KR20160041873A - Etching composition for patterned metal layer - Google Patents

Abstract

The present invention relates to an etchant composition for a patterned metal layer used to manufacture an ultrathin layer liquid display device (TFT-LCD). The etchant composition for the patterned metal layer comprises: hydrogen peroxide as a main oxidant; and an organic composition or an inorganic composition containing one or more ions or the one or more ions selected from Ag, Fe, Cu, Ni, Mn, and Ce as an auxiliary oxidant. According to the present invention, the etchant composition forms a pixel electrode of a fine pattern at a rapid speed by improving an etchant speed using the auxiliary oxidant. Moreover, the etchant composition improves productivity by reducing a generation of a precipitate even if a number of processing is increased as the etchant composition improves solubility of a metal ion using a precipitation prevention agent.

Description

[0001] The present invention relates to a composition for a metal wiring film,

The present invention relates to a composition for a metal wiring film, and more particularly, to an etchant composition useful for multi-layer etching such as a molybdenum alloy film used as a TFT-LCD pixel electrode and an indium / tin oxide film.

For the pixel electrode of the semiconductor device and the liquid crystal display device such as the TFT-LCD, a single film of a molybdenum alloy film and an indium oxide film, or a multi-layer film of a molybdenum alloy film and an indium oxide film is used. The pixel electrodes are generally stacked on a substrate by a method such as sputtering, a photoresist is uniformly applied on the substrate, light is irradiated through a mask engraved with a pattern, and a photoresist of a desired pattern is formed through development Next, a pattern is transferred to a metal film under the photoresist by dry or wet etching, and then a series of lithography processes are performed to remove unnecessary photoresist by a peeling process.

When the etching of the molybdenum alloy film and the indium oxide film is performed by using the same etching solution, the manufacturing process can be simplified. However, the molybdenum alloy film generally has a problem in that wet etching is not easy because of its excellent chemical resistance, There is a problem that the molybdenum alloy film can not be etched with the oxalic acid based etching solution.

In the prior art, Korean Patent Laid-Open Publication No. 2008-0070101 discloses a molybdenum alloy film containing hydrogen peroxide, a fluorine compound, a water-soluble cyclic amine compound, an inorganic acid and water, and an etchant of indium oxide, Patent Publication No. 2008-0107502 A Fe ^{3 +} compound, a molybdenum alloy film including hydrogen fluoride and water, and an indium oxide film etching solution. However, the fluorine compound in the above composition etches the SiNx, which is the insulating film between the source and drain electrodes and the pixel electrode, together with the molybdenum alloy film, the indium oxide film or the molybdenum alloy film and the indium oxide film. If the etching of the insulating film increases, it may cause defective operation that the TFT-LCD does not operate normally due to non-uniform application during the application of the alignment film in the subsequent process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for etching a metal wiring film, which has an etching rate of 15 Å / s or less, And to provide an etchant composition which can be improved.

The present invention relates to a process for the production of a catalyst which comprises hydrogen peroxide as a main oxidizing agent and at least one ion selected from silver (Ag), iron (Fe), copper (Cu), nickel (Ni), manganese (Mn) And an organic or inorganic compound containing these ions. The present invention also provides an etchant composition for a metal wiring film.

According to one embodiment, it is preferable that the content of the auxiliary oxidizing agent is 0.02 to 10 parts by weight relative to 100 parts by weight of hydrogen peroxide which is a peroxide.

According to one embodiment, the auxiliary oxidant is preferably at least one inorganic acid salt selected from silver (Ag), iron (Fe), copper (Cu), nickel (Ni), manganese (Mn) and cerium .

According to one embodiment, the composition may further comprise a glycolic acid compound as an precipitating agent.

According to one embodiment, the precipitation inhibitor is preferably at least one selected from the group consisting of diglycolic acid and thiodiglycolic acid.

According to one embodiment, the metal wiring may be a single film selected from a molybdenum film, a molybdenum alloy film, an indium and tin oxide film, or a multiple film in which two or more thereof are laminated.

