KR100631308B1 - Reflective liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

The present invention discloses a reflective liquid crystal display having a reflective electrode having an uneven structure including a circular concave portion and a convex portion, and a manufacturing method thereof. The reflective liquid crystal display includes functional dummy patterns formed together in the formation of the components for forming the thin film transistor. The reflective electrode is stacked on the dummy patterns, and has a corresponding uneven structure according to the uneven structure of the dummy patterns. Since the uneven structure of the reflective electrode is formed together during the patterning process for forming the thin film transistor without a separate pattern forming process, the process is simplified.

Description

Reflective liquid crystal display device and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a reflective liquid crystal display device having a reflective electrode having an uneven structure including a concave portion and a convex portion, and a manufacturing method thereof.

Cathode ray tubes (CRTs) employed in displays such as televisions and computer monitors are limited in their installation and movement because of their large weight, device space, and power consumption. In order to compensate for these disadvantages, display panels using flat panel panels, such as liquid crystal displays using liquid crystals, plasma display panels (PDPs) using surface discharge, and displays using electroluminescence, have been proposed and are widely used.

Among the flat panel displays, the liquid crystal display has low power consumption, low voltage operation, high definition, full color display, close to the cathode ray tube, and other electronic devices due to the ease of manufacturing process. It is applied in the field.

Such liquid crystal displays include a projection type liquid crystal display using an external light source and a reflection type liquid crystal display using natural light instead of an external light source.

The advantages of the reflective liquid crystal display include low power consumption, thin and light weight requiring no backlight device, and excellent display outdoors. Because of this feature, portable devices have the best conditions.

However, since the current reflective LCD display screen is dark and does not correspond to high-definition display and color display, it is used only for extremely low price products requiring only simple pattern display such as numbers among portable devices. In order to use the reflective liquid crystal display in a portable information device having a function such as a Document Viewer, Internet Viewer, etc., not only the improvement of reflection luminance but also high definition and colorization are required.

In order to make a monochromatic display liquid crystal display mainly displaying characters in a portable information device easy to see, improvement in reflection brightness and high definition are required, and an active matrix substrate including a switching element such as a thin film transistor is required for the realization.

However, since the displayable information is limited in a monochromatic display device, the price setting of the entire device is inevitably low, and the adoption of a thin film transistor having a high panel cost is fatal for a monochromatic display device. In addition, in the future, the coloration of the portable information device is essential, and thus, the product life of the monochromatic display device may be short. Accordingly, the development of the reflective liquid crystal display is in progress in the coloration direction.

However, despite the large development in both panel technology and the market, reflective color liquid crystals have not been practically used until now. The reason is the lack of performance in terms of brightness, contrast and response speed.

The improvement of brightness is realized by the combination of two techniques, namely, the technique of increasing the reflection efficiency of the reflective electrode and the ultra-high opening ratio technique. A technique for improving the reflection efficiency has already been used in the conventional guest host liquid crystal, and a technique for maximizing the reflection efficiency by making fine irregularities in the electrode provided with the reflection function is disclosed in US Patent No. 5,408,345. By adopting such a structure, the reflectance is gradually improved.

The uneven structure is formed by first patterning the organic insulating film into the uneven structure, and then depositing and patterning a reflective film such as aluminum on top of the patterned organic insulating film. The reflective film deposited on the organic insulating film of the uneven structure keeps the uneven structure of the organic film almost intact.

However, the patterning process of the organic insulating film requires a plurality of masking processes such as applying a photoresist film on top thereof, and exposing, developing, flowing, and dry etching and removing the photoresist pattern, thus complicating the process and producing cost. To increase. Therefore, it is required to form the uneven structure of this organic insulating film by a simple method.

An object of the present invention is to simplify the manufacturing process of the reflective electrode having the uneven structure by omitting the masking step of forming the uneven structure in the insulating film under the reflective electrode using the photosensitive film mask in the reflective liquid crystal display.

Another object of the present invention is to make the reflective film into an uneven structure by having a non-electrically functional pattern made of the same material as that of the thin film transistor on the same plane.

