KR102230959B1 - Color filter on thin film transistor structure liquid crystal display device and fabricating method thereof - Google Patents

Abstract

The present invention discloses a liquid crystal display device. In particular, the present invention relates to a COT structure liquid crystal display device in which a color filter is formed on a lower substrate, and a method of manufacturing the same.
The COT structure liquid crystal display according to an exemplary embodiment of the present invention has an effect of improving stitch parallax and image quality by implementing a pixel metal layer in a multilayer structure having a low reflection layer.

Description

Citi structure liquid crystal display and its manufacturing method {COLOR FILTER ON THIN FILM TRANSISTOR STRUCTURE LIQUID CRYSTAL DISPLAY DEVICE AND FABRICATING METHOD THEREOF}

The present invention relates to a liquid crystal display device, and more particularly, to a COT structure liquid crystal display device in which a color filter is formed on a lower substrate, and a method of manufacturing the same.

FPD (Flat Panel Display) replaces the conventional cathode ray tube (CRT) display device to reduce the size and weight of not only desktop computer monitors, but also portable computers such as notebook computers and PDAs, and mobile phone terminals. It is an essential display device to implement the system. Currently commercialized flat panel displays include liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light emitting diodes (OLEDs). A display device is in the spotlight as a display device used in mobile devices, computer monitors, and HDTVs, due to its advantages such as excellent visibility, easy thin film, low power consumption and low heat generation.

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

Referring to FIG. 1, in a general liquid crystal display device, an array substrate 1 and a color filter substrate 2 are largely bonded together while maintaining a cell gap by a spacer (not shown), and the array substrate 1 and the color filter It consists of a substrate 2 and a liquid crystal layer 3 formed therebetween.

In addition, the array substrate 1 is arranged vertically and horizontally so that a plurality of gate lines 4 and data lines 5 defining a plurality of pixel regions P, and the gate lines 4 and data lines 5 are formed. It consists of a thin film transistor T, which is a switching element formed in the crossing region, and a pixel electrode 6 formed on the pixel region P.

The color filter substrate 2 includes a color filter 8 composed of a plurality of sub-color filters 7 implementing colors of red (Red, R), green (green, G), and blue (blue, B), and , A black matrix (BM) 8 that divides between the sub-color filters 7 and blocks light passing through the liquid crystal layer 3, and a transparent layer that applies a voltage to the liquid crystal layer 3 It consists of a common electrode (not shown).

The array substrate 1 and the color filter substrate 2 configured as described above are bonded to each other by a sealant (not shown) formed outside the image display area to form the liquid crystal display 100.

However, during the manufacturing process of the liquid crystal display device having the above-described general structure, a bonding error may occur in the process of bonding the array substrate 1 and the color filter substrate 2, so the black matrix ( When designing 8), there is a certain value of margin.

This, as the opening area is reduced by the margin, the aperture ratio is lowered and thus the luminance is lowered. In addition, when a bonding error beyond the margin occurs, a light leakage defect may occur in which the light leakage region is not completely covered by the black matrix.

In order to solve this problem, a color filter on TFT (COT) structure in which the color filter 5 and the black matrix 8 formed on the color filter substrate 2 are formed on the array substrate 1 has been proposed.

2 is a diagram schematically showing the structure of a conventional COT structure liquid crystal display.

Referring to FIG. 2, a conventional COT structure liquid crystal display device 10 includes a lower substrate sub1 and an upper substrate sub2, and a liquid crystal layer LC interposed therebetween.

In the lower substrate sub1, various signal lines 25 are formed on the transparent substrate 11, and a pixel region P is defined between the signal lines 25. In each pixel region P, a pixel pattern PT including a thin film transistor and two counter electrodes is formed. In this COT structure, color filters 33, 34, and 35 corresponding to red (R), green (G), and blue (B) are formed on the pixel pattern PT, respectively.

A planarization layer 40 is formed on the top thereof to improve the level difference due to the color filters 33, 34, and 35 and prevent contamination of the liquid crystal. A pixel electrode 48 is formed on the planarization layer 40.

