TW201513320A - Manufacturing method of an array substrate for liquid crystal display - Google Patents

Abstract

Disclosed is a manufacturing method of an array substrate for a liquid crystal display. The method comprises: (a) forming a gate electrode wiring on a substrate; (b) forming a gate electrode insulation layer on the substrate with the gate electrode wiring; (c) forming a semiconductor layer on the gate electrode insulation layer; (d) forming source electrodes and drain electrodes on the semiconductor layer; and (e) forming pattern-unitary electrodes connected with the drain electrodes, wherein steps of (a) or (d) include: forming a Cu-based metal film on the substrate or the semiconductor layer, and forming the gate electrode wiring or the source and drain electrodes by using an etching composition to etch the Cu-based metal film, the etching composition comprises H2O2, phosphorous acid or polybasic base compound, and water, and is applicable to Cu-based metal film.

Description

Method for manufacturing array substrate for liquid crystal display [Reciprocal Reference of Related Applications]

The present application claims the benefit of the Korean Patent Application KR 10-2013-0115037 filed on Sep. 27, 2013, and the Korean Patent Application KR 10-2013-0124525 filed on Oct. 18, 2013, the entire disclosure of which is hereby This is incorporated herein by reference.

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

In a semiconductor device, a process of forming a metal wiring on a substrate generally includes forming a metal film by sputtering or the like, coating a photoresist, performing exposure and development to form a photoresist on a selected region, and performing etching, wherein The cleaning process is performed before or after each individual process. The etching process is a process of using a photoresist as a mask to enable a metal film to remain in a selected region, and the etching process generally includes dry etching using plasma or the like or wet etching using an etchant composition.

Generally, for materials for gate wiring and data wiring, a copper film layer or a copper alloy film layer including copper, or a metal oxide layer in which copper has good conductivity and low electrical resistance, metal oxide layer and Copper layer or The copper alloy film layer has good interface adhesion.

In this regard, Korean Patent Application Publication No. 10-2007-0055259 discloses an etchant composition for a Cu-based metal film, including hydrogen peroxide, an organic acid, a phosphate compound, etc., which is used for etching copper. Molybdenum alloy film layer.

However, if an etchant composition is applied to a thick film of a Cu-based metal film, a defect problem may occur in a subsequent process due to a high taper angle caused by a phosphate monobasic.

[reference list]

[Patent Literature]

(Patent Document 1) Korean Patent Application Publication No. 10-2007-0055259A.

In order to solve the aforementioned problems, it is an object of the present invention to provide a method of manufacturing an array substrate which is used for a liquid crystal display and which is composed of a Cu-based metal film.

In order to solve the aforementioned problems, another object of the present invention is to batch-etch a Cu-based metal film using the etchant composition of the present invention, the etchant composition of the present invention is used for a Cu-based metal film and includes phosphorous acid (H ₃ PO ₃ ) or a polybasic compound.

In order to achieve the above object, the present invention provides a method of manufacturing an array substrate for a liquid crystal display, the method comprising: a) forming a gate wiring on a substrate; b) forming a gate on the substrate having the gate wiring An insulating layer; c) forming a semiconductor layer on the gate insulating layer; d) forming a source electrode and a drain electrode on the semiconductor layer; and e) forming a picture electrode connected to the drain electrode, wherein a) the step or d) the step of: forming a Cu-based metal film on the substrate or the semiconductor layer, and forming the gate wiring or the source electrode and the drain electrode by etching the Cu-based metal film using an etchant composition, and the etching The agent composition is an etchant composition for a Cu-based metal film, comprising: hydrogen peroxide (H ₂ O ₂ ), a phosphorous acid or a polybasic compound, and water.

Further, the present invention provides an etchant composition for a Cu-based metal film comprising: hydrogen peroxide (H ₂ O ₂ ), a phosphorous acid or a polybasic compound, and water.

Furthermore, the present invention provides an array substrate for a liquid crystal display, the array substrate comprising: at least one selected from the group consisting of a gate wiring, a source electrode, and a drain electrode, the gate wiring, the source electrode, and the drain electrode passing through the Etchant composition etching for Cu-based metal films.

An etchant composition for a Cu-based metal film including a phosphorous acid (H ₃ PO ₃ ) or a polybasic compound is advantageous for increasing the etching rate, and it can be applied to a thick film having a thick thickness.

