KR101742009B1 - Salts and photoresist compositions - Google Patents

Abstract

상기 화학식 I에서,
Q¹ 및 Q²는, 서로 독립적으로, 불소 원자 또는 탄소수 1 내지 6의 퍼플루오로알킬기이고,
L¹은, 단결합 또는 치환기를 가지고 있어도 되는 2가의 탄소수 1 내지 17의 포화 탄화수소기이고, 당해 포화 탄화수소기에 포함되는 1개 이상의 -CH₂-는, -O- 또는 CO-로 치환되어도 되며,
R¹은, 불소 원자를 포함하는 탄소수 1 내지 6의 알킬기이고,
Z⁺은, 유기 양이온이다.≪ / RTI >
Formula I

In the formula (I)
Q ¹ and Q ² are each independently a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms,
L ¹ is a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a single bond or a substituent and at least one -CH ₂ - included in the saturated hydrocarbon group may be substituted with -O- or CO-,
R ¹ is an alkyl group having 1 to 6 carbon atoms containing a fluorine atom,
Z ⁺ is an organic cation.

Description

Salts and photoresist compositions [0002]

The present invention relates to salts and photoresist compositions.

The photoresist composition used for microfabrication of semiconductors using lithography technology contains salts for acid generators.

Japanese Patent Laid-Open No. 2007-161707 discloses triphenylsulfonium (2-adamantyloxycarbonyl) difluoromethanesulfonate as a salt for an acid generator.

According to the present invention,

[1] Salts of formula I;

(I)

In Formula 1,

Q ¹ and Q ² are, independently of each other, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms,

L ¹ is a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a single bond or a substituent and at least one -CH ₂ - contained in the saturated hydrocarbon group may be substituted with -O- or CO-,

R ¹ is an alkyl group having 1 to 6 carbon atoms containing a fluorine atom,

Z ⁺ is an organic cation.

[2] In the above item [1], the ^{L 1, * -CO-OC (} R 3) (R 4) -C (R 5) (R 6) - ( wherein, R ^3, R ^4, R ⁵ And R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and * is a bonding site with -C (Q ¹ ) (Q ² ) -;

[3] A salt according to item [1] or [2], wherein R ¹ is a trifluoromethyl group;

[4] A salt according to any one of items [1] to [3], wherein R ³ and R ⁴ are a hydrogen atom;

[5] A salt according to any one of items [1] to [4], wherein Z ⁺ is a triarylsulfonium cation;

[6] An acid generator containing a salt according to any one of items [1] to [5] above;

[7] A resin containing an acid generator and a resin according to the above item [6], wherein the resin has an acid labile group and is insoluble or hardly soluble in an aqueous alkali solution and can be dissolved in an alkali aqueous solution by the action of an acid Photoresist compositions;

[8] The photoresist composition according to item [7], further comprising a basic compound.

(9) A process for producing a photoresist composition, comprising the steps of: (1) applying a photoresist composition according to the item [7] or [8]

(2) a step of drying the formed photoresist composition layer to form a photoresist film,

(3) a step of exposing the photoresist film,

(4) a step of heating the photoresist film after exposure, and

(5) a step of developing the photoresist film after heating;

And the like.

The salt of the present invention can be used as an acid generator for a photoresist composition, and a resist pattern having excellent resolution and shape can be obtained by using a photoresist composition containing the salt.

The salt of the present invention is represented by the general formula (I) and can be used as an acid generator for a photoresist composition.

(I)

In Formula 1,

Q ¹ and Q ² are, independently of each other, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms,

L ¹ is a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a single bond or a substituent and at least one -CH ₂ - contained in the saturated hydrocarbon group may be substituted with -O- or CO-,

R ¹ is an alkyl group having 1 to 6 carbon atoms containing a fluorine atom,

Z ⁺ is an organic cation.

Examples of the perfluoroalkyl group having 1 to 6 carbon atoms include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro-sec-butyl group, Tert-butyl group, perfluoro-tert-butyl group, perfluoropentyl group and perfluorohexyl group.

Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, and it is more preferable that Q ¹ and Q ² are fluorine atoms.

Examples of the divalent saturated hydrocarbon group having 1 to 17 carbon atoms include a straight chain alkylene group having 1 to 17 carbon atoms, a branched alkylene group having 3 to 17 carbon atoms, and a divalent monocyclic or polycyclic saturated cyclic hydrocarbon group having 3 to 17 carbon atoms have.

Specific examples include methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane- Diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, A dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16- , Heptadecane-1,17-diyl group, and the like;

Methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, Branched alkylene groups having 3 to 17 carbon atoms such as a methylbutane-1,4-diyl group;

Mono-cyclic saturated groups such as cyclopentane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group and cyclooctane- Cyclic hydrocarbon group:

Polycyclic saturated cyclic hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane- group; And a group formed by combining two or more of these groups.

The divalent saturated hydrocarbon group having 1 to 17 carbon atoms may have a substituent, and examples of the substituent include a halogen atom such as a fluorine atom. Further, at least one -CH ₂ - included in the saturated hydrocarbon group may be substituted with -O- or CO-.

Specific examples of the group in which at least one -CH ₂ - in the saturated hydrocarbon group is substituted with -O- or CO- include groups represented by the following formulas: IL-1, IL-2, IL-3, -5 and the group of the formula IL-6 and the group of the formula IL-1, the formula IL-2, the formula IL-3 or the formula IL-4 is preferable, the compound of the formula IL- Do.

[Chemical Formula IL-1]

[Chemical formula IL-2]

[Chemical Formula IL-3]

[Chemical Formula IL-4]

[Chemical formula IL-5]

[Chemical formula IL-6]

In the above IL-1, IL-2, IL-3, IL-4, IL-5 and IL-

L ² is a single bond or a saturated hydrocarbon group of 1 to 15 carbon atoms,

L ³ is a single bond or an alkylene group having 1 to 12 carbon atoms,

L ⁴ is an alkylene group having 1 to 12 carbon atoms, provided that the total number of carbon atoms of L ³ and L ⁴ is 13 or less,

L ⁵ and L ⁶ are each independently an alkylene group having 1 to 14 carbon atoms, provided that the total number of carbon atoms of L ⁵ and L ⁶ is 15 or less,

L ⁷ and L ⁸ each independently represent an alkylene group having 1 to 15 carbon atoms; Provided that the total number of carbon atoms of L ⁷ and L ⁸ is 16 or less,

L ⁹ and L ¹⁰ each independently represent an alkylene group having 1 to 13 carbon atoms, provided that the total number of carbon atoms of L ⁹ and L ¹⁰ is 14 or less,

L ¹¹ and L ¹² each independently represent an alkylene group having 1 to 10 carbon atoms,

L ¹³ is a saturated hydrocarbon group having 1 to 10 carbon atoms, provided that the total number of carbon atoms of L ¹¹ , L ¹² and L ¹³ is 12 or less,

** is a bonding site with -C (Q ¹ ) (Q ² ) -.

Among them, a group of the formula IL-1 is preferable, L ² is a single bond, -CH ₂ - A group of formula IL-1 wherein -C (R ³ ) (R ⁴ ) -C (R ⁵ ) (R ⁶ ) - is particularly preferred.

As the group of the formula IL-1, the following groups may be mentioned.

As the group of the formula IL-2, the following groups may be mentioned.

As the group of the formula IL-3, the following groups may be mentioned.

As the group of the formula (IL-4), the following groups may be mentioned.

As the group of the formula IL-5, the following groups may be mentioned.

As the group of the formula IL-6, the following groups may be mentioned.

Examples of the alkyl group having 1 to 6 carbon atoms and containing a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2- Ethyl group, pentafluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoro 2-ethylhexyloxy) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexa Fluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2 - trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2- 2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoro (Perfluorobutyl) ethyl group, 1, 1, 2, 2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group , A perfluoropentylmethyl group and a perfluorohexyl group, and an alkyl group having 1 to 4 carbon atoms including a fluorine atom is preferable, and a trifluoromethyl group, a pentafluoroethyl group and a perfluoropropyl group are more preferable , And a trifluoromethyl group are particularly preferable.

The salt of the formula (I) preferably has the following anions.

In this formula,

Q ¹ and Q ² are the same as defined above.