In order to achieve the above object, the reflective liquid crystal display of the present invention comprises a transparent first insulating substrate having a thin film transistor on the inner surface including a gate electrode, a gate insulating film, an active layer, a source electrode and a drain electrode; At least one of a gate electrode, a gate insulating film, an active layer, a source electrode, and a drain electrode pattern of the thin film transistor is disposed on the same plane on the first insulating substrate, and the gate electrode, the gate insulating film, the active layer, the source electrode, and the drain electrode are disposed on the same plane. A plurality of dummy patterns insulated from and separated from each other at regular intervals; An insulating film disposed on the insulating substrate so as to cover the thin film transistor and the dummy pattern, and having an uneven structure due to a step between the dummy pattern and a lower layer having the dummy pattern; And a reflective film formed on a surface of the insulating film and having a corresponding uneven structure along the uneven structure of the insulating film.

According to the present invention, an insulating substrate is provided. A thin film transistor including a gate electrode, a gate insulating film, an active layer, a source and a drain electrode is formed on the insulating substrate. Here, in forming a pattern for the components of the thin film transistor, a dummy pattern having a predetermined height without a function is simultaneously formed on the same plane as the layer on which the components of the thin film transistor are formed. Next, an organic insulating film is formed to a predetermined thickness on the entire surface of the resulting substrate. Next, a contact hole for contacting the drain and the thin film transistor is formed in a predetermined portion of the organic insulating layer. Then, a reflective film is formed on the entire surface of the organic insulating film including the contact hole.

Here, the reflective film has an uneven structure due to the step between the dummy pattern and the lower layer on which the dummy pattern is formed.

Other objects, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view of a reflective liquid crystal display according to an exemplary embodiment of the present invention and partially illustrates a unit pixel area of a thin film transistor substrate.

Referring to FIG. 1, a gate electrode 12 for providing a thin film transistor is disposed on an insulating substrate, for example, a glass substrate 10. On the same plane as the lower layer on which the gate electrode 12 is disposed, i.e., on the surface of the glass substrate 10, a dummy pattern 14 having no function electrically insulated from the signal transfer wiring is spaced apart from the gate electrode 12 by a predetermined distance. Spaced apart.

The dummy pattern 14 is made of the same material as the gate electrode 12 and made together during the deposition and patterning process of the selected metal material for the formation of the gate electrode 12.

The dummy pattern 14 may have a shape that allows the layer to be formed on the upper surface to have a concavo-convex structure due to the step between the surface thereof and the surface of the glass substrate 10, but preferably, the diameter of the upper surface is lower. It has a cylindrical shape smaller than the diameter of the surface.

The gate insulating film 16, which is the first insulating film, is coated on the entire surface of the glass substrate 10 including the dummy pattern 14 and the gate electrode 12. The gate insulating film 16 is made of a silicon oxide film (SiO ₂ ) or a silicon nitride film (Si _x N _y , x and y are integers).

The semiconductor layer 18 serving as a channel layer is formed on the gate insulating film 16 on the gate electrode 12. Here, the gate insulating film 16 has a structure in which convex portions and concave portions are alternately irregular by a step between a portion where the dummy pattern 14 is present and a portion that is not. The convex portion corresponds to a portion where the dummy pattern 14 is present at the lower portion, and the concave portion corresponds to a portion between the dummy patterns 14.

At both ends of the semiconductor layer, a contact layer 19, which is an amorphous semiconductor layer (n + a-Si) doped with a high concentration of n-type impurities, is disposed. The contact layers 19 are separated from each other and are in contact with the upper source electrode 22 and the drain electrode 24. The source electrode 22, the drain electrode 24, the contact layer 19, the semiconductor layer 18, the gate insulating film 16, and the gate electrode 12 constitute a thin film transistor.

Although not shown in the drawing, the gate electrode 12 is a portion vertically branched from the gate lines arranged in the first direction, for example, the row direction, so as to transmit the scan signal, and the source electrode 22 is the gate. The data signal is transmitted to the source electrode 22 as a portion vertically branched from the data lines arranged in the second direction orthogonal to the line, for example, in the column direction. The unit pixel area is defined as an area bordered by a pair of adjacent gate lines and a pair of adjacent data lines. The dummy pattern 14 proposed in the above embodiment is disposed in the pixel region.

The organic insulating film 26 having a contact hole exposing a predetermined portion of the drain electrode 24 of the thin film transistor is applied to the entire surface of the substrate including the gate bus line 104.

In the coated organic insulating film 26, the portion laminated on the gate insulating film 16 having the uneven structure maintains the uneven structure corresponding to the uneven structure of the gate insulating film 16. As shown in FIG.

The reflective electrode 28 is disposed in the pixel region on the organic insulating layer 26. The reflective electrode 28 is in contact with the drain electrode 24 through the contact hole formed in the organic insulating layer 26.

