JP6147995B2 - Forming method of plating model - Google Patents

Description

  The present invention relates to a method for forming a plated model.

  Currently, photofabrication is the mainstream of precision micromachining technology. Photofabrication is the application of a photoresist composition to the workpiece surface to form a photoresist layer, patterning the photoresist layer by photolithography technology, chemical etching and electrolysis using the patterned photoresist layer (photoresist pattern) as a mask. A generic term for technologies for manufacturing various precision parts such as semiconductor packages by performing etching or electroforming mainly composed of electroplating.

  In recent years, with the downsizing of electronic devices, high-density packaging technology for semiconductor packages has progressed, and the use of multi-pin thin film packaging for packages, miniaturization of package size, two-dimensional packaging technology by flip chip method, and three-dimensional packaging technology. Based on this, the mounting density is improved. In such a high-density mounting technology, as connection terminals, for example, protruding electrodes (mounting terminals) such as bumps protruding on the package, or metal posts that connect the rewirings extending from the peripheral terminals on the wafer and the mounting terminals. Etc. are arranged on the substrate with high accuracy.

  A photoresist composition is used for the above photofabrication, and as such a photoresist composition, a chemically amplified photoresist composition containing an acid generator is known (Patent Documents 1, 2, etc.). See). The chemically amplified photoresist composition generates an acid from the acid generator by irradiation (exposure), and the acid diffusion is promoted by the heat treatment to cause an acid catalytic reaction to the base resin or the like in the composition. The alkali solubility changes.

  Such a chemically amplified positive photoresist composition is used, for example, for forming bumps and metal posts by a plating process. Specifically, using a chemically amplified photoresist composition, a photoresist layer having a desired film thickness is formed on a substrate serving as a support, exposed through a predetermined mask pattern, developed, and exposed to bumps or metal. A photoresist pattern is formed by selectively removing (stripping) the portion where the post is to be formed. And after embedding conductors, such as copper, in this removed part (non-resist part) by plating, the bump and metal post which are plating modeling objects can be formed by removing the surrounding photoresist pattern. .

JP 9-176112 A JP 11-52562 A

  In the formation of a plated model by the above plating process, it is desirable that the width of the bottom (the side in contact with the substrate surface) of the formed model is larger than the width of the top facing the bottom. This is because the contact area between the bottom surface of the plated model and the substrate increases, and the plated model and the substrate can be stably adhered.

  However, when a conventionally known chemically amplified positive photoresist composition as disclosed in Patent Documents 1 and 2, etc. is used to form a photoresist pattern for forming a plated shaped article, an opening is formed in a non-resist portion. It is difficult to form a photoresist pattern including a non-resist portion where the bottom width of the non-resist portion is larger than the width of the portion (top side). For this reason, when using a chemically amplified positive photoresist composition as disclosed in Patent Documents 1 and 2 and the like, it is difficult to form a plated model that can be stably adhered to the substrate.

  The present invention has been made in view of the above problems, and the width of the bottom (the side in contact with the substrate surface) is larger than the width of the top facing the bottom, and can be stably adhered to the substrate. It aims at providing the formation method of a molded article.

The inventors of the present invention formed a composite film composed of a lower layer film and an upper layer film made of a positive photoresist composition on a substrate, and determined the dissolution rate ^RL of the exposed lower layer film in an alkaline developer after the exposure. It has been found that the above problem can be solved by setting the upper layer film to a dissolution rate ^RU higher than that of the alkali developer, and the present invention has been completed. Specifically, the present invention provides the following.

Aspects of the present invention include
An underlayer film forming step of forming an underlayer film on the substrate;
An upper layer film forming step of forming an upper layer film by applying a positive photoresist composition on the lower layer film;
An exposure step of selectively exposing a composite film composed of a lower layer film and an upper layer film;
A development step of developing the composite film after exposure with an alkaline developer to obtain a pattern of the composite film;
A plating step of plating the portion where the composite film in the pattern of the composite film has been removed, and
Dissolution rate R ^L in an alkali developer of the lower film after exposure is greater than the dissolution rate R ^U in an alkali developing solution of the upper layer film after exposure, a method of forming a plating shaped object.

  According to the present invention, there is provided a method for forming a plated shaped article that can stably adhere to a substrate, wherein the width of the bottom (the side in contact with the substrate surface) is larger than the width of the top facing the bottom. Can do.

It is a figure which shows the outline of the formation method of the plating molded article of this invention.

In the method for forming a plated model according to the present invention, a composite film composed of a lower layer film and an upper layer film is formed on a substrate. The composite film is selectively exposed and then developed with an alkali developer. The dissolution rate ^RL of the exposed lower layer film in the alkali developer is equal to the dissolution rate of the exposed upper layer film in the alkali developer. it is greater than R ^U. Hereinafter, an upper layer film, a lower layer film, and a specific method for forming a plated model will be described.

≪Upper layer film≫
The upper layer film is formed by applying a positive photoresist composition on the lower layer film described later. Positive photoresist composition used for forming the upper layer film, the dissolution rate R ^L in an alkali developer of the lower film after exposure, unless it is greater than the dissolution rate R ^U in an alkali developing solution of the upper layer film after exposure It is not limited. The positive photoresist composition for forming the upper layer film can be appropriately selected from various positive resist compositions used for masks when forming a plated model.

  Among the positive photoresist compositions (hereinafter, simply referred to as “photoresist compositions”), an acid generator (A) that generates an acid upon irradiation with actinic rays or radiation, and an alkali by an action of an acid. What contains resin (B) from which solubility increases, and an organic solvent (S) are mentioned.

<Acid generator (A)>
The acid generator (A) is a compound that generates an acid upon irradiation with actinic rays or radiation, and is not particularly limited as long as it is a compound that generates an acid directly or indirectly by light. As an acid generator (A), the acid generator of the 1st-5th aspect demonstrated below is preferable. Hereinafter, preferred ones of the acid generator (A) suitably used in the photoresist composition will be described as first to fifth aspects.

  As a 1st aspect in an acid generator (A), the compound represented by the following general formula (a1) is mentioned.

In the general formula (a1), X ^1a represents a sulfur atom or an iodine atom having a valence g, and g is 1 or 2. h represents the number of repeating units in the structure in parentheses. R ^1a is an organic group bonded to X ^1a and is an aryl group having 6 to 30 carbon atoms, a heterocyclic group having 4 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, or an alkyl group having 2 to 30 carbon atoms. Represents an alkenyl group or an alkynyl group having 2 to 30 carbon atoms, and R ^1a represents alkyl, hydroxy, alkoxy, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, arylthiocarbonyl, acyloxy, arylthio, alkylthio, aryl , Heterocyclic, aryloxy, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, alkyleneoxy, amino, cyano, nitro groups, and at least one selected from the group consisting of halogen may be substituted. The number of R ^1a is g + h (g−1) +1, and R ^1a may be the same as or different from each other. Also, directly with each other two or more ^{R 1a,} or _{-O -, - S -, -} SO -, - SO 2 -, - NH -, - NR 2a -, - CO -, - COO -, - CONH- May be bonded via an alkylene group having 1 to 3 carbon atoms or a phenylene group to form a ring structure containing X ^1a . R ^2a is an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms.

X ^2a is a structure represented by the following general formula (a2).

In the general formula (a2), X ^4a represents an alkylene group having 1 to 8 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a divalent group of a heterocyclic compound having 8 to 20 carbon atoms, and X ^4a represents It may be substituted with at least one selected from the group consisting of alkyl having 1 to 8 carbons, alkoxy having 1 to 8 carbons, aryl having 6 to 10 carbons, hydroxy, cyano, nitro, and halogen. Good. X ^5a is _{-O -, - S -, -} SO -, - SO 2 -, - NH -, - NR 2a -, - CO -, - COO -, - CONH-, alkylene group having 1 to 3 carbon atoms, Or represents a phenylene group. h represents the number of repeating units in the structure in parentheses. The h + 1 X ^4a and the h X ^5a may be the same or different. R ^2a is the same as defined above.

X ^3a- is an onium counter ion, and examples thereof include a fluorinated alkyl fluorophosphate anion represented by the following general formula (a17) or a borate anion represented by the following general formula (a18).

