JP2017199791A - Etchant composition and etching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an etchant composition which is small in the thinning of a width by etching, suppresses the occurrence of a chip in an upper portion of a thin wire, and enables the formation of a thin wire having a desired width even if it contains no hydrogen chloride, and which can suppress the thinning of a thin wire even if an etching process is continued after the end of inter-thin wire etching.SOLUTION: An etchant composition for etching an indium oxide-based layer comprises: (A)0.01-15 mass% of hydrogen peroxide; (B)1-40 mass% of sulfuric acid; (C)0.01-20 mass% of an amino acid compound; and water.SELECTED DRAWING: None

Description

  The present invention relates to an etching solution composition and an etching method using the same. More specifically, the present invention relates to an etching solution composition used for etching an indium oxide-based layer and an etching method using the same.

  Various techniques relating to wet etching of indium oxide-based layers used for transparent conductive films and the like are known. Among them, an aqueous solution containing hydrochloric acid is often used as an etchant composition because it is inexpensive and has a good etching rate.

  For example, Patent Document 1 discloses an etching solution composition for indium-tin oxide (hereinafter also referred to 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, which are copper or copper alloy etchants. Has been.

JP 2009-231427 A JP 2006-111953 A

  However, when an etching solution containing hydrogen chloride such as the etching solution composition disclosed in Patent Document 1 is used to collectively etch an ITO layer or a laminate composed of an ITO layer and a copper layer, a substrate or a peripheral member Discoloration of the substrate, roughening of the surface of the base material and the peripheral member, elution of metal components from the surface of the base material and the peripheral member, and poor linearity of the formed thin lines are likely to occur.

  In addition, when an etching solution that does not contain hydrogen chloride, such as the etching agent disclosed in Patent Document 2, is used to etch an ITO layer or a laminate composed of an ITO layer and a copper layer in a lump, the fine lines that are formed are thinned. It is difficult to form a large thin wire having a desired width, and there is a problem in that chipping occurs in the upper portion of the thin wire. Furthermore, if the etching process is continued after the etching between the fine lines is completed, a further significant thinning occurs in the fine lines.

  Accordingly, the present invention has been made to solve the above problems, and the problem is that even if it does not contain hydrogen chloride, the narrowing width due to etching is small, and the occurrence of chipping at the upper portion of the thin line is suppressed, An object of the present invention is to provide an etching solution composition capable of forming a thin line having a desired width and capable of suppressing the thin line from being thinned even if an etching process is continued after completion of etching between the thin lines. And Moreover, the place made into the subject of this invention is providing the etching method using the said etching liquid composition.

  As a result of intensive studies to solve the above problems, the present inventors have found that an etching solution composition containing a specific component can solve the above problems, and have reached the present invention.

That is, according to the present invention, there is provided an etching solution composition for etching an indium oxide-based layer, wherein (A) 0.01 to 15% by mass of hydrogen peroxide; (B) 1 to 40% by mass of sulfuric acid;
(C) An etching liquid composition containing 0.01 to 20% by mass of an amino acid compound; and water is provided.

  Moreover, according to this invention, the etching method which has the process of etching an indium oxide type layer using said etching liquid composition is provided.

  According to the present invention, even if hydrogen chloride is not contained, the narrowing width by etching is small, the occurrence of chipping at the upper part of the thin wire is suppressed, and it is possible to form a thin wire having a desired width. Thus, it is possible to provide an etching solution composition that can suppress thinning of the fine line even if the etching process is continued after the completion of the step. The etching solution composition of the present invention exhibits the above-described effects even when the indium oxide-based layer and the metal-based layer are etched together. For this reason, the etching liquid composition of this invention is suitable as an etching liquid for etching the laminated body which consists of an indium oxide type layer and a metal type layer collectively. Moreover, according to this invention, the etching method using the said etching liquid composition can be provided.

