KR20110052478A - Salts and photoresist compositions - Google Patents

Abstract

PURPOSE: Salts are provided to enable use as a photoacid generator and to obtain photoresist patterns with excellent shape and line edge roughness. CONSTITUTION: Salts are represented by chemical formula I. In chemical formula I, Q^1 and Q^2 are independently fluorine atom or C1-6 perfluoroalkyl group; L^1 is a single bond or substituted or unsubstituted divalent C1-17 saturated hydrocarbon; Y^1 is (m+1)-valent C3-18 saturated cyclic hydrocarbon, wherein at least one -CH2- included in the saturated cyclic hydrocarbon group may be substituted with -O-, -CO- or SO2-; X^1 is C1-12 aliphatic hydrocarbon radical having at least one fluorine element; m is 1 or 2; and Z^+ is organic counter ions.

Description

Salts and photoresist compositions

The present invention relates to salts and photoresist compositions comprising them.

The photoresist composition used for the microfabrication of a semiconductor using lithography technique contains a salt for an acid generator.

Japanese Patent Laid-Open No. 2006-257078 describes triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate as a salt for an acid generator.

The present invention,

[1] salts of formula (I);

Formula I

In Formula I above,

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

L ¹ is a divalent C1-C17 saturated hydrocarbon group which may have a single bond or a substituent, at least one -CH ₂ -contained in the saturated hydrocarbon group may be substituted with -O- or CO-,

Y ¹ is a (m + 1) valence saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, and one or more -CH ₂ -included in the saturated cyclic hydrocarbon group may be substituted with -O-, -CO-, or SO _2- . ,

X ¹ is an aliphatic hydrocarbon group having 1 to 12 carbon atoms having at least one fluorine atom, and one or more hydrogen atoms contained in the aliphatic hydrocarbon group may be substituted with a hydroxyl group,

m is 1 or 2,

Z ⁺ is an organic counterion.

[2] The above item [1], wherein L ¹ is * -CO-OL ^2- , wherein L ² is a single bond or an alkylene group having 1 to 15 carbon atoms, and * is -C (Q ¹ ) (Q ² ) -Binding site);

[3] the salt according to the above item [1] or [2], wherein Y ¹ is a group derived from a cyclohexane ring, a norbornane ring or an adamantane ring;

[4] The salt according to any one of the above items [1] to [3], wherein X ¹ is a group of the formula (Ix);

Formula Ix

In Formula Ix above,

n is 0 or 1;

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

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

[7] A resin containing an acid generator and a resin according to item [6], wherein the resin has a group that is unstable with an acid, insoluble or poorly soluble in an aqueous alkali solution, and soluble in an aqueous alkaline solution by the action of an acid. , Photoresist compositions;

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

[9] (1) a step of forming a photoresist composition layer by applying the photoresist composition according to item [7] or [8] on a substrate;

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

(3) exposing the photoresist film;

(4) heating the photoresist film after exposure, and

(5) a method for producing a photoresist pattern, including a step of developing a photoresist film after heating; And so on.

The salt of the present invention can be used as an acid generator for a photoresist composition, and by using the photoresist composition containing the salt, there are few defects and a photoresist having excellent shape and line edge roughness. A pattern can be obtained.

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

Formula I

In Formula I above,

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

L ¹ is a divalent C1-C17 saturated hydrocarbon group which may have a single bond or a substituent, at least one -CH ₂ -contained in the saturated hydrocarbon group may be substituted with -O- or CO-,

Y ¹ is a (m + 1) valence saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, and one or more -CH ₂ -included in the saturated cyclic hydrocarbon group may be substituted with -O-, -CO-, or SO _2- . ,

X ¹ is an aliphatic hydrocarbon group having 1 to 12 carbon atoms having at least one fluorine atom, at least one hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxyl group,

m is 1 or 2,

Z ⁺ is an organic counterion.

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 perfluorosecondary-butyl group, Perfluoro tert- butyl group, a perfluoro pentyl group, and a perfluorohexyl group are mentioned.

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

As a divalent C1-C17 saturated hydrocarbon group, a C1-C17 linear alkylene group, a C3-C17 branched alkylene group, and a C3-C17 divalent monocyclic or polycyclic saturated cyclic hydrocarbon group are mentioned. have.

Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1, 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl Linear alkylene groups having 1 to 17 carbon atoms such as heptadecane-1,17-diyl group;

1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, 2- C3-C17 branched alkylene groups, such as a methyl butane-1, 4- diyl group;

Monocyclic saturation such as cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group and cyclooctane-1,5-diyl group Cyclic hydrocarbon groups;

Polycyclic saturated cyclic hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group group; And groups formed by combining two or more kinds of these groups.

The divalent C1-C17 saturated hydrocarbon group may have a substituent, and halogen atoms, such as a fluorine atom, are mentioned as said substituent. In addition, one or more -CH ₂ -contained in the saturated hydrocarbon group may be substituted with -O- or CO-.

Specific examples of the group in which one or more -CH ₂ -included in the saturated hydrocarbon group are substituted with -O- or CO- include the formula IL-1, the formula IL-2, the formula IL-3, the formula IL-4, and the formula IL -5 and a group of formula IL-6, and groups of formula IL-1, formula IL-2, formula IL-3 or formula IL-4 are preferred, and groups of formula IL-1 or formula IL-2 are more preferred. Do.

Formula IL-1

Formula IL-2

Formula IL-3

Formula IL-4

Formula IL-5

Formula IL-6

In the above formula IL-1 to IL-6,

L ² is a single bond or an alkylene group having 1 to 15 carbon atoms,

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

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

L ⁵ is an alkylene group having 1 to 15 carbon atoms,

L ⁶ and L ⁷ are each independently an alkylene group having 1 to 15 carbon atoms, provided that the sum of carbon atoms of L ⁶ and L ⁷ is 16 or less,

L ⁸ is an alkylene group having 1 to 14 carbon atoms,

L ⁹ and L ¹⁰ are each independently an alkylene group having 1 to 11 carbon atoms, provided that the sum of the carbon numbers of L ⁶ and L ⁷ is 12 or less,

** is the binding site with -C (Q ¹ ) (Q ² )-.

Of these, groups of formula IL-1 are preferred, and groups of formula IL-1 wherein L ² is a single bond or CH ₂ — are more preferred.

Examples of the group represented by the formula IL-1 include the following groups.

Examples of the group represented by the formula IL-2 include the following groups.

Examples of the group represented by the formula IL-3 include the following groups.

Examples of the group represented by the formula IL-4 include the following groups.

Examples of the group represented by the formula IL-5 include the following groups.

Examples of the group represented by the formula IL-6 include the following groups.

In particular, the L ¹ ** - CO-O - is preferably - (** ^{are, -C (Q 1) (Q} 2) is the binding site of the).

As Y <^1> , group formed by the (m + 1) hydrogen atom of arbitrary positions becomes a coupling | bonding site | part from the ring of general formula Y1-Y27.

It is preferable that the (m + 1) valent saturated cyclic hydrocarbon group is a group formed by (m + 1) hydrogen atoms contained in any one of the formulas Y1 to Y19 being a bonding site, and are represented by the formulas Y4, Y9 or More preferably, (m + 1) hydrogen atoms contained in the ring of Y11 are formed by being a bonding site, and (m + 1) hydrogen atoms contained in the ring of Formula Y4, Y9 or Y11 It is especially preferable that it is the group formed by making.