In the general formula (a17), R ^3a represents an alkyl group in which 80% or more of hydrogen atoms are substituted with fluorine atoms. j shows the number and is an integer of 1-5. j R ^3a may be the same or different.

In the general formula (a18), R ^{4a to} R ^7a each independently represents a fluorine atom or a phenyl group, and part or all of the hydrogen atoms of the phenyl group are selected from the group consisting of a fluorine atom and a trifluoromethyl group. It may be substituted with at least one selected.

  Examples of the onium ion in the compound represented by the general formula (a1) include triphenylsulfonium, tri-p-tolylsulfonium, 4- (phenylthio) phenyldiphenylsulfonium, bis [4- (diphenylsulfonio) phenyl] sulfide. Bis [4- {bis [4- (2-hydroxyethoxy) phenyl] sulfonio} phenyl] sulfide, bis {4- [bis (4-fluorophenyl) sulfonio] phenyl} sulfide, 4- (4-benzoyl-2 -Chlorophenylthio) phenylbis (4-fluorophenyl) sulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium, 7-isopropyl-9-oxo- 10-thia-9,10-dihydroanthra N-2-yldiphenylsulfonium, 2-[(diphenyl) sulfonio] thioxanthone, 4- [4- (4-tert-butylbenzoyl) phenylthio] phenyldi-p-tolylsulfonium, 4- (4-benzoylphenylthio) phenyl Diphenylsulfonium, diphenylphenacylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 2-naphthylmethyl (1-ethoxycarbonyl) ethylsulfonium, 4-hydroxyphenylmethylphenacylsulfonium, phenyl [4- (4-biphenylthio) phenyl] 4-biphenylsulfonium, phenyl [4- (4-biphenylthio) phenyl] 3-biphenylsulfonium, [4- (4-acetophenylthio) phenyl] diphenylsulfonium, oct Decylmethylphenacylsulfonium, diphenyliodonium, di-p-tolyliodonium, bis (4-dodecylphenyl) iodonium, bis (4-methoxyphenyl) iodonium, (4-octyloxyphenyl) phenyliodonium, bis (4-decyloxy) Examples thereof include phenyliodonium, 4- (2-hydroxytetradecyloxy) phenylphenyliodonium, 4-isopropylphenyl (p-tolyl) iodonium, and 4-isobutylphenyl (p-tolyl) iodonium.

  Among the onium ions in the compound represented by the general formula (a1), a preferable onium ion includes a sulfonium ion represented by the following general formula (a19).

In the general formula (a19), R ^8a is independently a hydrogen atom, alkyl, hydroxy, alkoxy, alkylcarbonyl, alkylcarbonyloxy, alkyloxycarbonyl, halogen atom, aryl optionally having substituent, arylcarbonyl, Represents a group selected from the group consisting of X ^2a represents the same meaning as X ^2a in the general formula (a1).

  Specific examples of the sulfonium ion represented by the general formula (a19) include 4- (phenylthio) phenyldiphenylsulfonium, 4- (4-benzoyl-2-chlorophenylthio) phenylbis (4-fluorophenyl) sulfonium, 4 -(4-benzoylphenylthio) phenyldiphenylsulfonium, phenyl [4- (4-biphenylthio) phenyl] 4-biphenylsulfonium, phenyl [4- (4-biphenylthio) phenyl] 3-biphenylsulfonium, [4- ( 4-acetophenylthio) phenyl] diphenylsulfonium, diphenyl [4- (p-terphenylthio) phenyl] diphenylsulfonium.

In the fluorinated alkyl fluorophosphate anion represented by the general formula (a17), R ^3a represents an alkyl group substituted with a fluorine atom, preferably having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms. is there. Specific examples of the alkyl group include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and octyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl and tert-butyl; and cyclopropyl, cyclobutyl and cyclopentyl. And the ratio of the hydrogen atom of the alkyl group substituted by a fluorine atom is usually 80% or more, preferably 90% or more, and more preferably 100%. When the substitution rate of fluorine atoms is less than 80%, the acid strength of the onium fluorinated alkyl fluorophosphate represented by the general formula (a1) is lowered.

Particularly preferred R ^3a is a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms and a substitution rate of 100% of fluorine atoms. Specific examples include CF ₃ , CF ₃ CF ₂ , (CF ₃ ) ₂ CF, CF ₃ CF ₂ CF ₂ , CF ₃ CF ₂ CF ₂ CF ₂ , (CF ₃ ) ₂ CFCF ₂ , CF ₃ CF ₂ (CF ₃ ) CF, (CF ₃ ) ₃ C may be mentioned. . The number j of R ^3a is an integer of 1 to 5, preferably 2 to 4, particularly preferably 2 or 3.

Specific examples of preferred fluorinated alkyl fluorophosphate anions include [(CF ₃ CF ₂ ) ₂ PF ₄ ] ⁻ , [(CF ₃ CF ₂ ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) _2. PF ₄ ] ⁻ , [((CF ₃ ) ₂ CF) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₂ PF ₄ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ] ⁻ , [((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ CF ₂ ) ₂ PF ₄ ] ⁻ , or [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , and among these, [(CF ₃ CF ₂ ) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , _{[((CF 3) 2 CF} ) 3 PF 3 ^{_{-, [((CF 3)}} 2 CF) 2 PF 4] -, [((CF 3) 2 CFCF 2) 3 PF 3] -, or _{[((CF 3) 2 CFCF} 2) 2 PF 4] - is Particularly preferred.

Preferred specific examples of the borate anion represented by the general formula (a18) include tetrakis (pentafluorophenyl) borate ([B (C ₆ F ₅ ) ₄ ] ⁻ ), tetrakis [(trifluoromethyl) phenyl] borate. ([B (C ₆ H ₄ CF ₃ ) ₄ ] ⁻ ), difluorobis (pentafluorophenyl) borate ([(C ₆ F ₅ ) ₂ BF ₂ ] ⁻ ), trifluoro (pentafluorophenyl) borate ([( C ₆ F ₅ ) BF ₃ ] ⁻ ), tetrakis (difluorophenyl) borate ([B (C ₆ H ₃ F ₂ ) ₄ ] ⁻ ) and the like. Among these, tetrakis (pentafluorophenyl) borate ([B (C ₆ F ₅ ) ₄ ] ⁻ ) is particularly preferable.

  As a second aspect of the acid generator (A), 2,4-bis (trichloromethyl) -6-piperonyl-1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2 -(2-furyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (5-methyl-2-furyl) ethenyl] -s-triazine, 2,4-bis ( Trichloromethyl) -6- [2- (5-ethyl-2-furyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (5-propyl-2-furyl) ethenyl ] -S-triazine, 2,4-bis (trichloromethyl) -6- [2- (3,5-dimethoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2 -(3,5-diethoxyf Nyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3,5-dipropoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl)- 6- [2- (3-Methoxy-5-ethoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3-methoxy-5-propoxyphenyl) ethenyl]- s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3,4-methylenedioxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- (3 , 4-methylenedioxyphenyl) -s-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis- Lichloromethyl-6- (2-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) styrylphenyl-s-triazine, 2,4- Bis-trichloromethyl-6- (3-bromo-4-methoxy) styrylphenyl-s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-Methoxynaphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl)- 1,3,5-triazine, 2- [2- (5-methyl-2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3 , 5- Dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl)- 1,3,5-triazine, 2- (3,4-methylenedioxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, tris (1,3-dibromopropyl) -1 , 3,5-triazine, halogen-containing triazine compounds such as tris (2,3-dibromopropyl) -1,3,5-triazine, and the following general formulas such as tris (2,3-dibromopropyl) isocyanurate ( and halogen-containing triazine compounds represented by a3).

In the general formula (a3), R ^9a , R ^10a and R ^11a each independently represent a halogenated alkyl group.

  In addition, as a third aspect in the acid generator (A), α- (p-toluenesulfonyloxyimino) -phenylacetonitrile, α- (benzenesulfonyloxyimino) -2,4-dichlorophenylacetonitrile, α- (benzene Sulfonyloxyimino) -2,6-dichlorophenylacetonitrile, α- (2-chlorobenzenesulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, and oxime sulfonate The compound represented by the following general formula (a4) containing a group is mentioned.

In the general formula (a4), R ^12a represents a monovalent, divalent, or trivalent organic group, and R ^13a represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group, or aromatic group. N represents the number of repeating units having a structure in parentheses.