And, the upper substrate (sub2) is bonded to face the lower substrate (sub1) so as to be spaced apart by a predetermined distance. The upper substrate sub2 includes a transparent substrate 51 and a column spacer 55 for maintaining a gap with the lower substrate sub1 on the transparent substrate 51. A liquid crystal layer LC is interposed between the upper and lower substrates sub1 and sub2. According to this structure, the electric field generated by the pixel pattern PT changes the light transmittance of the liquid crystal layer LC to display an image, and the color is determined by the color filter.

In the COT structure liquid crystal display of this structure, color filters 33 to 35 are formed on the pixel pattern PT in the lower substrate sub2, not the upper substrate sub2, so that the bonding margin with the upper substrate sub1 There is no need to consider Accordingly, compared to a structure in which the black matrix and the color filter are provided on the upper substrate (sub2), the aperture area is enlarged to improve luminance, and light leakage due to a bonding error does not occur, thereby realizing high luminance.

However, in the COT structure liquid crystal display, as different color filters are formed for each pixel area P, the overlapping difference of the resin material constituting the color filter in the area where the two pixel areas P are adjacent to each other causes the upper There is a problem in that the refractive index of the auxiliary electrode provided is different, so that a stitch defect is visually perceived. In addition, a problem arises in the difference in the reflectivity of each side bezel of the liquid crystal display device and the difference in reflectance of the pixel metal layer existing in the pixel area.

FIG. 3 is a diagram illustrating a structure of an arbitrary two area and a bezel area among points adjacent to two pixel areas in a conventional CMOS structure liquid crystal display. Referring to FIG. 3, each pixel area has a color filter of a different color. (32, 33) is formed, and the reflection direction of light is changed by a step difference in the corresponding portion according to the shape in which the neighboring color filters 32 and 33 overlap each other in an area adjacent to each other.

When forming the color filters 32 and 33, depending on the limitations of the process, the shape of the color filters 32 and 33 adjacent to each other is not formed in the same manner in all areas of the liquid crystal display. In some areas, the two color filters 32 and 32 Since 33) do not contact each other, the upper planarization layer 40 becomes concave (a), and in other areas, the two color filters 32 and 33 contact each other, so that the planarization layer 40 on the upper surface becomes convex. .

Accordingly, in the case of the structure a, the auxiliary electrode 48a is made of the same metal as the pixel electrode on the planarization layer 40 to block light, and the auxiliary electrode 48a disposed so as to overlap the data line 25 is concave to prevent external light. The angle of refraction of light L1 is largely reflected, but in the case of structure b, the auxiliary electrode 48b is convex, so that the angle of refraction of light by external light is small, so that the path of light reflected from the two structures (a, b) is It becomes different. Eventually, this difference is perceived by the viewer as a stitch parallax difference.

Also, due to the difference between the degree of reflection of light (L1 or L2) due to external light in the pixel area and the degree of reflection of light (L3) due to external light in the bezel area, the boundary between the edge and the bezel is clearly visible. There is a difference.

The present invention was conceived to solve the above-described problem, and the present invention relates to a stitch parallax difference, an edge portion, and a bezel portion caused by a step difference of a color filter in a COT structure liquid crystal display device in which a color filter is formed on a lower substrate. The purpose of this is to improve the visibility difference in which this boundary is clearly visible.

In the COT structure liquid crystal display device according to a preferred embodiment of the present invention, a gate metal layer, a gate insulating layer, and a data metal layer are sequentially provided on a substrate, and a color filter layer provided on the gate insulating layer and the data line is formed. As provided, it has a COT structure. In addition, a planarization layer provided on the color filter, a pixel metal layer formed on the planarization layer, and a second substrate disposed opposite to the first substrate are included, and a liquid crystal layer is interposed between the first and second substrates. It constitutes one liquid crystal display device.

