JP5580558B2 - Photoresist composition - Google Patents

Description

  The present invention relates to a photoresist composition (hereinafter sometimes abbreviated as “resist composition”) used for semiconductor microfabrication and the like.

  In a chemically amplified resist composition containing an acid generator, the acid released from the acid generator by light irradiation acts as a catalyst, so that even with a small amount of light, a curing reaction (in the case of a negative resist composition) or a solubilization reaction ( In the case of a positive resist composition) sufficiently proceeds and high sensitivity is achieved.

  In order to suppress the deterioration of the performance of the resist film caused by the acid diffusion accompanying holding after exposure, a basic compound is usually added as a quencher to the chemically amplified resist composition containing an acid generator. For example, in the example of Patent Document 1, 2,6-diisopropylaniline or tetrabutylammonium hydroxide is used as a quencher.

JP 2005-331918 A

  In the field of photoresists, there is a demand for resist compositions that can form patterns with good shape and line edge roughness. However, conventional resist compositions are not always satisfactory in pattern shape and line edge roughness.

  The present invention has been made paying attention to such circumstances, and an object of the present invention is to provide a resist composition capable of forming a pattern having a shape and line edge roughness better than those of conventional ones.

  As a result of intensive studies by the present inventors in order to achieve the above object, ammonium hydroxide {salt represented by the following formula (C1)} is contained as a basic compound, and the solvent content thereof is 90% by mass in the composition. The present inventors have found that a good pattern shape and line edge roughness can be achieved by using a resist composition of at least%, and the present invention has been completed. In Example 9 of Patent Document 1, tetrabutylammonium hydroxide is used as the basic compound (quencher), but its solvent content is as low as 89.3% by mass, and is shown in Comparative Example 2 below. As described above, a good pattern shape and line edge roughness cannot be achieved as in the resist composition of the present invention.

  The photoresist composition of the present invention capable of achieving the above object is a composition containing a resin, an acid generator, a salt represented by the formula (C1) and a solvent, and the salt represented by the formula (C1). The solid content of the composition is 0.05% by mass or more and less than 2% by mass, and the content of the solvent is 90% by mass or more and 99.9% by mass or less in the composition. Hereinafter, the “salt represented by the formula (C1)” may be abbreviated as “salt (C1)”. Similarly, compounds or groups represented by other chemical formulas may be abbreviated as well.

In formula (C1), R ^{c1 to} R ^c4 each independently represents a linear, branched or cyclic C _1-10 saturated aliphatic hydrocarbon group which may have a substituent, A C _7-18 aralkyl group which may have a group, or a C _6-18 aromatic hydrocarbon group which may have a substituent.

In the present specification, the “C _xy saturated aliphatic hydrocarbon group” represents a saturated aliphatic hydrocarbon group having x to y in number. However, this carbon number does not include the carbon number of the substituent that the saturated aliphatic hydrocarbon group has. “C _xy ” of a group other than a saturated aliphatic hydrocarbon group has the same meaning.

R ^{c1 to} R ^c4 are each independently preferably a linear or branched C _1-7 alkyl group which may have a substituent, and the salt (C1) is tetrabutylammonium. More preferably, it is at least one selected from the group consisting of hydroxide, tetrapropylammonium hydroxide, and (2-hydroxyethyl) trimethylammonium hydroxide.

  The acid generator is preferably a fluorine-containing acid generator, and more preferably represented by the formula (B1).

In formula (B1), Q ¹ and Q ² each independently represent a fluorine atom or a C _1-6 perfluoroalkyl group. L ^b1 represents a single bond or a linear, branched or cyclic divalent C _1-17 saturated aliphatic hydrocarbon group which may have a substituent; The methylene group (—CH ₂ —) of the group hydrocarbon group may be substituted with an oxygen atom (—O—) or a carbonyl group (—CO—). Y represents an optionally substituted cyclic C _3-36 aliphatic hydrocarbon group; the methylene group (—CH ₂ —) of the aliphatic hydrocarbon group is an oxygen atom (—O—); ) Or a carbonyl group (—CO—). Z ⁺ represents an organic cation.

In the present specification, “an aliphatic hydrocarbon group in which a methylene group (—CH ₂ —) is substituted with an oxygen atom (—O—)” or the like means “apparently a methylene group of an aliphatic hydrocarbon group ( -CH _2- ) means a group considered to be substituted with an oxygen atom (-O-) "or the like, and" actually, after synthesizing an aliphatic hydrocarbon group, a methylene group (-CH _2- ) It does not mean “a group obtained by substitution with an oxygen atom (—O—)” or the like. Expressions such as “aliphatic hydrocarbon group in which a hydrogen atom is substituted with a halogen atom” have the same meaning.

In the formula (B1), Z ⁺ is preferably an arylsulfonium cation, and Y is preferably an adamantyl group which may have a substituent.

  The content of the acid generator is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

  The resin is preferably a resin that becomes alkali-soluble by the action of an acid. Note that “becomes soluble in an alkali by the action of an acid” means “insoluble or hardly soluble in an aqueous alkali solution before contact with an acid but becomes soluble in an aqueous alkali solution after contact with an acid”. To do.

  If the resist composition of the present invention containing salt (C1) and having a solvent content of 90% by mass or more in the composition is used, a resist pattern having a better pattern shape and line edge roughness can be formed.

  The resist composition of the present invention contains a salt (C1) and a solvent (D) as the resin (A), the acid generator (B), and the basic compound (C). Hereinafter, each component will be described in order.

<Resin (A)>
The resin (A) is preferably a resin that becomes alkali-soluble by the action of an acid. A resin that becomes alkali-soluble by the action of an acid can be produced by polymerizing a monomer whose hydrophilicity is improved by the action of an acid (hereinafter sometimes abbreviated as “acid-solubilizing monomer (a1)”). As the acid solubilizing monomer (a1), one type may be used alone, or two or more types may be used in combination.

<Acid solubilizing monomer (a1)>
Examples of the acid solubilizing monomer (a1) include monomers having an acid labile group. Here, the “acid-labile group” means a group that forms a hydrophilic group (for example, a hydroxy group or a carboxy group) by cleaving the leaving group upon contact with an acid. Examples of the acid labile group include an alkoxy represented by the formula (1) in which an oxygen atom (—O—) is bonded to a tertiary carbon atom (excluding a bridged carbon atom of a bridged cyclic hydrocarbon group). Examples include a carbonyl group (that is, an ester bond having a tertiary alcohol residue). Hereinafter, the group represented by the formula (1) is abbreviated as “acid-labile group (1)”.

In the group (1), R ^{a1 to} R ^a3 each independently represents a linear or branched aliphatic hydrocarbon group; or R ^a1 and R ^a2 are bonded to each other to form a ring. It may be. The “*” mark in the formula (1) represents the bonding position of the group (1). The same applies to other chemical formulas.

Examples of the acid labile group (1) include a 1,1-dialkylalkoxycarbonyl group (in the group (1), R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group), 2 -Alkyl-2-adamantyloxycarbonyl group (in the group (1), R ^a1 , 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 group (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

The acid solubilizing monomer (a1) is preferably a monomer having an acid labile group (1) and an olefinic double bond, more preferably a (meth) acryl having an acid labile group (1). Monomer. In the present specification, "(meth) acrylic monomer" means "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " at least one monomer having the structure To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

Among the (meth) acrylic monomers having an acid labile group (1), those having a cyclic C _5-20 aliphatic hydrocarbon group are preferred. If a resin obtained by polymerizing an acid-solubilizing monomer (a1) having a bulky structure such as a cyclic aliphatic hydrocarbon group is used, the resolution of the resist can be improved. The cyclic aliphatic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic aliphatic hydrocarbon group include a cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group) and a cycloalkenyl group (eg, cyclopentenyl group, cyclohexenyl group, cycloheptenyl group, Cyclooctenyl group) and the like. Examples of the polycyclic aliphatic hydrocarbon group include a group obtained by hydrogenating a condensed aromatic hydrocarbon group (for example, a hydronaphthyl group), a bridged cyclic hydrocarbon group (for example, an adamantyl group, a norbornyl group), and the like. . The bridged cyclic hydrocarbon group may have an unsaturated bond therein (for example, a norborneneyl group). In addition, a group having a shape in which a bridged ring (for example, norbornane ring) and a single ring (for example, cycloheptane ring or cyclohexane ring) or a polycycle (for example, decahydronaphthalene ring) are condensed, or A group having a condensed shape is also included in the cyclic aliphatic hydrocarbon group.

