KR20050017033A - Thin film transistor array panel - Google Patents

Abstract

PURPOSE: A TFT(Thin Film Transistor) substrate is provided to reduce light leakage generated around a data line and increase the aperture ratio of pixels by forming a semiconductor layer such that the width of the semiconductor layer is wider than the width of the data line. CONSTITUTION: A TFT substrate includes an insulating substrate, a gate line(121), storage electrodes(133a,133b), a gate insulating layer, a semiconductor layer, a source electrode, a drain electrode(175), a data line(171), a passivation layer, and a pixel electrode(190). The gate line is formed on the insulating substrate and has a gate electrode(124). The storage electrodes are extended from a storage electrode line(131) arranged in parallel with the gate line. The gate insulating layer is formed on the gate line. The semiconductor layer is formed on the gate insulating layer. The source electrode is superposed on a part of the semiconductor layer. The data line is connected to the source electrode and has a portion intersecting the gate line and a bent portion. The drain electrode is superposed on a part of the semiconductor layer. The passivation layer covers the semiconductor layer. The pixel electrode is formed on the passivation layer and electrically connected to the drain electrode. The width of the semiconductor layer is wider than the width of the data line.

Description

Thin Film Transistor Display Panels {THIN FILM TRANSISTOR ARRAY PANEL}

The present invention relates to a thin film transistor array panel, and more particularly, to a thin film transistor array panel for a liquid crystal display device.

In general, a liquid crystal display device injects a liquid crystal material between an upper display panel on which a common electrode, a color filter, and the like are formed, and a lower display panel on which a thin film transistor and a pixel electrode are formed. By applying a different potential to form an electric field to change the arrangement of the liquid crystal molecules, and through this to control the light transmittance is a device that represents the image.

However, it is an important disadvantage that the liquid crystal display device has a narrow viewing angle. In order to overcome these disadvantages, various methods for widening the viewing angle have been developed. Among them, liquid crystal molecules are oriented vertically with respect to the upper and lower display panels, and a method of forming a constant incision pattern or forming protrusions on the pixel electrode and the common electrode that is opposite thereto. This is becoming potent.

However, in the method of forming the protrusions or the incision pattern, the opening ratio is lowered due to the protrusions or the incision pattern portion. In order to compensate for this, an ultra-high-aperture structure that forms the pixel electrode as wide as possible has been devised. However, since the distance between adjacent pixel electrodes is very close, a lateral field formed between the pixel electrodes is strongly formed. Accordingly, the liquid crystals positioned at the edges of the pixel electrodes are affected by the lateral electric field, and thus the alignment is disturbed, resulting in texture or light leakage.

In order to mask such light leakage and textures, the black matrix is formed to overlap not only the data line but also the boundary line of the pixel electrode. Therefore, the width of the black matrix is increased to decrease the aperture ratio of the pixel.

The present invention provides a thin film transistor array panel capable of reducing light leakage generated around a data line and increasing an aperture ratio of a pixel.

The thin film transistor array panel according to the present invention for achieving the above object is formed on an insulating substrate, a gate line having a gate electrode, parallel to the gate line, the sustain electrode line and the sustain electrode line extending in the form of the sustain electrode line, the gate line A gate insulating film formed on the gate insulating film, a semiconductor layer formed on the gate insulating film, a source electrode overlapping at least a portion of the semiconductor layer, a data line connected to the source electrode and intersecting the gate line and having a bent portion, and a source around the gate electrode A drain electrode facing the electrode and at least partially overlapping the semiconductor layer, a protective film covering the semiconductor layer, and a pixel electrode formed on the protective film and electrically connected to the drain electrode, wherein the width of the semiconductor layer is wider than the data line width. It is.

Here, the edge of the semiconductor layer preferably overlaps with the sustain electrode.

It is preferable that the sustain electrode is formed in the pixel region and formed parallel to the curved portion of the data line.

In this case, it is preferable that the curved portion of the data line is formed of 45 degrees with respect to the gate line and -45 degrees with respect to the gate line.

In addition, the protective film is preferably formed of an inorganic material, and the pixel electrode preferably has a portion bent along the data line.