In particular, in the present invention, the pixel metal layer formed on the planarization layer is made of one metal material or alloy, and includes first and second metal layers having at least two or more different characteristics, and at least one of the first and second metal layers is low. By having a reflective characteristic, there is a characteristic that stitch defects and edge spectral difference defects due to light reflection of the metal layer are improved, and this structure does not implement a multilayer structure through separate metal targets and chambers, but one in the same chamber. It is characterized by forming a metal layer to have a low reflection characteristic using a metal target of.

The COT structure liquid crystal display device according to an exemplary embodiment of the present invention has an effect of improving stitch parallax and edge parallax and improving image quality by implementing a pixel metal layer in a multilayer structure having a low-reflective layer.

In addition, the manufacturing method of the COT structure liquid crystal display device according to the embodiment of the present invention, in forming an oxide layer on a pixel metal layer, is not a thin film process using a different chamber for each metal layer and oxide layer, but a metal layer and a metal layer in the same chamber. By forming an oxide layer, there is an effect of efficiently manufacturing a liquid crystal display device without adding material cost and increasing TACT TIME.

1 is an exploded perspective view schematically showing the structure of a general liquid crystal display device.
2 is a diagram schematically showing the structure of a conventional COT structure liquid crystal display.
FIG. 3 is a diagram illustrating a structure of a bezel region and two arbitrary regions among points adjacent to two pixel regions in a conventional COT structure liquid crystal display.
4 is a plan view illustrating a structure of one pixel of a COT structure liquid crystal display according to an exemplary embodiment of the present invention.
FIG. 5 is a diagram showing a cross-sectional view of III-III' and IV-IV' of FIG. 4.
6 is a diagram illustrating a structure of an arbitrary two region of a point where two pixel regions are adjacent in a COT structure liquid crystal display according to an embodiment of the present invention.
7 to 9 are diagrams illustrating a method of manufacturing a metal layer applied to a COT structure liquid crystal display device according to an exemplary embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. The same reference numerals refer to the same elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In the case where'to have','include','have','consist of', etc. mentioned in the present specification are used, other parts may be added unless'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of the two parts is described as'upper','upper of','lower of','next to', etc.,'right' Alternatively, one or more other parts may be located between the two parts unless'direct' is used.

In the case of a description of a temporal relationship, for example,'after','following','after','before', etc. It may also include cases that are not continuous unless' is used.

First, second, etc. are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other or can be implemented together in an association relationship. May be.

Hereinafter, a COT structure liquid crystal display and a method of manufacturing the same according to a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 4 is a plan view showing a structure of one pixel of a COT structure liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 5 is a view showing a cutaway view of Ⅲ-Ⅲ' and Ⅳ-IV' of FIG. to be.

4 and 5, the COT structure liquid crystal display device 100 of the present invention includes a lower substrate sub1 on which a thin film transistor T and color filters 132, 133, and 134 are formed, and It includes an upper substrate (sub2) that is bonded by being spaced apart by a predetermined distance, and a liquid crystal layer (LC) interposed between the two substrates (sub1, sub2).

The lower substrate sub1 is formed of the same metal on the transparent substrate 101 and has a gate wiring 102 formed in one direction and a common wiring 104 formed parallel to the gate wiring 102.

The gate wiring 102 divides the substrate 101 into a plurality of regions in addition to the data wiring 125 to be described later, and the partitioned region is defined as a pixel region P. Further, a region surrounding the pixel region P and in which the gate wiring 102 and the common wiring 104 and the thin film transistor T are formed is defined as a peripheral region O. The common wiring 104 is connected to each other by an extension wiring 104b at the top and bottom.

A gate formed by depositing one selected from a group of inorganic insulating materials including _{silicon nitride (SiN X} ) and silicon oxide (SiO ₂ ) over the entire surface of the substrate 101 on the top of the gate wiring 102 and the common wiring 104 An insulating layer 105 is formed.

A gate wiring 102 is formed on the top of the gate insulating layer 105, and a data wiring 125 is formed in a direction crossing the gate wiring 102 when viewed in a plan view, and a gate electrode 102a is formed at an overlapping point. And a thin film transistor T composed of a semiconductor layer 117, a source electrode 124 and a drain electrode 128.

