KR101811881B1 - Salt and photoresist composition - Google Patents

Abstract

(식 중, R¹ 및 R² 는 각각 독립적으로, 하이드록시기 (-OH) 또는 탄소수 1 ∼ 12 의 알킬기를 나타내고, 그 알킬기에 함유되는 -CH₂- 는 -O- 또는 -CO- 로 치환되어 있어도 된다.
R³ 은 탄소수 1 ∼ 6 의 알킬기를 나타낸다.
l, m 및 n 은 각각 독립적으로, 0 ∼ 3 의 정수를 나타낸다.
p 는 1 ∼ 3 의 정수를 나타낸다.
S^＋ 를 함유하는 함황 복소고리에 함유되는 -CH₂- 는 -O- 또는 -CO- 로 치환되어 있어도 된다.
R⁴ 및 R⁵ 는 각각 독립적으로, 불소 원자 또는 탄소수 1 ∼ 6 의 퍼플루오로알킬기를 나타낸다.
L¹ 은 탄소수 1 ∼ 17 의 2 가의 포화 탄화수소기를 나타내고, 그 2 가의 포화 탄화수소기에 함유되는 -CH₂- 는 -O- 또는 -CO- 로 치환되어 있어도 된다.
Y 는 치환기를 가지고 있어도 되는 탄소수 1 ∼ 18 의 지방족 탄화수소기 또는 치환기를 가지고 있어도 되는 탄소수 3 ∼ 18 의 포화 고리형 탄화수소기를 나타내고, 그 지방족 탄화수소기 및 그 포화 고리형 탄화수소기에 함유되는 -CH₂- 는 -O-, -SO₂- 또는 -CO- 로 치환되어 있어도 된다) 로 나타내는 염.The formula (I)

(Wherein R ¹ and R ² each independently represent a hydroxyl group (-OH) or an alkyl group having 1 to 12 carbon atoms, and -CH ₂ - contained in the alkyl group is substituted with -O- or -CO- .
R ³ represents an alkyl group having 1 to 6 carbon atoms.
l, m and n each independently represent an integer of 0 to 3;
p represents an integer of 1 to 3;
-CH ₂ - contained in the sulfur heterocyclic ring containing S ⁺ may be substituted with -O- or -CO-.
R ⁴ and R ⁵ each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.
Y is -CH which represents a group having a carbon number of 3 to 18 saturated cyclic hydrocarbon group which may have a substituent group or an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, those groups containing an aliphatic hydrocarbon group and the saturated cyclic hydrocarbon _2- May be substituted with -O-, -SO ₂ - or -CO-.

Description

[0001] SALT AND PHOTORESIST COMPOSITION [0002]

The present invention relates to a salt and a photoresist composition containing the same.

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

Japanese Patent Application Laid-Open No. 2004-59882 discloses a salt for an acid generator, which is represented by the formula (X1):

≪ / RTI > is described.

(Patent Document 1) Japanese Laid-Open Patent Publication No. 2004-59882

The present invention

[1] Formula (I):

(Wherein R ¹ and R ² each independently represent a hydroxyl group (-OH) or an alkyl group having 1 to 12 carbon atoms, and -CH ₂ - contained in the alkyl group is substituted with -O- or -CO- .

R ³ represents an alkyl group having 1 to 6 carbon atoms.

l, m and n each independently represent an integer of 0 to 3;

p represents an integer of 1 to 3;

-CH ₂ - contained in the sulfur heterocyclic ring containing S ⁺ may be substituted with -O- or -CO-.

R ⁴ and R ⁵ each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.

L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.

Y is -CH which represents a group having a carbon number of 3 to 18 saturated cyclic hydrocarbon group which may have a substituent group or an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, those groups containing an aliphatic hydrocarbon group and the saturated cyclic hydrocarbon _2- May be substituted with -O-, -SO ₂ - or -CO-)

;

[2] The compound according to [1], wherein L ¹ is * -CO-O- (CH ₂ ) _{j 1} - (* represents a bonding site with -C (R ⁴ ) (R ⁵ ) -, and j 1 represents 0 or 1) Lt; / RTI >;

[3] the salt according to [1] or [2], wherein p is 1 or 2;

[4] An acid generator containing a salt according to any one of [1] to [3];

[5] A photoresist composition comprising a resin capable of dissolving in an alkali aqueous solution by the action of an acid, as a resin having an acid labile group and insoluble or hardly soluble in an aqueous alkali solution, ;

[6] The photoresist composition according to [5], further comprising a basic compound;

[7] A process for producing a photoresist composition, comprising the steps of: (1) applying a photoresist composition described in [5] or [6]

(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,

A method of manufacturing a photoresist pattern comprising: And the like.

The salt of the present invention can be used as an acid generator for a photoresist composition, and a photoresist pattern having an excellent mask error factor (MEF) can be obtained by using a photoresist composition containing the salt.

The salt of the present invention is a salt of the formula (I):

(Wherein R ¹ and R ² each independently represent a hydroxyl group (-OH) or an alkyl group having 1 to 12 carbon atoms, and -CH ₂ - contained in the alkyl group is substituted with -O- or -CO- .

R ³ represents an alkyl group having 1 to 6 carbon atoms.

l, m and n each independently represent an integer of 0 to 3;

p represents an integer of 1 to 3;

-CH ₂ - contained in the sulfur heterocyclic ring containing S ⁺ may be substituted with -O- or -CO-.

R ⁴ and R ⁵ each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.

L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.

Y is -CH which represents a group having a carbon number of 3 to 18 saturated cyclic hydrocarbon group which may have a substituent group or an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, those groups containing an aliphatic hydrocarbon group and the saturated cyclic hydrocarbon _2- May be substituted with -O-, -SO ₂ - or -CO-]

And can be used as an acid generator for a photoresist composition.

Examples of the alkyl group having 1 to 12 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, A methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group and a cyclooctyl group. Examples of the group in which -CH ₂ - contained in the alkyl group is substituted with -O- or -CO- include a methoxy group, an ethoxy group, a butoxy group, an acetyl group and a methoxycarbonyl group.

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ³ include methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl and hexyl.

Examples of the group substituted with -O- or -CO- in -CH ₂ - contained in a sulfide heterocyclic ring containing S ⁺ include the following groups.

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, A perfluoro-tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group.

R ⁴ and R ⁵ are each independently preferably a perfluoromethyl group or a fluorine atom, and more preferably R ⁴ and R ⁵ are fluorine atoms.

Examples of the divalent saturated hydrocarbon group having 1 to 17 carbon atoms include a linear alkylene group, a branched alkylene group, a monocyclic or polycyclic saturated cyclic hydrocarbon group, and a group formed by combining two or more of these groups. 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 such as a methylbutane-1,4-diyl group; Monocyclic saturated cyclic hydrocarbon groups such as a 1,3-cyclobutylene group, a 1,3-cyclopentylene group, a 1,4-cyclohexylene group and a 1,5-cyclooctylene group; And polycyclic saturated cyclic hydrocarbon groups such as a 1,4-norbornylene group, a 2,5-norbornylene group, a 1,5-adamantylene group and a 2,6-adamantylene group. Further, from the monovalent saturated cyclic hydrocarbon group described below, bivalent saturated cyclic hydrocarbon groups having one arbitrary hydrogen atom as a bonding number (bonding hand) can be used.

One or more -CH ₂ - contained in such a divalent saturated hydrocarbon group having 1 to 17 carbon atoms may be substituted with -O- or CO-, and -CH ₂ - contained in the saturated hydrocarbon group may be replaced by -O- or -CO - include groups represented by formulas (b1-1) to (b1-6). Is preferably a group represented by formula (b1-1), formula (b1-2), formula (b1-3), formula (b1-4) or formula (b1-6) 1), (b1-2) or (b1-6). * In the formulas (b1-1) to (b1-6) means a bonding site to -C (R ⁴ ) (R ⁵ ) -.

