TW201815754A - Salt, acid generator, resist composition and method for producing resist pattern - Google Patents

Abstract

A salt represented by the formula (I). [In the formula (I), R1 and R2 each independently represent an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. R3 represents a group having a lactone structure. X1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 18 carbon atoms; the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. A- represents an organic anion.].

Description

 Salt, acid generator, photoresist composition and photoresist pattern manufacturing method  

The present invention relates to a method for producing a salt, an acid generator, a photoresist composition, and a photoresist pattern.

JP-A-2011-85878 discloses a salt containing a salt represented by the following formula as an acid generator.

Japanese Laid-Open Patent Publication No. 2013-47211 discloses a salt containing a salt represented by the following formula as an acid generator.

The present invention provides the invention shown below.

[1] A salt represented by the formula (I).

[In the formula (I), R ¹ and R ² each independently represent an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

R ³ represents a group having a lactone structure.

X ¹ represents a divalent aliphatic saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group.

A ^- represents an organic anion. 〕

[2] The salt according to [1], wherein the X ¹ of the formula (I) is an alkanediyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkanediyl group may be substituted with an oxygen atom or a carbonyl group.

[3] The salt according to [1] or [2], wherein R ¹ and R ^{2 of the} above formula (I) each independently represent a phenyl group which may have a substituent.

The salt of any one of the above-mentioned formula (I), wherein R ³ of the above formula (I) has an internal formula (R ³ -1) or an internal formula (R ³ -2) The base of the ester ring group.

[In the formula (R ³ -1), * represents a bond bond.

Z ¹² represents an oxygen atom, a sulfur atom or a group represented by -C(R ⁴ ) ₂ -.

M3 represents any integer from 0 to 5.

R ³¹ represents a group selected from the following P1 group, and when m3 is 2 or more, a plurality of R ³¹ may be the same or different from each other.

Two R ^{4 's} each independently represent a group or a hydrogen atom selected from the group of P1 described below.

In the formula (R ³ -2), * represents a bonding bond.

M4 represents any integer from 0 to 5.

R ³² represents a group selected from the group of P1 described below, and when m4 is 2 or more, several R ³² may be the same or different from each other.

M5 represents any integer from 1 to 3.

P1 group: a halogen atom; a hydroxyl group; a carboxyl group; a cyano group; an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxyl group; an alkoxy group having 1 to 12 carbon atoms; an aryl group having 6 to 12 carbon atoms; Aralkyl group of 7 to 12; glycidyloxy group; alkoxycarbonyl group having 2 to 12 carbon atoms; and alkylcarbonyl group having 2 to 4 carbon atoms]

[5] An acid generator comprising the salt according to any one of [1] to [4].

[6] A photoresist composition comprising a resin comprising an acid generator and a structural unit having an acid labile group, and the acid generator according to any one of [1] to [4] .

[7] The photoresist composition according to [6], which further contains a salt of an acid which is lower in acidity than that produced by the acid generator.

[8] A method for producing a photoresist pattern, comprising: (1) a step of applying the photoresist composition according to [6] or [7] to a substrate, and (2) drying the coated composition. The step of forming a composition layer, (3) the step of exposing the composition layer, (4) the step of heating the exposed composition layer, and (5) the step of developing the heated composition layer.

When a photoresist composition containing the salt of the present invention as an acid generator is used, a photoresist pattern having good CD uniformity (CDU) can be produced.

In the present specification, the "(meth)acrylic monomer" means at least one of the monomers having a structure of "CH ₂ =CH-CO-" or "CH ₂ =C(CH ₃ )-CO-". Similarly, "(meth)acrylate" and "(meth)acrylic" mean "at least one of acrylate and methacrylate" and "at least one of acryl and methacrylic", respectively.

In the present specification, the "solid content of the photoresist composition" means the total of the components after removing the solvent (E) described later from the total amount of the photoresist composition.

The photoresist composition of the present invention contains a resin (A) having an acid labile group and an acid generator, and the acid generator contains a salt represented by the formula (I) (hereinafter, also referred to as "salt (I) as the case may be) ".).

The acid generator of the present invention may contain the salt (I) or an acid generator (B) other than the salt (I). The photoresist composition of the present invention may contain a resin (X) other than the resin (A), a solvent (E), a quencher (C), a salt (I), and an acid produced, if necessary, having a lower acidity than the acid. The acid salt produced by the acid generator (B) and other components (F). Hereinafter, these components will be described.

<salt represented by formula (I)>

The salt of the present invention is a salt represented by the formula (I).

[In the formula (I), R ¹ and R ² each independently represent an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

R ³ represents a group having a lactone structure.

X ¹ represents a divalent aliphatic saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group.

A ^- represents an organic anion. 〕

In the formula (I), when -CH ₂ - contained in the aliphatic saturated hydrocarbon group is substituted with -O- or -C(=O)-, the carbon number before the substitution is made the carbon number of the aliphatic saturated hydrocarbon group.

<Cation constituting formula (I)>

Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ¹ and R ² include an aryl group such as a phenyl group, a naphthyl group, an anthracenyl group, a biphenyl group, a phenanthryl group or a fluorenyl group, and a phenyl group, a naphthyl group and The sulfhydryl group is preferred, and the phenyl group and the naphthyl group are more preferred, and the phenyl group is more preferred.

Examples of the substituent which the aromatic hydrocarbon group having 6 to 18 carbon atoms of R ¹ and R ² may have include a hydroxyl group, a carboxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and a carbon number of 3. An alicyclic hydrocarbon group of up to 12 and a group of such groups.

The alkyl group having 1 to 12 carbon atoms may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a decyl group, an undecyl group or a dodecyl group. Wait.

Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, and an anthracene group. Oxyl, decyloxy, undecyloxy, dodecyloxy and the like.

Examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms include the groups shown below. * indicates the bond key to the ring.

Among these substituents, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms is preferred, and a hydroxyl group or an alkyl group having 1 to 12 carbon atoms is more preferred, and the carbon number is 1 The alkyl group to 12 is more preferably, and the alkyl group having 1 to 6 carbon atoms is most preferred.

R ¹ and R ² are preferably a phenyl group or a substituted phenyl group, and more preferably a phenyl group or a phenyl group having an alkyl group having 1 to 6 carbon atoms.

Further, it is preferred that any one of R ¹ and R ² is a phenyl group, and the other one is a phenyl group having an alkyl group having 1 to 6 carbon atoms.

R ³ represents a group having a lactone structure. The "base having a lactone structure" means a group having a lactone ring. The group having a lactone structure may be a group formed of a lactone ring.

The lactone ring is a cyclic ester and contains a ring of -CO-O-. The lactone ring may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring or a δ-valerolactone, or a condensed ring of a monocyclic lactone ring and other rings. Among these lactone rings, it is preferred that the salt (I) to be described later is a condensed ring of a γ-butyrolactone ring, an adamantol lactone ring, and a γ-butyrolactone ring and another ring.

The lactone ring may contain a hetero atom other than -CO-O-, and the hydrogen atom of the lactone ring may be substituted with a group selected from the P1 group described later.

The lactone ring in the above lactone structure may, for example, be a lactone ring having 3 to 18 carbon atoms, and more specifically, a formula (R-1), a formula (R-2), and a formula (R-3) a compound represented by the formula (R-4), the formula (R-5), the formula (R-6), the formula (R-7) and the formula (R-8). Meanwhile, as the compound represented by the formula (R-3) or the formula (R-8), as the atomic group constituting the ring, a hetero atom may be contained in addition to -CO-O-. Meanwhile, the hydrogen atom contained in the lactone ring may be substituted with a group selected from the P1 group described later.

The above lactone ring is preferably a ring represented by the formula (R-1) or the formula (R-2).

Specific examples of the group selected from the above P1 group will be described.

The P1 group is composed of a halogen atom; a hydroxyl group; a carboxyl group; a cyano group; an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxyl group; an alkoxy group having 1 to 12 carbon atoms; an aryl group having 6 to 12 carbon atoms; a group of 7 to 12 aralkyl groups; a glycidyloxy group; an alkoxycarbonyl group having 2 to 12 carbon atoms; and an alkylcarbonyl group having 2 to 4 carbon atoms.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

An alkyl group among the alkyl groups having 1 to 12 carbon atoms which may have a halogen atom or a hydroxyl group, and includes an alkyl group exemplified in the range of 1 to 12 carbon atoms. A part or all of a hydrogen atom contained in the alkyl group is substituted by a halogen atom or a hydroxyl group, and is equivalent to an "alkyl group which may have a halogen atom or a hydroxyl group", and specific examples thereof include a hydroxymethyl group, a hydroxyethyl group and three Fluoromethyl and the like. Among these groups, when the substituent of the lactone ring compound is an alkyl group which may have a halogen atom or a hydroxyl group, the group is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group.

Specific examples of the alkoxy group and the aryl group include those exemplified as the substituent of the aromatic hydrocarbon represented by R ¹ and R ² , respectively. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the thiol group include an ethyl group, a propyl group, and a butyl group. The above alkoxy group is bonded to a carbonyl group to correspond to an alkoxycarbonyl group. The alkoxycarbonyl group preferably has 6 or less carbon atoms, and more preferably a methoxycarbonyl group.

R ³ is preferably a group formed by a ring of a γ-butyrolactone ring, an adamantol lactone ring and a γ-butyrolactone ring which may have a substituent and a condensed ring of another ring, and is represented by the formula (R ^{3 )} -1) and the formula represented by the formula (R ³ -2) are more preferable (hereinafter, the base case represented by the formula (R ³ -1) and the formula (R ³ -2) is referred to as "base" (R ³ - 1)" and "base (R ³ -2)".), and the base represented by the formula (R ³ -1) is even better.

[In the formula (R ³ -1), * represents a bond bond.

Z ¹² represents an oxygen atom, a sulfur atom or a group represented by -C(R ⁴ ) ₂ -.

M3 represents any integer from 0 to 5.

R ³¹ represents a group selected from the group of P1, and when m3 is 2 or more, a plurality of R ³¹ may be the same or different from each other.

Two R ^{4 's} each independently represent a group selected from the P1 group or a hydrogen atom.

In the formula (R ³ -2), * represents a bonding bond.

M4 represents any integer from 0 to 5.

R ³² represents a group selected from the group of P1, and when m4 is 2 or more, a plurality of R ³² may be the same or different from each other.

M5 represents any integer from 1 to 3.

The P1 group is the same as described above. 〕

The m3-yl group and ^{(3 -1 R) (R 3} -2) in m4, the salt is described later (I) of the system is easy to manufacture in 0 preferred.

In the group (R ³ -1), Z ¹² is preferably a group represented by -C(R ⁴ ) ₂ -, and more preferably -CH ₂ -.

Examples of the group (R ³ -1) and the group (R ³ -2) include the following groups.

The divalent aliphatic saturated hydrocarbon group represented by X ¹ may, for example, be an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, or a combination of two or more of these groups. .

Specific examples thereof include a methylene group, an ethylidene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6- group. Diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1.9-diyl, decane-1,10-diyl, undecane-1,11-di Base, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane- Linear alkanediyl groups such as 1,16-diyl and heptadecane-1,17-diyl; ethane-1,1-diyl, propane-1,1-diyl, propane-1,2- Diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane -1,4-diyl, 2-methylbutane-1,4-diyl, etc. branched alkyldiyl; cyclobutane-1,3-diyl, cyclopentane-1,3-diyl a monocyclic divalent alicyclic saturated hydrocarbon group of a cyclohexanediyl group such as cyclohexane-1,4-diyl or cyclooctane-1,5-diyl; norbornane-1,4-diyl And a polycyclic bivalent alicyclic saturated hydrocarbon group such as norbornane-2,5-diyl, adamantane-1,5-diyl, adamantane-2,6-diyl or the like.

In X ¹ , the methylene group constituting the aliphatic saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, and may be, for example, an ether bond, an ester bond (-O-CO- or -CO-O-), and -O-CO-O. - an optionally substituted aliphatic saturated hydrocarbon group.

In X ¹ , when a methylene group constituting an aliphatic saturated hydrocarbon group is substituted with an oxygen atom or a carbonyl group, the carbon number before the substitution is made to form the carbon number of the aliphatic saturated hydrocarbon group.

The divalent aliphatic saturated hydrocarbon group represented by X ¹ is preferably an alkanediyl group, a methylene group constituting the alkanediyl group which may be substituted with an oxygen atom or a carbonyl group, and an alkanedi group having 1 to 12 carbon atoms. More preferably, the methylene group constituting the alkanediyl group may be substituted with an oxygen atom or a carbonyl group.

Specifically, X ¹ may be a group represented by the formula (X ¹ -1).

*-O-CO-X ² -OX ³ - (X ¹ -1) wherein X ² and X ³ each independently represent a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms, and constitute the divalent fat. The methylene group of the saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group. However, the total carbon number of X ² and X ³ is 2 or more and 15 or less. * indicates the bond with R ³ . 〕

The aliphatic saturated hydrocarbon group represented by X ² and X ³ may specifically be a methylene group, an ethylidene group, a propane-1,3-diyl group, a butane-1,4-diyl group or a pentane-1,5. -diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,9-diyl, decane-1,10 -diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, fifteen a linear alkanediyl group such as an alkane-1,15-diyl group; an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2- Diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, 2 -methylbutane-1,4-diyl aliquoted alkanediyl; cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4- Monocyclic divalent alicyclic saturated hydrocarbon group of dicyclo, cyclooctane-1,5-diyl and the like cycloalkanediyl; norbornane-1,4-diyl, norbornane-2,5 a polycyclic bivalent alicyclic saturated hydrocarbon group such as a diyl group, an adamantane-1,5-diyl group or an adamantane-2,6-diyl group.