To describe the method of manufacturing such a thin film transistor (T), first, pure amorphous silicon (a-Si:H) and amorphous silicon (n+a-Si:H) containing impurities are deposited on the gate insulating layer 105. By patterning, the active layer 117 and the ohmic contact layer 121 are formed on the gate insulating layer 105 adjacent to the gate electrode 102a. However, the present invention is not limited thereto, and a polysilicon thin film or an oxide semiconductor may be used as the active layer 117.

Next, chromium (Cr) or molybdenum (Mo) is deposited on the entire surface of the substrate 101 on which the active layer 117 and the ohmic contact layer 121 are formed, and patterned by a mask process, and the ohmic contact layer 121 and each A source electrode 124, a drain electrode 128, and a data line 125 connected to the source electrode 124 are formed in contact with each other. The source electrode 124, the drain electrode 128, and the data line 125 are formed of the same data metal layer.

In addition, although not shown, a protective layer (not shown) by depositing one selected from a group of inorganic insulating materials including _{silicon (SiN 2} ) and silicon oxide (SiO ₂ ) on the front surface of the substrate 101 on which the thin film transistor (T) is formed. May be further formed, and a semiconductor layer may be further formed under the data line 125.

In addition, although the drawing illustrates a thin film transistor T having a bottom gate structure in which the gate electrode 102a is located under the active layer 117, it is not limited thereto. A top gate structure located on the top can also be applied. That is, the thin film transistor T provided in the COT structure liquid crystal display device of the present invention is not limited to a specific structure.

Color filters 132, 133, and 134 for implementing red (R), green (G), and blue (B) colors are formed on the thin film transistor T. On the pixel area P, each of the red (R), green (G), and blue (B) color filters corresponding to the pixel is formed in a single layer, and the peripheral area O surrounding the pixel area P is By replacing the black matrix, at least two of the red (R), green (G) and blue (B) color filters are formed to overlap each other. When two or more color filters are formed by overlapping, the light transmittance is significantly lower than that of a single color filter, so that the function of the conventional black matrix can be replaced.

Accordingly, when the color filters 132 to 134 are formed, a photosensitive color resin of a color corresponding to each pixel region P is applied to the entire surface of the substrate 101 including the thin film transistor T and then patterned. A color filter of is formed, and two or more dyes are sequentially overlapped with respect to the peripheral region O to form a stacked structure of upper and lower layers. In the drawing, an example of a structure in which the red color filter 132 is disposed on the lower layer of the blue color filter 133 is shown, but the stacking order and the type of color filter may vary according to the intention of the designer.

A planarization layer 140 is formed over the entire surface of the substrate 101 on the color filters 132 to 134. The planarization layer 140 serves to remove a step difference due to the lower color filters 132 to 134 and prevent contamination of the liquid crystal by the color filter. In addition, the planarization layer 140 may be formed of an organic insulating material, such as benzocyclobutene (BCB) and acrylic resin (acryl resin).

On the planarization layer 140, a pixel electrode 146 having a finger structure in contact with the drain electrode 128 of the thin film transistor T and having a plurality of them arranged side by side in one direction is formed, and the pixel electrode 146 The common electrodes 144 are disposed side by side so as to face each other. The drawing shows an example in which the pixel electrode 146 and the common electrode 144 have a bent structure.

The pixel electrode 146 is connected to the drain electrode 128 through a contact hole penetrating the color filters 132 to 134 below and the planarization layer 140, and the common electrode 144 is a common wiring 104 of the lower layer. ).

The common electrode 144 and the pixel electrode 146 are transparent including indium-tin-oxide (ITO) and indium-zinc-oxide (IZO) on the entire surface of the substrate 101 on which the planarization layer 140 and contact holes are formed. It can be formed by depositing and patterning selected one of the conductive metal groups.

