JP6207248B2 - Etching solution composition and etching method - Google Patents

Description

  The present invention relates to an etching solution composition and an etching method using the etching solution composition. More specifically, the present invention relates to an etching solution composition for collectively etching a laminated film composed of a titanium-based coating and a copper-based coating, and the etching solution composition. The present invention relates to an etching method using an etching solution composition.

  Wiring materials for display devices typified by flat panel displays, etc., employ copper and copper-based wiring to meet the demands for larger displays and higher resolution, and titanium and nitride are used as barrier films. It is known that titanium-based metals represented by titanium and the like are used in combination. Various techniques relating to wet etching of copper and titanium multilayer coatings are known.

  For example, Patent Document 1 discloses a copper layer and a titanium layer that contain hydrogen peroxide, nitric acid, a fluoride ion source, an azole, a quaternary ammonium hydroxide, and a hydrogen peroxide stabilizer and have a pH of 1.5 to 2.5. An etching solution for multilayer thin film containing is disclosed. Patent Document 2 discloses an etching solution including a fluorine ion supply source, hydrogen peroxide, sulfate, phosphate, azole compound, and a solvent.

WO2011-093445 JP 2008-288575 A

  However, for example, when the etching solution disclosed above is used to form a fine line composed of a titanium-based film and a copper-based film by collectively etching a laminated film composed of a titanium-based film and a copper-based film, etching is performed. There is a problem that the speed cannot be controlled and a thin line having a desired width cannot be obtained, or a thin line having a desired cross-sectional shape cannot be obtained. The preferred cross-sectional shape of the fine line is a shape in which the width of the upper part of the fine line is less than the width of the lower part of the fine line, and conversely, in the cross-sectional shape of the fine line, It is not preferable. When a conventional etching solution is used, in the cross-sectional shape of the fine line, the width of the upper part of the fine line is often more than the width of the lower part of the fine line.

  Accordingly, an object of the present invention is to provide an etching solution capable of obtaining a fine wire having a desired width and obtaining a thin wire having a preferred cross-sectional shape in the batch etching of a laminated film composed of a titanium-based film and a copper-based film. It is in providing the composition and the etching method using this etching liquid composition.

  As a result of intensive studies to solve the above problems, the present inventors have (A) hydrogen peroxide, (B) a fluoride ion source, (C) an organic carboxylic acid, (D) an azole compound, and nitrogen. An etching solution composition comprising an aqueous solution containing at least one compound selected from compounds having a hetero 6-membered ring having at least one atom and having three double bonds in the structure. The inventors have found that the problem can be solved and have reached the present invention.

  That is, the present invention relates to an etching solution composition for collectively etching a laminated film composed of a titanium-based film and a copper-based film. (A) Hydrogen peroxide: 0.1 to 15% by mass, (B) Fluoride Ion source: 0.02 to 2% by mass, (C) organic carboxylic acid: 5 to 60% by mass, and (D) a complex 6-membered compound containing at least one azole compound and one nitrogen atom and having three double bonds The present invention provides an etching solution composition comprising an aqueous solution containing at least one compound selected from compounds having a ring in the structure: 0.01 to 5% by mass.

  Moreover, this invention provides the etching method which etches collectively the laminated film which consists of a titanium-type film and a copper-type film characterized by using the said etching liquid composition.

  According to the present invention, in an etching solution composition used for collectively etching a laminated film composed of a titanium-based film and a copper-based film, a thin line having a desired width can be obtained, and in the cross-sectional shape of the thin line A thin line having an upper width smaller than that of the lower fine line can be obtained. An etching solution composition and an etching method using the etching solution composition can be provided.

Hereinafter, embodiments of the present invention will be specifically described.
First, the “titanium-based coating” described in the present specification is not particularly limited as long as it is a film containing titanium, but is selected from titanium alloys typified by titanium metal and titanium-nickel alloys. This is a general term for films composed of one or more kinds.
In addition, the “copper-based coating” described in the present specification is not particularly limited as long as it is a film containing copper, and is selected from, for example, copper alloys typified by metallic copper and copper-nickel alloys. It is a collective term for one or more types of films.

