CN115404479A - Chemical solution for etching treatment - Google Patents

Abstract

The invention provides a chemical solution for etching treatment, which can well etch a copper thin film as a seed layer and prevent excessive etching of a copper-plated shaped object, and provides a method for manufacturing a substrate with the copper-plated shaped object, which comprises etching by using the chemical solution. An oxidizing substance (A) and water (W) are contained in a chemical solution for etching a target object obtained by stacking a substrate, a copper thin film formed by a method other than plating, and a copper-plated shaped object in this order in the thickness direction of the substrate, a combination of an oxoacid (A1 a) and a peroxide (A1 b) or a peracid (A2) is used as the oxidizing substance (A), and at least one of acetic acid as the oxoacid (A1 a) and peracetic acid as the peracid (A2) is contained in the oxidizing substance (A).

Description

Chemical solution for etching

technical field

The present invention relates to a chemical solution used for etching a target object obtained by sequentially stacking a substrate, a copper thin film, and a copper-plated molded object in the thickness direction of the substrate, and a substrate equipped with a copper-plated molded object using the chemical solution. Manufacturing method.

Background technique

In response to the increase in functionality and miniaturization of semiconductor devices, flip-chip mounting is widely used as a method of mounting and bonding semiconductor devices on a substrate. In flip chip mounting, a plurality of electrodes (bumps) through which a semiconductor device is connected to the substrate are formed on a seed layer mainly composed of copper on a substrate.

As a method of manufacturing a wiring board with bumps applicable to flip-chip mounting, a method has been proposed in which a resist is provided as a mold for electrode formation on a seed layer on a substrate formed by electroless plating. After filming, the substrate is electroplated to form stud bumps made of copper in the mold, and then the resist film is removed and the seed layer exposed on the substrate surface is removed by etching (refer to Patent Document 1).

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2018-157051

Contents of the invention

The technical problem to be solved by the invention

However, in Patent Document 1, the removal of the copper thin film as the seed layer by etching after removal of the plating mold has not been sufficiently studied. In the method described in Patent Document 1, if the seed layer is etched by a conventionally known method, not only the copper thin film as the seed layer, but also copper-plated molded objects such as copper terminals formed by plating will be damaged. heavily etched.

The present invention has been accomplished in view of the above-mentioned circumstances, and its object is to provide a chemical solution for etching that can properly etch a copper thin film as a seed layer while preventing excessive etching of copper-plated objects and providing A method of manufacturing a substrate having a copper-plated molded object, including etching using the chemical solution.

A solution to the above technical problems

The inventors of the present invention have found that the above-mentioned technical problems can be solved by making the oxidizing substance (A) and water (W) contained in the substrate, the copper thin film formed by a method other than plating, and the copper-plated molded object in sequence. In the chemical solution for the etching treatment of the object to be processed stacked in the thickness direction of the substrate, as the oxidizing substance (A), a combination of an oxyacid (A1a) and a peroxide (A1b) or a peracid (A2 ), and at least one of acetic acid as oxyacid (A1a) and peracetic acid as peracid (A2) is contained in oxidizing substance (A), and the present invention has been completed.

A first aspect of the present invention is a chemical solution used for etching treatment of an object to be processed obtained by sequentially stacking a substrate, a copper thin film, and a copper-plated molded object in the thickness direction of the substrate,

The liquid medicine contains oxidizing substances (A) and water (W),

The oxidizing substance (A) comprises a combination of an oxoacid (A1a) and a peroxide (A1b) or comprises a peracid (A2),

The oxidizing substance (A) contains 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 part of the main surface of the substrate,

Copper thin film is a film formed by methods other than plating,

The copper-plated molded object is a molded object formed by plating with a copper thin film as a seed layer.

The second solution of the present invention is a method of manufacturing a substrate with a copper-plated molded object, comprising:

A process of forming a copper thin film on a substrate;

The process of forming a mold for plating on a copper film;

A process of performing copper plating on a substrate with a mold and forming a copper-plated shape in the mold;

After the formation of the copper-plated shape, the process of stripping the mold;

After the mold is peeled off, the copper thin film is etched using the chemical solution of the first aspect.

Invention effect

According to the present invention, it is possible to provide a chemical solution for etching that can properly etch a copper thin film as a seed layer while preventing excessive etching of a copper-plated object, and to provide a chemical solution comprising the use of the chemical solution. Method for manufacturing etched substrates with copper-plated moldings.

Detailed ways

Hereinafter, the embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments at all, and can be implemented with appropriate changes within the scope of the purpose of the present invention.

"Liquid"

The chemical solution is used for etching treatment of a target object obtained by stacking a substrate, a copper thin film, and a copper-plated molded object sequentially in the thickness direction of the substrate.

The copper thin film covers at least a part of the main surface of the substrate. The copper thin film is a film formed by a method other than plating. The copper-plated molded object is a molded object formed by plating using the copper thin film as a seed layer.

By etching the object to be processed with a chemical solution described later, it is possible to etch only a small amount of copper-plated molded objects, while etching a large amount of desired copper thin films formed by methods other than plating.