As a group in which one or more -CH ₂ -contained in a (m + 1) valent saturated cyclic hydrocarbon group is substituted with -O-, -CO- or SO _2- , a group having a cyclic ether structure (-CH ₂ -is- the group substituted with O-), cyclic saturated hydrocarbon group having an oxo group (-CH ₂ - is substituted with a group -CO-), sultone ventilation (-CH ₂ -CH ₂ - one of the -CH ₂ - is - O- which is substituted by the other side of the -CH ₂ - is -SO ₂ - group which is substituted with a) and lactone ventilation (-CH ₂ -CH ₂ - one of the -CH ₂ - is replaced by -O- other Group in which -CH ₂ -is substituted with -CO-.

As a substituent of the (m + 1) valent saturated cyclic hydrocarbon group, a halogen atom, a hydroxyl group, a carboxyl group, a C6-C18 aromatic hydrocarbon group, a C7-C21 aralkyl group, a C2-C4 acyl group, and glycy And dialkyl groups. As a halogen atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned. As an aromatic hydrocarbon group, a phenyl group, a naphthyl group, anthranyl group, p-methylphenyl group, p-tert- butylphenyl group, p-adamantylphenyl group; And aryl groups such as tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, anthryl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group and naphthylethyl group. As an acyl group, an acetyl group, a propionyl group, and a butyryl group are mentioned.

Examples of the aliphatic hydrocarbon group having 1 to 12 carbon atoms having at least one fluorine atom include methyl group, ethyl group, 1-methylethyl group, 1,1-dimethylethyl group, 2,2-dimethylethyl group, propyl group, 1-methylpropyl group and 2 , 2-dimethylpropyl group, 1-ethylpropyl group, butyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-propylbutyl group, pentyl group, 1-methylpentyl group, hex Carbon number, such as a real group, a 1, 4- dimethylhexyl group, a heptyl group, a 1-methylheptyl group, an octyl group, a methyl octyl group, a methyl nonyl group, 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group And groups in which one or more hydrogen atoms of the alkyl groups of 1 to 12 are substituted with fluorine atoms.

It is preferable that the one or more hydrogen atoms contained in the said aliphatic hydrocarbon group may be substituted by the hydroxyl group, and the one hydrogen atom contained in the said aliphatic hydrocarbon group is substituted by the hydroxyl group.

Hydrogen atoms may be substituted with a fluorine atom in - a concrete example, there may be mentioned a group of the formula Ix, Ix in the formula, when n is 1, -CH _2.

Formula Ix

In Formula Ix above,

n is 0 or 1;

The salt of the formula (I) preferably has an anion of the formula (Ia-1), (Ia-2), (Ia-3) or (Ia-4).

Formula Ia-1

Formula Ia-2

Formula Ia-3

Formula Ia-4

In Chemical Formulas Ia-1 to Ia-4 above,

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

Examples of Z ⁺ include onium cations such as sulfonium cations, iodonium cations, ammonium cations, benzothiazolium cations and phosphonium cations, and sulfonium cations and iodonium cations are preferred, and triarylsulfonium cations are more preferred. Do.

Z ⁺ is preferably a cation of any one of formulas Iz-1 to Iz-4.

Chemical Formula Iz-1

Chemical Formula Iz-2

Chemical Formula Iz-3

Chemical Formula Iz-4

In Formula Iz-1 above,

P ^a to P ^c are each independently an aliphatic hydrocarbon group having 1 to 30 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aliphatic hydrocarbon group is a hydroxyl group and 1 to 12 carbon atoms. May be substituted with an alkoxy group or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the saturated cyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the aromatic hydrocarbon group may be a halogen atom or a hydroxyl group. It may be substituted by the actual group, a C1-C36 aliphatic hydrocarbon group, a C3-C36 saturated cyclic hydrocarbon group, or a C1-C12 alkoxy group.

In Formula Iz-2 above,

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

i and j are each independently an integer of 0-5.

In Formula Iz-3 above,

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

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

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

P ⁹ is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aromatic hydrocarbon group is an aliphatic hydrocarbon group having 1 to 12 carbon atoms and 1 to 12 carbon atoms. May be substituted with an alkoxy group, a saturated C3-C18 cyclic hydrocarbon group or an alkylcarbonyloxy group, and P ⁶ and P ⁷ and P ⁸ and P ⁹ are each independently bonded to each other to form a three to 12 membered ring, preferably Preferably, 3- to 7-membered rings may be formed, and one or more -CH ₂ -contained in these rings may be substituted with -O-, -S-, -CO-.

In Formula Iz-4 above,

P ¹⁰ to P ¹⁵ are each independently a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms,

E is -S- or O-,

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

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

q is 0 or 1,

When p, r, x, y, v and w are two or more, some P <^10> -P <^15> may mutually be same or different, respectively.

In formulas (Iz-1) to (Iz-4), preferred aliphatic hydrocarbon groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, secondary-butyl, tert-butyl, pentyl and hex. It is a real group, an octyl group, and 2-ethylhexyl group.

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

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

A benzyl group etc. are mentioned as an aliphatic hydrocarbon group (aralkyl group) whose substituent is an aromatic hydrocarbon group.

As an alkoxy group, a methoxy group, an ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, secondary-butoxy group, tert-butoxy group, n-pentoxy group, n-hexoxy group, heptoxy group , Octoxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and dodecyloxy group.

Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, 1-methylethylcarbonyloxy group, 1,1-dimethylethylcarbonyloxy group, 2,2-dimethylethylcarbonyloxy group, propylcarbonyloxy group, 1 -Methylpropylcarbonyloxy group, 2,2-dimethylpropylcarbonyloxy group, 1-ethylpropylcarbonyloxy group, butylcarbonyloxy group, 1-methylbutylcarbonyloxy group and 2-methylbutylcarbonyloxy group.

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

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

Among these, the cation of general formula (Iz-1) is preferable and the cation of general formula (Iz-5) is more preferable.

Chemical Formula Iz-5

In the above formula Iz-5,

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

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

The aliphatic hydrocarbon group may be substituted with a hydroxyl group, a C1-C12 alkoxy group, or a C6-C18 aromatic hydrocarbon group. The saturated cyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group.

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

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

In particular, triphenylsulfonium cation (in formula Iz-5, z1, z2 and z3 are 0) is preferred.

As a cation of general formula (Iz-1), the following are mentioned.

As a cation of general formula (Iz-2), the following are mentioned.

As a cation of general formula (Iz-3), the following are mentioned.

As a cation of general formula (Iz-4), the following are mentioned.

The salt of the formula (I) may arbitrarily combine the above anions and organic cations. Among these, the salts of the following formulas (I-1), (I-2), (I-3) and (I-4) are preferred.

Formula I-1

Formula I-2

Formula I-3

Formula I-4

In the above formulas (I-1) to (I-4),

P ¹⁹ to P ²¹ , Q ¹ , Q ² , z ¹ , z ² and z 3 are the same as defined above.

More preferable are salts of the following formulas (I-5), (I-6), (I-7) and (I-8).

Formula I-5

Formula I-6

Formula I-7

Formula I-8

In the above formulas (I-5) to (I-8),

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

Salts of the formula (I) can be produced, for example, by a production method represented by the following scheme. In addition, in the following reaction formula, the definition of each substituent shows the same meaning as the above-mentioned unless it mentions specially.

Salts of formula (Ib), wherein L ¹ is -CO-O-, for example, the compound of formula (1) is hydrolyzed under basic conditions in a solvent to give a compound of formula (2), and the obtained compound of formula (2) The salt of general formula (3) can be manufactured by dehydration condensation.

Here, a commercial item can be used for the compound of General formula (1). Moreover, it can also manufacture using the method as described in Unexamined-Japanese-Patent No. 2003-40840, 2004-83900, etc.

