JPWO2020080178A1 - Etching liquid composition and etching method - Google Patents

Abstract

Provided are an etching solution composition for a silver-containing material capable of etching a silver-containing material at a higher speed and forming fine lines having a small width in the abdomen, and an etching method using the same. An etching solution composition used for etching a silver-containing material, and an etching method including a step of etching a silver-containing material using the etching solution composition. The etching solution composition contains (A) hydrogen peroxide 0.1 to 30% by mass, (B) organic carboxylate 0.05 to 60% by mass, and water, and has a pH of 2.5 or more.

Description

The present invention relates to an etching solution composition used for etching a silver-containing material, and an etching method using the same. More specifically, the present invention relates to an etching solution composition for a silver-containing material capable of satisfactorily etching a circuit wiring having a fine pattern without a shape defect, and an etching method using the same.

A printed wiring board (or film) having a circuit formed on its surface is widely used for mounting electronic components, semiconductor elements, and the like. Most of the wiring used for these printed wiring boards and the like uses copper, but wiring using silver is also being actively studied. In recent years, with the demand for miniaturization and high functionality of electronic devices, it is desired to reduce the thickness of printed wiring boards and the like and increase the density of circuit wiring. As a method of forming a high-density circuit wiring by wet etching, there are a method called a subtractive method and a semi-additive method.

In order to form a circuit wiring with a fine pattern, there should be no residual film on the etching part, the side surface of the circuit wiring seen from above should be straight, the cross section of the circuit wiring should be rectangular, and a high etching factor should be shown. Ideally, the etching rate should be high, the wiring should have the desired width, and there should be no damage to the substrate or surrounding members.

Many etching solutions used for etching silver have been reported so far. For example, Patent Document 1 discloses an etching solution composition containing phosphoric acid, nitric acid, acetic acid, and water, which is used for etching a metal thin film containing silver as a main component. Further, Patent Document 2 discloses an etching solution for a silver-based thin film in which iodine and iodide are contained in an aqueous medium. Further, Patent Document 3 discloses an etching solution for a silver thin film composed of an acidic aqueous solution containing ferric sulfate as an active ingredient.

Further, Patent Document 4 discloses a silver-plated layer solution containing a carboxylic acid compound such as acetic acid and hydrogen peroxide. Patent Document 4 discloses that the content of hydrogen peroxide is higher than that of acetic acid, and that the content of hydrogen peroxide is preferably 900 mL / L or more and 990 mL / L or less. ..

Japanese Unexamined Patent Publication No. 2004-176115 Japanese Unexamined Patent Publication No. 2003-213460 Japanese Unexamined Patent Publication No. 10-060671 Japanese Unexamined Patent Publication No. 2012-194024

When the conventional etching solution compositions for silver-containing materials are used, there have been problems that the etching rate is slow and that the abdomen of the fine wire often has a large thinning. In addition, the solution disclosed in Patent Document 4 requires careful handling because high-concentration hydrogen peroxide may explosively decompose. Further, the solution disclosed in Patent Document 4 has a problem that the fine wire tends to have a large narrow width, so that it is difficult to form a fine pattern and the fine wire is easily peeled off from the substrate.

Therefore, the present invention has been made to solve the above problems, and the subject thereof is that the silver-containing material can be etched at a higher speed and a fine line having a small abdominal width is formed. It is an object of the present invention to provide an etching solution composition for a silver-containing material which can be used. Another object of the present invention is to provide an etching method using the above-mentioned etching solution composition.

As a result of diligent studies to solve the above problems, the present inventors have found that an etching solution composition containing a specific component at a specific concentration and having a pH in a predetermined range can solve the above problems. We have found and completed the present invention.

That is, according to the present invention, it is an etching solution composition used for etching a silver-containing material, wherein (A) hydrogen peroxide 0.1 to 30% by mass and (B) organic carboxylate 0.05. An etching solution composition containing ~ 60% by mass and water and having a pH of 2.5 or more is provided.

Further, according to the present invention, there is provided an etching method including a step of etching a silver-containing material using the above-mentioned etching solution composition.

