KR20050050893A - Liquid crystal display device and method for fabricating the same - Google Patents

Abstract

To provide a liquid crystal display device and a manufacturing method thereof suitable for solving the light leakage problem between the data wiring and the pixel electrode, the liquid crystal display device for achieving the above object and the first substrate facing each other at a predetermined interval and A second substrate; Gate and data lines formed on the first substrate in a length and width direction to define pixel regions; A thin film transistor formed of a gate electrode, a source electrode, and a drain electrode at an intersection of the gate wiring and the data wiring; A pixel electrode formed on the pixel region in contact with the drain electrode; And a first passivation layer having a contact hole so that the drain electrode is exposed and having a thickness greater than that of the other regions in the region between the data line and the pixel electrode.

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY DEVICE AND METHOD FOR FABRICATING THE SAME}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device suitable for reducing light leakage between a data line and a pixel electrode and a manufacturing method thereof.

As the information society develops, the demand for display devices is increasing in various forms, and in recent years, liquid crystal displays (LCDs), plasma display panels (PDPs), electro luminescent displays (ELDs), and vacuum fluorescent displays (VFDs) have been developed. Various flat panel display devices have been studied, and some of them are already used as display devices in various devices.

Among them, LCD is the most widely used as a substitute for CRT (Cathode Ray Tube) for the use of mobile image display device because of the excellent image quality, light weight, thinness, and low power consumption, and mobile type such as monitor of notebook computer. In addition, it is being developed in various ways, such as a television for receiving and displaying broadcast signals, and a monitor of a computer.

As described above, although various technical advances have been made in order for the liquid crystal display device to serve as a screen display device in various fields, the task of improving the image quality as the screen display device has many advantages and disadvantages.

Therefore, in order for a liquid crystal display device to be used in various parts as a general screen display device, development of high quality images such as high definition, high brightness, and large area is maintained while maintaining the characteristics of light weight, thinness, and low power consumption. It can be said.

Such a liquid crystal display device may be broadly divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel includes first and second glass substrates having a space and are bonded to each other; It consists of a liquid crystal layer injected between the said 1st, 2nd glass substrate.

The first glass substrate (TFT array substrate) may include a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing each gate line and data line, and a plurality of thin films that transmit signals of the data line to each pixel electrode by being switched by signals of the gate line The transistor is formed.

The second glass substrate (color filter substrate) includes a black matrix layer for blocking light in portions other than the pixel region, an R, G, B color filter layer for expressing color colors, and a common electrode for implementing an image. Is formed. Of course, the common electrode is formed on the first glass substrate in the transverse electric field type liquid crystal display device.

The first and second glass substrates are bonded by a sealing material having a predetermined space by a spacer and having a liquid crystal injection hole, and a liquid crystal is injected between the two substrates.

In this case, in the liquid crystal injection method, the liquid crystal is injected between the two substrates by osmotic pressure when the liquid crystal injection hole is immersed in the liquid crystal container by maintaining the vacuum state between the two substrates bonded by the reality. When the liquid crystal is injected as described above, the liquid crystal injection hole is sealed with a sealing material.

On the other hand, the driving principle of the liquid crystal display device as described above uses the optical anisotropy and polarization of the liquid crystal.

Since the liquid crystal is thin and long in structure, the liquid crystal has a direction in the arrangement of molecules, and the liquid crystal may be artificially applied to control the direction of the molecular arrangement.

Accordingly, when the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light polarized by optical anisotropy may be arbitrarily modulated to express image information.

Such liquid crystals may be classified into positive liquid crystals having a positive dielectric anisotropy and negative liquid crystals having a negative dielectric anisotropy according to an electrical specific classification, and liquid crystal molecules having a positive dielectric anisotropy are long axes of liquid crystal molecules in a direction in which an electric field is applied. The liquid crystal molecules arranged in parallel and having negative dielectric anisotropy are arranged perpendicularly to the direction in which the electric field is applied and the major axis of the liquid crystal molecules.

1 is an exploded perspective view illustrating a part of a general TN liquid crystal display device.

As shown in FIG. 1, the lower substrate 1 and the upper substrate 2 bonded to each other with a predetermined space, and the liquid crystal layer 3 injected between the lower substrate 1 and the upper substrate 2 are composed of. It is.

