JP7200614B2 - Photosensitive composition, method for forming resist pattern, and method for producing plated model - Google Patents

Description

The present invention relates to a photosensitive composition, a method of forming a resist pattern, and a method of manufacturing a plated model.

Various members of semiconductor elements and display elements such as liquid crystal displays and touch panels are formed by forming a resist pattern on a substrate and using the resist pattern as a mask to perform processing such as plating and etching on the substrate. Then, the processed resist pattern is removed from the substrate by, for example, wet treatment using a resist stripper.

Alkaline compounds are generally used in resist stripping solutions used in wet processing in order to decompose organic substances in the resist pattern so that the resist pattern can be easily removed from the substrate. However, alkaline compounds are known to corrode copper and other metals used in electrodes and wiring, and in particular, it is known that coexistence of alkaline compounds with water accelerates the corrosion of copper ( See Patent Documents 1 to 3). Water is usually used for the purpose of dissolving alkaline compounds, and since alkaline compounds have hygroscopicity and deliquescence, they take in water from the air. Therefore, when an alkaline compound is used for the resist stripping solution, it is very difficult to prevent the resist stripping solution from completely containing water. In other words, as long as an alkaline compound is used in the resist stripping solution, it is very difficult to completely eliminate corrosion of metals such as copper.

JP 2006-146272 A JP 2005-043874 A Japanese Unexamined Patent Application Publication No. 2017-040928

Therefore, it is difficult to completely eliminate corrosion of metals such as copper without using a resist stripping solution that does not contain an alkaline compound. In other words, if the resist pattern can be stripped with a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound, it is possible to completely eliminate corrosion of metals such as copper.

The present invention provides a photosensitive composition capable of forming a resist pattern that can be stripped with a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound, and a resist pattern capable of forming the resist pattern. It is an object of the present invention to provide a formation method and a method of manufacturing a plated model using the resist pattern.

The present invention for achieving the above object relates to, for example, the following [1] to [7].
[1] A polymerizable compound (A) having two or more radically polymerizable unsaturated double bond groups and an acid dissociable group present in the molecular chain connecting the two unsaturated double bond groups, photoradical A photosensitive composition comprising a polymerization initiator (B), a polyfunctional thiol (C), and an acid generator (D).
[2] The photosensitive composition according to [1] above, which contains 80 to 150 parts by mass of the polyfunctional thiol (C) relative to 100 parts by mass of the polymerizable compound (A).
[3] The photosensitive composition according to [1] or [2], wherein the polymerizable compound (A) is a (meth)acrylate compound represented by the following formula (1).

（式（１）において、ｐは２以上の整数を示し、Ｚは末端の炭素のうち少なくとも１つが三級炭素であるｐ価の有機基を示し、Ｒ¹ は、水素原子またはメチル基を示す）
［４］ さらに、アルカリ可溶性樹脂（Ｆ）を含有する前記［１］～［３］のいずれかに記載の感光性組成物。
［５］ 前記酸発生剤（Ｄ）が、熱酸発生剤（Ｄ１）である前記［１］～［４］のいずれかに記載の感光性組成物。
［６］ 前記［１］～［５］のいずれかに記載の感光性組成物を基板上に塗布して塗膜を形成する工程（１）、前記塗膜を露光する工程（２）、露光後の塗膜を現像する工程（３）、を有することを特徴とするレジストパターンの形成方法。
［７］ 前記［６］に記載のレジストパターンの形成方法によって形成したレジストパターンをマスクにして、前記基板に対してメッキ処理を行う工程（４）、およびレジストパターンを、アルカリ性化合物を含まない実質的に有機溶剤のみからなるレジスト剥離液で除去する工程（５）を有することを特徴とするメッキ造形物の製造方法。

(In formula (1), p represents an integer of 2 or more, Z represents a p-valent organic group in which at least one of the terminal carbons is a tertiary carbon, and R ¹ represents a hydrogen atom or a methyl group. )
[4] The photosensitive composition according to any one of [1] to [3], further comprising an alkali-soluble resin (F).
[5] The photosensitive composition according to any one of [1] to [4], wherein the acid generator (D) is a thermal acid generator (D1).
[6] The step (1) of applying the photosensitive composition according to any one of the above [1] to [5] on a substrate to form a coating film, the step of exposing the coating film (2), and exposing A method for forming a resist pattern, comprising the step (3) of developing the subsequent coating film.
[7] The step (4) of plating the substrate using the resist pattern formed by the method of forming a resist pattern according to [6] as a mask; A method for producing a plated modeled article, characterized in that it has a step (5) of removing with a resist stripping solution consisting essentially of an organic solvent.

The photosensitive composition of the present invention can form a resist pattern that can be easily stripped from a substrate with a resist stripping solution that does not contain an alkaline compound and substantially contains only an organic solvent. The resist pattern formed using the photosensitive composition of the present invention is subjected to processing such as plating, and then stripped with a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound. Corrosion of metal such as copper used for wiring can be prevented.

For the reasons described above, the method for manufacturing a plated modeled article can manufacture a plated modeled article without causing corrosion of metal such as copper used for the plated modeled article such as electrodes and wiring.