As a solvent, the mixed solution of 1, 4- dioxane and water etc. are mentioned.

Sodium hydroxide etc. are mentioned as a base catalyst.

The salt of general formula (3) can be manufactured by the method of Unexamined-Japanese-Patent No. 2008-127367, for example.

Monochlorobenzene etc. are mentioned as a solvent used for dehydration condensation of the compound of General formula (2) and the salt of General formula (3).

Sulfuric acid etc. are mentioned as a dehydration condensation catalyst.

A salt of formula (Ic), wherein L ¹ is -CO-O-CH ₂ -CO-O-, reacts the compound of formula (2) with the compound of formula (4) under a basic catalyst to give a compound of formula (5), the compound of formula (5) obtained It can be prepared by reacting with a salt of formula (3) in the presence of a catalyst.

In the above scheme,

X ² and X ³ are each independently a halogen atom.

As a halogen atom, a chlorine atom is preferable.

Tetrahydrofuran etc. are mentioned as a solvent used for reaction of the compound of General formula (2) and the compound of General formula (4).

Pyridine etc. are mentioned as a base catalyst.

N, N-dimethylformamide, etc. are mentioned as a solvent used for reaction of the salt of general formula (3) and the compound of general formula (5).

Potassium carbonate, potassium iodide, etc. are mentioned as a catalyst.

Regardless of the type of L ¹ , other salts can be produced in accordance with the above.

The acid generator of the present invention contains a salt of formula (I). The acid generator of the present invention may consist only of a salt of the formula (I), and may be added to a salt of the formula (I) to form a known salt other than the salt of the formula (I), a salt comprising a cation contained in the salt of the formula (I) and a known anion, and It may contain the salt etc. which consist of an anion and a well-known cation contained in the salt of general formula (I). The acid generator of this invention may also contain 2 or more types of salts of general formula (I). In addition, when the acid generator of this invention contains well-known salts other than the salt of general formula (I), the ratio (mass ratio) of content of well-known salts other than the salt of general formula (I) with respect to content of the salt of general formula (I) is 1:99 normally. To 99: 1, preferably from 10:90 to 90:10.

As a well-known salt other than the salt of general formula (I), the following salt is mentioned, for example.

In the photoresist composition containing the acid generator of the present invention, the amount of acid generator used is preferably in the range of about 0.1 to 30% by weight in the total solids of the photoresist composition. In addition, in this specification, "solid content in a photoresist composition" means the sum total of the photoresist composition component except the solvent mentioned later. Solid content in a composition, content of resin mentioned later about this, etc. can be measured by well-known analytical means, such as liquid chromatography or gas chromatography, for example.

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

In the photoresist composition of the present invention, an acid is generated from the salt of the formula (I) by exposure. The acid catalyzes and cleaves on the group unstable with the acid in the resin, and the resin is soluble in an aqueous alkali solution. It is suitable for such a photoresist composition to function as a positive type of chemically amplified type. However, in the photoresist composition of this invention, you may use together well-known salts other than the salt of general formula (I) as an acid generator.

<Resin (A)>

Resin (A) is resin which becomes alkali-soluble by the action of an acid. Resin which becomes alkali-soluble by the action of an acid can be manufactured by superposing | polymerizing the monomer (Hereinafter, it may be called "monomer which has an acid-labile group") which has a group which is unstable with an acid, and alkali solubility is easy by the action of an acid. do. "Alkali-soluble by the action of an acid" means "is insoluble or poorly soluble in aqueous alkali solution before contact with acid, but soluble in aqueous alkali solution after contact with acid". The monomer which has an acid-labile group may be used individually by 1 type, or may use 2 or more types together.

<Monomers having groups labile to acids>

An "acid labile group" means a group in which a leaving group cleaves when it comes into contact with an acid to form a hydrophilic group (for example, a hydroxyl group or a carboxyl group (-C00H)). Examples of the group labile to an acid include a group represented by the formula (IIa). In addition, below, the group of general formula (IIa) may be called "acid-labile group (IIa)."

Formula IIa

In Formula IIa above,

R ¹ to R ³ are each independently an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group, and R ² and R ³ may be bonded to each other,

* Is a binding site.

When R <^2> and R <^3> combine with each other, although a ring is formed with the bond carbon, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, etc. are mentioned as said ring.

As an alicyclic hydrocarbon group, the said monocyclic or polycyclic saturated cyclic hydrocarbon group is mentioned.

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

R ¹ to R ³ are preferably groups having 1 to 20 carbon atoms, and more preferably groups having 1 to 12 carbon atoms.

Examples of the group (IIa) labile to an acid include 1,1-dialkylalkoxycarbonyl groups (in groups (1), R ¹ to R ³ are alkyl groups, preferably tert-butoxycarbonyl groups) and 2-alkyl -2-adamantyloxycarbonyl group (in formula 1, R ¹ , R ² and carbon atoms form adamantyl group, R ³ is alkyl group) and 1- (1-adamantyl) -1-alkyl Alkoxycarbonyl group (In formula (1), R <^1> and R <^2> is an alkyl group and R <^3> is an adamantyl group.) Is mentioned.

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

In this specification, "(meth) acrylic acid" means acrylic acid and / or methacrylic acid and "(meth) acrylate" means acrylate and / or methacrylate.

It is preferable to have a C5-20 saturated cyclic hydrocarbon group also in the (meth) acrylic-acid monomer which has group (IIa) unstable to an acid. By using a resin obtained by polymerizing a monomer having a bulky structure such as a saturated cyclic hydrocarbon group, the resolution of the photoresist can be improved. In particular, monomers having groups labile to acids of formula (IIa1) or (IIa2) are preferred. These may be used independently or may use 2 or more types together.

Formula IIa1

Formula IIa2

In Formula IIa1 and Formula IIa2 above,

M ¹ are each independently * -O- or * -O- (CH ₂ ) _k -CO-O-, k is an integer from 1 to 7, * is a binding site with -CO-,

Each R ⁴ is independently a hydrogen atom or a methyl group,

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

s is an integer from 0 to 14,

t is an integer of 0-10.

k becomes like this. Preferably it is an integer of 1-4, More preferably, it is 1.

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

R ⁴ is preferably a methyl group.

The aliphatic hydrocarbon group of R ⁵ is preferably a group having 6 or less carbon atoms, and the saturated cyclic hydrocarbon group is preferably a group having 8 or less carbon atoms, and more preferably a group having 6 or less carbon atoms.

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

As a monomer of general formula (IIa1), the following are mentioned, for example.

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

As a monomer of general formula (IIa2), the following are mentioned, for example.

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

The content rate of the structural unit derived from the monomer of general formula (IIa1) or general formula (IIa2) in resin is 10-95 mol% normally in the total structural unit of resin, Preferably it is 15-90 mol%, More preferably, 20 to 85 mol%.

As a monomer which has an acid labile group and a carbon-carbon double bond, the monomer of general formula (IIa3) is mentioned, for example. Since the resin having a structural unit derived from monomer (IIa3) having a group unstable in acid has a bulky structure, the resolution of the photoresist can be improved. In addition, the monomer (IIa3) having an acid labile group can improve the dry etching resistance of the photoresist by introducing a rigid norbornane ring into the main chain of the resin.

