Chemical solution used for etching treatment

Abstract

This invention provides an etching solution that can effectively etch a copper thin film as a seed layer while preventing excessive etching of a copper-plated molded object, and provides a method for manufacturing a substrate having a copper-plated molded object, including etching using this solution. An oxidizing agent (A) and water (W) are included in the etching solution for an object to be processed, obtained by sequentially stacking a substrate, a copper thin film formed by a method other than plating, and a copper-plated molded object in the thickness direction of the substrate. The oxidizing agent (A) is a combination of an oxyacid (A1a) and a peroxide (A1b) or a peracid (A2), and at least one of acetic acid (A1a) and peracetic acid (A2) is included in the oxidizing agent (A).

Description

Technical Field

[0001] []

[0002] The present invention relates to an etching solution for an object to be processed obtained by sequentially stacking a substrate, a copper thin film and a copper-plated shaped object in the thickness direction of the substrate, and a method for manufacturing a substrate having a copper-plated shaped object using the etching solution. [] Prior Technology

[0003] []

[0004] In response to the increasing power and miniaturization of semiconductor devices, flip-chip mounting is widely used as a method for mounting and bonding semiconductor devices on a substrate. In flip-chip mounting, multiple electrodes (bumps) are formed on a seed layer, mainly composed of copper, on the substrate, through which the semiconductor device is connected to the substrate.

[0005] As a method for manufacturing a bumped wiring substrate suitable for flip-chip mounting, the following method is proposed: after setting a resist film for forming an electrode mold on a seed layer on a substrate formed by chemical plating, electroplating is performed on the substrate, thereby forming copper pillar bumps in the mold. Then, the resist film is removed and the seed layer exposed on the substrate surface is removed by etching (see Patent Document 1). Previous technical documents Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-157051 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, Patent Document 1 does not adequately study the removal of the copper thin film serving as the seed layer by etching after removing the mold used for plating. In the method described in Patent Document 1, if the seed layer is etched using conventionally known methods, not only the copper thin film serving as the seed layer, but also copper-plated shapes such as copper terminals formed by plating will be extensively etched.

[0009] The present invention was made in view of the above-mentioned situation, and its object is to provide an etching solution that can effectively etch a copper thin film as a seed layer while preventing excessive etching of the copper-plated molded object, and to provide a method for manufacturing a substrate having a copper-plated molded object, including etching using the etching solution. The means to solve the problem

[0010] The inventors have discovered that the above-mentioned technical problems can be solved by the following solution: An oxidizing agent (A) and water (W) are included in an etching solution for an object to be processed, which is obtained by sequentially stacking a substrate, a copper thin film formed by a method other than plating, and a copper-plated shape in the thickness direction of the substrate. The oxidizing agent (A) is a combination of an oxyacid (A1a) and a peroxide (A1b) or a peracid (A2), and at least one of acetic acid (A1a) and peracetic acid (A2) is included in the oxidizing agent (A), thereby completing the present invention.

[0011] The first embodiment of the present invention is a solution used for etching a substrate, a copper thin film, and a copper-plated shaped object sequentially stacked in the thickness direction of the substrate. The solution contains an oxidizing agent (A) and water (W). Oxidizing substances (A) include combinations of oxyacids (A1a) and peroxides (A1b) or contain peracids (A2). The oxidizing substance (A) includes at least one of acetic acid as an oxyacid (A1a) and peracetic acid as a peracid (A2). At least a portion of the main surface of the copper thin film coated substrate, Copper thin film is a film formed by methods other than plating. Copper-plated shapes are shapes formed by plating a thin copper film as a seed crystal layer.

[0012] The second aspect of the present invention is a method for manufacturing a substrate having a copper-plated shape, comprising: The step of forming a copper thin film on a substrate; The step of forming a plating mold on a copper thin film; The steps include copper plating on a substrate with a mold, and forming a copper-plated shape within the mold; The step of peeling off the mold after the copper-plated shape is formed; After the mold is removed, the copper film is etched using the solution of the first state sample. Invention Effects

[0013] According to the present invention, an etching solution can be provided that can effectively etch a copper thin film serving as a seed layer while preventing excessive etching of the copper-plated molded object, and a method for manufacturing a substrate having a copper-plated molded object including etching using the etching solution can be provided. Implementation

[0014] The embodiments of the present invention will be described in detail below. However, the present invention is not limited to any of the following embodiments. Appropriate modifications can be made to implement the invention within the scope of its objectives.

[0015] Medicine The chemical solution is used for etching the substrate, copper thin film and copper-plated shaped object that are stacked sequentially in the thickness direction of the substrate. A copper thin film covers at least a portion of the main surface of the aforementioned substrate. The copper thin film is formed by a method other than plating. The copper-plated shape is a shape formed by plating the aforementioned copper thin film as a seed layer.

[0016] By etching the above-mentioned workpiece using the solution described later, it is possible to etch only a small amount of copper-plated shapes, while on the other hand, it is possible to perform a large amount of etching on copper films formed by methods other than plating.

