KR102209686B1 - Etching solution composition for metal layer and manufacturing method of an array substrate for liquid crystal display using the same - Google Patents

Abstract

The present invention provides a metal film oxidizing agent; Nitrogen atom-containing compounds; Polyethylene glycol containing terminal carboxylic acid groups; And an etchant composition comprising water, and a method of manufacturing an array substrate for a liquid crystal display, comprising using the composition.

Description

Etching liquid composition of metal film and manufacturing method of array substrate for liquid crystal display using the same {ETCHING SOLUTION COMPOSITION FOR METAL LAYER AND MANUFACTURING METHOD OF AN ARRAY SUBSTRATE FOR LIQUID CRYSTAL DISPLAY USING THE SAME}

The present invention relates to an etchant composition for a metal film and a method of manufacturing an array substrate for a liquid crystal display using the same.

In the case of flat panel displays such as LCD, PDP and OLED, especially TFT-LCD, a single film made of copper or copper alloy, and furthermore, copper or copper is used to reduce wiring resistance and increase adhesion with silicon insulating film while becoming larger. The adoption of a multilayer of two or more layers of alloys/other metals, alloys of other metals, or metal oxides has been widely studied. For example, a copper/molybdenum film, a copper/titanium film, or a copper/molybdenum-titanium film can form a source/drain wire constituting a gate wire and a data line of a TFT-LCD, thereby contributing to the enlargement of the display. I can. Accordingly, there is a need to develop a composition having excellent etching properties capable of etching a metal film including the copper-based film as described above.

As the above-described etching composition, an etching solution based on hydrogen peroxide and amino acid, an etching solution based on hydrogen peroxide and phosphoric acid, and an etching solution based on hydrogen peroxide and polyethylene glycol are known.

For example, Korean Patent Laid-Open No. 10-2011-0031796 discloses an etchant containing hydrogen peroxide (H ₂ O ₂ ), persulfate, a water-soluble compound having an amine group and a carboxyl group, and water.

Republic of Korea Patent Publication No. 10-2012-0044630 discloses a copper-containing metal film etching solution containing hydrogen peroxide, phosphoric acid, a cyclic amine compound, sulfate, boronic acid and water.

Republic of Korea Patent Publication No. 10-2012-0081764 discloses an etching solution containing ammonium hydroxide, hydrogen peroxide, a fluorine-containing compound, a polyhydric alcohol, and water.

However, the above etchants do not sufficiently satisfy the conditions required in this field in terms of CD loss, taper, pattern straightness, metal residue, storage stability, and number of processed sheets for a metal film including a copper-based film. have.

Republic of Korea Patent Publication No. 10-2011-0031796 Republic of Korea Patent Publication No. 10-2012-0044630 Republic of Korea Patent Publication No. 10-2012-0081764

The present invention is to solve the problems of the prior art as described above, and has excellent work safety, storage stability, and etching rate, and in particular, an etchant composition for a metal film having a large amount of substrate processing capability and an array substrate for a liquid crystal display device using the same. It aims to provide a manufacturing method.

The present invention,

Metal film oxidizer (A); Nitrogen atom-containing compound (B); Polyethylene glycol (C) containing terminal carboxylic acid groups; And it provides an etchant composition comprising the water (D).

In the present invention, the terminal carboxylic acid group-containing polyethylene glycol (C) may be represented by the following formulas 1 to 4:

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

In the above formula,

n is an integer of 2 to 100,

R ₁ is hydrogen, a C1 ~ C10 straight or branched chain alkyl group, or a C6 ~ C12 aromatic hydrocarbon,

R ₂ is a C2-C8 aliphatic hydrocarbon or a C6-C12 aromatic hydrocarbon.

In addition, the present invention

a) forming a gate electrode on the substrate;

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

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

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

e) A method of manufacturing an array substrate for a liquid crystal display device comprising the step of forming a pixel electrode connected to the source/drain electrode,

Step a), d) or e) comprises forming a metal film, and etching the metal film with the etchant composition of the present invention to form an electrode. to provide.

The metal film etchant composition of the present invention includes a low content of a metal film oxidizing agent, thereby providing excellent work safety and an effect of economically disposing of the etchant, while providing an excellent etching rate.

In particular, the etchant composition of the present invention includes polyethylene glycol containing a terminal carboxylic acid group, and provides an effect of improving an etching rate and processing a large amount of substrates.

In addition, the manufacturing method of an array substrate for a liquid crystal display device using the etchant composition of the present invention is to prepare an array substrate for a liquid crystal display device having excellent driving characteristics by forming an electrode having an excellent etching profile on an array substrate for a liquid crystal display device. Makes it possible.

