JP7806403B2 - Manufacturing method for plating objects - Google Patents

Description

The present invention relates to a photosensitive resin composition, a method for producing a resist pattern film, and a method for producing a plated object.

The performance of mobile devices such as smartphones and tablet terminals is improved by packaging semiconductor chips with different functions using high-density packaging technologies such as FO-WLP (Fan-Out Wafer Level Package), FO-PLP (Fan-Out Panel Level Package), TSV (Through Silicon Via), and silicon interposers.

With this type of packaging technology, the wiring and bumps used for electrical connections between semiconductor chips are becoming increasingly dense. Therefore, there is a demand for fine, high-density resist pattern films used to form the wiring and bumps.

Wiring and bumps are typically plated objects, and are produced by applying a photosensitive resin composition to a metal film, such as a copper film, on a substrate having the metal film to form a resist coating, exposing and developing the resist coating using a mask to form a resist pattern film, and then plating the substrate using the resist pattern film as a mold (see Patent Documents 1 and 2).

JP 2010-008972 A Japanese Patent Application Laid-Open No. 2006-330368

The resulting plated object must have the following characteristics: The shape of the template pattern must be faithfully transferred, and it must be faithful to the mask dimensions.

Conventionally, chemically amplified positive-tone radiation-sensitive resin compositions containing a polymer with acid-dissociable functional groups that dissociate in the presence of acid to generate acidic functional groups, a component that generates acid upon exposure to radiation, and other additives have been widely used as resists for bump processing. Resists made from these compositions have excellent sensitivity and resolution.

However, when the above-mentioned chemically amplified positive-tone radiation-sensitive resin composition is exposed to amines present in the environment after exposure, the cross-sectional shape of the formed pattern tends to become a T-top shape as shown in Figure 1. In such cases, the pattern width and spacing are measured from the top surface of the pattern, so the measured pattern width and spacing tend to be estimated to be larger than the actual pattern width and spacing. As the impact of this issue has become greater due to shrinking processing dimensions, improvements are being called for.

The objective of the present invention is to provide a photosensitive resin composition and a pattern formation method that can improve the T-top shape caused by the influence of amines present in the environment in which the photosensitive resin composition is used, and that can obtain accurate pattern dimensions even when measured from the top surface of the pattern. Furthermore, the objective is to provide a method for manufacturing a plated object with designed pattern dimensions using the pattern obtained by the pattern formation method as a mold.

The inventors conducted research to solve the above-mentioned problems. As a result, they discovered that the above-mentioned problems could be solved by a photosensitive resin composition having the following configuration, and thus completed the present invention. Specifically, the present invention relates to, for example, the following [1] to [7].

[1] A composition comprising a polymer (A) having an acid-dissociable group, a photoacid generator (B), and a surfactant (C),
A photosensitive resin composition, characterized in that the surfactant (C) is a fluorine-based or silicon-based surfactant that satisfies the following condition (i), and is contained in an amount of 0.5 to 6 parts by mass per 100 parts by mass of the polymer (A):
Condition (i): The absorbance of a 0.1% by mass aqueous solution of the surfactant at a wavelength of 300 nm with an optical path length of 10 mm measured using an ultraviolet-visible-near infrared spectrophotometer is 0.30 or less.

[2] The photosensitive resin composition according to item [1], wherein the surfactant (C) has a weight average molecular weight of 8,000 or more.
[3] The photosensitive resin composition according to item [1] or [2], further comprising a sulfur-containing compound (D) having at least one structure selected from a mercapto group, a sulfide bond, and a polysulfide bond.
[4] The photosensitive resin composition according to any one of items [1] to [3], further comprising a novolak resin (E).

[5] A step (1) of forming a resin film of the photosensitive resin composition according to any one of items [1] to [4] on the metal film of a substrate having a metal film;
a step (2) of exposing the resin film to light;
(3) a step of developing the resin film after exposure;
A method for producing a resist pattern film, comprising:

[6] A method for producing a plated object, comprising the step (5) of performing a plating process using the resist pattern film produced by the method according to item [5] as a mold.
[7] The method for producing a plated object according to item [6], further comprising a step (4) of performing a plasma treatment with an oxygen-containing gas before the step (5).

The present invention provides a photosensitive resin composition that improves the T-top shape and allows accurate pattern dimensions to be obtained even when measured from the top surface of the pattern, a method for producing a resist pattern film using the photosensitive resin composition, and a method for producing a plated object using the resist pattern film.

FIG. 1 is a schematic diagram showing an example of the cross-sectional shape (T-top shape) of a pattern formed from a positive-type radiation-sensitive resin composition. FIG. 2 is a schematic diagram showing an example of the cross-sectional shape (T-top shape) of a pattern formed from a positive-type radiation-sensitive resin composition. FIG. 3 is a schematic diagram showing an example of the cross-sectional shape (T-top shape) of a pattern formed from a positive-type radiation-sensitive resin composition. FIG. 4 is a schematic diagram showing an example of the cross-sectional shape (T-top shape) of a pattern formed from a positive-type radiation-sensitive resin composition.

Unless otherwise specified, each of the components exemplified herein, such as each component in the photosensitive resin composition and each structural unit in the polymer (A), may be contained alone or in combination of two or more types.

[Photosensitive resin composition]
The photosensitive resin composition of the present invention (hereinafter also referred to as "the composition") contains a polymer (A) having an acid-dissociable group (hereinafter also referred to as "polymer (A)"), a photoacid generator (B), and a surfactant (C) described below. The composition preferably further contains a sulfur-containing compound (D) (hereinafter also referred to simply as "compound (D)") having at least one structure selected from a mercapto group, a sulfide bond, and a polysulfide bond, and a novolak resin (E).

<Polymer (A)>
The polymer (A) has an acid-dissociable group.
The acid-dissociable group is a group that can be dissociated by the action of an acid generated from the photoacid generator (B). As a result of the dissociation, acidic functional groups such as carboxyl groups and phenolic hydroxyl groups are generated in the polymer (A). As a result, the solubility of the polymer (A) in an alkaline developer changes, and the composition can form a resist pattern film.

Polymer (A) has an acidic functional group protected by an acid-dissociable group. Examples of the acidic functional group include a carboxy group and a phenolic hydroxyl group. Examples of polymer (A) include a (meth)acrylic resin in which the carboxy group is protected by an acid-dissociable group, and a polyhydroxystyrene resin in which the phenolic hydroxyl group is protected by an acid-dissociable group.

The weight-average molecular weight (Mw) of polymer (A) measured by gel permeation chromatography in terms of polystyrene is typically 1,000 to 500,000, preferably 3,000 to 300,000, more preferably 10,000 to 100,000, and even more preferably 20,000 to 60,000.

The ratio (Mw/Mn) of the Mw of polymer (A) to the polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography is typically 1 to 5, preferably 1 to 3.

The present composition may contain one or more polymers (A).
The content of the polymer (A) in the composition is usually 70 to 99.5 mass%, preferably 80 to 99 mass%, and more preferably 90 to 98 mass%, based on 100 mass% of the solid content of the composition. The solid content refers to all components other than the organic solvent described below.

<Structural unit (a1)>
The polymer (A) usually has a structural unit (a1) having an acid-dissociable group.
Examples of the structural unit (a1) include a structural unit represented by formula (a1-10) and a structural unit represented by formula (a1-20), and the structural unit represented by formula (a1-10) is preferred.