In the reflective electrode 28, the portion disposed above the organic insulating film 26 having the uneven structure maintains the uneven structure corresponding to the uneven structure of the organic insulating film 26.

On the other hand, in the above-described embodiment, the case where the data line is integrated with the source electrode 22 and disposed on a plane different from the reflective electrode 28 has been described by way of example. It may be disposed on the same plane, that is, on the organic insulating layer 26. In this case, the organic insulating film 26 has another contact hole exposing a predetermined portion of the surface of the source electrode 22, and an extension line of the data bus line is contacted with the source electrode through this contact hole.

In addition, unlike the above-described embodiments, the source electrode 22 is integrated with the data line disposed on the organic insulating layer 26, and the drain electrode 24 is the reflective electrode 28 disposed on the organic insulating layer 26. The concept of the present invention can be applied even when the structure is integrated with

2 is a cross-sectional view partially illustrating a thin film transistor substrate of a reflective liquid crystal display according to another exemplary embodiment of the present invention.

Referring to FIG. 2, the first dummy pattern 14 separated from the gate electrode 12 is disposed on the same plane as the plane on which the gate electrode 12 is disposed, that is, on the surface of the glass substrate 10, and the active layer ( The second dummy pattern 21 made of the same material as the active layer 20 is disposed on the same plane, that is, on the gate insulating layer 16, separately from the active layer 20.

The second dummy pattern 21 is to compensate for the disadvantage that the reflective electrode 28 does not have a sufficient step between the convex portion and the concave portion only by the first dummy pattern 14 in the embodiment of FIG. 1. It is to be located above (14). When the second dummy pattern 21 is disposed between the first dummy patterns, the step between the convex portion and the concave portion of the reflective electrode 28 is rather reduced, so that such a situation is avoided.

The second dummy pattern 21 may be selectively laminated with only one of the semiconductor layer 18a and the contact layer 19a. However, in consideration of advantages in the manufacturing process, the two dummy patterns 21 are preferably stacked together.

Meanwhile, the modification applied in the embodiment of FIG. 1 may be equally applied to the case of FIG. 2.

3 is a view partially illustrating a thin film transistor substrate of a reflective liquid crystal display according to another exemplary embodiment of the present invention.

Referring to FIG. 3, the first dummy pattern 14 separated from the gate electrode 12 is disposed on the same plane as the plane on which the gate electrode 12 is disposed, that is, on the surface of the glass substrate 10, and the active layer ( The second dummy pattern 21 made of the same material as the active layer 20 is disposed on the same plane as the plane on which the 20 is disposed, that is, separated from the active layer 20, and the second dummy pattern 21 is formed on the gate insulating layer 16. The third dummy pattern 25 formed of the same material as the source electrode 22 and the drain electrode 24 is disposed on the pattern 21.

The third dummy pattern 25 is used to compensate for the disadvantage that the reflective electrode 28 does not have a sufficient step between the convex portion and the concave portion with only the first and second dummy patterns 14 and 21 in the embodiment of FIG. 2. In this case, the second dummy pattern 21 should be positioned above the second dummy pattern 21. When the third dummy pattern 25 is disposed between the second dummy patterns 21, the step between the convex portion and the concave portion of the reflective electrode 28 is rather reduced, so as to avoid such a situation. In addition, in order to have a curved concave-convex structure, it is preferable that the 3rd dummy pattern 25 should have a diameter equal to or smaller than the 2nd dummy pattern 21.

4 illustrates a first dummy pattern 14 formed of the same material as the gate electrode 12, disposed on the same plane as the gate electrode 12, and a source electrode. 22 and the second dummy pattern 25 made of the same material as the drain electrode 24 and disposed on the same plane as the active layer 20 are shown.

This is to avoid a case in which a sufficient step cannot be secured by only the first dummy pattern 14, as in the previous embodiments, and the second dummy pattern 25 is disposed on the first dummy pattern 14. .

In the present embodiment, since the other configuration is the same as the previous embodiment, the description thereof is omitted here.

FIG. 5 is a cross-sectional view partially illustrating a thin film transistor substrate in a reflective liquid crystal display device according to another exemplary embodiment of the present invention, which is on the same plane as the plane on which the active layer 20 is disposed, that is, on the gate insulating layer 16. The case in which the dummy pattern 21 made of the same material as the active layer 20 is disposed separately from the active layer 20 is shown.

