KR100600931B1 - Structure of a color filter - Google Patents

Abstract

The present invention relates to a color filter structure, wherein an indium tin oxide layer is formed on a glass substrate, and then a silicon nitride layer, an amorphous silicon layer, an n-type silicon layer, and a metal layer are sequentially formed on the indium tin oxide layer to function as a color filter. In the color filter structure, the thickness of the layers and the conditions of the process can be adjusted so as to provide various color filters such as black matrix, reflective red color filter, reflective green color filter, and reflective blue color filter. And to provide an inexpensive color filter structure.

Description

Color filter structure {STRUCTURE OF A COLOR FILTER}

1 is a schematic diagram of a conventional liquid crystal display panel structure.

2 is a cross-sectional view according to a preferred embodiment of the present invention.

3 is a spectrum of reflectance according to an embodiment of the present invention.

4 is a cross-sectional view according to another embodiment of the present invention.

5 is a schematic diagram of a reflective liquid crystal display panel structure, and

6 is a cross-sectional view according to another preferred embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

110: light source 102, 106: thin film transistor

104: substrate 108 liquid crystal

120b: color filter 202: glass substrate

204: indium tin oxide layer 206: silicon layer

208: amorphous silicon layer 210: n-type silicon layer

212: metal layer

FIELD OF THE INVENTION The present invention relates to devices for LCDs, and in particular to color filter structures.
Liquid crystals are substances that have intermediate properties between crystals and liquids. The alignment of the liquid crystal molecules changes depending on external stimuli such as an electric field generated by an applied voltage. Therefore, these liquid crystal molecules are useful for making display units.
Color thin film transistor liquid crystal displays (TFT-LCDs) are currently produced by a technology of manufacturing thin film transistor array substrates and color filter substrates, and then combining them together. The color filter substrate includes three colors of red, green, and blue filters and a black matrix. The black matrix shields a thin film transistor, wiring on indium tin oxide (ITO), and a part of the display area near the electrode. The part near the electrode generally experiences light leakage problems due to non-uniform distributions of electric or in-plane electric fields. In addition, since the main function of the black matrix is to increase the contrast of the display and prevent light from damaging the thin film transistor, the black matrix must have optical properties of low reflectance and high optical density.
1 is a schematic diagram of a conventional liquid crystal display panel structure. The thin film transistor 106 is positioned on the thin film transistor substrate 102, and the thin film transistor 106 is responsible for the change of voltage to control the alignment of the liquid crystal 108. The black matrix 118 is under the thin film transistor 106, and the black matrix 118 is usually made of the metal 112 and the oxide 114. Today chromium and chromium oxide are commonly used to make the black matrix 118. The color filter 120a is between the black matrices 118 and filters the light from the light source 110 to red, green, and blue light in other areas. In addition, the black matrix 118 and the color filter 120a are both located on the substrate 104.
In general, black matrices of conventional metal / oxide structures experience problems of excessive reflection of external light and insufficient light shading. The thin film transistor is very sensitive to light and easily generates a photocurrent by weak light affecting its operation. In addition, more light may damage the thin film transistor. Insufficient shading does not provide sufficient shading for the thin film transistor, and makes the basic color of the display panel appear only dark blue, not black, which can visually improve contrast. Excessive reflection of external light degrades the visibility of the liquid crystal display and causes inconvenience in its use.

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It is therefore an object of the present invention to provide a color filter structure which satisfies the problems of conventional black matrices, namely the so-called poor shading and excessive reflection.

It is another object of the present invention to provide a structure of a reflective color filter having excellent quality and simple structure.

The color filter structure according to the above and other objects of the present invention will be described. The color filter is formed of a substrate, an indium tin oxide layer, a silicon nitride layer, an amorphous silicon layer, an n-type silicon layer, and a metal layer.

In one embodiment of the present invention, the thicknesses of the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer, and the metal layer of the black matrix are about 420 kPa, 500 kPa, 500 kPa, 500 kPa, and 780 kPa, respectively. The high frequency power of the chemical vapor deposition process for growing the silicon nitride layer is 1.6 KW, and the material of the metal layer is chromium.

The thicknesses of the metal layers of the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, the n-type silicon layer, and the reflective blue color filter are about 420 GPa, 500 GPa, 500 GPa, 500 GPa, and 780 GPa, respectively. The high frequency power of the chemical vapor deposition process for growing the silicon nitride layer is 2.1 KW, and the material of the metal layer is chromium.

The thicknesses of the metal layers of the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, the n-type silicon layer, and the reflective green color filter are about 168 kPa, 300 kPa, 500 kPa, 500 kPa, and 780 kPa, respectively. The high frequency power of the chemical vapor deposition process for growing the silicon nitride layer is 1.6 KW, and the material of the metal layer is chromium.