According to the present invention, it is possible to provide an etching solution composition for a silver-containing material capable of etching a silver-containing material at a higher speed and forming fine lines having a small width of the abdomen. can. Further, according to the present invention, it is possible to provide an etching method using the above-mentioned etching solution composition.

Hereinafter, embodiments of the present invention will be specifically described. As used herein, the term "etching" 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 for silver-containing materials of the present invention include, for example, a removing agent, a surface smoothing agent, a surface roughening agent, a pattern forming agent, a cleaning solution of a component adhering to a substrate in a trace amount, and the like. be able to. The etching solution for a silver-containing material of the present invention can be suitably used as a removing agent because the removal rate of the silver-containing layer is high. Further, when it 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 it can be suitably used as a pattern forming agent. Further, the "silver-containing material" in the present specification may be any material containing silver, for example, metallic silver (silver alone); silver alloy such as silver-copper alloy, silver-tin alloy; silver nanowire, etc. Examples thereof include silver nanoparticles, materials containing a conductive polymer and silver, silver chloride, silver oxide and the like. Among them, the silver-containing material is preferably a material containing 1% by mass or more of silver, and more preferably a material containing 5% by mass or more of silver.

Examples of the above-mentioned conductive polymer include polymers containing carbon nanotubes, polypyrrole, and poly [2-methoxy-5- (3', 7'-dimethyloctyloxy) 1,4-phenylene vinylene] (MDMO-PPV). , 1- (3-methoxycarbonyl) -propyl-1-phenyl [6,6] C61 (PCBM), poly (3-hexyl-thiophene) polymer, poly (3,4-ethylenedioxythiophene) (PedOT), Examples thereof include poly (styrene sulfonate) (PSS) and combinations of these polymers.

The etching solution composition according to an embodiment of the present invention is a liquid composition used for etching a silver-containing material, and is (A) hydrogen peroxide 0.1 to 30% by mass and (B) organic carboxylic acid. It contains 0.05 to 60% by mass of acid salt and water, and has a pH of 2.5 or more.

The concentration of (A) hydrogen peroxide (hereinafter, also referred to as “component (A)”) in the etching solution composition is 0.1 to 30% by mass. If the concentration of the component (A) is less than 0.1% by mass, the etching rate becomes significantly slow. On the other hand, if the concentration of the component (A) is more than 30% by mass, the etching rate becomes too high, and it becomes difficult to control the etching rate. When the concentration of the component (A) is 0.5 to 15% by mass, the etching rate is as fast as the controllable range, which is preferable.

The (B) organic carboxylate (hereinafter, also referred to as “component (B)”) contained in the etching solution composition may be a well-known and general organic carboxylate. Examples of the component (B) include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, and olein. Aliper monocarboxylic acids such as acids, linoleic acid, linolenic acid, arachidonic acid, docosahexaenoic acid, eikosapentaenoic acid; Aliper polyvalent carboxylic acids such as acids; hydroxy acids such as lactic acid, malic acid, citric acid, glycolic acid, tartaric acid, gluconic acid; aromatic monocarboxylic acids such as benzoic acid, salicylic acid, gallic acid, cinnamic acid; phthalic acid , Isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, melitonic acid, biphenyldicarboxylic acid, biphenyltetracarboxylic acid, naphthalenedicarboxylic acid and other aromatic polyvalent carboxylic acids; be able to.

Examples of the counter cation constituting the organic carboxylate include ammonium ion and metal ion, and ammonium ion, alkali metal, and alkaline earth metal ion can be preferably used. Of these, ammonium ions are preferable.
Among the organic carboxylates, organic carboxylate sodium salts such as monosodium citrate, disodium citrate, trisodium citrate, and sodium acetate and their hydrates; ammonium acetate, triammonium citrate, hydrogen citrate. It is preferable to use an ammonium salt of an organic carboxylate such as diammonium or diammonium citrate and a hydrate thereof because the narrowing width of the fine line can be made smaller. Of these, ammonium acetate, triammonium citrate, diammonium hydrogen citrate, diammonium citrate and hydrates thereof are particularly preferable.

