Liquid crystal display device and method for fabricating the same

This invention relates to a liquid crystal display device that reduces a parasitic capacitance, and a fabricating method thereof.A liquid crystal display device, including: a gate line with a multi-layer structure having a transparent first conductive layer and an opaque second conductive layer; a data line crossing the gate line with a gate insulating film in between to define a pixel area; a thin film transistor connected to the gate line and the data line; a pixel electrode formed of the first conductive layer in the pixel area, wherein the second conductive layer remains along an edge of the first conductive layer at an edge of the pixel area; a transmission hole that penetrates from an organic insulating film on the thin film transistor to the gate insulating film to expose the first conductive layer of the pixel electrode; a reflection electrode on the organic insulating film extending along a part of a side surface of the transmission hole to connect the pixel electrode and a drain electrode of the thin film transistor; and a floating electrode on the organic insulating film that overlaps both sides of the data line.

This application claims the benefit of Korean Patent Application No. P2004-112579 filed on 24 Dec. 2004, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device, and more particularly to a transflective thin film transistor substrate that reduces parasitic capacitance, and a fabricating method thereof.

2. Discussion of the Related Art

A liquid crystal display device controls a light transmittance of a liquid crystal that has dielectric anisotropy, by use of an electric field, thereby displaying a picture. The liquid crystal display device includes a liquid crystal display panel for displaying a picture through a liquid crystal cell matrix and a drive circuit for driving the liquid crystal display panel.

Referring toFIG. 1, a liquid crystal display panel of the related art includes a color filter substrate10and a thin film transistor substrate20that are bonded together with a liquid crystal24therebetween.

The color filter substrate10includes a black matrix4, a color filter6, and a common electrode8that are sequentially formed on an upper glass substrate2. The black matrix4is formed in a matrix shape on the upper glass substrate2. The black matrix4divides an area of the upper glass substrate2into a plurality of cell areas where the color filters are to be formed, and the black matrix4prevents light interference between adjacent cells and an external light reflection. The color filter6is divided into red R, green G, and blue B in the cell areas divided by the black matrix4. The common electrode8formed of a transparent conductive layer on the entire surface of the color filter6supplies a common voltage Vcom or a reference voltage when driving a liquid crystal24. Also, an overcoat layer (not shown) might be further formed between the color filter6and the common electrode8to level the color filter6.

The thin film transistor substrate20includes a thin film transistor18and a pixel electrode22that are formed at each cell area defined by the crossing of a gate line14and a data line16on a lower glass substrate12. The thin film transistor18supplies a data signal from the data line16to the pixel electrode22in response to a gate signal of the gate line14. The pixel electrode22formed of the transparent conductive layer supplies the data signal from the thin film transistor18to the liquid crystal24.

The liquid crystal24having dielectric anisotropy controls the light transmittance by rotating the liquid crystals in accordance with an electric field formed by the data signal on the pixel electrode22and the common voltage Vcom of the common electrode8.

The liquid crystal display panel further includes a spacer (not shown) for uniformly maintaining a cell gap between the color filter substrate10and the thin film transistor substrate20.

The color filter substrate10and the thin film transistor substrate20of the liquid crystal display panel are formed by use of a plurality of mask processes. One mask process includes many processes such as depositing (coating) a thin film, cleaning, photolithography, etching, photo-resist stripping, inspecting, etc. Specifically, the thin film transistor substrate is manufactured using a semiconductor process and requires a plurality of mask processes, thus its fabricating process is complicated is a major contributor to the manufacturing cost of the liquid crystal display panel.

Further, the liquid crystal display panels are divided into three different types: a transmission type that displays a picture by use of a light incident from a backlight unit; a reflection type that displays a picture by reflecting an external light such as a natural light; and a transflective type that combines the transmission type and the reflection type.

There is a problem in that the transmission type display consumes too much power due to the backlight and the reflection type display cannot display a picture in a dark environment because the reflection type depends on the external light. But, the transflective type display operates in a reflection mode if the external light is sufficient and in a transmission mode using the backlight unit if the external light is not sufficient, thus the power consumption can be reduced versus the transmission type display and the transflective type display is not dependent on external light like the reflection type.