[0017] The solution contains an oxidizing agent (A) and water (W). The oxidizing substance (A) comprises a combination of an oxyacid (A1a) and a peroxide (A1b) or comprises a peracid (A2). In addition, the oxidizing substance (A) comprises at least one of acetic acid as an oxyacid (A1a) and peracetic acid as a peracid (A2). In addition, the solution may contain any component such as corrosion inhibitor (B) or surfactant (C).

[0018] The solution can be a single-liquid composition containing an oxidizing agent (A) and water (W), and may contain any other components as needed. Alternatively, the solution can be a multi-liquid composition consisting of two or more liquids with different compositions.

[0019] Examples of pharmaceutical solutions that are multi-liquid compositions include: 1) A pharmaceutical solution consisting of a first solution containing an oxidizing agent (A) and water (W) and a second solution containing a corrosion inhibitor (B); 2) A pharmaceutical solution consisting of a first solution containing an oxidizing agent (A) and water (W) and a second solution containing a surfactant (C); 3) A pharmaceutical solution consisting of a first solution containing an oxidizing agent (A) and water (W) and a second solution containing a corrosion inhibitor (B) and a surfactant (C); 4) A pharmaceutical solution consisting of a first solution containing an oxyacid (Ala) and water (W) and a second solution containing a peroxide (Alb); 5) A pharmaceutical solution consisting of a first solution containing acetic acid (Ala) and water (W) and a second solution containing a peroxide (Alb); 6) A pharmaceutical solution comprising a first solution containing acetic acid (Ala) and water (W), a second solution containing an oxyacid other than acetic acid (Ala) and water (W), and a third solution containing a peroxide (Alb); 7) A solution comprising a first solution containing an oxyacid (Ala) and water (W), a second solution containing a peroxide (Alb), and a third solution containing a corrosion inhibitor (B); 8) A pharmaceutical solution comprising a first solution containing an oxyacid (Ala) and water (W), a second solution containing a peroxide (Alb), and a third solution containing a surfactant (C); 9) A pharmaceutical solution comprising a first solution containing an oxyacid (Ala) and water (W), a second solution containing a peroxide (Alb), and a third solution containing a corrosion inhibitor (B) and a surfactant (C); 10) A solution comprising a first solution containing acetic acid (Ala) and water (W), a second solution containing a peroxide (Alb), and a third solution containing a corrosion inhibitor (B); 11) A pharmaceutical solution comprising a first solution containing acetic acid (Ala) and water (W), a second solution containing a peroxide (Alb), and a third solution containing a surfactant (C); 12) A pharmaceutical solution comprising a first solution containing acetic acid (Ala) and water (W), a second solution containing a peroxide (Alb), and a third solution containing a corrosion inhibitor (B) and a surfactant (C); 13) A solution comprising a first solution containing acetic acid (Ala) and water (W), a second solution containing an oxyacid other than acetic acid (Ala) and water (W), a third solution containing a peroxide (Alb), and a fourth solution containing a corrosion inhibitor (B); 14) A pharmaceutical solution comprising a first solution containing acetic acid (Ala) and water (W), a second solution containing an oxyacid other than acetic acid (Ala) and water (W), a third solution containing a peroxide (Alb), and a fourth solution containing a surfactant (C); 15) A pharmaceutical solution comprising a first solution containing acetic acid (Ala) and water (W), a second solution containing an oxyacid other than acetic acid (Ala) and water (W), a third solution containing a peroxide (Alb), and a fourth solution containing a corrosion inhibitor (B) and a surfactant (C); 16) A solution comprising a first solution containing superacid (Alb) and water (W) and a second solution containing a corrosion inhibitor (B); 17) A pharmaceutical solution consisting of a first solution containing peracid (Ala) and water (W) and a second solution containing a surfactant (C); 18) A pharmaceutical solution consisting of a first solution containing superacid (Ala) and water (W) and a second solution containing a corrosion inhibitor (B) and a surfactant (C); 19) A pharmaceutical solution comprising a first solution containing peracetic acid (Alb) and water (W) and a second solution containing a corrosion inhibitor (B); 20) A pharmaceutical solution comprising a first solution containing peracetic acid (Alb) and water (W) and a second solution containing a surfactant (C); 21) A pharmaceutical solution comprising a first solution containing peracetic acid (Alb) and water (W) and a second solution containing an inhibitor (B) and a surfactant (C); 22) A solution comprising a first solution containing peracetic acid (Alb) and water (W), a second solution containing a peracid other than peracetic acid (Alb) and water (W), and a third solution containing a corrosion inhibitor (B); 23) A pharmaceutical solution comprising a first solution containing peracetic acid (Alb) and water (W), a second solution containing a peracid other than peracetic acid (Alb) and water (W), and a third solution containing a surfactant (C); 24) A pharmaceutical solution comprising a first solution containing peracetic acid (Alb) and water (W), a second solution containing peracetic acid other than peracetic acid (Alb) and water (W), and a third solution containing a corrosion inhibitor (B) and a surfactant (C). The liquid composition of a multi-liquid type is not limited to the examples 1) to 24) above.