6 is a cross-sectional view partially illustrating a thin film transistor substrate in a reflective liquid crystal display device according to still another embodiment of the present invention.

According to the present embodiment, the thin film transistor substrate has a source and drain electrode portion, a first dummy pattern 44 disposed on the same plane as the gate electrode, and an active layer (compared with the embodiments of FIGS. 1 to 5). The configuration of the second dummy pattern 53 arranged on the same plane as that of 50 is different from each other.

Referring to FIG. 6, a first dummy pattern 44 separated from the gate electrode 42 is disposed on the same plane as the plane on which the gate electrode 42 is disposed, that is, on the surface of the glass substrate 40.

The first dummy pattern 44 is composed of a plurality of bars having a long side and a short side, as shown in FIG. 8, and these bar patterns are arranged along the row direction.

The second dummy pattern 53 made of the same material as the active layer 50 is disposed on the same plane as the plane on which the active layer 50 is disposed, that is, separated from the active layer 50.

The second dummy pattern 53 is composed of a plurality of bars having a long side and a short side, as shown in FIG. 8, and these bar patterns are arranged along the column direction.

A step occurs between a portion where the first dummy pattern 51 and the second dummy pattern 53 having a bar shape pass, and a portion where the second dummy pattern 53 passes, and in particular, the first dummy pattern 51 and the second dummy pattern 53 cross each other. The portion to be formed has a step corresponding to the sum of the thicknesses of the first and second dummy patterns 51 and 53. Due to these steps, the reflective electrode 54 has the surface of the uneven structure.

Meanwhile, in the present embodiment, the source electrode 60 and the drain electrode 59 are made of the same material as the reflective electrode 58, and although not shown, the data line is coplanar with the reflective electrode 58, that is, It is disposed on the second insulating film 54.

Although not shown, the same effect can be obtained by applying the first dummy pattern 44 and the second dummy pattern 53 to the thin film transistor structure shown in FIGS. 1 to 5 according to the present embodiment.

7 is a plan view illustrating a thin film transistor liquid crystal display device according to the exemplary embodiment of FIGS. 1 to 6, illustrating a unit pixel area and a peripheral portion thereof.

Referring to FIG. 7, the reflective electrode 28 has a hemispherical concave-convex structure, and when viewed from the top, the protruding portions are shown to have irregularly arranged circles having different diameters.

Meanwhile, in the present embodiment, the protrusions are positioned and positioned in the pixel area. However, as long as the insulating structure between the data line and the reflective electrode, the gate line, and the reflective electrode is maintained, the reflective electrode is disposed on the upper portion of the data line and the gate line. By extending so that these protruding portions can extend the distribution area to the top of the data line and the gate line.

Hereinafter, a process of manufacturing a reflective liquid crystal display device having the above structure will be described with reference to the accompanying drawings.

9 is a process flowchart illustrating a process of manufacturing a reflective liquid crystal display device having a concave-convex structure according to another embodiment of the present invention.

Referring to FIG. 9A, a tantalum metal layer 93 having a thickness of about 3,000 μm is deposited on an insulating substrate 92 such as a glass substrate by sputtering. The tantalum metal layer 93 is patterned by photolithography to form a gate bus line (not shown), a gate electrode 94 extending from the gate bus line, and a plurality of dummy patterns 95 separated from the gate bus line and the gate electrode. To form as shown in Figure 9b.

Here, the dummy patterns 95 are mainly formed in the pixel area, which is an area bordered by a pair of gate bus lines and a pair of data bus lines (not shown). The dummy pattern 95 preferably has a cylindrical shape, and optionally, may have a shape of an elliptical column, a square column, or the like.

Next, referring to FIG. 9C, a silicon nitride film (Si _x N _y , x, y of an integer of about 4,000 μm on the substrate 92 including the gate electrode 94 and the plurality of dummy patterns 95 is an integer. ) Or a gate insulating film 96 made of a silicon oxide film (SiO ₂ ) is formed by a plasma chemical vapor deposition method. Here, the deposited gate insulating film 96 has a concave-convex surface in which hemispherical convex portions and concave portions are irregularly distributed due to the presence of a dummy pattern.

Next, an amorphous silicon (a-Si) layer 97 having a thickness of about 1,000 μm and an amorphous silicon (n + a-Si) layer (or contact layer) 98 doped with a high concentration of n-type impurities having a thickness of about 400 μm. These are formed continuously in the order mentioned. The amorphous silicon layer 98 doped with a high concentration of n-type impurities and the lower amorphous silicon layer 98 are patterned to form an active layer 99 including a semiconductor layer serving as a channel layer and an upper contact layer.