In the above general formula (a4), the aromatic compound group refers to a group of a compound exhibiting physical and chemical properties peculiar to an aromatic compound. For example, an aryl group such as a phenyl group or a naphthyl group, or furyl And heteroaryl groups such as a thienyl group and the like. These may have one or more suitable substituents such as a halogen atom, an alkyl group, an alkoxy group, and a nitro group on the ring. R ^13a is particularly preferably an alkyl group having 1 to 6 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. In particular, a compound in which R ^12a is an aromatic compound group and R ^13a is an alkyl group having 1 to 4 carbon atoms is preferable.

As the acid generator represented by the general formula (a4), when n = 1, R ^12a is any one of a phenyl group, a methylphenyl group, and a methoxyphenyl group, and R ^13a is a methyl group, Specifically, α- (methylsulfonyloxyimino) -1-phenylacetonitrile, α- (methylsulfonyloxyimino) -1- (p-methylphenyl) acetonitrile, α- (methylsulfonyloxyimino) -1- (p -Methoxyphenyl) acetonitrile, [2- (propylsulfonyloxyimino) -2,3-dihydroxythiophene-3-ylidene] (o-tolyl) acetonitrile, and the like. When n = 2, the acid generator represented by the general formula (a4) specifically includes an acid generator represented by the following formula.

  Moreover, as a 4th aspect in an acid generator (A), the onium salt which has a naphthalene ring in a cation part is mentioned. This “having a naphthalene ring” means having a structure derived from naphthalene, and means that at least two ring structures and their aromaticity are maintained. The naphthalene ring may have a substituent such as a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. The structure derived from the naphthalene ring may be a monovalent group (one free valence) or a divalent group (two free valences) or more, but may be a monovalent group. Desirable (however, at this time, the free valence is counted excluding the portion bonded to the substituent). The number of naphthalene rings is preferably 1 to 3.

  As the cation portion of the onium salt having a naphthalene ring in such a cation portion, a structure represented by the following general formula (a5) is preferable.

In the general formula (a5), at least one of R ^14a , R ^15a and R ^16a represents a group represented by the following general formula (a6), and the rest is a linear or branched group having 1 to 6 carbon atoms. An alkyl group, a phenyl group which may have a substituent, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. Alternatively, one of R ^14a , R ^15a and R ^16a is a group represented by the following general formula (a6), and the remaining two are each independently a linear or branched group having 1 to 6 carbon atoms. It is an alkylene group, and these terminals may be bonded to form a ring.

In the general formula (a6), R ^17a and R ^18a are each independently a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, or a linear or branched group having 1 to 6 carbon atoms. Represents an alkyl group, and R ^19a represents a straight-chain or branched alkylene group having 1 to 6 carbon atoms which may have a single bond or a substituent. l and m each independently represent an integer of 0 to 2, and l + m is 3 or less. However, when a plurality of R ^17a are present, they may be the same as or different from each other. When a plurality of R ^18a are present, they may be the same as or different from each other.

Of the R ^14a , R ^15a and R ^16a , the number of groups represented by the general formula (a6) is preferably one from the viewpoint of the stability of the compound, and the rest is a straight chain having 1 to 6 carbon atoms. Or branched alkylene groups, and these ends may be bonded to form a ring. In this case, the two alkylene groups constitute a 3- to 9-membered ring including a sulfur atom. The number of atoms (including sulfur atoms) constituting the ring is preferably 5-6.

  Examples of the substituent that the alkylene group may have include an oxygen atom (in this case, a carbonyl group is formed together with a carbon atom constituting the alkylene group), a hydroxyl group, and the like.

  Examples of the substituent that the phenyl group may have include a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, and a linear or branched alkyl group having 1 to 6 carbon atoms. Is mentioned.

  Suitable examples of these cation moieties include those represented by the following formulas (a7) and (a8), and the structure represented by the following formula (a8) is particularly preferred.

  Such a cation moiety may be an iodonium salt or a sulfonium salt, but a sulfonium salt is desirable from the viewpoint of acid generation efficiency and the like.

  Therefore, an anion capable of forming a sulfonium salt is desirable as a suitable anion portion for an onium salt having a naphthalene ring in the cation portion.

  The anion portion of such an acid generator is a fluoroalkyl sulfonate ion or an aryl sulfonate ion in which a part or all of hydrogen atoms are fluorinated.

  The alkyl group in the fluoroalkylsulfonic acid ion may be linear, branched or cyclic having 1 to 20 carbon atoms, and preferably has 1 to 10 carbon atoms from the bulk of the acid generated and its diffusion distance. In particular, a branched or annular shape is preferable because of its short diffusion distance. Moreover, since it can synthesize | combine cheaply, a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group etc. can be mentioned as a preferable thing.

  The aryl group in the aryl sulfonate ion is an aryl group having 6 to 20 carbon atoms, and examples thereof include an alkyl group, a phenyl group which may or may not be substituted with a halogen atom, and a naphthyl group. In particular, an aryl group having 6 to 10 carbon atoms is preferable because it can be synthesized at low cost. Specific examples of preferable ones include a phenyl group, a toluenesulfonyl group, an ethylphenyl group, a naphthyl group, and a methylnaphthyl group.

  In the fluoroalkyl sulfonate ion or aryl sulfonate ion, the fluorination rate when part or all of the hydrogen atoms are fluorinated is preferably 10 to 100%, more preferably 50 to 100%, In particular, those in which all hydrogen atoms are substituted with fluorine atoms are preferred because the strength of the acid is increased. Specific examples thereof include trifluoromethane sulfonate, perfluorobutane sulfonate, perfluorooctane sulfonate, and perfluorobenzene sulfonate.

  Among these, preferable anion moieties include those represented by the following general formula (a9).

In the general formula (a9), R ^20a is a group represented by the following general formulas (a10) and (a11) or a group represented by the following formula (a12).

In the general formula (a10), x represents an integer of 1 to 4. In the general formula (a11), R ^21a represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 6 carbon atoms. Represents a group, and y represents an integer of 1 to 3. Among these, trifluoromethanesulfonate and perfluorobutanesulfonate are preferable from the viewpoint of safety.

  Moreover, as an anion part, what contains the nitrogen represented by the following general formula (a13) and (a14) can also be used.

Above general formula (a13), in (a14), X ^a represents a linear or branched alkylene group having at least one hydrogen atom is substituted with a fluorine atom, the carbon number of the alkylene group having 2 to 6 Preferably 3 to 5 and most preferably 3 carbon atoms. Y ^a and Z ^a each independently represents a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, Is 1-7, more preferably 1-3.

The smaller the carbon number of the alkylene group of X ^a or the carbon number of the alkyl group of Y ^a and Z ^a , the better the solubility in an organic solvent, which is preferable.

Further, in the alkylene group of X ^a or the alkyl group of Y ^a and Z ^a , the larger the number of hydrogen atoms substituted with fluorine atoms, the more preferable the strength of the acid. The proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

  Preferable examples of the onium salt having a naphthalene ring in such a cation moiety include compounds represented by the following formulas (a15) and (a16).

  The fifth aspect of the acid generator (A) includes bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (2,4- Bissulfonyldiazomethanes such as dimethylphenylsulfonyl) diazomethane; 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, nitrobenzyl tosylate, dinitrobenzyl tosylate, nitrobenzyl sulfonate, Nitrobenzyl derivatives such as nitrobenzyl carbonate and dinitrobenzyl carbonate; pyrogallol trimesylate, pyrogallol tritosylate, benzyl tosylate, benzyl sulfonate, N-methylsulfonyloxysuccine Sulfonic acid esters such as amide, N-trichloromethylsulfonyloxysuccinimide, N-phenylsulfonyloxymaleimide and N-methylsulfonyloxyphthalimide; trifluoromethanesulfonic acid esters such as N-hydroxyphthalimide and N-hydroxynaphthalimide; Iodonium hexafluorophosphate, (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, bis (p-tert-butylphenyl) iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, (4-methoxyphenyl) diphenylsulfonium Trifluoromethanesulfonate, (p-tert-butylphenyl) diphenylsulfonium trifluoro Onium salts such as Tan sulfonate; benzoin tosylate, benzoin tosylate such as α- methyl benzoin tosylate; other diphenyliodonium salts, triphenylsulfonium salts, phenyldiazonium salts, benzyl carbonate and the like.