More specifically, the lower substrate 1 has a plurality of gate lines 4 arranged in one direction at regular intervals to define the pixel region P, and in a direction perpendicular to the gate lines 4. A plurality of data lines 5 are arranged at regular intervals, and a pixel electrode 6 is formed in each pixel region P where the gate line 4 and the data line 5 intersect, and each gate line The thin film transistor T is formed at the portion where (4) and the data line 5 intersect.

The upper substrate 2 includes a black matrix layer 7 for blocking light in portions other than the pixel region P, an R, G, and B color filter layer 8 for expressing color colors, and an image. The common electrode 9 is formed to implement the.

The thin film transistor T may include a gate electrode protruding from the gate line 4, a gate insulating film (not shown) formed on the front surface, an active layer formed on the gate insulating film above the gate electrode, and the data. And a source electrode protruding from the line 5 and a drain electrode to face the source electrode.

The pixel electrode 6 uses a transparent conductive metal having a relatively high light transmittance, such as indium-tin-oxide (ITO).

In the liquid crystal display device configured as described above, the liquid crystal layer 3 positioned on the pixel electrode 6 is aligned by a signal applied from the thin film transistor T, and the liquid crystal layer 3 is aligned with the alignment degree of the liquid crystal layer 3. Accordingly, the image can be expressed by controlling the amount of light passing through the liquid crystal layer 3.

As described above, the liquid crystal panel drives the liquid crystal by an electric field applied up and down, and has excellent characteristics such as transmittance and aperture ratio, and the common electrode 9 of the upper substrate 2 serves as a ground to discharge static electricity. It is possible to prevent the destruction of the liquid crystal cell.

Hereinafter, a liquid crystal display according to the related art will be described with reference to the accompanying drawings.

FIG. 2 is an enlarged plan view showing a unit pixel of a lower substrate of a conventional TN liquid crystal display, FIG. 3A is a structural cross-sectional view showing a liquid crystal display according to the prior art, and FIG. 3B is a conventional cross-sectional view taken along line II-II 'of FIG. 4 is a cross-sectional view illustrating a liquid crystal array according to the technology, and FIG. 4 is a transmission simulation result diagram corresponding to the cross-sectional view of FIG. 3B.

As shown in FIGS. 2 and 3A, a liquid crystal display according to the related art includes gate lines 21 and data lines 24 formed vertically and horizontally on a transparent lower substrate 20 to define pixel regions. A gate electrode 21a protruding from one side of the gate line 21, a gate insulating film 22 formed of a material such as SiNx or SiOx on the entire surface of the lower substrate 20 including the gate electrode 21a, and the gate An active layer 23 formed in an island shape on the gate insulating layer 22 on the electrode 21a and a source electrode protruding from the data line 24 and overlapping an upper portion of the active layer 23. 24a, a lower substrate spaced apart from the source electrode 24a, and having a drain electrode 24b overlapping the other side of the active layer 23, and a contact hole 26 so that the drain electrode 24b is exposed. Beam formed with uniform thickness on the front of 20 A film formed on the entire surface of the lower substrate 20 including the pixel electrode 27 and the pixel electrode 27 formed on the pixel region so as to contact the drain electrode 24b through the contact hole 26. It consists of one alignment film 28.

Reference numeral 23a denotes an ohmic contact layer, 30 is an upper substrate, 31 is a black matrix layer, 32 is a color filter layer, 33 is a transparent electrode layer, and 34 is a second alignment layer.

The pixel electrode 27 formed in the left and right pixel areas around the data line 24 does not form a large step with the protective film 25 formed between the data line 24 and the pixel electrode 27.

In the conventional liquid crystal display device configured as described above, as shown in FIG. 3B, when an electric field is applied to the data line 24 and the pixel electrode 27 to make the screen black, the data line 24 ), The electric field is distorted in the region between the pixel electrodes 27 and the pixel electrode 27, thereby causing the liquid crystal to be distorted to cause light leakage.

This light leakage phenomenon, as shown in the simulation result of Figure 4, when the black (black) state should be implemented, the transmittance in the region between the data wiring 54 and the pixel electrode 57 increases to approximately 35% You can see it.

The entire cross section of FIG. 4 corresponds one-to-one with the structure of FIG. 3B, where the 27.5 μm point of the X axis corresponds to the central portion of the data line 54, and the point (20 μm and 32.5 μm) of 35% transmittance is used for the data line. It corresponds to the area between 54 and the pixel electrode 57.