Next, referring to FIG. 9E, an organic insulating film 100 having a thickness of about 1-3 μm is coated on the entire surface of the resulting substrate on which the active layer 99 is formed, and a predetermined portion of the active layer 99 on the gate electrode 94 is formed. A contact hole 102 exposing is formed as shown in FIG. 9F. Here, the coated organic insulating film 100 has a concave-convex structure corresponding to the concave-convex structure of the gate insulating film 96 as a lower layer.

Next, referring to FIG. 9G, an aluminum film having a thickness of about 2,000 mm on the front surface is deposited by sputtering, and patterned so that a predetermined portion of the surface of the active layer 99 is exposed to the data bus line and the data bus shown in FIG. A source electrode 106 extending from the line and contacting one surface of the active layer 99, a reflective electrode 104, and a drain electrode extending from the reflective electrode 104 and contacting the other surface of the active layer 99 ( 105).

Then, the active layer 99 exposed between the source electrode 106 and the drain electrode 105 is etched using the source electrode 106 and the drain electrode 105 as a mask.

According to the present embodiment, during the patterning process for forming the gate bus line and the gate electrode 94, the dummy pattern 95 having no function is formed together in the pixel area, thereby forming the reflective electrode 104 into the uneven structure. There is no need for a separate patterning process and subsequent flow process, which has been done to the organic insulating film in the prior art, to make it. As described above, in the present invention, the process of the thin film transistor and the reflective electrode is completed by only four masking processes, so that the process is simplified, reliability is improved, and manufacturing cost is reduced.

On the other hand, in the above-described embodiment, patterning for separation of the contact layer in contact with the source electrode and the drain electrode was performed after patterning for formation of the source electrode and the drain electrode, but, optionally, the patterning step is performed with the semiconductor layer and the contact layer. It may also be carried out immediately after the deposition.

10A to 10G are flowcharts illustrating a process of manufacturing a reflective liquid crystal display device having a concave-convex structure according to another embodiment of the present invention. The present embodiment is a first dummy pattern formed with a gate electrode 94. Only 95 can be applied to the case where the reflective electrode does not secure sufficient level difference.

Since the process to FIGS. 10A-10C is the same as the process of FIGS. 9A-9C, the description is abbreviate | omitted here.

Referring to FIG. 10D, a patterning process of a first amorphous silicon (a-Si) layer 97 and a second amorphous silicon (n + a-Si) layer (or contact layer) 98 heavily doped with n-type impurities is performed. At this time, the first and second amorphous silicon layers 97 and 98 are patterned so as to remain not only on the gate electrode 94 but also on the first dummy pattern 95. Hereinafter, the first and second amorphous silicon layer patterns remaining on the gate insulating layer 96 on the first dummy pattern 95 are referred to as a second dummy pattern 199.

Since the second dummy pattern 199 further increases the step with the portion where the dummy pattern does not exist, the reflective film formed on the upper part of the second dummy pattern 199 may have a surface having a larger step than that shown in FIG. 9G. Have

Since the process of FIGS. 10E-10G is the same as the process of FIGS. 9D-9G, the description is abbreviate | omitted here.

As in the embodiment described in FIGS. 9A-9G, the present embodiment also has no function in the pixel region during the patterning process for forming the gate bus line and the gate electrode 94 and the patterning process for forming the active layer 99. By forming the first and second dummy patterns 95 and 199 together, there is no need for a separate patterning process and a subsequent flow process that have been performed on the organic insulating film in the prior art to make the reflective electrode 104 an uneven structure. . As described above, the present invention does not require a separate masking process for forming a dummy pattern, and thus the process of the thin film transistor and the reflective electrode is completed by only four masking processes. Therefore, the process is simplified, the reliability is improved, and the manufacturing cost is reduced.

11A to 11G are flowcharts illustrating a manufacturing process of a reflective liquid crystal display device having a reflective electrode having a concave-convex structure according to another embodiment of the present invention.

Referring to FIG. 11A, a tantalum metal layer 93 having a thickness of about 3,000 μm is deposited on an insulating substrate 92 such as a glass substrate by sputtering. The tantalum metal layer 93 is patterned by photolithography to form a gate bus line (not shown), a gate electrode 94 extending from the gate bus line, and a plurality of first dummy patterns separated from the gate bus line and the gate electrode. 44) are formed as shown in FIG. 11B. Here, the first dummy patterns 44 are mainly formed in the pixel area, which is an area bordered by a pair of gate bus lines and a pair of data bus lines (not shown).