  In the etching solution composition of the present invention, the concentration of (A) hydrogen peroxide [hereinafter sometimes abbreviated as component (A)] is a laminate composed of a titanium-based film and a copper-based film, which are desired materials to be etched. Although it may be adjusted as appropriate depending on the thickness and width of the film, it is preferably 0.1 to 15% by mass, particularly preferably 0.5 to 10% by mass. When the concentration of the component (A) is less than 0.1% by mass, it is not preferable because a sufficient etching rate cannot be obtained. On the other hand, when the concentration is higher than 15% by mass, it is difficult to control the etching rate. This is not preferable.

  The (B) fluoride ion supply source [hereinafter sometimes abbreviated as component (B)] used in the etching solution composition of the present invention may be any material that generates fluoride ions in the etching solution composition. Although not particularly limited, for example, hydrofluoric acid, ammonium fluoride, ammonium hydrogen fluoride, sodium fluoride, potassium fluoride, lithium fluoride and the like can be mentioned. Here, the alkali metal fluoride salt is preferably hydrofluoric acid, ammonium fluoride, or ammonium hydrogen fluoride because the alkali metal may remain on the substrate to be etched after the etching treatment.

  In the etching solution composition of the present invention, the concentration of the component (B) may be appropriately adjusted depending on the thickness and width of the laminated film composed of a titanium-based film and a copper-based film, which is a desired material to be etched. 0.02 to 2% by mass is preferable, and 0.05 to 1% by mass is particularly preferable. When the concentration of the component (B) is less than 0.02% by mass, a sufficient etching rate cannot be obtained. On the other hand, when the concentration is higher than 2% by mass, glass is used for the substrate to be etched. In such a case, the glass may be corroded.

  In the etching solution composition of the present invention, the (C) organic carboxylic acid [hereinafter sometimes abbreviated as (C) component] may be any organic compound having a carboxyl group, and is not particularly limited. Examples include tetracarboxylic acid, tricarboxylic acid, dicarboxylic acid, monocarboxylic acid, and anhydrides thereof.

  Examples of the tetracarboxylic acid, tetracarboxylic dianhydride or tetracarboxylic dianhydride include dehydrating tetracarboxylic acid and tetracarboxylic acid of the compounds (C-1) to (C-19) listed below. And monoanhydrides or dianhydrides.

  Examples of the tricarboxylic acid and tricarboxylic acid monoanhydride include monoanhydrides obtained by dehydrating the tricarboxylic acid and tricarboxylic acid of the compounds (C-20) to (C-23) listed below.

  Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, and monoanhydrides obtained by dehydrating these dicarboxylic acids.

  Examples of the monocarboxylic acid include acetic acid, formic acid, propionic acid, and the like.

  In the etching solution composition of the present invention, suitable components (C) include, for example, citric acid, succinic acid, glutaric acid, adipic acid, oxalic acid and acetic acid. When citric acid is used, the etching solution This is particularly preferable because of high storage stability.

  In the etching solution composition of the present invention, the concentration of the component (C) may be appropriately adjusted depending on the thickness and width of the laminated film composed of a titanium-based film and a copper-based film, which is a desired material to be etched. 60% by mass, preferably 10 to 50% by mass. When the concentration of the component (C) is less than 5% by mass, the etching ability may be deactivated when the etching solution is used continuously for a long time. When the concentration is higher than 50% by mass, it may be difficult to control the etching rate, which is not preferable.

  (D) at least one compound selected from (D) an azole compound used in the etching solution composition of the present invention and a compound having one or more nitrogen atoms and a hetero 6-membered ring having three double bonds in the structure [ Hereinafter, (may be abbreviated as component (D)) will be described.

