KR20060078581A - Thin film transistor substrate of transflective type and method for fabricating the same - Google Patents

Abstract

The present invention is to provide a semi-transmissive thin film transistor substrate and a method for manufacturing the same that can simplify the process and reduce the manufacturing cost.

The semi-transmissive thin film transistor substrate of the present invention includes a buffer layer formed on the substrate; A gate line and a data line formed to cross each other with the first and second insulating layers interposed therebetween to define a pixel area; A thin film transistor provided at an intersection of the gate line and the data line and having an active layer made of polysilicon; An organic insulating layer formed to cover the gate line, the data line, and the thin film transistor, the organic insulating layer having a first hole exposing at least one of the substrate and the buffer layer in a pseudo pixel area; A pixel electrode formed on one of the substrate and the buffer layer exposed by the first hole and the organic insulating layer, and connected to the thin film transistor; And a reflective electrode formed to overlap the pixel electrode in an area excluding the first hole.

Description

Semi-transparent thin film transistor substrate and manufacturing method thereof {Thin Film Transistor Substrate of Transflective Type And Method for Fabricating The Same}

1 is a plan view showing an image display unit of a conventional polysilicon thin film transistor substrate.

FIG. 2 is a cross-sectional view taken along the line II ′ of the thin film transistor substrate of FIG. 1.

3 is a plan view illustrating a transflective thin film transistor substrate according to an exemplary embodiment of the present invention.

4 is a cross-sectional view taken along the line II-II 'of the transflective thin film transistor substrate shown in FIG. 3.

5A and 5B are a plan view and a cross-sectional view for describing a first mask process of a transflective thin film transistor substrate according to an exemplary embodiment of the present invention.

6A and 6B are a plan view and a cross-sectional view for describing a second mask process of a transflective thin film transistor substrate according to an exemplary embodiment of the present invention.

7A and 7B are plan views and cross-sectional views illustrating a third mask process of a semi-transmissive thin film transistor substrate according to an exemplary embodiment of the present invention.

8A and 8B are a plan view and a cross-sectional view for describing a fourth mask process of a transflective thin film transistor substrate according to an exemplary embodiment of the present invention.

9A and 9B are a plan view and a cross-sectional view for describing a fifth mask process of a semi-transmissive half-film transistor substrate according to an embodiment of the present invention.

10A and 10B are plan and cross-sectional views for describing a sixth mask process of a transflective thin film transistor substrate according to an exemplary embodiment of the present invention.

11A and 11F are cross-sectional views for describing a sixth mask process of a transflective thin film transistor substrate according to an exemplary embodiment of the present invention in detail.

<Description of Main Parts of Drawing>

2, 102: gate line 4, 104: data line

16,116: active layer 40, 140: lower substrate

44,144 gate insulating film 9, 109 gate electrode

46, 146: interlayer insulating film 8, 108: source electrode

10, 110: drain electrode 50: protective film

18, 118: pixel electrode 154: organic insulating film

156: reflective electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film transistor substrate, and more particularly, to a semi-transmissive thin film transistor substrate capable of reducing manufacturing costs by simplifying a process and a manufacturing method thereof.

In general, a liquid crystal display (LCD) displays an image corresponding to a video signal on a liquid crystal panel in which liquid crystal cells are arranged in a matrix by adjusting light transmittance of liquid crystal cells according to a video signal. In this case, a thin film transistor (TFT) is commonly used as a device for switching liquid crystal cells.

The thin film transistor used in such a liquid crystal display device uses amorphous silicon or polysilicon as a semiconductor layer. The amorphous silicon type thin film transistor has the advantage that the uniformity of the amorphous silicon film is relatively good and the characteristics are stable. However, the amorphous silicon thin film transistor has a disadvantage in that the response speed is low due to low charge mobility. Accordingly, the amorphous silicon thin film transistor has a disadvantage in that it is difficult to apply to a driving device of a high resolution display panel, a gate driver, and a data driver that require fast response speed.

The polysilicon thin film transistor is suitable for a high resolution display panel requiring fast response speed due to high charge mobility, and has the advantage of embedding peripheral driving circuits in the display panel. Accordingly, liquid crystal displays using polysilicon thin film transistors have emerged.