The present invention,

Metal film oxidizer (A); Nitrogen atom-containing compound (B); Polyethylene glycol (C) containing terminal carboxylic acid groups; And it relates to an etchant composition comprising water (D).

The metal film oxidizing agent is not particularly limited, and may be typically at least one selected from the group consisting of hydrogen peroxide, peracetic acid, metal oxide, nitric acid, persulfate, halogen acid, and halide salt.

The metal oxide refers to an oxidized metal, for example, Fe ^{3 +} , Cu ^{2 +} and the like, and the metal oxide also includes a compound that dissociates into the Fe ^{3 +} , Cu ^{2 +} and the like in a solution state. The persulfate includes ammonium persulfate, persulfate alkali metal salt, oxone, and the like, and the halide salt includes chlorate, perchlorate, bromate, perbromate, and the like.

The terminal carboxylic acid group-containing polyethylene glycol (C) may be represented by the following Chemical Formulas 1 to 4:

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

In the above formula,

n is an integer of 2 to 100,

R ₁ is hydrogen, a C1 ~ C10 straight or branched chain alkyl group, or a C6 ~ C12 aromatic hydrocarbon,

R ₂ is a C2-C8 aliphatic hydrocarbon or a C6-C12 aromatic hydrocarbon.

The present inventors have made diligent efforts to treat waste, process safety issues, secure price competitiveness, and improve the number of processed etchants. The etchant includes a nitrogen atom-containing compound and a terminal carboxylic acid group-containing polyethylene glycol, etc. The present invention was completed as a composition.

Hereinafter, each component constituting the etchant composition of the present invention will be described. However, the present invention is not limited to these components.

(A) Metal film Oxidant

In the present invention, the metal film oxidizing agent is a main component that oxidizes the metal of the metal film, and is not particularly limited, and is typically at least one selected from the group consisting of hydrogen peroxide, peracetic acid, metal oxide, nitric acid, persulfate, halogen acid, halide, etc. It may be, and more preferably hydrogen peroxide.

The metal oxide refers to an oxidized metal, for example, Fe ^{3 +} , Cu ^{2 +} and the like, and the metal oxide also includes a compound that dissociates into the Fe ^{3 +} , Cu ^{2 +} and the like in a solution state. The persulfate includes ammonium persulfate, persulfate alkali metal salt, oxone, and the like, and the halide salt includes chlorate, perchlorate, bromate, perbromate, and the like.

In the present invention, the metal film oxidizer is a main component that oxidizes copper, molybdenum or titanium. The metal film oxidizing agent is preferably contained in an amount of 1 to 25% by weight, preferably 1 to 10% by weight, more preferably 1 to 5% by weight, based on the total weight of the composition. When the above-described range is satisfied, a decrease in etching rates of copper, molybdenum, and titanium is prevented, an appropriate amount of etching may be implemented, and an excellent etching profile may be obtained. However, outside the above-described range, the layer to be etched may not be etched, or over-etching may occur, resulting in loss of patterns and loss of functions as a metal wiring.

The content of the metal layer oxidizing agent may be appropriately adjusted according to the type and characteristics of the oxidizing agent.

(B) Nitrogen atom Containing compound

The nitrogen atom-containing compound contained in the etchant composition of the present invention generally inhibits the decomposition reaction of a metal film oxidizer, particularly hydrogen peroxide, in the etchant composition, and serves to improve the etching rate and the number of treated sheets of the etchant.

The nitrogen atom-containing compound is preferably contained in an amount of 1 to 10% by weight, more preferably 1 to 5% by weight, based on the total weight of the composition. When the nitrogen atom-containing compound is included in the above-described range, the etching rate of the etching solution and the number of processed sheets may be improved.

The nitrogen atom-containing compound may be used without limitation, known in the art, and representatively, a compound containing an amino group and a carboxylic acid group in the molecule may be used.

Compounds containing an amino group and a carboxylic acid group in the molecule include an alpha amino acid containing 1 carbon atom between the carboxylic acid and the amino group, and representatively, 1 And polyvalent amino acids such as iminodiacetic acid, nitrilotriacetic acid and ethylene glycol tetraacetic acid. The nitrogen atom-containing compounds may be used alone or in combination of two or more.

(C) Terminal carboxylic acid group contain Polyethylene glycol

Polyethylene glycol containing terminal carboxylic acid groups contained in the etchant composition of the present invention suppresses the activity of metal ions by enclosing metal ions dissolved in the etchant after etching the metal film, thereby inhibiting the decomposition reaction of metal film oxidizers, especially hydrogen peroxide. Plays a role. When the activity of the metal ions is lowered in this way, the process can be stably performed while the etchant is used, and the number of substrates processed is increased. In particular, the polyethylene glycol of the present invention has the advantage of improving the etching rate and the number of processed sheets by including a carboxylic acid group at the terminal.