[Photosensitive composition]
The photosensitive composition of the present invention is a polymerizable compound having two or more radically polymerizable unsaturated double bond groups and an acid dissociable group present in the molecular chain connecting the two unsaturated double bond groups. (A) (hereinafter also referred to as "polymerizable compound (A)"), photoradical polymerization initiator (B), polyfunctional thiol (C), and acid generator (D).

A resist pattern formed from the photosensitive composition of the present invention can be stripped from a substrate with a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound.
When the photosensitive composition of the present invention is coated on a substrate to form a coating film, and this coating film is selectively exposed to light, the photosensitive composition of the present invention is a negative type. Due to the action of radicals generated from the radical photopolymerization initiator (B), the polymerizable compound (A) is polymerized at the radically polymerizable unsaturated double bond groups to form a crosslinked product. At this time, it is thought that the polyfunctional thiol (C) also participates in the polymerization, and the structural units derived from the polyfunctional thiol constitute a part of the crosslinked product.

Since the polymerizable compound (A) has an acid-labile group, the crosslinked body formed as described above contains an acid-labile group. After the exposed coating film is developed to form a resist pattern, the acid dissociable groups contained in the crosslinked product are dissociated by the action of acid generated from the acid generator (D). For this reason, the crosslinked structure in the resist pattern is decomposed, and the resist pattern can be stripped from the substrate even with a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound.

Here, the photosensitive composition used for forming the resist pattern contains a polymerizable compound (A), a photoradical polymerization initiator (B) and an acid generator (D), and does not contain a polyfunctional thiol (C). In some cases, it is difficult to strip the formed resist pattern from the substrate with a resist stripper containing substantially only an organic solvent that does not contain an alkaline compound.

When the photosensitive composition does not contain a polyfunctional thiol (C), it is difficult to strip the resist pattern from the substrate with a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound. Radical polymerization of the polymerizable compound (A) alone results in chain polymerization, and the polymerization progresses in the vicinity of the radical active species, resulting in a locally dense crosslinked structure. For this reason, the crosslink density of the formed crosslinked body becomes too high, and the permeation of the resist stripping solution into the resist pattern becomes weak. Furthermore, in the sequential reaction, one molecule of thiol reacts with one molecule of acrylate, so that a degradable group is introduced into the main chain. On the other hand, in chain polymerization, since acrylates react with each other, it is difficult to introduce a decomposable group into the main chain. Therefore, the former has a smaller size when decomposed, and thus has a higher solubility.

When the photosensitive composition contains the polyfunctional thiol (C) together with the polymerizable compound (A), the enethiol reaction by the polyfunctional thiol (C) extends the life of the radical active species, resulting in sequential polymerization and crosslinking of the crosslinked body. It is thought that the density becomes lower. Therefore, it is considered that the resist stripping solution can sufficiently permeate the resist pattern, and as a result, the resist pattern can be easily stripped from the substrate.

That is, the photosensitive composition of the present invention has the effect that the crosslinked structure is decomposed by the action of the acid generator (D) due to the polymerizable compound (A), and the polyfunctional thiol (C). A resist pattern that can be easily stripped from a substrate by a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound is formed by a combined effect of the effect of lowering the crosslink density of the crosslinked body. be.

The polymerizable compound (A) having two or more radically polymerizable unsaturated double bond groups and an acid-labile group is a component that is radically polymerized by active species generated from a radical photopolymerization initiator upon exposure. As described above, the radically polymerizable unsaturated double bond group is a group that contributes to polymerization by the action of radicals generated from the radical photopolymerization initiator (B), and the acid dissociable group is the acid generator (D). is a group dissociated by the action of an acid generated from

Examples of the polymerizable compound (A) include (meth)acrylate compounds having two or more (meth)acryloyl groups. Examples of such (meth)acrylate compounds include compounds represented by the following formula (1).

式（１）において、ｐは２以上の整数であり、好ましくは２～３、より好ましくは２である。Ｚはｐ価の有機基である。Ｒ¹ は、水素原子またはメチル基である。

In formula (1), p is an integer of 2 or more, preferably 2 to 3, more preferably 2. Z is a p-valent organic group. R ¹ is a hydrogen atom or a methyl group.

At least one of the terminal carbons of Z is preferably a tertiary carbon. When the polymerizable compound (A) is a (meth)acrylate compound in which the carbon atom bonded to the (meth)acryloyloxy group is a tertiary carbon, it is easily dissociated by the action of the acid generated from the acid generator (D). It is preferable because it becomes easy to decompose the crosslinked product.
Examples of Z include groups represented by the following formula (2) or (3).