A liquid crystal display using a conventional polysilicon thin film transistor includes an image display unit including a pixel matrix, a data driver for driving data lines of the image display unit, and a gate driver for driving gate lines of the image display unit.

In the image display unit, liquid crystal cells are arranged in a matrix to display an image. Each of the liquid crystal cells is a switching element connected to the intersection of the gate line and the data line and is driven by a thin film transistor (TFT) using polysilicon implanted with a predetermined impurity.

1 is a plan view illustrating a conventional thin film transistor substrate using polysilicon, and FIG. 2 is a cross-sectional view taken along line II ′ of FIG. 1.

The thin film transistor substrate 96 illustrated in FIGS. 1 and 2 includes a gate line 2 and a data line 4 crossing the gate insulating film 44 and the interlayer insulating film 46 therebetween to define a pixel region. The thin film transistor 6 connected with the gate line 2 and the data line 4 and the recovery electrode 118 connected with the thin film transistor 6 are provided.

The thin film transistor 6 includes a gate electrode 9 connected to the gate line 2, a source electrode 8 connected to the data line 4, and a drain contact hole 14 penetrating through the passivation layer 50. A drain electrode 10 is connected to the pixel electrode 18.

The gate electrode 9 is formed to overlap the channel region 16C of the active layer 16 formed on the buffer layer 42 and the gate insulating layer 44. The source electrode 8 is formed to be insulated with the gate electrode 9 and the interlayer insulating layer 46 interposed therebetween, for example, the source region 16S and the source contact hole 26S of the active layer 16 implanted with n + ions. Contact through). The drain electrode 10 is formed to be soft with the gate electrode 9 and the interlayer insulating film 46 interposed therebetween, through the drain region 16D and the drain contact hole 26D of the active layer 16 into which n + ions are implanted. Contact.

The thin film transistor 6 causes the liquid crystal cell LC to charge the video signal from the data line 4, that is, the pixel signal, in response to the scan pulse from the gate line 2. Accordingly, the liquid crystal cell LC adjusts the light transmittance according to the charged pixel signal.

The pixel electrode 18 is connected to the drain electrode 10 of the thin film transistor 6 through the drain contact hole 14 penetrating the protective film 50. The pixel electrode 18 generates a potential difference from the common electrode formed on the upper substrate (not shown) by the charged pixel voltage. Due to this potential difference, the liquid crystal positioned between the thin film transistor substrate and the upper substrate rotates by dielectric anisotropy, and transmits light incident through the pixel electrode 18 from the light source (not shown) toward the upper substrate.

The polysilicon thin film transistor substrate 96 is formed using a plurality of mask processes. One mask process includes a plurality of processes, such as a thin film deposition (coating) process, a cleaning process, a photolithography process (hereinafter, a photo process), an etching process, a photoresist stripping process, an inspection process, and the like. In particular, as the thin film transistor substrate includes a semiconductor process and requires a plurality of mask processes, the manufacturing process is complicated and becomes an important cause of an increase in the manufacturing cost of the liquid crystal display device.

Furthermore, the liquid crystal has a transmissive type that displays an image using light incident from a back light unit, a reflective type that displays an image by reflecting external light such as natural light, and a transmissive type and a reflective type. It is roughly classified into a transmission type.

The transmissive type has a high power consumption of the backlight unit, and the reflective type has a problem in that an image cannot be displayed in a dark environment because it depends on external light. On the other hand, the transflective type is operated in a reflective mode when sufficient external light is provided, and in a transmissive mode using a backlight unit when insufficient external light can reduce power consumption than the transmissive type, and unlike the reflective type, it is not subject to external light constraints.

To this end, in the transflective liquid crystal panel, each pixel is divided into a reflection area and a transmission area. Therefore, the semi-transmissive thin film transistor substrate must be added with a reflective electrode formed in the reflective region as compared with the thin film transistor substrate 20 shown in FIG. As a result, since the number of mask processes must be increased, the conventional semi-transmissive thin film transistor substrate has a complicated manufacturing process.

Accordingly, an object of the present invention is to provide a semi-transmissive thin film transistor substrate and a method of manufacturing the same, which can simplify the process and reduce the manufacturing cost.