According to one embodiment, the etchant composition for a metal wiring film according to the present invention comprises 5 to 25 wt% of hydrogen peroxide, 0.0001 to 2 wt% of a co-oxidant, 0.01 to 2 wt% of a corrosion inhibitor, 0.01 to 1 wt% By weight of a fluorinated compound, from 0.01 to 5% by weight of a fruit water stabilizer, from 0.001 to 1% by weight of a precipitation inhibitor, from 0.001 to 2% by weight of a sulfonic acid group, May include.

The corrosion inhibitor is preferably at least one selected from a ring heteroaromatic compound, a ring heteroaliphatic compound or a polyhydric alcohol.

The fluorinated compound is preferably a compound capable of dissociating to provide fluorine (F ^- ) or hydrogen fluoride (HF ₂ ^- ) ions.

The hydrous stabilizer is preferably a glycol compound.

The sulfonate group-containing compound may be at least one selected from the group consisting of alkyl sulfonate, alkyl disulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl phenylether sulfonate, a polymer of formaldehyde and naphthalene sulfonate, a polymer of acrylamide methylpropane sulfonate, a polymer of acrylic acid and acrylamide methylpropane sulfonate, Copolymers and vinylbenzene sulfonate polymers, and low molecular weight and high molecular compounds having sulfonic acid groups and salts thereof.

The present invention also provides a method of etching a monolayer selected from a molybdenum film, a molybdenum alloy film, an indium and tin oxide film, or a multilayer in which two or more thereof are stacked, using the above-described etching liquid composition.

The etchant composition according to the present invention can improve the etch rate of a single layer or multiple layers of a molybdenum alloy film used as a TFT-LCD pixel electrode and an indium / tin oxide layer to form a pixel electrode having a fine pattern in a shortened process time, It is possible to reduce the generation of precipitates as the number of treatments increases.

1 is a photograph of a cross section of a specimen after scanning a molybdenum titanium alloy film (MoTi) using an etching solution composition according to Example 2 with a scanning electron microscope.
FIG. 2 is a photograph of a cross section of a specimen obtained by etching an indium and tin oxide film (ITO) using the etching composition according to Example 2 under a scanning electron microscope.
3 is a photograph of a cross section of a specimen after scanning a molybdenum titanium alloy film (MoTi) using an etching solution composition according to Comparative Example 1 with a scanning electron microscope.
FIG. 4 is a photograph of a cross section of a specimen after scanning an indium and tin oxide film (ITO) using the etching composition according to Comparative Example 1 with a scanning electron microscope.
FIG. 5 is a photograph of a chemical solution when 1,000 ppm of molybdenum powder, indium and tin oxide powder were added to the etchant composition according to Example 2, followed by stirring.
FIG. 6 is a photograph of a chemical solution when 1,000 ppm of molybdenum powder, indium and tin oxide powder were added to the etchant composition of Comparative Example 1, and then stirred.

Hereinafter, the present invention will be described in detail.

The present invention relates to an etching composition for a metal wiring film, wherein the metal wiring film can be a single film or a multiple film selected from a molybdenum film, a molybdenum alloy film and an indium / tin oxide film.

The etchant composition according to the present invention comprises hydrogen peroxide as a main oxidizing agent and is selected from silver (Ag), iron (Fe), copper (Cu), nickel (Ni), manganese (Mn) and cerium One or more ions or organic or inorganic compounds containing them.

The auxiliary oxidizing agent may be an organic compound or an inorganic compound including silver (Ag), iron (Fe), copper (Cu), nickel (Ni), manganese (Mn) and cerium (Ce) And serves to assist etching of indium and tin oxide films.

According to one embodiment, the content of the auxiliary oxidizer may be 0.02 to 10 parts by weight, or 0.1 to 10 parts by weight, or 0.5 to 8 parts by weight, or 1 to 5 parts by weight, based on 100 parts by weight of hydrogen peroxide which is a main oxidizing agent.