  This acid generator (A) may be used alone or in combination of two or more. Moreover, it is preferable to set it as 0.1-10 mass% with respect to the total mass of a photoresist composition, and, as for content of an acid generator (A), it is more preferable to set it as 0.5-3 mass%. By making the usage-amount of an acid generator (A) into said range, it is easy to prepare the photoresist composition which is provided with favorable sensitivity, is a uniform solution, and is excellent in storage stability.

<Resin (B)>
The resin (B) whose solubility in an alkali is increased by the action of an acid is not particularly limited, and any resin whose solubility in an alkali is increased by the action of an acid can be used. Among these, it is preferable to contain at least one resin selected from the group consisting of novolac resin (B1), polyhydroxystyrene resin (B2), and acrylic resin (B3).

[Novolac resin (B1)]
As the novolac resin (B1), a resin containing a structural unit represented by the following general formula (b1) can be used.

In the general formula (b1), R ^1b represents an acid dissociable, dissolution inhibiting group, and R ^2b and R ^3b each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Examples of the acid dissociable, dissolution inhibiting group represented by R ^1b include groups represented by the following general formulas (b2) and (b3), linear, branched or cyclic alkyl groups having 1 to 6 carbon atoms. , A vinyloxyethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, or a trialkylsilyl group.

In the general formulas (b2) and (b3), R ^4b and R ^5b each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ^6b represents a carbon number. Represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, R ^7b represents a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, and o represents 0 or 1 Represent.

  Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. . Examples of the cyclic alkyl group include a cyclopentyl group and a cyclohexyl group.

  Here, specific examples of the acid dissociable, dissolution inhibiting group represented by the general formula (b2) include a methoxyethyl group, an ethoxyethyl group, an n-propoxyethyl group, an isopropoxyethyl group, and an n-butoxyethyl group. , Isobutoxyethyl group, tert-butoxyethyl group, cyclohexyloxyethyl group, methoxypropyl group, ethoxypropyl group, 1-methoxy-1-methyl-ethyl group, 1-ethoxy-1-methylethyl group and the like. Specific examples of the acid dissociable, dissolution inhibiting group represented by the general formula (b3) include a tert-butoxycarbonyl group and a tert-butoxycarbonylmethyl group. Examples of the trialkylsilyl group include those having 1 to 6 carbon atoms in each alkyl group such as a trimethylsilyl group and a tri-tert-butyldimethylsilyl group.

[Polyhydroxystyrene resin (B2)]
As polyhydroxystyrene resin (B2), resin containing the structural unit represented by the following general formula (b4) can be used.

In the general formula (b4), R ^8b represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ^9b represents an acid dissociable, dissolution inhibiting group.

  The said C1-C6 alkyl group is a C1-C6 linear, branched, or cyclic alkyl group, for example. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Examples of the cyclic alkyl group include a cyclopentyl group and a cyclohexyl group.

As the acid dissociable, dissolution inhibiting group represented by R ^9b , the same acid dissociable, dissolution inhibiting groups as exemplified in the general formulas (b2) and (b3) can be used.

  Furthermore, the polyhydroxystyrene resin (B2) can contain other polymerizable compounds as constituent units for the purpose of appropriately controlling physical and chemical properties. Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds. Examples of such a polymerizable compound include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; 2-methacryloyloxyethyl succinic acid, 2- Methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, 2-methacryloyloxyethylhexahydrophthalic acid and other methacrylic acid derivatives having a carboxyl group and an ester bond; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (Meth) acrylic acid alkyl esters such as (meth) acrylate; (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; phenyl (meta Acrylic esters containing aromatic groups such as acrylate and benzyl (meth) acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxy Vinyl group-containing aromatic compounds such as styrene, α-methylhydroxystyrene and α-ethylhydroxystyrene; Vinyl group-containing aliphatic compounds such as vinyl acetate; Conjugated diolefins such as butadiene and isoprene; Acrylonitrile, methacrylonitrile Nitrile group-containing polymerizable compounds such as; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide;

[Acrylic resin (B3)]
As acrylic resin (B3), resin containing the structural unit represented by the following general formula (b5)-(b7) can be used.

In the above general formulas (b5) to (b7), R ^{10b to} R ^17b each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, or 1 to 6 carbon atoms. Represents a linear or branched fluorinated alkyl group (wherein R ^11b is not a hydrogen atom), and X ^b is a hydrocarbon having 5 to 20 carbon atoms together with the carbon atom to which it is bonded. forms a ring, Y ^b is substituted represents those aliphatic cyclic group or an alkyl group, p represents an integer of 0 to 4, q represents 0 or 1.

  Examples of the linear or branched alkyl group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. Can be mentioned. The fluorinated alkyl group is one in which part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms.

R ^11b is preferably a linear or branched alkyl group having 2 to 4 carbon atoms from the viewpoint of easily forming an upper film having high contrast and excellent resolution, depth of focus, and the like. ^13b , R ^14b , R ^16b and R ^17b are preferably a hydrogen atom or a methyl group.

^Xb forms an aliphatic cyclic group having 5 to 20 carbon atoms together with the carbon atom to which it is bonded. Specific examples of such an aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Specifically, one or more hydrogen atoms were removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Groups. In particular, a group obtained by removing one or more hydrogen atoms from cyclohexane or adamantane (which may further have a substituent) is preferable.

Furthermore, when the aliphatic cyclic group of ^Xb has a substituent on the ring skeleton, examples of the substituent include polar groups such as a hydroxyl group, a carboxy group, a cyano group, and an oxygen atom (═O). And a linear or branched alkyl group having 1 to 4 carbon atoms. As the polar group, an oxygen atom (═O) is particularly preferable.

Y ^b is an aliphatic cyclic group or an alkyl group, and examples thereof include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. . Specifically, one or more hydrogen atoms were removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Groups and the like. In particular, a group in which one or more hydrogen atoms are removed from adamantane (which may further have a substituent) is preferable.

Furthermore, the alicyclic group of the abovementioned Y ^b is, if they have a substituent on the ring skeleton, examples of the substituent, a hydroxyl group, a carboxyl group, a cyano group, an oxygen atom (= O) polar groups such as And a linear or branched alkyl group having 1 to 4 carbon atoms. As the polar group, an oxygen atom (═O) is particularly preferable.

Also, if Y ^b is an alkyl group, having 1 to 20 carbon atoms, it is preferred that preferably a linear or branched alkyl group having 6 to 15. Such an alkyl group is particularly preferably an alkoxyalkyl group. Examples of the alkoxyalkyl group include 1-methoxyethyl group, 1-ethoxyethyl group, 1-n-propoxyethyl group, 1-isopropoxy group. Ethyl group, 1-n-butoxyethyl group, 1-isobutoxyethyl group, 1-tert-butoxyethyl group, 1-methoxypropyl group, 1-ethoxypropyl group, 1-methoxy-1-methyl-ethyl group, 1 -Ethoxy-1-methylethyl group etc. are mentioned.

  Preferable specific examples of the structural unit represented by the general formula (b5) include those represented by the following formulas (b5-1) to (b5-33).

In the above formulas (b5-1) to (b5-33), R ^18b represents a hydrogen atom or a methyl group.

  Preferable specific examples of the structural unit represented by the general formula (b6) include those represented by the following formulas (b6-1) to (b6-24).

In the above formulas (b6-1) to (b6-24), R ^18b represents a hydrogen atom or a methyl group.

  Preferable specific examples of the structural unit represented by the general formula (b7) include those represented by the following formulas (b7-1) to (b7-15).

In the above formulas (b7-1) to (b7-15), R ^18b represents a hydrogen atom or a methyl group.

  Further, the acrylic resin (B3) is made of a copolymer containing structural units derived from a polymerizable compound having an ether bond with respect to the structural units represented by the general formulas (b5) to (b7). A resin is preferred.

  Examples of the polymerizable compound having an ether bond include radical polymerizable compounds such as a (meth) acrylic acid derivative having an ether bond and an ester bond, and specific examples include 2-methoxyethyl (meth) acrylate. 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) Examples thereof include acrylate, methoxypolypropylene glycol (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate. The polymerizable compound having an ether bond is preferably 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, or methoxytriethylene glycol (meth) acrylate. These polymerizable compounds may be used alone or in combination of two or more.

