JP6695203B2 - Salt, acid generator, resist composition, and method for producing resist pattern - Google Patents

Description

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

  Patent Document 1 describes a salt represented by the following formula, and a resist composition containing the salt as an acid generator.

Patent Document 2 describes a salt represented by the following formula, and a resist composition containing the salt as an acid generator.

JP, 2011-16794, A JP 2012-252322 A

  In the resist composition containing the salt represented by the above formula, the CD uniformity (CDU) of the resist pattern may not always be sufficiently satisfied.

The present invention includes the following inventions.
[1] A salt represented by the formula (I).
[In the formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² are the same or different from each other.
X ¹ represents * -CO-O-, * -O-CO-, * -O-CO-O- or * -O-, and * represents C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² ) is represented.
A ¹ and A ² each independently represent a single bond or * -L ¹ —CO—O— (L ² —CO—O) _g —. * Represents a bond with X ¹ or an oxygen atom.
L ¹ and L ² each independently represent a divalent hydrocarbon group having 1 to 12 carbon atoms.
g represents 0 or 1.
A ³ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms.
R ³ represents an alicyclic hydrocarbon group having 5 to 18 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. The hydrogen atom contained in the hydrogen group may be substituted with a hydroxy group, or two hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with oxygen atoms, respectively, and the two oxygen atoms and the fluorine atom may be substituted. It may form a ketal structure together with the optionally substituted alkanediyl group having 1 to 8 carbon atoms.
Z ⁺ represents an organic cation. ]
[2] X ¹ represents * -CO-O-, * -O-CO- or * -O-, and * represents C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² ). The salt according to [1], which represents the bonding position of
[3] X ¹ is * -CO-O-, and * is a salt according to [2], which represents a bonding position with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² ).
[4] The salt according to any one of [1] to [3], wherein A ³ is a single bond.
[5] The salt according to any one of [1] to [4], wherein A ¹ and A ² are single bonds.
[6] R ³ is a cyclohexyl group or an adamantyl group, and the methylene group contained in the cyclohexyl group and the adamantyl group may be replaced by an oxygen atom or a carbonyl group, and is contained in the cyclohexyl group and the adamantyl group. The hydrogen atom may be substituted with a hydroxy group, or two hydrogen atoms contained in the cyclohexyl group and the adamantyl group may be substituted with oxygen atoms to have the two oxygen atoms and a fluorine atom. The salt according to any one of [1] to [5], which may form a ketal ring together with an alkanediyl group having 1 to 8 carbon atoms.
[7] An acid generator containing the salt according to any one of [1] to [6].
[8] A resist composition containing the acid generator according to [7] and a resin containing a structural unit having an acid labile group.
[9] The description of [8], wherein the structural unit having an acid labile group is at least one selected from the structural unit represented by formula (a1-1) and the structural unit represented by formula (a1-2). Resist composition.
[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent -O- or ^* -O- (CH ₂ ) _k1- CO-O-, k1 represents an integer of 1 to 7, and * represents a bond with -CO-. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1 'represents the integer of 0-3. ]
[10] The resist composition according to [8] or [9], further including an acid generator represented by formula (B1).
[In the formula (B1),
Q ¹ , Q ² and Z ⁺ have the same meanings as described above.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the monovalent alicyclic hydrocarbon group is, -O - - -CH ₂ contained in the hydrogen radical, - SO ₂ - or -CO- may be replaced with. ]
[11] The resist composition according to any one of [8] to [10], further containing a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[12] The resist composition according to any one of [8] to [11], which further contains a resin containing a structural unit having a fluorine atom.
[13] (1) A step of applying the resist composition according to any one of [8] to [12] onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) exposing the composition layer
A method for producing a resist pattern, which comprises (4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  In the resist composition containing the salt of the present invention, the CD uniformity (CDU) of the resist pattern becomes good.

In the present specification, unless otherwise specified, in the description of the structural formula of the compound, “aliphatic hydrocarbon group” means a linear or branched hydrocarbon group, and “alicyclic hydrocarbon group” means an aliphatic hydrocarbon group. It means a group obtained by removing a number of hydrogen atoms corresponding to the valence from a ring of a cyclic hydrocarbon. The "aromatic hydrocarbon group" also includes a group in which a hydrocarbon group is bound to an aromatic ring. When stereoisomers are present, all stereoisomers are included.
In the present specification, "(meth) acrylic monomer" means at least one monomer having a _"CH 2 = _CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of To do. Similarly, “(meth) acrylate” means “at least one of acrylate and methacrylate”. The expressions such as “(meth) acrylic acid” and “(meth) acryloyl” have the same meaning. In addition, any of the groups described in the present specification that can have both a linear structure and a branched structure may be used.
In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described below from the total amount of the resist composition.

<Salt (I)>
The salt of the present invention is a salt represented by the formula (I) (hereinafter sometimes referred to as “salt (I)”).
[In the formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² are the same or different from each other.
X ¹ represents * -CO-O-, * -O-CO-, * -O-CO-O- or * -O-, and * represents C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² ) is represented.
A ¹ and A ² each independently represent a single bond or * -L ¹ —CO—O— (L ² —CO—O) _g —. * Represents a bond with an oxygen atom.
L ¹ and L ² each independently represent a divalent hydrocarbon group having 1 to 12 carbon atoms.
g represents 0 or 1.
A ³ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms.
R ³ represents an alicyclic hydrocarbon group having 5 to 18 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. The hydrogen atom contained in the hydrogen group may be substituted with a hydroxy group, or two hydrogen atoms contained in the alicyclic hydrocarbon group are each substituted with an oxygen atom, and the two oxygen atoms have the carbon number of 5 above. The ketal structure which may contain a fluorine atom may be formed together with the alkanediyl group having 1 to 8 carbon atoms in the alicyclic hydrocarbon group having 18 carbon atoms.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group of Q ¹ , Q ² , R ¹ and R ² includes a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group and a perfluorotert-butyl group. , Perfluoropentyl group, perfluorohexyl group and the like.
Q ¹ and Q ² independently of each other are preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.
R ¹ and R ² are independently of each other, preferably a hydrogen atom or a fluorine atom.
z is preferably 0.

X ¹ is preferably * -CO-O- (* represents a bonding position with CR ¹ R ² or CQ ¹ Q ² ).

The divalent hydrocarbon group having 1 to 12 carbon atoms of L ¹ , L ² and A ³ is an alkanediyl group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group or a combination thereof. And a divalent group formed thereby.
Examples of the alkanediyl group include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group and hexane-1,6-diyl group. In the chain alkanediyl group, and the linear alkanediyl group, an alkyl group (in particular, an alkyl group having 1 to 4 carbon atoms, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, tert-butyl group, etc.), ethane-1,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3- Examples thereof include branched alkanediyl groups such as diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

  Examples of the alicyclic hydrocarbon group include a cyclopentanediyl group, a cyclohexanediyl group, an adamantanediyl group and a norbornanediyl group. Of these, a cyclohexanediyl group and an adamantanediyl group are preferable, and an adamantanediyl group is more preferable.

  Examples of the aromatic hydrocarbon group include phenylene group, naphthylene group, anthrylene group, p-methylphenylene group, p-tert-butylphenylene group, p-adamantylphenylene group, tolyl group, xylylene group, cumenylene group, mesitylene group and biphenylene group. Group, phenanthrylene group, 2,6-diethylphenylene group, 2-methyl-6-ethylphenylene and the like.

The divalent hydrocarbon group having 1 to 12 carbon atoms of L ¹ and L ² is preferably an alkanediyl group, a divalent alicyclic hydrocarbon group or a divalent group formed by combining these. , Alkanediyl groups are more preferred, and methylene groups are even more preferred.
A ¹ and A ² are preferably, independently of each other, a single bond or * —CH ₂ —CO—O— (* represents a bonding position with an oxygen atom), and more preferably a single bond.
A ³ is preferably a single bond.

Examples of the alicyclic hydrocarbon group having 5 to 18 carbon atoms of R ³ include a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group and the like, preferably a cyclopentyl group, a cyclohexyl group and an adamantyl group, and more preferably Include an adamantyl group and a cyclohexyl group, and more preferably an adamantyl group.
Two hydrogen atoms contained in the alicyclic hydrocarbon group having 5 to 18 carbon atoms are replaced by oxygen atoms, and the two oxygen atoms and an alkanediyl group having 1 to 8 carbon atoms which may have a fluorine atom. the ketal structure formed _{together, * 1-O- (CH 2} ) 2 -O- * 2, * 1-O- (CH 2) 3 -O- * 2, * 1-O- ( _{CH 2) 4 -O- * 2,} * 1-O-CH 2 - (CF 2) 2 -CH 2 -O- * 2, * 1-O-CH 2 - (CF 2) 3 -CH 2 -O _{- * 2, * 1-O} -CH 2 - (CF 2) 4 -CH 2 -O- * 2 , and the like. Among _{them, * 1-O-CH 2} - (CF 2) 2 -CH 2 -O- * 2, * 1-O-CH 2 - (CF 2) 3 -CH 2 -O- * 2, * 1- _{O-CH 2 - (CF 2} ) 4 -CH 2 -O- * 2 are _{preferred, * 1-O-CH 2} - (CF 2) 2 -CH 2 -O- * 2, * 1-O-CH 2 _{- (CF 2) 3 -CH 2} -O- * 2 are more _{preferred, * 1-O-CH 2} - (CF 2) 2 -CH 2 -O- * 2 is more preferred. * 1 and * 2 each represent a bond, and * 1 and * 2 bond to the same carbon atom contained in the alicyclic hydrocarbon group.