[0020] In the case of a liquid formulation that is a multi-liquid component, where the corrosion inhibitor (B) and surfactant (C) are in liquid form, the liquid containing the corrosion inhibitor (B) and / or surfactant (C) may also be solvent-free. Water (W) can be used as the solvent. Various organic solvents can also be used as the solvent, as long as they do not impair the desired effect.

[0021] Considering that it is better to etch only a small amount of copper-plated shapes and to perform a large amount of etching on copper films formed by methods other than plating, and that the preparation and use of the solution are easier, the solution as a multi-liquid composition is preferably a solution composed of a first solution containing acetic acid (Ala) and water (W) and a second solution containing peroxide (Alb). The first liquid, which contains acetic acid (A1a) and water (W), may also contain oxyacids other than acetic acid. The first liquid containing acetic acid (A1a) and water (W), and the second liquid containing peroxide (A1b), may also contain corrosion inhibitor (B) and / or surfactant (C), respectively.

[0022] When the solution is a multi-liquid composition, the object to be treated is etched using a mixture obtained by mixing two or more liquids constituting the multi-liquid composition.

[0023] The following describes the workpiece to be etched using the above-mentioned solution, and the necessary or optional components contained in the solution.

[0024] <The object being processed> As mentioned above, the object to be etched using the above-mentioned solution can be a workpiece obtained by stacking a substrate, a copper thin film, and a copper-plated shaped object sequentially in the thickness direction of the substrate. A copper thin film covers at least a portion of the main surface of the aforementioned substrate. The copper thin film is formed by a method other than plating. A copper-plated shape is a shape formed by plating a thin film as a seed layer.

[0025] As the substrate constituting the object to be processed, a substrate suitable for mounting methods such as flip-chip mounting can be used without particular limitation. As the material of the surface of the substrate covered by the copper thin film (described later), a metal that is conventionally used in combination with a copper thin film as a material for a bump under-metal layer can be used, for example. Examples of metals used as bump under-metal layers include titanium, titanium-tungsten alloys, and titanium-copper alloys. As the material of other layers in the substrate that are in contact with the layer corresponding to the bump under-metal layer, semiconductors such as silicon can be used, for example. That is, as the substrate constituting the object to be processed, a semiconductor substrate having a layer corresponding to the aforementioned bump under-metal layer on at least one main surface is preferably used.

[0026] A copper thin film is formed by means other than plating, in a manner that covers at least a portion of the main surface of a substrate. Examples of methods for forming a copper thin film include physical vapor deposition (PVD), ion plating, and sputtering. Among these methods, physical vapor deposition is preferred from the perspective of easily forming a copper thin film that is easily etched by a chemical solution. There is no particular limitation on the thickness of the copper thin film. Typically, the thickness of the copper thin film is preferably 50 nm to 300 nm, more preferably 70 nm to 250 nm, and even more preferably 100 nm to 200 nm.

[0027] Copper-plated shapes are shapes formed by plating a thin copper film as a seed layer. The manufacturing method for copper-plated shapes is not particularly limited. Typically, a mold with gaps corresponding to the shape of the copper-plated shape is formed on the thin copper film serving as the seed layer at the location where the copper-plated shape will be formed. Then, copper plating is performed on a substrate equipped with the mold using a known method to form the copper-plated shape. Furthermore, the thin copper film serving as the seed layer is exposed in the aforementioned gaps. There are no particular limitations on the method of mold formation. Typically, a mold can be formed using a photosensitive composition via conventional photolithography. There are no particular limitations on the photosensitive composition as long as it can form a film that is durable to the plating solution. The photosensitive composition can be a negative composition that hardens upon exposure and is therefore insoluble in the developer, or a positive composition that is soluble in the developer upon exposure. After copper plating as described above, the mold is peeled off from the substrate using a known method corresponding to the type of components used to form the mold.

[0028] The copper-plated protrusions are typically bumps (electrodes) like metal pillars, or copper wiring or copper rewiring. The shape of the copper-plated protrusions is not particularly limited. In the case of a rewiring layer, the height of the copper-plated protrusion in the thickness direction of the substrate is preferably 2 μm to 6 μm, more preferably 2.5 μm to 4 μm. In the case of bumps, the height of the copper-plated protrusion in the thickness direction of the substrate is preferably 10 μm to 300 μm, more preferably 20 μm to 70 μm.

[0029] <Oxidizing Substance (A)> Oxidizing substances (A) include combinations of oxyacids (A1a) and peroxides (A1b) or peracids (A2). In addition, the oxidizing substance (A) must contain at least one of acetic acid as an oxyacid (A1a) and peracetic acid as a peracid (A2). The solution, by containing the aforementioned oxidizing substance (A), can etch only a small amount of copper-plated shapes, while on the other hand, it can perform a large amount of etching on copper films formed by methods other than plating.

