KR101717648B1 - Display device and method for fabricating the same - Google Patents

Abstract

The present invention relates to a display device and a manufacturing method thereof, and a display device according to the present invention includes a gate wiring formed in a matrix form on a substrate; A data line formed on the substrate and defining a pixel region crossing the gate line; A common wiring arranged in parallel with the gate wiring; A gate electrode formed at a point of intersection between the gate wiring and the data wiring and spaced apart from the gate electrode branched from the gate wiring and the gate insulating film, the active layer, the ohmic contact layer, the source electrode branched from the data wiring, A thin film transistor including a drain electrode formed; A protective layer formed on the thin film transistor and including a contact hole exposing a part of the drain electrode; And a pixel electrode formed of a conductive layer formed on the protective layer and a conductive metal oxide layer and electrically connected to the drain electrode through the contact hole.

Description

TECHNICAL FIELD [0001] The present invention relates to a display device and a method of manufacturing the same,

The present invention relates to a display device, and more particularly, to a display device capable of reducing processing time due to an enlargement of the aperture ratio and a refinement process through fine patterning at the time of forming the electrode wiring including the pixel electrode of the display device, .

2. Description of the Related Art In general, a thin film transistor (TFT) is widely used as a switching device in a semiconductor device and a thin film transistor liquid crystal display (TFT LCD) as a display device.

Of the display devices, the thin film transistor liquid crystal display device is attracting attention as a next-generation advanced display device with low power consumption, good portability, and high value-added.

Of these display devices, an active matrix type liquid crystal display device having a thin film transistor, which is a switching device capable of controlling on and off of a voltage for each pixel, have.

To miniaturize a pixel electrode electrically connected to a thin film transistor widely used as a switching element in a semiconductor device as well as the display device, many technical problems such as process time and etching uniformity are caused. In particular, the difficulty in making a high aperture ratio is accompanied by the limitation of the luminance increase.

From this point of view, the liquid crystal display according to the related art will be described as an example of the display device with reference to FIG.

1 is a cross-sectional view schematically showing a structure of a liquid crystal display according to a related art.

1, a color filter substrate (not shown) having a color filter and a thin film transistor array substrate 11 are opposed to each other, and a color filter substrate (not shown) (Not shown) is interposed between the thin film transistor array substrate 11 and the thin film transistor array substrate 11.

Here, on the thin film transistor array substrate 11, a plurality of common electrodes 13b spaced apart from each other in parallel with the gate wiring are formed together with a gate wiring (not shown) and a gate electrode 13a branched from the gate wiring .

A gate insulating film 15 is formed on the entire surface of the array substrate 11 including the gate electrode 13a and sequentially formed thereon an active layer 17 in the form of an island and a semiconductor layer (Not shown). At this time, the active layer 17 is formed of pure amorphous silicon (a-Si: H), and the ohmic contact layer 19 is formed of impurity amorphous silicon (n + a-Si).

A data line 23 is formed on the ohmic contact layer 19 so as to intersect with the gate line (not shown) to define a pixel region. A source electrode 23a branched from the data line 23, And a drain electrode 23b facing the gate electrode 13a at a predetermined distance from the source electrode 23a. At this time, the gate electrode 13a and the semiconductor layer 21, and the source electrode 23a and the drain electrode 23b constitute a thin film transistor T.

A protective layer 25 is formed on the entire surface of the source and drain electrodes 23a and 23b and the exposed active layer 17 and includes a contact hole (not shown) exposing a part of the drain electrode 23b have.

A pixel electrode 31a is formed on the passivation layer 25 to be in contact with the drain electrode 23b through the contact hole (not shown). At this time, the pixel electrode 31a is formed of ITO, which is a transparent conductive material, and a plurality of pixel electrodes 31a are arranged at regular intervals in a unit pixel region.

Accordingly, a plurality of common electrodes 13b and a plurality of pixel electrodes 31a formed on the thin film transistor array substrate 11 are horizontally arranged so as to be spaced apart from each other, and a horizontal electric field is formed according to voltages applied to the common electrodes 13b At this time, the liquid crystal molecules between the horizontal electric fields are influenced and driven.

A method of manufacturing a liquid crystal display device according to the related art having the above structure will be described with reference to FIGS. 2A to 2E.

2A to 2E are cross-sectional views schematically showing a method of manufacturing a liquid crystal display device according to the related art.

As shown in Fig. 2A, on the transparent substrate 11, a plurality of gate wirings (not shown) and a gate electrode 13a extending vertically to the gate wirings are formed. At this time, on the substrate 11, a gate electrode (not shown) and a gate electrode 13a branched from the gate wiring are arranged in parallel with the gate wiring (not shown) (Not shown) in which the electrode 13b is branched.

Next, a gate insulating film 15 is formed on the entire surface of the substrate 11 including the gate electrode 13a, and a semiconductor layer (not shown) composed of an island-shaped active layer 17 and an ohmic contact layer 19 21). At this time, the active layer 17 is formed of pure amorphous silicon (a-Si: H), and the ohmic contact layer 19 is formed of impurity amorphous silicon (n + a-Si).

A source electrode 23a branched from the data line 23 and a source electrode 23b branched from the data line 23 are formed on the ohmic contact layer 19 along with the data line 23 arranged to cross the gate line A drain electrode 23b spaced from the source electrode 23a by a predetermined distance is formed around the gate electrode 13a. At this time, the gate electrode 13a and the semiconductor layer 21, and the source electrode 23a and the drain electrode 23b constitute a thin film transistor T.

A protective layer 25 made of an inorganic insulating material is formed on the entire surface of the substrate 11 including the data line 23, the source electrode 23a and the drain electrode 23b.

Then, as shown in FIG. 2B, the protective layer 25 is selectively etched through an exposure process and a patterning process using a photolithography process technique to form a contact hole 27 for exposing the drain electrode 23b do.