  Among (meth) acrylic monomers having an acid labile group (1) and a cyclic aliphatic hydrocarbon group, acid solubilization represented by formula (a1-1) or formula (a1-2) Monomers are preferred. 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 are each independently —O—, —O— (CH ₂ ) _k1 —CO—O—, —N (R ^a8 ). — (CH ₂ ) _k1 —CO—O—; k1 represents an integer of 1 to 7; R ^a8 represents a hydrogen atom or a linear or branched C _1-6 aliphatic hydrocarbon group; Represents. However, —O— and the like enumerated for L ^a1 and L ^a2 are respectively bonded to the carbonyl group of the formula (a1-1) and the formula (a1-2) on the left side and to the adamantyl group or cyclohexyl group on the right side. It means to do. R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group. R ^a6 and R ^a7 each independently represent a linear or branched C _1-8 aliphatic hydrocarbon group or a cyclic C _3-10 aliphatic hydrocarbon group; Represents an integer of 14; n1 represents an integer of 0 to 10; However, m1 or n1 being 0 means that no methyl group exists. The chemical formula in this specification includes stereoisomers.

R ^a4 and R ^a5 are preferably methyl groups. The carbon number of the linear or branched aliphatic hydrocarbon group of R ^a6 and R ^a7 is preferably 6 or less, and the carbon number of the cyclic aliphatic hydrocarbon group is preferably 8 or less, More preferably, it is 6 or less. Examples of the linear or branched aliphatic hydrocarbon group represented by R ^a6 and R ^a7 include a methyl group, an ethyl group, a 1-methylethyl group (isopropyl group), a 1,1-dimethylethyl group (tert- Butyl group), 2,2-dimethylethyl group, propyl group, 1-methylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, butyl group, 1-methylbutyl group, 2-methylbutyl group, 3- Examples include methylbutyl group, 1-propylbutyl group, pentyl group, 1-methylpentyl group, hexyl group, 1,4-dimethylhexyl group, heptyl group, 1-methylheptyl group, octyl group and the like. Examples of the cyclic aliphatic hydrocarbon group represented by 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. Can be mentioned. R ^a8 is preferably a hydrogen atom, a methyl group or an ethyl 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. k1 is preferably an integer of 1 to 4, more preferably 1.

  Examples of the acid-solubilizing monomer (a1-1) having an adamantyl group include the following. Among these, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) Acrylate and 2-isopropyl-2-adamantyl (meth) acrylate are preferred, and those in the form of methacrylate are more preferred.

  Examples of the acid solubilizing monomer (a1-2) having a cyclohexyl group include the following, among which 1-ethyl-1-cyclohexyl (meth) acrylate is preferable, and 1-ethyl-1-cyclohexyl is preferred. More preferred is methacrylate.

  The monomer having an acid labile group (1) and an olefinic double bond may be, for example, an acid solubilizing monomer having a norbornene ring represented by the formula (a1-3). Since the resin having a structural unit derived from the acid-solubilizing monomer (a1-3) has a bulky structure, the resolution of the resist can be improved. Furthermore, the acid solubilizing monomer (a1-3) can improve the dry etching resistance of the resist by introducing a rigid norbornane ring into the main chain of the resin.

In formula (a1-3), R ^a9 represents a hydrogen atom, a C _1-3 aliphatic hydrocarbon group, a carboxy group, a cyano group, or an alkoxycarbonyl group (which may have a substituent (for example, a hydroxy group)). -COOR ^a13 ); R ^a13 represents a linear, branched or cyclic C _1-8 aliphatic hydrocarbon group; the hydrogen atom of the aliphatic hydrocarbon group is substituted with a hydroxy group The methylene group (—CH ₂ —) of the aliphatic hydrocarbon group may be substituted with an oxygen atom (—O—) or a carbonyl group (—CO—). R ^{a10 to} R ^a12 each independently represent a linear, branched or cyclic C _1-12 aliphatic hydrocarbon group; or R ^a10 and R ^a11 are bonded to each other to form a ring The hydrogen atom of the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like; the methylene group (—CH ₂ —) of the aliphatic hydrocarbon group is an oxygen atom (—O—) Alternatively, it may be substituted with a carbonyl group (—CO—).

Examples of the aliphatic hydrocarbon group which may have a substituent for 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 cyclic aliphatic hydrocarbon group formed by R ^a10 , R ^a11 and the carbon to which they are bonded include a cyclohexyl group and an adamantyl group.

  Examples of the acid solubilizing monomer (a1-3) having a norbornene ring include 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5- 1-methylcyclohexyl norbornene-2-carboxylate, 2-methyl-2-adamantyl 5-norbornene-2-carboxylate, 2-ethyl-2-adamantyl 5-norbornene-2-carboxylate, 5-norbornene-2-carboxyl 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, 5-norbornene-2-carboxylic acid 1- ( - adamantyl) -1-methylethyl and the like.

  The resin (A) is preferably a copolymer of an acid-solubilizing monomer (a1) and a monomer having no acid-labile group (hereinafter sometimes abbreviated as “acid-stable monomer”). . An acid stable monomer may be used individually by 1 type, and may use 2 or more types together. When the resin (A) is a copolymer of an acid-solubilizing monomer (a1) and an acid-stable monomer, the structural unit derived from the acid-solubilizing monomer (a1) is preferably based on 100 mol% of all structural units. Is 10 to 80 mol%, more preferably 20 to 60 mol%. Moreover, it is preferable that the structural unit derived from the acid-solubilizing monomer having an adamantyl group (particularly, the acid-solubilizing monomer (a1-1)) is 15 mol% or more with respect to 100 mol% of the acid-solubilizing monomer (a1). . When the ratio of the acid solubilizing monomer having an adamantyl group is increased, the dry etching resistance of the resist is improved.

  As the acid stable monomer, those having a hydroxy group or a lactone ring are preferred. Derived from an acid stable monomer having a hydroxy group (hereinafter referred to as “acid stable monomer having a hydroxy group (a2)”) or an acid stable monomer having a lactone ring (hereinafter referred to as “acid stable monomer having a lactone ring (a3)”) If a resin having a structural unit to be used is used, the resolution of the resist and the adhesion to the substrate can be improved.

<Acid-stable monomer having a hydroxy group (a2)>
When the resist composition is used for KrF excimer laser exposure (248 nm), sufficient transmittance can be obtained even if hydroxystyrenes are used as the acid-stable monomer (a2) having a hydroxy group. However, when using shorter-wavelength ArF excimer laser exposure (193 nm) or the like, an acid-stable monomer having a hydroxyadamantyl group represented by the formula (a2-1) is used as the acid-stable monomer (a2) having a hydroxy group. It is desirable to do. The acid stable monomer (a2-1) having a hydroxyadamantyl group may be used alone or in combination of two or more.

In the formula (a2-1), L ^a3 represents an oxygen atom (—O—), a carbonyl group (—CO—), —N (R ^a17 ) —, a linear or branched C _1-17 alkane. Represents a diyl group or a combination thereof; R ^a17 represents a hydrogen atom or a linear or branched C _1-6 aliphatic hydrocarbon group; R ^a14 represents a hydrogen atom or a methyl group. R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group. o1 represents an integer of 0 to 10. However, o1 being 0 means that no methyl group is present.