The principle of improving the etching rate and the number of sheets treated by the polyethylene glycol containing terminal carboxylic acid groups of the present invention can be interpreted as follows.

The etching process of metal proceeds in three steps: 1) oxidation of metal to metal oxide by a metal film oxidizer, 2) hydrolysis of metal hydroxide by metal oxide, and 3) dissolution of metal hydroxide from the metal surface into a solution. . The polyethylene glycol containing a terminal carboxylic acid group of the present invention acts as a catalyst to promote 2) and 3) during the etching process, and this characteristic is interpreted because the polyethylene glycol containing the terminal carboxylic acid group has a high bonding strength with the oxidized metal component.

In addition, the reason for the improvement in the number of treated sheets is that the carbonyl structure of carboxylic acid forms a stable structure through stronger chelating with metal cation, which is an etching by-product, compared to polyethylene glycol containing an alkyl group or hydroxy group at the terminal. It is interpreted that this is because it suppresses the reduction of the etching action due to the increase in the number of processed sheets by suppressing the recombination to the metal surface.

The terminal carboxylic acid group-containing polyethylene glycol may be preferably used by selecting one or more from the group consisting of compounds represented by the following Formulas 1 to 4.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

In the above formula,

n is an integer of 2 to 100,

R ₁ is hydrogen, a C1 ~ C10 straight or branched chain alkyl group, or a C6 ~ C12 aromatic hydrocarbon,

R ₂ is a C2-C8 aliphatic hydrocarbon or a C6-C12 aromatic hydrocarbon.

Polyethylene glycol containing a terminal carboxylic acid group of the present invention may be more preferably the following Formulas 1-1 to 4-1.

[Formula 1-1]

[Formula 2-1]

[Formula 3-1]

[Formula 4-1]

In the above formula,

n is an integer of 2 to 100.

The content of the terminal carboxylic acid group-containing polyethylene glycol is 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the total weight of the composition. When the content of polyethylene glycol is less than 0.1% by weight, it is difficult to expect an increase in the number of processed substrates, the etching uniformity is lowered, and the decomposition of hydrogen peroxide may be accelerated, and when it exceeds 10% by weight, It is difficult to expect an increase in the effect any more, and rather, it is not preferable because the increase in the viscosity of the etchant may cause a decrease in the etching rate and cause a lot of bubbles.

(D) water

The water contained in the etchant composition of the present invention is not particularly limited, but preferably means deionized water, and more preferably, water having a specific resistance of 18 MΩ/cm or more is used as deionized water for semiconductor processing.

The content of water may be included as a balance based on 100% by weight of the total composition.

The etchant composition of the present invention may further include at least one selected from the group consisting of a fluorinated compound, an acid containing a sulfur (S) atom or a phosphorus (P) atom.

The fluorinated compound contained in the etchant composition of the present invention is It serves to remove the etching residue and serves to etch the titanium-based metal film.

The fluorinated compound is preferably contained in an amount of 0.1 to 5% by weight, more preferably 0.1 to 2% by weight, based on the total weight of the composition. If the above-described range is satisfied, it is preferable because the etching residue is prevented and the etching of the glass substrate or the lower silicon film is not caused. However, outside the above-described range, stains may occur in the substrate due to non-uniform etching characteristics, the lower layer may be damaged due to an excessive etching rate, and it may be difficult to control the etching rate during processing.

The fluorine-containing compound is preferably a compound capable of dissociating into fluorine ions or polyatomic fluorine ions. The compound that can be dissociated into the fluorine ion or polyatomic fluoride ion may be one or two or more selected from the group consisting of hydrofluoric acid, ammonium fluoride, sodium fluoride, potassium fluoride, sodium bifluoride, and potassium bifluoride, and further It is preferably ammonium fluoride and/or hydrofluoric acid.

The acid containing sulfur (S) atoms or phosphorus (P) atoms contained in the etchant composition of the present invention may be included in an amount of 0.01 to 10% by weight, more preferably 0.01 to 1% by weight, based on the total weight of the composition. . When the content of the acid satisfies the above-described range, the risk of excessive etching of the metal layer due to the acid and corrosion of other lower layers can be avoided, and the problem of lowering the etching rate of the metal layer due to the too low acid content does not occur. Therefore, it can perform its original function.

