KR101473964B1 - Etchant for etching Al, Mo and ITO - Google Patents

Abstract

The present invention relates to an etchant for etching molybdenum (Mo), aluminum (Al) and indium-tin-oxide (ITO), comprising 50 to 75 wt% phosphoric acid, 3 to 10 wt% 0.05 to 3 wt% of a chlorine compound, 0.05 to 3 wt% of a chlorine stabilizer, 0.1 to 5 wt% of a phosphate compound, 0.05 to 5 wt% of a lithium compound, 0.05 to 5 wt % Nitrate flame based compound and the balance water.

Accordingly, an object of the present invention is to provide an array substrate for a liquid crystal display device using an etchant capable of simultaneously etching molybdenum (Mo), aluminum (Al), and indium-tin-oxide (ITO) Unlike etching solutions, the use of a single etchant in each mask process can improve productivity and reduce the cost of equipment construction.

Molybdenum (Mo), aluminum (Al), indium-tin-oxide (ITO)

Description

(Etchant for etching Al, Mo and ITO) for etching aluminum, molybdenum, indium-tin-

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

2 is a sectional view of a general array substrate for a liquid crystal display;

FIGS. 3A and 3C illustrate a dual layer of a molybdenum (Mo) / aluminum alloy (AlNd) composed of a gate electrode and a material forming a gate wiring after the wet etching process by the etching solution according to the embodiment of the present invention, (Mo) layer made of a material for forming the pixel electrode, and a section after the etching of the indium-tin-oxide (ITO) layer made of the material for forming the pixel electrode by a scanning electron microscope.

4 is a cross-sectional view of an array substrate for a liquid crystal display device, which is patterned using an etching solution according to the present invention.

5A and 5B are graphs showing the relationship between the gate electrode (including the gate wiring) and the molybdenum (Mo) / the source and drain electrodes (including the data lines) after the wet etching process according to the first comparative example of the present invention, A photograph of a cross section of a double layer of aluminum alloy (AlNd) and a single layer of molybdenum (Mo) by scanning electron microscope.

6A and 6B are graphs showing the relationship between the gate electrode (including the gate wiring) and the molybdenum (Mo) / the source and drain electrodes (including the data lines) after the wet etching process according to the second comparative example of the present invention, A photograph of a cross section of a double layer of aluminum alloy (AlNd) and a single layer of molybdenum (Mo) by scanning electron microscope.

7A and 7B are graphs showing the relationship between the gate electrode (including the gate wiring) and the molybdenum (Mo) / the source and drain electrodes (including the data lines) after the wet etching process according to the third comparative example of the present invention, A photograph of a cross section of a double layer of aluminum alloy (AlNd) and a single layer of molybdenum (Mo) by scanning electron microscope.

8 is a cross-sectional view of a double layer of molybdenum (Mo) / aluminum alloy (AlNd), which is a material layer forming a gate wiring and a gate electrode, after a wet etching process using an etchant according to a fourth comparative example of the present invention was observed with a scanning electron microscope Picture.

9 is a scanning electron microscope (SEM) image of a cross section of an indium-tin-oxide (ITO) layer as a material layer forming a pixel electrode after a wet etching process using an etchant according to a fifth comparative example of the present invention.

10 shows a cross section of a molybdenum (Mo) / aluminum alloy (AlNd) double layer, which is a material layer forming a gate wiring and a gate electrode after a wet etching process using an etchant according to a sixth comparative example of the present invention, by scanning electron microscopy Picture.

11 is a cross-sectional view of a double layer of a molybdenum (Mo) / aluminum alloy (AlNd), which is a material layer forming a gate wiring and a gate electrode after a wet etching process using an etchant according to a seventh comparative example of the present invention, Picture.

FIG. 12 is a photograph of a section of a molybdenum (Mo) layer as a material layer between a data line and a source electrode and a drain electrode after a wet etching process using an etching solution according to an eighth comparative example of the present invention with a scanning electron microscope.

The present invention relates to an etchant for etching aluminum (Al), molybdenum (Mo) and indium-tin-oxide (ITO), and more particularly to an etchant for etching aluminum, molybdenum, indium-tin- For etching with an etchant consisting of a single solution.

Recently, liquid crystal display devices have been attracting attention as next generation advanced display devices with low power consumption, good portability, and high value-added.

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

Generally, a liquid crystal display device forms an array substrate and a color filter substrate through an array substrate manufacturing process for forming thin film transistors and pixel electrodes, and a color filter substrate manufacturing process for forming color filters and common electrodes, And a liquid crystal cell interposed therebetween.

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

As shown in the figure, the array substrate 10 and the color filter substrate 20 are bonded to each other with the liquid crystal layer 30 interposed therebetween. A plurality of gate wirings 14 and data wirings 16 are arranged to define a plurality of pixel regions P. A thin film transistor T which is a switching element is formed at the intersection of these two wirings 14, And are connected in a one-to-one correspondence with the pixel electrodes 18 provided in the respective pixel regions P.

The upper portion of the color filter substrate 20 facing the array substrate is covered with a non-display region such as the gate wiring 14, the data wiring 16, and the thin film transistor T, Green, and blue color filter layers 26 (red, green, and blue), which are sequentially and repeatedly arranged in correspondence to the respective pixel regions P within these lattices, are formed in the lattice-like black matrix 25 And a transparent common electrode 28 is provided over the entire surface of the black matrix 25 and the red, green and blue color filter layers 26.

Although not shown in the drawings, the two substrates 10 and 20 are sealed with a sealant or the like along their edges to prevent leakage of the liquid crystal layer 30 interposed therebetween An upper and a lower alignment films for providing reliability in the molecular alignment direction of the liquid crystal are interposed at the boundary between the substrates 10 and 20 and the liquid crystal layer 30 at at least one outer side surface of each of the substrates 10 and 20 A polarizing plate is provided.