  Furthermore, other polymerizable compounds can be included in the acrylic resin (B3) as structural units for the purpose of appropriately controlling physical and chemical properties. Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds.

  Examples of such polymerizable compounds include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; 2-methacryloyloxyethyl succinic acid, and 2-methacryloyloxy. Methacrylic acid derivatives having a carboxyl group and an ester bond such as ethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth ) (Meth) acrylic acid alkyl esters such as acrylate and cyclohexyl (meth) acrylate; (meth) acrylic acid hydroxyal such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate Aromatic esters such as phenyl (meth) acrylate and benzyl (meth) acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; styrene, α-methylstyrene, chloro Vinyl group-containing aromatic compounds such as styrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; butadiene, isoprene, etc. Conjugated diolefins; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; This Can.

  Examples of the polymerizable compound include (meth) acrylic acid esters having a non-acid dissociable aliphatic polycyclic group, and vinyl group-containing aromatic compounds. As the non-acid-dissociable aliphatic polycyclic group, a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, a norbornyl group, and the like are particularly preferable in terms of industrial availability. These aliphatic polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

  Specific examples of (meth) acrylic acid esters having an acid non-dissociable aliphatic polycyclic group include those having the structures of the following formulas (b8-1) to (b8-5). it can.

In the above formulas (b8-1) to (b8-5), R ^19b represents a hydrogen atom or a methyl group.

  Among the resins (B), it is preferable to use an acrylic resin (B3). Among such acrylic resins (B3), those derived from the structural unit represented by the general formula (b5), structural units derived from (meth) acrylic acid, and (meth) acrylic acid alkyl esters. A copolymer having a structural unit and a structural unit derived from an aromatic group-containing (meth) acrylic acid ester, and having an acid non-dissociable aliphatic polycyclic group (meta) ) A copolymer containing structural units derived from acrylates is preferred.

Such a copolymer is preferably a copolymer represented by the following general formula (b9).

In the general formula (b9), R ^20b represents a hydrogen atom or a methyl group, R ^21b represents a linear or branched alkyl group having 2 to 4 carbon atoms, and X ^b has the same meaning as described above. , R ^22b represents a linear or branched alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 1 to 6 carbon atoms, R ^23b represents an aryl group having 6 to 12 carbon atoms, and R ^24b Represents an acid non-dissociable aliphatic polycyclic group. As the non-acid dissociable aliphatic polycyclic group, a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, a norbornyl group, and the like are preferable. The non-acid dissociable aliphatic polycyclic group may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

  Furthermore, in the copolymer represented by the general formula (b9), s, t, u, v, and w represent the molar ratio of each structural unit, s is 5 to 45 mol%, and t is 10 ˜65 mol%, u is 5 to 25 mol%, v is 5 to 25 mol%, and w is preferably 0 to 45 mol%. More preferably, w is 5 to 40 mol%.

  The polystyrene equivalent mass average molecular weight of the resin (B) is preferably 10,000 to 600,000, more preferably 20,000 to 400,000, and still more preferably 30,000 to 300,000. By setting it as such a mass average molecular weight, sufficient intensity | strength of an upper film can be hold | maintained, and also the expansion of the profile at the time of plating and generation | occurrence | production of a crack can be prevented.

  The resin (B) is preferably a resin having a dispersity of 1.05 or more. Here, the degree of dispersion is a value obtained by dividing the mass average molecular weight by the number average molecular weight. By setting it as such a dispersion degree, the problem that the stress tolerance with respect to desired plating and the metal layer obtained by a plating process become easy to swell can be avoided.

  The content of the resin (B) is preferably 5 to 60% by mass with respect to the total mass of the photoresist composition.

<Alkali-soluble resin (C)>
The photoresist composition used for forming the upper layer film preferably further contains an alkali-soluble resin (C) in order to improve crack resistance. Here, the alkali-soluble resin is a resin film having a resin concentration of 20% by mass (solvent: propylene glycol monomethyl ether acetate), and a 1 μm-thick resin film is formed on the substrate to form a 2.38% by mass TMAH aqueous solution. When immersed for 1 minute, it means one that dissolves by 0.01 μm or more. The alkali-soluble resin (C) is preferably at least one resin selected from the group consisting of a novolak resin (C1), a polyhydroxystyrene resin (C2), and an acrylic resin (C3).

[Novolac resin (C1)]
The novolak resin (C1) can be obtained, for example, by addition condensation of an aromatic compound having a phenolic hydroxyl group (hereinafter simply referred to as “phenols”) and an aldehyde in the presence of an acid catalyst.

Examples of the phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2 , 3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5- Examples include trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, phloroglicinol, hydroxydiphenyl, bisphenol A, gallic acid, gallic acid ester, α-naphthol, β-naphthol and the like.
Examples of the aldehydes include formaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, acetaldehyde and the like.
The catalyst for the addition condensation reaction is not particularly limited. For example, hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid and the like are used as the acid catalyst.

  In addition, it is possible to further improve the flexibility of the novolak resin by using o-cresol, by replacing the hydrogen atom of the hydroxyl group in the resin with another substituent, or by using bulky aldehydes. It is.

  The mass average molecular weight of the novolak resin (C1) is not particularly limited as long as the object of the present invention is not impaired, but is preferably 1000 to 50000.

[Polyhydroxystyrene resin (C2)]
Examples of the hydroxystyrene compound constituting the polyhydroxystyrene resin (C2) include p-hydroxystyrene, α-methylhydroxystyrene, α-ethylhydroxystyrene, and the like.
Furthermore, the polyhydroxystyrene resin (C2) is preferably a copolymer of a hydroxystyrene compound and a styrene compound. Examples of the styrene compound constituting such a styrene resin include styrene, chlorostyrene, chloromethylstyrene, vinyltoluene, α-methylstyrene, and the like.

  Although the mass average molecular weight of polyhydroxystyrene resin (C2) is not specifically limited in the range which does not inhibit the objective of this invention, It is preferable that it is 1000-50000.

[Acrylic resin (C3)]
The acrylic resin (C3) preferably includes a structural unit derived from a polymerizable compound having an ether bond and a structural unit derived from a polymerizable compound having a carboxyl group.

  Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxypolyethylene glycol ( Examples include (meth) acrylic acid derivatives having an ether bond and an ester bond such as (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate. The polymerizable compound having an ether bond is preferably 2-methoxyethyl acrylate or methoxytriethylene glycol acrylate. These polymerizable compounds may be used alone or in combination of two or more.

  Examples of the polymerizable compound having a carboxyl group include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; 2-methacryloyloxyethyl succinic acid, and 2-methacryloyloxy. Examples thereof include compounds having a carboxyl group and an ester bond such as ethylmaleic acid, 2-methacryloyloxyethylphthalic acid, and 2-methacryloyloxyethylhexahydrophthalic acid. The polymerizable compound having a carboxyl group is preferably acrylic acid or methacrylic acid. These polymerizable compounds may be used alone or in combination of two or more.

  Although the mass average molecular weight of an acrylic resin (C3) is not specifically limited in the range which does not inhibit the objective of this invention, It is preferable that it is 50000-800000.

  The content of the alkali-soluble resin (C) is preferably 0 to 80 parts by mass and more preferably 0 to 60 parts by mass when the total of the resin (B) and the alkali-soluble resin (C) is 100 parts by mass. . By making content of alkali-soluble resin (C) into said range, there exists a tendency which can improve crack tolerance and can prevent the film loss at the time of image development.

<Acid diffusion control agent (D)>
The photoresist composition preferably further contains an acid diffusion control agent (D) in order to improve the shape of the pattern to be formed and the stability of the placement. As the acid diffusion controller (D), a nitrogen-containing compound (D1) is preferable, and an organic carboxylic acid, or an oxo acid of phosphorus or a derivative thereof (D2) can be further contained as necessary.

