KR20160001296A - 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 relates to an etching solution composition for a metal layer and a manufacturing method of an array substrate for a liquid crystal display using the same. The etching solution composition for a metal layer comprises: an oxidizing agent for a metal layer; a compound containing nitrogen atoms; pyridine; and water. Therefore, the present invention provides excellent work safety and etching speed and enables the treatment of a great deal of substrates.

Description

TECHNICAL FIELD The present invention relates to an etching solution composition for a metal film and an array substrate for a liquid crystal display using the same,

The present invention relates to an etching liquid 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 LCDs, PDPs and OLEDs, in particular, in the case of TFT-LCDs, a single film of copper or copper alloy, or copper or copper alloy, in order to reduce the wiring resistance and increase the adhesion with the silicon insulating film, An alloy / other metal, an intermetallic alloy or a metal oxide 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 wiring constituting a gate wiring and a data line of the TFT-LCD, . Therefore, it is required to develop a composition having excellent etching properties capable of etching a metal film including the copper-based film.

Such etching compositions are typically known as etching solutions based on hydrogen peroxide and amino acids, etching solutions based on hydrogen peroxide and phosphoric acid, etching solutions based on hydrogen peroxide and polyethylene glycol, and the like.

For example, Korean Patent Laid-Open No. 10-2011-0031796 discloses an etching solution comprising A) a hydrogen peroxide (H ₂ O ₂ ) B) and a sulfate, C) a water-soluble compound having a carboxyl group and an amine group, and water.

Korean Patent Laid-Open No. 10-2012-0044630 discloses a copper-containing metal film etchant containing A) hydrogen peroxide, B) phosphoric acid, C) cyclic amine compound, D) sulfate, E) boron fluoride acid and F) have.

Korean Patent Publication No. 10-2012-0081764 discloses an etching solution comprising A) ammonium hydroxide, B) hydrogen peroxide, C) fluorine compound, D) polyhydric alcohol and E) water.

However, such etchants do not sufficiently satisfy the conditions required in this field in terms of CD loss, taper, pattern straightness, metal residue, storage stability, number of treatments, etc. with respect to a metal film containing a copper-based film have.

Korean Patent Publication No. 10-2011-0031796 Korean Patent Publication No. 10-2012-0044630 Korean Patent Publication No. 10-2012-0081764

It is an object of the present invention to provide an etchant composition for a metal film which has excellent work safety and has an excellent etching rate and a large amount of substrate processing ability.

In particular, it is an object of the present invention to provide an etchant composition for a metal film excellent in side-etching control and a method for manufacturing an array substrate for a liquid crystal display device using the same.

According to the present invention,

Metal film oxidizer; A nitrogen atom-containing compound; Pyridine represented by the following formula (1); And water. ≪ Desc / Clms Page number 2 >

 [Chemical Formula 1]

In Formula 1,

R ₁ and R ₂ are each independently hydrogen, NH ₂ Or COOH, preferably when R ₁ is NH ₂ , R ₂ is hydrogen and when R ₁ is COOH, R _{2 is} also COOH.

The present invention also provides a method of manufacturing a semiconductor device, comprising the steps of: a) forming a gate electrode on a 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 a source / drain electrode on the semiconductor layer; And e) forming a pixel electrode connected to the source / drain electrode, wherein the steps a), d) or e) comprise forming a metal film, And etching the film with the etchant composition of the present invention to form an electrode. The present invention also provides a method of manufacturing an array substrate for a liquid crystal display.

The metal film etchant composition of the present invention comprises Thereby providing an effect of treating a large amount of substrates. In particular, it facilitates side etching control.

In addition, the etching solution composition of the metal film including the copper-based film, which is an embodiment of the present invention, includes a low content of hydrogen peroxide, thereby providing excellent work safety and economical disposal of the etchant, Respectively.

The method for manufacturing an array substrate for a liquid crystal display device using the etching liquid composition of the present invention is characterized in that an electrode having an excellent etching profile is formed on an array substrate for a liquid crystal display device to manufacture an array substrate for a liquid crystal display .

Hereinafter, the present invention will be described in detail. The following detailed description is merely an example of the present invention, and therefore, the present invention is not limited thereto.

The etching solutions of the prior art do not sufficiently satisfy the requirements in this field in terms of CD loss, taper, pattern straightness, metal residue, storage stability, number of treatments, etc. for the metal film including the copper-based film. In particular, etching performance of the side etching formed by the etching is deteriorated, so that the desired shape can not be realized.