Ｙは、エーテル結合を含んでもよい炭素数１～２０の炭化水素基であり、ｍは０又は１を示す。Ｒ² は炭素数１～８の直鎖、分岐鎖又は環状のアルキル基であり、Ｒ³ は水素原子又は炭素数１～８の直鎖、分岐鎖又は環状のアルキル基、Ｒ⁴ は炭素数１～８の直鎖、分岐鎖又は環状のアルキル基を示す。Ｒ² 同士、Ｒ² とＹとは互いに結合して環を形成してもよい。ｉは１以上の整数であり、ｊは０以上の整数であり、ｑは１以上の整数であり、ｒは１以上の整数であり、ｓは０～４の整数、好ましくは０又は１である
重合性化合物（Ａ）としては、例えば、下記式（４）で表わされる化合物が好ましい。

Y is a hydrocarbon group having 1 to 20 carbon atoms which may contain an ether bond; m is 0 or 1; R ² is a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, R ³ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, and R ⁴ is a carbon number 1 to 8 linear, branched or cyclic alkyl groups. R ² may be bonded to each other, or R ² and Y may be bonded to each other to form a ring. i is an integer of 1 or more, j is an integer of 0 or more, q is an integer of 1 or more, r is an integer of 1 or more, s is an integer of 0 to 4, preferably 0 or 1 As the polymerizable compound (A), for example, a compound represented by the following formula (4) is preferable.

これらの重合性化合物（Ａ）は、１種単独で用いてもよく、２種以上を併用してもよい。

These polymerizable compounds (A) may be used singly or in combination of two or more.

The radical photopolymerization initiator (B) is a compound that generates radicals upon irradiation with exposure light and initiates radical polymerization of the photopolymerizable compound (A).
Examples of photoradical polymerization initiators (B) include oxime compounds, organic halogenated compounds, oxydiazole compounds, carbonyl compounds, ketal compounds, benzoin compounds, acridine compounds, organic peroxide compounds, azo compounds, coumarin compounds, Azide compounds, metallocene compounds, hexaarylbiimidazole compounds, organic boric acid compounds, disulfonic acid compounds, onium salt compounds, and acylphosphine (oxide) compounds. Among these, from the viewpoint of sensitivity, the oxime radical photopolymerization initiator (B1), particularly the photoradical polymerization initiator having an oxime ester structure is preferred.

A radical photopolymerization initiator having an oxime ester structure may have geometric isomers resulting from the double bond of the oxime, but these are not distinguished and are all included in the radical photopolymerization initiator (B).

Photoradical polymerization initiators having an oxime ester structure include, for example, WO2010/146883, JP-A-2011-132215, JP-A-2008-506749, JP-A-2009-519904, and JP-A-2009-519991. Photoradical polymerization initiators described in publications may be mentioned.

Specific examples of radical photopolymerization initiators having an oxime ester structure include N-benzoyloxy-1-(4-phenylsulfanylphenyl)butan-1-one-2-imine and N-ethoxycarbonyloxy-1-phenylpropane. -1-one-2-imine, N-benzoyloxy-1-(4-phenylsulfanylphenyl)octan-1-one-2-imine, N-acetoxy-1-[9-ethyl-6-(2-methyl benzoyl)-9H-carbazol-3-yl]ethan-1-imine, and N-acetoxy-1-[9-ethyl-6-{2-methyl-4-(3,3-dimethyl-2,4-di Oxacyclopentanylmethyloxy)benzoyl}-9H-carbazol-3-yl]ethan-1-imine, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl] -, 1-(O-acetyloxime) and the like.
These radical photopolymerization initiators (B) may be used singly or in combination of two or more.

The content of the photoradical polymerization initiator (B) in the present photosensitive resin composition is usually 1 to 40 parts by mass, preferably 3 to 35 parts by mass, more preferably 5 to 30 parts by mass. When the content of the radical photopolymerization initiator (B) is within the above range, a suitable amount of radicals can be obtained and excellent resolution can be obtained.

As described above, the polyfunctional thiol (C) polymerizes together with the polymerizable compound (A) to lower the crosslink density of the crosslinked product, thereby facilitating the peeling of the resist pattern from the substrate.

A polyfunctional thiol (C) is a compound having two or more thiol groups (mercapto groups) in the molecule. As the polyfunctional thiol (C), a low-molecular-weight compound having a molecular weight of 100 or more is preferable.

The number of functional groups of the polyfunctional thiol (C) is preferably 2 to 10 functional groups, more preferably 2 to 8 functional groups, and still more preferably 2 to 4 functional groups. When the number of functional groups is large, the film strength is excellent, while when the number of functional groups is small, the storage stability is excellent. In the case of the said range, these can be made compatible.

As the polyfunctional thiol (C), an aliphatic polyfunctional thiol compound is preferred. Preferable examples of the aliphatic polyfunctional thiol compound are compounds comprising a combination of an aliphatic hydrocarbon group, -O- and -C(=O)-, in which at least two hydrogen atoms of the aliphatic hydrocarbon group Compounds in which one is substituted with a thiol group are exemplified.

The thiol group in the polyfunctional thiol (C) may be a primary thiol group, a secondary thiol group, or a tertiary thiol group, but from the viewpoint of sensitivity and chemical resistance Therefore, it is preferably a primary or secondary thiol group, more preferably a secondary thiol group. From the viewpoint of storage stability, secondary or tertiary thiol groups are preferred, and secondary thiol groups are more preferred.