A back-light is provided on the outer surface of the array substrate to supply light. An on / off signal of the thin film transistor T is sequentially scanned by the gate wiring 14, When the image signal of the data line 16 is transferred to the pixel electrode 18 of the selected pixel region P, the liquid crystal molecules therebetween are driven by the vertical electric field therebetween. As a result, It is possible to display branch images.

The array substrate used in such a liquid crystal display device is manufactured by patterning a specific material layer by performing several mask processes.

2 is a cross-sectional view of one pixel region including a thin film transistor which is a switching element of an array substrate for a liquid crystal display. Referring to FIG. 2, a method of manufacturing an array substrate for a liquid crystal display will be described.

As shown in the figure, after a first metal layer (not shown) is formed on a transparent insulating substrate 40, gate wirings (not shown) extending in one direction and gate wirings (not shown) And the branched gate electrode 44 is formed. The first metal layer may be formed of a metal such as aluminum (Al), aluminum alloy (AlNd), molybdenum (Mo), tungsten (W), chromium (Cr) , A molybdenum (Mo) layer is further provided to form a double layer.

The first mask process will now be described in more detail.

The first mask process first applies a photo-resist to the top of the first metal layer (not shown) to form a photoresist layer (not shown). At this time, the photoresist layer is made of a positive type photoresist in which a light-receiving portion is removed during development.

After a mask (not shown) composed of a transmissive region and a blocking region is placed on the photoresist layer, an exposing process for irradiating light on the mask and a developing process for removing the exposed region are performed A photoresist pattern (not shown) is formed on the first metal layer.

Then, the first metal layer (not shown) exposed to the outside of the photoresist pattern (not shown) is removed by wet etching to form a gate wiring (not shown) and a gate wiring .

The etchant used in the wet etching for forming the gate wiring and the gate electrode 44 of the bilayer structure is an etchant consisting of phosphoric acid, nitric acid, and acetic acid.

Next, the photoresist pattern remaining on the gate wiring (not shown) and the gate electrode 44 is removed by an ashing process.

Next, the gate insulating film 47 is laminated on the substrate 40 on which the double-layered gate wiring (not shown) and the gate electrode 44 are formed. The gate insulating film 47 is formed of silicon nitride (SiNx) 0.0 &_gt; SiO2). ≪ / _RTI >

Next, a pure amorphous silicon layer, an impurity amorphous silicon layer, and a second metal layer are sequentially formed on the gate insulating film 47, and a second metal layer including a series of unit processes such as photoresist application, exposure and development, etching, The semiconductor layer 52 composed of the active layer 52a of pure amorphous silicon and the ohmic contact layer 52b of the impurity amorphous silicon is sequentially formed from the gate insulating film 47 by the mask process and the source and drain Electrodes 57 and 59 are formed. At this time, a data line 55 connected to the source electrode 57 and intersecting the gate line (not shown) to define the pixel region P is also formed.

Here, molybdenum (Mo) is mainly used for the second metal layer constituting the data line 55 and the source and drain electrodes 57 and 59.

At this time, in the second mask process, a new photoresist layer is formed on the second metal layer, and then a second photoresist pattern is formed by exposing and developing the second mask .

Thereafter, the second metal layer exposed to the outside of the second photoresist pattern is removed by wet etching, and the pure amorphous silicon layer and the impurity amorphous silicon layer are dry-etched to form an active layer 52a of pure amorphous silicon And source and drain electrodes 57 and 59 are formed on the ohmic contact layer 52b of the impurity amorphous silicon and on the ohmic contact layer 52b.

At this time, the etchant for etching the second metal layer made of molybdenum (Mo) is an etchant comprising phosphoric acid, nitric acid, acetic acid, or a hydrous etchant.

Next, the second photoresist pattern remaining on the data line 55 and the source and drain electrodes 57 and 59 is removed by an ashing process, and the data line 55, the source and drain electrodes 57 and 59, etc. (57, 59) over the benzocyclobutene (BCB) and an arc reel (acryl) resins (resin), a transparent organic insulating material, one applied to, or silicon nitride (SiNx) and silicon oxide (SiO ₂₎ a selected one, such as the A protective layer 65 is formed by depositing a selected one of the inorganic insulating materials, and a third mask process is performed to pattern the same to form a drain contact hole 67 exposing a part of the drain electrode 59.

Next, a transparent conductive metal material including indium-tin-oxide (ITO) is deposited on the protective layer 65, and the drain electrode 59b is formed through the drain contact hole 67 by a fourth mask process. Thereby forming the pixel electrode 70 to be in contact.

In this case, the fourth mask process includes a wet etching process in a similar manner to the first and second mask processes, and an etchant for forming the pixel electrode 70 made of indium-tin-oxide (ITO) Use an oxalic acid etchant or an oxalic acid etchant.

In the above-described array substrate of the liquid crystal display device, since different etchants are used for etching the respective metal layers in each mask process, the etchant is managed twice and the equipment configurations are made independent of each other, There is a problem in that the burden on the user is increased.

The present invention is a method for patterning a wiring or an electrode made of aluminum (Al), molybdenum (Mo), indium-tin-oxide (ITO) or the like by making the etchant for etching each of the above- The goal is to unify the management of the etchant by making it possible to etch all the etchants, and to reduce the initial investment cost.

In order to achieve the above object, an etchant according to an embodiment of the present invention comprises 50 to 75 wt% phosphoric acid; 3 to 10 wt% nitric acid; 4 to 22 wt% of acetic acid; 0.05 to 3 wt% of a chlorine-based compound; 0.05 to 3 wt% of a chlorine stabilizer; 0.1 to 5 wt% of a phosphate compound; 0.05 to 5 wt% of a lithium-based compound; 0.05 to 5 wt% nitrate based compound; And the sum of the weight% (wt%) of each material including the remaining water including the residual water is 100 wt%.