In general, the amino acid in the etching solution composition chelates copper ions to inhibit the decomposition reaction of an oxidizing agent such as hydrogen peroxide, and maintains the pH of the etching solution at a constant level. Further, it functions to improve the storage stability of the etching solution. However, the etching control composition of the side etching is insufficient in the conventional etching composition.

Accordingly, the present inventors have made intensive efforts to improve the etching control of the side etching of the etching solution. When the pyridine represented by the following formula (1) is included in the etching solution composition, it is confirmed that the side etching control performance is remarkably improved. It was completed.

That is, the present invention relates to a metal film oxidizing agent; A nitrogen atom-containing compound; Pyridine represented by the following formula (1); And water.

 [Chemical Formula 1]

In the above formula (1), R ₁ and R ₂ each independently may be hydrogen, NH ₂ or COOH, preferably when R ₁ is NH ₂ , R ₂ may be hydrogen, and another preferred example is R _{When 1} is COOH, R ₂ can also be COOH.

The etchant composition of the present invention can be used regardless of the etching film quality, but can be 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 the same.

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

The multilayered film may be a multilayer film of a molybdenum-based metal / 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 double-layer film of a copper-based metal film / molybdenum-based metal film and a molybdenum-based metal film / a copper-based metal film / molybdenum-based metal film having a molybdenum-based metal film as a lower film and a copper- And a multi-layered film of a triple-layered film in which a copper-based metal and a molybdenum-based metal film are alternately stacked, such as a copper-based metal film / molybdenum-based metal film / copper-based metal film.

The multi-layered film may be a double-layered film of a titanium-based metal film / copper-film-based metal film having a copper-based metal film as a lower film and a titanium-based metal film as an upper film, a titanium-based metal film as a lower film, A copper-based metal / a titanium-based metal film / a copper-based metal film / a titanium-based metal film or a copper-based metal film / a titanium-based metal film / And a multi-layered film of alternately stacked films.

The interlayer coupling structure can be determined by taking into account the composition of the film disposed on the upper part of the multilayer film or the material constituting the film disposed on the lower part of the multilayer film or adhesion with the films.

The term "copper, molybdenum or titanium alloy film" as used herein refers to a metal film made of copper, molybdenum or titanium as a main component and made of an alloy using another metal, depending on the characteristics of the film. For example, the molybdenum alloy film is made of molybdenum as a main component and at least one selected from among titanium (Ti), tantalum (Ta), chromium (Cr), nickel (Ni), neodymium (Nd) And the like.

Hereinafter, the constitution of the etching liquid composition of the present invention will be described.

First, the metal film oxidizing agent of the present invention will be described.

The metal film oxidizing agent of the present invention serves to oxidize a multilayer film including a metal.

The metal film oxidizing agent may be contained in an amount of 1 to 40% by weight based on the total weight of the composition of the present invention, and the content of the metal film oxidizing agent may be appropriately controlled depending on the type and characteristics of the oxidizing agent.

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, halide acid salt and the like. The metal oxide means an oxidized metal, for example, Fe ^{3 +} , Cu ^{2 +} or the like. The metal oxide also includes a compound dissociated into Fe ^{3 +} , Cu ^{2 +} or the like in a solution state, Sulfates include ammonium persulfate, persulfate alkali metal salts, oxone and the like, and halide salts include chlorate, perchlorate, bromate, perbromate and the like.

According to a preferred embodiment of the present invention, hydrogen peroxide may be used as the metal film oxidizing agent, and the hydrogen peroxide is a main component for oxidizing copper, molybdenum, and titanium. The hydrogen peroxide 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-mentioned range is satisfied, deterioration of the etching rate of copper, molybdenum, and titanium is prevented, an appropriate amount of etching can be realized, and an excellent etching profile can be obtained. However, if the range is out of the above range, the film to be etched may not be etched, or an excessive angle may be generated, and pattern loss and function as a metal wiring may be lost.

Next, the nitrogen atom-containing compound will be described.

The nitrogen atom-containing compound contained in the etchant composition of the present invention has a role of improving the etching rate and the number of treatments of the etching solution. As the nitrogen atom-containing compound, any compound known in the art can be used without limitation. Typically, a compound containing an amino group and a carboxylic acid group in a molecule may be used. Examples of the compound containing an amino group and a carboxylic acid group in the molecule include a carboxylic acid and an amino group Include alpha amino acids containing one carbon atom. Representative examples include monovalent amino acids such as glycine, glutamic acid, glutamine, isoleucine proline, tyrosine, arginine and the like, and polyvalent amino acids such as iminodiacetic acid, nitrilodriacetic acid and ethylene glycol tetraacetic acid. These nitrogen atom-containing compounds may be used alone or in combination of two or more.