X ² and X ³ are preferably each independently an alkanediyl group having 1 to 14 carbon atoms, and more preferably an alkanediyl group having 1 to 4 carbon atoms.

Specific examples of the cation constituting the salt (I) include the cations represented by the following formulas (I-c-1) to (I-c-24).

The cation (I) is preferably a cation represented by the formula (Ic-1) to the formula (Ic-17) or the formula (Ic-24), and is represented by the formula (Ic-1) to the formula (Ic-9), Ic-15), the cation represented by the formula (Ic-17) is more preferable, and the formula (Ic-1), the formula (Ic-2), the formula (Ic-7), the formula (Ic-15), the formula (Ic) The cation represented by -17) is even better.

<Organic anion constituting salt (I)>

Examples of the organic anion (A-) constituting the salt (I) include a sulfonate anion, a sulfonyl imide anion, a sulfonyl methide anion, and a carboxylic acid anion. Among these anions, a sulfonic acid anion is preferred, and a sulfonic acid anion represented by the formula (I-A) is more preferred.

[In the formula (IA), Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.

L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group may be substituted with -O- or -CO-, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group. .

Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and -CH ₂ - contained in the alicyclic hydrocarbon group may be substituted into -O-, -SO ₂ - Or -CO-. 〕

In the formula (IA), when the -CH ₂ - contained in the saturated hydrocarbon group or the alicyclic hydrocarbon group is substituted into -O-, -C(=O)- or -SO ₂ -, the carbon number before the substitution is respectively made into the saturation. Hydrocarbon group, carbon number of the alicyclic hydrocarbon group.

Examples of the perfluoroalkyl group of Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro second butyl group, and a perfluoro group. Tributyl, perfluoropentyl and perfluorohexyl.

Q ¹ and Q ² are preferably a fluorine atom or a trifluoromethyl group which is independent of each other, and a fluorine atom is more preferable.

The divalent saturated hydrocarbon group of L ^b1 may, for example, be a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, or may be one of these groups. The above formed groups are formed.

Specific examples thereof include a methylene group, an ethylidene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6- group. Dibasic, heptane-1,7-diyl, octane-1,8-diyl, decane-1,9-diyl, decane-1,10-diyl, undecane-1,11 -diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexa a linear alkanediyl group such as alkane-1,16-diyl and heptadecane-1,17-diyl; ethane-1,1-diyl, propane-1,1-diyl, propane-1, 2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, Pentane-1,4-diyl, 2-methylbutane-1,4-diyl, etc. branched alkanediyl; cyclobutane-1,3-diyl, cyclopentane-1,3- Monocyclic divalent alicyclic saturated hydrocarbon group of dicyclo, cyclohexane-1,4-diyl, cyclooctane-1,5-diyl, etc. cycloalkanediyl; norbornane-1,4- A polycyclic bivalent alicyclic saturated hydrocarbon group such as a diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, an adamantane-2,6-diyl group or the like.

The group in which -CH ₂ - contained in the divalent saturated hydrocarbon group of L ^b1 is substituted with -O- or -CO- may, for example, be a group represented by any one of the formulae (b1-1) to (b1-3). . Further, in the specific examples of the formulae (b1-1) to (b1-3) and the following, * represents a bond bond with -Y.

In the formula (b1-1), L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and -CH ₂ - contained in the saturated hydrocarbon group may be substituted with - O- or -CO-.

However, the total carbon number of L ^b2 and L ^b3 is 22 or less.

In the formula (b1-2), L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and -CH ₂ - contained in the saturated hydrocarbon group may be substituted with - O- or -CO-.

However, the total carbon number of L ^b4 and L ^b5 is 22 or less.

In the formula (b1-3), L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and -CH ₂ - contained in the saturated hydrocarbon group may be substituted into - O- or -CO-.

However, the total carbon number of L ^b6 and L ^b7 is 23 or less. 〕

In the formula (b1-1) to the formula (b1-3), when -CH ₂ - contained in the saturated hydrocarbon group is substituted with -O- or -CO-, the carbon number before the substitution is made into the carbon number of the saturated hydrocarbon group.

The divalent saturated hydrocarbon group and the -CH ₂ - or hydrogen atom contained in the saturated hydrocarbon group may be the same as the above-mentioned substituted group, and may be the same as the divalent saturated hydrocarbon group of L ^b1 .

L ^b2 is preferably a single bond.

L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and more preferably an alkanediyl group having 1 to 4 carbon atoms.

L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and more preferably an alkyldiyl group having 1 to 4 carbon atoms.

L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond.

L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and -CH ₂ - contained in the divalent saturated hydrocarbon group, Can be substituted into -O- or -CO-.

The -CH ₂ -O- or -CO-substituted group contained in the divalent saturated hydrocarbon group of L ^b1 is preferably a group represented by the formula (b1-1) or the formula (b1-2), and is represented by the formula (b) In b1-1), L ^b2 is a single bond, L ^b3 is an alkanediyl group having 1 to 4 carbon atoms, and in the formula (b1-2), L ^b4 is an alkanediyl group having 1 to 4 carbon atoms, and L ^b5 is The base of a single bond is better.

The formula (b1-1) may be a group represented by any one of the formulae (b1-4) to (b1-8).

In the formula (b1-4), L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

In the formula (b1-5), L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.

L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b9 and L ^b10 is 20 or less.

In the formula (b1-6), L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.

L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b11 and L ^b12 is 21 or less.

In the formula (b1-7), L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.

L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.

L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b13 to L ^b15 is 19 or less.

In the formula (b1-8), L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.

L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.

L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b16 to L ^b18 is 19 or less. 〕

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.

L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.

L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.

L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.

L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

The formula (b1-3) may be a group represented by any one of the formulae (b1-9) to (b1-11).

[In the formula (b1-9), L ^b19 represents a single bond or 2 carbon atoms of the monovalent saturated hydrocarbon group having 1 to 23, the hydrogen atoms of the divalent saturated hydrocarbon group contained, may be substituted with a fluorine atom.

L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

However, the total carbon number of L ^b19 and L ^b20 is 23 or less.

In the formula (b1-10), L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

However, the total carbon number of L ^b21 to L ^b23 is 21 or less.

In the formula (b1-11), L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. The -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

However, the total carbon number of L ^b24 to L ^b26 is 21 or less. 〕

In the formula (b1-9) to the formula (b1-11), when a hydrogen atom contained in a divalent saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the carbon number of the alkylcarbonyloxy group and the CO in the ester bond are also included. And the number of O, the carbon number of the divalent saturated hydrocarbon group is prepared.

The alkylcarbonyloxy group may, for example, be an ethoxycarbonyl group, a propenyloxy group, a butoxy group, a cyclohexylcarbonyloxy group or an adamantylcarbonyloxy group.

The group represented by the formula (b1-4) includes the following groups.

The group represented by the formula (b1-5) includes the following groups.

The group represented by the formula (b1-6) includes the following groups.

The group represented by the formula (b1-7) includes the following groups.

The group represented by the formula (b1-8) includes the following groups.

The group represented by the formula (b1-2) includes the following groups.

The group represented by the formula (b1-9) includes the following groups.

The group represented by the formula (b1-10) includes the following groups.

The group represented by the formula (b1-11) includes the following groups.

The monovalent alicyclic hydrocarbon group represented by Y in the formula (I-A) includes a group represented by the formula (Y1) to the formula (Y11) and the formula (Y36) to the formula (Y38).

When -CH ₂ - contained in the monovalent alicyclic hydrocarbon group represented by Y is substituted by -O-, -SO ₂ - or -CO-, the number thereof may be one or a plurality of two or more. Examples of such a group include a group represented by the formula (Y12) to the formula (Y35).

Among them, preferred is a formula represented by any one of the formulae (Y1) to (Y20), (Y30), and (Y31), and more preferably, the formula (Y11), the formula (Y15), and the formula (Y16) Further, the group represented by the formula (Y20), the formula (Y30) or the formula (Y31) is more preferably a group represented by the formula (Y11), the formula (Y15) or the formula (Y30).

When Y is a spiro ring such as a formula (Y28) to a formula (Y33), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Meanwhile, among the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably an unsubstituted fluorine atom.

The substituent of the methyl group represented by Y in the formula (IA) includes a halogen atom, a hydroxyl group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a epoxypropyloxy group. Or -(CH ₂ ) _ja -O-CO-R ^b1 group (wherein R ^b1 represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms or a carbon number of 6 to 18 The monovalent aromatic hydrocarbon group. ja represents any integer from 0 to 4) and the like.

The substituent of the monovalent alicyclic hydrocarbon group represented by Y in the formula (IA) includes a halogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group, and an alicyclic hydrocarbon group having 3 to 16 carbon atoms. Alkoxy group having 1 to 12 carbon atoms, aromatic hydrocarbon group having 6 to 18 carbon atoms, aralkyl group having 7 to 21 carbon atoms, fluorenyl group having 2 to 4 carbon atoms, epoxypropyloxy group or -CH ₂ ) _ja -O-CO-R ^b1 group (wherein R ^b1 represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms or a monovalent carbon number of 6 to 18 An aromatic hydrocarbon group, ja represents any integer from 0 to 4, and the like.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group and the like.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthracenyl group, a p-methylphenyl group, a p-t-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, and an isopropyl group. An aryl group such as a phenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group or a 2-methyl-6-ethylphenyl group.

The alkyl group may, for example, be methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, t-butyl, n-pentyl, n-hexyl, heptyl, 2 Ethylhexyl, octyl, decyl, decyl, undecyl, dodecyl and the like.

The alkyl group which may be substituted with a hydroxyl group may, for example, be a hydroxyalkyl group such as a hydroxymethyl group or a hydroxyethyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group.

Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group.

Examples of the thiol group include an ethyl group, a propyl group, and a butyl group.

The alicyclic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent represented by Y in the formula (I-A) includes the following groups.

In the formula (IA), when Y is a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 24 carbon atoms, the -CH of the divalent saturated hydrocarbon group at a binding position to Y ₂ - is preferably substituted with -O- or -CO-.

Y, preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably an adamantyl group which may have a substituent, -CH ₂ - constituting the alicyclic hydrocarbon group or adamantyl group It can be substituted into -O-, -SO ₂ - or -CO-. Y is more preferably an adamantyl group, a hydroxyadamantyl group, a pendant oxyadamantyl group or a group represented by the following.

The sulfonic acid anion represented by the formula (IA) is an anion represented by the formula (B1-A-1) to the formula (B1-A-54) [hereinafter, corresponding to the formula number, also referred to as "anion (B1-A-1)" Wait. 〕 is preferably, and is of the formula (B1-A-1) to the formula (B1-A-4), the formula (B1-A-9), the formula (B1-A-10), the formula (B1-A-24) Any of the formulas (B1-A-33), (B1-A-36) to (B1-A-40), and (B1-A-47) to (B1-A-54) The anion is better.

[In the formula (B1-A-1) to the formula (B1-A-54), R ⁱ² to R ⁱ⁷ represent an alkyl group having 1 to 4 carbon atoms, and a methyl group or an ethyl group is preferred.

R ⁱ⁸ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, and is preferably an alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these groups. More preferably, it is a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

L ^A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms.

Q ¹ 1 and Q ² represent the same meaning as described above. 〕

The sulfonic acid anion represented by the formula (I-A) may, for example, be an anion represented by the formula (B1a-1) to the formula (B1a-30).

Among them, the sulfonate anion is preferably an anion represented by any one of the formulae (B1a-1) to (B1a-3) and (B1a-7) to (B1a-19) and (B1a-22).

Specific examples of the salt represented by the formula (I) include a salt in which the above cation and an anion are arbitrarily combined. Specific examples of the salt represented by the formula (I) are shown in the following tables.

In the following tables, each symbol indicates a symbol attached to the structure representing the above anion or cation. For example, the salt (I-1) is a salt formed by an anion represented by the formula (BIa-1) and a cation represented by the formula (I-c-1), and is a salt represented by the following.

The acid generator (I) is a salt (I-1), a salt (I-2), a salt (I-3), a salt (I-16), a salt (I-17), a salt (I-18), Salt (I-19), salt (I-22), salt (I-23), salt (I-24), salt (I-25), salt (I-38), salt (I-39), salt (I-40), salt (I-41), salt (I-44), salt (I-45), salt (I-46), salt (I-47), salt (I-60), salt ( I-61), salt (I-62), salt (I-63), salt (I-66), salt (I-133), salt (I-134), salt (I-135), salt (I -148), salt (I-149), salt (I-150), salt (I-151), salt (I-154), salt (I-309), salt (I-310), salt (I- 311), salt (I-324), salt (I-325), salt (I-326), salt (I-327), salt (I-330), salt (I-353), salt (I-354) ), salt (I-355), salt (I-368), salt (I-369), salt (I-370), salt (I-371), and salt (I-374) are preferred.

