JP6180298B2 - 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, the etching solution disclosed above was continuously used in order 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. In this case, the dissolved copper dissolves in the etching solution, so that the copper concentration in the etching solution increases and a thin wire having a desired etching width cannot be obtained.

  Accordingly, the present invention provides an etching solution composition capable of obtaining a thin wire having a desired width even when the copper concentration in the etching solution is increased in the batch etching of a laminated film composed of a titanium-based coating and a copper-based coating, and An object is to provide an etching method.

  As a result of intensive studies to solve the above problems, the present inventors have (A) hydrogen peroxide, (B) a fluoride ion source, (C) phosphonobutanetricarboxylic acid or a salt thereof, (D) Etching solution composition comprising an azole compound and an aqueous solution containing at least one compound selected from compounds having at least one nitrogen atom and a hetero 6-membered ring having three double bonds in the structure It has been found that a product can solve the above problems, and has led to the present invention.

  That is, the present invention provides an etching solution composition for collectively etching a laminated film composed of a titanium-based film and a copper-based film, wherein (A) hydrogen peroxide; (B) a fluoride ion supply source; (C) phospho Nobutanetricarboxylic acid or a salt thereof; 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. The present invention relates to an etching solution composition comprising an aqueous solution containing the etching solution.

The present invention also relates to an etching method for collectively etching a laminated film composed of a titanium-based film and a copper-based film, characterized by using the above-mentioned etching solution composition.

According to the present invention, in an etching solution composition used for collectively etching a laminated film composed of a titanium-based coating and a copper-based coating, a thin line having a desired width is formed even when the copper concentration in the etching solution is increased. An etching liquid composition that can be obtained and an etching method using the etching liquid composition can be provided.

Hereinafter, 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 coating containing titanium, but is selected from titanium alloys typified by metallic titanium and titanium-nickel alloys. The coating consisting of one or more types is generically named.
In addition, the “copper-based coating” described in the present specification is not particularly limited as long as it is a coating containing copper. For example, from a copper alloy typified by metallic copper and a copper-nickel alloy The film consisting of one or more selected types is generically named.

  (A) Hydrogen peroxide used in the etching solution composition of the present invention [hereinafter sometimes abbreviated as component (A). ] Is 0.1 to 15% by mass. When the concentration of the component (A) is less than 0.1% by mass, a sufficient etching rate may not be obtained, which is not preferable. On the other hand, when the concentration of the component (A) is higher than 15% by mass, it may be difficult to control the etching rate, which is not preferable. The concentration of the component (A) may be appropriately adjusted within the above-described concentration range depending on the thickness and width of the laminated film composed of a titanium-based film and a copper-based film, which are desired materials to be etched. It is preferable to be within the range of -10% by mass.

  (B) Fluoride ion source used in the etching solution composition of the present invention [hereinafter sometimes abbreviated as component (B). ] Is not particularly limited as long as it generates fluoride ions in the etching solution composition. For example, hydrofluoric acid, ammonium fluoride, ammonium hydrogen fluoride, sodium fluoride, Examples include potassium fluoride and lithium fluoride. In the case of an alkali metal fluoride salt, hydrofluoric acid, ammonium fluoride, or ammonium hydrogen fluoride is preferably used because alkali metal may remain on the substrate to be etched after the etching treatment.

The preferable density | concentration of (B) component in the etching liquid composition of this invention is 0.02-2 mass%. When the concentration of the component (B) is less than 0.02% by mass, a sufficient etching rate may not be obtained, which is not preferable. On the other hand, when the concentration of the component (B) is higher than 2% by mass, the glass may be corroded when glass is used for the substrate to be etched, which is not preferable. The concentration of the component (B) may be appropriately adjusted within the above-described concentration range 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. It is preferable to be within the range of mass%.

  (C) Phosphonobutanetricarboxylic acid or salt thereof used in the etching solution composition of the present invention [hereinafter sometimes abbreviated as component (C). ] Can be a known compound. When the component (C) is phosphonobutanetricarboxylic acid, examples of the counter cation include alkali metal ions and alkaline earth metal ions, and more specifically ions such as lithium, sodium, potassium, and magnesium.

  As the suitable component (C) used in the etching solution composition of the present invention, when the copper concentration in the etching composition is high, the effect of preventing the thin line from being narrowed is high. (Hereafter, it may be abbreviated as PBTC.).