Examples of Z ⁺ include an onium cation such as a sulfonium cation, an iodonium cation, an ammonium cation, a benzothiazolium cation, and a phosphonium cation, and a sulfonium cation and an iodonium cation are preferable, and a triarylsulfonium cation is a desirable.

Z ⁺ is preferably any one of the cations of the formulas Iz-1 to Iz-4.

[Chemical formula Iz-1]

In the above chemical formula Iz-1,

Each of P ^a to P ^c is independently an aliphatic hydrocarbon group of 1 to 30 carbon atoms, a saturated cyclic hydrocarbon group of 3 to 36 carbon atoms, or an aromatic hydrocarbon group of 6 to 18 carbon atoms, and the aliphatic hydrocarbon group may have a hydroxyl group, An alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the saturated cyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group, The group may be substituted with a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

[Chemical formula Iz-2]

In the above chemical formula Iz-2,

P ⁴ and P ⁵ are each independently a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms,

i and j are each independently an integer of 0 to 5;

[Chemical formula Iz-3]

In the above chemical formula Iz-3,

P ⁶ and P ⁷ are each independently an aliphatic hydrocarbon group having 1 to 36 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms,

P ⁸ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms,

The aliphatic hydrocarbon group of P ⁶ to P ⁸ is preferably an aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the saturated cyclic hydrocarbon group is preferably a saturated cyclic hydrocarbon group having 4 to 12 carbon atoms,

P ⁹ is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aromatic hydrocarbon group is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, A saturated cyclic hydrocarbon group having 3 to 18 carbon atoms or an alkylcarbonyloxy group, P ⁶ and P ^7, and P ⁸ and P ⁹ are each independently bonded to form a 3- to 12-membered ring, Preferably 3 to 7-membered rings, and one or more -CH ₂ - included in the ring may be substituted with -O-, -S- or -CO-.

[Chemical formula Iz-4]

In the above chemical formula Iz-4,

P ¹⁰ to P ¹⁵ 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,

E is -S- or O-,

p, r, x and y are each independently an integer of 0 to 5,

v and w are each independently an integer of 0 to 4;

q is 0 or 1;

When p, r, x, y, v and w are two or more, the plural P ¹⁰ to P ¹⁶ may be the same or different from each other.

Preferred aliphatic hydrocarbon groups in the general formulas Iz-1 to Iz-4 include aliphatic hydrocarbon groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec- Hexyl group, octyl group and 2-ethylhexyl group.

Preferred saturated cyclic hydrocarbon groups are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclodecyl, 2-alkyl-2-adamantyl, 1- (1-adamantyl) 1-alkyl group and isoboronyl group.

Preferred aromatic hydrocarbon groups are phenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-cyclohexylphenyl, 4-methoxyphenyl, biphenylyl and naphthyl.

Examples of the aliphatic hydrocarbon group (aralkyl group) in which the substituent is an aromatic hydrocarbon group include a benzyl group and the like.

Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, , Octoxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and dodecyloxy group.

Examples of the alkylcarbonyloxy group include methylcarbonyloxy, ethylcarbonyloxy, 1-methylethylcarbonyloxy, 1,1-dimethylethylcarbonyloxy, 2,2-dimethylethylcarbonyloxy, Methylpropylcarbonyloxy group, 1-methylpropylcarbonyloxy group, 1-methylpropylcarbonyloxy group, 1-ethylpropylcarbonyloxy group, butylcarbonyloxy group, 1-methylbutylcarbonyloxy group, And 2-methylbutylcarbonyloxy group.

Examples of the ring formed by P ⁶ and P ⁷ include a thioran-1-ium ring (tetrahydrothiophenium ring), a thien-1-ium ring and a 1,4-oxathiane-4-ium ring.

Examples of the ring formed by P ⁸ and P ⁹ include oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring and oxoadamantane ring.

Among them, the cation of the formula Iz-1 is preferable, and the cation of the formula Iz-5 is more preferable.

[Chemical formula Iz-5]

In the above chemical formula Iz-5,

P ¹⁹ to p ²¹ each independently represent a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.

The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the saturated cyclic hydrocarbon group is preferably a saturated cyclic hydrocarbon group having 4 to 36 carbon atoms.

The aliphatic hydrocarbon group may be substituted with a hydroxyl group, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The saturated cyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group.

z1, z2 and z3 each independently represent an integer of 0 to 5 (preferably 0 or 1). z1, z2 and z3 is when 2 or more, respectively, a plurality of p ¹⁹ to p ²¹ are, the same or different from each other.

In the chemical formula Iz-5, P ¹⁹ to P ²¹ preferably each independently represent a halogen atom (more preferably a fluorine atom), a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms And z1, z2 and z3 each independently represent an integer of 0 to 5 (preferably 0 or 1).

Particularly, a triphenylsulfonium cation (in the formula Iz-5, z1, z2 and z3 is preferably 0).

Examples of the cation of the formula Iz-1 include the following.

Examples of the cation of the formula Iz-2 include the following.

Examples of the cation of the formula Iz-3 include the following.

Examples of the cation of the formula Iz-4 include the following.

The salt of the formula (I) can be arbitrarily combined with the above-mentioned anion and organic cations. Among them, salts of the formulas I-1 to I-8 are preferable, and salts of the formulas I-1, I-2 and I-3 are more preferable.

(I-1)

[Formula I-2]

[Formula I-3]

[Formula I-4]

[Formula I-5]

[Formula I-6]

In Formulas I-1, I-2, I-3, I-4, I-5 and I-6,

P ¹ to P ³ , z ¹ , z 2, z 3, Q ¹ and Q ² are as defined above.

Among them, salts of the following formulas (I-7) to (I-22) are more preferable.

[Formula I-7]

[Formula I-8]

[Formula I-9]

[Formula I-10]

[Formula I-11]

[Formula I-12]

[Formula I-13]

[Formula I-14]

[Formula I-15]

[Formula I-16]

[Formula I-17]

[Formula I-18]

[Formula I-19]

[Formula I-20]

[Formula I-21]

[Formula I-22]

The salt of the formula (I) can be produced, for example, by a production method shown by the following reaction formula. In the following reaction formulas, unless otherwise specified, the definition of each substituent has the same meaning as described above.

The salt of formula (Ia) wherein L ¹ is -CO-OC (R ³ ) (R ⁴ ) -C (R ⁵ ) (R ⁶ ) - can be obtained by, for example, hydrolyzing a compound of formula To obtain the compound of formula (2). Here, the compound of formula (1) can be produced, for example, by the method described in JP-A-2007-45787. As the solvent to be used, a mixed solvent of 1,4-dioxane and water may, for example, be mentioned. Examples of the base catalyst include sodium hydroxide and the like.

The salt of formula (I-a) can then be obtained by dehydration condensation of the salt of formula (3) and the compound of formula (2). Here, the salt of the formula (3) can be obtained, for example, by the method described in JP-A-2008-127367. As the solvent to be used, monochlorobenzene and the like can be mentioned. Examples of the dehydration condensation catalyst include sulfuric acid and the like.

Salts of formula (Ib) wherein L ¹ is -CO-O-CH ₂ -CO-OC (R ³ ) (R ⁴ ) -C (R ⁵ ) (R ⁶ ) - can be prepared, for example, 4 is reacted under basic catalysis to give the compound of formula 5. Here, X ¹ and X ² each independently represent a halogen atom, and a chlorine atom is preferable. As the solvent to be used, tetrahydrofuran and the like can be mentioned. Examples of the base catalyst include pyridine and the like.

The salt of formula I-b is then obtained by reacting the salt of formula 3 with the compound of formula 5 in the presence of a catalyst. As the solvent to be used, N, N-dimethylformamide and the like can be mentioned. Examples of the catalyst include potassium carbonate, potassium iodide and the like.

Further, regardless of the kind of L < ¹ >, other salts can be produced in accordance with the above.

The acid generator of the present invention contains a salt of the formula (I). The acid generator of the present invention may be composed solely of a salt of the formula (I), and in addition to the salt of the formula (I), a known salt other than the salt of the formula (I) An anion contained in the salt of formula (I) and a salt comprising a known cation. The acid generator of the present invention may contain two or more salts of the formula (I). In addition, when the acid generator of the present invention contains a known salt other than the salt of the general formula I, the ratio (by mass ratio) of the content of the known salt other than the salt of the general formula (I) to the salt content of the general formula (I) To 99: 1, and preferably from 10:90 to 90:10.

