KR20080014522A - Array substrate for liquid crystal display device and the method of fabricating the same - Google Patents

Abstract

An array substrate for an LCD and a method for manufacturing the same are provided to form a storage electrode of a transparent conductive layer, which is electrically connected to a gate line, to overlap a pixel electrode, thereby improving the aperture ratio and the brightness. A first storage electrode(103) of a transparent conductive material is formed within a pixel region on a substrate. An insulating layer is formed on the resultant substrate including the first storage electrode. A data line is formed on the insulating layer. A source electrode(110) is electrically connected to the data line, and a drain electrode(113) faces the source electrode. A pixel electrode(120) is contacted with the drain electrode. A second storage electrode(127) is extended from the pixel electrode, and overlaps the first storage electrode. An organic semiconductor layer is formed at a region between the source electrode and the drain electrode. A gate insulating layer and a gate electrode(145) are sequentially deposited on the organic semiconductor layer. A first passivation layer is formed on the gate electrode, the source electrode, the drain electrode, and the data line. The first passivation layer has a gate contact hole(155) and a storage contact hole(158) for exposing the gate electrode and the first storage electrode respectively. A gate line(165) is formed on the first passivation layer, wherein the gate line is contacted with the gate electrode through the gate contact hole and contacted with the first storage electrode through the storage contact hole. The gate line crosses the data line to define the pixel region.

Description

Array substrate for liquid crystal display device and method for manufacturing the same

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

FIG. 2 is a plan view illustrating one pixel area of a conventional array substrate for a liquid crystal display device including an organic thin film transistor manufactured using an organic semiconductor material, in particular, a liquid type low molecular organic semiconductor material.

3 is a plan view of one pixel area of an array substrate for a liquid crystal display device including an organic semiconductor layer according to an embodiment of the present invention.

4 is a cross-sectional view of a portion cut along the cutting line IV-IV of FIG.

Figures 5a to 5h is a cross-sectional view of the production step by step for cutting the cut line IV-IV in Figure 3;

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

101 substrate 103 first storage electrode

108: data wiring 110: source electrode

113: drain electrode 120: pixel electrode

127: second storage electrode 145: gate electrode

155: gate contact hole 158: storage contact hole

StgC: Storage Capacitor Tr: (Organic) Thin Film Transistor

The present invention relates to a liquid crystal display device, and more particularly, to an array substrate for a liquid crystal display device using an organic semiconductor material and a method of manufacturing the same.

In recent years, as the society enters the information age, the display field that processes and displays a large amount of information has been rapidly developed, and recently, the thin film transistor (Thin) having excellent performance of thinning, light weight, and low power consumption has recently been developed. Film Transistor (TFT) type liquid crystal display (TFT-LCD) has been developed to replace the existing cathode ray tube (CRT).

The image realization principle of the liquid crystal display device uses the optical anisotropy and polarization property of the liquid crystal. As is well known, the liquid crystal has a thin and long molecular structure and optical anisotropy having an orientation in an array, and when placed in an electric field, the liquid crystal has an orientation of molecular arrangement depending on its size. This change is polarized. In this regard, the liquid crystal display device is a surface facing each other with the liquid crystal layer interposed therebetween, and the liquid crystal panel formed by bonding an array substrate and a color filter substrate on which pixel electrodes and a common electrode are formed are essential components. In addition, it is a non-light emitting device which artificially adjusts the arrangement direction of liquid crystal molecules through the electric field change between these electrodes and displays various images by using the light transmittance which is changed at this time.

Recently, the active matrix type, in which pixels, which are the basic units of image expression, are arranged in a matrix manner, and switching elements are arranged in each pixel, is controlled to have excellent attention in terms of resolution and video performance. In addition, thin film transistors (TFTs) are well known as TFT-LCDs (Thin Firm Transistor Liquid Crystal Display devices).

In more detail, as shown in FIG. 1, which is an exploded perspective view of a general liquid crystal display device, the array substrate 10 and the color filter substrate 20 face each other with the liquid crystal layer 30 interposed therebetween. The array substrate 10 includes a plurality of gate lines 14 and data lines 16 arranged vertically and horizontally to the first transparent substrate 12 and upper surfaces thereof to define a plurality of pixel regions P. Thin film transistors T are provided at the intersections of the wirings 14 and 16 and are connected one-to-one with the pixel electrodes 18 provided in the pixel regions P. FIG.

In addition, the upper color filter substrate 20 facing the second transparent substrate 22 and its rear surface cover the non-display area of the gate line 14, the data line 16, the thin film transistor T, and the like. A grid-like black matrix 25 is formed that borders each pixel region P. The red, green, and blue color filter layers 26 are sequentially and repeatedly arranged to correspond to the pixel regions P in the grid. Is formed, and a transparent common electrode 28 is provided over the entirety of the black matrix 25 and the red, green, and blue color filter layers 26.