The liquid medicine contains an oxidizing substance (A) and water (W).

The oxidizing substance (A) comprises a combination of an oxyacid (A1a) and a peroxide (A1b) or a peracid (A2). In addition, the oxidizing substance (A) contains at least one of acetic acid which is the oxyacid (A1a) and peracetic acid which is the peracid (A2).

In addition, the chemical solution may contain an optional component such as a corrosion inhibitor (B) or a surfactant (C).

The chemical solution may be a single-component composition containing the oxidizing substance (A) and water (W) and optional components as necessary. In addition, the medicinal liquid may be a multi-liquid type composition composed of two or more liquids with different compositions.

As an example of the case where the medicinal liquid is a multi-liquid type composition, it may be mentioned:

1) A chemical solution composed of a first liquid containing an oxidizing substance (A) and water (W) and a second liquid containing an anticorrosive agent (B);

2) A chemical liquid composed of a first liquid containing an oxidizing substance (A) and water (W) and a second liquid containing a surfactant (C);

3) A chemical solution composed of a first liquid containing an oxidizing substance (A) and water (W), and a second liquid containing an anticorrosion agent (B) and a surfactant (C);

4) A medicinal liquid composed of a first liquid containing an oxyacid (A1a) and water (W) and a second liquid containing a peroxide (A1b);

5) A chemical solution composed of a first liquid containing acetic acid as an oxyacid (A1a) and water (W), and a second liquid containing a peroxide (A1b);

6) From the first liquid containing acetic acid as the oxyacid (A1a) and water (W), the second liquid containing an oxyacid other than acetic acid as the oxyacid (A1a) and water (W), and the liquid containing The liquid medicine composed of the third liquid of peroxide (A1b);

7) A chemical solution composed of a first liquid containing an oxyacid (A1a) and water (W), a second liquid containing a peroxide (A1b), and a third liquid containing an anticorrosion agent (B);

8) A medical solution composed of a first liquid containing an oxyacid (A1a) and water (W), a second liquid containing a peroxide (A1b), and a third liquid containing a surfactant (C);

9) From the first liquid containing oxyacid (A1a) and water (W), the second liquid containing peroxide (A1b), and the third liquid containing anticorrosion agent (B) and surfactant (C) the composition of the medicinal solution;

10) A chemical solution composed of a first liquid containing acetic acid as an oxyacid (A1a) and water (W), a second liquid containing a peroxide (A1b), and a third liquid containing an anticorrosion agent (B) ;

11) A medicine consisting of a first liquid containing acetic acid as an oxyacid (A1a) and water (W), a second liquid containing a peroxide (A1b), and a third liquid containing a surfactant (C). liquid;

12) Comprising a first liquid containing acetic acid as an oxyacid (A1a) and water (W), a second liquid containing a peroxide (A1b), and a liquid containing an anticorrosion agent (B) and a surfactant (C) The liquid medicine composed of the third liquid;

13) From the first liquid containing acetic acid as the oxyacid (A1a) and water (W), the second liquid containing an oxyacid other than acetic acid as the oxyacid (A1a) and water (W), A chemical solution composed of the third solution of the oxide (A1b) and the fourth solution containing the anticorrosion agent (B);

14) From the first liquid containing acetic acid as the oxyacid (A1a) and water (W), the second liquid containing an oxyacid other than acetic acid as the oxyacid (A1a) and water (W), A chemical solution composed of the third solution of the oxide (A1b) and the fourth solution containing the surfactant (C);

15) From the first liquid containing acetic acid as the oxyacid (A1a) and water (W), the second liquid containing an oxyacid other than acetic acid as the oxyacid (A1a) and water (W), A chemical solution composed of the third solution of the oxide (A1b), and the fourth solution containing the anticorrosion agent (B) and the surfactant (C);

16) A chemical solution composed of a first liquid containing peracid (A2) and water (W) and a second liquid containing anticorrosion agent (B);

17) A medicinal liquid composed of a first liquid containing a peracid (A2) and water (W) and a second liquid containing a surfactant (C);

18) A chemical solution composed of a first liquid containing a peracid (A2) and water (W) and a second liquid containing an anticorrosion agent (B) and a surfactant (C);

19) A chemical solution composed of a first liquid containing peracetic acid as a peracid (A2) and water (W), and a second liquid containing an anticorrosion agent (B);

20) A medical solution composed of a first liquid containing peracetic acid as a peracid (A2) and water (W), and a second liquid containing a surfactant (C);

21) A chemical solution composed of a first liquid containing peracetic acid as a peracid (A2) and water (W), and a second liquid containing an anticorrosion agent (B) and a surfactant (C);

22) From the first solution containing peracetic acid as peracid (A2) and water (W), the second solution containing peracid other than peracetic acid as peracid (A2) and water (W), and the solution containing Chemical liquid composed of the third liquid of corrosive agent (B);

23) From the first liquid containing peracetic acid as peracid (A2) and water (W), the second liquid containing peracid other than peracetic acid as peracid (A2) and water (W), and the surface A liquid medicine composed of the third liquid of the active agent (C);

24) From the first solution containing peracetic acid as peracid (A2) and water (W), the second solution containing peracid other than peracetic acid as peracid (A2) and water (W), and the solution containing Chemical solution composed of the third solution of corrosive agent (B) and surfactant (C).