  Examples of the anion in the salt (I) include the following anions. Of these, anions represented by formulas (Ia-1) to (Ia-14) are preferable.

Examples of the cation Z ⁺ in the salt (I) include an organic onium cation, for example, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, an organic phosphonium cation, and the like, preferably an organic sulfonium cation or an organic sulfonium cation. It is an iodonium cation, more preferably an arylsulfonium cation.
Among them, a cation represented by any of the formulas (b2-1) to (b2-4) (hereinafter, may be referred to as “cation (b2-1)” depending on the formula number) is preferable.

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may together form a ring containing a sulfur atom to which they are bound, and the methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group. ..

R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 represent the integer of 0-5 mutually independently.
When m2 is 2 or more, a plurality of R ^b7 may be the same or different, and when n2 is 2 or more, a plurality of R ^b8 may be the same or different.

R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may together form a ring containing a sulfur atom to which they are bound, and the methylene group contained in the ring may be replaced with an oxygen atom, a sulfinyl group or a carbonyl group. ..
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and included in the aliphatic hydrocarbon. The hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be an alkoxy group having 1 to 12 carbon atoms or 1 to 12 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be bonded together to form a ring containing —CH—CO—, and the methylene group contained in the ring may be an oxygen atom, a sulfinyl group or a carbonyl group. It may be replaced.

R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 represent the integer of 0-4 mutually independently.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13 may be the same or different, when p2 is 2 or more, a plurality of R ^b14 may be the same or different, and when q2 is 2 or more. R ^b15 may be the same or different, when r2 is 2 or more, R ^b16 may be the same or different, and when s2 is 2 or more, R ^b17 is ^They may be the same or different, and when t2 is 2 or more, a plurality of R ^b18 may be the same or different.

Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group and an n-octyl group. Group and an alkyl group of a 2-ethylhexyl group. In particular, the carbon number of the aliphatic hydrocarbon group of R ^{b9 to} R ^b12 is preferably 1 to 12.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group. Group, cyclooctyl group, cyclodecyl group and other cycloalkyl groups. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.

In particular, the carbon number of the alicyclic hydrocarbon group of R ^{b9 to} R ^b12 is preferably 3 to 18, more preferably 4 to 12.

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

As the aromatic hydrocarbon group, phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p-adamantylphenyl group And aryl groups such as biphenylyl group, naphthyl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group.
When the aliphatic hydrocarbon group or the alicyclic hydrocarbon group is contained in the aromatic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms or the alicyclic hydrocarbon group having 3 to 18 carbon atoms is preferable.
A p-methoxyphenyl group etc. are mentioned as an aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group.
Examples of the aliphatic hydrocarbon group in which a hydrogen atom is replaced with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group and naphthylethyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkylcarbonyloxy group, a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentyl carbonyloxy group, a hexyl carbonyloxy group, an octyl carbonyloxy group and a 2-ethylhexyl carbonyloxy group.

The ring containing a sulfur atom formed by R ^b4 and R ^b5 together may be any ring of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated. .. Examples of this ring include a ring having 3 to 18 carbon atoms, and preferably a ring having 4 to 18 carbon atoms. The ring containing a sulfur atom may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. The following rings are mentioned.

The ring formed by R ^b9 and R ^{b10 taken} together may be any of a monocyclic ring, a polycyclic ring, an aromatic ring, a non-aromatic ring, a saturated ring and an unsaturated ring. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include thiolane-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, and 1,4-oxathian-4-ium ring.
The ring formed by R ^b11 and R ^b12 together may be any of a monocyclic ring, a polycyclic ring, an aromatic ring, a non-aromatic ring, a saturated ring and an unsaturated ring. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof 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.
Examples of the cation (b2-1) include the following cations.

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

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

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

  Salt (I) is a combination of the above-mentioned sulfonate anion and organic cation. These anions and cations can be combined arbitrarily. Table 1 shows specific examples of the salt (I).

For example, the salt (I-1) in Table 1 is the salt shown below.

  Among them, salt (I) includes salt (I-1), salt (I-2), salt (I-3), salt (I-4), salt (I-15) and salt (I-16). , Salt (I-17), salt (I-18), salt (I-29), salt (I-30), salt (I-31), salt (I-32), salt (I-43), Salt (I-44), salt (I-45), salt (I-46), salt (I-57), salt (I-58), salt (I-59), salt (I-60), salt (I-71), salt (I-72), salt (I-73), salt (I-74), salt (I-85), salt (I-86), salt (I-87), salt ( I-88), salt (I-101), salt (I-102), salt (I-103), salt (I-104), salt (I-109), salt (I-110), salt (I -111), salt (I-112), salt (I-117), salt (I-118), salt (I-119), salt (I-120), salt (I-125), salt (I- 126), salt (I-127), salt (I-128), salt (I-133), salt (I-134), salt (I-135), salt (I-136), salt (I-141) ), Salt (I-142), salt (I-143), salt (I-144), salt (I-149), salt (I-150), salt (I-151) and salt (I-152). Is preferred.

<Method for producing salt (I)>
A salt represented by the formula (I1) (X ¹ is a group represented by * —CO—O— (* represents C (R ¹ R ² or C (bonding position with Q ¹ Q ² )). In this case, the salt (I)) is produced, for example, by reacting the salt represented by the formula (I1-a) with the compound represented by the formula (I1-b) in a solvent such as acetonitrile. be able to.
[In the formula, all symbols have the same meanings as described above. ]

The compound represented by the formula (I1-a) is obtained by reacting the compound represented by the formula (I1-c) with the compound represented by the formula (I1-d) in a solvent such as acetonitrile. Obtainable.
[In the formula, all symbols have the same meanings as described above. ]

Examples of the compound represented by the formula (I1-c) include compounds represented by the following, and the compound can be produced by the method described in JP-A-2008-127367.

The compound represented by formula (I1-b) is obtained by reacting the compound represented by formula (I1-e) with the compound represented by formula (I1-f) in the presence of a catalyst in a solvent. Can be obtained.
[In the formula, all symbols have the same meanings as described above. ]

Examples of the solvent include chloroform and tetrahydrofuran.
Examples of the catalyst include pyridine and dimethylaminopyridine.
Examples of the compound represented by the formula (I1-e) include salts represented by the following formulas, which can be easily obtained from the market and can be easily produced.

Examples of the compound represented by the formula (I1-b) include salts represented by the following formulas, which can be easily obtained from the market and can be easily produced.

The compound represented by formula (I1-b) is obtained by reacting the compound represented by formula (I1-e) with the compound represented by formula (I1-g) in a solvent. You can also
[In the formula, all symbols have the same meanings as described above. ]

The compound represented by the formula (I1-g) is obtained by reacting the compound represented by the formula (I1-h) with the compound represented by the formula (I1-d) in a solvent such as acetonitrile. Obtainable.

Examples of the compound represented by the formula (I1-h) include salts represented by the following formulas, which can be easily obtained from the market and can be easily produced.

A salt represented by the formula (I2) (X ¹ is * -O-CO-O- (* represents C (R ¹ R ² or C (bonding position with Q ¹ Q ² )), bonded to oxygen atom; When CR ¹ R ² is a methylene group, the salt (I)) is, for example, a salt represented by the formula (I2-a) and a compound represented by the formula (I2-b), acetonitrile or the like. It can be manufactured by reacting in a solvent.
[In the formula, all symbols have the same meanings as described above. ]
Represents. )
Examples of the solvent include acetonitrile and chloroform.

Examples of the salt represented by the formula (I2-a) include salts represented by the following formula and the like, which are easily available on the market.

The salt represented by the formula (I2-b) can be produced by reacting the salt represented by the formula (I2-c) with the compound represented by the formula (I2-d) in a solvent. ..
[In the formula, all symbols have the same meanings as described above. ]
Examples of the solvent include acetonitrile and chloroform.

The salt represented by the formula (I2-c) can be produced by subjecting the salt represented by the formula (I2-e) to a reduction reaction in a solvent.
[In the formula, all symbols have the same meanings as described above. ]
Tetrahydrofuran etc. are mentioned as a solvent.
Examples of the reducing agent include lithium aluminum hydride and the like.

Examples of the compound represented by the formula (I2-e) include compounds represented by the following formula and the like, and they are easily available on the market.

The compound represented by formula (I2-d) can be produced by reacting the compound represented by formula (I1-b) with the compound represented by formula (I1-d) in a solvent. ..
[In the formula, all symbols have the same meanings as described above. ]
Examples of the solvent include acetonitrile and chloroform.

<Acid generator>
The acid generator of the present invention contains salt (I) as an active ingredient. The salt (I) may be contained alone or in combination of two or more kinds.
The acid generator of the present invention may contain, as an active ingredient other than the salt (I), an acid generator known in the resist field described below (hereinafter sometimes referred to as “acid generator (B)”). .. These known acid generators may be contained alone or in combination of two or more.
When the salt (I) and the acid generator (B) are contained as the acid generator, the mass ratio of the contents of the salt (I) and the acid generator (B) (salt (I): acid generator (B)) ) Is usually 1:99 to 99: 1, preferably 2:98 to 98: 2, more preferably 5:95 to 95: 5, further preferably 90:10 to 60:40, and particularly It is preferably 85:15 to 70:30.

