JP6078394B2 - 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, and more specifically, an etching solution composition used for collectively etching a laminated film composed of an indium oxide film and a metal film. And an etching method using the etching solution composition.

  Various techniques relating to wet etching of indium oxide-based coatings used for transparent conductive films and the like are known, but since they are inexpensive and have good etching rates, aqueous solutions containing hydrochloric acid are often used as etching solution compositions. ing.

For example, Patent Document 1 discloses an etching solution composition for indium-tin oxide (hereinafter sometimes abbreviated as ITO) containing ferric chloride and hydrochloric acid.
Further, as an etchant that does not use hydrochloric acid, for example, Patent Document 2 discloses an aqueous solution containing cupric ions, organic acids, halogen ions, azoles, and polyalkylene glycols as copper or copper alloy etchants. Yes. Here, polyalkylene glycol is used to suppress dissolution of the electrolytic copper plating layer and promote etching of the electroless copper plating layer which is the underlying conductive layer.

JP 2009-231427 A JP 2006-111953 A

  However, for example, when the etching solution disclosed above is used to form a thin line made of an ITO film and a copper film by collectively etching a laminated film made of an ITO film and a copper film, the etching rate is controlled. In some cases, a thin line having a desired width cannot be obtained, or a large chip having a length of 3 μm or more (hereinafter sometimes abbreviated as a mouse bite) may occur in the thin line. There was a problem.

  Accordingly, the present invention has been made to solve the above-described problem. When a laminated film composed of an indium oxide-based film and a metal-based film is etched at once, a fine wire composed of an indium oxide-based film and a metal-based film. It is an object of the present invention to provide an etching solution composition that has a small width and that does not generate a mouth bite on a thin line.

  As a result of intensive studies to solve the above problems, the present inventors have found that at least one oxidizing agent component selected from ferric ions and cupric ions, a hydrogen chloride component, the following general formula (1) An aqueous solution containing at least one compound component selected from the group consisting of a compound represented by formula (1) and a linear or branched alcohol having 1 to 4 carbon atoms, and at least one acid component selected from sulfuric acid or phosphoric acid. It has been found that an etching solution composition characterized by comprising the above-mentioned problems can be solved, and has led to the present invention.

（式中、Ｒ^１、Ｒ^３は各々独立に水素または炭素数１〜４の直鎖若しくは分岐状アルキル基を表し、Ｒ^２は炭素数１〜４の直鎖若しくは分岐状アルキレン基を表し、ｎは１〜３の数を表す。）

(Wherein R ¹ and R ³ each independently represent hydrogen or a linear or branched alkyl group having 1 to 4 carbon atoms, R ² represents a linear or branched alkylene group having 1 to 4 carbon atoms, n represents a number of 1 to 3)

  That is, the present invention provides an etching solution composition for collectively etching a laminated film composed of an indium oxide-based film and a metal-based film. (A) At least one selected from ferric ions and cupric ions (B) Hydrogen chloride component (hereinafter sometimes abbreviated as B component); (C) Compound represented by the above general formula (1) And at least one compound component selected from the group consisting of linear or branched alcohols having 1 to 4 carbon atoms (hereinafter sometimes abbreviated as C component); and (D) selected from sulfuric acid or phosphoric acid. The present invention provides an etching solution composition comprising an aqueous solution containing at least one acid component (hereinafter sometimes abbreviated as D component).

  The present invention also provides an etching method for collectively etching a laminated film composed of an indium oxide-based film and a metal-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 an indium oxide-based film and a metal-based film, the difference between the width of the resist and the width of the fine line obtained after etching is small. Therefore, it is possible to provide an etching solution composition in which a desired fine line width can be obtained, and no mouth bite is generated on the thin line, and an etching method using the etching solution composition.

Hereinafter, embodiments of the present invention will be specifically described.
First, the “indium oxide-based film” described in the present specification is not particularly limited as long as it is a film containing indium oxide, and examples thereof include an indium oxide film, an indium-tin oxide film, and indium. -It is a generic term for a film comprising at least one selected from zinc oxide films.
The “metal-based coating” described in the present specification is not particularly limited as long as it is a coating made of a metal. For example, copper, nickel, titanium, chromium, silver, molybdenum, aluminum, platinum 2 selected from the group consisting of copper, nickel, titanium, chromium, silver, molybdenum, aluminum, platinum, palladium, and the like, such as CuNi, CuNiTi, NiCr, Ag-Pd-Cu, etc. It is a generic term for a film composed of one or more selected from alloy films containing at least one kind of metal.