In addition, the etchant composition of the present invention can be applied to a high-resolution device due to a low taper angle at the time of etching.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

1 shows a scanning electron microscope (SEM) image of an etched profile when the etchant composition for Cu-based metal film of Example 3 is used under conditions of 300 ppm of copper; FIG. 2 shows Scanning electron microscope (SEM) image of the etched profile when the etchant composition for Cu-based metal film of Example 3 was used under the conditions of 3000 ppm of copper; and FIG. 3 shows the condition of copper at 6000 ppm Next, when the etchant composition for Cu-based metal film of Example 3 was used, a scanning electron microscope (SEM) image of the cross section was etched.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display using an etchant composition for a Cu-based metal film, and the manufacturing method is as follows.

The manufacturing method includes: a) forming a gate wiring on a substrate; b) forming a gate insulating layer on the substrate having the gate wiring; c) forming a semiconductor layer on the gate insulating layer; d) forming on the semiconductor layer a source electrode and a drain electrode; and e) forming a picture element electrode connected to the drain electrode, wherein the step a) or the step d) comprises: forming a Cu-based metal film on the substrate or the semiconductor layer, and etching by using the etchant composition A Cu-based metal film is used to form a gate wiring or a source electrode and a drain electrode.

The etchant composition is an etchant composition for a Cu-based metal film, comprising: hydrogen peroxide (H ₂ O ₂ ), a phosphorous acid or a polybasic compound, and water.

In particular, the etchant composition is an etchant composition for a Cu-based metal film, and includes: 15 to 25% by weight of hydrogen peroxide (H ₂ O ₂ ) based on the total weight of the composition; 0.3 to 5 % by weight of phosphorous acid or 0.1 to 5% by weight of a polybasic compound; and the balance of water such that the total weight of the composition is 100% by weight.

An array substrate for a liquid crystal display is a thin film transistor (TFT) substrate.

Further, the present invention relates to an etchant composition for a Cu-based metal film comprising: hydrogen peroxide (H ₂ O ₂ ), a phosphorous acid or a polybasic compound, and water.

Recently, in the case of a display, particularly in the case of a TV, in order to exhibit a high resolution, a lateral wiring width of an array substrate for a liquid crystal display is produced in a narrow manner. However, since the wiring width is narrowed, there arises a problem that the resistance is increased. Thus, in order to prevent such a problem from occurring, in an array substrate for a liquid crystal display, a thick film having a thick thickness of a metal film prepared by increasing the wiring thickness in the axial direction is used.

In the case where a thick film is etched using a conventional etchant composition, the etching rate is slow and the processing time is increased, wherein the conventional etchant composition does not include a phosphorous acid or a polybasic compound. Therefore, conventional etchant compositions cannot be applied to thick films that require etching rates in excess of 150 Å/sec.

In addition, since a problem may occur in a subsequent process in the case of a taper angle exceeding 60°, the taper angle must be lowered. However, due to conventional etching The cone angle of the composition is too large, so it cannot be applied to etching thick films.

Meanwhile, the etchant composition for a Cu-based metal film according to the present invention solves the above problems, and thus it can be applied to a thick film in which the etchant composition of the present invention includes a phosphorous acid or a polybasic compound. Preferably, in the Cu-based metal film, it can be used to etch a thick film of a copper film or a copper alloy film having a thickness of 5000 Å or more.

The Cu-based metal film includes copper as a composition, and includes a single layer film of copper or a copper alloy; and a multilayer film including at least one selected from the group consisting of a copper film and a copper alloy film, and selected from a molybdenum film, a molybdenum alloy film, At least one of a titanium film and a titanium alloy film. The alloy film includes a nitride or an oxide.

Examples of the multilayer film include a two-layer film or a three-layer film such as a copper/molybdenum film, a copper/molybdenum alloy film, a copper alloy/molybdenum alloy film, a copper/titanium film, or the like.

The copper/molybdenum film refers to a film including a molybdenum film and a copper film formed on the molybdenum film; the copper/molybdenum alloy film refers to a film including a molybdenum alloy film and a copper film formed on the molybdenum alloy film; The molybdenum alloy film refers to a film including a molybdenum alloy film and a copper alloy film formed on the molybdenum alloy film; and the copper/titanium film refers to a film including a titanium film and a copper film formed on the titanium film.

