KR20080055325A - Thin film transistor and liquid crystal display device having same - Google Patents

Abstract

The present invention is to provide a thin film transistor and a liquid crystal display device having the same to increase the W / L ratio and to improve the vertical crosstalk, the thin film transistor for achieving the above object is formed in one direction on the substrate A gate electrode; A gate insulating film formed on the substrate including the gate electrode; A semiconductor layer overlapping the gate electrode; A source electrode overlapping the upper portion of the gate electrode and having a bent portion and having a plurality of irregularities inside the bent portion; It characterized in that it comprises a drain electrode spaced apart from the source electrode at a predetermined interval and engaged with the concave-convex portion inside the bent portion of the source electrode and inserted into the bent portion.

Description

Thin Film Transistor and Liquid Crystal Display Device Having the same

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

2 is a plan view showing a liquid crystal display device for applying the present invention.

3 to 5 are plan views of a thin film transistor according to an embodiment of the present invention.

6 to 8 are plan views illustrating a liquid crystal display device according to a first embodiment of the present invention.

9 is a plan view illustrating a liquid crystal display according to a second exemplary embodiment of the present invention.

10 is a plan view illustrating a liquid crystal display according to a third exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

30, 40, 50, 60a, 70a, 80a, 90a, 111a: gate electrode

31, 41, 51, 63, 73, 83, 93, 112: semiconductor layer

32a, 42a, 52a, 65a, 75a, 85a, 95a, 113a: source electrode

32b, 42b, 52b, 65b, 75b, 85b, 95b, 113b: drain electrode

60, 70, 80, 90, 111: gate line

65, 75, 85, 95, 113: data line

67, 77, 87, 97, 113c: pixel electrode

68, 78, 88, 98: drain contact hole

111b: common wiring 113d: storage electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a thin film transistor suitable for increasing the W / L ratio and thereby improving vertical crosstalk, and a liquid crystal display device having the same.

As the information society develops, the demand for display devices is increasing in various forms.In recent years, liquid crystal display (LCD), plasma display panel (PDP), electro luminescent display (ELD), and vacuum fluorescent display (VFD) 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 developments 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.

Hereinafter, a configuration of a general liquid crystal display device will be described with reference to the accompanying drawings.

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

As shown in FIG. 1, a general TN liquid crystal display device includes a lower substrate 1 and an upper substrate 2 bonded to each other with a predetermined space, and a liquid crystal injected between the lower substrate 1 and the upper substrate 2. It consists of layer (3).

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 to be arranged to define the pixel region P, and pixels are formed in each pixel region P defined by crossing the gate line 4 and the data line 5. The electrode 6 is formed, and the thin film transistor T is formed at a portion where the gate lines 4 and the data lines 5 intersect each other.

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 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.

Since the liquid crystal display device is driven independently for each pixel in the static driving, the liquid crystal display device is almost unaffected by the signal voltage of other pixels. However, in the line addressing driving, the signal is distorted according to the information of the adjacent pixels. (cross-talk) may occur.

Generally, the crosstalk is divided into horizontal crosstalk and vertical crosstalk. Horizontal crosstalk is caused by capacitor coupling between the common electrode and the source electrode, and vertical crosstalk is caused by the capacitance between the source electrode and the drain electrode.

The vertical crosstalk can be reduced by increasing the ratio of the channel length to the channel width (W / L) of the TFT LCD, but there is a limit in increasing the capacitance between the source electrode and the drain electrode only with the general channel structure as shown in FIG.

Accordingly, there is a need for improving the structure of the liquid crystal display device to improve vertical crosstalk.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a thin film transistor and a liquid crystal display device having the same to increase the W / L ratio and to improve the vertical cross talk.

A thin film transistor according to the present invention for achieving the above object comprises a gate electrode formed in one direction on a substrate; A gate insulating film formed on the substrate including the gate electrode; A semiconductor layer overlapping the gate electrode; A source electrode overlapping the upper portion of the gate electrode and having a bent portion and having a plurality of irregularities inside the bent portion; It characterized in that it comprises a drain electrode spaced apart from the source electrode at a predetermined interval and engaged with the concave-convex portion inside the bent portion of the source electrode and inserted into the bent portion.

The source electrode has at least one bent portion, and the bent portion of the source electrode further includes a '⊂' shape or a 'back' shape or a '∈' shape or 'reverse' shape.