Examples of aliphatic polyfunctional thiol compounds include pentaerythritol tetrakis (3-mercaptobutyrate), 1,4-bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyryloxyethyl )-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, trimethylolpropane tris (3-mercaptobutyrate), trimethylolethane tris (3-mercaptobutyrate), tri Methylolpropane tris(3-mercaptopropionate), tris[(3-mercaptopropionyloxy)ethyl]isocyanurate, pentaerythritol tetrakis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate) , and dipentaerythritol hexakis (3-mercaptopropionate), etc. Among these, pentaerythritol tetrakis (3-mercaptobutyrate), 1,4-bis (3-mercaptobutyryloxy ) butane and 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione are more preferable.

Examples of commercially available aliphatic polyfunctional thiols (C) include Karenz MT-PE-1, Karenz MT-BD-1, Karenz MT-NR-1, TPMB, and TEMB (manufactured by Showa Denko K.K.). , TMMP, TEMPIC, PEMP, EGMP-4, and DPMP (manufactured by Sakai Chemical Industry Co., Ltd.).

These polyfunctional thiols (C) may be used singly or in combination of two or more.
The content of the polyfunctional thiol (C) is preferably 80 to 150 parts by weight with respect to 100 parts by weight of the polymerizable compound (A), from the viewpoint of suitably expressing the action of the polyfunctional thiol (C). More preferably 100 to 140 parts by mass, still more preferably 105 to 130 parts by mass.

As described above, the acid generator (D) dissociates the acid dissociable group contained in the crosslinked portion formed from the polymerizable compound (A) in the resist pattern to decompose the crosslinked structure. It has the function of facilitating the peeling of the resist pattern from the substrate.

Examples of the acid generator (D) include thermal acid generators and photoacid generators (however, the absorption wavelength range thereof is different from that of the photoradical polymerization initiator (B)). Agent (D1) is particularly preferred.

The thermal acid generator (D1) is not particularly limited as long as it can generate an acid by heat, and examples thereof include onium salts such as sulfonium salts, benzothiazolium salts, ammonium salts and phosphonium salts. Specific examples include those described in paragraphs [0051] and [0057] of JP-A-2009-215328, benzyl(4-hydroxyphenyl)methylsulfonium, (4-acetoxyphenyl)dimethylsulfonium, ( 4-hydroxyphenyl)dimethylsulfonium, (2-methylbenzyl)(4-hydroxyphenyl)methylsulfonium, (1-naphthylmethyl)(4-hydroxyphenyl)methylsulfonium and benzyl(4-acetoxyphenyl)methylsulfonium the group consisting of a cation and tris(pentafluoroethyl)trifluorophosphate, hexafluorophosphate, tetrakis(pentafluorophenyl)borate, hexafluoroantimonate, p-toluenesulfonate, dodecylbenzenesulfonate, trifluoromethanesulfonate, perfluorobutanesulfonate Anion salts selected from

Commercial products of the thermal acid generator (D1) include trade names "PP-33", "CP-66" and "CP-77" (manufactured by ADEKA Corporation), trade name "FC-509" (US 3M), trade name "UVE1014" (manufactured by General Electric Company of the United States), trade names "San-Aid SI-45L", "San-Aid SI-60L", "San-Aid SI-80L", "San-Aid SI-100L", " San-Aid SI-110L", "San-Aid SI-150L", "San-Aid SI-45", "San-Aid SI-60", "San-Aid SI-80", "San-Aid SI-100", "San-Aid SI-110", "San-Aid" SI-150", "San-Aid SI-300", "San-Aid SI-360", "San-Aid SI-B2A", "San-Aid SI-B3", "San-Aid SI-B3A", "San-Aid SI-B4", "San-Aid SI -B5” (manufactured by Sanshin Chemical Industry Co., Ltd.), trade name “CG-24-61” (manufactured by BASF), trade name “TA-60”, “TA-100”, “TA-120”, “ TA-160” (manufactured by San-Apro Co., Ltd.), trade names “CXC-1612”, “CXC-1733”, “CXC-1738”, “CXC-1615”, “CXC-1614”, “CXC-1821” , "TAG-2700", "TAG-2713", "TAG-2689", "CXC-2689", "CXC-1742", "TAG-2690", "TAG-2678", "CXC-1820", " TAG-1820", "TAG-2172", "TAG-2179", "TAG-2507", "CXC-1889", "CXC-1890", and "CXC-1880" (manufactured by KING, USA). be done.

The decomposition temperature of the thermal acid generator (D1) is preferably 80 to 200°C, more preferably 100 to 180°C, still more preferably 110 to 160°C. When the decomposition temperature of the thermal acid generator (D1) is within the above range, the thermal acid generator (D1) is not decomposed by the heat treatment in the step (1) or the step (2), and the thermal acid generator (D1) is not decomposed in the step (5). Since the resist pattern can be easily decomposed by heat treatment, the resist pattern can be easily peeled off, which is preferable.

The content of the acid generator (D) is preferably 5 to 70 parts by mass with respect to 100 parts by mass of the polymerizable compound (A), from the viewpoint of favorably expressing the action of the acid generator (D). More preferably 10 to 40 parts by mass, still more preferably 15 to 30 parts by mass.

The photosensitive composition of the present invention can contain a polymerizable compound (E) other than the polymerizable compound (A).
Polymerizable compound (E) preferably has at least one ethylenically unsaturated double bond in one molecule.