[0030] [Oxyacids (A1a)] As mentioned above, the oxyacid (Ala) must contain acetic acid. The content of acetic acid in the solution is not particularly limited as long as it does not impair the desired effect. Relative to the mass of the solution, the content of acetic acid in the solution is preferably 0.001% by mass or more and 5% by mass, more preferably 0.002% by mass or more and 2% by mass, and even more preferably 0.003% by mass or more and 1% by mass. Alternatively, the solution may also be a multi-liquid form with two or more liquids, as described below. In the case of a multi-liquid solution, the acetic acid content is the ratio of the mass of acetic acid to the total mass of the various liquids.

[0031] Oxyacids (Ala) may contain only acetic acid, or they may contain acetic acid and other oxyacids. Furthermore, in this application's specification, oxyacids (Ala) are oxyacids that are not peroxides containing -OO- bonds. Examples of oxyacids other than acetic acid include carboxylic acids other than acetic acid, halooxyacids, silicic acid, nitrous acid, nitric acid, phosphorous acid, phosphoric acid, sulfurous acid, sulfuric acid, and sulfonic acids. In addition, oxyacids (A1a) are monocarboxylic acids with one acidic group in their molecules, rather than polycarboxylic acids with two or more acidic groups in their molecules. Specific examples of carboxylic acids other than acetic acid include formic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, benzoic acid, and lactic acid. Specific examples of halogenated oxyacids include hypochlorous acid, chlorous acid, chloric acid, hypobromic acid, bromic acid, and bromic acid. Among the aforementioned oxyacids that can be used with acetic acid, phosphoric acid (H3PO4) is preferred from the viewpoint that it is easy to etch copper films formed by methods other than plating.

[0032] The content of oxyacids other than acetic acid in the medicinal solution is not particularly limited as long as it does not impair the desired effect. Relative to the mass of the medicinal solution, the content of oxyacids other than acetic acid in the medicinal solution is preferably 0.1% by mass to 10% by mass, more preferably 0.2% by mass to 7% by mass, and even more preferably 0.5% by mass to 5% by mass. Alternatively, the solution may also be a multi-liquid form with two or more liquids, as described later. In the case of a multi-liquid solution, the content of oxyacids other than acetic acid in the solution is the ratio of the mass of the oxyacids other than acetic acid to the total mass of the various liquids.

[0033] [Peroxide (Alb)] There is no particular limitation on the peroxide (Alb) as long as it is a compound having an -OO- bond. The peroxide can also be a compound equivalent to the peracid (Alc) described later. In the specification of this application, when the pharmaceutical solution contains both an oxyacid (Ala) and a peracid, the pharmaceutical solution contains both the oxyacid (Ala) and the peracid as a peroxide (Alb).

[0034] Specific examples of peroxides (Alb) include inorganic peroxides such as hydrogen peroxide, lithium peroxide, and potassium peroxide; organic peroxides such as tert-butyl hydrogen peroxide, cumene hydrogen peroxide, di-tert-butyl peroxide, dimethyldiethylene oxide, acetone peroxide, methyl ethyl ketone peroxide, and hexamethylene triperoxide; and peracids such as persulfate, percarbonate, perphosphoric acid, hypoperchloric acid, hypoperbromic acid, hypoperiodic acid, and percarboxylic acid. Examples of percarboxylic acids include performic acid, perbenzoic acid, and m-chloroperbenzoic acid.

[0035] Of the peroxides (Alb) mentioned above, hydrogen peroxide is preferred, considering its low cost, ease of handling, and ease of forming copper films by means other than plating using chemical etching.

[0036] The content of peroxide (Alb) in the drug solution is less than 5% by mass relative to the overall mass of the drug solution, preferably less than 1% by mass.

[0037] [Superacid (A2)] The solution may also contain peracid (A2) as an oxidizing agent (A). As described above, in the specification of this application, when the solution contains both an oxyacid (A1a) and a peracid, the solution contains both an oxyacid (A1a) and a peracid as a peroxide (A1b).

[0038] In cases where the solution contains peracetic acid (A2), the solution contains peracetic acid as peracetic acid (A2). The amount of peracetic acid in the solution is not particularly limited as long as it does not impair the desired effect. Relative to the mass of the medicinal solution, the content of peracetic acid in the medicinal solution is preferably 0.001% by mass or more and 5% by mass, more preferably 0.002% by mass or more and 2% by mass, and even more preferably 0.003% by mass or more and 1% by mass. Alternatively, the solution may also be a multi-liquid form with two or more liquids, as described later. In the case of a multi-liquid solution, the peracetic acid content is the ratio of the mass of peracetic acid to the total mass of the various liquids.

[0039] The solution may also contain peracetic acid and other peracids as peracids (A2). As peracids other than peracetic acid, the same compounds as those described for peroxides (A1b) can be used. Of the peracids other than peracetic acid that can be used with peracetic acid, perphosphoric acid is preferred from the viewpoint that it is easy to etch copper films formed by methods other than plating.