The drug solution as a multi-component composition is not limited to the examples of 1) to 24) above.

In the example of the chemical solution as a multi-component composition, when the anticorrosion agent (B) and the surfactant (C) are liquid, the anticorrosion agent (B) and/or the surfactant (C) The liquid may also contain no solvent. As a solvent, water (W) can be used. As the solvent, various organic solvents can be used as long as the desired effect is not impaired.

In view of the fact that only a small amount of copper-plated molded objects are etched, and on the other hand, a large amount of copper thin film formed by a method other than plating is etched to a desired degree. The effect is relatively good, and the preparation and use of the chemical solution are relatively easy. The drug solution of the multi-component composition is preferably a drug solution composed of a first liquid containing acetic acid as the oxyacid (A1a) and water (W), and a second liquid containing a peroxide (A1b).

The first solution containing acetic acid and water (W) as the oxyacid (A1a) may contain oxyacids other than acetic acid.

The first liquid containing acetic acid and water (W) as the oxyacid (A1a) and the second liquid containing the peroxide (A1b) may contain an anticorrosion agent (B) and/or a surfactant (C) respectively. .

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

Hereinafter, an object to be processed and essential or optional components contained in the chemical solution used for etching using the chemical solution described above will be described.

<object being processed>

As described above, as an object to be etched by the chemical solution, an object to be processed in which a substrate, a copper thin film, and a copper-plated molded object are sequentially stacked in the thickness direction of the substrate can be used.

The copper thin film covers at least a part of the main surface of the substrate. The copper thin film is a film formed by a method other than plating. A copper-plated molded object is a molded object formed by plating using a thin film as a seed layer.

As the substrate constituting the object to be processed, a substrate suitable for a mounting method such as flip-chip mounting can be used without particular limitation. As the material of the surface covered with the copper thin film described later in the substrate, for example, a metal used as a material of the under bump metal layer conventionally used in combination with the copper thin film can be used. The metal used as the material of the under bump metal layer may, for example, be titanium, a titanium-tungsten alloy, or a titanium-copper alloy. As a material of other layers in the substrate that are in contact with the layer corresponding to the under bump 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 above-mentioned under bump metal layer on at least one main surface can be preferably used.

The copper thin film is formed to cover at least a part of the main surface of the substrate by a method other than plating. As a method of forming a copper thin film, a physical vapor deposition method (PVD method), an ion plating method, a sputtering method, etc. are mentioned. Among these methods, the physical vapor deposition method is preferable because it is easy to form a copper thin film that is easily etched by a chemical solution.

The film thickness of the copper thin film is not particularly limited. The film thickness of the copper thin film is typically preferably from 50 nm to 300 nm, more preferably from 70 nm to 250 nm, still more preferably from 100 nm to 200 nm.

The copper-plated molded object is a molded object formed by plating with a copper thin film as a seed layer. The method of manufacturing the copper-plated molded object is not particularly limited. Typically, after forming a mold having a void corresponding to the shape of the copper-plated molded object at the position where the copper-plated molded object is to be formed on the thin copper film as the seed layer, copper plating is performed on a substrate having the molded object by a known method. , forming a copper-plated shape. In addition, in the void, the copper thin film as the seed layer was exposed.

The method of forming the mold is not particularly limited. Typically, the casting mold can be formed by general photolithography using a photosensitive composition.

The photosensitive composition is not particularly limited as long as it can form a film having durability against a plating solution. The photosensitive composition may be a negative-type composition that is cured by exposure to be insoluble in a developing solution, or may be a positive-type composition that is soluble in a developing solution by exposure.

After performing copper plating as described above, the mold is peeled off from the substrate by a known method corresponding to the type of composition used to form the mold.

The copper-plated molding is typically a bump (electrode) such as a metal post, or copper wiring or copper rewiring. The shape of the copper-plated shape is not particularly limited. In the case of the rewiring layer, the height of the copper-plated shape 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 , the height of the copper-plated molded object in the thickness direction of the substrate is preferably from 10 μm to 300 μm, and more preferably from 20 μm to 70 μm.

<Oxidizing substance (A)>

The oxidizing substance (A) comprises a combination of an oxyacid (A1a) and a peroxide (A1b) or a peracid (A2).

In addition, the oxidizing substance (A) must contain at least one of acetic acid as the oxyacid (A1a) and peracetic acid as the peracid (A2).

By containing the above-mentioned oxidizing substance (A), the chemical solution can etch only a small amount of copper-plated molded objects, and on the other hand, it is possible to etch a large amount of copper thin film formed by a method other than plating to a desired extent.

