KR19990040307A - Liquid Crystal Display Using Molybdenum-Tungsten Alloy and Manufacturing Method Thereof - Google Patents

Abstract

The present invention provides wiring formation of the lower plate of the liquid crystal display device using the Mo-W alloy.

A liquid crystal display using the Mo-W alloy includes a switching element including a gate electrode, a source electrode and a drain electrode, a gate bus line connected to the gate electrode, a data bus line connected to the source electrode, and the drain electrode. A lower panel of a liquid crystal display device including a pixel electrode connected to the gate electrode, the gate electrode branched from the gate bus line and the gate bus line, the drain electrode and the source electrode formed from the data bus line and the data bus line. The wiring formation of is characterized in that it is formed using a wiring material formed of Mo-W alloy. In this case, the wiring material formed of the Mo-W alloy is characterized in that it has a tungsten (W) of 15%.

Accordingly, the wiring of the lower panel of the liquid crystal display device formed by using the Mo-W alloy is dry etching or In the process of forming a pixel electrode or a contact hole by removing a part of the ITO film B 'or the passivation layer of the liquid crystal display using wet etching or the like, cracks or pin holes of the passivation layer Through holes, the surface of the data bus line pad part, the data bus line 170, the source electrode 170a, and the drain electrode 170c may be prevented from being overetched.

Description

Liquid Crystal Display Using Mo-W Alloy and Manufacturing Method Thereof

The present invention relates to a liquid crystal display device using a wiring material made of Mo-W alloy, and more particularly, to a data bus line, a data bus line pad part, a gate bus line, a gate bus line pad part, and each of the gates of the liquid crystal display device. In the formation of a work gate electrode, a source electrode, and a drain electrode branched from a bus line and a data bus line, the bus line, the pad portion, and the electrodes are formed by using a metal wiring material made of a Mo-W alloy. .

In general, a liquid crystal display (LCD) includes an upper plate 30, a lower plate 10, and a liquid crystal 20 filled between the two substrates as shown in FIG. 1. On each of the outer surfaces of the two substrates 10 and 30, polarizing plates 11 and 31 for linearly polarizing visible light are attached.

That is, the polarizing plate 31 is attached to one surface of the upper plate 30, and the opposite surface on which the polarizing plate 31 is not attached includes the color filter 32 and the common electrode 33. In addition, a polarizing plate 11 is attached to one side of the lower plate 10, and the opposite side to which the polarizing plate 11 is not attached is formed of a plurality of gate bus lines 12 and gate buses formed of molybdenum (Mo) metal. A line pad portion 12b, a plurality of data bus lines 17 and data bus line pad portions 17b, and a branch from the gate electrode 12a and the data bus line 17 branched from the gate bus line 12; And a switching element A including the source electrode 17a, the drain electrode 17c, and the like, the pixel electrode 19, and the like.

The structure of the lower panel 10 of the liquid crystal display will be described with reference to the schematic diagram shown in FIG.

The plurality of gate bus lines 12 form a parallel structure with each other, and the plurality of data bus lines 13 form a mattress structure that is orthogonal to each other with the plurality of gate bus lines 12. In a predetermined space formed by the gate bus line 12 and the data bus line 13 orthogonal to each other, the gate bus line 12 a branched from the gate bus line 12 and the data bus line 13 branch from the data bus line 13. The TFT switching element A, which consists of the source electrode 13a and the drain electrode 14, is positioned, and the pixel electrode 15 is connected to the drain electrode 14, which is an output terminal of the switching element A.

The manufacturing process of the above-described lower panel of the liquid crystal display device will be described with reference to the cross-sectional views shown in FIGS. 3A to 3F.

A glass substrate or the like is used to form a transparent substrate under the liquid crystal display device. Molybdenum (Mo) is deposited on the transparent substrate by sputtering to form a molybdenum (Mo) metal film (FIG. 3A).

Dry etching of the molybdenum (Mo) metal film Etching is performed in a predetermined pattern using a method such as wet etching. For example, using a phosphate mixed acid solution as an etchant In the case of wet etching, the molybdenum metal is oxidized by nitric acid (HNO ₃ ) in the mixed acid solution. At this time, phosphoric acid (H ₃ PO ₄ ) has a water-soluble property to dissolve the oxidized molybdenum metal in water (H ₂ O), acetic acid (CH ₃ COOH) is the oxidation reaction of nitric acid (HNO ₃ ) To act as an accelerator. As a result, the molybdenum (Mo) metal is etched to form a plurality of gate bus lines 12, gate bus line pad portions 12b, and gate electrodes 12a (FIG. 3B).

A gate insulating film is formed using SiNx, SiOx, or the like having good interfacial properties and high dielectric breakdown voltage on a liquid crystal display substrate including the plurality of gate bus lines 12, the gate bus line pad part 12b, and the gate electrode 12a. (13) is formed (FIG. 3C).