The chlorine-based compound is preferably a compound capable of dissociating into Cl- ¹ , and is preferably KCl or HCl. The chlorine stabilizer may be a Zn-based compound, a Cd-based compound, a Pb-based compound, a Ba- Zn (NO ₃ ) ₂ or Zn (CH ₃ COO) ₂ , and the phosphate compound is preferably (NH ₄ ) ₂ HPO ₄ or KH ₂ PO ₄ as a compound which can be dissociated into PO ₄ ^3- , and the lithium- LiNO ₃ or CH ₃ COOLi, and the nitrate compound is preferably KNO ₃ or LiNO ₃ .

Further, it is preferable that the water is pure water filtered through an ion exchange resin and is ultrapure water having a resistivity of 18 M? Or more.

A method of manufacturing an array substrate for a liquid crystal display using an etchant according to the present invention includes the steps of: forming a gate wiring and a gate electrode by etching a first metal layer on a substrate using an etching composition; Forming an insulating film over the gate wiring and the gate electrode; Forming a semiconductor layer on the insulating layer; Etching the second metal layer over the semiconductor layer using the etching composition to form data lines crossing the gate lines and source and drain electrodes spaced apart from each other above the gate electrodes; Forming a protective layer over the data line and the source and drain electrodes; Etching the third metal layer over the passivation layer using the etching composition to form a pixel electrode contacting the drain electrode through the drain contact hole, wherein the composition for etching comprises 50 to 75 wt % Of phosphoric acid, 3 to 10 wt% of nitric acid, 4 to 22 wt% of acetic acid, 0.05 to 3 wt% of chlorine compound, 0.05 to 3 wt% of chlorine stabilizer, 0.1 to 5 wt% of phosphate Based compound, 0.05 to 5 wt% of a lithium-based compound, 0.05 to 5 wt% of a nitrate-based compound, and a remaining amount of water.

At this time, the first metal layer is made of a double layer of an aluminum alloy (AlNd) and molybdenum (Mo), the second metal layer is made of molybdenum (Mo), and the third metal layer is made of indium-tin- .

The chlorine-based compound is composed of a compound that can dissociate into Cl- ¹ , and the chlorine stabilizer is composed of a Zn-based compound, a Cd-based compound, a Pb-based compound, a Ba-based compound and oleic acid, compound is made of a compound that can be dissociated as PO ₄ ^3-, wherein the water is characterized by more than the specific resistance is 18MΩ as pure filtered through an ion exchange resin.

The gate wiring, the gate electrode, the data wiring, the source and drain electrodes, and the pixel electrode, which are etched by the etching composition, have a tapered cross-sectional structure, and an angle formed by the bottom surface and the side surface of each of the wirings and the electrode That is, the inclination angle of the side surface with respect to the bottom surface is formed to be 30 to 70 degrees.

Hereinafter, an etchant composition according to an embodiment of the present invention and a method of manufacturing an array substrate for a liquid crystal display using the same will be described with reference to the accompanying drawings.

<Examples>

A liquid crystal display device formed by etching using an etchant according to the present invention includes a lower layer made of an aluminum alloy (AlNd) and a gate wiring and a gate electrode formed of a double layer of an upper layer made of molybdenum (Mo) And a pixel electrode formed of source and drain electrodes and indium-tin-oxide (ITO).

The etchant according to the present invention is a single etchant for etching the aluminum (AlNd), molybdenum (Mo) and indium-tin-oxide (ITO), 50 to 75 wt%, preferably 62 to 72 wt% By weight, preferably 0.05 to 3% by weight, more preferably 0.07 to 2% by weight, based on 4 to 8% by weight of nitric acid and 4 to 22% by weight and preferably 6 to 20% 0.05 to 3 wt.%, Preferably 0.07 to 2 wt.% Of a chlorine stabilizer, 0.1 to 5 wt.%, Preferably 0.5 to 3 wt.% Of a phosphate compound, 0.05 to 5 wt. Of the lithium-based compound, 0.05 to 5 wt%, preferably 0.1 to 3 wt% of the nitrate-based compound, and the remaining amount of water.

The role and type of the constituents of the etchant according to the present invention will be described in more detail.

The aluminum nitrate reacts with aluminum to form aluminum oxide (Al ₂ O ₃ ). When the content of nitric acid is within the above range (3 to 10 wt%), the selection ratio between molybdenum (Mo) .

However, when the amount of nitric acid is less than 3 wt%, an undercut phenomenon occurs in which the lower layer of the aluminum alloy (AlNd) is excessively etched in the bilayer structure of molybdenum (Mo) and aluminum alloy (AlNd).

The undercut phenomenon occurs when two metals are in contact with each other in an aqueous solution, and Al (E = -1.66 V), which is a metal having a potential of Electrode Potential, (Local cell or galvanic cell) in which dissolution is accelerated and Mo (E = -0.20 V), which is a noble metal, is protected as a negative electrode and is delayed in relative dissolution (electrochemical etching) It is interpreted to be due to local erosion (Galvanic Corrosion).

If the pattern of the gate electrode is not formed uniformly due to the local erosion phenomenon, there arises a problem that it is difficult to realize high resolution and high definition color of the image of the liquid crystal display device.

On the other hand, phosphoric acid serves to decompose aluminum oxide (Al ₂ O ₃ ). When phosphoric acid content is within the above range (50 to 75 wt%), aluminum oxide (Al ₂ O ₃ ) is appropriately decomposed to rapidly etch an aluminum alloy (AlNd) layer which is a lower layer of the gate electrode, thereby improving the productivity.

Acetic acid is a buffer for controlling the reaction rate. When the content of acetic acid is within the above range (4 to 22 wt%), the reaction rate is appropriately controlled to improve the etching rate, thereby improving the productivity.

However, when the content of acetic acid is less than 4 wt%, an undercut of the lower layer which is an aluminum alloy occurs in the double layer structure of molybdenum (Mo) / aluminum alloy (AlNd) constituting the gate wiring and the gate electrode.