  The concentration of the component (C) in the etching solution composition of the present invention is 5 to 60% by mass in terms of phosphonobutanetricarboxylic acid. When the concentration of the component (C) is lower than 5% by mass, the etching ability may be deactivated when the etching solution is used continuously for a long time, which is not preferable. On the other hand, when the concentration of the component (C) is higher than 50% by mass, the etching rate becomes too fast, which may be difficult to control. The concentration of the component (C) may be appropriately adjusted within the above concentration range 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, but preferably 5 to 5%. It is 50 mass%, More preferably, it exists in the range of 5-25 mass%.

(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, it 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; 1 , 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-1 -Tetrazole compounds such as tetrazole and 5-amino-1H-tetrazole (hereinafter sometimes abbreviated as 5-aminotetrazole); thiazole compounds such as 1,3-thiazole, 4-methylthiazole and isothiazole, isoxazole and the like Of the oxazole compound. Of these, adenine and tetrazole compounds are preferred, and 5-aminotetrazole is particularly preferred.

In addition, the compound having a hetero 6-membered ring having at least one nitrogen atom and having three double bonds in the structure is not particularly limited, and the structure has at least one nitrogen atom and at least three 2 Any compound having a hetero 6-membered ring having a heavy bond may be used. For example, an alkylpyridine compound represented by 2-methylpyridine, an amino represented by 2-aminopyridine and 2- (2-aminoethyl) pyridine. Examples thereof include pyridine compounds, pyridine, pyrazine, pyrimidine, pyridazine, triazine and tetrazine, and aminopyridine compounds are preferable, and 2-aminopyridine is particularly preferable.

The density | concentration of (D) component in the etching liquid composition of this invention is 0.01-5 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. This is not preferable. On the other hand, even if the concentration of the component (D) is added in an amount exceeding 5% by mass, the improvement of the blending effect is not observed, which is not preferable. The concentration of the component (D) may be appropriately adjusted within the above-described concentration range depending on the thickness, width, and desired thin line shape of the laminated film composed of a titanium-based film and a copper-based film, which is a desired material to be etched. The range of 0.05 to 0.5% by mass is particularly preferable. 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 is used by mixing the azole compound and the pyridine compound. In this case, it means the sum of the concentrations of the azole compound and the pyridine compound. When the azole compound and the pyridine compound are mixed and used, the concentration ratio of the azole compound and the pyridine compound is preferably in the range of 1:30 to 30: 1, and in the range of 1:25 to 25: 1. Is 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. The additive includes 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 oxidant, and a reduction agent. An agent, a surfactant and the like can be mentioned, and the concentration when these additives are used is generally in the range of 0.001% by mass to 50% by mass.

  Among the above additives, examples of the pH adjuster include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid and salts thereof, water-soluble organic acids and salts thereof, lithium hydroxide, sodium hydroxide and potassium hydroxide. Alkali metal hydroxides such as calcium hydroxide, alkaline earth metal hydroxides such as strontium hydroxide and barium hydroxide, alkali metal carbonates such as ammonium carbonate, lithium carbonate, sodium carbonate and potassium carbonate, tetramethyl Examples thereof include quaternary ammonium hydroxides such as ammonium hydroxide and choline, organic amines such as ethylamine, diethylamine, triethylamine and hydroxyethylamine, and ammonia, which are used in one kind or a mixture of two or more kinds. When these are used, they may be added as much as desired pH. Here, it is desirable that the etching solution composition of the present invention is in the range of pH 1 to 4. If the pH is too low, the etching rate of copper becomes too high, and the copper wiring becomes thin, which is not preferable. On the other hand, if the pH exceeds 4, not only the stability of hydrogen peroxide is lowered, but also the dissolution rate of copper, particularly titanium, becomes extremely slow, and etching may take time, which is not preferable.

As said 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 these surfactants 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, it is provided in the form of an aqueous solution containing a necessary 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. Further, 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. In the laminated film composed of the titanium-based film and the copper-based film, the titanium-based film and the copper-based film may be alternately laminated.

  The etching method is not particularly limited because the laminated film composed of the titanium-based film and the copper-based film using the etching composition of the present invention is collectively etched, and a well-known general etching method may be used. For example, there are dip type, spray type, spin type and vacuum type etching methods.

  For example, when a substrate laminated with titanium and copper in this order on a glass substrate is etched by a spray-type etching method, the etching solution composition of the present invention is sprayed onto the substrate under appropriate conditions. The titanium film and the copper film can be etched on the glass substrate.