The thicknesses of the metal layers of the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, the n-type silicon layer, and the reflective red color filter are about 420 GPa, 400 GPa, 400 GPa, 400 GPa, and 780 GPa, respectively. The high frequency power of the chemical vapor deposition process for growing the silicon nitride layer is 2.1 kW, and the material of the metal layer is chromium.

The thicknesses of the metal layers of the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, the n-type silicon layer, and the reflective red color filter are about 168 kPa, 400 kPa, 400 kPa, 400 kPa, and 780 kPa, respectively. The high frequency power of the chemical vapor deposition process for growing the silicon nitride layer is 1.6 KW, and the material of the metal layer is chromium.

According to another embodiment of the present invention, a high brightness reflective color filter structure is described. The color filter is made of a substrate, a silicon nitride layer, an amorphous silicon layer, and an n-type silicon layer.

In one embodiment of the present invention, the thicknesses of the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer, and the metal layers of the high brightness red color filter are about 500 mW, 400 mW, 400 mW, and 780 mW, respectively. The high frequency power of the chemical vapor deposition process for growing the silicon nitride layer is 1.6 KW, and the material of the metal layer is chromium.

The thicknesses of the metal layers of the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, the n-type silicon layer, and the high luminance green color filter are about 500 mW, 500 mW, 500 mW, and 780 mW, respectively. The high frequency power of the chemical vapor deposition process for growing the silicon nitride layer is 1.6 KW, and the material of the metal layer is chromium.

The black matrix structure of the present invention provides good shading and low reflectance. The reflectance is less than 5% in the long wave region (650 nm to 790 nm), thereby improving the problem of the conventional black matrix having excellent reflectivity and poor shading in the long wave region.

The silicon nitride layer, amorphous silicon layer, and n-type silicon layer of the present invention are all grown by a chemical vapor deposition process, but a conventional black matrix made of metal / oxide is made by a physical vapor deposition process. If optical interference occurs in a thin film, the uniformity and thickness of the thin film will be very important. When forming thin films on patterned surfaces, chemical vapor deposition is better than physical vapor deposition to control the uniformity and thickness of thin films. Therefore, the present invention provides better quality thin film and light interference effect than the prior art.

The foregoing general description and the following detailed description are exemplary only, and further description of the invention is set forth in the claims.

These and other features, aspects, and advantages of the present invention will be better understood from the following detailed description, claims, and accompanying drawings.

Preferred embodiments of the present invention will be described in detail. Like reference numerals are used to refer to the same or similar parts in the drawings and the detailed description wherever possible with reference to those shown in the accompanying drawings.

The present invention first forms an indium tin oxide layer on a glass substrate, and then a silicon nitride layer, an amorphous silicon layer, an n-type silicon layer, and a metal layer are sequentially formed on the indium tin oxide layer. When external light is illuminated from the glass substrate with the color filter of the present invention, the amorphous silicon layer and the n-type silicon layer first absorb the light, and then the metal layer blocks and reflects the light. The incident light and the reflected light cause destructive interference between the indium tin oxide layer and the silicon nitride layer. In addition, since the incident light is reflected by the metal layer, the amorphous silicon layer and the n-type silicon layer absorb the light again.

2 is a cross-sectional view of a preferred embodiment of the present invention. The indium tin oxide layer 204 is first grown on the glass substrate 202 by a physical vapor deposition (PVD) process. A chemical vapor deposition process is then performed in order to grow the silicon nitride layer 206, the amorphous silicon layer 208, and the n-type silicon layer 210. Finally, metal layer 212 is formed by a physical vapor deposition process to complete the structure of the color filter.

In a preferred embodiment of the black matrix of the present invention, the indium tin oxide layer 204, the silicon nitride layer 206, the amorphous silicon layer 208, the n-type silicon layer 210 and the metal layer 212, respectively, 420 Hz, 500 Hz, 500 Hz, 500 Hz, and 780 Hz. The high-frequency power of the chemical vapor deposition process for growing the silicon nitride layer 206 is 1.6 KW, the material of the metal layer is chromium (Cr), and phosphorus (P) is doped into the n-type silicon layer 210. As a result, a black matrix structure having good light shielding and low reflectance is completed.