In addition, the edge of the pixel electrode preferably overlaps with the sustain electrode.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

[First Embodiment]

1 is a layout view of a thin film transistor array panel according to a first embodiment of the present invention, FIG. 2 is a layout view of a common electrode display panel according to a first embodiment of the present invention, and FIG. 3 is a liquid crystal including FIGS. 1 and 2. 4 is a layout view of the display device, and FIG. 4 is a cross-sectional view taken along the line IV-IV′-IV ″ of FIG. 3.

The liquid crystal display according to the first exemplary embodiment of the present invention is a liquid crystal molecule injected into and included between the thin film transistor array panel 100, the common electrode panel 200 facing the thin film transistor panel 100, and the two display panels 100 and 200. The major axis of is made of the liquid crystal layer 3 oriented perpendicular to the display panels 100 and 200.

Next, the thin film transistor array panel according to the first exemplary embodiment of the present invention will be described with reference to FIGS. 1, 3, and 4.

In the thin film transistor array panel according to the first exemplary embodiment of the present invention, a gate line 121 extending in one direction is formed on the transparent insulating substrate 110. A portion of the gate line 121 or a branched portion is used as the gate electrode 124 of the thin film transistor. One end 129 of the gate line 121 is used to receive a signal transmitted from a gate driving circuit (not shown) and may have a width wider than the width of the gate line 121.

In order to increase the storage capacitance of the pixel, the storage electrode line 131 and the storage electrodes 133a and 133b extending in parallel with the gate line 121 are formed. The storage electrode line 131 is parallel to the gate line 121, and the storage electrodes 133a and 133b extend in a direction of 45 degrees with respect to the storage electrode line 131, and are extended by a predetermined length by bending 90 degrees. In this case, the storage electrode line 131 may be formed to overlap the drain electrode 175 in order to minimize the reduction of the aperture ratio of the pixel.

The gate lines 121 and 124, the storage electrode lines 131, and the storage electrodes 133a and 133b may be formed of chromium, molybdenum, tungsten, titanium, aluminum, alloys thereof, or the like in a single layer or a plurality of layers.

A gate insulating layer 140 formed of silicon nitride, silicon oxide, or the like is formed on the substrate 110 to cover them 121, 124, and 131.

A semiconductor layer 151 made of amorphous silicon without doping impurities is formed in a predetermined region of the gate insulating layer 140. The semiconductor layer 151 extends along the data line 171 below the data line 171, which will be described later, and has a linear shape, and the drain electrode 175, which will be described later, in a form 154 in which a portion of the semiconductor layer 151 protrudes. It is formed to extend underneath.

The semiconductor layer 151 is formed wider than the data line width. The width of the semiconductor layer 151 may be formed to overlap the sustain electrodes 133a and 133b (see FIG. 5). At this time, light leakage around the data line can be prevented more reliably than in the embodiment shown in FIG.

As such, when the semiconductor layer 151 is formed wider than the data line width, light leaking around the data line may be blocked. At this time, the semiconductor layer, which is not covered by the data line, is exposed to light, so that parasitic capacitance due to excess carriers generated by light may increase, thereby causing a water fall. In the present invention, sustain electrodes 133a and 133b may occur. ) Completely blocks the light, so no water flow occurs.

In addition, ohmic contacts 161 and 165 including amorphous silicon or silicide doped with impurities are formed on the semiconductor layer 151. The ohmic contacts 161 and 165 are islands facing the portion of the linear portion 161 around the linear portion 161 and the gate electrode 124 extending along the data line 171 together with the semiconductor layer 151. It consists of a mold 165. The island portion 165 is formed at a predetermined distance away from the linear portion 161, and they have the same planar pattern as the semiconductor layer 151 except for a predetermined region of the semiconductor layer 151. The predetermined region of the semiconductor layer 151 is a channel portion that forms a channel of the thin film transistor.

A data line 171 is formed on the gate insulating layer 140 and the ohmic contact layer 161 to cross the gate line 121 to define a pixel area. The data line 171 is formed on the linear portion of the semiconductor layer 151 and has a width narrower than the width of the linear portion 151 of the semiconductor layer. The data line 171 is branched and has a source electrode 173 overlapping the semiconductor layer 154. In this case, the data line 171 is formed such that a repeatedly curved portion and a vertically extending portion appear with a length of the pixel.