2C, ITO (Indium Tin Oxide), which is a transparent conductive material, is deposited on the passivation layer 25 including the contact hole 27 to form a transparent conductive layer 31 having a single-layer structure.

Next, after a photosensitive material is applied on the transparent conductive layer 31, an exposure mask (not shown) for defining a position defined as a pixel electrode is disposed on the photosensitive material layer (not shown) A photoresist pattern 33 is formed by performing an exposure process and a development process of irradiating the photosensitive material layer with ultraviolet light through a mask (not shown).

2D, the transparent conductive layer 31 is selectively etched by a wet etch process using the photoresist pattern 33 as a blocking layer to form a pixel electrode 31a. Although not shown in the figure, the pixel electrodes 31a are arranged in a plurality of electrode shapes spaced apart from each other by a predetermined distance. In addition, the plurality of pixel electrodes 31a are spaced apart from each other by a plurality of common electrodes 13b.

Then, as shown in FIG. 2E, the transparent conductive layer 31 is selectively removed through the wet etching process to form the pixel electrode 31a, and then the remaining photoresist pattern 33 is removed, Thereby completing a process for manufacturing a transistor array substrate.

Although not shown in the drawings, a color filter array substrate including a black matrix layer (not shown) and a color filter layer (not shown) and a liquid crystal layer (not shown) are formed between the color filter array substrate and the thin film transistor array substrate 11 The process of forming the display device is completed to complete the process of manufacturing the display device.

As described above, the display device according to the related art and the manufacturing method thereof have the following problems.

According to the display device and the method of manufacturing the same according to the related art, the etching process is performed in consideration of the etching ability depending on the metal characteristics in the single metal layer used for forming the pixel electrode, for example, ITO, molybdenum titanium alloy or aluminum. The process progress becomes complicated. That is, it is difficult to realize uniformity over the limit due to a large etchant fluctuation depending on the kind of the metal. As a result, the etch processability is lowered and the application to the new metal material becomes difficult.

In addition, the conventional display device and its manufacturing method have poor etch uniformity in top and bottom, right and left sides in the case of a metal film of a single film, and it is difficult to realize fine wiring.

In the conventional display device and its manufacturing method, since the metal film is exposed to the outside during the etching of the metal film of the single film, the metal film is damaged and it becomes difficult to form a uniform wiring, The productivity is decreased due to the increase of etching process time.

Furthermore, in order to form a pixel electrode or other metal wiring, for example, a gate line or a data line, as a fine electrode having a fine line width w1, Uniformity, and damage to the metal. Therefore, there are many difficulties in the display process that requires a high aperture ratio, and thus there is a limit to expect the luminance increase.

In addition, ITO (Indium Tin Oxide), which is a transparent conductive material used in a conventional display device, has a high transmittance but a low contrast ratio, and it is difficult to realize a line width w1 of about 3.0 μm or less.

On the other hand, when a molybdenum titanium alloy (MoTi) is used as a material capable of solving such a problem, the contrast ratio is improved, but the external light is reflected by the metal electrode and passes through a polarizer, There is a possibility that a rainbow stain phenomenon appears. Therefore, in order to prevent the iridescence phenomenon which is generated by passing through the polarization axis after being reflected by the conventional metal electrode, a low reflection electrode which can reduce the reflectivity of the electrode is desperately required.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems of the prior art, and it is an object of the present invention to provide a method of manufacturing a display device, And to provide a display device capable of improving productivity by reducing the processing time, and a method of manufacturing the same.

Another object of the present invention is to provide a display device applicable to fine patterning of a metal wiring including a pixel electrode of a display device, fine patterning of metal wiring of a semiconductor device or fine patterning of metal wiring of another display device and And a manufacturing method thereof.

It is another object of the present invention to provide a display device applicable as a low-reflection electrode capable of reducing the reflectivity and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a display device including: a gate wiring formed in a matrix on a substrate; A data line formed on the substrate and defining a pixel region crossing the gate line; A common wiring arranged in parallel with the gate wiring; A gate electrode formed at a point of intersection between the gate wiring and the data wiring and spaced apart from the gate electrode branched from the gate wiring and the gate insulating film, the active layer, the ohmic contact layer, the source electrode branched from the data wiring, A thin film transistor including a drain electrode formed; A protective film formed on the thin film transistor and including a contact hole exposing a portion of the drain electrode; And a pixel electrode formed of a conductive layer formed on the protective film and a conductive metal oxide film or metal nitride film formed on the conductive layer and electrically connected to the drain electrode through the contact hole. do.

According to an aspect of the present invention, there is provided a method of manufacturing a display device, including: forming a gate wiring having a gate electrode on a substrate; forming a common wiring disposed in parallel with the gate wiring and having a plurality of common electrodes; Forming a gate insulating film on the entire surface of the substrate including the gate electrode; Forming a semiconductor layer on the gate electrode, the ohmic contact layer being spaced apart from the active layer by a channel region with the gate insulating film interposed therebetween; A data line crossing the gate line and defining a pixel region on the semiconductor layer; a source electrode branched from the data line; and a drain electrode spaced apart from the source electrode; Forming a protective film over the entire substrate including the source electrode, the drain electrode, and the data line; Patterning the passivation layer to form a contact hole exposing a portion of the drain electrode; Forming a conductive layer on the protective film in contact with the drain electrode through the contact hole, and stacking a metal oxide film or a metal nitride film having conductivity on the conductive layer; And forming a pixel electrode composed of a conductive layer pattern and a metal oxide film pattern or a metal nitride film pattern by successively etching the conductive layer and the metal oxide film or the metal nitride film.

The display device and the manufacturing method thereof according to the present invention have the following effects.