In order to achieve the above object, the transflective thin film transistor substrate according to the present invention includes a buffer layer formed on the substrate; A gate line and a data line formed to cross each other with the first and second insulating layers interposed therebetween to define a pixel area; A thin film transistor provided at an intersection of the gate line and the data line and having an active layer made of polysilicon; An organic insulating layer formed to cover the gate line, the data line, and the thin film transistor, the organic insulating layer having a first hole exposing at least one of the substrate and the buffer layer in a pseudo pixel area; A pixel electrode formed on one of the substrate and the buffer layer exposed by the first hole and the organic insulating layer, and connected to the thin film transistor; And a reflective electrode formed to overlap the pixel electrode in an area excluding the first hole.

The thin film transistor may include the first insulating layer covering the active layer; A gate electrode overlapping a channel provided in the active layer with the first insulating layer interposed therebetween; The second insulating layer covering the gate electrode; A source contact hole and a drain contact hole penetrating the first and second insulating layers to expose the active layer; And a source electrode connected to the active layer through the source contact hole, and a drain electrode connected to the active layer through the drain contact hole.

The organic insulating layer further includes a second hole exposing the drain electrode of the thin film transistor, and the pixel electrode is connected to the drain electrode through the second hole.

The organic insulating film and the pixel electrode have an embossed surface such that the reflective electrode has an embossed surface.

A method of manufacturing a thin film transistor substrate according to the present invention includes: a first mask process of forming a buffer layer on a substrate and forming an active layer made of polysilicon on the buffer layer; Forming a first insulating layer to cover the active layer, and forming a gate pattern including a gate line and a gate electrode connected to the gate line on the first insulating layer; Forming a second insulating layer on the gate pattern and forming a source contact hole and a drain contact hole through the first and second insulating layers to expose the active layer; A source electrode connected to the active layer through the source contact hole, a drain electrode connected to the active layer through the drain contact hole, and the first and second insulating layers interposed therebetween; A fourth mask process of forming a source / drain pattern including data lines defining a pixel region; A fifth mask process for forming an organic insulating layer formed to cover the gate line, the source electrode, and the data line, the organic insulating layer having a first hole in the pixel region, the first hole exposing one of the substrate and the buffer layer; Reflection formed on one of the substrate and the buffer layer exposed by the first hole and the organic insulating layer to form a pixel electrode connected to the drain electrode, and overlapping the pixel electrode in a region except the first hole. And a sixth mask process for forming an electrode.

The organic insulating layer further includes a second hole exposing the drain electrode, and the pixel electrode is connected to the drain electrode through the second hole.

The first mask process may further include forming a storage lower electrode extending from the active layer, and the second mask process may be parallel to the gate line and may be connected to the storage lower electrode with the first insulating layer therebetween. And forming a storage upper electrode which is formed to overlap and constitutes a storage capacitor.

The sixth mask process may include sequentially depositing a transparent conductive film and a reflective metal layer on the organic insulating film; Forming first and second photoresist patterns having different thicknesses on the reflective metal layer; Patterning the transparent conductive layer and the reflective metal layer by an etching process using the first and second photoresist patterns as a mask to form the pixel electrode and the reflective electrode; Removing the reflective electrode on the pixel electrode formed on the pixel region by an etching process using the first photoresist pattern as a mask; And removing the first photoresist pattern.

Other objects and advantages of the present invention in addition to the above object will become apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 11F.

3 is a plan view illustrating a transflective thin film transistor substrate using polysilicon according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view of the transflective thin film transistor substrate illustrated in FIG. 3 taken along line II-II '. It is a cross section.

3 and 4 may include a gate line 102 and a data line 104 crossing the gate insulating layer 144 and the interlayer insulating layer 146 on the lower substrate 140 to define a pixel region. ), The thin film transistor 106 connected to the gate line 102 and the data line 104, the pixel electrode 118 formed in each pixel region and connected to the thin film transistor 106, and the pixel electrode in the reflection region of each pixel. And a reflective electrode 156 formed to be in overlap with the 118. Accordingly, each pixel area is divided into a reflection area in which the reflection electrode 156 and the pixel electrode 118 are formed, and a transmission area in which the pixel electrode 118 is exposed through the opening of the reflection electrode 156.