The content of the auxiliary oxidizing agent may be 0.0001 to 2% by weight, or 0.001 to 1% by weight based on the total weight of the composition. When the amount of the auxiliary oxidizing agent is less than 0.0001% by weight, the etching rate of the molybdenum alloy and indium and tin oxide If it exceeds 2% by weight, an additional effect of increasing the etching rate can not be obtained.

According to another embodiment of the present invention, it may further comprise a glycolic acid compound as an precipitating agent. And more preferably a diglycolic acid compound, and more preferably at least one selected from the group consisting of diglycolic acid and thiodiacetic acid.

The precipitation inhibitor increases the solubility of metal ions to control the generation of precipitates in order to prevent generation of precipitates as the metal ion content increases in the chemical solution due to the increase in the number of treatments as the molybdenum alloy film and the indium / tin oxide film are etched repeatedly.

The precipitation inhibitor may be contained in an amount of 0.001 to 1% by weight, or 0.01 to 0.8%, or 0.01 to 0.5% by weight based on the total weight of the composition. If it is contained in an amount of less than 0.001% by weight, precipitation can not be effectively prevented, and if it is contained in an amount exceeding 1% by weight, etching of a copper film used as a source drain electrode can be caused.

According to one embodiment of the invention, the etchant composition comprises 5 to 25% by weight of hydrogen peroxide, 0.0001 to 2% by weight of co-oxidant, 0.01 to 2% by weight of corrosion inhibitor, 0.01 to 1% A fluorine compound, 0.01 to 5 wt% of a peroxide stabilizer, 0.001 to 1 wt% of an anti-deposition agent, 0.001 to 2 wt% of a sulfonic acid group, and water to make the total weight of the entire composition 100 wt% have.

In the present invention, the above-mentioned corrosion inhibitor acts to prevent the etching of the copper film used as the source and drain electrodes, which can be caused by cracks in the contact holes of the pixel electrode, the source and drain electrodes, and the insulating film in the pixel electrode etching process.

The corrosion inhibitor may be included in an amount of 0.01 to 2% by weight, or 0.1 to 2% by weight based on the total weight of the composition. If it is contained in an amount of less than 0.01% by weight, corrosion resistance against the copper film is not sufficient and it is not preferable because it is difficult to prevent corrosion of the copper film used as the source drain electrode. If it exceeds 2% by weight, corrosion resistance to the copper film Although the performance is excellent, the etch rate of the molybdenum alloy film, the indium and tin oxide film or the molybdenum alloy film and the indium and tin oxide film, which constitute the pixel electrode, may be lowered, which is undesirable.

As the above-mentioned corrosion inhibitor, a ring heteroaromatic compound, a ring heteroaliphatic compound or polyhydric alcohols can be used. Specifically, the ring heteroaromatic compound may be selected from the group consisting of furane, thiophene, pyrrole, oxazole, thiazole, imidazole, pyrazole, But are not limited to, triazole, tetrazole, benzofuran, benzothiophene, indole, benzothiazole, benzoimidazole, benzopyrazole, Aminotetrazole, methyltetrazole, tolutriazole, hydrotolutriazole, or hydroxytolutriazole. The term " aminotetrazole "

The cyclic heteroaliphatic compound is exemplified by piperazine, methylpiperazine, hydroxyethylpiperazine, pyrrolidine, alloxan, and the like.

Examples of the polyhydric alcohols include aromatic polyhydric alcohols such as gallic acid, methyl gallate, ethyl gallate, propyl gallate or butyl gallate, and linear chain polyhydric alcohols such as glycerol, erythritol, sorbitol, mannitol, or xylitol. It is preferable that the polyhydric alcohol is at least one selected from the group consisting of glycerol, erythritol, sorbitol, mannitol, and xylitol.