Although not clearly shown in the drawings, these two substrates 10 and 20 are each sealed with a sealing agent or the like along the edges to prevent leakage of the liquid crystal layer 30 interposed therebetween. An upper and lower alignment layer is provided at the boundary between the substrates 10 and 20 and the liquid crystal layer 30 to provide reliability in the molecular alignment direction of the liquid crystal, and at least one outer surface of each of the substrates 10 and 20 has a polarizing plate. Attached.

In addition, a backlight is provided on the back of the liquid crystal panel to supply light. The on / off signal of the thin film transistor T is sequentially scanned and applied to the gate wiring 14. When the image signal of the data wiring 16 is transmitted to the pixel electrode 18 of the pixel region P, the liquid crystal molecules are driven by the vertical electric field therebetween, and various images are changed due to the change in the transmittance of light. I can display it.

Meanwhile, in the liquid crystal display device, glass substrates have been traditionally used for the first and second insulating substrates 12 and 22, which are the matrixes of the array substrate 10 and the color filter substrate 20. As small portable terminals such as personal digital assistants (PDAs) are widely used, liquid crystal panels using plastic substrates have been introduced that are lighter, lighter, and more flexible than glass so that they can be applied to them.

However, liquid crystal panels using plastic substrates have a high temperature process requiring a high temperature of 200 ° C. or higher, especially in the fabrication of an array substrate on which a thin film transistor, which is a switching element, is formed. Since it is difficult to manufacture the array substrate from the falling plastic substrate, only the color filter substrate constituting the upper substrate is manufactured from the plastic substrate, and the array substrate, the lower substrate, is used to manufacture a liquid crystal display device using a conventional glass substrate. .

In order to solve this problem, a technique for manufacturing an array substrate, which is characterized by forming a thin film transistor by performing a low temperature process below 200 ° C. using an organic semiconductor material, has recently been proposed. The manufacturing of the array substrate by such a low temperature process uses a coating apparatus rather than manufacturing using an expensive vacuum deposition equipment, so that the initial equipment cost is very low, and as a result, a reduction in manufacturing cost can be achieved. Naturally, the present invention is not limited to the production using the organic substrate, but may be manufactured using the organic substrate.

Hereinafter, a method of manufacturing an array substrate using an organic semiconductor material undergoing a low temperature process of 200 ° C. or less will be described.

In forming a pixel including a thin film transistor at a low temperature process of 200 ° C. or lower, the characteristics of the thin film transistor may be formed even by forming a metal material, an insulating film, a protective layer, or the like that form an interconnection with an electrode through low temperature deposition or coating. Although it does not affect much, when the semiconductor layer forming the channel is deposited by using a low temperature process using amorphous silicon, which is a commonly used semiconductor material, the internal structure of the semiconductor layer is not dense and important characteristics such as conductivity are deteriorated. A problem arises.

Therefore, in order to overcome this, it is proposed to form an organic semiconductor layer using an organic material having semiconductor characteristics instead of a conventional semiconductor material such as amorphous silicon.

The organic semiconductor material is largely divided into a powder type organic semiconductor material (mostly a low molecular organic semiconductor material) and a liquid type organic semiconductor material (mostly a polymer organic semiconductor material). Typically, the powder type is a low molecular organic semiconductor material. The organic semiconductor material having a powder form forms an organic semiconductor layer on the substrate through evaporation at room temperature, and the liquid type is usually a polymer organic semiconductor material and forms an organic semiconductor layer on the substrate through coating at room temperature. .

In general, since the semiconductor characteristics of the powder type low molecular organic semiconductor material are superior to those of the liquid type polymer organic semiconductor material, a liquid crystal display device having a thin film transistor formed by using the low molecular organic semiconductor material as an organic semiconductor layer is mainly used. In order to form a low molecular organic semiconductor material and a high molecular organic semiconductor material such as a high molecular organic semiconductor material on a substrate by a coating method, a liquid crystal display device using the same has been developed.

However, in the case of an array substrate for a liquid crystal display device including an organic thin film transistor using an organic semiconductor material, characterized in that the low-temperature process, the characteristics of the organic thin film transistor using amorphous silicon or polysilicon in a high temperature atmosphere In order to overcome this problem, the thin film transistor is separated from the thin film transistor. Therefore, in order to overcome this problem, the width ratio of the channel ratio, i.e., the length of the channel formed inside the semiconductor layer, is increased. In order to prevent chemical damage, the semiconductor layer is largely formed.

