WO2020261995A1

WO2020261995A1 - Composition and etching method

Info

Publication number: WO2020261995A1
Application number: PCT/JP2020/022859
Authority: WO
Inventors: 阿部　徹司; 裕太野口
Original assignee: 株式会社Adeka
Priority date: 2019-06-28
Filing date: 2020-06-10
Publication date: 2020-12-30
Also published as: TW202108820A

Abstract

Provided is a composition that can be used to etch a metal layer, e.g. a copper layer, and that makes it possible to form a fine pattern that has excellent dimensional precision and little cross-sectional narrowing of fine lines while suppressing the generation of a residual film. A composition that is an aqueous solution that contains (A) 0.1–25 mass% of at least one type of component selected from the group that consists of cupric ions and ferric ions, (B) 0.1–30 mass% of chloride ions, (C) 0.01–10 mass% of a compound that is represented by general formula (1) and has a number average molecular weight of 350–1,200, (D) 0.01–10 mass% of at least one type of component selected from the group that consists of unsaturated carboxylic acids and salts and anhydrides thereof, and water.

Description

Composition and etching method

The present invention relates to a composition containing a specific compound and an etching method using the same.

As a circuit forming method for printed circuit boards and semiconductor package substrates, there are an additive method in which a circuit pattern is added to the substrate later, and a subtractive method (etching method) in which an unnecessary part is removed from a metal foil on the substrate to form a circuit pattern. Are known. Currently, the subtractive method (etching method), which has a low manufacturing cost, is generally adopted for manufacturing printed circuit boards. With the recent miniaturization and higher performance of electronic devices, the development of an etching solution capable of forming a fine pattern having a cross-sectional shape close to a rectangle on a printed circuit board is being promoted.

For example, Patent Document 1 discloses a microetching agent containing cupric oxide, formic acid, sodium chloride, a polymer and an acetylene glycol polyoxyethylene adduct. Further, Patent Document 2 discloses an etching solution for copper or a copper alloy containing iron (III) chloride, oxalic acid, and ethylenediaminetetrapolyoxyethylenepolyoxypropylene as the etching solution. Further, Patent Document 3 discloses a micro-etching agent containing nitric acid, ferric nitrate and unsaturated carboxylic acid.

International Publication No. 2013/187537 Japanese Unexamined Patent Publication No. 2012-107286 Japanese Unexamined Patent Publication No. 9-241870

However, when an attempt is made to form a fine wire by etching a copper-based layer using the etching solution disclosed in the above patent document, the cross section of the thin wire becomes a constricted shape, and the fine wire has a desired dimensional accuracy. There have been problems that it is difficult to form a pattern and that a residual film that causes disconnection or short circuit is likely to occur. The constricted shape indicates a shape in which the width of the central portion of the thin wire is narrower than the width of the upper portion of the thin wire and the width of the lower portion of the thin wire in the cross-sectional shape of the thin wire when the cross section of the thin wire is observed.

Therefore, the present invention is useful for etching a metal layer such as a copper-based layer, which can form a fine pattern having a small cross-sectional constriction and excellent dimensional accuracy while suppressing the generation of a residual film. It is intended to provide a composition. Further, the present invention is intended to provide an etching method using the above composition.

As a result of diligent studies to obtain the above composition, the present inventors have found that a composition containing a specific component can solve the above problem, and have reached the present invention.

That is, according to the present invention, at least one component selected from the group consisting of (A) ferric ion and ferric ion is 0.1 to 25% by mass; (B) chloride ion 0.1 to 30% by mass; (C) 0.01 to 10% by mass of the compound represented by the following general formula (1); (D) at least one selected from the group consisting of unsaturated carboxylic acids, salts thereof and anhydrides thereof. A composition which is an aqueous solution containing 0.01 to 10% by mass of components; and water is provided.

(In the general formula (1), R ¹ represents a single bond or a linear or branched alkanediyl group having 1 to 4 carbon atoms, and R ² and R ³ are independent carbon atoms. Represents a linear or branched alkanediyl group of numbers 1 to 4, and R ⁴ and R ⁵ each independently have a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. Represented by n, each independently represents a number in which the number average molecular weight of the compound represented by the general formula (1) is 350 to 1,200.)

Further, according to the present invention, there is provided an etching method including a step of etching using the above composition.

