KR20070114471A - Etch solution for etching aluminum, molybdenum and indium tin oxide - Google Patents

Abstract

The present invention relates to an etching solution for etching molybdenum (Mo), aluminum (Al) and indium tin oxide (ITO), 50 to 75 wt% phosphoric acid, 3 to 10 wt% nitric acid, 4 to 22 wt 0.05-3 wt% chlorine compound, 0.05-3 wt% chlorine stabilizer, 0.1-5 wt% phosphate compound, 0.05-5 wt% lithium compound, 0.05-5 wt% It is characterized by consisting of a% nitride compound and the remaining amount of water.

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

Description

Etching liquid for etching aluminum, molybdenum and indium tin oxide {Etchant for etching Al, Mo and ITO}

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

2 is a cross-sectional view of an array substrate for a general liquid crystal display device.

3A and 3C illustrate a double layer of molybdenum (Mo) / aluminum alloy (AlNd) made of a material forming a gate electrode and a gate wiring after a wet etching process using an etchant according to an embodiment of the present invention, and data and source and drain electrodes A photograph of the molybdenum (Mo) layer made of a material forming a film and an indium-tin-oxide (ITO) layer made of a material forming a pixel electrode after etching with a scanning electron microscope.

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

5A and 5B illustrate molybdenum (Mo) /, which is a material layer forming a gate electrode (including gate wiring) and a source and drain electrode (including data wiring) after a wet etching process using an etchant according to a first comparative example of the present invention. A photograph of a double layer of aluminum alloy (AlNd) and a single layer of molybdenum (Mo) observed with a scanning electron microscope.

6A and 6B illustrate molybdenum (Mo) /, which is a material layer forming a gate electrode (including gate wiring) and a source and drain electrode (including data wiring) after a wet etching process using an etchant according to a second comparative example of the present invention. A photograph of a double layer of aluminum alloy (AlNd) and a single layer of molybdenum (Mo) observed with a scanning electron microscope.

7A and 7B illustrate molybdenum (Mo) /, which is a material layer forming a gate electrode (including gate wiring) and a source and drain electrode (including data wiring) after a wet etching process using an etchant according to a third comparative example of the present invention. A photograph of a double layer of aluminum alloy (AlNd) and a single layer of molybdenum (Mo) observed with a scanning electron microscope.

8 is a cross-sectional view 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 fourth comparative example of the present invention; Picture.

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

FIG. 10 is a cross-sectional view 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; Picture.

FIG. 11 is a cross-sectional view 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 seventh comparative example of the present invention; Picture.

FIG. 12 is a photograph illustrating a cross section of a molybdenum (Mo) layer, which is a material layer constituting a data line and a source and drain electrode, after a wet etching process using an etchant according to an eighth comparative example of the present invention. FIG.

The present invention relates to an etchant for etching aluminum (Al), molybdenum (Mo), indium tin oxide (ITO), in particular aluminum (Al), molybdenum (Mo), indium tin oxide (ITO) It is for etching with an etching solution consisting of a single solution.

Recently, liquid crystal displays have been spotlighted as next generation advanced display devices having low power consumption, good portability, high technology value, and high added value.

Among the liquid crystal display devices, an active matrix liquid crystal display device having a thin film transistor, which is a switching element that can control voltage on and off for each pixel, has the best resolution and video performance. I am getting it.

In general, a liquid crystal display device forms an array substrate and a color filter substrate through an array substrate manufacturing process for forming a thin film transistor and a pixel electrode and a color filter substrate manufacturing process for forming a color filter and a common electrode, and between the two substrates. It completes through the liquid crystal cell process through liquid crystal in the process.

1 is an exploded perspective view schematically illustrating 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 faced to each other with the liquid crystal layer 30 interposed therebetween, wherein the lower array substrate 10 crosses each other. A plurality of gate wirings 14 and data wirings 16 are arranged to define a plurality of pixel regions P. Thin film transistors T, which are switching elements, are formed at the intersections of the two wirings 14 and 16. And a one-to-one correspondence with the pixel electrodes 18 provided in the pixel regions P.

In addition, the upper color filter substrate 20 facing the array substrate may cover a non-display area such as the gate line 14, the data line 16, and the thin film transistor T on the rear surface of the transparent substrate 22. Grid-like black matrix 25 is formed so as to border each pixel region P, and the red, green, and blue color filter layers 26 are sequentially arranged to correspond to each pixel region P in the grid. ) Is formed, and a transparent common electrode 28 is provided over the entirety of the black matrix 25 and the red, green, and blue color filter layers 26.

Although not shown in the drawings, these two substrates 10 and 20 are sealed with a sealant or the like along the edges to prevent leakage of the liquid crystal layer 30 interposed therebetween. In the boundary portion of each substrate (10, 20) and the liquid crystal layer 30 is interposed upper and lower alignment layer that provides reliability in the molecular alignment direction of the liquid crystal, and at least one outer surface of each substrate (10, 20) A polarizing plate is provided.

