KR100840253B1 - LCD and its manufacturing method - Google Patents

Abstract

Disclosed are a liquid crystal display and a method of manufacturing the same, which can reduce the number of manufacturing steps and improve display characteristics. The liquid crystal display device includes a thin film transistor substrate, a color filter substrate, and liquid crystal injected between two substrates. The thin film transistor substrate is completed by forming the pixel electrode and the TFT in the same process on the first substrate having the uneven structure or the organic insulating film having the uneven structure. The pixel electrode is formed in the same process as the gate electrode of the TFT or in the same process as the source and drain electrodes of the TFT. Here, the pixel electrode has a plurality of unevennesses because it is formed on an organic insulating film or a first substrate having a plurality of unevennesses. Therefore, the number of manufacturing steps of the liquid crystal display device can be reduced, and display characteristics can be improved.

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY APPARATUS AND METHOD FOR MANUFACTURING THEREOF}

1 is a cross-sectional view showing a conventional reflective liquid crystal display device.

2 is a cross-sectional view of a conventional reflective-transmissive liquid crystal display device.

3 is a cross-sectional view illustrating in detail a reflective liquid crystal display device according to an exemplary embodiment of the present invention.

4 to 8B are diagrams specifically illustrating a manufacturing process of the TFT substrate illustrated in FIG. 3.

9 is a cross-sectional view illustrating in detail a reflective liquid crystal display device according to another exemplary embodiment of the present invention.

10 to 14B are diagrams specifically illustrating a manufacturing process of the TFT substrate illustrated in FIG. 10.

The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly, to a liquid crystal display device and a method for manufacturing the same, which can reduce the number of manufacturing processes and improve display characteristics.

At present, with the rapid progress of semiconductor technology, liquid crystal display devices with thin and light display devices and low power consumption are widely used in accordance with the miniaturization and light weight of various information processing devices.

The liquid crystal display device is classified into a transmissive liquid crystal display device that receives an image of the first light generated from the outside and displays an image and a reflective liquid crystal display device that receives the second light generated by itself and displays an image.

1 is a cross-sectional view showing a conventional reflective liquid crystal display device.

Referring to FIG. 1, the reflective liquid crystal display device 90 includes a thin film transistor (TFT) substrate 60, a color filter substrate 70 provided to face the TFT substrate 60, and the thin film transistor 70. The liquid crystal layer 80 is injected between the TFT substrate 60 and the color filter substrate 70.

The TFT substrate 60 may include an organic insulating layer formed on the first substrate 10, the TFT 20 formed on the first substrate 10, and the first substrate 10 including the TFT 20. 30 and the pixel electrode 40 formed on the organic insulating layer 30.

Specifically, the TFT 20 formed on the first substrate 10 has a gate electrode 21, a source electrode 25, and a drain electrode 26. In this case, the gate electrode 21 is insulated from the source electrode 25 and the drain electrode 26 through the gate insulating layer 22. The active layer 23 and the ohmic contact layer 24 for applying power from the source electrode 25 to the drain electrode 26 as power is applied to the gate electrode 21 on the gate insulating layer 22. ) Is formed. Source and drain electrodes 25 and 26 are formed thereon.

In this case, since the drain electrode 26 and the source electrode 25 are formed on the same layer, the TFT 20 and the pixel are connected to connect the pixel electrode 40 only with the drain electrode 26. The organic insulating film 30 is interposed between the electrode 40. Here, a contact hole 31 for exposing the drain electrode 26 is formed in the organic insulating layer 40. The pixel electrode 40 is formed to have a uniform thickness on the drain electrode 26 exposed by the organic insulating layer 30 and the contact hole 31, so that the pixel electrode 40 and the drain electrode 26 are formed. Is connected.

The pixel electrode 40 may be a transmissive electrode or a reflective electrode depending on the case where the liquid crystal display device is a transmissive type or a reflective type. That is, when the pixel electrode 40 is made of an indium tin oxide (ITO) material or an indium zinc oxide (IZO) material, the pixel electrode 40 is a transmissive electrode and is made of aluminum (Al) or aluminum. When the alloy is made of a material having good reflectance such as Al alloy, it is a reflective electrode.