The meanings of the symbols in formulae (a1-10) and (a1-20) are as follows:
R ¹¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group in which at least one hydrogen atom in the alkyl group is substituted with another group such as a halogen atom such as a fluorine atom or a bromine atom, an aryl group such as a phenyl group, a hydroxyl group, or an alkoxy group (hereinafter also referred to as a "substituted alkyl group").

R ¹² is a divalent organic group having 1 to 10 carbon atoms.
Ar is an arylene group having 6 to 10 carbon atoms.
R ¹³ is an acid-dissociable group.

m is an integer of 0 to 10, preferably 0 to 5, and more preferably 0 to 3.
Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a pentyl group, and a decyl group.

Examples of the divalent organic group having 1 to 10 carbon atoms include alkanediyl groups having 1 to 10 carbon atoms, such as methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, and decane-1,10-diyl; and groups in which at least one hydrogen atom in the alkanediyl group has been substituted with another group, such as a halogen atom such as a fluorine atom or a bromine atom, an aryl group such as a phenyl group, a hydroxyl group, or an alkoxy group.

Examples of the arylene group having 6 to 10 carbon atoms include a phenylene group, a methylphenylene group, and a naphthylene group.

The acid-dissociable group includes a group that dissociates under the action of an acid and, as a result of the dissociation, generates an acidic functional group such as a carboxy group or a phenolic hydroxyl group in the polymer (A). Specific examples include the acid-dissociable group shown in formula (g1) and a benzyl group, with the acid-dissociable group shown in formula (g1) being preferred.

In formula (g1), R ^a1 to R ^a3 each independently represent an alkyl group, an alicyclic hydrocarbon group, or a group in which at least one hydrogen atom in the alkyl group or the alicyclic hydrocarbon group has been substituted with another group such as a halogen atom such as a fluorine atom or a bromine atom, an aryl group such as a phenyl group, a hydroxyl group, or an alkoxy group, and R ^a1 and R ^a2 may be bonded to each other to form an alicyclic structure together with the carbon atom C to which R ^a1 and R ^a2 are bonded.

Examples of the alkyl group of R ^a1 to R ^a3 include alkyl groups having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a pentyl group, and a decyl group.

Examples of the alicyclic hydrocarbon groups of R ^a1 to R ^a3 include monocyclic saturated cyclic hydrocarbon groups such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; monocyclic unsaturated cyclic hydrocarbon groups such as a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group; and polycyclic saturated cyclic hydrocarbon groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group, and a tetracyclododecyl group.

Examples of the alicyclic structure formed by R ^a1 , R ^a2 and the carbon atom C include monocyclic saturated cyclic hydrocarbon structures such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; monocyclic unsaturated cyclic hydrocarbon structures such as cyclobutenyl, cyclopentenyl, and cyclohexenyl; and polycyclic saturated cyclic hydrocarbon structures such as norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl.

As the acid-dissociable group represented by formula (g1), groups represented by formulas (g11) to (g15) are preferred.

In formulas (g11) to (g15), R ^a4 is independently an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, or an n-butyl group, and n is an integer from 1 to 4. Each ring structure in formulas (g11) to (g14) may have one or more substituents, such as an alkyl group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom or a bromine atom, a hydroxyl group, or an alkoxy group. * indicates a bond.

In addition to the structural units shown in formulae (a1-10) and (a1-20), examples of the structural unit (a1) include structural units having an acetal-based acid-dissociable group described in JP-A Nos. 2005-208366, 2000-194127, U.S. Pat. No. 6,444,394, and U.S. Pat. No. 2006/0210913; structural units having a sultone ring described in U.S. Pat. No. 2013/0095425; and structural units having a crosslinked acid-dissociable group described in JP-A Nos. 2000-214587 and U.S. Pat. No. 6,156,481, etc.

The structural units described in the above publications are intended to be as described in this specification.
The polymer (A) can have one or more types of structural units (a1).
The content of the structural unit (a1) in the polymer (A) is usually 10 to 50 mol %, preferably 15 to 45 mol %, and more preferably 20 to 40 mol %.

In this specification, the content of each structural unit in polymer (A) is a value when the total of all structural units constituting polymer (A) is taken as 100 mol %. Each of the structural units is usually derived from a monomer used in synthesizing polymer (A). The content of each structural unit can be measured by ^1H -NMR.

In one embodiment, polymer (A) preferably has, as the structural unit (a1), a structural unit represented by formula (a1-10) in which R ¹¹ is a hydrogen atom, and a structural unit represented by formula (a1-10) in which R ¹¹ is an alkyl group or substituted alkyl group having 1 to 10 carbon atoms. In this embodiment, the resolution of the composition can be further improved, and the swelling resistance and cracking resistance of the resist pattern film to a plating solution tend to be further improved.

<Structural unit (a2)>
The polymer (A) may further include a structural unit (a2) having a group that promotes solubility in an alkaline developer (hereinafter also referred to as a "solubility-promoting group"). The polymer (A) may include the structural unit (a2), which allows adjustment of the lithographic properties, such as the resolution, sensitivity, and depth of focus, of a resin film formed from the composition.

Examples of structural unit (a2) include structural units having at least one group or structure selected from a carboxy group, a phenolic hydroxyl group, an alcoholic hydroxyl group, a lactone structure, a cyclic carbonate structure, a sultone structure, and a fluoroalcohol structure (excluding those corresponding to structural unit (a1)). Among these, structural units having a phenolic hydroxyl group are preferred, as they are capable of forming a resist pattern film that is resistant to indentation from the plating during the formation of a plated object.

Examples of structural units having a carboxy group include structural units derived from monomers such as (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, cinnamic acid, 2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, and 3-carboxypropyl (meth)acrylate, as well as structural units described in JP-A-2002-341539.

Examples of structural units having a phenolic hydroxyl group include structural units derived from monomers having a hydroxyaryl group, such as 2-hydroxystyrene, 4-hydroxystyrene, 4-isopropenylphenol, 4-hydroxy-1-vinylnaphthalene, 4-hydroxy-2-vinylnaphthalene, and 4-hydroxyphenyl (meth)acrylate. Examples of hydroxyaryl groups include hydroxyphenyl groups such as hydroxyphenyl, methylhydroxyphenyl, dimethylhydroxyphenyl, dichlorohydroxyphenyl, trihydroxyphenyl, and tetrahydroxyphenyl; and hydroxynaphthyl groups such as hydroxynaphthyl and dihydroxynaphthyl.

Examples of structural units having an alcoholic hydroxyl group include structural units derived from monomers such as 2-hydroxyethyl (meth)acrylate and 3-(meth)acryloyloxy-4-hydroxytetrahydrofuran, as well as structural units described in JP 2009-276607 A.

Examples of structural units having a lactone structure include those described in JP 2017-058421 A, US 2010/0316954 A, JP 2010-138330 A, US 2005/0287473 A, JP 2016-098350 A, and US 2015/0323865 A.

Examples of structural units having a cyclic carbonate structure include those described in JP-A-2017-058421, JP-A-2009-223294, and JP-A-2017-044875.

Examples of structural units having a sultone structure include those described in JP 2017-058421 A, JP 2014-029518 A, US 2016/0085149 A, and JP 2013-007846 A.

Examples of structural units having a fluorine alcohol structure include those described in US 2004/0106755, US 2003/0031952, US 2004/0144752, and JP 2005-133066 A.