2 is a plan view illustrating one pixel area of a conventional array substrate for a liquid crystal display device including an organic thin film transistor manufactured using an organic semiconductor material, in particular, a liquid type low molecular organic semiconductor material.

As shown in the drawing, the data line 52 and the gate line 77 cross each other to define the pixel region P, and the two lines 55 are disposed near the intersection point of the two lines 55 and 77. And an organic thin film transistor Tr including a source and drain electrodes 57 and 59, an organic semiconductor layer (not shown), a gate insulating film (not shown), and a gate electrode 73 as switching elements, respectively. The pixel electrode 63 is connected to the organic thin film transistor Tr and is formed in the pixel region P.

In this case, the portion 66 of the pixel electrode overlaps the portion of the gate wiring 80 to form a storage capacitor StgC, and the first storage electrode (stgC) may be used to secure the capacity of the storage capacitor StgC. The area of the gate wiring portion 80 forming the second storage electrode 80 overlapping with the pixel electrode portion 66 forming the 66 is formed to be large. Therefore, it can be seen that the width of the gate wiring 77 is formed very thick.

However, in the case of an array substrate for a liquid crystal display device including a conventional organic thin film transistor (Tr) having such a structure, most of the pixel region (P) is a storage capacitor (StgC) and a thin film transistor (Tr) that is a switching element. It can be seen that the opening area OA through which light passes in the pixel area P becomes very small by occupying. Therefore, there is a problem that the aperture ratio becomes very small and the luminance characteristic is lowered.

When manufacturing an array substrate for a liquid crystal display device having an organic thin film transistor, the aperture ratio is lowered due to an increase in channel ratio for improving characteristics and an increase in size of the organic semiconductor layer to minimize chemical damage of the organic semiconductor material.

Accordingly, there is a need for a pixel design capable of simultaneously satisfying the device characteristics of an organic thin film transistor and the charging characteristics and aperture ratios at the same time driving each pixel of a liquid crystal display device having an organic thin film transistor.

An object of the present invention is to provide an array substrate for a liquid crystal display device that can increase the luminance by increasing the aperture ratio while ensuring sufficient storage capacity by increasing the area of the storage capacitor to solve the above problems. .

An array substrate for a liquid crystal display device having an organic semiconductor layer according to the present invention for achieving the above object comprises: a first storage electrode formed of a transparent conductive material in a pixel region on the substrate; An insulating layer formed on a front surface of the first storage electrode; A data line extending in one direction over the insulating layer; A source electrode electrically connected to the data line, and a drain electrode facing the source electrode and spaced apart from each other; A pixel electrode formed in contact with the drain electrode and a second storage electrode extending from the pixel electrode and overlapping the first storage electrode; An organic semiconductor layer formed at one end of the source and drain electrodes spaced apart from each other, and at a spaced area between the two electrodes; A gate insulating film and a gate electrode sequentially stacked on the organic semiconductor layer; A first protective layer having a gate contact hole and a storage contact hole exposing the gate electrode and the first storage electrode on a front surface of the gate electrode, the exposed source and drain electrodes, and a data line; A gate wiring formed on the first passivation layer and contacting the gate electrode through the gate contact hole and simultaneously contacting the first storage electrode through the storage contact hole and defining the pixel area crossing the data line; Include.

In this case, the pixel electrode is made of a transparent conductive material, and in this case, the transparent conductive material is made of indium tin oxide (ITO).

The insulating layer may be formed of silicon oxide (SiO ₂ ) or silicon nitride (SiNx), and the gate insulating layer and the gate electrode may have the same pattern shape as the organic semiconductor layer.

The semiconductor device may further include a second protective layer formed over the gate line.

A method of manufacturing an array substrate for a liquid crystal display device having an organic semiconductor layer according to the present invention includes forming a first storage electrode in a pixel region with a transparent conductive material on a substrate on which a pixel region is defined; Forming an insulating layer on a front surface of the first storage electrode; Forming a data line extending in one direction over the insulating layer; Forming a source electrode electrically connected to the data line on the insulating layer, and a drain electrode facing and spaced apart from the source electrode; Forming a pixel electrode on the insulating layer in contact with the drain electrode and partially overlapping the first storage electrode to form a second storage electrode in the pixel area; Forming an organic semiconductor layer, a gate insulating film, and a gate electrode sequentially stacked on the separation regions of the two electrodes, including the source and drain electrode ends spaced apart from each other; Forming a first passivation layer on the front surface of the gate electrode, the first protective layer having a gate contact hole and a storage contact hole respectively exposing the gate electrode part and the first storage electrode part; A gate wiring is formed on the first passivation layer to contact the gate electrode through the gate contact hole and at the same time to the first storage electrode through the storage contact hole and to cross the data line to define the pixel area. It includes a step.