[0040] The content of peracids other than peracetic acid in the medicinal solution is not particularly limited as long as it does not impair the desired effect. Relative to the mass of the medicinal solution, the content of peracids other than peracetic acid in the medicinal solution is preferably 0.1% by mass to 10% by mass, more preferably 0.2% by mass to 7% by mass, and even more preferably 0.5% by mass to 5% by mass. Alternatively, the solution may also be a multi-liquid form with two or more liquids, as described later. In the case of a multi-liquid solution, the content of peracids other than peracetic acid in the solution is the ratio of the mass of peracids other than peracetic acid to the total mass of the various liquids.

[0041] [Corrosion Inhibitor (B)] The solution may also contain a corrosion inhibitor (B). By including a corrosion inhibitor (B) in the solution, the copper film can be etched while suppressing the increase in surface roughness of the etched copper-plated form. As the corrosion inhibitor (B), compounds known as corrosion inhibitors for copper can be used without particular limitation.

[0042] Preferred examples of corrosion inhibitors (B) include nitrogen-containing compounds selected from 1H-imidazolium, pyrazole, thiazole, triazole, and guanidine compounds. These can be used alone or in combination of two or more.

[0043] Examples of 1H-imidazolium derivatives include 1H-imidazolium, 2-methyl-1H-imidazolium, 2-ethyl-1H-imidazolium, 2-isopropyl-1H-imidazolium, 2-propyl-1H-imidazolium, 2-butyl-1H-imidazolium, 4-methyl-1H-imidazolium, 2,4-dimethyl-1H-imidazolium, 2-ethyl-4-methyl-1H-imidazolium, 2-amino-1H-imidazolium, and 1H-benzimidazole-2-thiol (2-mercaptobenzimidazole). Examples of pyrazoles include 3,5-dimethylpyrazole, 3-methyl-5-pyrazoleone, 3-amino-5-methylpyrazole, 3-amino-5-hydroxypyrazole, and 3-amino-5-methylpyrazole. Examples of thiazoles include 2-aminothiazole, 4,5-dimethylthiazole, 2-amino-2-thiazoline, 2,4-dimethylthiazole, and 2-amino-4-methylthiazole. Examples of triazoles include 1,2,4-triazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 1,2,4-triazolo[1,5-a]pyrimidine, 1,2,3-triazolo[4,5-b]pyridine, benzotriazole, and 5-methylbenzotriazole. Examples of guanidines include guanidine, 1,3-diphenylguanidine, and 1-(o-tolyl)biguanidine.

[0044] The content of the corrosion inhibitor (B) in the solution is not particularly limited as long as it does not impair the desired effect. The preferred range for the content of the corrosion inhibitor (B) in the solution relative to the mass of the solution is preferably 0.0001% by mass to 10% by mass, more preferably 0.001% by mass to 5% by mass, and even more preferably 0.01% by mass to 1% by mass.

[0045] [Surfactant (C)] By including a surfactant (C) in the solution, the wettability of the solution on the material constituting the copper-plated molds and other treated objects can be improved. As a result, even when the copper film is located near the lower part of multiple copper-plated molds that are very close together, the solution can penetrate well into the gaps between the copper-plated molds and effectively etch the copper film.

[0046] There are no particular limitations on the surfactant (C), and any conventionally known surfactant can be used. Any anionic surfactant, cationic surfactant, amphoteric surfactant, or nonionic surfactant can be used as surfactant (C).

[0047] As a nonionic surfactant, it is preferably an alkylene oxide adduct of a diol having a carbon-carbon triple bond or an alkylene oxide adduct of a monool having a carbon-carbon triple bond. As an epoxide adduct of a diol having a carbon-carbon triple bond, a nonionic surfactant represented by the following formula (c-1) is preferred. HO-(R c6-O) n1-CR c3R c4-C≡C-CR c1R c2-(OR c5) n2-OH･･･(c-1) In formula (c-1), Rc1 to Rc4 are each independently a straight-chain or branched alkyl group having 1 to 6 carbon atoms. Rc5 and Rc6 are each independently a straight-chain or branched alkylene chain having 2 to 4 carbon atoms. n1 and n2 are each independently an integer between 0 and 30.

[0048] Rc1 to Rc4 are preferably methyl, ethyl, and isopropyl. Rc5 and Rc6 are preferably ethane-1,2-diyl (ethylene), propane-1,3-diyl, propane-1,2-diyl, and butane-1,4-diyl. n1 and n2 are preferably integers of 0 to 16.

[0049] Specific examples of alkylene oxide adducts of diols having carbon-carbon triple bonds and alkylene oxide adducts of monools having carbon-carbon triple bonds include OLFINE EXP4200 manufactured by Nissin Chemical Industries, Ltd.; the "SURFYNOL104 series" including SURFYNOL104E, SURFYNOL104H, SURFYNOL104A, SURFYNOL104PA, and SURFYNOL104PG-50 manufactured by Air Products and Chemicals, Ltd.; and the "SURFYNOL400 series" including SURFYNOL420, SURFYNOL445, SURFYNOL465, and SURFYNOL485 manufactured by Air Products and Chemicals, Ltd. Among these, the "SURFYNOL400 series" is preferred.