  Hereinafter, embodiments of the present invention will be specifically described. “Etching” in the present specification means a technique of plastic forming or surface processing utilizing a corrosive action such as chemicals. Specific examples of the use of the etching solution composition of the present invention include a removing agent, a surface smoothing agent, a surface roughening agent, a pattern forming agent, and a cleaning solution for a component adhering to a trace amount on a substrate. The etching solution composition of the present invention can be suitably used as a remover because the removal rate of the layer containing indium oxide is fast. Moreover, since it can obtain a pattern with a desired shape such as a rectangle when it is used for forming a finely shaped pattern having a three-dimensional structure, it can also be suitably used as a pattern forming agent.

  The “indium oxide-based layer” in the present specification is not particularly limited as long as it is a layer containing indium oxide. The “indium oxide-based layer” is a general term for a layer composed of at least one selected from, for example, indium oxide, indium-tin oxide, and indium-zinc oxide.

  The “metal-based layer” in the present specification is not particularly limited as long as it is a layer made of metal. “Metal-based layer” is, for example, selected from metal layers such as copper, nickel, titanium, chromium, silver, molybdenum, platinum, palladium, and metal alloys represented by CuNi, CuNiTi, NiCr, Ag—Pd—Cu, etc. It is a general term for the layer which consists of 1 or more types.

  When etching the laminated body of an indium oxide-based layer and a metal-based layer at once using the etching solution composition of the present invention, the metal-based layer is a conductive layer containing 10% by mass or more of copper. Is preferred. Examples of the conductive layer containing 10% by mass or more of copper include a conductive layer formed of metallic copper and a conductive layer formed of a copper alloy such as CuNi, CuNiTi, NiCr, and Ag—Pd—Cu. Can do. Furthermore, when the indium oxide-based layer is an indium oxide-based layer containing indium-tin oxide and the metal-based layer is a conductive layer containing 10% by mass or more of copper, a desired fine line can be obtained with higher accuracy. Can be formed. Furthermore, it is preferable because it can be etched at a higher speed.

  The etching solution composition of the present invention contains (A) hydrogen peroxide (hereinafter also referred to as “component (A)”). The concentration of the component (A) in the etching solution composition is in the range of 0.01 to 15% by mass. When the concentration of the component (A) is less than 0.01% by mass, the etching rate becomes too slow, and the productivity is significantly reduced. On the other hand, if the concentration of the component (A) is more than 15% by mass, the etching rate becomes too fast and it becomes difficult to control the etching rate. (A) The density | concentration of a component becomes like this. Preferably it is the range of 0.1-12 mass%, More preferably, it is the range of 1-10 mass%.

  The etching solution composition of the present invention contains (B) sulfuric acid (hereinafter also referred to as “component (B)”). The density | concentration of (B) component in an etching liquid composition is the range of 1-40 mass%. When the concentration of the component (B) is less than 1% by mass, the etching rate becomes too slow and productivity is lowered. On the other hand, when the concentration of the component (B) is more than 40% by mass, the etching rate becomes too high, and it becomes difficult to control the etching rate, or the member or resist around the object to be etched is deteriorated. May end up. (B) The density | concentration of a component becomes like this. Preferably it is the range of 5-30 mass%, More preferably, it is the range of 10-25 mass%.

  The etching solution composition of the present invention contains (C) an amino acid compound (hereinafter also referred to as “component (C)”). The amino acid compound may be any compound having at least one amino group and one carboxy group, and a known general amino acid compound can be used. Specific examples of the amino acid compound include glycine, alanine, valine, leucine, serine, phenylalanine, tryptophan, glutamic acid, aspartic acid, lysine, arginine, histidine, tyrosine, phenylalanine, 4-chlorophenylalanine, 4-bromophenylalanine, 4-nitro. Examples thereof include phenylalanine, 3- (3,4-dihydrophenyl) alanine, α-methylphenylalanine, and salts thereof. Examples of the salt include alkali metal salts and ammonium salts. These amino acid compounds can be used alone or in combination of two or more.