La ³ having a shape in which an oxygen atom (—O—), a C _1-17 alkanediyl group, or the like is combined preferably has 17 or fewer atoms constituting its main chain. The L ^a3 combination shape, for example -O-C _1-16 alkanediyl -, - C _1-16 alkanediyl -O -, - C _j1 alkanediyl -O-C _i1 alkanediyl - (wherein, 1 ≦ j1, 1 ≦ i1, j1 + i1 ≦ 16, and so on);
-CO-C _1-16 alkanediyl-, -C _1-16 alkanediyl-CO-, -C _j1 alkanediyl-CO-C _i1 alkanediyl-;
-N (R ^a17) -C _1-16 alkanediyl -, - C _1-16 alkanediyl ^{-N (R a17) -, -} C j1 alkanediyl -N (R ^a17) -C _i1 alkanediyl -;
-CO-O-, -CO-O-C _1-15 alkanediyl-, -C _1-15 alkanediyl-CO-O-, -C _h1 alkanediyl-CO-O-C _g1 alkanediyl- 1 ≦ h1, 1 ≦ g1, h1 + g1 ≦ 15, and so on);
-O-CO-, -O-CO-C _1-15 alkanediyl-, -C _1-15 alkanediyl-O-CO-, -C _h1 alkanediyl-O-CO-C _g1 alkanediyl-;
-O-C _1-14 alkanediyl-CO-O-, -CO-O-C _1-14 alkanediyl-O-, -CO-O-C _1-13 alkanediyl-CO-O-;
Etc. In addition, —O—C _1-16 alkanediyl- and the like enumerated for ^{La 3} mean that they are bonded to the carbonyl group of the formula (a2-1) on the left side and to the hydroxyadamantyl group on the right side.

L ^a3 is preferably —O—, —O— (CH ₂ ) _f1 —CO—O—, —N (R ^a17 ) — or —N (R ^a17 ) — (CH ₂ ) _e1 —CO—O—. (Wherein R ^a17 is preferably a hydrogen atom, a methyl group or an ethyl group, and f1 and e1 are each independently an integer of 1 to 4), more preferably —O—. . R ^a4 is preferably a methyl group. R ^a15 is preferably a hydrogen atom. R ^a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

  Examples of the acid-stable monomer (a2-1) having a hydroxyadamantyl group include the following. Among these, 3-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl ( 1- (3,5-dihydroxy-1-adamantyloxycarbonyl) methyl (meth) acrylate and (meth) acrylate are preferred; 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl ( More preferred are (meth) acrylates; 3-hydroxy-1-adamantyl methacrylate and 3,5-dihydroxy-1-adamantyl methacrylate are even more preferred.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid-stable monomer (a3) may be a single ring such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a monocyclic lactone ring and another ring. A condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring and a condensed ring of a γ-butyrolactone ring and another ring are preferable.

  The acid stable monomer (a3) having a lactone ring is preferably represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). These 1 type may be used independently and may use 2 or more types together.

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 each independently represent an oxygen atom (—O—), a carbonyl group (—CO—), —N (R ^a24 ) —, A linear or branched C _1-17 alkanediyl group, or a combination thereof; R ^a24 represents a hydrogen atom or a linear or branched C _1-6 aliphatic hydrocarbon group; Represents. R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group. R ^a21 represents a C _1-4 aliphatic hydrocarbon group, and p1 represents an integer of 0 to 5. R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group or a C _1-4 aliphatic hydrocarbon group, and q1 and r1 each independently represent an integer of 0 to 3. However, p1, q1 or r1 being 0 means that R ^a21 , R ^a22 or R ^a23 does not exist, respectively, and when p1, q1 or r1 is 2 or more, a plurality of R ^a21 , R 1, respectively. ^a22 or R ^a23 may be the same as or different from each other.

Examples of L ^{a4 to} L ^a6 include those described for L ^a3 . L ^{a4 to} L ^a6 are each independently preferably —O—, —O— (CH ₂ ) _d1 —CO—O—, —N (R ^a24 ) —, or —N (R ^a24 ) — (CH ₂ ). _c1 —CO—O— (wherein R ^a24 is preferably a hydrogen atom, a methyl group or an ethyl group, and d1 and c1 are each independently an integer of 1 to 4), -O- is preferable. However, —O— and the like enumerated for L ^{a4 to} L ^a6 mean that they are bonded to the carbonyl group of the formula (a3-1) to the formula (a3-3) on the left side and bonded to the lactone ring on the right side. . 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 carboxy 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 acid stable monomer (a3-1) having a γ-butyrolactone ring include the following.

  Examples of the acid stable monomer (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring include the following.

  Examples of the acid stable monomer (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring include the following.

Among acid-stable monomers (a3) 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, 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yloxy) -2-oxoethyl (meth) acrylate Are preferred, and those in the form of methacrylate are more preferred.

<Other acid stable monomers (a4)>
Examples of the other acid stable monomer (a4) include maleic anhydride represented by formula (a4-1), itaconic anhydride represented by formula (a4-2), and formula (a4-3). And acid-stable monomers having a norbornene ring.

In formula (a4-3), R ^a25 and R ^a26 each independently represent a hydrogen atom, a C _1-3 aliphatic hydrocarbon group ^optionally having a substituent (for example, a hydroxy group), a cyano group, or a carboxy group. R ^a25 and R ^a26 are bonded to each other to form a carbonyloxycarbonyl group: —CO—O—CO—; R ^a27 is a straight-chain group, or an alkoxycarbonyl group (—COOR ^a27 ); Represents a branched or cyclic C _1-36 aliphatic hydrocarbon group; the methylene group (—CH ₂ —) of the cyclic aliphatic hydrocarbon group is an oxygen atom (—O—) or a carbonyl group ( -CO-) may be substituted. However, those in which —COOR ^a27 is an acid labile group are excluded (that is, R ^a27 does not include those in which a tertiary carbon atom is bonded to an oxygen atom (—O—)).

^Examples of the aliphatic hydrocarbon group which may have a substituent for R ^a25 and R ^a26 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group. The carbon number of the linear or branched aliphatic hydrocarbon group of R ^a27 is preferably 1-8, more preferably 1-6, and the carbon number of the cyclic aliphatic hydrocarbon group is preferably Is 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 acid-stable monomer (a4-3) having a norbornene ring include 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene-2-carboxylic acid, methyl 5-norbornene-2-carboxylate, and 5-norbornene. Examples include 2-hydroxy-1-ethyl-2-carboxylate, 5-norbornene-2-methanol, 5-norbornene-2,3-dicarboxylic acid anhydride, and the like.

  A preferred resin (A) is a copolymer obtained by polymerizing at least an acid-solubilizing monomer (a1), an acid-stable monomer (a2) having a hydroxy group, and an acid-stable monomer (a3) having a lactone ring. In this preferable copolymer, the acid-solubilizing monomer (a1) is more preferably at least of an acid-solubilizing monomer (a1-1) having an adamantyl group and an acid-solubilizing monomer (a1-2) having a cyclohexyl group. One type (more preferably an acid solubilizing monomer (a1-1) having an adamantyl group), and an acid stable monomer (a2) having a hydroxy group, preferably an acid stable monomer (a2-1) having a hydroxyadamantyl group The acid-stable monomer (a3) having a lactone ring is more preferably an acid-stable monomer (a3-1) having a γ-butyrolactone ring and an acid-stable monomer having a condensed ring of a γ-butyrolactone ring and a norbornane ring ( a3-2). 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).

  It is preferable that content of resin (A) is 80 mass% or more in solid content of a composition. In the present specification, the “solid content in the composition” means the total of the composition components excluding the solvent (D). The solid content in the composition and the content of the resin (A) relative thereto can be measured by known analytical means such as liquid chromatography or gas chromatography.