Formula IIa3

In Formula IIa3 above,

R ⁶ is a hydrogen atom, a substituent (e.g., hydroxyl group), and also take a carbon number aliphatic hydrocarbon group of 1 to 3, a carboxyl group, a cyano group or -C00R ⁵⁰ is a, R ⁵⁰ is an aliphatic hydrocarbon group having 1 to 8 carbon atoms Group or a saturated cyclic hydrocarbon group having 3 to 8 carbon atoms, and the hydrogen atom 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 substituted with -O- or CO-,

R ⁷ to R ⁹ are each independently an aliphatic hydrocarbon group having 1 to 12 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 12 carbon atoms,

R ⁸ and R ⁹ may be bonded to each other to form a ring, and the hydrogen atom of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with a hydroxyl group or the like, and the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be -CH ₂ -may be substituted with -O- or CO-.

As an aliphatic hydrocarbon group which may have a substituent of R <^6> , a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and 2-hydroxyethyl group are mentioned.

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

Examples of R ⁷ to R ⁹ include a methyl group, an ethyl group, a cyclohexyl group, a methylcyclohexyl group, a hydroxycyclohexyl group, an oxocyclohexyl group, and adamantyl group. Cyclohexyl group and adamantyl group are mentioned as a saturated cyclic hydrocarbon group which R <^8> , R <^9> and the carbon which these couple | bond form form.

Examples of the monomer of the formula (IIa3) include 5-norbornene-2-carboxylic acid tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, and 5-norbornene-2-carboxylic acid 1-. Methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2- Carboxylic acid 1- (4-methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-oxocyclohexyl) ethyl and 5-norbornene-2-carboxylic acid 1- (1-adamantyl) -1-methylethyl are mentioned.

The content rate of the structural unit derived from the monomer of general formula (IIa3) in resin is 10-95 mol% normally in the all the structural units of resin, Preferably it is 15-90 mol%, More preferably, it is 20-85 Molar%.

As a monomer which has an acid labile group and a carbon-carbon double bond, the monomer of general formula (IIa4) is mentioned.

Formula IIa4

In Formula IIa4 above,

R ¹⁰ is a C1-C6 alkyl group which may have a hydrogen atom, a halogen atom or a halogen atom,

R ¹¹ is 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, acryloyl group or meta It is a chlorophyll group,

h is an integer of 0-4, when h is an integer of 2 or more, some R <^11> may be a group of the same kind or another kind,

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

X ⁴ is a divalent C1-C17 saturated hydrocarbon group which may have a single bond or a substituent, and -CH ₂ -contained in the saturated hydrocarbon group is -CO-, -O-, -S-, -SO _2- Or N (R ^c )-, and R ^c is a hydrogen atom or an aliphatic hydrocarbon group having 1 to 6 carbon atoms,

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

Examples of the alkyl group which may have a halogen atom include perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosecondary-butyl group, and perfluoro3 A quaternary-butyl group, a perfluoropentyl group, and a perfluorohexyl group are mentioned.

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

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

As an acyloxy group, an acetyloxy group, a propionyloxy group, and a butyryloxy group are mentioned.

As the hydrocarbon group, those as exemplified by aliphatic hydrocarbons and saturated cyclic hydrocarbons, and combinations thereof (for example, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) -1-alkyl group, etc.) and the like Can be mentioned.

As a monomer of general formula (IIa4), the following monomers are mentioned, for example.

The content rate of the structural unit derived from the monomer of general formula (IIa4) in resin is 10-95 mol% normally in the total structural unit of resin, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol %to be.

Resin (A), Preferably, it is a copolymer of the monomer which has a group which is unstable with an acid, and the monomer which does not have a group which is unstable with an acid (henceforth an "acid stable monomer"). An acid stable monomer may be used individually by 1 type, or may use 2 or more types together.

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 the monomer having an labile group having an acid is preferably 10 to 80 mol% with respect to 100 mol% of the total structural units. More preferably, it is 20-60 mol%.

Moreover, it is preferable to make the structural unit derived from the monomer which has an adamantyl group (especially monomer (IIa1) which has an acid labile group) to 15 mol% or more with respect to 100 mol% of monomers which have 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.

As an acid stable monomer, what has a hydroxyl group or a lactone ring is preferable. By using the resin which has a structural unit derived from the acid stable monomer which has a hydroxyl group, or the acid stable monomer containing a lactone ring, the resolution of a photoresist and adhesiveness with respect to a board | substrate can be improved.

<Acid stable monomer having a hydroxyl group>

When the photoresist composition is used for high-energy ray exposure such as KrF excimer laser exposure (248 nm), electron beam, or EUV light, an acid-stable monomer having a hydroxyl group, and an acid having a phenolic hydroxyl group such as hydroxystyrene, etc. Preference is given to using stable monomers. When using a short wavelength ArF excimer laser exposure (193 nm) etc., it is preferable to use the acid stable monomer which has a hydroxyl adamantyl group of general formula (IIc) as an acid stable monomer which has a hydroxyl group. The acid stable monomer which has a hydroxyl group may be used individually by 1 type, or may use 2 or more types together.

As a monomer which has a phenolic hydroxyl group, styrene type monomers, such as p- or m-hydroxy styrene of general formula (IIb), are mentioned.

Formula IIb

In Formula IIb above,

R <^14> is a C1-C6 alkyl group which may have a hydrogen atom, a halogen atom, or a halogen atom,

R ¹⁵ is 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, acryloyl group or methacryloyl group ego,

b is an integer of 0-4 and when b is an integer of 2 or more, some R <^15> may be a group of the same kind or a different kind of group.

When obtaining the copolymer resin which has a structural unit derived from the monomer which has such a phenolic hydroxyl group, it obtains by radically polymerizing this (meth) acrylic acid ester monomer, acetoxy styrene, and styrene, and then deacetylating with an acid. can do.

As a monomer which has a phenolic hydroxyl group, the following monomers are mentioned, for example.

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

The content rate of the structural unit derived from the monomer of general formula (IIb) in resin is 5 to 90 mol% normally in the all the structural units of resin, Preferably it is 10 to 85 mol%, More preferably, it is 15-80 Molar%.

As an acid stable monomer which has a hydroxyadamantyl group, the monomer of general formula (IIc) is mentioned.

Formula IIc

In Formula IIc above,

M ² is * -O- or * -O- (CH ₂ ) _k -CO-O-, k is an integer from 1 to 7, * is a binding site with -CO-,

R ¹⁶ is a hydrogen atom or a methyl group,

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

c is an integer of 0 to 10.

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

R ¹⁶ is preferably a methyl group.

R ¹⁷ is preferably a hydrogen atom.

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

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

As a monomer of general formula (IIc), the following are mentioned, for example. Among them, 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate and (meth) acrylic acid 1- (3,5-di Hydroxy-1-adamantyloxycarbonyl) methyl is preferred, and 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) acrylic The rate is more preferable, and 3-hydroxy-1-adamantyl methacrylate and 3,5-dihydroxy-1-adamantyl methacrylate are more preferable.

The content rate of the structural unit derived from the monomer of general formula (IIc) in resin is 3 to 45 mol% normally in the all the structural units of resin, Preferably it is 5 to 40 mol%, More preferably, it is 5 to 35 Molar%.

<Acid stable monomer containing lactone ring>

The lactone ring possessed by the acid stable monomer may be, for example, a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. Among these lactone rings, a condensed ring of a γ-butyrolactone ring and a γ-butyrolactone ring and another ring is preferable.

Acid stable monomers having a lactone ring are represented, for example, by the formula (IId), (IIe) or (IIg). These 1 type may be used independently, or 2 or more types may be used together.

Formula IId

Formula IIe

Formula IIg

In the above formula (IId), (IIe) and (IIg),

M ² are each independently * -O- or * -O- (CH ₂ ) _k -CO-O-, k is an integer from 1 to 7, * is a binding site with -CO-,

Each R ¹⁹ is independently a hydrogen atom or a methyl group,

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

d is an integer from 0 to 5,

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

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

When d, e and g are two or more, some R <^20> , R <^21> or R <^22> may mutually be same or different, respectively.