[Nitrogen-containing compound (D1)]
Examples of the nitrogen-containing compound (D1) include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tri-n-pentylamine, tribenzylamine, diethanolamine, triethanolamine, and n-hexylamine. , N-heptylamine, n-octylamine, n-nonylamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4 '-Diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-di Tylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea Imidazole, benzimidazole, 4-methylimidazole, 8-oxyquinoline, acridine, purine, pyrrolidine, piperidine, 2,4,6-tri (2-pyridyl) -S-triazine, morpholine, 4-methylmorpholine, piperazine, Examples include 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, pyridine and the like. These may be used alone or in combination of two or more.

  The nitrogen-containing compound (D1) is usually used in a range of 0 to 5 parts by mass and in a range of 0 to 3 parts by mass with respect to 100 parts by mass of the total mass of the resin (B) and the alkali-soluble resin (C). It is particularly preferred that

[Organic carboxylic acid or phosphorus oxo acid or derivative (D2)]
Among organic carboxylic acids or phosphorus oxo acids or derivatives thereof (D2), specifically, as malonic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are preferable. In particular, salicylic acid is preferred.

  Examples of phosphorus oxo acids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and the like phosphoric acid and derivatives thereof such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid- Phosphonic acids such as di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester and derivatives thereof; phosphinic acids such as phosphinic acid and phenylphosphinic acid and their esters Derivatives thereof, and the like. Among these, phosphonic acid is particularly preferable. These may be used alone or in combination of two or more.

  The organic carboxylic acid or phosphorus oxo acid or derivative thereof (D2) is usually used in the range of 0 to 5 parts by mass with respect to 100 parts by mass of the total mass of the resin (B) and the alkali-soluble resin (C). And is particularly preferably used in the range of 0 to 3 parts by mass.

  In order to form a salt and stabilize, it is preferable to use an organic carboxylic acid, or an oxo acid of phosphorus or a derivative thereof (D2) in an amount equivalent to the nitrogen-containing compound (D1).

<Organic solvent (S)>
The photoresist composition contains an organic solvent (S). The type of the organic solvent (S) is not particularly limited as long as the object of the present invention is not hindered, and can be appropriately selected from organic solvents conventionally used in positive photoresist compositions.

  Specific examples of the organic solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate Polyhydric alcohols such as dipropylene glycol, dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, monophenyl ether and derivatives thereof; cyclic ethers such as dioxane; ethyl formate, lactic acid Methyl, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, pyruvin Ethyl, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate , Esters such as 3-methoxybutyl acetate and 3-methyl-3-methoxybutyl acetate; aromatic hydrocarbons such as toluene and xylene; and the like. These may be used alone or in combination of two or more.

  The content of the organic solvent (S) is not particularly limited as long as the object of the present invention is not impaired. The photoresist composition preferably contains the organic solvent (S) in a range where the solid content concentration is 10 to 55% by mass, preferably 30 to 55% by mass.

<Other ingredients>
The photoresist composition may further contain a polyvinyl resin in order to improve plasticity. Specific examples of the polyvinyl resin include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoic acid, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl phenol, and copolymers thereof. Is mentioned. The polyvinyl resin is preferably polyvinyl methyl ether because of its low glass transition point.

  The photoresist composition may further contain an adhesion assistant in order to improve the adhesion with the lower layer film.

  In addition, the photoresist composition may further contain a surfactant in order to improve coating properties, antifoaming properties, leveling properties, and the like. Specific examples of the surfactant include BM-1000, BM-1100 (all manufactured by BM Chemie), MegaFuck F142D, MegaFuck F172, MegaFuck F173, MegaFak F183 (all manufactured by Dainippon Ink & Chemicals, Inc.) ), Fluorard FC-135, Fluorard FC-170C, Fluorard FC-430, Fluorard FC-431 (all manufactured by Sumitomo 3M), Surflon S-112, Surflon S-113, Surflon S-131, Surflon S-141, Commercially available fluorosurfactants such as Surflon S-145 (all manufactured by Asahi Glass Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (all manufactured by Toray Silicone Co., Ltd.) However, it is not limited to these.

  Further, the photoresist composition may further contain an acid, an acid anhydride, or a high boiling point solvent in order to finely adjust the solubility in the developer.

  Specific examples of the acid and acid anhydride include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid and cinnamic acid; lactic acid, 2-hydroxybutyric acid, Hydroxy monocarboxylic acids such as 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid and syringic acid Acids: oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid Acid, butanetetracarboxylic acid, trimellitic acid, pyromellitic acid, cyclopentanetetracarbo Polycarboxylic acids such as acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid; itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarbanilic anhydride, maleic anhydride, Hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hymic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, anhydrous And acid anhydrides such as trimellitic acid, benzophenone anhydride tetracarboxylic acid, ethylene glycol bistrimellitic anhydride, and glycerin tris anhydrous trimellitate.

  Specific examples of the high boiling point solvent include N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzyl Ethyl ether, dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate , Propylene carbonate, phenyl cellosolve acetate and the like.

  The photoresist composition may further contain a sensitizer in order to improve sensitivity.

<Preparation of photoresist composition>
The photoresist composition can be prepared by simply mixing and stirring the above-mentioned components by a usual method. If necessary, the photoresist composition may be dispersed and mixed using a disperser such as a dissolver, a homogenizer, or a three-roll mill. Moreover, after mixing, you may filter using a mesh, a membrane filter, etc. further.

<< Underlayer >>
Underlayer film formed on the substrate, which is soluble in an alkaline developer, the dissolution rate R ^L in an alkali developer of the lower film after exposure, the dissolution rate R ^U in an alkali developing solution of the upper layer film after exposure There is no particular limitation as long as it is larger. The lower layer film is preferably formed by applying a film forming material containing an alkali-soluble resin or a positive photoresist composition on a substrate. Hereinafter, a film forming material containing an alkali-soluble resin and a positive photoresist composition will be described in order.

<Film forming material containing alkali-soluble resin>
The film forming material containing an alkali-soluble resin is not particularly limited as long as it is a composition containing an alkali-soluble resin and can form a lower layer film having a desired thickness. The film-forming material containing the alkali-soluble resin contains other components and an organic solvent (S) contained in the positive photoresist composition used for forming the upper layer film as long as the object of the present invention is not impaired. Also good.

  As the alkali-soluble resin contained in the film-forming material containing the alkali-soluble resin, the same resin as the alkali-soluble resin (C) contained in the positive photoresist composition described above can be used. Resin (B) whose solubility in alkali is increased by the action of the acid described above can also be used, among which acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, 2-methacryloyloxyethyl succinic acid. A resin containing a structural unit derived from an unsaturated compound having a carboxyl group, such as 2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid, 2-methacryloyloxyethylhexahydrophthalic acid, is suitable as an alkali-soluble resin Can be used for As such a resin, the resin represented by the general formula (b9) is preferable.

  When the film-forming material containing an alkali-soluble resin contains an organic solvent (S), the content of the organic solvent (S) is not particularly limited as long as the object of the present invention is not impaired. The content of the organic solvent (S) in the film-forming material containing the alkali-soluble resin is adjusted to such an extent that a lower layer film having a thickness of 1/10 or less of the upper layer film can be formed when the lower layer film is formed. Is preferred.

<Positive photoresist composition>
As the positive photoresist composition used for forming the lower layer film, the same composition as the positive photoresist composition used for forming the upper layer film is used.

≪Formation method of plating molding≫
In the method of forming a plated model according to the present invention, a lower layer film and an upper layer film are laminated in this order on a substrate to form a composite film. The formed composite film is selectively exposed and then developed using an alkaline developer. In this way, a composite film pattern is formed. Plating is performed on the portion where the composite film of the composite film pattern is removed, and a plated model is formed.

Also, dissolution rate R ^L in an alkali developer of the lower film after exposure is greater than the dissolution rate R ^U in an alkali developing solution of the upper layer film after exposure, a ratio R ^{L /} R ^U for R ^U of R ^L is It is preferably greater than 1 and 100 or less. In the method of forming a plated model according to the present invention, the composite film pattern formed by exposure and development is combined by forming a composite film composed of a lower layer film and an upper layer film having different dissolution rates. At the place where the film is removed, the width of the part corresponding to the bottom of the plated model can be wider than the width of the part corresponding to the top. Thereby, according to the formation method of the plating molded article of this invention, the width | variety of a bottom (side which is in contact with the board | substrate surface) is larger than the width | variety of the top which opposes a bottom, and it can adhere | attach with a board | substrate stably. A method for forming a plated model can be provided.