In the present invention, the fluorine compound functions as a main etching agent for the molybdenum alloy film and the indium and tin oxide films, and has an effect of increasing the etching rate and removing the residue. The fluorinated compound may be contained in an amount of 0.1 to 2% by weight, or 0.1 to 1% by weight based on the total weight of the composition. If it is contained in an amount of less than 0.1% by weight, the etching rate is slowed, and the molybdenum alloy film and indium and tin oxide film residues may be generated after the etching. If the etching rate is more than 2% by weight, It is undesirable because it can excessively etch the copper film formed thereon.

The fluorinated compound is a compound capable of dissociating and capable of providing fluorine (F ^- ) or hydrogen fluoride (HF ₂ ^- ) ions. The fluorinated compound may be HF, NaF, KF, AlF ₃ , HBF ₄ , NH ₄ F, NH ₄ HF ₂ , NaHF ₂ , KHF ₂ or NH ₄ BF ₄ And the like.

In the present invention, the hydrogen peroxide stabilizer controls the decomposition reaction of hydrogen peroxide even when the molybdenum alloy film and the indium and tin oxide films are repeatedly etched so that the metal ion content increases in the chemical solution, The maximum number of processings of the process. The fruit stabilizer may be included in an amount of 0.01 to 5% by weight, or 0.01 to 3%, or 0.1 to 2% by weight based on the total weight of the composition. When the hydrous stabilizer is contained in an amount of less than 0.01% by weight, the hydrolysis reaction can not be effectively inhibited. If the hydrous stabilizer is contained in an amount exceeding 5% by weight, the etching rate may be lowered.

As the above-mentioned hydrous stabilizer, a glycol compound may be used. The glycols may be at least one selected from the group consisting of ethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol. More preferably, it may be polyethylene glycol having a molecular weight of 1,000 or less. When the molecular weight is more than 1,000, the amount of bubbles to be generated increases, which may be unsuitable for application to etching equipment using spray.

In the present invention, the sulfonate group-containing compound protects SiNx, which serves as an insulating layer, to reduce the etching rate of SiNx while maintaining the etching rate of the molybdenum alloy and the indium and tin oxide films in the presence of the fluorine compound. That is, the sulfonic acid group-containing compound can control the etching selectivity of SiNx as compared with the etching of the molybdenum alloy film and the indium / tin oxide film.

The compound having a sulfonic acid group may be contained in an amount of 0.001 to 2% by weight, or 0.01 to 2% by weight, or 0.01 to 1% by weight, based on the total weight of the composition. If the amount of the compound having a sulfonic acid group based on the total weight of the composition is less than 0.001% by weight or exceeds 2% by weight, the effect of controlling the etching selectivity of SiNx may be insignificant or even deteriorated.

Examples of the sulfonate group-containing compound include alkyl sulfonate, alkyl disulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkylphenyl ether sulfonate, disulfonate, a polymer of formaldehyde and naphthalene sulfonate, a polymer of acrylamide methylpropane sulfonate, a polymer of acrylic acid and acrylamide methylpropane sulfonate Copolymers and vinylbenzene sulfonate polymers, and low-molecular and high-molecular compounds having sulfonic acid groups and salts thereof.

In the present invention, it is preferable that the water is deionized water, more preferably deionized water having a resistivity value of 18 M? / Cm or more, which indicates the degree of removal of ions in water.

The etchant composition of the present invention having the above composition prevents the etching process from being deteriorated due to an increase in the process time when fine patterns are formed at the time of etching the molybdenum alloy film and the indium and tin oxide films at an etching rate of 15 A / Which improves the problem of operation of process equipment.

Hereinafter, embodiments of the present invention will be described in more detail so that those skilled in the art can readily implement the present invention. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

& Lt; Example 1 and Comparative Example 1 & gt; Preparation of etching liquid composition

The compositions of Example 1 and Comparative Example 1 according to the present invention were prepared by mixing the respective components with the ingredient contents shown in Table 1 below.