According to the present invention, it is useful for etching a metal layer such as a copper-based layer, which can form a fine pattern having a small cross-sectional constriction and excellent dimensional accuracy while suppressing the generation of a residual film. The composition can be provided. Further, according to the present invention, it is possible to provide an etching method using the above composition.

It is sectional drawing which shows typically the test substrate after etching.

Hereinafter, embodiments of the present invention will be described in detail. The composition of one embodiment of the present invention (hereinafter, may be referred to as "the present composition") is at least one selected from the group consisting of (A) ferric ion and ferric ion. Component (hereinafter, also referred to as "(A) component"); (B) Chloride ion (hereinafter, also referred to as "(B) component"); (C) Compound represented by the general formula (1) (hereinafter, also referred to as "component"). , "(C) component";); (D) At least one component selected from the group consisting of unsaturated carboxylic acids, salts thereof and anhydrides (hereinafter, also referred to as "(D) component"). ; And an aqueous solution containing water as an essential component.

This composition is suitable as an etching solution composition used for etching a metal layer such as a copper-based layer. Examples of the copper-based layer include a silver-copper alloy, a copper alloy such as an aluminum-copper alloy; and a layer containing copper and the like. Among them, this composition is suitable as an etching solution composition used for etching a copper-based layer containing copper.

"Etching" in the present specification means a technique of plastic molding or surface processing utilizing the corrosive action of chemicals and the like. Specific uses of the etching solution composition based on this composition include, for example, a removing agent, a surface smoothing agent, a surface roughening agent, a pattern forming agent, a cleaning solution of a component slightly adhered to a substrate, and the like. .. When the etching solution composition is used for forming a pattern having a fine shape having a three-dimensional structure, a pattern having a desired shape such as a rectangle can be obtained, so that the etching solution composition can be suitably used as a pattern forming agent. Further, since the removal rate of the copper-containing layer is high, it can be suitably used as a removing agent.

As the component (A), ferric ion and ferric ion are used alone or in combination. By blending the copper (II) compound, the cupric oxide ion can be contained in the composition. That is, a copper (II) compound can be used as a source of cupric ion. Further, by blending the iron (III) compound, ferric ions can be contained in the composition. That is, an iron (III) compound can be used as a source of ferric ions.

Examples of the copper (II) compound include copper (II) chloride, copper (II) bromide, copper (II) sulfate, and copper (II) hydroxide. Examples of the iron (III) compound include iron (III) chloride, iron (III) bromide, iron (III) iodide, iron (III) sulfate, iron (III) nitrate, and iron (III) acetate. Can be mentioned. One of these compounds can be used alone or in combination of two or more. Among these compounds, copper (II) chloride and iron (III) chloride are preferable, and copper (II) chloride is even more preferable.

The concentration of the component (A) in the present composition is 0.1 to 25% by mass, preferably 0.5 to 23% by mass, and more preferably 1 to 20% by mass. For example, when this composition is used as an etching solution composition, the concentration of the component (A) can be appropriately adjusted according to the thickness and width of the object to be etched. The concentration of the component (A) means the concentration of ferric ion or the concentration of ferric ion when ferric ion or ferric ion is used alone. When ferric ions and ferric ions are used in combination (mixed), it means the sum of the concentration of ferric ions and the concentration of ferric ions. For example, when copper (II) chloride is contained in an amount of 10% by mass, the concentration of the component (A) is about 4.7% by mass. When copper (II) chloride is contained in an amount of 10% by mass and iron (III) chloride is contained in an amount of 10% by mass, the concentration of the component (A) is about 8.2% by mass. When ferric ions and ferric ions are used in combination (mixed), the concentration of ferric ions is preferably less than 5% by mass.

Sources of component (B) component (chloride ion) include hydrogen chloride, sodium chloride, calcium chloride, potassium chloride, barium chloride, ammonium chloride, iron (III) chloride, copper (II) chloride, manganese (II) chloride. , Cobalt (II) chloride, cerium (III) chloride, zinc (II) chloride and the like can be used. One of the sources of the component (B) can be used alone or in combination of two or more. Among them, when this composition is used as an etching solution composition, hydrogen chloride, iron (III) chloride, and copper chloride are easy to control because the etching rate is easy to control and the shape of the wiring pattern is easy to control. (II) is preferable, and hydrogen chloride is more preferable.

