WO2012015089A1 - Method for preparing array substrate for liquid crystal display device - Google Patents

Abstract

The present invention relates to preparation method for an array substrate for the use in a liquid crystal display device, using an etchant composition comprising: a) 5-25 wt% of hydrogen peroxide (H₂O₂); b) 0.1-5 wt% of an organic acid; c) 0.1-5 wt% of a phosphate compound; d) 0.1-5 wt% of a water-soluble cyclic amine compound; e) 0.1-5 wt% of a water-soluble compound having a nitrogen atom and a carboxyl group in a molecule; f) 0.01-1.0 wt% of a fluorine-containing compound; g) 0.001-5 wt% of a polyhydric alcohol-based surfactant; and h) the balance of water based on the total weight of the composition.

Description

Manufacturing Method of Array Substrate for Liquid Crystal Display

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display device.

The process of forming a metal wiring on a substrate in a semiconductor device is composed of a metal film forming process, a photoresist forming process and an etching process in a selective region by photoresist coating, exposure and development. In addition, the process of forming the said metal wiring includes the washing | cleaning process, etc. before and after an individual unit process. The etching process refers to a process of leaving a metal film in a selective region using a photoresist as a mask. As the etching process, a dry etching using a plasma or the like or a wet etching using an etchant composition is usually used.

In such semiconductor devices, the resistance of metallization has recently emerged as a major concern. Because resistance is a major factor causing RC signal delay, especially in the case of TFT-LCD (thin film transistor-liquid crystal display), increasing panel size and realizing high resolution are key to the development of technology. Therefore, in order to realize the reduction of the RC signal delay which is essential for the large-sized TFT-LCD, it is necessary to develop a material of low resistance. Therefore, chromium (Cr, resistivity: 12.7 X10 ^-8 Ωm), molybdenum (Mo, resistivity: 5X10 ^-8 Ωm), aluminum (Al, resistivity: 2.65X10 ^-8 Ωm) and alloys thereof, which have been mainly used in the past, are large It is difficult to use the gate and data wiring used in the TFT LCD.

An object of the present invention is to provide an etching liquid composition of a copper-based metal film in which a tapered profile excellent in linearity is formed upon etching the copper-based metal film and no residue is left.

In addition, an object of the present invention is to provide an etching liquid composition of a copper-based metal film capable of collective etching with respect to a gate electrode and a gate wiring, a source / drain electrode and a data wiring.

It is also an object of the present invention to provide an etching method of a copper-based metal film using the etching solution composition and a method of manufacturing an array substrate for a liquid crystal display device.

1) forming a gate electrode by etching a copper-based metal film on the substrate with an etchant composition; 2) forming a gate insulating layer that insulates the gate electrode; 3) forming a semiconductor layer on the gate insulating layer; 4) forming an insulating layer to insulate the semiconductor layer; 5) forming a copper-based metal film on the insulating layer to insulate the semiconductor layer and etching the copper-based metal film with an etchant composition to form source / drain electrodes; And 6) forming a pixel electrode electrically connected to the drain electrode,

The etchant composition in steps 1) and 5), a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ) to the total weight of the composition; b) 0.1 to 5% by weight of organic acid; c) 0.1 to 5 weight percent of a 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) 0.01 to 1.0 wt% of a fluorine-containing compound; g) 0.001 to 5 wt% of a polyhydric alcohol-based surfactant; And h) provides a method of manufacturing an array substrate for a liquid crystal display device comprising a residual amount of water.

The present invention comprises the steps of: a) forming a copper-based metal film on the substrate; B) selectively leaving a photoreactive material on the copper-based metal film; And c) etching the copper-based metal film using an etchant composition, wherein the etchant composition comprises: a) 5 to 25 weight percent hydrogen peroxide (H ₂ O ₂ ) based on the total weight of the composition; b) 0.1 to 5% by weight of organic acid; c) 0.1 to 5 weight percent of a 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) 0.01 to 1.0 wt% of a fluorine-containing compound; g) 0.001 to 5 wt% of a polyhydric alcohol-based surfactant; And h) provides a method for etching the copper-based metal film comprising a residual amount of water.

The present invention relates to a total weight of the composition: a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ); b) 0.1 to 5% by weight of organic acid; c) 0.1 to 5 weight percent of a 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) 0.01 to 1.0 wt% of a fluorine-containing compound; g) 0.001 to 5 wt% of a polyhydric alcohol-based surfactant; And h) provides an etching liquid composition for a copper-based metal film comprising a residual amount of water.