( ^Wherein L ^b2 represents a single bond or a saturated hydrocarbon group of 1 to 15 carbon atoms, L ^b3 represents a single bond or a saturated hydrocarbon group of 1 to 12 carbon atoms, L ^b4 represents a saturated hydrocarbon group of 1 to 13 carbon atoms, L ^b5 represents a saturated hydrocarbon having a carbon number of 1 ~ 15, L ^b6 and L ^b7 are, each independently, represent a saturated hydrocarbon having a carbon number of 1 ~ 15, L ^b8 represents a saturated hydrocarbon having a carbon number of 1 ~ 14, L ^b9 and L ^b10 Each independently represent a saturated hydrocarbon group having 1 to 11 carbon atoms)

Among them, a group represented by formula (b1-1) or (b1-6) is preferable. As the group represented by the formula (b1-1), L ^b2 It is a single bond or -CH ₂ - groups are preferred represented by the formula (b1-1). As the group represented by the formula (b1-6), L ^b9 It is a single bond or -CH ₂ - group of formula preferably represents a (b1-6), and L ^b9 a single bond or -CH ₂ - and, L ^b10 the formula

The group represented by formula (L1-6) is more preferred.

Examples of the group represented by the formula (b1-1) include the following groups.

Examples of the group represented by the formula (b1-2) include the following groups.

Examples of the group represented by the formula (b1-3) include the following groups.

Examples of the group represented by the formula (b1-4) include the following groups.

Examples of the group represented by the formula (b1-5) include the following groups.

Examples of the group represented by the formula (b1-6) include the following groups.

As the aliphatic hydrocarbon group for Y, the above-mentioned alkyl groups can be exemplified. Among them, an alkyl group having 1 to 6 carbon atoms is preferable.

As the saturated cyclic hydrocarbon group for Y, there can be mentioned one in which one hydrogen atom is bonded to one of the above-mentioned divalent saturated cyclic hydrocarbon. Specific examples thereof include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, A monocyclic saturated cyclic hydrocarbon group such as a cyclohexyl group, a cyclohexyl group, a cycloheptyl group, and a cycloalkyl group such as a cyclooctyl group, a decahydronaphthyl group, an adamantyl group, a norbornyl group, a methylnorbornyl group, , And a group represented by formulas (Y1) to (Y26).

Examples of the substituent which the aliphatic hydrocarbon group or the saturated cyclic hydrocarbon group in Y may have include a halogen atom (excluding a fluorine atom), a hydroxyl group, an oxo group (= O), an aliphatic hydrocarbon group having 1 to 12 carbon atoms , A hydroxyl-substituted aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 16 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, 1-4 of an acyl group, a glycidyloxy group and a - (CH ₂₎ group (in the formula, R ^b1 is a saturated ring having a carbon number of 1 to 16 aliphatic hydrocarbon group, having a carbon number of 3 to 16, represented by _j2 -O-CO-R ^b1 An aromatic hydrocarbon group having 6 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and j2 is an integer of 0 to 4).

Examples of the hydroxyl group-containing aliphatic hydrocarbon group include a hydroxyalkyl group having 1 to 12 carbon atoms such as a hydroxymethyl group and a hydroxyethyl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The aliphatic hydrocarbon group includes an alkyl group.

Examples of the alkoxy group include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy, pentyloxy and hexyloxy.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, an p-methylphenyl group, a p-tert-butylphenyl group, a p- An aryl group such as a 2,6-diethylphenyl group or a 2-methyl-6-ethylphenyl group.

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

Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.

The aliphatic hydrocarbon group, saturated cyclic hydrocarbon group, aromatic hydrocarbon group and aralkyl group which are substituents of Y may further have a substituent. Examples of the substituent include an alkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, an oxo group, and the like.

As the group substituted with -CH ₂ - in -O- or -CO- in the aliphatic hydrocarbon group or saturated cyclic hydrocarbon group represented by Y, an ether bond or a cyclic ether bond (-CH ₂ - substituted with -O-) A saturated cyclic hydrocarbon group having an oxo group (a group in which -CH ₂ - is substituted with -CO-), a sultone ring group (two adjacent -CH ₂ - are -O- and -SO ₂ -) and a lactone ring group (groups in which two adjacent -CH- are replaced with -O- and -CO-, respectively).

Examples of Y which is a saturated cyclic hydrocarbon group substituted with an aliphatic hydrocarbon group include the following groups.

Examples of Y, which is a saturated cyclic hydrocarbon group substituted with a hydroxyl group or a hydroxyl group-containing aliphatic hydrocarbon group, include the following groups.

Examples of Y which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group include the following groups.

As Y which is a saturated cyclic hydrocarbon group substituted with a group represented by - (CH ₂ ) _{j 2} -O-CO-R ^b1 , the following groups may be mentioned.

Y is preferably an adamantyl group which may have a substituent (for example, an oxo group or a hydroxyl group), more preferably an adamantyl group having a hydroxy group, a hydroxyalkyl group having a carbon number of 1 to 12 An adamantyl group and an oxo-adamantyl group.

Specific examples of the anion of the salt represented by the formula (I) include the following anions.

The anion of the salt represented by the formula (I) is preferably an anion wherein L ^b1 is a group represented by the formula (b1-1), and an anion represented by the formula (b1-1-1) to (b1-1-9) Temperature is more preferable.

(In the formulas (b1-1-1) to (b1-1-9), R ⁴ , R ⁵ and L ^b2 have the same meanings as defined above, and R ^b2 and R ^b3 each independently represent a An aliphatic hydrocarbon group (preferably a methyl group)

Of these, isoanone is preferable,

Examples of the salt represented by the formula (I) include the following salts.

The salt represented by the formula (I) can be produced, for example, by the following method. In the following reaction formulas, unless otherwise stated, the definitions of the respective substituents have the same meanings as described above.

The salt represented by the formula (IA) can be produced by reacting the salt represented by the formula (IA-a) and the salt represented by the formula (IA-b) in a solvent such as chloroform. The salt represented by the formula (IA-b) can be synthesized by the method described in JP-A-2008-209917.

The salt represented by the formula (IA-a) can be obtained by heating the compound represented by the formula (IA-c) in a solvent such as acetonitrile at 50 to 85 캜.

The compound represented by the formula (IA-c) can be obtained by reacting the compound represented by the formula (IA-d) with methanesulfonium chloride in a solvent such as chloroform or dichloromethane in the presence of a base catalyst such as triethylamine.

The compound represented by the formula (IA-d) can be obtained by reacting the compound represented by the formula (IA-e) with the compound represented by the formula (IA-f) in a solvent such as acetone in the presence of a base catalyst such as triethylamine have.

Examples of the compound represented by the formula (IA-e) include 1-naphthalenethiol.

Examples of the compound represented by the formula (IA-f) include 4-chloro-1-butanol and 5-chloro-1-pentanol.

The salt represented by the formula (I) can be obtained by reacting the salt represented by the formula (I-a) and the salt represented by the formula (I-b) in a solvent such as chloroform.

The salt represented by the formula (I-b) can be produced by the method described in Japanese Laid-Open Patent Publication No. 2008-209917.

The salt represented by the formula (I-a) can be obtained by reacting the compound represented by the formula (I-c) and the compound represented by the formula (I-d) in the presence of methanesulfonic acid and two phosphorus pentoses.

Examples of the compound represented by the formula (I-c) include 1-ethoxynaphthalene and 1-butoxynaphthalene. 1-Alkoxynaphthalene can be obtained by reacting 1-naphthol and 1-iodoalkane in a solvent such as acetone in the presence of a catalyst such as potassium carbonate.

Examples of the compound represented by the formula (I-d) include tetrahydrothiophene 1-oxide.

The acid generator of the present invention contains a salt represented by the formula (I). The acid generator of the present invention may contain two or more kinds of salts represented by formula (I).

The acid generator of the present invention may be composed solely of the salt represented by the formula (I), or may contain an acid generator different from the salt represented by the formula (I), in addition to the salt represented by the formula (I).

Examples of the acid generator which is different from the salt represented by the formula (I) include a salt comprising the anion represented by the formula (I) and the triarylsulfonium cation. Specifically, the salts represented by the formulas (B1-1) to (B1-21) can be mentioned. Among them, the formula (B1-1), (B1-2), the formula (B1-3), the formula (B1-6), the formula (B1-11), the formula (B1-12) The salt represented by the formula (B1-14) is preferred.

The content of the salt represented by the formula (I) in the acid generator of the present invention is preferably 10 parts by mass or more (more preferably 30 parts by mass or more) relative to 100 parts by mass of the acid generator, and usually 100 parts by mass Or less, preferably 90 parts by mass or less (more preferably 70 parts by mass or less).

The content of the acid generator in the photoresist composition of the present invention is preferably 1 part by mass or more (more preferably 3 parts by mass or more), and preferably 30 parts by mass or less (more preferably, 25 parts by mass or less).

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

In the photoresist composition of the present invention, an acid is generated from the salt represented by the formula (I) by exposure. The acid catalytically acts on an acid-labile group in the resin to cleave an acid-unstable group, thereby allowing the resin to be soluble in an aqueous alkali solution.