The thin film transistor 106 may include a gate electrode 109 connected to the gate line 102, a source electrode 108 connected to the data line 104, and a drain contact hole 114 passing through the passivation layer 154. A drain electrode 110 connected to the pixel electrode 118 is provided.

The gate electrode 109 is formed to overlap the channel region 116C of the active layer 116 formed on the buffer layer 142 with the gate insulating layer 144 therebetween. The source electrode 108 is formed to be insulated with the gate electrode 109 and the interlayer insulating layer 146 interposed therebetween, for example, the source region 116S and the source contact hole (for example, n + ion implanted) 126S). The drain electrode 110 is formed to be soft with the gate electrode 109 and the interlayer insulating film 146 interposed therebetween, through the drain region 116D and the drain contact hole 126D of the active layer 116 implanted with n + ions. Contact.

The thin film transistor 106 causes the liquid crystal cell LC to charge the video signal from the data line 104, that is, the pixel signal, in response to the scan pulse from the gate line 102. Accordingly, the liquid crystal cell LC adjusts the light transmittance according to the charged pixel signal.

The pixel electrode 118 is formed in the pixel region defined by the intersection of the gate line 102 and the data line 104. In detail, the pixel electrode 118 includes a drain contact hole 114 penetrating the organic insulating layer 154 and the passivation layer 150 in the pixel region, and a transmission hole penetrating from the organic insulating layer 154 to the gate insulating layer 144. It is formed on the organic insulating film 154 via 170. Accordingly, the pixel electrode 118 is connected to the drain electrode 112 through the drain contact hole 114 and also comes into contact with the substrate 140 through the transmission hole 170. In addition, the pixel electrode 118 overlaps the reflective electrode 156 formed thereon in the reflective region, and is exposed through the opening of the reflective electrode 156 in the transmissive region to transmit light. The pixel electrode 118 generates a potential difference with a common electrode of a color filter substrate (not shown) by the pixel signal supplied through the thin film transistor TFT. Due to the potential difference, the liquid crystal having dielectric anisotropy rotates to adjust the transmittance of the light passing through the liquid crystal layer of each of the reflection region and the transmission region, so that the luminance varies according to the video signal.

The reflective electrode 156 is formed in the reflective region of each pixel to reflect external light. In detail, the reflective electrode 156 exposes the pixel electrode 118 formed in the transmission hole 170 to define a transmission region, and overlaps with the rest of the pixel electrode 118 surrounding the transmission region to form the reflection region. define. The reflective electrode 156 is formed together with the pixel electrode 118 to be separated from the reflective electrode 156 and the pixel electrode 118 of an adjacent pixel on a signal line such as the data line 104 and the gate line 102. . In this case, the reflective electrode 156 may have the same edge portion as that of the pixel electrode 118, or the edge portion of the reflective electrode 156 may be positioned slightly inward of the edge portion of the pixel electrode 118. The reflective electrode 156 has an embossed shape along the surface of the organic insulating layer 154 together with the pixel electrode 118, thereby increasing reflection efficiency due to a scattering effect.

Here, the transmission hole 170 is formed to penetrate through the relatively thick organic insulating film 154, and the interlayer insulating film 150 and the gate insulating film 144 thereunder, so that the optical path passes through the liquid crystal layer in the reflection region and the transmission region. Make the lengths equal. As a result, the transmission efficiency of the reflection mode and the transmission mode becomes equal.

In addition, the thin film transistor substrate of the present invention further includes a storage capacitor 120 connected to the drain electrode 110 to maintain the video signal supplied to the pixel electrode 118 stably.

The storage capacitor 120 includes a storage lower electrode 124 extending from the active layer 116, and a storage upper electrode 122 overlapping the storage lower electrode 124 with the gate insulating layer 144 therebetween. Here, the storage upper electrode 122 may be formed in parallel with the gate line 102, and PH3 may be injected into the storage lower electrode 124. The storage capacitor 120 allows the pixel signal charged in the pixel electrode 118 to remain stable until the next pixel signal is charged.

The thin film transistor substrate according to the embodiment of the present invention having such a configuration is formed in a six mask process as follows.

5A and 5B illustrate a plan view and a cross-sectional view for describing a first mask process in a method of manufacturing a thin film transistor substrate according to an exemplary embodiment of the present invention.