In addition, a back-light is provided on the outer surface of the array substrate to supply light. The on / off signals of the thin film transistor T are sequentially scanned by the gate wiring 14. When the image signal of the data wiring 16 is transmitted to the pixel electrode 18 of the pixel region P applied and selected, the liquid crystal molecules are driven by the vertical electric field therebetween, and thus the light transmittance is changed. Branch images can be displayed.

In manufacturing an array substrate used in such a liquid crystal display device, a specific material layer is patterned and manufactured by performing several mask processes.

FIG. 2 is a cross-sectional view of one pixel area including a thin film transistor which is a switching element of a general liquid crystal display device array substrate, and a method of manufacturing an array substrate for liquid crystal display devices will be described with reference to FIG. 2.

As shown, after forming the first metal layer (not shown) on the transparent insulating substrate 40, the gate wiring (not shown) and the gate wiring (not shown) extending in one direction by performing the first mask process A branched gate electrode 44 is formed. The first metal layer may be a metal such as aluminum (Al), aluminum alloy (AlNd), molybdenum (Mo), tungsten (W), chromium (Cr), in particular, aluminum alloy (AlNd) having a low resistance characteristics In the case of using, a molybdenum (Mo) layer is further provided to constitute a double layer.

Here, the first mask process will be described in more detail.

In the first mask process, a photoresist is first applied onto the first metal layer (not shown) to form a photoresist layer (not shown). In this case, the photoresist layer will be described as an example of a positive type photoresist in which the lighted portion is removed during development.

After placing a mask (not shown) consisting of a transmission region and a blocking region on the photoresist layer, by performing an exposing step of irradiating light from the upper portion of the mask and a developing step of removing the exposed portion A photoresist pattern (not shown) is formed on the first metal layer.

Subsequently, when the first metal layer (not shown) exposed to the outside of the photoresist pattern (not shown) is removed by wet etching, the gate wiring (not shown) and the gate electrode 44 having a double layer structure as shown in FIG. Is formed.

Here, an etchant consisting of phosphoric acid, nitric acid, and acetic acid is used as an etchant used for wet etching to form the gate wiring and the gate electrode 44 having the double layer structure.

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

Next, a gate insulating layer 47 is stacked on the double layer structure gate wiring (not shown) and the substrate 40 on which the gate electrode 44 is formed. The gate insulating layer 47 may be formed of silicon nitride (SiNx) or silicon oxide ( Selected one of inorganic insulating materials such as SiO ₂ ).

Next, a pure amorphous silicon layer, an impurity amorphous silicon layer, and a second metal layer are sequentially formed on the gate insulating layer 47, and the second process includes a series of unit processes such as photoresist coating, exposure and development, etching, and stripping. The semiconductor layer 52 composed of the active layer 52a of pure amorphous silicon and the ohmic contact layer 52b of impurity amorphous silicon and the source and drain spaced apart from each other above the gate insulating film 47 by the mask process. Electrodes 57 and 59 are formed. In this case, a data line 55 connected to the source electrode 57 and crossing the gate line (not shown) to define the pixel area P is also formed.

The second metal layer forming the data line 55 and the source and drain electrodes 57 and 59 mainly uses molybdenum (Mo).

In this case, the second mask process forms a new photoresist layer on the second metal layer, and then forms a second photoresist pattern by placing the second mask to perform an exposing process and a developing process. .

Subsequently, the second metal layer exposed to the outside of the second photoresist pattern is removed by wet etching, and the bottom pure amorphous silicon layer and the impurity amorphous silicon layer are dry etched to dry-etch the active layer 52a of pure amorphous silicon. ) And source and drain electrodes 57 and 59 spaced apart from each other on the ohmic contact layer 52b of impurity amorphous silicon and the ohmic contact layer 52b.

In this case, the etchant for etching the second metal layer made of molybdenum (Mo) may be an etchant consisting of phosphoric acid, nitric acid, acetic acid, or a permeate 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 and the source and drain electrodes are removed. (57, 59) Apply one selected from a transparent organic insulating material such as benzocyclobutene (BCB) and acryl-based resin, or silicon nitride (SiNx) and silicon oxide (SiO ₂ ) The protective layer 65 is formed by depositing a selected one of the inorganic insulating materials, and is patterned by performing a third mask process to form a drain contact hole 67 exposing a portion of the drain electrode 59.

Next, a transparent conductive metal material including indium tin oxide (ITO) is deposited on the passivation layer 65 and the drain electrode 59b and the drain contact hole 67 are formed by a fourth mask process. The pixel electrode 70 in contact is formed.

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 etching solution for forming the pixel electrode 70 made of indium-tin oxide (ITO). As an aqua regia solution or an oxalic acid etchant is used.

As described above, the array substrate of the liquid crystal display device uses different etchant to etch each metal layer in the masking process. As the management of the etchant is dualized, the composition of the equipment is independently achieved, resulting in low productivity and equipment investment cost. There is a problem that the burden of is increased.