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

R ¹⁹ and R ²⁰ are preferably methyl groups.

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

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

As a monomer of general formula (IId), the following are mentioned, for example.

As a monomer of general formula (IIe), the following are mentioned, for example.

As a monomer of general formula (IIg), the following are mentioned, for example.

Among the acid stable monomers having a lactone ring, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan- ² -yl, (meth) acrylic acid tetrahydro-2-oxo-3- Furyl, (meth) acrylic acid 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan- ² -yloxy) -2-oxoethyl is preferred, and methacrylic acid (5-oxo- 4-oxatricyclo [4.2.1.0 ^3,7 ] nonan- ² -yl, tetrahydro-2-oxo-3-furyl, methacrylic acid 2- (5-oxo-4-oxatricyclo [4.2 .1.0 ^3,7 ] nonan- ² -yloxy) -2-oxoethyl is more preferred.

The content rate of the structural unit derived from the monomer of general formula (IId), general formula (IIe), or general formula (IIg) in resin is 5-65 mol% normally in all the structural units of resin, Preferably it is 10-60 mol%, More Preferably it is 10-55 mol%.

<Other acid stable monomer>

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

Formula IIh

Formula IIi

Formula IIj

In Formula IIj above,

R ²³ and R ²⁴ are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a substituent (for example, a hydroxyl group), a cyano group, a carboxyl group, or -C00R ^25, or R ²³ and R ²⁴ Combine with each other to form -CO-O-CO-,

R ²⁵ is an aliphatic hydrocarbon group having 1 to 36 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and -CH ₂ -of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with -O- or CO-, provided that Except that C00R ²⁵ is an acid labile group (ie R ²⁵ does not include the bonding of tertiary carbon atoms with —O—).

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

As a monomer of Formula (IIj), 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene-2-carboxylic acid, 5-norbornene-2-carboxylic acid methyl, 5-norbornene- 2-carboxylic acid 2-hydroxy-1-ethyl, 5-norbornene-2-methanol and 5-norbornene-2,3-dicarboxylic acid anhydride are mentioned.

The content rate of the structural unit derived from the monomer of general formula (IIh), general formula (IIi), or general formula (IIj) in resin is 2-40 mol% normally in the all structural units of resin, Preferably it is 3-30 mol%, More Preferably it is 5-20 mol%.

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

Resin (A) can be manufactured by a well-known polymerization method (for example, radical polymerization method).

The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less). The weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene standard by gel permeation chromatography analysis, and the detailed analysis conditions of the said analysis are explained in full detail in the Example of this application.

It is preferable that the content rate of resin (A) is 80 mass% or more in solid content of a photoresist composition.

<Basic compound>

The photoresist composition of the present invention may contain a basic compound. It is preferable that the content rate of a basic compound is about 0.01-1 mass% based on solid content of a photoresist composition.

The basic compound is preferably a basic nitrogen-containing organic compound (eg amine and ammonium salts). The amine may be either an aliphatic amine or an aromatic amine. Aliphatic amine can use either a primary amine, a secondary amine, and a tertiary amine. The aromatic amine may be any one in which an amino group is bonded to an aromatic ring such as aniline or a heteroaromatic amine such as pyridine. Preferred basic compounds include aromatic amines of formula C2, in particular aniline of formula C2-1.

Formula C2

Formula C2-1

In Formula C2 and Formula C2-1 above,

Ar is an aromatic hydrocarbon group,

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

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

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

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, the aromatic hydrocarbon group is preferably a group having 6 to 10 carbon atoms, and the alkoxy group is preferably Preferably an alkoxy group having 1 to 6 carbon atoms,

o is an integer of 0-3, and when o is 2 or more, some T <^3> may mutually be same or different.

As aromatic amine (C2), 1-naphthylamine and 2-naphthylamine are mentioned.

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

Moreover, as a basic compound, the compound of Formula C3-Formula C11 is mentioned.

In Formula C3 to Formula C11 above,

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

T ⁴ is an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group or an alkanoyl group,

The aliphatic hydrocarbon group is preferably a group having 1 to 6 carbon atoms, the saturated cyclic hydrocarbon group is preferably a group having 3 to 6 carbon atoms, and the alkanoyl group is preferably a group having 2 to 6 carbon atoms.

u is an integer from 0 to 8,

When o or u is an integer of 2 or more, a plurality of T ³ or T ⁴ may be the same or different from each other,

Each independently represents a divalent aliphatic hydrocarbon group (preferably an alkylene group), -CO-, -C (= NH)-, -C (= NR ³⁴ )-, -S-, -SS-, or Combination,

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

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

Here, as an alkanoyl group, an acetyl group, an ethylcarbonyl group, and a heptylcarbonyl group are mentioned.

Examples of the compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine and tri Ethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldi Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyl Dioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamineethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane and 4,4'-diamino-3,3'-diethyldiphenylmethane.

Piperazine is mentioned as a compound (C4).

A morpholine is mentioned as a compound (C5).

As a compound (C6), the hindered amine compound which has a piperidine and the piperidine frame | skeleton of Unexamined-Japanese-Patent No. 11-52575 is mentioned.

2,2'- methylenebisaniline is mentioned as a compound (C7).

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

Pyridine and 4-methylpyridine are mentioned as a compound (C9).

Examples of the compound (C10) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene and 1,2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4'-di Pyridylsulfide, 4,4'-dipyridyldisulfide, 2,2'-dipyridylamine and 2,2'-dipicorylamine.

Bipyridine is mentioned as a compound (C11).

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

<Solvent>

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

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 ester, such as (gamma) -butyrolactone, is mentioned. A solvent may be used individually by 1 type, or may use 2 or more types together.

<Other Ingredients>

The photoresist composition of this invention may contain other components as needed. There are no limitations on these other components, and additives known in the photoresist field, for example, sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

<Photoresist composition and preparation method thereof>

The photoresist composition of this invention can be prepared by mixing resin (A), the acid generator of this invention, and a solvent, or by mixing resin (A), the acid generator of this invention, a basic compound, and a solvent. . In such mixing, the mixing order is arbitrary and is not limited. Mixing temperature can select a suitable temperature range in the range of 10-40 degreeC according to the kind, such as resin, solubility to solvents, such as resin, etc., for example. Mixing time can select a suitable time from 0.5 to 24 hours according to mixing temperature. Moreover, a mixing means does not have a restriction | limiting in particular, either, stirring mixing, etc. can be used.

For example, after mixing each of resin (A), the acid generator and solvent of this invention, and the basic compound or other component used as needed in a preferable content, it is obtained using the filter of about 0.2 micrometer in diameter. The filtered photoresist composition of this invention can be prepared by filtering the mixed liquid.

<Production Method of Photoresist Pattern>

The manufacturing method of the photoresist pattern of this invention,

(1) applying said photoresist composition onto a substrate to form a photoresist composition layer,

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

(3) exposing the photoresist film;

(4) heating the photoresist film after exposure, and

(5) The process of developing the photoresist film after a heating is included.

Application | coating of the photoresist composition on the base | substrate can be performed by the apparatus used normally, such as a spin coater.

In the process of drying a photoresist composition layer and removing a solvent, removal of a solvent is performed by evaporating a solvent using a heating apparatus, such as a hotplate, or using a pressure reduction apparatus, The photoresist film from which is removed is formed. A drying temperature is about 50-200 degreeC. Moreover, about 1-1.0 * 10 <^5> Pa of pressure is mentioned.

