KR20140031552A - Etching composition for copper and molibdenum alloy - Google Patents

Abstract

The present invention relates to an etchant composite for a copper and molybdenum alloy film. Provided in the present invention is the etchant composite which comprises, for the total weight of the composite: 5-40 weight% of hydrogen peroxide; 0.1-5 weight% of an etching restrainer; 0.1-5 weight% of a chelating agent; 0.1-5 weight% of an etching additive; 0.01-2 weight% of a fluorine compound; 0.01-2 weight% of a hydrogen peroxide stabilizer; 0.01-2 hydrogen peroxide of a glass etching restrainer; and water for making the total weight of the composite become 100 weight%. The etchant composite minimizes the etching speed of a gate, a glass substrate which is the lower film of source drain, and SiNx in order to minimize the potential defects in a post-process, a rework process, and a slimming process, thereby reducing the manufacturing costs.

Description

[0001] ETCHING COMPOSITION FOR COPPER AND MOLIBDENUM ALLOY [0002]

The present invention relates to an etchant composition of a copper and molybdenum alloy film, and more particularly to an etchant composition of a copper and molybdenum alloy film used as an electrode of a display such as a TFT-LCD or an OLED.

A fine circuit such as a semiconductor device, a TFT-LCD, and an OLED may be formed by uniformly applying a photoresist to a conductive metal film such as aluminum, aluminum alloy, copper and copper alloy formed on a substrate or an insulating film such as a silicon oxide film or a silicon nitride film, After a light is irradiated through a mask having a pattern, a photoresist of a desired pattern is formed through development, a pattern is transferred to a metal film or an insulating film under the photoresist by dry or wet etching, And then removed through a series of lithography processes.

Gate and data metallization of large displays use copper metal, which has lower resistance and environmental friendliness than conventional aluminum and chromium wiring. Copper has low adhesion to glass substrate and silicon insulating film and diffuses into silicon film, and titanium, molybdenum and the like are used as the lower barrier metal.

Korean Patent Laid-Open Publication Nos. 2003-0082375, 2004-0051502, 2006-0064881, and 2006-0099089 disclose a hydrogen peroxide-based copper / molybdenum alloy etchant.

The copper / molybdenum alloy etchant contains a fluorine compound to etch the molybdenum alloy, and the fluorine compound improves the etch rate of the molybdenum alloy when the copper / molybdenum alloy is etched at the same time, thereby removing the residue of the molybdenum alloy to be. However, the fluorine compound is not only a molybdenum alloy but also a glass substrate, which is a lower film of a gate wiring which is a copper / molybdenum alloy, and SiNx which is a lower film of the source / drain wiring. The increase in the etching of the lower film increases defects due to etching stains in the post-process and the rework process and defects due to etching stains in the slimming process.

As mobile devices become more advanced, the thickness of displays needs to be reduced. Slimming processes are being carried out to thin glass substrates after manufacturing TFT-LCD display cells. If the etching of the glass substrate increases in the etching process, unevenness in the slimming process may cause unevenness in the staining. Since the glass substrate used for the TFT-LCD display is expensive, in order to reduce the manufacturing cost, if a defect occurs in the deposition and etching process during the photolithography process, the entire process is etched using the etching solution to perform the rework process . If the etching of the glass substrate occurs excessively, etching unevenness remains on the substrate, which causes defects.

Patent Publication No. 2003-0082375 Patent Publication No. 2004-0051502 Patent Publication No. 2006-0064881 Patent Publication No. 2006-0099089

Accordingly, it is an object of the present invention to minimize the etch rate of the SiNx and the glass substrate, which are the gate and source drain bottom films, when etching the copper / molybdenum alloy film at the same time, thereby minimizing defects that may occur in the post- To provide an etchant composition.

In order to achieve the above object, the present invention provides a hydrogen peroxide-based etching solution composition containing a glass etching inhibitor.