  The (A) at least one oxidizing agent component selected from ferric ions and cupric ions used in the etching solution composition of the present invention is a component constituting the main component of the etching solution composition of the present invention. . As the component (A), cupric ions and ferric ions can be used alone or as a mixture thereof. These ferric ions and cupric ions can be contained in the etching composition by blending an iron (III) compound and a copper (II) compound as a supply source. Examples of iron (III) compounds include iron (III) chloride, iron (III) bromide, iron (III) iodide, iron (III) sulfate, iron (III) nitrate, and iron (III) acetate. Can be mentioned. Moreover, as a copper (II) compound, copper chloride (II), copper bromide (II), copper sulfate (II), copper hydroxide (II) etc. are mentioned, for example. These compounds can be used individually or in mixture of 2 or more types. Among these compounds, iron (III) sulfate, iron (III) chloride, copper (II) chloride, and copper sulfate (II) from the viewpoints of cost, stability of the etching solution composition, and controllability of the etching rate. ) Are preferred, and iron (III) chloride and iron (III) sulfate are more preferred.

  The concentration of the preferred component (A) in the etching solution composition of the present invention may be appropriately adjusted depending on the thickness and width of the laminated film composed of the indium oxide-based film and the metal-based film, which are desired materials to be etched. It is 0.01-15 mass% in conversion, Preferably it is 0.1-10 mass%. Here, in terms of ion conversion, when ferric ion or cupric ion is used alone, it means ferric ion conversion or cupric ion conversion, and ferric ion and cupric ion. When mixed and used, it means ion conversion of both ferric ions and cupric ions. Here, when the concentration of the component (A) is less than 0.01% by mass, a sufficient etching rate cannot be obtained. On the other hand, when the concentration of the component (A) exceeds 15% by mass, the compound may be insolubilized when the compound represented by the general formula (1) used as the component (C) described later is used. .

  The (B) hydrogen chloride component used in the etching solution composition of the present invention is a component constituting the main component of the etching solution composition of the present invention. The preferable concentration of the component (B) in the etching solution composition of the present invention may be adjusted as appropriate depending on the thickness and width of the material to be etched, that is, the laminated film composed of the indium oxide-based film and the metal-based film. -25% by mass, preferably 1-20% by mass. Here, if the concentration of the component (B) is less than 0.1% by mass, a sufficient etching rate cannot be obtained. On the other hand, even if the concentration of the component (B) exceeds 25% by mass, the etching rate cannot be further improved, and on the contrary, problems such as corrosion on the apparatus members may occur.

  (C) used in the etching solution composition of the present invention is at least one compound selected from the group consisting of a compound represented by the above general formula (1) and a linear or branched alcohol having 1 to 4 carbon atoms. When used in combination with the (A) component and the (B) component, when etching a laminated film composed of an indium oxide-based film and a metal-based film into the etching solution composition of the present invention, The effect which prevents that generate | occur | produces can be provided.

In the general formula (1), R ¹ and R ³ each independently represent hydrogen or a linear or branched alkyl group having 1 to 4 carbon atoms, specifically hydrogen, methyl, ethyl, propyl, isopropyl Butyl, secondary butyl, tertiary butyl, and isobutyl. R ² represents a linear or branched alkylene group having 1 to 4 carbon atoms, and specific examples include methylene, ethylene, propylene, isopropylene, butylene, second butylene, third butylene, and isobutylene.

  (C) Examples of the compound represented by the general formula (1) and the linear or branched alcohol having 1 to 4 carbon atoms include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, and ethylene glycol mono Isopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether , Propylene glycol mono Propyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether And glycol ethers such as dipropylene glycol dimethyl ether; alcohols such as methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, isobutanol, and t-butanol.

（式中、Ｒ^１、Ｒ^３は各々独立に水素または炭素数１〜４の直鎖若しくは分岐状アルキル基を表し、ｎは１〜３の数を表す。） In the case where at least one compound selected from the group consisting of a compound represented by the following general formula (2) and a linear or branched alcohol having 1 to 4 carbon atoms is used, even when the addition amount is small It is preferable because it can prevent a mouse bite from being generated on a thin line:

(Wherein R ¹ and R ³ each independently represent hydrogen or a linear or branched alkyl group having 1 to 4 carbon atoms, and n represents a number of 1 to 3).

  Further, when dipropylene glycol monomethyl ether or 2-propanol is used, the effects as described above are particularly high, which is particularly preferable. Moreover, the compound represented by the said General formula (1) and a C1-C4 linear or branched alcohol may use 2 or more types together.

  The preferable concentration of the component (C) in the etching solution composition of the present invention may be appropriately adjusted according to the thickness and width of the material to be etched, that is, the laminated film of the indium oxide-based film and the metal-based film. -10 mass%, preferably 0.1-5 mass%. When the concentration of the component (C) is less than 0.01% by mass, the mating effect is not exhibited, which is not preferable. When the concentration exceeds 10% by mass, no further improvement in the blending effect is observed.