According to the present invention, the etching solution for etching each of the above-described metal layers is composed of a single common solution, thereby patterning a wiring or an electrode made of aluminum (Al), molybdenum (Mo), and indium-tin-oxide (ITO). Its purpose is to allow all the etching equipment to be etched to unify the management of the etchant and reduce the initial investment cost.

In order to achieve the above object, the etching solution according to an embodiment of the present invention, 50 to 75 wt% phosphoric acid; 3-10 wt% nitric acid; 4 to 22 wt% acetic acid; 0.05-3 wt% of a chlorine compound; 0.05-3 wt% of a chlorine stabilizer; 0.1-5 wt% of a phosphate compound; 0.05-5 wt% of a lithium compound; 0.05-5 wt% of a nitride salt compound; It is characterized by including the remaining amount of water and the sum of the weight% (wt%) of each material including the remaining amount of water is 100 wt%.

At this time, the chlorine compound is a compound capable of dissociating into Cl ^-1 is preferably KCl or HCl, the chlorine stabilizer is Zn-based compound, Cd-based compound, Pb-based compound, Ba-based compound, oleic acid Consisting of Zn (NO ₃ ) ₂ or Zn (CH ₃ COO) ₂ It is preferable that the phosphate compound is a compound that can be dissociated into PO ₄ ^3- (NH ₄ ) ₂ HPO ₄ or KH ₂ PO ₄ It is preferable that the lithium compound Preferably, it is LiNO ₃ or CH ₃ COOLi, and the nitride compound is preferably KNO ₃ or LiNO ₃ .

In addition, the water is pure water filtered through an ion exchange resin is preferably ultrapure water having a specific resistance of 18 MPa or more.

A method of manufacturing an array substrate for a liquid crystal display device using an etchant according to the present invention may include forming a gate wiring and a gate electrode by etching a first metal layer on an upper surface of the substrate using an etching composition; Forming an insulating film over the gate wiring and the gate electrode; Forming a semiconductor layer over the insulating film; Etching the second metal layer on 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 on the gate electrodes; Forming a protective layer over the data line and the source and drain electrodes; Etching the third metal layer on the passivation layer using the etching composition to form a pixel electrode contacting the drain electrode through the drain contact hole, wherein the etching composition includes: 50 to 75 wt % Phosphoric acid, 3-10 wt% nitric acid, 4-22 wt% acetic acid, 0.05-3 wt% chlorine compound, 0.05-3 wt% chlorine stabilizer, 0.1-5 wt% phosphate It is characterized by consisting of a system compound, a 0.05-5 wt% lithium compound, a 0.05-5 wt% nitride salt compound, and a residual amount of water.

In this case, the first metal layer is made of a double layer of aluminum alloy (AlNd) and molybdenum (Mo), the second metal layer is made of molybdenum (Mo), the third metal layer is made of indium-tin-oxide (ITO) It is characteristic that it was made.

In addition, the chlorine compound is composed of a compound that can be dissociated with Cl ^-1 , the chlorine stabilizer is composed of a Zn-based compound, Cd-based compound, Pb-based compound, Ba-based compound, oleic acid, the phosphate The compound is composed of a compound that can be dissociated into PO ₄ ^3- , wherein the water is pure water filtered through an ion exchange resin, and has a specific resistance of 18 MPa or more.

In addition, the gate wirings, the gate electrodes, the data wirings, the source and drain electrodes, and the pixel electrodes, which are formed by etching by the etching composition, have a tapered shape in cross-sectional structure, and an angle between bottom surfaces and side surfaces of the wirings and electrodes. That is, the inclination angle of the side with respect to the base is characterized in that it is formed 30 to 70 degrees.

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

<Example>

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

Meanwhile, 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% of phosphoric acid, 3 ~ 10 wt% preferably 4-8 wt% nitric acid, 4-22 wt% preferably 6-20 wt% acetic acid with 0.05-3 wt% preferably 0.07-2 wt% chlorine based Compound, 0.05-3 wt% preferably 0.07-2 wt% chlorine stabilizer, 0.1-5 wt% preferably 0.5-3 wt% phosphate compound, 0.05-5 wt% preferably 0.1-3 wt% Lithium-based compound, 0.05 to 5 wt%, preferably 0.1 to 3 wt% of a nitride compound and the balance of water.

The role and type of components of the etching solution according to the present invention will be described in more detail.

Nitric acid reacts with aluminum to form aluminum oxide (Al ₂ O ₃ ), and when the content of nitric acid is within the above range (3-10 wt%), the selectivity between the upper layer of molybdenum (Mo) and the lower layer of aluminum alloy (AlNd) Adjust effectively.

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

This undercut phenomenon occurs because, when two metals are in contact with an aqueous solution, Al (E = -1.66V), which is a metal having an electropotential base, is an anode. Dissolution is accelerated, and a noble metal Mo (E = -0.20V) becomes a negative electrode and protected so that the dissolution (electrochemical etching) is relatively delayed by a local cell (Local Cell or Galvanic Cell). It is interpreted to be due to Galvanic Corrosion.