The etching liquid composition according to the present invention may implement a taper profile excellent in linearity when etching the copper-based metal film. In addition, when etching the copper-based metal film with the etchant composition according to the present invention, no residue is generated, thereby preventing problems such as electrical shorts, wiring defects, and reduced luminance. In addition, when manufacturing an array substrate for a liquid crystal display device using the etchant composition according to the present invention, it is possible to collectively etch the gate electrode and gate wiring, the source / drain electrode and the data wiring, so that the process is very simplified to maximize the process yield have. Furthermore, when the etchant composition according to the present invention is used for etching low-resistance copper or copper alloy wirings, a large screen, high brightness circuit can be realized, and an environmentally friendly array substrate for a liquid crystal display device can be manufactured.

1 is a scanning electron micrograph of the etching cross-section after etching the Cu / Mo-Ti film using the etchant composition according to Example 1 of the present invention,

FIG. 2 is a scanning electron micrograph of etching a Cu / Mo-Ti film using an etchant composition according to Example 1 of the present invention and then observing an overall etching profile.

3 is an electron scanning microscope photograph of a copper wiring peripheral surface after etching a Cu / Mo-Ti film using an etchant composition according to Example 1 of the present invention to confirm that no etching residues remain.

Hereinafter, the present invention will be described in detail.

The present invention provides a composition comprising a) hydrogen peroxide (H ₂ O ₂ ), b) organic acid, c) phosphate compound, d) water-soluble cyclic amine compound, e) water-soluble compound having a nitrogen atom and a carboxyl group in one molecule, and f) a fluorine-containing compound. and g) a polyhydric alcohol-based surfactant and h) water.

In the present invention, the copper-based metal film includes copper as a constituent of the film, and is a concept including a multilayer film such as a single film and a double film. For example, a copper molybdenum film, a copper molybdenum alloy film, etc. are contained as a single film | membrane of copper or a copper alloy, and a multilayer film. The copper molybdenum film is meant to include a molybdenum layer and a copper layer formed on the molybdenum layer, and the copper molybdenum alloy film means a copper layer formed on the molybdenum alloy layer and 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 (In), and the like. Means alloy.

A) Hydrogen peroxide (H ₂ O ₂ ) included in the etchant composition of the present invention is a main component for etching the copper-based metal film. The a) hydrogen peroxide is contained in 5 to 25% by weight, 10 to 20% by weight relative to the total weight of the composition. If it is less than the above-mentioned range, the etching of the copper-based metal is not etched or the etching rate is very slow. In addition, when the above-mentioned range is exceeded, the etching rate becomes faster overall, which makes it difficult to control the process.

B) The organic acid included in the etchant composition of the present invention adjusts the pH appropriately to make the environment of the etchant easy to etch the copper-based metal film. B) The organic acid is contained in 0.1 to 5% by weight, and preferably in 1 to 3% by weight based on the total weight of the composition. If it is less than the above-described range, it is difficult to maintain the pH of about 0.5 to 4.5 because of insufficient influence to adjust the pH. In addition, when the above-mentioned range is exceeded, as the etching rate of copper is increased and the etching rate of molybdenum or molybdenum alloy is slowed, CD loss is increased and the possibility of residue of molybdenum or molybdenum alloy is increased.

B) the organic acid is acetic acid, butanoic acid, citric acid, formic acid, formic acid, gluconic acid, glycolic acid, malonic acid, and malonic acid. And pentanic acid (pentanoic acid), oxalic acid (oxalic acid) is preferably one or two or more selected from the group consisting of.

The c) phosphate compound included in the etchant composition of the present invention is a component that makes the taper profile of the pattern good. If the c) phosphate compound is not present in the etchant composition of the present invention, the etching profile may be poor. The c) phosphate compound is included in 0.1 to 5% by weight, and 0.5 to 3% by weight relative to the total weight of the composition. If it is less than the above-described range, the etching profile may be poor. If it exceeds the above-described range, a problem that the etching speed is slow may occur.

The c) phosphate compound is not particularly limited as long as it is selected from salts in which hydrogen is substituted with monovalent or divalent cations in phosphoric acid, but is not limited to sodium phosphate, potassium phosphate and ammonium phosphate. It is preferable that it is 1 type, or 2 or more types selected from the group which consists of.

