KR101266077B1 - Etchant for etching Al, Mo and ITO - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching solution for a liquid crystal display device. In particular, a gate electrode composed of a double layer of molybdenum and aluminum alloy (Mo / AlNd), a source / drain electrode composed of molybdenum (Mo), and a pixel electrode composed of ITO For etching using a solution.

The present invention is composed of 40 ~ 70wt% phosphoric acid, 2 ~ 15wt% nitric acid, 4 ~ 35wt% acetic acid as a main component of 0.05 ~ 5wt% chlorine compound, 0.05 ~ 5wt% chlorine stabilizer, 0.05 ~ 5wt% lithium It comprises a compound, an additive containing a sulfur salt compound of 0.05 ~ 5wt% and an etching solution containing a residual amount of water.

As a result, by using a single etchant in each mask process as a single etchant, productivity and material cost are reduced.

Molybdenum (Mo), Aluminum Alloy (AlNd), ITO, etchant

Description

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

1 is a view schematically showing a general liquid crystal panel.

2 schematically illustrates an array substrate according to an embodiment of the invention.

3A to 3B are photographs of a cross section of a gate electrode after a wet etching process using an etchant according to an embodiment of the present invention with a scanning electron microscope;

4A to 4B are photographs of cross-sections of source and drain electrodes after a wet etching process using an etchant according to an embodiment of the present invention with a scanning electron microscope;

5A and 5B are photographs of a cross section of a pixel electrode after a wet etching process using an etchant according to an embodiment of the present invention with a scanning electron microscope;

6A to 6B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a first comparative example of the present invention.

7A to 7B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a second comparative example of the present invention.

8A to 8B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a third comparative example of the present invention.

9A to 9B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a fourth comparative example of the present invention.

10 is a scanning electron micrograph showing a cross section of a pixel electrode composed of ITO after a wet etching process with an etchant according to a fifth comparative example of the present invention.

11A to 11B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a sixth comparative example of the present invention.

12A to 12B are scanning electron micrographs showing a cross section of a molybdenum monolayer constituting a source and a drain electrode after a wet etching process using an etchant according to a seventh comparative example of the present invention.

<Description of the symbols for the main parts of the drawings>

111 substrate 115 gate electrode

117: gate insulating film 119: active layer

121: ohmic contact layer 123a, 123b: source and drain electrodes

125: protective film 135: pixel electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching solution for a liquid crystal display device. In particular, a gate electrode composed of a double layer of molybdenum and aluminum alloy (Mo / AlNd), a source / drain electrode composed of molybdenum (Mo), and a pixel electrode composed of ITO For etching using a solution.

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 a liquid crystal.

Referring to FIG. 1, a method of manufacturing a general liquid crystal panel as described above is described in detail. First, an array substrate 11 is divided into a display area AA and a non-display area NA, and then the display of the lower substrate 11 is performed. A conductive metal material such as molybdenum (Mo), aluminum (Al), aluminum alloy (AlNd), tungsten (W), and chromium (Cr) is deposited on the entire surface of the area AA and the non-display area NA.

In particular, when using a low resistance aluminum alloy (AlNd) is composed of a double layer using molybdenum (Mo).

Next, after applying the photoresist, exposing with a mask, and developing the photoresist, a mask process including a series of processes such as wet etching and removing the exposed metal material layer is performed to perform the substrate ( The gate electrode 15 is formed by patterning the metal material deposited on 11).

In this case, an etchant consisting of phosphoric acid, nitric acid, and acetic acid is used as the etchant used during the wet etching.

A gate insulating film 17 is formed by depositing an insulating material on the entire surface of the substrate 11 including the gate electrode 15, and an amorphous silicon layer and an n + layer are deposited on the gate insulating film 17, and then a conductive metal is deposited. Molybdenum (Mo) is deposited on the front surface of the material.

Next, after placing a mask (not shown) on the molybdenum (Mo) metal material, after the application of photoresist, exposure using a mask, and photoresist development, the exposed molybdenum (Mo) metal material is wet-etched and removed. Dry etching the lower amorphous silicon layer and the n + layer to form an active layer 19 which is a pure amorphous silicon layer and an ohmic contact layer 21 which is an impurity amorphous silicon layer, and source and drain electrodes on both sides of the gate electrode 15. (23a, 23b) are formed.