The buffer layer 142 is entirely formed on the lower substrate 140 by the first mask process, and the active layer 116 and the storage lower electrode 124 extended from the active layer 116 are formed on the buffer layer 142. Is formed.

Specifically, the buffer layer 142 is formed by depositing the entire surface of the lower substrate 140 with an insulating material such as SiO ₂ . After the amorphous silicon film is deposited on the lower substrate 140 on which the buffer film 142 is formed, the amorphous silicon film is crystallized by a laser to form a polysilicon film. By patterning. As a result, the active layer 116 of the thin film transistor 106 and the storage lower electrode 124 extending from the active layer 116 are formed.

6A and 6B illustrate a plan view and a cross-sectional view for describing a second mask process in a method of manufacturing a thin film transistor substrate according to an exemplary embodiment of the present invention.

The gate insulating layer 144 is formed on the lower substrate 142 on which the active layer 116 and the storage lower electrode 124 are formed by the second mask process, and the gate line 102, the gate electrode 109, and the storage upper electrode are formed. 122 is formed.

In detail, the gate insulating layer 144 is formed by entirely depositing an insulating material such as SiO ₂ on the lower substrate 140 on which the active layer 116 and the storage lower electrode 124 are formed. Thereafter, the gate metal layer is formed through a deposition method such as a sputtering method. As the gate metal layer, Al alloys such as Mo, Cu, Al, Ti, Cr, Mo alloys, AlNd, Cu alloys are used as a single layer structure, or 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 is used in a double or more multilayer structure.

Subsequently, the gate metal layer is patterned by a photolithography process and an etching process using a second mask, so that the gate includes the gate electrode 109 connected to the gate line 102 and the storage upper electrode 122 parallel to the gate line 102. A metal pattern is formed.

Certain impurities, for example, n + ions are implanted into regions not overlapped with the gate electrode 108 and the storage upper electrode 122. Accordingly, the source region 116S and the drain region 116D of the active layer 116 are formed, and impurities are partially injected into the storage lower electrode 122.

7A and 7B illustrate a plan view and a cross-sectional view for describing a third mask process in a method of manufacturing a thin film transistor substrate according to an exemplary embodiment of the present invention.

The source contact hole 126S and the drain contact hole exposing the interlayer insulating layer 146 and the source region 116S and the drain region 116D of the active layer on the lower substrate 140 on which the gate metal pattern is formed in the third mask process. 126D is formed.

Specifically, an interlayer insulating film 146 is formed by depositing an insulating material on the lower substrate 140 on which the gate metal pattern is formed. Thereafter, the interlayer insulating film 146 and the gate insulating film 144 are patterned by a photolithography process and an etching process to expose the source contact hole 126S and the drain exposing the source region 116S and the drain region 116D of the active layer. The contact hole 126D is formed.

8A and 8B illustrate a plan view and a cross-sectional view for describing a fourth mask process in a method of manufacturing a thin film transistor substrate according to an exemplary embodiment of the present invention.

In the fourth mask process, a source / drain pattern including the data line 104, the source electrode 108, and the drain electrode 110 is formed on the lower substrate 140 on which the interlayer insulating layer 146 is formed.

Specifically, a source / drain metal layer is formed on the lower substrate 140 on which the interlayer insulating film 146 is formed by using a deposition method such as sputtering or PECVD. Here, as the source / drain metal layer, Al alloys such as Mo, Cu, Al, Ti, Cr, Mo alloys, AlNd, Cu alloys are used as a single layer structure, or 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 It is used in two or more multilayer structures such as alloy / Al, Cu alloy / Mo alloy, Cu alloy / Al alloy, Al / Mo alloy, Mo alloy / Al, Al alloy / Mo alloy, Mo alloy / Al alloy.

In addition, the source / drain metal layer is patterned by a photolithography process and an etching process to be connected to the data line 104 and the data line 104 and to the source region 116S of the active layer through the source contact hole 126S. A source / drain pattern including a source electrode 108 and a drain electrode 110 facing the source electrode 108 and connected to the source region 116D of the active layer through the drain contact hole 126D is formed.

9A and 9B illustrate a plan view and a cross-sectional view for describing a fifth mask process in a method of manufacturing a thin film transistor substrate according to an exemplary embodiment of the present invention.