If the pattern of the gate electrode is not uniformly formed due to such a local erosion phenomenon, it becomes difficult to implement high resolution and high definition color of the image of the liquid crystal display.

Meanwhile, phosphoric acid plays a role of decomposing aluminum oxide (Al ₂ O ₃ ). When the content of phosphoric acid is within the above range (50 to 75 wt%), aluminum oxide (Al) formed by reacting with nitric acid and aluminum (Al) ₂ O ₃ ) is properly decomposed to quickly etch the aluminum alloy (AlNd) layer, which is the lower layer of the gate electrode, thereby improving 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 adjusted to improve the etching rate, thereby improving productivity.

However, when the acetic acid is less than 4wt%, 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.

The chlorine compound is a compound capable of dissociating into Cl ^−1, and may be 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 , CrCl ₃ and the like, any of these may be used as a composition constituting the etching solution according to the invention, in particular Most preferably using KCl or HCl.

When the content of the chlorine compound is within the range (0.05 to 3 wt%), the etching rate of the indium-tin-oxide (ITO), molybdenum (Mo), and molybdenum (Mo) / aluminum alloy (AlNd) bilayers is controlled, and molybdenum ( Not only does not undercut the underlayer aluminum alloy (AlNd) in the double layer structure of Mo) / aluminum alloy (AlNd), but also has excellent profile in indium-tin-oxide (ITO) and molybdenum (Mo) ) And at the same time controls the etching rate.

However, when the chlorine compound is less than 0.05 wt%, the etching rate of the indium-tin-oxide (ITO) layer constituting the pixel electrode is decreased, resulting in a decrease in productivity. In contrast, when the content exceeds 3 wt%, the gate wiring is reduced. And an undercut of an underlayer of aluminum alloy (AlNd) occurs in a double layer structure of molybdenum (Mo) / aluminum alloy (AlNd) constituting the gate electrode.

Chlorine stabilizers consist of Zn-based compounds, Cd-based compounds, Pb-based compounds, Ba-based compounds 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 ) ₂ , and the like, and any of these may be used as the composition of the etchant according to the present invention, but in particular Zn (NO ₃ ) _2, Zn (CH Most preferably, ₃ COO) ₂ is 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 show a good profile having an inclination angle of 60 ° or less. By increasing the life of the process will increase the margin on the process.

Phosphate compounds are compounds that can be dissociated into PO ₄ ^3- NaH 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 , Ca ₃ PO _4, and the like. Although it can be used as a composition, it is most preferable to use (NH ₄ ) ₂ HPO ₄ or KH ₂ PO ₄ .

The phosphate-based compound controls the etching rate of the double layer of molybdenum (Mo) / aluminum alloy (AlNd) forming the gate wiring and the gate electrode, and the aluminum alloy which is a lower layer in the double layer of molybdenum (Mo) / aluminum alloy (AlNd) Not only does not generate an undercut phenomenon of (AlNd), but also has an effect of forming an excellent profile even in a molybdenum (Mo) single layer.

Lithium compounds include 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 Etc., any of these may be used as the composition of the etchant according to the present invention, it is most preferred to use LiNO ₃ , CH ₃ COOLi.

 The lithium-based compound serves to improve 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-based compound is less than 0.05 wt%, a reverse taper or shoulder phenomenon occurs in the molybdenum (Mo) single layer forming the data line and the source and drain electrodes, and the molybdenum forming the gate line and the gate electrode ( An undercut of the aluminum alloy (AlNd), which is a lower layer, occurs in the Mo) / aluminum alloy (AlNd) bilayer.

In addition, when the lithium compound exceeds 5 wt%, the molybdenum (Mo) single layer, which forms the data line and the source and drain electrodes, decreases the etching rate, and the molybdenum (Mo) / aluminum alloy forms the gate line and the gate electrode. The (AlNd) bilayer would result in the formation of a stepped profile rather than a tapered structure with the desired gentle slope.

Nitride compounds include 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 may be used as the composition of the etchant according to the present invention, but KNO ₃ , LiNO ₃ is most preferred. Do.

The nitride compound improves the etch rate of the molybdenum (Mo) single layer constituting the data line and the source and drain electrodes, and at the same time, improves a profile having a gentle taper.

In this case, when the nitride compound is less than 0.05 wt%, a reverse taper and shoulder phenomenon occurs in a molybdenum (Mo) single layer, and when 5 wt% or more, molybdenum (Mo) forming a data line and a source and drain electrode is present. ) Decreases the etching rate of the monolayer.

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

At this time, it is preferable to use pure water filtered through the ion exchange resin as the remaining amount of water, and in particular, it is preferable to use ultrapure water having a specific resistance of 18 kPa · cm or more.

Refer to the photographs observed with the scanning electron microscope, which shows the state of etching in each manufacturing step when manufacturing the array substrate for the liquid crystal display using the etching solution containing the weight% of the appropriate range of each composition described above. An embodiment of the present invention will be described. In this case, the etchant according to the embodiment of the present invention is 65 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 1.0 lithium compound A wt%, 1.5 wt% of a nitride compound and 12.8 wt% of water (ultra pure water) were used.