As the known salts other than the salt of the formula (I), for example, the following salts may be mentioned.

In the photoresist composition containing the acid generator of the present invention, the amount of the acid generator used is preferably in the range of about 0.1 to 30% by weight of the total solid content of the photoresist composition. In the present specification, the term "solid content in the photoresist composition" means the sum of the components of the photoresist composition excluding the solvent to be described later. The solid content in the composition and the content of the resin to be described hereinafter can be measured by a known analytical means such as liquid chromatography or gas chromatography.

The photoresist composition of the present invention contains an acid generator containing a salt of the formula (I) and a resin (hereinafter sometimes referred to as " resin (A) "). The resin (A) here is a resin which has an acid-labile group, is insoluble or hardly soluble in an aqueous alkali solution, and can be dissolved in an alkali aqueous solution by the action of an acid.

In the photoresist composition of the present invention, an acid is generated from the salt of formula (I) by exposure. The acid is catalytically active with respect to an acid-labile group in the resin and is cleaved to allow the resin to be dissolved in an aqueous alkali solution. Such a photoresist composition is preferably chemically amplified to function as a positive type. In the photoresist composition of the present invention, a known salt other than the salt of the formula (I) may be used in combination as the acid generator.

≪ Resin (A) >

Resin (A) is a resin which is alkali-soluble by the action of an acid. The resin which becomes alkali-soluble by the action of an acid can be produced by polymerizing a monomer having an acid-unstable group (hereinafter sometimes referred to as " monomer having an unstable group in acid "), do. By " alkali solubility by the action of an acid " is meant that it is insoluble or hardly soluble in an aqueous alkaline solution before contact with the acid, but soluble in an aqueous alkaline solution after contact with the acid. The monomers having an acid labile group may be used singly or in combination of two or more kinds.

≪ Monomer having an unstable group in an acid &

The term " acid labile group " means a group in which a leaving group is cleaved on contact with an acid to form a hydrophilic group (e.g., a hydroxyl group or a carboxyl group (-COOH)). As an acid labile group, for example, a group of the formula (IIa) can be mentioned. Hereinafter, the group of formula (IIa) may be referred to as " acid-unstable group (IIa) ".

≪ RTI ID = 0.0 &

In the above formula (IIa)

R ¹ to R ³ are each independently an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group,

R ² and R ³ may be bonded to each other,

* Is the binding site.

When R < ² > and R < ³ > are bonded to each other, a ring is formed together with the bonding carbon. Examples of the ring include an alicyclic hydrocarbon group and an aromatic hydrocarbon group.

Examples of the alicyclic hydrocarbon group include the above-mentioned monocyclic or polycyclic saturated cyclic hydrocarbon group.

In formula (IIa), in R ¹ to R ³ , the hydrogen atom of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with a hydroxyl group or the like. The -CH ₂ - of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with -O- or CO-.

R ¹ to R ³ are preferably a group of 1 to 20 carbon atoms, and more preferably a group of 1 to 12 carbon atoms.

Examples of the acid labile group (IIa) include 1,1-dialkylalkoxycarbonyl groups (in the group (1), R ¹ to R ³ are alkyl groups, preferably tert-butoxycarbonyl groups) (1-adamantyl) -1-alkylalkoxycarbonyl group (wherein R ¹ , R ² and the carbon atom form an adamantyl group and R ³ is an alkyl group) and an adamantyloxycarbonyl group In the formula (1), R ¹ and R ² are alkyl groups and R ³ is an adamantyl group).

The monomer having an acid labile group is preferably a (meth) acrylic acid monomer having an acid labile group (IIa) and a monomer having a carbon-carbon double bond, more preferably an acid labile group (IIa).

As used herein, "(meth) acrylic acid" means acrylic acid and / or methacrylic acid, and "(meth) acrylate" means acrylate and / or methacrylate.

Of the (meth) acrylic acid monomers having an acid labile group (IIa), those having a saturated cyclic hydrocarbon group of 5 to 20 carbon atoms are preferred. The use of a resin obtained by polymerizing a monomer having a bulky structure such as a saturated cyclic hydrocarbon group can improve the resolution of the photoresist. In particular, monomers having an acid labile group of formula (IIa1) or (IIa2) are preferred. These may be used alone or in combination of two or more.

≪ EMI ID =

(IIa2)

In the above formulas (IIa1) and (IIa2)

M ¹ is, independently of each other, * -O- or * -O- (CH ₂ ) _k -CO-O-,

k is an integer of 1 to 7,

* Is a bonding site with -CO-,

R ⁴ are each independently a hydrogen atom or a methyl group,

R ⁵ is independently an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 10 carbon atoms,

s is an integer from 0 to 14,

and t is an integer of 0 to 10.

k is preferably an integer of 1 to 4, more preferably 1.

M ¹ is preferably * -O- or * -O- (CH ₂ ) _f -CO-O- (f is an integer of 1 to 4), more preferably * -O-.

R ⁴ is preferably a methyl group.

The aliphatic hydrocarbon group of R < ⁵ > is preferably a group having 6 or less carbon atoms. The saturated cyclic hydrocarbon group is preferably a group having not more than 8 carbon atoms, more preferably not more than 6 carbon atoms.

s is preferably an integer of 0 to 3, more preferably 0 or 1. t is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the monomer of the formula (IIa1) include the followings.

Among them, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate and 2-isopropyl-2-adamantyl Adamantyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate and 2-isopropyl-2-adamantyl methacrylate methacrylate are more preferable.

As the monomer of formula (IIa2), for example, the following can be given.

Among these, 1-ethyl-1-cyclohexyl (meth) acrylate is preferable, and 1-ethyl-1-cyclohexyl methacrylate is more preferable.

The content of the structural unit derived from the monomer represented by the general formula (IIa1) or (IIa2) in the resin is generally 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably, 20 to 85 mol%.

Examples of the monomer having an acid labile group and a carbon-carbon double bond include monomers of formula (IIa3). Resins having a structural unit derived from a monomer (IIa3) having an acid labile group have a bulky structure, so that the resolution of the photoresist can be improved. Further, the monomer (IIa3) having an acid labile group can introduce a norbornane ring rigid in the main chain of the resin to improve the dry etching resistance of the photoresist.

[Formula IIa3]

In formula (IIa3)

R ⁶ represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a carboxyl group, a cyano group or -COOR ⁵⁰ which may have a hydrogen atom, a substituent (for example, a hydroxyl group), R ⁵⁰ represents an aliphatic A hydrocarbon group or a saturated cyclic hydrocarbon group of 3 to 8 carbon atoms, and the hydrogen atoms of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with a hydroxyl group, and the -CH ₂ - may be substituted with -O- or CO-,

R ⁷ to R ⁹ each independently represent an aliphatic hydrocarbon group having 1 to 12 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 12 carbon atoms, or R ⁸ and R ⁹ may be bonded to each other to form a ring, and the aliphatic hydrocarbon And the hydrogen atom of the saturated cyclic hydrocarbon group may be substituted with a hydroxyl group or the like, and -CH ₂ - of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with -O- or CO-.

Examples of the aliphatic hydrocarbon group which may have a substituent for R ⁶ include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.

Examples of R ⁵ include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group and a 2-oxo-oxolan-4-yl group.

Examples of R ⁷ to R ⁹ include a methyl group, an ethyl group, a cyclohexyl group, a methylcyclohexyl group, a hydroxycyclohexyl group, an oxocyclohexyl group and an adamantyl group. Examples of the saturated cyclic hydrocarbon group formed by R ⁸ and R ⁹ and the carbon to which they are bonded include a cyclohexyl group and an adamantyl group.

Examples of the monomer represented by the formula (IIa3) include 5-norbornene-2-carboxylic acid-3-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene- Norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene- -Carbamic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2- Methyl-1- (4-oxocyclohexyl) ethyl and 5-norbornene-2-carboxylic acid 1- (1-adamantyl) -1-methylethyl.

The content of the structural unit derived from the monomer of the formula (IIa3) in the resin is generally 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol% in the total structural units of the resin Mol%.

Examples of the monomer having an acid labile group and a carbon-carbon double bond include a monomer represented by the formula (IIa4).