The concentration of the component (B) in the etching solution composition is 0.05 to 60% by mass. If the concentration of the component (B) is less than 0.05% by mass, the etching rate becomes significantly slow. On the other hand, if the concentration of the component (B) exceeds 60% by mass, the salt may be difficult to dissolve. The concentration of the component (B) is preferably 0.05 to 50% by mass because the etching rate is as fast as possible within a controllable range, and particularly preferably 0.1 to 30% by mass.

The etching solution composition is an aqueous solution containing the component (A), the component (B), and water, and has a pH of 2.5 or more. When the pH of the etching solution composition is 3.5 to 10, it is preferable because the effect of suppressing peeling of fine wires after etching is higher, and the pH is particularly preferably 4 to 9. If the pH of the etching solution composition is less than 2.5, the fine wires may be peeled off from the substrate.

It is preferable that the etching solution composition further contains (C) an organic carboxylic acid (hereinafter, also referred to as “component (C)”). The component (C) has the effect of slowing down the etching rate. Therefore, by including the component (C), the etching rate can be adjusted, and it becomes possible to form a very precise fine wire.

As the organic carboxylic acid, the same examples as the specific examples of the organic carboxylic acid constituting the above-mentioned component (B) ((B) organic carboxylic acid salt) can be exemplified. The component (C) may be the same as or different from the organic carboxylic acid constituting the component (B). The concentration of the component (C) in the etching solution composition is preferably 0.1 to 30% by mass. If the concentration of the component (C) is less than 0.1% by mass, the effect of slowing the etching rate may not be obtained. On the other hand, even if the concentration of the component (C) exceeds 30% by mass, the effect obtained by blending the component (C) is not improved.

The etching solution composition contains water. In the etching solution composition, water can be used as a solvent, and the etching solution composition can be in the form of an aqueous solution. The content of water in the etching solution composition is preferably the balance thereof, depending on the concentration of the above-mentioned components (A) to (C). When an additive described later is used, the content of water in the etching solution composition is preferably the balance of the components (A) to (C) and the concentration of the additive.

In addition to the above-mentioned components and water, the etching solution composition may further contain well-known additives as long as the effects of the present invention are not impaired. Additives include reducing agents, surfactants, stabilizers for etching solution compositions, solubilizers for each component, defoaming agents, specific gravity adjusting agents, viscosity adjusting agents, wettability improving agents, oxidizing agents, and polyalkylenes. Examples thereof include glycol compounds, azole compounds, pyrimidine compounds, thiourea compounds, alkylpyrrolidones compounds, polyacrylamide compounds, and persulfates. The concentrations of these additives are generally in the range of 0.001 to 50% by weight, respectively.

Examples of the polyalkylene glycol compound include polyethylene glycol; polyethylene glycol dimethyl ether; poly made by blocking or randomly adding ethylene oxide and propylene oxide to diols such as ethylene glycol, propylene glycol, 1,3-butanol and 1,4-butanol. Alkylene glycol can be mentioned.

Examples of the surfactant include a fluorine-based amphoteric surfactant such as fluoroalkyl betaine and fluoroalkyl polyoxyethylene ether; and a nonionic surfactant other than the above polyalkylene glycol compound.

Examples of the azole compounds include alkyl imidazoles such as imidazole, 2-methyl imidazole, 2-undecyl-4-methyl imidazole, 2-phenyl imidazole, and 2-methyl benzo imidazole; benzo imidazole, 2-methyl benzo imidazole, and the like. Benzoimidazoles such as 2-undecylbenzoimidazole, 2-phenylbenzoimidazole, and 2-mercaptobenzoimidazole; 1,2,3-triazole, 1,2,4-triazole, 5-phenyl-1,2,4 -Triazole, 5-amino-1,2,4-triazole, 1,2,3-benzotriazole, 1-aminobenzotriazole, 4-aminobenzotriazole, 1-bisaminomethylbenzotriazole, 1-methyl-benzotriazole , Triazoles such as triltriazole, 1-hydroxybenzotriazole, 5-methyl-1H-benzotriazole, and 5-chlorobenzotriazole; 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-Phenyl-1H-tetrazole, 5-mercapto-1H-tetrazole, 1-phenyl-5-mercapto-1H-tetrazole, 1-cyclohexyl-5-mercapto-1H-tetrazole, and 5,5'-bis-1H- Tetraazoles such as tetrazole; as well as benzothiazole, 2-mercaptobenzothiazole, 2-phenylthiazole, 2-aminobenzothiazole, 2-amino-6-nitrobenzothiazole, 2-amino-6-methoxybenzothiazole, and 2- Examples thereof include thiazoles such as amino-6-chlorobenzothiazole.