As the acid containing the sulfur (S) atom or phosphorus (P) atom, components known in this field such as sulfuric acid, sulfonic acid, phosphoric acid, and phosphoric acid may be used without limitation, and phosphoric acid may be preferably used. . The phosphoric acid provides hydrogen ions to the etchant to promote copper etching of the metal layer oxidizer. In addition, the solubility in water is increased by bonding with oxidized copper ions to form phosphate, thereby removing residues of the copper metal film after etching.

The etchant composition of the present invention may further include at least one of an etch control agent, a surfactant, a metal ion sequestering agent, a corrosion inhibitor, and a pH adjuster in addition to the above-mentioned components.

It is preferable that the components constituting the etchant composition of the present invention have a purity for semiconductor processing.

The etchant composition of the present invention may be used regardless of the quality of the etching film, but may be more preferably used for etching a copper-based metal film, a molybdenum-based metal film, a titanium-based metal film, or a multilayer film made of them.

The copper-based metal film refers to a copper film or a copper alloy film, the molybdenum-based metal film refers to a molybdenum film or a molybdenum alloy film, and the titanium-based metal film refers to a titanium film or a titanium alloy film.

The multilayer film may include, for example, a double layer of a molybdenum-based metal film/copper-based metal film having a copper-based metal film as a lower film and a molybdenum-based metal film as an upper film; A copper-based metal film with a molybdenum-based metal film as a lower film and a copper-based metal film as an upper film/double film of a molybdenum-based metal film, a double film of a copper-based metal film/molybdenum-titanium-based metal film, and a molybdenum-based metal film Metal film/copper-based metal film/molybdenum-based metal film, or copper-based metal film/molybdenum-based metal film/copper-based metal film. Includes multiple membranes.

In addition, the multilayer film is, for example, a copper-based metal film as a lower film, a titanium-based metal film as an upper film, a titanium-based metal film/copper-based metal film as a double film, a titanium-based metal film as a lower film, and a copper-based metal film as an upper film. A copper-based metal such as a copper-based metal film/titanium-based metal film, and a titanium-based metal film/copper-based metal film/titanium-based metal film or a copper-based metal film/titanium-based metal film/copper-based metal film And a triple or more multilayer in which a titanium-based metal film is alternately stacked.

In the multilayer film, the interlayer bonding structure may be determined in consideration of a material constituting a film disposed above or below the multilayer film, or adhesion with the films.

In the above, the copper, molybdenum, or titanium alloy film refers to a metal film made of an alloy using copper, molybdenum, or titanium as a main component according to the characteristics of the film. For example, the molybdenum alloy film contains molybdenum as a main component, and at least one selected from titanium (Ti), tantalum (Ta), chromium (Cr), nickel (Ni), neodymium (Nd), and indium (In) It means a film made of an alloy formed including.

The etchant composition is particularly preferably used for etching a copper-based metal film, a copper-based metal film/molybdenum metal film, a copper-based metal film/titanium-based metal film, or a copper-based metal film/molybdenum-titanium-based metal film. I can. However, the use of the composition is not limited to the film quality.

The present invention also,

a) forming a gate electrode on the substrate;

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

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

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

e) A method of manufacturing an array substrate for a liquid crystal display device comprising the step of forming a pixel electrode connected to the source/drain electrode,

Step a), d), or e) comprises forming a metal film, and etching the metal film with the etchant composition of the present invention to form an electrode. It is about.

The array substrate for a liquid crystal display manufactured by the above method includes an electrode having an excellent etching profile, and thus has excellent driving characteristics.

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

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are for explaining the present invention more specifically, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

Example 1-6 and Comparative example 1-4: Etchant Preparation of the composition

An etchant composition was prepared by mixing the components shown in Table 1 below in the corresponding amount.

division Metal film oxidizer Glycine Dissension
ammonium Phosphoric acid Polyethylene
Glycol Deionized water Example 1 nitric acid 20 3 Formula 1-2 5 Balance Example 2 ammonium
Persulfate 20 3 Formula 1-2 5 Balance Example 3 Hydrogen peroxide 5 3 Formula 1-2 5 Balance Example 4 Hydrogen peroxide 5 3 1.5 Formula 2-2 5 Balance Example 5 Hydrogen peroxide 5 3 1.5 0.5 Formula 3-2 5 Balance Example 6 Hydrogen peroxide 5 3 1.5 0.5 Formula 4-2 5 Balance Comparative Example 1 Hydrogen peroxide 5 3 Balance Comparative Example 2 Hydrogen peroxide 10 3 1.5 0.5 Balance Comparative Example 3 Hydrogen peroxide 5 3 1.5 0.5 Formula 5 5 Balance Comparative Example 4 Hydrogen peroxide 5 3 1.5 0.5 Formula 6 5 Balance