≪ EMI ID =

In the above formula (IIa4)

R ¹⁰ is an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom,

R ¹¹ each independently represents a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, Or a methacryloyl group,

h is an integer of 0 to 4, and when h is an integer of 2 or more, a plurality of R < ¹¹ > s may be the same kind or different kinds,

R ¹² and R ¹³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms,

X ⁴ is a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a single bond or a substituent and -CH ₂ - included in the saturated hydrocarbon group is -CO-, -O-, -S-, -SO ₂ - or N (R ^c ) -, R ^c is a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms,

Y ⁴ is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aliphatic hydrocarbon group, saturated cyclic hydrocarbon group and aromatic hydrocarbon group have substituents .

Examples of the alkyl group which may have a halogen atom include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro-sec-butyl group, A tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group.

The alkyl group in R ¹⁰ and R ¹¹ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms, and particularly preferably a methyl group.

The alkoxy group for R ¹¹ is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably an alkoxy group having 1 to 2 carbon atoms, and particularly preferably a methoxy group.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group and a butyryloxy group.

Examples of the hydrocarbon group include those exemplified as aliphatic hydrocarbons and saturated cyclic hydrocarbons and combinations thereof (e.g., 2-alkyl-2-adamantyl group, 1- (1-adamantyl) And the like.

As the monomer of the formula (IIa4), for example, the following monomers can be mentioned.

The content of the structural unit derived from the monomer of the formula (IIa4) in the resin is generally 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol% in the total structural units of the resin Mol%.

The resin (A) is preferably a copolymer of a monomer having an acid labile group and a monomer having no acid labile group (hereinafter sometimes referred to as " acid stable monomer "). The acid stable monomers may be used singly or in combination of two or more kinds.

When the resin (A) is a copolymer of a monomer having an acid labile group and an acid stable monomer, the structural unit derived from a monomer having an acid labile group is preferably 10 to 80 mol% , And more preferably 20 to 60 mol%.

Further, it is preferable that the structural unit derived from a monomer having an adamantyl group (in particular, the monomer (IIa1) having an acid labile group) is at least 15 mol% based on 100 mol% of the monomer having an acid labile group. When the proportion of the monomer having an adamantyl group is increased, dry etching resistance of the resist is improved.

The acid-stable monomer preferably has a hydroxyl group or a lactone ring. When a resin having a structural unit derived from an acid stable monomer containing a hydroxyl group or an acid stable monomer containing a lactone ring is used, the resolution of the photoresist and the adhesion to the substrate can be improved.

<Acid-stable monomers having a hydroxyl group>

When the photoresist composition is used for exposure to high energy radiation such as KrF excimer laser exposure (248 nm), electron beam or EUV light, an acid stable monomer having a hydroxyl group, an acid having a phenolic hydroxyl group such as hydroxystyrene It is preferable to use a stable monomer. When ArF excimer laser exposure (193 nm) with a short wavelength is used, it is preferable to use an acid stable monomer having a hydroxyadamantyl group of the formula (IIc) as an acid stable monomer having a hydroxyl group. The acid stable monomers having a hydroxyl group may be used singly or in combination of two or more kinds.

As the monomer having a phenolic hydroxyl group, a styrene-based monomer such as p- or m-hydroxystyrene represented by the general formula (IIb) may be mentioned.

&Lt; RTI ID =

In the above formula (IIb)

R ¹⁴ is an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom,

R ¹⁵ represents a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group or methacryloyl group Diary,

b is an integer of 0 to 4, and when b is an integer of 2 or more, plural R ^{15 s} may be the same kind or different kinds.

In the case of obtaining a copolymer resin having a structural unit derived from a monomer having a phenolic hydroxyl group, the corresponding (meth) acrylic acid ester monomer is subjected to radical polymerization with acetoxystyrene and styrene, and then deacetyl .

As the monomer having a phenolic hydroxyl group, for example, the following monomers can be mentioned.

Among the above monomers, 4-hydroxystyrene or 4-hydroxy- alpha -methylstyrene is particularly preferable.

The content of the structural unit derived from the monomer of the general formula (IIb) in the resin is generally 5 to 90 mol%, preferably 10 to 85 mol%, and more preferably 15 to 80 mol% in the total structural units of the resin Mol%.

As acid stable monomers having a hydroxyadamantyl group, monomers of the formula (IIc) can be mentioned.

(IIc)

In the above formula (IIc)

M ² is * -O- or * -O- (CH ₂ ) _k -CO-O-,

k is an integer of 1 to 7,

* Is a bonding site with -CO-,

R ¹⁶ is a hydrogen atom or a methyl group,

R ¹⁷ and R ¹⁸ are each independently a hydrogen atom, a methyl group or a hydroxyl group,

and c is an integer of 0 to 10.

M ² is preferably * -O-, * -O- (CH ₂ ) _f -CO-O- (wherein f is an integer of 1 to 4), more preferably * -O- .

R ¹⁶ is preferably a methyl group.

R ¹⁷ is preferably a hydrogen atom.

R ¹⁸ is preferably a hydrogen atom or a hydroxyl group.

c is preferably an integer of 0 to 3, more preferably 0 or 1.

As the monomer of the general formula (IIc), for example, the following can be given. Among them, 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate, and (meth) acrylic acid 1- Adamantyloxycarbonyl) methyl is preferable, and 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) More preferred are 3-hydroxy-1-adamantyl methacrylate and 3,5-dihydroxy-1-adamantyl methacrylate.

The content of the structural unit derived from the monomer of the general formula (IIc) in the resin is generally 3 to 45 mol%, preferably 5 to 40 mol%, and more preferably 5 to 35 mol% in the total structural units of the resin Mol%.

&Lt; Acid-stable monomers containing lactone rings >

The lactone ring of the acid stable monomer may be a monocyclic ring such as a? -Propiolactone ring, a? -Butyrolactone ring, a? -Valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. Among these lactone rings, a condensed ring of a? -Butyrolactone ring and? -Butyrolactone ring and another ring is preferable.

An acid stable monomer having a lactone ring is represented, for example, by the formula (IId), (IIe) or (IIg). One of these may be used alone, or two or more of them may be used in combination.

&Lt; RTI ID = 0.0 &

[Formula IIe]

[Formula IIg]

In the above formulas IId, IIe and IIg,

M ² is, independently of each other, * -O- or * -O- (CH ₂ ) _k -CO-O-,

k is an integer of 1 to 7,

* Is a bonding site with -CO-,

R ¹⁹ each independently represents a hydrogen atom or a methyl group,

R ²⁰ is an aliphatic hydrocarbon group having 1 to 4 carbon atoms,

d is an integer from 0 to 5,

R ²¹ and R ²² are each independently a carboxyl group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms,

e and g are each independently an integer of 0 to 3,

When d, e, and g are two or more, a plurality of R ²⁰ , R ^21, or R ²² may be the same or different from each other.

M ² is preferably independently of each other * -O-, * -O- (CH ₂ ) _f -CO-O- (f is an integer of 1 to 4), more preferably * O-.

R ¹⁹ and R ²⁰ are preferably methyl groups.

R ²¹ and R ²² are each independently preferably a carboxyl group, a cyano group or a methyl group.

d, e and g are each independently preferably 0 to 2, more preferably 0 or 1.

As the monomer of the formula (IId), for example, the following can be given.

As the monomer of the general formula (IIe), for example, the following can be given.

As the monomer of formula (IIg), for example, the following can be given.

Among the acid stable monomers having a lactone ring, the (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] (Meth) acrylic acid 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan- ² -yloxy) 4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yl methacrylate, tetrahydro-2-oxo-3-furyl methacrylate, 2- 0.0 &gt; ^3,7 ] nonan- ² -yloxy) -2-oxoethyl &lt; / RTI &gt;

The content of the structural unit derived from the monomer of the formula (IId), the formula (IIe) or the formula (IIg) in the resin is generally 5 to 65 mol%, preferably 10 to 60 mol% And preferably 10 to 55 mol%.

<Other acid stable monomers>

Examples of other acid stable monomers include maleic anhydride of formula (IIh), itaconic anhydride of formula (IIi), acid stable monomers having a norbornene ring of formula (IIj), and the like.

