KR20080048606A - Thin film transistor substrate and manufacturing method thereof - Google Patents

Abstract

A TFT(Thin Film Transistor) and a manufacturing method thereof are provided to form a bridge electrode for connecting a storage electrode in a data layer, thereby reducing the loss of the aperture ratio. A gate line(21) and a data line are formed on a substrate by a matrix shape and define a pixel region. A TFT is connected with the gate line and the data line and formed at every pixel region. A pixel electrode(90) is connected with the TFT. A storage electrode(22) is overlapped with the pixel electrode. A bridge electrode(95) is formed by the same metal materials as the metal pattern of the TFT and connects the storage electrode with an adjacent storage electrode. The bridge electrode is formed by the same metal materials as the data layer of the TFT. The TFT includes a source electrode(60), a drain electrode(70) and an ohmic contact layer(50) for performing an ohmic contact between semiconductor layers(40). The TFT supplies an image data signal to the pixel electrode in response to the scan signal of the gate line.

Description

Thin film transistor substrate and manufacturing method thereof {THIN FILM TRANSISTOR SUBSTRATE AND MANUFACTURING METHOD THEREOF}

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

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

3A to 3F are cross-sectional views sequentially illustrating a method of manufacturing a thin film transistor substrate according to a first embodiment of the present invention.

4A through 4E are cross-sectional views sequentially illustrating a method of manufacturing a thin film transistor substrate according to a second embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10 substrate 20 gate electrode

21: gate line 22: storage electrode

24: first contact hole 25: second contact hole

30 gate insulating film 40 semiconductor layer

50: ohmic contact layer 60: source electrode

61 data line 70 drain electrode

80: inorganic protective film 85: organic protective film

81: pixel contact hole 90: pixel electrode

95 bridge electrode 100 thin film transistor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film transistor substrate, and more particularly, to a thin film transistor substrate and a method of manufacturing the same, by forming a bridge electrode connecting a storage electrode as a data layer to reduce an aperture ratio loss.

In general, liquid crystal displays have been widely used in display devices such as mobile phones, computers, monitors, and TVs due to advantages such as small size, light weight, and low power consumption.

The liquid crystal display displays an image by adjusting the light transmittance of the liquid crystal through an electric field. To this end, the liquid crystal display includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix, and a driving circuit for driving the liquid crystal panel. The liquid crystal panel includes a thin film transistor substrate on which a thin film transistor is formed, a color filter substrate on which a color filter is formed, and a liquid crystal formed between two substrates.

In the liquid crystal panel, the liquid crystal cell is positioned in an area defined by the intersection of the gate line and the data line. Each of the liquid crystal cells is formed with a pixel electrode to which a pixel data voltage is applied and a common electrode to which a common voltage is applied. In the liquid crystal cells, thin film transistors connected to the gate line, the data line, and the pixel electrode are formed to supply the pixel voltage supplied to the data line to the pixel electrode every time the scan signal is supplied to the gate line to display an image. . In this case, a storage electrode is formed on the thin film transistor substrate to maintain the voltage supplied to the pixel electrode for one frame.

The storage electrode is formed in parallel with at least one of the gate line and the data line, and overlaps with the pixel electrode to form a storage capacitor. As a result, a difference in current supply between the center part and the edge part occurs. Therefore, defects such as various stains occur.

Currently, Induim Tin Oxide (ITO) and Indium Zinc Oxide (IZO) bridges are applied to minimize the difference in current supply between the center and the edge. However, the aperture ratio loss occurs when ITO and IZO bridges are applied.

Accordingly, an aspect of the present invention is to provide a thin film transistor substrate and a method of manufacturing the same, in which the bridge electrode is formed of the same metal material as that of the data metal layer, thereby forming a stable storage capacitor without loss of aperture ratio.

In order to achieve the above technical problem, the thin film transistor substrate of the present invention is formed on the substrate in a matrix form a gate line and a data line to define a pixel region; A thin film transistor connected to the gate line and the data line and formed in each pixel area; A pixel electrode connected to the thin film transistor; A storage electrode formed to overlap the pixel electrode; And a bridge electrode formed of the same metal material as the metal pattern of the thin film transistor and connecting the storage electrode to an adjacent storage electrode.

The bridge electrode may be formed of the same metal material as the data layer of the thin film transistor.

