KR101539765B1 - Manufacturing method of an array substrate for liquid crystal display - Google Patents

Abstract

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display, comprising the steps of: forming a copper-based metal film on a substrate in a gate electrode formation step and etching the substrate with an etchant composition to form a gate wiring; Wherein the etchant composition comprises 5 to 30% by weight of hydrogen peroxide (H ₂ O ₂ ) based on the total weight of the composition, and forming the source and drain electrodes by etching with an etchant composition after forming the copper- ; 0.1 to 5% by weight of organic acid; 0.1 to 5% by weight of a phosphate compound; 0.1 to 5% by weight of a water-soluble cyclic amine compound; 0.1 to 5% by weight of a water-soluble compound having a nitrogen atom and a carboxyl group in one molecule; From 0.01 to 1.0% by weight of a compound in which fluorine ions are dissociated in solution; 0.01 to 5.0% by weight hydrogen peroxide hydrolysis inhibitor; 0.001 to 4% by weight of a surfactant; And a remaining amount of water; and a method of manufacturing the array substrate for a liquid crystal display device. The etchant composition; And a method of etching a copper-based metal film.

Copper film, etchant, liquid crystal display, array substrate

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing an array substrate for a liquid crystal display

The present invention relates to a method for manufacturing an array substrate for a liquid crystal display, an etching liquid composition for a copper-based metal film, and a method for etching a copper-based metal film using the etching liquid composition.

The process of forming a metal wiring on a substrate in a semiconductor device is generally composed of a metal film forming process by sputtering or the like, a photoresist coating process, a photoresist forming process in an optional region by exposure and development, and an etching process , A cleaning process before and after the individual unit process, and the like. This etching process refers to a process of leaving a metal film in a selective region using a photoresist as a mask. Typically, dry etching using plasma or wet etching using an etching composition is used.

In such a semiconductor device, resistance of metal wiring has recently become a major concern. This is because the resistance is a key factor that causes the RC signal delay, especially in the case of thin film transistor liquid crystal display (TFT LCD), which is the key to increasing panel size and realizing high resolution. Therefore, in order to realize reduction of the RC signal delay, which is indispensably required for enlarging the TFT LCD, it is necessary to develop a low-resistance material, and chromium (Cr, specific resistance: 12.7 x 10-8? M), molybdenum , Resistivity: 5 x 10-8? M), aluminum (Al, resistivity: 2.65 x 10-8? M), and alloys thereof are difficult to use as gate and data lines used in large-area TFT LCDs.

Under such background, there is a high interest in a copper-based metal film such as a copper film and a copper molybdenum film and an etchant composition thereof as a new low-resistance metal film.

However, research on the copper-based metal film is different, and various kinds are used as an etchant composition for the copper-based metal film, but the performance required by the user is not satisfied.

Accordingly, the present invention provides an etching solution for a copper-based metal film capable of forming a taper profile having excellent linearity at the time of etching a copper-based metal film, leaving no residue of the copper-based metal film, A method of etching a copper-based metal film using the etchant composition, and a method of manufacturing an array substrate for a liquid crystal display device.

The present invention relates to

A) 5 to 30% by weight of hydrogen peroxide (H ₂ O ₂ );

B) 0.1 to 5% by weight of organic acids;

C) 0.1 to 5% by weight phosphate compound;

D) 0.1 to 5% by weight of a water-soluble cyclic amine compound;

E) 0.1 to 5% by weight of a water-soluble compound having a nitrogen atom and a carboxyl group in one molecule;

F) from 0.01 to 1.0% by weight of a compound in which fluorine ions are dissociated in solution;

G) 0.01 to 5.0% by weight hydrogen peroxide hydrolysis inhibitor;

H) from 0.001 to 4% by weight of a surfactant; And

I) balance of water. ≪ IMAGE >

In addition,

I) forming a copper-based metal film on a substrate;

II) selectively leaving a photoreactive material on the copper-based metal film; And

III) A method for etching a copper-based metal film comprising the step of etching the copper-based metal film using the etchant composition of the present invention.