Examples of the pyrimidine compounds include diaminopyrimidine, triaminopyrimidine, tetraaminopyrimidine, mercaptopyrimidine and the like.

Examples of the thiourea compound include thiourea, ethylenethiourea, thiodiglycol, and mercaptan.

Examples of alkylpyrrolidone compounds include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-butyl-2-pyrrolidone, N-amyl-2-pyrrolidone, and N. -Hexyl-2-pyrrolidone, N-heptyl-2-pyrrolidone, N-octyl-2-pyrrolidone and the like can be mentioned.

Examples of the polyacrylamide compound include polyacrylamide and t-butylacrylamide sulfonic acid.

Examples of the persulfate include ammonium persulfate, sodium persulfate, and potassium persulfate.

The etching method according to the embodiment of the present invention includes a step of etching a silver-containing material using the above-mentioned etching solution composition. The method for etching the silver-containing material is not particularly limited, and a general etching method may be adopted. For example, an etching method such as a dip type, a spray type, or a spin type can be mentioned. Examples of the silver-containing material to be etched include silver alloys such as silver-copper alloys and silver. Of these, silver is preferable. Further, the etching method and conditions are not particularly limited, and various well-known general methods such as a batch method, a flow method, an etchant oxidation-reduction potential, a specific gravity, and an auto-control method based on an acid concentration can be adopted.

The silver-containing material to be etched is usually formed on a substrate in the form of a film. As the substrate, a substrate formed from a material generally used in the art can be used. Examples of the material of the substrate include glass, silicon, PP, PE, PET and the like.

By etching a film formed of a silver-containing material on a substrate with an etching solution composition, a wiring pattern composed of various fine wires can be formed. In particular, the etching solution composition according to the embodiment of the present invention can be collectively etched when the laminated film is etched. Therefore, it is not necessary to perform selective etching in which the type of etching solution composition is changed for each layer constituting the laminated film, and the etching process can be simplified.

A wiring pattern can be formed by forming a resist pattern corresponding to the wiring pattern on the coating film and peeling off the resist pattern after etching. The type of resist is not particularly limited, and a photoresist such as a dry film resist can be used.

The etching conditions in the dip-type etching method are not particularly limited, and may be arbitrarily set according to the shape and film thickness of the substrate (object to be etched). For example, the etching temperature is preferably 10 to 40 ° C, more preferably 20 to 40 ° C. The temperature of the etching solution composition may rise due to the heat of reaction. Therefore, if necessary, the temperature of the etching solution composition may be controlled by a known means so as to maintain the temperature within the above range. Further, the etching time may be a time sufficient to complete the etching, and is not particularly limited. For example, if the film thickness is about 1 nm to 100 μm, etching may be performed in the above temperature range for about 10 seconds to 1 hour.

When etching a substrate on which silver is formed on a glass epoxy substrate by a spray-type etching method, the silver on the glass epoxy substrate is etched by spraying the etching solution composition onto the substrate under appropriate conditions. Can be done.

The etching conditions in the spray-type etching method are not particularly limited, and may be arbitrarily set according to the shape and film thickness of the object to be etched. For example, the spraying conditions can be selected from the range of 0.01 to 1.0 MPa, preferably in the range of 0.02 to 0.1 MPa, and more preferably in the range of 0.03 to 0.08 MPa. When thin lines are formed by the spray method using the etching solution composition of the present invention, if the spray pressure is in the range of 0.03 to 0.08 MPa, the difference between the upper width and the lower width of the formed fine lines is It is especially preferable because it can be made very small. The etching temperature is preferably 10 to 60 ° C, more preferably 20 to 40 ° C. The temperature of the etching solution composition may rise due to the heat of reaction. Therefore, if necessary, the temperature of the etching solution composition may be controlled by a known means so as to maintain the temperature within the above range. Further, the etching time may be a time sufficient to complete the etching, and is not particularly limited. For example, if the film thickness is about 1 nm to 100 μm, etching may be performed in the above temperature range for about 10 seconds to 1 hour.

