KR102674217B1 - Etching composition - Google Patents

Abstract

The present invention relates to an etchant composition, and provides an etchant composition that can minimize damage to the lower metal film during the process of etching the upper metal film. According to the etchant composition according to the present invention, damage to the lower film can be suppressed during the etching process of the upper film, the generation of metal precipitates can be minimized, and process efficiency can be improved by preventing the occurrence of skew.

Description

Etching solution composition {ETCHING COMPOSITION}

The present invention relates to an etchant composition for selectively etching an upper metal film and minimizing the generation of metal precipitates during the process.

Microcircuits such as semiconductor devices and TFT-LCD and OLED are made by uniformly applying photoresist to a conductive metal film such as aluminum, aluminum alloy, copper and copper alloy, or an insulating film such as silicon oxide or silicon nitride film formed on a substrate, After irradiating light through a mask with a pattern engraved on it and developing it to form a photoresist of the desired pattern, the pattern is transferred to the metal film or insulating film below the photoresist by dry or wet etching, and then the unnecessary photoresist is subjected to a peeling process. It is completed through a series of lithographic processes that remove it.

Meanwhile, with the development of the display field, a problem has arisen in which the resistance of the wiring increases in relation to the extension of the gate wiring connected to the thin film transistor. When commonly used metals or metal alloys such as aluminum, molybdenum, and chromium are applied to wiring, it is difficult to solve problems caused by increased resistance. Therefore, in order to minimize resistance, efforts to use films and wiring containing silver (Ag) and research on suitable etchants are increasing.

When a general etchant is used for a film containing silver (Ag), residues or re-adsorption may occur, and an increase in the viscosity of the etchant causes the problem that it is difficult to etch nano-sized patterns. Additionally, the silver film is excessively etched or the degree of etching is not uniform, resulting in a poor profile on the side of the wiring.

Accordingly, a composition containing hydrogen peroxide or phosphoric acid is disclosed as a conventional silver etchant. However, when etching a coated silver film to protect the nanopattern, the speed at which the etchant penetrates the object to be etched decreases, resulting in a significant decrease in process efficiency. Problems may arise, and the viscosity of the etchant may be too high, which may result in the etching process not proceeding smoothly.

Therefore, a composition is needed to solve the above problems.

The purpose of the present invention is to provide a composition for minimizing damage to the lower film while etching the upper film and minimizing the generation of metal precipitates during the etching process.

In order to solve the above problem, the present invention,

nitric acid;

organic acids;

sulfur-containing compounds; and

Contains copper-containing compounds,

wherein the organic acid does not contain sulfur and copper atoms,

An etchant composition is provided wherein the sulfur-containing compound includes a compound of Formula 1, a sulfate salt, or a combination thereof.

[Formula 1]

In Formula 1,

X is H, Na, K or ammonium, and the ammonium is substituted or unsubstituted,

Y is H or OH,

R is selected from substituted or unsubstituted C1-C20 alkyl groups.

According to one embodiment, the sulfur-containing compound may include a compound of Formula 1 and a sulfate.

According to one embodiment, the compound of Formula 1 is methanesulfonic acid, ethane sulfonic acid, benzene sulfonic acid, toluene sulfonic acid, and phenol sulfonic acid. , hydroxymethanesulfonic acid, hydroxyethanesulfonic acid, hydroxypropanesulfonic acid, and their respective salts.

According to one embodiment, the sulfate is ammonium hydrogen sulfate, ammonium sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium sulfate, and sulfuric acid. It may include one or more selected from the group consisting of potassium sulfate, potassium persulfate, sodium persulfate, and ammonium persulfate.

According to one embodiment, the organic acid may be a compound containing a carboxy group.

Specifically, the organic acids include citric acid, butanetetracarboxylic acid, acetic acid, butanoic acid, formic acid, glycolic acid, and succinic acid. acid, glutaric acid, adipic acid, pimelic acid, suberic acid, lactic acid, caproic acid, caprylic acid (caprylic acid), phenylacetic acid, benzoic acid, benzene-monocarboxylic acid, nitrobenzoic acid, hydroxybenzoic acid, dihydroxybenzene benzene, aminobenzonic acid, pyruvic acid, gluconic acid, diacetic acid, iminodiacetic acid, nitrilotriacetic acid, ethylene Ethylenediamine tetra acetic acid, diethylene triamine pentaacetic acid, alanine, glutamic acid, aminobutyric acid, iminodisuccinic acid, ethylene Ethylene diamine disuccinic acid, polyimino disuccinic acid, malic acid, sorbic acid, fumaric acid, malonic acid, oxalic acid , pentanoic acid, propionic acid, tartaric acid, and pyroglutamic acid.