Further, according to the present invention,

a) forming a gate wiring on the substrate;

b) forming a gate insulating layer on the substrate including the gate wiring;

c) forming a semiconductor layer on the gate insulating layer;

d) forming source and drain electrodes on the semiconductor layer; And

e) forming a pixel electrode connected to the drain electrode, the method comprising the steps of:

In the step a), a copper-based metal film is formed on the substrate, and then a gate wiring is formed by etching with the etching solution composition of the present invention. In the step d), a copper-based metal film is formed, And forming a source electrode and a drain electrode on the substrate.

The present invention also provides an array substrate for a liquid crystal display comprising at least one of gate wiring and source and drain electrodes etched using the etchant composition.

When the copper-based metal film is etched with the etchant composition according to the present invention, a taper profile having an excellent linearity is formed and the residue of the copper-based metal film is not left, so that the copper-based metal film is free from problems such as electrical shorts, poor wiring, have.

In addition, since the gate electrode, the gate wiring, the data electrode, and the data wiring can be etched in a batch by using only the etchant composition according to the present invention, the process can be greatly simplified and the process yield can be maximized.

Further, when the etchant composition according to the present invention is used, it is possible to manufacture a semiconductor device having environment-friendly characteristics by realizing a large-sized circuit and a high-brightness circuit by using copper or copper alloy wiring with low resistance.

The present invention relates to a water-soluble cyclic amine compound, which comprises A) hydrogen peroxide (H ₂ O ₂ ), B) an organic acid, C) a phosphate compound, D) a water-soluble cyclic amine compound, E) a water-soluble compound having a nitrogen atom and a carboxyl group in one molecule, A compound in which fluorine ions are dissociated, G) a hydrogen peroxide hydrolysis inhibitor, H) a surfactant, and I) water.

In the present invention, the copper-based metal film includes copper as a constituent component of the film, and includes a multilayer film such as a single film and a double film. For example, a single film of copper or a copper alloy, a copper molybdenum film, a copper molybdenum alloy film, or the like as a multilayer film. The copper molybdenum film includes a molybdenum layer and a copper layer formed on the molybdenum layer, and the copper molybdenum alloy film includes a molybdenum alloy layer and a copper layer formed on the molybdenum alloy layer. The molybdenum alloy layer may include at least one selected from the group consisting of titanium (Ti), tantalum (Ta), chromium (Cr), nickel (Ni), neodymium (Nd), indium Alloy.

The hydrogen peroxide (H ₂ O ₂ ) is a main component for etching the copper-based metal film, and the content thereof is preferably 5 to 30% by weight based on the total weight of the composition. If the content of hydrogen peroxide is less than 5% by weight, etching of the copper-based metal may not be performed or the etching rate may be very slow. If the content of hydrogen peroxide is more than 30% by weight, the etching speed may be accelerated.

In this case, the pH of the organic acid is suitably adjusted (pH 0.5 to 4.5) so that the copper-based metal film can be etched in the etchant environment. Specific examples of the organic acid include acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid Pentanoic acid, and oxalic acid. These may be used singly or in combination of two or more.

The content of the organic acid is preferably 0.1 to 5% by weight based on the total weight of the composition. If it is less than 0.1% by weight, it is difficult to maintain the pH at 0.5 to 4.5, and if it exceeds 5.0% by weight, the etching rate of copper becomes faster and the etching rate of molybdenum or molybdenum alloy becomes slower, (CD Loss) is increased and the possibility of residue of molybdenum or molybdenum alloy is increased.

The phosphate compound is a component that makes the taper profile good. If the phosphate compound is not present, the etch profile may be poor. As such a phosphate compound, various types can be used, and it is preferable to use one in which phosphoric acid is replaced with one or two salts of hydrogen with an alkali metal or an alkaline earth metal. Specific examples thereof include sodium phosphate, potassium phosphate and ammonium phosphate. These may be used singly or in combination of two or more.

The content of the phosphate compound is preferably 0.1 to 5% by weight based on the total weight of the composition. If the amount is less than 0.1% by weight, the etching profile may be poor. If the amount exceeds 5% by weight, .

The water-soluble cyclic amine compound controls the etch rate of the copper-based metal and reduces the CD loss of the pattern, thereby enhancing the process margin. Specific examples include aminotetrazole, imidazole, indole, purine, pyrazole, pyridine, pyrimidine, pyrrole, pyrrole, Pyrrolidine and pyrroline. These may be used singly or in combination of two or more.