The display device and the method of manufacturing the same according to the present invention can be used as a pixel electrode by etching a metal film and a conductive metal oxide film or a metal nitride film to obtain a faster etch rate than a conventional metal film , Thereby making it possible to form a stable high-aperture-ratio microelectrode or fine wiring having a fine line width.

In particular, since the present invention can reduce the etching time to form a microelectrode, the fine line width W2 of the pixel electrode can be reduced compared with the prior art, and the aperture ratio can be improved. As a result, .

Furthermore, since the present invention can form a microelectrode having a fine line width (W2), for example, a pixel electrode and a common electrode, it is possible to increase the number of common electrodes and pixel electrodes arranged in the unit pixel region.

Accordingly, the present invention can increase the intensity of the electric field by maintaining the aperture ratio as it is while keeping the distance d2 between the pixel electrode and the common electrode narrower than that of the conventional device, thereby increasing the reaction force of the liquid crystal reacting by the electric field, May be increased.

Therefore, the pixel electrode or other metal wiring forming process of the display device according to the present invention can be performed more quickly and uniformly than before, so that it is expected to secure a high aperture ratio through miniaturization of electrodes, and the process time due to the miniaturization process is reduced .

Further, the display device and the method of manufacturing the same according to the present invention can be realized by using a double-layered structure composed of a metal film and a metal oxide film or a metal nitride film which is conductive when a pixel electrode or other metal wiring of a display device is formed, The etching speed can be secured faster than the metal film having the structure, and the etching process time is reduced.

Therefore, since the display device and the method of manufacturing the same according to the present invention can secure a faster etch rate than a metal film, which is a conventional single film, the fine line width of the electrode can be reduced and the aperture ratio and brightness can be increased through the microelectrode , The etching process time is reduced and the productivity is improved.

The display device and the method of manufacturing the same according to the present invention can realize uniform micro wiring by etching and patterning the double film structure of the metal film and the metal oxide film or the metal nitride film having conductivity and the metal film can be formed as a metal oxide film or a metal nitride film So that damage to the metal film can be reduced.

Furthermore, in the display device and the method of manufacturing the same according to the present invention, the metallic electrode, which is a conventional single film, has a high reflectivity, resulting in a rainbow stain phenomenon. However, the metal film used in the present invention and the metal oxide film or the metal nitride film Since the metal electrode has low reflectivity, it can be used as a low reflection electrode. That is, since the metal oxide film or the metal nitride film has a lower light reflectance than the metal film, the metal oxide film or the metal nitride film serves to reduce the reflectance at the upper portion of the metal film having a high reflectance, .

Further, the display device and the manufacturing method thereof according to the present invention are applicable not only to various metal lines including pixel electrodes of a liquid crystal display device, but also to various devices such as a low reflection electrode of a solar cell, a metal line including a microelectrode of a semiconductor device, It is also applicable to metal wiring including electrodes.

1 is a cross-sectional view schematically showing a structure of a liquid crystal display device according to the related art.
2A to 2E are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to the related art.
3 is a plan view of a thin film transistor array substrate of a liquid crystal display device according to the present invention.
FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3, and is a schematic cross-sectional view illustrating the structure of a liquid crystal display device according to the present invention.
5A to 5N are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to the present invention.
6 is a graph showing a corrosion potential distribution for each metal in the method of manufacturing the display device according to the present invention.
7 is a graph showing the current density according to the potentials of the metal film and the metal oxide film or the metal nitride film in the method for manufacturing the display device according to the present invention and is a graph schematically showing the potential difference between the metal film and the metal oxide film or metal nitride film to be.
FIG. 8 is a graph showing the results of a case where a single film composed of a molybdenum titanium alloy (MoTi) and a copper nitride film (CuNx) and a conventional molybdenum titanium alloy (MoTi) is used in a method of manufacturing a display device according to the present invention , And the etching bias according to the etching time.
9 is a graph showing a change in the fine line width w2 according to an etching time in the case of using a bilayer composed of a molybdenum titanium alloy (MoTi) and a copper nitride film (CuNx) in a method of manufacturing a display device according to the present invention.
10 is a graph showing the relationship between the line width w2 realized according to the etching time in the case of a single film made of a metal film and a double film structure made of a metal film and a metal oxide film or a metal nitride film, ) In the state of change.

Hereinafter, a display device according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Hereinafter, a liquid crystal display device will be described as an example of the present invention. However, the display device according to the present invention is not limited thereto. For example, an organic light emitting diode (OLED) And may be various kinds of display devices used.
3 is a plan view of a thin film transistor array substrate of a liquid crystal display device according to the present invention.

delete

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3, and is a schematic cross-sectional view illustrating the structure of a liquid crystal display device according to the present invention.

As shown in Fig. 3, the display device according to the present invention includes a plurality of gate wirings (not shown) spaced apart from each other on a display substrate array substrate (103); A common wiring 104 formed in parallel with the gate wiring 103 in proximity to the gate wiring 103; A plurality of data wirings 113a extending in the vertical direction are formed to intersect the gate wirings 103 and define the pixel region P. [

A gate electrode 103a formed by branching from the gate wiring 103 is formed at the intersection of the gate wiring 103 and the data wiring 113a in each pixel region P, A semiconductor layer 111 composed of an active layer 107 and an ohmic contact layer 109 is formed on the gate insulating film 105 and a source electrode 113b formed in contact with the semiconductor layer 111, And a thin film transistor T composed of a drain electrode 113c are formed. At this time, the source electrode 113b is branched at the data line 113a.

A plurality of common electrodes 104a branched from the common wiring 104 formed in parallel with the gate wiring 103 in parallel are formed in the pixel region P in parallel with the data wiring 113a And a plurality of pixel electrodes 141a are disposed between the common electrodes 104a so as to be offset from the common electrode 104a. At this time, the plurality of pixel electrodes 141a are branched at the pixel electrode wirings 141 connected to the drain electrodes 113c.