According to one embodiment, the copper-containing compound is copper nitrate, copper sulfate, copper chloride, copper acetate, copper fluoride, copper carbonate, copper oxide, copper fluoroborate, copper methanesulfonate, copper ethanesulfonate, copper propanolsulfonate, and copper acetate. And it may include one or more selected from the group consisting of copper citrate.

According to one embodiment, the composition contains additional additives such as imidazole, triazole, benzotriazol, aminotetrazole, tolyltriazole, indole, One or more selected from the group consisting of purine, pyrazole, pyridine, pyrrole, pyrrolidine, pyrroline, and succinimide. It can be included.

According to one embodiment, the present invention,

1 to 20% by weight of nitric acid;

1 to 80% by weight of organic acid;

2 to 80% by weight of sulfur-containing compound; and

It may contain 0.0001 to 1% by weight of a copper-containing compound.

According to one embodiment,

1 to 20% by weight of nitric acid;

1 to 50% by weight of organic acid;

1 to 40% by weight of a compound of Formula 1;

1 to 40% by weight of sulfate; and

It may contain 0.0001 to 1% by weight of a copper-containing compound.

According to one embodiment, the etchant composition can be used to selectively etch an indium oxide film, a silver film, or a combination thereof.

Specific details of other embodiments of the present invention are included in the detailed description below.

According to the etchant composition according to the present invention, damage to the lower film containing aluminum can be suppressed during the etching process of the upper film, the generation of metal reducing precipitates can be minimized, and process efficiency can be improved by preventing the occurrence of skew. there is.

Since the present invention can be modified in various ways and have various embodiments, specific embodiments will be exemplified and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Terms or words used in this specification and claims should not be construed as limited to their common or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

Hereinafter, the etchant composition according to an embodiment of the present invention will be described in more detail.

In the etching process, the role of the etchant to efficiently etch the target area is important. For example, if a problem occurs in which the unintended lower metal film is damaged during the process of etching the upper metal film, the efficiency of the product is greatly reduced. In addition, metal precipitates generated during the etching process change electrical properties and interfere with the coating of the upper protective layer, reducing the reliability of the product. The present invention is to solve this problem,

nitric acid;

organic acids;

sulfur-containing compounds; and

Contains copper-containing compounds,

wherein the organic acid does not contain sulfur and copper atoms,

An etchant composition is provided wherein the sulfur-containing compound includes a compound of Formula 1, a sulfate salt, or a combination thereof.

[Formula 1]

In Formula 1,

X is H, Na, K or ammonium, and the ammonium is substituted or unsubstituted,

Y is H or OH,

R is selected from substituted or unsubstituted C1-C20 alkyl groups.

According to one embodiment, the term 'substitution' means that at least one hydrogen contained in a compound or functional group is a halogen atom, an alkyl group with 1 to 10 carbon atoms, a halogenated alkyl group, a cycloalkyl group with 3 to 30 carbon atoms, or an aryl group with 6 to 30 carbon atoms. , hydroxyl group, alkoxy group having 1 to 10 carbon atoms, carboxylic acid group, aldehyde group, epoxy group, cyano group, nitro group, amino group, sulfonic acid group, and derivatives thereof. .

According to one embodiment, R may include a linear, branched, or cyclic structure. The 'linear' structure can be described interchangeably with the 'straight chain' structure. A 'branched' structure refers to a structure with branched or side chains extending from the main chain, and includes a dendrimer-type structure with repetitive side chains. Dendrimeric structures can be symmetric or asymmetric. The 'ring-shaped' structure can be described interchangeably with the 'ring' structure.

The present invention can increase etching uniformity and reduce damage to the underlying film by not containing peroxide, phosphoric acid, hydrofluoric acid, or their salts.

According to one embodiment, the sulfur-containing compound may include a compound of Formula 1 and a sulfate.

According to one embodiment, the content of the sulfur-containing compound may be, for example, 2 to 80% by weight, for example, 10 to 50% by weight, or for example, 20 to 40% by weight.

The compounds of Formula 1 and sulfates can be broadly classified by the number of oxygen atoms bonded to sulfur atoms. Specifically, the compound of Formula 1 has three oxygen atoms bonded to sulfur (S) atoms, and the sulfate has four oxygen atoms bonded to sulfur atoms.