The first dummy pattern 44 is composed of a plurality of bars (hereinafter referred to as first bars) having long and short sides, as shown in FIG. 8, and these first bar patterns are arranged along the row direction. Are arranged.

Next, referring to FIG. 11C, a silicon nitride film (Si _x N _y , x and y having an integer of about 4,000 μm on the substrate 92 including the gate electrode 94 and the first dummy patterns 44 is an integer. ) Or a gate insulating film 96 made of a silicon oxide film (SiO ₂ ) is formed by a plasma chemical vapor deposition method. Here, the deposited gate insulating layer 96 has a concave-convex surface in which valleys and acids alternate with each other due to the presence of the first dummy pattern 44.

Next, a first amorphous silicon (a-Si) layer 97 having a thickness of about 1,000 μm and a second amorphous silicon (n + a-Si) layer (or contact) heavily doped with an n-type impurity of about 400 μm thick Layer 98) is formed continuously in the order mentioned. The second amorphous silicon layer 98 and the lower first amorphous silicon layer 97 are patterned so that an active layer 99 including a semiconductor layer serving as a channel layer and an upper contact layer is formed on the gate electrode 94. In the pixel electrode region, a second dummy pattern 53 made of these first and second amorphous silicon layers 97 and 98 is formed.

The second dummy pattern 53 is composed of a plurality of bars having a long side and a short side, as shown in FIG. 8, and these bar patterns are arranged along the column direction.

A step occurs between a portion where the first dummy pattern 44 and the second dummy pattern 53 having a bar shape pass, and a portion where the second dummy pattern 53 passes, and in particular, the first dummy pattern 44 and the second dummy pattern 53 cross each other. The portion to be formed has a step corresponding to the sum of the thicknesses of the first and second dummy patterns 44 and 53. Due to these steps, the organic insulating film 100 and the reflective electrode 104 to be formed in a subsequent step have a surface of an uneven structure.

Next, referring to FIG. 11E, an organic insulating film 100 having a thickness of about 1-3 μm is coated on the entire surface of the resulting substrate on which the active layer 99 and the second dummy pattern 53 are formed, and the upper portion of the gate electrode 94 is formed. A contact hole 102 exposing a predetermined portion of the contact layer 98 is formed. Here, the coated organic insulating film 100 has a concave-convex structure corresponding to the concave-convex structure of the gate insulating film 96 as a lower layer.

Next, referring to FIG. 11G, an aluminum film of about 2,000 mm thick is deposited on the entire surface by sputtering, and patterned so that a predetermined portion of the surface of the active layer 99 is exposed to the data bus line and the data bus shown in FIG. A source electrode 106 extending from the line and contacting one surface of the active layer 99, a reflective electrode 104, and a drain electrode extending from the reflective electrode 104 and contacting the other surface of the active layer 99 ( 105).

Then, the active layer 99 exposed between the source electrode 106 and the drain electrode 105 is etched using the source electrode 106 and the drain electrode 105 as a mask.

According to the present embodiment, the patterning process for forming the gate bus line and the gate electrode 94, and the patterning process for forming the active layer 99, are orthogonal to each other in the pixel region, and have no function first or second. By forming the dummy patterns 44 and 53 together, a separate patterning process and subsequent flow process, which have been performed on the organic insulating film in the prior art, to form the uneven structure of the reflective electrode 104, are unnecessary. As described above, in the present invention, the process of the thin film transistor and the reflective electrode is completed by only four masking processes, so that the process is simplified, reliability is improved, and manufacturing cost is reduced.

On the other hand, in the above-described embodiment, patterning for separation of the contact layer in contact with the source electrode and the drain electrode was performed after patterning for formation of the source electrode and the drain electrode, but, optionally, the patterning step is performed with the semiconductor layer and the contact layer. It may also be carried out immediately after the deposition.

12A to 12J are flowcharts illustrating a manufacturing process of a reflective liquid crystal display device having a reflective electrode having a concave-convex structure according to still another embodiment of the present invention, wherein the organic insulating layer is interposed between the reflective electrode and the gate insulating layer. By providing photosensitivity, a method of completing the thin film transistor and the reflective electrode in only four masking processes is shown.