The nitrogen atom-containing compound may be contained in an amount of 0.1 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 contained in the above-mentioned range, the etching rate and the number of the etching solutions can be improved.

Next, the pyridine represented by the following formula (1) will be described.

[Chemical Formula 1]

In the above formula (1), R ₁ and R ₂ each independently may be hydrogen, NH ₂ or COOH, preferably when R ₁ is NH ₂ , R ₂ may be hydrogen, and another preferred example is R _{When 1} is COOH, R ₂ can also be COOH.

The pyridine represented by the above formula (1) used in the etchant composition of the present invention controls the etching rate of a metal film, for example, a copper-containing metal film. And to reduce the CD (critical dimension) loss of the metal film, for example, the copper-containing metal film pattern, thereby enhancing the process margin. That is, the pyridine represented by the above formula (1) controls the etching rate to obtain a metal wiring having a desired width.

Specifically, the role of the pyridine represented by the formula (1) in the etching solution composition of the present invention will be explained by the mechanism.

The pyridine represented by the above formula (1) acts as an inhibitor for protecting the etching by the oxidizing agent by binding to the metal of the metal film, for example, copper of the copper film. The etchant composition containing the pyridine represented by the formula (1) serving as the protective agent is sprayed onto the surface of the metal of the metal film, for example, the copper film of the copper film. The bottom surface of the metal of the metal film, for example, the copper film, is fast due to the pressure of the spray, and the pyridine represented by the formula (1) serving as a protecting agent is disadvantageous to adsorb on the copper surface. On the other hand, the side portion becomes an environment in which pyridine represented by the formula (1), which acts as a protecting agent by a slow flow rate, is easily adsorbed on the copper surface.

The pyridine represented by the general formula (1) serving as the protecting agent of the present invention has a strong peeling force due to the flow rate versus the binding force from the bottom surface of the etchant having a high flow rate, and the adsorption rate is low, and the side portion is a metal, The binding force of the film with copper is relatively stronger than the peeling force due to the flow velocity, so that the adsorption rate is increased.

Therefore, the side etching is controlled, and the critical dimension (CD) loss of the metal film of the multilayer film, for example, the copper film is reduced, thereby enhancing the process margin.

According to such a mechanism, the etching solution composition containing pyridine represented by the above formula (1) of the present invention has better control of side etching than the etching composition used in general, so that it is possible to implement the etching of a desired shape.

The content of the pyridine represented by the formula (1) may be 0.1 to 10% by weight, preferably 0.1 to 5% by weight based on the total weight of the composition. If the content of pyridine represented by the above formula (1) is less than 0.1% by weight, etching uniformity may be lowered and decomposition of hydrogen peroxide may be accelerated. When the content of pyridine exceeds 10% by weight, Disadvantages may arise.

According to a preferred embodiment of the present invention, 1 to 40% by weight of the metal film oxidizing agent is added to the total weight of the etching solution composition of the present invention; 0.1 to 10% by weight of a nitrogen atom-containing compound; 0.1 to 10% by weight of pyridine represented by the general formula (1) and the balance water.

The etchant composition of the present invention may further comprise at least one selected from glycols, fluorine compounds, and acids containing sulfur (S) and phosphorus (P) atoms.

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

As the glycols contained in the etchant composition of the present invention, known components in this field can be used without limitation, and polyethylene glycol is particularly preferably used.

Polyethylene glycol is an addition polymer of ethylene oxide and may be either a hydroxyl group or an ether group at the end, but at least one of them is preferably a hydroxyl group. In order to prevent the viscosity of the solution from increasing excessively, desirable.

The content of the glycols 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 glycols is less than 0.1% by weight, the effect of improving the number of substrates to be processed is not expected to be improved, and etching uniformity may be lowered. When the content of glycols is more than 10% by weight, Disadvantages may arise.

The fluorine compound contained in the etching solution composition of the present invention serves to remove the etching residue and to etch the titanium-based metal film.

The fluorinated compound is preferably a compound capable of dissociating into a fluorine ion or a polyatomic fluorine ion. The compound capable of dissociating into fluorine ion or polyatomic fluorine ion may be one or more selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, sodium bisulfite, and potassium bisulfate.

The fluorinated compound may be 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. When the above-mentioned range is satisfied, it is preferable to prevent etching residues and not to etch the glass substrate or the lower silicon film. However, deviating from the above-described range may cause unevenness in the substrate due to non-uniform etching characteristics, excessive etching may damage the underlying film, and etching rate control may be difficult during processing.