〔Oxyacid (A1a)〕

As mentioned above, the oxyacid (A1a) must contain acetic acid. The content of acetic acid in the chemical solution is not particularly limited as long as the desired effect is not impaired. The content of acetic acid in the chemical solution is preferably from 0.001% by mass to 5% by mass, more preferably from 0.002% by mass to 2% by mass, still more preferably from 0.003% by mass to 1% by mass, based on the mass of the chemical solution.

In addition, the medicinal solution may be a multi-component type of two or more components as will be described later. When the chemical liquid is a multi-liquid type, the content of acetic acid in the chemical liquid is the ratio of the mass of acetic acid to the total mass of the multiple liquids.

The oxyacid (A1a) may contain only acetic acid, or may contain acetic acid and oxyacids other than acetic acid. In addition, in the specification of this application, an oxyacid (A1a) is an oxyacid other than a peroxide which has -O-O-bond. Examples of oxyacids other than acetic acid include carboxylic acids other than acetic acid, halogenated oxyacids, silicic acid, nitrous acid, nitric acid, phosphorous acid, phosphoric acid, sulfurous acid, sulfuric acid, and sulfonic acids.

In addition, the oxyacid (A1a) is a monobasic acid having one acidic group in the molecule, not a polybasic acid having two or more acidic groups in the molecule.

Specific examples of carboxylic acids other than acetic acid include formic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, benzoic acid, and lactic acid. Specific examples of the halogenated oxyacids include hypochlorous acid, chlorous acid, chloric acid, hypobromous acid, bromous acid, and bromic acid.

Among the above-mentioned oxyacids that can be used together with acetic acid, phosphoric acid (H ₃ PO ₄ ) is preferable in terms of easy etching of copper thin films formed by methods other than plating.

The content of oxyacids other than acetic acid in the chemical solution is not particularly limited as long as the desired effect is not impaired. The content of oxyacids other than acetic acid in the medicinal solution is preferably 0.1 mass % to 10 mass %, more preferably 0.2 mass % to 7 mass %, and still more preferably 0.5 mass % or greater with respect to the mass of the medicinal liquid. Mass% or less.

In addition, the medicinal solution may be a multi-component type of two or more components as will be described later. When the chemical liquid is a multi-liquid type, the content of the oxyacids other than acetic acid in the chemical liquid is the ratio of the mass of the oxyacids other than acetic acid to the total mass of the multiple liquids.

[Peroxide (A1b)]

The peroxide (A1b) is not particularly limited as long as it is a compound having an -O-O- bond. The peroxide may be a compound corresponding to the peracid (A2) described later. In the specification of the present application, when the chemical solution contains the oxyacid (A1a) and also contains the peracid, the chemical solution contains the oxyacid (A1a) and the peracid as the peroxide (A1b).

Specific examples of the peroxide (A1b) include inorganic peroxides such as hydrogen peroxide, lithium peroxide, and potassium peroxide, t-butyl hydroperoxide, cumene hydroperoxide, di-t-butyl peroxide, etc. Oxide, dimethyldioxirane, acetone peroxide, methyl ethyl ketone peroxide and hexamethylene triperoxide diamine and other organic peroxides; persulfuric acid, percarbonic acid, superphosphoric acid, secondary Peracids such as perchloric acid, hypoperbromic acid, hypoperiodic acid, and percarboxylic acid.

Examples of percarboxylic acids include performic acid, perbenzoic acid, and m-chloroperbenzoic acid.

Among the peroxides (A1b) described above, hydrogen peroxide is preferred because it is inexpensive, easy to handle, and easy to etch a copper thin film formed by a method other than plating with a chemical solution.

The content of the peroxide (A1b) in the chemical solution is 5% by mass or less, preferably 1% by mass or less, based on the mass of the entire chemical solution.

[Peracid (A2)]

The chemical solution may also contain peracid (A2) as the oxidizing substance (A). As described above, in the specification of the present application, when the medical solution contains the oxyacid (A1a) and also contains the peracid, the medical solution contains the oxyacid (A1a) and the peracid as the peroxide (A1b). .

In the case where the chemical solution contains a peracid (A2), the chemical solution contains peracetic acid as the peracid (A2). The content of peracetic acid in the chemical solution is not particularly limited as long as the desired effect is not impaired.

The content of peracetic acid in the chemical solution is preferably from 0.001% by mass to 5% by mass, more preferably from 0.002% by mass to 2% by mass, still more preferably from 0.003% by mass to 1% by mass, based on the mass of the chemical solution.

In addition, the medicinal solution may be a multi-component type of two or more components as will be described later. When the chemical liquid is a multi-liquid type, the content of peracetic acid in the chemical liquid is the ratio of the mass of peracetic acid to the total mass of the multiple liquids.

The chemical solution may contain peracetic acid and may contain peracids other than peracetic acid as peracids (A2). As peracids other than peracetic acid, the same compounds as those described for the peroxide (A1b) can be used.

Among peracids other than peracetic acid that can be used together with peracetic acid, superphosphoric acid is preferable in terms of easy etching of a copper thin film formed by a method other than plating.