As the polymerizable compound (E), a (meth)acrylate compound having a (meth)acryloyl group and a compound having a vinyl group are preferable. The (meth)acrylate compound is classified into a monofunctional (meth)acrylate compound and a polyfunctional (meth)acrylate compound, and any compound may be used.

Examples of the monofunctional (meth)acrylate compounds include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, ) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate ) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate ) acrylate, dodecyl amyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, ethoxy Ethyl (meth) acrylate, butoxyethyl (meth) acrylate, glycerol (meth) acrylate, ethylene glycol monomethyl ether (meth) acrylate, ethylene glycol monoethyl ether (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono ( meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, phenoxy polypropylene glycol (meth) acrylate , tricyclo[5.2.1.0 ^2,6 ]decadienyl (meth)acrylate, tricyclo[5.2.1.0 ^2,6 ]decanyl (meth)acrylate, tricyclo[5.2.1.0 ^{2, 6} ] Decenyl (meth)acrylate, isobornyl (meth)acrylate, bornyl (meth)acrylate, cyclohexyl (meth)acrylate, acrylic amide, methacrylic amide, diacetone (meth)acrylamide amide, isobutoxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, tert-octyl (meth)acrylamide, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 7-amino-3,7 - dimethyloctyl (meth)acrylate and the like.

Examples of the polyfunctional (meth)acrylate compound include, for example, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane PO (propylene oxide)-modified tri(meth)acrylate, and tetramethylolpropane. Tetra (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, tris(2-hydroxy) Ethyl)isocyanurate tri(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, epoxy(meth)acrylate obtained by adding (meth)acrylic acid to diglycidyl ether of bisphenol A, bisphenol A di(meth)acryloyl Oxyethyl ether, bisphenol A di(meth)acryloyloxymethylethyl ether, bisphenol A di(meth)acryloyloxyethyloxyethyl ether, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta( meth)acrylates, dipentaerythritol hexa(meth)acrylates, polyester (meth)acrylates (trifunctional or higher), reaction products of phthalic acid and epoxy acrylates, and the like.

A commercially available compound can be used as it is as the polymerizable compound (E). Examples of commercially available compounds include Aronix M-210, Aronix M-309, Aronix M-310, Aronix M-320, Aronix M-400, Aronix M-7100, Aronix M-8030, Aronix M-8060, M-8100, M-9050, M-240, M-245, M-6100, M-6200, M-6250, M-6300, M-6400, M-6500 ( Above, manufactured by Toagosei Co., Ltd.), KAYARAD R-551, R-712, TMPTA, HDDA, TPGDA, PEG400DA, MANDA, HX-220, HX-620, R-604, DPCA-20, DPCA-30, DPCA-60, DPCA-120 (manufactured by Nippon Kayaku Co., Ltd.), Viscoat #295, 300, 260, 312, 335HP, 360, GPT, 3PA, 400 (manufactured by Osaka Organic Chemical Industry Co., Ltd.) and the like.

These polymerizable compounds (E) may be used singly or in combination of two or more.
The content of the polymerizable compound (E) is preferably 1 to 100 parts by mass, more preferably 5 to 50 parts by mass, and still more preferably 10 to 30 parts by mass with respect to 100 parts by mass of the polymerizable compound (A). be.

The photosensitive composition of the present invention preferably contains an alkali-soluble resin (F). When the photosensitive composition contains the alkali-soluble resin (F), the resist can be imparted with resistance to the plating solution, and development can be performed with an alkali developer.

The alkali-soluble resin (F) is a resin having a property of dissolving in an alkaline developer to the extent that the intended development processing is possible. As the alkali-soluble resin (F), for example, JP-A-2008-276194, JP-A-2003-241372, JP-A-2009-531730, WO2010/001691, JP-A-2011-123225, JP Examples include alkali-soluble resins described in JP-A-2009-222923, JP-A-2006-243161, and the like.

Polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography of the alkali-soluble resin (F) is usually 1,000 to 1,000,000, preferably 2,000 to 50,000, and more It is preferably in the range of 3,000 to 20,000.

The alkali-soluble resin (F) preferably has a phenolic hydroxyl group from the viewpoint of improving the plating solution resistance of the resist.
As the alkali-soluble resin (F) having a phenolic hydroxyl group, an alkali-soluble resin (F1) having a structural unit represented by the following formula (5) (hereinafter also referred to as "structural unit (5)") is preferable.

（式（５）中、Ｒ⁵は、水素原子、炭素数１～１０の置換若しくは非置換のアルキル基、またはハロゲン原子を示し、Ｒ⁶は、単結合又はエステル結合を示し、Ｒ⁷はヒドロキシアリール基を示す。）

(In formula (5), R ⁵ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a halogen atom, R ⁶ represents a single bond or an ester bond, and R ⁷ represents a hydroxy indicates an aryl group.)

By using the alkali-soluble resin (F1) as the alkali-soluble resin (F), it is possible to obtain a resist pattern that is less likely to swell in step (4) of plating a substrate, which will be described later. As a result, the resist pattern does not float or come off from the base material, so even when plating is performed for a long time, the plating solution can be prevented from seeping out to the interface between the base material and the resist pattern. . Further, by using the alkali-soluble resin (A1) as the alkali-soluble resin (A), the resolution of the photosensitive composition can be improved.