According to this structure, when a common voltage (Vcom) and a pixel voltage (Vdata) are applied to the common electrode 144 and the pixel electrode 146, respectively, a transverse electric field is formed. The transmittance is changed to display the gradation of the image.

Further, an auxiliary electrode 148 is formed on the planarization layer 140 to overlap the data line 125 below by using the same metal material as the common electrode 144 and the pixel electrode 146. The auxiliary electrode 128 serves to prevent light leakage occurring between the data line 125 and the connection line 104b, and the light mixed in the area where the two color filters 133 and 134 meet is emitted to the outside. It plays a role in minimizing it. According to this structure, the common electrode 144, the pixel electrode 146, and the auxiliary electrode 128 are formed of the same pixel metal layer.

In particular, the boundary where the two color filters 133 and 134 meet is not formed in an even shape over the entire area of the liquid crystal display 100, but a level difference of different heights for each boundary. Such a step difference is not improved even by the planarization layer 140, and therefore, the cross-section of the upper auxiliary electrode 148 has an irregular concave or convex shape for each region. According to this structure, when external light incident on the front surface of the liquid crystal display 100 is reflected by the auxiliary electrode 148, a stitch failure occurs, and a difference in visibility between the pixel region and the bezel region occurs.

In order to improve this problem, the liquid crystal display device 100 according to the exemplary embodiment of the present invention is characterized in that the auxiliary electrode 148 is subjected to a low-reflective treatment to minimize the stitch and edge parallax defect. In particular, in the low-reflective treatment of the auxiliary electrode 148, when forming the auxiliary electrode 148, rather than coating a low-reflective film through a separate thin film forming process or forming a multilayer using two or more metal materials. One metal layer is formed, but it is continuously formed in a structure equivalent to a multilayer structure by different process conditions in the same chamber.

That is, the auxiliary electrode 148 provided in the liquid crystal display device of the present invention is made of a single metal, and may be divided into a lower layer and an upper layer, or a lower layer, an intermediate layer, and an upper layer according to its characteristics, and one of the layers is low-reflective. It is characterized by consisting of a metal oxide layer having characteristics.

Here, the low-reflection property refers to the property of a metal oxide capable of reflecting only a part of light incident from the outside of the liquid crystal display and absorbing most of it.

To this end, metal materials for generating the auxiliary electrode 148 include copper (Cu), manganese (Mn), moldibdenum (Mo), zinc (Zn), copper-manganese alloy (Cu-Mn), and copper alloy ( Any one selected from among Cu alloy, Zn alloy, Ti alloy, and Ni alloy may be used.

Accordingly, a separate chamber and a target for generating the low-reflective film are omitted, so that cost reduction and process time reduction can be expected.

In addition, since the auxiliary electrode 148 has a multilayer structure of a single metal or an alloy, the common electrode 144 and the pixel electrode 146 made of the same metal layer also have the same structure.

6 is a diagram illustrating a structure of an arbitrary two region of a point where two pixel regions are adjacent in a COT structure liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 6, in each pixel region, a height difference according to a step difference occurs above the color filters 132 and 133 according to the shape of the boundary surface of the color filters 132 and 133 of different colors.

Specifically, the color of the pixel region is distinguished around the data line 125, and color filters 132 and 133 of different colors are formed for each pixel region.

When the color filter is formed, when the coating of the resin material is insufficient at the interface (a), the interface between the two color filters 132 and 133 is depressed so that the planarization layer 140 and the auxiliary electrode 1847 have a central region when viewed from the cross-section. It becomes a concave shape. In addition, when the resin material is applied excessively (b), the interface between the two color filters 132 and 133 protrudes so that the planarization layer 140 and the auxiliary electrode 1482 have a convex central area when viewed from the cross section. . Accordingly, the two auxiliary electrodes 1481 and 1482 have different reflection angles for external light.