The obtained photoresist film is exposed using an exposure machine. At this time, you may use a liquid immersion exposure machine. Usually, exposure is performed through the mask corresponded to a requested photoresist pattern. From as an exposure light source, KrF excimer laser (wavelength: 248nm), ArF excimer laser (wavelength: 193nm), F ₂ laser is to emit the ultraviolet region, such as (wavelength 157nm) laser, solid state laser light source (YAG or a semiconductor laser, etc.) Various wavelengths can be used, such as converting the laser beam into a wavelength and emitting high frequency laser light in the far ultraviolet or vacuum ultraviolet region.

The photoresist film after exposure is heated. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.

The photoresist film after heating is normally developed using an alkaline developing solution arbitrarily using a developing apparatus. The alkaline developer used herein may be any alkaline aqueous solution used in this field. For example, aqueous solution of tetramethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide (common name choline), etc. are mentioned.

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

<Use>

The photoresist composition of the present invention is particularly useful as a chemically amplified photoresist composition, and is suitably used for a wide range of applications such as microfabrication of semiconductors, production of circuit boards such as liquid crystals, thermal heads, and other photopublishing processes. Can be. In particular, excimer laser lithography such as ArF and KrF, ArF immersion exposure lithography, and EB exposure lithography, in that the occurrence of defects can be suppressed and the resolution, shape, and line edge roughness of the pattern obtained can be further improved. It can be used as a chemically amplified photoresist composition suitable for EUV exposure lithography. Moreover, in addition to liquid immersion exposure, it can be used also for dry exposure. It can also be used for double imaging, which is industrially useful.

[Example]

Hereinafter, an Example demonstrates this invention in detail.

In an Example and a comparative example,% and part which show content and usage-amount are a mass reference | standard unless there is special mention.

The weight average molecular weight is the value calculated | required by gel permeation chromatography (The type of HLC-8120GPC by the Tosoh Corporation, three "TSKgel Multipore HXL-M" and a solvent 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 ℃

Injection volume: 100 μl

Molecular weight standard: standard polystyrene [see Tosoh Corporation]

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

Content of the structural unit in resin measured the amount of unreacted monomer in the reaction mixture after completion | finish of polymerization using liquid chromatography, and computed it from the obtained result.

Example 1 Synthesis of Acid Generator B1

30.00 parts of the compound of formula B1-a and 90.00 parts of 1,4-dioxane obtained from Central Glass Co., Ltd. were mixed. To the mixture obtained, an aqueous solution obtained by dissolving 2.64 parts of sodium hydroxide in 60.00 parts of ion exchanged water was added dropwise over 30 minutes while stirring at 23 ° C. The resulting mixture was stirred at 90 ° C. for 36 hours. After cooling the obtained reaction mixture, 450.00 parts of ion-exchanged water, 500.0 parts of ethyl acetate, and 186.0 parts of sodium chloride were added. The obtained mixture was stirred and then separated. After adding 400.0 parts of 3N hydrochloric acid to the obtained organic layer, the obtained mixture was stirred and liquid-separated. The obtained organic layer was washed three times with 400.00 parts of ion-exchanged water. The obtained organic layer was concentrated, and the obtained residue was subjected to column purification (60-200 mesh of silica gel manufactured by Merck Co., Ltd. developing solvent: n-heptane / ethyl acetate = 3/1) to obtain a compound of formula B1-b as a white solid. 7.96 parts were obtained.

2.99 parts of the compound of the formula B1-c, 30.00 parts of the monochlorobenzene and 3.53 parts of the compound of the formula B1-b obtained by the method described in JP-A-2008-127367 are mixed, and the obtained mixture is stirred at 23 DEG C for 30 minutes. Stirred. Thereafter, 0.13 parts of sulfuric acid and 12.00 parts of molecular resin (manufactured by 4A Wako Pure Chemical Industries, Ltd.) were added, and the obtained mixture was dehydrated at reflux for 3 hours at 130 ° C. The reaction mixture obtained was concentrated. To the residue, 73.34 parts of chloroform and 36.67 parts of ion-exchanged water were added, and the obtained mixture was stirred and subjected to liquid separation. Water washing of the obtained organic layer was performed 6 times. 0.99 parts of activated carbon was added to the obtained organic layer, stirred at 23 ° C. for 30 minutes, and then filtered. The filtrate was concentrated, and 11.58 parts of acetonitrile were added to the obtained concentrate, and a solution was obtained. The obtained solution was concentrated. Further, 32.04 parts of methyl tert-butyl ether was added to the obtained concentrate and stirred. The precipitate was filtered and dried to yield 0.58 part of a salt of the formula B1 as a white solid. The obtained salt is called acid generator B1.

MS (ESI (+) Spectrum): M ⁺ 263.1

MS (ESI (-) Spectrum): M ^- 589.0

Example 2: Synthesis of Acid Generator B2

3.28 parts of compound of formula B2-c, 30.00 parts of monochlorobenzene and 3.53 parts of compound of formula B1-b were mixed and the resulting mixture was stirred at 23 ° C. for 30 minutes. Thereafter, 0.13 parts of sulfuric acid and 12.00 parts of molecular resin (manufactured by 4A Wako Pure Chemical Industries, Ltd.) were added, and the obtained mixture was dehydrated at reflux for 3 hours at 130 ° C. After the obtained reaction mixture was concentrated, 80 parts of chloroform and 40 parts of ion-exchanged water were injected into the concentrated residue, followed by stirring and separation. Water washing of the obtained organic layer was performed 6 times. 1.00 parts of activated carbon was injected into the obtained organic layer, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated and 15 parts of acetonitrile were added to the obtained concentrate, and a solution was obtained. The obtained solution was concentrated. Further, 30 parts of methyl tert-butyl ether was added and stirred to the obtained concentrate. The precipitate was filtered and dried to obtain 0.89 parts of the salt of the formula (B2). The obtained salt is called acid generator B2.

MS (ESI (+) Spectrum): M ⁺ 305.1

MS (ESI (-) Spectrum): M ^- 589.0

Example 3: Synthesis of Acid Generator B3

3.11 parts of compound of formula B3-c, 30.00 parts of monochlorobenzene and 3.53 parts of compound of formula B1-b were mixed and the resulting mixture was stirred at 23 ° C. for 30 minutes. Thereafter, 0.13 parts of sulfuric acid and 12.00 parts of molecular resin (manufactured by 4A Wako Pure Chemical Industries, Ltd.) were added, and the obtained mixture was dehydrated at reflux for 3 hours at 130 ° C. The reaction mixture obtained was concentrated. 80 parts of chloroform and 40 parts of ion-exchanged water were injected into the obtained concentrated residue, followed by stirring and separation. Water washing of the obtained organic layer was performed 6 times. 1.00 parts of activated carbon was injected into the obtained organic layer, stirred at 23 ° C. for 30 minutes, and filtered. After the filtrate was concentrated, 20 parts of acetonitrile were added to the obtained concentrate, and a solution was obtained. The obtained solution was concentrated, 30 parts of ethyl acetate was added to the concentrated residue, and the mixture was stirred. The supernatant was removed from the obtained mixture. To the obtained residue, 30 parts of methyl tert-butyl ether was added and stirred, and the supernatant was removed from the obtained mixture. The obtained residue was dissolved in chloroform, and the obtained solution was concentrated, and then the obtained concentrated residue was subjected to column purification (silica gel 60-200 mesh manufactured by Merck, developing solvent: chloroform / methanol = 5/1) to obtain a compound of formula B3. 0.76 parts of salt were obtained. The obtained salt is called acid generator B3.