As an etchant for wet etching the molybdenum (Mo) metal layer, an etchant consisting of phosphoric acid, nitric acid, acetic acid or an aqueous permeate etchant is used.

At this time, the process of exposing the lower active layer 19 by removing the ohmic contact layer 21 exposed to the spaced apart lower portions of the source and drain electrodes 23a and 23b is performed.

Subsequently, the passivation layer 25 is entirely deposited on the top of the source and drain electrodes 23a and 23b including the active layer 19.

Next, the protective layer 25 is etched through a mask process to form a drain contact hole (not shown) exposing a part of the drain electrode 23b.

Next, a transparent pixel electrode 35 in contact with the drain electrode 23b is formed in the pixel region P through a mask process, wherein the pixel electrode 35 also includes the gate electrode 15 and the source and drain electrodes. (23a, 23b) A mask process including a series of processes such as application of a photoresist, exposure using a mask, photoresist development, and wet etching to remove the exposed metal layer by a method similar to the formation process (23a, 23b). Proceed to form the pixel electrode.

In this case, aqua regia etchant or oxalic acid etchant is used as an etchant for etching the pixel electrode 35.

On the other hand, one surface of the color filter substrate 13 facing the array substrate 11 is deposited on the entire surface of the lattice-like black resin, and selectively not displayed on the lower substrate 11 through a mask (not shown) process The black matrix 27 is formed at a position corresponding to the area NA.

Next, a photoresist color resin representing red, green, and blue color resin is applied to the entire surface of the substrate 13 on which the black matrix 27 is formed to form a color resin layer, and then patterned through a mask (not shown) process. Thus, red, green, and blue color filters 29 are sequentially formed in an area corresponding to the pixel area P. FIG.

Subsequently, a transparent electrode is deposited on the front surface of the color filter substrate 13 to form a common electrode 31 to complete the color filter substrate.

As such, when the process of the array substrate 11 and the color filter substrate 13 is completed, a process of forming a seal pattern (not shown) and bonding the two substrates apart from each other is performed, and then spaced apart from the two substrates. The liquid crystal layer 50 is formed in this.

As described above, the liquid crystal display device is completed by depositing and patterning a plurality of materials, and the deposition-> exposure-> development-> etching process, etc. must be repeated for each component layer, and in particular, the array substrate etches each metal layer. There is a problem using different etchant.

This causes a problem that the etching process is complicated, the efficiency and productivity of the process is lowered, thereby causing a problem that the process cost is increased.

The present invention is to solve the above problems, the gate electrode consisting of a double layer of aluminum alloy (AlNd) and molybdenum (Mo), the source and drain electrodes composed of molybdenum (Mo), and the pixel electrode (ITO) is etched The first object is to etch using a single etchant in the process.

In addition, the second object is to simplify the process and reduce the process cost.

In order to achieve the object as described above, the present invention is 40 to 70wt% phosphoric acid; 2-15 wt% of nitric acid; Acetic acid of 4 to 35 wt%; 0.05-5 wt% of a chlorine compound; 0.05 to 5 wt% chlorine stabilizer; An etching solution including 0.05 to 5 wt% of a lithium compound, 0.05 to 5 wt% of a sulfur salt compound, and a balance of water is provided.

The chlorine compound is characterized in that consisting of a compound that can be dissociated with Cl ^-1 , the chlorine stabilizer is characterized by consisting of Zn, Cd, Pb, Ba-based compound and oleic acid.

In addition, the lithium-based compound is LiNO ₃ , CH ₃ COOLi, C ₄ H ₅ O ₃ Li, LiCl, Lif, Lil, C ₂ HLiO ₄ , Li ₂ O ₂ , Li ₂ SO ₄ , LiH ₂ PO ₄ , Li ₃ PO ₄ , wherein the sulfide-based compound is H ₂ SO ₄ , Na ₂ SO ₄ , Na ₂ S ₂ O ₈ , KHSO ₄ , K ₂ SO ₄ , K ₂ S ₂ O ₈ , CaSO ₄ , (NH ₄ ) ₂ S ₂ O ₈ .

In addition, the water is characterized in that using pure water filtered through an ion exchange resin.