Further, the molybdenum alloy film is preferably composed of molybdenum (Mo) and at least one metal selected from the group consisting of titanium (Ti), tantalum (Ta), chromium (Cr), nickel (Ni), niobium (Nd), and molybdenum (In). .

The etchant composition for a Cu-based metal film of the present invention is preferably applied to a multilayer film including at least one selected from the group consisting of a copper film and a copper alloy film, and selected from the group consisting of a molybdenum film and a molybdenum alloy film. At least one.

In addition, in the case where the etchant composition for a Cu-based metal film of the present invention includes only phosphorous acid, the etchant composition may additionally include At least one of the following: a fluorine-containing compound, an azole compound, a water-soluble compound having a N atom and a carboxyl group in the molecule, a phosphate compound, and a polyol surfactant.

In addition, in the case where the etchant composition for a Cu-based metal film of the present invention includes a polybasic compound or includes a phosphorous acid and a polybasic compound, the etchant composition may additionally contain a substance selected from the group consisting of At least one of: a fluorine-containing compound, an azole compound, a water-soluble compound having an N atom and a carboxyl group in a molecule, and a polyol surfactant.

In the case where the etchant composition for a Cu-based metal film of the present invention includes a polybasic compound, the etchant composition for the Cu-based metal film is acidic, and preferably has a pH of 1.5 to 4.

If the etchant composition for the Cu-based metal film is lower than pH 1.5, excessive etching may occur due to a rapid etching rate, and in the case of higher than pH 4, etching may not be possible due to a slow etching rate.

Hereinafter, the etchant composition for a Cu-based metal film of the present invention will be described in detail.

Hydrogen peroxide (H ₂ O ₂ )

Hydrogen peroxide (H ₂ O ₂ ) contained in the etchant composition for a Cu-based metal film of the present invention is a main oxidant which affects etching of a Cu-based metal film, wherein the Cu-based metal film includes a molybdenum film and A copper-molybdenum film of a copper film formed on the molybdenum film, or a copper-molybdenum alloy film including a molybdenum alloy film and a copper film formed on the molybdenum alloy film.

Hydrogen peroxide (H ₂ O ₂ ) is set to 15 to 25% by weight, preferably 18 to 23% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

At a range of less than 15% by weight of the above amount, etching may be insufficient due to lack of etching ability to the Cu-based metal film.

In addition, at a range of the above amount of more than 25% by weight, the thermal stability is highly lowered due to an increase in the rise of copper ions.

Phosphorous acid (H ₃ PO ₃ )

The phosphorous acid contained in the etchant composition for a Cu-based metal film of the present invention enhances the etching rate by adjusting the pH. If the etchant composition for a Cu-based metal film of the present invention does not contain phosphorous acid, the etching rate is very slow and thus the etching profile may be poor when etching a thick film of a Cu-based metal film.

The phosphorous acid is set to be 0.3 to 5.0% by weight, preferably 0.5 to 3.0% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

The etching profile may be poor at a range of less than 0.3% by weight of the above amount.

Further, in the range of the above amount of more than 5% by weight, there is a possibility that the etching rate of the copper or copper alloy film is too fast or the etching rate of the molybdenum or molybdenum alloy film is too slow.

Polybasic compound

The polybasic compound contained in the etchant composition for a Cu-based metal film of the present invention makes the etching profile good and does not increase the taper angle when etching a thick film of a Cu-based metal film having a thick thickness.

If the etchant composition for the Cu-based metal film includes only phosphoric acid The hydrogen salt compound does not include a phosphorous acid and a polybasic compound, and the etchant composition causes an increase in the taper angle due to the number of sheets to be processed, so that it cannot be applied to a thick film of a Cu-based metal film.

Therefore, among the polybasic compounds, a polybasic phosphate compound is preferred and a dibasic phosphate compound is more preferred.

The dihydrogen phosphate salt is not particularly limited as long as it is selected from two phosphates in which the hydrogen is replaced by an alkali metal or an alkaline earth metal, preferably selected from the group consisting of diammonium hydrogen phosphate, disodium hydrogen phosphate and dipotassium hydrogen phosphate, more preferably Diammonium hydrogen phosphate.