<Acid generator (B)>
The acid generator (B) is classified into a nonionic type and an ionic type. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, DNQ 4- Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the onium salt anion include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include not only an acid generator (particularly a photoacid generator) used in the resist field, but also a photoinitiator for photocationic polymerization, a photodecolorant for dyes, or a photochromic agent Known compounds that generate an acid by radiation (light) and mixtures thereof can also be used as appropriate. For example, JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A 62-153853, Acid can be obtained by radiation described in Japanese Utility Model Laid-Open No. 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. The resulting compound can be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (B1).

In formula (B1), Q ¹ and Q ² each independently represent a fluorine atom or a C _1-6 perfluoroalkyl group. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. . Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

In formula (B1), Y represents a cyclic C _3-36 aliphatic hydrocarbon group. Y may apparently be a cyclic aliphatic hydrocarbon group in which a methylene group (—CH ₂ —) is substituted with an oxygen atom (—O—) or a carbonyl group (—CO—). That is, Y represents, for example, a cyclic ether group {methylene group (—CH ₂ —) substituted with an oxygen atom (—O—)}, a cyclic aliphatic hydrocarbon group having an oxo group {methylene group (—CH ₂ — ) Is substituted with a carbonyl group (—CO—)} or a lactone ring group {two adjacent methylene groups (—CH ₂ —) are each an oxygen atom (—O—) or a carbonyl group (—CO—), respectively. Replacement}.

  Examples of the cyclic aliphatic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y24).

  The cyclic aliphatic hydrocarbon group is preferably a group represented by any one of the formulas (Y1) to (Y19), more preferably the formula (Y11), the formula (Y14), the formula (Y15) or It is group represented by a formula (Y19), More preferably, it is group represented by a formula (Y11) or a formula (Y14).

Y may have a substituent. Examples of the substituent for Y include a halogen atom (excluding a fluorine atom), a hydroxy group, an oxo group, a linear or branched C _1-12 aliphatic hydrocarbon group, and a hydroxy group-containing C _1-12. Aliphatic hydrocarbon group, C _1-12 alkoxy group, C _6-18 aromatic hydrocarbon group, C _7-21 aralkyl group, C _2-4 acyl group, glycidyloxy group, or — (CH ₂ ) _j2 —O —CO—R ^b1 group (wherein R ^b1 represents a linear, branched or cyclic C _1-16 aliphatic hydrocarbon group or a C _6-18 aromatic hydrocarbon group. J2 Represents an integer of 0 to 4, where j2 is 0 means that no methylene group is present. The aliphatic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are substituents for Y, may further have a substituent. Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. Examples of the linear or branched aliphatic hydrocarbon group include those described for the resin (A). Examples of the hydroxy group-containing aliphatic hydrocarbon group include a hydroxymethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group. Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthranyl group, a p-methylphenyl group, a p-tert-butylphenyl group, and a p-adamantylphenyl group. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group, and the like. Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group. The plurality of substituents may be the same as or different from each other.

  Hereinafter, Y having a substituent is exemplified. First, examples of Y having an aliphatic hydrocarbon group include the following.

  Examples of Y having a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group include the following.

  Examples of Y having an aromatic hydrocarbon group include the following.

Examples of Y having a — (CH ₂ ) _j2 —O—CO—R ^b1 group include the following.

  Y is preferably an adamantyl group optionally having a substituent (for example, an oxo group), more preferably an adamantyl group or an oxoadamantyl group.

In formula (B1), L ^b1 represents a single bond or a linear, branched or cyclic divalent C _1-17 saturated aliphatic hydrocarbon group which may have a substituent. . As the divalent saturated aliphatic hydrocarbon group, first, a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a 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 group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl Group, heptadecane-1,17-diyl group. L ^b1 may be a branched alkanediyl group. Examples of the branched alkanediyl group include, for example, the above-mentioned linear alkanediyl group, an apparently linear or branched C _1-4 alkyl group (for example, a methyl group, an ethyl group, a propyl group, And isopropyl group, butyl group, sec-butyl group, tert-butyl group and the like). Examples of the cyclic divalent saturated aliphatic hydrocarbon group include a cycloalkanediyl group (for example, cyclohexanediyl group) and a divalent bridged cyclic hydrocarbon group (for example, adamantanediyl group). The shape of the saturated aliphatic hydrocarbon group for L ^b1 may be a combination of at least two of linear, branched and cyclic.

The divalent saturated aliphatic hydrocarbon group represented by L ^b1 is, for example, a halogen atom, a hydroxy group, a C _6-18 aromatic hydrocarbon group, a C _7-21 aralkyl group, a C _2-4 acyl group, or a substituent. It may have a glycidyloxy group.

The methylene group (—CH ₂ —) of L ^b1 may be substituted with an oxygen atom (—O—) or a carbonyl group (—CO—). L ^b1 is preferably any one of the formulas (b1-1) to (b1-6), more preferably any of the formulas (b1-1) to (b1-4), and even more preferably the formula (b1- 1) or represented by formula (b1-2). Note the formula (b1-1) ~ formula (b1-6) has its left and right are described in accordance with the formula (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side - Combine with Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

Formula (b1-1) and L ^{b2 each} represent a single bond or a linear or branched C _1-15 alkanediyl group.
In the formula (b1-2), L ^b3 represents a single bond or a linear or branched C _1-12 alkanediyl group; L ^b4 represents a linear or branched C _{1. -13} represents an alkanediyl group. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13 or less.
In formula (b1-3), L ^b5 represents a linear or branched C _1-15 alkanediyl group.
In formula (b1-4), L ^b6 and L ^b7 each independently represent a linear or branched C _1-15 alkanediyl group. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 16 or less.
In formula (b1-5), L ^b8 represents a linear or branched C _1-14 alkanediyl group.
In formula (b1-6), L ^b9 and L ^b10 each independently represent a linear, branched, or cyclic C _1-11 alkanediyl group. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 12 or less.
Connecting portions Among these (b1-1) is preferable, L ^b2 represents a single bond or a methylene group (-CH ₂ -) connection part is (b1-1) is preferable.

  As a connection part (b1-1), the following are mentioned, for example.

  As a connection part (b1-2), the following are mentioned, for example.

  As a connection part (b1-3), the following are mentioned, for example.

  As a connection part (b1-4), the following are mentioned, for example.

  As a connection part (b1-5), the following are mentioned, for example.

  As a connection part (b1-6), the following are mentioned, for example.

  What has a connection part (b1-1) for a sulfonate anion is preferable, and what is represented by a formula (b1-1-1)-a formula (b1-1-9) is more preferable.

In formula (b1-1-1) to formula (b1-1-9), Q ¹ , Q ² and L ^b2 are the same as described above. R ^b2 and R ^b3 each independently represent a C _1-4 aliphatic hydrocarbon group (preferably a methyl group).

  Next, specific sulfonate anions are exemplified. First, for example, a sulfonate anion containing unsubstituted Y and a linkage (b1-1); or a sulfonate anion containing Y having an aliphatic hydrocarbon group and a linkage (b1-1); Can be mentioned.

Examples of the sulfonate anion containing Y having — (CH ₂ ) _j2 —O—CO—R ^b1 group and the connecting portion (b1-1) include the following.

  Examples of the sulfonate anion containing Y having a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and the linking part (b1-1) include the following.

  Examples of the sulfonate anion containing Y having an aromatic hydrocarbon group or aralkyl group and the linking part (b1-1) include the following.

  Examples of the sulfonate anion containing Y which is a cyclic ether and the linking part (b1-1) include the following.

  Examples of the sulfonate anion containing the lactone ring Y and the linking part (b1-1) include the following.

  Examples of the sulfonate anion containing Y having an oxo group and the linking part (b1-1) include the following.