Referring to FIG. 12A, a tantalum metal layer 93 having a thickness of about 3,000 μm is deposited on the glass substrate 92 by sputtering. The tantalum metal layer 93 is patterned by photolithography to form a gate bus line 34 shown in FIG. 7 and a gate electrode 94 extending from the gate bus line 34.

Next, referring to FIG. 12B, a silicon nitride film (Si _x N _y , x and y are integers) or a silicon oxide film (SiO ₂ ) having a thickness of about 4,000 μm is disposed on the insulating substrate 92 including the gate electrode 94. ) Is formed by a plasma chemical vapor deposition method. Next, an amorphous silicon (a-Si) layer 97 of about 1,000 microns thick and an amorphous silicon (n + a-Si) layer 98 doped with a high concentration of n-type impurities of about 400 microns thick are in the order mentioned. It is formed continuously. The active layer 99 is formed by patterning the amorphous silicon layer 98 heavily doped with n-type impurities and the amorphous silicon layer 97 thereunder.

As shown in FIG. 12E, a photosensitive organic insulating film 122 is formed on the entire surface of the resulting substrate 92 on which the active layer 99 is formed to a thickness of about 1-3 μm.

Next, referring to FIG. 12F, the mask 112 including a light transmitting part that transmits incident light and a light blocking part that blocks incident light is aligned so that the light transmitting part is positioned at predetermined portions of the thin film transistor part and the pixel electrode, and then the thin film transistor. The upper photosensitive organic insulating film 122 is exposed for a time that can be sufficiently exposed.

Next, by removing the exposed portions by developing, the photosensitive organic insulating film pattern 109 as shown in FIG. 12G is formed.

Next, referring to FIG. 12H, the resultant substrate on which the developing process is completed is subjected to heat treatment at a temperature range of about 120 ° C. to 250 ° C. FIG. By the heat treatment, the photosensitive organic insulating layer pattern 109 flows to form the photosensitive organic insulating layer pattern 110 having an uneven structure in which the hemispherical convex portion and the concave portion alternate. As a result, the photosensitive organic insulating film of the concave-convex structure in the pixel region functions as a micro lens that reflects incident light at a higher density and reflects at a wider angle than the flat surface.

Next, referring to FIG. 12I, a metal layer having a high reflectance and a low resistivity, such as aluminum, is deposited on the photosensitive organic insulating layer pattern 110 including the thin film transistor portion, and then contacted with one side region of the active layer 99. Then, the reflective electrode 114 covered on the photosensitive organic insulating layer pattern 110 having the uneven structure and the data bus line contacting the other region of the active layer are formed by patterning. Hereinafter, a portion of the active layer that is in contact with one region is referred to as a drain electrode 105 and a portion of the active layer which is in contact with the other region is referred to as a source electrode 106.

Next, as shown in FIG. 12J, an upper high concentration impurity layer of the active layer 99 exposed between the source electrode 106 and the drain electrode 105 is used as the source electrode 106 and the drain electrode 105 as an etching mask. Removed by etching.

According to the embodiment described above, since a photosensitive organic insulating film is used to make the uneven structure in the pixel region, the reflective electrode and the thin film transistor can be manufactured using only four masking processes. Compared with the manufacturing method of the liquid crystal display device which has, the process becomes simple.

In all the embodiments described above, in the present invention has been shown and described an example in which a glass substrate is used, it is a matter of course that a transparent quartz substrate, a light-shielding semiconductor substrate, for example, a silicon substrate can also be used.

As described above, according to the present invention, a dummy pattern is formed in the pixel area during patterning of the constituent members of the thin film transistor, thereby manufacturing a reflective liquid crystal display device having an uneven structure having high reflectivity without any additional process. can do.

In addition, by using the photosensitive organic insulating layer, a reflective liquid crystal display device having a concave-convex structure having a high reflectance can be manufactured by only four masking processes without any additional process.

In addition, the reflectance can be improved by stacking the first and second dummy patterns in the bar shape in the pixel region so as to be orthogonal to each other so that the reflective film has double unevenness.

Meanwhile, although specific embodiments of the present invention have been described and illustrated herein, modifications will be made by those skilled in the art from the detailed description of the present invention. Accordingly, the following claims are to be embraced as including such variations and modifications without departing from the spirit and spirit of the invention.

1 is a schematic partial cross-sectional view of a reflective liquid crystal display device according to an embodiment of the present invention.

2 is a schematic partial cross-sectional view of a reflective liquid crystal display device according to another exemplary embodiment of the present invention.

