270, 280, and 290 for each pixel area PA1, PA2, and PA3. ) Is provided adjacent to. That is, the thin film transistor 312 and the photonic crystal units 270, 280, and 290 are formed on the same substrate.

The liquid crystal layer 330 changes transmittance for incident light according to electrical control, and is provided between the two transparent substrates 230 and 360. Alignment layers 340 and 320 are provided on the upper and lower portions of the liquid crystal layer 330, respectively. As the liquid crystal layer 330, various kinds of liquid crystals well known to those skilled in the art may be employed. For example, a twisted nematic (TN) liquid crystal, a mixed-mode TN (MTN) liquid crystal, a polymer dispersed liquid crystal (PDLC), a Heilmeier-Zanoni (HZ) liquid crystal, a Cole-Kashnow (CK) liquid crystal, or the like may be employed.

The transparent electrode 350 is provided on one surface of the upper transparent substrate 360 facing the liquid crystal layer 330, and the polarizer 370 is provided on the other surface thereof. Depending on the specific type and driving mode of the liquid crystal layer 330, the polarizing plate 370 may not be necessary, or a polarizing plate or a quarter-wave plate having a polarization axis perpendicular to the polarization axis of the polarizing plate 370 may be further provided.

The display apparatus 300 according to the embodiment of the present invention has a structure in which the photonic crystal units 270, 280, 290 and the thin film transistor 312 of the reflective color filter 200 are formed on the same substrate, and thus the reflective color filter 200 and the TFT are formed. The array layer 310 may be manufactured in the same process step. Such a structure has various manufacturing advantages when compared to that in which a color filter is provided on an upper substrate and a TFT array is provided on a lower substrate in a general liquid crystal display device. For example, when a color filter and a TFT array are separately manufactured and bonded, the color filters and the TFT arrays must be lined up and bonded together in pixel units, and an alignment error may occur in this process. This error can be reduced because a TFT array is provided.

Although the thin film transistor 312 and the photonic crystal units 270, 280, and 290 are illustrated and described on the same substrate in the present exemplary embodiment, the present invention is not limited thereto. Unlike the illustrated example, the reflective color filter 200 and the TFT-array layer 310 may be formed as separate layers.

6A to 6K are views for explaining a method of manufacturing a reflective color filter according to an embodiment of the present invention.

Reflective color filter manufacturing method according to an embodiment of the present invention comprises the steps of forming a barrier layer on a transparent substrate; On the barrier layer, a first material having a high refractive index and a second material having a relatively low refractive index are periodically arranged, the first material forms island-shaped patterns, and an optical cutoff layer is formed on the first material. Forming a photonic crystal layer of structure; And forming an absorbing layer under the transparent substrate.

Looking at the above process in more detail as follows.

First, referring to FIG. 6A, the barrier layer 450 and the silicon layer 462 corresponding to the first material are sequentially formed on the transparent substrate 430.

For example, a glass substrate may be used as the transparent substrate 430.

The silicon layer 462 is selected in that the silicon material has a large real part refractive index and a small imaginary part refractive index. This property is provided in particular in the case of monocrystalline silicon or polysilicon. The silicon layer 462 may be formed of amorphous silicon. In this case, as will be described later, the silicon layer 462 is subjected to a recrystallization step.

The barrier layer 450 is proposed because it is difficult to form a single crystal silicon thin film directly on the glass substrate. That is, impurities in the glass substrate employed as the transparent substrate 430 may be incorporated into the silicon layer 462 in the crystallization step to be described later to reduce crystal purity. The barrier layer 450 prevents such a phenomenon. . The barrier layer 450 may also serve as an etch stop during etching of the silicon layer 462 to reduce process errors such as under-trenching. The barrier layer 450 may be formed of a material such as PC, PS, PMMA, Si ₃ N ₄ , and SiO _2, and a material having a small difference in refractive index from the transparent substrate 430 may be employed.

Next, as shown in FIG. 6B, a hard mask layer 464 is formed on the silicon layer 462. The hard mask layer 464 serves as a hard mask for etching when the silicon layer 462 is patterned, and is provided to secure an etching selectivity. As the material of the hard mask layer 464, a silicon oxide film (SiO 2) or a silicon nitride film (Si 3 N 4) may be employed. A part of the hard mask layer 464 remains even after the silicon layer 462 is patterned. The silicon oxide film (SiO 2) or the silicon nitride film (Si 3 N 4) has a lower refractive index than that of the silicon material to reduce the cut-off characteristics of the reflective color filter. To improve.

Next, to form a resist pattern, a resin layer 465 ′ is formed on the hard mask layer 464 as shown in FIG. 6C. As the material of the resin layer 465 ′, for example, an ultraviolet curable resin may be employed.