<Resist composition>
The resist composition of the present invention contains a resin containing a structural unit having an acid labile group (hereinafter sometimes referred to as “resin (A)”) and an acid generator containing salt (I). Here, the “acid-labile group” has a leaving group, the leaving group is released by contact with an acid, and the constituent unit has a hydrophilic group (for example, a hydroxy group or a carboxy group). Means a group to be converted into.
The resist composition preferably contains a quencher (hereinafter sometimes referred to as “quencher (C)”), and preferably contains a solvent (hereinafter sometimes referred to as “solvent (E)”).

<Acid generator containing salt (I)>
In the resist composition of the present invention, the content of the acid generator containing the salt (I) is preferably 1 to 30% by mass, and 1 to 25% by mass or 2 to 20% by mass with respect to the resin (A). The content is more preferably mass%, and further preferably 2 to 15 mass%.

<Acid generator (B)>
The resist composition of the present invention contains an acid generator (B). The acid generator generates an acid upon exposure to light, and the generated acid acts as a catalyst to eliminate a group that is eliminated by the acid of the resin (A1).
The acid generator is classified into a nonionic type and an ionic type, and any of them may be used in the acid generator (B) of the resist composition of the present invention.
Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate) and sulfones. (For example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, and JP-A-63-163452. JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712, etc. The compounds capable of generating an acid by the radiation described in 1. can be used. Moreover, you may use the compound manufactured by the well-known method.

The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).
[In the formula (B1),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the monovalent alicyclic hydrocarbon group is, -O - - -CH ₂ contained in the hydrogen radical, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group of Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group and a perfluoroalkyl group. A hexyl group and the like can be mentioned.
Q ¹ and Q ² are preferably, independently of each other, a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and It may be a group formed by combining two or more of the groups.
Specifically, methylene group, ethylene group, propane-1,3-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 group , Straight chain such as tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group An alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- A branched alkanediyl group such as a 1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group;
A monocyclic 2 which is a cycloalkanediyl group such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group and a cyclooctane-1,5-diyl group. Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group and adamantane-2,6-diyl group Groups and the like.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced with —O— or —CO— include, for example, any of formula (b1-1) to formula (b1-3). And a group represented by. In the formulas (b1-1) to (b1-3) and the following specific examples, * represents a bond with -Y.
[In Formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total carbon number of L ^b2 and L ^b3 is 22 or less.
In formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total carbon number of L ^b4 and L ^b5 is 22 or less.
In formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, the total number of carbon atoms of L ^b6 and L ^b7 is 23 or less. ]

In the formulas (b1-1) to (b1-3), when the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group, the number of carbon atoms before replacement is the carbon number of the saturated hydrocarbon group. Let it be a number.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L ^b1 .

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group contained in the divalent saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.

The group represented by formula (b1-1) or formula (b1-3) is a group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced with —O— or —CO—. Is preferred.

Examples of formula (b1-1) include groups represented by formula (b1-4) to formula (b1-8).
[In the formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In formula (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^{b13 to} L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. ..
However, the total carbon number of L ^{b16 to} L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

Examples of formula (b1-3) include groups represented by formula (b1-9) to formula (b1-11).
[In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. Good. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
However, the total carbon number of L ^{b21 to} L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an acyloxy group. May be. The methylene group contained in the acyloxy group may be replaced with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the acyloxy group may be replaced with a hydroxy group.
^However, the total number of carbon atoms of L b24 ^{~L b26} is 21 or less. ]

  In formulas (b1-9) to (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an acyloxy group, the carbon number of the acyloxy group, CO in the ester bond, and Including the number of O, the carbon number of the divalent saturated hydrocarbon group is used.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group and an adamantylcarbonyloxy group.
Examples of the acyloxy group having a substituent include an oxoadamantylcarbonyloxy group, a hydroxyadamantylcarbonyloxy group, an oxocyclohexylcarbonyloxy group and a hydroxycyclohexylcarbonyloxy group.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-4) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-5) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-6) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-7) include the following.

Among the groups represented by the formula (b1-1), examples of the group represented by the formula (b1-8) include the following.

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

Among the groups represented by the formula (b1-3), examples of the group represented by the formula (b1-9) include the following.

Among the groups represented by the formula (b1-3), examples of the group represented by the formula (b1-10) include the following.

Among the groups represented by the formula (b1-3), examples of the group represented by the formula (b1-11) include the following.

Examples of the monovalent alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11).
It is -O - - -CH ₂ included in a monovalent alicyclic hydrocarbon group represented by Y, - SO ₂ - or The group replaced by -CO-, formula (Y12) ~ formula (Y38) And a group represented by.

  That is, in Y, two hydrogen atoms contained in the alicyclic hydrocarbon group are respectively replaced by oxygen atoms, and the two oxygen atoms together with the alkanediyl group having 1 to 8 carbon atoms form a ketal ring. It may also include a structure in which oxygen atoms are bonded to different carbon atoms. However, in the case of forming a spiro ring represented by formula (Y28) to formula (Y33) or the like, it is preferable that the alkanediyl group between two oxygens has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

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

As the substituent of the monovalent alicyclic hydrocarbon group represented by Y, a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms To 16 monovalent alicyclic hydrocarbon groups, C1 to C12 alkoxy groups, C6 to C18 monovalent aromatic hydrocarbon groups, C7 to C21 aralkyl groups, C2 to C2 4 acyl group, glycidyloxy group, or _{- (CH 2) ja -O-} CO-R b1 group ^{(wherein, R b1} represents an alkyl group having 1 to 16 carbon atoms, monovalent cycloaliphatic of 3 to 16 carbon atoms It represents a cyclic hydrocarbon group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and ja represents an integer of 0 to 4) and the like.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group and mesityl group. Group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl, and the like.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and a naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the alkyl group, alicyclic hydrocarbon group and the like in the substituent of Y include the same groups as those exemplified for Y.

Examples of Y include the following.

Y is preferably a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent. The methylene group constituting the group may be replaced with an oxygen atom, a sulfonyl group or a carbonyl group. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented by the following.

  As the sulfonate anion in the salt represented by the formula (B1), an anion represented by the formula (B1-A-1) to the formula (B1-A-46) [hereinafter, referred to as "anion (B1 -A-1) "or the like. ] Are preferable, Formula (B1-A-1) -Formula (B1-A-4), Formula (B1-A-9), Formula (B1-A-10), Formula (B1-A-24) -Formula The anion represented by any of (B1-A-40) is more preferable.

Here, R ^{i2 to} R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. Is more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ¹ and Q ² are the same as above.
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include anions described in JP2010-204646A.

Preferred examples of the sulfonate anion in the salt represented by the formula (B1) include anions represented by the formulas (B1a-1) to (B1a-22).

  Especially, Formula (B1a-1) -Formula (B1a-3) and Formula (B1a-7) -Formula (B1a-16), Formula (B1a-18), Formula (B1a-19), Formula (B1a-22). Anion represented by any of (1) to (4) is preferable.

Examples of the Z ⁺ organic cation include an organic onium cation, for example, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, an organic phosphonium cation, and the like, preferably an organic sulfonium cation or an organic iodonium cation. And more preferably an arylsulfonium cation.
Z ⁺ in the formula (B1) is preferably a cation represented by any of the formulas (b2-1) to (b2-4) [hereinafter, "cation (b2-1)" depending on the formula number, etc. There is a case. ].

[In the formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 are, independently of each other, a monovalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent one having 6 to 36 carbon atoms. Represents an aromatic hydrocarbon group, and the hydrogen atom contained in the monovalent aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or a monovalent alicyclic carbon group having 3 to 12 carbon atoms. It may be substituted with a hydrogen group or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the monovalent alicyclic hydrocarbon group is a halogen atom or 1 to 18 carbon atoms. Which may be substituted with a monovalent aliphatic hydrocarbon group, an acyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the hydrogen atom contained in the monovalent aromatic hydrocarbon group is a halogen atom or a hydroxy group. It may be substituted with a group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may form a ring together with the sulfur atom to which they are bound, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. ..
R ^b7 and R ^b8 each independently represent a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 represent the integer of 0-5 mutually independently.
When m2 is 2 or more, a plurality of R ^b7 may be the same or different, and when n2 is 2 or more, a plurality of R ^b8 may be the same or different.
R ^b9 and R ^b10 independently of each other represent a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may form a ring together with the sulfur atom to which they are bound, and —CH ₂ — contained in the ring may be replaced with —O—, —SO— or —CO—. ..
R ^b11 represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 36 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 36 carbon atoms, or a monovalent aromatic carbon group having 6 to 18 carbon atoms. Represents a hydrogen group.
R ^b12 is a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the monovalent aliphatic hydrocarbon may be substituted with a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms and is contained in the monovalent aromatic hydrocarbon group. The hydrogen atom may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may be bonded together to form a ring containing —CH—CO—, and —CH ₂ — contained in the ring is —O—, —SO—. Alternatively, it may be replaced with -CO-.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, a monovalent aliphatic hydrocarbon group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents -S- or -O-.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 represent the integer of 0-4 mutually independently.
u2 represents 0 or 1.
When o2 is 2 or more, a plurality of R ^b13 may be the same or different, when p2 is 2 or more, a plurality of R ^b14 may be the same or different, and when q2 is 2 or more. R ^b15 may be the same or different, when r2 is 2 or more, R ^b16 may be the same or different, and when s2 is 2 or more, R ^b17 is ^They may be the same or different, and when t2 is 2 or more, a plurality of R ^b18 may be the same or different. ]

Examples of the monovalent aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 And an alkyl group of an ethylhexyl group. In particular, the monovalent aliphatic hydrocarbon group represented by R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The monovalent alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic monovalent alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Examples thereof include cycloalkyl groups such as cyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic monovalent alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.