According to one embodiment, the compound of Formula 1 is, for example, methane sulfonic acid, ethane sulfonic acid, benzene sulfonic acid, toluene sulfonic acid, phenol sulfonic acid ( It may include one or more selected from the group consisting of phenol sulfonic acid, hydroxymethane sulfonate, hydroxyethane sulfonate, hydroxypropane sulfonate, and salts of each of these. For example, it may include sodium hydroxymethane sulfonate. Additionally, it may be included in the composition in an amount of, for example, 1 to 40% by weight, for example, 4 to 40% by weight, for example, 4 to 20% by weight. The compound of Chemical Formula 1 as described above can serve to etch the silver (Ag) film.

According to one embodiment, the sulfate is ammonium hydrogen sulfate, ammonium sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium sulfate, and sulfuric acid. It may contain one or more selected from the group consisting of potassium sulfate, potassium persulfate, sodium persulfate, and ammonium persulfate, for example, 1 to 40% by weight. , for example, may contain 5 to 30% by weight. Sulfate compounds can also play a role in etching silver (Ag) films.

By using the compound of Formula 1 and sulfate together, the dissociation concentration of Formula 1 can be kept constant, and as a result, the uniformity of the etch rate can be increased.

According to one embodiment, the organic acid does not contain a sulfur atom, so it can be distinguished from the compound of Formula 1, and because it does not contain a copper atom, it can be distinguished from a copper-containing compound, and has one carboxy group (-COOH) in its structure. It may include more.

Specifically, citric acid, butanetetracarboxylic acid, acetic acid, butanoic acid, formic acid, glycolic acid, succinic acid, and glue. Glutaric acid, adipic acid, pimelic acid, suberic acid, lactic acid, caproic acid, caprylic acid , phenylacetic acid, benzoic acid, benzene-monocarboxylic acid, nitrobenzoic acid, hydroxybenzoic acid, dihydroxy benzene, amino Benzoic acid, pyruvic acid, gluconic acid, diacetic acid, iminodiacetic acid, nitrilotriacetic acid, ethylene diamine tetraacetic acid ( ethylenediamine tetra acetic acid, diethylene triamine pentaacetic acid, alanine, glutamic acid, aminobutyric acid, iminodisuccinic acid, ethylenediamine disuccinic acid ( ethylene diamine disuccinic acid, polyimino disuccinic acid, malic acid, sorbic acid, fumaric acid, malonic acid, oxalic acid, pentanoic acid ( It may include one or more selected from the group consisting of pentanoic acid, propionic acid, tartaric acid, and pyroglutamic acid.

The content of the organic acid may be, for example, 1 to 80% by weight, for example 20 to 70% by weight, for example 1 to 50% by weight, for example 20 to 50% by weight. Organic acids can play a role in improving the surface wettability of the etching film, preventing corrosion, and improving etching uniformity during the process. Specifically, during the etching process, the carboxyl group of the organic acid may chelate the metal ion and stabilize it so that it can be dissolved in the etching solution, thereby preventing the metal ion from being reduced and re-adsorbed to the substrate. You can.

According to one embodiment, the copper-containing compound is copper nitrate, copper sulfate, copper chloride, copper acetate, copper fluoride, copper carbonate, copper oxide, copper fluoroborate, copper methanesulfonate, copper ethanesulfonate, copper propanolsulfonate, and copper acetate. And it may include one or more selected from the group consisting of copper citrate. The copper-containing compound may be included at, for example, 0.0001 to 1% by weight, for example, 0.005 to 0.05% by weight, and can improve wiring straightness by suppressing the formation of a silver (Ag) oxide film caused by oxygen. .

According to one embodiment, the composition according to the present invention may further include additives such as corrosion inhibitors, surfactants, and etch stabilizers commonly used in the art in addition to the above-mentioned components as additional additives, and specifically contains sulfur. It may include compounds that are not included in compounds and organic acid compounds.

The corrosion inhibitor may be a monocyclic heterocyclic compound containing one or more heteroatoms selected from oxygen, sulfur, and nitrogen in the molecule, or a heterocyclic compound having a condensation structure of the monocyclic heteroring and a benzene ring. The monocyclic heterocyclic compound may be a heterocyclic aromatic compound or a heterocyclic aliphatic compound having a monocyclic structure of 1 to 10 carbon atoms, and specific examples include furane, thiophene, and pyrrole. , oxazole, imidazole, pyrazole, triazole, tetrazole, 5-aminotetrazole, methyltetrazole, pipe Piperazine, methylpiperazine, hydroxyethylpiperazine, pyrrolidine, alloxan, benzofurane, benzothiophene, indole ), benzimidazole, benzpyrazole, tolutriazole, hydrotolutriazole, hydroxytolutriazole, or a mixture of two or more of these. You can.