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3, and is a schematic cross-sectional view illustrating the structure of a liquid crystal display device according to the present invention.

Although the pixel electrode structure of the display device is mainly described here, it is noted that the present invention is equally applicable to other metal wirings, for example, a gate wiring including a gate electrode, a common wiring, or a data wiring structure including source and drain electrodes . It is to be understood that the present invention is also applicable to a semiconductor device, a display device, and a low-reflection electrode of a solar cell other than a metal wiring of a display device, a metal electrode having a fine line width or a metal wiring, and other display devices.

As shown in Fig. 4, a display device according to the present invention includes a substrate 101, gate wirings (not shown in Fig. 3, refer to 103) including a gate electrode 103a, And a plurality of common electrodes 104a branched from the common wiring (not shown) are formed on the gate insulating layer 105. A gate insulating layer 105 is formed on the entire surface of the common electrode 104a, 105, a semiconductor layer 111 having an active layer 107 and an ohmic contact layer 109 is formed corresponding to the gate electrode 103a. At this time, the gate electrode 103a and the common electrode 104a branched off from the gate wiring are also formed. In addition, the gate wiring (not shown) and the common wiring (not shown) may be formed as a single film, a double film, or a triple film structure. Here, the bilayer structure includes a lamination structure of a conductive layer and a metal oxide film or a metal nitride film, and the triple film structure includes a laminated structure of two conductive layers and a metal oxide film or a metal nitride film. At this time, the conductive layer material constituting the double layer may be selected from a conductive metal group containing molybdenum titanium alloy (MoTi), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) Or two or more may be used, or one or two or more selected from ITO, AZO, ZnO, IZO or other transparent metal materials may be used.

As the metal included in the metal oxide film and the metal nitride film, copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), molybdenum titanium (MoTi) alloy and the like are used. The active layer 107 is formed of pure amorphous silicon (a-Si: H), and the ohmic contact layer 109 is formed of impurity amorphous silicon (n + a-Si).

A data line 113a is formed on the gate insulating film 105 so as to intersect the gate line and the common line (not shown), and the semiconductor layer 111, And a source electrode 113b branched from the data line 113a and a drain electrode 113c spaced apart from the source electrode 113c and in contact with the semiconductor layer 111 are formed. At this time, the data line 113a, the source electrode 113b, and the drain electrode 113c may have a double or triple film structure, but they are shown as a single film structure for the sake of convenience. Here, the bilayer structure includes a lamination structure of a conductive layer and a metal oxide film or a metal nitride film, and the triple layer structure includes a laminate structure of two conductive layers and a metal oxide film or a metal nitride film. At this time, the conductive layer material constituting the double layer is selected from a conductive metal group including molybdenum titanium (MoTi) alloy, aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) One or two or more of them may be used, or one or two or more selected from ITO, AZO, ZnO, IZO or other transparent metal materials may be used.

As the metal included in the metal oxide film and the metal nitride film, copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), molybdenum titanium (MoTi) alloy and the like are used.

A protective layer 125 is formed on the entire surface of the gate insulating layer 105 including the source and drain electrodes 113b and 113c. The protective layer 125 is formed on the passivation layer 125 through the contact hole 127, A plurality of pixel electrodes 141a branched from the pixel electrode lines 141 which are in contact with the drain electrodes 113c are staggered between a plurality of common electrodes 104a formed under the pixel electrodes 141a. At this time, the plurality of pixel electrodes 141a may be formed on the passivation layer 125, or may be formed on a gate insulating layer on which a source electrode and a drain electrode are formed, though not shown.

Here, the pixel electrode 141a and the pixel electrode wiring 141 are formed in a laminated structure of the conductive layer pattern 129a and the metal oxide film pattern or the metal nitride film pattern 131a. At this time, the conductive layer pattern 129a may be formed of a conductive metal group including molybdenum titanium alloy (MoTi), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) One or two or more of them may be used, or one or two or more selected from ITO, AZO, ZnO, IZO or other transparent metal materials may be used. As the metal included in the metal oxide film and the metal nitride film, copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), or molybdenum titanium alloy (MoTi) is used.

Although not shown in the drawings, a color filter substrate (not shown in the drawing) 151 (see FIG. 5n) is disposed at a predetermined interval on a transparent substrate 101 used as the thin film transistor array substrate, Layer (not shown in Fig. 5N "161") is formed.

The method of manufacturing a display device according to the present invention will now be described with reference to FIGS. 5A to 5N.

5A to 5N are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to the present invention.

Here, the pixel electrode structure of the display device according to the present invention is mainly described, but the same can be applied to other metal wirings, for example, a gate wiring including a gate electrode, a common wiring, or a data wiring structure including source and drain electrodes . It is to be noted that the present invention is also applicable to a semiconductor device, a display device or a low-reflection electrode of a solar cell, in addition to a metal wiring of a display device, a microelectrode having a fine line width or a metal wiring.

5A, a conductive metal (Al) containing aluminum (Al), an aluminum alloy, chromium (Cr), tungsten (W), molybdenum titanium alloy (MoTi), copper The conductive layer 103 is formed by depositing one or two or more metal materials selected from the group. At this time, the conductive layer 103 may have a single-layer structure, a double-layer structure, or a triple-layer structure.

Here, the bilayer structure includes a lamination structure of a conductive layer and a metal oxide film or a metal nitride film, and the triple film structure includes a laminated structure of two conductive layers and a metal oxide film or a metal nitride film. At this time, the conductive layer material constituting the double layer may be selected from a conductive metal group containing molybdenum titanium alloy (MoTi), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) Or two or more may be used, or one or two or more selected from ITO, AZO, ZnO, IZO or other transparent metal materials may be used.