Chlorine-based compound is a compound which can be dissociated into ^{Cl -1, KCl, HCl, LiCl} , NH 4 Cl, NaCl, CuCl 2, FeCl 3, FeCl 2, CaCl 2, CoCl 2, NiCl 2, ZnCl 2, AlCl 3, BaCl ₂ , BeCl ₂ , BiCl ₃ , CdCl ₂ , CeCl ₂ , CsCl ₂ , H ₂ PtCl ₆ , and CrCl _3. Any of them may be used as a constituent material of the etching solution according to the present invention, It is most preferable to use KCl or HCl.

(ITO), molybdenum (Mo) and molybdenum (Mo) / aluminum alloy (AlNd) bilayer when the content of the chlorine compound is within the above range (0.05 to 3 wt% (AlNd) in the double layer structure of Al / Mo / aluminum alloy (AlNd) as well as in the indium-tin-oxide (ITO) and molybdenum (Mo) ) And to control the etching rate.

However, when the content of the chlorine compound is less than 0.05 wt%, productivity is lowered by lowering the etching rate of the indium-tin-oxide (ITO) layer constituting the pixel electrode. On the other hand, And an undercut of a lower layer of an aluminum alloy (AlNd) in a bilayer structure of molybdenum (Mo) / aluminum alloy (AlNd) constituting the gate electrode.

A chlorine stabilizing agent is Zn-based compound, a Cd-based compound, a Pb-based compound, made of a Ba-based compound and oleic acid, specifically, _{ZnCl 2, Zn (NO 3)} 2, Zn (CH 3 COO) 2, Zn (C 17 H _{35 COO) 2, C 2 H} 2 O 4 Zn, Zn 3 (PO 4) 2, ZnCO 3, Cd (CH 3 COO) 2, CdCl 2, CdI 2, Cd (NO 3) 2, CdCO 3, Pb ( _{CH 3 COO) 2, C 12} H 10 O 14 Pb 3, PbI 4, Pb (NO 3) 2, Pb (C 17 H 35 COO) 2, Ba (CH 3 COO) 2, BaCO 3, BaCl 2, BaI _{2, Ba (NO 3) 2} , Ba (H 2 PO 4) , and the _second, etc. any of these, but can be used as composition material of the etching solution according to the invention, in particular _{Zn (NO 3) 2, Zn} (CH ₃ COO) ₂ is most preferably used.

When the content of the chlorine stabilizer is within the above range (0.01 to 5 wt%), the etch rate of the indium-tin-oxide (ITO) constituting the pixel electrode is controlled to exhibit a good profile with an inclination angle of 60 ㅀ or less, So as to increase the process margin.

Phosphate-based compound is a compound which can be dissociated into NaH ^{_{PO 4 3- 2 PO 4, Na}} 2 HPO 4, NA 3 PO 4, NH 4 H 2 PO 4, (NH 4) 2 HPO 4, (NH 4) 3 PO ₄ , KH ₂ PO ₄ , K ₂ HPO ₄ , K ₃ PO ₄ , Ca (H ₂ PO ₄ ) ₂ , Ca ₂ HPO ₄ and Ca ₃ PO ₄ . It is most preferable to use (NH ₄ ) ₂ HPO ₄ or KH ₂ PO ₄ .

The phosphate compound controls the etching rate of the double layer of molybdenum (Mo) / aluminum alloy (AlNd) constituting the gate wiring and the gate electrode. In the double layer of the molybdenum (Mo) / aluminum alloy (AlNd) The undercut phenomenon of AlNd does not occur and an excellent profile is formed even in a single layer of molybdenum (Mo).

The lithium-based compound is preferably selected from the group consisting of LiNO ₃ , CH ₃ COOLi, C ₄ H ₅ O ₃ Li, LiF, LiI, C ₂ HLiO ₄ , LiClO ₄ , Li ₂ O ₂ , Li ₂ SO ₄ , LiH ₂ PO ₄ , Li ₃ PO ₄ And the like. Any of them may be used as a material for forming the etching solution according to the present invention, but it is most preferable to use LiNO ₃ or CH ₃ COOLi.

 The lithium-based compound improves the profile of the molybdenum (Mo) / aluminum alloy (AlNd) double layer constituting the gate wiring and the gate electrode.

At this time, when the lithium compound is less than 0.05 wt%, reverse taper or shoulder phenomenon occurs in the single layer of molybdenum (Mo) forming the data line and the source and drain electrodes, and molybdenum Mo) / aluminum alloy (AlNd) In the double layer, an undercut of the aluminum alloy (AlNd) as the lower layer occurs.

If the amount of the lithium-based compound exceeds 5 wt%, the etching rate of the molybdenum (Mo) single layer constituting the data line and the source and drain electrodes is lowered, and molybdenum (Mo) / aluminum alloy (AlNd) bilayer, a stepped profile rather than a tapered structure with a desirable gentle slope is formed.

Be a flame-based compound is _{NH 4 NO 3, KNO 3,} LiNO 3, Ca (NO 3) 2, NaNO 3, Zn (NO 3) 2, Co (NO 3) 2, Ni (NO 3) 2, Fe (NO _{3) 3, Cu (NO 3} ) 2, Ba (NO 3) 2 and the like, any of these, but can be used as composition material of the etching solution according to the invention, in particular, it is most preferable to use a KNO _3, LiNO ₃ Do.

The nitrided compound improves the etch rate of the molybdenum (Mo) monolayer forming the data line and the source and drain electrodes, and at the same time improves the profile that has a smooth taper.

At this time, when the nitrate compound is less than 0.05 wt%, reverse taper and shoulder phenomenon occurs in the monolayer of molybdenum (Mo), and when it is 5 wt% or more, molybdenum (Mo ) Lowering the etch rate of the single layer.

The remaining water serves to decompose the aluminum oxide (Al ₂ O ₃ ) produced by the reaction of nitric acid and aluminum and to dilute the etching composition.