, X ¹ is of formula (I), the formula (X ¹ -1) yl ^{[* -O-CO-X 2 -OX} 3 - ] represents a salt (I represents a salt of (I) [Formula (I1) of (Salt (II))] can be produced by reacting a salt represented by the formula (I1-a) with a compound represented by the formula (I1-b) in the presence of a base in a solvent.

[In the formula, all the symbols represent the same meaning as above. 〕

The solvent used in this reaction is, for example, acetonitrile or the like.

As the base, triethylamine or the like can be used.

The reaction is usually carried out at a temperature of from 15 to 90 ° C for from 0.5 to 24 hours.

The compound represented by the formula (I1-b) includes the compounds shown below, and can be easily obtained from the market.

The salt represented by the formula (I1-a) can be produced by reacting a salt represented by the formula (I1-c) with a compound represented by the formula (I1-d) in the presence of a catalyst in a solvent.

[In the formula, all the symbols represent the same meaning as above. The catalyst may, for example, be copper (II) benzoate or the like, and the solvent may, for example, be monochlorobenzene or the like.

The reaction is usually carried out at a temperature of from 20 to 120 ° C for from 0.5 to 24 hours.

The salt represented by the formula (I1-c) includes the salts shown below, and can be easily obtained from the market.

The compound represented by the formula (I1-d) includes the compounds shown below, and can be easily obtained from the market.

In the formula (I), the salt (I) when X ¹ is *-O-CO-X ³ - (the salt (I) (salt (I2)) represented by the following formula (I2)) can be made by The salt represented by (I2-b) is reacted with a carbonyl diimidazole in a solvent, and then reacted with a compound represented by the formula (I2-a) to produce a salt.

[In the formula, all the symbols represent the same meaning as above. 〕

The solvent may, for example, be acetonitrile or chloroform.

The reaction is usually carried out at a temperature of from 15 to 80 ° C for from 0.5 to 24 hours.

The compound represented by the formula (I2-a) includes the compounds shown below, and can be easily obtained from the market.

The compound represented by the formula (I2-b) includes the compounds shown below.

In the formula (I), the salt (I) when X ¹ is *-OX ³ - (the salt (I) (salt (I3)) represented by the following formula (I3)) can be obtained by formula (I2- The compound represented by a) is produced by reacting a salt represented by the formula (I1-b) with a solvent in the presence of a base catalyst.

[In the formula, all the symbols represent the same meaning as above. 〕

The solvent may, for example, be acetonitrile or the like.

The alkali catalyst may, for example, be potassium hydroxide or the like.

The reaction is usually carried out at a temperature of from 5 to 80 ° C for from 0.5 to 24 hours.

In the formula (I), the salt (I) when X ¹ is *-O-CO-OX ³ - (the salt (I) (salt (I4)) represented by the following formula (I4)) can be The salt represented by the formula (I1-b) is reacted with a carbonyl diimidazole in a solvent, and then reacted with a compound represented by the formula (I1-a) to produce a salt.

[In the formula, all the symbols represent the same meaning as above. 〕

The solvent may, for example, be acetonitrile or chloroform.

The reaction is usually carried out at a temperature of from 15 to 80 ° C for from 0.5 to 24 hours.

In the formula (I), the salt (I) when X ¹ is *-CO-OX ³ - (the salt (I) (salt (I5)) represented by the following formula (I5)) can be obtained by The salt represented by I5-b) is reacted with a carbonyl diimidazole in a solvent, and then reacted with a compound represented by the formula (I1-a) to produce a salt.

[In the formula, all the symbols represent the same meaning as above. 〕

The solvent may, for example, be acetonitrile or chloroform.

The reaction is usually carried out at a temperature of from 15 to 80 ° C for from 0.5 to 24 hours.

The compound represented by the formula (I5-b) includes the compounds shown below.

<Photoresist composition>

The photoresist composition of the present invention contains an acid generator containing a salt (I) and a resin having an acid labile group (hereinafter also referred to as "resin (A)"). Here, the "acid-labile group" means a group having a debonding group and decomposing the debonding group by contact with an acid to convert a constituent unit into a constituent unit having a hydrophilic group (for example, a hydroxyl group or a carboxyl group).

The photoresist composition of the present invention is preferably a quenching agent (hereinafter also referred to as "quenching agent (C)") containing a salt which is weaker than the acid generated by the acid generator, and contains a solvent (hereinafter also referred to as "quenching agent (C)"). The following is also referred to as "solvent (E)").

<acid generator>

The acid generator of the present invention contains the salt (I). The acid generator of the present invention contains one or more of the salts (I). In the following, the salt (I) which is an acid generator is specifically referred to as "acid generator (I0)".

The acid generator of the present invention may contain another acid generator known in the field of photoresist other than the acid generator (I0) (hereinafter also referred to as "acid generator (B").

When the acid generator (I0) and the acid generator (B) are used as the acid generator, the mass ratio of the acid generator (I0) and the acid generator (B), the acid generator (I0): the acid generator ( B), usually from 1:99 to 99:1, preferably from 2:98 to 98:2, more preferably from 5:95 to 95:5, and even more preferably from 25:75 to 75:25.

The content of the acid generator (I0) in the photoresist composition is preferably from 1.5 to 40 parts by weight, based on 100 parts by weight of the resin (A), and more preferably from 3 to 35 parts by weight.

<acid generator (B)>

The acid generator (B) may be a known acid generator, and may be an ionic acid generator or a nonionic acid generator. The nonionic acid generator may include an organic halide or a sulfonate compound (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimine, sulfonium sulfonate) Oxy ketone, diazonaphthoquinone 4-sulfonate), hydrazine compound (for example, diterpene, ketoxime, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include an ionic acid generator formed by combining a known cation with a known anion, and a sulfonium salt containing a phosphonium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, Iodine salt) is representative. The anion of the onium salt may be a sulfonic acid anion, a sulfonyl imine anion, a sulfonyl methide anion or the like.

For the acid generator (B), JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, and JP-A-63 -163452, Japanese Patent Laid-Open No. 62-153853, Japanese Patent Laid-Open No. Sho 63-146029, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3,914,407, European Patent No. 126,712, etc. An acid generator which generates an acid by radiation, an acid generator described in JP-A-2013-68914, JP-A-2013-3155, and JP-A-2013-11905. Meanwhile, a compound produced by a known method can also be used.

The acid generator (B) may, for example, be an organic sulfonate or the like, preferably a fluorine-containing acid generator, and more preferably an acid generator represented by the formula (B1) (hereinafter also referred to as "acid generation". Agent (B1)").

[In the formula (B1), Q ¹¹ and Q ¹² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.

L ^B1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-, and a hydrogen atom contained in the divalent saturated hydrocarbon group may also be used. A fluorine atom or a hydroxyl group is substituted.

Y ^B1 represents a methyl group which may have a substituent or a condensed hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and -CH ₂ - contained in the alicyclic hydrocarbon group may be substituted into -O-, -SO ₂ -or-CO-.

Z ⁺ represents an organic cation. 〕

The perfluoroalkyl group of Q ¹¹ and Q ¹² may be the same as those exemplified for the perfluoroalkyl group represented by Q ¹ and Q ² .

Q ¹¹ and Q ¹² are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom. The Q ¹¹ and Q ¹² systems are preferably a fluorine atom together.

The divalent saturated hydrocarbon group represented by L ^B1 is the same as the divalent saturated hydrocarbon group represented by L ^b1 .

The -CH ₂ --O- or -CO--substituted group contained in the divalent saturated hydrocarbon group represented by L ^B1 may be -CH ₂ -trans-O- contained in the divalent saturated hydrocarbon group represented by L ^b1 Or the same as the -CO-substituted group. Specifically, the base represented by the above formula (b1-1) to formula (b1-3) can be mentioned. Further, when L ^B1 is a group represented by the formula (b1-1) to the formula (b1-3), * in the group represented by the formulae (b1-1) to (b1-3) represents a bond with Y ^B1 .

L ^B1 is preferably any one of the groups represented by formula (b1-1) to formula (b1-3), and is represented by *2-CO-O-(CH ₂ ) _t1 -, *2-(CH ₂ ) _T2 -O-CO- (t1 represents any integer from 0 to 6. t2 represents any integer from 1 to 6. *2 represents a bonding bond with -C(Q ¹¹ )(Q ¹² )-.) .

The monovalent alicyclic hydrocarbon group represented by Y ^B1 may be a single ring, and may be a polycyclic ring or a spiro ring. Specifically, a monovalent alicyclic hydrocarbon group represented by Y ^B1 (a group represented by the above formula (Y1) to formula (Y38)) may be mentioned. Among the groups represented by Y ^B1 , preferred groups are the same as the preferred range of the group represented by Y.

The anion of the salt represented by the formula (B1) includes the formula (B1-A-1) to the formula (B1-A-55). An anion represented by the formula (B1-A-1) to the formula (B1-A-55) (hereinafter, the corresponding formula number is referred to as "anion (B1-A-1)" or the like. 〕 is preferably, and is of the formula (B1-A-1) to the formula (B1-A-4), the formula (B1-A-9), the formula (B1-A-10), the formula (B1-A-24) Any of the formulas (B1-A-33), (B1-A-36) to (B1-A-40), and (B1-A-47) to (B1-A-55) The anion is better.

Here, R ⁱ² to R ^{i7 are} , for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group.

R ^{i8 is} , for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining the groups, more preferably Methyl, ethyl, cyclohexyl or adamantyl.

L ⁴⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.

Q ¹¹ and Q ¹² 12 are the same as described above.

The anion in the salt represented by the formula (B1) includes an anion represented by the formula (Ia-1) to the formula (Ia-34), respectively.

Wherein, and the formula (B1a-1) to the formula (B1a-3) and the formula (B1a-7) to the formula (B1a-16), the formula (B1a-18), the formula (B1a-19), the formula (B1a- 22) An anion represented by any one of the formulae (B1a to 34) is preferred.

The cation Z ⁺ system in the acid generator (B1) is preferably an organic phosphonium cation. Examples of the organic phosphonium cation include an organic sulfonium cation, an organic iodonium cation, an organic ammonium phosphonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among them, an organic sulfonium cation and an organic iodonium cation are preferred, and an aryl sulfonium cation is more preferred. Specifically, a cation represented by any one of the formulae (b2-1) to (b2-4) (hereinafter, the corresponding formula number is referred to as "cation (b2-1)" or the like).

[In the formulae (b2-1) to (b2-4), R ^b4 to R ^b4 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or a carbon number of 6 to The aromatic hydrocarbon group of 36, the hydrogen atom contained in the chain hydrocarbon group may be substituted by a hydroxyl group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted by a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the aromatic hydrocarbon group is contained therein. The hydrogen atom may be substituted by a halogen atom, a hydroxyl group or an alkoxy group having 1 to 12 carbon atoms.

R ^b4 and R ^b5 may be bonded to each other to form a ring together with the bonded sulfur atom, and -CH ₂ - contained in the ring may be substituted with -O-, -S=- or -C=O-.

R ^b7 and R ^b8 each independently represent a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.

M2 and n2 each independently represent any integer from 0 to 5.

When m2 is 2 or more, a plurality of R ^b7 may be the same or different from each other, and when n 2 is 2 or more, a plurality of R ^b8 may be the same or different from each other.

R ^b9 and R ^b10 each independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.

R ^b9 and R ^b10 may be bonded to each other to form a ring together with the sulfur atom to be bonded, and -CH ₂ - contained in the ring may be substituted into -O-, -S- or -CO-.

R ^b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms.

R ^b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the chain hydrocarbon group may have a carbon number of 6 to 18 The aromatic hydrocarbon group is substituted, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.

R ^b11 and R ^b12 may be bonded to each other to form a ring containing the bonded -CH-CO-, and -CH ₂ - contained in the ring may be substituted with -O-, -S- or -CO-.

R ^b13 to R ^b18 each independently represent a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.

L ^b31 represents a sulfur atom or an oxygen atom.

O2, p2, s2, and t2 each independently represent any integer from 0 to 5.

Q2 and r2 each independently represent any integer from 0 to 4.

U2 means 0 or 1.

When o2 is 2 or more, a plurality of R ^b13 may be the same or different from each other, and when p2 is 2 or more, a plurality of R ^b14 may be the same or different from each other, and when q 2 is 2 or more, a plurality of R ^b15 may be mutually When r2 is 2 or more, several R ^b16 may be the same or different from each other, and when s2 is 2 or more, several R ^b17 may be the same or different from each other, and when t2 is 2 or more, several R ^B18 can be the same or different from each other. 〕

The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group.

The chain hydrocarbon group may, for example, be an alkyl group of a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a second butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group or a 2-ethylhexyl group.

In particular, the chain hydrocarbon group of R ^b9 to R ^b12 is preferably a carbon number of from 1 to 12.

The alicyclic hydrocarbon group may be either a monocyclic or polycyclic formula, a monocyclic alicyclic hydrocarbon group, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. a cycloalkyl group such as a fluorenyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups.

Particularly, the alicyclic hydrocarbon group of R ^b9 to R ^b12 is preferably a carbon number of 3 to 18, and more preferably a carbon number of 4 to 12.

Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, and 2 - Isopropylcycloalkan-2-yl, methylnorbornyl, isobornyl, and the like. In the alicyclic hydrocarbon group in which the hydrogen atom is substituted with an aliphatic hydrocarbon group, the total carbon number of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

Examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a xylyl group, a cumyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, and a p-cyclohexylphenyl group. An aryl group such as p-adamantylphenyl, biphenylyl, naphthyl, phenanthryl, 2,6-diethylphenyl, 2-methyl-6-ethylphenyl.

Further, when the aromatic hydrocarbon group contains a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferred.

The aromatic hydrocarbon group in which the hydrogen atom is substituted with an alkoxy group may, for example, be a p-methoxyphenyl group.

The chain hydrocarbon group in which the hydrogen atom is substituted with an aromatic hydrocarbon group may, for example, be an aralkyl group such as a benzyl group, a phenethyl group, a phenylpropyl group, a tolyl group, a naphthylmethyl group or a naphthylethyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group.

Examples of the alkylcarbonyl group include an ethyl group, a propyl group, a butyl group and the like.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkylcarbonyloxy group may, for example, be a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a second butylcarbonyloxy group or the third group. Butylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, octylcarbonyloxy and 2-ethylhexylcarbonyloxy and the like.

A ring in which R ^b4 and R ^b5 are bonded to each other and a sulfur atom bonded to the groups may be a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. The ring may be a ring having 3 to 18 carbon atoms, and preferably a ring having 4 to 18 carbon atoms. Meanwhile, the ring containing a sulfur atom may be a 3-membered ring to a 12-membered ring, and preferably a 3-membered ring to a 7-membered ring, and examples thereof include the following rings.

The ring formed by R ^b9 together with R ^b10 may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. This ring can be exemplified by a 3-member ring to a 12-member ring, and a 3-member ring to a 7-member ring. For example, thiolane-1-ium (ium) ring (tetrahydrothiophene ring), thiane-1-anthracene, 1,4-thiathiane (1,4-oxathiane) ) -4- ring and so on.

The ring formed by R ^b11 together with R ^b12 may be any ring of monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. This ring can be exemplified by a 3-member ring to a 12-member ring, and a 3-member ring to a 7-member ring. A side oxycycloheptane ring, a side oxycyclohexane ring, a side oxygen norbornane ring, a side oxyadamantane ring, etc. are mentioned.

Among the cations (b2-1) to cations (b2-4), a cation (b2-1) is preferred.

Examples of the cation (b2-1) include the following cations.

Examples of the cation (b2-2) include the following cations.

Examples of the cation (b2-3) include the following cations.

Examples of the cation (b2-4) include the following cations.

Wherein, and by the formula (b2-c-1), (b2-c-10), (b2-c-12), (b2-c-14), (b2-c-27), (b2-c- The cations represented by 30) and (b2-c-31) are preferred.

Examples of the acid generator (B) include an organic sulfonic acid, an organic sulfonium salt, and the like. For example, JP-A-2013-68914, JP-A-2013-3155, and JP-A-2013-11905 The acid generator or the like. Specifically, any of the formulae (B1-1) to (B1-48) can be expressed. Wherein, the aryl sulfonium cation is preferred, and the formula (B1-1) to the formula (B1-3), the formula (B1-5) to the formula (B1-7), the formula (B1-11) to Any of the formula (B1-14), the formula (B1-17), the formula (B1-20) to the formula (B1-26), the formula (B1-29), the formula (B1-31) to the formula (B1-48) One formula indicates that the salt is better.

<Structural unit of resin (A)>

The resin (A) contains a structural unit having an acid labile group (hereinafter also referred to as "structural unit (a1)"). The resin (A) is preferably a structural unit other than the structural unit (a1). The structural unit other than the structural unit (a1) includes a structural unit having no acid labile group (hereinafter also referred to as "structural unit (s)"), and other structural units (hereinafter also referred to as "structural unit (t)" ).

<Structural unit (a1) having an acid labile group>

The structural unit (a1) may be derived from a monomer having an acid labile group (hereinafter also referred to as "monomer (a1)"). Here, the "acid-labile group" means a group having a leaving group and forming a hydrophilic group (for example, a hydroxyl group or a carboxyl group) by desorbing the leaving group by contact with an acid.

<acid unstable group>

In the resin (A), the acid-labile group contained in the structural unit (a1) is preferably a group represented by the following formula (1) and/or a group represented by the formula (2).

[In the formula (1), R ^a1 to R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent or a combination of the groups The group, but R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atom to which the groups are bonded.

Ma and na each independently represent 0 or 1, and at least one of ma and na is 1.

* indicates the key combination. 〕

[In the formula (2), R ^{a1 '} and R ^{a2 '} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 '} represents a hydrocarbon group having 1 to 20 carbon atoms, but R ^a2' and R ^a3' are mutually The carbon atom bonded to the groups and X together form a hetero ring having 3 to 20 carbon atoms, and the hydrocarbon group and the methylene group contained in the hetero ring may be substituted with an oxygen atom or a sulfur atom. X represents an oxygen atom or a sulfur atom. Na' means 0 or 1. * indicates the key combination. 〕

The alkyl group of R ^a1 to R ^a3 may, for example, be a methyl group, an ethyl group, a propyl group, a n-butyl group, a n-pentyl group, a n-hexyl group, a n-heptyl group or a n-octyl group.

The alicyclic hydrocarbon group of R ^a1 to R ^a3 may be either a monocyclic or polycyclic formula. The monocyclic alicyclic hydrocarbon group may, for example, be a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group or a cyclooctyl group. The polycyclic alicyclic hydrocarbon group may, for example, be a decahydronaphthyl group, an adamantyl group, a norbornyl group or a group (* represents a bonding bond). The carbon number of the alicyclic hydrocarbon group of R ^a1 to R ^a3 is preferably from 3 to 16.

The substituent of the alkyl group having 1 to 8 carbon atoms which may have a substituent may, for example, be an alicyclic hydrocarbon group having 3 to 20 carbon atoms. The substituent of the alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent may, for example, be an alkyl group having 1 to 8 carbon atoms. More specifically, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, a norbornyl ethyl group, etc. are mentioned.

The ma system is preferably 0, and the n is preferably 1.

When R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring, -C(R ^a1 )(R ^a2 )(R ^a3 ) may be exemplified. The non-aromatic hydrocarbon ring system preferably has a carbon number of from 3 to 12. * indicates the bond key with -O-.

The group represented by the formula (1) includes a 1,1-dialkylalkoxycarbonyl group (wherein R ^a1 to R ^a3 in the formula (1) are a group of an alkyl group, and a third butoxycarbonyl group is preferred) , 2-alkyladamantan-2-yloxycarbonyl (in the formula (1), R ^a1 , R ^a2 and a carbon atom to which these groups are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantan-1-yl)-1-alkylalkoxycarbonyl (in the formula (1), R ^a1 and R ^a2 are an alkyl group, and R ^a3 is a group of an adamantyl group).

^Examples of the hydrocarbon group of R ^{a1 '} to R ^{a3 '} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups.

The alkyl group and the alicyclic hydrocarbon group are the same as those described above.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthracenyl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, and a cumene. An aryl group such as a benzyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group or a 2-methyl-6-ethylphenyl group.

The heterocyclic ring in which R ^{a2 '} and R ^a3' are bonded to each other and the carbon atom bonded to the group and X together may be exemplified by the following groups. * indicates the key combination.

It is preferred that at least one of R ^{a2 '} and R ^{a3 '} is a hydrogen atom.

Specific examples of the group represented by the formula (1) include the following groups. * indicates the key combination.

Specific examples of the group represented by the formula (2) include the following groups. * is the key combination.

The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer having an acid labile group.

Among the (meth)acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. When the resin (A) having a structural unit derived from the monomer (a1) having a bulky structure like an alicyclic hydrocarbon group is used for the photoresist composition, the resolution of the photoresist pattern can be improved.

<Specific example of structural unit (a1)>

The structural unit derived from the (meth)acrylic monomer having a group represented by the formula (1) is preferably a structural unit represented by the formula (a1-0) (hereinafter also referred to as a structural unit (a1-0)). a structural unit represented by the formula (a1-1) (hereinafter also referred to as a structural unit (a1-1)) or a structural unit represented by the formula (a1-2) (hereinafter also referred to as a structural unit (a1-2)). These structural units may be used singly or in combination of two or more.

[In the formula (a1-0), L ^a01 represents an oxygen atom or *-O-(CH ₂ ) _k01 -CO-O-, k01 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.

R ^a01 represents a hydrogen atom or a methyl group.

R ^a02 , R ^a03 and R ^a04 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group in which these groups are combined. 〕

L ^a01 is preferably an oxygen atom or *-O-(CH ₂ ) _k01 -CO-O-, and more preferably an oxygen atom. K01 is preferably any integer from 1 to 4, and more preferably one.

The alkyl group, the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^{a04 and} the group of these groups are the same as those exemplified in R ^a1 to R ^a3 of the formula (1).

The alkyl group of R ^a02 , R ^a03 and R ^a04 is preferably a carbon number of 6 or less.

The alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably a carbon number of 3 to 8, and more preferably a carbon number of 3 to 6.

The alkyl group and the alicyclic hydrocarbon group are combined into a group, and the total carbon number of the alkyl group in combination with the alicyclic hydrocarbon group is preferably 18 or less. Examples of such a group include methylcyclohexyl group, dimethylcyclohexyl group, and methylnorbornyl group.

R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.

R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

[In the formula (a1-1) and the formula (a1-2), L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, and k1 represents 1 to 7 Any integer, * indicates a bond with -CO-.

R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.

R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these groups.

M1 represents any integer from 0 to 14.

N1 represents any integer from 0 to 10.

N1' represents any integer from 0 to 3. 〕

L ^a1 and L ^a2 are preferably -O- or ^* -O-(CH ₂ ) _k1' -CO-O-, and more preferably -O-. K1' is any integer from 1 to 4 and is preferably one.

R ^a4 and R ^a5 are preferably a methyl group.

The alkyl group of R ^a6 and R ^a7 may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group, a third butyl group, a n-pentyl group or a n-hexyl group. , n-heptyl, 2-ethylhexyl, n-octyl and the like.

The alicyclic hydrocarbon group of R ^a6 and R ^a7 may be either a monocyclic or polycyclic formula, and a monocyclic alicyclic hydrocarbon group may, for example, be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group or a ring. A cycloalkyl group such as a hexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group or a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include, for example, decahydronaphthyl, adamantyl, 2-alkyladamantan-2-yl, 1-(adamantan-1-yl)alkan-1-yl, and Borneol base, methylnorbornyl base and isobornyl base.

The group formed by combining the alkyl group of R ^a6 and R ^a7 with the alicyclic hydrocarbon group may, for example, be an aralkyl group, and examples thereof include a benzyl group and a phenethyl group.

The carbon number of the alkyl group of R ^a6 and R ^a7 is preferably 6 or less.

The carbon number of the alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably from 3 to 8, more preferably from 3 to 6.

M1 is preferably any integer from 0 to 3, and more preferably 0 or 1.

N1 is preferably any integer from 0 to 3, and more preferably 0 or 1.

N1' is preferably 0 or 1.

The structural unit (a1-0) is preferably a structural unit represented by any one of the formulae (a1 - 0-1) to (a1 - 0 - 12), and is expressed by the formula (a1 - 0) to ( The structural unit represented by any of a1-0-10) is more preferable.

In the above formula (a1-0-1) to the formula (a1-0-12), a structural unit corresponding to a methyl group of R ^a01 substituted with a hydrogen atom may be exemplified as a specific example of the structural unit (a1-0). .

The structural unit (a1-1), for example, a structural unit derived from a monomer described in JP-A-2010-204646, and having the formula (a1-1-1) to the formula (a1-1-8) The structural unit represented by any of the formulae is preferable, and the structural unit represented by any of the formulae (a1-1-1) to (a1-1-4) is more preferable.

The structural unit (a1-2) is preferably a structural unit represented by any one of the formulae (a1-2-1) to (a1-2-12), and is represented by the formula (a1-2-3) and the formula (a1). -2-4), the structural unit represented by the formula (a1-2-9) or the formula (a1-2-10) is more preferable, and is represented by the formula (a1-2-3) or the formula (a1-2-9) The structural unit is even better.

When the resin (A) contains the structural unit (a1-0) and/or the structural unit (a1-1) and/or the structural unit (a1-2), the structural unit of the total structural unit of the resin (A) The total content of the mixture is usually from 10 to 95 mol%, preferably from 15 to 90 mol%, and more preferably from 20 to 85 mol%.

The structural unit (a1) having an acid labile group can be a structural unit represented by the formula (a1-5) (hereinafter also referred to as "structural unit (a1-5)").

[In the formula (a1-5), R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.

Z ^a1 represents a single bond or *-(CH ₂ ) _h3 -CO-L ⁵⁴ -, h3 represents any integer from 1 to 4, and * represents a bond with L ⁵¹ .

L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.

S1 represents any integer from 1 to 3.

S1' represents any integer from 0 to 3. 〕

In the formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.

L ⁵¹ is preferably -O-.

L ⁵² and L ⁵³ are preferably -O- on one side and -S- on the other.

The s1 system is preferably 1.

S1' is preferably any integer from 0 to 2.