In this case, the transparent conductive material is preferably indium tin oxide (ITO) or indium zinc oxide (IZO), and the insulating layer is formed by depositing silicon oxide (SiO ₂ ) or silicon nitride (SiNx). It is preferable.

The forming of the organic semiconductor layer, the gate insulating layer, and the gate electrode may include forming an organic semiconductor material layer by coating an organic semiconductor material over the source and drain electrodes and the pixel electrode; Applying an organic insulating material over the organic semiconductor material layer to form an organic insulating material layer; Depositing a metal material on the organic insulating material layer to form a metal material layer; Forming a photoresist pattern on the metal material layer; Forming the gate electrode by first removing the metal material layer exposed to the outside of the photoresist pattern by performing first etching; Removing the photoresist pattern remaining on the gate electrode; Removing the organic insulating material layer and an organic semiconductor material layer below the organic insulating material layer exposed to the outside of the gate electrode by performing a second etching using the gate electrode as an etching mask, wherein the organic semiconductor material layer Is formed by coating using one of an inkjet apparatus, a nozzle coating apparatus, a bar coating apparatus, a slit coating apparatus, a spin coating apparatus or a printing apparatus.

In addition, after the forming of the gate line, the method may further include forming a second protective layer over the gate line.

In addition, the forming of the data line and the forming of the source and drain electrodes spaced apart from each other may be performed by the same mask process using the same metal material. The forming of the pixel electrode is characterized in that the same material is performed by the same mask process. In this case, the same material is preferably indium-tin-oxide (ITO).

Hereinafter, the present invention will be described in more detail with reference to the drawings.

3 is a plan view of one pixel area of an array substrate for a liquid crystal display device including an organic semiconductor layer according to an exemplary embodiment of the present invention, and FIG. 4 is a view illustrating a portion cut along the cutting line IV-IV of FIG. 3. It is a cross section. In this case, for convenience of description, a portion in which the thin film transistor, which is a switching element, is formed in the pixel region is defined as a switching region and a region in which a storage capacitor is formed as a storage region.

First, referring to FIG. 3, a gate line 165 extending in one direction is formed, and a data line 108 defining a pixel area P is formed to cross the gate line 165.

In addition, a thin film transistor Tr, which is connected to these two wires 165 and 108 and is a switching element, is formed near an intersection point of the gate and data lines 165 and 108. The thin film transistor Tr includes source and drain electrodes 110 and 113, an organic semiconductor (not shown), a gate insulating layer (not shown), and a gate electrode 145, and the source electrode 110 includes the data. The gate electrode 145 is directly connected to the wiring 107 and is connected to the gate wiring 165 through the gate contact hole 155. In addition, the drain electrode 113 is in direct contact with and electrically connected to the pixel electrode 120 formed of a transparent conductive material for most of the pixel region P.

Meanwhile, the most distinctive feature of the present invention is that the (first) storage electrode 103 made of the transparent conductive material is formed by overlapping the pixel electrode part 127 and simultaneously contacting the gate wiring 165. A storage capacitor StgC is formed together with a portion of the pixel electrode 120 forming the second storage electrode 127.

Typically, one of the two storage electrodes constituting the storage capacitor uses a gate wiring made of a low resistance metal material. In this case, the low resistance metal material becomes an opaque material, which causes a decrease in aperture ratio. In this case, a portion 127 of the pixel electrode 120 is formed as the second storage electrode 127, and the first storage capacitor 103 is formed of a transparent conductive material that is the material forming the pixel electrode 120 to transmit light. The characteristic constitution is that the opening ratio can be prevented from being lowered by reducing the aperture ratio.

Next, a cross-sectional structure of an array substrate for a liquid crystal display device according to the present invention will be described with reference to FIG. 4.

First, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) corresponding to the pixel area P and the region GLA on which the gate wiring is to be formed is formed on the transparent insulating substrate 101. The first storage electrode 103 is formed, and an insulating film 105 is formed on the entire surface thereof by using an inorganic insulating material, for example, silicon oxide (SiO ₂ ) or silicon nitride (SiNx). In this case, the insulating film is formed of silicon oxide (SiO ₂ ) having hydrophilic property, in particular, to improve contact characteristics with the organic semiconductor layer 130 formed in contact therewith.