In order to achieve the above technical problem, a method of manufacturing a thin film transistor substrate of the present invention comprises the steps of forming a first conductive pattern group including a gate electrode, a gate line and a storage electrode on the substrate; Forming a gate insulating layer, a semiconductor layer, a source, and an ohmic contact layer on the first conductive pattern group; Forming first and second contact holes on the storage electrode of the gate insulating layer; Forming a second conductive pattern group including a source electrode and a drain electrode on the gate insulating layer, and a bridge electrode connecting the storage electrode and the storage electrode adjacent to the storage electrode through the first and second contact holes on the gate insulating layer; step; Forming an organic passivation layer and an inorganic passivation layer having pixel contact holes on the second conductive pattern group and the first and second contact holes; And forming a pixel electrode on the pixel contact hole of the passivation layer.

The forming of the bridge electrode is characterized in that the source electrode and the drain electrode are formed, the same metal material.

In order to achieve the above technical problem, a method of manufacturing a thin film transistor substrate of the present invention comprises the steps of forming a first conductive pattern group including a gate electrode, a gate line and a storage electrode on the substrate; Forming a gate insulating layer, a semiconductor layer, and an ohmic contact layer on the first conductive pattern group, and forming first and second contact holes on the storage electrode of the gate insulating layer; Forming a second conductive pattern group including a source electrode and a drain electrode on the gate insulating layer, and a bridge electrode connecting the storage electrode and the storage electrode adjacent to the storage electrode through the first and second contact holes on the gate insulating layer; step; Forming an inorganic passivation layer having a pixel contact hole on the second conductive pattern group and the first and second contact holes; And forming a pixel electrode on the pixel contact hole of the passivation layer.

The forming of the bridge electrode is characterized in that the source electrode and the drain electrode are formed, the same metal material.

Other objects and features of the present invention in addition to the above objects will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a plan view illustrating a thin film transistor substrate according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a cross section taken along line II ′ of the thin film transistor substrate illustrated in FIG. 1.

1 and 2, a thin film transistor substrate according to an exemplary embodiment of the present invention may include a gate line 21 and a data line 61, a thin film transistor substrate 10, a pixel electrode 90, and a storage electrode. And a bridge electrode 95.

Specifically, the substrate 10 uses an insulating substrate such as transparent glass or plastic. The gate line 21 and the data line 61 are formed on the substrate 10.

The gate line 21 supplies a scan signal, and the data line 61 supplies an image data signal. The gate line 21 and the data line 61 intersect with the gate insulating layer 30 therebetween to define a pixel area.

In the pixel region, the thin film transistor 100 connected to the gate line 21 and the data line 61 is formed. In addition, a pixel electrode 90 is formed in each pixel region.

The thin film transistor 100 includes a gate electrode 20 connected to a gate line 21, a source electrode 60 connected to a data line 61, a drain electrode 70 connected to a pixel electrode 90, and a gate electrode. And a semiconductor layer 40 overlapping with the gate insulating film 30 therebetween to form a channel between the source electrode 60 and the drain electrode 70. In addition, the thin film transistor 100 further includes an ohmic contact layer 50 for ohmic contact between the source electrode 60, the drain electrode 70, and the semiconductor layer 40. The thin film transistor 100 supplies the image data signal of the data line 61 to the pixel electrode 90 in response to the scan signal of the gate line 21.

The storage electrode 22 is formed adjacent to the data line 21 and parallel to the data line 21. The storage electrode 22 overlaps the pixel electrode 90 in the pixel area to form a storage capacitor. In addition, the storage electrode 22 is formed to float in each pixel area in order to avoid overlapping with the gate line 21, and each of the storage electrodes 21 is connected through the bridge electrode 95. In this case, the bridge electrode 95 is formed of the same metal material as the data layer of the thin film transistor 100.

The pixel electrode 90 is formed on the passivation layers 80 and 85 covering the thin film transistor 100 and is connected to the drain electrode 70 via the pixel contact hole 81 passing through the passivation layers 80 and 85. When the image data signal from the thin film transistor 100 is supplied, the pixel electrode 90 drives the liquid crystal with a voltage difference from the common electrode of the color filter substrate to adjust the light transmittance. The pixel electrode 90 is preferably formed of a transparent conductive metal material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

3A to 3F are cross-sectional views sequentially illustrating a method of manufacturing a thin film transistor substrate according to a first embodiment of the present invention. 3A to 3F are cross-sectional views illustrating a method of manufacturing a thin film transistor substrate using a six mask process for each mask process.

3A is a cross-sectional view illustrating a first mask process in a method of manufacturing a thin film transistor substrate according to a first exemplary embodiment of the present invention.