Next, the mold M is prepared as shown in FIG. 6D. The mold M is provided for the nanoimprint process, and the specific shape is made to correspond to island-shaped patterns to be formed by the silicon layer 462. For example, it may have any one of the pixel arrays described with reference to FIGS. 4A to 4C, and have different patterns and periods corresponding to each color.

Next, as shown in FIG. 6E, the mold M is placed on the resin layer 465 ′ and irradiated with ultraviolet rays. After the mold M is separated as shown in FIG. 6F, a resist pattern 465 is formed.

Next, as shown in FIG. 6G, the hard mask layer 464 is etched using the resist pattern 465 as a mask to expose the silicon layer 462.

Next, as shown in FIG. 6H, the silicon layer 462 is etched to expose the barrier layer 450 using the resist pattern 465 and the hard mask layer 464 as a mask. As illustrated, the silicon layer 462 forms island-shaped patterns.

The patterning of the silicon layer 462 is performed by the nanoimprint process as described above, and in this case, the pixel array shape may be selected without restriction as compared with the case of using the photolithography process. For example, the delta type array has the best color mixing characteristics and the simple driving circuit among the various pixel arrays illustrated in FIGS. 4A to 4C, but it is known that it is difficult to apply it using a photolithography process. In the case of using the nanoimprint process, there are almost no process differences depending on the shape of the pixel array, and thus it is easy to apply the delta array.

Next, as illustrated in FIG. 6I, a supporting layer 466 may be further formed to fill the island-shaped patterns. As shown, the supporting layer 466 may be formed to cover the island-shaped patterns and the silicon layer 462 as a whole.

Next, as shown in FIG. 6J, the silicon layer 462 is recrystallized. The excimer laser EL is irradiated onto the silicon layer 462 for crystallization. In this excimer laser annealing process, the silicon layer 462 may be melted to cause a shape change. The supporting layer 466 serves to reduce the shape change by protecting the silicon layer 462.

FIG. 6K illustrates a case in which the scanning direction is a flat leading end method when the excimer laser is irradiated, and FIG. 6L illustrates the pattern in which the silicon layer 462 is formed. The angle of 45˚ to the arrangement direction (tapered leading end method) is shown. In the drawings, the arrow direction indicates the scan direction. As shown in FIGS. 6K and 6L, the crystallization of the silicon layer 462 made of amorphous silicon occurs due to the excimer laser irradiation, which is changed into the crystalline silicon layer 463. In the tapered leading end method of FIG. The nucleation of can be facilitated and crystallization may be easier.

Through the above-described processes, the reflective color filter 400 of FIG. 6M is manufactured.

Although the step of forming the absorbing layer below the transparent substrate 430 is omitted in the above description, the method may further include providing an absorbing layer on the lower surface of the transparent substrate 430, for example, the absorbing layer in the step of FIG. 6A. It is possible to perform the processes described for the transparent substrate 430 formed on the lower surface.

Such an optical filter, a reflective color filter, a display device, and a manufacturing method thereof according to the present invention have been described with reference to the embodiments shown in the drawings for clarity, but this is merely an example, and those skilled in the art It will be appreciated that various modifications and other equivalent embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

1 is a perspective view showing a schematic structure of an optical filter according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the optical filter of FIG. 1.

3 is a cross-sectional view showing a schematic structure of a reflective color filter according to an embodiment of the present invention.

4A to 4C show various embodiments of an arrangement structure of a plurality of photonic crystal units of the reflective color filter of FIG. 3.

5 is a cross-sectional view illustrating a schematic structure of a display device according to an embodiment of the present invention.

6A to 6M are views for explaining a method of manufacturing a reflective color filter according to an embodiment of the present invention.

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

100 ... optical filter 110,210 ... absorption layer

130,230,360,460 ... transparent board 150,250,450 ... barrier layer

160,270,280,290 ... Photonic crystal unit 162,272,282,292 ... First material

   164,274,284,294,464 ... light cutoff layer 166,276,286,296 ... second material

   200 ... reflective color filter 300 ... display unit

  310 ... TFT-array layer 312 ... thin film transistor

   Pixel electrodes 320, 340

   330 ... liquid crystal layer 350 ... transparent electrode

   370 ... Polarizing plate 462 ... Silicone layer

   463 ... crystalline silicon layer 465 '... resin layer

   465 ... resist pattern 466 ... supporting layer

Claims (29)