Additionally, additional additives may include, for example, glycols, amines, polyhydric alcohols, or mixtures thereof. Additional additives such as glycols and polyhydric alcohols contain hydroxyl groups (OH), and the glycols may specifically include, for example, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, or a combination of two or more of these. . Polyhydric alcohols may include, for example, glycerol, erythritol, sorbitol, mannitol, xylitol, or a combination of two or more of these. Also, for example, imidazole, triazole, benzotriazol, aminotetrazole, tolyltriazole, indole, purine, pyra It may further include one or more additives selected from the group consisting of pyrazole, pyridine, pyrrole, pyrrolidine, pyrroline, and succinimide. . By adding such additives, effects such as etching uniformity and etching speed control can be improved. The content of the additive can be appropriately selected depending on the purpose of use of each additive, but from the viewpoint of not impairing the effect of the present invention, for example, the total of all additives is 10% by weight or less, for example, 5% by weight or less. It can be included in the range.

According to one embodiment, it may contain 1 to 20% by weight of nitric acid, for example, 5 to 15% by weight. Nitric acid can be used as an oxidizing agent and can play a role in controlling the etching rate of metals, especially silver (Ag).

According to one embodiment, the indium oxide film, the silver film, or a combination thereof can be selectively etched using the above-described etchant. In addition, by suppressing the generation of silver (Ag) reducible precipitates, process problems caused by metal precipitates can be minimized and the occurrence of bias can be prevented.

Since the present invention can be modified in various ways and implemented in various embodiments, it will be described in detail below so that those skilled in the art can easily implement the present invention. The following examples are only for illustrating the present invention, and the content of the present invention is not limited by the following examples, and should be understood as all conversions, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Example

An etchant composition was prepared with the composition shown in Table 1.

Comparative example

An etchant composition was prepared with the composition shown in Table 2.

Experimental Example 1: Etching rate evaluation

In order to evaluate the etching speed according to the etchant composition of Examples and Comparative Examples, a laminated film (70Å/1000Å/70Å) made of SD layer, Ti/Al/Ti as the lower film and ITO/AG/ITO as the upper film was used as a specimen. It was cut into 30mm sizes and used.

After filling 10 kg of the evaluation chemical solution into a wet etcher, the prepared evaluation specimen was etched for 120 seconds at a temperature of 40°C. The etched specimen was rinsed with ultrapure water for about 30 seconds and then dried with nitrogen at a pressure of 3.0 kgf/cm ² . The etch rate of the specimen is as shown in Equation 1 below, and the ITO/AG/ITO film thickness before and after the etching treatment was compared and converted to an etch rate per second. The thickness of the film was measured using a non-contact thin film thickness measuring device (ST-4000DLXn, K-MAC).

[Equation 1]

Etching speed (Å/sec) = (Thickness before etching - Thickness after etching)/Processing time (converted to seconds)

Experimental Example 2: Residue Evaluation

In order to evaluate the degree of residue after etching according to the etchant composition of the Examples and Comparative Examples, each specimen according to the results of Experimental Example 1 was observed with a scanning electron microscope, and the residue was measured by the area of the residual metal film in the area between the ITO/Ag/ITO wiring. The formation was determined (10% residual area per unit).

Experimental Example 3: Precipitate evaluation

In order to evaluate the degree of precipitate formation during the etching process according to the etchant compositions of Examples and Comparative Examples, each specimen according to the results of Experimental Example 1 was observed with a scanning electron microscope to determine whether residues were formed. The area of silver (Ag) particles generated on the top of the Ti/Al/Ti wiring was judged to be 1 to 10 units.

Experimental Example 4: Etching uniformity evaluation

In order to evaluate the etching uniformity according to the etchant composition of Examples and Comparative Examples, each specimen according to the results of Experimental Example 1 was observed with a scanning electron microscope to measure the uniformity of the formed wiring.

Experimental Example 5: Evaluation of lower membrane damage

In order to evaluate the etching uniformity according to the etchant composition of Examples and Comparative Examples, each specimen according to the results of Experimental Example 1 was observed with a scanning electron microscope to measure the decrease in width of the Ti/Al/Ti film.