The alkali-soluble resin (F) may be used singly or in combination of two or more.
The content of the alkali-soluble resin (F) is generally 100-300 parts by mass, preferably 150-250 parts by mass, per 100 parts by mass of the polymerizable compound (A). When the content of the alkali-soluble resin is within the above range, it becomes possible to form a resist having excellent plating solution resistance.

The photosensitive composition of the present invention includes, as other components, a photoradical polymerization initiator other than the photoradical polymerization initiator (B), a solvent, a surfactant, an adhesion aid, a sensitizer, an inorganic filler, and a polymerization inhibitor. etc. may be included as long as the objects and characteristics of the present invention are not impaired.
By containing a solvent, the photosensitive composition of the present invention is improved in handleability, easily adjusted in viscosity, and improved in storage stability.

As a solvent,
Alcohols such as methanol, ethanol, propylene glycol;
Cyclic ethers such as tetrahydrofuran and dioxane;
Glycols such as ethylene glycol and propylene glycol;
Alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether;
Alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate;
aromatic hydrocarbons such as toluene and xylene;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone;
ethyl acetate, butyl acetate, ethyl ethoxyacetate, ethyl hydroxyacetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, 3 -esters such as ethyl methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl lactate;
N-methylformamide, N,N-dimethylformamide, N-methylformanilide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzyl ethyl ether, dihexyl ether, acetonylacetone, isophorone , caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate and the like.

A solvent may be used individually by 1 type, and may use 2 or more types together.
The amount of the solvent used can be such that the solid content of the present photosensitive composition is 5 to 80% by mass when forming a resist pattern with a film thickness of 0.1 to 100 μm.
The photosensitive composition of the present invention can be produced by uniformly mixing the above components.

[Method of forming a resist pattern]
The method for forming a resist pattern of the present invention includes the step (1) of applying the above-described photosensitive composition on a substrate to form a coating film, the step (2) of exposing the coating film, and exposing the coating film after exposure. It is characterized by having a step (3) of developing.

In step (1), the photosensitive composition is applied onto a substrate to form a coating film.
Examples of the substrate include semiconductor substrates, glass substrates, silicon substrates, and substrates formed by providing various metal films on the surfaces of semiconductor plates, glass plates, and silicon plates. There are no particular restrictions on the shape of the substrate. It may be in the shape of a flat plate, or may be in the shape of a flat plate provided with recesses (holes) like a silicon wafer. In the case of a substrate having recesses and a copper film on the surface, the copper film may be provided on the bottom of the recesses as in the TSV structure.

Examples of the method for applying the photosensitive composition include a spray method, a roll coating method, a spin coating method, a slit die coating method, a bar coating method, and an inkjet method, and the spin coating method is particularly preferred. In the spin coating method, the rotation speed is usually 800-3000 rpm, preferably 800-2000 rpm, and the rotation time is usually 1-300 seconds, preferably 5-200 seconds. After spin-coating the photosensitive composition, the resulting coating film is generally dried by heating at 50 to 180° C., preferably 60 to 150° C., more preferably 70 to 110° C. for about 1 to 30 minutes.

The thickness of the coating film is usually 0.1 to 200 μm, preferably 5 to 150 μm, more preferably 20 to 100 μm, still more preferably 30 to 80 μm.
In step (2), the coating film is exposed. That is, the coating film is selectively exposed so as to obtain a resist pattern in step (3).

Exposure is usually carried out through a desired photomask using, for example, a contact aligner, stepper or scanner, to expose the coating film. As exposure light, light with a wavelength of 200 to 500 nm (eg, i-line (365 nm)) is used. The amount of exposure varies depending on the type and amount of components in the coating film, the thickness of the coating film, etc., but when i-line is used as the exposure light, it is usually 1 to 10,000 mJ/cm ² .

Heat treatment can also be performed after exposure. The conditions for the heat treatment after exposure are appropriately determined depending on the types and amounts of components in the coating film, the thickness of the coating film, etc., and are usually 70 to 180° C. for 1 to 60 minutes.

In step (3), the exposed coating film is developed. A resist pattern is thus formed.
Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3. An aqueous solution of 0]-5-nonane can be used. Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the above aqueous solution of alkalis can be used as a developer.

The development time is usually 30 to 600 seconds, although it varies depending on the type and blending ratio of each component in the composition, the thickness of the coating film, and the like. The method of development may be any of a liquid swell method, a dipping method, a paddle method, a spray method, a shower development method, and the like.
The resist pattern may be washed with running water or the like. After that, it may be air-dried using an air gun or the like, or dried under heat such as a hot plate or an oven.

[Manufacturing method of plated model]
The method for producing a plated model of the present invention includes the step (4) of plating the substrate using the resist pattern formed by the above-described method for forming a resist pattern as a mask, and applying an alkaline compound to the resist pattern. It is characterized by having a step (5) of removing with a resist stripping solution (hereinafter also referred to as “resist stripping solution”) substantially containing no organic solvent.