The polybasic compound is set to be 0.1 to 5% by weight, preferably 0.5 to 3% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

When the range of the above amount is less than 0.1% by weight, the etching profile is not good due to partial excessive erosion. In addition, at a range of the above amount of more than 5% by weight, a problem that the corrosion rate of the copper or copper alloy film is lowered and the etching rate of the molybdenum or molybdenum alloy film is lowered may occur.

Fluorine-containing compound

The fluorine-containing compound means a compound which generates fluorine ions when dissociated in water. The fluorine-containing compound is an auxiliary oxidant which affects the etching rate of the molybdenum alloy film, and it adjusts the etching rate of the molybdenum alloy film.

The fluorine-containing compound is not particularly limited as long as it is used in the related art, but is preferably selected from _{HF, NaF, NH 4 F,} NH 4 BF 4, NH 4 FHF, NH 4 F 2, KF, KHF 2, At least one of AlF ₃ and HBF ₄ , and more preferably NH ₄ F ₂ .

The fluorine-containing compound is set to be 0.01 to 5.0% by weight, preferably 0.1 to 3.0% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

At a range of less than 0.01% by weight of the above amount, the etching rate of the molybdenum alloy film becomes slow.

Further, in the range of the above amount of more than 5.0% by weight, the etching profile is improved, but the total etching rate is also improved, and thus the undercut of the lower layer (n+a-Si:H, a-Si:G) is obtained. Or the damage caused by etching is too large.

Azole compound

The azole compound contained in the etchant composition for Cu-based metal film of the present invention is used for adjusting the etching rate of the Cu-based metal film, reducing the CD loss of the pattern, and increasing the profit in the process by reducing the change in the etching profile. .

The azole compound may contain, for example, pyrrole, pyrazole, imidazole, triazole, tetrazole, penzozole, oxazole, isoxazole, thiazole, isothiazole, etc., and it may be used alone or It is used in combination of two or more. Among the azole compounds, a triazole compound or a tetrazole compound is preferred, and more preferably 3-aminotriazole, 4-aminotriazole, 5-methyltetrazole and 5-aminotetrazole. At least one.

In the present invention, 3-aminotriazole, 4-aminotriazole, 5-methyltetrazole, 5-aminotetrazole, and 5-aminotetrazole may be used in combination, and in this case, since the compound is etched depending on the compound The rate and ability to reduce etch profile changes will vary with the number of sheets to be processed, so it is preferred to calculate and apply the mixing ratio based on process conditions.

The azole compound is set to be 0.1 to 5.0% by weight, preferably 0.5 to 1.5% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

At a range of less than 0.1% by weight of the above amount, a large CD loss may be caused due to a high etching rate.

In addition, at a range of the above amount of more than 5.0% by weight, the processing time is increased due to the etching rate of the Cu-based metal film being too slow, and undercut may be generated due to the relative acceleration of the etching rate of the metal oxide layer (undercut ).

a water-soluble compound having an N atom and a carboxyl group in a molecule

The water-soluble compound having an N atom and a carboxyl group in the molecule contained in the etchant composition for a Cu-based metal film of the present invention prevents self-decomposition reaction of hydrogen peroxide which may occur during storage of the etchant composition, Also, variations in etching characteristics when etching a large number of substrates are also prevented.

Generally, in the case of an etchant composition using hydrogen peroxide, the storage period is not long due to self-decomposition of hydrogen peroxide during storage, and there is also a risk factor that the container may explode.

However, if a water-soluble compound having an N atom and a carboxyl group in the molecule is contained, since the decomposition rate of hydrogen peroxide is reduced by nearly 10 times, a long shelf life and stability can be ensured.

Specifically, in the case of a copper layer, if copper ions are retained in a large amount in the etchant composition, passivation is formed and thus further etching may not be possible after oxidative discoloration (char). However, this can be prevented by adding a compound.

The water-soluble compound having an N atom and a carboxyl group in the molecule may be selected from the group consisting of alanine, aminobutyric acid, glutamic acid, glycine, iminodiacetic acid, amine triacetic acid, and creatinine. Among these compounds, iminodiacetic acid is preferred.

The water-soluble compound having N atom and carboxyl group in the molecule is set to 0.5 to 5.0% by weight, preferably 1.0 to 3.0% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

At a range of less than 0.5% by weight of the above amount, it is difficult to obtain sufficient process profit due to passivation after etching a large number of substrates (about 500 sheets).