(Unit: wt%)

week)

Polyethylene glycol:

[Formula 1-2]

[Formula 2-2]

[Chemical Formula 3-2]

[Formula 4-2]

[Formula 5]

[Formula 6]

Test example One: Etchant Composition of Etching characteristics evaluation

(One) Cu Single curtain Etching

A single Cu layer was etched using the etchant compositions of Examples 1 to 3 and Comparative Example 1. During the etching process, the temperature of the etchant composition was set to about 30°C and etching was performed for 100 seconds. By measuring EPD (End Point Detection, metal etching time) with the naked eye, an etching rate according to time was obtained. The results are shown in Table 2 below.

(2) Cu / Mo - Ti Double membrane Etching

The Cu/Mo-Ti double layer was etched using the etchant compositions of Examples 4 to 6 and Comparative Examples 2 to 4. During the etching process, the temperature of the etchant composition was set to about 30°C and etching was performed for 100 seconds. By measuring EPD (End Point Detection, metal etching time point) with the naked eye, an etching rate according to time was obtained, and the results are shown in Table 2 below.

Test example 2: Evaluation of the number of processed sheets

A reference etch test was performed with the etchant compositions of Examples 1 to 6 and Comparative Examples 1 to 4, and 4,000 ppm of copper powder was added to the reference test etchant to completely dissolve. Thereafter, etching was performed again, a reference etching test was performed, and the rate of decrease of the etching rate was evaluated and described in Table 2 below.

<Evaluation criteria>

○: Excellent (less than 10% etch rate decrease)

△: Good (Etch rate decrease rate 10% ~ 20%)

×: Defective (Etch rate reduction rate exceeds 20%)

division Etching characteristics Number of processing Etching speed (Å/sec) Example 1 167 ○ Example 2 182 ○ Example 3 137 ○ Example 4 139 ○ Example 5 141 ○ Example 6 144 ○ Comparative Example 1 117 × Comparative Example 2 125 × Comparative Example 3 112 △ Comparative Example 4 122 △

Claims (10)

Based on the total weight of the composition,
1 to 25% by weight of metal film oxidizer;
1 to 10% by weight of a nitrogen atom-containing compound;
0.1 to 10% by weight of polyethylene glycol containing terminal carboxylic acid groups; And
Includes the remaining amount of water,
The polyethylene glycol containing the terminal carboxylic acid group is an etchant composition, characterized in that at least one selected from the group consisting of the following formulas 1 to 4:
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

In the above formula,
n is an integer of 2 to 100,
R ₁ is hydrogen, a C1-C10 straight or branched chain alkyl group, or a C6-C12 aromatic hydrocarbon,
R ₂ is a C2-C8 aliphatic hydrocarbon or a C6-C12 aromatic hydrocarbon. delete The method according to claim 1,
The metal film oxidizing agent is an etchant composition, characterized in that at least one selected from the group consisting of hydrogen peroxide, peracetic acid, metal oxide, nitric acid, persulfate, halogen acid and halide. delete The method according to claim 1,
An etching solution composition, characterized in that it further comprises at least one selected from the group consisting of 0.1 to 5% by weight of a fluorinated compound and 0.01 to 10% by weight of an acid containing a sulfur (S) atom or a phosphorus (P) atom. The method according to claim 1,
The etchant composition is used for etching a copper-based metal film, a molybdenum-based metal film, a titanium-based metal film, or a multilayer film made of the same. The method according to claim 1,
The nitrogen atom-containing compound is an amino acid, and the acid containing a sulfur (S) atom or a phosphorus (P) atom is phosphoric acid. The method of claim 6,
The etchant composition, wherein the multilayer film is a copper-based metal film/molybdenum metal film, a copper-based metal film/titanium-based metal film, or a copper-based metal film/molybdenum-titanium-based metal film. The method of claim 3,
The metal film oxidizing agent is an etchant composition, characterized in that hydrogen peroxide. a) forming a gate electrode on the substrate;
b) forming a gate insulating layer on the substrate including the gate electrode;
c) forming a semiconductor layer on the gate insulating layer;
d) forming source/drain electrodes on the semiconductor layer; And
e) A method of manufacturing an array substrate for a liquid crystal display device comprising the step of forming a pixel electrode connected to the source/drain electrode,
The step a), d) or e) comprises forming a metal film, and forming an electrode by etching the metal film with the etchant composition of any one of claims 1, 3, and 5 to 9. A method of manufacturing an array substrate for a liquid crystal display device.