The azole compound is not particularly limited as long as it is a compound having a hetero 5-membered ring having one or more nitrogen atoms and having two double bonds in the structure. For example, 1-methylpyrrole Azole compounds such as alkylpyrrole and pyrrole represented by 1; diazole compounds such as alkylimidazole represented by 1-methylimidazole, adenine, 1,3-imidazole (hereinafter sometimes abbreviated as imidazole) and pyrazole; Triazole compounds such as 2,4-triazole, 5-methyl-1H-benzotriazole and 1H-benzotriazole (hereinafter sometimes abbreviated as benzotriazole) and 3-amino-1H-triazole; 1H-tetrazole, 5-methyl-1H -Tetrazole, 5-phenyl-1H- Tetrazole compounds such as tolazole and 5-amino-1H-tetrazole (hereinafter sometimes abbreviated as 5-aminotetrazole); thiazole compounds such as 1,3-thiazole, 4-methylthiazole and isothiazole; oxazoles such as isoxazole Compounds. Of these, adenine and tetrazole compounds are preferable, and adenine and 5-amino-1H-tetrazole are particularly preferable. As the component (D), when an azole-based compound is used, it is preferable because the quality of the fine line obtained is not affected even when the etching process is performed for the minimum etching time necessary for forming the fine line. .

  The compound having a hetero 6-membered ring having one or more nitrogen atoms and having three double bonds in the structure is not particularly limited, and has three double bonds containing one or more nitrogen atoms in the structure. Any compound having a hetero 6-membered ring having a ring (hereinafter sometimes referred to as a pyridine compound) may be used. For example, alkylpyridine compounds represented by 2-methylpyridine, 2-aminopyridine and 2- ( Examples include aminopyridine compounds represented by 2-aminoethyl) pyridine, pyridine, pyrazine, pyrimidine, pyridazine, triazine and tetrazine, with aminopyridine compounds being preferred, and 2-aminopyridine being particularly preferred.

  In the etching solution composition of the present invention, the concentration of the component (D) is appropriately adjusted according to the thickness and width of the laminated film composed of a titanium-based film and a copper-based film, which is a desired material to be etched, and the shape of the desired thin line. What is necessary is just 0.01-5 mass%, Preferably it is 0.05-0.5 mass%. When the concentration of the component (D) is less than 0.01% by mass, in the cross-sectional shape of the fine line obtained after etching, a fine line in which the width of the upper part of the fine line is equal to or larger than the width of the lower part of the fine line may be obtained. For this reason, it is not preferable. On the other hand, even if an amount exceeding 5% by mass is added, no improvement in the blending effect is observed. The concentration of the component (D) means the concentration of the azole compound or pyridine compound when the azole compound or pyridine compound is used alone, and the azole compound or pyridine compound is mixed and used. In the case, it means the sum of concentrations of azole compounds or pyridine compounds. When the azole compound and the pyridine compound are mixed and used, the concentration ratio of the azole compound or the pyridine compound is preferably in the range of 1:30 to 30: 1, and in the range of 1:25 to 25: 1. Some cases are more preferable, and the range of 1: 5 to 5: 1 is particularly preferable because the effect of addition is particularly high.

  In addition to the components (A), (B), (C), and (D), the etching solution composition of the present invention is well known as long as the effects of the present invention are not impaired. Additives can be blended. Examples of the additive include an etchant composition stabilizer, a solubilizer for each component, an antifoaming agent, a pH adjuster, a specific gravity adjuster, a viscosity adjuster, a wettability improver, a chelating agent, an oxidizing agent, and a reduction agent. An agent, a surfactant and the like can be mentioned, and the concentration when these are used is generally in the range of 0.001% by mass to 50% by mass.