Here, each auxiliary electrode (1481, 1482) is made of a single metal material, the upper layers (1481b, 1482b) are oxidized, and accordingly, the external light (L1, L2) incident on the upper layers (1481b, 1482b) is absorbed. It will not be admitted to the viewer. Since the lower layers 1481a and 1482a are not subjected to oxidation, they maintain the same performance in signal transmission.

Hereinafter, a method of manufacturing a multilayered pixel metal layer made of a single material of a COT structure liquid crystal display device according to an exemplary embodiment of the present invention will be described with reference to the drawings. In the following description, for convenience of explanation, a method of manufacturing an auxiliary electrode is described as an example of directly forming an auxiliary electrode on a substrate. When applied to an actual COT structure liquid crystal display device, a planarization layer and other low-reflective films are required as described above. It is formed on the top of the layer.

7 to 9 are diagrams illustrating a method of manufacturing a metal layer applied to a COT structure liquid crystal display device according to an exemplary embodiment of the present invention.

Referring to FIG. 7, in the method for manufacturing a metal layer of a COT structure liquid crystal display device according to an embodiment of the present invention, a target substrate (sub) for forming a metal layer in one chamber is prepared, and one metal material or alloy is used as a target material. As a result, the metal layer deposition process is performed.

Target materials used at this time include copper (Cu), manganese (Mn), moldibdenum (Mo), zinc (Zn), copper-manganese alloy (Cu-Mn), copper alloy, and zinc alloy (Zn). alloy), a titanium alloy, and a nickel alloy may be used.

First, the target material is deposited on a substrate sub through a sputtering process (a). In the sputtering process, argon gas is injected between a target made of a metal material to be deposited to which a high voltage is applied and an anode electrode, and argon ions (Ar+) are excited using plasma discharge, and argon ions accelerated by a high voltage ( Ar+) has a high kinetic energy to collide with the target. At this time, if the applied impact energy is greater than the binding energy between metal atoms, the atoms on the metal surface fall off, and the sputtered atoms consume energy through mutual collision and interference, and grow into a thin film as they are bonded to each other on the surface of the glass substrate. do.

When the metal layer 200 of the desired thickness is formed, the gas atmosphere in the chamber is then composed of argon + oxygen (Ar + O ₂ ), and the lower metal layer 210 and the upper metal layer (which is a metal oxide layer) are formed by a reactive sputtering process. 220) is formed (b). The reactive sputtering process is a process of depositing an oxide layer for each layer by injecting a reactive gas during deposition in the same chamber and reacting atoms sputtered from a target with the injected gas.

At this time, the gas atmosphere (O ₂ / Ar+O ₂ ) may be adjusted between 0% and 100%, and the thickness of the upper metal layer 220 may be formed between 100Å and 600Å. Also, the lower metal layer 210 may be formed between 100 Å and 500 Å.

8 shows a method of manufacturing a metal layer of a COT structure liquid crystal display device according to another embodiment of the present invention.

Referring to FIG. 8, after forming a metal layer 300 on a substrate (sub) through a sputtering process in the same manner as in the exemplary embodiment (a), oxygen (O ₂ ) is implanted according to the intention of the designer. A metal oxide layer is formed on the uppermost or intermediate layer of the metal layer (b1, b2). That is, an oxide layer having semiconductor characteristics is formed by reacting the metal material of the base metal layer with the implanted oxygen ions, but by adjusting the dose and energy of oxygen ions, the upper oxide layer-the lower metal layer, the upper metal layer-the middle oxide layer-the lower metal layer Alternatively, a metal layer having an upper metal layer-lower oxide layer structure is formed.

In the upper case (b1), oxygen ions (O ₂ +) are implanted into the metal layer 300 formed on the substrate sub through ion implantation. At this time, the implantation energy is adjusted between 10 keV and 10 MeV to determine the position of the oxide layer 320, and the dose can be adjusted to 10 ¹² /cm ^{2 to 10 20} /cm ^2.

Here, it is preferable that the metal layer forming the metal layer 310 is formed of the oxide layer 320 only by heat applied during a subsequent process without an additional heat treatment process using a metal material sensitive to oxidation reaction, and the candidate is among the metal materials described above. Either can be used.