In addition, the present invention comprises the steps of forming a gate electrode by etching the first metal layer on the substrate using the etchant; Forming an insulating film on the gate electrode; Stacking a semiconductor layer and a second metal layer on the insulating film; Etching the second metal layer through the etchant to form source and drain electrodes; Forming a protective layer having a drain contact hole exposing the drain electrode over the source and drain electrodes; It provides a method of manufacturing an array substrate for a liquid crystal display device comprising the step of forming a pixel electrode on the protective layer through the etching solution.

The first metal layer is characterized in that the bilayer of molybdenum and aluminum alloy, the second metal layer is characterized in that made of molybdenum.

In addition, the pixel electrode is made of indium tin oxide (ITO).

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

2 is a view schematically showing an array substrate according to an embodiment of the present invention.

As shown, first, a conductive metal material such as molybdenum (Mo), aluminum (Al), aluminum alloy (AlNd), tungsten (W), and chromium (Cr) is sputtered on the entire surface of the substrate 111. Deposition forms a first metal layer.

In particular, when using a low resistance aluminum alloy (AlNd) is composed of a double layer using molybdenum (Mo).

Next, a photoresist is coated on the first metal layer to form a PR layer (not shown), exposed using a mask (not shown), and then a developing process of removing the photoresist of the exposed portion is performed. .

In this process, a PR pattern (not shown) is formed, and the exposed first metal layer is 40 to 70 wt% phosphoric acid (H ₃ PO ₄ ), which is a single etching solution according to an embodiment of the present invention, and 2 to 15 wt% nitric acid (HNO ₃ ). %, acetic acid (CH ₃ COOH) additives containing 4 ~ 0.05 ~ 5wt% to the chlorine-containing compound mainly composed of 35wt%, a chlorine stabilizer 0.05 ~ 5wt%, the lithium-based compound 0.05 ~ 5wt%, sulfate- compound 0.05 ~ 5wt% And wet etching using an etchant including a residual amount of water to form a gate electrode 115 on the substrate 111.

A gate insulating layer 117 is formed by depositing an insulating material such as silicon nitride (SiN _x ) or silicon oxide (SiO ₂ ) on the entire surface of the substrate 111 including the gate electrode 115, and the gate insulating layer 117. After the amorphous silicon layer and the n + layer is deposited on the upper surface, the second metal layer is formed by depositing molybdenum (Mo), which is a conductive metal material, by sputtering.

Next, after placing a mask (not shown) on the second metal layer, a photoresist is applied to form a PR layer (not shown), and exposed using a mask (not shown). A developing process of removing the photoresist is performed to form a PR pattern (not shown).

Next, the exposed second metal layer is removed by wet etching through an etchant according to an exemplary embodiment of the present invention, and the underlying amorphous silicon layer and the n + layer are dry etched to remove the active layer 119 and the impurity amorphous silicon, which are pure amorphous silicon layers. The ohmic contact layer 121, which is a layer, is formed, and source and drain electrodes 123a and 123b are formed on both sides of the gate electrode 115.

In this case, the process of exposing the lower active layer 119 is performed by removing the ohmic contact layer 121 exposed to the spaced lower portions of the source and drain electrodes 123a and 123b.

Subsequently, one selected from transparent organic insulating materials such as benzocyclobutene (BCB) and an acrylic resin is coated on the source and drain electrodes 123a and 123b including the active layer 119, or silicon nitride (SiN) is applied. _x ) and one of inorganic insulating materials such as silicon oxide (SiO ₂ ) are deposited to deposit the protective film 125 on the entire surface.

Next, the passivation layer 125 is patterned through a mask process to form a drain contact hole (not shown) exposing a part of the drain electrode 123b.

Next, a transparent pixel electrode 135 in contact with the drain electrode 123b is formed in the pixel region through a mask process. In this case, the pixel electrode 135 also includes the gate electrode 115 and the source and drain electrodes 123a, 123b) A mask including a series of processes such as application of photoresist, exposure using a mask (not shown), photoresist development, and wet etching to remove the exposed metal layer by a method similar to the formation process. The process proceeds to form the pixel electrode 135.

At this time, the etchant used during the wet etching of the pixel electrode 135 composed of ITO is also composed of phosphoric acid 40 ~ 70wt%, nitric acid 2 ~ 15wt%, acetic acid 4 ~ 35wt% as a main component 0.05 ~ 5wt%, chlorine stabilizer An etchant including 0.05 to 5 wt% of lithium-based compound, 0.05 to 5 wt% of sulfur-based compound, and 0.05 to 5 wt% of sulfide-based compound and residual amount of water is used.