The structural units described in the above publications are intended to be as described in this specification.
The polymer (A) can have one or more types of structural units (a2).
The content of the structural unit (a2) in the polymer (A) is usually 10 to 80 mol %, preferably 20 to 65 mol %, and more preferably 25 to 60 mol %. When the content of the structural unit (a2) is within this range, the dissolution rate in an alkaline developer can be increased, and as a result, the resolution of the present composition in a thick film can be improved.

Polymer (A) can contain structural unit (a2) in the same or a different polymer as the polymer containing structural unit (a1), but it is preferable for structural units (a1) and (a2) to be contained in the same polymer.

<Structural unit (a3)>
The polymer (A) may further have a structural unit (a3) other than the structural units (a1) and (a2).

Examples of the structural unit (a3) include:
Structural units derived from vinyl compounds such as styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, and 4-methoxystyrene;
Structural units derived from aliphatic (meth)acrylate compounds, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, lauroxytetraethylene glycol (meth)acrylate, lauroxydipropylene glycol (meth)acrylate, and lauroxytripropylene glycol (meth)acrylate;
Structural units derived from alicyclic (meth)acrylic acid ester compounds, such as cyclopentyl (meth)acrylate, norbornyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, tetrahydrofuranyl (meth)acrylate, and tetrahydropyranyl (meth)acrylate;
Structural units derived from aromatic ring-containing (meth)acrylic acid ester compounds such as phenyl (meth)acrylate and phenethyl (meth)acrylate;
Structural units derived from unsaturated nitrile compounds such as (meth)acrylonitrile, crotononitrile, maleonitrile, and fumaronitrile;
Structural units derived from unsaturated amide compounds such as (meth)acrylamide and N,N-dimethyl(meth)acrylamide;
Structural units derived from unsaturated imide compounds such as maleimide, N-phenylmaleimide, and N-cyclohexylmaleimide;
Examples include:

The polymer (A) can have one or more types of structural units (a3).
The content of the structural unit (a3) in the polymer (A) is usually 40 mol % or less.
The polymer (A) may contain the structural unit (a3) in the same or different polymer as the polymer containing the structural unit (a1) and/or the structural unit (a2), but it is preferable that the structural units (a1) to (a3) are contained in the same polymer.

<Method for producing polymer (A)>
The polymer (A) can be produced by subjecting monomers corresponding to the respective structural units to a known polymerization method such as ionic polymerization or radical polymerization in an appropriate polymerization solvent. Of these, radical polymerization is preferred.

Examples of radical polymerization initiators used in the radical polymerization method include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(methyl isobutyrate), and 2,2'-azobis-(2,4-dimethylvaleronitrile); and organic peroxides such as benzoyl peroxide, lauryl peroxide, and t-butyl peroxide.

Furthermore, molecular weight regulators such as mercaptan compounds and halogenated hydrocarbons can be used during polymerization, if necessary.

<Photoacid Generator (B)>
The photoacid generator (B) is a compound that generates an acid upon exposure. The action of this acid dissociates the acid-dissociable groups in the polymer (A), generating acidic functional groups such as carboxyl groups and phenolic hydroxyl groups. As a result, the exposed areas of the resin film formed from this composition become readily soluble in an alkaline developer, allowing the formation of a positive resist pattern film. Thus, this composition functions as a chemically amplified positive photosensitive resin composition.

Examples of the photoacid generator (B) include compounds described in JP 2004-317907 A, JP 2014-157252 A, US 2003/0008241 A, JP 2017-102260 A, JP 2016-018075 A, and US 2016/0320698 A. These are incorporated herein by reference.

Specific examples of the photoacid generator (B) include:
Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium tetrafluoroborate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, 4-t-butylphenyl diphenylsulfonium trifluoromethanesulfonate, 4-t- Onium salt compounds such as butylphenyl diphenylsulfonium benzenesulfonate, 4,7-di-n-butoxynaphthyltetrahydrothiophenium trifluoromethanesulfonate, 4,7-di-n-butoxynaphthyltetrahydrothiophenium bis(trifluoromethanesulfonyl)imide anion, 4,7-di-n-butoxynaphthyltetrahydrothiophenium bis(nonafluorobutylsulfonyl)imide anion, and 4,7-di-n-butoxynaphthyltetrahydrothiophenium tris(nonafluorobutylsulfonyl)methide;
Halogen-containing compounds such as 1,10-dibromo-n-decane, 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane, phenyl-bis(trichloromethyl)-s-triazine, 4-methoxyphenyl-bis(trichloromethyl)-s-triazine, styryl-bis(trichloromethyl)-s-triazine, and naphthyl-bis(trichloromethyl)-s-triazine;
Sulfone compounds such as 4-trisphenacylsulfone, mesitylphenacylsulfone, and bis(phenylsulfonyl)methane;
sulfonic acid compounds such as benzoin tosylate, pyrogallol tristrifluoromethanesulfonate, o-nitrobenzyl trifluoromethanesulfonate, and o-nitrobenzyl-p-toluenesulfonate;
sulfonimide compounds such as N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)-4-butyl-naphthylimide, N-(trifluoromethylsulfonyloxy)-4-propylthio-naphthylimide, N-(4-methylphenylsulfonyloxy)succinimide, N-(4-methylphenylsulfonyloxy)phthalimide, N-(4-methylphenylsulfonyloxy)diphenylmaleimide, N-(4-methylphenylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(4-fluorophenylsulfonyloxy)bicyclo[2.1.1]heptane-5,6-oxy-2,3-dicarboximide, N-(4-fluorophenylsulfonyloxy)naphthylimide, and N-(10-camphorsulfonyloxy)naphthylimide;
Diazomethane compounds such as bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, cyclohexylsulfonyl-1,1-dimethylethylsulfonyldiazomethane, and bis(1,1-dimethylethylsulfonyl)diazomethane;
Examples include:

Among these, onium salt compounds and/or sulfonimide compounds are preferred because they are capable of forming a resist pattern film that has excellent resolution and plating solution resistance.
The present composition may contain one or more photoacid generators (B).

The content of photoacid generator (B) in the composition is typically 0.1 to 20 parts by mass, preferably 0.3 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of polymer (A). When the content of photoacid generator (B) is within this range, a resist pattern film with superior resolution tends to be obtained.

<Surfactant (C)>
The surfactant (C) is a fluorine-based or silicon-based surfactant that satisfies the following condition (i):

Condition (i): The absorbance of a 0.1% by mass aqueous solution of the surfactant measured using an ultraviolet-visible-near-infrared spectrophotometer at a wavelength of 300 nm with an optical path length of 10 mm is 0.30 or less.

The upper limit of absorbance under condition (i) is preferably 0.26 or less, more preferably 0.22 or less, and even more preferably 0.18 or less, and the lower limit is preferably 0.001 or more, more preferably 0.005 or more, and even more preferably 0.01 or more.

When a resin film is formed using this composition containing a hydrophilic surfactant (C) that satisfies condition (i), the surfactant (C) segregates to the surface of the resin film, improving the development solubility of the outermost surface of the resin film, which is thought to result in an improved T-top shape.

The content of surfactant (C) in this composition is 0.5 to 6 parts by mass, preferably 0.8 to 5.5, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the polymer (A). Inclusion of surfactant (C) within this range is effective in improving the T-top shape. In conventional photosensitive resin compositions, surfactants are typically used to improve the uniformity (coatability) of the coating film, and in such cases, their content is typically around 0.1% by mass or less. However, the present invention has demonstrated an improvement in the T-top shape within a range significantly outside the above range, which is conventional common technical knowledge.