As shown in FIG. 1, a plurality of irregularities are formed on the surface of the organic insulating layer 30, and when the pixel electrode 40 is formed as a reflective electrode, the reflection area is increased to improve the reflection efficiency, and also the reflection angle. You can secure a wide viewing angle by adjusting.

The alignment layer 50 is entirely formed on the first substrate 10 on which the TFT 20 and the pixel electrode 40 are formed.

Meanwhile, the color filter substrate 70 is a substrate on which the RGB color pixel 72, the common electrode 73, and the alignment layer 74 are formed on the second substrate 71, and the common electrode 73 is the pixel electrode. It is provided to face the TFT substrate 60 so as to face 40. As such, when the color filter substrate 70 and the TFT substrate 60 are opposed to each other, the liquid crystal 80 is injected between the color filter substrate 70 and the TFT substrate 60.

However, the transmissive liquid crystal display device has advantages of high luminance and excellent image quality, but has a disadvantage of high power consumption because it generates light by itself. On the other hand, the reflection type liquid crystal display device has the advantage that the power consumption is smaller than the transmissive liquid crystal display device, on the other hand has a disadvantage of low brightness and poor image quality.

Therefore, recently, a reflection-transmissive liquid crystal display device has been developed to secure visibility appropriate to the ambient light by taking advantage of both a reflective liquid crystal display device and a transmissive liquid crystal display device to realize high quality images while reducing power consumption. It is becoming. The reflection-transmissive liquid crystal display displays an image using the first light generated from the outside when the amount of external light is abundant, and uses the second light generated by consuming the electric energy charged therein when the amount of external light is insufficient. Display the image.

2 is a cross-sectional view of a conventional reflective-transmissive liquid crystal display device. In FIG. 2, the rest of the structure except for the structure of the TFT substrate is the same as that of the reflection type liquid crystal display device, and thus description thereof is omitted.

Referring to FIG. 2, the TFT substrate 60 of the reflection-transmissive liquid crystal display device 91 is a substrate on which the TFT 20 and the pixel electrode 40 are formed on the first substrate 10. The drain electrode 26 of the TFT 20 is connected to a pixel electrode 40 including a transmission electrode 41 and a reflection electrode 42.

Specifically, when the TFT 20 is formed on the first substrate 10, the organic insulating layer 30 is formed thereon. The pixel electrode 40 is connected to the drain electrode 26 of the TFT 20 through a contact hole 31 formed in the organic insulating layer 30. Here, a plurality of irregularities are formed on the surface of the organic insulating layer 30.

The transmission electrode 41 is formed on the drain electrode 26 exposed by the organic insulating layer 30 and the contact hole 31, and the transmission electrode 41 is partially formed on the transmission electrode 41. The reflective electrode 42 is formed while exposing. Here, the transmission electrode 41 is made of ITO or IZO material, and the reflective electrode 42 is made of aluminum (Al) or aluminum alloy (Al alloy). Since the transmissive electrode 41 and the reflecting electrode 42 are stacked with a uniform thickness, a plurality of irregularities are formed on the surface.

The following problems arise in the structure of the above-described reflective, transmissive or reflective-transmissive liquid crystal display device.

In order to manufacture a conventional reflective, transmissive, or reflective-transmissive liquid crystal display, five to six masks are used. Here, each time the mask used in the manufacturing process is increased, the manufacturing cost of the liquid crystal display is increased, and the defective rate is increased, thereby rapidly lowering the productivity of the liquid crystal display.                         

In addition, since a relatively thick organic insulating film 30 is formed on the TFT 20 and the pixel electrode 40 of the TFT substrate 60, a stepped portion of the organic insulating film 30 (for example, , The contact resistance is increased in the contact hole portion, and a problem arises that the orientation is not good.

The organic insulating layer is also formed in the pad portion, and contact holes for exposing the gate pad and the data pad are formed in the organic insulating layer 30 formed in the pad portion. In this case, the contact hole is formed by an etching process. In this process, an undercut region is generated in the contact hole, and the disconnection between the gate pad and the reflective electrode is generated due to the undercut region. The problem of deterioration arises.

Accordingly, an object of the present invention is to provide a liquid crystal display device which can reduce the number of manufacturing steps and improve display characteristics.

Another object of the present invention is to provide a method of manufacturing a liquid crystal display device capable of reducing the number of manufacturing processes and improving display characteristics.