When the screen is to have a black state as described above, if the transmittance is increased in the region between the data line 54 and the pixel electrode 57 by the electric field distortion, light leakage occurs in the region. .

On the other hand, in order to prevent the light leakage problem as described above, the width of the black matrix layer formed on the upper substrate is also widened. If the width of the black matrix layer is widened, light leakage can be prevented, but the aperture ratio is reduced. A problem arises.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display device and a manufacturing method thereof suitable for solving the light leakage problem between the data wiring and the pixel electrode.

The liquid crystal display device of the present invention for achieving the above object comprises a first substrate and a second substrate facing each other at a predetermined interval; Gate and data lines formed on the first substrate in a length and width direction to define pixel regions; A thin film transistor formed of a gate electrode, a source electrode, and a drain electrode at an intersection of the gate wiring and the data wiring; A pixel electrode formed on the pixel region in contact with the drain electrode; And a first passivation layer having a contact hole so that the drain electrode is exposed and having a thickness greater than that of the other regions in the region between the data line and the pixel electrode.

The first passivation layer may be configured between the thin film transistor and the pixel electrode.

The thickness between the pixel electrode and the first passivation layer is configured to be at least 2000 GPa.

The second substrate may include a black matrix layer formed in a region corresponding to the gate wiring, the data line, and the thin film transistor, a color filter layer formed in a region corresponding to each pixel region, and a color filter layer. The transparent electrode layer and the second alignment layer formed on the transparent electrode layer is characterized in that the configuration.

According to another exemplary embodiment of the present invention, a liquid crystal display includes: a first substrate and a second substrate facing each other at predetermined intervals; Gate and data lines formed on the first substrate in a length and width direction to define pixel regions; A thin film transistor formed of a gate electrode, a source electrode, and a drain electrode at an intersection of the gate wiring and the data wiring; A second passivation layer formed on the first substrate to have contact holes to expose the drain electrode; And an additional passivation layer formed on the data line and adjacent regions, and a pixel electrode formed on the pixel region to be in contact with the drain electrode.

The additional passivation layer may be formed in an area between the data line including the upper portion of the data line and the pixel electrode.

The thickness of the additional protective film is configured to be at least 2000 되도록.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including: forming a gate wiring having a gate electrode on a substrate; Forming a gate insulating film on the substrate including the gate wiring; Forming an active layer on the gate electrode; Forming data lines intersecting with the gate lines to define pixel areas; Forming a source electrode and a drain electrode to overlap one side and the other side of the active layer; Forming a first passivation layer on the substrate so as to have a step higher than another area in an adjacent area including the data line; The pixel electrode may be formed in the pixel region to be in contact with the drain electrode.

The first protective film, the step of applying a first photosensitive film on the first protective film; Exposing, developing and patterning the first photoresist film using a mask; And etching the first passivation layer by using the patterned first photoresist layer.

The mask is a pixel electrode forming mask, and the first photosensitive film is a negative photosensitive film.

In particular, the first passivation layer may be formed to have a higher level than other regions in the region between the data line and the pixel electrode.

The pixel electrode sequentially forming a transparent conductive film and a second photoresist film on the entire surface of the substrate including the first protective film; Exposing and developing the second photoresist film using the mask to pattern the second photoresist film so as to remain only in an upper portion of the pixel region; And etching the transparent conductive layer using the patterned second photoresist layer as a mask to form a pixel electrode in a pixel region.

The pixel electrode may be formed using the same mask as the first passivation layer.

The second photosensitive film is characterized in that the positive photosensitive film.

When the first photoresist film is a positive photoresist film, the second photoresist film is a negative photoresist film.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including forming a gate wiring having a gate electrode on a substrate; Forming a gate insulating film on the substrate including the gate wiring; Forming an active layer on the gate electrode; Forming data lines intersecting with the gate lines to define pixel areas; Forming a source electrode and a drain electrode to overlap one side and the other side of the active layer; Forming a second passivation layer on the substrate; Forming an additional passivation layer on the second passivation layer so as to have a step higher than another area in an adjacent area including the data line; The pixel electrode may be formed in the pixel region to be in contact with the drain electrode.