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

  Examples of the monovalent alicyclic hydrocarbon group having a hydrogen atom substituted with an aliphatic hydrocarbon group include, for example, a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, and a methylnorbornyl group. Group, isobornyl group and the like. In the monovalent alicyclic hydrocarbon group in which a hydrogen atom is replaced by a monovalent aliphatic hydrocarbon group, the total number of carbon atoms of the monovalent alicyclic hydrocarbon group and the monovalent aliphatic hydrocarbon group Is preferably 20 or less.

Examples of the monovalent aromatic hydrocarbon group include phenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group, p- Examples of the aryl group include an adamantylphenyl group, a biphenylyl group, a naphthyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
When the monovalent aromatic hydrocarbon group contains a monovalent aliphatic hydrocarbon group or a monovalent alicyclic hydrocarbon group, a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms or carbon A monovalent alicyclic hydrocarbon group of the number 3 to 18 is preferable.
A p-methoxyphenyl group etc. are mentioned as a monovalent | monohydric aromatic hydrocarbon group by which the hydrogen atom was substituted by the alkoxy group.
Examples of the monovalent aliphatic hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group and naphthylethyl group. ..

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkylcarbonyloxy group, a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentyl carbonyloxy group, a hexyl carbonyloxy group, an octyl carbonyloxy group and a 2-ethylhexyl carbonyloxy group.

The ring which R ^b4 and R ^b5 may form together with the sulfur atom to which they are bonded is a monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated ring. It may be. Examples of this ring include rings having 3 to 18 carbon atoms, and preferably rings having 4 to 18 carbon atoms. Examples of the ring containing a sulfur atom include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and specific examples include the following rings.

The ring formed by R ^b9 and R ^b10 together with the sulfur atom to which they are bonded may be a monocyclic ring, polycyclic ring, aromatic ring, non-aromatic ring, saturated ring or unsaturated ring. Good. Examples of this ring include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include a thiolane-1-ium ring (tetrahydrothiophenium ring) and thian-1-ium. Ring, 1,4-oxathian-4-ium ring and the like.
The ring formed by R ^b11 and R ^b12 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring. Be done.

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

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

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

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

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

  The acid generator (B1) is a combination of the above-mentioned sulfonate anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B1) is preferably an anion and a cation (b2) represented by any of the formula (B1a-1) to the formula (B1a-3) and the formula (B1a-7) to the formula (B1a-15). -1) or a combination with a cation (b2-3).

  The acid generator (B1) preferably includes those represented by formulas (B1-1) to (B1-32), among which formula (B1-1) and formula (B1) containing an arylsulfonium cation. -2), formula (B1-3), formula (B1-5), formula (B1-6), formula (B1-7), formula (B1-11), formula (B1-12), formula (B1- 13), formula (B1-14), formula (B1-13), formula (B1-20), formula (B1-21), formula (B1-23), formula (B1-24), formula (B1-25). ), The formula (B1-26), the formula (B1-29), the formula (B1-31) or the formula (B1-32).

<Resin (A)>
The resin (A) has a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”). The resin (A) preferably further contains a structural unit other than the structural unit (a1). Examples of the structural unit other than the structural unit (a1) include a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”).

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”). An "acid-labile group" has a leaving group, and the leaving group is released by contact with an acid, and the constituent unit is converted into a constituent unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). Means a group that

The acid labile group contained in the resin (A) is preferably the group (1) and / or the group (2).
[In the formula (1), R ^{a1 to} R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group in which these are combined, or ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
na represents 0 or 1.
* Represents a bond. ]

[In formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. Or R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and the hydrocarbon group and the divalent heterocyclic group. -CH ₂ contained in ring - may be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
* Represents a bond. ]

^Examples of the alkyl group of R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group and an n-octyl group.
The alicyclic hydrocarbon group for R ^{a1 to} R ^a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 is preferably an alicyclic hydrocarbon group of 3 to 16 carbon atoms.

Examples of the group in which an alkyl group and an alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group and a norbornylethyl group. Can be mentioned.
na is preferably 0.

In the case where R ^a1 and R ^a2 are bonded to each other to form a divalent alicyclic hydrocarbon group, -C (R ^a1 ) (R ^a2 ) (R ^a3 ) includes the groups below. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^{a1 to} R ^a3 in the formula (1) are alkyl groups, preferably a tert-butoxycarbonyl group), 2- An alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and the carbon atom to which they are bonded form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantane- 1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group) and the like.

Examples of the hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and the alicyclic hydrocarbon group are the same as above.
As the aromatic hydrocarbon group, phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl Group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl, and the like.
^{Examples of the} divalent heterocyclic group formed by R ^{a2 ′} and R ^{a3 ′} bonded to each other and the carbon atom to which they are bonded and X include the following groups. * Represents a bond.
At least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

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

  Among the (meth) acrylic monomers having an acid labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If the resin (A) having a structural unit derived from the monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

  The structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1) is preferably a structural unit represented by the formula (a1-0) or a formula (a1-1). The structural unit or the structural unit represented by the formula (a1-2) can be mentioned. These may be used alone or in combination of two or more. In the present specification, the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) are respectively represented by the structural unit (a1 -0), the structural unit (a1-1) and the structural unit (a1-2), a monomer that induces the structural unit (a1-0), a monomer that induces the structural unit (a1-1), and the structural unit (a1- The monomer that induces 2) may be referred to as a monomer (a1-0), a monomer (a1-1), and a monomer (a1-2), respectively.

[In the formula (a1-0),
L ^a01 represents an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond with a carbonyl group.
R ^a01 represents a hydrogen atom or a methyl group.
R ^{a02 to} R ^a04 each independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these. ]

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or * —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond with —CO—. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1 'represents the integer of 0-3. ]

L ^a01 is preferably an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O— (provided that k01 is preferably an integer of 1 to 4, more preferably 1), and more preferably. Is an oxygen atom.
Examples of the alkyl group of R ^{a02 to} R ^a04 , the alicyclic hydrocarbon group, and a group in which these are combined include the same groups as those described for R ^{a1 to} R ^a3 of the formula (1).
The alkyl group of R ^{a02 to} R ^a04 preferably has 6 or less carbon atoms.
The carbon number of the alicyclic hydrocarbon group of R ^{a02 to} R ^a04 is preferably 8 or less, more preferably 6 or less.
The group in which an alkyl group and an alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in which these alkyl groups and an alicyclic hydrocarbon group are combined. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a methyladamantyl group, a cyclohexylmethyl group, a methylcyclohexylmethyl group, an adamantylmethyl group, and a norbornylmethyl group. Be done.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

L ^a1 and ^{L a2} are preferably -O- or _{^{* -O- (CH 2) k1 '}} -CO-O- and is (however, k1' is an integer from 1 to 4, is preferably 1 ), And more preferably -O-.
R ^a4 and R ^a5 are preferably methyl groups.
Examples of the alkyl group of R ^a6 and R ^a7 , the alicyclic hydrocarbon group, and a group in which these are combined include the same groups as the groups described for R ^{a1 to} R ^a3 of the formula (1).
The carbon number of the alkyl group of R ^a6 and R ^a7 is preferably 6 or less.
The alicyclic hydrocarbon group of R ^a6 and R ^a7 preferably has 8 or less carbon atoms, and more preferably 6 or less carbon atoms.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the monomer (a1-0), for example, a monomer represented by any of the formulas (a1-0-1) to (a1-0-12) is preferable, and the formula (a1-0-1) to the formula (a1-0-1). a1-0-10) is more preferable.

In the above structural unit, a structural unit in which a methyl group corresponding to R ^a01 is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a1-0).

Examples of the monomer (a1-1) include the monomers described in JP2010-204646A. Among them, the monomer represented by any of the formulas (a1-1-1) to (a1-1-8) is preferable, and any of the formulas (a1-1-1) to (a1-1-4) is preferable. The monomer represented by is more preferable.

  Examples of the monomer (a1-2) include 1-methylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth). Acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, 1-ethylcycloheptan-1-yl (meth) acrylate, 1-ethylcyclooctane-1-yl (meth) acrylate, 1-isopropylcyclopentane-1 Examples include -yl (meth) acrylate, 1-isopropylcyclohexane-1-yl (meth) acrylate and the like. The monomer represented by any of the formulas (a1-2-1) to (a1-2-12) is preferable, and the formula (a1-2-3), the formula (a1-2-4), and the formula (a1- 2-9) and the monomer represented by Formula (a1-2-10) are more preferable, and the monomers represented by Formula (a1-2-3) and Formula (a1-2-9) are still more preferable.