&Lt; RTI ID = 0.0 &

&Lt; RTI ID = 0.0 &

&Lt; RTI ID = 0.0 &

In the above formula (IIj)

R ²³ and R ²⁴ are, each independently, a hydrogen atom, a substituent (e.g., hydroxyl group), an aliphatic hydrocarbon having 1-3 carbon atoms which may have a group, a cyano group, or a carboxyl group or a -COOR ^25, R ^23, and R ²⁴ is bonded to each other to form -CO-O-CO-, R ²⁵ is an aliphatic hydrocarbon group having 1 to 36 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and an aliphatic hydrocarbon group and a saturated cyclic hydrocarbon group -CH ₂ - may be substituted with -O- or CO- except that -COOR ²⁵ is an acid labile group (that is, R ²⁵ does not include a bond of a tertiary carbon atom with -O-) .

Examples of the aliphatic hydrocarbon group which may have a substituent for R ²³ and R ²⁴ include methyl, ethyl, propyl, hydroxymethyl and 2-hydroxyethyl. The aliphatic hydrocarbon group of R ²⁵ is preferably a group having 1 to 8 carbon atoms, more preferably a group having 1 to 6 carbon atoms, and the saturated cyclic hydrocarbon group is preferably a group having 4 to 36 carbon atoms, Group having 4 to 12 carbon atoms. Examples of R ²⁵ include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group and a 2-oxo-oxolan-4-yl group.

Examples of the monomer of formula (IIj) include 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene-2-carboxylic acid, 5-norbornene- Carboxylic acid 2-hydroxy-1-ethyl, 5-norbornene-2-methanol and 5-norbornene-2,3-dicarboxylic acid anhydride.

The content of the structural unit derived from the monomer of the formula (IIh), the formula (IIi) or the formula (IIj) in the resin is usually 2 to 40 mol%, preferably 3 to 30 mol% And preferably 5 to 20 mol%.

Preferred resin (A) is a copolymer obtained by polymerizing at least a monomer having an acid labile group, an acid stable monomer having a hydroxyl group and / or an acid stable monomer having a lactone ring. In this preferred copolymer, the monomer having an acid labile group is more preferably a monomer of formula (IIa1) and at least one (more preferably, a monomer of formula (IIa1)) of the monomer of formula (IIa2). The acid stable monomers having a hydroxy group are preferably monomers of the formula (IIc). The acid stable monomer having a lactone ring is more preferably at least one monomer of the formula (IId) and a monomer of the formula (IIe).

The resin (A) can be produced by a known polymerization method (for example, a radical polymerization method).

The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less). The weight average molecular weight as referred to herein is obtained as a conversion value based on standard polystyrene by gel permeation chromatography analysis, and detailed analysis conditions of the analysis are described in Examples herein.

The content of the resin (A) is preferably 80% by mass or more of the solid content of the photoresist composition.

&Lt; Basic compound >

The photoresist composition of the present invention may contain a basic compound. The content of the basic compound is preferably about 0.01 to 1% by mass based on the solid content of the photoresist composition.

The basic compound is preferably a basic nitrogen-containing organic compound (for example, an amine and an ammonium salt). The amine may be an aliphatic amine or an aromatic amine. As the aliphatic amine, any one of primary amine, secondary amine and tertiary amine can be used. The aromatic amine may be either an aromatic ring such as an aniline bonded with an amino group or a heteroaromatic amine such as pyridine. Preferable basic compounds include aromatic amines of the formula C2, in particular the anilines of the formula C2-1.

(C2)

(C2-1)

Among the formulas (C2) and (C2-1)

Ar is an aromatic hydrocarbon group,

T ¹ and T ² are each independently a hydrogen atom, an aliphatic hydrocarbon group (preferably an alkyl group), a saturated cyclic hydrocarbon group (preferably a cycloalkyl group) or an aromatic hydrocarbon group,

T ³ is an aliphatic hydrocarbon group (preferably an alkyl group), an alkoxy group, a saturated cyclic hydrocarbon group (preferably a cycloalkyl group) or an aromatic hydrocarbon group,

The hydrogen atom of the aliphatic hydrocarbon group, the saturated cyclic hydrocarbon group, the aromatic hydrocarbon group or the alkoxy group may be substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms, and the amino group may have 1 to 4 carbon atoms Alkyl group,

The aliphatic hydrocarbon group is preferably a group having 1 to 6 carbon atoms, and the saturated cyclic hydrocarbon group is preferably a group having 5 to 10 carbon atoms, and the aromatic hydrocarbon group is preferably a group having 6 to 10 carbon atoms, The group is preferably an alkoxy group having 1 to 6 carbon atoms,

o is an integer of 0 to 3, and when o is 2 or more, a plurality of T ³ may be mutually the same or different.

Examples of the aromatic amine (C2) include 1-naphthylamine and 2-naphthylamine.

Examples of the aniline (C2-1) include aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline and diphenylamine . Among them, diisopropylaniline (especially 2,6-diisopropylaniline) is preferable.

Examples of the basic compound include the compounds of the formulas C3 to C11.

&Lt; RTI ID = 0.0 &

(C4)

(C5)

[Formula C6]

(C7)

(C8)

(C9)

Lt; RTI ID = 0.0 &

[Chemical formula C11]

In the above formulas C3 to C11,

T ¹ , T ² , T ³ and o are the same as defined above,

T ⁴ is an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group or an alkanoyl group, the aliphatic hydrocarbon group is preferably a group having 1 to 6 carbon atoms, the saturated cyclic hydrocarbon group is preferably a group having 3 to 6 carbon atoms, The oil group is preferably a group having 2 to 6 carbon atoms,

u is an integer of 0 to 8, and when o or u is an integer of 2 or more, a plurality of T ³ or T ⁴ may be the same or different from each other,

A represents, each independently, a divalent aliphatic hydrocarbon group (preferably an alkylene group), -CO-, -C (= NH ) -, -C (= NR 34) -, -S-, -SS-, or A combination thereof,

The divalent aliphatic hydrocarbon group is preferably a group having 1 to 6 carbon atoms,

R ³⁴ is an alkyl group having 1 to 4 carbon atoms.

Here, examples of the alkanoyl group include an acetyl group, an ethylcarbonyl group and a heptylcarbonyl group.

Examples of the compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, Examples of the amines include methylamine, ethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldi There may be mentioned hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldodecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyl (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylenediamine, tetramethylenediamine, tetramethylenediamine, tetramethylenediamine, 4,4'-diamino-1,2-diphenyl Diamine, 4,4'-diamino-3,3'-dimethyldiphenylmethane and 4,4'-diamino-3,3'-diethyldiphenylmethane.

As the compound (C4), piperazine can be mentioned.

As the compound (C5), morpholine can be mentioned.

Examples of the compound (C6) include piperidine and a hindered amine compound having a piperidine skeleton described in Japanese Patent Application Laid-Open No. 11-52575.

As the compound (C7), 2,2'-methylenebis aniline can be mentioned.

Examples of the compound (C8) include imidazole and 4-methylimidazole.

Examples of the compound (C9) include pyridine and 4-methylpyridine.

Examples of the compound (C10) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) (4-pyridyl) ethane, di (2-pyridyl) ketone, 4,4'-di Pyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine and 2,2'-dipipyrylamine.

As the compound (C11), there can be mentioned bipyridine.

Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (tri Fluoromethyl) phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate and choline.

<Solvent>

The photoresist composition of the present invention may contain a solvent in an amount of 90 mass% or more in the photoresist composition. The photoresist composition of the present invention containing a solvent is suitable for producing a thin film photoresist. The content of the solvent is 90 mass% or more (preferably 92 mass% or more, and more preferably 94 mass% or more) and 99.9 mass% or less (preferably 99 mass% or less) in the composition. The content of the solvent can be measured by a known analytical means such as liquid chromatography or gas chromatography.

Examples of the solvent include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; Glycol ethers such as propylene glycol monomethyl ether; chain esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; Ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; and cyclic esters such as? -butyrolactone. The solvent may be used alone, or two or more solvents may be used in combination.

<Other ingredients>

The photoresist composition of the present invention may contain other components as required. There is no limitation to these other components, and additives known in the photoresist field such as a sensitizer, a dissolution inhibiting agent, a surfactant, a stabilizer, a dye and the like can be used.

&Lt; Photoresist composition and preparation method thereof >

The photoresist composition of the present invention can be prepared by mixing the resin (A), the acid generator and the solvent of the present invention, or by mixing the resin (A), the acid generator of the present invention, a basic compound and a solvent . In such a mixture, the order of mixing is arbitrary and not limited. The mixing temperature can be selected within a range of, for example, 10 to 40 占 폚, and an appropriate temperature range can be selected depending on the kind of the resin, the solubility in a solvent such as a resin and the like. The mixing time may be appropriately selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring mixing or the like may be used.