  As the amino acid compound, it is preferable to use at least one selected from the group consisting of glutamic acid, a compound represented by the following general formula (1), and salts thereof. By containing these amino acid compounds in the etching solution composition, the fine line width formed by etching the indium oxide-based layer can be made smaller, and a thin line having a desired width can be efficiently formed. Furthermore, it is possible to more effectively suppress the occurrence of chipping at the upper part of the fine line, and more effectively suppress the deterioration of the fine line even when the etching process is continued after the etching between the fine lines is completed. It is preferable because it is possible. In particular, it is preferable to use at least one selected from the group consisting of glutamic acid, tyrosine, and phenylalanine as the amino acid compound.

In general formula (1), R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. Examples of the hydrocarbon group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a secondary butyl group, and a tertiary butyl group.

In general formula (1), R ² represents a hydrogen atom, a hydroxyl group, a halogen atom, or a nitro group. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, etc. can be mentioned, for example.

  In general formula (1), A represents an alkanediyl group having 1 to 4 carbon atoms. Examples of the alkanediyl group having 1 to 4 carbon atoms include a methylene group, an ethylene group, and a butylene group.

In general formula (1), (i) R ¹ is a hydrogen atom or a methyl group; (ii) R ² is a hydrogen atom or a hydroxyl group; or (iii) A is a methylene group, an indium oxide-based layer The narrow width of the fine line formed by etching the film can be made smaller, and a thin line with a desired width can be efficiently formed. Furthermore, it is possible to more effectively suppress the occurrence of chipping at the upper part of the fine line, and more effectively suppress the deterioration of the fine line even when the etching process is continued after the etching between the fine lines is completed. It is preferable because it is possible. In general formula (1), n is preferably 1 or 2.

  The density | concentration of (C) component in an etching liquid composition is the range of 0.01-20 mass%. When the concentration of the component (C) is less than 0.01% by mass, the narrow width of the thin line formed by etching the indium oxide-based layer increases. On the other hand, even if the concentration of the component (C) exceeds 20% by mass, the effect obtained by blending the component (C) does not improve. (C) The density | concentration of a component becomes like this. Preferably it is the range of 0.05-15 mass%, More preferably, it is the range of 0.1-10 mass%.

  The etching liquid composition of this invention contains water as essential components other than (A) component, (B) component, and (C) component. Further, in the etching solution composition of the present invention, as a component other than (A) component, (B) component, (C) component, and water, a well-known addition is made within a range not inhibiting the effect of the present invention. An agent can be blended. Examples of additives include a stabilizer for an etching solution composition, a solubilizing agent for each component, an antifoaming agent, a pH adjusting agent, a specific gravity adjusting agent, a viscosity adjusting agent, a wettability improving agent, a chelating agent, an oxidizing agent, and a reducing agent. And surfactants. The concentration of these additives is generally in the range of 0.001 to 50% by weight.

  Examples of the chelating agent include ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, tetraethylenepentaminepentaacetic acid, pentaethylenehexamineoctacetic acid, nitrilotriacetic acid, and alkali metal (preferably sodium) salts thereof. Aminocarboxylic acid-based chelating agents; 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, their anhydrides and their alkali metal (preferably sodium) salts such as divalent or higher carboxylic acids Acid compounds, or Divalent or higher carboxylic acid compound can be exemplified an anhydride or dianhydride dehydrated. The concentration of these chelating agents is generally in the range of 0.01 to 40% by weight.

  When the etching rate is high, it is preferable to use a reducing agent as an additive. Specific examples of the reducing agent include copper chloride, ferrous chloride, copper powder, silver powder and the like. The concentration of these reducing agents is generally in the range of 0.01 to 10% by mass.

  The etching method of the present invention includes a step of etching an indium oxide-based layer using the above-described etching solution composition of the present invention. If the etching liquid composition of this invention is used, the laminated body which consists of an indium oxide type layer and a metal type layer can be etched collectively. The indium oxide based layer constituting the laminate may be one layer or two or more layers. Further, the metal-based layer constituting the laminate may be one layer or two or more layers. In the laminate, the metal-based layer may be disposed in the upper layer, the lower layer, or the upper layer and the lower layer. Furthermore, indium oxide-based layers and metal-based layers may be alternately stacked.