≪ Resin (A) >

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

≪ Monomer having an acid labile group >

The term " acid labile group " means a group which is cleaved on contact with an acid to form a hydrophilic group (for example, a hydroxyl group (-OH) or a carboxyl group (-COOH)). Examples of the group unstable to the acid include a group represented by the formula (1). In the following, the group represented by the formula (1) is sometimes referred to as a "group (1) unstable to the acid".

( ^Wherein R ^a1 to R ^a3 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 20 carbon atoms, and R ^a2 and R ^a3 are bonded to each other, May form a ring having 3 to 20 carbon atoms. The aliphatic hydrocarbon group, the saturated cyclic hydrocarbon group and -CH ₂ - of the ring may be substituted with -O-, -S- or -CO-. * Represents a binding site)

The acid-unstable group (1) has a structure in which tertiary carbon atoms are bonded to -O-.

The number of carbon atoms of the saturated cyclic hydrocarbon group is preferably 3 to 16.

When R < ^a2 > and R < ^a3 > are bonded to each other, a ring is formed together with the bonding carbon atoms. Examples of the ring include an alicyclic ring and an aromatic ring. A ring having 3 to 12 carbon atoms is preferable. As the -C (R ^a1 ) (R ^a2 ) (R ^a3 ) group when R ^a2 and R ^a3 are bonded to each other and form a ring with the bonding carbon atom, the following groups may be mentioned.

Examples of the acid labile group (1) include 1,1-dialkylalkoxycarbonyl groups (in the formula (1), R ^a1 to R ^a3 are alkyl groups, preferably tert-butoxycarbonyl groups) Adamantyloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 and a carbon atom form an adamantyl group and R ^a3 is an alkyl group) and 1- (1-adamantyl) -1-alkylalkoxycarbonyl group (In the formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group).

An unstable group on the mountain may be the prayer denoted by Eq. (2). Hereinafter, the group represented by the formula (2) may be referred to as a " acid-unstable group (2) ".

(Wherein R ^{a1 '} and R ^a2' each independently represent a hydrogen atom or a hydrocarbon group of 1 to 12 carbon atoms, R ^{a3 '} represents a hydrocarbon group of 1 to 20 carbon atoms, and R ^a2' and R ^{a3 '} May bond together to form a ring containing an oxygen atom having 3 to 20 carbon atoms together with the bonding carbon atom and the bonding oxygen atom, and the hydrocarbon group and -CH ₂ - of the ring may be replaced by -O- or -S - < * > represents a bonding site)

The acid-unstable group (2) has an acetal structure.

Examples of the hydrocarbon group include an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group and an aromatic hydrocarbon group.

It is preferable that at least one of R ^{a1 '} and R ^a2' is a hydrogen atom.

Examples of the acid labile group (2) include the following groups.

The monomer having an acid-unstable group is preferably a (meth) acrylic acid-based monomer having an acid-unstable group and a carbon-carbon double bond-containing monomer, more preferably an acid-unstable group, (Meth) acrylic acid-based monomer having a group (1) or an acid-unstable group (2).

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

Among (meth) acrylic acid monomers having an acid labile group, a (meth) acrylic acid monomer having an acid labile group (1) is preferable, and a saturated cyclic hydrocarbon group having 5 to 20 carbon atoms is more preferable. When a resin obtained by polymerizing a monomer having a bulky structure such as a saturated cyclic hydrocarbon group is used, the resolution of the photoresist pattern can be improved. As the monomer having an acid-unstable group (1), monomers represented by the formula (a1-1) or (a1-2) are particularly preferable. These may be used alone or in combination of two or more.

In formula (a1-1) and formula (a1-2), L ^a1 and L ^a2 each independently represent * -O- or * -O- (CH ₂ ) _k1 -CO-O-, k1 is 1 ≪ / RTI > * Represents a bonding site 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 M1 represents an integer of 0 to 14, n1 represents an integer of 0 to 10, and n2 represents an integer of 0 to 3. The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group of 3 to 10 carbon atoms.

L ^a1 and L ^a2 are preferably * -O- or * -O- (CH ₂ ) _{f 1} -CO-O- (f1 is an integer of 1 to 4), more preferably * -O- .

R ^a4 and R ^a5 are preferably methyl groups. The carbon number of the aliphatic hydrocarbon group of R ^a6 and R ^a7 is preferably 6 or less, and the carbon number of the saturated cyclic hydrocarbon group is preferably 8 or less, more preferably 6 or less. ^Examples of the aliphatic hydrocarbon group represented by R ^a6 and R ^a7 include a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, a 2,2-dimethylethyl group, a propyl group, A methyl group, an ethyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a 1-methylbutyl group, a 2-methylbutyl group, , A heptyl group, a 1-methylheptyl group and an octyl group. ^Examples of the saturated cyclic hydrocarbon group of R ^a6 and R ^a7 include a cycloheptyl group, a methylcycloheptyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a norbornyl group and a methylnorbornyl group.

m1 is preferably an integer of 0 to 3, more preferably 0 or 1. n1 is preferably an integer of 0 to 3, more preferably 0 or 1. n2 is preferably 0 or 1. k1 is preferably an integer of 1 to 4, more preferably 1.

Examples of the monomer represented by the formula (a1-1) include the following monomers.

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.

Examples of the monomer represented by the formula (a1-2) include the following monomers.

Among them, 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 formula (a1-1) or the formula (a1-2) in the resin (A) is usually 10 to 95 mol% based on the total structural units of the resin (A) , Preferably 15 to 90 mol%, and more preferably 20 to 85 mol%.

Examples of the monomer having an acid-unstable group (1) and a carbon-carbon double bond include monomers represented by the formula (a1-3). Resin (A) having a structural unit derived from a monomer represented by formula (a1-3) has a bulky structure, so that the resolution of the photoresist pattern can be improved. Further, the resin (A) having a structural unit derived from a monomer represented by the formula (a1-3) has a norbornane ring rigid in its main chain, so that dry etching resistance of the photoresist pattern is improved.

(Wherein, R ^a9 is a hydrogen atom or a hydroxyl group (having a carbon number of the aliphatic hydrocarbon group of 1 to 3 which may have a -OH), carboxyl group (-COOH), a cyano group or a -COOR ^a13, R ^a13 is An aliphatic hydrocarbon group of 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group of 3 to 20 carbon atoms, the hydrogen atoms of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with a hydroxy group, And -CH ₂ - of the saturated cyclic hydrocarbon group may be substituted with -O- or -CO-. R ^a10 to R ^a12 each independently represent a hydrocarbon group having 1 to 12 carbon atoms An aliphatic hydrocarbon group or an aliphatic hydrocarbon group having 3 to 20 carbon atoms A saturated cyclic hydrocarbon group, or R ^a10 and R ^a11 are bonded to each other to form a ring. 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 - of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by -O- or -CO- Or may be substituted.

^Examples of the aliphatic hydrocarbon group which may have a hydroxy group of R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.

^Examples of R ^a13 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 ^a10 to R ^a12 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 ^a10 and R ^a11 and the carbon to which they are bonded include a cyclohexyl group and an adamantyl group.

Examples of the monomer represented by the formula (a1-3) include tert-butyl 5-norbornene-2-carboxylate, 1-cyclohexyl-1-methylethyl 5-norbornene- Norbornene-2-carboxylic acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene- Norbornene-2-carboxylic acid 1- (4-methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- 1-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 represented by the formula (a1-3) in the resin (A) is generally 10 to 95 mol%, preferably 15 to 90 mol%, based on the total structural units of the resin (A) %, More preferably 20 to 85 mol%.

Examples of the monomer having an acid-unstable group (2) and a carbon-carbon double bond include monomers represented by the formula (a1-4).

(Wherein, R ^a32 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom. R ^a33 are each independently, 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 a methacryloyl group.

and la represents an integer of 0 to 4. R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group of 1 to 12 carbon atoms. X ^a2 represents a monovalent or divalent saturated hydrocarbon group of 1 to 17 carbon atoms, and the hydrogen atom of the saturated hydrocarbon group is preferably a halogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, -O-, -S-, -SO ₂ -, or N ((C ₁ -C 4) alkoxy groups having 2 to 4 carbon atoms or an acyloxy group having 2 to 4 carbon atoms. R ^c ) -. R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Y ^a3 represents an ^{alkyl 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 hydrogen atom of the aliphatic hydrocarbon group, the saturated cyclic hydrocarbon group and the aromatic hydrocarbon group may be substituted with a halogen atom, 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, or an acyloxy group having 2 to 4 carbon atoms)

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 perfluoro a tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a perchloromethyl group, a perboromethyl group and a periodomethyl group.