More specifically, the present invention relates to a polishing composition comprising 5 to 40 wt% of hydrogen peroxide, 0.1 to 5 wt% of an etching inhibitor, 0.1 to 5 wt% of a chelating agent, 0.1 to 5 wt% of an etching additive, 0.01 to 2 wt% 0.01 to 2% by weight of a fluorine compound, 0.01 to 2% by weight of a hydrous stabilizer, 0.01 to 2% by weight of a glass etching inhibitor, and water so that the total weight of the entire composition is 100% by weight.

The etchant composition according to the present invention minimizes the etching of the lower film in the etching process, thereby minimizing the defects that may occur in the post-process glass substrate slimming process or rework process. In particular, the glass etch inhibitor imparts a selectivity to reduce the etch rate of SiNx and the underlying glass substrate while maintaining the etch rate improvement of the molybdenum alloy film in the etchant containing the fluorine compound.

1 is a scanning electron micrograph (side view) of a profile when a copper / molybdenum alloy film is etched using the etchant according to Example 6. FIG.
2 is a scanning electron micrograph (plane) of the profile when the copper / molybdenum alloy film is etched using the etchant according to Example 6. FIG.
FIG. 3 is a scanning electron microscope (SEM) image showing the damage of the glass when the etching solution according to Example 6 is used.
FIG. 4 is a scanning electron microscope (SEM) image showing the damage of the glass when the etching solution according to Comparative Example 1 is used.

The etchant composition of the present invention may simultaneously etch the copper / molybdenum alloy. Here, the term "copper / molybdenum alloy film" refers to a copper film and a molybdenum alloy film, and the molybdenum alloy is an alloy of molybdenum and various metals, preferably an alloy of titanium, tantalum, chromium, neodymium, nickel, indium or tin , And most preferably an alloy with titanium.

The etchant composition of the present invention comprises 5 to 40 wt% of hydrogen peroxide, 0.1 to 5 wt% of an etch inhibitor, 0.1 to 5 wt% of a chelating agent, 0.1 to 5 wt% of an etch additive, 0.01 to 2 wt% 0.01 to 2% by weight of a fluorine compound, 0.01 to 2% by weight of a hydrous stabilizer, 0.01 to 2% by weight of a glass etching inhibitor, and water so that the total weight of the entire composition is 100% by weight.

In the etchant composition of the present invention, hydrogen peroxide acts as the main oxidizing agent for the copper and molybdenum alloy. The hydrogen peroxide is preferably contained in an amount of 5 to 40 wt%, more preferably 10 to 30 wt%, based on the total weight of the composition. If it is contained in an amount of less than 5% by weight, the etching ability of the copper and molybdenum alloy may not be sufficient, and if it is contained in an amount exceeding 40% by weight, the etching speed becomes too fast.

The etch inhibitor contained in the etchant composition of the present invention modulates the copper and molybdenum alloy etch rates to provide an etch profile with appropriate taper angles. The etching inhibitor is preferably contained in an amount of 0.1 to 5% by weight, more preferably 0.5 to 3% 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 ability to control the taper angle is deteriorated, and if it is contained in an amount exceeding 5% by weight, the etching rate is decreased, which is inefficient.

The etching inhibitor in the etching composition of the present invention is preferably a heterocyclic compound having 1 to 10 carbon atoms which contains at least one hetero atom selected from oxygen, sulfur and nitrogen, and which does not simultaneously contain a nitrogen atom and a sulfur atom. Specifically, there can be mentioned, for example, furan, thiophene, pyrrole, oxazole, imidazole, pyrazole, triazole, tetrazole, benzofuran, benzothiophene, indole, benzimidazole, benzpyrazole, aminotetrazole, Methylpiperazine, hydroxylethylpiperazine, pyrrolidine and aloxane, and heterocyclic aliphatic compounds such as piperazine, methylpiperazine, hydroxylethylpiperazine, pyrrolidine and alooxane, in a solvent such as tetrahydrofuran, tetrahydrofuran, . These may be used alone or in combination of two or more.