Examples of the plated article include bumps, wiring, and the like.
The formation of the resist pattern is carried out according to the method of forming the resist pattern described above.
The plating treatment in step (4) includes wet plating treatments such as electrolytic plating treatment, electroless plating treatment and hot dip plating treatment, and dry plating treatments such as chemical vapor deposition and sputtering. When forming wiring and connection terminals in wafer-level processing, plating is usually performed by electroplating.

In order to increase the affinity between the inner wall surface of the resist pattern and the plating solution, the inner wall surface of the resist pattern may be subjected to pretreatment such as ashing, fluxing, and desmearing prior to electrolytic plating.

In the case of electrolytic plating, a layer formed on the inner wall of the resist pattern by sputtering or electroless plating can be used as a seed layer. It can also be used as a layer.

The barrier layer may be formed before forming the seed layer, or the seed layer may be used as the barrier layer.
Plating solutions used for electrolytic plating include, for example, 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; is mentioned.

The plating process can be performed sequentially with different plating processes. For example, solder copper pillar bumps can be formed by first performing a copper plating process, then performing a nickel plating process, and then performing a molten solder plating process.

In step (5), the resist pattern is removed with a resist remover.
Before removing with a resist stripping solution, acid is generated from the acid generator (D) contained in the resist pattern to decompose the crosslinked structure of the polymerizable compound (A) in the resist pattern.
In order to generate an acid from the acid generator (D), usually, when the acid generator (D) is the thermal acid generator (D1), heat treatment is performed at 80 to 250° C. to obtain the acid generator (D). is a photoacid generator, UV irradiation treatment is performed.

After the acid is generated from the acid generator (D), heat treatment can be performed at 80 to 250° C. in order to accelerate the decomposition of the crosslinked structure by the polymerizable compound (A).
In addition, both the heat treatment for generating acid from the thermal acid generator (D1) and the heat treatment for promoting the decomposition of the crosslinked structure by the polymerizable compound (A) having an acid-dissociable group are Generally, the temperature is higher than the heating temperature for drying the coating film after spin coating the photosensitive composition in step (1).

After decomposing the cross-linked structure of the polymerizable compound (A) in the resist pattern, the resist pattern is stripped by bringing the resist stripper into contact with the resist pattern.
Examples of the method of contacting the resist stripping solution with the resist pattern include a method of pouring the resist stripping solution on the substrate having the resist pattern, and a method of immersing the substrate having the resist pattern in the resist stripping solution.

The contact time between the resist stripping solution and the resist pattern is usually 1000 seconds or less, preferably 600 seconds or less, and the lower limit is 30 seconds or more.
The resist stripping solution can be used after being warmed to, for example, 50 to 150° C. in order to facilitate the stripping of the resist pattern.

As the resist stripping solution, an organic solvent such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, cyclohexanone, acetone, N-methyl-2-pyrrolidone, ethyl lactate, or methyl amyl ketone; or a combination thereof; liquid.

In the method for forming a resist pattern, since the resist pattern is formed using the above-described photosensitive composition, it can be easily removed from the substrate with a resist stripping solution containing substantially only an organic solvent that does not contain an alkaline compound. possible resist patterns can be formed. Therefore, using this resist pattern as a mask, the substrate is subjected to processing such as plating, and then the resist pattern is stripped with a resist stripping solution containing essentially only an organic solvent that does not contain an alkaline compound, thereby forming a bump electrode or a wiring. It is possible to manufacture a plated modeled article without causing corrosion to metal such as copper used for the plated modeled article.

EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the description of the following examples and the like, "part" is used to mean "part by mass".
The weight average molecular weight (Mw) of the alkali-soluble resin is a value calculated by polystyrene conversion in the gel permeation chromatography method under the following conditions.
Column: TSK-M and TSK2500 columns manufactured by Tosoh Corporation are connected in series.
・Solvent: Tetrahydrofuran ・Column temperature: 40°C
・Detection method: refractive index method ・Standard material: polystyrene ・GPC device: manufactured by Tosoh Corporation, device name “HLC-8220-GPC”

<Production of photosensitive composition>
[Examples 1A-2A and Comparative Examples 1A-3A]
Using propylene glycol monomethyl ether acetate as a solvent, each component in the amount shown in Table 1 below was added to the solvent so that the solid content concentration was 65% by mass, mixed, and filtered through a capsule filter (pore size 3 μm). Examples 1A-2A, and Comparative Examples 1A-3A
was prepared. The details of each component shown in Table 1 are as follows.
A-1: a compound represented by the above formula (4) B-1: a compound represented by the following formula (B-1)