To this end, the transflective type liquid crystal display panel has each pixel divided into a reflection area and a transmission area. Accordingly, the transflective thin film transistor substrate should further include a reflection electrode formed in the reflection area, and an organic insulating film formed to be relatively thick under the reflection electrode in order to equalize a light path length of the reflection area to that of the transmission area. As a result, the number of mask processes increases, so that the related art transflective thin film transistor: substrate has a problem in that its fabricating process is more complicated.

Further, the related art transflective thin film transistor substrate has a pixel electrode that overlaps both side parts of the data line, thus a parasitic capacitance is increased generating problems such as vertical cross talk, increased of power consumption etc.

FIG. 2is a plan view illustrating a part of a transflective thin film transistor substrate according to the related art, andFIGS. 3 and 4are cross sectional views illustrating the transflective thin film transistor substrate shown inFIG. 2, taken along the lines I-I′, II-II′.

The transflective thin film transistor shown inFIGS. 2 to 4includes: a gate line102and a data line104that are formed on a lower substrate142to cross each other with a gate insulating film therebetween to define a pixel area; a thin film transistor106connected to the gate line102and the data line104; a reflection electrode152formed in a reflection area of each pixel; a pixel electrode118formed at each pixel area connected to the thin film transistor106through the reflection electrode152; a storage upper electrode122connected to the pixel electrode118through the reflection electrode152; and a storage capacitor120formed to overlap the pre-stage gate line102.

The thin film transistor106includes a gate electrode108connected to the gate line102; a source electrode110connected to the data line104; a drain electrode112that faces the source electrode110and is connected to the pixel electrode118; an active layer114that overlaps the gate electrode108with a gate insulating film144therebetween to form a channel between the source electrode110and the drain electrode112; and an ohmic contact layer116formed on the active layer114except in the channel region for being in ohmic contact with the source electrode110and the drain electrode112.

Herein, the gate line102and the gate electrode108has a double layer structure where a first conductive layer101of a transparent conductive layer is deposited and a second conductive layer103of a metal layer is deposited thereon.

Then, a semiconductor pattern115including the active layer114and the ohmic contact layer116is formed to overlap the data line104.

The reflection electrode152formed in the reflection area has an embossed shape in accordance with a shape of an organic insulating film thereunder, thereby increasing the reflection efficiency by a scattering effect.

The pixel electrode118is connected to the drain electrode112through the reflection electrode152that is formed at each pixel area and passes through an edge area of a transmission hole154. The pixel electrode118has a double layer structure where the first and second conductive layers101,103are deposited like the gate line102, and the second conductive layer103is opened in the transmission area leaving just the first conductive layer101of the transparent conductive layer exposed to a transmission area.

The transmission hole154is formed to penetrate from an organic insulating film to the gate insulating film in the transmission area. Accordingly, the length of the light path passing through a liquid crystal layer in the reflection area becomes equal to that in the transmission area, thus the transmission efficiency of the reflection mode becomes the same as that of the transmission mode.

The storage capacitor120is formed by connecting a storage upper electrode122to the pixel electrode118to overlap the pre-stage gate line102with the gate insulating film144therebetween. The storage upper electrode122is connected to the pixel electrode118through the reflection electrode152passing through an edge area of the transmission hole154, and the semiconductor pattern115further overlaps with and under the storage upper electrode122.

In this way, in the transflective thin film transistor substrate shown inFIGS. 2 to 4, the pixel electrode118with the double structure is formed together with the gate line102, and the second conductive layer103is etched through the reflection electrode152, and the first conductive layer101is exposed in the transmission area. Further, the pixel electrode118is connected to the drain electrode112and the storage upper electrode122through the reflection electrode152. Accordingly, the transflective thin film transistor substrate may be formed by four mask processes.

On the other hand, as shown inFIG. 4, the reflection electrode156connected to the pixel electrode118overlaps both sides of the data line104with the organic insulating film148and a passivation film146in between, thus the parasitic capacitance Cdp1, Cdp2is increased. The vertical cross talk and the electric power consumption are increased due to the increase of the parasitic capacitance Cdp1, Cdp2.