A liquid crystal display device according to the present invention for achieving the above object, a) a first substrate, b) a first insulating film formed on the first substrate and having an uneven structure, c) uniform on the first insulating film A gate wiring formed to a thickness and branched from the gate electrode and extending in a row direction, the gate wiring including a gate pad and a pixel electrode extending from an end of the gate line, d) the gate wiring including the gate wiring; A second insulating film formed on the first insulating film and having a first contact hole for exposing the pixel electrode and a second contact hole for exposing the gate pad, e) the second electrode including a region in which the gate electrode is formed; A channel layer formed on the insulating film, f) a data line formed on the second insulating film including the channel layer and extending in a column direction, to the data line A thin film transistor substrate comprising a source electrode branched from the source electrode, a drain electrode connected to the pixel electrode through the first contact hole, and a data pad extending from an end of the data line; And a color filter substrate having a common electrode facing the pixel electrode on a second substrate, and a liquid crystal layer interposed between the thin film transistor substrate and the color filter substrate.

The object of the present invention described above is a) a first substrate, b) a first insulating film formed on the first substrate, a concave-convex structure, c) a first insulating film formed on the first insulating film, and a gate electrode and the gate electrode. A gate line branched from the gate line and extending in a row direction, a gate line including a gate pad extending from an end of the gate line, and c) formed on the first insulating film including the gate line and exposing the gate pad. A second insulating film having a contact hole formed thereon, d) a channel layer formed on the second insulating film including a region where the gate electrode is formed, and e) being formed to have a uniform thickness on the second insulating film including the channel layer, A data line extending in a column direction, a source electrode branched from the data line, a drain electrode, a data pad extending from an end of the data line, and the drain A thin film transistor substrate comprising a data line including a pixel electrode connected to an electrode, a color filter substrate provided to face the thin film transistor substrate, a common electrode facing the pixel electrode on a second substrate, and the thin film transistor substrate; It is achieved by a liquid crystal display device comprising a liquid crystal layer interposed between the color filter substrate.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method including: a) forming a first insulating film having an uneven structure on a first substrate, b) a gate electrode on the first insulating film, Forming a gate wiring having a uniform thickness, the gate wiring including a gate line branched from the gate electrode and extending in a row direction, a gate pad extending from an end of the gate line, and a pixel electrode having an uneven structure; c) the gate wiring Forming a second insulating layer on the first substrate including a first contact hole for exposing the pixel electrode and a second contact hole for exposing the gate pad, d) the gate electrode is formed Forming a channel layer on said second insulating film comprising a region, e) extending in a column direction on said second insulating film comprising a channel layer; Forming a data line including a source line, a source electrode branched from the data line, a drain electrode connected to the pixel electrode through the first contact hole, and a data pad extending from an end of the data line, f) the Forming a common electrode facing the pixel electrode on a second substrate provided opposite to the first substrate, g) aligning the first substrate and the second substrate with each other, and h) the first substrate; Injecting liquid crystal between the second substrate and the second substrate.

Another object of the present invention as described above, a) forming a first insulating film having a concave-convex structure on the first substrate, b) a gate electrode, branched from the gate electrode and extending in the row direction on the first insulating film Forming a gate line including a gate line and a gate pad extending from an end of the gate line, c) a contact hole including a contact hole for exposing the gate pad on the first substrate including the gate line; 2) forming an insulating film, d) forming a channel layer on the second insulating film including a region where the gate electrode is formed, e) extending in a column direction on the second insulating film including the channel layer A data line, a source electrode branched from the data line, a drain electrode, a data pad extended from an end of the data line, and the drain front Forming a data line having a uniform thickness, the data line including a pixel electrode having an uneven structure, and f) forming a common electrode facing the pixel electrode on a second substrate provided to face the first substrate. And g) aligning the first substrate and the second substrate with each other, and h) injecting a liquid crystal between the first substrate and the second substrate. Is achieved.

According to the above-described liquid crystal display and its manufacturing method, the thin film transistor substrate is completed by forming an organic insulating film having an uneven structure on the first substrate and then forming a pixel electrode and a TFT on the organic insulating film in the same process. . That is, the pixel electrode is formed in the same process as the gate electrode of the TFT or in the same process as the source and drain electrodes of the TFT.