The content of peracids other than peracetic acid in the chemical solution is not particularly limited as long as the desired effect is not impaired. The content of peracids other than peracetic acid in the chemical liquid 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 the mass of the chemical liquid. Mass% or less.

In addition, the medicinal solution may be a multi-component type of two or more components as will be described later. When the chemical liquid is a multi-liquid type, the content of peracids other than peracetic acid in the chemical liquid is the ratio of the mass of peracids other than peracetic acid to the total mass of the multiple liquids.

〔Corrosion inhibitor (B)〕

The chemical solution may also contain an anticorrosion agent (B). By making the chemical solution contain the anticorrosion agent (B), the copper thin film can be etched while suppressing the increase in the surface roughness of the copper-plated molded object after etching. As the anticorrosion agent (B), compounds known to be used as an anticorrosion agent against copper can be used without particular limitation.

Preferable examples of the corrosion inhibitor (B) include nitrogen-containing compounds selected from 1H-imidazoles, pyrazoles, thiazoles, triazoles, and guanidines. These can be used individually by 1 type or in combination of 2 or more types.

Examples of 1H-imidazoles include 1H-imidazole, 2-methyl-1H-imidazole, 2-ethyl-1H-imidazole, 2-isopropyl-1H-imidazole, 2-propyl-1H-imidazole, 2-butyl-1H-imidazole, 4-methyl-1H-imidazole, 2,4-dimethyl-1H-imidazole, 2-ethyl-4-methyl-1H-imidazole, 2-amino-1H- Imidazole, 1H-benzimidazole-2-thiol (2-mercaptobenzimidazole), etc.

Examples of pyrazoles include 3,5-dimethylpyrazole, 3-methyl-5-pyrazolone, 3-amino-5-methylpyrazole, 3-amino-5-hydroxypyrazole, 3-amino-5-methylpyrazole, etc.

The thiazoles may, for example, be 2-aminothiazole, 4,5-dimethylthiazole, 2-amino-2-thiazoline, 2,4-dimethylthiazole or 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-triazole Azolo[1,5-a]pyrimidine, 1,2,3-triazolo[4,5-b]pyridine, benzotriazole, 5-methylbenzotriazole and the like.

The guanidines may, for example, be guanidine, 1,3-diphenylguanidine or 1-(o-tolyl)biguanide.

The content of the corrosion inhibitor (B) in the chemical solution is not particularly limited within the range that does not impair the desired effect. The preferred range of the content of the anticorrosion agent (B) in the chemical 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 relative to the mass of the chemical solution The above is 1% by mass or less.

〔Surfactant (C)〕

By including the surfactant (C) in the chemical solution, the wettability of the chemical solution to materials constituting the object to be treated such as a copper-plated molded object can be improved. As a result, even when the copper thin film is located in the vicinity of the lower portion of a plurality of copper-plated shapes that are adjacent to each other in a very close position, the chemical solution can well penetrate into the gap between the copper-plated shapes, and it can be favorably etched copper film.

The surfactant (C) is not particularly limited, and conventionally known surfactants can be used. Any of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants can be used as the surfactant (C).

As the nonionic surfactant, for example, an alkylene oxide adduct of a diol having a carbon-carbon triple bond or an alkylene oxide adduct of a monoalcohol having a carbon-carbon triple bond is preferable.

As the alkylene oxide adduct of diol having a carbon-carbon triple bond, for example, a nonionic surfactant represented by the following formula (c-1) is preferable.

HO-(R ^c6 -O) _n1 -CR ^c3 R ^c4 -C≡C-CR ^c1 R ^c2 -(OR ^c5 ) _n2 -OH…(c-1)

In formula (c-1), R ^c1 to R ^c4 are each independently a linear or branched alkyl group having 1 to 6 carbon atoms. R ^c5 and R ^c6 are each independently a linear or branched alkylene chain having 2 or more and 4 or less carbon atoms. n1 and n2 are each independently an integer of 0 to 30.

R ^c1 to R ^c4 are preferably methyl, ethyl and isopropyl. R ^c5 and R ^c6 are preferably ethane-1,2-diyl (ethylene), propane-1,3-diyl, propane-1,2-diyl and butane-1,4-diyl base. As n1 and n2, it is preferable that it is an integer of 0-16.

Specific examples of alkylene oxide adducts of diols having a carbon-carbon triple bond and alkylene oxide adducts of monoalcohols having a carbon-carbon triple bond include OLFINE EXP4200 manufactured by Nissin Chemical Industry Co., Ltd. , SURFYNOL104E, SURFYNOL104H, SURFYNOL104A, SURFYNOL104PA and SURFYNOL104PG-50 manufactured by Air Products, respectively, and SURFYNOL420, SURFYNOL445, SURFYNOL465 and SURFYNOL485 manufactured by Air Products, etc. SURFYNOL4000000NOL. Among these, "SURFYNOL400 series" is preferable.

As an anionic surfactant, the anionic surfactant represented by following formula (c-2), for example is mentioned.