At this time, it is preferable to use pure water filtered through the ion-exchange resin and water of the remaining amount, and ultrapure water having a resistivity of 18 M OMEGA. Or more is preferably used.

And the etching solution containing the weight percentage of the appropriate range of each composition described above is used to etch the array substrate for each step of manufacturing the array substrate for a liquid crystal display device, An embodiment of the present invention will be described. In this case, the etchant according to an embodiment of the present invention includes 65 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% of chlorine compound, 0.1 wt% of chlorine stabilizer, 1.5 wt% of phosphate compound, 1.0 wt.%, nitrate compound 1.5 wt.%, and water (ultrapure water) 12.8 wt.%.

FIGS. 3A, 3B and 3C illustrate a dual layer of a molybdenum (Mo) / aluminum alloy (AlNd) composed of a material for forming a gate electrode and a gate wiring after a wet etching process according to an embodiment of the present invention, A molybdenum (Mo) layer made of a material for forming a drain electrode, and an indium-tin-oxide (ITO) layer made of a material for forming a pixel electrode are observed by a scanning electron microscope. At this time, since the photoresist pattern PR by the ashing process is not removed after the etching, the photoresist pattern PR still remains above each material layer.

First, referring to FIG. 3A, which shows a cross section after molybdenum (Mo) and an aluminum alloy (AlNd) are sequentially stacked to form a gate wiring and a gate electrode and etched using the etching solution according to the present invention, Similarly, it can be seen that the double layer of molybdenum (Mo) / aluminum alloy (AlNd) under the photoresist pattern (PR) is formed with excellent profile characteristics without undercut phenomenon.

Referring to FIG. 3B, which is a cross-sectional view of the photoresist pattern PR after depositing molybdenum to form data lines, source and drain electrodes, and etching using the etchant according to the present invention, It can be seen that the molybdenum (Mo) layer is formed with excellent profile characteristics having a taper of 45 to 70..

Referring to FIG. 3C, which is a cross-sectional view illustrating the step of depositing indium-tin-oxide (ITO) to form a pixel electrode and etching the substrate using the etchant according to the present invention, It can be seen that indium-tin-oxide (ITO) as the lower part is formed with excellent profile characteristics with a taper of 30 to 60..

Therefore, when etching the gate wirings and the gate electrodes, the drain electrodes, the source and drain electrodes, and the pixel electrodes using the etchant having the composition ratio according to the present invention, Since the insulating film formed on the upper and lower wirings and the upper portion of the insulating film formed on the upper and lower electrodes has an abrupt tapered structure, it is possible to manufacture the array substrate without any defect such as breakage, .

Since the embodiment of the present invention is only an example of the range of the etchant composition according to the embodiment of the present invention, it can be understood that the same effect is obtained within the range of the etchant composition according to the embodiment of the present invention.

Hereinafter, a method for manufacturing an array substrate for a liquid crystal display device using the etchant according to the embodiment of the present invention will be briefly described with reference to the drawings.

FIG. 4 is a cross-sectional view of an array substrate for a liquid crystal display device, which is patterned by using an etching solution according to the present invention, and will be described in accordance with a four mask process sequence.

As shown in the figure, an aluminum alloy (AlNd) and molybdenum (Mo) are sequentially deposited on a transparent insulating substrate 100 to form a first metal layer having a bilayer structure.

Thereafter, a photoresist is coated on the first metal layer to form a photoresist layer, exposure is performed through the transmissive region and the first mask region, and a developing process is performed to form a photoresist pattern.

Next, the first metal layer exposed to the outside of the photoresist pattern was etched with an etching solution according to the above-described embodiment of the present invention, namely, 65 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% Wet etching is performed using an etchant consisting of 0.1 wt% of a stabilizer, 1.5 wt% of a phosphate compound, 1.0 wt% of a lithium compound, 1.5 wt% of a nitride compound, and 12.8 wt% of water (ultrapure water) (Not shown) and a gate electrode 104 having a suitable taper angle without forming a gate electrode (not shown).

Thereafter, the photoresist pattern remaining on the gate wiring (not shown) and the gate electrode 104 is removed by an ashing process or a strip process.

Next, silicon oxide (SiO ₂ ) or silicon nitride (SiNx), which is an inorganic insulating material, is deposited on the substrate 100 on which the gate wiring (not shown) and the gate electrode 104 are formed to form a gate insulating film 107 on the entire surface do.

Next, pure amorphous silicon, impurity amorphous and molybdenum are sequentially deposited on the gate insulating layer 107 to form a pure amorphous silicon layer, an impurity amorphous silicon layer, and a second metal layer. Then, the active layer 112a, the ohmic contact layer 112b, the data line 115, and the source and drain electrodes 117 and 119 are formed by patterning by the second mask process.

In the second mask process, a second photoresist layer is formed on the second metal layer, a second mask having a transmissive region, a reflective region and a transflective region is positioned, diffraction exposure or halftone exposure is performed And then developing the exposed second photoresist layer to form a photoresist pattern having a first and a second thickness, respectively, and exposing the second metal layer to the outside of the photoresist pattern having the first and second thickness, Wet etching and removing the pure amorphous silicon layer and the impurity amorphous silicon layer under the etching by wet etching with the etching solution according to the embodiment of the present invention. In addition, ashing is performed in addition to the above-described process to remove the thin second photoresist pattern, and the exposed second metal layer and the underlying impurity amorphous silicon layer are dry etched by removing the photoresist pattern of the second thin thickness. The source and drain electrodes 117 and 119 spaced apart from each other and the ohmic contact layer 112b of impurity amorphous silicon separated from each other below the source and drain electrodes 117 and 119 are formed and the remaining photoresist pattern of the first thickness is ashed or striped Further comprising the steps of:

Next, a selected one of transparent organic insulating materials such as benzocyclobutene (BCB) and acryl resin is coated on the data line 115 and the source and drain electrodes 117 and 119, An inorganic insulating material such as silicon nitride (SiNx) and silicon oxide (SiO2) is deposited to form a protective layer 125 and the protective layer 125 is patterned successively through a third mask process, Drain contact hole 127 exposing a part of the drain contact hole 119 is formed.