  When the resin (A) contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content of these is the total structure of the resin (A). It is usually 10 to 95 mol%, preferably 15 to 90 mol%, and more preferably 20 to 85 mol% based on the total of the units.

Further, the structural unit (a1) having the group (1) also includes a structural unit represented by the formula (a1-3). The structural unit represented by the formula (a1-3) may be referred to as a structural unit (a1-3). Further, the monomer that induces the structural unit (a1-3) may be referred to as a monomer (a1-3).
[In the formula (a1-3),
R ^a9 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, a carboxy group, a cyano group, a hydrogen atom or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, and the aliphatic hydrocarbon group and The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxy group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—. Alternatively, it may be replaced with -CO-.
R ^{a10 to} R ^a12 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group formed by combining these, or R ^a10 and R ^a11 is bonded to each other to form, together with the carbon atom to which they are bonded, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. ]

Examples of the aliphatic hydrocarbon group which may have a hydroxy group for R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.
^Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms of R ^a13 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and n. Examples include -hexyl group, n-heptyl group, 2-ethylhexyl group and n-octyl group.
^Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms of R ^a13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantyl methyl group, a 1-adamantyl-1-methylethyl group, and 2-oxo-oxolane-3-. Examples thereof include an yl group and a 2-oxo-oxolan-4-yl group.
^Examples of —COOR ^a13 include groups in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.
^Examples of the alkyl group of R ^{a10 to} R ^a12 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, Examples thereof include n-heptyl group, 2-ethylhexyl group and n-octyl group.
The alicyclic hydrocarbon group of R ^{a10 to} R ^a12 may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be, for example, a cyclopropyl group, a cyclobutyl group or a cyclopentyl group. Examples thereof include cycloalkyl groups such as group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and norbornyl. Group, a methylnorbornyl group, an isobornyl group, and the like.
As -C (R ^a10 ) (R ^a11 ) (R ^a12 ), when R ^a10 and R ^a11 are bonded to each other to form a divalent alicyclic hydrocarbon group together with the carbon atom to which they are bonded, The following groups are preferable.

  Specific examples of the monomer (a1-3) include 5-tert-butyl 5-norbornene-2-carboxylic acid, 1-cyclohexyl-1-methylethyl 5-norbornene-2-carboxylic acid, and 5-norbornene-2-carboxylic acid. 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-oxo Examples thereof include cyclohexyl) ethyl and 1- (1-adamantyl) -1-methylethyl 5-norbornene-2-carboxylic acid.

  The resin (A) containing the structural unit (a1-3) contains a sterically bulky structural unit, so that the resin composition of the present invention containing such a resin (A) has a higher molecular weight. A resist pattern can be obtained with a resolution. Further, since a rigid norbornane ring is introduced into the main chain, the obtained resist pattern tends to have excellent dry etching resistance.

  When the resin (A) contains the structural unit (a1-3), its content is preferably 10 to 95 mol% with respect to the total of all structural units of the resin (A), and preferably 15 to 90 mol%. %, More preferably 20 to 85 mol%.

As the structural unit (a1) having a group represented by the group (2), a structural unit represented by the formula (a1-4) (hereinafter, may be referred to as “structural unit (a1-4)”). Can be mentioned.
[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or Represents a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, a plurality of R ^a33 may be the same as or different from each other.
R ^a34 and ^{R a35} are independently of each other, represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon ^{atoms, R a36} may represent a hydrocarbon group having 1 to 20 carbon ^{atoms, R a35} and ^{R a36} are each And C—O to which they are bonded to form a divalent heterocyclic group having 3 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent heterocyclic group is —O. -Or-S- may be substituted. ]

^Examples of the alkyl group of R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group and a hexyl group. As the alkyl group, an alkyl group having 1 to 4 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is further preferable.
Examples of the halogen atom of R ^a32 and R ^a33 include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group which may have a halogen atom include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1,1,2,2-tetrafluoro Ethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluoro Butyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group, n-perfluorohexyl group, etc. Can be mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
Examples of the hydrocarbon group R ^a34 and ^{R a35,} include the same groups as ^{R a1 'and R a2'} of formula (2).
R ^a36 is an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. Can be mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and further preferably a methoxy group.
la is preferably 0 or 1, and more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a methyl group or an ethyl group.
The hydrocarbon group for R ^a36 is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. And a C3-C18 alkyl group, a C3-C18 alicyclic aliphatic hydrocarbon group, or a C7-C18 aralkyl group. The alkyl group in R ^a36 and the alicyclic hydrocarbon group are preferably unsubstituted. When the aromatic hydrocarbon group for R ^a36 has a substituent, the substituent is preferably an aryloxy group having 6 to 10 carbon atoms.

  Examples of the monomer that leads to the structural unit (a1-4) include the monomers described in JP2010-204646A. Among them, the monomers represented by the formulas (a1-4-1) to (a1-4-8) are preferable, and the formulas (a1-4-1) to (a1-4-5) and the formula (a1-). The monomers represented by 4-8) are more preferable.

  When the resin (A) has the structural unit (a1-4), its content is preferably 10 to 95 mol% with respect to the total of all structural units of the resin (A), and preferably 15 to 90. It is more preferably mol%, and further preferably 20 to 85 mol%.

As the structural unit derived from the (meth) acrylic monomer having the group represented by the formula (2), a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)” There is also).
[In formula (a1-5),
^Ra8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or _{* - (CH 2) h3 -CO} -L 54 - represents, h3 represents an integer of 1 to 4, * ^represents a bond to ^{L 51.}
L ⁵¹ ~L ^54, independently of each other, represent -O- or -S-.
s1 represents an integer of 1 to 3.
s1 'represents the integer of 0-3. ]

Examples of the halogen atom include a fluorine atom and a chlorine atom, preferably a fluorine atom. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group and trifluoromethyl. Groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
It is preferable that one of L ⁵² and L ⁵³ is —O—, and the other is —S—.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

Examples of the monomer that leads to the structural unit (a1-5) include the monomers described in JP 2010-61117 A. Among them, the monomers represented by formulas (a1-5-1) to (a1-5-4) are preferable, and the monomers represented by formula (a1-5-1) or formula (a1-5-2) are preferred. Is more preferable.

  When the resin (A) has the structural unit (a1-5), its content is preferably 1 to 50 mol% based on the total of all structural units of the resin (A), and 3 to 45. It is more preferably mol%, and further preferably 5 to 40 mol%.

As the structural unit (a1) having an acid labile group in the resin (A), the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2) and the structural unit (a1-5). One or more selected from the group consisting of), more preferably two or more, a combination of structural unit (a1-1) and structural unit (a1-2), structural unit (a1-1) and structural unit (a1- 5) combination, structural unit (a1-1) and structural unit (a1-0) combination, structural unit (a1-2) and structural unit (a1-0) combination, structural unit (a1-5) and structure Combination of units (a1-0), structural unit (a1-0), combination of structural unit (a1-1) and structural unit (a1-2), structural unit (a1-0), structural unit (a1-1) And a combination of structural units (a1-5) are more preferable, and a combination of structural units (a1-1) and structural units (a1-2), a combination of structural units (a1-1) and structural units (a1-5) are Even more preferable.
The structural unit (a1) preferably includes the structural unit (a1-1).

<Structural unit (s)>
The resin (A) of the present invention may further have a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”).
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). As the monomer for deriving the structural unit (s), a monomer having no acid labile group known in the resist field can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure unit having a hydroxy group and not having an acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a lactone ring and having no acid labile group When a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When a resist pattern is produced from the resist composition of the present invention, a high-energy ray such as KrF excimer laser (248 nm), electron beam or EUV (extreme ultraviolet light) is used as an exposure light source, the structural unit (a2) is used. It is preferable to use the structural unit (a2) having a phenolic hydroxy group. When using an ArF excimer laser (193 nm) or the like, the structural unit (a2) is preferably the structural unit (a2) having an alcoholic hydroxy group, and more preferably the structural unit (a2-1). As the structural unit (a2), one type may be included alone, or two or more types may be included.

Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “structural unit (a2-0)”).
[In the formula (a2-0),
R ^a30 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
ma represents the integer of 0-4. When ma is an integer greater than or equal to 2, some R ^<a31 > may be mutually same or different. ]

^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom of R ^a30 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1 , 1,2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl Group, an n-perfluorohexyl group and the like. As R ^a30 , a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is preferable, a hydrogen atom, a methyl group or an ethyl group is more preferable, and a hydrogen atom or a methyl group is further preferable.
^Examples of the alkoxy group of R ^a31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further preferable.
Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like.
As ma, 0, 1 or 2 is preferable, 0 or 1 is more preferable, and 0 is particularly preferable.

Examples of the monomer that derives the structural unit (a2-0) include the monomers described in JP 2010-204634 A.
Among them, the structural unit (a2-0) is represented by the formula (a2-0-1), the formula (a2-0-2), the formula (a2-0-3) and the formula (a2-0-4). Embedded image is preferable, and the structural unit represented by formula (a2-0-1) or formula (a2-0-2) is more preferable.