  The (D) component used in the etching solution composition of the present invention is used in combination with the (A) component; the (B) component and the (C) component, so that the indium oxide film In addition, it is possible to further reduce the difference between the resist width and the width of the fine line after etching, while maintaining the effect of preventing the occurrence of a mouth bite when etching a laminated film made of metal and a metal film. Therefore, it is possible to provide a particularly excellent effect that a desired fine line width can be obtained. As the component (D), sulfuric acid or phosphoric acid can be used alone or as a mixture thereof.

  The preferable concentration of the component (D) in the etching liquid composition of the present invention may be appropriately adjusted depending on the thickness and width of the material to be etched, that is, the laminated film composed of the indium oxide-based film and the metal-based film. It is -35 mass%, Preferably it is 1-30 mass%. When the concentration of the component (D) is less than 0.1% by mass, the effect of reducing thinning of the thin line cannot be obtained sufficiently. On the other hand, even if the concentration of the component (D) is increased from 35% by mass, no further improvement in the blending effect is observed. The concentration of the component (D) means the concentration of sulfuric acid or phosphoric acid when sulfuric acid or phosphoric acid is used alone, and sulfuric acid and phosphoric acid when mixed with sulfuric acid and phosphoric acid. It means the sum of acid concentrations. The ratio of the concentration of sulfuric acid and phosphoric acid in the case of using a mixture of sulfuric acid and phosphoric acid is preferably 1:30 to 30: 1, more preferably 1:25 to 25: 1. The range of 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, surfactant, etc. are mentioned, The density | concentration in the case of using these is generally in the range of 0.001-50 mass%, Preferably it is 0.01-40 mass%.

  Among such additives, for example, as the chelating agent, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, tetraethylenepentaminepentaacetic acid, pentaethylenehexamineoctacetic acid, nitrilotriacetic acid, and alkalis thereof Aminocarboxylic acid-based chelating agents represented by metal (preferably sodium) salts; hydroxyethylidene diphosphonic acid, nitrilotrismethylenephosphonic acid, phosphonobutanetricarboxylic acid and their alkali metal (preferably sodium) salts Phosphonic acid-based chelating agents; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, malic acid, tartaric acid, citric acid and their anhydrides and alkali metals (preferably sodium) To salt Monoanhydride divalent or higher carboxylic acid compound or a divalent or more carboxylic acid compound represented become dehydrated or dianhydride. The concentration in the case of using these is generally 0.01 to 40% by mass, preferably 0.05 to 30% by mass.

  In addition, when the etching speed | rate of the etching liquid composition of this invention is quick, it is preferable to use a reducing agent as an additive, Specifically, copper chloride, ferrous chloride, copper powder, silver powder, etc. are mentioned. The concentration in the case of using these is generally in the range of 0.01 to 10% by mass, preferably 0.05 to 5% by mass.

  The etching solution composition of the present invention is used when collectively etching a laminated film composed of an indium oxide film and a metal film. The indium oxide-based film may be a single layer or a laminated film of two or more layers. Further, the metal-based film may be a single layer or a laminated film of two or more layers. In the laminated film composed of the indium oxide-based film and the metal-based film, the metal-based film may be an upper layer, a lower layer, or an upper layer and a lower layer. Further, in the laminated film composed of the indium oxide-based film and the metal-based film, the indium oxide-based film and the metal-based film may be alternately laminated.

  The above-described etching solution of the present invention is an etching solution composition suitable as an etching solution composition used for forming a fine line by etching an ITO film and a metal film-based film at once.

  Moreover, the etching method which etches the laminated film of the indium oxide film and the metal film using the etching composition of the present invention is not particularly limited, and a well-known general etching method may be used. . For example, there are dip type, spray type and spin type etching methods.

  For example, in the case of etching a base material in which a CuNi / Cu / ITO layer is formed on a PET substrate by a dip type etching method, the base material is immersed in the etching agent of the present invention, and an appropriate etching condition is set. The CuNi / Cu / ITO layer on the PET substrate can be collectively etched by pulling up after being immersed.

  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 etching temperature is preferably 10 ° C to 60 ° C, and particularly preferably 30 ° C to 50 ° C. 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 500 to 2000 mm as in wiring manufacturing on an electronic circuit board, the etching may be performed for about 0.2 to 5 minutes within the above temperature range.

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

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited by these.
Example 1
Using the compounds shown in Table 1 as the component (C), the etching solution composition was formulated according to the formulation shown in Table 2, and Products 1 to 27 of the present invention were obtained. The balance of the content is water.

Comparative Example 1
The etching liquid composition was mix | blended with the mixing | blending shown in Table 3, and the comparative products 1-5 were obtained. The balance of the content is water.