In the exemplary embodiment of the present invention, 40 to 70 wt% of phosphoric acid (55 to 65 wt% is most preferred) and 2 to 15 wt% of nitric acid (4 to 4) as a single etchant for etching aluminum (Al), molybdenum (Mo), and ITO. 10 wt% is most preferred), 4 to 35 wt% acetic acid (8 to 25 wt% is most preferred), 0.05 to 5 wt% chlorine compound (0.07 to 3 wt% is most preferred), 0.05 to 5 wt% chlorine stabilizer (0.07 to 3 wt% is the most preferred), 0.05 to 5 wt% lithium compound (0.3 to 3 wt% is the most preferred), 0.05 to 5 wt% sulfide salt compound (0.1 to 3 wt% is the most preferred) And residual amount of water.

Looking at the single etching solution of the present invention in more detail, first, the phosphoric acid serves to decompose aluminum oxide (Al ₂ O ₃ ), when the phosphoric acid content is within the 40 ~ 70wt% by reacting nitric acid and aluminum As the formed aluminum oxide (Al ₂ O ₃ ) is decomposed, the metal layer of the aluminum alloy (AlNd), which is the lower layer of the gate electrode 115, can be etched quickly, thereby increasing the etching speed.

This brings about the effect of productivity improvement.

In addition, the nitric acid reacts with aluminum to form aluminum oxide (Al ₂ O ₃ ), and when the nitric acid content is within the range of 2 to 15 wt%, between the upper layer of molybdenum and the lower layer of the aluminum alloy. Effectively adjust the etching selectivity.

However, when the nitric acid is less than 2wt%, an undercut phenomenon occurs in which the underlying aluminum alloy is excessively etched in the double layer of molybdenum and aluminum alloy.

This occurs because the etching rates of the molybdenum and the aluminum alloy are different from each other. That is, the phosphoric acid and the aluminum alloy reacts to etch the aluminum alloy and the nitric acid and molybdenum react to etch the molybdenum layer. When the content of the nitric acid is less than 2wt%, the reactivity of the aluminum alloy and the phosphoric acid is increased. This is because it becomes larger than the reactivity.

This phenomenon has a problem that it is difficult to implement a high resolution and vivid color of the LCD image.

Acetic acid is a buffer for controlling the reaction rate. When the content of acetic acid is within 4 to 35wt%, the reaction rate is appropriately adjusted to improve the etching rate.

This also brings the effect of productivity improvement.

However, when the content of acetic acid is less than 5wt%, an undercut phenomenon occurs in the double layer of molybdenum and aluminum alloy.

This is also because the etching rate of the molybdenum and the aluminum alloy is different.

In addition, the chlorine compound, which is an additive added to the etchant of the present invention, may be dissociated into Cl ^−1, and may be KCl, HCl, LiCl, NH ₄ Cl, 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, etc., of which KCl and HCl are most preferred. .

When the content of the chlorine compound is within 0.05 to 5wt%, it controls the etching rate of the double layer of ITO, molybdenum, molybdenum and aluminum alloy, and does not cause the undercut of the aluminum alloy as the lower layer in the double layer of molybdenum and aluminum alloy. In addition, ITO and molybdenum also form excellent profiles.

However, when the content of the chlorine compound is less than 0.05wt%, the etching rate of ITO is slowed down, and when the content of the chlorine compound is 5wt% or more, an undercut phenomenon occurs in the double layer of molybdenum and aluminum alloy.

In addition, the chlorine stabilizer is composed of Zn, Cd, Pb, Ba-based compound and oleic acid, 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 , Cdl ₂ , Cd (NO ₃ ) ₂ , CdCO ₃ , Pb (CH ₃ COO) ₂ , C ₁₂ H ₁₀ O ₁₄ Pb ₃ , Pbl ₄ , Pb (NO ₃ ) ₂ , Pb (C ₁₇ H ₃₅ COO) ₂ , Ba (CH ₃ COO) ₂ , BaCO ₃ , BaCl ₂ , Bal ₂ , Ba (NO ₃ ) ₂ , BaHPO ₄ and the like. At this time, Zn (NO ₃ ) _2, Zn (CH ₃ COO) ₂ is most preferred.