Among these, examples of the pH adjuster include, for example, inorganic acids selected from hydrochloric acid, sulfuric acid and nitric acid, and salts thereof, water-soluble organic acids [excluding the organic carboxylic acid of component (C) above], and salts thereof , Alkali hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkaline earth metals such as calcium hydroxide, strontium hydroxide and barium hydroxide, ammonium carbonate, lithium carbonate, sodium carbonate, Examples include alkali metal carbonates such as potassium carbonate, quaternary ammonium hydroxides such as tetramethylammonium hydroxide and choline, organic amines such as ethylamine, diethylamine, triethylamine and hydroxyethylamine, and ammonia. Can be used in a mixture of two or more Kill. When using a pH adjuster, it may be added as much as the desired pH. In addition, as for the etching liquid composition of this invention, it is desirable to exist in the range of pH1-5. If the pH is too low, the copper etching rate becomes too high, and the copper wiring becomes thin. If the pH exceeds 5, not only the stability of hydrogen peroxide is lowered, but also the dissolution rate of copper, particularly titanium, is extremely slow, and etching is time consuming, which is not preferable.

  Moreover, as a surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant can be added. Nonionic surfactants include, for example, polyoxyalkylene alkyl ether, polyoxyalkylene alkenyl ether, polyoxyethylene polyoxypropylene alkyl ether (addition form of ethylene oxide and propylene oxide may be random or block) .), Polyethylene glycol propylene oxide adduct, polypropylene glycol ethylene oxide adduct, random or block adduct of alkylenediamine with ethylene oxide and propylene oxide, glycerin fatty acid ester or ethylene oxide adduct thereof, sorbitan fatty acid ester, polyoxyethylene Sorbitan fatty acid ester, alkyl polyglucoside, fatty acid monoethanolamide or ethylene oxide thereof Adduct, fatty acid-N-methyl monoethanolamide or its ethylene oxide adduct, fatty acid diethanolamide or its ethylene oxide adduct, sucrose fatty acid ester, alkyl (poly) glycerin ether, polyglycerin fatty acid ester, polyethylene glycol fatty acid ester, Examples include fatty acid methyl ester ethoxylate, N-long chain alkyldimethylamine oxide, and the like. Among these, when random or block adducts of ethylene oxide and propylene oxide of alkylene diamine are used, it is preferable because the linearity of the obtained thin line is good and the storage stability of the etching solution is good. Among the random or block adducts of ethylenediamine and propylene oxide of alkylenediamine, the reverse type is more preferred because of its low foaming property. Examples of the cationic surfactant include alkyl (alkenyl) trimethyl ammonium salt, dialkyl (alkenyl) dimethyl ammonium salt, alkyl (alkenyl) quaternary ammonium salt, mono- or dialkyl (ether group, ester group or amide group). Alkenyl) quaternary ammonium salt, alkyl (alkenyl) pyridinium salt, alkyl (alkenyl) dimethylbenzyl ammonium salt, alkyl (alkenyl) isoquinolinium salt, dialkyl (alkenyl) morphonium salt, polyoxyethylene alkyl (alkenyl) amine, alkyl (alkenyl) Examples include amine salts, polyamine fatty acid derivatives, amyl alcohol fatty acid derivatives, benzalkonium chloride, and benzethonium chloride. Examples of the amphoteric surfactant include carboxybetaine, sulfobetaine, phosphobetaine, amide amino acid, imidazolinium betaine surfactant and the like. The concentration in the case of using a surfactant is generally in the range of 0.001% by mass to 10% by mass.

  In the etching solution composition of the present invention, the component other than the above components is water. Therefore, the etching solution composition of the present invention is provided in the form of an aqueous solution containing a predetermined amount of the above components.

  The etching solution composition of the present invention is used for collectively etching a laminated film composed of a titanium film and a copper film. The titanium-based film may be a single layer or a laminated film of two or more layers. The copper-based film may be a single layer or a laminated film of two or more layers. In the laminated film composed of the titanium-based film and the copper-based film, the copper-based film may be an upper layer, a lower layer, or an upper layer and a lower layer. Moreover, in the laminated film which consists of a titanium-type film and a copper-type film, the thing of the structure on which the titanium-type film and the copper-type film were laminated | stacked alternately may be sufficient.