Z ^a1 is preferably a single bond or *-CH ₂ -CO-O-.

The monomer of the derivatized structural unit (a1-5) may, for example, be a structural unit derived from a monomer described in JP-A-2010-61117. Wherein, the structural unit represented by any one of the formulae (a1-5-1) to (a1-5-4) is preferred, and the formula (a1-5-1) or the formula (a1-5-2) is preferred. The structural unit represented is better.

When the resin (A) has the structural unit (a1-5), the content of the total structural unit of the resin (A) is preferably from 1 to 50 mol%, more preferably from 3 to 45 mol%. And 5 to 40 mol% is even better.

Further, the structural unit (a1) includes the following structural units.

When the resin (A) contains the above structural unit, the content of the entire structural unit of the resin (A) is preferably from 10 to 95 mol%, more preferably from 15 to 90 mol%, and from 20 to 85. Moore is even better.

<Structural unit (s) having no acid labile group>

The structural unit (s) may be derived from a monomer having no acid labile group (hereinafter also referred to as "monomer (s)"). As the monomer (s) of the derivatized structural unit (s), a monomer having no acid labile group known in the field of photoresist can be used.

The structural unit (s) is preferably a structural unit having a hydroxyl group or a lactone ring and having no acid labile group. A structural unit having a hydroxyl group and having no acid labile group (hereinafter also referred to as "structural unit (a2)") and/or a structural unit having a lactone ring and having no acid labile group (hereinafter also referred to as "structure" The resin of the unit (a3)") is used for the photoresist composition of the present invention, and the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>

The hydroxyl group which the structural unit (a2) has may be a phenolic hydroxyl group or an alcoholic hydroxyl group.

When a photoresist pattern is produced from the photoresist composition of the present invention, a high energy line such as KrF excimer laser (248 nm), electron beam or EUV (ultraviolet light) is used as an exposure light source to have a structure having a phenolic hydroxyl group. The unit (a2) is preferable as the structural unit (a2). Meanwhile, when an ArF excimer laser (193 nm) or the like is used, a structural unit (a2) having an alcoholic hydroxyl group is preferably used as the structural unit (a2). The structural unit (a2) may be contained alone or in combination of two or more.

The structural unit (a2) having a phenolic hydroxyl group may, for example, be a structural unit derived from a monomer described in JP-A-2010-204634.

When the resin (A) contains a structural unit (a2-0) having a phenolic hydroxyl group, the content of the entire structural unit of the resin (A) is preferably from 5 to 95 mol%, and is from 10 to 80 mol%. % is better, and 15 to 80% is better.

The structural unit (a2) having an alcoholic hydroxyl group is a structural unit represented by the formula (a2-1) (hereinafter also referred to as "structural unit (a2-1)".

[In the formula (a2-1), L ^a3 represents -O- or *-O-(CH ₂ ) _k2 -CO-O-, and k2 represents any integer of 1 to 7. * indicates a bond with -CO-.

R ^a14 represents a hydrogen atom or a methyl group.

R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxyl group.

O1 represents any integer from 0 to 10. 〕

In the formula (a2-1), L ^a3 is preferably -O-, -O-(CH ₂ ) _f1 -CO-O- (any of the above-mentioned f1 systems 1 to 4), and is -O- Better.

R ^a14 is preferably a methyl group.

R ^a15 is preferably a hydrogen atom.

R ^a16 is preferably a hydrogen atom or a hydroxyl group.

O1 is preferably any integer from 0 to 3, and more preferably 0 or 1.

The structural unit (a2-1) is a structural unit represented by any one of the formulae (a2-1-1) to (a2-1-6), as described in Japanese Laid-Open Patent Publication No. 2010-204646. Preferably, the structural unit represented by any one of the formulae (a2-1-1) to (a2-1-4) is more preferable, and the formula (a2-1-1) to the formula (a2-1-3) Any of the structural units represented by the formula is even better.

The monomer which derivatizes the structural unit (a2) which has an alcoholic hydroxyl group, for example, the monomer described in Unexamined-Japanese-Patent No. 2010-204646.

When the resin (A) contains the structural unit (a2) having an alcoholic hydroxyl group, the content of the total structural unit of the resin (A) is usually from 1 to 45 mol%, and preferably from 1 to 40 mol%. It is preferably from 1 to 35 mol%, and more preferably from 2 to 20 mol%.

<Structural unit (a3)>

The structural unit (a3) has an inner alicyclic ring which may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring or a δ-valerolactone ring, or a monocyclic lactone ring and others. The ring condensed ring, preferably a lactone ring, may preferably be a γ-butyrolactone ring, an adamantane lactone ring or a bridge ring containing a γ-butyrolactone ring structure.

The structural unit (a3) is preferably a structural unit represented by any one of the formulae (a3-1) to (a3-4). The resin (A) may contain one type of these structural units, or may contain two or more types.

[In the formula (a3-1), L ^a4 represents a group represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents an integer of 1 to 7). * indicates a bond to a carbonyl group.

R ^a18 represents a hydrogen atom or a methyl group.

R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

P1 represents any integer from 0 to 5. When p1 is 2 or more, several R ^a21 may be the same or different from each other.

In the formula (a3-2), L ^a5 represents a group represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents an integer of 1 to 7). * indicates a bond to a carbonyl group.

R ^a19 represents a hydrogen atom or a methyl group.

R ^a22 represents a carboxyl group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

Q1 represents any integer from 0 to 3. When q1 is 2 or more, several R ^a22 may be the same or different from each other.

In the formula (a3-3), L ^a65 represents a ^group represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents any integer of 1 to 7). * indicates a bond to a carbonyl group.

R ^a20 represents a hydrogen atom or a methyl group.

R ^a23 represents a carboxyl group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

R1 represents any integer from 0 to 3. When r1 is 2 or more, several R ^a23 may be the same or different from each other.

R ^a24 in the formula (a3-4) represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.

L ^a7 represents ^{* -O -, * - OL a8} -O -, * - OL a8 -CO-O -, * - OL a8 -CO-OL a9 -CO-O- or * -OL ^a8 -O-CO- L ^a9 -O-.

R ^a25 represents a carboxyl group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

w represents any integer from 0 to 8.

* The bond between the table and the carbonyl group.

L ^a8 and L ^a9 independently of each other represent an alkanediyl group having 1 to 6 carbon atoms. 〕

^Examples of the aliphatic hydrocarbon group of R ^a21 , R ^a22 , R ^a23 and R ^a25 include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group and a third butyl group. base.

The halogen atom of R ^a24 may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The alkyl group of R ^a24 may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group, a third butyl group, a n-pentyl group or a n-hexyl group. The alkyl group having 1 to 4 carbon atoms is preferred, and the methyl group or ethyl group is more preferred.

R ^a24 may have a halogen alkyl group, and examples thereof include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro second butyl group, and a perfluoro third group. Butyl, perfluoropentyl, perfluorohexyl, trichloromethyl, tribromomethyl, triiodomethyl, and the like.

Examples of the alkanediyl group of L ^a8 and L ^a9 include a methylene group, an ethylidene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane group. Alkan-1,5-diyl, hexane-1,6-diyl, heptane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1, 2-diyl, pentane-1,4-diyl, 2-methylbutane-1,4-diyl and the like.

In the formulae (a3-1) to (a3-3), L ^a4 to L ^a6 are independent of each other, and -O- or k3 is an integer of any one of 1 to 4 *-O-(CH ₂ ) _k3 -CO The base of -O- is preferred, and -O- and *-O-CH ₂ -CO-O- are more preferred, and -O- is more preferred.

R ^a18 to R ^a21 are preferably a methyl group.

R ^a22 and R ^a23 are independent of each other, and a carboxyl group, a cyano group or a methyl group is preferred.

P1, q1, r1 and w are independent of each other, preferably any integer from 0 to 2, and more preferably 0 or 1.

In the formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.

L ^a7 is preferably *-O- or *-OL ^a8 -CO-O-, and is *-O-, *-O-CH ₂ -CO-O- or *-OC ₂ H ₄ -CO-O - Better.

The formula (a3-4) is particularly preferably the formula (a3-4)'.

(wherein R ^a24 and L ^{a7 are} the same as described above.)

The monomer of the derivative structural unit (a3) is a monomer described in JP-A-2010-204646, and a monomer described in JP-A-2000-122294, and JP-A-2012-41274 Said monomer. The structural unit (a3) is of the formula (a3-1-1) to the formula (a3-1-4), the formula (a3-2-1) to the formula (a3-2-4), and the formula (a3-3-1) It is preferable that the structural unit represented by any one of the formula (a3-3-4) and the formula (a3-4-1) to the formula (a3-4-12) is preferable, and the formula (a3-1-1), (a3-1-2), a structural unit represented by any one of formula (a3-2-3) to formula (a3-2-4) and formula (a3-4-1) to formula (a3-4-12) More preferably, the structural unit represented by any one of the formulae (a3-4-1) to (a3-4-12) is more preferable, and the formula (a3-4-1) to the formula (a3-4-) The structural unit represented by any of 6) is optimal.

The structural unit (a3) may be contained alone or in combination of two or more. The structural unit (a3) includes the following structural units.

In the structural unit represented by the above formula (a3-4-1) to the formula (a3-4-12), a compound corresponding to a methyl group of R ^a24 substituted with a hydrogen atom may be mentioned as a structural unit (a3-4). Specific example.

When the resin (A) contains the structural unit (a3), the total content of the total structural unit of the resin (A) is usually 5 to 70 mol%, and preferably 10 to 65 mol%, and 10 to 60% of the moles is better.

For the entire structural unit of the resin (A), the respective content ratios of the structural units represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), and the formula (a3-4) are usually 5 to 60% by mole, preferably 5 to 50% by mole, and more preferably 10 to 50% by mole.

<Other structural units (t)>

The resin (A) may further contain other structural units (t). Structural unit (t) is a structural unit other than the structural unit (a2) and the structural unit (a3), and includes a structural unit having a halogen atom (hereinafter, also referred to as "structural unit (a4)"). A structural unit that desorbs from a hydrocarbon group (hereinafter also referred to as "structural unit (a5)").

<Structural unit (a4)>

The halogen atom in the structural unit (a4) is preferably a fluorine atom. The structural unit (a4) may be a structural unit represented by the formula (a4-0).

[In the formula (a4-0), R ⁵ represents a hydrogen atom or a methyl group.

L ⁵ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.

L ³ represents a perfluoroalkanediyl group having a carbon number of 1 to 8 or a perfluorocycloalkanediyl group having a carbon number of 5 to 12.

R ⁶ represents a hydrogen atom or a fluorine atom. 〕

The aliphatic saturated hydrocarbon group of L ⁵ may, for example, be an alkylenediyl group having 1 to 4 carbon atoms, and examples thereof include a methylene group, an ethylidene group, a propane-1,3-diyl group, and a butane-1,4-diene group. a linear alkanediyl group having a straight chain, a side chain having an alkyl group (wherein a methyl group, an ethyl group, etc.), an ethane-1,1-diyl group, a propane-1,2- Dibasic, butane-1,3-diyl, 2-methylpropane-1,3-diyl and 2-methylpropane-1,2-diyl isomerized alkanediyl.

Examples of the perfluoroalkanediyl group of L ³ include a difluoromethylene group, a perfluoroextended ethyl group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, and a perfluoropropane-1. 2-diyl, perfluoropropane-2,2-diyl, perfluorobutane-1,4-diyl, perfluorobutane-2,2-diyl, perfluorobutane-1,2-di Base, perfluoropentane-1,5-diyl, perfluoropentane-2,2-diyl, perfluoropentane-3,3-diyl, perfluorohexane-1,6-diyl, Perfluorohexane-2,2-diyl, perfluorohexane-3,3-diyl, perfluoroheptane-1,7-diyl, perfluoroheptane-2,2-diyl, perfluoro Heptane-3,4-diyl, perfluoroheptane-4,4-diyl, perfluorooctane-1,8-diyl, perfluorooctane-2,2-diyl, perfluorooctane -3,3-diyl, perfluorooctane-4,4-diyl, and the like.

Examples of the perfluorocycloalkanediyl group of L ³ include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

The L ⁵ group is preferably a single bond, a methylene group or an ethylidene group, and is preferably a single bond or a methylene group.

The L ³ is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

The structural unit (a4-0) may, for example, be the following.

In the above structural unit, a structural unit corresponding to a methyl group of R ⁵ substituted with a hydrogen atom may be mentioned as a specific example of the structural unit (a4-0).

The structural unit (a4) may be a structural unit represented by the formula (a4-1).

[In the formula (a4-1), R ^a41 represents a hydrogen atom or a methyl group.

R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - which is contained in the hydrocarbon group may be substituted with -O- or -CO-.

A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by the formula (a-g1). However, at least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.

[In the formula (a-g1), s represents 0 or 1.

A ^a42 and A ^a44 each independently represent a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.

A ^a43 represents a divalent aliphatic hydrocarbon group or a single bond having 1 to 5 carbon atoms which may have a substituent.

X ^a41 and X ^a42 each independently represent -O-, -CO-, -CO-O- or -O-CO-.

However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 6 or less.