In particular, the additional passivation layer is formed in a region between the data line and the pixel electrode.

Hereinafter, a liquid crystal display and a manufacturing method thereof according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

5 is an enlarged plan view illustrating a unit pixel of a lower substrate of the TN liquid crystal display according to the present invention, FIG. 6A is a cross-sectional view of a structure of a TN liquid crystal display according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a structure of a TN liquid crystal display device according to an exemplary embodiment.

7 is a view comparing the structure between the data wiring and the pixel electrode of the prior art and the present invention, and FIG.

As shown in FIGS. 5 and 6A, the liquid crystal display according to the first exemplary embodiment of the present invention has a gate line 51 and a data line formed on a transparent lower substrate 50 vertically and horizontally to define a pixel area. 54, a gate electrode 51a protruding from one side of the gate wiring 51, and a gate insulating film 52 formed of a material such as SiNx or SiOx on the entire surface of the lower substrate 50 including the gate electrode 51a. ), An active layer 53 formed in an island shape on the gate insulating layer 52 on the gate electrode 51a, and protruding from the data line 54 to be formed on one side of the active layer 53. The overlapped source electrode 54a, the drain electrode 54b spaced apart from the source electrode 54a by a predetermined interval, and the overlapped electrode electrode 54b on the other side of the active layer 53, and the contact hole 56 is exposed. Lower part to have a different thickness A first passivation layer 55 formed on the front surface of the plate 50, a pixel electrode 57 formed on the pixel region to contact the drain electrode 54b through the contact hole 56, and a lower portion including the pixel electrode. The first alignment layer 58 is formed on the substrate 50.

The first alignment layer 58 is made of polyimide.

The first passivation layer 55 is formed to be thicker in the pixel area than in other areas. In particular, it has a step so that the thickness between the data line 54 and the pixel electrode 57 is formed thicker than the thickness in other areas.

The reason why the first passivation layer 55 is configured to have the step is to solve the electric field distortion caused by the voltage difference between the data line 54 and the pixel electrode 57 and the light leakage problem.

In the above description, the thickness 't1' between the pixel electrode 57 and the first passivation layer 55 is about 2000 μs or more by subtracting the top height of the pixel electrode 57 from the top height of the first passivation layer 55. It is configured to have.

As such, when the thickness of the first passivation layer 55 between the data line 54 and the pixel electrode 57 is increased, the voltage difference between the data line 54 and the pixel electrode 57 can be reduced.

As described above, when the thickness of the first passivation layer 55 is increased in the region where light leakage occurs (that is, the region between the data line 54 and the pixel electrode 57), the thickness of the liquid crystal layer in this region is increased. Since it can be made thinner than the actual cell gap thickness, it is possible to reduce the transmittance, that is, light leakage phenomenon.

The thickness of the liquid crystal layer between the data line 54 and the pixel electrode 57 can be seen in FIGS. 3A, 6A, and 7. In the conventional and the present invention, the lower substrate 50 and the upper substrate ( When the cell gap between 61 is 4.8 占 퐉, the cell gap between the data wiring 24 and the pixel electrode 27 is 4.9 占 퐉, whereas the present invention provides a gap between the data line 54 and the pixel electrode 57. The cell gap of 4.3 m was thinner than the conventional one. At this time, the thickness 't1' between the pixel electrode 57 and the first passivation layer 55 of the present invention is approximately 0.5 mu m.

In addition, a black matrix layer 62 is formed on an area corresponding to the gate wiring, the data wiring, and the thin film transistor to prevent light leakage on the lower substrate 50 and the upper substrate 61 corresponding to the above-described lower substrate 50. In addition, a color filter layer 63 formed of color filter elements of R, G, and B for realizing color is formed in each pixel area, and a transparent electrode layer is formed on the entire surface of the upper substrate 61 including the color filter layer 63. 64 is formed, and the second alignment layer 65 is formed on the transparent electrode layer 64.