Transparent substrates; A barrier layer formed on the transparent substrate; A first material having a relatively high refractive index and a second material having a relatively low refractive index, which are formed on the barrier layer to reflect light in a wavelength band corresponding to a photonic bandgap, and the first material being periodically arranged And a photonic crystal layer having a structure in which an optical cutoff layer is formed thereon. The method of claim 1, And the first material forms island-shaped patterns. The method of claim 1, And a difference between the real part component of the refractive index of the first material and the second material is 2 or more. The method of claim 1, The imaginary component of the refractive index of the first material and the second material is 0.1 or less in the visible light wavelength band. The method of claim 1, The first material is any one of single crystal Si, Poly Si, AlSb, AlAs, AlGaAs, AlGaInP, BP, ZnGeP ₂ . The method of claim 1, The second material is any one of air, PC, PS, PMMA, Si ₃ N ₄ , SiO ₂ . The method of claim 1, The optical cutoff layer is formed of a silicon oxide film (SiO 2) or a silicon nitride film (Si 3 N 4). The method according to any one of claims 1 to 7, An optical filter having an absorption layer formed on the lower portion of the transparent substrate. The method according to any one of claims 1 to 7, The first material forms an island-shaped pattern, The second material is an optical filter forming a supporting layer for supporting an island-shaped pattern made of the first material. 10. The method of claim 9, The barrier layer is made of the same material as the second material. Transparent substrates; A barrier layer formed on the transparent substrate and having a plurality of pixel regions; A first material having a relatively high refractive index and a second material having a relatively low refractive index, which are formed in the plurality of pixel regions and reflect light in a wavelength band corresponding to a photonic bandgap, And a plurality of photonic crystal units having a structure in which a light cutoff layer is formed on the first material. The method of claim 11, The plurality of photonic crystal units, A plurality of red photonic crystal units for reflecting red light; A plurality of green photonic crystal units for reflecting green light; And a plurality of blue photonic crystal units for reflecting blue light. The method of claim 12, And the plurality of red photonic crystal units, the green photonic crystal units, and the blue photonic crystal units are arranged in a stripe shape, a mosaic shape, or a delta shape. The method of claim 11, A reflective color filter in which the first material forms island shaped patterns. The method of claim 11, A reflection type color filter, wherein a difference between a real part component of a refractive index of the first material and the second material is two or more. The method of claim 11, The imaginary component of the refractive index of the first material and the second material is 0.1 or less in the visible light wavelength band. The method of claim 11, The first material is any one of single crystal Si, Poly Si, AlSb, AlAs, AlGaAs, AlGaInP, BP, ZnGeP ₂ . The method of claim 11, The second material is a reflective color filter made of any one of air, PC, PS, PMMA, Si ₃ N ₄ , SiO ₂ . The method of claim 11, The optical cutoff layer is a reflective color filter consisting of a silicon oxide film (SiO 2) or a silicon nitride film (Si 3 N 4). The method according to any one of claims 11 to 19, A reflective color filter having an absorption layer formed on the lower portion of the transparent substrate. The method according to any one of claims 11 to 19, The first material forms island-shaped patterns, The second material is a reflective color filter forming a supporting layer for supporting the island-shaped patterns of the first material. The method of claim 21, The barrier layer is a reflective color filter made of the same material as the second material. A liquid crystal layer in which transmittance with respect to incident light is electrically controlled; The reflective color filter of claim 21, which reflects light of a wavelength band corresponding to a photonic band gap among the light incident through the liquid crystal layer; An absorbing layer provided on a lower surface of the transparent substrate; And a TFT-array layer including a plurality of thin film transistors for driving the liquid crystal layer in accordance with image information. The method of claim 23, wherein Each of the plurality of thin film transistors is provided adjacent to each of the plurality of photonic crystal units for each pixel region, And the plurality of thin film transistors and the plurality of photonic crystal units are provided on the same substrate. Forming a barrier layer on the transparent substrate; On the barrier layer, a first material having a high refractive index and a second material having a relatively low refractive index are periodically arranged, the first material forms island-shaped patterns, and an optical cutoff layer is formed on the first material. Forming a photonic crystal layer of the structure; reflective color filter manufacturing method comprising a. The method of claim 25, Forming the photonic crystal layer, Sequentially forming a silicon layer corresponding to the first material and a hard mask layer to be the light cutoff layer on the barrier layer; Forming a resist pattern on the hard mask layer corresponding to the island-shaped patterns by an imprint process; Etching the hard mask layer using the resist pattern as a mask; Etching the silicon layer using the resist pattern and the hard mask layer as a mask to expose the barrier layer; Crystallization of the silicon layer; reflective color filter manufacturing method comprising a. The method of claim 26, Before the recrystallization step, And forming a supporting layer filling the island-shaped patterns. The method of claim 26 or 27, The crystallization step, A method of manufacturing a reflective color filter carried out by an excimer laser annealing process. The method of claim 28, The scanning direction during excimer laser irradiation is a direction of forming an angle of 45 degrees with the array direction of the island-shaped pattern of the reflective color filter manufacturing method.

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