Therefore, the number of manufacturing processes can be reduced by not using a mask used to form the pixel electrode, and the display electrode can be improved by forming the pixel electrode on an organic insulating film having a plurality of irregularities.

Hereinafter, a liquid crystal display and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view illustrating in detail a reflective liquid crystal display device according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the reflective liquid crystal display 200 includes a thin film transistor (hereinafter, referred to as TFT) substrate 150, a color filter substrate 160 provided to face the TFT substrate 150, and the TFT. The liquid crystal layer 170 is injected between the TFT substrate 150 and the color filter substrate 160.

The TFT substrate 150 is coupled to the color filter substrate 160 to be coupled to each other and to display an image, a gate pad region GP and a data pad region formed around the display region D. DP). Specifically, the display area D of the TFT substrate 150 is formed on the first substrate 110, the organic insulating film 120 having the uneven structure, and the TFT 120 formed on the organic insulating film 120. And a reflective electrode 131b formed on the same layer as the TFT 130 and coupled to the drain electrode 135b of the TFT 130.

The TFT 130 has a gate electrode 131a, a source electrode 135a, and a drain electrode 135b. The gate electrode 131a and the reflective electrode 131b are formed on the organic insulating layer 120 by the same process. Thereafter, a gate insulating layer 132 is formed on the organic insulating layer 120 including the gate electrode 131a and the reflective electrode 131b. A first contact hole 132a is formed in the gate insulating layer 132 to expose the reflective electrode 131b. As power is applied to the gate electrode 131a on the gate insulating layer 132, a channel layer 133 and an ohmic contact layer 134 for applying power from the source electrode 135a to the drain electrode 135b. Is formed. Source and drain electrodes 135a and 135b are formed thereon. The drain electrode 135b is connected to the reflective electrode 131b through the first contact hole 132a.

An alignment layer 140 is formed on the first substrate 110 on which the TFT 130 and the reflective electrode 131b are formed. The alignment layer 140 not only adjusts the arrangement angle of the liquid crystal layer 170 to be injected later, but also serves to protect the TFT 130 and the reflective electrode 131b.

The gate pad region GP is formed on the first substrate 110, and includes an organic insulating layer 120 having an uneven structure and a gate pad 131c formed on the organic insulating layer 120. The data pad region DP is formed on the first substrate 110, the organic insulating layer 120 having an uneven structure, the gate insulating layer 132 and the gate insulating layer formed on the organic insulating layer 120. 132 is formed on the data pad 135c.

Meanwhile, the color filter substrate 160 is a substrate on which the RGB color pixel 162, the common electrode 163, and the alignment layer 164 are formed on the second substrate 161. The TFT substrate 150 is provided to face the pole 164. As such, when the color filter substrate 160 and the TFT substrate 150 are coupled to face each other, the liquid crystal 170 is injected between the color filter substrate 160 and the TFT substrate 150.

4 to 8B are views specifically showing a process of manufacturing a TFT substrate.

First, referring to FIG. 4, an organic insulating material such as a photosensitive acrylic resin is coated on a first substrate 110 made of an insulating material such as glass, quartz, or sapphire, and having a flat surface structure. Subsequently, after the patterned first mask (not shown) is formed on the organic insulating material, when the organic insulating material is exposed and developed, an organic insulating layer 120 having an uneven structure corresponding to the patterning is formed.

The organic insulating layer 120 is formed on the entirety of the display area D, the gate pad area GP, and the data pad area DP.

 Although not shown in the drawings, the surface of the first substrate may be formed in an uneven structure. That is, when the surface of the first substrate is formed of the uneven structure, the organic insulating film is formed to have a uniform thickness thereon, so that the organic insulating film has a surface structure corresponding to the uneven structure of the first substrate.

5A and 5B, on the organic insulating layer 120, aluminum (Al), aluminum alloy (Al alloy), silver (Ag), silver alloy (Ag alloy), molybdenum (Mo), and molybdenum alloy having good reflectances may be used. A first metal film (not shown) made of any one of (Mo alloy), chromium (Cr), and nickel (Ni) is formed. Subsequently, after forming a patterned second mask (not shown) on the first metal film, the first metal film is exposed and developed to form a gate wiring. The gate line includes a gate line 131d, a gate electrode 131a, a gate pad 131c, and a reflective electrode 131b.