When the content of the chlorine stabilizer is within 0.05 ~ 5wt%, it shows a good profile with an inclination angle of 60 각 or less by adjusting the etching rate, and increases the process margin by extending the life of the etching solution.

The lithium-based compound serves to improve the profile of the molybdenum monolayer constituting the source and drain electrodes 123a and 123b and the bilayer of molybdenum and aluminum alloy constituting the gate electrode 115, and LiNO ₃ and CH ₃ COOLi. , C ₄ H ₅ O ₃ Li, LiCl, Lif, Lil, C ₂ HLiO ₄ , Li ₂ O ₂ , Li ₂ SO ₄ , LiH ₂ PO ₄ , Li ₃ PO ₄ . At this time, LiNO ₃ and CH ₃ COOLi is most preferred.

When the content of the lithium compound is less than 0.05wt%, reverse taper and shoulder phenomena occur in the molybdenum single layer, and undercut phenomenon of the aluminum alloy, which is a lower layer, occurs in the double layer of molybdenum and aluminum alloy. Done.

In addition, when the content of the lithium-based compound is 5wt% or more, the etching rate of the molybdenum single layer is lowered, a stepped profile is formed in the double layer of molybdenum and aluminum alloy.

The sulfide-based compound serves to improve the etching rate and profile of the molybdenum monolayer constituting the source and drain electrodes 123a and 123b, H ₂ SO ₄ , Na ₂ SO ₄ , Na ₂ S ₂ O ₈ , KHSO ₄ , K ₂ SO ₄ , K ₂ S ₂ O ₈ , CaSO ₄ , (NH ₄ ) ₂ S ₂ O _8, and the like. Where K ₂ SO ₄ and KHSO ₄ is most preferred.

When the content of the sulfide-based compound is less than 0.05wt% presented in the embodiment of the present invention, a CD bias in which a small pattern is formed in the molybdenum monolayer is large and a shoulder is generated.

In addition, when the content of the sulfide salt compound is 5wt% or more, an undercut phenomenon of the aluminum alloy, which is the lower layer of the double layer of molybdenum and the aluminum alloy, occurs.

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

In particular, it is preferable to use pure water filtered through ion exchange resin as the residual amount of water, and in particular, ultrapure water having a specific resistance of 18 kPa or more is preferably used.

As described above, the gate electrode 115 composed of a double layer of molybdenum and aluminum alloy of the present invention, the source and drain electrodes 123a, 123b composed of a single layer of molybdenum, and the pixel electrode 135 composed of ITO are implemented. We will explain in more detail through the photograph after the wet etching process using the etchant according to the example.

3A through 5B are cross-sectional views of gate electrodes, source and drain electrodes, and pixel electrodes after a wet etching process using an etchant according to an exemplary embodiment of the present invention with a scanning electron microscope.

3A is a photograph showing a cross-section after a wet etching process of a gate electrode composed of a double layer of molybdenum and an aluminum alloy, before the PR pattern is removed by the ashing process, and the upper portion of the photograph indicates the remaining PR pattern. 3B is a photograph after the PR pattern is removed after the ashing process.

As shown, the bilayer of molybdenum and aluminum alloy can be seen to form a good profile without the undercut phenomenon.

4A is a photograph showing a cross section after a wet etching process of a source and a drain electrode composed of a single layer of molybdenum. Before the PR pattern is removed by the ashing process, the upper portion of the photograph indicates a remaining PR pattern. It is a photograph after the PR pattern is removed after the ashing process.

As shown, the source and the drain electrode composed of molybdenum monolayer form an excellent profile with a taper of 45 to 70 microns.

FIG. 5A is a photograph showing a cross section after a wet etching process of a pixel electrode composed of ITO. Before the PR pattern is removed by the ashing process, the upper portion of the photo shows the remaining PR pattern, and FIG. 5B is a PR pattern after the ashing process. This is a picture after it is removed.

As shown, the pixel electrode composed of ITO can be seen to form an excellent profile having a taper of 30 ~ 60 °.

That is, in the formation of each of the gate electrode, the source and drain electrodes, and the pixel electrode, it can be seen that after the etching process, the shape of both sides of the electrode forms a profile having a gentle inclination.

As described above, in manufacturing an array substrate for a liquid crystal display device, by using the etching solution used in each mask process as a single solution, the etching solution is easily managed, and the manufacturing cost is reduced by constructing a single facility. This leads to an increase in productivity.