The semiconductor layer 14 is formed on the gate insulating layer 13 on the gate electrode 12a by using polycrystalline silicon (a-Si) or the like. An ohmic contact layer 15 is formed on the semiconductor layer 14 for good ohmic contact between the semiconductor layer 14 and the source electrode 17a / drain electrode 17c (FIG. 3D).

Molybdenum (Mo) is applied to the entire surface of the substrate by sputtering to form a molybdenum (Mo) metal film.

By etching the molybdenum (Mo) metal film in a predetermined pattern using a method such as dry etching, a plurality of data bus lines having a direction perpendicular to the forming direction of the gate bus line 12 described above. 17 and the data bus line pad portion 17b are formed. At this time, at the same time as the pattern formation of the data bus line 17, a source electrode 17a branching from the data bus line 17 is formed, and functions as an output terminal at a position opposite to the source electrode 17a. The drain electrode 17c is formed.

The gate bus line 12, the data bus line 17, the gate electrode 12a, the gate insulating film 13, the semiconductor layer 14, the source electrode 17a, and the drain are formed by the above-described series of processes. A switching element A having a TFT structure composed of an electrode 17c or the like is formed on the lower plate 10 of the liquid crystal display device (Fig. 3E).

An insulating film, such as SiNx, SiOx, Benzocyclobutene (BCB), is coated on the liquid crystal display substrate including the gate bus line 12, the data bus line 17, and the switching element A to form a protective film 18. . A portion of the protective layer 18 is removed to form a contact hole so that a portion of the drain electrode 17c, which is an output terminal of the switching element existing at the lower end of the protective layer 18, is exposed (FIG. 3F).

An ITO (Indium Tin Oxide) film B is deposited on the entire surface of the protective film 18 having the contact hole by using a sputtering method (FIG. 3G).

Dry etching the ITO film in a predetermined pattern; By etching using wet etching or the like, a pixel electrode 19 connected to the drain electrode 17c, which is an output terminal of the switching element A, is formed through the contact hole (FIG. 3H). By the above-described series of processes, the manufacturing process of the lower plate of the liquid crystal display device is performed.

According to the conventional process of forming the liquid crystal display wiring, the molybdenum (Mo) metal is formed into the data bus line 17, the data bus line pad part 17b, the gate bus line 12, and the gate bus line pad part ( 12b) and used as a metal wiring material for forming the gate electrodes 12a, the source electrodes 17a, and the drain electrodes 17c branched from the gate bus lines 12 and the data bus lines 17, respectively. .

However, as shown in FIG. 3B, the molybdenum (Mo) metal is deposited on the transparent substrate 1 and etched to form the gate bus line 12, the gate electrode 12 a, and the gate bus line pad part 12 b. In the forming process, edges of the gate bus line 12, the gate electrode 12a, and the gate bus line pad part 12b are overetched by an etchant for etching the molybdenum (Mo) metal. over etching).

In addition, as shown in FIG. 3G, an ITO film B is deposited on the entire surface of the lower plate of the liquid crystal display device including the switching element A, the protective film 18, and the like, and is etched in a predetermined pattern to output the protective film 18. In the process of forming the pixel electrode 19 connected to the drain electrode 17c as a terminal, an etchant for etching the ITO film B may be a crack generator or a pinhole of the passivation layer 18. ) Penetrates into the lower portion of the passivation layer 18 through the generator. Therefore, a problem arises in that the surfaces of the source electrode 17a and the drain electrode 17c of the switching element A positioned under the passivation layer 18 are over etched.

In the process of depositing the ITO film B on the lower plate of the liquid crystal display device, the ITO film B is the data bus line 17 and the data bus line pad portion 17b coated with the protective film 18. It is also deposited on the upper end (Figs. 4A, 5A). Thus, as illustrated in FIGS. 4B and 5B, an etchant for removing the ITO film B may be formed through the crack generator or the pinhole generator of the passivation layer 18 in the process of removing the deposited ITO film B. FIG. A problem arises in that the surface of the data bus line 17 and the surface of the data bus line pad portion 17b are overetched. Also, in the process of removing the protective film 18 on the upper end of the data bus line pad part 17b to expose the data bus line pad part 17b, the protective film 18 is removed as shown in FIG. 5D. A problem arises in that the surface of the data bus line pad portion 17b is over etched by the etchant.

Accordingly, the present invention has been invented to solve the above problems, and an object of the present invention is to provide a wiring material for the lower panel of the liquid crystal display device using a Mo-W alloy.

That is, dry etching In the process of forming a pixel electrode 19 or a contact hole by removing a part of the ITO film B or the protective film 18 using wet etching or the like, a crack of the protective film 18 Mo-W alloy for preventing the surface of the data bus line pad portion 17b, the data bus line 17, the source electrode 17a and the drain electrode 17c from being etched through a pin hole. It is an object of the present invention to provide wiring.