The acid containing the sulfur (S) atom or the phosphorus (P) atom included in the etchant composition of the present invention may be any of those known in the art such as sulfuric acid, sulfonic acid, phosphoric acid, and phosphonic acid, Can be preferably used. The phosphoric acid promotes copper etching of hydrogen peroxide by providing hydrogen ions to the etching solution. In addition, it forms a phosphate by binding with oxidized copper ions, thereby increasing solubility in water and eliminating residues of the metal film after etching.

The acid may be contained 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-mentioned range, it is possible to avoid the excessive etching of the metal film and the corrosion of the lower film due to the acid, and the acid content is too low to lower the etching rate of the metal film. Function can be performed.

The water used in the present invention means deionized water and is used for semiconductor processing, preferably water of 18 M / cm or more.

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

The etchant composition of the present invention is a specific example,

Hydrogen peroxide may be used as the metal film oxidizing agent, and it may further include glycols together with the nitrogen atom-containing compound, pyridine represented by the formula (1) and water.

It may further contain at least one selected from the group consisting of fluorine compounds and acids containing sulfur (S) atoms and phosphorus (P) atoms.

According to a preferred embodiment of the present invention, the etchant composition comprises 1 to 25% by weight of hydrogen peroxide based on the total weight of the composition; 0.1 to 10% by weight of a nitrogen atom-containing compound; 0.1 to 10% by weight of pyridine represented by the general formula (1) and the balance of water, 0.1 to 10% by weight of glycols, 0.1 to 5% by weight of a fluorine compound, and sulfur (S) And 0.01 to 10% by weight of an acid.

The components constituting the etchant composition of the present invention preferably have purity for semiconductor processing.

The present invention also provides a method of manufacturing a semiconductor device, comprising: a) forming a gate electrode on a 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 a source / drain electrode on the semiconductor layer; And e) forming a pixel electrode connected to the source / drain electrode, wherein the steps a), d) or e) comprise forming a metal film, And etching the film with the etchant composition of the present invention to form an electrode. [0002] The present invention relates to a method of manufacturing an array substrate for a liquid crystal display device.

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

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

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are intended to further illustrate the present invention, 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 to 8 and Comparative Example 1 ~ 4: Etchant  Preparation of composition

The components listed in Table 1 below were mixed in the respective amounts to prepare an etchant composition.

division Metal film oxidizing agent Pyridine Glycine Ammonium fluoride Phosphoric acid Triethylene glycol Deionized water Example 1 nitric acid 10 (1-1) One X X X Balance Example 2 Ammonium persulfate 10 (1-1) One X X X Balance Example 3 Hydrogen peroxide 10 (1-1) One X X X Balance Example 4 Hydrogen peroxide 10 (1-1) One X X 5 Balance Example 5 Hydrogen peroxide 10 (1-1) One One X X Balance Example 6 Hydrogen peroxide 5 (1-1) One One 0.1 X Balance Example 7 Hydrogen peroxide 5 (1-1) One One 0.1 5 Balance Example 8 Hydrogen peroxide 5 1-2 One One 0.1 5 Balance Comparative Example 1 Hydrogen peroxide 10 X One X X X Balance Comparative Example 2 Hydrogen peroxide 10 X One One X X Balance Comparative Example 3 Hydrogen peroxide 10 X One One 0.1 X Balance Comparative Example 4 Hydrogen peroxide 10 X One One 0.1 5 Balance

(Unit: wt%)

Formula 1-1:

(1-2)

Test Example  One: Etching rate  And CD Ross rating

(One) Cu Monolayer Etching

A copper film was deposited on the glass substrate by chemical vapor deposition. The thickness of the film was about 2000 to 2500 Å. The photoresist was then applied to form a copper monolayer at the selective site, selectively exposed using a mask, and partially photoresist removed with a developer. Etching of the Cu monolayer was performed using the etchant compositions of Examples 1 to 4 and Comparative Example 1. During the etching process, the etchant composition was etched at a temperature of about 30 캜 for 100 seconds. EPD (End Point Detection) was measured with the naked eye to obtain the etching rate with time. The profile of the etched Cu single layer was measured by SEM (Hitachi, Model S-4700), and the results are shown in Table 2 below.

(2) Cu / Mo - Ti Bilayer Etching

Alloy films of molybdenum and titanium (50:50) and copper films were continuously deposited on the glass substrate by chemical vapor deposition. The thickness of each film was about 300 to 400 Å for a molybdenum-titanium alloy film and about 2000 to 2500 Å for a copper film. The photoresist was then applied to form a copper / molybdenum-titanium bilayer at a selective site, selectively exposed using a mask, and partially photoresist removed with a developer. Etching of the Cu / Mo-Ti bilayers was performed using the etchant compositions of Examples 5 to 8 and Comparative Examples 2 to 4. During the etching process, the etchant composition was etched at a temperature of about 30 캜 for 100 seconds. EPD (End Point Detection) was measured with the naked eye to obtain the etching rate with time. The profile of the etched Cu / Mo-Ti bilayer was measured by SEM (Hitachi, model name S-4700) and the results are shown in Table 2 below.