  Examples of the sulfonate anion containing unsubstituted Y and the linking part (b1-2); or the sulfonate anion containing Y having an aliphatic hydrocarbon group and the linking part (b1-2); Is mentioned.

Examples of the sulfonate anion containing Y having — (CH ₂ ) _j2 —O—CO—R ^b1 group and the linking moiety (b1-2) include the following.

  Examples of the sulfonate anion containing Y having a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and the linking part (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a cyclic ether and the linking part (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a lactone ring and the linking part (b1-2) include the following.

  Examples of the sulfonate anion containing Y having an oxo group and the linking moiety (b1-2) include the following.

  Examples of the sulfonate anion containing Y having an aromatic hydrocarbon group and the linking part (b1-2) include the following.

  Examples of the sulfonate anion containing unsubstituted Y and the linking part (b1-3); or the sulfonate anion containing Y having an aliphatic hydrocarbon group and the linking part (b1-3); Is mentioned.

  Examples of the sulfonate anion containing Y having an alkoxy group and the linking part (b1-3) include the following.

  Examples of the sulfonate anion containing Y having a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and the linking part (b1-3) include the following.

  Examples of the sulfonate anion containing Y having an oxo group and the linking part (b1-3) include the following.

  Examples of the sulfonate anion containing Y having an aliphatic hydrocarbon group and the connecting portion (b1-4) include the following.

  Examples of the sulfonate anion containing Y having an alkoxy group and the linking part (b1-4) include the following.

  Examples of the sulfonate anion containing Y having a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and the linking part (b1-4) include the following.

  Examples of the sulfonate anion containing Y having an oxo group and the linking part (b1-4) include the following.

  Among the above-mentioned ones, the following sulfonate anions having the connecting portion (b1-1) are preferable.

  Next, the cation contained in the acid generator (B) will be described. Examples of the cation of the acid generator include onium cations such as sulfonium cations, iodonium cations, ammonium cations, benzothiazolium cations, and phosphonium cations. Among these, a sulfonium cation and an iodonium cation are preferable, and an arylsulfonium cation is more preferable.

Z ⁺ in formula (B1) is preferably represented by any of formula (b2-1) to formula (b2-4).

In formula (b2-1), R ^{b4 to} R ^b6 are each independently a linear, branched or cyclic C _1-30 aliphatic hydrocarbon group, or a C _6-18 aromatic hydrocarbon. Represents a group. The linear, branched or cyclic aliphatic hydrocarbon group includes a hydroxy group, and a linear or branched C _1-12 alkoxy group and a C _6-18 aromatic hydrocarbon group. The cyclic aliphatic hydrocarbon group may be substituted with at least one selected from the group consisting of a halogen atom, a C _2-4 acyl group, and a glycidyloxy group. The aromatic hydrocarbon group may be a halogen atom, a hydroxy group, a linear, branched or cyclic C _1-36 aliphatic hydrocarbon group, and a C _1-12 alkoxy It may be substituted with at least one selected from the group consisting of groups.

In formula (b2-2), R ^b7 and R ^b8 each independently represent a hydroxy group, a linear or branched C _1-12 aliphatic hydrocarbon group, or a linear or branched chain the C _1-12 alkoxy group, the m2 and n2, integer (preferably 0 or 1) each independently 0-5 represent a. However, m2 or n2 is 0 means that each substituent does not exist, and when m2 or n2 is 2 or more, a plurality of R ^b7 and R ^b8 may be the same or different from each other. .

In formula (b2-3), R ^b9 and R ^b10 each independently represent a linear, branched, or cyclic C _1-36 aliphatic hydrocarbon group. R ^b11 represents a hydrogen atom, a linear, branched or cyclic C _1-36 aliphatic hydrocarbon group, or a C _6-18 aromatic hydrocarbon group. The carbon number of the linear or branched aliphatic hydrocarbon group of R ^{b9 to} R ^b11 is preferably 1 to 12, and the carbon number of the cyclic aliphatic hydrocarbon group is preferably 3 to 36, more preferably 4-12. R ^b12 represents a linear, branched or cyclic C _1-12 aliphatic hydrocarbon group or a C _6-18 aromatic hydrocarbon group. The aromatic hydrocarbon group includes a linear, branched or cyclic C _1-12 aliphatic hydrocarbon group, a linear or branched C _1-12 alkoxy group, and an alkylcarbonyloxy The alkyl group may be substituted with at least one selected from the group consisting of a group (including a cyclic saturated aliphatic hydrocarbon group). R ^b9 and R ^b10 and R ^b11 and R ^b12 may be independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring); These rings may contain at least one selected from the group consisting of an oxygen atom (O), a sulfur atom (S), and a carbon atom (CO) bonded to an oxo group as atoms forming the ring. .

In formula (b2-4), R ^{b13 to} R ^b18 each independently represent a hydroxy group, a linear or branched C _1-12 aliphatic hydrocarbon group, a linear or branched chain C _1-12 represents an alkoxy group. L ^b11 represents a sulfur atom or an oxygen atom. o2, p2, s2 and t2 each independently represent an integer of 0 to 5 (preferably an integer of 0 to 2), and q2 and r2 each independently represent an integer of 0 to 4 (preferably an integer of 0 to 2) ) And u2 represents 0 or 1. However, when any of o2 to u2 is 0, it means that each substituent does not exist. When any of o2 to t2 is 2, any one of a plurality of R ^{b13 to} R ^b18 is present. May be the same as or different from each other.

Next, substituents included in the formulas (b2-1) to (b2-4) will be described. Examples of the aliphatic hydrocarbon group and the aromatic hydrocarbon group include those described above. Preferred linear or branched aliphatic hydrocarbon groups are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl. A group, an octyl group, and a 2-ethylhexyl group. Preferred cyclic aliphatic hydrocarbon groups are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclodecyl, 2-alkyl-2-adamantyl, 1- (1-adamantyl) -1- An alkyl group and an isobornyl 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, naphthyl group. It is. Examples of the aliphatic hydrocarbon group (aralkyl group) whose substituent is an aromatic hydrocarbon group include a benzyl group. Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, n-hexoxy, heptoxy, octoxy Group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like. Examples of the ring formed by R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. ^Examples of the ring formed by R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, the cation represented by the formula (b2-1-1) is more preferable, and the triphenylsulfonium cation (formula (b2) In (1-1), v2 = w2 = x2 = 0) is more preferable.

In formula (b2-1-1), R ^{b19 to} R ^b21 each independently represent a halogen atom, a hydroxy group, a linear, branched, or cyclic C _1-36 aliphatic hydrocarbon group, or A linear or branched C _1-12 alkoxy group is represented. The linear or branched aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, and the cyclic aliphatic hydrocarbon group preferably has 4 to 36 carbon atoms. The linear, branched or cyclic aliphatic hydrocarbon group includes a hydroxy group, and a linear or branched C _1-12 alkoxy group and a C _6-18 aromatic hydrocarbon group. The cyclic aliphatic hydrocarbon group may be substituted with at least one selected from the group consisting of a halogen atom, a C _2-4 acyl group, and a glycidyloxy group. May be substituted. v2 to x2 each independently represents an integer of 0 to 5 (preferably 0 or 1). However, when any one of v2 to x2 is 0, it means that R ^{b19 to} R ^b21 do not exist, respectively, and when any one of v2 to x2 is 2 or more, a plurality of R ^{b19 to} R ^b21 respectively. May be the same as or different from each other.

R ^{b19 to} R ^b21 in formula (b2-1-1) are each independently preferably a halogen atom (more preferably a fluorine atom), a hydroxy group, a linear or branched C _1-12. Represents an alkyl group or a C _1-12 alkoxy group; v2 to x2 each independently represents an integer of 0 to 5 (preferably 0 or 1). However, if any of v2 to x2 is 0, it means that R ^{b19 to} R ^b21 do not exist, respectively.