In this case, the curved portion of the data line 171 is composed of two straight portions, one of the two straight portions forms 45 degrees with respect to the gate line 121, and the other portion with respect to the gate line 121. Achieve -45 degrees. The source electrode 173 is connected to a vertically extending portion of the data line 171, and the portion crosses the gate line 121 and the storage electrode line 131. Therefore, the pixel region formed by the intersection of the gate line 121 and the data line 171 is formed in a band shape.

One end 179 of the data line may be wider than the width of the data line 171 to receive a signal transmitted from a data driving circuit (not shown).

The drain electrode 175 is formed on the ohmic contact layer 165 to face the gate electrode 124 at a predetermined distance from the source electrode 173 and overlaps a portion of the semiconductor layer 154. In this case, the data line 171 is in contact with the linear portion 161 of the ohmic contact layer and the drain electrode 175 is in contact with the island portion 165.

In the data line 171, a portion of the data line 171 connected to the pixel electrode 190 overlaps the storage electrode line 131. A constant voltage is applied to the storage electrode line 131 to form a storage capacitor between the storage electrode line 131, the storage electrodes 133a and 133b, and the drain electrode 175.

The passivation layer 180 made of an inorganic insulating material such as silicon nitride is formed on the substrate 110 to cover the semiconductor layer 151 that is not covered by the data lines 171, 173, and 179 and the drain electrode 175. have.

The passivation layer 180 is formed with a contact hole 185 exposing the drain electrode 175 and a contact hole 182 exposing one end of the data line 171. The sidewalls of the contacts 182 and 185 preferably have a gentle slope of between 30 and 85 degrees with respect to the substrate surface or have a stepped profile.

The pixel electrode 190 is formed on the passivation layer 180 through a contact hole 183 and is connected to the drain electrode 175 and has a band shape that is bent along the shape of the pixel area. In this case, the edge of the pixel electrode 190 is formed to be separated from the data line 171 by a predetermined distance in order to prevent a coupling phenomenon with the data line 171. In FIG. 1, the electrodes are formed at a predetermined distance from the sustain electrodes 133a and 133b, but they may overlap (not shown) the sustain electrodes 133a and 133b.

In addition, a contact auxiliary member 82 connected to one end 179 of the data line 171 through the contact hole 182 is formed on the passivation layer 180. When the end portion of the gate line 121 also has a structure for connecting with the driving circuit like the end portion 179 of the data line, a gate contact auxiliary member is formed on the passivation layer 180.

However, the gate driving circuit may be formed together with the thin film transistor on the substrate 110. In this case, since the gate line 121 and the thin film transistor are directly connected, a contact auxiliary member is not required. The contact assistant member is not essential to serve to complement the adhesion with the external circuit device and to protect the ends, and their application is optional.

Finally, an alignment layer 11 is formed on the pixel electrode 190, the contact auxiliary member 82, the sustain electrode connection leg 84, and the passivation layer 180. The alignment layer 11 is subjected to a rubbing process for determining the horizontal direction of the liquid crystal molecules.

Next, the common electrode display panel will be described with reference to FIGS. 2, 3, and 4.

A black matrix 220 and red, green, and blue color filters 230R, 230G, and 230B are formed on the lower surface of the upper substrate 210 made of a transparent insulating material such as glass, and the color filter. An overcoat film 250 made of an organic material is formed on the 230R, 230G, and 230B. On the overcoat layer 250, a common electrode 270 made of a transparent conductive material such as ITO or IZO and having domain dividing means 271 is formed. The domain dividing means 271 can be formed with cutouts or protrusions (not shown).

The black matrix 220 may include a linear portion corresponding to the curved portion of the data line 171, a vertically extending portion of the data line 171, and a portion corresponding to the thin film transistor portion. The color filters 230R, 230G, and 230B are vertically elongated along the pixel columns partitioned by the black matrix 220 and are periodically bent along the shape of the pixels.

The domain dividing means 271 of the common electrode 270 is also bent so as to divide the curved pixel region from side to side. The alignment layer 21 is formed on the common electrode 270. The alignment layer 21 vertically aligns the liquid crystal with the alignment layer 21.