In order to solve this problem, the transflective thin film transistor substrate according to the present invention floats the reflection electrode that overlaps the data line, thereby decreasing the parasitic capacitance.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a liquid crystal display device and method for fabricating the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An advantage of the present invention is to provide a transflective thin film transistor substrate that reduces a parasitic capacitance as well as simplifying its fabrication process, and a fabricating method thereof.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a liquid crystal display device, including: a gate line with a multi-layer structure having a transparent first conductive layer and an opaque second conductive layer; a data line crossing the gate line with a gate insulating film in between to define a pixel area; a thin film transistor connected to the gate line and the data line; a pixel electrode formed of the first conductive layer in the pixel area, wherein the second conductive layer remains along an edge of the first conductive layer at an edge of the pixel area; a transmission hole that penetrates from an organic insulating film on the thin film transistor to the gate insulating film to expose the first conductive layer of the pixel electrode; a reflection electrode on the organic insulating film extending along a part of a side surface of the transmission hole to connect the pixel electrode and a drain electrode of the thin film transistor; and a floating electrode on the organic insulating film that overlaps both sides of the data line.

In another aspect of the present invention, a liquid crystal display device, including: a gate line with a multi-layer structure having a transparent first conductive layer and an opaque second conductive layer; a data line crossing the gate line with a gate insulating film in between to define a pixel area; a thin film transistor connected to the gate line and the data line; a pixel electrode formed of the first conductive layer in the pixel area, wherein the second conductive layer remains along an edge of the first conductive layer at an edge of the pixel area; a transmission hole that penetrates from an organic insulating film on the thin film transistor to the gate insulating film to expose the first conductive layer of the pixel electrode; and a reflection electrode on the organic insulating film that does not overlap the data line and that extends along a side surface of the transmission hole to connect the pixel electrode and a drain electrode of the thin film transistor.

In another aspect of the present invention, a method of fabricating a liquid crystal display device, including: forming a first mask pattern group including a gate line, a gate electrode, and a pixel electrode having a double layer structure of a transparent first conductive layer and an opaque second conductive layer; forming a gate insulating film on the first mask pattern group, a semiconductor pattern on the gate insulating film, and a source/drain metal pattern having a data line, a source electrode and a drain electrode on the semiconductor pattern; forming an organic insulating film on the source/drain metal pattern; forming a transmission hole penetrating from the organic insulating film to the gate insulating film to expose the pixel electrode; forming a reflection electrode on the organic insulating film to extend along a part of a side surface of the transmission hole to connect the pixel electrode and the drain electrode, and a floating electrode on the organic insulating film that overlaps both sides of the data line; and removing the second conductive layer of the pixel electrode exposed through the reflection electrode and the floating electrode.

In another aspect of the present invention, a method of fabricating a liquid crystal display device, including: forming a first mask pattern group including a gate line, a gate electrode, and a pixel electrode having a double layer structure of a transparent first conductive layer and an opaque second conductive layer; forming a gate insulating film on the first mask pattern group, a semiconductor pattern on the gate insulating film, and a source/drain metal pattern having a data line, a source electrode, and a drain electrode on the semiconductor pattern; forming an organic insulating film on the source/drain metal pattern; forming a transmission hole penetrating from the organic insulating film to the gate insulating film to expose the pixel electrode; forming a reflection electrode on the organic insulating film that does not overlap the data line that extends along a side surface of the transmission hole to connect the pixel electrode and the drain electrode; and removing the second conductive layer of the pixel electrode exposed through the reflection electrode.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

With reference toFIGS. 5 to 13B, embodiments of the present invention will be explained as follows.

FIG. 5is a plan view illustrating a transflective thin film transistor substrate according to a first embodiment of the present invention.FIG. 6is a cross sectional view illustrating the transflective thin film transistor substrate shown inFIG. 5, taken along the lines III-III′, IV-IV′.

The transflective thin film transistor substrate shown inFIGS. 5 and 6includes a gate line202and a data line204that are formed on a lower substrate242to cross each other with a gate insulating film244therebetween to define a pixel area; a thin film transistor206connected to the gate line202and the data line204; first and second reflection electrodes252,256formed in a reflection area of each pixel; a pixel electrode218formed at each pixel area to be connected to the thin film transistor206through the first reflection electrode152; and a storage capacitor220formed by a storage line225overlapping a drain electrode212.