The surfactant (C) may be a fluorine-based surfactant, a silicon-based surfactant, or a surfactant containing both fluorine and silicon atoms, but fluorine-based surfactants are preferred due to their ease of availability. Furthermore, surfactant (C) may be used alone or in combination of two or more types.

Commercially available examples of surfactant (C) include "Megafac F553," "Megafac F559," "Megafac F477," "Megafac F570," "Megafac F557," and "Megafac F556" (all manufactured by DIC Corporation), "Ftergent 212M" and "Ftergent 602A" (both manufactured by Neos Corporation), and "Polyflow LE-607" (manufactured by Kyoeisha Chemical Co., Ltd.).

The weight-average molecular weight of surfactant (C) is preferably 8,000 or more, more preferably 9,000 to 100,000, and even more preferably 10,000 to 80,000. Having the weight-average molecular weight of surfactant (C) within this range tends to facilitate segregation on the resin film surface.

<Compound (D)>
The compound (D) has at least one selected from the group consisting of a mercapto group, a sulfide bond, and a polysulfide bond. In one embodiment, when a photoacid generator (B) having such a group or bond is used, a compound (D) other than the photoacid generator can be selected and used.

The total number of mercapto groups, sulfide bonds, and polysulfide bonds in compound (D) is not particularly limited, but is typically 1 to 10, preferably 1 to 6, and more preferably 2 to 4.

Examples of compound (D) include compound (D1) shown in formula (D1), compound (D2) shown in formula (D2), a polymer of compound (D2), and compound (D3) shown in formula (D3), which are explained below. Compound (D1) and compound (D2) are preferred, with compound (D2) being more preferred, as they can prevent the resist pattern film from peeling from the substrate during plating.

In one embodiment, compound (D) tends to be highly hydrophobic. The partition coefficient serves as an indicator of the hydrophobicity of compound (D). The partition coefficient of compound (D) is preferably 2 to 10, more preferably 3 to 7. The partition coefficient is the octanol/water partition coefficient (log P) value calculated by the Clog P method, and a larger value indicates higher hydrophobicity (lipid solubility).

The composition may contain one or more compounds (D).
The content of compound (D) in the composition is, relative to 100 parts by mass of the polymer component containing polymer (A), typically 0.01 parts by mass, preferably 0.05 parts by mass, more preferably 0.1 parts by mass, and particularly preferably 0.2 parts by mass. The upper limit of the content is typically 10 parts by mass, preferably 3.0 parts by mass, more preferably 2.0 parts by mass, and particularly preferably 1.0 parts by mass. In this embodiment, the positive-tone composition can more effectively exhibit the effects described above. For example, if the content of compound (D) is 0.2 parts by mass or more, a resist pattern film with higher rectangularity tends to be formed. Furthermore, for example, if the content of compound (D) is 2.0 parts by mass or less, the adhesion of the plated object to a substrate having a metal film tends to be higher.

<<Compound (D1)>>
The compound (D1) is a compound represented by formula (D1).

In formula (D1), R ³¹ is independently a monovalent hydrocarbon group or a group in which at least one hydrogen atom in the monovalent hydrocarbon group has been substituted with a mercapto group (hereinafter also referred to as a "mercapto substituent"). p is an integer of 1 or greater, preferably an integer of 1 to 4, and more preferably an integer of 2 to 3. For example, when p is 3, compound (D1) has a trisulfide bond. When p is 1, it is preferable that at least one R ³¹ is a group in which at least one hydrogen atom in the monovalent hydrocarbon group has been substituted with a mercapto group.

The monovalent hydrocarbon group of R ³¹ is usually a monovalent hydrocarbon group having a carbon number of 1 to 12. Examples of the monovalent hydrocarbon group include an alkyl group, an aryl group, and an arylalkyl group.

Examples of the alkyl group for R ³¹ include alkyl groups having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a pentyl group, and a decyl group.
Examples of the aryl group for R ³¹ include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a methylphenyl group, and a naphthyl group.

Examples of the arylalkyl group for R ³¹ include arylalkyl groups having 7 to 12 carbon atoms, such as benzyl and phenethyl groups.
An example of a mercapto substituent is a 4-mercaptophenyl group.

In compound (D1), the sulfide bond (when p = 1), the polysulfide bond (when p = 2 or more), or the mercapto group (when R ³¹ is a mercapto substituent) is bonded to a hydrocarbon structure, which is presumably why compound (D1) has high hydrophobicity.

Examples of compound (D1) include compounds represented by the following formulas (D1-1) to (D1-3).

<Compound (D2) and multimer thereof>
The compound (D2) is a compound represented by formula (D2).

The meanings of the symbols in formula (D2) are as follows:
R ³² is a divalent hydrocarbon group, preferably an alkanediyl group, an arylene group, or an arylenealkanediyl group, and among these, an alkanediyl group is more preferred because it allows for the production of a plated object in a good condition.

R ³³ is a divalent hydrocarbon group or a group in which at least one -CH ₂ - group (excluding both terminals) in the divalent hydrocarbon group has been substituted with -S- or -O-, preferably an alkanediyl group, a group in which at least one -CH ₂ - group (excluding both terminals) in the alkanediyl group has been substituted with -S- or -O- (hereinafter also referred to as a "substituted alkanediyl group"), an arylene group, or an arylenealkanediyl group, and of these, an alkanediyl group is more preferred because it allows for the production of plated objects in good condition.

The number of carbon atoms in the alkanediyl group is typically 1 to 12, preferably 2 to 12. Examples of the alkanediyl group include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, octane-1,8-diyl, decane-1,10-diyl, and dodecane-1,12-diyl; and branched alkanediyl groups such as 1-methylpropane-1,3-diyl, 2-methylpropane-1,3-diyl, 1-methylbutane-1,4-diyl, and 2-methylbutane-1,4-diyl. Of these, linear alkanediyl groups are preferred.

Examples of the substituted alkanediyl group include a group represented by --CH ₂ --CH ₂ --S--CH ₂ --CH ₂ -- and a group represented by --CH ₂ --CH ₂ --O--CH ₂ --CH ₂ --O--CH ₂ --CH ₂ --.

Examples of the arylene group include arylene groups having 6 to 10 carbon atoms, such as phenylene, methylphenylene, and naphthylene.

The arylenealkanediyl group is a divalent group in which one or more arylene groups and one or more alkanediyl groups are bonded in any order. Specific examples of each arylene group and alkanediyl group include those listed above.

R ³⁴ represents a glycoluril ring structure or an isocyanuric ring structure. Although the glycoluril ring structure and the isocyanuric ring structure have a bond that can reduce hydrophobicity, it is presumed that the bond does not deteriorate the hydrophobicity of compound (D2) due to their high structural symmetry.

m is 1 or 0.
q is an integer of 1 to 4. When ^{R 34} is a glycoluril ring structure, q is an integer of 1 to 4. When ^{R 34} is an isocyanuric ring structure, q is an integer of 1 to 3. When q is an integer of 2 or more, the groups represented by -(R ³² -S) _m -R ³³ -SH in formula (D2) may be the same or different.