The concentration of the component (B) in the present composition is 0.1 to 30% by mass, preferably 0.5 to 28% by mass, and more preferably 1 to 25% by mass. For example, when this composition is used as an etching solution composition, the concentration of the component (B) can be appropriately adjusted according to the thickness and width of the object to be etched. If the concentration of the component (B) is less than 0.1% by mass, the etching rate may be insufficient when this composition is used as an etching solution composition. On the other hand, if the concentration of the component (B) exceeds 30% by mass, problems such as corrosion of the device members may easily occur.

In the present composition, the mass ratio of the component (B) to the component (A) is preferably (B) / (A) = 0.5 to 2, more preferably 0.6 to 1.8. It is more preferably 0.7 to 1.7, and particularly preferably 0.8 to 1.7. When the value of (B) / (A) is 2 or less, it becomes easy to form a fine wiring pattern having excellent dimensional accuracy when this composition is used as an etching solution composition. On the other hand, when the values of (B) / (A) are 0.5 or more, it becomes easy to increase the etching rate when the present composition is used as the etching solution composition.

The component (C) is a compound having a number average molecular weight of 350 to 1,200 represented by the following general formula (1). One of the components (C) can be used alone or in combination of two or more.

(In the general formula (1), R ¹ represents a single bond or a linear or branched alkanediyl group having 1 to 4 carbon atoms, and R ² and R ³ have independent carbon atoms. Represents 1 to 4 linear or branched alkanediyl groups, and R ⁴ and R ⁵ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. , N each independently represent a number in which the number average molecular weight of the compound represented by the general formula (1) is 350 to 1,200.)

In the general formula (1), R ¹ represents a single bond or a linear or branched alkanediyl group having 1 to 4 carbon atoms. Further, R ² and R ³ independently represent a linear or branched alkanediyl group having 1 to 4 carbon atoms. The linear or branched alkanediyl groups having 1 to 4 carbon atoms represented by R ¹ , R ² and R ³ include methylene group, ethylene group, propylene group, methyl ethylene group, butylene group and ethyl. Ethylene group, 1-methylpropylene group, and 2-methylpropylene group can be mentioned. The alkanediyl group may be only one kind or a combination of two or more kinds. When this composition is used as an etching solution composition, it is easy to control the etching rate and suppress side etching. Therefore, R ¹ is preferably an ethylene group, and R ² and R ³ are preferably a methyl ethylene group.

In the general formula (1), R ⁴ and R ⁵ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. The linear or branched alkyl group having 1 to 4 carbon atoms represented by R ⁴ and R ⁵ includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a secondary butyl group. , Tertiary butyl group can be mentioned. When this composition is used as an etching solution composition, hydrogen atoms are preferable for R ⁴ and R ⁵ because the etching rate can be easily controlled and side etching can be easily suppressed.

In the general formula (1), n independently represents a number in which the number average molecular weight of the compound represented by the general formula (1) is 350 to 1,200. When this composition is used as an etching solution composition, it is easy to control the etching rate and suppress side etching. Therefore, n is preferably a number having a number average molecular weight of 450 to 1,050. It is more preferable that the number is 550 to 950. The number average molecular weight can be determined by GPC (gel permeation chromatography) using polystyrene as a standard.

As a preferable specific example of the compound represented by the general formula (1), the following formula No. 1 to No. The compound represented by 36 can be mentioned. The following formula No. 1 to No. In 36, "Me" represents a methyl group, "Et" represents an ethyl group, and "iPr" represents an isopropyl group. In addition, n is independently No. 1 to No. It represents a number in which the number average molecular weight of the compound represented by 36 is 350 to 1,200.

The method for producing the component (C) is not particularly limited, and the component (C) can be produced by applying a well-known reaction. For example, the above formula No. The compound represented by 17 can be produced by using ethylenediamine and propylene oxide as raw materials by the reaction represented by the following formula (3). "Me" in the following formula (3) represents a methyl group.

The concentration of the component (C) in the present composition is 0.01 to 10% by mass, preferably 0.05 to 8% by mass, and more preferably 0.1 to 5% by mass. If the concentration of the component (C) is less than 0.01% by mass, it may not be possible to obtain the desired effect by blending the component (C). On the other hand, when the concentration of the component (C) is more than 10% by mass, the etching rate tends to decrease when this composition is used as an etching solution composition. In addition, the etching solution composition may easily permeate into the interface between the metal layer such as a copper-based layer and the resist, and defects in the pattern shape may easily occur.