Referring to FIG. 3A, a first conductive pattern group including a gate line 21, a gate electrode 20, and a storage electrode 22 is formed on a substrate 10 through a first mask process.

Specifically, the first conductive layer is formed on the substrate 10 through a deposition method such as sputtering. In the first conductive layer, aluminum (Al), molybdenum (Mo), chromium (Cr), copper (Cu), or an alloy thereof is formed in a single layer or a multilayer structure. For example, AlNd and molybdenum (Mo) are formed in a stacked structure.

The first conductive pattern group including the gate line 21, the gate electrode 20, and the storage electrode 22 is formed by patterning the first conductive layer by a photolithography process and an etching process using the first mask. The storage electrode 22 is formed to be parallel to the data line 61 adjacent to a region where the data line 61 is to be formed in the pixel area.

3B is a cross-sectional view illustrating a second mask process in the method of manufacturing the thin film transistor substrate according to the first embodiment of the present invention.

Referring to FIG. 3B, the gate insulating layer 30, the semiconductor layer 40, and the ohmic contact layer 50 are sequentially stacked on the substrate on which the first conductive pattern group is formed through the second mask process.

Specifically, a plasma chemical vapor deposition method is performed on the gate insulating film 30, the amorphous silicon layer, and the impurity doped amorphous silicon layer on the substrate 10 on which the gate line 21, the gate electrode 20, and the storage electrode 22 are formed. It is sequentially deposited through a deposition method such as Plasma Enhanced Cemical Vapor Deposition (PECVD). Subsequently, the semiconductor layer 40 and the ohmic contact layer 50 are formed by patterning the amorphous silicon layer and the impurity doped amorphous silicon layer by a photolithography process and an etching process using a second mask. As the gate insulating film 30, an inorganic insulating material or an organic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx) is used.

3C is a cross-sectional view illustrating a third mask process in the method of manufacturing the thin film transistor substrate according to the first embodiment of the present invention.

Referring to FIG. 3C, first and second contact holes 24 and 25 are formed in a specific region on the storage electrode 22 in the gate insulating layer 30 through a third mask process.

Specifically, the semiconductor layer 40 and the ohmic contact layer 50 are formed on the gate electrode 20 on the gate insulating layer 30. Subsequently, a gate insulating layer 30 having first and second contact holes 24 and 25 positioned in a specific region on the storage electrode 22 is formed by a photolithography process and an etching process using a third mask.

3D is a cross-sectional view illustrating a fourth mask process in the method of manufacturing the thin film transistor substrate according to the first embodiment of the present invention.

Referring to FIG. 3D, the data line 61, the source electrode 60, and the drain electrode 70 are formed on the gate insulating layer 30 on which the semiconductor layer 40 and the ohmic contact layer 50 are formed through a fourth mask process. The second conductive pattern group and the bridge electrode 95 are formed.

In detail, the data line 61 is formed on the gate insulating layer 30 in parallel with the storage electrode 22. The drain electrode 70 is formed on the gate insulating layer 30 on which the semiconductor layer 40 and the ohmic contact layer 50 are formed. The source electrode 60 protrudes from the data line 61 and is formed on the gate insulating layer 30 on which the semiconductor layer 40 and the ohmic contact layer 50 are formed to face the drain electrode 70. The second conductive pattern group is formed by forming a second conductive layer through a deposition method such as sputtering, and then patterning the second conductive layer by a photolithography process and an etching process using a fourth mask process. As the second conductive layer, metals such as aluminum (Al), chromium (Cr), copper (Cu), and molybdenum (Mo) or alloys thereof are formed in a single layer or in a multilayered structure composed of a combination thereof. For example, it is formed using molybdenum (Mo). In this case, the bridge electrode 95 electrically connects each of the storage electrodes 22 of the adjacent pixel region through the first and second contact holes 24 and 25.

3E is a cross-sectional view illustrating a fifth mask process in the method of manufacturing the thin film transistor substrate according to the first embodiment of the present invention.

Referring to FIG. 3E, passivation layers 80 and 85 having pixel contact holes 81 are formed on the gate insulating layer 30 on which the second conductive pattern group is formed through the fifth mask process.

Specifically, the passivation layers 80 and 85 are formed on the substrate on which the second conductive pattern group is formed through a deposition method such as PECVD or spin coating. The passivation layers 80 and 85 are formed by a photolithography process and an etching process using a fifth mask. ), A pixel contact hole 81 is formed to expose the drain electrode 70. In the passivation layers 80 and 85, an inorganic passivation layer 80 and an organic passivation layer 85 are formed.