A liquid crystal display device according to the present invention having a thin film transistor having the above structure comprises: a gate line and a data line arranged in an alternating manner to define a pixel region; A gate electrode connected to the gate line and a gate electrode connected to the gate line, a source electrode having a bent portion and having a plurality of irregularities in the bent portion, and a protrusion to be engaged with the uneven portion of the source electrode. A thin film transistor having a drain electrode having a drain electrode inserted into the bent portion; And a pixel electrode connected to the drain electrode of the thin film transistor and formed in the pixel region.

The source electrode may have at least one bent portion, and the bent portion of the source electrode may further include a '자' shape, a 'reverse' shape, or a '자' shape or a 'reverse' shape.

The bent portion of the source electrode is configured in a direction parallel or perpendicular to the gate line.

The semiconductor layer further includes a lower portion of the source electrode, the drain electrode, and the data line.

The liquid crystal display further includes a common electrode formed in the pixel area in parallel with the data line, and a transverse electric field type liquid crystal display in which the pixel electrode is arranged between the common electrodes.

As described above, in the liquid crystal display device, vertical crosstalk may occur due to a lack of capacitance between the source electrode and the drain electrode, and there is a need for improving the structure of the thin film transistor of the liquid crystal display device.

Hereinafter, a configuration of the liquid crystal display device for applying the present invention will be described.

2 is a plan view illustrating a liquid crystal display for applying the present invention.

As shown in FIG. 2, the liquid crystal display according to the present invention includes a gate line 10 arranged in one direction on a substrate, a gate electrode 10a protruding from one side of the gate line 10, and A thin film having an '⊂'-shaped channel formed at an intersection of the data line 15 crossing the gate line 10 to define a pixel region and the gate line 10 and the data line 15. And a pixel electrode 17a formed in the pixel region so as to be connected to the transistor TFT and the drain electrode 15b of the thin film transistor.

The thin film transistor TFT may include a gate electrode 10a protruding from one side of the gate line 10, a semiconductor layer 13 overlapping the gate electrode 10a, and a data line 15. A source electrode 15a protruding from one side and a drain electrode 15b spaced apart from the source electrode 15a by a predetermined interval are formed.

The drain electrode 15b is connected to the pixel electrode 17a through the drain contact hole 18.

The semiconductor layer 13 is for forming a conductive channel between the source electrode 15a and the drain electrode 15b by the gate voltage supplied to the gate electrode 10a.

Although not shown in the drawings, a gate insulating film (not shown) is further provided on the substrate including the gate line 10 and the gate electrode 10a, and between the semiconductor layer 13 and the source electrode 15a. And an ohmic contact layer (not shown) between the semiconductor layer 13 and the drain electrode 15b to reduce the resistance.

The thin film transistor receives a gate signal from the gate line 10 and is turned on / off, and selectively supplies the data signal transferred from the data line 15 to the pixel electrode 17a.

The pixel electrode 17a is positioned in a pixel region defined by crossing the data line 15 and the gate line 10 and is made of a transparent conductive material having high light transmittance.

Here, the thin film transistor is bent to have a channel structure of a '⊂' shape, such a channel structure, the source electrode 15a protruding from the data line 15 '⊂' in parallel with the gate line 10. It is formed by bending in a shape.

The drain electrode 15b is inserted and positioned inside the bent source electrode 15a so as to be spaced apart from the bent source electrode 15a by a predetermined interval.

However, even when the thin film transistor is configured to have a '⊂'-shaped channel as described above, the above structure alone has a limitation in improving vertical crosstalk by increasing the capacitance between the source electrode and the drain electrode in the limited area of the thin film transistor. have.

In other words, in the liquid crystal display, the ratio of the channel length to the channel width (W / L) can be designed only by adjusting the channel length (L) of the thin film transistor, where the channel length (L) is approximately 5.5 μm. Because of this, the designer has a small range to choose from. In addition, since the W / L value is small, the on current Ion value is small and sufficient charging is not performed, which may cause vertical crosstalk.

Accordingly, in the present invention, when the thin film transistor is configured in the same area, the thin film transistor suitable for increasing the capacitance between the source electrode and the drain electrode and the liquid crystal display including the same will be described with reference to the accompanying drawings.

3 to 5 are plan views of a thin film transistor according to an exemplary embodiment of the present invention.