[0050] Anionic surfactants, for example, can be represented by the following formula (c-2). R c7-SO 3H･･･(c-2)

[0051] In formula (c-2), Rc7 is a straight-chain or branched alkyl group with 7 to 20 carbon atoms. This alkyl group may have hydroxyl and / or carboxyl groups, and may be interrupted by phenylene and / or oxygen atoms. As Rc7, a straight-chain or branched alkyl group having 8 to 11 carbon atoms is preferred.

[0052] Examples of anionic surfactants represented by formula (c-2) include n-octanesulfonic acid, n-nonanesulfonic acid, n-decanesulfonic acid, and n-undecanesulfonic acid. Among these, n-octanesulfonic acid, n-nonanesulfonic acid, and n-decanesulfonic acid are preferred.

[0053] The content of surfactant (C) in the solution is not particularly limited as long as it does not impair the desired effect. The preferred range for the content of surfactant (C) in the solution relative to the mass of the solution is 0.0001% by mass to 10% by mass, more preferably 0.001% by mass to 5% by mass, and even more preferably 0.01% by mass to 1% by mass.

[0054] [Chlorinating agent (D)] The drug solution may also contain a chelating agent (D). A chelating agent (D) is a compound that is not a monobasic acid, i.e., an oxyacid (A1a) mentioned above, that has one acidic group in its molecule. The presence of a chelating agent (D) in the drug solution can stabilize peroxides (A1b) or peracids (A2) in the drug solution. Examples of chelating agents include hydroxyethylidene diphosphonic acid (HEDP), nitrotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), glutamic acid diacetic acid (CMGA), aminotrimethylenephosphonic acid (ATMP), ethylenediaminetetramethylenephosphonic acid (EDTMP), phosphonobutane tricarboxylic acid (PBTC), citric acid, succinic acid, oxalic acid, phthalic acid, malic acid, tartaric acid, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraaminehexaacetic acid (TTHA), and ethylene glycol ether diaminetetraacetic acid (GEDTA). These chelating agents can be used as salts such as alkali metal salts or ammonium salts.

[0055] The content of the chelating agent (D) in the drug solution is not particularly limited within a range that does not impair the desired effect. The preferred range for the content of the chelating agent (D) in the drug solution relative to the mass of the drug solution is preferably 0.001% by mass to 10% by mass, more preferably 0.01% by mass to 5% by mass, and even more preferably 0.1% by mass to 2% by mass.

[0056] [Water-soluble organic solvent (O)] Without compromising the desired effect, the solution may also contain a water-soluble organic solvent (O). By including a water-soluble organic solvent (O) in the solution, components that are difficult to dissolve in water (W) can be easily dissolved in the solution.

[0057] Specific examples of water-soluble organic solvents (O) include: cyclobutane; trimethylamine hexamethylphosphate; dimethyl sulfoxide and other sulfoxides; dimethyl sulfoxide, diethyl sulfoxide, ethyl methyl sulfoxide, ethyl isopropyl sulfoxide, 3-methyl sulfoxide, bis(2-hydroxyethyl) sulfoxide, tetramethylene sulfoxide and other sulfoxides; N,N-dimethylformamide, N-methylformamide, N,N-dimethylacetamide, N-methylacetamide, N,N-diethylacetamide and other acetamides; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone and other lactamides; 1,3-dimethyl-2-imidazolium Imidazolinones such as 1,3-diethyl-2-imidazolinone and 1,3-diisopropyl-2-imidazolinone; alkanols such as methanol, ethanol, and isopropanol; polyols such as ethylene glycol, propylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, glycerol, and diethylene glycol; lactones such as β-propiolactone, γ-butyrolactone, δ-valerolactone, γ-valerolactone, and γ-nonanolactone; propylene carbonate; tetrahydrofuran; the above-mentioned lactones, as well as 1-methylimidazolium, and 1-(3-aminopropyl)imidazolium, guanidine, 2-oxazolidinone, etc., which are not classified as corrosion inhibitors (B) and are liquid nitrogen-containing heterocyclic compounds at atmospheric pressure and 25°C.

[0058] The content of water-soluble organic solvent (O) in the medicinal solution is not particularly limited as long as it does not impair the desired effect. For example, the content of water-soluble organic solvent (O) in the medicinal solution is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 10% by mass or less, relative to the mass of the medicinal solution. The medicinal solution preferably contains only water (W) as a solvent.

[0059] [Other ingredients] In addition to the above-mentioned ingredients, the solution may also contain defoamers, etc. The amount of these ingredients used should be appropriately determined based on the usual amount used for each ingredient.

[0060] [Water (W)] There are no particular limitations on the water (W) as long as it does not impair the desired effect, and water of various qualities can be used. For example, ion-exchanged water, distilled water, ion-exchanged distilled water, etc., are preferred, and ion-exchanged distilled water is more preferred. The desired amount of the required or optional components of the above-described solution are dissolved in water (W) to prepare the solution.