The alkyl group in R ^a32 and R ^a33 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 in R ^a33 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 groups similar to those exemplified for the aliphatic hydrocarbon and the saturated cyclic hydrocarbon and combinations thereof (for example, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) ), An aromatic hydrocarbon group, and the like.

^Examples of the hydrocarbon group of R ^a34 and R ^a35 include an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a 2- ethylhexyl group, a cyclohexyl group, 2-alkyladamantan-2-yl group, 1- (adamantan-1-yl) alkan-1-yl group and isobornyl group are preferable.

The substituent which X ^a2 and Y ^a3 may have is preferably a hydroxyl group.

The monomer represented by the formula (a1-4) includes, for example, the following monomers.

The content of the structural unit derived from the monomer represented by the formula (a1-4) in the resin (A) is usually 10 to 95 mol%, preferably 15 to 90 mol%, based on the total structural units of the resin (A) %, More preferably 20 to 85 mol%.

Examples of the monomer having an acid-unstable group (2) and a carbon-carbon double bond include monomers represented by the formula (a1-5).

(Wherein R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom, L ³¹ represents -O-, -S- or -O- (CH ₂ ) _{k 1} - CO-O-, k1 is an integer of 1 to 7, and * is a bonding site with -CO- L ³² and L ³³ each independently represent -O- or -S-, Z ¹ represents a single bond or an alkylene group having 1 to 6 carbon atoms, and -CH ₂ - in the alkylene group may be substituted with -O- or -CO-. S 1 and s 2 are each independently 0 to 4 Lt; / RTI >

R ³¹ is preferably a hydrogen atom or a methyl group.

L ³¹ is preferably -O-.

L ³² and L ³³ are preferably one of -O- and the other is -S-.

s1 is preferably 1,

s2 is preferably an integer of 0 to 2.

Z ¹ is preferably a single bond or -CH ₂ -CO-O-.

Specific examples of the monomer represented by the formula (a1-5) include the following monomers.

The content ratio of the structural unit derived from the monomer represented by the formula (a1-5) in the resin (A) is generally 10 to 95 mol%, preferably 15 to 90 mol% based on the total structural units of the resin (A) %, More preferably 20 to 85 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 moles %, More preferably 20 to 60 mol%.

The structural unit derived from a monomer having an adamantyl group (in particular, the monomer (a1-1) having an acid labile group) is preferably 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, the dry etching resistance of the resist is improved.

The acid-stable monomer preferably has a hydroxyl group or a lactone ring. The use of a resin having a structural unit derived from an acid stable monomer containing a hydroxyl group-containing acid stable monomer or a lactone ring can improve the resolution of the photoresist pattern and the adhesion to the substrate.

<Acid-stable monomers having a hydroxy 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 phenolic hydroxy group such as hydroxystyrene as an acid stable monomer having a hydroxy group Is preferably used. When ArF excimer laser exposure (193 nm) or the like with a short wavelength is used, it is preferable to use an acid stable monomer having a hydroxyadamantyl group represented by the formula (a2-1) as the acid stable monomer having a hydroxy group . The acid-stable monomers having a hydroxy group may be used singly or in combination of two or more.

Examples of the monomer having a phenolic hydroxy group include styrene monomers such as p- or m-hydroxystyrene represented by the formula (a2-0).

(Wherein R ^a30 represents an alkyl group having 1 to 6 carbon atoms which may have a hydrogen atom, a halogen atom or a halogen atom, and each R ^a31 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, an acryloyl group or a methacryloyl group, and ma represents an integer of 0 to 4)

In the case of obtaining a copolymer having a structural unit derived from a monomer having a phenolic hydroxy group, a styrene monomer having a phenolic hydroxy group protected by a protecting group and a monomer copolymerizing with the styrene monomer are subjected to radical polymerization, Followed by deprotection by an acid or a base. Examples of the protecting group include an acetyl group, a 1-ethoxyethan-1-yl group and a tert-butoxycarbonyl group.

Examples of the monomer having a phenolic hydroxy group include the following monomers.

Among them, 4-hydroxystyrene or 4-hydroxy-? -Methylstyrene is preferable.

The content of the structural unit derived from the monomer represented by the formula (a2-0) in the resin (A) is usually 5 to 90 mol%, preferably 10 to 85 mol%, based on the total structural units of the resin (A) %, And more preferably from 15 to 80 mol%.

As the acid stable monomer having a hydroxyadamantyl group, a monomer represented by the formula (a2-1) may be mentioned.

( ^Wherein L ^a3 represents -O- or * -O- (CH ₂ ) _{k 2} -CO-O-, * represents a bonding site with -CO-, and k 2 represents an integer of 1 to 7. R ^a14 represents a hydrogen atom or a methyl group. R ^a15 and R ^a16 are each independently, represent a hydrogen atom, a methyl group or hydroxy, respectively. o1 is an integer of 0 to 10)

L ^a3 is preferably -O- or -O- (CH ₂ ) _f1 -CO-O- (f1 is an integer of 1 to 4), more preferably -O-. 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 an integer of 0 to 3, more preferably 0 or 1.

Examples of the monomer represented by the formula (a2-1) include the following monomers. Among them, 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate, and (meth) 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 represented by the formula (a2-1) in the resin (A) is usually 3 to 40 mol%, preferably 5 to 35 mol% based on the total structural units of the resin (A) %, More preferably 5 to 30 mol%, and particularly preferably 5 to 15 mol%.

&Lt; Acid-stable monomers containing a lactone ring >

The lactone ring possessed by the acid-stable monomer may be, for example, a? -Propiolactone ring, a? -Butyrolactone ring, a? -Valerolactone ring or a monocyclic ring, and the ring- It may be a ring. Of these lactone rings, condensation rings of? -Butyrolactone rings and? -Butyrolactone rings with other rings are preferable.

The acid stable monomer having a lactone ring is represented by, for example, formula (a3-1), formula (a3-2), or formula (a3-3). One of these may be used alone, or two or more of them may be used in combination.

In formulas (a3-1) to (a3-3), L ^a4 to L ^a6 each independently represent -O- or * -O- (CH ₂ ) _k3 -CO-O-, * represents -CO -, and k3 represents an integer of 1 to 7. Each of R ^a18 to R ^a20 independently represents a hydrogen atom or a methyl group. R ^a21 is a group having 1 to 4 carbon atoms An aliphatic hydrocarbon group, and p1 represents an integer of 0 to 5. R ^a22 and R ^a23 each independently represent a carboxyl group, a cyano group or a And q1 and r1 each independently represents an integer of 0 to 3;

^Examples of L ^a4 to L ^a6 include those described for L ^a3 . Each of L ^a4 to L ^a6 is preferably independently -O- or -O- (CH ₂ ) _{d 1} -CO-O- (d1 is an integer of 1 to 4), more preferably -O - to be. R ^a18 to R ^a20 are preferably methyl groups. R ^a21 is preferably a methyl group. R ^a22 and R ^a23 Are each independently preferably a carboxyl group, a cyano group or a methyl group. p1 to r1 are each independently preferably 0 to 2, more preferably 0 or 1.

Examples of the monomer represented by the formula (a3-1) include the following monomers.

Examples of the monomer represented by the formula (a3-2) include the following monomers.

Examples of the monomer represented by the formula (a3-3) include the following monomers.

Among the acid-stable monomers having a lactone ring, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan- ² -yloxy) -2-oxoethyl is preferable, and methacrylic acid (5-oxo- 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 ratio of the structural unit derived from the monomer represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3) in the resin (A) Is 5 to 50 mol%, preferably 10 to 45 mol%, and more preferably 15 to 40 mol%. When the resin (A) contains a structural unit derived from an acid stable monomer having a lactone ring, its content is usually 5 to 60 mol%, preferably 15 to 55 mol%, based on the total structural units of the resin (A) Mol%.

The resin (A) may have a structural unit derived from an acid labile monomer having a lactone ring, and examples of the monomer that leads to a structural unit derived from an acid labile monomer having a lactone ring include the following monomers.

<Other acid stable monomers>

Examples of other acid-stable monomers include maleic anhydride represented by the formula (a4-1), itaconic anhydride represented by the formula (a4-2), or a norbornene ring represented by the formula (a4-3) And the like.