Examples and Comparative Examples Hydrogen peroxide
[weight%] Auxiliary oxidant
[weight%] Corrosion inhibitor
[weight%] Fluorine compound
[weight%] Fruit stabilizer
[weight%] Precipitation inhibitor
[weight%] Sulfonic acid group-containing compound
[weight%] Deionized water
[weight %] Example 1 15 CuSO ₄ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 - - SI 0.5 81.5 Comparative Example 1 15 - - MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 - - SI 0.5 82.0

Abbreviations used in the above table are as follows.

MTZ: methyltetrazole,

PEG: Polyethylene glycol (poly (ethylene glycol),

SI: poly (acrylate-2-methylpropane sulfonic acid) (poly (acrylic acid-2-methylpropane sulfonic acid)

< Example  2 to 10> Etchant  Preparation of composition

The compositions of Examples 2 to 10 were prepared by adding diglycolic acid (DA) and thiodiacetic acid (TA) as the precipitating agent. The specific composition is shown in Table 2.

Examples and Comparative Examples Hydrogen peroxide
[weight%] Auxiliary oxidant
[weight%] Corrosion inhibitor
[weight%] Fluorine compound
[weight%] Fruit stabilizer
[weight%] Precipitation inhibitor
[weight%] Sulfonic acid group-containing compound
[weight%] Deionized water
[weight %] Example 2 15 Ag ₂ SO ₄ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 0.1 SI 0.5 81.4 Example 3 15 Fe ₂ (SO ₄ ) ₃ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 0.1 SI 0.5 81.4 Example 4 15 CuSO ₄ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 0.1 SI 0.5 81.4 Example 5 15 NiSO ₄ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 0.1 SI 0.5 81.4 Example 6 15 MnSO ₄ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 0.1 SI 0.5 81.4 Example 7 15 Ce ₂ (SO ₄ ) ₃ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 0.1 SI 0.5 81.4 Example 8 15 CuSO ₄ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 TA 0.1 SI 0.5 81.4 Example 9 15 CuSO ₄ 2.0 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 0.1 SI 0.5 79.9 Example 10 15 CuSO ₄ 0.5 MTZ 1.0 NH ₄ HF ₂ 0.5 PEG 1.0 DA 2.0 SI 0.5 79.5

< Experimental Example  1> Etchant  Performance testing of the composition

A 300 Å thick molybdenum titanium alloy film and a 500 Å thick indium and tin oxide film (ITO) were deposited on a glass substrate, respectively, and then a photolithography process was performed to form a pattern. The etching was carried out in a sprayable apparatus (Mini-etcher ME-001).

In order to verify the etch characteristics, a molybdenum titanium alloy film and indium and tin oxide films were etched for 80 seconds and etched for 120 seconds in order to check the damage of the copper film used in the source drain wiring.

Etch characteristics of the molybdenum alloy film, indium and tin oxide film and the thickness of the copper film after etching were observed using a scanning electron microscope (Hitachi, S-4800).

To confirm the occurrence of precipitates, 1,000 ppm of molybdenum powder and 1,000 ppm of indium and tin oxide powder were dissolved in the etchant composition to visually observe the presence of precipitates (FIGS. 5 and 6).

Figures 1 and 2 show a molybdenum titanium alloy film (MoTi) etch profile and an indium and tin oxide (ITO) etch profile using the composition according to Example 2, respectively.

FIGS. 3 and 4 show a molybdenum titanium alloy film (MoTi) etching profile and an indium and tin oxide film (ITO) etching profile using the composition according to Comparative Example 1, respectively.

The experimental results are summarized in Table 3 and Table 4.

Examples and Comparative Examples Molybdenum titanium
Alloy film etching
bias (탆) / 80s etching Indium and tin
Oxide film etching
bias (탆) / 80s etching Copper film thickness reduction
(A) / 120s etch Presence or absence of precipitates Example 1 0.28 0.26 25 Occurred Comparative Example 1 0.07 0.20 10 Occurred

Referring to Table 3, when the molybdenum titanium alloy film and the indium and tin oxide films were etched for 80 seconds with the composition according to Example 1 and Comparative Example 1 according to the present invention, it was confirmed that the etching rate was significantly increased in the composition of Example 1 .