R ^c7 -SO ₃ H...(c-2)

In formula (c-2), R ^c7 is a linear or branched alkyl group having 7 to 20 carbon atoms. The alkyl group may have a hydroxyl group and/or a carboxyl group, and may be interrupted by a phenylene group and/or an oxygen atom.

R ^c7 is preferably a linear or branched alkyl group having 8 to 11 carbon atoms.

Specific examples of the anionic surfactant represented by the formula (c-2) include n-octanesulfonic acid, n-nonanesulfonic acid, n-decanesulfonic acid, and n-undecanesulfonic acid. Among them, n-octanesulfonic acid, n-nonanesulfonic acid, and n-decanesulfonic acid are preferable.

The content of the surfactant (C) in the drug solution is not particularly limited within the range that does not impair the desired effect. The preferred range of the content of the surfactant (C) in the drug 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 relative to the mass of the drug solution. % to 1% by mass.

〔Chelating agent (D)〕

The drug solution may also contain a chelating agent (D). The chelating agent (D) is a compound other than the above-mentioned oxyacid (A1a) which is a monobasic acid having one acidic group in the molecule. The chelating agent (D) contained in the drug solution can stabilize the peroxide (A1b) or peracid (A2) in the drug solution.

Examples of chelating agents include hydroxyethylenediphosphonic acid (HEDP), nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), glutamic acid diacetic acid (CMGA), aminotriacetic acid Methylphosphonic acid (ATMP), ethylenediaminetetramethylenephosphonic acid (EDTMP), phosphonobutanetricarboxylic acid (PBTC), citric acid, succinic acid, oxalic acid, phthalic acid, malic acid, tartaric acid, Ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraaminehexaacetic acid (TTHA) and glycol ether diaminetetraacetic acid (GEDTA), etc.

These chelating agents can be used as salts such as alkali metal salts or ammonium salts.

The content of the chelating agent (D) in the drug solution is not particularly limited within the range that does not impair the desired effect. The preferred range of the content of the chelating agent (D) in the medicinal solution is preferably 0.001 mass % to 10 mass %, more preferably 0.01 mass % to 5 mass %, and even more preferably 0.1 mass % with respect to the mass of the medicinal liquid Above 2% by mass or less.

[Water-soluble organic solvent (O)]

The chemical solution may contain a water-soluble organic solvent (O) within a range that does not impair the desired effect. By making the chemical solution contain the water-soluble organic solvent (O), components that are difficult to dissolve in water (W) can be easily dissolved in the chemical solution.

Specific examples of the water-soluble organic solvent (O) include: sulfolane; hexamethylphosphoric triamide; sulfoxides such as dimethylsulfoxide; dimethylsulfone, diethylsulfone, ethylmethylsulfone, Ethyl isopropyl sulfone, 3-methyl sulfone, bis(2-hydroxyethyl) sulfone, tetramethylene sulfone and other sulfones; N, N-dimethylformamide, N-methylformamide, N , N-dimethylacetamide, N-methylacetamide, N,N-diethylacetamide and other amides; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propane Lactams such as base-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl imidazolinones such as base-2-imidazolinone and 1,3-diisopropyl-2-imidazolinone; alkanols such as methanol, ethanol and isopropanol; ethylene glycol, propylene glycol, 1,2 -Butanediol, 1,3-butanediol, 2,3-butanediol, glycerol, diethylene glycol and other polyols; β-propiolactone, γ-butyrolactone, δ-valerolactone, Lactones such as γ-valerolactone and γ-nonanolide; propylene carbonate; tetrahydrofuran; the above-mentioned lactams, as well as 1-methylimidazole, 1-(3-aminopropyl) imidazole, piperidine, Nitrogen-containing heterocyclic compounds that are liquid at 25° C. under atmospheric pressure, such as 2-oxazolidinone, are not included in the anticorrosion agent (B).

The content of the water-soluble organic solvent (O) in the chemical solution is not particularly limited as long as the desired effect is not impaired. For example, the content of the water-soluble organic solvent (O) in the drug solution is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 10% by mass or less, based on the mass of the drug solution. The medical solution preferably contains only water (W) as a solvent.

[other ingredients]

The chemical solution may contain an antifoaming agent and the like in addition to the above components. The usage-amount of these components considers the usual usage-amount of each component, and is determined suitably.

[Water (W)]

The water (W) is not particularly limited as long as the desired effect is not inhibited, and water of various qualities can be used. As water (W), ion-exchange water, distilled water, ion-exchange distilled water, etc. are preferable, for example, and ion-exchange distilled water is more preferable.

A drug solution is prepared by dissolving desired amounts of essential or optional components of the drug solution described above in water (W).

By using the above-described chemical solution, it is possible to satisfactorily etch the copper thin film as the seed layer and prevent excessive etching of the copper-plated molded object.

More specifically, for the chemical solution described above, it is preferable that the ratio of the etching rate ER1 to the etching rate ER1 on the copper-plated object and the etching rate ER2 on the copper thin film, that is, ER2/ER1, be 2.5 or more, more preferably 2.9 or more, particularly preferably 3.0 above.

The value of the ratio ER2/ER1 tends to increase as the content of acetic acid or peracetic acid in the chemical solution increases.