Next, indium-tin-oxide (ITO) is deposited on the passivation layer 125 having the drain contact hole 127 to form an indium-tin-oxide (ITO) A masking process is performed and patterned to form a transparent pixel electrode 130 that contacts the drain electrode 119 through the drain contact hole 127.

In this case, the fourth mask process is performed in a similar manner to the first mask process and a photoresist layer is formed on the indium-tin-oxide (ITO) layer, exposed through a fourth mask, Thereby forming a photoresist pattern, and wet etching the indium-tin-oxide (ITO) layer exposed to the outside of the photoresist pattern with the etching solution according to an embodiment of the present invention.

After the pixel electrode 130 is formed through the fourth mask process, the photoresist pattern remaining on the pixel electrode 130 is removed by ashing or stripping, An array substrate for a liquid crystal display device using an etching liquid can be completed.

In this manner, in the manufacture of the array substrate for a liquid crystal display device, the etchant used in each mask process is treated with a single solution according to the present invention, thereby facilitating the management of the etchant. In addition, By constructing the equipment, it is possible to reduce the initial investment cost and improve the productivity by reducing defects by forming gates and data lines, gates and source and drain electrodes having a gentle taper angle.

Meanwhile, the method of manufacturing an array substrate for a liquid crystal display using the etching solution according to the present invention is shown as an example in which a 4-mask process that is generally applied to the present production is used. However, the 4-mask process is an example But the mask process may be any.

In order to further support the embodiments of the present invention, an etchant composition that is out of the range of the etchant composition according to an embodiment of the present invention will be described as a comparative example with reference to the accompanying drawings. The composition ratios of the etchants used in Examples of the present invention and Comparative Examples (Comparative Examples 1 to 8) are summarized in Table 1 below.

<Table 1>

division Example Comparative Example One 2 3 4 5 6 7 8 Phosphoric acid 65 45 65 65 65 65 65 63 63 nitric acid 5 5 2 5 5 5 5 5 5 Acetic acid 13 13 13 3 13 13 13 13 13 Chlorine system
compound 0.1 0.1 0.1 0.1 3.5 0.1 0.1 0.1 0.1 Goat
stabilizator 0.1 0.1 0.1 0.1 0.1 3.5 0.1 0.1 0.1 Phosphate system
compound 1.5 1.5 1.5 1.5 1.5 1.5 0.05 1.5 1.5 Lithium series
compound 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.03 1.0 Nitrate-based
compound 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 0.03 water
(Ultrapure water) 12.8 32.8 15.8 22.8 9.4 9.4 14.25 15.77 16.27

                                                              Unit wt%

&Lt; Comparative Example 1 >

The etchant according to the first comparative example of the present invention comprises 45 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% of chlorine compound, 0.1 wt% of chlorine stabilizer, 1.5 wt% of phosphate compound, 1.0 wt %, A nitrate compound of 1.5 wt% and water (ultrapure water) of 32.8 wt%. That is, the range of the etching solution composition according to the embodiment of the present invention is different from that of the etching solution composition according to the embodiment of the present invention.

5A and 5B are graphs showing the relationship between the gate electrode (including the gate wiring) and the molybdenum (Mo) / the source and drain electrodes (including the data lines) after the wet etching process according to the first comparative example of the present invention, 2 shows a photograph of a cross section of a double layer of an aluminum alloy (AlNd) and a single layer of a molybdenum (Mo) with a scanning electron microscope.

Referring to FIG. 5A, as shown in FIG. 5A, an undercut occurs due to excessive etching of an aluminum alloy (AlNd) layer as a lower layer of a molybdenum (Mo) / aluminum alloy (AlNd) double layer.

Referring to FIG. 5B, as shown in FIG. 5B, a single layer of molybdenum (Mo) has a steep profile having a taper of 40 to 70 않고 and an angle of more than 70 을. And a shoulder having a shape protruding from the side surface is formed at the top of the shoulder.

If the source and drain electrodes having such a shape are formed and then a protective layer is deposited on the protective layer, it may not be uniformly deposited and may be broken.

This shows that the result is obtained when the content of phosphoric acid is 45 wt%, but it is the same as the effect when the content of phosphoric acid is out of the range of the etching solution composition according to the embodiment of the present invention, that is, the content of phosphoric acid is less than 50 wt% .

&Lt; Comparative Example 2 >

The etchant according to the second comparative example of the present invention is composed of 65 wt% of phosphoric acid, 2 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% of chlorine compound, 0.1 wt% of chlorine stabilizer, 1.5 wt% of phosphate compound, 1.0 wt %, Nitrate-based compound 1.5 wt% and water (ultrapure water) 15.8 wt%. That is, the range of nitric acid in the range of the etching solution composition according to the embodiment of the present invention is different from that of the etching solution composition according to the embodiment of the present invention.

6A and 6B are graphs showing the relationship between the gate electrode (including the gate wiring) and the molybdenum (Mo) / the source and drain electrodes (including the data lines) after the wet etching process according to the second comparative example of the present invention, 2 shows a photograph of a cross section of a double layer of an aluminum alloy (AlNd) and a single layer of a molybdenum (Mo) with a scanning electron microscope.

Referring to FIG. 6A, an undercut of the aluminum alloy (AlNd) layer occurs in a double layer of molybdenum (Mo) / aluminum alloy (AlNd) as shown in FIG. 6A. Further, .

Referring to FIG. 6B, it can be seen that a single layer of molybdenum (Mo) forms a poor profile in a steep profile and a shoulder has occurred, as shown.

 This is understood to be the same effect as when the content of nitric acid is 2 wt%, but is out of the range of the etching solution composition according to the embodiment of the present invention, i.e., when the content of nitric acid is less than 3 wt% .