In compound (D2), the mercapto group or sulfide bond (when m is 1) is bonded to a hydrocarbon structure or a hydrocarbon structure having -S- or -O- in part. Therefore, compound (D2) is presumed to have high hydrophobicity.

As compound (D2), compound (D2-1) represented by formula (D2-1) and compound (D2-2) represented by formula (D2-2) are preferred, with compound (D2-1) being more preferred.

In formulas (D2-1) and (D2-2), X is each independently a hydrogen atom or a monovalent group shown in formula (g2). However, in formula (D2-1), at least one X is a monovalent group shown in formula (g2), and preferably all Xs are monovalent groups shown in formula (g2). Also, in formula (D2-2), at least one X is a monovalent group shown in formula (g2), and preferably all Xs are monovalent groups shown in formula (g2).

In formula (g2), R ³² , R ³³ and m have the same meanings as R ³² , R ³³ and m in formula (D2), respectively, and * represents a bond to the nitrogen atom in formula (D2-1) or (D2-2).

Examples of compound (D2-1) include 1,3,4,6-tetrakis[2-mercaptoethyl]glycoluril, 1,3,4,6-tetrakis[3-(2-mercaptoethylsulfanyl)propyl]glycoluril, 1,3,4,6-tetrakis[3-(3-mercaptopropylsulfanyl)propyl]glycoluril, 1,3,4,6-tetrakis[3-(4-mercaptobutylsulfanyl)propyl]glycoluril, 1,3,4,6-tetrakis[3-(5-mercaptopentylsulfanyl)propyl]glycoluril, and 1,3,4,6-tetrakis[3-(6-mercaptohexylsulfanyl)propyl]glycoluril. Examples include glycoluril, 1,3,4,6-tetrakis[3-(8-mercaptooctylsulfanyl)propyl]glycoluril, 1,3,4,6-tetrakis[3-(10-mercaptodecylsulfanyl)propyl]glycoluril, 1,3,4,6-tetrakis[3-(12-mercaptododecylsulfanyl)propyl]glycoluril, 1,3,4,6-tetrakis{3-[2-(2-mercaptoethylsulfanyl)ethylsulfanyl]propyl}glycoluril, and 1,3,4,6-tetrakis(3-{2-[2-(2-mercaptoethoxy)ethoxy]ethylsulfanyl}propyl)glycoluril.

Examples of compound (D2-2) include 1,3,5-tris[2-mercaptoethyl]isocyanurate, 1,3,5-tris[3-(2-mercaptoethylsulfanyl)propyl]isocyanurate, 1,3,5-tris[3-(3-mercaptopropylsulfanyl)propyl]isocyanurate, 1,3,5-tris[3-(4-mercaptobutylsulfanyl)propyl]isocyanurate, 1,3,5-tris[3-(5-mercaptopentylsulfanyl)propyl]isocyanurate, and 1,3,5-tris[3-(6-mercaptohexylsulfanyl)propyl]isocyanurate. Examples include 1,3,5-tris[3-(8-mercaptooctylsulfanyl)propyl]isocyanurate, 1,3,5-tris[3-(10-mercaptodecylsulfanyl)propyl]isocyanurate, 1,3,5-tris[3-(12-mercaptododecylsulfanyl)propyl]isocyanurate, 1,3,5-tris{3-[2-(2-mercaptoethylsulfanyl)ethylsulfanyl]propyl}isocyanurate, and 1,3,5-tris(3-{2-[2-(2-mercaptoethoxy)ethoxy]ethylsulfanyl}propyl)isocyanurate.

Compound (D2) can be synthesized, for example, by the methods described in JP-A-2016-169174, JP-A-2016-164135, and JP-A-2016-164134.

Compound (D2) may form a multimer. The multimer is obtained by forming disulfide bonds between multiple compounds (D2) through coupling of mercapto groups. The multimer is, for example, a dimer to pentamer of compound (D2).

<Compound (D3)>
The compound (D3) is a compound represented by formula (D3).

In formula (D3), R ³⁵ and R ³⁶ each independently represent a hydrogen atom or an alkyl group. R ³⁷ represents a single bond or an alkanediyl group. R ³⁸ represents an r-valent aliphatic group which may contain atoms other than carbon atoms. r represents an integer of 2 to 10.

Examples of the alkyl group of R ³⁵ and R ³⁶ include alkyl groups having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a pentyl group, and a decyl group. A combination of R ³⁵ and R ³⁶ in which one is a hydrogen atom and the other is an alkyl group is preferred.

The number of carbon atoms in the alkanediyl group of R ³⁷ is usually 1 to 10, and preferably 1 to 5. Examples of the alkanediyl group include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and decane-1,10-diyl; and branched alkanediyl groups such as 1-methylpropane-1,3-diyl, 2-methylpropane-1,3-diyl, 1-methylbutane-1,4-diyl, and 2-methylbutane-1,4-diyl. Of these, linear alkanediyl groups are preferred.

R ³⁸ is an r-valent (2 to 10) aliphatic group which may contain atoms other than carbon atoms. Examples of atoms other than carbon atoms include nitrogen atoms, oxygen atoms, sulfur atoms, fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. The structure of the aliphatic group may be linear, branched, or cyclic, or may be a combination of these structures.

Examples of the aliphatic group include an r-valent hydrocarbon group having 2 to 10 carbon atoms, an r-valent oxygen-containing aliphatic group having 2 to 10 carbon atoms, and a trivalent group having 6 to 10 carbon atoms and an isocyanuric ring structure.

Examples of compound (D3) include compounds represented by the following formulas (D3-1) to (D3-4).

<Novolac Resin (E)>
The novolac resin (E) may be any resin as long as it is alkali-soluble and may be obtained by a conventional method. The polymer (A) of the present composition is hydrophobic, while the surfactant (C) is hydrophilic. The use of the novolac resin (E) in the present composition improves the compatibility of the composition when a hydrophilic component and a hydrophobic component are mixed, such as the polymer (A) and the surfactant (C), although the reason for this is unclear. Furthermore, because the alkali solubility can be appropriately controlled, a rectangular pattern shape can be obtained by adjusting the mixing ratio with the polymer (A) and the composition of the novolac resin (E), which will be described later.

Novolak resin (E) can be produced, for example, by condensation polymerization of a phenolic compound with an aldehyde such as formaldehyde, acetaldehyde, or a substituted or unsubstituted benzaldehyde, or by condensation polymerization of a phenolic compound with a substituted or unsubstituted methylol compound, using an acid catalyst.

Suitable novolak resins (E) include those obtained by the condensation reaction of phenolic compounds such as phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, and the like with aldehyde compounds such as formaldehyde in the presence of an acid or polyvalent metal ion catalyst.

The weight average molecular weight of the novolak resin (E) is usually 1,000 to 30,000, preferably 1,000 to 15,000, and more preferably 1,000 to 10,000.
The novolak resin (E) may be a blend of two or more kinds.

The novolak resin (E) used in the present invention is preferably a cresol-based novolak resin. Cresol novolak resins, which use m-cresol or p-cresol as the phenolic compound and formaldehyde as the aldehyde, are particularly preferred because they are widely available, are easily available, and allow for adjustment of alkali solubility.

<Quencher>
The composition may further contain a quencher.
The quencher is a component used, for example, to control the diffusion of the acid generated from the photoacid generator (B) upon exposure in the resin film, and as a result, the resolution of the composition can be improved.