6 to 8 are plan views illustrating a liquid crystal display device according to a first embodiment of the present invention, FIG. 9 is a plan view illustrating a liquid crystal display device according to a second embodiment of the present invention, and FIG. A planar configuration diagram of a liquid crystal display device according to a third embodiment of the present invention.

First, in the thin film transistor according to the exemplary embodiment of the present invention, as shown in FIG. 3, a gate electrode 30 is formed in one direction on a substrate (not shown), and the substrate including the gate electrode 30 is formed. A gate insulating film (not shown) is formed on the semiconductor layer 31, and the semiconductor layer 31 is patterned so as to overlap the gate electrode 30.

In addition, a source electrode 32a having a bent portion overlapping with an upper side of the gate electrode 30 and having a plurality of irregularities is formed in the bent portion.

In FIG. 3, an example in which the source electrode 32a is bent in a '⊂' shape, and three recesses are provided, one at each of the upper, lower, and side portions inside the bent portion is illustrated.

In addition, the drain electrode 32b is formed at a portion spaced apart from the source electrode 32a by a predetermined interval and inserted into the bent portion, and has a plurality of protrusions at a portion corresponding to the recessed portion inside the bent portion of the source electrode 32a. have.

In the configuration as described above, even if the source electrode 32a and the drain electrode 32b are formed in the same area, the drain electrode 32b formed with the unevenness inside the bent portion of the source electrode 32a and the protruding portion to engage with it. This can increase the ratio W / L of the channel length L to the channel width W.

In FIG. 3, although the source electrode 32a has a configuration example having a '절' -shaped bent portion and three recesses therein, the configuration is only one embodiment and is not intended to limit the present invention. The source electrode 32a may be configured to have a variety of bent portions that can be designed in the same area and have a plurality of irregularities therein, and constitute a drain electrode having protrusions in accordance with the irregularities of the source electrode spaced apart from the source electrode by a predetermined distance. You can.

For example, the bent portion of the source electrode may be configured as a '⊂' shape or 'inverse' shape, or '∈' shape or 'inverse' shape, and each bent portion may have a plurality of unevenness inside. The drain electrode may be configured to protrude in accordance with the unevenness of the source electrode to be spaced apart from the source electrode at a predetermined interval.

Next, another example of the thin film transistor according to the number of irregularities will be described with reference to the drawings when the source electrode in the configuration is formed in a '⊂' shape.

As shown in FIG. 4, a gate electrode 40 is formed in one direction on a substrate (not shown), and a gate insulating film (not shown) is formed on the substrate including the gate electrode 40. The semiconductor layer 41 is patterned to overlap the gate electrode 40.

In addition, a source electrode 42a having a U-shaped bent portion overlapping in one upper direction of the gate electrode 40 and having a plurality of irregularities inside the bent portion is formed. 4 illustrates an example in which four recesses and two recesses on the side and one on the side are configured.

The drain electrode 42b is formed to be inserted into the bent portion spaced apart from the source electrode 42a by a predetermined interval, and to have a plurality of protrusions at a portion corresponding to the recessed portion inside the bent portion of the source electrode 42a. .

In the configuration as described above, even if the source electrode 42a and the drain electrode 42b are formed in the same area, the channel length is due to the unevenness inside the bent portion of the source electrode 42a and the drain electrode 42b formed in engagement therewith. It is possible to further increase the ratio (W / L) of (L) to channel width (W).

As described above, in Fig. 4, the source electrode 42a has been described with reference to a configuration example having a bent portion having a '⊂' shape and five recesses inside.

Next, another configuration example of the thin film transistor will be described with reference to the accompanying drawings. As shown in FIG. 5, a gate electrode 50 is formed on a substrate (not shown) in one direction, and the gate electrode ( A gate insulating film (not shown) is formed on the substrate including the semiconductor layer 50, and the semiconductor layer 51 is patterned so as to overlap the gate electrode 50.

A source electrode 52a having a U-shaped bent portion overlapping the upper portion of the gate electrode 50 and having a plurality of irregularities inside the bent portion is formed. 5 shows an example in which six recesses and three recesses on the side and one on the side are configured.

The drain electrode 52b is formed to be inserted into the bent portion spaced apart from the source electrode 52a by a predetermined interval, and to have a plurality of protrusions at a portion corresponding to the recessed portion inside the bent portion of the source electrode 52a. .