In the formula (a4-3)

R ^a25 and R ^a26 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, a cyano group, a carboxy group, or an alkoxycarbonyl group (-COOR ^a27 ), or R ^a25 and R ^a26 are bonded to each other to form -CO-O-CO-, R ^a27 represents a saturated cyclic hydrocarbon having 1 to 18 carbon atoms or an aliphatic hydrocarbon group having a carbon number of 3 to 36, the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon -CH ₂ - in the group may be substituted with -O- or -CO-. Provided that -COOR ^a27 does not become an acid labile group (i.e., R ^a27 does not include that the tertiary carbon atom is bonded to -O-).

^Examples of the aliphatic hydrocarbon group which may have a hydroxy group of R ^a25 and R ^a26 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group and a 2-hydroxyethyl group. The number of carbon atoms of the aliphatic hydrocarbon group of R ^a27 is preferably 1 to 8, more preferably 1 to 6, and the number of carbon atoms of the saturated cyclic hydrocarbon group is preferably 4 to 36, more preferably 4 to 12 . ^{Examples of} R ^a27 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 represented by the formula (a4-3) include 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene- Norbornene-2-carboxylic acid 2-hydroxy-1-ethyl, 5-norbornene-2-methanol and 5-norbornene-2,3-dicarboxylic acid anhydride, .

The content ratio of the structural unit derived from the monomer represented by the formula (a4-1), the formula (a4-2) or the formula (a4-3) in the resin (A) Is usually 2 to 40 mol%, preferably 3 to 30 mol%, and more preferably 5 to 20 mol%.

Other acid-stable monomers include acid-stable monomers having a sultone ring represented by the formula (a4-4).

(Wherein, L ^a7 is -O- or * -O- (CH _{2) k4} represents -CO-O-, k4 represents an integer of from 1-7, * represents a binding site with -CO-. R ^a28 represents a hydrogen atom or a methyl group, and W ¹ represents a sultone ring which may have a substituent)

Examples of the sultone ring include the following rings.

Examples of the substituent that the sultone ring may have include a hydroxyl group, a cyano group, an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, An alkoxycarbonyl group having 1 to 7 carbon atoms, an acyl group having 1 to 7 carbon atoms, and an acyloxy group having 1 to 8 carbon atoms.

Examples of the fluorinated alkyl group include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, , 1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2- A 2,2-tetrafluoroethyl group, a perfluoropropyl group, a 1,1,2,2-tetrafluorobutyl group, a 1,1,2,2,3,3-hexafluorobutyl group, a 1,1,2,2,3,3-hexafluorobutyl group, , 2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoromethyl) -2,2,2-trifluoroethyl group, 2- (Perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4- (Trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, a perfluoropentyl group, a 2- (purple Ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3, A 3,4,4,5,5,6,6-dodecafluorohexyl group, a perfluoropentylmethyl group, and a perfluorohexyl group.

Examples of the hydroxyalkyl group include a hydroxymethyl group, a 2-hydroxyethyl group, a 3-hydroxypropyl group, and a hydroxyisopropyl group.

Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of the monomer having a sultone ring represented by the formula (a4-4) include the following monomers.

The content of the structural unit derived from the monomer represented by the formula (a4-4) in the resin (A) is usually 2 to 40 mol%, preferably 3 to 35 mol% based on the total structural units of the resin (A) %, More preferably 5 to 30 mol%.

Other acid-stable monomers include acid-stable monomers having fluorine atoms.

Examples of the acid-stable monomer having a fluorine atom include the following monomers.

Among them, (meth) acrylic acid 5- (3,3,3-trifluoro-2-hydroxy-2- [trifluoromethyl] propyl) bicyclo [2.2.1] hepto Yl), (meth) acrylic acid 6- (3,3,3-trifluoro-2-hydroxy-2- [trifluoromethyl] propyl) bicyclo [2.2.1] hept- And (meth) acrylic acid 4,4-bis (trifluoromethyl) -3-oxatricyclo [4.2.1.0 ^2,5 ] nonyl are preferable.

The content of the structural unit derived from the acid-stable monomer having a fluorine atom in the resin (A) is usually 1 to 20 mol%, preferably 2 to 15 mol%, based on the total structural units of the resin (A) , And more preferably 3 to 10 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 hydroxy group and / or an acid stable monomer having a lactone ring. In the preferred copolymer, the monomer having an acid labile group is more preferably a monomer having at least one group selected from the group consisting of a monomer represented by the formula (a1-1) and a monomer represented by the formula (a1-2) -1)). The acid-stable monomer having a hydroxy group is preferably a monomer represented by the formula (a2-1). The acid stable monomer having a lactone ring is more preferably at least one kind of a monomer represented by the formula (a3-1) and a monomer represented by the formula (a3-2).

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 particularly preferably 3,500 or more), and 50,000 or less (more preferably 30,000 or less, particularly preferably 10,000 or less). The weight average molecular weight as referred to herein is obtained as a converted value on the basis of standard polystyrene by gel permeation chromatography analysis, and detailed analysis conditions of the analysis will be described in detail in the examples of the present application.

The content of the resin (A) is preferably 80% by mass or more, and more preferably 99% by mass or less, of the solid content of the photoresist composition. In the present specification, &quot; solid content in the composition &quot; means the total of components other than the solvent in the photoresist composition. The solid content in the composition and the content of the resin (A) in the composition can be measured by known analytical means such as liquid chromatography or gas chromatography.

&Lt; Basic compound >

The photoresist composition of the present invention may contain a basic compound. Preferably, the photoresist composition of the present invention contains 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 of a primary amine, a secondary amine and a tertiary amine can be used. The aromatic amine may be an aromatic ring such as aniline, or an aromatic amine such as pyridine. Preferable basic compounds include aromatic amines represented by the formula (C2), particularly anilines represented by the formula (C2-1).

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

Ar represents an aromatic hydrocarbon group.

T ¹ and T ² each independently represent 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 each independently represents 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 be an alkyl group having 1 to 4 carbon atoms Or may be substituted.

The aliphatic hydrocarbon group is preferably a group having 1 to 6 carbon atoms, 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 alkoxy group preferably has 1 to 6 carbon atoms Alkoxy group.

and o represents an integer of 0 to 3.

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 compounds represented by formulas (C3) to (C11).

Among the formulas (C3) to (C11)

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

T ⁴ represents 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, and the alkanoyl group is preferably a group having 2 to 6 carbon atoms.

u represents an integer of 0 to 8;

A is each independently, a divalent aliphatic hydrocarbon group (preferably an alkylene group), -CO-, -C (= NH ) -, -C (= NR 34) -, -S-, -SS- , or their Combination.

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

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

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, But are not limited to, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl There may be mentioned aliphatic amines such as dihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldodecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylenediamine, tetramethylenediamine, tetramethylenediamine, , 4,4'-diamino-1,2-diphenylethane, 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 JP-A-11-52575.

Examples of the compound (C7) include 2,2'-methylenebis aniline.

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) Di (4-pyridyl) ethane, di (2-pyridyl) ketone, 4,4'- Dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridyl amine and 2,2'-dipicolyl amine.

Examples of the compound (C11) include bipyridine.

Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- ( Trifluoromethyl) 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; cyclic esters such as? -butyrolactone; . The solvent may be used alone, or two or more solvents may be used in combination.

&Lt; Other components >

The photoresist composition of the present invention may contain other components as required. Such other components are not limited, and additives known in the photoresist field can be used, for example, a sensitizer, a dissolution inhibiting agent, a surfactant, a stabilizer, a dye and the like.

&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 mixing, the order of mixing is arbitrary and not limited. An appropriate temperature range can be selected depending on the kind of the resin (A) and the like, the solubility in a solvent such as the resin (A), etc., in the range of, for example, 10 to 40 캜. The mixing time can be 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 each mixed in a desired amount, and then a filter having a pore diameter of about 0.2 탆 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 of the present invention 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 photoresist composition may be applied on a substrate by a commonly used apparatus such as a spin coater.

In the step of drying the photoresist composition layer to remove the solvent, the removal of the solvent may be carried out, for example, by evaporating the solvent using a heating apparatus such as a hot plate, or by using a decompression apparatus, The removed photoresist film is formed. 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. Exposure is usually performed 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 Laser, or the like) to radiate a harmonic laser beam in an atomic or vacuum ultraviolet region, an electron beam (EB), extreme ultraviolet light (EUV), or the like.