D) The water-soluble cyclic amine compound included in the etchant composition of the present invention controls the etching rate of the copper-based metal and serves to increase the process margin by reducing the CD loss of the pattern. The d) water-soluble cyclic amine compound is included in an amount of 0.1 to 5% by weight, and 1 to 3% by weight based on the total weight of the composition. If it is included below the above-mentioned range, the cisidross may be generated too large. When included in excess of the above-mentioned range, since the etching rate of copper is increased and the etching rate of molybdenum or molybdenum alloy is slowed, the possibility of increasing the CDiros and remaining of molybdenum or molybdenum alloy is increased.

The d) water-soluble cyclic amine compound is aminotetrazole, imidazole, indole, purine, pyrazole, pyridine, pyrimidine, pyrrole It is preferably one or two or more selected from the group consisting of (pyrrole), pyrrolidine and pyrroline.

E) Water-soluble compounds having a nitrogen atom and a carboxyl group in one molecule of the present invention prevent the self-decomposition reaction of hydrogen peroxide water that may occur during storage of the etchant composition and the etching characteristics when etching a large number of substrates Prevent it from changing. In general, in the case of the etching liquid composition using the hydrogen peroxide solution, the hydrogen peroxide water itself decomposes during storage, and its storage period is not long, and there is a risk factor for the container to explode. However, when a water-soluble compound having a nitrogen atom and a carboxyl group is included in one molecule, the decomposition rate of the hydrogen peroxide solution is reduced by nearly 10 times, which is advantageous for securing the storage period and stability. Particularly, in the case of the copper layer, when a large amount of copper ions remain in the etching liquid composition, a passivation film may be formed to oxidize black and then no longer etched, but the addition of the compound may prevent this phenomenon. .

E) The water-soluble compound having a nitrogen atom and a carboxyl group in one molecule is preferably contained in 0.1 to 5% by weight, 0.5 to 2% by weight based on the total weight of the composition. When included below the above-mentioned range, a passivation film is formed after etching a large amount of substrates (about 500 sheets), making it difficult to obtain sufficient process margin. In addition, when included beyond the above range, the etching rate of the copper is lowered and the etching rate of the molybdenum or molybdenum alloy is faster, so that in the case of the copper molybdenum film or copper molybdenum alloy film, the taper angle is increased.

E) The water-soluble compound having a nitrogen atom and a carboxyl group in one molecule may be alanine, aminobutyric acid, glutamic acid, glycine, glycine, iminodiacetic acid, nitrilotriacetic acid ( nitrilotriacetic acid) and sarcosine (sarcosine) is preferably one or two or more selected from the group consisting of.

The f) fluorine-containing compound refers to a compound capable of dissociating in water to give F ions. The f) fluorine-containing compound serves to remove the residue that is inevitably generated in the solution to simultaneously etch the copper film and molybdenum film. The f) fluorine-containing compound is preferably contained in 0.01 to 1.0% by weight, and 0.1 to 0.5% by weight relative to the total weight of the composition. When included in less than the above-described range, an etching residue may occur. When included in excess of the above-described range, there is a disadvantage that the glass substrate etching rate is greatly generated.

The f) fluorine-containing compound is a substance used in the art, and is not particularly limited as long as it is a compound capable of dissociating into fluorine ions or polyatomic fluoride ions in a solution, but is not limited to ammonium fluoride and sodium fluoride. , Potassium fluoride (potassium fluoride), ammonium bifluoride (ammonium bifluoride), sodium bifluoride (sodium bifluoride) and potassium bifluoride (potassium bifluoride) is preferably one or two or more selected from the group.

G) polyalcohol-based surfactants included in the etchant composition of the present invention lowers the surface tension and serves to increase the uniformity of etching. In addition, the g) polyhydric alcohol-based surfactant is to surround the copper ions dissolved in the etchant after etching the copper film to suppress the activity of the copper ions to inhibit the decomposition reaction of hydrogen peroxide. When the activity of copper ions is lowered in this way, the process can be stably performed while using the etching solution. The content of the g) polyalcohol-based surfactant is included in 0.001 to 5% by weight, and 0.1 to 3% by weight based on the total weight of the composition. If included below the above range, there may be a problem that the etching uniformity is lowered and the decomposition of hydrogen peroxide is accelerated. If it exceeds the above-mentioned range, there is a disadvantage that a lot of bubbles are generated.