In addition, 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, further preferably 90° or less, particularly preferably 85° or less. Here, the above-mentioned contact angle is a value measured before the plated molded object comes into contact with the chemical solution.

By making the contact angle of the chemical solution on the surface of the copper-plated molded object satisfy the above-mentioned conditions, even if the copper thin film is located in the vicinity of the lower part of a plurality of copper-plated molded objects adjacent to each other, the chemical solution can It penetrates well into the gap between copper-plated moldings and can etch copper thin films well.

As a method of reducing the contact angle of the above-mentioned chemical solution, a method of containing a surfactant (C) in the chemical solution, a method of adding a water-soluble organic solvent to the chemical solution, and the like may, for example, be mentioned.

Here, the contact angle of the above chemical solution is a static contact angle. The static contact angle of the chemical solution can be determined as, for example, using Dropmaster 700 (manufactured by Kyowa Interface Science Co., Ltd.), after dropping 2.0 μL of the chemical solution on the surface of the copper-plated molded object that has been in contact with the chemical solution, and then dropping it for 5 seconds. The contact angle is measured.

When the chemical solution is in contact with the copper-plated object for 200 seconds, the arithmetic average height Ra of the surface of the copper-plated object measured by an atomic force microscope (AFM) is preferably 35 nm or less, more preferably 30 nm or less, and even more preferably below 20nm.

When the chemical solution is in contact with the copper-plated object for 200 seconds, the root-mean-square height Rq of the surface of the copper-plated object measured by an atomic force microscope (AFM) is preferably 50 nm or less, more preferably 40 nm or less, and further It is preferably 30 nm or less.

When the chemical solution is in contact with the copper-plated object for 200 seconds, the Z range (Z range) of the surface of the copper-plated object measured by an atomic force microscope (AFM) is preferably 500 nm or less, more preferably 400 nm or less, More preferably, it is 300 nm or less. The Z range is the difference between the highest height value and the lowest height value of the height information related to the unevenness of the surface to be measured before the plane fitting process obtained by an atomic force microscope (AFM).

"Manufacturing method of substrate with copper-plated molded object"

The manufacturing method of the substrate with copper-plated moldings includes:

A process of forming a copper thin film on a substrate;

The process of forming a mold for plating on a copper film;

A process of performing copper plating on a substrate with a mold and forming a copper-plated shape in the mold;

After the formation of the copper-plated shape, the process of stripping the mold; and

After the mold is peeled off, the copper thin film is etched using the chemical solution mentioned above.

Regarding the process of forming a copper thin film on a substrate, the process of forming a plating mold on a copper thin film, the process of applying copper plating to a substrate equipped with a mold and forming a copper-plated molded object in the mold, and forming a copper-plated molded object The process of peeling off the mold afterward is as described above for the chemical solution.

In the step of etching the copper thin film using the above-mentioned chemical solution after peeling off the mold, the etching method is not particularly limited as long as the copper thin film can be brought into contact with the above-mentioned chemical solution.

As a method of etching the above-mentioned chemical solution in contact with a substrate, a copper thin film, and a copper-plated molded object sequentially stacked in the thickness direction of the substrate, a spray method, a dipping method, a liquid filling method, etc. can be exemplified. .

In the etching by the spray method, for example, the object to be processed is conveyed or rotated in a predetermined direction, and the etching liquid is sprayed into the space to bring the etching liquid into contact with the object to be processed. If necessary, the etching solution may be sprayed while rotating the object to be processed using a spinner.

In the etching by the immersion method, the object to be processed is immersed in a liquid bath composed of a chemical solution, and the object to be processed is brought into contact with the chemical solution in the liquid bath.

In etching by the liquid filling method, a chemical solution is contained on the surface of an object to be etched, and the object to be processed is brought into contact with the chemical solution.

These etching methods may be appropriately and flexibly used according to the structure and material of the object to be processed.

The time for bringing the chemical solution into contact with the object to be treated is appropriately determined in consideration of the thickness of the copper thin film and the like. The temperature of the chemical solution at the time of etching is not particularly limited as long as the copper-plated molded object is not excessively etched or the substrate is not damaged. The temperature of the chemical solution is typically preferably from 10°C to 40°C, more preferably from 15°C to 30°C.

Example

The following examples are shown to describe the present invention more specifically, but the scope of the present invention is not limited by the following examples.

[Examples 1 to 9 and Comparative Example 1]

In the embodiment and the comparative example, the object to be processed is used, and the object to be processed has: a silicon substrate provided with a titanium thin film on one main surface, and a surface formed by a physical vapor deposition method covering the exposed surface of the titanium thin film in the silicon substrate. A copper thin film with a thickness of 800 nm, and a copper-plated molded object with a thickness of 4 μm covering a part of the copper thin film.

The types and amounts of the components listed in Table 1 were uniformly mixed to obtain the medicinal solutions of Examples 1 to 9 and Comparative Example 1.