The etching method according to the embodiment of the present invention preferably further includes a step of adding a replenishing liquid to the etching liquid composition in order to recover the deterioration of the etching liquid composition due to repeated etching. In particular, in the case of the above-mentioned auto-control type etching, if the replenishing liquid is set in the etching apparatus in advance, the replenishing liquid can be appropriately added to the etching liquid composition. As the replenisher, for example, an aqueous solution containing the component (A), the component (B), and water, an aqueous solution containing the component (B) and water, and the like can be used. The concentration of each component may be about 3 to 20 times the concentration of each component in the etching solution composition. Each of the above-mentioned components contained as an essential component or an optional component in the etching solution composition may be added to the supplement solution, if necessary.

According to the above-mentioned etching solution composition and etching method, a precise circuit wiring having a fine pattern can be formed. Therefore, the above-mentioned etching solution composition and etching method include a printed wiring board for forming electrodes for a touch sensor, a packaging substrate that requires a fine pitch, a subtractive method for COF, and a TAB, and a semi. It can be suitably used for the additive method.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited by the following examples and the like.

<Etching liquid composition (1)>
(Examples 1 to 13)
Each component was mixed so as to have the composition shown in Table 1 to obtain an etching solution composition (Example Compositions Nos. 1 to 13). In Table 1, the components other than the component (A) and the component (B) are water blended so that the total of the etching solution compositions is 100% by mass.

(Comparative Examples 1 to 6)
Each component was mixed so as to have the composition shown in Table 2 to obtain an etching solution composition (Comparative Example Compositions 1 to 6). In Table 2, the components other than the component (A) and the component (B) are water blended so that the total of the etching solution compositions is 100% by mass.

<Etching method (1)>
(Examples 14 to 26)
A resist pattern having a width of 60 μm and an opening of 60 μm is formed on a substrate in which a laminated film (thickness 80 to 100 nm) of metallic silver, silver nanowires, and a silver alloy layer is formed on a glass substrate using a positive dry film resist. bottom. The substrate on which the resist pattern was formed was cut into 50 mm × 50 mm to obtain a test piece. Regarding the obtained test piece, Example Composition No. By using 1 to 13 and performing etching treatment by a dip method at 35 ° C. under stirring for a time until the residue between the wirings cannot be visually confirmed, the evaluation pattern No. 1 to 13 were formed.

(Comparative Examples 7 to 12)
Example Composition No. Comparative patterns 1 to 6 were formed in the same manner as in Examples 14 to 26 described above, except that Comparative Example compositions 1 to 6 were used instead of 1 to 13.

<Evaluation>
(Evaluation 1)
A laser microscope was used to evaluate the peeling of thin lines and the deviation between the width of the resist pattern and the width of the thin lines. Regarding the peeling of the thin line, the one in which the peeling was confirmed in the thin line was evaluated as "-", and the one in which the peeling was not confirmed in the thin line was evaluated as "+". ^{Regarding the deviation between the width of the resist pattern and the width of the thin line, the absolute value "L 1} " of the difference between the width of the resist pattern before the etching process and the width of the upper part of the formed thin line is obtained from the following formula (A). Was calculated and evaluated. When the value of "L ¹ " is "0", it means that the width of the resist pattern before the etching process and the width of the formed thin line are the same, and the thin line of the desired width is formed. .. On the other hand, the ^{larger the value of "L 1} ", the larger the difference between the width of the resist pattern before the etching process and the width of the formed thin lines, which means that the thin lines having the desired width were not formed. The evaluation results are shown in Table 3.

L ¹ =
｜ (Width of resist pattern before etching)-(Width of upper part of formed thin line) ｜
... (A)

From the results shown in Table 3, it can be seen that no peeling was confirmed in Evaluation Examples 1-1 to 1-13, and that L ¹ showed a small value. On the other hand, in Comparative Evaluation Example 1-1, etching was not possible. Further, in Comparative Evaluation Examples 1-2 to 1-6, it was confirmed that the peeling occurred. Furthermore, in Comparative Evaluation Examples 1-2 to 1-6, L ^{1 of the} thin line that was not peeled off also showed a relatively large value.