  A method for etching the indium oxide layer or the stacked body of the indium oxide layer and the metal layer at a time is not particularly limited, and a general etching method may be employed. For example, an etching method such as a dip method, a spray method, or a spin method can be given. For example, when etching a base material on which a Cu / ITO layer is formed on a PET substrate by a dip etching method, the base material is dipped in an etching solution composition under appropriate etching conditions and then pulled up. Thus, the Cu / ITO layer on the PET substrate can be etched together.

  The etching conditions in the dip etching method are not particularly limited, and may be set arbitrarily according to the shape, film thickness, etc. of the base material (object to be etched). For example, the etching temperature is preferably 10 to 60 ° C., more preferably 20 to 40 ° C. The temperature of the etchant composition may increase due to reaction heat. For this reason, you may control temperature by a well-known means so that the temperature of an etching liquid composition may be maintained in said range as needed. The etching time is not particularly limited as long as it is sufficient to complete the etching. For example, in the wiring manufacturing of an electronic circuit board, if the film thickness is about 5 to 500 nm, the etching may be performed for about 10 to 600 seconds in the above temperature range.

  When etching a base material on which a Cu / ITO layer is formed on a PET substrate by a spray-type etching method, the etching solution composition is sprayed on the base material under appropriate conditions, so that Cu / The ITO layer can be etched.

  The etching conditions in the spray-type etching method are not particularly limited, and may be set arbitrarily according to the shape and film thickness of the object to be etched. For example, spray conditions can be selected from the range of 0.01 to 1.0 MPa, preferably 0.02 to 0.5 MPa, and more preferably 0.05 to 0.2 MPa. The etching temperature is preferably 10 to 60 ° C, and more preferably 20 to 40 ° C. The temperature of the etchant composition may increase due to reaction heat. For this reason, you may control temperature by a well-known means so that the temperature of an etching liquid composition may be maintained in said range as needed. The etching time is not particularly limited as long as it is sufficient to complete the etching. For example, in the wiring manufacturing of an electronic circuit board, if the film thickness is about 5 to 500 nm, the etching may be performed for about 5 to 600 seconds in the above temperature range.

  The etching method of the present invention preferably further includes a step of adding a replenisher to the etchant composition in order to recover the performance of the etchant composition that has deteriorated due to repeated etching. For example, in the case of the auto-control type etching method as described above, if a replenisher is set in the etching apparatus in advance, the replenisher can be added to the etchant composition. As the replenisher, for example, an aqueous solution containing the component (A), the component (B), the component (C), and water; or an aqueous solution containing the component (C) and water can be used. The concentration of each component in these aqueous solutions (replenisher) may be, for example, about 3 to 20 times the concentration of each component in the etching solution composition. Moreover, you may add each above-mentioned component contained in the etching liquid composition of this invention as an essential component or an arbitrary component to a replenisher as needed.

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

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited by these.

<Etching solution composition>
(Examples 1-9)
Etching liquid compositions (Examples 1 to 9) were obtained by using the amino acid compounds shown in Table 1 and mixing the components so as to have the composition shown in Table 2. In addition, water was mix | blended so that the sum total of a component might be 100 mass%.

(Comparative Examples 1-5)
Each component was mixed so that it might become the mixing | blending shown in Table 3, and the etching liquid composition (Comparative Examples 1-5) was obtained. In addition, water was mix | blended so that the sum total of a component might be 100 mass%.