Next, as shown in FIG. 6B, the liquid crystal display according to the second exemplary embodiment of the present invention is formed vertically and horizontally on the transparent lower substrate 50 so as to define the pixel region and the gate wiring 51 and the data wiring ( 54, a gate electrode 51a protruding from one side of the gate wiring 51, and a gate insulating film 52 formed of a material such as SiNx or SiOx on the entire surface of the lower substrate 50 including the gate electrode 51a. ), An active layer 53 formed in an island shape on the gate insulating layer 52 on the gate electrode 51a, and protruding from the data line 54 to be formed on one side of the active layer 53. The overlapped source electrode 54a, the drain electrode 54b spaced apart from the source electrode 54a by a predetermined interval, and the overlapped electrode electrode 54b on the other side of the active layer 53, and the contact hole 56 is exposed. Second beam formed on the front surface of the lower substrate 50 to have The pixel 59, an additional passivation layer 60 formed in the data line 54 and the region adjacent thereto, and a pixel electrode 57 formed on the pixel region to be in contact with the drain electrode 54b through the contact hole 56. ) And a first alignment layer 58 formed on the lower substrate 50 including the pixel electrode 57.

As described above, in the liquid crystal display according to the second exemplary embodiment of the present invention, the second passivation layer 59 is formed to have a uniform thickness on the entire surface of the lower substrate 50 including the data line 54, and the data line The same configuration as the liquid crystal display according to the first embodiment of the present invention except that an additional passivation layer 60 is further formed in the region between the data wiring 54 including the upper portion of the pixel 54 and the pixel electrode 57. Has

If the additional passivation layer 60 is further formed as described above, since the step difference between the passivation layer is formed between the data line 54 and the pixel electrode 57, the light leakage phenomenon due to the electric field distortion is prevented as in the first embodiment of the present invention. It is possible to prevent and further reduce the transmittance (light leakage) as the liquid crystal cell gap is reduced.

At this time, the thickness 't2' of the additional protective film 59 is configured to be approximately 2000 GPa or more.

The structure is effective when the normally black mode is applied, and when the black state is black, the transmittance between the data line 54 and the pixel electrode 57 is reduced to provide stable black. (black) can be implemented.

Hereinafter, the two-dimensional simulation results of the transmittance of the liquid crystal display having the configuration of the present invention will be described.

As shown in FIG. 8, the simulation result of the transmittance shows that the transmittance between the data line and the pixel electrode according to the prior art (-◆-) was 2.62%, whereas the data according to the present invention (-■-) was high. The transmittance between the wiring and the pixel electrode was as low as 0.76%.

As in the above simulation results, when the first passivation layer between the data line 54 and the pixel electrode 57 is formed thick, the transmittance between the data line 54 and the pixel electrode 57 is lowered and thus black. It can be seen that the light leakage phenomenon is reduced when implementing the (black) state.

Next, a method of manufacturing a liquid crystal display device according to an embodiment of the present invention having the above configuration will be described.

9A to 9E are cross-sectional views illustrating a method of manufacturing a TN liquid crystal display device according to the present invention.

In the method of manufacturing the liquid crystal display device according to the first embodiment of the present invention, as shown in FIG. 9A, the conductive metal is deposited on the transparent lower substrate 50, and the conductive metal is patterned using photo and etching processes. Thus, a gate pad (not shown) having one end widened to a predetermined area, a gate wiring 51 extending in one direction from the gate pad, and a gate electrode 51a protruding from the gate wiring 51 in one direction. ).

Thereafter, the gate insulating layer 52 is formed on the entire surface of the lower substrate 50 on which the gate electrode 51a is formed.

The gate insulating layer 52 may use a silicon nitride layer (SiNx) or a silicon oxide layer (SiO ₂ ).

Thereafter, as shown in FIG. 9B, a semiconductor layer (amorphous silicon + impurity amorphous silicon) is formed on the gate insulating film 52.

Subsequently, the semiconductor layer is patterned by photo and etching processes to form an active layer 53 having an island shape on the gate electrode 51a.

Subsequently, a conductive metal is deposited on the entire surface of the lower substrate 50 on which the active layer 53 is formed, and patterned through photo and etching processes to intersect the gate wiring 51 to define a pixel region 54. ) And a source pad (not shown) having a predetermined area at an end thereof, the source electrode 54a protruding in one direction from the data line 54, and the source electrode 54a separated from each other by a predetermined distance. A drain electrode 54b is formed.

When the source electrode 54a and the drain electrode 54b are formed, an amorphous silicon layer over the channel region is excessively etched to form a gap between the source electrode 54a and the active layer 53 and between the drain electrode 54b and the active layer. An ohmic contact layer 53b is formed therebetween.