  The etching conditions are not particularly limited, and can be arbitrarily set according to the shape and 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 agent may be increased by reaction heat, the temperature may be controlled by a known means so as to keep 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 and the etching method using the composition of the present invention are mainly used when processing electrodes and wirings of liquid crystal displays, plasma displays, touch panels, organic EL, solar cells, lighting fixtures and the like.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but it should be understood that the present invention is not limited thereto.
[Example 1]
An etching solution composition was formulated according to the formulation shown in Table 1 below. 1-15 were obtained. The balance of the content is water.

[Production Example 1]
The etching liquid composition was mix | blended with the mixing | blending shown in the following Table 2, and the comparative products 1-6 were obtained. The balance of the content is water.

In Table 2,
* 1 EDTA: ethylenediaminetetraacetic acid * 2 EDTAP: ethylenediaminetetra (methylenephosphonic acid)
* 3 NTMP: Nitrilotris (methylenephosphonic acid)
* 4 HEDP: hydroxyethylidene diphosphonic acid * 5 The component (C) was not dissolved and could not be blended.

[Example 2]
A substrate on which a resist pattern having a line width of 10 μm and an opening of 100 μm is formed on a substrate in which a titanium film (30 nm) and a copper film (400 nm) are laminated in this order on a glass substrate is cut into 10 mm × 10 mm. A plurality of test pieces were prepared, and the present invention product No. The pattern etching by the dip method was continuously performed at 35 ° C. using 1-15. Prior to the etching treatment, the copper concentration in each etching solution was measured by a titration method. The etching processing time was set to a time obtained by adding 80 seconds to the time when the copper residue between the wirings disappeared in each etching solution composition.

[Comparative Example 1]
A substrate on which a resist pattern having a line width of 10 μm and an opening of 100 μm is formed on a substrate in which a titanium film (30 nm) and a copper film (400 nm) are laminated in this order on a glass substrate is cut into 10 mm × 10 mm. A plurality of test pieces were prepared, and the comparative product No. Pattern etching by the dip method was continuously performed at 35 ° C. using 1, 2, 5 and 6. Prior to the etching treatment, the copper concentration in each etching solution was measured by a titration method. The etching processing time was set to a time obtained by adding 80 seconds to the time when the copper residue between the wirings disappeared in each etching agent.

[Evaluation Example 1]
About the test piece obtained by Example 2 and the comparative example 1, it confirmed whether the thin wire | line was formed by confirming the upper part of this test piece with the optical microscope, and also measured the thin width of the thin wire | line. In the evaluation, the test pieces subjected to the etching treatment were evaluated when the copper concentration in each etching solution composition became 0 ppm, 5000 ppm and 10000 ppm. The results are shown in Table 3. The case where the narrowing width on one side of the wiring was less than 0.7 μm was marked as “◎”, the case where it was 0.7 μm or more to less than 1 μm, and the case where it was 1 μm or more as “X”.

In Table 3, * 6 The Ti layer was not etched sufficiently and no fine line was formed.

From the results of Table 3, Evaluation Examples 1-1 to 1-45 are capable of forming fine lines, and even when the copper concentration in the etching solution composition is high, the thin lines are thin. It was found that a thin line can be formed. In particular, it was found that Evaluation Examples 1-1 to 1-33 can form fine lines with a very small width even when the copper concentration in the etching solution composition is high.
On the other hand, Comparative Examples 1 to 3 and Comparative Examples 7 to 12 could not form fine lines. Comparative product No. Comparative Examples 4 to 6 using 2 are comparative product Nos. It was found that when the copper concentration in 2 was 0 ppm, a fine line could be formed with a small thin line width, but when the copper concentration exceeded 5000 ppm, a fine line could not be formed.
From the above, it was found that the etching solution composition of the present invention is an etching solution composition that can obtain a thin wire having a desired width even when the copper concentration in the etching solution is increased.

Claims (4)

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 0.1-15% by mass;
(B) Fluoride ion source 0.02-2 mass%;
(C) 5-60 mass% of phosphonobutane tricarboxylic acid or a salt thereof in terms of phosphonobutane tricarboxylic acid;
(D) 0.01 to 5% by mass of 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.
An etching solution composition comprising an aqueous solution containing   The etching solution composition according to claim 1, wherein (D) is 5-aminotetrazole.   One selected from the group consisting of stabilizers, solubilizers, antifoaming agents, pH adjusters, specific gravity adjusters, viscosity adjusters, wettability improvers, chelating agents, oxidizing agents, reducing agents and surfactants Or the etching liquid composition of Claim 1 or 2 containing 2 or more types of additives.   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 3 as an etching liquid composition, Etching method to do.