Next, a plurality of data wires 108 extending in one direction are formed on the insulating film 105. In addition, a plurality of data wires 108 are formed on the insulating film 105 so as to contact the data wires 108 and correspond to the switching region TrA. A source electrode 110 formed of a metal having the largest work function value, for example, gold (Au) is formed, and the same material forming the source electrode 110 at a predetermined interval from the source electrode 110 is formed. The drain electrode 113 is formed to face the source electrode 110. In this case, the data line 108 and the source and drain electrodes 110 and 113 are all formed of gold (Au), so that the source electrode 110 has a form branched from the data line 108. However, the data line and the source electrode (including the drain electrode) may be formed in a form of overlapping contact rather than branching by forming different materials.

Next, a portion of the portion in which the first storage electrode 103 is formed is directly contacted with the drain electrode 113 in the pixel region P, and a transparent conductive material such as indium tin oxide (ITO) or The pixel electrode 120 is formed of indium zinc oxide (IZO). In this case, an area overlapping the first storage electrode 103 of the pixel electrode 120 forms a second storage electrode 127, and these two electrodes 103 and 127 are the first and second storage electrodes 103. , A storage capacitor StgC is formed using the insulating layer 105 formed between the first and second electrodes 127 as a dielectric layer.

Next, in the switching region TrA, the organic semiconductor layer has the same pattern shape on the spaced apart regions of the two electrodes 110 and 113 including one end of the source and drain electrodes 110 and 113 facing each other. The 130, the gate insulating layer 136, and the gate electrode 145 are sequentially stacked. In this case, the source and drain electrodes 110 and 113, the organic semiconductor layer 130, the gate insulating layer 136, and the gate electrode 145 form an organic thin film transistor Tr.

Next, an organic insulating material, for example, benzocyclobutene (BCB), photo acryl, and PVA, is formed on the organic thin film transistor Tr and the exposed pixel electrode 120 and the second storage electrode 127. A protective layer 150 having a single layer or a double layer structure is formed of one or two materials of poly vinyl alcohol or a fluoropolymer. In this case, the single layer or double layer protective layer 150 may be removed together with the gate contact hole 155 exposing a part of the protective layer 150 corresponding to the gate electrode 145 and the insulating layer 105 disposed below the first layer. The storage electrode 103 has a storage contact hole 158 exposing a part of the end thereof. In this case, the protective layer 150 is formed in a single layer form.

Next, a low resistance material is formed on the passivation layer 150 having the gate and storage contact holes 155 and 158, and the gate electrode 145 and the first through the gate and storage contact holes 155 and 158, respectively. A gate line 165 is formed in contact with the first storage electrode 103 and intersects with the data line 108 to define the pixel area P.

Although not shown in the drawings, a second passivation layer (not shown) may be further formed on the gate line 165.

In the case of the array substrate 101 for a liquid crystal display device including the organic semiconductor layer 130 according to the present invention, the (first) storage electrode is not formed of the same material on the same layer as the gate wiring 165, By forming the (first) storage electrode 103 to overlap the portion of the pixel electrode 127 and the pixel region P by using a transparent conductive material, the opening ratio of the storage capacitor StgC is prevented from being lowered. It is the most characteristic of this invention.

In the case of an array substrate for a liquid crystal display device including a conventional organic thin film transistor, a gate made of an opaque metal having the low resistance characteristic by forming one story electrode by connecting the gate wiring with the same material to the same layer as the gate wiring Although the wiring is expanded to have a thick width inside the pixel region, the aperture ratio in the pixel region is reduced. However, in the present invention, the transparent storage material is dualized with the gate wiring 165 to transmit light. The formation of the electrode 103 has a characteristic feature that the capacity of the storage capacitor StgC can be expanded without lowering the aperture ratio.

Hereinafter, a method of manufacturing an array substrate for a liquid crystal display device according to the present invention will be described.

5A to 5H are cross-sectional views illustrating the manufacturing steps of the cut portion IV-IV of FIG. 3.

First, as shown in FIG. 5A, a transparent conductive material such as indium-tin-oxide (ITO) or indium-ink-oxide (101) may be disposed on a transparent insulating substrate 101, for example, a glass or plastic substrate 101. IZO) is deposited on the entire surface to form a transparent conductive material layer, and a photoresist is applied thereon to form a photoresist layer (not shown), followed by exposure using an exposure mask that selectively transmits light, and the photoresist layer (not shown). Development), etching of the transparent conductive material layer using a photoresist layer (not shown) remaining after development, and stripping or ashing of the remaining photoresist layer (not shown). The first storage electrode 103 is formed to correspond to the pixel region P except the switching region TrA and a portion of the region GLA where the gate wiring is to be formed by patterning the mask process. In this case, the first storage electrode 103 has a form that is independently patterned for each pixel region (P).