Thereafter, as shown in FIG. 9C, the first passivation layer 55 is formed on the entire surface of the lower substrate 50 on which the data line 54 is formed.

The first passivation layer 55 may be formed using at least one of acryl, polyimide, benzocyclobutene (BCB), oxide film, and nitride film.

Subsequently, a first photosensitive film 70 is coated on the first passivation film 55. At this time, the first photoresist film 70 is a negative photoresist film and has a property that the exposed portion remains.

Next, the first photoresist film 70 is exposed and developed by using the pixel electrode forming mask 71 to pattern the first photoresist film 70 except for the pixel region.

Subsequently, as shown in FIG. 9D, only the first passivation layer 55 on the pixel region is further etched using the patterned first photoresist layer 70 as a mask to form a first passivation layer 55 having a step. do.

This process is to reduce the transmittance by increasing the thickness of the first passivation layer 55 between the data line 54 and the pixel electrode.

Next, the transparent conductive film 57a and the second photosensitive film 72 are sequentially formed on the entire lower substrate 50 including the first protective film 55. At this time, the second photosensitive film 72 is a positive photosensitive film and has a property of removing only the exposed portion.

Thereafter, the second photosensitive film 72 is exposed and developed using the pixel electrode forming mask 71 used above, and the second photosensitive film 72 is patterned so as to remain only in the upper portion of the pixel region.

Next, as shown in FIG. 9E, the transparent conductive film 57a is etched using the patterned second photosensitive film 72 as a mask to form the pixel electrode 57 in the pixel region.

Subsequently, a first alignment layer 58 is formed on the entire surface of the lower substrate 50 including the pixel electrode 57.

When the first photoresist layer 70 is a positive photoresist layer, the second photoresist layer 72 uses a negative photoresist layer, and in this case, a mask for shielding portions except the pixel electrode 57 is used.

As a result of the above process, the first passivation layer 55 has a step between the data line 54 and the pixel electrode 57 and is thicker than other regions.

In addition, since the first passivation film 55 and the pixel electrode 57 are formed using the same mask 71, an additional mask is not required to form the first passivation film 55 having the step, thereby reducing the production cost. Can be.

On the other hand, although not shown in the drawings, the manufacturing method for forming the liquid crystal display according to the second embodiment of the present invention, instead of the first protective film 55, the second protective film on the entire surface of the lower substrate 50 including the thin film transistors After depositing the 59 to a uniform thickness, the third passivation layer is deposited on the second passivation layer 59, and then the third passivation layer is etched by a photo process to remove the third passivation layer between the data line 54 and the pixel electrode 57. 2 is the same as the method of manufacturing the liquid crystal display device according to the first embodiment of the present invention except that an additional passivation layer 60 is further formed on the passivation layer 59.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the above embodiments, but should be defined by the claims.

The liquid crystal display device and its manufacturing method of the present invention having the above structure have the following effects.

First, since the first passivation layer between the data line and the pixel electrode is formed thick so as to have a step, it is possible to prevent light leakage due to the electric field distortion between the data line and the pixel electrode.

Second, since the formation of the first passivation layer and the pixel electrode may be performed using the same mask, a first passivation layer having a step may be formed without the need for an additional mask. This leads to the effect of saving the production cost.

1 is an exploded perspective view showing a part of a typical TN liquid crystal display device

2 is an enlarged plan view illustrating a unit pixel of a lower substrate of a conventional TN liquid crystal display device;

3A is a structural cross-sectional view of a liquid crystal display according to the related art.

3B is a cross-sectional view illustrating a liquid crystal array according to the related art on the line II-II ′ of FIG. 2.

4 is a transmission simulation result corresponding to the cross-sectional view of FIG.

5 is an enlarged plan view illustrating unit pixels of a lower substrate of a TN liquid crystal display according to an exemplary embodiment of the present invention.

6A is a structural cross-sectional view of a TN liquid crystal display device according to a first embodiment of the present invention.

6B is a structural cross-sectional view of a TN liquid crystal display device according to a second embodiment of the present invention.

7 is a view comparing the structure between the data wiring and the pixel electrode of the prior art and the present invention;

8 is a transmission simulation result in accordance with an embodiment of the present invention

9A to 9E are cross-sectional views illustrating a method of manufacturing a TN liquid crystal display device according to the present invention.