  The resin (A) containing the structural unit (a2-0) undergoes a polymerization reaction using a monomer in which the phenolic hydroxy group of the monomer that induces the structural unit (a2-0) is protected with a protecting group, and then deprotected. It can be produced by processing. However, it is necessary to perform the deprotection treatment so that the acid labile group contained in the structural unit (a1) is not significantly impaired. An acetyl group etc. are mentioned as such a protective group.

  When the resin (A) has a structural unit (a2-0) having a phenolic hydroxy group, its content is 5 to 95 mol% based on the total of all structural units of the resin (A). Is preferable, 10 to 80 mol% is more preferable, and 15 to 80 mol% is further preferable.

  Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).

[In the formula (a2-1),
L ^a3 is, -O- or _{* -O- (CH 2) k2 -CO} -O- the stands,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10. ]

In formula (a2-1), L ^a3 is preferably —O—, —O— (CH ₂ ) _f1 —CO—O— (where f1 is an integer of 1 to 4), and more preferably -O-.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

  Examples of the monomer that derives the structural unit (a2-1) include the monomers described in JP2010-204646A. The monomer represented by any of the formulas (a2-1-1) to (a2-1-6) is preferable, and the monomer represented by any of the formulas (a2-1-1) to (a2-1-4) is represented. Is more preferable, and the monomer represented by formula (a2-1-1) or formula (a2-1-3) is further preferable.

  When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol%, preferably 1 to 40 mol, based on the total of all structural units of the resin (A). %, More preferably 1 to 35 mol%, further preferably 2 to 20 mol%.

<Structural unit (a3)>
The lactone ring contained in the structural unit (a3) may be a single 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. But it's okay. Preferably, a bridged ring containing a γ-butyrolactone ring, an adamantane lactone ring or a γ-butyrolactone ring structure is used.

The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) or the formula (a3-4). These may be contained alone or in combination of two or more.
[In the formula (a3-1),
L ^a4 represents a group represented by -O- or * -O- (CH ₂ ) _k3- CO-O- (k3 represents an integer of 1 to 7). * Represents a bond with the carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents the integer of 0-5. When p1 is 2 or more, a plurality of R ^a21 may be the same as or different from each other.
In formula (a3-2),
L ^a5 represents a group represented by —O— or * —O— (CH ₂ ) _k3— CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with the carbonyl group.
R ^a19 represents a hydrogen atom or a methyl group.
^Ra22 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, a plurality of R ^a22 may be the same as or different from each other.
In formula (a3-3),
L ^a6 represents a group represented by —O— or * —O— (CH ₂ ) _k3— CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with the carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
R ^a23 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, a plurality of R ^a23 may be the same as or different from each other.
In formula (a3-4),
R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a25 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
L ^a7 represents a single ^{bond, * -O-, * -O -L a8} -O-, * -O -L a8 -CO-O-, * -O -L a8 -CO-O-L a9 -CO- Represents O- or ^* -O- ^La8- O-CO- ^La9- O-.
* Represents a bond with the carbonyl group.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
w1 represents an integer of 0-8. When w1 is 2 or more, a plurality of R ^a25 may be the same as or different from each other. ]

Examples of the aliphatic hydrocarbon group having 1 to 4 carbon atoms of R ^a21 , R ^a22 , R ^a23, and R ^a25 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-group. Examples thereof include a butyl group.
Examples of the halogen atom of R ^a24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group for R ^a24 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group and an n-hexyl group. Of these, an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.
Examples of the alkyl group having a halogen atom of R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro. Hexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group and the like can be mentioned.

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

In formulas (a3-1) to (a3-3), L ^{a4 to} L ^a6 are independently of each other, preferably —O—, or k3 is an integer of 1 to 4 * —O— (CH ₂ ). a _k3 -CO-O-group represented by, more preferably -O- _{and, * - O-CH 2 -CO} -O- and, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are independently of each other, preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are independently of each other, preferably an integer of 0 to 2, and more preferably 0 or 1.

In formula (a3-4),
R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group.
L ^a7 is preferably a single bond, ^* -O- or ^* -O -L ^a8 -CO-O-, more preferably an a single _{^{bond, * -O-, * -O -CH 2}} -CO- O- or ^* -O -C ₂ H ₄ is -CO-O-.
R ^a25 is preferably a carboxy group, a cyano group or a methyl group.
w1 is preferably an integer of 0 to 2, and more preferably 0 or 1.
Particularly, the formula (a3-4) is preferably the formula (a3-4) ′.
(In the formula, R ^a24 and L ^a7 have the same meanings as described above.)

  Examples of the monomer that leads to the structural unit (a3) include the monomer described in JP 2010-204646 A, the monomer described in JP 2000-122294 A, and the monomer described in JP 2012-41274 A. Can be mentioned. As the structural unit (a3), formula (a3-1-1) to formula (a3-1-6), formula (a3-2-1) to formula (a3-2-4), formula (a3-3-). 1) to the formula (a3-3-4) and the formula (a3-4-1) to the formula (a3-4-12), a structural unit represented by any of the formulas (a3-1-1), It is represented by any one of formula (a3-1-2), formula (a3-2-3) to formula (a3-2-4) and formula (a3-4-1) to formula (a3-4-12). The structural unit represented by any of the formulas (a3-4-1) to (a3-4-12) is more preferable, and the formula (a3-4-1) to the formula (a3-4) are more preferable. The structural unit represented by any of 4-6) is even more preferable.

In the following structural unit, a compound in which a methyl group corresponding to R ^a24 is replaced with a hydrogen atom can also be mentioned as a specific example of the structural unit (a3-4).

When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol% with respect to the total of all structural units of the resin (A). And more preferably 10 to 60 mol%.
In addition, the content rates of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), and the structural unit (a3-4) are independent of each other, and all the structural units of the resin (A). Is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and further preferably 10 to 50 mol%.

The resin (A) of the present invention may further have another structural unit (hereinafter sometimes referred to as “structural unit (t)”).
<Structural unit (t)>
As the structural unit (t), in addition to the structural unit (a2) and the structural unit (a3), a structural unit having a halogen atom (hereinafter, sometimes referred to as “structural unit (a4)”) and a non-eliminating hydrocarbon group. Examples thereof include structural units (hereinafter sometimes referred to as “structural unit (a5)”).

Examples of the structural unit (a4) include structural units represented by the formula (a4-0).
[In formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁵ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the aliphatic saturated hydrocarbon group for L ⁵ include alkanediyl groups having 1 to 4 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group. Such as a straight-chain alkanediyl group, a straight-chain alkanediyl group having a side chain of an alkyl group (particularly, methyl group, ethyl group, etc.), ethane-1,1-diyl group, propane-1, Examples thereof include branched alkanediyl groups such as 2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.

Examples of the perfluoroalkanediyl group for L ³ include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group and a perfluoropropane-2,2. -Diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -Diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -Diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2 -Diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
Examples of the perfluorocycloalkanediyl group of L ³ include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group and a perfluoroadamantanediyl group.

L ⁵ is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group.
L ³ is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

Examples of the structural unit (a4-0) include the structural units shown below.

Examples of the structural unit (a4) include structural units represented by the formula (a4-1).
[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and —CH ₂ — contained in the hydrocarbon group may be replaced with —O— or —CO—. Good.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). ]

[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
X ^a41 and X ^a42 each independently represent —O—, —CO—, ^—CO —O—, or —O—CO—.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41, and X ^a42 is 7 or less.
Of the two bonds represented by *, the * on the right side is a bond with -O-CO- ^Ra42 . ]

^Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
The chain and cyclic aliphatic hydrocarbon groups may have a carbon-carbon unsaturated bond, but the chain and cyclic aliphatic saturated hydrocarbon groups and combinations thereof are preferable. The aliphatic saturated hydrocarbon group includes a linear or branched alkyl group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a fat formed by combining an alkyl group and an alicyclic hydrocarbon group. Group hydrocarbon groups and the like can be mentioned.

  Examples of the chain type aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group. Group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group. As the cyclic aliphatic hydrocarbon group, a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* are bonded And a polycyclic alicyclic hydrocarbon group such as.

  Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group and a fluorenyl group.

^Examples of the substituent of R ^a42 include a halogen atom or a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having at least one halogen atom and having 1 to 17 carbon atoms.
* Represents a bond. ]
^As the aliphatic hydrocarbon group for A ^a45, the same groups as those exemplified for R ^a42 can be mentioned.

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an aliphatic hydrocarbon group having an alkyl group having a halogen atom and / or a group represented by the formula (a-g3). ..
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and further preferably a carbon number. It is a perfluoroalkyl group having 1 to 6 and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group and the like.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by formula (a-g3), the aliphatic hydrocarbon including the carbon number contained in the group represented by formula (a-g3) The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When the group represented by formula (a-g3) has a substituent, the number thereof is preferably 1.

The aliphatic hydrocarbon group having a group represented by formula (a-g3) is more preferably a group represented by formula (a-g2).
[In the formula (a-g2),
A ^a46 represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47, and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* Represents a bond with the carbonyl group. ]

The aliphatic hydrocarbon group for A ^a46 preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.
The aliphatic hydrocarbon group for A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and further preferably a cyclohexyl group or an adamantyl group.

A more preferable structure of the partial structure represented by * -A ^a46 -X ^a44 -A ^a47 is the following structure.