*, ** is the bonding key, * is the bonding key with -O-CO-R ^a42 . 〕

However, at least one of A ^a41 and R ^a42 is a group having a halogen atom as a substituent. 〕

s is 0 is better.

^Examples of the hydrocarbon group of R ^a42 include a chain type and a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. The chain aliphatic hydrocarbon group may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a hexadecyl group or a pentadecyl group. An alkyl group such as hexyl decyl, heptadecyl or octadecyl. The cycloaliphatic aliphatic hydrocarbon group may, for example, be a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group or a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* A polycyclic alicyclic hydrocarbon group such as a bond bond.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthracenyl group, a biphenyl group, a phenanthryl group, and an anthracenyl group.

The hydrocarbon group of R ^a42 is preferably a chain-formed and cyclic aliphatic hydrocarbon group and a group formed by combining these groups. These groups may have a carbon-carbon unsaturated bond, but are preferably formed by a chain and a cyclic aliphatic saturated hydrocarbon group and a group formed by combining the groups.

The substituent of R ^a42 includes a halogen atom and a group represented by the formula (a-g3). The halogen atom may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and preferably a fluorine atom.

*-X ^a43 -A ^a45 (a-g3) [In the formula (a-g3), X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.

A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms having at least one halogen atom.

* indicates a bond to a hydrocarbon group of R ^a42 . 〕

The aliphatic hydrocarbon group of A ^a45 may be the same as the aliphatic hydrocarbon group exemplified in R ^a42 .

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and is preferably an alkyl group having a halogen atom and/or an aliphatic hydrocarbon group having a group represented by the formula (a-g3).

When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, and more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and a perfluoroalkyl group having 1 to 6 carbon atoms. More preferably, a perfluoroalkyl group having a carbon number of 1 to 3 is particularly preferred. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. The perfluorocycloalkyl group may, for example, be a perfluorocyclohexyl group.

When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), the number of carbon atoms contained in the group represented by the formula (a-g3) is included, and the total carbon number of the aliphatic hydrocarbon group is preferably 15 or less. It is better to be 12 or less. When the group represented by the formula (a-g3) is used as a substituent, the number is preferably one.

The aliphatic hydrocarbon having a group represented by the formula (a-g3) is more preferably a group represented by the formula (a-g2).

*-A ^a46 -X ^a44 -A ^a47 (a-g2) In the formula (a-g2), A ^a46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.

X ^a44 represents a carbonyloxy group or an oxycarbonyl group.

A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.

However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.

* indicates a bond to a carbonyl group. 〕

The carbon number of the aliphatic hydrocarbon group of A ^a46 is preferably from 1 to 6, more preferably from 1 to 3.

The carbon number of the aliphatic hydrocarbon group of A ^a47 is preferably 4 to 15, more preferably 5 to 12, and still more preferably cyclohexyl or adamantyl.

The group represented by the formula (a-g2) includes the following groups.

The alkanediyl group of A ^a41 may, for example, be a methylene group, an ethyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group or a hexane- a linear alkanediyl group such as 1,6-diyl; propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,2-diyl, 1-methyl Butane-1,4-diyl, 2-methylbutane-1,4-diyl isomerized alkanediyl.

The substituent in the alkanediyl group of A ^a41 may, for example, be a hydroxyl group or an alkoxy group having 1 to 6 carbon atoms.

A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylidene group.

The aliphatic hydrocarbon group of A ^a42 , A ^a43 and A ^a44 in the group represented by the formula (a-g1) (hereinafter, referred to as "base (a-g1)" as the case may be mentioned), methylene group, and extension B Base, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, 1-methylpropane-1,3-diyl, 2-methylpropane-1 , 3-diyl, 2-methylpropane-1,2-diyl and the like. Examples of such a substituent include a hydroxyl group and an alkoxy group having 1 to 6 carbon atoms.

X ^a42 is a group (a-g1) of an oxygen atom, and the following group etc. are mentioned. In the following examples, * and ** represent the bonding key, respectively, and ** is the bonding key with -O-CO-R ^a42 .

X ^a42 is a carbonyl group (a-g1), and the following groups and the like are mentioned.

X ^a42 is a group (a-g1) of a carbonyloxy group, and the following group etc. are mentioned.

The group (-g1) in which X ^a42 is an oxycarbonyl group may, for example, be the following group.

The structural unit represented by the formula (a4-1) is preferably a structural unit represented by the formula (a4-2).

[In the formula (a4-2), R ^f1 represents a hydrogen atom or a methyl group.

A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.

R ^f2 represents a hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom. 〕

The alkanediyl group of A ^f1 may, for example, be a methylene group, an ethyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group or a pentane-1. a linear alkanediyl group such as 5-diyl or hexane-1,6-diyl; 1-methylpropane-1,3-diyl, 2-methylpropane-1,3-diyl, 2 a branched alkyldiyl group such as methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl or 2-methylbutane-1,4-diyl.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and an aliphatic hydrocarbon group, which includes a chain form, a cyclic form, and a group formed by combining these groups. The aliphatic hydrocarbon group is preferably an alkyl group or an alicyclic hydrocarbon group.

The alkyl group may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group, a tert-butyl group, a n-pentyl group, a n-hexyl group or a n-octyl group. 2-ethylhexyl.

The alicyclic hydrocarbon group may be either a monocyclic or polycyclic formula, and a monocyclic alicyclic hydrocarbon group may, for example, be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group or a methylcyclohexyl group. A cycloalkyl group such as dimethylcyclohexyl, cycloheptyl, cyclooctyl or cyclodecyl. The polycyclic alicyclic hydrocarbon group may, for example, be decahydronaphthyl, adamantyl, 2-alkyladamantan-2-yl, 1-(adamantan-1-yl)alkyl-1-yl, norbornyl Base, methylnorbornyl and isobornyl.

The hydrocarbon group having a fluorine atom of R ^f2 may, for example, be an alkyl group having a fluorine atom or an alicyclic hydrocarbon group having a fluorine atom.

Specifically, the alkyl group having a fluorine atom may, for example, be difluoromethyl, trifluoromethyl, 1,1-difluoroethyl, 2,2-difluoroethyl or 2,2,2-trifluoroethyl. Base, perfluoroethyl, 1,1,2,2-tetrafluoropropyl, 1,1,2,2,3,3-hexafluoropropyl, perfluoroethylmethyl, 1-(trifluoromethyl) -1,2,2,2-tetrafluoroethyl, perfluoropropyl, 1,1,2,2-tetrafluorobutyl, 1,1,2,2,3,3-hexafluorobutyl 1,1,2,2,3,3,4,4-octafluorobutyl, perfluorobutyl, 1,1-bis(trifluoro)methyl-2,2,2-trifluoroethyl, 2-(perfluoropropyl)ethyl, 1,1,2,2,3,3,4,4-octafluoropentyl, perfluoropentyl, 1,1,2,2,3,3,4 ,4,5,5-decafluoropentyl, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl, perfluoropentyl, 2-(perfluorobutane Ethyl, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl, 1,1,2,2,3,3,4,4,5,5,6 a fluorinated alkyl group such as 6-dodecylhexyl, perfluoropentylmethyl and perfluorohexyl.

The alicyclic hydrocarbon group having a fluorine atom may, for example, be a fluorinated cycloalkyl group such as a perfluorocyclohexyl group or a perfluoroadamantyl group.

In the formula (a4-2), A ^f1 is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethyl group.

R ^f2 is preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

The structural unit (a4-2) may, for example, be a structural unit represented below and a structural unit corresponding to a methyl group of R ^{f1 in} the following structural unit substituted with a hydrogen atom.

The structural unit (a4) includes, for example, the following structural unit and a structural unit in which a methyl group bonded to the main chain is substituted with a hydrogen atom.

When the resin (A) has the structural unit (a4), the content of the entire structural unit of the resin (A) is preferably from 1 to 20 mol%, more preferably from 2 to 15 mol%, and more preferably 3 Up to 10% by mole is better.

<Structural unit (a5)>

The non-desorbed hydrocarbon group of the structural unit (a5) may, for example, be a linear, branched or cyclic hydrocarbon group, and preferably an alicyclic hydrocarbon group. The structural unit (a5) may, for example, be a structural unit represented by the formula (a5-1).

[In the formula (a5-1), R ⁵¹ represents a hydrogen atom or a methyl group.

R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. However, the hydrogen atom bonded to the carbon atom at the binding position to L ⁵⁵ cannot be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.

L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group. 〕

The alicyclic hydrocarbon group of R ⁵² may be either a monocyclic or polycyclic formula. The monocyclic alicyclic hydrocarbon group may, for example, be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group or a cyclohexyl group. The polycyclic alicyclic hydrocarbon group may, for example, be an adamantyl group or a norbornyl group.

The aliphatic hydrocarbon group having 1 to 18 carbon atoms may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a second butyl group, a tert-butyl group, a pentyl group, a hexyl group or a octyl group. And an alkyl group such as 2-ethylhexyl.

The alicyclic hydrocarbon group having a substituent may, for example, be 3-methyladamantyl.

R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

The divalent saturated hydrocarbon group of L ⁵⁵ may, for example, be a divalent aliphatic saturated hydrocarbon group or a divalent aliphatic cyclic hydrocarbon group, and preferably a divalent aliphatic saturated hydrocarbon group.

The divalent aliphatic saturated hydrocarbon group may, for example, be an alkanediyl group such as a methylene group, an ethylidene group, a propylenediyl group, a butylene group or a pentanediyl group.

The divalent aliphatic saturated hydrocarbon group may be either a monocyclic or polycyclic formula. The monocyclic alicyclic saturated hydrocarbon group may, for example, be a cycloalkanediyl group such as a cyclopentanediyl group or a cyclohexanediyl group. The polycyclic divalent alicyclic saturated hydrocarbon group may, for example, be an adamantane diyl group or a norbornane diyl group.

The group in which the methylene group contained in the saturated hydrocarbon group is substituted with an oxygen atom or a carbonyl group may, for example, be a group represented by the formula (L1-1) to the formula (L1-4). In the following formula, * represents a bond bond with an oxygen atom.

[In the formula (L1-1), X ^x1 represents a carbonyloxy group or an oxycarbonyl group.

L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.

L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.

However, the total carbon number of L ^x1 and L ^x2 is 16 or less.

In the formula (L1-2), L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.

L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.

However, the total carbon number of L ^x3 and L ^x4 is 17 or less.

In the formula (L1-3), L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.

L ^x6 and L ^x7 independently of each other represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.

However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.

In the formula (L1-4), L ^x8 and L ^x9 independently of each other represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.

W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.

However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less. 〕

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylidene group.

L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond.

L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethyl group.

L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethyl group.

L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.

L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.

W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantanediyl group.

The group represented by the formula (L1-1) includes, for example, a divalent group represented below.

The group represented by the formula (L1-2) includes, for example, a divalent group represented below.

The group represented by the formula (L1-3) includes, for example, a divalent group represented below.

The group represented by the formula (L1-4) includes, for example, a divalent group represented below.

L ⁵⁵ is preferably a group represented by a single bond, a methylene group, an extended ethyl group or a formula (L1-1), and is preferably a single bond or a group represented by the formula (L1-1).

The structural unit (a5-1) includes a structural unit represented below and a structural unit corresponding to a methyl group of R ^{51 in} the following structural unit substituted with a hydrogen atom.

When the resin (A) has the structural unit (a5), the content of the entire structural unit of the resin (A) is preferably from 1 to 30 mol%, more preferably from 2 to 20 mol%, and more preferably 3 Up to 15% by mole is better.

The resin (A) may have a structural unit other than the above structural unit, and such a structural unit may be a structural unit known in the art.

<Resin (A)>

The resin (A) is preferably a resin formed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s).

The structural unit (a1) is preferably at least one selected from the group consisting of structural unit (a1-1) and structural unit (a1-2) (preferably, the structural unit having a cyclohexyl group or a cyclopentyl group), and The structural unit (a1-1) or at least two selected from the structural unit (a1-1) and the structural unit (a1-2) (preferably, the structural unit having a cyclohexyl group or a cyclopentyl group) are more preferable.

The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1). The structural unit (a3) is a structural unit selected from the formula (a3-1-1) to the formula (a3-1-4), and the formula (a3-2-1) to the formula (a3-2-4) and the formula At least one of (a3-4-1) to the structural unit represented by the formula (a3-4-2) is preferred.

Each of the structural units constituting the resin (A) may be used singly or in combination of two or more kinds thereof, and a monomer derived from these structural units may be used and produced by a known polymerization method (for example, a radical polymerization method). The content ratio of each structural unit of the resin (A) can be adjusted by the amount of the monomer used in the polymerization.

The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, and still more preferably 15,000 or less). In the present specification, the weight average molecular weight is a value obtained by a gel permeation chromatography under the conditions described in the examples.

<Resin (X) other than resin (A)>

The photoresist composition of the present invention may contain a resin (X) other than the resin (A) and which does not contain the structural unit (a1) having an acid labile group. Examples of such a resin (X) include a resin containing a structural unit (t).

The resin (X) is preferably a resin containing the structural unit (a4) exemplified as the structural unit (t). In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, and more preferably 45 mol% or more, and 50 mol%, of the total structural unit of the resin (X). The above is even better.

The structural unit which the resin (X) may have may include a structural unit (a2) having no acid labile group, a structural unit (a3), and a structural unit derived from another known monomer.