As the metal included in the metal oxide film and the metal nitride film, copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), molybdenum titanium (MoTi) alloy and the like are used.

Next, although not shown in the drawing, a first photoresist layer (not shown) is coated on the conductive layer 103, and then the first photoresist layer (not shown) is exposed through an exposure process and a development process using an exposure mask Is selectively removed to form a first photoresist pattern (not shown).

Next, as shown in FIG. 5B, the conductive layer 103 is selectively etched through the etching process using the first photoresist pattern (not shown) as a blocking layer to form a plurality of gate wirings (not shown) in one direction. (Not shown) (see "103" in FIG. 3) and a gate electrode 103a extending and protruding from the gate wiring (not shown) And a plurality of common electrodes 104a are formed.

5C, the first photoresist pattern (not shown) is removed, and a silicon oxide film (SiO ₂ ) and a silicon nitride film (SiN _x ) are formed on the entire surface of the substrate 101 on which the gate wiring and the like are formed A gate insulating film 105 is formed by depositing or applying one selected from the group consisting of an inorganic insulating material and an organic insulating material group composed of a benzocyclobutene and an acrylic resin as the case may be.

Next, an active layer 107 made of amorphous silicon (a-Si: H) used as a channel region and an ohmic contact layer 109 made of an impurity-doped amorphous silicon doped with n + impurities are sequentially formed on the gate insulating film 105 .

Next, a conductive material is deposited on the ohmic contact layer 109 by a sputtering method to form a conductive layer 113. At this time, the conductive layer 113 may be made of a material selected from the group consisting of molybdenum titanium (MoTi), tantalum (Ta), chromium (Cr), nickel (Ni), indium (In), molybdenum (Mo), titanium Cu, Al, and aluminum alloys, or one or more selected from the group consisting of ITO, AZO, ZnO, IZO, and other transparent metal materials.

In addition, the conductive layer 113 may have a single-layer structure, a double-layer structure, or a triple-layer structure. Here, in the case of the above-mentioned double-layer structure, it includes a lamination structure of a conductive layer and a metal oxide film or a metal nitride film, and the triple film structure includes a laminated structure of two conductive layers and a metal oxide film or a metal nitride film. At this time, the conductive layer material constituting the double layer may be selected from a conductive metal group containing molybdenum titanium alloy (MoTi), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) Or two or more may be used, or one or two or more selected from ITO, AZO, ZnO, IZO or other transparent metal materials may be used.

 As the metal included in the metal oxide film and the metal nitride film, copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), molybdenum titanium (MoTi) alloy and the like are used.

5D and 5E, the second photoresist layer 115 is coated on the conductive layer 113, and then the second photoresist layer 115 is formed on the second photoresist layer 115 by a photolithography process using a diffraction mask 120. Then, 115 are exposed and developed to form a second photoresist pattern 115a.

At this time, a slit mask or a half-tone mask is used as the diffraction mask 120, and a general mask may be used in addition to the diffraction mask.

The diffraction mask 120 includes a light shielding region 120a, a semi-transmission region 120b, and a transmission region 120c. The second light shielding film 120 is exposed through the transflective region 120b, The thickness of the second photoresist pattern 115a is formed to be thinner than the thickness of the remaining second photoresist pattern 115a exposed through the light blocking area 120a and developed. The portion of the second photoresist pattern 115a located below the transflective region 120b corresponds to the channel region and the portion of the second photoresist pattern 115a located below the photoresist region 120a corresponds to the source / Drain region.

Next, as shown in FIG. 5F, the conductive layer 113, the ohmic contact layer 109, and the active layer 107 are sequentially etched using the second photoresist pattern 115a as a blocking layer.

5G, the second photoresist pattern 115a is removed by a predetermined thickness through an ashing process to expose the upper surface of the conductive layer 113 corresponding to the channel region .

5H, portions of the exposed conductive layer 113 are selectively etched using the second photoresist pattern 115a as an etching mask so as to intersect perpendicularly to the gate wiring (not shown) A source electrode 113b protruding upward from one side of the gate electrode 103a in the data line 113a and a source electrode 113b protruded from the source electrode 113b by a predetermined distance Thereby forming a drain electrode 113c. At this time, when the conductive layer 113 located in the channel region is etched, portions of the ohmic contact layer 109 below the conductive layer 113 are simultaneously etched.

5I, after the photoresist pattern 115a is removed, an organic insulating material group is formed on the entire surface of the substrate 101 on which the data line 113a and the source and drain electrodes 113b and 113c are formed. In this case, A protective layer 125 is formed by selectively depositing one of the inorganic insulating material groups, and then a third photoresist layer (not shown) is coated on the protective layer 125. At this time, as the material for forming the protective layer 125, an inorganic insulating material group including the silicon oxide film (SiO ₂ ) and the silicon nitride film (SiN _x ), benzocyclobutene, And an organic insulating material group composed of an acrylic resin is deposited or applied.

Then, a third photoresist pattern (not shown) is formed by exposing and developing the third photoresist layer (not shown) through a photolithography process.

Referring to FIG. 5J, the protective layer 125 is selectively etched using the third photoresist pattern (not shown) as a mask to form a contact hole 127 exposing the drain electrode 113c.

5K, after the third photoresist pattern (not shown) is removed, a conductive layer 129 is deposited on the passivation layer 125 including the contact hole 127 by a sputtering method. The conductive layer 129 may be formed of a conductive metal group including molybdenum titanium alloy (MoTi), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) One or two or more transparent conductive materials including ITO, AZO, ZnO, and IZO may be used.