Explanation of symbols on the main parts of the drawings

50: lower substrate 51: gate wiring

51a: gate electrode 52: gate insulating film

53 active layer 53a ohmic contact layer

54: data wiring 54a: source electrode

54b: drain electrode 55: first protective film

56 contact hole 57 pixel electrode

57a: transparent conductive film 58: first alignment film

59: second protective film 60: additional protective film

61: upper substrate 62: black matrix layer

63 color filter layer 64 transparent electrode layer

65 second alignment film 70 first photosensitive film

71: mask 72: second photosensitive film

Claims (17)

A first substrate and a second substrate facing each other at a predetermined interval; Gate and data lines formed on the first substrate in a length and width direction to define pixel regions; A thin film transistor formed of a gate electrode, a source electrode, and a drain electrode at an intersection of the gate wiring and the data wiring; A pixel electrode formed on the pixel region in contact with the drain electrode; And a first passivation layer having a contact hole so that the drain electrode is exposed, and having a thickness greater than that of the other region between the data line and the pixel electrode. The method of claim 1, Wherein the first passivation layer is formed between the thin film transistor and the pixel electrode. The method of claim 1, And the thickness between the pixel electrode and the first passivation layer is at least 2000 GPa. The method of claim 1, In the second substrate, A black matrix layer formed in a region corresponding to the gate wiring, the data wiring, and the thin film transistor; A color filter layer formed in a region corresponding to each pixel region, A transparent electrode layer formed on the front surface including the color filter layer; And a second alignment layer formed on the transparent electrode layer. A first substrate and a second substrate facing each other at a predetermined interval; Gate and data lines formed on the first substrate in a length and width direction to define pixel regions; A thin film transistor formed of a gate electrode, a source electrode, and a drain electrode at an intersection of the gate wiring and the data wiring; A second passivation layer formed on the first substrate to have contact holes to expose the drain electrode; An additional passivation layer formed on and adjacent to the data line; And a pixel electrode formed on the pixel region in contact with the drain electrode. The method of claim 5, And the additional passivation layer is formed in a region between the data line including the upper portion of the data line and the pixel electrode. The method of claim 5, And the thickness of the additional protective layer is at least 2000 GPa. Forming a gate wiring having a gate electrode on the substrate; Forming a gate insulating film on the substrate including the gate wiring; Forming an active layer on the gate electrode; Forming data lines intersecting with the gate lines to define pixel areas; Forming a source electrode and a drain electrode to overlap one side and the other side of the active layer; Forming a first passivation layer on the substrate so as to have a step higher than another area in an adjacent area including the data line; And forming a pixel electrode in the pixel region in contact with the drain electrode. The method of claim 8, The first protective film, Applying a first photoresist film on the first passivation film; Exposing, developing and patterning the first photoresist film using a mask; And etching the first passivation layer by using the patterned first photoresist layer. The method of claim 9, And the mask is a pixel electrode forming mask, and the first photosensitive film is a negative photosensitive film. The method of claim 8, In particular, the first passivation layer is formed to have a step higher than another area in the area between the data line and the pixel electrode. The method of claim 8, The pixel electrode sequentially forming a transparent conductive film and a second photoresist film on the entire surface of the substrate including the first protective film; Exposing and developing the second photoresist film using the mask to pattern the second photoresist film so as to remain only in an upper portion of the pixel region; And forming a pixel electrode in a pixel region by etching the transparent conductive layer using the patterned second photoresist layer as a mask. The method of claim 12, The pixel electrode is formed using the same mask as the first passivation layer. The method of claim 12, And the second photosensitive film is a positive photosensitive film. The method according to claim 9 or 12, And the second photoresist film is a negative photoresist film when the first photoresist film is a positive photoresist film. Forming a gate wiring having a gate electrode on the substrate; Forming a gate insulating film on the substrate including the gate wiring; Forming an active layer on the gate electrode; Forming data lines intersecting with the gate lines to define pixel areas; Forming a source electrode and a drain electrode to overlap one side and the other side of the active layer; Forming a second passivation layer on the substrate; Forming an additional passivation layer on the second passivation layer so as to have a step higher than another area in an adjacent area including the data line; And forming a pixel electrode in the pixel region in contact with the drain electrode. The method of claim 16, In particular, the additional protective layer is formed in the region between the data line and the pixel electrode.