The g) polyhydric alcohol-based surfactant is preferably one or two selected from the group consisting of glycerol, triethylene glycol and polyethylene glycol.

The remaining amount of h) water contained in the etchant composition of the present invention is included, and the kind thereof is not particularly limited, but deionized water is preferable. More preferably, deionized water having a specific resistance value of the water (that is, the degree to which ions are removed in the water) is 18 kV / cm or more is preferably used.

In addition to the above components, a conventional additive may be further added to the etching liquid composition according to the present invention, and as the additive, a metal ion blocking agent, a corrosion inhibitor, or the like may be used.

In addition, the additive is not limited thereto, and in order to further improve the effects of the present invention, various other additives known in the art may be selected and added.

A) hydrogen peroxide (H ₂ O ₂ ), b) organic acid, c) phosphate compound, d) water-soluble cyclic amine compound, e) water-soluble compound having a nitrogen atom and a carboxyl group in one molecule, f) fluorine-containing Compound, g) It is preferable that the polyhydric alcohol type surfactant has the purity for a semiconductor process.

In the etching liquid composition of the copper-based metal film according to the present invention, the gate electrode, the gate wiring, the source / drain electrode and the data wiring of the liquid crystal display device made of the copper-based metal may be collectively etched.

In addition, the present invention,

A) forming a copper-based metal film on the substrate;

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

C) 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.

In addition, the present invention,

1) forming a gate electrode by etching the copper-based metal film on the substrate with an etchant composition;

2) forming a gate insulating layer that insulates the gate electrode;

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

4) forming an insulating layer to insulate the semiconductor layer;

5) forming a copper-based metal film on the insulating layer to insulate the semiconductor layer and etching the copper-based metal film with an etchant composition to form source / drain electrodes; And

6) forming a pixel electrode electrically connected to the drain electrode;

It relates to a method of manufacturing an array substrate for a liquid crystal display device using the etchant composition in steps 1) and 5).

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

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

Examples 1 to 6: Preparation of etching liquid composition of the copper-based metal film

To the etchant composition of Examples 1 to 6 according to the composition shown in Table 1.

Table 1 H ₂ O ₂ (% by weight) Glycolic acid (% by weight) Aminotetrazole (% by weight) Imino diacetic acid (% by weight) Potassium Phosphate (% by weight) Ammonium fluoride (% by weight) Triethylene glycol (wt%) Deionized Water (wt%) Example 1 5 2 One 0.5 0.5 0.1 One Remaining amount Example 2 10 5 One 0.5 0.5 0.2 0.5 Remaining amount Example 3 13 0.5 0.2 0.5 One 0.1 2 Remaining amount Example 4 8 One One 0.5 3 0.2 4 Remaining amount Example 5 22 2 2 0.5 One 0.3 0.1 Remaining amount Example 6 25 2 5 One One 0.5 0.5 Remaining amount

Test Example: Evaluation of Characteristics of Etch Liquid Composition

An etching process of the copper-based metal film (Cu single layer and Cu / Mo-Ti double layer) was performed using the etching solution compositions of Examples 1 to 6. During the etching process, the temperature of the etchant composition was about 30 ° C., but the proper temperature may be changed as needed by other process conditions and other factors. The etching time may vary depending on the etching temperature, but usually proceeds about 30 to 180 seconds. The profile of the copper-based metal film etched in the etching process was examined using a cross-sectional SEM (Model S-4700, manufactured by Hitachi), and the results are shown in Table 2.

TABLE 2 Etching Speed (Å / sec) Cu monolayer Cu / Mo-Ti Double Layer Cu Mo Example 1 40 to 60 40 to 60 6 to 8 Example 2 60 to 90 60 to 90 5 to 8 Example 3 20 to 40 20 to 40 4 to 6 Example 4 40 to 60 40 to 60 6 to 8 Example 5 50 to 80 50 to 80 6 to 8 Example 6 70 to 90 70 to 90 6 to 8

Referring to Table 2, the etching rate of the copper-based metal using Examples 1 to 6 was found to be appropriate. In addition, as can be seen in Figures 1 and 2, the copper film etched with the etchant composition according to Example 1 showed a good etching profile, as can be seen in Figure 3, as an etchant composition according to Example 1 When the copper film was etched, no etching residues remained.