Example 2
A substrate in which a resist pattern having a width of 100 μm and an opening of 45 μm is formed by using a dry film resist on a substrate in which ITO (50 nm), Cu (200 nm), and CuNiTi (30 nm) are laminated in this order on a 200 μm thick PET substrate is 20 mm long X Cut to 20 mm in width to obtain a test piece. This test piece was subjected to a dip etching process under stirring at 35 ° C. for 1 to 27 of the present invention.

Comparative Example 2
A substrate in which a resist pattern having a width of 100 μm and an opening of 45 μm is formed by using a dry film resist on a substrate in which ITO (50 nm), Cu (200 nm), and CuNiTi (30 nm) are laminated in this order on a 200 μm thick PET substrate is 20 mm long X Cut to 20 mm in width to obtain a test piece. This test piece was subjected to a dip etching process at 35 ° C. for 1 minute with stirring using Comparative Products 1 to 5.

[Evaluation Example 1]
Regarding the thin lines obtained in Example 2 and Comparative Example 2, the state of the thin line and the deviation between the resist width and the width of the obtained thin line were confirmed using a laser microscope. The state of the fine line was evaluated by confirming the presence or absence of a chip having a length of 3 μm or more at the corner of the fine line. Specifically, the case where a chip with a length of 3 μm or more was observed on the fine wire was marked with “X” when the chip with a length of 3 μm or more was not observed.
The difference between the width of the resist and the width of the thin line obtained was compared by calculating the absolute value (L ¹ ) of the difference between the width of the resist pattern before the etching process and the width of the thin line obtained after the etching process. Meaning that if L ¹ is 0 is the width and the width of the thin line obtained after the etching treatment of the resist pattern are the same before the etching process, it means that the fine line of desired width is obtained Yes. Further, if L ¹ is a higher number, it means that the width of the fine line obtained after the width and the etching process before the resist pattern to be etched is significantly different, that fine line of desired width can not be obtained I mean. The results are shown in Table 4.

From the results in Table 4, it was found that all of the evaluation examples 1 to 27 were not confirmed to have a length of 3 μm or more, and the fine line state after the etching treatment was good.
Further, it was found that none compared to Evaluation Example 1 to 27 may be L ¹ has a low number and Comparative Examples A-E.
As described above, the etching solution composition of the present invention can be used when etching an indium oxide-based film and a metal-based film in a lump to obtain a thin line with a desired width without generating a mouth bite on the thin line. Therefore, it has been found that the etching solution composition is particularly useful as an etching solution composition used when etching an indium oxide-based film and a metal-based film at once.

Claims (4)

An indium oxide-based film that is one or more layers selected from the group consisting of an indium oxide film, an indium-tin oxide film, and an indium-zinc oxide film, and copper, nickel, titanium, chromium, silver, molybdenum, aluminum, platinum And a metal film selected from the group consisting of palladium, from a group consisting of an alloy film containing two or more metals selected from the group consisting of copper, nickel, titanium, chromium, silver, molybdenum, aluminum, platinum and palladium In an etching solution composition for collectively etching a laminated film made of a metal-based film that is one or more selected layers ,
(A) at least one oxidizing agent component selected from ferric ions and cupric ions;
(B) Hydrogen chloride component;
(C) at least one compound component selected from the group consisting of a compound represented by the following general formula (1) and a linear or branched alcohol having 1 to 4 carbon atoms; and (D) from sulfuric acid or phosphoric acid. An etching solution composition comprising an aqueous solution containing at least one selected acid component:

(Wherein R ¹ and R ³ each independently represent hydrogen or a linear or branched alkyl group having 1 to 4 carbon atoms, and R ² represents a linear or branched alkylene group having 1 to 4 carbon atoms. N represents a number of 1 to 3) The etching according to claim 1, wherein the component (C) is at least one compound component selected from the group consisting of a compound represented by the following general formula (2) or a branched alcohol having 3 to 4 carbon atoms. Liquid composition:

(Wherein R ¹ and R ³ each independently represents hydrogen or a linear or branched alkyl group having 1 to 4 carbon atoms, and n represents a number of 1 to 3).   The etching solution composition according to claim 1 or 2, wherein the component (C) contains at least dipropylene glycol monomethyl ether or 2-propanol. An indium oxide-based film that is one or more layers selected from the group consisting of an indium oxide film, an indium-tin oxide film, and an indium-zinc oxide film, and copper, nickel, titanium, chromium, silver, molybdenum, aluminum, platinum And a metal film selected from the group consisting of palladium, from a group consisting of an alloy film containing two or more metals selected from the group consisting of copper, nickel, titanium, chromium, silver, molybdenum, aluminum, platinum and palladium In the etching method which etches collectively the laminated film which consists of a metal-type film which is the 1 layer or more selected, using the etching liquid composition of any one of Claim 1 thru | or 3 as an etching liquid composition Etching method characterized.