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 alkaline developer 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 the 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 in a wide range of applications such as microfabrication of semiconductors, production of circuit boards such as liquid crystal, thermal heads, and other photofabrication processes . Particularly, excimer laser lithography such as ArF and KrF and ArF liquid immersion lithography, EB lithography, and electron beam lithography, which can suppress the occurrence of defects and further improve the resolution, shape and line edge roughness of the obtained pattern, Can be used as a chemically amplified photoresist composition suitable for EUV exposure lithography. In addition to immersion exposure, it can also be used in dry exposure.

[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.

In the following examples, the structure of the compound was confirmed by mass analysis (LC: Agilent Model 1100, MASS: Agilent LC / MSD type or LC / MSD TOF type).

The weight average molecular weight is a value obtained by gel permeation chromatography (HLC-8120GPC type, manufactured by TOSO 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)

Example 1: Synthesis of salt represented by formula (B1)

10.60 parts of the compound represented by the formula (B1-a), 26.78 parts of triethylamine and 53.00 parts of acetone were mixed. After the resulting mixture was stirred at 23 占 폚 for 30 minutes, 7.18 parts of the compound represented by the formula (B1-b) was added dropwise over 30 minutes. The resulting mixture was stirred at 23 占 폚 for 12 hours, 159 parts of ethyl acetate and 212 parts of ion-exchanged water were added and stirred, followed by liquid separation. 70.67 parts of a 10% sodium hydroxide aqueous solution was added to the obtained organic layer, followed by stirring and separating. This alkaline washing was carried out three times. 70.67 parts of a 5% oxalic acid aqueous solution was added to the obtained organic layer, and the mixture was stirred and separated. This acid cleaning was carried out three times. 70.67 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out three times. The obtained organic layer was concentrated to obtain 13.54 parts of a compound represented by the formula (B1-c).

13.54 parts of the compound represented by the formula (B1-c), 12.87 parts of triethylamine and 67.70 parts of dichloroethane were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes and then cooled to 0 占 폚. 7.68 parts of the compound represented by the formula (B1-d) was added dropwise to the mixture over 30 minutes. The resulting mixture was stirred at 0 占 폚 for 1 hour, then heated to 23 占 폚, and 67.70 parts of a 10% aqueous sodium hydrogencarbonate solution was added, stirred and separated. This alkaline washing was carried out three times. To the obtained organic layer, 67.70 parts of a 5% oxalic acid aqueous solution was added, stirred, and liquid separated. 67.70 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out five times. The obtained organic layer was concentrated to obtain 14.12 parts of a compound represented by the formula (B1-e).

13.54 parts of the compound represented by the formula (B1-e) and 70.60 parts of acetonitrile were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes, then heated to 70 占 폚, and stirred at 70 占 폚 for 12 hours. After the obtained reaction mixture was cooled to 23 캜, 70.60 parts of ion-exchanged water was added. The resulting mixture was stirred at 23 DEG C for 30 minutes and then concentrated. To the obtained concentrate, 23.53 parts of tert-butyl methyl ether was added, and the mixture was stirred at 23 占 폚 for 30 minutes and separated to obtain an aqueous layer containing a salt represented by the formula (B1-f). 7.89 parts of the compound represented by the formula (B1-g) and 78.85 parts of chloroform were added to the aqueous layer containing the salt represented by the formula (B1-f) and stirred at 23 占 폚 for 5 hours. 23.63 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out five times. 0.78 parts of activated carbon was added to the obtained organic layer, stirred at 23 ° C for 30 minutes, and filtered. The resulting filtrate was concentrated. To the resulting concentrate was added 4.26 parts of acetonitrile, and the resulting solution was concentrated. To the obtained residue, 10.08 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and then concentrated. To the resulting concentrate was added 2.57 parts of acetonitrile, and the resulting solution was concentrated. To the obtained residue, 38.55 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. To the obtained concentrate, 2.08 parts of acetonitrile was added and the resulting solution was concentrated to obtain 2.37 parts of a salt represented by the formula (B1).

MS (ESI (+) Spectrum): M ⁺ 215.1

MS (ESI (-) Spectrum): M ^- 323.0

Example 2: Synthesis of salt represented by formula (B2)

15.37 parts of the compound represented by the formula (B2-a), 26.78 parts of triethylamine and 65.00 parts of acetone were mixed. After the resulting mixture was stirred at 23 占 폚 for 30 minutes, 7.18 parts of the compound represented by the formula (B1-b) was added dropwise over 30 minutes. The resulting mixture was stirred at 23 占 폚 for 12 hours, 159 parts of ethyl acetate and 220 parts of ion-exchanged water were added and stirred, followed by liquid separation. 77.87 parts of a 10% sodium hydroxide aqueous solution was added to the obtained organic layer, followed by stirring and separating. This alkaline washing was carried out three times. 77.87 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer, followed by stirring and separating. This acid cleaning was carried out three times. 77.87 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out three times. The obtained organic layer was concentrated to obtain 17.89 parts of a compound represented by the formula (B2-c).

17.74 parts of the compound represented by the formula (B2-c), 12.87 parts of triethylamine and 80.00 parts of dichloroethane were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes and then cooled to 0 占 폚. 7.68 parts of the compound represented by the formula (B1-d) was added dropwise to the mixture over 30 minutes. The resulting mixture was stirred at 0 占 폚 for 1 hour, then heated to 23 占 폚, and 67.70 parts of a 10% aqueous sodium hydrogencarbonate solution was added, stirred and separated. This alkaline washing was carried out three times. 80.00 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer, stirred, and separated. 80.00 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred and separated. This water washing was carried out three times. The obtained organic layer was concentrated to obtain 17.89 parts of a compound represented by the formula (B2-e).

16.69 parts of the compound represented by the formula (B2-e) and 75.00 parts of acetonitrile were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes, then heated to 70 占 폚, and stirred at 70 占 폚 for 12 hours. After the obtained reaction mixture was cooled to 23 캜, 75.00 parts of ion-exchanged water was added. The resulting mixture was stirred at 23 DEG C for 30 minutes and then concentrated. To the resulting concentrate, 25.48 parts of tert-butyl methyl ether was added. The resulting mixture was stirred at 23 占 폚 for 30 minutes and then separated to obtain an aqueous layer containing a salt represented by the formula (B2-f). To the water layer containing the salt represented by the formula (B2-f), 8.26 parts of the compound represented by the formula (B2-g) and 80.00 parts of chloroform were added. The resultant mixture was stirred at 23 占 폚 for 5 hours and separated. 25.00 parts of ion-exchanged water was added to the obtained organic layer, stirred, and liquid separated. This water rinse was performed eight times. 0.50 parts of activated carbon was added to the obtained organic layer, stirred at 23 ° C for 30 minutes, and filtered. The resulting filtrate was concentrated. To the obtained concentrate, 3.50 parts of acetonitrile was added, and the resulting solution was concentrated. To the obtained residue, 8.72 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. To the obtained concentrate, 2.20 parts of acetonitrile was added, and the resulting solution was concentrated. To the obtained residue, 32.80 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. To the obtained concentrate, 2.00 parts of acetonitrile was added, and the obtained solution was concentrated to obtain 1.18 parts of a salt represented by the formula (B2).

MS (ESI (+) Spectrum): M ⁺ 287.2

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

Example 3: Synthesis of salt represented by formula (B2)

18.72 parts of the compound represented by the formula (B2-a), 23.90 parts of the compound represented by the formula (B2-b), 17.95 parts of potassium carbonate and 93.62 parts of acetone were mixed. The resulting mixture was refluxed at 55 캜 for 22 hours and then concentrated. 119.36 parts of ethyl acetate and 35.81 parts of 10% aqueous sodium hydroxide solution were added to the resulting concentrate, stirred, and liquid separated. This alkaline washing was carried out twice. 35.81 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out four times. The resulting organic layer was concentrated, and the obtained concentrate was collected by column (silica gel, 60-200 mesh developing solvent: heptane, Merck) to obtain 17.04 parts of a compound represented by the formula (B2-c).