[0061] By using the solution described above, it is possible to effectively etch the copper film serving as the seed layer while preventing excessive etching of the copper-plated structure. More specifically, for the solution described above, the ratio of the etching rate ER1 of the copper-plated object to the etching rate ER2 of the copper film, i.e., ER2 / ER1, is preferably 2.5 or more, more preferably 2.9 or more, and particularly preferably 3.0 or more. The higher the content of acetic acid or peracetic acid in the drug solution, the greater the value of the above ratio ER2 / ER1 tends to be.

[0062] Furthermore, the contact angle of the chemical solution on the surface of the copper-plated molded object is preferably less than 100˚, more preferably 95˚ or less, even more preferably 90˚ or less, and particularly preferably 85˚ or less. Here, the contact angle mentioned above is a value measured before the plated molded object comes into contact with the chemical solution. By ensuring that the contact angle of the solution on the surface of the copper-plated mold meets the above conditions, even when the copper film is located near the lower part of multiple copper-plated molds that are very close to each other, the solution can penetrate well into the gap between the copper-plated molds and effectively etch the copper film.

[0063] Examples of methods to reduce the contact angle of the above-mentioned drug solution include containing a surfactant (C) in the drug solution and adding a water-soluble organic solvent to the drug solution. Here, the contact angle of the aforementioned drug solution is the static contact angle. The static contact angle of the drug solution can be measured, for example, by using a Dropmaster 700 (manufactured by Kyowa Interface Science Co., Ltd.) to drop a drop of 2.0 μL of the drug solution onto the surface of a copper-plated mold that has been in contact with the drug solution, and then measuring the contact angle after 5 seconds.

[0064] When the liquid solution is in contact with the copper-plated mold for 200 seconds, the arithmetic mean height Ra of the surface of the copper-plated mold, measured by atomic force microscopy (AFM), is preferably 35 nm or less, more preferably 30 nm or less, and even more preferably 20 nm or less. When the solution is in contact with the copper-plated mold for 200 seconds, the root mean square height Rq of the surface of the copper-plated mold, measured by atomic force microscopy (AFM), is preferably 50 nm or less, more preferably 40 nm or less, and even more preferably 30 nm or less. When the solution is in contact with the copper-plated prototyping object for 200 seconds, the Z-range of the surface of the copper-plated prototyping object, measured by atomic force microscopy (AFM), is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. The Z-range is the difference between the highest and lowest height values, relating to the height information of the surface of the measured object before planar fitting processing obtained by atomic force microscopy (AFM), and related to the unevenness of the surface.

[0065] Method for manufacturing a substrate with copper-plated shapes A method for manufacturing a substrate with a copper-plated shape includes: The step of forming a copper thin film on a substrate; The step of forming a plating mold on a copper thin film; The steps include copper plating on a substrate with a mold, and forming a copper-plated shape within the mold; After the copper-plated shape is formed, the mold is peeled off; and... After the mold is removed, the copper film is etched using the above-mentioned solution.

[0066] Regarding the steps of forming a copper thin film on a substrate, forming a plating mold on the copper thin film, performing copper plating on a substrate with a mold and forming a copper-plated shape within the mold, and peeling off the mold after the formation of the copper-plated shape, the chemical solution is as described above.

[0067] In the step of etching the copper film using the above-mentioned solution after the mold is removed, the etching method is not particularly limited as long as it allows the copper film to come into contact with the above-mentioned solution. Etching methods include spraying, immersion, and liquid-filled etching, which involve contacting the aforementioned solution with a substrate, a copper thin film, and a copper-plated molded object stacked sequentially in the thickness direction of the substrate. In etching using a spray method, for example, the object to be treated is conveyed or rotated in a specified direction, and the etching solution is sprayed into the space to bring the etching solution into contact with the object. Alternatively, the etching solution can be sprayed while the object is being rotated using a spin coater, as needed. In etching using the immersion method, the workpiece is immersed in a liquid bath composed of a chemical solution, and the workpiece is brought into contact with the chemical solution within the liquid bath. In etching using the liquid-filling method, a liquid is placed on the surface of the object to be etched, so that the object to be etched comes into contact with the liquid. These etching methods can be used flexibly and appropriately depending on the structure or material of the object being processed.

[0068] The contact time between the etching solution and the workpiece is appropriately determined considering factors such as the thickness of the copper film. The temperature of the etching solution is not particularly limited as long as it does not over-etch the copper-plated form or damage the substrate. The temperature of the etching solution is typically preferred to be between 10°C and 40°C, and more preferably between 15°C and 30°C. Example

[0069] The following embodiments further illustrate the present invention in detail, but the scope of the present invention is not limited to the following embodiments.

[0070] [Examples 1-9 and Comparative Example 1] In the embodiments and comparative examples, a processed body was used, which comprises: a silicon substrate having a titanium thin film on one main surface, a copper thin film with a thickness of 800 nm formed by physical vapor deposition covering the exposed surface of the titanium thin film in the silicon substrate, and a copper-plated shape with a thickness of 4 μm covering a portion of the copper thin film.