  Next, specific cations contained in the acid generator (B) are exemplified. First, specific examples of the cation (b2-1-1) include the following.

  Specific examples of the cation (b2-2) include the following.

  Specific examples of the cation (b2-3) include the following.

  Specific examples of the cation (b2-4) include the following.

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, but any one of anion (b1-1-1) to anion (b1-1-9) and a cation (b2-1-1), and an anion ( A combination of any one of b1-1-3) to (b1-1-5) and a cation (b2-3) is preferable.

  Preferred acid generators (B1) are those represented by formulas (B1-1) to (B1-16), and among these, acid generators (B1-1) and (B1) containing a triphenylsulfonium cation. -2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14) are more preferred.

  The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 20 parts by mass or less (more preferably 15 parts by mass) with respect to 100 parts by mass of the resin (A). Part or less).

<Salt (C1)>
One feature of the resist composition of the present invention is that it contains a salt (C1) as the basic compound (C) (quencher). By using the salt (C1), the pattern shape and line edge roughness of the resist can be improved.

In formula (C1), R ^{c1 to} R ^c4 each independently represents a linear, branched or cyclic C _1-10 saturated aliphatic hydrocarbon group, C _7-18 aralkyl group, or C _{6. Represents an -18} aromatic hydrocarbon group, which may have a substituent. Carbon number of the said linear or branched saturated aliphatic hydrocarbon group (namely, alkyl group) becomes like this. Preferably it is 1-7, More preferably, it is 2-6. The cyclic saturated aliphatic hydrocarbon group preferably has 3 to 10 carbon atoms, more preferably 5 to 10 carbon atoms. The aralkyl group preferably has 7 to 10 carbon atoms. The aromatic hydrocarbon group preferably has 6 to 10 carbon atoms. The hydrogen atoms of the saturated aliphatic hydrocarbon group, aralkyl group and aromatic hydrocarbon group are each independently substituted with at least one selected from the group consisting of a hydroxy group, an amino group and a C _1-6 alkoxy group. The hydrogen atom of the amino group may be substituted with a linear or branched C _1-4 alkyl group. The hydrogen atom on the aromatic ring of the aralkyl group and aromatic hydrocarbon group may be substituted with a linear, branched or cyclic C _1-30 saturated aliphatic hydrocarbon group.

Examples of the linear or branched alkyl group such as R ^c1 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. And heptyl group. Examples of the cyclic saturated aliphatic hydrocarbon group such as R ^c1 include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, norbornyl group, 1- Examples thereof include an adamantyl group, a 2-adamantyl group, and an isobornyl group. Examples of the aralkyl group such as R ^c1 include a benzyl group, a phenylethyl group, and a phenylpropyl group. Examples of the aromatic hydrocarbon group such as R ^c1 include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, xylyl group, cumenyl group, mesityl group. Group, biphenylyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl and the like.

  Examples of the salt (C1) include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetra-n-hexylammonium hydroxide, tetra-n. -Heptylammonium hydroxide, phenyltrimethylammonium hydroxide, (3-trifluoromethyl) phenyltrimethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide (common name: choline), benzyltriethylammonium hydroxide, etc. . Among these, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and (2-hydroxyethyl) trimethylammonium hydroxide are preferable.

  A salt (C1) may be used individually by 1 type, and may use 2 or more types together. The content of the salt (C1) is 0.05% by mass or more (preferably 0.1% by mass or more) and 2% by mass or less (preferably 1% by mass or less) in the solid content of the composition.

<Other basic compounds (C)>
The resist composition of the present invention may contain another basic compound (C) different from the salt (C1). However, in order not to impair the effects of the present invention, the content of the other basic compound (C) is preferably 200 parts by mass or less, more preferably with respect to 100 parts by mass of the salt (C1). It is desirable to limit it to 150 parts by mass or less, more preferably 100 parts by mass or less. Moreover, when using another basic compound (C), the total amount of it and a salt (C1) is in solid content of a composition, Preferably it is 2 mass% or less, More preferably, it is 1 mass% or less.

  The other basic compound (C) is preferably a basic nitrogen-containing organic compound (for example, an amine). The amine may be an aliphatic amine or an aromatic amine. As the aliphatic amine, any of primary amine, secondary amine and tertiary amine can be used. The aromatic amine may be any of an amino group bonded to an aromatic ring such as aniline and a heteroaromatic amine such as pyridine. Preferable other basic compounds (C) include aromatic amines represented by the formula (C2), particularly anilines represented by the formula (C2-1).

In the formula (C2), Ar ^c1 represents an aromatic hydrocarbon group. R ^c5 and R ^c6 each independently represent a hydrogen atom, a linear, branched or cyclic aliphatic hydrocarbon group (preferably a linear or branched alkyl group or a cycloalkyl group). Or represents an aromatic hydrocarbon group. However, the hydrogen atom of the aliphatic hydrocarbon group or the aromatic hydrocarbon group may be substituted with a hydroxy group, an amino group, or a linear or branched C _1-6 alkoxy group; The amino group may be substituted with a linear or branched C _1-4 alkyl group. The linear or branched aliphatic hydrocarbon group preferably has about 1 to 6 carbon atoms, and the cyclic aliphatic hydrocarbon group preferably has about 5 to 10 carbon atoms. The number of carbon atoms of the aromatic hydrocarbon group is preferably about 6 to 10.

In formula (C2-1), R ^c5 and R ^c6 are the same as described above. R ^c7 represents a linear, branched or cyclic aliphatic hydrocarbon group (preferably a linear or branched alkyl group or a cycloalkyl group), a linear or branched chain An alkoxy group or an aromatic hydrocarbon group is represented. However, the hydrogen atom of an aliphatic hydrocarbon group, an alkoxy group, or an aromatic hydrocarbon group may have the substituent described in Formula (C2). m3 represents an integer of 0 to 3. However, m3 being 0 means that R ^c7 does not exist. When m3 is 2 or more, a plurality of R ^{c7 s} may be the same or different. The preferred number of carbon atoms of the aliphatic hydrocarbon group and aromatic hydrocarbon group of R ^c7 is independently in are the same as those of the formula (C2), the carbon number of the alkoxy group R ^c7 is independently in, preferably about 1-6.

  Examples of the aromatic amine (C2) include 1-naphthylamine and 2-naphthylamine. Examples of aniline (C2-1) include aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine and the like. Of these, diisopropylaniline (particularly 2,6-diisopropylaniline) is preferable.

  Moreover, as another basic compound (C), the compound represented by Formula (C3)-Formula (C11) is mentioned.

R ^c8 in formula (C3) represents any of the groups described for R ^c7 in formula (C2). R ^c9 , R ^c10 , R ^{c11 to} R ^c14 , R ^{c16 to} R ^c19 and R ^c22 bonded to the nitrogen atom in formula (C3) to formula (C8) are each independently R ^{c5 in} formula (C2) and It represents one of the groups described for R ^c6 . R ^c20 , R ^c21 and R ^{c23 to} R ^c28 bonded to the aromatic carbon in formula (C7) to formula (C11) are each independently any group described for R ^c7 in formula (C2-1) Represents. O3 to u3 in Formula (C7) and Formula (C9) to Formula (C11) each independently represents an integer of 0 to 3. However, when any of o3 to u3 is 0, it means that each substituent does not exist. When any of o3 to u3 is 2 or more, any of a plurality of R ^{c20 to} R ^c28 is present. May be the same or different.

R ^c15 in formula (C6) represents a linear, branched or cyclic aliphatic hydrocarbon group, or an alkanoyl group, and n3 represents an integer of 0 to 8. However, n3 being 0 means that R ^c15 does not exist. When n3 is 2 or more, a plurality of R ^{c15 s} may be the same as or different from each other. The carbon number of the aliphatic hydrocarbon group for R ^c15 is preferably about 1 to 6, and the carbon number of the alkanoyl group for R ^c15 is preferably about 2 to 6.