3 is a spectrum of reflectivity of one preferred embodiment of the present invention, wherein the range of measured wavelengths is from about 390 nm to 780 nm. The spectral line 310 represents the reflectance of the conventional black matrix made of chromium / chromium oxide, and the other spectral line 320 represents the reflectance of the black matrix of the present invention. As shown in FIG. 3, the reflectance of the black matrix of the present invention is about 2% between about 390 nm and 650 nm, which is lower than about 4% of the conventional black matrix. In the red and infrared region between 650 nm and 790 nm, the reflectance of the conventional black matrix increases by about 25% depending on the wavelength, but the reflectance of the black matrix of the present invention is still less than about 5%, the black matrix of the present invention As a result, it is possible to maintain low reflectance in the long wavelength region and to reduce the occurrence of light reflection.

In addition to the black matrix, the present invention also provides a variety of colors and variations by adjusting the conditions of the process, such as varying the thickness of the layers and the high frequency power of the chemical vapor deposition process for growing the silicon nitride layer 206. Provides various color filters of luminance. The following description describes the reflective color filter of the present invention and provides various embodiments having various colors and various luminance.

The thickness and process conditions of the embodiment of the red, green and blue reflective color filter are shown in Table 1. Table 1 provides two sets of thicknesses and process conditions for the red color filter, and shows that the present invention can obtain color filters of the same color having various sets of thicknesses and process conditions. The thickness of the indium tin oxide layer 204, the silicon nitride layer 206, the amorphous silicon layer 208, the n-type silicon layer 210, and the metal layer 212 and the silicon nitride layer 206 for growing the The high frequency powers of the chemical vapor deposition process are all shown in Table 1. In addition, the raw material of the metal layer of Table 1 is chromium, and phosphorus is added to the n-type silicon layer 210. FIG.

Process Parameters of Reflective Color Filters of Different Colors thickness enemy enemy rust blue Indium tin oxide layer (204) 168 420 168 420 Silicon Nitride Layer (206) 400 400 300 500 Amorphous silicon layer (208) 400 400 500 500 n-type silicon layer 210Å 400 400 500 500 Metal layer (212) 780 780 780 780 High frequency power (KW) for growing the silicon nitride layer 206 1.6 2.1 1.6 2.1

According to another embodiment of the present invention, the structure of the reflective color filter is changed, and the indium tin oxide layer 204 is not grown in order to obtain a high brightness reflective color filter. As shown in FIG. 4, the structure of FIG. 4 is devoid of indium tin oxide layer 204, while the remainder is identical to FIG. 2. Table 2 shows the thicknesses of the silicon nitride layer 206, the amorphous silicon layer 208, the n-type silicon layer 210, and the metal layer 212 and the high frequency of the chemical vapor deposition process for growing the silicon nitride layer 206. It includes power and describes the process parameters of high-brightness reflective red and green color filters. In addition, the metal of the metal layer 212 of Table 2 is chromium, and phosphorus is added to the n-type silicon layer 210. As shown in FIG.

Process Parameters for High Brightness Reflective Red and Green Color Filters thickness enemy rust Silicon Nitride Layer (206) 500 500 Amorphous silicon layer (208) 400 500 n-type silicon layer 210Å 400 500 Metal layer (212) 780 780 High frequency power (KW) for growing the silicon nitride layer 206 1.6 1.6
The present invention can also grow the layer in reverse. The metal layer is first formed on the substrate, and an n-type silicon layer, an amorphous silicon layer, a silicon nitride layer, and an indium tin oxide layer are sequentially grown on the metal layer. When external light is dimmed from the indium tin oxide layer to the color filter of the present invention, the amorphous silicon layer and the n-type silicon layer first absorb light of a specific wavelength, and the metal layer reflects the light.

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In the indium tin oxide layer and the silicon nitride layer, the incident light and the reflected light cause interference at a certain wavelength, thereby removing a specific wavelength. In addition, since the incident light is reflected by the metal layer, the amorphous silicon layer and the n-type silicon layer absorb the light again, but do not absorb light of a specific wavelength. Therefore, the color filter of the present invention filters out unnecessary light and reflects only light of a specific wavelength. The following description uses another embodiment of the present invention to explain the reverse growth sequence and color filters employing the same.

5 is a schematic view of a reflective liquid crystal display panel structure. The thin film transistor 106 is positioned on the thin film transistor substrate 102, and the thin film transistor 106 adjusts a voltage to control the alignment of the liquid crystal 108. The black matrix 118 is positioned below the thin film transistor 106 and is formed on the substrate 104. The color filters 120b are positioned on the thin film transistor substrate 102. Light from the light source 110 passes through the substrate 104 to reach the color filters 120b. The color filters 120b filter and reflect light into red, green, and blue light of other regions, and emit the light through the substrate 104.