Next, an inorganic insulating material, for example, silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited on the entire surface of the first storage electrode 103 to form an insulating layer 105. At this time, the insulating layer 105 is preferably formed of silicon oxide (SiO ₂ ), which is silicon oxide (SiO ₂ ) having a hydrophilic property, which is formed later on the organic semiconductor layer (not shown) This is because the organic semiconductor layer (not shown) has an effect of forming an even thickness at the same time to improve the contact characteristics with.

Next, as shown in FIG. 5B, a metal material having low resistance on the insulating layer 105, for example, gold (Au), silver (Ag), aluminum (Al), aluminum alloy (AlNd), and molybdenum ( One of the materials selected from Mo, copper (Cu), and copper alloy is deposited on the entire surface, and patterned by patterning a mask process to form a data line 108 extending in one direction. Thereafter, source and drain electrodes 110 and 113 are formed in the switching region TrA so as to be spaced apart from each other by the same process in which the data line 108 is formed. In this case, the source electrode 110 is formed in contact with the data line 108. In this case, the source and drain electrodes 110 and 113 in contact with the organic semiconductor layer formed later have to be formed of a metal material having a large work function value, so that the thin film transistor (Tr) characteristic of a switching role is excellent. It should be formed of a metal material having a work function value, and the metal material is preferably gold (Au) or indium-tin-oxide (ITO).

Therefore, when the data line 108 is formed of gold (Au), the source and drain electrodes 110 and 113 may be formed by the same process as the data line 108 is formed, as shown. The data line 108 and the source and drain electrodes 110 and 113 may be dualized to form different materials. For example, the data line 108 is formed of one metal material except gold (Au) of the low resistance metal material, and the source and drain electrodes 110 and 113 are made of indium tin oxide (ITO). In this case, first, the data line 108 may be formed, and then the source and drain electrodes 110 and 113 may be formed in the step of forming the pixel electrode to be formed in the next process. In the drawing, the data line 108 and the source and drain electrodes 110 and 113 are formed of the same material, that is, Au in the same process.

Next, as shown in FIG. 5C, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is formed over the data line 108 and the source and drain electrodes 110 and 113. Is deposited, and the pixel electrode 120 is formed in the pixel region P by patterning the mask process. In this case, the pixel electrode 120 is in direct contact with one end of the drain electrode 113 and overlaps with the first storage electrode 103. In this case, the pixel electrode 120 has a smaller area than the first storage electrode 103 and is not formed in the region GLA where the gate wiring is to be formed. In this case, the pixel electrode overlapped with the first storage electrode 103 forms the second storage electrode 127.

On the other hand, as a modification, when the source and drain electrodes are formed of indium tin oxide (ITO), the source and drain electrodes may be simultaneously formed in the forming of the pixel electrode. It is formed in a form branched from the pixel electrode.

In addition, when the source and drain electrodes are formed of indium tin oxide (ITO), an oxygen (O ₂ ) plasma process is further performed to enhance the work function value of the indium tin oxide (ITO). The indium tin oxide (ITO) before the oxygen (O ₂ ) plasma process is about 4.6 eV work function, but the indium tin oxide (ITO) after the oxygen (O ₂ ) plasma process is It has a work function value of about 4.8 eV to about 4.9 eV.

 Next, as shown in FIG. 5D, a liquid organic semiconductor material, especially mobility, is formed on the entire surface of the substrate 101 on which the source and drain electrodes 110 and 113, the pixel electrode 120, and the second storage electrode 127 are formed. Low molecular organic semiconductor materials, which are relatively good in mobility (e.g., liquid pentacene or polythiophene), such as ink jet devices, nozzle coating devices, bar coating devices, slits ) To form an organic semiconductor material layer 129 by coating using a coating apparatus, a spin coating apparatus or a printing apparatus.

 Thereafter, the organic insulating material is not reacted even when the organic semiconductor material layer 129 is continuously contacted with the organic semiconductor material layer 129 and does not affect the organic semiconductor material layer 129 at all. By applying a material, for example, a fluoropolymer, a gate insulating material layer 135 is formed on the front surface, and a metal material, such as molybdenum, which is easily dry-etched on the front surface of the gate insulating material 135 is successively formed. The second metal layer 144 is formed by depositing Mo) or chromium (Cr).

Thereafter, a photoresist pattern 191 is formed by coating, exposing and developing photoresist or photosensitive polyvinyl alcohol (PVA) or photoacryl on the second metal layer 144.