  The etching method is not particularly limited to collectively etch a laminated film composed of a titanium-based film and a copper-based film using the etching agent composition of the present invention, and a well-known general etching method can be used. Examples of the etching method include a dip method, a spray method, and a spin method. For example, when etching a substrate in which titanium and copper are laminated in this order on a glass substrate by a spray-type etching method, the etching solution composition of the present invention is sprayed on the base material to thereby form titanium on the glass substrate. The coating and the copper coating can be etched.

  Note that the etching conditions at this time are not particularly limited, and can be arbitrarily set according to the shape or film thickness of the etching target. For example, the spraying condition is preferably 0.01 Mpa to 0.2 Mpa, and particularly preferably 0.01 Mpa to 0.1 MPa. Moreover, 10 to 50 degreeC is preferable and, as for etching temperature, 20 to 50 degreeC is especially preferable. Since the temperature of the etching solution composition may increase due to heat of reaction, the temperature can be controlled by a known means so as to maintain it within the above temperature range if necessary. Further, the etching time is not particularly limited because it may be a time sufficient for the object to be etched to be completely etched. For example, in the case of an etching target having a film thickness of about 1 μm, a line width of about 10 μm, and an opening of about 100 μm, the etching may be performed for about 10 to 300 seconds within the above temperature range.

  The etching solution composition of the present invention and the etching method using the etching solution composition are preferably used mainly when processing electrodes and wirings of liquid crystal displays, plasma displays, touch panels, organic EL, solar cells, lighting fixtures, etc. can do.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited by these.
[Example 1]
An etching solution composition was formulated according to the formulation shown in Table 1, and the product No. 1-22 were obtained. The balance of the content is water.

[Comparative Example A]
The etchant composition was blended with the formulation shown in Table 2, and the comparative product No. 1-7 were obtained. The balance of the content is water.

[Example 2]
A substrate in which a resist pattern having a line width of 10 μm and an opening of 100 μm is formed on a substrate in which titanium (30 nm) and copper (500 nm) are laminated in this order on a glass substrate using a positive liquid resist is cut into 10 mm × 10 mm and tested. This test piece is the product No. of the present invention. The pattern etching by the spray method was performed on the conditions of 35 degreeC and spray pressure 0.05MPa using 1-22. The etching processing time was carried out only for the time when there was no inter-wiring residue in each etching agent, and this time was defined as “optimum etching time”.

[Comparative Example B]
A substrate in which a resist pattern having a line width of 10 μm and an opening of 100 μm is formed on a substrate in which titanium (30 nm) and copper (500 nm) are laminated in this order on a glass substrate using a positive liquid resist is cut into 10 mm × 10 mm and tested. This test piece is a comparative product No. 1-7 were used for pattern etching by spraying at 35 ° C. and a spray pressure of 0.05 MPa. The etching processing time is the optimum etching time.

[Evaluation Example 1]
About the test piece obtained by Example 2 and Comparative Example B, it was confirmed whether the thin wire | line was formed by confirming the test piece upper part with an optical microscope. Here, the case where a thin line was formed was evaluated as ◯, and the case where a thin line was not formed was evaluated as x. Moreover, the cross section of the test piece was observed using a scanning electron microscope, and the widths of the upper and lower portions of the thin line were confirmed. The case where the width of the upper portion of the thin line was less than the width of the lower portion of the thin line was evaluated as Δ, and the case where the width of the upper portion of the thin line was equal to or larger than the width of the lower portion of the thin line was evaluated as Δ ′. When the width of the upper portion of the thin line is less than the width of the lower portion of the thin line (Δ), it is preferable because the thin line is stable. When the width of the upper portion of the thin line is equal to or larger than the width of the lower portion of the thin line (Δ ′) It is unsuitable because it tends to collapse. The results are shown in Table 3.

  From the results of Table 3, it was found that in each of the evaluation examples 1 to 22, a thin line could be formed in all the samples, and the width of the upper part of the thin line was less than the width of the lower part. On the other hand, in Comparative Examples 1 to 6, only Comparative Examples 3 and 5 were able to form a thin line, and only Comparative Example 3 was able to form a thin line having an upper width less than the lower width. there were.