The metal layers of the upper metal layer-intermediate oxide layer-lower metal layer and upper metal layer-lower oxide layer structure are also formed by controlling the above-described injection energy (b2). In the drawing, the structure in which the oxide layer 340 into which ions are implanted is positioned between the lower metal layer 330 and the upper metal layer 350 is illustrated, and the position is determined according to the dose amount.

9 illustrates a method of manufacturing a metal layer of a COT structure liquid crystal display device according to another exemplary embodiment of the present invention.

Referring to FIG. 9, a metal layer 400 is formed on a substrate sub by a sputtering process using a three-component (α+β+γ)-based metal target (a). Next, one of the three-component (α+β+γ) metals forming the metal layer 400 through heat treatment is oxidized to form an oxide layer 420 on the surface, thereby forming the lower metal layer 410 and the upper oxide layer. (420) is formed (b). The metal layer 400 may have a thickness of 100 Å to 1000 Å, and the oxide layer 420 may have a thickness of 100 Å to 500 Å.

Here, the use of a three-component (α+β+γ) metal target means that even if an oxide layer is formed and the reflectance of the surface is lowered when the two-component metal material is heat treated, the color coordinates are affected by the color of the remaining metal layer and are reflected. This is because there may be a problem in that the color of light changes, and the transmittance of the metal may increase because any one of the two-component metals loses the properties of the alloy.

Therefore, in the embodiment of the present invention, a metal layer is formed using a three-component alloy. As the three-component metal material used here, a metal material having low resistance, high diffusivity to facilitate diffusion of the metal material to the top during heat treatment, and having a small band gap for forming an oxide layer is used.

As an example, as the three-component metal material, copper (Cu) or aluminum (Al) may be used as the base metal material α, and the ratio of the base metal may be adjusted to 50% to 90%. In addition, as the conductive material γ, it is possible to use manganese (Mn) or molybdenum (Mo), which are metals that are relatively easy to form oxides compared to other materials due to their high diffusivity and high Gibbs free energy. The proportion of these conductive metals can be adjusted from 10% to 30%.

In addition, the metal (β) added as a three-component metal material maintains an alloy state with the remaining materials of the lower layer during heat treatment and prevents the remaining material from having a specific color. Nickel (Ni), titanium (Ti) ) And zinc (Zn), etc. may be used. The ratio of these additional metals can be adjusted from 1% to 20%.

Accordingly, the three-component metal layer may be typically composed of a copper-nickel-manganese (Cu-Ni-Mn) alloy, a copper-titanium-molybdenum (Cu-Ti-Mo) alloy, or a combination of the above metal materials.

Meanwhile, in the above embodiments, only a structure in which the metal layer having a multilayer of the present invention is applied to the auxiliary electrode, the pixel electrode, and the common electrode of the top emission type COT structure liquid crystal display device is shown, but the rear emission type organic light emitting display device In order to improve the light reflection problem in the direction of the substrate, it may be applied to a gate electrode other than the above electrode, or to the source and drain electrodes of the thin film transistor.

Although the preferred embodiments of the present invention have been described in detail above, those of ordinary skill in the art will appreciate that various modifications and other equivalent embodiments are possible therefrom.

P: Pixel area O: Peripheral area
T: thin film transistor R,G,B: red, green, blue areas
sub1: lower substrate sub2: upper substrate
LC: liquid crystal layer 100: liquid crystal display
101, 151: substrate 102: gate wiring
104: common wiring 105: gate insulating layer
117: semiconductor layer 121: ohmic contact layer
124: drain electrode 125: data wiring
128: source electrode 132: red color filter
133: green color filter 134: blue color filter
140: planarization layer 144: common electrode
146: pixel electrode 148: auxiliary electrode

Claims (15)