1 is a perspective view schematically showing a structure of a general liquid crystal display device.

2 is a schematic view showing the structure of a lower plate of a general liquid crystal display device;

3A to 3H are cross-sectional views showing a switching element manufacturing process of a lower plate of a conventional liquid crystal display device.

4A to 4B are cross-sectional views showing an ITO film removing process on the upper end of a data bus line of a lower panel of a conventional liquid crystal display device.

5A to 5C are cross-sectional views showing a pad portion manufacturing process of a lower plate of a conventional liquid crystal display device.

6A to 6H are sectional views showing a switching element manufacturing process of a lower plate of a liquid crystal display device according to the present invention;

7A to 7B are sectional views showing an ITO film removal process on the upper end of the data bus line of the lower panel of the liquid crystal display according to the present invention.

8A to 8C are cross-sectional views illustrating a pad portion manufacturing process of a lower panel of a liquid crystal display device according to the present invention.

<Description of Signs of Major Parts of Drawings>

1: transparent substrate 10: bottom plate

11,31: polarizer 12,120: gate bus line

12a, 120a: gate electrode 12b, 120b: gate bus line pad portion

13,130 gate insulating film 14,140 semiconductor layer

15,150: Ohmic contact layer 17,170: Data bus line

17a, 170a: source electrode 17b, 170b: data bus line pad portion

17c, 170c: drain electrode 18, 180: protective film

19,190: pixel electrode 20: liquid crystal

30: top 32: color filter

33: common electrode

A: switching element B, B ': ITO film

In order to achieve the above object, the wiring of the liquid crystal display device using the Mo-W alloy according to the present invention includes a switching element including a gate electrode, a source electrode and a drain electrode, a gate bus line connected to the gate electrode, and the source. In the lower panel of a liquid crystal display including a data bus line connected to an electrode and a pixel electrode connected to the drain electrode, the gate bus line, the gate electrode, the data bus line, the source electrode, and the drain electrode may each contain 15% of tungsten ( W) is characterized in that it is formed of a Mo-W alloy having a content.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The lower panel of the liquid crystal display device is located in a plurality of gate bus lines, a plurality of data bus lines formed to cross each other through the gate bus lines and the gate insulating film, and a predetermined space formed by the gate bus lines and the data bus lines adjacent to each other. And a pixel electrode connected to the drain electrode which is an output terminal of the switching element.

A detailed manufacturing process of the lower panel of the liquid crystal display device using the Mo-W alloy according to the exemplary embodiment of the present invention configured as described above will be described in detail with reference to FIGS. 6A to 6H.

A glass substrate or the like is used to form a transparent substrate under the liquid crystal display device. A metal film is formed on the transparent substrate using Mo-W metal alloyed with molybdenum (Mo) of about 15% tungsten (W) (FIG. 6A).

Dry etching of the Mo-W metal film A plurality of gate bus lines 120, gate bus line pad portions 120b, and gate electrodes 120a are formed by etching in a predetermined pattern using a method such as wet etching (FIG. 6B).

A gate insulating film is formed using SiNx, SiOx, or the like having good interfacial properties and high dielectric breakdown voltage on a liquid crystal display substrate including the plurality of gate bus lines 120, the gate bus line pad part 120b, and the gate electrode 120a. 130 is formed (FIG. 6C).

The semiconductor layer 140 is formed on the gate insulating layer 130 on the gate electrode 120a by using polycrystalline silicon (a-Si) or the like. An ohmic contact layer 150 is formed on the semiconductor layer 140 for good ohmic contact between the semiconductor layer 140 and the source electrode 170a / drain electrode 170c (FIG. 6D).

The Mo-W alloy bundle is applied to the entire surface of the substrate by sputtering to form a Mo-W metal film.

Dry etching of the Mo-W metal film By etching in a predetermined pattern using a method such as wet etching, a plurality of data bus lines 170 and data bus line pad portions having a direction perpendicular to the formation direction of the above-described gate bus line 120 ( 170b). At this time, at the same time as the pattern formation of the data bus line 170, a source electrode 170a branching from the data bus line 170 is formed, and functions as an output terminal at a position opposite to the source electrode 170a. The drain electrode 170c is formed.

The gate bus line 120, the data bus line 170, the gate electrode 120a, the gate insulating film 130, the semiconductor layer 140, the source electrode 170a, and the drain electrode are formed by the above-described series of processes. A switching element having a TFT structure composed of 170c and the like is formed on the lower plate of the liquid crystal display device (Fig. 6E).