The content of the water-soluble cyclic amine compound is preferably from 0.1 to 5% by weight based on the total weight of the composition. When the content of the water-soluble cyclic amine compound is less than 0.1% by weight, the seedloss may be too large, And the etch rate of the molybdenum or molybdenum alloy is slowed to increase the seed loss and increase the likelihood of residues of molybdenum or molybdenum alloys remaining.

The water-soluble compound having a nitrogen atom and a carboxyl group in the molecule prevents the self-decomposition reaction of the hydrogen peroxide water which may occur during storage of the etching solution composition and prevents the etching property from changing when a large number of substrates are etched. Specific examples include alanine, aminobutyric acid, glutamic acid, glycine, iminodiacetic acid, nitrilotriacetic acid, and sarcosine. These may be used singly or in combination of two or more.

The content of the water-soluble compound having a nitrogen atom and a carboxyl group in the molecule is preferably 0.1 to 5% by weight. When the amount is less than 0.1% by weight, a passivation film is formed after etching a large number of substrates (about 500 sheets) If it exceeds 5.0% by weight, the etching rate of copper is slowed down and the etching rate of molybdenum or molybdenum alloy is accelerated, so that the taper angle of the copper molybdenum film or the copper molybdenum alloy film becomes large.

In general, the etching solution using hydrogen peroxide water has self-decomposition of the hydrogen peroxide solution during storage, and the storage period is not long, and the container has explosion risk. However, when a water-soluble compound having a nitrogen atom and a carboxyl group is included in the molecule, the decomposition rate of the hydrogen peroxide solution is reduced to about 10 times, which is advantageous for securing the storage period and stability. Particularly, in the case of a copper layer, when a large amount of copper ions remain in the etchant composition, a passivation film is formed, which is then oxidized to black and then etched. However, such a phenomenon can be prevented by adding this compound .

The compound in which the fluorine ions are dissociated in the solution serves to remove residues which are inevitably generated in the solution for simultaneously etching the copper film and the molybdenum film. And it is preferable to use ammonium fluoride, sodium fluoride, potassium fluoride and the like as well as their intermediate compounds such as ammonium bifluoride, Sodium bifluoride, potassium bifluoride, and the like, which can be dissociated into a fluoride ion or a polyatomic fluoride ion in a solution, can be used. These compounds may be used singly or in combination of two or more.

The content of the compound in which the fluorine ions are dissociated in the solution is preferably 0.01 to 1.0% by weight based on the total weight of the composition. When the amount is less than 0.01% by weight, etch residues may be generated. When the amount exceeds 1.0% There is a disadvantage that a large rate is generated.

The hydrogen peroxide hydrolysis inhibitor plays a role in assisting the performance of a water-soluble compound having a nitrogen atom and a carboxyl group in the molecule, and plays a role of slowing down the hydrolysis rate of hydrogen peroxide. The hydrogen peroxide hydrolysis inhibitor is not particularly limited, and various kinds can be used. For example, a cyclohexane amine can be used.

The content of the hydrogen peroxide decomposition inhibitor is preferably 0.01 to 5.0% by weight based on the total weight of the composition. When the content is less than 0.01% by weight, the decomposition rate of the hydrogen peroxide solution is lowered. When the content exceeds 5.0% .

The surfactant serves to lower the surface tension and increase the uniformity of the etching. As such a surfactant, a surfactant which is resistant to an etching solution and has compatibility with the surfactant is preferable. Examples thereof include any anionic, cationic, amphoteric or nonionic, polyhydric alcohol type surfactants and the like.

The content of the surfactant is preferably 0.001 to 4% by weight based on the total weight of the composition. If the amount is less than 0.001% by weight, etching uniformity is deteriorated. If the amount is more than 4% by weight,

The water is not particularly limited, but deionized water is preferred. More preferably, it is preferable to use deionized water having a resistivity value of water (i.e., the degree of removal of ions in water) of 18 M? / Cm or more.

In the etchant composition according to the present invention, conventional additives may be further added in addition to the above-mentioned components. Metal ion sequestrants and corrosion inhibitors may be used as additives.

In addition, the additives are not limited thereto, and various other additives known in the art may be selected and added for better effect of the present invention.

The hydrogen peroxide (H ₂ O ₂ ), the organic acid, the phosphate compound, the water-soluble cyclic amine compound, the water-soluble compound having a nitrogen atom and a carboxyl group in one molecule, the compound in which the fluorine ion dissociates in the solution, Compounds containing an inhibitor and a surfactant can be prepared by a conventionally known method, and preferably have purity for semiconductor processing.