In detail, the gate line 131d extends in the row direction in the display area D, and the gate electrode 131a is formed to branch from the gate line 131d. The reflective electrode 131b is formed to be spaced apart from the gate electrode 131a at a predetermined interval, and is formed to be spaced apart from the adjacent reflective electrode at a predetermined interval. The gate pad 131c has a width wider than that of the gate line 131d and extends from an end of the gate line 131d to be formed in the gate pad region GP.

Since the gate wiring is formed on the organic insulating layer 120 with a uniform thickness, a plurality of irregularities are formed on the surface of the reflective electrode 131b like the organic insulating layer 120. As such, a plurality of irregularities are formed on the surface of the reflective electrode 131b, thereby increasing the surface area of the reflective electrode 131b to increase the efficiency of light, and adjusting the reflection angle of the light incident from the outside to extend the viewing angle. .

Subsequently, referring to FIG. 6, an inorganic material such as silicon nitride is coated on the organic insulating layer 120 including the gate wiring to a uniform thickness by a plasma-enhanced chemical vapor deposition (PECVD) method. The gate insulating film 132 is formed.

7A and 7B, an active layer and an ohmic contact layer are formed on the gate insulating layer 132 at a position corresponding to the gate electrode 131a. Specifically, an amorphous silicon film, for example, is deposited on the gate insulating layer 132 by a PECVD method, and an n ⁺ doped amorphous silicon film, for example, is deposited thereon as an ohmic contact layer. At this time, the active layer and the ohmic contact layer are deposited in-situ in the same chamber of the PECVD facility.

Subsequently, the gate insulating layer, the active layer, and the ohmic contact layer are patterned by a photolithography process using a third mask (not shown), and an active pattern made of an amorphous silicon layer on the gate insulating layer 132 over the gate electrode 131a. 133 and an ohmic contact pattern 134 formed of n ⁺ doped amorphous silicon film.

In the etching process, a first contact hole 132a for exposing the reflective electrode 131b and a second contact hole 132b for exposing the gate pad 131c are formed in the gate insulating layer 132. . Here, the first contact hole 132a exposes the reflective electrode 131b as a whole, thereby preventing the reflection efficiency of the reflective electrode 131b from being lowered by the gate insulating layer 132.

8A and 8B, a second metal film (not shown) such as chromium (Cr) is uniformly deposited on the ohmic contact pattern 134 and the gate insulating layer 132, and then a fourth marquee ( The second metal layer is patterned by a photolithography process using a not shown) to form data lines. The data line may include a data line 135e extending perpendicular to the gate line 131d in the column direction, a source electrode 135a and a drain electrode 135b branched from the data line 135e, and the data. Data pad 135c extending from the end of line 135e.

The drain electrode 135b is connected to the reflective electrode 131b through the first contact hole 132a of the gate insulating layer 132. Accordingly, power applied to the data line 135e by the gate driving voltage applied to the gate electrode 131a through the gate line 131d passes from the source electrode 135a to the drain electrode 135b. It is applied to the reflective electrode 131b.

Referring to FIG. 3 again, an alignment layer 140 is formed on the first substrate 110 on which the TFT 130 and the reflective electrode 131b are formed. Here, the alignment layer 140 not only aligns the liquid crystal by forming an alignment groove (not shown) by a rubbing process, but also serves as a protective film for protecting the TFT 130 and the reflective electrode 131b. .

As described above, the reflective electrode 131b is formed in the same process as the gate electrode 131a of the TFT 130. Here, although the reflective liquid crystal display 200 is shown as an example, the transparent liquid crystal display in which the transmissive electrode is formed in the same process as the gate wiring may be implemented by forming the gate wiring as ITO or IZO.

In addition, although not shown in the drawings, the reflection-transmissive liquid crystal display device may also be implemented by further providing a transmissive area for forming a small area of the reflective electrode 131b to transmit the generated light as it is.

9 is a cross-sectional view illustrating in detail a reflective liquid crystal display device according to another exemplary embodiment of the present invention. However, in describing FIG. 9, the same reference numerals are used for components that perform the same functions as the components illustrated in FIG. 3, and the description thereof will be omitted.