For example, the resin (A), the acid generator and the solvent of the present invention, and the basic compound or other components to be used, if necessary, are mixed in a desired amount, and then a filter having a pore diameter of about 0.2 탆 is used, The obtained mixed solution is filtered to prepare the photoresist composition of the present invention.

&Lt; Method for producing photoresist pattern >

The method for producing a photoresist pattern of the present invention comprises:

(1) a step of applying the above-mentioned photoresist composition onto a substrate to form a photoresist composition layer,

(2) a step of drying the formed photoresist composition layer to form a photoresist film,

(3) a step of exposing the photoresist film,

(4) a step of heating the photoresist film after exposure, and

(5) a step of developing the photoresist film after heating.

The application of the photoresist composition onto the substrate can be carried out by a commonly used apparatus such as a spin coater.

In the step of drying the photoresist composition layer and removing the solvent, removal of the solvent is carried out, for example, by evaporating the solvent using a heating apparatus such as a hot plate, or by using a decompression apparatus, The photoresist film is removed. The drying temperature may be about 50 to 200 占 폚. The pressure may be about 1 to 1.0 x 10 &lt; ⁵ &gt; Pa.

The obtained photoresist film is exposed using an exposure machine. At this time, a liquid immersion exposure apparatus may be used. Normally, exposure is carried out through a mask corresponding to the required photoresist pattern. Examples of the exposure light source include those emitting ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), solid laser light source And a high-frequency laser beam of a vacuum ultraviolet region is radiated, and the like can be used.

The exposed photoresist film is heated. The heating temperature is usually about 50 to 200 占 폚, preferably about 70 to 150 占 폚.

The photoresist film after heating is usually developed using an alkaline developer, optionally using a developing apparatus. The alkali developing solution used herein may be any of various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly referred to as choline) may, for example, be mentioned.

After development, it is preferable to rinse with ultrapure water to remove water remaining on the substrate and the pattern.

<Applications>

The photoresist composition of the present invention is particularly useful as a chemically amplified photoresist composition and is suitably used for a wide range of applications such as microfabrication of semiconductors, production of circuit substrates such as liquid crystal and thermal heads, and other photolithography processes . Particularly, in view of being capable of suppressing the occurrence of defects and further improving the resolution, shape and line edge roughness of the resulting pattern, it is possible to use an excimer laser lithography such as ArF or KrF, Can be used as chemically amplified photoresist compositions suitable for exposure lithography, EB exposure lithography, EUV exposure lithography. In addition to liquid immersion lithography, dry lithography can also be used. It can also be used for double imaging, which is industrially useful.

[Example]

Hereinafter, the present invention will be described in detail with reference to examples.

In Examples and Comparative Examples,% and parts indicating the content and amount are based on mass unless otherwise specified.

The weight average molecular weight is a value obtained by gel permeation chromatography (HLC-8120GPC type, manufactured by TOSOH CORPORATION, column: "TSKgel Multipore HXL-M", three solvents, tetrahydrofuran) using polystyrene as a standard product.

Column: TSKgel Multipore H _XL -Mx3 + guardcolumn (manufactured by Tosoh Corporation)

Eluent: tetrahydrofuran

Flow rate: 1.0 mL / min

Detector: RI detector

Column temperature: 40 DEG C

Injection volume: 100 μl

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

The structure of the compound was confirmed by mass spectrometry (LC: Agilent 1100, MASS: Agilent LC / MSD or LC / MSD TOF).

The content of the structural units in the resin was calculated from the results obtained by measuring the amount of unreacted monomers in the reaction mixture after completion of the polymerization using liquid chromatography.

Example 1: Synthesis of acid generator B1

10.00 parts of the compound represented by the formula B1-a (manufactured by Central Gara Chemicals Co., Ltd.) and 30.00 parts of 1,4-dioxane were mixed. To the obtained mixture, while stirring at 23 占 폚, an aqueous solution obtained by dissolving 0.88 parts of sodium hydroxide in 20.00 parts of ion-exchanged water was added dropwise over 30 minutes. The resulting mixture was stirred at 90 &lt; 0 &gt; C for 24 hours. After the reaction mixture was cooled, 150.00 parts of ion-exchanged water, 200.0 parts of ethyl acetate and 62.0 parts of sodium chloride were added and the liquid was separated by stirring. To the obtained organic layer, 140.0 parts of 3N hydrochloric acid was added and the solution was separated by stirring. The obtained organic layer was washed three times with 140.00 parts of ion-exchanged water. The obtained organic layer was concentrated, and the concentrated residue was purified by column purification (silica gel 60-200 mesh, Merck, developing solvent: ethyl acetate) to obtain 0.98 part of the compound of the formula B1-b.

1.00 parts of the compound of the formula B1-c (Example 1 of JP-A-2008-127367), 10.00 parts of the monochlorobenzene and 0.60 part of the compound of the formula B1-b were mixed. The resulting mixture was stirred at 23 캜 for 30 minutes, and then 0.04 parts of sulfuric acid and 4.00 parts of molecular sieve (4A, manufactured by Wako Pure Chemical Industries, Ltd.) were added thereto. The resulting mixture was refluxed and dehydrated at 130 DEG C for 3 hours. The obtained reaction mixture was concentrated, and 25.00 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained concentrated residue, followed by stirring and separating. The obtained organic layer was washed six times. 0.40 part of activated carbon was poured into the obtained organic layer, stirred at 23 DEG C for 30 minutes, and filtered. The filtrate was concentrated, and 4.00 parts of acetonitrile was added to the concentrate to dissolve. The obtained solution was concentrated, and 10 parts of ethyl acetate was added to the obtained concentrated residue. The supernatant was removed from the resulting mixture. 10 parts of tert-butyl methyl ether was added to the obtained residue, and the supernatant was removed from the resulting mixture. The obtained residue was dissolved in chloroform, and the obtained solution was concentrated to obtain 0.22 part of a salt of the formula (B1) as an oily product. The resulting salt is referred to as acid generator B1.

MS (ESI (+) Spectrum): M ⁺ 263.1

MS (ESI (-) Spectrum): M ^- 378.0

Example 2: Synthesis of acid generator B2

1.10 parts of the compound of the formula B2-c, 10.00 parts of the monochlorobenzene and 0.60 part of the compound of the formula B1-b were mixed. The resulting mixture was stirred at 23 캜 for 30 minutes, and then 0.04 parts of sulfuric acid and 4.00 parts of molecular sieve (4A, manufactured by Wako Pure Chemical Industries, Ltd.) were added thereto. The resulting mixture was refluxed and dehydrated at 130 DEG C for 3 hours. The obtained reaction mixture was concentrated, and 25.00 parts of chloroform and 12.50 parts of ion-exchanged water were poured into the obtained concentrated residue, followed by stirring and liquid separation. The obtained organic layer was washed six times. 0.50 part of activated carbon was poured into the resultant organic layer, stirred at 23 DEG C for 30 minutes, and filtered. The filtrate was concentrated, and 4.00 parts of acetonitrile was added to the concentrate to dissolve. The obtained solution was concentrated, and to the concentrated residue, 10 parts of ethyl acetate was added. The supernatant was removed from the resulting mixture. 10 parts of tert-butyl methyl ether was added to the obtained residue. The supernatant was removed from the resulting mixture. The obtained residue was dissolved in chloroform, and the obtained solution was concentrated to obtain 0.32 part of a salt of the formula (B2). The resulting salt is referred to as acid generator B2.