3F is a cross-sectional view illustrating a sixth mask process in the method of manufacturing the thin film transistor substrate according to the first embodiment of the present invention.

Referring to FIG. 3F, the pixel electrode 90 is formed on the passivation layers 80 and 85 through a sixth mask process.

Specifically, the pixel electrode 90 is formed by forming a transparent conductive layer on the passivation layers 80 and 85 by sputtering or the like, and then patterning the transparent conductive layer by photolithography and etching using a sixth mask. As the transparent conductive layer, transparent conductive materials such as indium tin oxide (ITO), induim zinc oxide (IZO), and tin oxide (TO) are used. The pixel electrode 90 is connected to the drain electrode 70 through the pixel contact hole 81.

4A to 4E are cross-sectional views illustrating a method of manufacturing a thin film transistor substrate according to a second exemplary embodiment of the present invention, for each mask process. 4A to 4E are cross-sectional views showing a five-mark process.

4A is a cross-sectional view illustrating a first mask process in a method of manufacturing a thin film transistor substrate according to a second exemplary embodiment of the present invention.

Referring to FIG. 4A, a first conductive pattern group including a gate line 21, a gate electrode 20, and a storage electrode 22 is formed on a substrate 10 through a first mask process.

Specifically, the first conductive layer is formed on the substrate 10 through a deposition method such as sputtering. In the first conductive layer, aluminum (Al), molybdenum (Mo), chromium (Cr), copper (Cu), or an alloy thereof is formed in a single layer or a multilayer structure. For example, AlNd and molybdenum (MO) are formed in a stacked structure. Subsequently, the first conductive pattern group including the gate line 21, the gate electrode 20, and the storage electrode 22 is formed by patterning the first conductive layer by a photolithography process and an etching process using the first mask. Here, the storage electrode 22 is formed in parallel with the data line 61 adjacent to a region where the data line 61 is to be formed in the pixel region.

4B is a cross-sectional view illustrating a second mask process in the method of manufacturing the thin film transistor substrate according to the second embodiment of the present invention.

Referring to FIG. 4B, the gate insulating layer 30, the semiconductor layer 40, and the ohmic contact layer 50 are sequentially stacked on the substrate 10 on which the first conductive layer is formed through the second mask process, and the gate insulating layer 30 is formed. First and second contact holes 24 and 25 are formed on the storage electrode 22 on the upper surface of the storage electrode 22.

Specifically, a plasma chemical vapor deposition method is performed on the gate insulating film 30, the amorphous silicon layer, and the impurity doped amorphous silicon layer on the substrate 10 on which the gate line 21, the gate electrode 20, and the storage electrode 22 are formed. It is sequentially deposited through a deposition method such as Plasma Enhanced Cemical Vapor Deposition (PECVD). Subsequently, the amorphous silicon layer and the impurity doped amorphous silicon layer are patterned by a photolithography process and an etching process using a second mask so that the first and second contact holes 24 and 25 positioned in a specific region on the storage electrode 22 are formed. A gate insulating film 30 having a semiconductor layer and a semiconductor layer 40 and an ohmic contact layer 50 positioned on the gate electrode 20 on the gate insulating film 30. As the gate insulating film 30, an inorganic insulating material or an organic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx) is used.

4C is a cross-sectional view illustrating a third mask process in the method of manufacturing the thin film transistor substrate according to the second embodiment of the present invention.

Referring to FIG. 4C, the data line 61, the source electrode 60, and the drain electrode 70 are formed on the gate insulating layer 30 on which the semiconductor layer 40 and the ohmic contact layer 50 are formed through a fourth mask process. The second conductive pattern group and the bridge electrode 95 are formed.

In detail, the data line 61 is formed on the gate insulating layer 30 in parallel with the storage electrode 22. The drain electrode 70 is formed on the gate insulating layer 30 on which the semiconductor layer 40 and the ohmic contact layer 50 are formed. The source electrode 60 protrudes from the data line 61 and is formed on the gate insulating layer 30 on which the semiconductor layer 40 and the ohmic contact layer 50 are formed to face the drain electrode 70. The second conductive pattern group is formed by forming a second conductive layer through a deposition method such as sputtering, and then patterning the second conductive layer by a photolithography process and an etching process using a fourth mask process. As the second conductive layer, metals such as aluminum (Al), chromium (Cr), copper (Cu), and molybdenum (Mo) or alloys thereof are formed in a single layer or in a multilayered structure composed of a combination thereof. For example, it is formed using molybdenum (Mo). In this case, the bridge electrode 95 electrically connects each of the storage electrodes 22 of the adjacent pixel region through the first and second contact holes 24 and 25.