The array substrate for a liquid crystal display device as described above may be manufactured by a four mask process which is generally used in production at present, but the four mask process is only one example of a method of manufacturing the array substrate, and the mask process may be any.

Hereinafter, to further support an embodiment of the present invention, an etchant composition according to an embodiment of the present invention and an etchant composition outside the range of the etchant composition of the present invention will be compared.

Table 1 is a table summarizing the etchant content of the Examples and Comparative Examples of the present invention.

division
Examples of the present invention
Example One 2 3 4 5 6 7 Phosphoric Acid 62 38 62 62 62 62 62 62 nitric acid 3.5 3.5 1.5 3.5 3.5 3.5 3.5 3.5 Acetic acid 15 15 15 3 15 15 15 15 Chlorine Compound 0.1 0.1 0.1 0.1 5.5 0.1 0.1 0.1 Chlorine stabilizer 0.1 0.1 0.1 0.1 0.1 6 0.1 0.1 Lithium compounds 2 2 2 2 2 2 0.02 2 Sulfur Compounds 2 2 2 2 2 2 2 0.02 water Up to 100wt%

Table 1 Etch Content

<First Comparative Example>

Etching solution according to an embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt% chlorine compound, 0.1wt% chlorine stabilizer, 2wt% lithium compound, 2wt% sulfide compound The etching solution of the most preferred content within the content of the etching solution of the embodiment, the first comparative example for comparison with the embodiment of the present invention is 38wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt chlorine compound %, Chlorine stabilizer 0.1wt%, lithium-based compound 2wt%, sulfide-based compound by varying the content of phosphoric acid, it is configured to deviate from the content of the etching solution composition according to an embodiment of the present invention.

6A to 6B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a first comparative example of the present invention.

In this case, before the PR pattern is removed by the ashing process, the photograph of FIG. 6A indicates that the upper part of the photograph indicates the remaining PR pattern.

As shown, the double layer of molybdenum (Mo) and aluminum alloy (AlNd) when the phosphoric acid content is less than 40wt% is excessively etched aluminum alloy (AlNd) of the lower layer to cause an undercut phenomenon.

The phosphoric acid decomposes aluminum oxide (Al ₂ O ₃ ) formed by reacting with nitric acid and aluminum (Al), and decomposes the aluminum oxide (Al ₂ O ₃ ) while the aluminum alloy (AlNd), which is a lower layer of the gate electrode. This is because the metal layer is etched too quickly compared to the upper layer of molybdenum (Mo).

<2nd comparative example>

Etching solution according to an embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt% chlorine compound, 0.1wt% chlorine stabilizer, 2wt% lithium compound, 2wt% sulfide compound The etching solution of the most preferred content within the content of the etching solution of the embodiment, the first comparative example for comparison with the embodiment of the present invention is 62wt% phosphoric acid, 1.5wt% nitric acid, 15wt% acetic acid, 0.1wt chlorine compound %, Chlorine stabilizer 0.1wt%, lithium-based compound 2wt%, sulfide-based compound by varying the content of nitric acid is configured to deviate from the content of the etchant composition according to an embodiment of the present invention.

7A to 7B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a second comparative example of the present invention.

In this case, the photograph of FIG. 7A is before the PR pattern is removed by the ashing process, and the upper portion of the photograph indicates the remaining PR pattern.

As shown, the double layer of molybdenum (Mo) and aluminum alloy (AlNd) when the content of nitric acid is less than 2wt% is excessively etched aluminum alloy (AlNd) of the lower layer to cause an undercut phenomenon.

This occurs because the etching rate of the molybdenum (Mo) and the aluminum alloy (AlNd) is different from each other. Because the phosphoric acid and the aluminum alloy (AlNd) reacts to etch the aluminum alloy (AlNd) and the nitric acid and molybdenum (Mo) to etch the molybdenum layer, when the content of the nitric acid is less than 2wt% the aluminum alloy (AlNd) This is because the reactivity of) and phosphoric acid is greater than that of molybdenum (Mo) and nitric acid.