In the above configuration, even if the source electrode 52a and the drain electrode 52b are formed in the same area, the channel length is due to the unevenness inside the bent portion of the source electrode 52a and the drain electrode 52b formed in engagement with this. The ratio W / L of (L) to channel width W can be increased more than in FIG.

In summary, in FIG. 5, the source electrode 52a has been described with reference to a configuration example having a bent portion having a '⊂' shape and seven recessed portions therein.

As described above, when forming the thin film transistor in the same area, the area occupied by the channel portion is limited, as described above, forming a concave-convex inside the bent of the source electrode, and the drain electrode having a protrusion to engage the concave-convex When formed, the channel width W and TFT characteristics can be derived as the designer intends, and the large channel width W can be obtained even in a small area.

Increasing the ratio of the channel length to the channel width (W / L) as described above improves the mobility of charges moving through the channel, thereby improving driving characteristics of the TFT.

Next, the configuration of the liquid crystal display device provided with the thin film transistor as described above will be described.

First, as shown in FIG. 6, the liquid crystal display according to the first exemplary embodiment of the present invention includes a gate line 60 arranged in one direction on a substrate and a gate protruding from one side of the gate line 60. Curved irregularities are formed at the intersection of the electrode 60a, the data line 65 crossing the gate line 60 to define a pixel region, and the gate line 60 and the data line 65. And a pixel electrode 67 formed in the pixel region so as to be connected to the drain electrode 65b of the thin film transistor.

The thin film transistor TFT may include a gate electrode 60a connected to the gate line 60, a semiconductor layer 63 overlapped with a routine portion of the gate electrode 60a, and a source connected to the data line 65. It consists of the drain electrode 65b connected to the pixel electrode 67 via the electrode 65a and the drain contact hole 68. FIG.

The semiconductor layer 63 is for forming a conductive channel between the source electrode 65a and the drain electrode 65b by the gate voltage supplied to the gate electrode 60a.

Although not shown in the drawings, a gate insulating film (not shown) is further provided on the substrate including the gate line 60 and the gate electrode 60a, and between the semiconductor layer 63 and the source electrode 65a. And an ohmic contact layer (not shown) between the semiconductor layer 63 and the drain electrode 65b to reduce the resistance.

The thin film transistor selectively supplies the data signal from the data line 65 to the pixel electrode 67 in response to the gate signal from the gate line 60.

The pixel electrode 67 is positioned in a pixel region divided by the data line 65 and the gate line 60 and is made of a transparent conductive material having high light transmittance.

For example, the pixel electrode 67 may be formed of indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO) or indium tin zinc oxide (indium tin zinc oxide). It is composed of a transparent conductive material such as: ITZO).

The source electrode 65a overlaps with an upper portion of one side of the gate electrode 60 to have a U-shaped bent portion, and has a plurality of irregularities inside the bent portion, and the drain electrode 65b is the source electrode. It is arrange | positioned at the bending part spaced apart from 65a, and it is comprised so that it may have a some protrusion part in the part corresponding to the recessed part inside the bend part of the source electrode 65a. In other words, the drain electrode 65b is configured to engage with the unevenness inside the bent portion of the source electrode 65a.

In the above-described configuration, even if the source electrode 65a and the drain electrode 65b are formed in the same area, the channel length is due to the unevenness inside the bent portion of the source electrode 65a and the drain electrode 65b formed in engagement therewith. It is possible to increase the ratio (W / L) of (L) to channel width (W).

The bent portion of the source electrode 65a may be configured to be bent in parallel or perpendicular to the gate line 60.

6 illustrates a configuration example of the thin film transistor of FIG. 3 having a bent portion having a U-shaped bent portion and three recessed portions therein, but this is merely an example, to limit the present invention. It is not intended that the source electrode 65a constitutes a variety of bends that can be designed in the same area, and can be configured to have a plurality of irregularities therein, and has a drain electrode 65b having a protrusion that engages with the unevenness of the source electrode. ) Can be configured.

For example, in the liquid crystal display according to the first embodiment of the present invention, as shown in FIGS. 7 and 8, the bent portions of the source electrodes 75a and 85 of the thin film transistor are formed to have a plurality of irregularities. Drain electrodes 75b and 85b having protrusions engaging with the concavities and convexities can be configured.