Examples of quenchers include basic compounds and compounds that generate bases, such as those described in JP 2011-029636 A, JP 2014-013381 A, JP 2015-526752 A, JP 2016-099483 A, and JP 2017-037320 A. These are all incorporated herein by reference.

Examples of quenchers include alkylamines such as n-hexylamine, n-heptylamine, di-n-butylamine, and triethylamine; aromatic amines such as aniline and 1-naphthylamine; alkanolamines such as triethanolamine; polyamino compounds such as ethylenediamine, 1,3-bis[1-(4-aminophenyl)-1-methylethyl]benzene, and polyethyleneimine; amide compounds such as formamide; urea compounds such as urea and methylurea; nitrogen-containing heterocyclic compounds such as imidazole and benzimidazole; and nitrogen-containing compounds having an acid-dissociable group such as N-(t-butoxycarbonyl)piperidine, N-(t-butoxycarbonyl)-4-hydroxypiperidine, N-(t-butoxycarbonyl)imidazole, N-(t-butoxycarbonyl)benzimidazole, and N-(t-butoxycarbonyl)-2-phenylbenzimidazole.

The composition may contain one or more quenchers.
The content of the quencher in the present composition is usually 0.001 to 10 parts by mass, preferably 0.01 to 5 parts by mass, per 100 parts by mass of the polymer (A).

<Other ingredients>
The composition may further contain other ingredients.
Examples of the other components include surfactants other than the surfactant (C) that act to improve the coatability, defoaming properties, etc. of the photosensitive resin composition; sensitizers that absorb exposure light and improve the acid generation efficiency of the photoacid generator; alkali-soluble resins and low-molecular-weight phenolic compounds that control the dissolution rate of a resin film formed from the photosensitive resin composition in an alkaline developer; ultraviolet absorbers that prevent photoreaction due to the leakage of scattered light into unexposed areas during exposure; thermal polymerization inhibitors that increase the storage stability of the photosensitive resin composition; and other components such as antioxidants, adhesion aids, and inorganic fillers.

<Organic solvent>
The present composition may further contain an organic solvent, which is used, for example, to uniformly mix the components contained in the present composition.

Examples of organic solvents include alcohol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, diethylene glycol monoethyl ether, ethyl lactate, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl acetoacetate, ethyl ethoxyacetate, and γ-butyrolactone; ketone solvents such as methyl amyl ketone and cyclohexanone; alkylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, and dipropylene glycol dimethyl ether; and alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol mono-n-propyl ether acetate.

The composition may contain one or more organic solvents.
The content of the organic solvent in the present composition is usually 40 to 90% by mass.

<Production of Photosensitive Resin Composition>
The composition can be produced by uniformly mixing the aforementioned components. After uniformly mixing the aforementioned components, the resulting mixture can be filtered to remove any foreign matter.

[Photosensitive resin composition kit]
One embodiment of the present invention is a photosensitive resin composition kit including a first part containing a compound (D) and an organic solvent, and a second part containing a polymer (A) having an acid-dissociable group, a photoacid generator (B), and a surfactant (C). Details of each component are as described above.

The content of compound (D) in the first agent is typically 0.0001 to 10% by mass, and preferably 0.001 to 1% by mass. The second agent may also contain the aforementioned quencher, other components, organic solvents, etc. The content (content ratio) of each component in the second agent is the same as the content (content ratio) of each component in the aforementioned photosensitive resin composition or its solid content.

The photosensitive resin composition kit can be used, for example, by applying the first agent to a metal film on a substrate having the metal film, and then forming a resin film of the second agent on the metal film that has been surface-treated with the first agent. Subsequent steps are the same as steps (2) and (3) described below. It is believed that this method also produces the effects of the present invention, for the presumed reason described above that a film containing compound (D) is formed on the metal film.

[Method of manufacturing resist pattern film]
The method for producing a resist pattern film of the present invention includes the steps of: (1) forming a resin film of the photosensitive resin composition of the present invention on a metal film of a substrate having the metal film; (2) exposing the resin film to light; and (3) developing the resin film after exposure.

<Step (1)>
Examples of the substrate include a semiconductor substrate and a glass substrate. The shape of the substrate is not particularly limited, and the surface shape may be flat or uneven, and the shape of the substrate may be circular or square. There is also no limit to the size of the substrate.

Examples of the metal film include films containing metals such as aluminum, copper, silver, gold, and palladium, as well as alloys of two or more of these metals. Copper films, i.e., films containing copper and/or copper alloys, are preferred. The thickness of the metal film is typically 100 to 10,000 Å, preferably 500 to 2,000 Å. The metal film is typically provided on the surface of the substrate. The metal film can be formed by methods such as sputtering.

The resin film is typically formed by applying the composition onto a metal film on a substrate that already has a metal film. Examples of methods for applying the composition include spin coating, roll coating, screen printing, and applicator methods. Of these, spin coating and screen printing are preferred.

After the composition is applied, the applied composition may be subjected to a heat treatment in order to volatilize the organic solvent, etc. The heat treatment conditions are usually 50 to 200°C for 0.5 to 20 minutes.
The thickness of the resin film is usually 1 to 100 μm, preferably 5 to 80 μm.

<Step (2)>
In step (2), the resin film formed in step (1) is exposed to light.

The exposure is typically performed selectively on the resin film by life-size projection exposure or reduced-size projection exposure through a photomask having a predetermined mask pattern. Examples of the exposure light include ultraviolet light or visible light having a wavelength of 150 to 600 nm, preferably 200 to 500 nm. Examples of the light source for the exposure light include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and lasers. The exposure dose can be appropriately selected depending on the type of exposure light, the type of photosensitive resin composition, and the thickness of the resin film, and is typically 100 to 20,000 mJ/ ^cm² .

After the resin film is exposed to light and before development, the resin film can be subjected to a heat treatment. The heat treatment conditions are typically 70 to 180°C for 0.5 to 10 minutes. This heat treatment can promote the dissociation reaction of the acid-dissociable groups in polymer (A) with acid.

<Step (3)>
In step (3), the resin film exposed in step (2) is developed to form a resist pattern film. Development is usually carried out using an alkaline developer. Examples of development methods include showering, spraying, immersion, puddling, and puddling. Development conditions are usually at 10 to 30°C for 1 to 30 minutes.

Alkaline developers include, for example, aqueous solutions containing one or more alkaline substances. Examples of alkaline substances include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, and piperidine. The concentration of the alkaline substance in alkaline developers is typically 0.1 to 10% by mass. The alkaline developer may further contain an organic solvent, such as methanol or ethanol, and/or a surfactant.

The resist pattern film formed by development can be washed with water or the like. The resist pattern film can then be dried using an air gun or hot plate.

In this way, a resist pattern film that serves as a mold for forming a plated object can be formed on the metal film of the substrate while suppressing the formation of a T-top shape, thereby obtaining a plating substrate having a resist pattern film (mold) on the metal film. The thickness of the resist pattern film is typically 1 to 100 μm, preferably 5 to 80 μm. The shape of the openings in the resist pattern film can be selected to suit the type of plated object. If the plated object is a wiring, the pattern shape is, for example, a line-and-space pattern, and if the plated object is a bump, the shape of the openings is, for example, a cubic hole pattern.

By using a plating substrate with a mold that suppresses the formation of T-top shapes, it is possible to produce plated objects with the exact pattern dimensions designed.