<Etching method (1)>
(Examples 10 to 18)
A resist pattern having a width of 10 μm and an opening of 10 μm was formed using a positive liquid resist on a substrate in which an ITO layer (15 nm) and a Cu layer (400 nm) were laminated in this order on a glass substrate. The substrate on which the resist pattern was formed was cut into a length of 20 mm × width of 20 mm to obtain a test piece. The obtained test piece was subjected to pattern etching (etching treatment) by a spray method using the etching solution compositions of Examples 1 to 9 at 35 ° C. and a spray pressure of 0.05 MPa. The etching process was performed until it was confirmed visually that there was no residue between the wirings. Note that “optimum etching time” in this specification means “etching processing time until there is no residue between wirings”.

(Comparative Examples 6 to 10)
Pattern etching by a spray method was performed in the same manner as in Examples 10 to 18 except that the etching solution compositions of Comparative Examples 1 to 5 were used.

<Evaluation (1)>
Using a laser microscope, the state of the thin line and the deviation between the width of the resist pattern and the width of the thin line were evaluated. The state of the thin 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 thin line. Specifically, “+” was evaluated when a chip with a length of 3 μm or longer could not be confirmed, and “−” was evaluated when a chip with a length of 3 μm or longer was confirmed. Further, the deviation between the width of the resist pattern and the width of the fine line was evaluated 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 upper portion of the formed fine line. 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 fine line are the same, and a thin line having a 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 fine line, which means that a thin line having a desired width was not formed. The case where the value of “L ¹ ” was less than 3 μm was evaluated as “+”, and the case where the value of “L ¹ ” was 3 μm or more was evaluated as “−”. The evaluation results are shown in Table 4.

From the results shown in Table 4, it can be seen that in Examples 10 to 18, no chipping with a length of 3 μm or more was confirmed, and the state of the fine line after the etching treatment was good. In Examples 10-18, it is understood that the values are both less than 3μm of "L ^1". As described above, when the etching solution composition of the present invention is used, it is possible to suppress the occurrence of chipping in the upper portion of the thin wire even when the indium oxide-based layer and the metal-based layer are collectively etched. It was found that a thin line with a width of

<Etching method (2)>
(Examples 19 to 27)
Pattern etching by a spray method was performed in the same manner as in Examples 10 to 18 described above except that the etching time was set to twice the optimum etching time.

(Comparative Examples 11-15)
Pattern etching by spraying was performed in the same manner as in Examples 19 to 27 except that the etching solution compositions of Comparative Examples 1 to 5 were used.

<Evaluation (2)>
“L ¹ ” was calculated using a laser microscope, and the deviation between the width of the resist pattern and the width of the fine line was evaluated. The case where the value of "L ^1" is less than 5μm and rated as "++", evaluates if the value of "L ^1" was 5~10μm as "+", the value of "L ^1" The case of over 10 μm was evaluated as “−”. The evaluation results are shown in Table 5.

  From the results shown in Table 5, it can be seen that in Examples 19 to 27, a thin line having a desired width could be formed despite the etching process significantly exceeding the optimum etching time, so that the process window was wide. Especially, in Examples 19-24, since the thinning of the thin wire | line could be suppressed significantly, it turns out that the etching liquid composition of Examples 1-6 is an especially excellent etching liquid.

Claims (4)

An etching solution composition for etching an indium oxide-based layer,
(A) 0.01 to 15% by mass of hydrogen peroxide;
(B) 1 to 40% by mass of sulfuric acid;
(C) An etching solution composition containing 0.01 to 20% by mass of an amino acid compound; and water. The etching solution composition according to claim 1, wherein the amino acid compound is at least one selected from the group consisting of glutamic acid, a compound represented by the following general formula (1), and salts thereof.

(In the general formula (1), R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, R ² represents a hydrogen atom, a hydroxyl group, a halogen atom, or a nitro group, and A represents the number of carbon atoms. 1 to 4 alkanediyl groups, n represents a number of 1 to 5)   The etching solution composition according to claim 1 or 2, wherein the amino acid compound is at least one selected from the group consisting of glutamic acid, tyrosine, and phenylalanine.   The etching method which has a process of etching an indium oxide type layer using the etching liquid composition as described in any one of Claims 1-3.