The etching solution composition of the present invention can minimize the etching rate of the glass substrate which is the lower film by including the glass etching inhibitor in addition to the etching inhibitor. The glass etching inhibitor is preferably a compound containing boron atoms and fluorine atoms at the same time . More preferably a borofluoric acid or a borofluoric acid salt, and most preferably selected from HBF ₄ , NaBF ₄ , KBF ₄ , NH ₄ BF ₄ or a mixture thereof.

The content of the glass etching inhibitor is preferably 0.01 to 2% by weight, more preferably 0.05 to 1% by weight. When the content is less than 0.01% by weight, the effect of inhibiting the glass etching is insignificant. When the content is more than 2% by weight, the etching rate is ineffective.

The etchant composition of the present invention contains from 0.1 to 5% by weight of etch additive to control the etch rate. Is preferably contained in an amount of 0.1 to 5% by weight, more preferably 0.5 to 3% 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 may become slow and the etching may not be performed at a time when the process can be controlled. If the amount exceeds 5% by weight, the etching speed becomes too fast.

The etching additive is preferably a compound containing an organic acid, an inorganic acid or a salt thereof, and a nitrogen and a sulfur, or a mixture thereof.

Organic acids include water-soluble organic acids such as acetic acid, formic acid, butanoic acid, citric acid, glycolic acid, oxalic acid, malonic acid, pentanoic acid, propionic acid, tartaric acid, gluconic acid, glycolic acid and succinic acid. These may be used alone or in combination of two or more.

The inorganic acid is preferably nitric acid, sulfuric acid, phosphoric acid, hydrochloric acid, hypochlorous acid, permanganic acid or a mixture thereof.

In the etchant composition of the present invention, the compound which simultaneously contains a nitrogen atom and a sulfur atom is preferably a monocyclic or bicyclic compound having 1 to 10 carbon atoms simultaneously containing a nitrogen atom and a sulfur atom, more preferably 5 to 10 Membered monocyclic or bicyclic compound. Specifically, there may be mentioned mercaptoimidazoline, 2-mercapto-1-methylimidazole, 2-mercaptothiazole, 2-aminothiazole, mercaptotriazole, aminomercaptotriazole, Sol, mercaptomethyltetrazole, thiazole, benzothiazole, 2-methylbenzothiazole, 2-aminobenzothiazole, and 2-mercaptobenzothiazole, and one or more of them Can be used.

Such an additive that simultaneously contains nitrogen and sulfur controls the etching inhibitor to excessively adsorb to the metal surface to reduce the etching rate, especially when the etching process is repeated to increase the metal ion content in the etchant. This allows the etch rate to be maintained even when the metal ion content in the etchant is high.

In the etching solution composition of the present invention, the chelating agent forms a chelate with the copper and molybdenum alloy ions generated during the etching process, thereby inactivating the chelating agent, thereby suppressing decomposition reaction of the etching solution with hydrogen peroxide. If the chelate is not added to the etching solution composition according to the present invention, the oxidized metal ions are not inactivated during the etching process, thereby accelerating the decomposition reaction of hydrogen peroxide as the etching solution composition, resulting in generation of heat and explosion. The chelating agent is preferably contained in an amount of 0.1 to 5% by weight, more preferably 0.5 to 3% 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 amount of metal ions deactivatable is too small to have an ability to control the hydrogen peroxide decomposition reaction. If the amount exceeds 5% by weight, an effect of deactivating the metal due to the formation of additional chelate can not be expected. .

The chelating agent of the present invention is preferably a compound having an amino group and a carboxylic acid group at the same time and specifically includes iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetri nylpentaacetic acid, aminotri (methylenephosphonic acid) Diethylene triamine penta (methylene phosphonic acid), sarcoic acid, alanine, glutamic acid, aminobutyric acid, glycine and the like can be used in combination with one or more of the following: 1-hydroxyethane (1,1-diylbispropionic acid), ethylenediaminetetra .