Next, a metal oxide or a metal nitride is deposited on the conductive layer 129 using a chemical vapor deposition (CVD) method or another vapor deposition method to form a metal oxide film or a metal nitride film 131. At this time, any one of copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), and molybdenum titanium alloy (MoTi) may be selected as the metal included in the metal tioxide film and the metal nitride film . The deposition thickness of the metal oxide film or the metal nitride film 131 is appropriate if the thickness of the conductive layer 129 below the metal oxide film or the metal nitride film 131 is such that the wet etching process can be performed smoothly.

 Next, a photosensitive material is coated on the metal oxide film or the metal nitride film 131 to form a fourth photosensitive film (not shown).

Next, an exposure mask (not shown) defining a position to be defined as a pixel electrode is disposed on the fourth photoresist layer (not shown), and then ultraviolet rays (not shown) are applied to the fourth photoresist layer A fourth photoresist pattern 133 is formed by performing an exposure process and a development process for irradiating light.

Then, as shown in FIG. 51, the metal oxide film or the metal nitride film 131 and the conductive layer 129 are selectively etched by a wet etch process using the fourth photoresist pattern 133 as a blocking film, A plurality of pixel electrodes 141a branched from the pixel electrode wirings 141 are formed together with the pixel electrode wirings 141 made of the conductive layer pattern 129a and the metal oxide film pattern or the metal nitride film pattern 131a.

At this time, when the wet etching process is performed, a metal oxide film or a metal nitride film 131 containing a metal component is deposited on the conductive layer 129. The conductive layer 129 becomes an anode, The oxide film or the metal nitride film 131 becomes a cathode so that electrons move from the metal oxide film or the metal nitride film 131 to the conductive layer 129. Therefore, the metal oxide film or the metal nitride film 131 that has lost electrons is accelerated by the galvanic effect, resulting in a bias that is larger than that of the conductive layer 129 as shown in FIG. 8 And the side surface of the conductive layer 129 is rapidly etched because the conductive layer 129 as the positive electrode is rapidly corroded.
That is, electron movement is accelerated by a difference in corrosion potential (electromotive-force) between a metal film composed of a metal double film, for example, MoTi, and a metal oxide film composed of CuNx or a metal nitride film . Therefore, the bilayer structure of the conductive layer 129 and the metal oxide film or the metal nitride film 131 is rapidly etched by the galvanic phenomenon. Therefore, the time required for etching the metal double-layered film, for example, the conductive layer and the metal oxide film or the metal nitride film at the time of forming the pixel electrode can be shortened, and fine electrodes or fine metal wires having a fine line width can be formed.
Therefore, when the etching process is performed in the state where the metal oxide film or the metal nitride film 131 is laminated on the conductive layer 129, the etching speed is higher than that in the case where only the conductive layer as the single film is etched, The patterning process is uniformly performed, and the process time is shortened.
The etching principle of the bilayer structure of the conductive layer 129 and the metal oxide film or the metal nitride film 131 will be briefly described with reference to FIGS. 6 and 7. FIG.

delete

delete

6 is a graph showing a corrosion potential distribution for each metal in the method of manufacturing the display device according to the present invention.

7 is a graph showing the current density according to the potentials of the metal film and the metal oxide film or the metal nitride film in the method of manufacturing the display device according to the present invention and schematically showing the potential difference between the metal film and the metal oxide film or the metal nitride film Graph.
Corrosion Potential is about -0.35 for a metal monolayer, and Corrosion Potential for a metal oxide or metal nitride film is about -0.025. However, in the case of the double-layer structure of the metal film and the metal oxide film or the metal nitride film used in the present invention, the corrosion potential is about 0.084.

Therefore, when the corrosion potential of the metal oxide film or the metal nitride film is high, the metal etching becomes difficult, and when the corrosion potential is low, the corrosion tendency is good. Therefore, when the corrosion potential difference between the metal film and the metal oxide film or the metal nitride film is large, it can be considered that the corrosion is likely to occur.

delete

As shown in FIG. 6, in the case of aluminum (Al) or molybdenum titanium alloy (MoTi), the corrosion potential is lower than that of molybdenum (Mo) or copper (Cu).

7, since the corrosion potential difference between a metal film having a low corrosion potential, for example, a molybdenum titanium alloy (MoTi) and a metal nitride film (CuNx) having a high corrosion potential is large, a galvanic effect is sufficiently generated, And the etching process of the metal nitride film can be performed quickly.

Therefore, when the metal double layer is etched for use as an electrode, the conductive layer 129 becomes an anode and the metal oxide layer or metal nitride layer 131 becomes a cathode to form a metal oxide layer or a metal nitride layer 131 Electrons are transferred to the conductive layer 129. At this time, the metal oxide film or the metal nitride film 131 which has lost electrons accelerates the etching due to the galvanic effect and thus exhibits a larger bias than the conductive layer 129, and the conductive layer 129, which is a positive electrode, The side etching of the conductive layer 129 proceeds rapidly. That is, the electron movement is accelerated by a difference in electromotive force between a metal film composed of a metal double film, for example, MoTi, and a metal nitride film composed of CuNx, that is, a difference in electromotive force .

Accordingly, the multilayer structure of the conductive layer 129, which is a metal double film, and the metal oxide film or the metal nitride film 131 is rapidly etched by the galvanic phenomenon, so that the metal double film, for example, The time of the etching process for forming the pixel electrode is shortened, and it is possible to form a fine electrode or other fine wiring having a fine line width.

As described above, according to the present invention, since the fine electrode can be formed by shortening the etching process time, the fine line width w2 of the pixel electrode can be reduced compared with the prior art, and the aperture ratio can be improved, .

Furthermore, since the present invention can form a microelectrode having a fine line width (w2), for example, a pixel electrode and a common electrode, the number of common electrodes and the number of pixel electrodes arranged in the unit pixel region can be increased.

Therefore, the present invention can increase the intensity of the electric field by narrowing the distance d2 between the pixel electrode and the common electrode while maintaining the aperture ratio, and by increasing the reaction force of the liquid crystal reacting by the electric field, The reaction rate may be increased.