[Method of manufacturing plated objects]
The method for producing a plated object of the present invention includes a step (5) of performing a plating process on a plating substrate having a resist pattern film produced by the method for producing a resist pattern film of the present invention on a metal film using the resist pattern film as a mold. The method for producing a plated object of the present invention may further include a step (4) of performing a plasma treatment with an oxygen-containing gas after the step (3) and before the step (5).

<Step (4)>
By carrying out a plasma treatment with an oxygen-containing gas (surface treatment of the plating substrate) in step (4), the affinity between the metal film surface and the plating solution can be increased.

In step (4), for example, a plating substrate having a resist pattern film on a metal film is placed in a vacuum chamber, and oxygen plasma is emitted to treat the surface of the plating substrate. Plasma treatment conditions typically include a power output of 50 to 300 W, an oxygen-containing gas flow rate of 20 to 150 mL, an internal pressure of 10 to 30 Pa, and a treatment time of 0.5 to 30 minutes. In addition to oxygen, the oxygen-containing gas may contain one or more gases selected from the group consisting of hydrogen, argon, and tetrafluoromethane. The plating substrate surface-treated by the plasma treatment can be washed with water or the like.

<Step (5)>
In step (5), the resist pattern film is used as a mold to form a plated object in the openings defined by the resist pattern film (portions removed by development) by plating.

Examples of plated objects include bumps and wiring. Plated objects are made of conductors such as copper, gold, and nickel. The thickness of the plated object varies depending on its application, but for example, for bumps, it is usually 5 to 100 μm, preferably 10 to 80 μm, and more preferably 20 to 60 μm, and for wiring, it is usually 1 to 30 μm, preferably 3 to 20 μm, and more preferably 5 to 15 μm.

Examples of plating processes include plating solutions using plating solutions. Examples of plating solutions include copper plating solutions, gold plating solutions, nickel plating solutions, and solder plating solutions. Specific examples include copper plating solutions containing copper sulfate or copper pyrophosphate, gold plating solutions containing potassium gold cyanide, and nickel plating solutions containing nickel sulfate or nickel carbonate. Of these, copper plating solutions are preferred. Plating solutions typically contain water and a hydrophilic solvent such as alcohol.

Specific examples of plating processes include wet plating processes such as electrolytic plating, electroless plating, and hot-dip plating. When forming bumps and wiring in wafer-level processing, electrolytic plating is usually used.

In the case of electrolytic plating, a plating film formed on the inner wall of a resist pattern film by sputtering or electroless plating can be used as a seed layer, or the metal film on the substrate can be used as a seed layer. A barrier layer can also be formed before forming the seed layer, and the seed layer can also be used as a barrier layer.

The conditions for electrolytic plating can be appropriately selected depending on the type of plating solution, etc. In the case of a copper plating solution, the temperature is usually 10 to 90°C, preferably 20 to 70°C, and the current density is usually 0.3 to 30 A/ ^dm2 , preferably 0.5 to 20 A/ ^dm2 . In the case of a nickel plating solution, the temperature is usually 20 to 90°C, preferably 40 to 70°C, and the current density is usually 0.3 to 30 A/ ^dm2 , preferably 0.5 to 20 A/ ^dm2 .

The plating process can be performed by sequentially applying different plating processes. For example, copper plating can be performed first, followed by nickel plating, and then molten solder plating to form a solder copper pillar bump.

<Other processes>
The method for producing a plated product of the present invention can further include a step of removing the resist pattern film after step (5). This step is specifically a step of stripping and removing the remaining resist pattern film, for example, by immersing the substrate having the resist pattern film and the plated product in a stripping solution. The temperature of the stripping solution and the immersion time are typically 20 to 80°C and 1 to 10 minutes.

Examples of the stripping solution include a stripping solution containing at least one selected from tetramethylammonium hydroxide, dimethyl sulfoxide, and N,N-dimethylformamide.

The method for manufacturing a plated object of the present invention may further include a step of removing the metal film from areas other than the area where the plated object is formed, for example, by a method such as wet etching.

The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples.

<Weight average molecular weight (Mw) of polymer>
The weight average molecular weight (Mw) of the polymer and surfactant was measured by gel permeation chromatography under the following conditions.
GPC device: manufactured by Tosoh Corporation, device name "HLC-8220-GPC"
Column: TSK-M and TSK2500 columns manufactured by Tosoh Corporation connected in series. Solvent: Tetrahydrofuran. Temperature: 40°C.
・Detection method: Refractive index method ・Standard material: Polystyrene

<Absorbance>
A 0.1% by mass aqueous solution of the surfactant was prepared and placed in a quartz cell with an optical path length of 10 mm. The absorbance was measured at an optical path length of 10 mm and a wavelength of 300 nm using an ultraviolet-visible-near infrared spectrophotometer ("Ultraviolet-Visible-Near Infrared Spectrophotometer V-7300" manufactured by JASCO Corporation).

[Synthesis Examples 1 and 2]
Polymers (A-1) to (A-3) having the structural units and their content ratios shown in Table 1 were produced by radical polymerization using 2,2'-azobis(methyl isobutyrate) as a radical polymerization initiator. Details of the structural units shown in Table 1 are shown in the following formulas (a1-1), (a1-4), (a2-1) to (a2-4), (a3-1), and (a4-1). The numerical values in columns a1-1 to a4-1 in Table 1 are in mol %. The content ratio of each structural unit was measured by ^1H -NMR.

<Production of Photosensitive Resin Composition>
[Examples 1A to 11A, Comparative Examples 1A to 3A] Preparation of Photosensitive Resin Compositions The photosensitive resin compositions of Examples 1A to 11A and Comparative Examples 1A to 3A were prepared by uniformly mixing the types and amounts of each component shown in Table 3 below. Details of each component other than the polymer component are as follows. The numerical values in Table 3 are in parts by mass.
B1: Compound represented by the following formula (B1) B2: Compound represented by the following formula (B2) B3: Compound represented by the following formula (B3)

C1: Fluorine-based surfactant "Megafac F553" (DIC Corporation)
C2: Fluorine-based surfactant "Ftergent 602A" (manufactured by Neos Co., Ltd.)
C3: Fluorine-based surfactant "Megafac F559" (DIC Corporation)
C4: Fluorine-based surfactant "Megafac F477" (DIC Corporation)
C5: Fluorine-based surfactant "Ftergent 212M" (manufactured by Neos Co., Ltd.)
C6: Fluorine-based surfactant "Megafac F-570" (DIC Corporation)
C7: Fluorine-based surfactant "Megafac F-563" (DIC Corporation)
The absorbance and weight average molecular weight of the surfactants (C1) to (C7) under the condition (i) are shown in Table 2 below.

D1: Karenz MT (registered trademark) PE1 manufactured by Showa Denko K.K.
D2: Karenz MT (registered trademark) NR1 manufactured by Showa Denko K.K.

E1: Cresol novolak resin (m-cresol:p-cresol=6:4 (molar ratio), polystyrene equivalent weight average molecular weight=12,000)
E2: Cresol novolak resin (m-cresol:p-cresol=4:6 (molar ratio), polystyrene equivalent weight average molecular weight=5,000)

S1: Propylene glycol monomethyl ether acetate S2: 3-methoxybutyl acetate S3: γ-butyrolactone

<Production of Resist Pattern Film>
[Examples 1B to 11B, Comparative Examples 1B to 3B]
Using the photosensitive resin compositions of Examples 1A to 11A and Comparative Examples 1A to 3A, two patterned substrates were produced according to the methods described under Conditions 1 and 2 below, and the T-top shapes of the resist pattern films were evaluated according to the evaluation methods and criteria described below.