MS (ESI (+) Spectrum): M ⁺ 281.0

MS (ESI (-) Spectrum): M ^- 589.0

Example 4: Synthesis of Acid Generator B4

2.61 parts of compound of formula B4-c, 30.00 parts of monochlorobenzene and 3.53 parts of compound of formula B1-b were mixed and the resulting mixture was stirred at 23 ° C. for 30 minutes. Thereafter, 0.13 parts of sulfuric acid and 12.00 parts of molecular resin (manufactured by 4A Wako Pure Chemical Industries, Ltd.) were added, and the obtained mixture was dehydrated at reflux for 3 hours at 130 ° C. The reaction mixture obtained was concentrated. 80 parts of chloroform and 40 parts of ion-exchanged water were poured into the obtained concentrated residue, and it stirred and liquid-separated. Water washing of the obtained organic layer was performed 6 times. 1.00 parts of activated carbon was injected into the obtained organic layer, stirred at 23 ° C. for 30 minutes, filtered and concentrated. To the obtained concentrate, 20 parts of acetonitrile were added and a solution was obtained. The obtained solution was concentrated, 30 parts of ethyl acetate was added to the concentrated residue, and the mixture was stirred. The supernatant was removed from the obtained mixture. To the obtained residue, 30 parts of tert-butylmethylether was added and stirred. The supernatant was removed from the obtained mixture. The obtained residue was dissolved in chloroform, and the obtained solution was concentrated, and then the obtained concentrate was subjected to column purification (silica gel 60 to 200 mesh manufactured by Merck, developing solvent: chloroform / methanol = 5/1) to obtain a compound of formula B4. 0.58 parts of salt were obtained. The obtained salt is called acid generator B4.

MS (ESI (+) Spectrum): M ⁺ 207.1

MS (ESI (-) Spectrum): M ^- 589.0

Example 5: Synthesis of Acid Generator B5

6.50 parts of the compound of formula B1-b and 20 parts of tetrahydrofuran were mixed. The resulting mixture was stirred at room temperature, and after confirming dissolution of the compound of formula B1-b, 1.43 parts of pyridine was injected and the resulting mixture was heated to 40 ° C., followed by 2.55 parts of chloroacetyl chloride and 5 parts of tetrahydrofuran. The mixed solution was added dropwise over 1 hour. The resulting mixture was stirred at 40 ° C. for 3 hours and then cooled to 5 ° C. After adding 10 parts of ion-exchanged water and 40 parts of ethyl acetate cooled to 5 degreeC, the obtained mixture was stirred and liquid-separated. The obtained organic layer was washed with 10 parts of 5% aqueous 10% potassium carbonate solution, and then the organic layer was washed again with 10 parts of ion-exchanged water. The washing operation with this water was repeated five times. After concentrating the obtained organic layer, the concentrated residue was subjected to column purification (60 to 200 mesh made by Merck Co., Ltd., developing solvent: ethyl acetate) to obtain 1.85 parts of the compound of the formula (B5-a).

1.92 parts of compound of formula B1-c and 9.59 parts of N, N-dimethylformamide were mixed, and the obtained mixture was stirred at 23 ° C. for 30 minutes. To the mixture obtained, 0.59 parts of potassium carbonate and 0.18 parts of potassium iodide were injected. The resulting mixture was stirred at 40 ° C. for 1 hour, and then the solution obtained by dissolving 1.80 parts of the compound of formula B5-a in 3.60 parts of N, N-dimethylformamide was added dropwise over 1 hour. The resulting mixture was stirred at 40 ° C. for 6 hours and then cooled to 23 ° C. To the obtained reaction mixture, 70.67 parts of chloroform, 10.71 parts of 5% oxalic acid aqueous solution and 6.96 parts of ion-exchanged water were added, followed by stirring and separation. The obtained organic layer was washed 7 times with 28.27 parts of ion-exchanged water. 1.00 parts of activated carbon was injected into the obtained organic layer, stirred at 23 ° C. for 30 minutes, and then filtered and concentrated. To the obtained concentrate, 10 parts of acetonitrile were added and the obtained solution was concentrated. 10 parts of ethyl acetate was added to the concentrated residue, and the supernatant was removed from the obtained mixture. 10 parts of methyl tert-butyl ether was added to the obtained residue, and the supernatant was removed from the obtained mixture. The obtained residue was dissolved in chloroform, the obtained solution was concentrated, and the obtained concentrate was then subjected to column purification (silica gel 60-200 mesh manufactured by Merck, developing solvent: chloroform / methanol = 5/1) to obtain a compound of formula B5. 0.61 parts of salt were obtained. The obtained salt is called acid generator B5.

MS (ESI (+) Spectrum): M ⁺ 263.1

MS (ESI (-) Spectrum): M ^- 647.0

Example 6: Synthesis of Acid Generator B6

21.61 parts of compounds of formula B6-a and 90.00 parts of 1,4-dioxane obtained from Central Glass Co., Ltd. were mixed. To the obtained mixture, an aqueous solution obtained by dissolving 2.64 parts of sodium hydroxide in 60.00 parts of ion exchanged water was added dropwise over 30 minutes while stirring at 23 ° C. The resulting mixture was stirred at 90 ° C. for 36 hours. After the reaction mixture was cooled, 200 parts of ion-exchanged water, 400 parts of ethyl acetate and 150 parts of sodium chloride were added. After the obtained mixture was stirred, liquid separation was performed. After adding 200 parts of 3N hydrochloric acid to the obtained organic layer, it stirred, and performed liquid-separation. The obtained organic layer was washed three times with 200 parts of ion-exchanged water. The obtained organic layer was concentrated, and the concentrated residue was subjected to column purification (60-200 mesh of silica gel manufactured by Merck Co., Ltd., developing solvent: n-heptane / ethyl acetate = 2/1) to obtain 5.69 parts of the compound of the formula B6-b.

2.99 parts of compound of formula B1-c, 30.00 parts of monochlorobenzene and 2.39 parts of compound of formula B6-b were mixed. The resulting mixture was stirred at 23 ° C. for 30 minutes, and then 0.13 parts of sulfuric acid and 12.00 parts of molecular (4A Wako Pure Chemical) were added. The resulting mixture was refluxed at 130 ° C. for 3 hours. The obtained reaction mixture was concentrated, 70 parts of chloroform and 35 parts of ion-exchanged water were added to the concentrated residue, followed by stirring and separation. Water washing of the obtained organic layer was performed 6 times. 1.00 parts of activated carbon was injected into the obtained organic layer, stirred at 23 ° C. for 30 minutes, filtered and concentrated. To the obtained concentrate, 20 parts of acetonitrile were added and the obtained solution was concentrated. 30 parts of ethyl acetate were added to the concentrated residue, and the supernatant was removed from the obtained mixture. 30 parts of methyl tert-butyl ether was added to the obtained residue, and the supernatant was removed from the obtained mixture. The obtained residue was dissolved in chloroform and the obtained solution was concentrated. The obtained concentrate was subjected to column purification (60-200 mesh of silica gel manufactured by Merck, developing solvent: chloroform / methanol = 5/1) to obtain 0.51 part of a salt of the general formula B6. The obtained salt is called acid generator B6.