MS (ESI (+) Spectrum): M ⁺ 305.1

MS (ESI (-) Spectrum): M ^- 378.0

Example 3: Synthesis of acid generator B3

0.95 parts of the compound of the formula B3-c, 10.00 parts of the monochlorobenzene and 0.60 parts of the compound (B1-b) were mixed. The resulting mixture was stirred at 23 캜 for 30 minutes, and then 0.04 parts of sulfuric acid and 4.00 parts of molecular sieve (4A, manufactured by Wako Pure Chemical Industries, Ltd.) were added thereto. The resulting mixture was refluxed and dehydrated at 130 DEG C for 3 hours. The obtained reaction mixture was concentrated, and 25.00 parts of chloroform and 12.50 parts of ion-exchanged water were poured into the concentrated residue, followed by stirring and liquid separation. The obtained organic layer was washed six times. 0.50 part of activated carbon was poured into the resultant organic layer, stirred at 23 DEG C for 30 minutes, and filtered. The filtrate was concentrated, and 4.00 parts of acetonitrile was added to the concentrate to dissolve. The resulting solution was concentrated, and 10 parts of ethyl acetate was added to the concentrated residue. The supernatant was removed from the resulting mixture. 10 parts of tert-butyl methyl ether was added to the obtained residue. The supernatant was removed from the resulting mixture. The obtained residue was dissolved in chloroform, and the obtained solution was concentrated. The resulting concentrate was purified by column purification (silica gel, 60-200 mesh, Merck & Co., developing solvent: chloroform / methanol = 5/1) 0.25 parts of a salt was obtained. The resulting salt is referred to as acid generator B3.

MS (ESI (+) Spectrum): M ⁺ 281.0

MS (ESI (-) Spectrum): M ^- 378.0

Example 4: Synthesis of acid generator B4

0.80 part of the compound of the formula B4-c, 10.00 parts of the monochlorobenzene and 0.60 part of the compound of the formula B1-b were mixed. The resulting mixture was stirred at 23 캜 for 30 minutes, and then 0.04 parts of sulfuric acid and 4.00 parts of molecular sieve (4A, manufactured by Wako Pure Chemical Industries, Ltd.) were added thereto. The resulting mixture was refluxed and dehydrated at 130 DEG C for 3 hours. The obtained reaction mixture was concentrated, and 25.00 parts of chloroform and 12.50 parts of ion-exchanged water were poured into the obtained concentrated residue, followed by stirring and liquid separation. The obtained organic layer was washed six times. 0.50 part of activated carbon was poured into the obtained organic layer, and the mixture was stirred at 23 캜 for 30 minutes and filtered. The filtrate was concentrated, and 4.00 parts of acetonitrile was added to the concentrate to dissolve. The resulting solution was concentrated, and 10 parts of ethyl acetate was added to the concentrated residue. The supernatant was removed from the resulting mixture. 10 parts of tert-butyl methyl ether was added to the obtained residue. The supernatant was removed from the resulting mixture. The obtained residue was dissolved in chloroform, and the resulting solution was concentrated. The obtained concentrate was purified by column purification (silica gel, 60-200 mesh, Merck & Co., developing solvent: chloroform / methanol = 5/1) 0.23 parts of a salt were obtained. The resulting salt is referred to as acid generator B4.

MS (ESI (+) Spectrum): M ⁺ 207.1

MS (ESI (-) Spectrum): M ^- 378.0

Example 5: Synthesis of acid generator B5

3.33 parts of the compound of the formula B1-b and 20 parts of tetrahydrofuran were mixed, and the obtained mixture was stirred at room temperature to confirm the dissolution of the compound of the formula B1-b. Then, 1.43 parts of pyridine was added. After the temperature of the resulting mixture was raised to 40 占 폚, a mixed solution of 2.55 parts of chloroacetyl chloride and 5 parts of tetrahydrofuran was added dropwise over 1 hour. The resulting mixture was stirred at 40 占 폚 for 3 hours and then cooled to 5 占 폚. To the reaction mixture, 10 parts of ion-exchanged water cooled at 5 占 폚 and 40 parts of ethyl acetate were added and stirred, followed by liquid separation. 10 parts of 10% aqueous potassium carbonate solution at 5 占 폚 was added to the obtained organic layer, followed by washing and separation. The obtained organic layer was washed with 10 parts of ion-exchanged water. This washing with water was repeated five times. The obtained organic layer was concentrated, and the obtained concentrated residue was purified by column (silica gel 60-200 mesh, Merck, eluent: ethyl acetate) to obtain 1.35 parts of a compound represented by the formula B5-a.

2.30 parts of the compound represented by the formula B1-c and 11.50 parts of N, N-dimethylformamide were mixed. After the obtained mixture was stirred at 23 DEG C for 30 minutes, 0.72 part of potassium carbonate and 0.22 part of potassium iodide were added. The obtained mixture was stirred at 40 占 폚 for 1 hour, and then the solution obtained by dissolving 1.30 parts of the compound represented by the formula B5-a in 2.60 parts of N, N-dimethylformamide was added dropwise over 1 hour. The resulting mixture was stirred at 40 占 폚 for 6 hours and then cooled to 23 占 폚. 74.56 parts of chloroform, 13.21 parts of 5% oxalic acid aqueous solution and 5.43 parts of ion-exchanged water were poured into the obtained reaction mixture, followed by stirring and liquid separation. The obtained organic layer was washed with 29.83 parts of ion-exchanged water. This washing with water was carried out seven times. 1.00 parts of activated carbon was poured into the obtained organic layer, stirred at 23 DEG C for 30 minutes, filtered and concentrated. To the obtained concentrate, 10 parts of acetonitrile was added and dissolved. The resulting solution was concentrated, and 10 parts of ethyl acetate was added to the concentrated residue. The supernatant was removed from the resulting mixture. 10 parts of tert-butyl methyl ether was added to the obtained residue. The supernatant was removed from the resulting mixture. The obtained residue was dissolved in chloroform, and the resulting solution was concentrated. The resulting concentrate was purified by column purification (silica gel, 60-200 mesh, Merck & Co., developing solvent: chloroform / methanol = 5/1) 0.58 parts of a salt was obtained. The obtained salt is referred to as acid generator B5.

MS (ESI (+) Spectrum): M ⁺ 263.1

MS (ESI (-) Spectrum): M ^- 436.0

Example 6: Synthesis of acid generator B6

9.03 parts of a compound represented by the formula B6-a (manufactured by Central Gara Chemicals Co., Ltd.) and 30.00 parts of 1,4-dioxane were mixed. To the obtained mixture, while stirring at 23 占 폚, an aqueous solution obtained by dissolving 0.88 parts of sodium hydroxide in 20.00 parts of ion-exchanged water was added dropwise over 30 minutes. The resulting mixture was stirred at 90 &lt; 0 &gt; C for 24 hours. After the reaction mixture was cooled, 150 parts of ion-exchanged water, 200 parts of ethyl acetate and 62 parts of sodium chloride were added, and liquid separation was carried out by stirring. To the obtained organic layer was added 140 parts of 3N hydrochloric acid, stirred, and liquid separation was carried out. The obtained organic layer was washed three times with 140 parts of ion-exchanged water. The obtained organic layer was concentrated, and the concentrated residue was subjected to column purification (silica gel, 60-200 mesh, Merck, developing solvent: ethyl acetate) to obtain 1.02 parts of the compound represented by the formula B6-b.

1.00 parts of the compound of the formula B1-c, 10.00 parts of the monochlorobenzene and 0.52 part of the compound of the formula B6-b were mixed. The resulting mixture was stirred at 23 캜 for 30 minutes, and then 0.04 parts of sulfuric acid and 4.00 parts of molecular sieve (4A, manufactured by Wako Pure Chemical Industries, Ltd.) were added thereto. The resulting mixture was refluxed and dehydrated at 130 DEG C for 3 hours. The obtained reaction mixture was concentrated, and 25.00 parts of chloroform and 12.50 parts of ion-exchanged water were poured into the concentrated residue, followed by stirring and liquid separation. The obtained organic layer was washed six times. 0.40 part of activated carbon was poured into the resultant organic layer, stirred at 23 DEG C for 30 minutes, filtered and concentrated. To the obtained concentrate, 4.00 parts of acetonitrile was added. The resulting solution was concentrated, and 10 parts of ethyl acetate was added to the concentrated residue. The supernatant was removed from the resulting mixture. 10 parts of tert-butyl methyl ether was added to the obtained residue. The supernatant was removed from the resulting mixture. The obtained residue was dissolved in chloroform, and the obtained solution was concentrated. The resulting concentrate was subjected to column purification (silica gel 60-200 mesh, Merck & Co., developing solvent: chloroform / methanol = 5/1) to obtain 0.24 part of a salt of the formula B6. The resulting salt is referred to as acid generator B6.