Next, as shown in FIG. 5E, the second metal layer exposed to the outside of the photosensitive pattern (191 of FIG. 5D) by performing a first dry etching using the photosensitive pattern (191 of FIG. 5D) as an etching mask. After the gate electrode 145 is formed by removing 144 of 5d, the photosensitive pattern (191 of FIG. 5D) remaining on the gate electrode 145 is stripped to remove the gate electrode 145. 145).

In this case, the etching of the second metal layer 144 of FIG. 5D may include a gate insulating material layer 135 completely covering the organic semiconductor material layer 129 under the second metal layer 144 of FIG. 5D. Bar (1) It is also possible to use wet etching using an etchant without proceeding to dry etching, but since the organic semiconductor material layer 129 is very vulnerable to chemicals such as etchant, there is a possibility of damage due to etching infiltration. It is desirable to pattern by dry etching to completely exclude it.

Next, as shown in FIG. 5F, a second dry etching process is performed using the gate electrode 145 as an etching mask, and the gate insulating material layer (135 of FIG. 5E) exposed to the outside of the gate electrode 145 is organic. By simultaneously removing the semiconductor material layer (129 of FIG. 5E), the gate insulating layer 136 and the organic semiconductor layer 130 having the same shape as the gate electrode 145 are formed under the gate electrode 145. In this case, the first and second dry etching is performed by changing the conditions. That is, the first dry time is etching the (second) metal layer (144 in FIG. 5D), and the second dry etching is the gate insulating material layer (135 in FIG. 5E) and the organic semiconductor material layer (FIG. 5E) made of the organic insulating material. 144 of the bar is etched, and thus the plasma electrode proceeds with different etching gases, so that the gate electrode 145 is also exposed to the second dry etching during the second dry etching, but the gate electrode 145 is not etched. Instead, only the gate insulating material layer 135 (FIG. 5E) and the organic semiconductor material layer 129 exposed to the outside of the gate electrode 145 are etched.

Accordingly, the data line 105 and the pixel electrode 120 are exposed in regions other than the switching region TrA, and at the same time, the source and drain electrodes 110 are spaced apart from each other in the switching region TrA. A gate insulating film 136 and a gate in contact with 113 and having the same shape as the organic semiconductor layer 130 above the island-shaped organic semiconductor layer 130 in a spaced area between the two electrodes 110 and 113. The electrode 145 is formed.

In this case, the source and drain electrodes 110 and 113, the organic semiconductor layer 130, the gate insulating layer 136, and the gate electrode 145 spaced apart from each other form an organic thin film transistor Tr as a switching element.

Next, as shown in FIG. 5G, an organic insulating material, for example, benzocyclobutene, is formed on the entire surface of the thin film transistor Tr, the exposed pixel electrode 120, the second storage electrode 127, and the data line 105. (BCB), photo acryl, polyvinyl alcohol (PVA) or fluoropolymer (fluoropolymer) of one or two selected materials are applied in succession to form a protective layer 150 of a single layer or double layer structure The gate contact hole 155 may be formed to expose a portion of the gate electrode 145 by patterning the mask process by exposing and developing the protective layer 150 having the single layer or the double layer structure. At the same time, a storage contact hole 158 exposing the insulating layer 105 is formed in a region GLA in which the gate wiring is to be formed, more precisely, in the pixel region P. By the insulating layer 105 to expose the storage contact hole 158 is removed to proceed with the third dry etching so as to expose to the first storage electrode 105.

Next, as shown in FIG. 5H, a low-resistance metal material such as silver (Ag), aluminum (Al), and aluminum is disposed on the protective layer 150 having the gate contact hole 155 and the storage contact hole 158. The gate contact hole 155 is formed by sputtering a material selected from an alloy (AlNd), molybdenum (Mo), copper (Cu), and a copper alloy at 200 ° C. or lower, and patterning it by performing a mask process. Contacting the gate electrode 145 and at the same time contacting the first storage electrode 103 through the storage contact hole 158 and crossing the data line 108 to define the pixel region P. By forming the gate wiring 165, an array substrate for a liquid crystal display device including an organic thin film transistor according to an exemplary embodiment of the present invention is completed.

In this case, although not shown, a second passivation layer (not shown) may be further formed on the gate line 165.

The liquid crystal display array substrate including the organic thin film transistor according to the present invention has a large storage capacitor capacity due to the characteristics of the organic thin film transistor, and is dually connected with the gate wiring to be electrically connected to the gate wiring and the pixel as a transparent ring conductive material. The storage electrode is formed in the pixel region to overlap the electrode, thereby improving the aperture ratio and the luminance.

In addition, by forming an organic semiconductor layer using a liquid semiconductor organic material without using expensive vacuum equipment, there is an effect of reducing the initial equipment cost to improve the price competitiveness of the product.