The etchant composition of the copper-based metal film according to the present invention can collectively etch gate electrodes, gate wirings, data electrodes, and data wirings of a liquid crystal display device made of a copper-based metal.

Further, according to the present invention,

I) forming a copper-based metal film on a substrate;

II) selectively leaving a photoreactive material on the copper-based metal film; And

III) etching the copper-based metal film using the etching solution composition of the present invention.

In the etching method of the present invention, the photoreactive material is preferably a conventional photoresist material, and may be selectively left by conventional exposure and development processes.

Further, according to the present invention,

a) forming a gate wiring on the substrate;

b) forming a gate insulating layer on the substrate including the gate wiring;

c) forming a semiconductor layer on the gate insulating layer;

d) forming source and drain electrodes on the semiconductor layer; And

e) forming a pixel electrode connected to the drain electrode, the method comprising the steps of:

In the step a), a copper-based metal film is formed on the substrate, and then a gate wiring is formed by etching with the etching solution composition of the present invention. In the step d), a copper-based metal film is formed, And forming a source electrode and a drain electrode on the substrate.

The array substrate for a liquid crystal display may be a thin film transistor (TFT) array substrate.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited by the following examples.

Example  1 to 6

The etchant compositions of Examples 1 to 6 were prepared according to the compositions shown in Table 1 below. Then, the etching process of the copper-based metal film (Cu single film and Cu / Mo double film) was performed using the etchant composition of Example 1.

The temperature of the etchant composition during the etching process is about 30 ° C, and the optimum temperature can be changed as needed depending on other process conditions and other factors. The etching time may vary depending on the etching temperature, but is usually 30 to 180 seconds.

The profile of the copper-based metal film etched by the above process was inspected using a cross-sectional SEM (product of Hitachi, Model S-4700). The measured etch rate showed a reasonable rate, as shown in Table 1. As can be seen from FIGS. 1 and 2, the copper film etched with the etchant composition according to Example 1 exhibited a good etching profile. As can be seen from FIG. 3, When the film was etched, the etch residue remained. Therefore, it can be seen that the etching solution composition of the present invention has an excellent taper profile of the copper-based metal film, a linearity of the pattern, and an appropriate etching rate, in particular, a property that no residue remains after etching.

H ₂ O ₂ / glycolic acid / imidazole / iminodiacetic acid / potassium phosphate / ammonium fluoride / cyclic nucleic acid amine / polyethylene glycol / deionized water Etching speed (Å / sec) Cu single membrane Cu / Mo bilayer Cu Mo One 5/2/1 / 0.5 / 0.5 / 0.1 / 0.5 / 1 / balance 40 to 60 40 to 60 6 to 8 2 10/5/1 / 0.5 / 0.5 / 0.2 / 0.2 / 0.5 / balance 60 to 90 60 to 90 5 ~ 8 3 13 / 0.5 / 0.2 / 0.5 / 1 / 0.1 / 1/2 / remaining amount 20 to 40 20 to 40 4 to 6 4 8/1/1 / 0.5 / 3 / 0.2 / 2/4 / balance 40 to 60 40 to 60 6 to 8 5 22/2/2 / 0.5 / 1 / 0.3 / 0.3 / 0.1 balance 50 to 80 50 to 80 6 to 8 6 25/2/5/1/1 / 0.5 / 0.5 / 0.5 / balance 70 to 90 70 to 90 6 to 8

1 is a scanning electron microscope (SEM) image of a copper film etched using an etchant composition according to Example 1 of the present invention,

2 is a scanning electron microscope (SEM) image of a copper film etched using the etchant composition according to Example 1 of the present invention,

3 is an electron micrograph of the surface of the copper wiring after etching the copper film using the etchant composition according to Example 1 of the present invention to confirm that no etching residue remains.