In the etchant composition of the present invention, the fluorine compound improves the etching rate of the molybdenum alloy when the copper and the molybdenum alloy are etched at the same time, thereby reducing the tail length and removing the residue of the molybdenum alloy that may be generated during the etching. Increasing the tail of the molybdenum alloy may reduce the brightness and it should be removed since residues left on the substrate and underlying film reduce electrical shorts, poor wiring and brightness. The amount of the fluorine compound is preferably 0.01 to 2% by weight, more preferably 0.1 to 1% by weight based on the total weight of the composition. If it is contained in an amount less than 0.01% by weight, the residue of the molybdenum alloy can not be effectively removed, and if it is contained in an amount exceeding 2% by weight, the bottom film can be etched.

The fluorine compound of the present invention is a compound capable of releasing F ^- or HF ₂ ^- by dissociation, and is a compound capable of releasing F ^- or HF ₂ ^- , such as HF, NaF, KF, AlF ₃ , HBF ₄ , NH ₄ F, NH ₄ HF ₂ , NaHF ₂ , KHF ₂ and NH ₄ BF ₄ , and the like, and one or more of them can be used together.

In the etchant composition of the present invention, the hydrothermal stabilizer acts to control the decomposition reaction of hydrogen peroxide when the metal ion content in the etchant is high, by repeating the etching process. As the water-soluble stabilizer, phosphates, glycols, amines and the like can be used, and the content is preferably 0.01 to 2% by weight.

The copper / molybdenum alloy etchant composition of the present invention may further comprise any additives known in the art to improve the etching performance. As an additive, a surfactant used for improving the etching performance can be mentioned. The kind of the surfactant may be used without limitation as long as it is used in the art.

The water used in the etchant composition of the present invention is not particularly limited, but it is preferable to use deionized water, and it is more preferable to use deionized water having a specific resistance value of 18 M OMEGA .

Etching the copper / molybdenum alloy film used as an electrode of a TFT-LCD display or an OLED using the etchant composition of the present invention minimizes the etching of the lower film, thereby preventing a defect in the organic substrate slimming process or the rework process, Can be minimized.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, these Examples are merely illustrative of the present invention, and the present invention is not limited to the following Examples.

< Example  1 to 6 and Comparative Example  1>

The compositions of Examples 1 to 6 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.

Example
And
Comparative Example Peroxide
Hydrogen
[weight%] Etch inhibitor
[% By weight] Chelating agent
[weight%] Etching additive
[% By weight] Fruit stabilizer Glass etch inhibitor [wt%] Fluoride
[weight%] water
[weight %] Example 1 20 ATZ 1.0 IDA 1.0 BTZ 1.0 PEG 0.5 HBF ₄ 0.1 NH ₄ HF ₂ 0.5 75.9 Example 2 20 ATZ 1.0 IDA 1.0 BTZ 1.0 PEG 0.5 HBF ₄ 0.2 NH ₄ HF ₂ 0.5 75.8 Example 3 20 ATZ 1.0 IDA 1.0 BTZ 1.0 PEG 0.5 HBF ₄ 0.3 NH ₄ HF ₂ 0.5 75.7 Example 4 20 ATZ 1.0 IDA 1.0 BTZ 1.0 PEG 0.5 NaBF ₄ 0.1 NH ₄ HF ₂ 0.5 75.9 Example 5 20 ATZ 1.0 IDA 1.0 BTZ 1.0 PEG 0.5 NaBF ₄ 0.2 NH ₄ HF ₂ 0.5 75.8 Example 6 20 ATZ 1.0 IDA 1.0 BTZ 1.0 PEG 0.5 NaBF ₄ 0.3 NH ₄ HF ₂ 0.5 75.7 Comparative Example 1 20 ATZ 1.0 IDA 1.0 BTZ 1.0 PEG 0.5 - - NH ₄ HF ₂ 0.5 76.0

ATZ: 5-aminotetrazole,

IDA: Iminodiacetic acid,

BTZ: benzothiazole,

PEG: Polyethylene glycol

< Etching  Performance Testing>

In order to evaluate the effect of the etching solution according to the present invention, a copper and molybdenum alloy film having a thickness of 3100 angstroms was deposited on a glass substrate, and then a photolithography process was performed to form a pattern to prepare a specimen.

Further, in order to evaluate the etching of the glass substrate, a photolithography process was performed on the glass substrate to form a pattern to prepare a test piece.