To 3.2.29 parts of methanesulfonic acid was added 3.23 parts of 2-pentoxide. The resulting mixture was stirred at 23 占 폚 for 30 minutes. To the obtained mixture, 13.02 parts of the compound represented by the formula (B2-c) was added. After the obtained mixture was cooled to 0 占 폚, 7.79 parts of the compound represented by the formula (B2-d) was added dropwise over 30 minutes. The resulting mixture was stirred at 0 占 폚 for 1 hour, 335.50 parts of ion-exchanged water was added, and then 23.57 parts of 28% ammonia water was added to neutralize the mixture. To the obtained reaction mixture, 100.65 parts of tert-butyl methyl ether was added and stirred, followed by liquid separation. This washing was carried out three times to obtain an aqueous layer containing a salt represented by the formula (B2-e). To the water layer containing the salt represented by the formula (B2-e), 11.80 parts of the compound represented by the formula (B2-f) and 353.24 parts of chloroform were added. The resultant mixture was stirred at 23 占 폚 for 12 hours and separated. 105.97 parts of ion-exchanged water was added to the obtained organic layer, stirred, and liquid separated. This water washing was carried out six times. 3.40 parts of activated carbon was added to the obtained organic layer, stirred at 23 DEG C for 30 minutes, filtered and the filtrate was concentrated. To the obtained residue, 82.30 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. 30 parts of acetonitrile was added to the resulting concentrate, and the resulting solution was concentrated. To the obtained residue, 59.85 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. 10 parts of acetonitrile was added to the obtained concentrate, and the obtained solution was concentrated to obtain 14.98 parts of a salt represented by the formula (B2).

MS (ESI (+) Spectrum): M ⁺ 287.2

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

Example 4: Synthesis of salt represented by formula (B3)

5.00 parts of the compound represented by the formula (B3-a), 12.63 parts of triethylamine and 16.00 parts of acetone were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes, and 3.83 parts of the compound represented by the formula (B3-b) was added dropwise over 30 minutes. The resultant mixture was stirred at 23 占 폚 for 12 hours, 45 parts of ethyl acetate and 60 parts of ion-exchanged water were added and the mixture was separated by stirring. 20 parts of a 10% aqueous solution of sodium hydroxide was added to the obtained organic layer, followed by stirring and separating. 20 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer, stirred, and liquid separated. This acid cleaning was carried out three times. 20 parts of ion-exchanged water was added to the obtained organic layer, stirred, and liquid separation was performed. This water washing was carried out three times. The obtained organic layer was concentrated to obtain 7.76 parts of a compound represented by the formula (B3-c).

7.50 parts of the compound represented by the formula (B3-c), 6.78 parts of triethylamine and 37.50 parts of dichloroethane were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes, cooled to 0 占 폚 and 4.01 parts of a compound represented by the formula (B3-d) was added dropwise over 30 minutes. The resulting mixture was stirred at 0 占 폚 for 1 hour, then heated to 23 占 폚, and 37.50 parts of a 10% aqueous sodium hydrogencarbonate solution was added, stirred, and liquid separated. This alkaline washing was carried out three times. 37.50 parts of 5% oxalic acid aqueous solution was added to the obtained organic layer, followed by stirring and separating. 37.50 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out five times. The obtained organic layer was concentrated to obtain 8.63 parts of a compound represented by the formula (B3-e).

8.50 parts of the compound represented by the formula (B3-e) and 42.50 parts of acetonitrile were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes, then heated to 70 占 폚, and stirred at 70 占 폚 for 12 hours. After the obtained reaction mixture was cooled to 23 캜, 42.50 parts of ion-exchanged water was added. The resulting mixture was stirred at 23 DEG C for 30 minutes and then concentrated. To the obtained concentrate, 14.17 parts of tert-butyl methyl ether was added. The resulting mixture was stirred at 23 캜 for 30 minutes and then separated to obtain an aqueous layer containing a salt represented by the formula (B3-f). To the aqueous layer containing the salt represented by the formula (B3-f), 4.54 parts of the compound represented by the formula (B3-g) and 45.36 parts of chloroform were added. The resultant mixture was stirred at 23 占 폚 for 5 hours and separated. 13.61 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out five times. 0.50 parts of activated carbon was added to the obtained organic layer, stirred at 23 ° C for 30 minutes, and filtered. The obtained filtrate was concentrated, and 3.12 parts of acetonitrile was added to the obtained concentrate to dissolve and concentrate. To the obtained residue, 7.24 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. To the obtained concentrate, 2.25 parts of acetonitrile was added, and the resulting solution was concentrated. To the obtained residue, 30.08 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. 10 parts of acetonitrile was added to the obtained concentrate, and the resulting solution was concentrated to obtain 2.18 parts of a salt represented by the formula (B3).

MS (ESI (+) Spectrum): M ⁺ 229.1

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

Example 5: Synthesis of salt represented by formula (B4)

18.72 parts of the compound represented by the formula (B4-a), 90 parts of the compound represented by the formula (B4-b), 17.95 parts of potassium carbonate and 93.62 parts of acetone were mixed. The resulting mixture was refluxed at 55 캜 for 22 hours and then concentrated. 119.36 parts of ethyl acetate and 35.81 parts of 10% aqueous sodium hydroxide solution were added to the resulting concentrate, stirred, and liquid separated. This alkaline washing was carried out twice. 35.81 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out four times. The obtained organic layer was concentrated, and then the resulting concentrate was collected from a column (silica gel, manufactured by Merck & Co., Inc., 60-200 mesh developing solvent: heptane) to obtain 17.04 parts of a compound represented by the formula (B4-c).

To 3.2.29 parts of methanesulfonic acid was added 3.23 parts of 2-pentoxide. The resulting mixture was stirred at 23 占 폚 for 30 minutes. To the obtained mixture, 13.02 parts of the compound represented by the formula (B4-c) was added. After the obtained mixture was cooled to 0 占 폚, 7.79 parts of the compound represented by the formula (B4-d) was added dropwise over 30 minutes. The resulting mixture was stirred at 0 占 폚 for 1 hour, 335.50 parts of ion-exchanged water was added, and then 23.57 parts of 28% ammonia water was added to neutralize the mixture. To the obtained reaction mixture, 100.65 parts of tert-butyl methyl ether was added and stirred, followed by liquid separation. This washing was carried out three times to obtain an aqueous layer containing a salt represented by the formula (B4-e). To the water layer containing the salt represented by the formula (B4-e), 11.28 parts of the compound represented by the formula (B4-f) and 337.60 parts of chloroform were added. The resultant mixture was stirred at 23 占 폚 for 12 hours and separated. 101.28 parts of ion-exchanged water was added to the obtained organic layer, followed by stirring and separating. This water washing was carried out six times. 3.20 parts of activated carbon was added to the obtained organic layer, stirred at 23 ° C for 30 minutes, and filtered. The resulting filtrate was concentrated, and 80.70 parts of tert-butyl methyl ether was added to the obtained residue. The mixture was stirred, and the supernatant was removed and concentrated. 30 parts of acetonitrile was added to the resulting concentrate, and the resulting solution was concentrated. To the obtained residue, 58.71 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. 10 parts of acetonitrile was added to the obtained concentrate, and the obtained solution was concentrated to obtain 14.74 parts of a salt represented by the formula (B4).

MS (ESI (+) Spectrum): M ⁺ 287.2

MS (ESI (-) Spectrum): M ^- 323.0

Example 6: Synthesis of salt represented by formula (B5)

13.54 parts of the compound represented by the formula (B1-e) and 70.60 parts of acetonitrile were mixed. The resulting mixture was stirred at 23 占 폚 for 30 minutes, then heated to 7 占 폚, and stirred at 70 占 폚 for 12 hours. After the obtained reaction mixture was cooled to 23 캜, 70.60 parts of ion-exchanged water was added. The resulting mixture was stirred at 23 DEG C for 30 minutes and then concentrated. To the obtained concentrate, 23.53 parts of tert-butyl methyl ether was added and the mixture was stirred at 23 占 폚 for 30 minutes and separated to obtain an aqueous layer containing the salt represented by the formula (B1-f). 8.26 parts of the compound represented by the formula (B2-g) and 80.00 parts of chloroform were added to the aqueous layer containing the salt represented by the formula (B1-f). The resultant mixture was stirred at 23 占 폚 for 5 hours and separated. 25.00 parts of ion-exchanged water was added to the obtained organic layer, stirred, and liquid separated. This water washing was carried out five times. 0.50 parts of activated carbon was added to the obtained organic layer, stirred at 23 ° C for 30 minutes, and filtered. The resulting filtrate was concentrated, 5.00 parts of acetonitrile was added to the resulting concentrate, and the resulting solution was concentrated. To the obtained residue, 10 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. 2.50 parts of acetonitrile was added to the resulting concentrate, and the resulting solution was concentrated. To the obtained residue, 35.83 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed and concentrated. To the obtained concentrate, 2.00 parts of acetonitrile was added, and the resulting solution was concentrated to obtain 2.37 parts of a salt represented by the formula (B5).