6 is a cross-sectional view of an embodiment used in the reflective liquid crystal display of the present invention. The metal layer 212 is first formed on the substrate 402 by a physical vapor deposition (PVD) process. Then, a chemical vapor deposition process is performed in order to grow the n-type silicon layer 210, the amorphous silicon layer 208, and the silicon nitride layer 206. Finally, indium tin oxide layer 204 is grown by a physical vapor deposition process to complete the reflective color filter structure.

By adjusting the thickness of the layers and the process conditions thereof, color filters of various colors and luminances can be provided. Many different process parameters are possible for color filters of the same color, and the invention is not limited to a single specific set. Indium tin oxide layer 204 may also be excluded to produce a high brightness reflective color filter.

In conclusion, the present invention has the following advantages.

1. The black matrix of the present invention provides good shading and low reflectance, the reflectance of which is less than 5% in the long wavelength region (650 nm to 790 nm), and thus has a problem with the conventional black matrix having high reflectance and poor shading in the long wavelength region. To improve.

2. The silicon nitride layer, amorphous silicon layer, and n-type silicon layer of the present invention are all grown by a chemical vapor deposition process, but a conventional black matrix made of metal / oxide is formed by a physical vapor deposition process. If light interference occurs in a thin film, it affects the uniformity and thickness of the thin films. Chemical vapor deposition is better than physical vapor deposition to form a thin film on a patterned surface. Therefore, the present invention provides better film quality and optical interference effect than the prior art.

3. The materials used in the present invention, such as the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer, are all present in reality and can be easily prepared in the LCD manufacturing process. In addition, these layers can be formed continuously in one chemical vapor deposition chamber and require no additional process or time. In addition, since the black matrix, red, green, and blue color filters can be obtained simply by adjusting the thickness and process conditions of the respective layers, the present invention provides a simple and inexpensive color filter structure.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope and spirit of the invention. In the above description, the present invention can be changed and modified within the scope of the following claims of the present invention.

Claims (4)

In the color filter structure used for the liquid crystal display, Board, An indium tin oxide layer formed on the substrate, A silicon nitride layer formed on the indium tin oxide layer, wherein a silicon nitride layer having a predetermined high frequency (RF) power value is used to grow the silicon nitride layer; An amorphous silicon layer located on the silicon nitride layer, An n-type silicon layer located on the amorphous silicon layer, and A metal layer located on the n-type silicon layer, Light is dimmed from the substrate to the color filter, and the light sequentially passes through the substrate, the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer, and then is reflected by the metal layer to provide a color filter. Will pass along the original route, The light is absorbed by the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer and subjected to the interference effect, And the light is dimmed from the color filter and then filtered with light of a specific color. In the color filter structure used for the liquid crystal display, Board, A silicon nitride layer formed on the substrate, wherein a silicon nitride layer having a predetermined high frequency power value is used to grow the silicon nitride layer; An amorphous silicon layer located on the silicon nitride layer, An n-type silicon layer located on the amorphous silicon layer, and A metal layer located on the n-type silicon layer, After the light is dimmed from the substrate to the color filter, and the light sequentially passes through the substrate, the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer, the original path is reflected by the metal layer and leaves the color filter. Will be delivered accordingly, The light is absorbed by the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer and subjected to the interference effect, And the light is dimmed from the color filter and then filtered with light of a specific color. In the color filter structure used for the liquid crystal display, Board, A metal layer formed on the substrate, An n-type silicon layer on the metal layer, An amorphous silicon layer located on the n-type silicon layer, A silicon nitride layer formed on the amorphous silicon layer, wherein a silicon nitride layer having a predetermined high frequency power value is used to grow the silicon nitride layer; Indium tin oxide layer formed on the silicon nitride layer, Light is dimmed from the indium tin oxide layer to the color filter, and the light sequentially passes through the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer, and then is reflected by the metal layer to color filter. Will be passed along the original path of The light is absorbed by the indium tin oxide layer, the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer and subjected to the interference effect, And the light is dimmed from the color filter and then filtered with light of a specific color. In the color filter structure used for the liquid crystal display, Board, A metal layer formed on the substrate, An n-type silicon layer on the metal layer, An amorphous silicon layer located on the n-type silicon layer, and A silicon nitride layer formed on the amorphous silicon layer, the silicon nitride layer having a predetermined high frequency power value used to grow the silicon nitride layer; Light is dimmed from the silicon nitride layer to the color filter, and the light sequentially passes through the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer, and is then reflected by the metal layer to leave the color filter. Will be delivered accordingly, The light is absorbed by the silicon nitride layer, the amorphous silicon layer, and the n-type silicon layer and subjected to the interference effect, And the light is dimmed from the color filter and then filtered with light of a specific color.

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