MS (ESI (+) Spectrum): M ⁺ 263.1

MS (ESI (-) Spectrum): M ^- 449.0

Example 7: Synthesis of Acid Generator B7

20.64 parts of the compound of the formula B7-a and 90.00 parts of 1,4-dioxane obtained from Central Glass Co., Ltd. were mixed. The resulting aqueous solution was added dropwise over 30 minutes while dissolving 2.64 parts of sodium hydroxide in 60.00 parts of ion-exchanged water while stirring at 23 ° C. The resulting mixture was stirred at 90 ° C. for 36 hours. After cooling the reaction mixture, 200 parts of ion-exchanged water, 400 parts of ethyl acetate and 150 parts of sodium chloride were added, stirred, and liquid separation was performed. 200 parts of 3N hydrochloric acid was added to the obtained organic layer, it stirred, and liquid-separated. The obtained organic layer was washed three times with 200 parts of ion-exchanged water. The organic layer was concentrated, and the concentrated residue was subjected to column purification (60 to 200 mesh of silica gel manufactured by Merck Co., Ltd., developing solvent: n-heptane / ethyl acetate = 2/1) to obtain 5.21 parts of the compound of the formula B7-b.

2.99 parts of compound of formula B1-c, 30.00 parts of monochlorobenzene and 2.18 parts of compound of formula B7-b were mixed. The resulting mixture was stirred at 23 ° C. for 30 minutes, and then 0.13 parts of sulfuric acid and 12.00 parts of molecular (manufactured by 4A Wako Pure Chemical) were added. The resulting mixture was refluxed at 130 ° C. for 3 hours. The obtained reaction mixture was concentrated, 70 parts of chloroform and 35 parts of ion-exchanged water were injected into the concentrated residue, followed by stirring and separation. Water washing of the obtained organic layer was performed 6 times. 1.00 parts of activated carbon was injected into the obtained organic layer, stirred at 23 ° C. for 30 minutes, filtered and concentrated. To the obtained concentrate, 20 parts of acetonitrile were added to dissolve and the obtained solution was concentrated. 30 parts of ethyl acetate was added to the concentrated residue, and the supernatant was removed from the obtained mixture. 30 parts of tert-butylmethylether were added to the obtained residue, and the supernatant was removed from the obtained mixture. The obtained residue was dissolved in chloroform and the obtained solution was concentrated. The obtained concentrate was subjected to column purification (60-200 mesh of silica gel manufactured by Merck Co., Ltd., developing solvent: chloroform / methanol = 5/1) to obtain 0.55 part of a salt of the general formula (B7). The obtained salt is called acid generator B7.

MS (ESI (+) Spectrum): M ⁺ 263.1

MS (ESI (-) Spectrum): M ^- 423.0

Synthesis Example 1 Synthesis of Resin A1

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

Synthesis Example 2 Synthesis of Resin A2

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

(Preparation of photoresist composition)

Each component shown below was mixed by the composition of Table 1, the obtained solution was filtered through the fluorine resin filter of 0.2 micrometer of pore diameters, and the photoresist composition was prepared.

<Resin>

Resin A1, A2

<Acid generator>

Acid Generator X1

<Basic Compound: Quencher>

Quencher C1: 2,6-diisopropylaniline

<Solvent>

Propylene glycol monomethyl ether acetate 265 parts

2-heptanone 20.0 parts

Propylene glycol monomethyl ether 20.0 parts

γ-butyrolactone 3.5 parts

(Defect assessment)

The defect generation at the time of immersion exposure was evaluated by the following simulation test.

The photoresist composition prepared above was spin-coated on a 12-inch silicon wafer so that the film thickness after prebaking might be 85 nm. Then, the prebaking was performed for 60 second on the direct hotplate at the temperature of the "PB" column of Table 1. Using a developer (ACT-12; manufactured by Tokyo Electron Co., Ltd.), the wafer on which the prebaked photoresist film was formed was washed with water for 60 seconds and dried. Then, the defect number of the photoresist film was measured using the defect inspection apparatus (KLA-2360; KLA Tencol make).

On the entire surface of the resist film produced on a 12 inch silicon wafer,

The defect number of more than 1,000 and less than 10,000 is a photoresist composition which does not have a problem practically, and was referred to as (triangle | delta) on the basis of this. The number of defects is 1,000 or less, the number of defects is small, and it is a favorable photoresist composition, (circle), and the number of defects is 10,000 or more.

Numerical values in parentheses indicate the number of defects (pieces).

(Evaluation of Photoresist Composition for Immersion Exposure)

On a 12-inch silicon wafer, an organic antireflection film composition [ARC-29; Nissan Chemical Co., Ltd.] was apply | coated, and it baked on the conditions of 205 degreeC and 60 second, and formed the organic antireflection film of thickness 78nm.

Next, the photoresist composition prepared above was spin-coated on the formed organic antireflective film so that the film thickness after drying might be 85 nm.

The obtained silicon wafer was prebaked (PB) for 60 seconds on the direct hotplate at the temperature described in the "PB" column of Table 1. The ArF excimer stepper for liquid immersion exposure [XT: 1900Gi; The line and space pattern was immersion-exposed by changing the exposure amount in steps using ASML, NA = 1.35, 3 / 4Annular X-Y deflection].

After exposure, the postexposure bake (PEB) was performed for 60 second on the hotplate at the temperature of the "PEB" column of Table 1.

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

Effective Sensitivity: The exposure amount at which the 50 nm line-and-space pattern is 1: 1 in each photoresist film was referred to as effective sensitivity.

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

Line edge roughness evaluation (LER): The wall surface of the photoresist pattern after the lithography process was observed with the scanning electron microscope, and it was set that the uneven | corrugated width | variety of the photoresist pattern side wall was 5 nm or less, and the thing exceeding 5 nm was x. The numerical values in parentheses represent the width (nm) of the unevenness of the sidewall of the resist pattern.

These results are shown in Table 2.

From the resist composition containing the salt of the present invention, a resist pattern with few defects and excellent shape and line edge roughness can be obtained.

Claims (9)

Salts of formula (I).
Formula I

In the above formula (I)
Q ¹ and Q ² are each independently a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms,
L ¹ is a divalent C1-C17 saturated hydrocarbon group which may have a single bond or a substituent, at least one -CH ₂ -contained in the saturated hydrocarbon group may be substituted with -O- or CO-,
Y ¹ is a (m + 1) valence saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, and one or more -CH ₂ -included in the saturated cyclic hydrocarbon group may be substituted with -O-, -CO-, or SO _2- . ,
X ¹ is an aliphatic hydrocarbon group having 1 to 12 carbon atoms having at least one fluorine atom, at least one hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxyl group,
m is 1 or 2,
Z ⁺ is an organic counterion. The compound of claim 1, wherein L ¹ is * -CO-OL ^2- , wherein L ² is a single bond or an alkylene group having 1 to 15 carbon atoms, and * is a bond to -C (Q ¹ ) (Q ² )-. Site). The salt according to claim 1, wherein Y ¹ is a group derived from a cyclohexane ring, a norbornane ring or an adamantane ring. The salt of claim 1, wherein X ¹ is a group of formula (Ix).
Formula Ix

In Formula Ix above,
n is 0 or 1; The salt of claim 1, wherein Z ⁺ is a triarylsulfonium cation. An acid generator containing the salt according to claim 1. A photoresist composition comprising the acid generator according to claim 6 and a resin, wherein the resin has a group that is unstable with an acid, is insoluble or poorly soluble in an aqueous alkali solution, and can be dissolved in an aqueous alkaline solution by the action of an acid. The photoresist composition of claim 7 further comprising a basic compound. (1) applying the photoresist composition according to claim 7 on a substrate to form a photoresist composition layer,
(2) drying the formed photoresist composition layer to form a photoresist film,
(3) exposing the photoresist film;
(4) heating the photoresist film after exposure, and
(5) The manufacturing method of the photoresist pattern including the process of developing the photoresist film after a heating.