The thin film transistor206includes a gate electrode208connected to the gate line202; a source electrode210connected to the data line204; a drain electrode212that faces the source electrode210and is connected to the pixel electrode218; an active layer214that overlaps the gate electrode208with a gate insulating film244therebetween to form a channel between the source electrode210and the drain electrode212; and an ohmic contact layer216formed on the active layer214except a channel part for being in ohmic contact with the source electrode210and the drain electrode212. The thin film transistor206charges and sustains a video signal of the data line204on the pixel electrode218in response to a scan signal of the gate line202.

Herein, the gate line202and the gate electrode208have a double layer structure where a first conductive layer201is a transparent conductive layer and a second conductive layer203is a metal layer thereon. Herein, the second conductive layer203might also be formed of a multi-layer structure where two or more metal layers are deposited.

A semiconductor pattern215having the active layer214and the ohmic contact layer216is formed to overlap the data line204.

The pixel electrode218is formed a double layer structure where the first and second conductive layers201,203are deposited together with the gate line202in each pixel area. The second conductive layer203of the pixel electrode218is removed within a transmission hole254to define a transmission area where the first conductive layer201is exposed. Further, the pixel electrode218is separated from the gate line202and also separated from the data line204without being overlapped therewith.

The transmission hole254is formed to penetrate a passivation film246and an organic insulating film248which are deposited to cover the thin film transistor206and the data line204, and to penetrate the gate insulating film244under the passivation film246as well. The transmission hole254penetrates as far as the second conductive layer203of the pixel electrode218to expose the first conductive layer201. Further, the transmission hole254exposes a side surface of the drain electrode212. The organic insulating film248is formed to have an embossed surface.

The first and second reflection electrode252,256are separated for each pixel area and are formed on the organic insulating film to define a reflection area that reflects an external light. The first reflection electrode252located in upper and lower parts of the transmission hole254overlaps a part of the gate line202and is extended along the side surface of the transmission hole254to be connected to the pixel electrode218. The first reflection electrode252encompassing the lower side surface of the transmission hole254connects the drain electrode212and the pixel electrode218. The first reflection electrode252projects at both side parts to overlap both side parts of the data line. A second reflection electrode256located at both sides of the transmission hole254overlaps both sides of the data line204to be floated. That is to say, the second reflection electrode256overlaps both sides of the data line204and is extended along the side surface of the transmission hole254, but the second reflection electrode256is not connected to the pixel electrode218so that it floats. Accordingly, the parasitic capacitance Cdp1, Cdp2formed by the overlapping of the second reflection electrode256and the data line204is decreased. The second reflection electrode256overlaps the data line204between projected parts of the first reflection electrode252. The first and second reflection electrodes252and256have an embossed shape in accordance with the shape of the organic insulating film248thereunder, thereby increasing the reflection efficiency by a scattering effect.

The second conductive layer203of the pixel electrode218is etched by using the first and second reflection electrodes252,256as a mask. Accordingly, the first reflection electrode252is connected to the second conductive layer203of the pixel electrode218, thus a contact resistance may be reduced. For example, in the case of using AlNd for the first and second reflection electrode252,256, ITO for the pixel electrode218, and Mo for the second conductive layer203, AlNd and ITO can only be connected through Mo, thus it is possible to prevent an increase of a contact resistance between AlNd and ITO caused by the generation of Al2O3.

The pixel electrode218generates a potential difference with the common electrode of the color filter substrate (not shown) by the pixel signal supplied through the thin film transistor. The liquid crystal having dielectric anisotropy rotates by the potential difference to control a transmittance of a light passing through the liquid crystal layer of each of the reflection area and the transmission area, thus the brightness is changed in accordance with the video signal.

In this case, the length of the light path passing through the liquid crystal layer in the reflection area becomes equal to that in the transmission area by the transmission hole254that penetrates the relatively thick organic insulating film248. Specifically, a path that the ambient light incident in the reflection area passes through is the same in length as a path that the transmitted light of the backlight unit incident to the transmission area passes through the liquid crystal layer, thus the transmission efficiency of the reflection mode is the same as that of the transmission mode.

The storage capacitor220is formed by the storage line223overlapping the drain electrode212with the gate insulating film244. Herein, the drain electrode212extends from the thin film transistor206to overlap the storage line225with the semiconductor pattern215and has its side surface exposed through the transmission hole254to be connected to the first reflection electrode252that is connected to the pixel electrode218. The storage line225is formed in a double structure where the first and second conductive layers201,203are deposited on the substrate242like the gate line202.