<Third comparative example>

Etching solution according to an embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt% chlorine compound, 0.1wt% chlorine stabilizer, 2wt% lithium compound, 2wt% sulfide compound The etching liquid of the most preferred content within the content of the etching solution of the embodiment, the first comparative example for comparison with the embodiment of the present invention is 62 wt% phosphoric acid, 3.5 wt% nitric acid, 3 wt% acetic acid, 0.1 wt% chlorine compound %, Chlorine stabilizer 0.1wt%, lithium-based compound 2wt%, sulfide-based compound by varying the content of acetic acid, is configured to deviate from the content of the etchant composition according to an embodiment of the present invention.

8A to 8B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a third comparative example of the present invention.

In this case, before the PR pattern by the ashing process is removed, the photograph of FIG. 8A indicates that the upper part of the photograph indicates the remaining PR pattern.

As shown in the figure, the double layer of molybdenum (Mo) and aluminum alloy (AlNd) when the content of acetic acid is less than 3wt% is excessively etched aluminum alloy (AlNd) of the lower layer, the undercut phenomenon occurs.

This is because the etching rate of the molybdenum (Mo) and the aluminum alloy (AlNd) is different.

<4th comparative example>

Etching liquid according to an embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt% chlorine compound, 0.1wt% chlorine stabilizer, 2wt% lithium-based compound, 2wt% sulfide-based compound, Examples of the etching solution of the most preferred content within the content does not deviate from the content of the etching solution, the first comparative example for comparison with the embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, chlorine compound 5.5 wt%, chlorine stabilizer 0.1wt%, lithium-based compound 2wt%, sulfide-based compound by varying the content of the chlorine-based compound, it is configured to deviate from the content of the etching solution composition according to an embodiment of the present invention.

9A to 9B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a fourth comparative example of the present invention.

In this case, the photographs of FIGS. 9A to 9B are before the PR pattern by the ashing process is removed, and the upper portion of the photograph indicates the remaining PR pattern.

As shown in the figure, the double layer of molybdenum (Mo) and aluminum alloy (AlNd) when the content of the chlorine-based compound is more than 5wt% is excessively etched aluminum alloy (AlNd) of the lower layer is generated undercut phenomenon.

In addition, as shown in FIG. 9B, an attack such that the PR pattern is melted or cracked by the etchant is generated.

This is because the chlorine compound affects the PR pattern by using more than 5wt% of the chlorine compound.

<Fifth Comparative Example>

Etching solution according to an embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt% chlorine compound, 0.1wt% chlorine stabilizer, 2wt% lithium compound, 2wt% sulfide compound The etching liquid of the most preferred content within the content of the etching solution of the embodiment, the first comparative example for comparison with the embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt chlorine compound %, Chlorine stabilizer 6wt%, lithium-based compound 2wt%, sulfide-based compound by varying the content of the chlorine stabilizer, it is configured to deviate from the content of the etchant composition according to an embodiment of the present invention.

FIG. 10 is a scanning electron micrograph showing a cross section of a pixel electrode composed of ITO after a wet etching process using an etchant according to a fifth comparative example of the present invention.

As shown, it can be seen that the etching rate of the ITO layer when the chlorine stabilizer content is more than 5wt% is reduced, and the residue A is not etched in perfect form during etching.

This is because the etching rate of the ITO layer is lowered by excessive use of the chlorine stabilizer.

<Sixth Comparative Example>

Etching solution according to an embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt% chlorine compound, 0.1wt% chlorine stabilizer, 2wt% lithium compound, 2wt% sulfide compound The etching liquid of the most preferred content within the content of the etching solution of the embodiment, the first comparative example for comparison with the embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt chlorine compound %, Chlorine stabilizer 0.1wt%, lithium-based compound 0.02wt%, sulfide-based compound by varying the content of the lithium-based compound, it is configured to deviate from the content of the etching solution composition according to an embodiment of the present invention.

11A to 11B are scanning electron micrographs showing a cross section of a double layer of molybdenum and an aluminum alloy constituting a gate electrode after a wet etching process using an etchant according to a sixth comparative example of the present invention.

In this case, before the PR pattern by the ashing process is removed, the photograph of FIG. 11A indicates that the upper part of the photograph indicates the remaining PR pattern.

As shown in the figure, the double layer of molybdenum (Mo) and aluminum alloy (AlNd) when the content of the lithium compound is less than 0.05wt% is excessively etched aluminum alloy (AlNd) of the lower layer, the undercut phenomenon occurs.

This is because the etching rate of the molybdenum monolayer is slowed down.