Condition 1 (board production without settling time)
Using a spin coater, the photosensitive resin compositions of Examples 1A to 11A and Comparative Examples 1A to 3A were applied to the copper sputtered film of a silicon wafer substrate. The coating was then heated on a hot plate at 120°C for 60 seconds to form a 6 μm-thick coating film. The coating was then exposed through a pattern mask using a stepper (Nikon Corporation, model "NSR-i10D"). The exposed coating was heated at 90°C for 60 seconds in an environment where the atmospheric amine concentration was controlled at 5 ppb, and then developed by immersion in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide for 180 seconds. The substrate was then rinsed with running water and blown with nitrogen to form resist pattern films (line width: 2 μm, line width/space width = 1/1) of Examples 1B to 11B and Comparative Examples 1B to 3B on the copper sputtered film of the substrate. The substrate with the resist pattern film thus formed is referred to as "Patterned Substrate-1." Under these conditions, the time required from exposure to post-exposure heating is within 30 minutes.

Condition 2 (substrate preparation with 24-hour post-exposure storage)
Using a spin coater, the photosensitive resin compositions of Examples 1A to 11A and Comparative Examples 1A to 3A were applied to the copper sputtered film of a silicon wafer substrate. The coating was then heated on a hot plate at 120°C for 60 seconds to form a 6 μm-thick coating film. The coating was then exposed through a pattern mask using a stepper (Nikon Corporation, model "NSR-i10D"). The exposed coating was then exposed for 24 hours in an environment contaminated with 5 ppb of atmospheric amine, heated at 90°C for 60 seconds, and then developed by immersion in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide for 180 seconds. The substrate was then rinsed with running water and purged with nitrogen to form resist pattern films (line width: 2 μm, line width/space width = 1/1) of Examples 1B to 11B and Comparative Examples 1B to 3B on the copper sputtered film of the substrate. The substrates thus formed with resist pattern films are referred to as "patterned substrate-2."

<Evaluation methods and criteria>
For the patterned substrate-1 and patterned substrate-2 prepared using each photosensitive resin composition, the T-top shapes of the resulting resist pattern films were observed using an electron microscope. As shown in FIG. 1 and other figures, the pattern width when the resist pattern was observed from directly above using an electron microscope was defined as W1, and the pattern width connecting points 3a and 3b where the T-top shape end (protruding portion) intersects with the pattern sidewall extending perpendicular to the substrate when the cross section of the resist pattern was observed using an electron microscope was defined as W2. The sum of the T-top widths (W1-W2) was determined, and the ratio of this width to the pattern width W2 ((W1-W2)/W2×100=Wt(%)) was calculated. The Wt of patterned substrate-1 was defined as Wt1, and the Wt of patterned substrate-2 was defined as Wt2. The shape of the pattern sidewall is not limited to a shape extending straight in the vertical direction from the patterned substrate as shown in Fig. 1, but may also include a shape extending in the vertical direction from the patterned substrate in a barrel-like bulge as shown in Fig. 2, a shape extending in the vertical direction from the patterned substrate in a tapered shape as shown in Fig. 3, and a shape extending in the vertical direction from the patterned substrate in an inverted tapered shape as shown in Fig. 4. For each photosensitive resin composition, Wt2 - Wt1 was calculated and evaluated according to the following criteria. The evaluation results are shown in Table 4.

⊚: (Wt2 - Wt1) is 0% or more and less than 10%.
Good: (Wt2-Wt1) is 10% or more and less than 20%.
△: (Wt2-Wt1) is 20% or more and less than 30%.
×: (Wt2 - Wt1) is 30% or more.

For each photosensitive resin composition, Wt1 showed almost no T-top shape due to the influence of environmental amines, but the larger (Wt2 - Wt1), the more likely it was that a T-top shape due to the influence of environmental amines occurred.

Furthermore, for the resulting patterned substrate-1, the state of the interface between the resist pattern film and the copper sputtered film was observed using an electron microscope, and the adhesion of the resist pattern film was evaluated according to the following criteria. The evaluation results are shown in Table 4.

⊚: No peeling of the pattern including the isolated wiring portion in the 2 μm LS pattern.
◯: No pattern peeling occurred except for isolated wiring portions in the 2 μm LS pattern.
×: Peeling of the pattern was observed in the 2 μm LS pattern.

<Production of plated objects>
[Examples 1C to 11C, Comparative Examples 1C to 3C]
Using the resist pattern film-1 as a mold, electrolytic plating was performed to produce plated objects. Except for Example 11C, as a pretreatment for the electrolytic plating, treatment with oxygen plasma (power 100 W, oxygen flow rate 100 mL, treatment time 60 seconds) was performed, followed by rinsing with water.

The pretreated patterned substrate-1 (an untreated patterned substrate in Example 11C) was immersed in 1 L of copper plating solution (product name "MICROFAB SC-40", manufactured by MacDermid Performance Solutions Japan, Inc.), and electrolytic plating was performed for 2 minutes and 10 seconds with the plating bath temperature set to 25°C and the current density set to 8.5 A/ ^dm2 , to produce a plated object.

The condition of the plated objects produced was observed using an electron microscope and evaluated according to the following criteria. The evaluation results are shown in Table 4 below.

◯: No plating peeling occurred and a rectangular shape was obtained.
×: Plating peeled off, or pattern peeling occurred, and therefore a rectangular shape was not obtained.

1... Substrate 2... Pattern 3a, 3b... Intersection of the T-top shape and the pattern sidewall extending perpendicular to the substrate when the cross section of the resist pattern is observed with an electron microscope W1... Pattern width when the resist pattern is observed from directly above with an electron microscope W2... Pattern width connecting 3a and 3b when the cross section of the resist pattern is observed with an electron microscope

Claims (5)

a step (1) of forming a resin film of a photosensitive resin composition on a metal film of a substrate having the metal film, the photosensitive resin composition comprising a polymer (A) having an acid-dissociable group, a photoacid generator (B), and a surfactant (C), the surfactant (C) being a fluorine-based surfactant that satisfies the following condition (i) and is contained in an amount of 0.5 to 6 parts by mass per 100 parts by mass of the polymer (A);
a step (2) of exposing the resin film to light;
(3) a step of developing the resin film after exposure;
A method for producing a plated object, comprising the step (5) of performing plating treatment using a resist pattern film produced by the method for producing a resist pattern film comprising the steps of :
Condition (i): The absorbance of a 0.1% by mass aqueous solution of the surfactant at a wavelength of 300 nm with an optical path length of 10 mm measured using an ultraviolet-visible-near infrared spectrophotometer is 0.30 or less. 2. The method for producing a plated object according to claim 1, wherein the surfactant (C) has a weight average molecular weight of 8,000 or more. 3. The method for producing a plated object according to claim 1, wherein the photosensitive resin composition further contains a sulfur-containing compound (D) having at least one structure selected from the group consisting of a mercapto group, a sulfide bond, and a polysulfide bond. 4. The method for producing a plated object according to claim 1 , wherein the photosensitive resin composition further contains a novolak resin (E). The method for producing a plated object according to any one of claims 1 to 4 , further comprising a step (4) of performing a plasma treatment with an oxygen-containing gas before the step (5).