A first substrate;
A gate wiring and a data wiring crossing each other on the first substrate to partition a plurality of pixel regions;
Red, green, and blue color filters disposed for each pixel area in the pixel area;
A planarization layer disposed on the red, green, and blue color filters;
A pixel metal layer provided on the planarization layer;
A second substrate disposed to face the first substrate; And
Including a liquid crystal layer interposed between the first substrate and the second substrate,
The pixel metal layer,
It is made of one metal material or alloy, and includes first and second metal layers having at least two or more different characteristics, and of the first and second metal layers, at least one is composed of a metal oxide layer,
At least two color filters of the red, green, and blue color filters are disposed to overlap each other in a peripheral area surrounding the pixel area. The method of claim 1,
The second metal layer,
A COT structure liquid crystal display device provided on the first metal layer, wherein the same metal material as the first metal layer is oxidized to produce less reflected light than at least the first metal layer. The method of claim 2,
The first metal layer has a thickness of 100 Å to 600 Å,
The second metal layer has a thickness of 100 Å to 500 Å. The method of claim 1,
The pixel metal layer,
Including a first metal layer to a third metal layer sequentially stacked,
COT structure liquid crystal display device in which at least one of the first to third metal layers is oxidized by oxygen ions. The method according to any one of claims 2 and 4 selected,
The pixel metal layer,
Copper (Cu), manganese (Mn), molybdenum (Mo), zinc (Zn), copper-manganese alloy (Cu-Mn), copper alloy, Zn alloy, Ti alloy And a COT structure liquid crystal display made of a metal material selected from among nickel alloys. The method of claim 1,
And an auxiliary electrode formed of the same metal material as the pixel metal layer on the planarization layer and overlapping the data line. The method of claim 6,
In the pixel area, different color filters are disposed for each pixel area based on the data line. The method of claim 7,
The COT structure liquid crystal display device, wherein a boundary surface between the two color filters on the data line is depressed so that a central region of the planarization layer and the auxiliary electrode is concave. The method of claim 7,
The COT structure liquid crystal display device, wherein a boundary surface of the two color filters on the data line protrudes so that a central region of the planarization layer and the auxiliary electrode has a convex shape. delete Forming a gate wiring and a data wiring crossing each other on the first substrate to partition the plurality of pixel regions;
Red, green, and blue color filters are formed in the pixel area for each pixel area, and at least two of the red, green, and blue color filters are formed to overlap the surrounding area surrounding the pixel area. The step of doing;
Forming a planarization layer on the red, green, and blue color filters;
Forming a pixel metal layer on the planarization layer; And
And bonding a second substrate facing the first substrate,
The pixel metal layer is made of one metal material or alloy, and includes first and second metal layers having at least two or more different characteristics, and at least one of the first and second metal layers is formed of a metal oxide layer. OT structure liquid crystal display manufacturing method. delete The method of claim 11,
Forming the pixel metal layer on the planarization layer,
Forming a pixel metal layer on the planarization layer by a sputtering process; And
By injecting oxygen ions (O ₂ ) into the pixel metal layer to form a metal oxide layer in the metal layer, the pixel metal layer has a stacked structure of a first metal layer to a third metal layer, and between the first metal layer and the third metal layer. A method of manufacturing a COT structure liquid crystal display device comprising the step of forming the metal oxide layer. The method of claim 13,
The oxygen ion implantation process,
The implantation energy is controlled between 10 keV and 10 MeV,
A method of manufacturing a COT structure liquid crystal display, characterized in that the ^{dose is adjusted to 10 12} /cm ² ~ 10 ²⁰ /cm ^2. The method of claim 11,
Forming the pixel metal layer on the planarization layer,
Forming a pixel metal layer made of the three-component alloy on the planarization layer by a sputtering process using a three-component alloy target; And
And treating the pixel metal layer to have a structure of a first metal layer made of a two-component metal among the three-component alloys and a second metal layer made of a one-component metal on the first metal layer through a heat treatment process on the pixel metal layer,
One of the two-component metals includes copper or aluminum, and the other includes nickel, titanium or zinc,
The method of manufacturing a COT structure liquid crystal display device including manganese or molybdenum as the one-component metal.

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