Referring to FIG. 9, the reflective liquid crystal display 210 includes a TFT substrate 180, a color filter substrate 160 provided to face the TFT substrate 180, and the TFT substrate 180 and the color filter substrate. And a liquid crystal layer 170 injected therebetween.

The display area D of the TFT substrate 180 is formed on the first substrate 110, the organic insulating layer 120 having an uneven structure, the TFT 130 formed on the organic insulating layer 120, and the TFT. And a reflective electrode 136c formed on the same layer as 130 and extending from the drain electrode 136b of the TFT 130.

The TFT 130 includes a gate electrode 131a, a source electrode 136a, and a drain electrode 136b. In detail, the gate electrode 131a is formed on the organic insulating layer 120, and then the gate insulating layer 132 is formed on the organic insulating layer 120 including the gate electrode 131a. The active layer 133 and the ohmic contact layer 134 for applying power from the source electrode 136a to the drain electrode 136b as power is applied to the gate electrode 131a on the gate insulating layer 132. Is formed. The source electrode 136a, the drain electrode 136b, and the reflective electrode 136c are formed on the same layer.

An alignment layer 140 is formed on the first substrate 110 on which the TFT 130 and the reflective electrode 136c are formed.                     

10 to 14B are diagrams specifically illustrating a manufacturing process of the TFT substrate illustrated in FIG. 9.

Referring to FIG. 10, an organic insulating material (not shown) such as a photosensitive acrylic resin is coated on a first substrate 110 made of an insulating material such as glass, quartz or sapphire, and having a flat surface structure. Subsequently, after the patterned first mask (not shown) is formed on the organic insulating material, when the organic insulating material is exposed and developed, an organic insulating layer 120 having an uneven structure corresponding to the patterning is formed. The organic insulating layer 120 is formed on the entire display area D, the gate pad area GP, and the data pad area DP.

 Although not shown in the drawings, the surface of the first substrate may be formed in an uneven structure. That is, when the surface of the first substrate is formed of the uneven structure, the organic insulating film is formed to have a uniform thickness thereon, so that the organic insulating film has a surface structure corresponding to the uneven structure of the first substrate.

11A and 11B, a first metal film (not shown) made of any one of molybdenum (Mo), chromium (Cr), and nickel (Ni) is formed on the organic insulating layer 120. Subsequently, after forming a patterned second mask (not shown) on the first metal film, the first metal film is exposed and developed to form a gate wiring. Here, the gate wiring includes a gate line 131d, a gate electrode 131a, and a gate pad 131c.

In detail, the gate line 131d extends in the row direction in the display area D, and the gate electrode 131a is branched from the gate line 131d. The gate pad 131c has a width wider than that of the gate line 131d and extends from an end of the gate line 131d to be formed in the gate pad region GP.

Referring to FIG. 12, an inorganic material such as silicon nitride is coated on the organic insulating layer 120 including the gate wiring to a uniform thickness by a plasma-enhanced chemical vapor deposition (PECVD) method. To form.

13A and 13B, an active layer and an ohmic contact layer are formed on the gate insulating layer 132 at a position corresponding to the gate electrode 131a. Specifically, an amorphous silicon film, for example, is deposited on the gate insulating layer 132 by a PECVD method, and an n ⁺ doped amorphous silicon film, for example, is deposited thereon as an ohmic contact layer. At this time, the active layer and the ohmic contact layer are deposited in-situ in the same chamber of the PECVD facility.

Subsequently, the gate insulating layer, the active layer, and the ohmic contact layer are patterned by a photolithography process using a third mask (not shown) to form an active pattern including an amorphous silicon layer on the gate insulating layer 132 on the gate electrode 131a. 133 and an ohmic contact pattern 134 formed of n ⁺ doped amorphous silicon film.

Meanwhile, a contact hole 132b for exposing the gate pad 131c is formed in the gate insulating layer 132 through the etching process.                     

14A and 14B, on the ohmic contact pattern 134 and the gate insulating layer 132, aluminum (Al), aluminum alloy (Ag), silver (Ag), and silver alloy (Ag) having good reflectances may be used. , A second metal film (not shown) made of any one of molybdenum (Mo), molybdenum alloy (MOalloy), chromium (Cr), and nickel (Ni) is formed. Thereafter, after forming a patterned fifth mask (not shown) on the second metal film, the second metal film is exposed and developed to form data lines. The data line may include a data line 136e, a source electrode 136a, a drain electrode 136b, a data pad 136d, and a reflective electrode 136c.