When the liquid crystal layer 3 is formed by combining the thin film transistor array panel and the color filter panel having the above structure and injecting liquid crystal therebetween, the liquid crystal display according to the first embodiment of the present invention is formed (FIGS. 3 and 4). Reference). At this time, the pixel electrode 190 is aligned to exactly overlap the color filters 230R, 230G, and 230B.

The liquid crystal molecules included in the liquid crystal layer 3 are aligned such that their directors are perpendicular to the display panels 100 and 200 without an electric field applied between the pixel electrode 190 and the common electrode 270.

In this way, the pixel region is divided into a plurality of domains by the domain dividing means 271. At this time, the pixel region is divided into left and right sides by the domain dividing means 271, but is divided into four domains in which the alignment directions of the liquid crystals are different from each other up and down around the bent portion of the pixel.

The liquid crystal display is formed by disposing elements such as a polarizing plate (not shown) and a backlight (not shown) on both sides of the basic panel. In this case, one polarizer is disposed on each side of the base panel, and the transmission axis thereof is arranged to be parallel to or perpendicular to the gate line 121.

When the liquid crystal display device is formed as described above, when an electric field is applied to the liquid crystal, the liquid crystal in each domain is inclined in a direction perpendicular to the long side of the domain. However, since this direction is perpendicular to the data line 171, the direction coincides with the direction in which the liquid crystal is inclined by a lateral electric field formed between two adjacent pixel electrodes 190 with the data line 171 therebetween. As a result, the lateral electric field assists the liquid crystal alignment of each domain.

As described above, the width of the semiconductor layer is wider than the width of the data line to completely block light leakage generated around the data line. Accordingly, unlike the related art, since the black matrix does not need to be formed to the edge of the pixel electrode, the width of the black matrix can be minimized, so that the aperture ratio of the pixel can be improved to provide a high luminance liquid crystal display device.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, when the width of the semiconductor layer is formed wider than the width of the data line, light leakage around the data line can be completely blocked. In addition, the formation of the storage electrode parallel to the data line does not cause water flow due to parasitic capacitance between the semiconductor layer and the data line, thereby providing a high quality thin film transistor array panel.

1 is a layout view of a thin film transistor array panel according to a first exemplary embodiment of the present invention.

2 is a layout view of a common electrode display panel according to a first exemplary embodiment of the present invention.

3 is a layout view of a liquid crystal display according to a first exemplary embodiment of the present invention;

4 is a cross-sectional view taken along the line IV-IV′-IV ″ of FIG. 3,

5 is a layout view of a thin film transistor array panel according to a second exemplary embodiment of the present invention.

* Description of symbols on the main parts of the drawings *

110, 210: insulated substrate 121: gate line

140: gate insulating film 151: semiconductor layer

161, 165: ohmic contact layer

171, 173: data line 175: drain electrode

190 pixel electrode 220 black matrix

230R, 230G, 230B: Red, Green, Blue Color Filter

270 common electrode

Claims (8)

Insulation board, A gate line formed on the insulating substrate and having a gate electrode, A storage electrode extending in the form of a branch of the storage electrode line parallel to the gate line and the storage electrode line; A gate insulating film formed on the gate line, A semiconductor layer formed on the gate insulating film, A source electrode overlapping at least a portion of the semiconductor layer; A data line connected to the source electrode and having a portion and a bent portion crossing the gate line, A drain electrode facing the source electrode with respect to the gate electrode and at least partially overlapping the semiconductor layer; A protective film covering the semiconductor layer, A pixel electrode formed on the passivation layer and electrically connected to the drain electrode; And a width of the semiconductor layer is wider than that of the data line. In claim 1, And a resistive contact layer formed between the data line and the drain electrode and the semiconductor layer. The method of claim 1 or 2, An edge of the semiconductor layer overlaps the sustain electrode. The method of claim 1 or 2, The sustain electrode is formed in the pixel area, and is formed to be parallel to the curved portion of the data line. In claim 4, The curved portion of the data line includes a portion that forms a 45 degree angle with respect to the gate line and a portion that forms a −45 degree portion with respect to the gate line. The method of claim 1 or 2, The passivation layer is formed of an inorganic material. The method of claim 1 or 2, The pixel electrode has a portion bent along the data line. In claim 7, An edge of the pixel electrode overlaps the sustain electrode.