L ^c1 and L ^{c2 in} formula (C7) and formula (C10) are each independently a divalent aliphatic hydrocarbon group (preferably an alkylene group), a carbonyl group (—CO—), an imino group, a thio group ( -S-), a dithio group (-SS-), or a combination thereof. The divalent aliphatic hydrocarbon group preferably has about 2 to 6 carbon atoms.

  Examples of the compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, Tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctyl Amine, methyl dinonyl amine, methyl didecyl amine, ethyl dibutyl amine, ethyl dipentyl amine, ethyl di Silamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylene Examples include diamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and the like.

  Examples of the compound (C4) include piperazine. Examples of the compound (C5) include morpholine. Examples of the compound (C6) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575. Examples of the compound (C7) include 2,2′-methylenebisaniline.

  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) 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′-dipyridyl sulfide, 4, 4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine and the like can be mentioned. Examples of the compound (C11) include bipyridine.

<Solvent (D)>
One feature of the resist composition of the present invention is that it contains the solvent (D) in an amount of 90% by mass or more in the composition. The resist composition of the present invention containing a large amount of solvent (D) is suitable for producing a thin film resist. The content of the solvent (D) is 90% by mass or more (preferably 92% by mass or more, more preferably 94% by mass or more) and 99.9% by mass or less (preferably 99% by mass or less) in the composition. The content of the solvent (D) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (D) 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; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (D) may be used individually by 1 type, and may use 2 or more types together.

<Other optional components (E)>
The resist composition of the present invention may contain other optional component (E) as necessary. The optional component (E) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, dyes and the like can be used.

<Method for producing resist pattern>
The resist pattern manufacturing method is usually
(1) A step of applying a resist composition onto a substrate to obtain a resist film (hereinafter abbreviated as “application step 1”);
(2) a step of pre-baking the resist film (hereinafter abbreviated as “pre-baking step 2”);
(3) a step of exposing the pre-baked resist film (hereinafter abbreviated as “exposure step 3”);
(4) a step of post-exposure baking of the exposed resist film (hereinafter abbreviated as “post-exposure baking step 4”);
(5) a step of developing a post exposure baked resist film with an alkali developer to obtain a resist pattern (hereinafter referred to as “development step 5”). Hereinafter, each process is demonstrated in order.

<Application process 1>
In applying the resist composition, it is desirable to previously mix the components of the resist composition in a solvent, and then filter through a filter having a pore size of about 0.2 μm or less. By filtering, the uniformity when applying the resist composition is improved.

  The substrate on which the resist composition is applied can be appropriately selected depending on the application. Examples of the substrate include a silicon wafer and a quartz wafer on which sensors, circuits, transistors, and the like are formed.

  As a method for forming a coating film of a resist composition on a substrate, a coating method known in the resist field can be adopted. Among known coating methods, the spin coating method is preferable. The resist composition of the present invention is suitable for the production of a thin film resist, and is applied by a spin coating method so that the thickness of the resist film after pre-baking is 80 nm or less (more preferably 75 nm or less, more preferably 70 nm or less). It is more preferable.

<Pre-baking process 2>
Pre-baking is performed using a heating device such as a hot plate, for example. By pre-baking, a composition layer (resist film after pre-baking) from which the solvent has been removed is formed. The prebake temperature is, for example, 50 to 200 ° C. The thickness of the resist film after pre-baking is preferably 10 nm or more (more preferably 30 nm or more, more preferably 50 nm or more), preferably 80 nm or less (more preferably 75 nm or less, and further preferably 70 nm or less). The film thickness of the resist film after pre-baking can be measured using a commercially available film thickness measuring device (for example, “Lambda Ace” manufactured by Dainippon Screen). In order to suppress variations in the measured value of the film thickness, it is preferable to employ sampling and averaging methods as in the following examples.

<Exposure process 3>
The pre-baked resist film is exposed through a mask corresponding to the required pattern. The exposure may be either dry exposure or immersion exposure. The exposure light source is preferably an ArF excimer laser. For example, a reduction projection type exposure machine is used as the exposure machine.

<Post-exposure baking process 4>
The exposed resist film is subjected to a heat treatment (post-exposure bake) in order to promote the deprotection group reaction by the acid in the exposed portion. The post-exposure bake temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

<Development step 5>
The resist film after post-exposure baking is developed with an alkaline developer by a developing device. As the alkaline developer, an alkaline aqueous solution known in the resist field, for example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline) can be used. After development, it is preferable to rinse with ultrapure water to remove water remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention is a resist composition for ArF excimer laser exposure, particularly a thin film ArF excimer laser in which the thickness of the resist film after pre-baking is 80 nm or less (more preferably 75 nm or less, more preferably 70 nm or less). It is suitable as a resist composition for exposure. If the resist composition of the present invention is used for the production of a thin film resist, the resist pattern shape and line edge roughness can be further improved.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and appropriate modifications are made within a range that can meet the above and the following purposes. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

  In the following,% and parts representing the content or amount used are based on mass unless otherwise specified.

The weight average molecular weight (hereinafter abbreviated as “Mw”) of the resin is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC (manufactured by Tosoh Corporation)
Column: 3 “TSKgel Multipore H _XL- M” + “guardcolumn” (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μL
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

  The structure of the compound is NMR (GX-270 type or EX-270 type; manufactured by JEOL Ltd.), mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type) It confirmed using.

1. Synthesis of Resin (A) Resin (A1) to Resin (A4) were synthesized using the following monomers. Table 1 summarizes the molar ratio of the monomers of the resin (A1) to the resin (A4) and Mw.

(1) Synthesis of Resin (A1) Monomer (a1-1-1), Monomer (a1-2-1), Monomer (a2-1-1), Monomer (a3-1-1), and Monomer (a3-2) -1) was charged at a molar ratio of 30: 14: 6: 20: 30, and then 1.5 mass times dioxane was added to the total mass of the monomers. To the resulting mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, based on the total number of moles of monomers. This was heated at 73 ° C. for about 5 hours. Thereafter, the reaction solution is purified by performing the operation of pouring it in a large amount of methanol and water mixed solvent (4: 1) and precipitating three times to obtain a copolymer having an Mw of about 8.1 × 10 ^3. Obtained at 65%. The obtained copolymer has a structural unit derived from each monomer, and this was made into resin (A1).

(2) Synthesis of Resin (A2) Monomer (a1-1-2), monomer (a2-1-1), monomer (a3-1-1) and monomer (a3-2-1) were mixed at a molar ratio of 40: The mixture was charged at a ratio of 10:20:30, and then 1.5 mass times dioxane was added to the total mass of the monomers. To the resulting mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, based on the total number of moles of monomers. This was heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol and water mixed solvent (4: 1) and precipitating three times to obtain a copolymer having a Mw of about 7.8 × 10 ^3. Obtained at 64%. The obtained copolymer had a structural unit derived from each monomer, and this was made into resin (A2).

(3) Synthesis of Resin (A3) Monomer (a1-1-3), monomer (a2-1-1) and monomer (a3-1-1) were charged in a molar ratio of 50:25:25, and then , 2.06 mass times dioxane was added to the total mass of the monomers. To the obtained mixture, azobisisobutyronitrile as an initiator was added in a proportion of 4 mol% based on the total number of moles of monomers, and this was heated at 87 ° C. for about 5 hours. Thereafter, the reaction solution is purified by performing the operation of pouring into a large amount of methanol and water mixed solvent (3: 1) and precipitating three times to obtain a copolymer having an Mw of about 1.46 × 10 ^4. Obtained at 52%. This copolymer has a structural unit derived from each monomer, and this was designated as resin (A3).