&Lt; Third Comparative Example &

The etchant according to the third comparative example of the present invention is composed of 65 wt% of phosphoric acid, 2 wt% of nitric acid, 3 wt% of acetic acid, 0.1 wt% of chloric compound, 0.1 wt% of chlorine stabilizer, 1.5 wt% of phosphate compound, 1.0 wt %, A nitrate compound of 1.5 wt% and water (ultrapure water) of 22.8 wt%. That is, the range of the acetic acid in the range of the etching solution composition according to the embodiment of the present invention is different from that of the etching solution composition according to the embodiment of the present invention.

7A and 7B are graphs showing the relationship between the gate electrode (including the gate wiring) and the molybdenum (Mo) / the source and drain electrodes (including the data lines) after the wet etching process according to the third comparative example of the present invention, 2 shows a photograph of a cross section of a double layer of an aluminum alloy (AlNd) and a single layer of a molybdenum (Mo) with a scanning electron microscope.

Referring to FIG. 7A, as shown in FIG. 7A, an undercut is formed in the molybdenum (Mo) / aluminum alloy (AlNd) double layer in which the aluminum alloy (AlNd) layer as the lower layer is excessively etched.

Referring to FIG. 7B, as shown in FIG. 7B, the molybdenum (Mo) single layer has a critical dimension loss due to the etching of the side portions of the photoresist pattern at a high speed, . If the CD loss is increased, the width of the wiring is narrower than the width of the desired wiring, the data wiring is formed, and signal delay occurs. Therefore, the design margin is required to be increased, which makes it difficult to implement a high-resolution product.

The third comparative example shows the result when the content of acetic acid is 4 wt%, but the same effect as that obtained when the content of acetic acid is out of the range of the etching solution composition according to the embodiment of the present invention, i.e., the content of acetic acid is less than 4 wt% &Lt; / RTI &gt;

&Lt; Comparative Example 4 >

The etchant according to the fourth comparative example of the present invention contains 65 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 3.5 wt% of chlorine compound, 0.1 wt% of chlorine stabilizer, 1.5 wt% of phosphate compound, 1.0 wt %, A nitrate compound of 1.5 wt% and water (ultrapure water) of 9.4 wt%. That is, the range of the chlorine-based compound in the range of the etchant composition according to the embodiment of the present invention is different from that of the etchant composition according to the embodiment of the present invention.

8 is a cross-sectional view of a double layer of molybdenum (Mo) / aluminum alloy (AlNd), which is a material layer forming a gate wiring and a gate electrode, after a wet etching process using an etchant according to a fourth comparative example of the present invention was observed with a scanning electron microscope Picture.

As shown, it can be seen that an undercut occurred in the double layer of molybdenum (Mo) / aluminum alloy (AlNd).

This shows that the content of the chlorine compound is 3.5 wt%. However, when the content of the chlorine compound exceeds 3 wt%, that is, when the chlorine compound exceeds the range of the etchant composition according to the embodiment of the present invention, It can be understood that the effect is the same.

&Lt; Comparative Example 5 &

The etchant according to the fifth comparative example of the present invention is prepared by mixing 65 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% of chlorine compound, 3.5 wt% of chlorine stabilizer, 1.5 wt% of phosphate compound, 1.0 wt %, A nitrate compound of 1.5 wt% and water (ultrapure water) of 9.4 wt%. That is, the scope of the etchant composition according to the embodiment of the present invention is different from that of the etchant composition according to the embodiment of the present invention.

FIG. 9 is a photograph of a cross section of an indium-tin-oxide (ITO) layer, which is a material layer of a pixel electrode after a wet etching process using an etchant according to a fifth comparative example of the present invention, by scanning electron microscopy.

As shown in the figure, the etching rate of the indium-tin-oxide (ITO) layer is reduced, and furthermore, indium-tin-oxide (ITO) remnants remain on the substrate after the etching, more precisely, on the protective layer. . The indium-tin-oxide which is not completely removed as described above adversely affects the display quality and adversely affects the formation of an alignment layer or the like formed on the upper portion of the indium-tin-oxide, which is reflected in the degradation of the display quality. The third comparative example shows the result when the content of the chlorine stabilizer is 3.5 wt%. However, when the content of the chlorine stabilizer exceeds the range of the etchant composition according to the embodiment of the present invention, that is, the chlorine stabilizer content exceeds 3 wt% In other words, it can be understood as the same effect as when it is used excessively.

&Lt; Comparative example 6 &

The etchant according to the sixth comparative example of the present invention comprises 65 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% of chlorine compound, 0.1 wt% of chlorine stabilizer, 0.05 wt% of phosphate compound, 1.0 wt %, A nitrate compound of 1.5 wt% and water (ultrapure water) of 14.25 wt%. That is, the range of the phosphate compound in the range of the etching solution composition according to the embodiment of the present invention is different from that of the etching solution composition according to the embodiment of the present invention.

10 shows a cross section of a molybdenum (Mo) / aluminum alloy (AlNd) double layer, which is a material layer forming a gate wiring and a gate electrode after a wet etching process using an etchant according to a sixth comparative example of the present invention, by scanning electron microscopy Picture.

As shown, it can be seen that an undercut occurred in the molybdenum (Mo) / aluminum alloy (AlNd) bilayer.

This indicates that the content of the phosphate compound is 0.05 wt%. However, when the content of the phosphate compound is less than 0.1 wt%, that is, when the amount of the phosphate compound is less than the range of the etchant composition according to the embodiment of the present invention, It can be understood that the effect is the same as when it appears.

&Lt; Comparative Example 7 &

The etchant according to the seventh comparative example of the present invention comprises 63 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% of chlorine compound, 0.1 wt% of chlorine stabilizer, 1.5 wt% of phosphate compound, 0.03 wt %, A nitrate compound of 1.5 wt% and water (ultrapure water) of 15.77 wt%. That is, the range of the lithium compound in the range of the etching solution composition according to the embodiment of the present invention is different, and the range of the etching solution composition according to the embodiment of the present invention is out of the scope.