Test Example  2: Evaluation of the number of processing

Reference etch tests were performed on the etchant compositions of Examples 1 to 8 and Comparative Examples 1 to 4, and 4,000 ppm of copper powder was added to the reference test etchant to completely dissolve them. Thereafter, etching was again carried out to carry out the reference etching test, and the etching rate was evaluated by the lowering rate of the etching rate.

<Evaluation Criteria>

Good: Excellent (lowering rate of etching rate is less than 10%)

?: Good (etching rate lowering rate: 10% to 20%)

×: poor (etching rate lowering rate exceeding 20%)

division Test Example 1 Test Example 2 Etching speed (Å / sec) CD loss (탆) Number of processing Example 1 148 2.8 △ Example 2 178 2.3 △ Example 3 129 2.4 △ Example 4 131 2.8 ○ Example 5 128 2.1 △ Example 6 123 2.4 △ Example 7 138 2.8 ○ Example 8 140 2.5 ○ Comparative Example 1 121 4.2 × Comparative Example 2 123 3.9 × Comparative Example 3 132 4.0 × Comparative Example 4 133 3.8 ○

The results of measurement are shown in Table 1, and it can be seen that in Examples 1 to 8, CD loss is significantly lower than in Comparative Examples 1 to 4. That is, it can be seen that the pyridine represented by Formula 1 of the present invention controls the side etching.

Specifically, the CD loss of Example 5 was the least, and the side etching effect was most excellent. Next, the side etching effect was shown in the order of Example 2, Examples 3 and 6. Example 2 was the best at the etching rate.

When the average value of the CD loss was compared, the CD loss average value of Comparative Examples 1 to 4 was about 3.9 mu m, and the CD loss average value of Examples 1 to 8 was about 2.5 mu m, Many appeared. In particular, in Comparative Example 4, CD loss was remarkably decreased to 3 占 퐉 even though it contained commonly used triethylene glycol.

Therefore, it can be seen that the etching solutions containing no pyridine represented by the general formula (1) are remarkably inferior in the side etching control.

Also, in the number of treatments, all of Comparative Examples 1 to 3 were inferior, and as a whole, the number of treatments of the Comparative Example was lower than that of the Examples.

Claims (9)

Metal film oxidizer; A nitrogen atom-containing compound; Pyridine represented by the following formula (1); And water. &Lt; / RTI &gt;
[Chemical Formula 1]

In Formula 1,
R ₁ and R ₂ are each independently hydrogen, NH ₂ or COOH. The method according to claim 1,
Wherein the metal film oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, peracetic acid, metal oxide, nitric acid, persulfate, halogen acid and halide,
Wherein the nitrogen atom-containing compound is an amino acid. The method according to claim 1,
1 to 40% by weight, based on the total weight of the composition, of a metal film oxidizing agent; 0.1 to 10% by weight of a nitrogen atom-containing compound; 0.1 to 10% by weight of pyridine represented by the formula (1); And an amount of water remaining. The method of claim 3,
And 0.1 to 5% by weight of a fluorine compound and 0.01 to 10% by weight of an acid containing a sulfur (S) atom or phosphorus (P) atom, &Lt; / RTI &gt; The method of claim 4,
Hydrogen peroxide as an oxidizing agent in an amount of 1 to 25% by weight based on the total weight of the composition; Wherein the glycols are polyethylene glycol and the acid containing the sulfur (S) atom or phosphorus (P) atom is phosphoric acid, and the fluorinated compound is selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, sodium bisulfite, Based on the total amount of the etching solution. The method according to claim 1,
When R ₁ is NH ₂ , R ₂ is hydrogen,
Wherein when R &lt; _{1 &gt;} is COOH, R &lt; _{2 &gt; is} also COOH. The method according to claim 1,
Wherein 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 of claim 7,
Wherein the multilayered film is a copper-based metal film / molybdenum metal film, or a copper-based metal film / titanium-based metal film. a) forming a gate electrode on a 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 a source / drain electrode on the semiconductor layer; And
e) forming pixel electrodes connected to the source / drain electrodes, the method comprising the steps of:
Characterized in that said step a), d) or e) comprises the step of forming a metal film and etching said metal film with the etching composition according to any one of claims 1 to 8 to form an electrode / RTI &gt;