In addition, the etching rate of the molybdenum film or the molybdenum alloy film becomes slow at a range of the above amount of more than 5.0% by weight, and thus in the case of a copper-molybdenum film or a copper-molybdenum alloy film, molybdenum or a molybdenum alloy may occur. The problem of the residue of the film.

Phosphate compound

The phosphate compound contained in the etchant composition for a Cu-based metal film of the present invention makes the etching profile good. If the etchant composition for a Cu-based metal film of the present invention does not contain a phosphate compound, local excessive erosion may occur.

The phosphate compound is not particularly limited as long as it is selected from phosphates in which one or two hydrogens are replaced by an alkali metal or an alkaline earth metal, preferably selected from ammonium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, and hydrogen phosphate. Diammonium, disodium hydrogen phosphate and dipotassium hydrogen phosphate, and more preferably diammonium hydrogen phosphate.

Among these phosphate compounds, when the etchant composition for the Cu-based metal film does not include a polybasic compound and includes only phosphorous acid, a monobasic compound such as diammonium hydrogen phosphate, disodium hydrogen phosphate, and phosphoric acid is used. Hydrogen II Potassium.

The phosphate compound is set to be 0.1 to 5.0% by weight, preferably 0.5 to 3.0% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

At a range of less than 0.1% by weight of the above amount, the etching profile may be made poor due to partial excessive erosion.

In addition, in the range of the above amount of more than 5.0% by weight, there may occur a problem that the corrosion rate of the copper or copper alloy film is lowered and the etching rate of the molybdenum or molybdenum alloy film is lowered.

Polyol surfactant

A polyol-based surfactant which may additionally be included in the etchant composition for a Cu-based metal film of the present invention is used to increase the uniformity of etching by reducing the surface tension.

Further, the polyol surfactant suppresses the decomposition reaction of hydrogen peroxide by encapsulating copper ions dissolved in the etchant composition after etching the Cu film, and thus suppresses the activity of copper ions.

When the activity of the copper ions is suppressed as described above, the process can be stably performed during the use of the etchant composition.

For the polyol surfactant, at least one selected from the group consisting of glycerin, triethylene glycol, and polyethylene glycol can be used. Among these compounds, triethylene glycol is preferred.

The polyol surfactant is set to be 0.001 to 5.0% by weight, and preferably 0.1 to 3.0% by weight, based on the total weight of the etchant composition for the Cu-based metal film.

At a range of less than 0.001% by weight of the above amount, there is a possibility that the etching uniformity is lowered and the decomposition of hydrogen peroxide is accelerated.

In addition, when it is in the range of the above amount of more than 5.0% by weight, there is a possibility that a large amount of bubbles are generated.

water

The water of the etchant composition for a Cu-based metal film according to the present invention is used in a balance such that the total weight of the etchant composition for the Cu-based metal film is 100% by weight.

The water is not particularly limited, but preferably contains deionized water. Particularly useful is the resistivity (ie, the extent of ions removed from the water) is at least 18 MΩ. Cm deionized water.

In addition to the above components, the etchant composition for a Cu-based metal film of the present invention may include an additive, and the additive may include a metal ion containment, a corrosion inhibitor, or the like.

The composition of the etchant composition for a Cu-based metal film used in the present invention can be prepared by a generally known method, and an etchant combination preferably used for a Cu-based metal film has a purity for a semiconductor process.

In addition, the present invention provides an array substrate for a liquid crystal display, the array substrate comprising: at least one of a gate wiring, a source electrode and a drain electrode, wherein the gate wiring, the source electrode and the drain electrode are used for Cu-based The etchant composition of the metal film is etched.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the examples are intended to illustrate the invention and are not intended to limit the scope of the invention. Those skilled in the art can implement these implementations within the scope of the present invention. Examples are subject to appropriate modifications and changes.

Preparation of an etchant composition for a Cu-based metal film

Example 1 to Example 4 and Comparative Example 1 to Comparative Example 2

180 kg of the etchant compositions for Cu-based metal films of Examples 1 to 4 and Comparative Examples 1 to 2 were prepared using the compositions shown in Tables 1 and 2 below.