When measuring the R ^L and R ^U, the same as when actually forming the plating shaped object, and pre-baking conditions, and exposure conditions, is employed and the developing conditions. Specific measuring method of the R ^L and R ^U are as follows.

First, a film forming material for forming a lower layer film or a positive photoresist composition for forming an upper layer film is applied on a silicon substrate. Then, prebaking the coated film, the lower layer film for R ^L and R ^U measuring or forming the upper layer. After the formed lower layer film or upper layer film is exposed, development is performed for 240 seconds using an alkali developer.

The amount of decrease in film thickness (nm) of the lower layer film or the upper layer film after 240 seconds of development is measured, and the amount of decrease in film thickness per second of development time is dissolved in the alkaline developer after exposure. rate R ^L, and the dissolution rate R ^U in an alkali developing solution of the upper layer film after exposure.

How to adjust the R ^L and R ^U are not particularly limited. As a method of adjusting the R ^U is the upper layer or the lower layer film, a method is a alkali-soluble by adjusting the content of novolac resin or polyhydroxystyrene dissolution rate is not so fast in an alkali developer, the upper layer after the exposure Examples thereof include a method for adjusting the amount of alkali-soluble groups such as carboxyl groups and phenolic hydroxyl groups contained in the resin contained in the film or the lower layer film, and a method for adjusting the molecular weight of the resin component contained in the upper layer film or the lower layer film. By increasing the content of the novolak resin or polyhydroxystyrene in the upper layer film or the lower layer film, the dissolution rate of the upper layer film or the lower layer film in the alkaline developer can be lowered. As the amount of alkali-soluble groups such as carboxyl groups and phenolic hydroxyl groups contained in the resin contained in the upper layer film or lower layer film after exposure increases or decreases, the dissolution rate of the upper layer film in the alkaline developer also increases or decreases. When the molecular weight of the resin component contained in the upper layer film or the lower layer film increases, the dissolution rate of the upper layer film or the lower layer film in the alkaline developer tends to decrease.

  The dissolution rate of the upper layer film or the lower layer film in the alkaline developer can also be adjusted by changing the temperature at the time of pre-baking or the heating time. By increasing the temperature at the time of pre-baking or extending the time, the dissolution rate of the upper layer film or the lower layer film in the alkaline developer tends to be slightly decreased. This seems to be because the film to be formed becomes dense due to severer heating conditions.

  Hereinafter, a method for forming a plated model according to the present invention will be described in the order of a lower layer film forming step, an upper layer film forming step, an exposure step, a developing step, a plating step, and a composite film removing step with reference to FIG.

<Lower layer formation process>
As shown in FIG. 1-i, in the lower layer film forming step, the lower layer film 11 is formed by applying the above-described film forming material for forming the lower layer film onto the substrate 10 and removing the solvent by heating as necessary. Form. The material of the substrate 10 is not particularly limited, and conventionally known materials can be used. Examples of the material of the surface on which the lower layer film 11 of the substrate 10 is formed include silicon, silicon nitride, titanium, tantalum, palladium, titanium tungsten, copper, chromium, iron, aluminum, and glass, and copper is preferable. . A wiring pattern may be formed on the surface of the substrate 10. Examples of the wiring pattern material include copper, solder, chromium, aluminum, nickel, gold, and the like.

  As a coating method of the film forming material, a spin coating method, a slit coating method, a roll coating method, a screen printing method, an applicator method or the like can be employed. The pre-baking conditions after applying the film forming material for forming the lower layer film 11 vary depending on the type of each component in the film forming material, the blending ratio, the coating film thickness, etc., but usually 70 to 150 ° C., preferably Is 80 to 140 ° C. and about 1 to 60 minutes.

The film thickness of the lower layer film 11 is not particularly limited as long as the object of the present invention is not impaired. Ratio T ^L / thickness of the film thickness T ^L of the lower film 11 formed in the lower film formation process to the thickness T ^P of the composite film 13 composed of the lower film 11 and the upper film 12 exposed in the exposure process described later. T ^P is preferably in the range of 0.02 to 0.1.

<Upper layer formation process>
As shown in FIG. 1-ii, in the upper layer film forming step, the above-described positive photoresist composition is applied onto the lower layer film 11 formed in the lower layer film forming step, and the solvent is removed by heating as necessary. Thus, the upper layer film 12 is formed. The coating method and pre-bake conditions for forming the upper layer film 12 are the same as those in the lower layer film forming step. In the upper layer film forming step, mixing in which the lower layer film 11 and the upper layer film 12 are mixed may occur at the interface between the lower layer film 11 and the upper layer film 12.

  The film thickness of the upper layer film 12 is not particularly limited as long as the object of the present invention is not impaired. The film thickness of the upper film 12 is preferably such that the film thickness of the composite film after pre-baking the upper film is 1 to 150 μm, more preferably 5 to 120 μm, and 10 to 100 μm. Such a thickness is particularly preferred.

<Exposure process>
As shown in FIG. 1-iii, in the exposure step, the composite film 13 composed of the lower layer film 11 and the upper layer film 12 is selectively exposed. A method of selectively exposing the composite film 13 is not particularly limited, but typically, a method of irradiating the exposure light 15 through a mask 14 having a predetermined pattern is preferable. The exposure light 15 is preferably actinic rays or radiation, for example, ultraviolet rays or visible rays having a wavelength of 300 to 500 nm.

As a radiation source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used. The radiation includes microwaves, infrared rays, visible rays, ultraviolet rays, X-rays, γ rays, electron beams, proton beams, neutron beams, ion beams, and the like. The amount of radiation irradiation varies depending on the composition of the photoresist composition according to the present invention, the film thickness of the photoresist layer, and the like, but is, for example, 50 to 10,000 mJ / cm ² when using an ultrahigh pressure mercury lamp. The radiation includes light that activates the acid generator (A) in order to generate an acid.

  After the exposure, the diffusion of the acid is promoted by heating using a known method to change the solubility of the exposed portion of the composite film 13 in the alkaline developer.

<Development process>
As shown in FIG. 1-iv, in the development step, the exposed composite film 13 is developed using an alkaline developer, whereby the exposed portion in the composite film is removed and the pattern of the composite film 13 is obtained. Form. In the development step, the lower film 11 is eroded by the alkaline developer wider than the upper film 12 because the lower film 11 has a higher dissolution rate in the alkaline developer than the upper film 12 in the alkaline developer. For this reason, the pattern of the composite film 13 in which the width of the part corresponding to the bottom of the plated model is wider than the width of the part corresponding to the top can be formed at the place where the composite film 13 is removed.

  Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, and methyldiethylamine. , Dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo [4,3 , 0] -5-nonane and the like 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 alkaline aqueous solution may be used as the alkaline developer.

  The development time varies depending on the composition of the lower layer film 11 and the upper layer film 12, the film thickness of the composite film 13, and the like, but is usually 1 to 30 minutes. The developing method may be any of a liquid piling method, a dipping method, a paddle method, a spray developing method, and the like.

  After the development, washing with running water is performed for 30 to 90 seconds, and dried using an air gun, an oven, or the like. In this way, the pattern of the composite film 13 can be manufactured.

<Plating process>
As shown in FIG. 1-v, in the plating process, plating is performed on the portion of the pattern of the composite film 13 where the composite film has been removed, thereby forming a plated model 16. The plating method is not particularly limited, and various conventionally known methods can be employed. As the plating solution, solder plating, copper plating, gold plating, or nickel plating solution is particularly preferably used.

<Composite membrane removal process>
As shown in FIG. 1-vi, the pattern of the composite film 13 remaining on the substrate 10 after the plating step is removed using a stripping solution as necessary.

  Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples.

[Examples 1-7 and Comparative Examples 1-3]
(Measurement of dissolution rate of lower layer film and upper layer film in alkaline developer)
A film-forming material for forming an underlayer film containing a resin or a resin mixture having the composition described in Table 3 and diluted with PM (propylene glycol monomethyl acetate) (solvent) to a solid content concentration (mass%) described in Table 3 Was prepared. The film forming material for forming the lower layer film used in Example 7 and Comparative Example 4 contains 2 parts by mass of an acid generator with respect to 100 parts by mass of the resin.