In the present composition, the mass ratio of the component (C) to the sum of the components (A) and (B) is preferably (C) / ((A) + (B)) = 0.005 to 0.2. Yes, more preferably 0.01 to 0.15, still more preferably 0.015 to 0.1. When the value of (C) / ((A) + (B)) is 0.2 or less, it becomes easy to increase the etching rate when this composition is used as an etching solution composition. On the other hand, when the value of (C) / ((A) + (B)) is 0.005 or more, it becomes easy to obtain the desired effect by blending the component (C).

The component (D) used in this composition is not particularly limited, and one or more of well-known and general unsaturated carboxylic acids, salts thereof and anhydrides thereof can be used. As used herein, unsaturated carboxylic acids also include aromatic carboxylic acids. Examples of unsaturated carboxylic acids include phthalic acid, fumaric acid, acrylic acid, methacrylic acid, maleic acid, acetylenedicarboxylic acid, pyromellitic acid, pyridinedicarboxylic acid, 3,5-dihydroxybenzoic acid, and galvanic acid. be able to. In addition, these salts and their anhydrides can be exemplified as salts of unsaturated carboxylic acids and anhydrides of unsaturated carboxylic acids, respectively. Examples of the cations constituting the salt of unsaturated carboxylic acid include sodium ion, potassium ion, calcium ion, ammonium ion and the like.

Among the above specific examples of the component (D), when this composition is used as an etching solution composition, the constriction of the cross section of the obtained fine line becomes small, so that phthalic acid, fumaric acid, acetylenedicarboxylic acid, and gallic acid are used. , Pyridoxydicarboxylic acid, 3,5-dihydroxybenzoic acid, and gallic acid, and salts and anhydrides thereof are preferred. Among these, monopotassium acetylenedicarboxylic acid, potassium hydrogen phthalate, 3,5-dihydroxybenzoic acid, and gallic acid are more preferable, and monopotassium acetylenedicarboxylic acid is even more preferable.

The concentration of the component (D) in the present composition is 0.01 to 10% by mass, preferably 0.03 to 5% by mass, and more preferably 0.05 to 1% by mass. When the concentration of the component (D) is less than 0.01% by mass, even if this composition is used as an etching solution composition, it is difficult to form a pattern in which the cross section of the fine line is small, and the concentration of the component (D) is high. Even if it exceeds 10% by mass, the effect of blending the component (D) is difficult to improve.

In the present composition, the mass ratio of the component (D) to the sum of the components (A), (B) and (C) is preferably (D) / ((A) + (B) + (C)). = 0.0005 to 0.1, more preferably 0.001 to 0.05, still more preferably 0.003 to 0.04, and particularly preferably 0.005 to 0.03. When the value of (D) / ((A) + (B) + (C)) is 0.1 or less, the component (D) can be easily dissolved. On the other hand, when the value of (D) / ((A) + (B) + (C)) is 0.0005 or more, it becomes easy to obtain the desired effect by blending the component (D).

This composition is an aqueous solution containing water as an essential component, in which each component is dissolved in water. As the water, water from which ionic substances and impurities have been removed, such as ion-exchanged water, pure water, and ultrapure water, can be used. The content of water in the composition may be about 50 to 99% by mass.

This composition is suitably used as an etching agent (etching solution) for etching a metal layer such as a copper-based layer, an additive for a non-electrolytic plating solution, an additive for metal electrorefining, a pesticide, an insecticide, and the like. Can be done. Among them, it is suitable as an etching agent composition used for etching a metal layer.

When the present composition is an etching solution composition, the effect of the present invention is contained in the etching solution composition as a component other than the component (A), the component (B), the component (C), the component (D) and water. Well-known additives and solvents can be blended within a range that does not impair. Additives include stabilizers for etching solution compositions, solubilizers for each component, pH adjusters, specific gravity adjusters, viscosity regulators, wettability improvers, chelating agents, oxidizing agents, reducing agents, and surfactants. Etc. can be mentioned. The concentration of each of these additives may be in the range of 0.001 to 50% by mass, preferably in the range of 0.001 to 49% by mass, and in the range of 0.001 to 40% by mass. Is more preferable.