3A, 3B, and 3C illustrate a double layer of molybdenum (Mo) / aluminum alloy (AlNd), a data line, and a source formed of a material forming a gate electrode and a gate wiring after a wet etching process using an etchant according to an embodiment of the present invention; A photomicrograph of the molybdenum (Mo) layer made of a material forming a drain electrode and an indium-tin-oxide (ITO) layer made of a material forming a pixel electrode is observed by scanning electron microscopy. At this time, since the photoresist pattern PR by the ashing process after the etching is removed, the photoresist pattern PR still remains on each material layer.

First, referring to FIG. 3A, which illustrates a cross-section after molybdenum (Mo) and aluminum alloy (AlNd) are sequentially stacked and etched using the etchant according to the present invention to form a gate wiring and a gate electrode. Likewise, it can be seen that the bilayer of molybdenum (Mo) / aluminum alloy (AlNd) under the photoresist pattern PR has an excellent profile characteristic without undercut phenomenon.

In addition, referring to FIG. 3B, which illustrates a cross-section after deposition of molybdenum and etching using the etchant according to the present invention, to form a data line and a source and drain electrode, as shown, below the photoresist pattern PR It can be seen that the molybdenum (Mo) layer was formed with excellent profile characteristics with a taper of 45-70 mm 3.

In addition, referring to FIG. 3C, which illustrates a cross section after deposition of indium tin oxide (ITO) and etching using the etchant according to the present invention to form a pixel electrode, as shown in FIG. It can be seen from the bottom that indium tin oxide (ITO) was formed having excellent profile characteristics with a taper of 30 to 60 Hz.

Therefore, when the gate wiring and the gate electrode, the drain electrode, the source and the drain electrode, and the pixel electrode are etched and patterned by using the etching solution having the composition ratio according to the present invention, the cross-sections of the electrodes or the wiring both sides after the etching are smooth. Since it is formed to have excellent profile characteristics forming an inclination of about 30 ~ 70 ㅀ, the array substrate is manufactured without defects such as breakage due to the sudden taper structure of the wiring formed on the lower layer and the wiring and the electrode formed thereon. You can do it.

At this time, since the embodiment of the present invention is only an example within the range of the etchant composition according to the embodiment of the present invention, it can be understood to have the same effect within the range of the etchant composition according to the embodiment of the present invention.

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

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

As shown, the first metal layer of the double layer structure is formed by sequentially depositing aluminum alloy (AlNd) and molybdenum (Mo) on the transparent insulating substrate (100).

Thereafter, a photoresist is formed on the first metal layer to form a photoresist layer, an exposure is performed through the first and second masks in the transmission region and the blocking region, and a photoresist pattern is formed by performing a developing process.

Next, the etchant according to the embodiment of the present invention described above with respect to the first metal layer exposed to the outside of the photoresist pattern, that is, 65 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, chlorine When wet etching is performed using an etchant comprising 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 (ultra pure water), undercutting is performed. The gate wiring (not shown) and the gate electrode 104 of the double layer structure which have an appropriate taper angle etc. do not generate | occur | produce, etc. are formed.

Thereafter, the photoresist pattern remaining on the gate line (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 line and the gate electrode 104 are formed to form a gate insulating layer 107 on the front 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. Subsequently, 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, after forming a second photoresist layer on the second metal layer, a second mask having a transmissive region, a reflective region, and a transflective region is positioned and subjected to diffraction exposure or halftone exposure. And developing the exposed second photoresist layer to form photoresist patterns having first and second thicknesses, respectively, and exposing the second metal layer exposed to the outside of the photoresist patterns having the first and second thicknesses. It is removed by wet etching (wet etching) with an etchant according to an embodiment of the present invention, and the step of dry etching to remove the pure amorphous silicon layer and the impurity amorphous silicon layer of the lower portion. In addition, ashing is performed in addition to the above-described process to remove the thin second thickness photoresist pattern, and the second metal layer exposed by removing the thin second thickness photoresist pattern and the impurity amorphous silicon layer thereunder are dry-etched. By forming the ohmic contact layer 112b of the source and drain electrodes 117 and 119 in the form of being spaced apart from each other and the impurity amorphous silicon spaced apart from each other below, by ashing or stripping the remaining photoresist pattern of the first thickness It further includes the step of removing.

Next, one selected from transparent organic insulating materials such as benzocyclobutene (BCB) and acrylic resin (resin) is applied onto the data line 115 and the source and drain electrodes 117 and 119, or silicon nitride Forming a protective layer 125 by depositing one selected from an inorganic insulating material such as (SiNX) and silicon oxide (SiO 2), and subsequently patterning the protective layer 125 through a third mask process to form the drain electrode ( A drain contact hole 127 exposing a portion of 119 is formed.

Next, an indium tin oxide (ITO) is deposited on the passivation layer 125 having the drain contact hole 127 to form an indium tin oxide (ITO) layer. By performing a 4 mask process and patterning, the transparent pixel electrode 130 contacting the drain electrode 119 through the drain contact hole 127 is formed.