The liquid crystal display shown in FIGS. 7 and 8 includes the liquid crystal display shown in FIG. 6 except that the source electrode and the drain electrode of the thin film transistor have the configuration of the thin film transistor shown in FIGS. 4 and 5, respectively. Since the structure is the same, it abbreviate | omits below.

As described above, when the ratio W / L of the channel length to the channel width is increased, the mobility of charges moving through the channel is improved, and the data applied through the data line even when a relatively small voltage is applied to the gate electrode. The signal can be supplied to the pixel electrode.

Next, a liquid crystal display according to a second embodiment of the present invention will be described.

First, as shown in FIG. 9, the gate line 90 arranged in one direction on the substrate, the gate electrode 90a protruding from one side of the gate line 90, and the gate line 90 intersect with each other. A data line 95 arranged to define a pixel region, a thin film transistor (TFT) configured to have a bent uneven channel at an intersection of the gate line 90 and the data line 95, and a drain of the thin film transistor It consists of the pixel electrode 97 formed in the pixel area so that it may be connected to the electrode 95b.

The thin film transistor is connected to the pixel electrode 97 through a gate electrode 90a connected to the gate line 90, a source electrode 95a and a drain contact hole 98 connected to the data line 95. The drain electrode 95b.

The semiconductor layer 93 is formed under the source electrode 95a, the drain electrode 95b, and the data line 95.

Although not shown in the drawings, a gate insulating film (not shown) is further provided on the substrate including the gate line 90 and the gate electrode 90a, and between the semiconductor layer 93 and the source electrode 95a. And an ohmic contact layer (not shown) between the semiconductor layer 93 and the drain electrode 95b to reduce resistance.

The thin film transistor selectively supplies the data signal from the data line 95 to the pixel electrode 97 in response to the gate signal from the gate line 90.

The pixel electrode 97 is positioned in a pixel region divided by the data line 95 and the gate line 90 and is made of a transparent conductive material having high light transmittance.

The source electrode 95a is overlapped on one side of the gate electrode 90 to have a U-shaped bent portion, and has a plurality of irregularities inside the bent portion, and the drain electrode 95b is the source electrode. It is inserted so that it is spaced apart from the 95a by predetermined intervals, and it is comprised so that it may have a some protrusion part in the part corresponding to the recessed part inside the bent part of the source electrode 95a. That is, the drain electrode 95b is configured with a protruding portion so as to engage with the unevenness inside the bent portion of the source electrode 95a.

In the above-described configuration, even if the source electrode 95a and the drain electrode 95b are formed in the same area, the channel length is due to the unevenness inside the bent portion of the source electrode 95a and the drain electrode 95b formed in engagement therewith. It is possible to increase the ratio (W / L) of (L) to channel width (W).

The bent portion of the source electrode 95a may be configured to be bent in parallel or perpendicular to the gate line 90.

In FIG. 9, the source electrode 95a of the thin film transistor has been described with reference to a configuration example of the thin film transistor of FIG. 3 having a bent portion having a '요' shape and three recessed portions therein. It is not intended to be limiting.

For example, the liquid crystal display device according to the second exemplary embodiment of the present invention may be configured so that the source electrode of the thin film transistor has various bends that can be designed in the same area, and has a plurality of irregularities therein. The drain electrode 95b having a protrusion may be configured to engage with the unevenness, and the semiconductor layer 93 may be formed under the source electrode 95a, the drain electrode 95b, and the data line 95.

On the other hand, the configuration of the thin film transistor having the structure described above can be applied to a transverse electric field type liquid crystal display device, one example of which will be described with reference to the drawings.

As shown in FIG. 10, a plurality of gate lines 111 are arranged in one direction at regular intervals to define pixel regions on a transparent lower substrate (not shown), and are perpendicular to the gate lines 111. The plurality of data lines 113 are arranged in one direction at regular intervals.

The gate line 111 and the data line 113 cross each other to define a pixel area, and a thin film transistor TFT1 is formed in each crossing area.

The thin film transistor may be formed on the gate electrode 111a protruding from the gate line 111, the gate insulating film formed on the entire surface of the lower substrate including the gate electrode 111a, and on the gate insulating film above the gate electrode 111a. The semiconductor layer 112 to be formed, the source electrode 113a protruding from the data line 113 and having a bent portion, and having a plurality of irregularities inside the bent portion, and the bent portion of the source electrode 113a are fixed. The drain electrode 113b is formed to be spaced apart from each other and is provided with a protrusion that engages with the unevenness of the source electrode 113a.