The results according to Experimental Examples 1 to 5 are shown in Table 3.

As can be seen from the results in Table 3, the results of the example compositions containing both a sulfur-containing compound and a copper-containing compound showed excellent results in all etching speed, residue, precipitate, and etching uniformity. In particular, the results of Examples 9 and 10, which contained both the compound of Formula 1 and sulfate along with the copper-containing compound, were all excellent. On the other hand, the etch rate of Comparative Example 9, which did not contain the copper-containing compound, was significantly reduced, and the residue and the occurrence of precipitates increased significantly. In addition, it can be seen that Comparative Examples 4 to 8 containing fruit water, phosphoric acid, or hydrofluoric acid have problems such as a significant increase in the production of precipitates or significant damage to the lower membrane.

As the specific parts of the present invention have been described in detail above, those skilled in the art will understand that these specific descriptions are merely preferred embodiments, thereby limiting the scope of the present invention to the specific embodiments described above. It doesn't work.

Claims (11)

nitric acid;
organic acids;
sulfur-containing compounds; and
Contains copper-containing compounds,
wherein the organic acid does not contain sulfur and copper atoms,
The sulfur-containing compound is one or more of methanesulfonic acid, ethanesulfonic acid, benzene sulfonic acid, toluene sulfonic acid, phenol sulfonic acid, hydroxy methane sulfonic acid, hydroxy ethane sulfonic acid, and hydroxy propane sulfonic acid; and sulfates,
An etchant composition that does not contain fruit water, phosphoric acid, hydrofluoric acid, or their salts. delete delete According to paragraph 1,
The sulfate is ammonium hydrogen sulfate, ammonium sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium sulfate, potassium sulfate, An etchant composition comprising at least one selected from the group consisting of potassium persulfate, sodium persulfate, and ammonium persulfate. According to paragraph 1,
An etchant composition wherein the organic acid contains a carboxylic acid group. According to paragraph 1,
The organic acids include citric acid, butanetetracarboxylic acid, acetic acid, butanoic acid, formic acid, glycolic acid, succinic acid, Glutaric acid, adipic acid, pimelic acid, suberic acid, lactic acid, caproic acid, caprylic acid ), phenylacetic acid, benzoic acid, benzene-monocarboxylic acid, nitrobenzoic acid, hydroxybenzoic acid, dihydroxy benzene, Aminobenzonic acid, pyruvic acid, gluconic acid, diacetic acid, iminodiacetic acid, nitrilotriacetic acid, ethylene diamine tetraacetic acid (ethylenediamine tetra acetic acid), diethylene triamine pentaacetic acid, alanine, glutamic acid, aminobutyric acid, iminodisuccinic acid, ethylenediamine disuccinic acid (ethylene diamine disuccinic acid), polyimino disuccinic acid, malic acid, sorbic acid, fumaric acid, malonic acid, oxalic acid, pentanoic acid An etchant composition comprising at least one selected from the group consisting of pentanoic acid, propionic acid, tartaric acid, and pyroglutamic acid. According to paragraph 1,
The copper-containing compound includes one or more selected from the group consisting of copper nitrate, copper sulfate, copper chloride, copper acetate, copper carbonate, copper oxide, copper methanesulfonate, copper ethanesulfonate, copper propanolsulfonate, copper acetate, and copper citrate. An etchant composition. According to paragraph 1,
The composition includes imidazole, triazole, benzotriazol, aminotetrazole, tolyltriazole, indole, purine, Further comprising at least one selected from the group consisting of pyrazole, pyridine, pyrrole, pyrrolidine, pyrroline, and succinimide, Etch composition. According to paragraph 1,
1 to 20% by weight of nitric acid;
1 to 80% by weight of organic acid;
2 to 80% by weight of sulfur-containing compound; and
An etchant composition comprising 0.0001 to 1% by weight of a copper-containing compound. According to paragraph 1,
1 to 20% by weight of nitric acid;
1 to 50% by weight of organic acid;
1 to 40% by weight of one or more compounds of methanesulfonic acid, ethanesulfonic acid, benzene sulfonic acid, toluene sulfonic acid, phenol sulfonic acid, hydroxy methane sulfonic acid, hydroxy ethane sulfonic acid and hydroxy propane sulfonic acid;
1 to 40% by weight of sulfate; and
An etchant composition comprising 0.0001 to 1% by weight of a copper-containing compound. According to paragraph 1,
An etchant composition for selectively etching an indium oxide film, a silver film, or a combination thereof.