In detail, the data line 136e extends in the column direction in the display area D, and the source and drain electrodes 136a and 136b are formed to branch from the data line 136e. The reflective electrode 136c extends from the drain electrode 136b and is spaced apart from the adjacent reflective electrode at a predetermined interval. The data pad 136d has a width wider than that of the data line 136e and extends from an end of the data line 136e to form the data pad region DP.

Referring back to FIG. 10, an alignment layer 140 is formed on the first substrate 110 on which the TFT 130 and the reflective electrode 136c are formed. Here, the alignment layer 140 not only aligns the liquid crystal by forming an alignment groove by a rubbing process, but also serves as a protective layer for protecting the TFT 130 and the reflective electrode 136c.

As described above, the reflective electrode 136c is formed in the same process as the source and drain electrodes 136a and 136b of the TFT 130. Here, although the reflective liquid crystal display device 210 is shown as an example, the transparent liquid crystal display device in which the transmissive electrode is formed in the same process as the data wire may be implemented by forming the data line as ITO or IZO.

In addition, although not shown in the drawings, the reflection-transmissive liquid crystal display device may also be implemented by further providing a transmissive area for forming a small area of the reflective electrode 136c to transmit the generated light as it is.

According to an embodiment of the present invention, the active layer and the ohmic contact layer are patterned using a third mask to form an active pattern 133 and an ohmic contact pattern 134, and then a second metal layer is laminated thereon, and the fourth A 'four mask' process is described in which source and drain electrodes 136a and 136b are formed using a mask.

However, the 'three-mask mask' process of forming the active layer and the ohmic contact layer and then forming the second metal layer thereon and patterning the three layers together with one mask may be sufficiently applied in the present invention. .

According to the above-described liquid crystal display and its manufacturing method, the thin film transistor substrate is completed by forming an organic insulating film having an uneven structure on the first substrate and then forming a pixel electrode and a TFT on the organic insulating film in the same process. . That is, the pixel electrode is formed in the same process as the gate electrode of the TFT or in the same process as the source and drain electrodes of the TFT.                     

Therefore, since the pixel electrode is formed on the organic insulating layer having an uneven structure, the reflection efficiency of the reflective electrode can be improved when the pixel electrode is a reflective electrode. In addition, by forming the organic insulating layer on the lowermost layer of the TFT substrate, an undercut region is prevented from occurring in the gate pad portion in the etching process of forming the contact hole in the organic insulating layer, thereby preventing the gate pad from disconnecting from the pixel electrode. can do. Thereby, the display characteristic of a liquid crystal display device can be improved.

In addition, by forming the pixel electrode in the same process as the TFT, the mask required when the pixel electrode is formed on the TFT can be omitted. Therefore, the cost for manufacturing the liquid crystal display device can be reduced, the number of manufacturing steps can be shortened, and the productivity of the liquid crystal display device can be increased.

Although described with reference to the examples, those skilled in the art can understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention described in the claims below. There will be.

Claims (20)