In this case, the fourth mask process proceeds in a similar manner to the first mask process and forms a photoresist layer on the indium tin oxide (ITO) layer, exposes the photoresist layer through a fourth mask, and develops the exposed photoresist layer. Thereby forming a photoresist pattern and wet etching the indium-tin-oxide (ITO) layer exposed to the outside of the photoresist pattern with an etchant 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 an ashing or strip process. The array substrate for the liquid crystal display device using the etchant can be completed.

As described above, in the manufacture of an array substrate for a liquid crystal display device, by treating the etching solution used in each mask process with a single solution according to the present invention, the etching solution is easily managed, and each etching solution is not formed with different etching equipment. By constructing the equipment, initial investment costs can be reduced, and gate and data wiring, gate electrodes, and source and drain electrodes with gentle taper angles can be formed to reduce defects and improve productivity.

On the other hand, the manufacturing method of the array substrate for the liquid crystal display device using the etchant according to the present invention was shown as an example that the four mask process is manufactured in a general application to the current production, but the four mask process is an example of the manufacturing method of the array substrate The mask process may be anything.

Hereinafter, in order to further support the embodiment of the present invention, an etchant composition out of the range of the etchant composition according to an embodiment of the present invention will be described with reference to the accompanying drawings. At this time, the composition ratio of the etchant used in the examples of the present invention and each comparative example (first to eighth comparative example) is 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 Compound 0.1 0.1 0.1 0.1 3.5 0.1 0.1 0.1 0.1 Chlorine stabilizer 0.1 0.1 0.1 0.1 0.1 3.5 0.1 0.1 0.1 Phosphate Compound 1.5 1.5 1.5 1.5 1.5 1.5 0.05 1.5 1.5 Lithium compounds 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.03 1.0 Nitride compounds 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 0.03 Water (ultra pure water) 12.8 32.8 15.8 22.8 9.4 9.4 14.25 15.77 16.27

                                                              Unit wt%

<First Comparative Example>

The etchant according to the first comparative example of the present invention is 45 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 1.0 wt% lithium compound %, 1.5 wt% of a nitride compound and 32.8 wt% of water (ultra pure water) were used. That is, the phosphoric acid in the range of the etchant composition according to the embodiment of the present invention is different from the range, which is outside the range of the etchant composition according to the embodiment of the present invention.

5A and 5B illustrate molybdenum (Mo) /, which is a material layer forming a gate electrode (including gate wiring) and a source and drain electrode (including data wiring) after a wet etching process using an etchant according to a first comparative example of the present invention. The photograph which observed the cross section of the double layer of aluminum alloy (AlNd), and the molybdenum (Mo) single layer with the scanning electron microscope is shown.

First, referring to FIG. 5A, it can be seen that as shown in FIG. 5, an undercut is caused by over-etching a double layer of molybdenum (Mo) / aluminum alloy (AlNd).

Referring also to FIG. 5B, as shown, the molybdenum (Mo) monolayer has a tapered poor profile with an angle of more than 70 μs without a taper of 40 to 70 μs. It can be seen that a shoulder having a shape protruding to the side at the top thereof is formed.

If the protective layer is formed by depositing the source and drain electrodes having the above shape after the formation of the source and drain electrodes, it may be impossible to evenly stack the layers.

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

<2nd comparative example>

The etchant according to the second comparative example of the present invention is 65 wt% phosphoric acid, 2 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 1.0 wt% lithium compound %, 1.5 wt% of a nitride compound and 15.8 wt% of water (ultra pure water) were used. That is, the nitric acid in the range of the etchant composition according to the embodiment of the present invention is different from the range, which is outside the range of the etchant composition according to the embodiment of the present invention.

6A and 6B illustrate molybdenum (Mo) /, which is a material layer forming a gate electrode (including gate wiring) and a source and drain electrode (including data wiring) after a wet etching process using an etchant according to a second comparative example of the present invention. The photograph which observed the cross section of the double layer of aluminum alloy (AlNd), and the molybdenum (Mo) single layer with the scanning electron microscope is shown.

First, referring to FIG. 6A, in the double layer of molybdenum (Mo) / aluminum alloy (AlNd), undercut of the aluminum alloy (AlNd) layer occurred, and the taper was formed almost vertically. It can be seen.

Referring to FIG. 6B, as illustrated, the molybdenum (Mo) single layer may form a poor profile having a steep shape, and a shoulder may be generated.

 This shows the result when the content of nitric acid is 2 wt%, but it can be understood to be the same as the effect that is out of the range of the etching liquid composition according to the embodiment of the present invention, that is, when the content of nitric acid is less than 3 wt%. .

<Third Comparative Example>

The etchant according to the third comparative example of the present invention is 65 wt% phosphoric acid, 2 wt% nitric acid, 3 wt% acetic acid, 0.1 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 1.0 wt% lithium compound %, 1.5 wt% of a nitride compound and 22.8 wt% of water (ultra pure water) were used. That is, the acetic acid in the range of the etchant composition according to the embodiment of the present invention is different from the range, it is outside the range of the etchant composition according to the embodiment of the present invention.