  Further, a positive photoresist composition containing a solid content with the composition shown in Table 1 and diluted to the solid content concentration (mass%) shown in Table 3 with PM (solvent) was prepared. The composition of the positive photoresist composition is as follows.

In the examples and comparative examples, the following compounds were used as acid generators.

In Examples and Comparative Examples, the following compounds were used as rust inhibitors.

Table 2 shows the ratio of the structural units and the mass average molecular weight (Mw) of resin A (novolak resin), resin B (polyhydroxystyrene), and resins C to F used in the examples.

The structure of each structural unit shown in Table 2 is as follows.

First, a film forming material for forming a lower layer film and a positive photoresist composition for forming an upper layer film were applied on two copper substrates, respectively. Then, the coating film for forming an underlayer film, a coating film for forming an upper layer film, and baked at baking conditions of the lower film and upper film described in Table 3, and the lower layer film for R ^L and R ^U determined An upper layer film was formed. The formed composite film composed of the lower layer film and the upper layer film was exposed with an exposure amount of 500 mJ / cm ² using an Ultratech Prism GHI5452 (manufactured by Ultratech). The exposed lower layer film and upper layer film were developed for 240 seconds using an aqueous solution of tetramethylammonium hydroxide having a concentration of 2.38% by mass. And development time, and a decrease in the film thickness at the time of development was calculated and dissolution rate R ^L in an alkali developer of the lower film, and a dissolution rate R ^U in an alkali developing solution of the upper layer film. ^RL and RU are ^listed in Table 3.

(Evaluation of the shape of the plated model)
On the copper substrate, a film forming material for forming the lower layer film was applied by a spin coater and then pre-baked under the conditions shown in Table 3 to form the lower layer film having the thickness shown in Table 3. Next, a positive photoresist composition for forming an upper layer film was applied onto the lower layer film by a spin coater, and then pre-baked under the conditions shown in Table 3 to form a composite film comprising a lower layer film having a thickness of 20 μm and an upper layer film. Formed. The formed composite film composed of the lower layer film and the upper layer film was exposed at an exposure amount of 500 mJ / cm ² using a hole pattern mask having an opening diameter of 20 μm and Ultratech Prism GHI5452 (manufactured by Ultratech). Next, the substrate was placed on a hot plate and post-exposure heating (PEB) was performed at 85 ° C. for 3 minutes. Thereafter, an aqueous solution (developer, NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) having a tetramethylammonium hydroxide concentration of 2.38% by mass is dropped onto the exposed composite film, and then allowed to stand at 23 ° C. for 60 seconds. Was repeated 4 times in total. The surface of the developed composite film was washed with running water and then blown with nitrogen to obtain a composite film pattern.

The pattern of the formed composite film was subjected to O ₂ plasma treatment for 60 seconds under the conditions of an output of 300 W, a pressure of 0.15 torr, and 40 ° C. Next, copper plating was performed for 10 minutes on the part where the composite film of the composite film pattern was removed under the condition of cathode current density (ASD) of 10 A / dm ² . Then, under the conditions of cathode current density (ASD) 5A / dm ^2, at a location composite film of the pattern of the composite film is removed, 5 minutes tin - plated with silver. After plating, the substrate on which the plated model was formed was immersed in a stripping solution (ST-120, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 60 ° C. for 10 minutes to peel the pattern of the composite film from the substrate. The shape of the formed plated article was observed from the side using a scanning electron microscope, and the shape of the plated article was evaluated. For a plated model, the case where the width of the bottom (the side in contact with the substrate surface) is wider than the width of the top facing the bottom and a highly rectangular model can be formed is ◎, and the width of the bottom is the bottom It is wider than the width of the opposite top, and the problem of the present application can be solved. In some cases, it was determined as x. Table 3 shows the evaluation results of the shape of the plated model in each example and comparative example.

According to Examples 1-9, it consists of a lower layer film and an upper layer film made of a positive photoresist composition, and the dissolution rate ^RL of the lower layer film after exposure in an alkaline developer is an alkali development of the upper layer film after exposure. The plated model formed by plating the composite film pattern formed by exposing and developing the composite film having a dissolution rate ^RU higher than the liquid to the bottom is the bottom (side in contact with the substrate surface). It can be seen that the width of is wider than the width of the top facing the bottom. In particular, it can be seen that an excellently shaped plated product can be formed by forming the composite films as in Examples 1 to 7.

On the other hand, according to Comparative Examples 1 to 3, the film comprises a lower layer film and an upper layer film made of a positive photoresist composition, and the dissolution rate ^RL of the lower layer film after exposure with respect to an alkaline developer is such that the upper layer film after exposure is A plated model formed by plating the composite film pattern formed by exposing and developing the composite film having a dissolution rate ^RU lower than that of the alkaline developer to the bottom is in contact with the bottom (the substrate surface). It can be seen that the width of the side) is narrower than the width of the top facing the bottom.

[Comparative Example 4]
Except for forming a photoresist film having a thickness of 20 μm using the positive photoresist composition used for forming the upper layer film in Example 1 instead of the composite film, exposure, Development, plating, and peeling of the photoresist pattern were performed to form a plated model. When the shape of the formed plated object was observed from the side using a scanning electron microscope, the shape of the plated object was the width of the top (the side in contact with the substrate surface) the width of the top facing the bottom It was narrower than.

DESCRIPTION OF SYMBOLS 10 Substrate 11 Lower layer film 12 Upper layer film 13 Composite film 14 Mask 15 Exposure light 16 Plating model

Claims (6)

An underlayer film forming step of forming an underlayer film on the substrate;
An upper layer film forming step of forming an upper layer film by applying a positive photoresist composition on the lower layer film;
An exposure step of selectively exposing a composite film composed of the lower layer film and the upper layer film;
A development step of developing the composite film after exposure with an alkaline developer to obtain a composite film pattern;
A plating step of plating the portion of the composite film pattern where the composite film has been removed, and
Dissolution rate R ^L with respect to the alkali developing solution of the lower film after the exposure, is greater than the dissolution rate R ^U to said alkaline developing solution of the upper layer film after the exposure, and the composite film is exposed in the exposure step the relative thickness ^{T P,} the ratio ^T L / ^{T P} in the thickness ^{T L} of the lower layer film formed in the lower film forming step is 0.02 to 0.1, the method of forming the plating shaped object.   The method of forming a plated model according to claim 1, wherein the lower layer film is formed by applying a film forming material containing an alkali-soluble resin or a positive photoresist composition on a substrate. An underlayer film forming step of forming an underlayer film on the substrate;
An upper layer film forming step of forming an upper layer film by applying a positive photoresist composition on the lower layer film;
An exposure step of selectively exposing a composite film composed of the lower layer film and the upper layer film;
A development step of developing the composite film after exposure with an alkaline developer to obtain a composite film pattern;
A plating step of plating the portion of the composite film pattern where the composite film has been removed, and
Dissolution rate R ^L with respect to the alkali developing solution of the lower film after the exposure, is greater than the dissolution rate R ^U to said alkaline developing solution of the upper layer film after the exposure,
The lower layer film is formed by applying a positive photoresist composition on a substrate, and the positive photoresist composition is selected from the group consisting of structural units represented by the following general formulas (b5) to (b7). A method for forming a plated model, comprising a resin containing at least one constituent unit.

(In the above general formulas (b5) to (b7), R ^{10b to} R ^17b are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, or 1 to 1 carbon atoms. 6 represents a linear or branched fluorinated alkyl group (wherein R ^11b is not a hydrogen atom), and X ^b has 5 to 20 carbon atoms together with the carbon atom to which it is bonded. form a hydrocarbon ring, Y ^b is substituted represents those aliphatic cyclic group or an alkyl group, p represents an integer of 0 to 4, q represents 0 or 1.) To the thickness ^{T P} of the composite film to be exposed in the exposure step, the ratio ^T L / ^{T P} in the thickness ^{T L} of the lower layer film formed in the lower film forming step, at 0.02 to 0.1 The formation method of the plating molded article of Claim 3 which exists. The dissolution rate ^R ratio ^R L / ^{R U} for the dissolution rate ^{R U} of ^L is 100 or less greater than 1, the method of forming the plating molded article according to any one of claims 1-4. The method for forming a plated model according to any one of claims 1 to 5 , further comprising a composite film removing step of removing the pattern of the composite film after the plating step.

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