An insulating film such as SiNx, SiOx, Benzocyclobutene (BCB) is coated on the liquid crystal display substrate including the gate bus line 120, the data bus line 170, and the switching element to form a passivation layer 180. A portion of the passivation layer 180 is removed to form a contact hole so that a portion of the drain electrode 170c, which is an output terminal of the switching element existing at the bottom of the passivation layer 180, is exposed (FIG. 6F).

An indium tin oxide (ITO) film B is deposited on the entire surface of the passivation layer 180 on which the contact hole is formed by using a sputtering method (FIG. 6G).

Dry etching the ITO film in a predetermined pattern; By etching using wet etching or the like, the pixel electrode 190 connected to the drain electrode 170c, which is an output terminal of the switching element, is formed through the contact hole (FIG. 6H). By the above-described series of processes, the manufacturing process of the lower plate of the liquid crystal display device is performed.

According to the manufacturing process of the liquid crystal display device using the Mo-W alloy according to the embodiment of the present invention described above, Mo-W metal alloyed with about 15% tungsten (W) to the molybdenum (Mo) Wiring to form the lower plate of the liquid crystal display device.

The liquid crystal display device wiring formed using the Mo-W alloy bundle has a dry etching or It has chemical resistance such that the surface is not etched by an etchant used for etching.

That is, as shown in FIG. 6G, an ITO film B ′ is deposited on the entire surface of the lower panel of the liquid crystal display device including the switching element and the passivation layer 180, and then etched in a predetermined pattern to be an output terminal of the passivation layer 180. In the process of forming the pixel electrode 190 connected to the drain electrode 170c, an etchant for etching the ITO film B ′ may be a crack generating part or a pinhole of the passivation layer 180. It penetrates into the lower portion of the passivation layer 180 through the generator. However, Mo-W alloy according to the present invention has a chemical resistance that the surface is not etched by the etchant. Therefore, the surface of the source electrode 170a and the drain electrode 170c of the switching element positioned below the passivation layer 180 may be prevented from being overetched.

In addition, in the process of removing the ITO film B 'deposited on the upper end of the data bus line 170 and the data bus line pad part 170b, an etchant for removing the ITO film B' is formed by the protective film ( Even though the surface of the data bus line 170 and the surface of the data bus line pad unit 170b are in contact with each other through the crack generating unit or the pinhole generating unit of 180, the data bus line 170 and the data bus line pad unit 170b may be in contact with each other. The surface is not over etched (FIG. 7B). Also, in the process of removing the passivation layer 180 on the upper end of the data bus line pad unit 170b to expose the data bus line pad unit 170b, the passivation layer 180 is removed as shown in FIG. 8D. The etchant to effect the surface of the data bus line pad portion 170b is not over-etched (over etching).

Although the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited thereto, and modifications and improvements are possible within the scope of ordinary knowledge of those skilled in the art.

Claims (8)

A liquid crystal display including a switching device including a gate electrode, a source electrode, and a drain electrode, a gate bus line connected to the gate electrode, a data bus line connected to the source electrode, and a pixel electrode connected to the drain electrode. The liquid crystal display according to claim 1, wherein the gate bus line, the gate electrode, the data bus line, the source electrode, and the drain electrode are formed of a Mo-W alloy having a content of tungsten (W) of 15%. The switching device of claim 1, wherein the switching device comprises: a gate electrode branched from the gate bus line; A gate insulating film for applying a lower plate of the liquid crystal display device including the gate electrode; A semiconductor layer formed on the gate electrode coated with the gate insulating film; A source electrode branched from the data bus line and formed on the semiconductor layer; And a drain electrode formed on the semiconductor layer and positioned symmetrically with the source electrode. The liquid crystal display device according to claim 2, wherein the gate insulating film comprises SiNx, SiOx, or the like. The liquid crystal display device according to claim 2, wherein an ohmic contact layer is interposed between the semiconductor layer, the source electrode, and the source electrode. And a switching device including a gate electrode, a source electrode, and a drain electrode, a gate bus line connected to the gate electrode, a data bus line connected to the source electrode, and a pixel electrode connected to the drain electrode. The method of claim 1, wherein the gate bus line, the gate electrode, the data bus line, the source electrode, and the drain electrode are formed of a Mo-W alloy having a content of tungsten (W) of 15%. The method of claim 5, wherein the forming of the switching device comprises: forming a gate electrode branched from the gate bus line; Forming a gate insulating film for applying a lower plate of the liquid crystal display device including the gate electrode; Forming a semiconductor layer on the gate electrode coated with the gate insulating film; And forming a source electrode and a drain electrode formed on an upper end of the semiconductor layer by branching from the data bus line. The method of claim 6, wherein the gate insulating layer comprises SiNx, SiOx, or the like. The method of claim 6, wherein an ohmic contact layer is interposed between the semiconductor layer, the source electrode, and the drain electrode.