MS (ESI (+) Spectrum): M ⁺ 350.1

MS (ESI (-) Spectrum): M ^- 378.0

Synthesis Example 1: Synthesis of Resin A1

The following Monomer E, Monomer F, Monomer B, Monomer C and Monomer D were mixed in a molar ratio of 30: 14: 6: 20: 30. To the obtained mixture, 1.5 times by mass of 1,4-dioxane was added to the total mass of all the monomers. To the resulting mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in a ratio of 1.00 mol% and 3.00 mol%, respectively, to the total molar amount of the total monomers. The resulting mixture was heated at 73 캜 for about 5 hours. Thereafter, the reaction mixture was poured into a large amount of a mixed solvent of methanol and water (4: 1), and the resulting copolymer was precipitated. The precipitated copolymer was taken out and purified by carrying out three times pouring into a large amount of a mixed solvent of methanol and water (4: 1) to obtain a copolymer having a weight average molecular weight of about 8.1 x 10 ³ in a yield of 65% . The obtained copolymer had a structural unit derived from each monomer of the following formula, which was referred to as Resin A1.

The molar ratio of each structural unit in the obtained resin A1 is a structural unit derived from monomer E: a structural unit derived from monomer F: a structural unit derived from monomer B: a structural unit derived from monomer C: a structure derived from monomer D Unit = 21.4: 13.3: 6.7: 23.4: 35.2.

Synthesis Example 2: Synthesis of Resin A2

The following Monomer A, Monomer B and Monomer C were mixed in a molar ratio of 50:25:25. To the obtained mixture, 1.5 times by mass of 1,4-dioxane was added to the total mass of all the monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in a proportion of 1 mol% and 3 mol%, respectively, to the total molar amount of the total monomers. The resulting mixture was heated at 80 DEG C for about 8 hours. Then, the reaction mixture was poured into a large amount of a mixed solvent of methanol and water (3: 1), and the resulting copolymer was precipitated. The precipitated copolymer was taken out and poured into a large amount of a mixed solvent of methanol and water (3: 1) three times to obtain a copolymer having a weight average molecular weight of about 9.2 × 10 ³ in a yield of 60% . This copolymer has a structural unit derived from each monomer of the following formula, which is referred to as Resin A2.

The molar ratio of each structural unit in the obtained resin A2 was the structural unit derived from monomer A: the structural unit derived from monomer B: the structural unit derived from monomer C = 42.6: 28.7: 28.7.

(Preparation of photoresist composition)

The components shown below were mixed in the composition shown in Table 1, and the obtained solution was filtered with a filter made of fluororesin having a pore diameter of 0.2 mu m to prepare a photoresist composition.

<Resin>

Resins A1, A2

<Acid Generator>

Acid generator B7

&Lt; Basic compound:

&Lt; tb &gt;&lt; SEP &gt; Quencher C1: 2,6-

<Solvent>

Propylene glycol monomethyl ether acetate 265 parts

2-heptanone 20.0 parts

Propylene glycol monomethyl ether 20.0 parts

3.5 parts of? -butyrolactone

(Evaluation of resist composition for immersion)

On a 12-inch silicon wafer, a composition for an organic anti-reflective film [ARC-29; Manufactured by Nissan Chemical Industries, Ltd.) was applied and baked under conditions of 205 DEG C for 60 seconds to form an organic anti-reflective film having a thickness of 78 nm.

Then, the photoresist composition prepared above was spin-coated on the formed organic anti-reflection film to a film thickness of 85 nm after drying.

The obtained silicon wafer was subjected to prebaking (PB) on a direct hot plate for 60 seconds at the temperature indicated in the column &quot; PB &quot; in Table 1. [ The wafer thus formed with the photoresist film was irradiated with ArF excimer stepper for liquid immersion lithography (XT: 1900Gi; (Manufactured by ASML, NA = 1.35, 3 / 4Annular X-Y deflection) was used to immerse the line and space pattern in a liquid immersion exposure by changing the exposure amount stepwise.

After exposure, post exposure bake (PEB) was performed on the hot plate at a temperature shown in the column of &quot; PEB &quot; in Table 1 for 60 seconds.

Further, paddle development was performed for 60 seconds with a 2.38 mass% tetramethylammonium hydroxide aqueous solution.

Effective sensitivity: The exposure amount at which a line and space pattern of 50 nm becomes 1: 1 in each photoresist film is called effective sensitivity.

Evaluation of resolution: In terms of effective sensitivity, the photoresist pattern was observed with a scanning electron microscope to find that a line and space pattern of 45 nm was resolved, a line and space pattern of more than 45 nm was resolved at 48 nm, &Quot; &amp; cir &amp; &quot; The results are shown in Table 2. Numerical values in parentheses indicate resolution (nm).

Shape Evaluation: A 50 nm line and space pattern was observed with a scanning electron microscope. The cross-sectional shape of the line pattern was close to a rectangle, and the shape was good, and the top shape of the cross-section was round or a fringe appeared.

The results are shown in Table 2.

From the resist composition containing the salt of the present invention, a resist pattern having excellent resolution and shape can be obtained.

Claims (9)

&Lt; / RTI &gt;
Formula I

In the formula (I)
Q ¹ and Q ² are, independently of each other, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms,
L ¹ is a group represented by the following formula (IL-1), (IL-2) or (IL-3)
The formula IL-1

The formula IL-2

The formula IL-3

In the above formulas IL-1, IL-2 or IL-3,
L ² is a single bond or a saturated hydrocarbon group of 1 to 15 carbon atoms;
L ³ is a single bond or an alkylene group having 1 to 12 carbon atoms;
L ⁴ is an alkylene group having 1 to 12 carbon atoms, provided that the total number of carbon atoms of L ³ and L ⁴ is 13 or less;
L ⁵ and L ⁶ are each independently an alkylene group having 1 to 14 carbon atoms, provided that the total number of carbon atoms of L ⁵ and L ⁶ is 15 or less,
R ¹ is an alkyl group having 1 to 6 carbon atoms containing a fluorine atom,
Z ⁺ is a cation represented by any one of the following formulas (Iz-1) to (Iz-3)
The chemical formula Iz-1

Iz-2

Iz-3

In the above chemical formula Iz-1,
Each of P ^a to P ^c is independently an aliphatic hydrocarbon group of 1 to 30 carbon atoms, a saturated cyclic hydrocarbon group of 3 to 36 carbon atoms, or an aromatic hydrocarbon group of 6 to 18 carbon atoms, and the aliphatic hydrocarbon group may have a hydroxyl group, An alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the saturated cyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group, The group may be substituted with a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms,
In the above chemical formula Iz-2,
P ⁴ and P ⁵ 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;
i and j are each independently an integer of 0 to 5,
In the above chemical formula Iz-3,
P ⁶ and P ⁷ are each independently an aliphatic hydrocarbon group having 1 to 36 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms;
P ⁸ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms;
P ⁹ is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aromatic hydrocarbon group is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, An alkoxy group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy group;
P ⁶ and P ⁷ and P ⁸ and P ⁹ may be bonded to each other to form a 3-membered to 12-membered ring, and one or more -CH ₂ - included in such a ring may be replaced by -O-, S-, or -CO-. According to claim 1, L ^{1, a, * -CO-OC (R 3} ) (R 4) -C (R 5) (R 6) - ( wherein, R ^3, R ^4, R ⁵ and R ⁶ is, Each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and * is a bonding site with -C (Q ¹ ) (Q ² ) -. 2. The salt of claim 1, wherein R &lt; ¹ &gt; is a trifluoromethyl group. ^{3. The} salt of claim 2 wherein R &lt; ³ &gt; and R &lt; ⁴ &gt; are hydrogen atoms. 2. The salt of claim 1 wherein Z ^& lt ^{; + &gt;} is a triarylsulfonium cation. An acid generator containing a salt according to claim 1. A photoresist composition containing an acid generator and a resin according to claim 6, wherein the resin has an acid labile group, is insoluble or hardly soluble in an aqueous alkali solution, and is soluble in an aqueous alkaline solution under the action of an acid. 8. The photoresist composition of claim 7, further comprising a basic compound. (1) a step of applying the photoresist composition according to claim 7 onto a substrate to form a photoresist composition layer,
(2) a step of drying the formed photoresist composition layer to form a photoresist film,
(3) a step of exposing the photoresist film,
(4) a step of heating the photoresist film after exposure, and
(5) A method for producing a photoresist pattern, comprising the step of developing the photoresist film after heating.