(4) Synthesis of Resin (A4) Monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1) were charged at a molar ratio of 50:25:25, and then , 1.5 mass times dioxane was added to the total mass of the monomers. To the resulting mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, based on the total number of moles of monomers, This was heated at 77 ° C. for about 5 hours. Then, the reaction solution was purified by pouring it into a large amount of methanol and water mixed solvent (4: 1) and precipitating three times to obtain a copolymer having a Mw of about 8.0 × 10 ^3. Obtained at 60%. The obtained copolymer has a structural unit derived from each monomer, and this was made into resin (A4).

2. Examples and Comparative Examples (1) Preparation of Compositions The following components are mixed and dissolved, and filtered through a fluororesin filter having a pore size of 0.2 μm to obtain a chemically amplified photoresist composition (hereinafter referred to as “resist composition”). (Abbreviated as “product”). The resist composition of Comparative Example 2 below corresponds to the resist composition of Example 9 of Patent Document 1.

  The components shown in Table 2 are as follows.

(I) Resin The above resins (A1) to (A4)

(Ii) Acid generator (B1-2): Triphenylsulfonium (3-hydroxy-1-adamantyl) methoxycarbonyldifluoromethanesulfonate (B2): (4-methylphenyl) diphenylsulfonium perfluorobutanesulfonate (B3) : 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium perfluorobutanesulfonate

(Iii) Basic compound (C1-1): Tetrabutylammonium hydroxide (C1-2): Tetrapropylammonium hydroxide (C1-3): (2-hydroxyethyl) trimethylammonium hydroxide (C2-1-1) ): 2,6-diisopropylaniline

(Iv) Solvents Solvents (D1) to (D6) having the compositions shown in Table 3.

(2) Characteristic evaluation A resist pattern was produced from the resist composition as follows, and the pattern shape and line edge roughness (LER) were evaluated. The evaluation results are shown in Table 4.

(I) Manufacture of resist pattern By applying a composition for organic antireflection film (ARC-29; manufactured by Nissan Chemical Co., Ltd.) to a silicon wafer and baking it at 205 ° C. and 60 seconds, the thickness is increased. A 78 nm organic antireflection coating was formed. Next, the resist composition was spin-coated on the organic antireflection film using “Clean Track ACT-12” manufactured by Tokyo Electron Limited. At this time, the rotation speed at the time of spin coating was adjusted so that the film thickness of the resist film after pre-baking (PB) became the film thickness shown in Table 4.

  After spin coating, the obtained silicon wafer was pre-baked on a direct hot plate for 60 seconds at the temperature described in the PB column of Table 4. After pre-baking, the obtained silicon wafer was air-cooled to room temperature, and the film thickness of the resist film after pre-baking was measured at 10 points, and the average value was taken as the film thickness of the resist film after pre-baking. The film thickness measurement points are (1) 5 points on a concentric circle having the same center as the silicon wafer and having a diameter of 30% of the diameter of the silicon wafer; and (2) dividing the diameter of the silicon wafer into 6 parts. , 5 points excluding both ends thereof. As a film thickness measuring device, “Lambda Ace” manufactured by Dainippon Screen was used. In addition, when the fluctuation of the film thickness at 10 measurement points was within 0.5 nm, it was considered that the coating was normally performed.

  Using an ArF excimer laser stepper (FPA5000-AS3; manufactured by Canon Inc., NA = 0.75, 2/3 Annular) on a silicon wafer on which a resist film after pre-baking was formed, the exposure amount was changed stepwise. The line and space pattern was exposed.

  After exposure, post-exposure baking was performed for 60 seconds at a temperature described in the PEB column of Table 4 on a hot plate, and paddle development was further performed for 60 seconds with an aqueous 2.38% tetramethylammonium hydroxide solution.

  The developed line and space pattern formed on the silicon wafer was observed with a scanning electron microscope, and the pattern shape and line edge roughness were evaluated. In the resist film after development, an exposure amount at which the line width of a pattern formed with a mask having a line width of 100 nm is 100 nm is defined as effective sensitivity.

(Ii) Evaluation of pattern shape An 85 nm pattern exposed with effective sensitivity is observed with a scanning electron microscope, and Comparative Example 1 is used as a reference (Δ), and the pattern shape is closer to a rectangle than Comparative Example 1 (good) ), The pattern shape is equivalent to that of Comparative Example 1, and the pattern shape is rounder than that of Comparative Example 1, the top of the pattern shape is too tight, close to the T-shape, or the resolution is lowered. The thing was evaluated as x (defect).

(Iii) Evaluation of Line Edge Roughness (LER) A wall surface of an 85 nm pattern exposed with effective sensitivity is observed with a scanning electron microscope, and Comparative Example 1 is used as a reference (Δ), and smoother than Comparative Example 1 (Good), equivalent to Comparative Example 1 were evaluated as Δ, and those that were less smooth than Comparative Example 1 were evaluated as × (defect).

  From comparison between Examples 1 to 13 and Comparative Examples 1 and 2, as a basic compound, salt (C1) (tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, or (2-hydroxyethyl) trimethylammonium hydroxide) was used. It can be seen that a good pattern shape and line edge roughness can be achieved by using a resist composition containing 90% by mass or more of the solvent. Further, from the comparison between Examples 1 to 12 and Example 13, if the resist composition is applied so that the film thickness of the resist film after pre-baking is 80 nm or less, the pattern shape of the resulting resist film is further improved. It turns out (approaches a rectangle).

  The photoresist composition of the present invention can achieve a good pattern shape and line edge roughness. The resist composition of the present invention is useful for both dry exposure and immersion exposure, and is particularly suitable as a chemically amplified photoresist composition for ArF excimer laser exposure.

Claims (9)

A composition containing a resin, an acid generator, a salt represented by the formula (C1) and a solvent, and the content of the salt represented by the formula (C1) is 0.05% by mass or more in the solid content of the composition A photoresist composition characterized by being less than 2% by mass and having a solvent content of 94 % by mass to 99.9% by mass in the composition.

[In Formula (C1), R ^{c1 to} R ^c4 each independently represents a linear, branched or cyclic C _1-10 saturated aliphatic hydrocarbon group which may have a substituent, It represents a C _7-18 aralkyl group which may have a substituent, or a C _6-18 aromatic hydrocarbon group which may have a substituent. ] The photoresist composition according to claim 1, wherein R ^{c1 to} R ^c4 are each independently a linear or branched C _1-7 alkyl group which may have a substituent.   The salt represented by the formula (C1) is at least one selected from the group consisting of tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, and (2-hydroxyethyl) trimethylammonium hydroxide. Photoresist composition.   The photoresist composition according to claim 1, wherein the acid generator is a fluorine-containing acid generator. The photoresist composition according to claim 4, wherein the fluorine-containing acid generator is represented by the formula (B1).
[In Formula (B1), Q ¹ and Q ² each independently represents a fluorine atom or a C _1-6 perfluoroalkyl group. L ^b1 represents a single bond or a linear, branched or cyclic divalent C _1-17 saturated aliphatic hydrocarbon group which may have a substituent; The methylene group (—CH ₂ —) of the group hydrocarbon group may be substituted with an oxygen atom (—O—) or a carbonyl group (—CO—). Y represents an optionally substituted cyclic C _3-36 aliphatic hydrocarbon group; the methylene group (—CH ₂ —) of the aliphatic hydrocarbon group is an oxygen atom (—O—); ) Or a carbonyl group (—CO—). Z ⁺ represents an organic cation. ] The photoresist composition according to claim 5, wherein Z ⁺ is an arylsulfonium cation.   The photoresist composition according to claim 5 or 6, wherein Y is an adamantyl group which may have a substituent.   Content of an acid generator is 1-20 mass parts with respect to 100 mass parts of resin, The photoresist composition in any one of Claims 1-7.   The photoresist composition according to claim 1, wherein the resin is a resin that becomes alkali-soluble by the action of an acid.