An organic insulating layer 154 covering the source / drain metal pattern is formed in the fifth mask process, and a through hole 170 and a drain contact hole 114 penetrating the organic insulating layer 154 are formed.

In detail, an organic layer 154 having an embossed surface in the reflective region and a transmission hole 170 and a drain contact hole 114 is formed on the lower substrate 140 on which the source / drain metal pattern is formed. The organic insulating layer 154 is formed by coating a photosensitive organic material such as photo acryl by a spin coating method or the like. Next, the organic layer 154 is patterned by a photolithography process using a fifth mask to correspond to the transmissive portion of the fifth mask so as to penetrate the organic insulating layer 154 to expose the buffer layer 142 on the substrate. ), A drain contact hole 114 exposing the drain electrode 110 is formed. Here, the through hole 170 may penetrate to the buffer layer 142 to expose the substrate 140.

In other words, the remaining portion of the fifth mask except for the transmissive portion has a structure in which the lower end portion and the diffractive exposure portion (or semi-transmissive portion) are repeated. And a diffraction exposure area (groove) is patterned in a repeating structure. Subsequently, by firing the organic film 154 where the protrusions and the groove portions are repeated, the surface of the organic film 154 in the reflection area has an embossed shape. By using the organic layer 154 as a mask, the gate insulating layer 144 and the interlayer insulating layer 146 below are patterned to form the through hole 170 and the drain contact hole 114.

10A and 10B illustrate a plan view and a cross-sectional view for describing a sixth mask process in a method of manufacturing a thin film transistor substrate according to an embodiment of the present invention, and FIGS. 11A through 11F illustrate a sixth mask process according to the present invention. Cross-sectional views for explaining in detail are shown.

The pixel electrode 118 and the reflective electrode 156 are formed on the organic insulating layer 154 having an embossed shape by a sixth mask process. The pixel electrode 118 and the reflective electrode 156 are formed using a diffraction exposure mask, a halftone mask, and a partial transmission mask.

Referring to FIG. 11A, a transparent conductive film 118a and a reflective metal layer 156a are stacked to cover the organic insulating layer 154 by a deposition method such as sputtering. ITO, TO, IZO, ITZO, etc. are used as the transparent conductive film 118a, and metal having high reflectance such as Al, AlNd, etc. is used as the reflective metal layer 156a, or a double structure such as AlNd / Mo. . Subsequently, a photoresist 239 is applied on the reflective metal layer 156a, and then exposed and developed by a photolithography process using a halftone mask, thereby forming a photoresist pattern 240 having a step as shown in FIG. 11B. .

Specifically, the halftone mask includes a transparent quartz substrate and a halftone transmissive layer and a blocking layer formed thereon. Here, the blocking portion P1 in which the half-tone transmissive layer and the blocking layer overlapping with each other is positioned is blocked in the ultraviolet UV, so that the reflective metal layer 156a and the transparent conductive film 118a must be present in FIG. 11B. As such, the first photoresist pattern 240A remains. The partially transmissive portion P2 where the halftone transmissive layer is positioned may have a second thinner than the first photoresist pattern 240A as shown in FIG. 11B in a region where only the transparent conductive film 118a should exist by partially transmitting ultraviolet rays UV. The photoresist pattern 240B remains. In addition, the full transmission part P3 transmits all the ultraviolet rays UV so that the photoresist pattern 240 does not exist as shown in FIG. 11B in the region where both the reflective metal layer 155 and the transparent conductive layer 117 should be removed. .

Referring to FIG. 11C, the reflective metal layer 156a and the transparent conductive layer 118a are patterned by an etching process using the photoresist pattern 240 as a mask, for example, a wet etching process, thereby forming the pixel electrode 118 and the pixel electrode ( The reflective electrode 156 overlapped with the 118 is formed to have the same edge portion. The pixel electrode 118 and the reflective electrode 156 are formed to overlap with the organic insulating layer 154 via the transmission hole 170 in the pixel region, and are connected to the drain electrode 110 via the drain contact hole 114. do. At this time, since the surface of the organic insulating layer 154 has an embossed shape, the pixel electrode 118 and the reflective electrode 156 formed thereon also have an embossed shape.

Referring to FIG. 11D, the thickness of the first photoresist pattern 240A is reduced by the ashing process, and the second photoresist pattern 240B is removed.