In the transflective thin film transistor substrate according to the first embodiment of the present invention, the first reflection electrode252overlapped with both sides of gate line202connects the pixel electrode and the drain electrode212through the side surface of the transmission hole254. But on the other hand, the second reflection electrode256overlapped with both sides of the data line204is opened with the pixel electrode218to be floated. Accordingly, the parasitic capacitance Cdp1, Cdp2caused by the second reflection electrode256overlapping the data line204is decreased, thereby enabling the vertical cross talk and the electric current consumption to decrease.

The transflective thin film transistor substrate according to the first and second embodiments of the present invention is formed by four mask processes as follows.

FIGS. 7A and 7Billustrate a plan view and a cross sectional view for explaining a first mask process in a fabricating method of a transflective thin film transistor substrate according to an embodiment of the present invention.

A gate pattern having the gate line202, the gate electrode208, the storage line225and the pixel electrode218is formed on the lower substrate242by a first mask process. The gate pattern is formed in a double layer structure where the first and second conductive layers201,203are deposited.

Specifically, the first and second conductive layers210,203are deposited on the lower substrate242by a deposition method such as sputtering. The deposited first and second conductive layers201,203are patterned by a photolithography process and an etching process using a first mask, thereby forming a first mask pattern group having the gate line202, the gate electrode208, the storage line225, and the pixel electrode218. The first conductive layer201may be formed of a transparent conductive material such as ITO, TO, ITZO, IZO, etc. The second conductive layer203may be formed in a single layer of a metal material such Mo, Ti, Cu, AlNd, Al, Cr, Mo alloy, Cu alloy, Al alloy, etc, or in a structure that includes two or more layers such as Al/Cr, Al/Mo, Al(Nd)/Al, Al(Nd)/Cr, Mo/Al(Nd)Mo, Cu/Mo, Ti/Al(Nd)/Ti, Mo/Al, Mo/Ti/Al(Nd), Cu alloy/Mo, Cu alloy/Al, Cu alloy/Mo alloy, Cu alloy/Al alloy, Al/Mo alloy, Mo alloy/Al, Al alloy/Mo alloy, Mo alloy/Al alloy, Mo/Al alloy, etc.

FIGS. 8A and 8Billustrate a plan view and a sectional view for explaining a second mask process in the fabricating method of the thin film transistor substrate according to an embodiment of the present invention.

A gate insulating film224is formed on the lower substrate242where the first mask pattern group is formed, and a second mask pattern group having a source/drain metal pattern having the data line204, the source electrode210and the drain electrode212and a semiconductor pattern215having the active layer214and the ohmic contact layer216that overlap along the rear surface of the source/drain metal pattern are formed thereon by a second mask process. The second mask pattern group is formed by one mask process using a diffractive exposure mask.

Specifically, the gate insulating film244, an amorphous silicon layer, an amorphous silicon layer doped with impurities (n+ or p+), and a source/drain metal layer are sequentially formed on the lower substrate242where the first mask pattern group is formed. For example, the gate insulating film244, the amorphous silicon layer, and the amorphous silicon layer doped with impurities (n+ or p+) may be formed by a PECVD method, and the source/drain metal layer may be formed by a sputtering method. The gate insulating film244may be formed of an inorganic insulating material such as silicon oxide SiOx, silicon nitride SiNx, etc. The source/drain metal layer may be formed in a single layer of a metal material such as Mo, Ti, Cu, AlNd, Al, Cr, Mo alloy, Cu alloy, Al alloy, etc, or in a structure that includes two or more layers such as Al/Cr, Al/Mo, Al(Nd)/Al, Al(Nd)/Cr, Mo/Al(Nd)Mo, Cu/Mo, Ti/Al(Nd)/Ti, Mo/Al, Mo/Ti/Al(Nd), Cu alloy/Mo, Cu alloy/Al, Cu alloy/Mo alloy, Cu alloy/Al alloy, Al/Mo alloy, Mo alloy/Al, Al alloy/Mo alloy, Mo alloy/Al alloy, Mo/Al alloy, etc.

A photo-resist pattern having a step difference is formed on the source/drain metal layer by the photolithography process using a diffractive exposure mask. The photo-resist pattern is formed to be relatively thicker in an area where the semiconductor pattern and the source/drain pattern are to be formed, and to be relatively thinner in an area where a channel of the thin film transistor is to be formed.