Claims (15)

A first storage electrode formed of a transparent conductive material in a pixel region on the substrate; An insulating layer formed on a front surface of the first storage electrode; A data line extending in one direction over the insulating layer; A source electrode electrically connected to the data line, and a drain electrode facing the source electrode and spaced apart from each other; A pixel electrode formed in contact with the drain electrode and a second storage electrode extending from the pixel electrode and overlapping the first storage electrode; An organic semiconductor layer formed at one end of the source and drain electrodes spaced apart from each other, and at a spaced area between the two electrodes; A gate insulating film and a gate electrode sequentially stacked on the organic semiconductor layer; A first protective layer having a gate contact hole and a storage contact hole exposing the gate electrode and the first storage electrode on a front surface of the gate electrode, the exposed source and drain electrodes, and a data line;     A gate wiring contacting the gate electrode over the first protective layer through the gate contact hole and simultaneously contacting the first storage electrode through the storage contact hole, and defining the pixel region to cross the data wiring; Array substrate for a liquid crystal display device comprising a. The method of claim 1, And the pixel electrode is made of a transparent conductive material. The method according to claim 1 or 2, And the transparent conductive material is made of indium tin oxide (ITO). The method of claim 1, And the insulating layer is formed of silicon oxide (SiO ₂ ) or silicon nitride (SiNx). The method of claim 1, And the gate insulating film and the gate electrode have the same pattern shape as the organic semiconductor layer. The method of claim 1, And a second passivation layer formed over the gate line. Forming a first storage electrode in the pixel region using a transparent conductive material on a substrate on which the pixel region is defined; Forming an insulating layer on a front surface of the first storage electrode; Forming a data line extending in one direction over the insulating layer; Forming a source electrode electrically connected to the data line on the insulating layer, and a drain electrode facing and spaced apart from the source electrode; Forming a pixel electrode on the insulating layer in contact with the drain electrode and partially overlapping the first storage electrode to form a second storage electrode in the pixel area; Forming an organic semiconductor layer, a gate insulating film, and a gate electrode sequentially stacked on the separation regions of the two electrodes, including the source and drain electrode ends spaced apart from each other; Forming a first passivation layer on the front surface of the gate electrode, the first protective layer having a gate contact hole and a storage contact hole respectively exposing the gate electrode part and the first storage electrode part; A gate wiring is formed on the first passivation layer to contact the gate electrode through the gate contact hole and at the same time to the first storage electrode through the storage contact hole and to cross the data line to define the pixel area. Steps to Method of manufacturing an array substrate for a liquid crystal display device comprising a. The method of claim 7, wherein The transparent conductive material is an indium tin oxide (ITO) or indium zinc oxide (IZO) manufacturing method of an array substrate for a liquid crystal display device. The method of claim 7, wherein The insulating layer is a method of manufacturing an array substrate for a liquid crystal display device formed by depositing silicon oxide (SiO ₂ ) or silicon nitride (SiNx). The method of claim 7, wherein Forming the organic semiconductor layer, the gate insulating film and the gate electrode, Forming an organic semiconductor material layer by coating an organic semiconductor material over the source and drain electrodes and the pixel electrode; Applying an organic insulating material over the organic semiconductor material layer to form an organic insulating material layer; Depositing a metal material on the organic insulating material layer to form a metal material layer; Forming a photoresist pattern on the metal material layer; Forming the gate electrode by first removing the metal material layer exposed to the outside of the photoresist pattern by performing first etching; Removing the photoresist pattern remaining on the gate electrode; Removing the organic insulating material layer exposed below the gate electrode and an organic semiconductor material layer below the second electrode by performing a second etching process using the gate electrode as an etching mask; Method of manufacturing an array substrate for a liquid crystal display device comprising a. The method of claim 10, The organic semiconductor material layer is formed by coating using one of an inkjet apparatus, a nozzle coating apparatus, a bar coating apparatus, a slit coating apparatus, a spin coating apparatus or a printing apparatus. The manufacturing method of the array substrate for liquid crystal display devices. The method of claim 7, wherein After forming the gate wiring, Forming a second passivation layer over the gate wiring Method of manufacturing an array substrate for a liquid crystal display device further comprising. The method of claim 7, wherein And the forming of the data line and the forming of the source and drain electrodes spaced apart from each other are performed by the same mask process using the same metal material. The method of claim 7, wherein The forming of the source and drain electrodes and the forming of the pixel electrode may be performed by the same mask process using the same material. The method of claim 14, The same material is an indium-tin-oxide (ITO) manufacturing method of an array substrate for a liquid crystal display device.

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