[0071] The components of the types and amounts recorded in Table 1 were mixed evenly to obtain the drug solutions of Examples 1-9 and Comparative Example 1. In the examples, 1,2,4-triazole was used as a corrosion inhibitor (B). In the examples, C1 to C3 listed below were used as surfactants (C). In the examples and comparative examples, hydroxyethylidene diphosphonic acid (HEDP) was used as a chelating agent (D). C1: OLFINE EXP4200 (manufactured by Nissin Chemical Industry) C2: SURFYNOL 104 (made by Air Products) C3: SURFYNOL 465 (made by Air Products) In addition, hydrogen peroxide was added to the drug solution as a 31% by mass hydrogen peroxide solution containing 0.56 parts by mass of hydrogen peroxide and 1.24 parts by mass of water. That is, of the amount of water (W) listed in Table 1, 1.24 parts by mass were derived from hydrogen peroxide solution.

[0072] Using the obtained solution, the etching rate, the contact angle of the solution on the surface of the copper film and the surface of the copper-plated mold, and the surface roughness of the copper-plated mold surface after contact with the solution were measured according to the following methods. These measurement results are recorded in Table 2.

[0073] <Measurement of Etching Rate> In the solutions of the various embodiments and comparative examples at approximately 20°C, the subjects were immersed for 200 seconds, and the thickness of the copper thin film and the thickness of the copper-plated mold were measured using a thin-film resistance meter to calculate the etching rate (Å / s).

[0074] <Measurement of the contact angle with the liquid medicine> The object to be treated before contact with the liquid medicine was used as a sample, and the contact angle of the liquid medicine on the surface of the copper thin film and the surface of the copper-plated mold was measured by the above method.

[0075] <Measurement of surface roughness of copper-plated molded objects after contact with the chemical solution> In the solutions of the various embodiments and comparative examples at approximately 20°C, the subjects were immersed for 200 seconds, and then rinsed with ion-exchanged distilled water for 30 seconds. After rinsing, nitrogen gas was blown onto the subjects for 20 seconds to dry them. The dried specimen was used as a measurement sample, and the arithmetic mean height Ra, root mean square height Rq, and Z range of the copper-plated model surface were measured using atomic force microscopy (AFM).

[0076]

[0077]

[0078] As can be seen from Tables 1 and 2, if the solution of the embodiment containing an oxidizing substance (A) containing an oxyacid (Ala) and a peroxide (Alb) and containing water (W), and containing acetic acid as an oxyacid (Ala), is used to etch a silicon substrate with a titanium film, a copper film formed by physical vapor deposition, and a copper-plated molded object stacked sequentially, it is possible to effectively etch the copper film while preventing excessive etching of the copper-plated molded object. On the other hand, as can be seen from Tables 1 and 2, when using a solution containing an oxidizing agent (A) containing oxyacid (A1a) and peroxide (A1b) and water (W) but not acetic acid, the copper-plated shapes were extensively etched.

Claims

1. A solution for use in etching a workpiece formed by sequentially stacking a substrate, a copper thin film, and a copper-plated mold in the thickness direction of the substrate, characterized in that the solution comprises an oxidizing agent (A) and water (W), the oxidizing agent (A) comprises a combination of an oxyacid (A1a) and a peroxide (A1b) or comprises a peracid (A2), the oxidizing agent (A) comprises at least one of acetic acid as the oxyacid (A1a) and peracetic acid as the peracid (A2), the copper thin film covers at least a portion of the main surface of the substrate, the copper thin film is a film formed by a method other than plating, the copper-plated mold is a mold formed by plating the copper thin film as a seed layer, and the ratio ER2 / ER1 of the etching rate ER1 of the copper-plated mold to the etching rate ER2 of the copper thin film is 2.5 or more.

2. The liquid in claim 1 also contains a corrosion inhibitor (B).

3. The solution, as requested in item 1 or 2, also contains a surfactant (C).

4. As in claim 1 or 2, the aforementioned oxyacid (A1a) contains phosphoric acid.

5. For the pharmaceutical solution requested in item 1 or 2, the aforementioned superacid (A2) includes superphosphate.

6. The contact angle of the solution with the copper-plated object surface when it is not in contact with the solution is less than 100˚, as claimed in claim 1 or 2.

7. The pharmaceutical solution of claim 1 or 2 is a two-liquid type pharmaceutical solution consisting of a first liquid containing the aforementioned acetic acid (Ala) and water (W) as the aforementioned oxyacid (Alb), and a second liquid containing the aforementioned peroxide (Alb).

8. A method for manufacturing a substrate having a copper-plated shape, characterized in that it includes: The step of forming a copper thin film on a substrate; The step of forming a plating mold on the aforementioned copper thin film; The steps include: copper plating on the substrate having the aforementioned mold, and forming a copper-plated shape within the aforementioned mold; peeling off the aforementioned mold after the formation of the aforementioned copper-plated shape; and etching the aforementioned copper film using the solutions of claims 1 to 7 after the peeling off of the aforementioned mold.

9. The method for manufacturing a substrate with a copper-plated shape as described in claim 8, wherein the copper thin film is formed on the substrate by physical vapor deposition.