11 is a cross-sectional view of a double layer of a molybdenum (Mo) / aluminum alloy (AlNd), which is a material layer forming a gate wiring and a gate electrode after a wet etching process using an etchant according to a seventh comparative example of the present invention, Picture.

As shown, it can be seen that an undercut occurred in the molybdenum (Mo) / aluminum alloy (AlNd) bilayer.

However, when the content of the lithium-based compound is less than 0.05 wt%, that is, when the amount of the lithium-based compound is less than 0.05 wt% It can be understood that the effect is the same as when it appears.

&Lt; Comparative Example 8 &

The etchant according to the eighth comparative example of the present invention comprises 63 wt% of phosphoric acid, 5 wt% of nitric acid, 13 wt% of acetic acid, 0.1 wt% of a chlorine compound, 0.1 wt% of a chlorine stabilizer, 1.5 wt% of a phosphate compound, 1.0 wt , 0.03 wt% nitrate-based compound and 16.27 wt% water (ultrapure water). That is, the scope of the etchant composition according to the embodiment of the present invention is different from that of the etchant composition according to the embodiment of the present invention.

12 is a photograph of a cross section of a data wiring and a molybdenum (Mo) layer as a material layer constituting a source and a drain electrode after a wet etching process according to an eighth comparative example of the present invention is observed with a scanning electron microscope.

As shown in the figure, it can be seen that the molybdenum (Mo) single layer has a reverse tapered structure, and furthermore, a side portion of the uppermost layer and a protruding shoulder are generated.

The comparison example 8 shows the result when the content of the nitrate compound is 0.03 wt%. However, when the content of the nitrate compound is out of the range of the etching solution composition according to the embodiment of the present invention, , That is, the effect which appears when a small amount is used.

By using the etchant of a single solution, which is capable of etching both aluminum alloy, molybdenum and indium-tin-oxide according to a preferred embodiment of the present invention, It is possible to reduce the manufacturing cost by reducing the initial facility investment since it is unnecessary to construct an etching apparatus provided with different etching liquids.

In addition, there is an effect that management is simplified by unifying the etchant.

Claims (17)

50 to 75 wt% phosphoric acid; 3 to 10 wt% nitric acid; 4 to 22 wt% of acetic acid; 0.05 to 3 wt% of a chlorine-based compound; 0.05 to 3 wt% of a chlorine stabilizer; 0.1 to 5 wt% of a phosphate compound; 0.05 to 5 wt% of a lithium-based compound; 0.05 to 5 wt% nitrate based compound; Residual water And the sum of the weight% (wt%) of each material including the remaining amount of water is 100 wt%, and the first metal layer made of an aluminum alloy, the second metal layer made of molybdenum and the second metal layer made of indium-tin- 3 metal layer can be visualized. The method according to claim 1, The chlorine-based compounds etching liquid made of a compound which can be dissociated into Cl ^-1. The method according to claim 1, Wherein the chlorine compound is KCl or HCl. The method according to claim 1, The chlorine stabilizer comprises an Zn-based compound, a Cd-based compound, a Pb-based compound, a Ba-based compound, and an oleic acid. 5. The method of claim 4, The chlorine stabilizer may be Zn (NO ₃ ) ₂ or Zn (CH ₃ COO) ₂ in Etchant. The method according to claim 1, Wherein the phosphate compound is a compound capable of dissociating into PO ₄ ^3- . The method according to claim 6, Wherein the phosphate compound is (NH ₄ ) ₂ HPO ₄ or KH ₂ PO ₄ . The method according to claim 1, Wherein the lithium-based compound is LiNO ₃ or CH ₃ COOLi. The method according to claim 1, The flame quality based compound is KNO _3, or LiNO ₃ in the etching liquid. The method according to claim 1, The water is pure water filtered through an ion exchange resin. 11. The method of claim 10, The pure water is ultrapure water having a specific resistance of 18 M? Etching the first metal layer on the substrate using an etching composition to form a gate wiring and a gate electrode; Forming an insulating film over the gate wiring and the gate electrode; Forming a semiconductor layer on the insulating layer; Etching the second metal layer over the semiconductor layer using the etching composition to form data lines crossing the gate lines and source and drain electrodes spaced apart from each other above the gate electrodes; Forming a protective layer over the data line and the source and drain electrodes; Etching the third metal layer on the protective layer using the etching composition to form a pixel electrode that contacts the drain electrode through the drain contact hole, The etching composition comprises 50 to 75 wt% phosphoric acid, 3 to 10 wt% of nitric acid, 4 to 22 wt% of nitric acid, 0.05 to 3 wt% of chlorine compound, 0.05 to 3 wt% of chlorine A stabilizer, 0.1 to 5 wt% of a phosphate compound, 0.05 to 5 wt% of a lithium compound, 0.05 to 5 wt% of a nitrate compound, and a balance of water, Wherein the first metal layer includes a lower layer made of an aluminum alloy and an upper layer made of molybdenum, the second metal layer is made of molybdenum, and the third metal layer is made of indium-tin-oxide / RTI &gt; delete delete delete 13. The method of claim 12, The chlorine-based compound is composed of a compound that can dissociate into Cl &lt; RTI ID = 0.0 &gt; ¹ , The chlorine stabilizer is composed of a Zn-based compound, a Cd-based compound, a Pb-based compound, a Ba-based compound, and an oleic acid, The phosphate compound is composed of a compound that can dissociate into PO ₄ ^3- , Wherein the water is pure water filtered through an ion exchange resin and has a specific resistance of 18 M? Or more. 13. The method of claim 12, The gate wiring, the gate electrode, the data wiring, the source and drain electrodes, and the pixel electrode, which are etched by the etching composition, And the inclined angle of the side surface with respect to the bottom surface is 30 to 70 degrees.

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