4D is a cross-sectional view illustrating a fourth mask process in the method of manufacturing the thin film transistor substrate according to the second embodiment of the present invention.

Referring to FIG. 4D, the passivation layer 80 having the pixel contact hole 81 is formed on the gate insulating layer 30 on which the second conductive pattern group is formed through the fourth mask process.

Specifically, the passivation layer 80 is formed on the substrate on which the second conductive pattern group is formed by a deposition method such as PECVD or spin coating, and penetrates the passivation layer 80 by a photolithography process and an etching process using a fourth mask. Thus, the pixel contact hole 81 exposing the drain electrode 70 is formed. As the protective film 80, an inorganic insulating material such as the gate insulating film 30 is used.

4E is a cross-sectional view illustrating a fifth mask process in the method of manufacturing the thin film transistor substrate according to the second embodiment of the present invention.

Referring to FIG. 4E, the pixel electrode 90 is formed on the passivation layer 80 through a fifth mask process.

Specifically, the pixel electrode 90 is formed by forming a transparent conductive layer on the passivation layer 80 by sputtering or the like, and then patterning the transparent conductive layer by photolithography and etching using a fifth mask. As the transparent conductive layer, transparent conductive materials such as indium tin oxide (ITO), induim zinc oxide (IZO), and tin oxide (TO) are used. The pixel electrode 90 is connected to the drain electrode 70 through the pixel contact hole 81.

As described above, the thin film transistor substrate and the manufacturing method thereof according to the present invention can reduce the aperture ratio loss by forming a bridge electrode electrically connecting the storage electrodes of each pixel region to the same metal material as the data metal layer in the process of forming the data metal layer. have.

In addition, it is possible to form a stable storage capacitor.

Although the detailed description of the present invention described above has been described with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art will have the idea of the present invention described in the claims to be described later. It is apparent that the present invention can be modified and modified in various ways without departing from the technical scope.

Claims (6)

A gate line and a data line formed in a matrix form on the substrate to define a pixel area; A thin film transistor connected to the gate line and the data line and formed in each pixel area; A pixel electrode connected to the thin film transistor; A storage electrode formed to overlap the pixel electrode; And And a bridge electrode formed of the same metal material as the metal pattern of the thin film transistor and connecting the storage electrode and the adjacent storage electrode. The method of claim 1, And the bridge electrode is formed of the same metal material as the data layer of the thin film transistor. Forming a first conductive pattern group including a gate electrode, a gate line, and a storage electrode on the substrate; Forming a gate insulating layer, a semiconductor layer, a source, and an ohmic contact layer on the first conductive pattern group; Forming first and second contact holes on the storage electrode of the gate insulating layer; Forming a second conductive pattern group including a source electrode and a drain electrode on the gate insulating layer, and a bridge electrode connecting the storage electrode and the storage electrode adjacent to the storage electrode through the first and second contact holes on the gate insulating layer; step; Forming an organic passivation layer and an inorganic passivation layer having pixel contact holes on the second conductive pattern group and the first and second contact holes; And Forming a pixel electrode on the pixel contact hole of the passivation layer. The method of claim 3, wherein Forming the bridge electrode In the forming of the source electrode and the drain electrode, a method of manufacturing a thin film transistor substrate, characterized in that formed of the same metal material. Forming a first conductive pattern group including a gate electrode, a gate line, and a storage electrode on the substrate; Forming a gate insulating layer, a semiconductor layer, and an ohmic contact layer on the first conductive pattern group, and forming first and second contact holes on the storage electrode of the gate insulating layer; Forming a second conductive pattern group including a source electrode and a drain electrode on the gate insulating layer, and a bridge electrode connecting the storage electrode and the storage electrode adjacent to the storage electrode through the first and second contact holes on the gate insulating layer; step; Forming an inorganic passivation layer having a pixel contact hole on the second conductive pattern group and the first and second contact holes; And Forming a pixel electrode on the pixel contact hole of the passivation layer. The method of claim 5, wherein Forming the bridge electrode In the forming of the source electrode and the drain electrode, a method of manufacturing a thin film transistor substrate, characterized in that formed of the same metal material.

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