MS (ESI (+) Spectrum): M ⁺ 215.1

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

The monomer used in the following Synthesis Examples is a monomer represented by the following formula (A) (hereinafter abbreviated as monomer (A)), a monomer represented by formula (B) (hereinafter abbreviated as monomer (B) A monomer represented by the following formula (C) (hereinafter abbreviated as a monomer (C)), a monomer represented by the following formula (D) (hereinafter abbreviated as a monomer (D) (Hereinafter abbreviated as monomer (E)), a monomer represented by formula (F) (hereinafter abbreviated as monomer (F)) and a monomer represented by formula (G) .

&Lt; Synthesis Example 1: Synthesis of Resin A1 >

The monomer (A), the monomer (E), the monomer (B), the monomer (C) and the monomer (D) D) was 30: 14: 6: 20: 30. Then, 1.5 times by mass of dioxane based on the total mass of the total monomers was added to the monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added at a ratio of 1.00 mol% and 3.00 mol% to the total molar amount of the total monomers, respectively. The resulting mixture was heated at 75 占 폚 for about 5 hours. Thereafter, the reaction mixture was poured into a mixed solvent (4: 1) of a large amount of methanol and water, and the resulting copolymer was precipitated. The precipitated copolymer was taken out and purified by pouring into a large amount of a mixed solvent of methanol and water (4: 1) three times to obtain a copolymer having a weight average molecular weight of about 7.2 x 10 ³ in a yield of 78%. This copolymer has a structural unit of the following formula, which is referred to as Resin A1.

&Lt; Synthesis Example 2: Synthesis of Resin A2 >

The monomer (A), the monomer (B) and the monomer (C) were mixed at a molar ratio (monomer (A): monomer (B): monomer (C)) of 50:25:25. Then, 1.5 times by mass of dioxane based on the total mass of the total monomers was added to the monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added at a ratio of 1 mol% and 3 mol%, respectively, to the total molar amount of the total monomers. The resulting mixture was heated at 80 占 폚 for about 8 hours. Thereafter, the reaction mixture was poured into a mixed solvent (3: 1) with a large amount of methanol and water, and the resulting copolymer was precipitated. The precipitated copolymer was taken out and purified by pouring 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 of the following formula, which is referred to as Resin A2.

&Lt; Synthesis Example 3: Synthesis of Resin A3 >

The monomer (F) and the monomer (G) were mixed at a molar ratio (monomer (F): monomer (G)) of 41:95. Then, 1.5 times by mass of dioxane based on the total mass of the total monomers was added to the monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added at a ratio of 1 mol% and 3 mol%, respectively, to the total molar amount of the total monomers. The resulting mixture was heated at 70 DEG C for about 8 hours. Thereafter, the reaction mixture was poured into a mixed solvent (3: 1) with a large amount of methanol and water, and the resulting copolymer was precipitated. The precipitated copolymer was taken out and purified by pouring 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 9.5 × 10 ³ in a yield of 58%. This copolymer has a structural unit of the following formula, which is referred to as Resin A3.

(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 a fluororesin having a pore size of 0.2 mu m to prepare a photoresist composition.

<Resin>

Resins A1, A2, A3

<Acid Generator>

B1: a salt represented by the formula (B1)

B2: a salt represented by the formula (B2)

B3: a salt represented by the formula (B3)

B4: a salt represented by the formula (B4)

B5: a salt represented by the formula (B5)

X1: a salt represented by the formula (X1)

X2: a salt represented by the formula (X2)

&Lt; Basic compound: Querche &

C1: 2,6-diisopropylaniline

<Solvent>

Propylene glycol monomethyl ether acetate 265 parts

2-heptanone 20.0 parts

Propylene glycol monomethyl ether 20.0 parts

? -butyrolactone? 3.5 parts

(Evaluation of photoresist composition for immersion exposure)

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 at 205 deg. C for 60 seconds to form an organic antireflection film having a thickness of 780 nm.

Subsequently, the photoresist composition prepared above was spin-coated on the formed organic anti-reflection film so that the film thickness after drying was 110 nm.

The obtained silicon wafer was pre-baked on a direct hot plate at a temperature indicated in the column of &quot; PB &quot; in Table 1 for 60 seconds. The wafer on which the photoresist film (photoresist composition layer) was formed in this manner was immersed in an ArF excimer stepper for liquid immersion lithography (XT: 1900Gi; The line and space pattern was subjected to liquid immersion lithography by changing the exposure amount step by step using NA = 1.35, 2-poles on axis illumination (σout = 0.97, σin = 0.77, Y polarization) manufactured by ASML.

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

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

Effective sensitivity: In each photoresist film, an exposure amount at which a 50 nm line and space pattern becomes 1: 1 is defined as an effective sensitivity.

Evaluation of focus margin (DOF): In terms of effective sensitivity, the focus distance was changed stepwise to form a photoresist pattern. The photoresist pattern (line pattern) obtained had a line width of 50 nm +/- 5% To 52.5 nm) was defined as a linewidth index (DOF).

When the DOF exceeded 0.17 mu m, the DOF was evaluated to be very good and expressed as &amp; cir &amp; A DOF of more than 0.14 탆 and not more than 0.17 탆 was rated as good by DOF. A DOF of more than 0.09 탆 and not more than 0.14 탆 was evaluated as normal and indicated by ∘. When the DOF was less than 0.09 탆, the DOF was evaluated as poor, and the result was indicated by x.

The numerical values in parentheses in the DOF column in Table 2 are values of the obtained DOF.

Evaluation of mask error factor (MEF): A mask having a mask size (line width) of 48 nm, 50 nm, and 52 nm (100 nm in pitch) was used for the effective sensitivity to form a photoresist pattern. The results are plotted in a graph in which the mask size is plotted on the abscissa and the line width of the photoresist pattern (line pattern) formed by using the mask of each mask size is taken as the ordinate. The slope of the regression line obtained from the plotted result was 2.3 or less, and the MEF was evaluated as being very good and indicated as? The MEF having a slope of more than 2.3 and less than or equal to 2.5 was rated as good and indicated as?. MEFs rated to have a slope greater than 2.5 and less than or equal to 3.0 were rated moderate and indicated by a circle. It was evaluated that the MEF exceeded the slope of 3.0, indicating that the MEF was poor and indicated by x.

The values in parentheses in the MEF column in Table 2 are the values of the obtained MEF.

The mask size refers to the size of the pattern transferred onto the substrate by exposure and is not the size of the light transmitting portion formed on the mask.

The results are shown in Table 2.

A photoresist composition containing the salt of the present invention provides a photoresist pattern exhibiting an excellent mask error factor (MEF).

Claims (7)

delete delete delete Formula (I):

(Wherein R ¹ and R ² each independently represent a hydroxyl group (-OH) or an alkyl group having 1 to 12 carbon atoms, and -CH ₂ - contained in the alkyl group is substituted with -O- or -CO- .
R ³ represents an alkyl group having 1 to 6 carbon atoms.
l, m and n each independently represent an integer of 0 to 3;
p represents an integer of 1 to 3;
-CH ₂ - contained in the sulfur heterocyclic ring containing S ⁺ may be substituted with -O- or -CO-.
R ⁴ and R ⁵ each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ¹ represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.
Y represents an aliphatic hydrocarbon group of 1 to 18 carbon atoms which may have a hydroxyl group or a saturated cyclic hydrocarbon group of 3 to 18 carbon atoms which may have a hydroxyl group or an alkyl group of 1 to 4 carbon atoms and the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group -CH ₂ - contained in the hydrocarbon group may be substituted with -O-, -SO ₂ - or -CO-) with a salt represented by the following formula (B1-1), (B1-2) (B1-14), (B1-6), (B1-11), (B1-12), (B1-13) and , And the content of the salt represented by the formula (I) is 30 parts by mass or more and 70 parts by mass or less based on 100 parts by mass of the acid generator.

4. A photoresist composition comprising the acid generator according to claim 4 and a resin which is insoluble or sparingly soluble in an aqueous alkali solution and has an acid labile group and is soluble in an alkali aqueous solution by the action of an acid. 6. The method of claim 5,
Further, a photoresist composition containing a basic compound. (1) A process for forming a photoresist composition layer by applying the photoresist composition according to any one of claims 5 to 6 on a substrate,
(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,
Wherein the photoresist pattern is a photoresist pattern.