Therefore, the etchant composition of the present invention provides excellent tapered profile of the copper-based metal film, the linearity of the pattern, and an appropriate etching rate, in particular, it can be seen that it has a characteristic that no residue remains after etching.

Claims (11)

1) forming a gate electrode by etching the copper-based metal film on the substrate with an etchant composition; 2) forming a gate insulating layer that insulates the gate electrode; 3) forming a semiconductor layer on the gate insulating layer; 4) forming an insulating layer to insulate the semiconductor layer; 5) forming a copper-based metal film on the insulating layer to insulate the semiconductor layer and etching the copper-based metal film with an etchant composition to form source / drain electrodes; And 6) forming a pixel electrode electrically connected to the drain electrode; The etchant composition in steps 1) and 5), a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ) to the total weight of the composition; b) 0.1 to 5% by weight of organic acid; c) 0.1 to 5 weight percent of a 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) 0.01 to 1.0 wt% of a fluorine-containing compound; g) 0.001 to 5 wt% of a polyhydric alcohol-based surfactant; And h) a residual amount of water. The method of claim 1, wherein the array substrate for a liquid crystal display device is a thin film transistor (TFT) array substrate. A) forming a copper-based metal film on the substrate; B) selectively leaving a photoreactive material on the copper-based metal film; And C) etching the copper-based metal film using an etchant composition, The etchant composition, a) 5 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ) relative to the total weight of the composition; b) 0.1 to 5% by weight of organic acid; c) 0.1 to 5 weight percent of a 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) 0.01 to 1.0 wt% of a fluorine-containing compound; g) 0.001 to 5 wt% of a polyhydric alcohol-based surfactant; And h) a residual amount of water. With respect to the total weight of the composition, a) 5 to 25 weight percent hydrogen peroxide (H ₂ O ₂ ); b) 0.1 to 5% by weight of organic acid; c) 0.1 to 5 weight percent of a 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) 0.01 to 1.0 wt% of a fluorine-containing compound; g) 0.001 to 5 wt% of a polyhydric alcohol-based surfactant; And h) an etching liquid composition for a copper-based metal film, comprising a residual amount of water. The method according to claim 4, B) the organic acid is acetic acid, butanoic acid, citric acid, formic acid, formic acid, gluconic acid, glycolic acid, malonic acid, and malonic acid. , Pentanic acid (pentanoic acid) and oxalic acid (oxalic acid) is one or two or more selected from the group consisting of etching liquid composition for a metal-based copper film. The method according to claim 4, The c) phosphate compound is a copper-based metal film etching solution composition, characterized in that one or two or more selected from the group consisting of sodium phosphate, potassium phosphate and ammonium phosphate. The method according to claim 4, The d) water-soluble cyclic amine compound is aminotetrazole, imidazole, indole, purine, pyrazole, pyridine, pyrimidine, pyrrole (Pyrrole), pyrrolidine (pyrrolidine) and pyrroline (pyrroline) is an etching liquid composition for a copper-based metal film, characterized in that at least one selected from the group consisting of. The method according to claim 4, E) The water-soluble compound having a nitrogen atom and a carboxyl group in one molecule is alanine, aminobutyric acid, glutamic acid, glycine, iminodiacetic acid, nitrilotriacetic acid. (nitrilotriacetic acid) and sarcosine (sarcosine) is an etching liquid composition for a copper-based metal film, characterized in that one or two or more selected from the group consisting of. The method according to claim 4, The f) fluorine-containing compound is a copper-based metal film etching liquid composition, characterized in that one or two or more selected from the group consisting of NH ₄ FHF, KFHF, NaFHF, NH ₄ F, KF, and NaF. The method according to claim 4, The g) polyhydric alcohol-based surfactant is a copper-based metal film etching liquid composition, characterized in that one or two or more selected from the group consisting of glycerol, triethylene glycol and polyethylene glycol. . The method according to claim 4, The copper-based metal film may be a single film of copper or copper alloy, a copper molybdenum film including a molybdenum layer and a copper layer formed on the molybdenum layer, or a copper molybdenum including a molybdenum alloy layer and a copper layer formed on the molybdenum alloy layer Etching liquid composition for a copper-based metal film, characterized in that the alloy film.

Images