The source/drain metal pattern including the data line204and the drain electrode212integrated with the source electrode210, and the semiconductor pattern215thereunder are formed by an etching process using the photo-resist pattern that has such a step difference. Herein, the drain electrode212overlaps the storage line225together with the semiconductor pattern215to form the storage capacitor220.

Then, a thin part of the photo-resist pattern is removed and a thick part thereof becomes thin by an ashing process. The source electrode210and the drain electrode212are separated by the etching process using the ashed photo-resist pattern, and the ohmic contact layer216thereunder is removed. Subsequently, the photo-resist pattern remaining on the source/drain metal pattern is removed by a stripping process.

FIGS. 9A and 9Bare a plan view and a cross sectional view for explaining a third mask process in the fabricating method of the thin film transistor according to the embodiment of the present invention.

A passivation film246and an organic insulating film248are formed on the gate insulating film244where the second mask pattern group is formed, by a third mask process, and the transmission hole penetrating the passivation film246and the organic insulating film248is formed in each pixel area. The passivation film246may formed of an inorganic insulating material like the gate insulating film. The organic insulating film248is formed by coating a photosensitive organic material like photo acryl on the passivation film246by a spin coating method, etc.

Then, the organic insulating film248is patterned by the photolithography process using the third mask, thereby forming the transmission hole254that penetrates the organic insulating film248in the transmission area corresponding to a transmission area of the third mask. Further, the remaining area except the transmission part of the third mask has a structure where a shielding area and a diffractive exposure area (or transflective area) are repeated, and corresponding thereto, the organic insulating film248is patterned in a structure where a shielding area (projected part) and a diffractive exposure area (groove part) having the step difference are repeated in a reflection area. Subsequently, the organic insulating film248where the projected part and the groove part are repeated is baked to make the organic insulating film248have an embossed shape in its surface in the reflection area.

Subsequently, the passivation film246and the gate insulating film244thereunder are patterned by the etching process, e.g., dry etching, using the organic insulating film248as a mask, thus the transmission hole254penetrates as far as the gate insulating film244. At this moment, the drain electrode212exposed through the transmission hole254and the semiconductor pattern215thereunder are also etched. Herein, the side surface of the gate insulating film244has a structure projecting further than the drain electrode212and the semiconductor pattern215thereunder due to an etching speed difference. The transmission hole254exposes the second conductive layer203of the pixel electrode218and the side surface of the drain electrode212is exposed through the side surface thereof.

FIGS. 10A and 10Billustrate a plan view and a cross sectional view for explaining a fourth mask process in the fabricating method of the thin film transistor according to the embodiment of the present invention.

The first and second reflection electrodes252,256are formed by a fourth mask process, and the first conductive layer201of the pixel electrode218is exposed within the transmission hole254through aperture parts of the first and second reflection electrodes252,256.

Specifically, a reflective metal layer is formed on the organic insulating film248having the embossed surface while keeping the embossed shape. The reflective metal layer is formed in a single layer structure with a high reflectability, such as Al, AlNd, etc, or in a double layer structure such as AlNd/Mo, etc. Then, the reflective metal layer is patterned by the photolithography process and the etching process using the fourth mask, thereby forming the first and second reflection electrode252,256at the reflection area of each pixel. At this moment, the second conductive layer203of the pixel electrode218that is exposed through the transmission hole254is etched together with the reflective metal layer that is deposited thereon, thereby exposing the first conductive layer201of the pixel electrode218. The first reflection electrode252located at the upper and lower parts of the transmission hole254overlaps a part of the gate line202and is extended along the side surface of the transmission hole254to connect the drain electrode212and the pixel electrode218. The first reflection electrode252is surface-connected to the second conductive layer203that remains behind along the edge of the first conductive layer201of the pixel electrode218, and might also project at both sides thereof to overlap with both side parts of the data line204. The second reflection electrode256located at both sides of the transmission hole254overlaps both side parts of the data line to be floated.

In this way, the fabricating method of the transflective thin film transistor substrate according to the first embodiment of the present invention uses four mask processes, thus the process may be simplified.