Ｂ－２：２，４，６－トリメチルベンゾイルジフェニルホスフィンオキサイド
Ｃ－１：ペンタエリスリトール テトラキス （３－メルカプトブチレート）（製品名「カレンズＭＴ ＰＥ１」、昭和電工（株）製）
Ｄ－１：ベンジル（４－ヒドロキシフェニル）メチルスルホニウムと、トリス（ペンタフルオロエチル）トリフルオロホスフェート との塩
Ｅ－１：ポリエステルアクリレート（製品名「アロニックスＭ－８０６０」、東亜合成（株）製）
Ｅ－２：水添フタル酸とエポキシアクリレートとの反応物（ 商品名「デナコールＤＡ－７２２」、ナガセケムテックス（株）社製）
Ｆ－１：下記式（Ｆ－１）に示す、記号ａ～ｅを付した構造単位を有するアクリル系樹脂（Ｍｗ：１８，０００、構造単位ａ～ｅの含有割合：ａ／ｂ／ｃ／ｄ／ｅ＝１０／１５／２０／２５／３０（質量％））

B-2: 2,4,6-trimethylbenzoyldiphenylphosphine oxide C-1: Pentaerythritol tetrakis (3-mercaptobutyrate) (product name "Karenzu MT PE1", manufactured by Showa Denko K.K.)
D-1: Salt of benzyl (4-hydroxyphenyl) methylsulfonium and tris (pentafluoroethyl) trifluorophosphate E-1: Polyester acrylate (product name "Aronix M-8060", manufactured by Toagosei Co., Ltd.)
E-2: Reaction product of hydrogenated phthalic acid and epoxy acrylate (trade name “Denacol DA-722”, manufactured by Nagase ChemteX Corporation)
F-1: Acrylic resin having structural units with symbols a to e shown in the following formula (F-1) (Mw: 18,000, content ratio of structural units a to e: a/b/c/ d/e = 10/15/20/25/30 (% by mass))

<Formation of resist pattern and production of plated model>
[Example 1B]
A substrate provided with a sputtered copper film on a 6-inch silicon wafer was coated with the photosensitive composition of Example 1A by spin coating and heated at 80° C. for 300 seconds on a hot plate to form a coating having a film thickness of 50 μm. A film was formed.

The coating film is exposed through a pattern mask using a stepper (manufactured by Nikon Corporation, model "NSR-i12D"), and developed by being immersed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide for 200 seconds, A resist pattern (20 μm long, 20 μm wide, 50 μm deep hole pattern) was formed.

Using the resist pattern as a mask, electroplating was performed to manufacture a plated model. As a pretreatment for the electroplating treatment, an oxygen plasma ashing treatment (output of 100 W, oxygen flow rate of 100 ml, treatment time of 60 seconds) was performed, and then water washing was performed. The substrate after pretreatment was immersed in 1 L of a copper plating solution (product name “Microfab Cu300”, manufactured by Nippon Electroplating Engineers Co., Ltd.), and the plating bath temperature was set to 40° C. and the current density to 2 A/dm ² . , electroplating was performed for 15 minutes to produce a plated model.

After manufacturing the plated model, the interface between the resist pattern and the substrate is observed with an electron microscope to see if the plating solution has permeated. It was evaluated according to the standard. The evaluation results are shown in Table 2 below.
A: No penetration of the plating solution.
B: Permeation of plating solution.
After the plating treatment, the resist pattern was removed with a remover.

The plated substrate was heated on a hot plate at 120° C. for 300 seconds. After heating, the substrate was returned to room temperature (23° C.), then immersed in propylene glycol monomethyl ether acetate at 23° C. as a stripping solution for 300 seconds, and dried on a hot plate.

The presence or absence of the resist pattern remaining on the substrate after immersion and drying was observed with an electron microscope, and the presence or absence of the resist pattern was evaluated as "resist pattern peelability" according to the following evaluation criteria. The evaluation results are shown in Table 2 below.
A: No resist pattern remains.
B: Resist pattern remains.

[Example 2B, Comparative Examples 1B to 3B]
In Example 1B, a resist pattern was formed and a plated model was produced in the same manner as in Example 1B, except that the photosensitive composition shown in Table 2 was used. evaluated the sex. Table 2 shows the evaluation results.

Claims (6)

A polymerizable compound (A) having two or more radically polymerizable unsaturated double bond groups and an acid dissociable group present in the molecular chain connecting the two unsaturated double bond groups, and a radical photopolymerization initiator (B), a polyfunctional thiol (C), and an acid generator (D) ,
A photosensitive composition, wherein the polymerizable compound (A) is a (meth)acrylate compound represented by the following formula (1) .

(In formula (1), p represents an integer of 2 or more, Z represents a p-valent organic group in which at least one of the terminal carbons is a tertiary carbon, and R ¹ represents a hydrogen atom or a methyl group. ) The photosensitive composition according to claim 1, containing 80 to 150 parts by mass of the polyfunctional thiol (C) with respect to 100 parts by mass of the polymerizable compound (A). 3. The photosensitive composition according to claim 1, further comprising an alkali-soluble resin (F). 4. The photosensitive composition according to any one of claims 1 to 3 , wherein the acid generator (D) is a thermal acid generator (D1). The step (1) of applying the photosensitive composition according to any one of claims 1 to 4 on a substrate to form a coating film, the step (2) of exposing the coating film, and the coating film after exposure. A method of forming a resist pattern, comprising a step (3) of developing a. A step (4) of plating the substrate using the resist pattern formed by the method of forming a resist pattern according to claim 5 as a mask; A method for manufacturing a plated model, comprising a step (5) of removing with a resist stripping solution consisting of only.