On the other hand, in the case of a single layer of molybdenum titanium alloy (MoTi), the light reflectance is about 61% and the light absorptance is about 31%, and the reflectance is high. A copper nitride film (CuNx) is laminated on the substrate to form a bilayer structure, whereby the reflectance can be remarkably lowered. That is, since the copper nitride film (CuNx) has a light reflectance of about 33% and a light absorptivity of about 64%, it plays a role of reducing the reflectance on the upper part of the molybdenum titanium alloy (MoTi) The metal electrode having a double film structure of a film and a metal oxide film or a metal nitride film can be applied as a low reflection electrode.

In addition, the wet etching process may be performed by etching using a chemical etching solution according to the thin film material of the conductive layer, and may also be performed by an etching method by plasma etching or RIE (reactive ion etching). Particularly, in the case of removing the conductive layer, a mixed solution of nitrogen acid, hydrochloric acid and acetic acid at a given concentration ratio can be used. At this time, as the etching solution used in the wet etching process, other etching solutions other than the above-mentioned solution may be used.

5M, the remaining fourth photoresist pattern 133 is removed to form the pixel electrode wirings 141 made of the conductive layer pattern 129a and the metal oxide film pattern or the metal nitride film pattern 131a, A plurality of pixel electrodes 141a branched from the pixel electrode wiring 141 are formed to complete the manufacturing process of the thin film transistor array substrate.

5N, a black matrix layer 153 for blocking light is formed on the transparent color filter substrate 151, and a black matrix layer 153 is formed on the color filter substrate 151 between the black matrix layers 153 A color filter layer 155 is formed.

 Subsequently, a step of forming a liquid crystal layer 161 between the color filter substrate 151 and the thin film transistor array substrate 101 is further performed to complete the process of manufacturing the display device.

FIG. 8 is a graph showing the relationship between a pixel electrode having a double-layered structure composed of a molybdenum titanium alloy (MoTi) and a copper nitride film (CuNx) according to the present invention and a pixel electrode having a single film structure composed of a conventional molybdenum titanium alloy (MoTi) FIG. 4 is a graph showing the etching bias according to the etching time in the case of using the etching mask. FIG.

As shown in FIG. 8, in the case of the prior art, the etch time of the single layer composed of the molybdenum titanium alloy (MoTi) is about 100 seconds, and the etching bias is about 0.7. In the case of the present invention, the molybdenum titanium alloy (MoTi) And the copper nitride film (CuNx) has an etching time of about 35 to 45 seconds, the etching bias is as large as about 1.44 to 1.65.

Therefore, the etch process is performed for a time shorter than the etching time of the prior art because the etching bias of the bilayer composed of the molybdenum titanium alloy (MoTi) and the copper nitride film (CuNx) according to the present invention is about 1.44 to 1.65, . Accordingly, the present invention can form a fine electrode having a fine line width (w2) because the etching process can be performed for a shorter time than the conventional method.

9 is a graph showing changes in fine line width according to an etching time when a double-layer structure pixel electrode composed of a molybdenum titanium alloy (MoTi) and a copper nitride film (CuNx) according to the present invention is used.

As shown in FIG. 9, in the case of a double-layer etching time consisting of a molybdenum titanium alloy (MoTi) and a copper nitride film (CuNx) according to an embodiment of the present invention, about 60 seconds to 84 seconds, To 1.60 mu m.

FIG. 10 is a photograph showing a change in the fine line width (w) according to the etching time in the case of a single film made of a metal film according to the present invention and a double film structure made of a metal film and a metal oxide film or a metal nitride film to be.

As shown in FIG. 10, when the etching process is performed for 10 seconds in the conventional case, a fine pattern having a fine line width of about 2.6 μm is formed. In the case of the present invention, the molybdenum titanium alloy (MoTi) In the case of a double-layer film made of a copper nitride film (CuNx), a fine pattern having a fine line width of about 2.0 μm is formed when the etching process is performed for about 40 seconds, and when the etching process is performed for about 60 seconds, It can be seen that a fine pattern having a line width is formed.

Therefore, the present invention is faster than conventional etching processes, and as the etching time is increased, the fine line width can be narrowed accordingly.

As described above, the display device and the method of manufacturing the same according to the present invention can be used as a pixel electrode by etching a bilayer structure composed of a metal film and a metal oxide film or a metal nitride film, Thus, it is possible to form a fine electrode having a high opening ratio or a fine wiring having a fine line width.

In particular, since the present invention can reduce the etching time to form a microelectrode, the fine line width W2 of the pixel electrode can be reduced compared with the prior art, and the aperture ratio can be improved. As a result, .

Furthermore, since the present invention can form a microelectrode having a fine line width (W2), for example, a pixel electrode and a common electrode, the number of pixel electrodes and common electrodes disposed in the unit pixel region can be increased.

Therefore, the present invention can increase the intensity of the electric field by narrowing the distance d2 between the pixel electrode and the common electrode while maintaining the aperture ratio, and by increasing the reaction force of the liquid crystal reacting by the electric field, The reaction rate may be increased.

Therefore, since the pixel electrode or other metal wiring forming process of the display device according to the present invention can be performed faster and uniformly than the conventional one, the high aperture ratio can be secured by miniaturizing the electrodes, and the process time for the miniaturization process can be reduced .

Further, the display device and the method of manufacturing the same according to the present invention are characterized in that a metal film and a metal oxide film or a metal nitride film are formed on the metal film at the time of forming a pixel electrode or other metal wiring of a display device to form a double- It is possible to obtain a faster etch rate than a conventional metal film, and the etching process time is reduced.