ABF: ammonium difluoride

5-ATZ: 5-aminotetrazole

5-MTZ: 5-methyltetrazole

IDA: Iminodiacetic acid

APD: dibasic ammonium phosphate

TEG: Triethylene glycol

GA: glycolic acid

NHP: sodium dihydrogen phosphate

Test Example 1: Etching process using the etchant composition for Cu-based metal film of Examples 1 to 4

The etching process was performed using each of the etchant compositions for Cu-based metal films of Examples 1 to 4. A spray type etching machine (ETCHER (TFT), available from SEMES) was used, and the temperature of the etchant composition for the Cu-based metal film in the etching process was set to about 33 °C. The etching time may vary with the temperature of the etching, and the LCD etching process is usually performed for about 30 to 80 seconds. The cut side and cross section of the Cu-based metal film etched in the etching process were observed using SEM (S-4700, available from HITACHI). The results are given in Table 3 below.

A Cu/Mo-Nb 3000/300Å film substrate was used as the Cu-based metal film in the etching process.

(○: good, △: normal, X: not good, Unetch: can't be etched)

The etchant compositions for Cu-based metal films of Examples 1 to 4 have good etching characteristics. In these embodiments, the etchant composition for the Cu-based metal film of Example 3 had a good etching profile and flatness, and did not produce Mo, Ti residue. In addition, the piece to be processed The amount of change in the number of materials (the amount of side etching change) satisfies the condition of 0.1 μm.

Test Example 2: Evaluation of etching characteristics by Cu concentration using the etchant composition for Cu-based metal film of Example 3 and Comparative Example 1 to Comparative Example 2

The etchant composition for the Cu-based metal film of Example 3 and Comparative Example 1 to Comparative Example 2 was used to evaluate the etching characteristics from the Cu concentration.

A Cu/Mo-Ti 6500/300 Å thick film substrate was used as the Cu-based metal film in the etching process.

The amount (μm) of the etching rate, the taper angle, the residue, and the side etching change were measured according to the Cu concentration. The etching rate refers to the thickness of Cu etched per unit time, the taper angle refers to the slope of the Cu sheet, and the side etch refers to the distance between the end of the photoresist and the end of the underlying metal measured after etching. .

When the etch rate is too slow, the processing time increases and the yield decreases, so a high etch rate is important.

In addition, when the taper angle is too high, cracks are caused by poor step coverage when the latter film is removed, and it is important to maintain an appropriate taper angle.

In addition, if the amount of side etching changes, stains may occur due to a change in signal transmission rate when the TFT is driven. Thus, it is preferred to minimize the amount of side erosion variation.

In this evaluation, the evaluation is performed to establish an etchant composition that can be continuously used in an etching process, the etchant composition having an etch rate higher than 150 Å/sec, a taper angle lower than 60°, and ±0.1 μm The amount of change in side erosion.

The results are given in Table 4 below.

The etchant composition for Cu-based metal film of Comparative Example 1 has a low etching rate, the etching rate is lowered according to the number of sheets to be processed, and heat is generated when eluting 4000 ppm, and thus the combination of Comparative Example 1 cannot be applied. Things.

In the case of the etchant composition for a Cu-based metal film of Comparative Example 2, the range of variation of the etching rate according to the number of sheets to be processed and the variation range of the side etching are not too large, but the etching rate is slow. And the taper angle was high, so the composition of Comparative Example 2 was not suitable for application to a thick film.

Therefore, it can be confirmed that the etchant composition for the Cu-based metal film of Comparative Example 1 and Comparative Example 2 cannot etch the thick film, wherein the etchant for the Cu-based metal film of Comparative Example 1 and Comparative Example 2 The composition does not include a phosphorous acid or a polybasic compound.

However, as shown in Table 4 above and FIGS. 1 to 3, in the case of the etchant composition (including phosphorous acid or polybasic compound) for the Cu-based metal film of Example 3, according to the to-be-processed The number of sheets remains above 180Å/ The etching rate of the second is 45° at the beginning and the taper angle is 53° at the end, thereby maintaining a taper angle lower than 60°, and the amount of side etching change satisfies the condition of ±0.1 μm, thereby confirming the implementation. The composition of Example 3 can be used until 6000 ppm is eluted.