Referring to FIG. 11E, the reflective electrode 156 exposed by the wet etching process using the ashed first photoresist pattern 240A as a mask is etched to expose the pixel electrode 118 in the transmission hole 170. In this case, the edge portion of the reflective electrode 156 on the pixel electrode 118 may be exposed and etched along the edge portion of the ashed first photoresist pattern 240A. Accordingly, the edge portion of the reflective electrode 156 may be located inward from the edge portion of the pixel electrode 118.

Referring to FIG. 11F, the first photoresist pattern 240A remaining on the reflective electrode 156 in FIG. 11E is removed by a strip process.

As described above, the transflective thin film transistor substrate and the method of manufacturing the same according to the present invention form the pixel electrode and the reflective electrode in one mask process. Accordingly, the present invention simplifies the process and reduces the manufacturing cost, such as to form a semi-transmissive thin film transistor substrate in a six mask process.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (8)

A buffer layer formed on the substrate; A gate line and a data line formed to cross each other with the first and second insulating layers interposed therebetween to define a pixel area; A thin film transistor provided at an intersection of the gate line and the data line and having an active layer made of polysilicon; An organic insulating layer formed to cover the gate line, the data line, and the thin film transistor, the organic insulating layer having a first hole exposing at least one of the substrate and the buffer layer in a pseudo pixel area; A pixel electrode formed on one of the substrate and the buffer layer exposed by the first hole and the organic insulating layer, and connected to the thin film transistor; And a reflective electrode formed to overlap with the pixel electrode in a region excluding the first hole. The method of claim 1, The thin film transistor is The first insulating layer covering the active layer; A gate electrode overlapping a channel provided in the active layer with the first insulating layer interposed therebetween; The second insulating layer covering the gate electrode; A source contact hole and a drain contact hole penetrating the first and second insulating layers to expose the active layer; And a source electrode connected to the active layer through the source contact hole, and a drain electrode connected to the active layer through the drain contact hole. The method of claim 2, The organic insulating layer further includes a second hole exposing the drain electrode of the thin film transistor, The pixel electrode is connected to the drain electrode through the second hole. The method of claim 1, And the organic insulating film and the pixel electrode have an embossed surface such that the reflective electrode has an embossed surface. Forming a buffer layer on the substrate and forming an active layer of polysilicon on the buffer layer; Forming a first insulating layer to cover the active layer, and forming a gate pattern including a gate line and a gate electrode connected to the gate line on the first insulating layer; Forming a second insulating layer on the gate pattern, and forming a source contact hole and a drain contact hole through the first and second insulating layers to expose the active layer; A source electrode connected to the active layer through the source contact hole, a drain electrode connected to the active layer through the drain contact hole, and the first and second insulating layers interposed therebetween; A fourth mask process of forming a source / drain pattern including data lines defining a pixel region; A fifth mask process for forming an organic insulating layer formed to cover the gate line, the source electrode, and the data line, the organic insulating layer having a first hole in the pixel region, the first hole exposing one of the substrate and the buffer layer; Reflection formed on one of the substrate and the buffer layer exposed by the first hole and the organic insulating layer to form a pixel electrode connected to the drain electrode, and overlapping the pixel electrode in a region except the first hole. And a sixth mask process for forming an electrode. The method of claim 5, The organic insulating layer further includes a second hole exposing the drain electrode, And the pixel electrode is connected with the drain electrode through the second hole. The method of claim 5, The first mask process may further include forming a storage lower electrode extending from the active layer. The second mask process may include forming a storage upper electrode that is parallel to the gate line and overlaps the storage lower electrode with the first insulating layer therebetween to form a storage capacitor. Method of manufacturing a transmissive thin film transistor substrate. The method of claim 5, The sixth mask process is Sequentially depositing a transparent conductive film and a reflective metal layer on the organic insulating film; Forming first and second photoresist patterns having different thicknesses on the reflective metal layer; Forming the pixel electrode and the reflective electrode by patterning the transparent conductive film and the reflective metal layer by an etching process using the first and second photoresist patterns as masks; Removing the reflective electrode on the pixel electrode formed on the pixel region by an etching process using the first photoresist pattern as a mask; And removing the first photoresist pattern.

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