The weight average molecular weight of the resin (X) is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as in the case of the resin (A).

When the resist composition contains the resin (X), the content of the resin (A) is preferably from 1 to 60 parts by mass, more preferably from 1 to 50 parts by mass, and from 1 to 40 parts by mass per 100 parts by mass of the resin (A). More preferably, it is more preferably from 1 to 20 parts by mass, and most preferably from 1.5 to 10 parts by mass.

The total content of the resin (A) and the resin (X) is preferably 80% by mass or more and 99% by mass or less based on the solid content of the resist composition. The solid content of the photoresist composition and the relative resin content can be measured by known analytical means such as a liquid chromatograph or a gas chromatograph.

<Solvent (E)>

In the resist composition, the content of the solvent (E) is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and 99.9% by mass or less and 99% by mass or less. It is better. The content of the solvent (E) can be measured by a known analytical means such as a liquid chromatograph or a gas chromatograph.

Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; and glycol ethers such as propylene glycol monomethyl ether. Ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; γ-butyrolactone and the like Esters; etc. The solvent (E) may be contained alone or in combination of two or more.

<Quenching agent (C)>

The quenching agent (C) may, for example, be a basic nitrogen-containing organic compound or an acid which is lower in acidity than an acid produced by an acid generator. The content of the quenching agent (C) is preferably about 0.01 to 5% by mass based on the solid content of the photoresist composition.

<Alkaline nitrogen-containing organic compounds>

The basic nitrogen-containing organic compound may, for example, be an amine or an ammonium salt. The amine may, for example, be an aliphatic amine or an aromatic amine. The aliphatic amine may, for example, be a primary amine, a secondary amine or a tertiary amine.

The amine may, for example, be 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N , N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, decylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine , dioctylamine, dimethylamine, dimethylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, Trioctylamine, tridecylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine,methyldiheptylamine, A Dioctylamine, methyldidecylamine, methyldidecylamine, ethyldibutylamine,ethyldipentylamine,ethyldihexylamine,ethyldiheptylamine,ethyldi Octylamine, ethyl dimethyl decylamine, ethyl dimethyl decylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, Ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3' - dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, Pyridine, 4-methylpyridine, 1,2-bis(2-pyridyl)ethane, 1,2-bis(4-pyridyl)ethane, 1,2-bis(2-pyridyl)ethene, 1 ,2-bis(4-pyridyl)ethene, 1,3-bis(4-pyridyl)propane, 1,2-bis(4-pyridyloxy)ethane, bis(2-pyridyl)one, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipyridylmethylamine, bipyridine, etc., preferably The diisopropylaniline can be mentioned, and 2,6-diisopropylaniline is more preferable.

The ammonium salt may, for example, be tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide or phenyltrimethyl Alkyl ammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

<The acidity of the acid produced is lower than the acid salt produced by the acid generator>

The acidity of the acid produced is lower than the acid salt produced by the acid generator. When the salt (I) is used as the acid generator, the acidity of the acid produced by the salt (I) is lower than that of the acid generator. The acid generator (B) containing the salt (I) and the acid generator other than the acid generator means that the acidity of the acid produced is lower than that of the salt (I) and the acid generator (B). salt.

The acidity of the acid produced is lower than the acidity of the acid salt produced by the acid generator, and is expressed by the acid dissociation constant (pKa). The acidity of the acid produced is lower than that of the acid produced by the acid generator. The acid dissociation constant of the acid produced by the salt is usually a salt of -3 < pKa, and a salt of -1 < pKa < 7 is preferred. A salt of 0 < pKa < 5 is more preferred.

The acidity of the acid produced is lower than the salt of the acid produced by the acid generator, and the salt represented by the following formula, JP-A-2012-229206, JP-A-2012-6908, and JP-A-2012 The salt described in the Japanese Patent Publication No. 2011-191745, and the Japanese Patent Publication No. 2011-191745.

In the solid content of the photoresist composition, the content of the acid salt having a low acidity is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass.

<Other ingredients (F)>

The photoresist composition of the present invention may contain components other than the above components as needed (hereinafter also referred to as "other components (F)"). The other component (F) is not particularly limited, and additives known in the field of photoresist such as a sensitizer, a dissolution preventing agent, a surfactant, a stabilizer, a dye, and the like can be used.

<Modulation of Photoresist Composition>

The photoresist composition of the present invention can be obtained by using the resin (A) and the salt (I) of the present invention, and optionally the resin (X), the acid generator (B), the solvent (E), and the quenching agent (C). ), and other components (F) are mixed and prepared. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing is selected from 10 to 40 ° C, the type of the resin or the like, the solubility of the solvent (E) such as a resin, and the like, and the appropriate temperature is selected. The mixing time is selected in an appropriate period of time by mixing the mixing temperature in 0.5 to 24 hours. Further, the mixing means is not particularly limited, and stirring and the like can be used.

It is preferred to mix the components and filter them with a filter having a pore diameter of about 0.003 to 0.2 μm.

<Method of Manufacturing Photoresist Pattern>

The method for producing a photoresist pattern of the present invention comprises the steps of: (1) a step of applying the photoresist composition of the present invention onto a substrate; and (2) drying the composition after coating to form a composition layer. And (3) a step of exposing the composition layer, (4) a step of heating the exposed composition layer, and (5) a step of developing the heated composition layer.

When the photoresist composition is applied onto a substrate, it can be carried out by a commonly used device such as a spin coater. The substrate may be an inorganic substrate such as a germanium wafer. The substrate may be washed before the photoresist composition is applied, or an anti-reflection film or the like may be formed on the substrate.

The composition layer is formed by drying the solvent after drying the composition. Drying can be carried out, for example, by evaporating a solvent (so-called prebaking) using a heating means such as a hot plate or by using a decompression device. The heating temperature is preferably from 50 to 200 ° C, and the heating time is preferably from 10 to 180 seconds. Meanwhile, the pressure at the time of drying under reduced pressure is preferably from about 1 to 1.0 × 10 ⁵ Pa.

The layer of the composition obtained is usually exposed by an exposure machine. The exposure machine can be a liquid immersion exposure machine. For exposure light source, laser light emitting ultraviolet light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), and solid laser light source (YAG or semiconductor laser, etc.) The laser light converts the wavelength and emits a variety of light sources such as a high-harmonic laser beam in the far ultraviolet region or the vacuum ultraviolet region, an electron beam, or an ultra-ultraviolet light (EUV). In addition, in this specification, the radiation which irradiated these is also called "exposure". At the time of exposure, exposure is usually performed through a photomask corresponding to the desired pattern. When the exposure light source is an electron beam, it can be exposed by direct drawing without using a photomask.

The exposed composition layer is subjected to heat treatment (so-called post exposure bake) to promote the deprotection reaction in the acid labile group. The heating temperature is usually about 50 to 200 ° C and preferably about 70 to 150 ° C.

The heated composition layer is usually developed using a developing device using a developing device. Examples of the development method include a dipping method, a paddle method, a spray method, and a dynamic distribution method. The development temperature is preferably, for example, 5 to 60 ° C, and the development time is preferably, for example, 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be produced by selecting the type of the developing liquid as follows.

When a positive resist pattern is produced from the photoresist composition of the present invention, an alkali developing solution is used as a developing liquid. The alkali developing solution may be any of various alkaline aqueous solutions used in the field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) can be mentioned. The alkali developing solution may contain a surfactant.

After the development, the photoresist pattern is washed with ultrapure water, and then the water remaining on the substrate and the pattern is preferably removed.

When a negative resist pattern is produced from the photoresist composition of the present invention, a developing liquid containing an organic solvent is used as a developing liquid (hereinafter also referred to as "organic-based developing liquid").

Examples of the organic solvent contained in the organic-based developing solution include a ketone solvent such as 2-hexanone or 2-heptanone; a glycol ether ester solvent such as propylene glycol monomethyl ether acetate; an ester solvent such as butyl acetate; and propylene glycol alone. A glycol ether solvent such as methyl ether; a guanamine solvent such as N,N-dimethylacetamide; an aromatic hydrocarbon solvent such as anisole or the like.

In the organic-based developing solution, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and more preferably substantially only an organic solvent.

Among them, the organic-based developing liquid is preferably a developing solution containing butyl acetate and/or 2-heptanone. In the organic-based developing solution, the total content of butyl acetate and 2-heptanone is preferably 50% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less, and substantially only It is preferably butyl acetate and/or 2-heptanone.

The organic-based developing solution may contain a surfactant. At the same time, organic imaging solutions can contain traces of water.

At the time of development, development can be stopped by substituting a solvent different from the organic imaging liquid.

It is preferable to wash the developed photoresist pattern with a rinse liquid. The rinse liquid is not particularly limited as long as it does not dissolve the photoresist pattern, and a solution containing a general organic solvent may be used, and an alcohol solvent or an ester solvent is preferred.

It is preferable to remove the rinse liquid remaining on the substrate and the pattern after washing.

<Use>

The photoresist composition of the present invention is suitable as a photoresist composition for KrF excimer laser exposure, a photoresist composition for ArF excimer laser exposure, a photoresist composition for electron beam (EB) exposure, or EUV. The photoresist composition for exposure is more suitable as a photoresist composition for ArF excimer laser exposure, and can be used for precision processing of semiconductors.

[Examples]

The examples are given to more specifically illustrate the invention. In the example, "%" and "parts" are included in the amount or amount of use, and are based on quality unless otherwise specified.

The weight average molecular weight is a value obtained by a gel permeation chromatography. Further, the analysis conditions of the gel permeation chromatography are as follows.

Separation column: TSK gel (Multipore) HXL-M x 3+ guide column (guardcolumn) (manufactured by Tosoh Corporation)

Washing solution: tetrahydrofuran

Flow rate: 1.0mL/min

Detector: RI detector

Separation column temperature: 40 ° C

Injection volume: 100μL

Molecular weight standard: Standard polystyrene (made by Tosoh Corporation)

The structure of the compound was confirmed by mass spectrometry (LC is Agilent Model 1100, MASS is Agilent LC/MSD type). In the following examples, the value of this molecular ion peak is indicated by "MASS".

[Example 1] Synthesis of salt represented by formula (I-2)

2.98 parts of the salt represented by the formula (I-2-a), 0.63 parts of the compound represented by the formula (I-2-b), and 24 parts of monochlorobenzene were placed in a reactor, and stirred at 23 ° C for 30 minutes. Then, 0.03 part of copper benzoate represented by the formula (I-2-c) was added, and the mixture was heated to about 100 ° C, and then stirred at this temperature for 1 hour. After the obtained reactant was concentrated, 45 parts of chloroform and 15 parts of ion-exchanged water were added to the obtained concentrate, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of a third butyl methyl ether was added, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was concentrated and concentrated. After the obtained concentrate was dissolved in acetonitrile, 1.59 parts of the salt represented by the formula (I-2-d) was obtained by concentration.

0.63 parts of the salt represented by the formula (I-2-d), 0.23 parts of the compound represented by the formula (I-2-e), and 15.00 parts of acetonitrile were placed in a reactor, and stirred at 23 ° C for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and the mixture was stirred at 75 ° C for 1 hour. The obtained mixture was cooled to 23 ° C, and 30 parts of chloroform and 20 parts of ion-exchanged water were added, and stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. 0.50 parts of activated carbon was added to the recovered organic layer, followed by stirring and filtration. The obtained filtrate was concentrated, and 10 parts of ethyl acetate was added thereto, followed by stirring, and the supernatant liquid was removed. 10 parts of the third butyl methyl ether was added to the obtained residue, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was removed and concentrated. After the obtained concentrate was dissolved in acetonitrile, 0.48 parts of the salt represented by the formula (I-2) was obtained by concentration.

MASS (ESI (+) Spectrum (Spectrum)): M ⁺ 481.2

MASS (ESI (-) Spectrum (Spectrum): M ^- 339.1

[Example 2] Synthesis of salt represented by formula (I-3)

2.91 parts of the salt represented by the formula (I-3-a), 0.63 parts of the compound represented by the formula (I-2-b), and 24 parts of monochlorobenzene were placed in a reactor, and stirred at 23 ° C for 30 minutes. To the obtained mixture, 0.03 part of copper benzoate represented by the formula (I-2-c) was added, and the mixture was heated to about 100 ° C, and then stirred at this temperature for 1 hour. The obtained reactant was concentrated. To the obtained concentrate, 45 parts of chloroform and 15 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of a third butyl methyl ether was added, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was removed and concentrated. After the obtained concentrate was dissolved in acetonitrile, 1.72 parts of the salt represented by the formula (I-3-d) was obtained by concentration.

0.61 part of the salt represented by the formula (I-3-d), 0.23 part of the compound represented by the formula (I-2-e), and 15.00 parts of acetonitrile were placed in a reactor, and stirred at 23 ° C for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and the mixture was stirred at 75 ° C for 1 hour. The obtained mixture was cooled to 23 ° C, and 30 parts of chloroform and 20 parts of ion-exchanged water were added, and stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. 0.50 parts of activated carbon was added to the recovered organic layer, followed by stirring and filtration. The obtained filtrate was concentrated, and 10 parts of ethyl acetate was added thereto, followed by stirring, and the supernatant liquid was removed. 10 parts of the third butyl methyl ether was added to the obtained residue, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was removed and concentrated. After the obtained concentrate was dissolved in acetonitrile, 0.48 parts of the salt represented by the formula (I-3) was obtained by concentration.