Claims (15)

A method of fabricating an array substrate for a liquid crystal display, the method comprising: a) forming a gate wiring on a substrate; b) forming a gate insulating layer on the substrate having the gate wiring; c) at the gate Forming a semiconductor layer on the insulating layer; d) forming a source electrode and a drain electrode on the semiconductor layer; and e) forming a picture electrode connected to the drain electrode, wherein step a) or step d) comprises: on the substrate or Forming a Cu-based metal film on the semiconductor layer, and forming the gate wiring or the source electrode and the drain electrode by etching the Cu-based metal film using an etchant composition, and the etchant composition is for the Cu-based An etchant composition for a metal film, comprising: hydrogen peroxide, phosphorous acid or a polybasic compound, and water. The method of claim 1, wherein the etchant composition comprises: 15 to 25% by weight of hydrogen peroxide, 0.3 to 5% by weight of phosphorous acid or 0.1 to 5% by weight of plural based on the total weight of the composition Base compound, and the balance of water, such that the total weight of the composition is 100% by weight. The method of claim 1, wherein the array substrate for the liquid crystal display is a thin film transistor array substrate. An etchant composition for a Cu-based metal film, the etchant composition comprising: hydrogen peroxide, phosphorous acid or a polybasic compound, and water. The etchant composition of claim 4, wherein the Cu-based metal film is a multilayer film comprising: at least one selected from the group consisting of a copper film and a copper alloy film; and at least one selected from the group consisting of a molybdenum film and a molybdenum alloy film One. The etchant composition of claim 5, wherein the copper film and the copper alloy film are thick films having a thickness of 5000 Å or more. The etchant composition of claim 5, wherein the molybdenum alloy film is composed of molybdenum and at least one metal selected from the group consisting of titanium, niobium, chromium, nickel, niobium, and indium. The etchant composition of claim 4, wherein the etchant composition comprises: 15 to 25% by weight of hydrogen peroxide, 0.3 to 5% by weight of phosphorous acid or 0.1 to 5 by weight based on the total weight of the composition % of the polybasic compound, and the balance of water, such that the total weight of the composition is 100% by weight. The etchant composition of claim 4, wherein, in the case where the etchant composition for the Cu-based metal film includes only phosphorous acid, the etchant composition further comprises at least one selected from the group consisting of: A fluorine compound, an azole compound, a water-soluble compound having a N atom and a carboxyl group in a molecule, a phosphate compound, and a polyol surfactant. The etchant composition of claim 9, the etchant composition further comprising: at least one selected from the group consisting of 0.3 to 5% by weight of phosphorous acid, 0.01 to 5% by weight, based on the total weight of the composition a fluorine-containing compound, 0.1 to 5% by weight of an azole compound, 0.5 to 5% by weight of a water-soluble compound having an N atom and a carboxyl group in the molecule, 0.1 to 5% by weight of a phosphate compound, and 0.001 to 5% by weight A polyol surfactant. The etchant composition of claim 4, wherein, in the case where the etchant composition for a Cu-based metal film includes a polybasic compound or includes a phosphorous acid and a polybasic compound, the etchant composition further includes At least one selected from the group consisting of fluorine-containing compounds and azoles A compound, a water-soluble compound having a N atom and a carboxyl group in the molecule, and a polyol surfactant. The etchant composition of claim 11, the etchant composition further comprising: at least one selected from the group consisting of 0.1 to 5% by weight of a polybasic compound, 0.3 to 5 by weight based on the total weight of the composition % of phosphorous acid, 0.01 to 5% by weight of a fluorine-containing compound, 0.1 to 5% by weight of an azole compound, 0.5 to 5% by weight of a water-soluble compound having an N atom and a carboxyl group in the molecule, and 0.001 to 5% by weight Polyol surfactants. The etchant composition of claim 4, wherein the polybasic compound is at least one selected from the group consisting of diammonium hydrogen phosphate, disodium hydrogen phosphate, and dipotassium hydrogen phosphate. The etchant composition of claim 4, wherein, in the case where the etchant composition for the Cu-based metal film includes a polybasic compound, the etchant composition is acidic and has a pH of 1.5 to 4. An array substrate for a liquid crystal display, comprising at least one selected from the group consisting of a gate wiring, a source electrode, and a drain electrode, the gate electrode, and the drain electrode being used for a Cu-based metal film as claimed in claim 4 The etchant composition is etched.