a) a first substrate, b) a first insulating film formed on the first substrate and having a plurality of irregularities formed on a surface thereof, c) a first metal film formed on the first insulating film on which the irregularities are formed, a gate electrode, A gate line branching from the gate electrode and extending in a column direction, a gate line extending from an end of the gate line and a gate electrode including a pixel electrode, d) formed on the first insulating film including the gate line and A second insulating film having a first contact hole for exposing the pixel electrode and a second contact hole for exposing the gate pad, e) a channel layer formed on the second insulating film including an area where the gate electrode is formed, f A data line formed in the second metal film formed on the second insulating film including the channel layer and extending in a row direction and branched from the data line. A thin film transistor substrate including a source electrode, a drain electrode connected to the pixel electrode through the first contact hole, and a data line including a data pad extending from an end of the data line; A color filter substrate provided to face the thin film transistor substrate and having a common electrode facing the pixel electrode on a second substrate; And And a liquid crystal layer interposed between the thin film transistor substrate and the color filter substrate. The liquid crystal display device according to claim 1, wherein the gate wiring is made of any one of aluminum, aluminum alloy, silver, silver alloy, molybdenum, molybdenum alloy, chromium and nickel. The liquid crystal display device according to claim 1, wherein the surface of the pixel electrode has an uneven structure. The liquid crystal display of claim 1, wherein the gate line is made of ITO or IZO, which is a transparent conductive material. The liquid crystal display of claim 1, wherein the first contact hole exposes the pixel electrode as a whole. delete a) a first substrate, b) a first insulating film formed on the first substrate and having a plurality of irregularities formed on a surface thereof, c) a first metal film formed on the first insulating film on which the irregularities are formed, a gate electrode, A gate line branched from the gate electrode and extending in a column direction, a gate line including a gate pad extending from an end of the gate line, d) formed on the first insulating film including the gate line, A second insulating film formed with a contact hole exposing a contact hole; e) a channel layer formed on the second insulating film including a region where the gate electrode is formed; and f) a second metal film formed on the second insulating film including the channel layer. A data line extending in a row direction, a source electrode branched from the data line, a drain electrode, and a data plate extending from an end of the data line; And a thin film transistor substrate made of the data line to a pixel electrode connected with the drain electrode; A color filter substrate provided to face the thin film transistor substrate and having a common electrode facing the pixel electrode on a second substrate; And And a liquid crystal layer interposed between the thin film transistor substrate and the color filter substrate. 8. The liquid crystal display device according to claim 7, wherein the data line is made of any one of aluminum, aluminum alloy, silver, silver alloy, molybdenum, molybdenum alloy, chromium and nickel. The liquid crystal display device according to claim 7, wherein the surface of the pixel electrode has a concave-convex structure. 8. The liquid crystal display device according to claim 7, wherein the data line is made of ITO or IZO which is a transparent conductive material. delete a) forming a first insulating film having a plurality of irregularities on the first substrate; b) patterning a first metal film formed on the first insulating film having irregularities to form a gate electrode, a gate line branched from the gate electrode and extending in a column direction, a gate pad extending from an end of the gate line, and an uneven structure Forming a gate wiring including a pixel electrode with a uniform thickness; c) forming a second insulating layer on the first substrate including the gate wiring, the second insulating layer including a first contact hole for exposing the pixel electrode and a second contact hole for exposing the gate pad; d) forming a channel layer on the second insulating film including a region where the gate electrode is formed; e) patterning a second metal film formed on the second insulating film including the channel layer to extend in a row direction, a source electrode branched from the data line, and connected to the pixel electrode through the first contact hole Forming a data line comprising a drain electrode and a data pad extending from an end of the data line; f) forming a common electrode facing the pixel electrode on a second substrate provided to face the first substrate; g) aligning the first substrate and the second substrate with each other; And h) injecting a liquid crystal between the first substrate and the second substrate. The method of claim 12, wherein the gate wiring is made of aluminum, an aluminum alloy, silver, a silver alloy, molybdenum, molybdenum alloy, chromium, or nickel. The method of claim 12, wherein the gate line is made of ITO or IZO, which is a transparent conductive material. The method of claim 12, wherein the first contact hole exposes the pixel electrode as a whole. delete a) forming a first insulating film having a plurality of irregularities on the first substrate; b) a gate wiring including a gate electrode, a gate line branching from the gate electrode and extending in a column direction by patterning a first metal film formed on the first insulating film having irregularities, and a gate pad extending from an end of the gate line. Forming a; c) forming a second insulating film including a contact hole for exposing the gate pad on the first substrate including the gate wiring; d) forming a channel layer on the second insulating film including a region where the gate electrode is formed; e) data lines extending in a row direction by patterning a second metal film formed on the second insulating film including the channel layer, a source electrode branched from the data line, a drain electrode, and data extended from an end of the data line; Forming a data line connected to the pad and the drain electrode and including a pixel electrode having an uneven structure to have a uniform thickness; f) forming a common electrode facing the pixel electrode on a second substrate provided to face the first substrate; g) aligning the first substrate and the second substrate with each other; And h) injecting a liquid crystal between the first substrate and the second substrate. 18. The method of claim 17, wherein the data line is made of aluminum, an aluminum alloy, silver, a silver alloy, molybdenum, molybdenum alloy, chromium, or nickel. 18. The method of claim 17, wherein the data line is made of ITO or IZO, which is a transparent conductive material. delete

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