Examples of the pH adjuster include inorganic acids such as sulfuric acid and nitric acid and salts thereof; water-soluble organic acids and salts thereof; alkali metals hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide; Alkaline hydroxide earth metals such as calcium hydroxide, strontium hydroxide and barium hydroxide; alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate; carbonates of alkali metals such as sodium hydrogen carbonate and potassium hydrogen carbonate Hydrogen salts; quaternary ammonium hydroxides such as tetramethylammonium hydroxide and choline; organic amines such as ethylamine, diethylamine, triethylamine and hydroxyethylamine; ammonium carbonate; ammonium hydrogencarbonate; ammonia; and the like. These pH adjusters can be used alone or in combination of two or more. The content of the pH adjuster may be an amount that makes the pH of the etching solution composition a desired pH.

Examples of the chelating agent include ethylenediamine tetraacetic acid, diethylenetriaminepentacetic acid, triethylenetetraminehexacetic acid, tetraethylenepentamineriacetic acid, pentaethylenehexamineoctacetic acid, nitrilotriacetic acid, and alkali metal (preferably sodium) salts thereof. Aminocarboxylic acid-based chelating agents; phosphonic acid-based chelating agents such as hydroxyethylidene diphosphonic acid, nitrilotrismethylenephosphonic acid, phosphonobutanetricarboxylic acid, and alkali metal (preferably sodium) salts thereof; oxalic acid, malonic acid , Divalent or higher carboxylic acid compounds such as succinic acid, glutaric acid, adipic acid, pimeric acid, malic acid, tartaric acid, citric acid, their anhydrides, and alkali metal (preferably sodium) salts thereof. Examples thereof include monoanhydrides and dianhydrides obtained by dehydrating the carboxylic acid compound of. The concentration of the chelating agent in the etching solution composition is generally in the range of 0.01 to 40% by mass, preferably in the range of 0.05 to 30% by mass.

As the surfactant, a cationic surfactant and an amphoteric surfactant can be used. Examples of the cationic surfactant include alkyl (alkenyl) trimethylammonium salt, dialkyl (alkenyl) dimethylammonium salt, alkyl (alkenyl) pyridinium salt, alkyl (alkenyl) dimethylbenzylammonium salt, alkyl (alkenyl) isoquinolinium salt, and dialkyl. Examples thereof include (alkenyl) morphonium salt, polyoxyethylene alkyl (alkenyl) amine, alkyl (alkenyl) amine salt, polyamine fatty acid derivative, amyl alcohol fatty acid derivative, benzalconium chloride, benzethonium chloride and the like. Examples of the amphoteric tenside agent include carboxybetaine, sulfobetaine, phosphobetaine, amide amino acid, imidazolinium betaine-based surfactant and the like. The concentration of the surfactant in the etching solution composition is generally in the range of 0.001 to 10% by mass.

As the solvent, an alcohol solvent, a ketone solvent, an ether solvent, or the like can be used. Examples of the alcohol solvent include methanol, ethanol, diethylene glycol, isopropyl alcohol, 2-ethylhexanol and the like. Examples of the ketone solvent include methyl acetate, ethyl acetate, propyl acetate and the like. Examples of the ether solvent include tetrahydrofuran, methyl cellosolve and the like.

The etching method according to the embodiment of the present invention includes a step of etching using the above-mentioned present composition (etching liquid composition). As this etching method, a process of a well-known general etching method can be adopted other than using the above-mentioned etching solution composition. Among the metal layers, a copper-based layer is particularly preferable as the object to be etched. Examples of the copper-based layer include copper alloys such as silver-copper alloys and aluminum-copper alloys; and layers containing copper and the like. Of these, copper is particularly preferable. As a specific etching method, for example, a dipping method, a spray method, or the like can be adopted. The etching conditions may be appropriately adjusted according to the composition of the etching solution composition to be used and the etching method. Further, various well-known methods such as a batch type, a flow type, an auto-control type based on the redox potential and specific gravity of the etchant, and an acid concentration may be adopted.

The etching conditions are not particularly limited, and can be arbitrarily set according to the shape and film thickness of the object to be etched. For example, it is preferable to spray the etching solution composition at 0.01 to 0.2 MPa, and further preferably at 0.01 to 0.1 MPa. The etching temperature is preferably 10 to 50 ° C, more preferably 20 to 50 ° C. Since the temperature of the etching solution composition may rise due to the heat of reaction, the temperature may be controlled by a known means so as to be maintained within the above temperature range, if necessary. The etching time may be a time during which the object to be etched can be sufficiently etched. For example, when an object to be etched having a film thickness of about 1 μm, a line width of about 10 μm, and an opening of about 100 μm is etched in the above temperature range, the etching time may be about 10 to 300 seconds.