7A and 7B illustrate molybdenum (Mo) /, which is a material layer forming a gate electrode (including gate wiring) and a source and drain electrode (including data wiring) after a wet etching process using an etchant according to a third comparative example of the present invention. The photograph which observed the cross section of the double layer of aluminum alloy (AlNd), and the molybdenum (Mo) single layer with the scanning electron microscope is shown.

First, referring to FIG. 7A, in the molybdenum (Mo) / aluminum alloy (AlNd) bilayer, an undercut over-etched an aluminum alloy (AlNd) layer, which is a lower layer, may occur.

Referring to FIG. 7B, as illustrated, the molybdenum (Mo) single layer is rapidly etched at the side of the photoresist pattern based on the end of the photoresist pattern, thereby increasing the critical dimension loss. Can be. If the CD loss becomes larger than the width of the desired wiring and the data wiring is formed, there is a problem such as signal delay. Therefore, it is difficult to implement a high resolution product because the design margin must be increased during design.

Although the above-described third comparative example shows the result when the content of acetic acid is 4 wt%, it is the same as the effect that is out of the range of the etching solution composition according to the embodiment of the present invention, that is, when the content of acetic acid is less than 4 wt%. It can be understood that.

<4th comparative example>

The etchant according to the fourth comparative example of the present invention is 65 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 3.5 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 1.0 wt% lithium-based compound %, 1.5 wt% of a nitride compound and 9.4 wt% of water (ultra pure water) were used. That is, the chlorine-based compound in the range of the etchant composition according to the embodiment of the present invention is different from the range, which is outside the range of the etchant composition according to the embodiment of the present invention.

8 is a cross-sectional view 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 fourth comparative example of the present invention; Represents a picture.

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

This shows the result when the content of the chlorine compound is 3.5 wt%, but it is outside the range of the etching liquid composition according to the embodiment of the present invention, that is, when the content of the chlorine compound is more than 3 wt%, that is when used in excess It can be understood as the effect shown.

<Fifth Comparative Example>

The etchant according to the fifth comparative example of the present invention is 65 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, 3.5 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 1.0 wt% lithium compound %, 1.5 wt% of a nitride compound and 9.4 wt% of water (ultra pure water) were used. That is, by varying the range of the chlorine stabilizer in the range of the etchant composition according to the embodiment of the present invention, it is beyond the range 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 forming a pixel electrode after a wet etching process using an etchant according to a fifth comparative example, of the present invention.

As shown, the etching rate of the indium-tin-oxide (ITO) layer decreases, and furthermore, after etching, the phenomenon that the indium-tin-oxide (ITO) residue remains on the substrate more precisely on the protective layer occurs. Can be. The indium tin oxide, which is not completely removed, adversely affects the display quality, and adversely affects that the alignment layer formed on the upper portion has an even thickness, which is reflected as a decrease in display quality. The third comparative example described above shows the result when the content of the chlorine stabilizer is 3.5 wt%, but when the content of the chlorine stabilizer is outside the range of the etching liquid composition according to the embodiment of the present invention, that is, the content of the chlorine stabilizer is more than 3 wt%, That is, it can be understood as the same effect that occurs when used excessively.

<Sixth comparative example>

The etchant according to the sixth comparative example of the present invention is 65 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 0.05 wt% phosphate compound, 1.0 wt% lithium compound %, 1.5 wt% of a nitride compound and 14.25 wt% of water (ultra pure water) were used. That is, by varying the range of the phosphate-based compound in the range of the etchant composition according to the embodiment of the present invention, it is beyond the range of the etchant composition according to the embodiment of the present invention.

FIG. 10 is a cross-sectional view 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; Represents a picture.

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

This shows the result when the content of the phosphate-based compound is 0.05 wt%, but it is out of the range of the etching solution composition according to the embodiment of the present invention, that is, when the content of the phosphate-based compound is less than 0.1 wt%, that is, a small amount was used. It can be understood as the effect that occurs when.

<7th comparative example>

The etchant according to the seventh comparative example of the present invention is 63 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 0.03 wt% lithium compound %, 1.5 wt% of a nitride compound and 15.77 wt% of water (ultra pure water) were used. That is, as varying the range of the lithium-based compound in the range of the etchant composition according to the embodiment of the present invention, it is beyond the range of the etchant composition according to the embodiment of the present invention.

FIG. 11 is a cross-sectional view 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 seventh comparative example of the present invention; Represents a picture.

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

This shows the result when the content of the lithium compound is 0.03 wt%, but it is out of the range of the etching liquid composition according to the embodiment of the present invention, that is, when the content of the lithium compound is less than 0.05 wt%, that is, a small amount is used. It can be understood as the effect that occurs when.