In Examples, 1,2,4-triazole was used as the corrosion inhibitor (B). In Examples, the following C1 to C3 were used as surfactants (C). In Examples and Comparative Examples, hydroxyethylene diphosphonic acid (HEDP) was used as the chelating agent (D).

C1: OLFINE EXP4200 (manufactured by Nissin Chemical Industry)

C2: SURFYNOL104 (manufactured by Air Chemicals)

C3: SURFYNOL465 (manufactured by Air Chemicals)

In addition, hydrogen peroxide was added to the chemical solution as hydrogen peroxide water having a concentration of 31% by mass including 0.56 parts by mass of hydrogen peroxide and 1.24 parts by mass of water. That is, in the quantity of the water (W) described in Table 1, 1.24 mass parts originate in hydrogen peroxide water.

Using the chemical solution obtained, the measurement of the etching rate, the measurement of the contact angle of the chemical solution on the surface of the copper thin film and the surface of the copper-plated object, and the contact angle of the copper-plated object surface after contacting the chemical solution were carried out according to the following methods. Measurement of surface roughness. These measurement results are recorded in Table 2.

<Measurement of Etching Rate>

/秒)。After immersing the above-mentioned object to be treated in the chemical solution of each example and comparative example at about 20°C for 200 seconds, the film thickness of the copper thin film and the film thickness of the copper-plated molded object were measured using a sheet resistance meter, and the etching rate was calculated. speed(

/second).

<Measurement of contact angle with chemical solution>

The object to be treated before contact with the chemical solution was used as a sample, and the contact angle of the chemical solution on the surface of the copper thin film and the surface of the copper-plated molded object was measured by the above-mentioned method.

<Measurement of surface roughness of copper-plated molding surface after contact with chemical solution>

After immersing the object to be treated in the chemical solution of each example and comparative example at about 20° C. for 200 seconds, the surface of the object to be treated was rinsed with ion-exchanged distilled water for 30 seconds. After rinsing, nitrogen gas was blown on the object to be processed for 20 seconds to dry the object to be processed.

The processed object after drying was used as a measurement sample, and the arithmetic mean height Ra, the root mean square height Rq, and the Z range of the surface of the copper-plated molded object were measured using an atomic force microscope (AFM).

【Table 1】

【Table 2】

According to Table 1 and Table 2, it can be seen that if the oxidizing substance (A) containing oxyacid (A1a) and peroxide (A1b) contains water (W), and contains acetic acid as oxyacid (A1a), The chemical solution of the embodiment etches the object to be processed obtained by sequentially stacking a silicon substrate having a titanium thin film, a copper thin film formed by physical vapor deposition, and a copper-plated molded object. At the same time, excessive etching of the copper-plated moldings is prevented.

On the other hand, according to Table 1 and Table 2, it can be seen that when using a drug containing an oxidizing substance (A) containing an oxoacid (A1a) and a peroxide (A1b) and containing water (W), but not containing acetic acid, In the case of liquid, copper-plated moldings are largely etched.

Claims (9)

1. A chemical solution used for etching an object to be processed in which a substrate, a copper thin film and a copper-plated molded article are stacked in this order in the thickness direction of the substrate,

the chemical liquid contains an oxidizing substance (A) and water (W),

the oxidizing substance (A) comprises a combination of an oxo acid (A1 a) and a peroxide (A1 b) or comprises a peracid (A2),

the oxidizing substance (A) contains at least one of acetic acid as the oxoacid (A1 a) and peracetic acid as the peracid (A2),

the copper thin film covers at least a part of the main surface of the substrate,

the copper thin film is a film formed by a method other than plating,

the copper-plated shaped article is formed by plating using the copper thin film as a seed layer.

2. The medical solution according to claim 1, further comprising an anticorrosive agent (B).

3. The medical solution according to claim 1 or 2, further comprising a surfactant (C).

4. The medical solution according to claim 1 or 2, wherein the oxo acid (A1 a) comprises phosphoric acid or the peracid (A2) comprises perphosphoric acid.

5. The chemical according to claim 1 or 2, wherein a ratio ER2/ER1 of an etching rate ER1 of the copper-plated shaped article to an etching rate ER2 of the copper thin film is 2.5 or more.

6. The chemical according to claim 1 or 2, wherein a contact angle of the chemical on a surface of the copper-plated shaped article in a state of not being in contact with the chemical is less than 100 °.

7. The chemical solution according to claim 1 or 2, which is prepared from A1 st solution containing the acetic acid as the oxoacid (A1 a) and water (W), and

a2 nd liquid containing the peroxide (A1 b).

8. A method for manufacturing a substrate having a copper-plated shaped object, comprising:

forming a copper thin film on a substrate;

forming a mold for plating on the copper thin film;

a step of plating copper on the substrate provided with the mold and forming a copper-plated molded article in the mold;

a step of peeling off the mold after the formation of the copper-plated molded article;

and a step of etching the copper thin film using the chemical solution according to claims 1 to 7 after the mold is peeled.

9. The method of manufacturing a substrate with a copper-plated shaped article according to claim 8, wherein the copper thin film is formed on the substrate by a physical vapor deposition method.