FIG. 11Ais a plan view illustrating a part of a transflective thin film transistor substrate according to a second embodiment of the present invention.FIG. 11Bis a cross sectional view illustrating a transflective thin film transistor substrate shown inFIG. 11A, taken along the lines III-III′, V-V′.

The transflective thin film transistor substrate shown inFIGS. 11A and 11Bincludes the same components as the thin film transistor substrate shown inFIGS. 5 and 6except that a first reflection electrode262does not overlap the data line204and only a floated second reflection electrode266overlaps the both side parts of the data line204, and is formed by the foregoing four mask processes. Accordingly, a detail description for the repeated components will be omitted.

The first reflection electrode262connected to the pixel electrode218overlaps the both side parts of the gate line and does not overlap the data line204. The floated second reflection electrode266overlaps both sides of the data line204, and is formed long along the data line204. Accordingly, the data line204is only overlapped with the floated second reflection electrode266, thus the parasitic capacitance Cdp1, Cdp2is further reduced to make it possible to further decrease the vertical cross talk and the electric current consumption.

FIG. 12Ais a plane view illustrating a part of a transflective thin film transistor substrate according to a third embodiment of the present invention, andFIG. 12Bis a cross sectional view illustrating the transflective thin film transistor substrate shown inFIG. 12A, taken along the line V-V′.

The transflective thin film transistor substrate shown inFIGS. 12A and 12Bincludes the same components as the transflective thin film transistor substrate shown inFIGS. 11A and 11Bexcept that the pixel electrode218overlaps the both side parts of the data line204to decrease a line width of a second reflection electrode276, and is formed by the foregoing four mask processes. Accordingly, a detailed description of the repeated components will be omitted.

The pixel electrode218overlaps the both side parts of the data line204. At this moment, a part where the first and second conductive layers201,203are deposited in the pixel electrode218overlaps the both side parts of the data lien204. Accordingly, it is possible to decrease the line width of the second reflection electrode276that overlaps both side parts of the data line204and is floated, without considering light leakage. Accordingly, a distance W2having the line width of the two second reflection electrodes276inFIG. 12Bmay be known to be more decreased than a distance W1having the line width of the two second reflection electrodes276that overlap both sides of the data line204inFIG. 11B. As a result, the transmission aperture ratio by which the first conductive layer of the pixel electrode is exposed may be improved as much as the line width of the second reflection electrode276is decreased.

FIG. 13Ais a plane view illustrating a part of a transflective thin film transistor substrate according to a fourth embodiment of the present invention, andFIG. 13Bis a cross sectional view illustrating the transflective thin film transistor substrate shown inFIG. 13A, taken along the line V-V′.

The transflective thin film transistor substrate shown inFIGS. 13A and 13Bincludes the same components as the transflective thin film transistor substrate shown inFIGS. 2 and 3except that a reflection electrode282is separated from the both side parts of the data line204without being overlapped and is connected to the pixel electrode218through the transmission hole254, and is formed by the foregoing four mask processes. Accordingly, a detailed description of the repeated components will be omitted.

The reflection electrode282, as shown inFIGS. 2 and 3, encompasses the side surface of the transmission hole254to be connected to the pixel electrode218, but on the other hand, the reflection electrode282is separated from the data line204without overlapping therewith. Accordingly, the parasitic capacitance Cdp1, Cdp2caused by the overlapping of the reflection electrode282and the data line204is decreased to make it possible to reduce the vertical cross talk and the electric current consumption. In this case, in order to prevent the light leakage cause by the separation of the reflection electrode282and the data line204, a black matrix300is added to the color filter substrate. The black matrix300overlaps the data line204and overlaps a part of the reflection electrode282to prevent the light leakage.

As described above, the transflective thin film transistor substrate and the fabricating method thereof according to the present invention divides the reflection electrode formed in the pixel area into the first reflection electrode that connects the pixel electrode and the drain electrode exposed through the transmission hole and the second reflection electrode that overlaps both sides of the data line and is floated, even while simplifying the process of the four mask processes.

Further, the transflective thin film transistor substrate and the fabricating method thereof according to the present invention forms the reflection electrode connected to the pixel electrode so that the reflection electrode does not overlap the data line.

Accordingly, the parasitic capacitance caused by the overlapping of the reflection electrode and the data line is decreased so as to reduce the vertical cross talk and the electric power consumption.