[Example 3]
A substrate in which a resist pattern having a line width of 10 μm and an opening of 100 μm is formed on a substrate in which titanium (30 nm) and copper (500 nm) are laminated in this order on a glass substrate using a positive liquid resist is cut into 10 mm × 10 mm and tested. This test piece is the product No. of the present invention. Using 2, 4, 5 and 16, pattern etching was performed by spraying at 35 ° C. and a spray pressure of 0.05 MPa. The etching processing time was increased by 30 seconds from the optimum etching time.

[Comparative Example C]
A substrate in which a resist pattern having a line width of 10 μm and an opening of 100 μm is formed on a substrate in which titanium (30 nm) and copper (500 nm) are laminated in this order on a glass substrate using a positive liquid resist is cut into 10 mm × 10 mm and tested. This test piece is a comparative product No. 3 was used for pattern etching by spraying under the conditions of 35 ° C. and spray pressure 0.05 MPa. The etching processing time was increased by 30 seconds from the optimum etching time.

[Evaluation Example 2]
About the test piece obtained by Example 3 and the comparative example C, it was confirmed whether the thin wire | line was formed by confirming the test piece upper part with an optical microscope. Here, the case where a thin line was formed was evaluated as ◯, and the case where a thin line was not formed was evaluated as x. Moreover, the cross section of this test piece was observed using the scanning electron microscope, and the width | variety of a thin wire | line upper part and the lower part was confirmed. The case where the width of the upper portion of the thin line was less than the width of the lower portion of the thin line was evaluated as Δ, and the case where the width of the upper portion of the thin line was equal to or larger than the width of the lower portion of the thin line was evaluated as Δ ′. When the width of the upper portion of the thin line is less than the width of the lower portion of the thin line (△), it is preferable because the thin line is stable. When the width of the upper portion of the thin line is equal to or greater than the width of the lower portion of the thin line (△ ') Is unsuitable for. The results are shown in Table 4.

※１：銅層が全て溶解し、無くなってしまった。

* 1: All the copper layer was dissolved and lost.

From the results of Table 4, it was found that in Comparative Example 7, the copper layer was completely dissolved. Therefore, it was found that the comparative product 3 had a very narrow process window. On the other hand, in the evaluation examples 23 to 25, it was found that all the samples were able to form fine lines in all the samples, and the width of the upper part of the fine lines was less than the width of the lower part.
Therefore, it was found that the etching solution composition of the present invention is an etching solution composition having a wide process window because it has no influence on the quality of the fine line obtained even when the etching treatment is performed for more than the optimum etching time.

Claims (5)

In an etching solution composition for etching a laminated film composed of a titanium-based film and a copper-based film at once,
(A) Hydrogen peroxide: 0.1 to 15% by mass;
(B) Fluoride ion source: 0.02 to 2% by mass;
(C) Organic carboxylic acid: 5 to 60% by mass; and
(D) At least one compound selected from an azole compound and a compound having one or more nitrogen atoms and a hetero 6-membered ring having three double bonds in the structure: 0.01 to 5% by mass
An etching solution composition comprising an aqueous solution.   (C) The etching liquid composition of Claim 1 whose organic carboxylic acid is a citric acid.   (D) At least one compound selected from an azole compound and a compound having one or more nitrogen atoms and a hetero 6-membered ring having three double bonds in the structure is 5-amino-1H-tetrazole and adenine The etching liquid composition of Claim 1 or 2 which is at least 1 sort (s) chosen from. The etching solution composition according to any one of claims 1 to 3, further comprising a stabilizer, a solubilizer, an antifoaming agent, a pH adjusting agent, a specific gravity adjusting agent, a viscosity adjusting agent, a wettability improving agent, a chelate. agents, oxidizing agents, Rue etching liquid composition to contain an additive selected from the reducing agents and surfactants in the range of 0.001 to 50 mass%.   In the etching method for etching the laminated film which consists of a titanium-type film and a copper-type film in a lump, using the etching liquid composition of any one of Claim 1 thru | or 4 as an etching liquid composition, Etching method to do.