MASS (ESI (+) spectrum): M ⁺ 481.2

MASS (ESI (-) spectrum): M ^- 323.0

[Example 3] Synthesis of salt represented by formula (I-18)

2.98 parts of the salt represented by the formula (I-18-a), 0.63 parts of the compound represented by the formula (I-2-b), and 24 parts of monochlorobenzene were placed in a reactor, and stirred at 23 ° C for 30 minutes. To the obtained mixture, 0.03 part of copper benzoate represented by the formula (I-2-c) was added, and the mixture was heated to about 100 ° C, and then stirred at this temperature for 1 hour. The obtained reactant was concentrated. To the obtained concentrate, 45 parts of chloroform and 15 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of a third butyl methyl ether was added, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was removed and concentrated. After the obtained concentrate was dissolved in acetonitrile, 1.62 parts of the salt represented by the formula (I-18-d) was obtained by concentration.

0.63 parts of the salt represented by the formula (I-18-d), 0.23 parts of the compound represented by the formula (I-2-e), and 15.00 parts of acetonitrile were placed in a reactor, and stirred at 23 ° C for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and the mixture was stirred at 75 ° C for 1 hour. The obtained mixture was cooled to 23 ° C, and 30 parts of chloroform and 20 parts of ion-exchanged water were added, and stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. 0.50 parts of activated carbon was added to the recovered organic layer, followed by stirring and filtration. The obtained filtrate was concentrated, and 10 parts of ethyl acetate was added thereto, followed by stirring, and the supernatant liquid was removed. 10 parts of the third butyl methyl ether was added to the obtained residue, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was removed and concentrated. After the obtained concentrate was dissolved in acetonitrile, 0.39 parts of the salt represented by the formula (I-18) was obtained by concentration.

MASS (ESI (+) spectrum): M ⁺ 481.2

MASS (ESI (-) spectrum): M ^- 339.1

[Example 4] Synthesis of salt represented by formula (I-19)

2.97 parts of the salt represented by the formula (I-19-a), 0.63 parts of the compound represented by the formula (I-2-b), and 24 parts of monochlorobenzene were placed in a reactor, and stirred at 23 ° C for 30 minutes. To the obtained mixture, 0.03 part of copper benzoate represented by the formula (I-2-c) was added, and the mixture was heated to about 100 ° C, and then stirred at this temperature for 1 hour. The obtained reactant was concentrated. To the obtained concentrate, 45 parts of chloroform and 15 parts of ion-exchanged water were added, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 ° C for 30 minutes. Then, it was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of a third butyl methyl ether was added, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was removed and concentrated. After the obtained concentrate was dissolved in acetonitrile, 1.82 parts of the salt represented by the formula (I-19-d) was obtained by concentration.

0.62 parts of the salt represented by the formula (I-19-d), 0.23 parts of the compound represented by the formula (I-2-e), and 15.00 parts of acetonitrile were placed in a reactor, and stirred at 23 ° C for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and the mixture was stirred at 75 ° C for 1 hour. The obtained mixture was cooled to 23 ° C, and 30 parts of chloroform and 20 parts of ion-exchanged water were added, and stirred at 23 ° C for 30 minutes. The obtained mixture was allowed to stand, and liquid was separated to obtain an organic layer. This washing operation was repeated 5 times. 0.50 parts of activated carbon was added to the recovered organic layer, followed by stirring and filtration. The obtained filtrate was concentrated, and 10 parts of ethyl acetate was added thereto, followed by stirring, and the supernatant liquid was removed. 10 parts of the third butyl methyl ether was added to the obtained residue, followed by stirring. The obtained supernatant was removed, and the residue after removal of the supernatant was removed and concentrated. After the obtained concentrate was dissolved in acetonitrile, 0.41 part of the salt represented by the formula (I-19) was obtained by concentration.

MASS (ESI (+) spectrum): M ⁺ 481.2

MASS (ESI (-) spectrum): M ^- 337.1

<Synthesis of Resin (A) and Resin (X)>

The compound (monomer) used for the synthesis of the resin (A1) of the resin (A) and the resin (X2) and the resin (X1) of the resin (X) and the resin (X2) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" or the like in combination with the formula number.

[Synthesis Example 1] Synthesis of Resin (A1)

The monomer (a1-1-3), the monomer (a1-2-9), the monomer (a2-1-1), and the monomer (a3-4-2) are used as monomers, as if they were monomer ratio [Monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-1): monomer (a3-4-2)] becomes 35:15:2.5:47.5 In a mixed manner, 1.5 parts by mass of propylene glycol monomethyl ether acetate as a whole monomer amount was added as a solution. For the total monomer amount, azobisisobutyronitrile 1 mol% and azobis(2,4-dimethylvaleronitrile) 3 mol%, respectively, as starting materials were added to the solution. The compounds were heated at 75 ° C for about 5 hours. The obtained reaction mixture was poured into a large amount of a methanol/water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was added to a methanol/water mixed solvent, and after repulping, filtration was carried out twice by a purification operation, and a resin (A1) having a weight average molecular weight of 8.0 × 10 ³ was obtained in a yield of 69%. This resin (A1) has the following structural unit.

[Synthesis Example 2] Synthesis of Resin (A2)

In addition to the use of monomer (a1-1-3), monomer (a1-2-11), monomer (a2-1-1) and monomer (a13-4-2) as monomers, the monomer ratio [Monomer (a1-1-3): monomer (a1-2-11): monomer (a2-1-1): monomer (a3-4-2)] becomes 35:15:2.5:47.5 In the same manner as in Synthesis Example 1, except that the mixture was mixed, a resin (A2) having a weight average molecular weight of 7.9 × 10 ³ was obtained in a yield of 65%. This resin (A2) has the following structural unit.

[Synthesis Example 3] Synthesis of Resin (X1)

Using the monomer (a4-1-7) as a monomer, 1.5 parts by mass of methyl isobutyl ketone in a total monomer amount was added as a solution. For the total monomer amount, 0.7 mole (%) by mole of azobisisobutyronitrile and 2.1 mole% of azobis(2,4-dimethylvaleronitrile), respectively, as initiators were added to the solution. The compounds were heated at 75 ° C for about 5 hours. The obtained reaction mixture was poured into a large amount of a methanol/water mixed solvent to precipitate a resin, and the resin was filtered to obtain a resin (X1) having a weight average molecular weight of 1.8 × 10 ⁴ in a yield of 77%. This resin (X1) has the following structural unit.

[Synthesis Example 4] Synthesis of Resin (X2)

Monomer (a5-1-1) and monomer (a4-0-12) were used as monomers to make their monomer ratio [monomer (a5-1-1): monomer (a4-0-12)] The mixture was mixed in a 50:50 manner, and a total monomer amount of 1.2 mass times of methyl isobutyl ketone was added as a solution. For the total monomer amount, azobis(2,4-dimethylvaleronitrile) 3 mol% as a starter was added to the solution, and heated at 70 ° C for about 5 hours. The obtained reaction mixture was poured into a large amount of a methanol/water mixed solvent to precipitate a resin, and the resin was filtered to obtain a resin (X2) having a weight average molecular weight of 1.0 × 10 ⁴ in a yield of 91%. This resin (X2) has the following structural unit.

<Modulation of Photoresist Composition>

Each component and solvent shown in Table 15 were mixed, and the obtained mixture was filtered with a fluororesin filter having a pore size of 0.2 μm to prepare a photoresist composition.

<Resin>

A1, A2, X1, X2: resin (A1), resin (A2), resin (X1), resin (X2)

<acid generator (B)>

B1-21: a salt represented by the formula (B1-21) (synthesized according to the example of JP-A-2012-224611)

B1-22: a salt represented by the formula (B1-22) (synthesized according to the example of JP-A-2012-224611)

<Comparing the salt used in the composition>

IX-1: (synthesized in accordance with the embodiment of Japanese Laid-Open Patent Publication No. 2011-85878)

IX-2: (synthesized according to the embodiment of Japanese Laid-Open Patent Publication No. 2013-47211)

IX-3: (synthesized according to the embodiment of Japanese Laid-Open Patent Publication No. 2013-47211)

<Quenching agent (C)>

D1: (Tokyo Chemical Industry Co., Ltd.)

<solvent>

[Examples 5 to 13, Comparative Examples 1 to 3] Fabrication and Evaluation of Photoresist Patterns

An organic anti-reflection film composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) was coated on a tantalum wafer, and baked at 205 ° C for 60 seconds to form an organic anti-reflection having a film thickness of 78 nm on the wafer. membrane. Next, the above-mentioned photoresist composition was applied (spin coating) to the organic antireflection film to have a film thickness after drying of 85 nm. After coating, the tantalum wafer was prebaked on a direct hot plate at a temperature of PB as described in the column "PB/PEB" of Table 15 for 60 seconds to form a composition layer. On the tantalum wafer on which the composition layer was formed, an ArF excimer stepper (XT: 1900Gi; manufactured by ASML, NA=1.35, 3/4 annular XY polarized light) was used for immersion exposure, and contact holes were formed. A photomask for a contact hole pattern (hole pitch: 90 nm / aperture: 55 nm) was exposed to a change in exposure amount in a stepwise manner. Further, the liquid immersion solvent is ultrapure water.

After the exposure, the post-exposure bake was carried out for 60 seconds on the hot plate at the temperature of the PEB described in the "PB/PEB" column of Table 15. Next, a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as a developing solution, and the composition layer on the ruthenium wafer was developed by a dynamic distribution method at 23 ° C for 20 seconds to produce a negative resist pattern. .

In the photoresist pattern obtained after development, an exposure amount of a hole diameter of 45 nm formed by the above-mentioned photomask was used as the effective sensitivity.

<CD Uniformity (CDU) Evaluation>

In the actual sensitivity, each of the apertures of the pattern formed by the mask having a pore diameter of 55 nm was measured 24 times, and the average value was made into the average pore diameter of each well. The standard deviation was determined by measuring 400 positions of the average aperture of the pattern formed by the mask having a aperture of 55 nm in the same wafer as a parent group.

When the standard deviation was 1.80 nm or less, the CDU was good and evaluated as A.

When the standard deviation is greater than 1.80 nm, it is regarded as poor in CDU, and it is evaluated as B.

The results are shown in Table 16. The values in parentheses indicate the standard deviation (nm).

 [Possibility of application in industry]  

The salt of the present invention and the photoresist composition containing the salt are excellent in semiconductor precision processing because they have a photoresist pattern having good CD uniformity (CDU), and are extremely useful industrially.

Claims (8)

a salt represented by the formula (I), In the formula (I), R ¹ and R ² each independently represent an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent; R ³ represents a group having a lactone structure; and X ¹ represents a carbon number of 1 to 18; The aliphatic saturated hydrocarbon group of the valence may be substituted with an oxygen atom or a carbonyl group to form a divalent aliphatic saturated hydrocarbon group; and A ^- represents an organic anion. The salt according to claim 1, wherein the X ¹ of the above formula (I) is an alkanediyl group having 1 to 12 carbon atoms, and the methylene group constituting the alkanediyl group may be substituted with an oxygen atom or a carbonyl group. The salt according to claim 1 or 2, wherein R ¹ and R ^{2 of the} above formula (I) each independently represent a phenyl group which may have a substituent. The salt according to any one of claims 1 to 3, wherein the R ³ of the above formula (I) is a group represented by the formula (R ³ -1) or the formula (R ³ -2); In the formula (R ³ -1), * represents a bond bond; Z ¹² represents an oxygen atom, a sulfur atom or a group represented by -C(R ⁴ ) ₂ -; m3 represents any integer of 0 to 5; and R ³¹ represents an option. When m3 is 2 or more from the group of the following P1 group, a plurality of R ³¹ may be the same or different from each other; and two R ⁴ independently represent a group or a hydrogen atom selected from the group of P1 described below; In the formula (R ³ -2), * represents a bond bond; m4 represents any integer from 0 to 5; R ³² represents a group selected from the group of P1 described below, and when m4 is 2 or more, there are several R ³² M1 may be the same or different; m5 represents any integer from 1 to 3; P1 group: halogen atom; hydroxyl group; carboxyl group; cyano group; alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxyl group; carbon number 1 to Alkoxy group of 12; aryl group having 6 to 12 carbon atoms; aralkyl group having 7 to 12 carbon atoms; glycidyloxy group; alkoxycarbonyl group having 2 to 12 carbon atoms; and 2 to 4 carbon atoms Alkylcarbonyl.  An acid generator comprising the salt of any one of claims 1 to 4.    A photoresist composition comprising a resin comprising an acid generator and a structural unit having an acid labile group, and the acid generator comprises the salt according to any one of claims 1 to 4.    The photoresist composition according to claim 6, wherein the acid produced further contains a lower acidity than the acid produced by the acid generator.    A method for producing a photoresist pattern comprising: (1) a step of applying a photoresist composition according to claim 6 or 7 to a substrate, and (2) drying the composition after coating to form a composition a step of the layer, (3) a step of exposing the composition layer, (4) a step of heating the exposed composition layer, and (5) a step of developing the heated composition layer.