(Evaluation 2)
Evaluation pattern No. in which the result of evaluation 1 was good. ^{For the comparison pattern 4 in which L 1} was a relatively small value although peeling was confirmed in 3, 4, and 8, the time S required for etching (the time until the residue between the wirings could not be visually confirmed (the time until the residue between the wirings could not be visually confirmed). Seconds)) was evaluated. It can be determined that the shorter the time until the residue between the wirings cannot be visually confirmed, the more productively the fine wires can be formed. The evaluation results are shown in Table 4.

From the results shown in Table 4, it can be seen that in Evaluation Examples 2-1 to 2-3, the etching was completed in a much shorter time than in Comparative Evaluation Example 2-1. Among them, in Evaluation Examples 2-1 and 2-2 using triammonium citrate as the component (B), it can be seen that fine lines can be formed with particularly excellent productivity.

<Etching liquid composition (2)>
(Examples 27 to 31)
Each component was mixed so as to have the composition shown in Table 5 to obtain an etching solution composition (Example Compositions Nos. 14 to 18). In Table 5, the components other than the component (A), the component (B), and the component (C) are water blended so that the total of the etching solution compositions is 100% by mass.

<Etching method (2)>
(Examples 32 to 36)
Example Composition No. Instead of 1 to 13, Example Composition No. The evaluation pattern No. 14 to 18 was used in the same manner as in Examples 14 to 26 described above, except that the etching solution compositions of 14 to 18 were used. Formed 14-18.

<Evaluation>
(Evaluation 3)
Evaluation pattern No. Evaluations 14 to 18 were evaluated in the same manner as in Evaluation 1 and Evaluation 2 described above. The results are shown in Table 6.

From the results shown in Table 6, the evaluation pattern No. It can be seen that no peeling was confirmed in 14 to 18, and that L ¹ showed a small value in each case. Among them, the evaluation pattern No. ^{It can be seen that L 1 of} 15 to 17 was a very small value. Comparing "S (seconds)" (Table 4) of Evaluation Examples 2-1 to 2-3 with "S (seconds)" (Table 6) of Evaluation Examples 3-1 to 5-5, Evaluation Example 3 The "S (seconds)" of -1 to 3-5 is larger. That is, it can be seen that in Evaluation Examples 3-1 to 3-5, etching was possible more slowly than in Evaluation Examples 2-1 to 2-3.

<Etching method (3)>
(Examples 37 to 49)
A substrate was prepared by laminating a material in which metallic silver and silver nanowires were mixed with a conductive polymer which is a composite composed of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid on a glass substrate. A resist pattern having a width of 60 μm and an opening of 60 μm was formed on the prepared substrate using a positive dry film resist. The substrate on which the resist pattern was formed was cut into 50 mm × 50 mm to obtain a test piece. Regarding the obtained test piece, Example Composition No. By using 1 to 13 and performing etching treatment by a dip method at 35 ° C. under stirring for a time until the residue between the wirings cannot be visually confirmed, the evaluation pattern No. 19-31 were formed.

<Evaluation>
(Evaluation 4)
Evaluation pattern No. ^{For 19 to 31, the absolute value “L 1} ” of the difference between the width of the resist pattern before the etching treatment and the width of the upper part of the formed thin line was calculated and evaluated in the same manner as in the above-mentioned evaluation 1. The evaluation results are shown in Table 7.

From the results shown in Table 7, it was confirmed that even for a material in which a silver material is mixed with a conductive polymer, fine lines with a small abdominal width can be formed.

Claims (3)

An etching solution composition used for etching a silver-containing material.
(A) Hydrogen peroxide 0.1 to 30% by mass,
(B) Contains 0.05 to 60% by mass of organic carboxylate and water.
An etching solution composition having a pH of 2.5 or higher. The etching solution composition according to claim 1, further comprising (C) 0.1 to 30% by mass of an organic carboxylic acid. An etching method comprising a step of etching a silver-containing material using the etching solution composition according to claim 1 or 2.