Examples and Comparative Examples Molybdenum titanium
Alloy film etching
bias (탆) / 80s etching Indium and tin
Oxide film etching
bias (탆) / 80s etching Copper film thickness reduction
(A) / 120s etch Presence or absence of precipitates Example 2 0.26 0.26 20 Never Example 3 0.25 0.25 20 Never Example 4 0.26 0.24 15 Never Example 5 0.27 0.25 20 Never Example 6 0.25 0.28 20 Never Example 7 0.26 0.27 15 Never Example 8 0.25 0.24 20 Never Example 9 0.27 0.25 20 Never Example 10 0.26 0.24 350 Never

In addition, referring to Table 4, it was confirmed that the compositions of Examples 2 to 10, in which diglycolic acid or an agent for preventing precipitation was contained in addition to the auxiliary oxidizing agent, did not generate precipitates while the etching rate was improved.

The results show that when the molybdenum titanium alloy film (MoTi) and the indium and tin oxide film (ITO) used as the TFT-LCD pixel electrode are etched, the etching rate is improved and the TFT - Improvement of LCD display profile and productivity can be improved.

Claims (12)

Hydrogen peroxide as a peroxide,
As the auxiliary oxidizing agent, at least one ion selected from silver (Ag), iron (Fe), copper (Cu), nickel (Ni), manganese (Mn) and cerium (Ce) By weight based on the total weight of the etching solution. The method according to claim 1,
Wherein the content of the auxiliary oxidizing agent is 0.02 to 10 parts by weight with respect to 100 parts by weight of hydrogen peroxide which is a peroxide. The method according to claim 1,
Wherein the auxiliary oxidizing agent is an inorganic acid salt containing at least one ion selected from silver (Ag), iron (Fe), copper (Cu), nickel (Ni), manganese (Mn) Etchant composition. The method according to claim 1,
Wherein the composition further comprises a glycolic acid compound as a precipitant preventing agent. 5. The method of claim 4,
Wherein the deposition inhibitor is at least one selected from the group consisting of diglycolic acid and thiodiglycolic acid. The method according to claim 1,
Wherein the metal wiring is a single film selected from a molybdenum film, a molybdenum alloy film, an indium and a tin oxide film, or a multiple film in which two or more thereof are laminated. The method according to claim 1,
From 0.01 to 2% by weight of a corrosion inhibitor, from 0.01 to 1% by weight of a fluorine compound, from 0.01 to 5% by weight of a peroxide stabilizer, from 0.01 to 5% by weight based on the total weight of the composition, from 5 to 25% by weight of hydrogen peroxide, from 0.0001 to 2% 0.001 to 1% by weight of a precipitating inhibitor, 0.001 to 2% by weight of a compound containing a sulfonic acid group, and water so that the total weight of the entire composition is 100% by weight. 8. The method of claim 7,
Wherein the corrosion inhibitor is at least one selected from ring heteroaromatics, ring heteroaliphatic compounds, and polyhydric alcohols. 8. The method of claim 7,
Wherein the fluorinated compound is a compound capable of dissociating and providing fluorine (F ^- ) or hydrogen fluoride (HF ₂ ^- ) ions. 8. The method of claim 7,
Wherein the hydrous stabilizer is a glycol compound. 11. The method of claim 10,
Wherein the glycols are at least one selected from the group consisting of ethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol. . 8. The method of claim 7,
The sulfonate group-containing compound may be an alkyl sulfonate, an alkyl disulfonate, an alkyl benzene sulfonate, an alkyl naphthalene sulfonate, an alkylphenyl ether disulfonate phenyl ether disulfonate, a polymer of formaldehyde and naphthalene sulfonate, a polymer of acrylamide methylpropane sulfonate, a polymer of acrylic acid and acrylamide methylpropane sulfonate ) And a vinylbenzene sulfonate polymer. The composition for an etchant for a metal wiring film according to claim 1,

Images