In addition, the common wiring 111b and the common electrode 111c are formed on the same layer as the gate line 111, where the common wiring 111b is formed to cross the pixel region in parallel with the gate line 111. The common electrode 111c is formed in plural in the pixel area parallel to the data line 113.

In this case, the common electrodes 111c are arranged up and down symmetrically with respect to the common wiring 111b and are connected to each other.

A protective film (not shown) is formed on the entire lower substrate including the data line 113.

In the pixel region defined by the intersection of the gate line 111 and the data line 113, the pixel electrode 113c is arranged between the common electrodes 111c at regular intervals in parallel with the common electrode 111c. have. In this case, the pixel electrodes 113c are also arranged up and down symmetrically with respect to the common wiring 111b.

The pixel electrode 113c is integrally formed with the drain electrode 113b of the thin film transistor (eg, TFT1).

The storage electrode 113d is formed integrally with the pixel electrode 113c and is formed in one region of the common wiring 111b. That is, the storage structure is composed of a storage on common structure.

The source electrode 113a has a bent portion having a '⊂' shape.

The liquid crystal display device having the configuration of FIG. 10 is merely an example of a transverse electric field type liquid crystal display device, and is not intended to limit the present invention, and the source electrode of the thin film transistor has a bent portion that can be designed in the same area, and is bent. It can be applied to a transverse electric field type liquid crystal display device having a plurality of constitutions except having a plurality of concavities and convexities on the inner side, and having a protruding portion and a drain electrode to be engaged with concavities and convexities of the source electrode.

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 thin film transistor and the liquid crystal display according to the present invention as described above have the following effects.

First, if the source electrode has a bent portion, a plurality of irregularities are formed inside the bent portion, and a drain electrode having a protrusion to be engaged with the unevenness inside the source electrode is disposed in the bent portion of the source electrode, the channel length versus channel in the same area. The ratio of width (W / L) can be increased.

Accordingly, since the mobility of charges moving through the channel is excellent, the driving characteristics of the thin film transistor may be improved.

Second, since the ratio of the channel length to the channel width (W / L) can be increased, the mobility of charges moving through the channel can be improved, thereby improving the driving characteristics of the liquid crystal display device.

Third, the ratio W / L of the channel length to the channel width can be increased, so that the on current Ion can be increased to improve vertical crosstalk through sufficient pixel charging.

Claims (9)

A gate electrode formed in one direction on the substrate; A gate insulating film formed on the substrate including the gate electrode; A semiconductor layer overlapping the gate electrode;  A source electrode overlapping the upper portion of the gate electrode and having a bent portion and having a plurality of irregularities inside the bent portion; And a drain electrode spaced apart from the source electrode at a predetermined interval and engaged with the concave-convex portion inside the bent portion of the source electrode and having a drain electrode inserted into the bent portion. The method of claim 1, And the source electrode has at least one bent portion. The method of claim 1, The bent portion of the source electrode is a thin film transistor, characterized in that further comprising a '⊂' shape, 'inverse' shape, or '∈' shape or 'inverse' shape. Gate lines and data lines intersecting to define pixel areas; A gate electrode connected to the gate line and a gate electrode connected to the gate line, a source electrode having a bent portion and having a plurality of irregularities in the bent portion, and a protrusion to be engaged with the uneven portion of the source electrode. A thin film transistor having a drain electrode having a drain electrode inserted into the bent portion; And a pixel electrode connected to the drain electrode of the thin film transistor and formed in the pixel region. The method of claim 4, wherein And the source electrode has at least one bent portion. The method of claim 4, wherein And the bent portion of the source electrode is configured to have a '⊂' shape, a 'reverse' shape, a '∈' shape, or a 'reverse' shape. The method of claim 4, wherein And the bent portion of the source electrode is configured in a direction parallel or perpendicular to the gate line. The method of claim 4, wherein And the semiconductor layer is formed under the source electrode, the drain electrode and the data line. The method of claim 4, wherein The liquid crystal display device further comprises a common electrode formed in the pixel area in parallel with the data line, and a transverse electric field type liquid crystal display device in which the pixel electrode is arranged between the common electrodes.

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