<Eighth Comparative Example>

The etchant according to the eighth comparative example of the present invention is 63 wt% phosphoric acid, 5 wt% nitric acid, 13 wt% acetic acid, 0.1 wt% chlorine compound, 0.1 wt% chlorine stabilizer, 1.5 wt% phosphate compound, 1.0 wt% lithium compound %, 0.03 wt% of nitride compound and 16.27 wt% of water (ultra pure water) were used. That is, as varying the range of the nitride compound in the range of the etchant composition according to the embodiment of the present invention, it is beyond the range of the etchant composition according to the embodiment of the present invention.

FIG. 12 is a photograph illustrating a cross section of a molybdenum (Mo) layer, which is a material layer constituting a data line and a source and drain electrode, after a wet etching process using an etchant according to an eighth comparative example of the present invention.

As shown, the molybdenum (Mo) monolayer has an inverse taper structure, and furthermore, it can be seen that a shoulder that protrudes from the side of the uppermost layer has occurred.

The eighth comparative example described above shows the result when the content of the nitride compound is 0.03 wt%, but is outside the range of the etchant composition according to the embodiment of the present invention, that is, the content of the nitride compound is 0.05 wt%. It can be understood as the same effect when less than, that is, when used in small amounts.

By using an etchant of a single solution, characterized in that the aluminum alloy, molybdenum and indium-tin-oxide can be etched according to a preferred embodiment of the present invention, each metal layer using a different etchant in each mask process When manufacturing the array substrate by patterning, since the configuration of the etching equipment is provided with a different etching solution is not necessary, there is an effect of reducing the manufacturing cost by reducing the initial equipment investment.

In addition, it is easy to manage by unifying the etchant.

Claims (17)

50 to 75 wt% of phosphoric acid; 3-10 wt% nitric acid; 4 to 22 wt% acetic acid; 0.05-3 wt% of a chlorine compound; 0.05-3 wt% of a chlorine stabilizer; 0.1-5 wt% of a phosphate compound; 0.05-5 wt% of a lithium compound; 0.05-5 wt% of a nitride salt compound; Remaining water Etching liquid comprising a sum of the weight percent (wt%) of each material, including the remaining amount of water. The method of claim 1, The chlorine compound is an etching solution consisting of a compound that can be dissociated with Cl ^-1 . The method of claim 1, The chlorine compound is KCl or HCl etching solution. The method of claim 1, The chlorine stabilizer is an etchant consisting of a Zn-based compound, a Cd-based compound, a Pb-based compound, a Ba-based compound, and oleic acid. The method of claim 4, wherein The chlorine stabilizer is Zn (NO ₃ ) ₂ or Zn (CH ₃ COO) ₂ Phosphorus Etchant. The method of claim 1, The phosphate compound is an etching solution consisting of a compound that can be dissociated into PO ₄ ^3- . The method of claim 6, The phosphate compound is an etching solution of (NH ₄ ) ₂ HPO ₄ or KH ₂ PO ₄ . The method of claim 1, The lithium compound is LiNO ₃ or CH ₃ COOLi etching solution. The method of claim 1, The nitride compound is an etchant KNO ₃ or LiNO ₃ . The method of claim 1, The water is an etchant liquid filtered through an ion exchange resin. The method of claim 10, The pure water is an etching solution of ultrapure water having a specific resistance of 18 MPa or more. Etching the first metal layer on the substrate using the 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 over the insulating film; Etching the second metal layer on 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 on the gate electrodes; Forming a protective layer over the data line and the source and drain electrodes; Etching the third metal layer on the passivation layer using the etching composition to form a pixel electrode in contact with the drain electrode through the drain contact hole; The etching composition includes 50 to 75 wt% phosphoric acid, 3 to 10 wt% nitric acid, 4 to 22 wt% acetic acid, 0.05 to 3 wt% chlorine compound, and 0.05 to 3 wt% chlorine. Manufacturing method of array substrate for liquid crystal display device which consists of stabilizer, 0.1-5 wt% phosphate compound, 0.05-5 wt% lithium compound, 0.05-5 wt% nitride compound, and residual amount of water . The method of claim 12, And the first metal layer is formed of a double layer of aluminum alloy (AlNd) and molybdenum (Mo). The method of claim 12, And the second metal layer is made of molybdenum (Mo). The method of claim 12, And the third metal layer is formed of indium tin oxide (ITO). The method of claim 12, The chlorine compound consists of a compound that can be dissociated with Cl ^-1 , The chlorine stabilizer is composed of Zn-based compound, Cd-based compound, Pb-based compound, Ba-based compound, oleic acid, The phosphate compound is composed of a compound that can be dissociated into PO ₄ ^3- , And said water is pure water filtered through ion exchange resin and has a specific resistance of 18 MPa or more. The method of claim 12, The gate wiring, the gate electrode, the data wiring, the source, the drain electrode, and the pixel electrode which are etched and formed by the etching composition, The cross-sectional structure of the liquid crystal display device array substrate characterized in that the tapered shape of the cross-section and the angle between the bottom and side of the wiring, that is, the inclination angle of the side with respect to the bottom is formed 30 to 70 degrees.

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