Claims (15)

a) forming a gate wiring on the substrate; b) forming a gate insulating layer on the substrate including the gate wiring; c) forming a semiconductor layer on the gate insulating layer; d) forming source and drain electrodes on the semiconductor layer; And e) forming a pixel electrode connected to the drain electrode, the method comprising the steps of: In the step a), a copper-based metal film is formed on the substrate, and then a gate wiring is formed by etching with an etchant composition. In the step d), a copper-based metal film is formed and then etched with an etchant composition to form source and drain electrodes Lt; / RTI & The etchant composition comprises, based on the total weight of the composition: A) from 5 to 30% by weight of hydrogen peroxide (H ₂ O ₂ ); B) 0.1 to 5% by weight of organic acids; C) 0.1 to 5% by weight phosphate compound; D) a compound selected from the group consisting of aminotetrazole, imidazole, indole, purine, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidine 0.1 to 5% by weight of one or more water-soluble cyclic amine compounds selected from the group consisting of pyrrolidine and pyrroline; E) From the group consisting of alanine, aminobutyric acid, glutamic acid, glycine, iminodiacetic acid, nitrilotriacetic acid and sarcosine. 0.1 to 5% by weight of a water-soluble compound having a nitrogen atom and a carboxyl group in one molecule or two or more kinds of molecules selected; F) from 0.01 to 1.0% by weight of a compound in which fluorine ions are dissociated in solution; G) 0.01 to 5.0% by weight of a cyclohexane amine; H) from 0.001 to 4% by weight of a surfactant; And I) the remaining amount of water. ≪ RTI ID = 0.0 > 11. < / RTI > The method of manufacturing an array substrate for a liquid crystal display according to claim 1, wherein the array substrate for a liquid crystal display is a thin film transistor (TFT) array substrate. A) 5 to 30% by weight of hydrogen peroxide (H ₂ O ₂ ), based on the total weight of the etchant composition; B) 0.1 to 5% by weight of organic acids; C) 0.1 to 5% by weight phosphate compound; D) a compound selected from the group consisting of aminotetrazole, imidazole, indole, purine, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidine 0.1 to 5% by weight of one or more water-soluble cyclic amine compounds selected from the group consisting of pyrrolidine and pyrroline; E) From the group consisting of alanine, aminobutyric acid, glutamic acid, glycine, iminodiacetic acid, nitrilotriacetic acid and sarcosine. 0.1 to 5% by weight of a water-soluble compound having a nitrogen atom and a carboxyl group in one molecule or two or more kinds of molecules selected; F) from 0.01 to 1.0% by weight of a compound in which fluorine ions are dissociated in solution; G) 0.01 to 5.0% by weight of a cyclohexane amine; H) from 0.001 to 4% by weight of a surfactant; And I) the remaining amount of water. The method of claim 3, wherein the organic acid is selected from the group consisting of acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, malonic acid, pentanoic acid, and oxalic acid. The etching solution composition of the copper-based metal film according to claim 1, The copper-based metal membrane according to claim 3, wherein the phosphate compound is at least one selected from the group consisting of sodium sulfate, potassium sulfate, and ammonium sulfate. Etchant composition. delete delete The method of claim 3, wherein the compound in which the fluorine ions are dissociated in the solution is one or more selected from the group consisting of NH ₄ FHF, KFHF, NaFHF, NH ₄ F, KF, and NaF. Etchant composition. delete The etchant composition of a copper-based metal film according to claim 3, wherein the surfactant is one or more selected from anionic surfactants and polyhydric alcohol surfactants. The copper-based metal film according to any one of claims 3 to 5, 8, and 10, wherein the copper-based metal film comprises a single film of copper or a copper alloy, a copper molybdenum film comprising a molybdenum layer and a copper layer formed on the molybdenum layer, And a copper layer formed on the molybdenum alloy layer, wherein the copper molybdenum alloy layer is formed on the molybdenum alloy layer. I) forming a copper-based metal film on a substrate; II) selectively leaving a photoreactive material on the copper-based metal film; And III) A method for etching a copper-based metal film, comprising etching the copper-based metal film using the etching liquid composition according to any one of claims 3 to 5, 8, and 10. 13. The method of claim 12, wherein the photoreactive material is a photoresist material and is selectively left by an exposure and development process. [12] The copper-based metal film according to claim 12, wherein the copper-based metal film is a copper molybdenum alloy film including a molybdenum layer and a copper layer formed on the molybdenum layer, and a copper layer formed on the molybdenum alloy layer Based metal film. An array substrate for a liquid crystal display comprising at least one of gate wiring and source and drain electrodes etched using the etchant composition of any one of claims 3 to 5, 8,

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