According to the etching method using the above-mentioned etching solution composition, it is possible to form a fine pattern in which the cross-section of the thin line is not constricted while suppressing the generation of a residual film. Therefore, in addition to the printed wiring board, it can be suitably used for a package substrate that requires a fine pitch, and a subtractive method for COF and TAB applications.

As described in detail above, the following configurations can be adopted for the above-described embodiment.
[1] 0.1 to 25% by mass of at least one component selected from the group consisting of (A) ferric ion and ferric ion; (B) 0.1 to 30% by mass of chloride ion; C) Compound 0.01 to 10% by mass represented by the above general formula (1); (D) At least one component 0.01 to selected from the group consisting of unsaturated carboxylic acid, a salt thereof and an anhydride thereof. A composition which is an aqueous solution containing 10% by mass; and water.
[2] The composition according to the above [1], wherein the mass ratio of the component (B) to the component (A) is (B) / (A) = 0.5 to 2.
[3] The mass ratio of the component (C) to the sum of the component (A) and the component (B) is (C) / ((A) + (B)) = 0.005 to 0.2. , The composition according to the above [1] or [2].
[4] The mass ratio of the component (D) to the sum of the component (A), the component (B), and the component (C) is (D) / ((A) + (B) + (C)). The composition according to any one of the above [1] to [3], which is 0.0005 to 0.1.
[5] The composition according to any one of the above [1] to [4], which is an etching solution composition used for etching a metal layer.
[6] The composition according to the above [5], wherein the metal layer is a copper-based layer.
[7] An etching method comprising a step of etching using the composition according to any one of the above [1] to [6].

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Table 1 shows the number average molecular weights of the component (C) used in Examples and Comparative Examples and the comparative components. The components (C) in Table 1, c-1, c-2 and c-3, are all represented by the above formula No. The compound represented by the above formula No. N in 17 is the above formula No. The number of compounds whose number average molecular weight of the compound represented by 17 is the value shown in Table 1. Further, c-4, which is a comparative component of the component (C), has the above formula No. N in 17 is the above formula No. Except that the number average molecular weight of the compound represented by 17 is the number shown in Table 1, the above formula No. It is a compound represented by the same formula as 17.

The component (D) used in Examples and Comparative Examples is shown below.

d-1: Monopotassium acetylenedicarboxylic acid d-2: Potassium hydrogen phthalate d-3: Pyromellitic acid d-4: 2,6-pyridinedicarboxylic acid d-5: Sodium hydrogen fumarate d-6: Gallic acid d -10: 3,5-dihydroxybenzoic acid

In addition, d-7 to d-9 shown below were prepared as comparative components of the component (D).
d-7: Sodium acetate d-8: Sodium potassium tartrate d-9: Tartaric acid

<Example 1 (Examples 1-1 to 1-14) and Comparative Example 1 (Comparative Examples 1-1 to 1-6)>
Copper (II) chloride, hydrogen chloride, component (C) or its comparative component, component (D) or its comparative component, and water were mixed so as to have the composition shown in Table 2, and the etching solution composition No. 1 to 20 were obtained. The balance in the composition of the etching solution composition shown in Table 2 is water.

<Example 2 (Examples 2-1 to 2-14) and Comparative Example 2 (Comparative Examples 2-1 to 2-6)>
A substrate in which a copper foil having a thickness of 8 μm was laminated on a polyimide resin substrate was prepared. A photoresist with a line width of 11 μm and an opening of 5 μm was formed on the copper foil of this substrate to prepare a test substrate. The prepared test substrate was subjected to wet etching by spraying the prepared etching solution composition for a just etching time (60 to 120 seconds) under the conditions of a treatment temperature of 45 ° C. and a treatment pressure of 0.05 MPa. The just etching time means the time calculated from the etching rate until the width of the lower part of the thin wire in the cross section of the thin wire becomes 8 μm. Then, the resist pattern was removed using a stripping solution to form a pattern (thin line).