Etchant compositions of Examples 1-6 and Comparative Example 1 The procedure was carried out on a sprayable equipment (Mini-etcher ME-001) using the etchant composition. After etching, etching properties of copper and molybdenum alloy films and etching of glass substrate were observed using a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.). In order to confirm the etch characteristics, etching was performed for 90 seconds, and etching was performed for 200 seconds to confirm the glass substrate etching.

The experimental results are shown in Table 2.

Example
And
Comparative Example Cu / MoTi
etch bias
(쨉 m, 90s etch) Cu / MoTi
Taper angle
(°, 90 s etch) MoTi
Tail length
(쨉 m, 90s etch) Molybdenum alloy
Residue Glass substrate etching
(Å, 200 s etch) Example 1 0.81 46.5 0.05 none. 215 Example 2 0.82 49.5 0.06 none. 157 Example 3 0.82 47.8 0.07 has exist. 65 Example 4 0.80 48.6 0.05 none. 198 Example 5 0.83 48.5 0.06 none 110 Example 6 0.83 48.2 0.07 none 25 Comparative Example 1 0.80 48.7 0.05 none. 665

As can be seen from Table 2, the compositions of Examples 1 to 6 according to the present invention are excellent in etch bias, taper angle, tail distance and the like, and the etching on the glass substrate is suppressed to about 1/33 to 1/3 .

FIGS. 1 and 2 are side and plan views of a cross section of a copper / molybdenum alloy film etched with a scanning electron microscope using the etchant composition according to Example 6. FIG.

FIGS. 3 and 4 are scanning electron micrographs showing the results of testing the etching performance of the glass substrate using the etching composition according to Example 6 and Comparative Example 1, respectively. It can be seen that the etching of the glass substrate of Comparative Example 1 is much more severe.

The above results show that when the etching solution composition of the present invention is used to etch a copper / molybdenum alloy film used as an electrode of a TFT-LCD display, the etching of the lower film can be minimized to occur in the organic substrate slimming process or the rework process Which can be minimized.

Claims (10)

5 to 40 wt% hydrogen peroxide, 0.1 to 5 wt% etch inhibitor, 0.1 to 5 wt% chelating agent, 0.1 to 5 wt% etch additive, 0.01 to 2 wt% fluorine compound, 0.01 to the total weight of the composition A copper and molybdenum alloy film etchant composition comprising from about 2 wt% of a water stabilizer, from 0.01 to 2 wt% of a glass etch inhibitor, and water such that the total weight of the total composition is 100 wt%.
The copper and molybdenum alloy film etchant composition according to claim 1, wherein the glass etching inhibitor is a compound containing a boron atom and a fluorine atom at the same time.
The copper and molybdenum alloy film etchant composition according to claim 2, wherein the glass etching inhibitor is hydrofluoric acid or borate.
The etchant composition of claim 3, wherein the glass etch inhibitor is selected from HBF ₄ , NaBF ₄ , KBF ₄ , NH ₄ BF _4, and mixtures thereof.
The etchant composition for copper and molybdenum alloy film according to claim 1, wherein the etching additive is a compound containing an organic acid, an inorganic acid or a salt thereof, and a nitrogen and a sulfur, or a mixture thereof.
The etching composition for copper and molybdenum alloy film according to claim 1, wherein the etching inhibitor is a heterocyclic compound having 1 to 10 carbon atoms, which contains at least one heteroatom selected from oxygen, sulfur and nitrogen.
The etching composition for copper and molybdenum alloy film according to claim 1, wherein the chelating agent is a compound having both an amino group and a carboxylic acid group.
The copper and molybdenum alloy film etchant composition of claim 1, wherein the fluorine compound is a compound capable of dissociating to provide F ^- or HF ₂ ^- ions.
The copper and molybdenum alloy film etchant composition of claim 1, wherein the hydrous stabilizer is selected from phosphates, glycols and amine compounds.
The copper and molybdenum alloy film etchant composition of claim 1, further comprising a surfactant.

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