Therefore, since the display device and the method of manufacturing the same according to the present invention can secure a faster etch rate than a metal film, which is a conventional single film, the fine line width of the electrode can be reduced and the aperture ratio and brightness can be increased through the microelectrode , The etching process time is reduced and the productivity is improved.

The display device and the method of manufacturing the same according to the present invention can realize a uniform micro wiring by etching a double film structure of a metal film and a metal oxide film or a metal nitride film to form an electrode, So that damage to the metal film can be reduced.

Furthermore, in the display device and the method of manufacturing the same according to the present invention, the metallic electrode, which is a conventional single film, has a high reflectivity, resulting in a rainbow stain phenomenon. However, the metal film used in the present invention and the metal oxide film or the metal nitride film Since the metal electrode has low reflectivity, it can be used as a low reflection electrode. That is, since the metal oxide film or the metal nitride film has a lower light reflectance than the metal film, the metal oxide film or the metal nitride film serves to reduce the reflectance at the upper portion of the metal film having a high reflectance, .

Further, the display device and the method of manufacturing the same according to the present invention can be applied not only to various metal wiring including pixel electrodes of a display device, but also to low reflection electrodes of solar cells, metal wiring including microelectrodes of semiconductor devices, The present invention can be applied to a metal wiring including a metal wiring.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

Therefore, it should be understood that the above-described embodiments are provided so that those skilled in the art can fully understand the scope of the present invention. Therefore, it should be understood that the embodiments are to be considered in all respects as illustrative and not restrictive, The invention is only defined by the scope of the claims.

101: substrate 103: gate wiring
103a: gate electrode 104: common wiring
104a: common electrode 105: gate insulating film
107: active layer 109: ohmic contact layer
111: semiconductor layer 113a: data line
113b: source electrode 113c: drain electrode
125: protective layer 127: contact hole
129a: conductive layer pattern 131a: metal oxide film pattern or metal nitride film pattern
141: pixel electrode wiring 141a: pixel electrode

Claims (20)

A gate wiring formed in the form of a matrix on a substrate;
A data line formed on the substrate and defining a pixel region crossing the gate line;
A gate electrode formed at a point of intersection of the gate wiring and the data wiring, the gate electrode branched from the gate wiring, the gate insulating film, the active layer, the source electrode branched from the data wiring, and the drain electrode spaced apart from the source electrode A thin film transistor including the thin film transistor;
A protective layer formed on the thin film transistor and including a contact hole exposing a part of the drain electrode; And
And a pixel electrode electrically connected to the drain electrode through the contact hole, the conductive layer including a conductive layer formed on the protective layer and a conductive metal oxide film formed on the conductive layer. The conductive layer according to claim 1, wherein the conductive layer comprises at least one of a conductive metal group including molybdenum titanium alloy (MoTi), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) Or at least one of ITO, AZO, ZnO, and IZO. The display device according to claim 1, wherein the metal oxide film comprises at least one of copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), or molybdenum titanium (MoTi) alloy. The display device according to claim 1, wherein at least one of the gate wiring, the common wiring, the data wiring, or the source and drain electrodes is a double-layer structure of a conductive layer and a metal oxide film. The conductive layer according to claim 4, wherein the conductive layer comprises at least one of a conductive metal group including a molybdenum titanium alloy (MoTi), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W) Or a transparent metal material including ITO, AZO, ZnO, and IZO. The display device according to claim 1, wherein the conductive layer comprises a double layer of a metal layer and a transparent conductive layer. The method according to claim 6, wherein the metal layer is at least one selected from the group consisting of molybdenum titanium (MoTi) alloy, aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), and copper , And at least one of ITO, AZO, ZnO, and IZO is used as the transparent conductive layer. Forming a gate wiring having a gate electrode on a substrate;
Forming a gate insulating film on the gate electrode;
Forming an active layer on top of the gate electrode with the gate insulating film interposed therebetween;
Forming a data line over the active layer to define a pixel region intersecting the gate line, a source electrode branched at the data line, and a drain electrode spaced apart from the source line;
Forming a protective layer on the entire surface of the substrate including the source electrode, the drain electrode, and the data line;
Forming a contact hole exposing a portion of the drain electrode by patterning the passivation layer;
Forming a conductive layer on the protective film in contact with the drain electrode through the contact hole and stacking a metal oxide film having conductivity on the conductive layer; And
And forming a pixel electrode by sequentially etching the metal oxide layer and the conductive layer. delete delete The method of manufacturing a display device according to claim 8, wherein the gate wiring, the common wiring, the data wiring, or the source and drain electrodes are formed of a double layer structure of a metal layer and a metal oxide layer. delete delete delete The display device according to claim 4, wherein the metal oxide film comprises at least one of copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), and molybdenum titanium (MoTi) alloy. A gate wiring formed in the form of a matrix on a substrate;
A data line formed on the substrate and defining a pixel region crossing the gate line;
A gate electrode formed at a point of intersection of the gate wiring and the data wiring, the gate electrode branched from the gate wiring, the gate insulating film, the active layer, the source electrode branched from the data wiring, and the drain electrode spaced apart from the source electrode A thin film transistor;
A protective layer formed on the thin film transistor and including a contact hole exposing a part of the drain electrode; And
And a pixel electrode electrically connected to the drain electrode through the contact hole, the conductive layer being formed on the conductive layer and the metal nitride film having conductivity formed on the conductive layer. . The display device according to claim 16, wherein the metal nitride film comprises at least one of copper (Cu), aluminum (Al), aluminum alloy, chromium (Cr), tungsten (W), or molybdenum titanium (MoTi) alloy. The display device according to claim 1, wherein the metal oxide film has a higher corrosion potential than the conductive layer. The display device according to claim 4, wherein the metal oxide film has a higher corrosion potential than the conductive layer. The method according to claim 8, wherein the metal oxide layer has a higher etching rate than the conductive layer.

Images