<7th comparative example>

The etchant according to an embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1wt% chlorine compound, 0.1wt% chlorine stabilizer, 2wt% lithium-based compound, 2wt% sulfide-based compound Examples of the etching solution of the most preferred content in the content does not deviate from the content of the etching solution, the first comparative example for comparison with the embodiment of the present invention is 62wt% phosphoric acid, 3.5wt% nitric acid, 15wt% acetic acid, 0.1-chlorine compound 0.1 wt%, chlorine stabilizer 0.1wt%, lithium-based compound 2wt%, sulfide-based compound by varying the content of the sulfide-based compound, configured to deviate from the content of the etchant composition according to an embodiment of the present invention do.

12A to 12B are scanning electron micrographs of a cross section of a molybdenum monolayer constituting a source and a gate electrode after a wet etching process using an etchant according to a seventh comparative example of the present invention.

At this time, before the PR pattern by the ashing process is removed, the photograph of FIG. 12A indicates that the upper part of the photograph indicates the remaining PR pattern.

As shown in the figure, the molybdenum (Mo) monolayer in the case where the content of the sulfide compound is less than 0.05wt% causes CD bais to be formed to have a smaller pattern size than the mask pattern size, resulting in a shoulder. Done.

This is because the rate at which the molybdenum (Mo) monolayer is etched is too fast.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

As described above, by using a single etching solution in accordance with the present invention, when using a different etching solution in each mask process does not require a more independent equipment configuration, there is an effect of simplifying the process and reducing the process cost.

In addition, there is an effect of improving productivity.

Claims (10)

40 to 70 wt% phosphoric acid; 2-15 wt% of nitric acid; Acetic acid of 4 to 35 wt%; 0.05-5 wt% of a chlorine compound; 0.05 to 5 wt% chlorine stabilizer; 0.05 to 5 wt% lithium compound 0.05 ~ 5wt% sulfur compound Contains the remaining amount of water, The chlorine stabilizer is composed of Zn, Cd, Pb, Ba-based compound and oleic acid, 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 , Cdl ₂ , Cd (NO ₃ ) ₂ , CdCO ₃ , Pb (CH ₃ COO) ₂ , C ₁₂ H ₁₀ O ₁₄ Pb ₃ , Pbl ₄ , Pb (NO ₃ ) ₂ , Pb (C ₁₇ H ₃₅ COO) ₂ , Ba (CH ₃ COO) ₂ , BaCO ₃ , BaCl ₂ , Bal ₂ , Ba (NO ₃ ) ₂ , BaHPO ₄ , and etching liquid for controlling the etching rate of indium tin oxide (ITO). The method of claim 1, The chlorine compound is an etching solution, characterized in that consisting of a compound that can be dissociated with Cl ^-1 . delete The method of claim 1, The lithium compound is LiNO ₃ , CH ₃ COOLi, C ₄ H ₅ O ₃ Li, LiCl, Lif, Lil, C ₂ HLiO ₄ , Li ₂ O ₂ , Li ₂ SO ₄ , LiH ₂ PO ₄ , Li ₃ PO ₄ Etching solution comprising a. The method of claim 1, The sulfide compound is H ₂ SO ₄ , Na ₂ SO ₄ , Na ₂ S ₂ O ₈ , KHSO ₄ , K ₂ SO ₄ , K ₂ S ₂ O ₈ , CaSO ₄ , (NH ₄ ) ₂ S ₂ O ₈ Etching solution comprising a. The method of claim 1, The water is an etchant, characterized in that using pure water filtered through an ion exchange resin. Forming a gate electrode by etching the first metal layer on the substrate using the etchant of claim 1; Forming an insulating film on the gate electrode; Stacking a semiconductor layer and a second metal layer on the insulating film; Etching the second metal layer through the etchant to form source and drain electrodes; Forming a protective layer having a drain contact hole exposing the drain electrode over the source and drain electrodes; Forming a pixel electrode on the passivation layer through the etching solution Method of manufacturing an array substrate for a liquid crystal display device comprising a. The method of claim 7, wherein And wherein the first metal layer is a double layer made of molybdenum and an aluminum alloy. The method of claim 7, wherein And the second metal layer is made of molybdenum. The method of claim 7, wherein The pixel electrode is made of indium tin oxide (ITO) array substrate manufacturing method for a liquid crystal display device.

Images