<Evaluation>
Using a laser microscope, the presence or absence of fine line formation and the presence or absence of residual film were confirmed. In addition, a focused ion beam processing observation device (JIB-4000, manufactured by JEOL Ltd.) was used to process the cross section of the thin wire, and the cross section of the thin wire was observed with a scanning electron microscope (SEM). Then, the fine line width was measured from the SEM image of the cross section of the thin line. Specifically, to explain with reference to FIG. 1, which is a cross-sectional view schematically showing the test substrate after etching, the width 4 on the resist 2 side (width of the upper part of the thin line) 4 in the cross section of the etched copper foil 1 It was measured. Further, the width 4 of the upper portion of the thin wire and the width 5 of the central portion of the thin wire narrower than the width 6 on the resin substrate 3 side (width of the lower portion of the thin wire) 6 in the cross section of the etched copper foil 1 were measured. Table 3 shows the evaluation results and measurement results of (1) to (5) shown below. The absence of a residual film (remaining etching portion) means that disconnection or short circuit is unlikely to occur. Further, the smaller the constriction width, the thinner the line having a cross-sectional shape closer to a rectangle.

(1) Presence or absence of thin line formation The case where the thin line was formed was evaluated as "++", and the case where the thin line was not formed was evaluated as "---".
(2) Presence or absence of residual film The case without residual film was evaluated as "++", and the case with residual film was evaluated as "---".
(3) Width of the upper part of the thin line The value measured as above was taken. The unit is "μm".
(4) Width of the center of the thin line The values measured as described above were taken. The unit is "μm".
(5) Constriction width Calculated from the following formula. The unit is "μm". However, if the thin line is not formed, the width of the upper part of the thin line and the width of the central part of the thin line cannot be measured, so the measurement is not possible.
"Constriction width" = "Measured value of width at the top of thin line"-"Measured value of width at center of thin line"

As shown in Table 3, in Examples 2-1 to 2-14, it can be seen that the constriction width was less than 2.0 μm, and a pattern having a small constriction width could be formed while suppressing the generation of residual film. Among them, in Examples 2-1 to 2-9, Examples 2-13, and Example 2-14, the constriction width is less than 1.5 μm, and a pattern having a smaller constriction width suppresses the generation of residual film. It can be seen that it was formed while doing so. In particular, in Examples 2-1 to 2-7 and Example 2-14, the constriction width was less than 1.0 μm, and it can be seen that a pattern having a particularly small constriction width could be formed while suppressing the generation of residual film. .. On the other hand, in Comparative Examples 2-1 to 2-5, the constriction width was 2.5 μm or more, and it can be seen that a pattern having a large constriction width was formed. Further, in Comparative Example 2-6, no pattern was formed. From the above results, according to the present embodiment, a residual film that causes disconnection or short circuit is less likely to occur, the constriction is small, and a fine pattern having a desired dimensional accuracy can be formed for etching. Compositions and etching methods can be provided.

1: Copper foil 2: Resist 3: Resin substrate 4: Width of the upper part of the thin line 5: Width of the center of the thin line 6: Width of the lower part of the thin line 7: Line width of the resist

Claims

(A) 0.1 to 25% by mass of at least one component selected from the group consisting of ferric ions and ferric ions;
(B) Chloride ion 0.1 to 30% by mass;
(C) Compound 0.01 to 10% by mass represented by the following general formula (1);
(D) 0.01 to 10% by mass of at least one component selected from the group consisting of unsaturated carboxylic acids, salts thereof and anhydrides;
A composition which is an aqueous solution containing water as well.

(In the general formula (1), R 1 represents a single bond or a linear or branched alkanediyl group having 1 to 4 carbon atoms, and R 2 and R 3 are independent carbon atoms. Represents a linear or branched alkanediyl group of numbers 1 to 4, and R 4 and R 5 each independently have a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. Represented by n, each independently represents a number in which the number average molecular weight of the compound represented by the general formula (1) is 350 to 1,200.)
The composition according to claim 1, wherein the mass ratio of the component (B) to the component (A) is (B) / (A) = 0.5 to 2.
Claim that the mass ratio of the component (C) to the sum of the component (A) and the component (B) is (C) / ((A) + (B)) = 0.005 to 0.2. The composition according to 1 or 2.
The mass ratio of the component (D) to the sum of the component (A), the component (B) and the component (C) is (D) / ((A) + (B) + (C)) = 0. The composition according to any one of claims 1 to 3, which is 0005 to 0.1.
The composition according to any one of claims 1 to 4, which is an etching solution composition used for etching a metal layer.
The composition according to claim 5, wherein the metal layer is a copper-based layer.
An etching method comprising a step of etching using the composition according to any one of claims 1 to 6.