3 is a schematic partial cross-sectional view of a reflective liquid crystal display device according to still another embodiment of the present invention;

4 is a schematic partial cross-sectional view of a reflective liquid crystal display device according to still another embodiment of the present invention;

5 is a schematic partial cross-sectional view of a reflective liquid crystal display device according to still another embodiment of the present invention.

6 is a schematic partial cross-sectional view of a reflective liquid crystal display device according to still another embodiment of the present invention.

7 is a schematic partial plan view of a reflective liquid crystal display device according to the present invention;

8 is a schematic partial plan view of the reflective liquid crystal display of FIG.

9A to 9G are flowcharts illustrating a process of manufacturing a reflective liquid crystal display according to an exemplary embodiment of the present invention.

10A to 10G are flowcharts illustrating a process of manufacturing a reflective liquid crystal display according to another exemplary embodiment of the present invention.

11A to 11G are flowcharts illustrating a process of manufacturing a reflective liquid crystal display device according to another exemplary embodiment of the present invention.

12A to 12J are process flowcharts illustrating a process of manufacturing a reflective liquid crystal display device according to another exemplary embodiment of the present invention.

Claims (10)

A first insulating substrate having a thin film transistor including an gate electrode, a gate insulating film, an active layer, a source electrode, and a drain electrode on an inner surface thereof; At least one of a gate electrode, a gate insulating film, an active layer, a source electrode, and a drain electrode pattern of the thin film transistor is disposed on the same plane on the first insulating substrate, and the gate electrode, the gate insulating film, the active layer, the source electrode, and the drain electrode are disposed on the same plane. A first dummy pattern including a plurality of bars insulated from and separated from each other by a predetermined distance and arranged along a first direction; At least one of a gate electrode, a gate insulating film, an active layer, a source electrode, and a drain electrode pattern of the thin film transistor, which is different from the first dummy pattern and is disposed on the same plane on the first insulating substrate, wherein the gate electrode, the gate insulating film, A second dummy pattern insulated from the active layer, the source electrode, and the drain electrode, the second dummy pattern including a plurality of bars separated from each other by a predetermined distance and arranged along a second direction perpendicular to the first direction; Unevenness due to a step between the thin film transistor and the lower layer disposed on the insulating substrate to cover the first and second dummy patterns, wherein the first and second dummy patterns and the first and second dummy patterns are disposed. An insulating film having a structure; And And a reflective film formed on a surface of the insulating film and having a corresponding uneven structure along the uneven structure of the insulating film. The reflective liquid crystal display of claim 1, wherein the first dummy pattern is disposed on the same plane as the gate electrode, and the second dummy pattern is disposed on the same plane as the active layer. The reflective liquid crystal display of claim 1, wherein the first dummy pattern is disposed on the same plane as the gate electrode, and the second dummy pattern is disposed on the same plane as the source electrode and the drain electrode. Device. The liquid crystal display device of claim 1, wherein the first dummy pattern is disposed on the same plane as the active layer, and the second dummy pattern is disposed on the same plane as the source electrode and the drain electrode. . Providing an insulating substrate; Forming a thin film transistor including a gate electrode, a gate insulating film, an active layer, a source, and a drain electrode on the insulating substrate, and forming a pattern for the components of the thin film transistor in a first direction to have a predetermined height without function. A first dummy pattern including a plurality of first bars arranged and a second dummy pattern including a plurality of second bars arranged in a second direction orthogonal to the first direction, the layer on which components of the thin film transistor are formed; Simultaneously forming on the same plane; Forming an organic insulating film on the entire surface with a predetermined thickness; Forming a contact hole for contact with a drain electrode of the thin film transistor in a predetermined portion of the organic insulating layer; And And forming a reflective film on the entire surface of the organic insulating film including the contact hole. The method of manufacturing a reflective liquid crystal display device according to claim 5, wherein the insulating substrate is a glass substrate. The method of claim 5, wherein the first dummy pattern is formed together with the gate electrode, and the second dummy pattern is formed together with the active layer. The method of claim 5, wherein the first dummy pattern is formed together with the gate electrode, and the second dummy pattern is formed together with the source electrode. The method of claim 5, wherein the first dummy pattern is formed together with the active layer, and the second dummy pattern is formed together with the source electrode. The method of claim 5, wherein the source electrode and the drain electrode of the thin film transistor are formed of the same material as the reflective electrode and formed together with the reflective electrode.