The alkanediyl group of A ^a41 includes a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group. A linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples thereof include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group of A ^a41 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and further preferably an ethylene group.

The aliphatic hydrocarbon group of A ^{a42 to} A ^a44 in the group (a-g1) may have a carbon-carbon unsaturated bond, but an aliphatic saturated hydrocarbon group is preferable. Examples of the aliphatic saturated hydrocarbon group include an alkanediyl group (the alkanediyl group may be linear or branched), a divalent alicyclic hydrocarbon group, an alkanediyl group and a divalent aliphatic group. Examples thereof include an aliphatic hydrocarbon group formed by combining cyclic hydrocarbon groups. Specifically, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, Examples thereof include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent of the aliphatic hydrocarbon group of A ^{a42 to} A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

^Examples of the group (a-g1) in which X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with -O-CO-Ra ⁴² .

As the structural unit represented by the formula (a4-1), structural units represented by the formula (a4-2) and the formula (a4-3) are preferable.
[In the formula (a4-2),
R ^f1 represents a hydrogen atom or a methyl group.
A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.
R ^f2 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

The alkanediyl group of A ^f1 includes a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group. , A linear alkanediyl group such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 Examples thereof include branched alkanediyl groups such as -diyl group, 1-methylbutane-1,4-diyl group and 2-methylbutane-1,4-diyl group.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain structure, a cyclic structure and a group formed by a combination thereof. The aliphatic hydrocarbon group is preferably an alkyl group or an alicyclic hydrocarbon group.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 And an ethylhexyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group. A cycloalkyl group is mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, a norbornyl group, Examples thereof include a methylnorbornyl group and an isobornyl group.

Examples of the hydrocarbon group having a fluorine atom of R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.
Examples of the alkyl group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, 1 , 1,2,2-Tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2- Tetrafluoroethyl group, 1- (trifluoromethyl) -2,2,2-trifluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3 , 3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2- Trifluoroethyl group, 2- (perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3 , 4,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, 2- (perfluorobutyl) ethyl group, 1 , 1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluoro Examples thereof include fluorinated alkyl groups such as a hexyl group, a perfluoropentylmethyl group, and a perfluorohexyl group.
Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

As A ^f1 in the formula (a4-2), an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.
R ^f1 is preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

[In the formula (a4-3),
R ^f11 represents a hydrogen atom or a methyl group.
A ^f11 represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents a divalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, which may have a fluorine atom.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom. ]

^Examples of the alkanediyl group of A ^f11 include the same groups as the alkanediyl group of A ^f1 .

The aliphatic hydrocarbon group for A ^f13 includes a chain and cyclic aliphatic hydrocarbon group, and a divalent aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. Be done.
Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group; a difluoromethylene group, a perfluoroethylene group. And perfluoroalkanediyl groups such as a group, a perfluoropropanediyl group, a perfluorobutanediyl group and a perfluoropentanediyl group.
The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either a monocyclic group or a polycyclic group. Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group and a perfluoroadamantanediyl group.

The aliphatic hydrocarbon group for A ^f14 includes any of a chain type and a cyclic type, and an aliphatic hydrocarbon group formed by combining these. This aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, but is preferably a saturated aliphatic hydrocarbon group.
The aliphatic hydrocarbon group which may have a fluorine atom of A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.
Examples of the chain type aliphatic hydrocarbon group which may have a fluorine atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1 , 2,2-Tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, Examples thereof include a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group.
The cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the group containing a monocyclic aliphatic hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group and a perfluorocyclohexyl group. Examples of the group containing a polycyclic aliphatic hydrocarbon group include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, a perfluoroadamantylmethyl group and the like.

In the formula ^{(a4-3), A f11} is preferably an ethylene group.
The aliphatic hydrocarbon group for A ^f13 is preferably an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and more preferably an aliphatic hydrocarbon group having 2 to 3 carbon atoms.
As the aliphatic hydrocarbon group of A ^f14, an aliphatic hydrocarbon group having 3 to 12 carbon atoms is preferable, and an aliphatic hydrocarbon group having 3 to 10 carbon atoms is more preferable. Among them, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

Examples of the structural unit represented by the formula (a4-2) include structural units represented by the formula (a4-1-1) to the formula (a4-1-22).

  Examples of the structural unit represented by the formula (a4-3) include structural units represented by the formulas (a4-1'-1) to (a4-1'-22).

The structural unit (a4) also includes a structural unit represented by the formula (a4-4).
[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 _{is, - (CH 2) j1 -} , - (CH 2) j2 -O- (CH 2) j3 - or _{- (CH 2) j4 -CO-} O- (CH 2) j5 - represents a.
j1 to j5 each independently represent an integer of 1 to 6.
R ^f22 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same as the hydrocarbon group of R ^f2 in the formula (a4-2). R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, and a C 1-10 alkyl having a fluorine atom. A group is more preferable, and a C 1-6 alkyl group having a fluorine atom is further preferable.

In formula ^(A4-4), as the _{^{A f21, - (CH 2)}} j1 - , more preferably an ethylene group or a methylene group, more preferably a methylene group.

Examples of the structural unit represented by the formula (a4-4) include the following structural units.

  When the resin (A) has the structural unit (a4), its content is preferably 1 to 20 mol%, and 2 to 15 mol% based on the total of all structural units of the resin (A). Is more preferable, and 3 to 10 mol% is further preferable.

<Structural unit (a5)>
Examples of the non-eliminating hydrocarbon group contained in the structural unit (a5) include linear, branched or cyclic hydrocarbon groups. Among them, the structural unit (a5) is preferably an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include structural units represented by the formula (a5-1).
[In the formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a hydroxy group. May be.
However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁵⁵ is not substituted with the aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group for R ⁵² may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
The aliphatic hydrocarbon group having 1 to 8 carbon atoms is, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include alkyl groups such as an octyl group and a 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-hydroxyadamantyl group and a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group for L ⁵⁵ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent aliphatic saturated hydrocarbon group. Be done.
Examples of the divalent saturated aliphatic hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

Examples of the group in which the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group include groups represented by formula (L1-1) to formula (L1-4). In the following formula, * represents a bond with an oxygen atom.
[In the formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total carbon number of L ^x1 and L ^x2 is 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total carbon number of L ^x3 and L ^x4 is 17 or less.
In formula (L1-3),
L ^x5 represents a divalent saturated aliphatic hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of L ^{x5 to} L ^x7 is 15 or less.
In formula (L1-4),
L ^x8 and L ^x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of L ^x8 , L ^x9, and W ^x1 is 15 or less. ]

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

Examples of the group represented by the formula (L1-1) include divalent groups shown below.

Examples of the group represented by the formula (L1-2) include divalent groups shown below.

Examples of the group represented by the formula (L1-3) include the following divalent groups.

Examples of the group represented by the formula (L1-4) include the following divalent groups.

L ⁵⁵ is preferably a single bond or a group represented by the formula (L1-1).

Examples of the structural unit (a5-1) include the followings.

In formulas (a5-1-19) to (a5-1-27), the structural unit in which the methyl group corresponding to R ⁵¹ is replaced with a hydrogen atom may be mentioned as a specific example of the structural unit (a5-1). it can.

  When the resin (A) has the structural unit (a5), its content is preferably 1 to 30 mol%, and 2 to 20 mol% based on the total of all structural units of the resin (A). Is more preferable, and 3 to 15 mol% is further preferable.

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

The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s).
The structural unit (a1) is preferably at least one selected from the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), and more preferably the structural unit (a1). at least two kinds selected from a1-1) and structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group).
The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1).
The structural unit (a3) is preferably selected from the structural unit represented by the formula (a3-1), the structural unit represented by the formula (a3-2) and the structural unit represented by the formula (a3-4). At least one.

  The resin (A) contains the structural unit (particularly the structural unit (a1-1)) derived from the monomer having an adamantyl group in an amount of 15 mol% or more based on the content of the structural unit (a1). preferable. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that induces these structural units. can do. The content of each structural unit contained in the resin (A) can be adjusted by the amount of the monomer used for the polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, further preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably) Is 15,000 or less). The weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the examples.

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). Examples of such a resin include a resin composed of only the structural unit (s) and a resin containing the structural unit (a4) (however, the structural unit (a1) is not included, and may be hereinafter referred to as “resin (X)”). Can be mentioned. Of these, the resin (X) is preferable.

In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, and more preferably 45 mol% or more, based on the total of all structural units of the resin (X). Is more preferably 50 mol% or more.
Examples of the structural unit that the resin (X) may further have include structural units (a2), structural units (a3) and structural units derived from other known monomers.
The weight average molecular weight of the resin (X) is preferably 5,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as that for the resin (A).
When the resist composition contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, and further 100 parts by mass of the resin (A). It is preferably 2 to 40 parts by mass, and particularly preferably 2 to 30 parts by mass.

  The total content of the resin (A) and resins other than the resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90 to 99% by mass, based on the solid content of the resist composition. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Quencher (C)>
Examples of the quencher (C) include salts that generate an acid having a weaker acidity than the acid generated from the basic nitrogen-containing organic compound or the acid generator (B).
Examples of basic nitrogen-containing organic compounds include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

  As amines, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, tri Isopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3 , 3'-Diethyldiphenylmethane, piperazine, morpholine, piperidine and hindered amine compounds having a piperidine skeleton described in JP-A-11-52575, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2- Di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethene, 1,3-di ( 4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridylsulfide, 4,4′-dipyridyldisulfide, 2,2′-dipyridylamine , 2,2′-dipicolylamine, bipyridine and the like are preferable, diisopropylaniline is preferable, and 2,6-diisopropylaniline is particularly preferable.

  Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, and 3- (trifluoromethyl) phenyltrimethyl. Examples thereof include ammonium hydroxide, tetra-n-butylammonium salicylate and choline.

As the salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B), a salt represented by the following formula, a weak acid intramolecular salt represented by the formula (D), and JP-A-2012- Salts described in JP-A-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502 and JP-A-2011-191745 can be mentioned. The weak acid inner salt represented by the formula (D) (hereinafter sometimes referred to as “weak acid inner salt (D)”) is preferable.
The acidity of a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) is represented by an acid dissociation constant (pKa). The salt that generates an acid having a weaker acidity than the acid generated from the salt (I) and the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3 <pKa, A salt of -1 <pKa <7 is preferable, and a salt of 0 <pKa <5 is more preferable.

[In the formula (D),
R ^D1 and R ^D2 are, independently of each other, a monovalent hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, and an acyloxy group having 2 to 7 carbon atoms. Represents an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom.
m ′ and n ′ each independently represent an integer of 0 to 4, when m ′ is 2 or more, a plurality of R ^D1 may be the same or different, and when n ′ is 2 or more, A plurality of R ^D2 may be the same or different. ]

In the weak acid inner salt (D), the hydrocarbon groups of R ^D1 and R ^D2 include a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group and The group etc. which are formed by combining these are mentioned.
Examples of the monovalent aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group and nonyl group.
The monovalent alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, cyclododecyl group, norbornyl group, adamantyl group and the like.
Examples of the monovalent aromatic hydrocarbon group include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4- Propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group And aryl groups such as cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, and 2-methyl-6-ethylphenyl.
The group formed by combining these includes an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, an aralkyl group (for example, a phenylmethyl group, a 1-phenylethyl group, a 2-phenylethyl group, a 1-phenyl- group. 1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc.) and the like.

Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, a cyclohexanecarbonyl group and the like.
Examples of the acyloxy group include groups in which an oxy group (—O—) is bonded to the above acyl group.
Examples of the alkoxycarbonyl group include groups in which a carbonyl group (—CO—) is bonded to the above alkoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom.

In formula (D), R ^D1 and R ^D2 are, independently of each other, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 to 2 carbon atoms. An acyl group having 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group or a halogen atom is preferable.
m ′ and n ′ are preferably, independently of each other, an integer of 0 to 2, and more preferably 0. When m ′ is 2 or more, the plurality of R ^D1 may be the same or different, and when n ′ is 2 or more, the plurality of R ^D2 may be the same or different.

Examples of the weak acid inner salt (D) include the following compounds.

  The weak acid inner salt (D) can be produced by the method described in "Tetrahedron Vol. 45, No. 19, p6281-6296". As the weak acid inner salt (D), a commercially available compound can be used.

  The content of the quencher (C) in the solid content of the resist composition is preferably 0.01 to 5% by mass, more preferably 0.01 to 4% by mass, and particularly preferably 0.01 to 3% by mass. %.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more, preferably 92% by mass or more, more preferably 94% by mass or more, and usually 99.9% by mass or less, preferably 99% by mass or less. Is. The content of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (E) 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 ethyl pyruvate. And the like; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; The solvent (E) may contain 1 type independently and may contain 2 or more types.

<Other ingredients>
The resist composition may contain a component other than the above-mentioned components (hereinafter sometimes referred to as “other component (F)”), if necessary. As the other component (F), additives known in the resist field, for example, sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

<Preparation of resist composition>
The resist composition is prepared by mixing the resin (A) and the acid generator (B), and if necessary, the resin (X), the solvent (E), the quencher (C) and the other component (F). can do. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can be selected from 10 to 40 ° C., depending on the type of resin or the like, the solubility of the resin or the like in the solvent (E), or the like. As the mixing time, an appropriate time can be selected from 0.5 to 24 hours according to the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for manufacturing resist pattern>
The method for producing a resist pattern of the present invention,
(1) A step of applying the resist composition of the present invention onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) exposing the composition layer
(4) A step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  The coating of the resist composition on the substrate can be carried out by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. The substrate may be washed before applying the resist composition, or an antireflection film or the like may be formed on the substrate.

The composition is dried to remove the solvent and form a composition layer. Drying is performed by evaporating the solvent using a heating device such as a hot plate (so-called prebaking) or using a decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. In addition, the pressure for drying under reduced pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure device. The exposure machine may be an immersion exposure machine. As the exposure light source, one that emits laser light in the ultraviolet region such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm), a solid-state laser light source (YAG or semiconductor laser Etc.) that emits harmonic laser light in the far-ultraviolet region or vacuum-ultraviolet region by wavelength-converting the laser light from, etc., electron beams, or those that emit ultra-ultraviolet light (EUV), etc. You can In the present specification, the irradiation of these radiations may be collectively referred to as “exposure”. At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, it may be exposed by direct drawing without using a mask.

  The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) in order to accelerate the deprotection reaction at the acid labile group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

  The composition layer after heating is usually developed using a developing device using a developing device. Examples of the developing method include a dip method, a paddle method, a spray method, a dynamic dispense method and the like. The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds. A positive resist pattern or a negative resist pattern can be manufactured by selecting the type of developer as follows.

When a positive resist pattern is produced from the resist composition, an alkali developing solution is used as the developing solution. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkaline developer may contain a surfactant.
After development, it is preferable to wash the resist pattern with ultrapure water, and then remove water remaining on the substrate and the pattern.

When a negative resist pattern is produced from a resist composition, a developer containing an organic solvent (hereinafter sometimes referred to as “organic developer”) is used as the developer.
Examples of the organic solvent contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether. Examples thereof include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and substantially only the organic solvent. Is more preferable.
As the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially. More preferably, it is only butyl acetate and / or 2-heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a small amount of water.
During development, the development may be stopped by substituting with a solvent of a different type from the organic developer.

It is preferable to wash the resist pattern after development with a rinse liquid. The rinse liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

<Use>
The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, especially ArF. It is suitable as a resist composition for excimer laser exposure and is useful for fine processing of semiconductors.

A more specific description will be given with reference to examples. In the examples, “%” and “part” indicating the content or the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Device: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore H _XL -M x 3 + 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)

  In addition, the structure of the compound was confirmed by measuring a molecular peak using mass spectrometry (LC: Agilent model 1100, MASS: Agilent model LC / MSD). In the following examples, the value of this molecular peak is indicated by "MASS".

Example 1: Synthesis of salt represented by formula (I-1)
12.30 parts of the compound represented by the formula (I-1-a) and 40 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. 11.63 parts of the compound represented by the formula (I-1-b) was added to the obtained mixed solution, and the mixture was further stirred at 40 ° C. for 1 hr. A mixed solution of 16.13 parts of the compound represented by the formula (I-1-c) and 20 parts of acetonitrile was added to the obtained reaction mass, and the mixture was further stirred at 23 ° C. for 3 hours. The obtained reaction product was concentrated, and the concentrated mass was separated by a column (Kanto Kagaku Silica Gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 1/2) to obtain a formula ( 10.48 parts of the compound represented by I-1-d) was obtained.

9.98 parts of the salt represented by the formula (I-1-e) and 50 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 4.04 parts of the compound represented by the formula (I-1-b) was added, and the mixture was further stirred at 70 ° C. for 2 hours to give the compound represented by the formula (I-1-f). A solution containing the desired salt was obtained.

  5.75 parts of the compound represented by the formula (I-1-d) was added to the obtained solution containing the salt represented by the formula (I-1-f), and the mixture was further stirred at 23 ° C. for 18 hours. And concentrated. Chloroform (100 parts) and ion-exchanged water (35 parts) were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, and the organic layer was separated. 35 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred to remove the supernatant. The obtained residue was concentrated to obtain 11.28 parts of the salt represented by the formula (I-1).

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 437.2

Example 2: Synthesis of salt represented by formula (I-2)
13.39 parts of the compound represented by the formula (I-2-a) and 40 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. 11.63 parts of the compound represented by the formula (I-2-b) was added to the obtained mixed solution, and the mixture was further stirred at 40 ° C. for 1 hour. A mixed solution of 16.13 parts of the compound represented by the formula (I-2-c) and 20 parts of acetonitrile was added to the obtained reaction mass, and the mixture was further stirred at 23 ° C. for 3 hours. The obtained reaction product was concentrated, and the concentrated mass was separated by a column (Kanto Kagaku Silica Gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 1/2) to obtain a formula ( 10.01 parts of the compound represented by I-2-d) was obtained.

9.98 parts of the salt represented by the formula (I-2-e) and 50 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 4.04 parts of the compound represented by the formula (I-2-b) was added, and the mixture was further stirred at 70 ° C. for 2 hours to give the compound represented by the formula (I-2-f). A solution containing the desired salt was obtained.

To the obtained solution containing the salt represented by the formula (I-2-f), 6.08 parts of the compound represented by the formula (I-2-d) was added, and the mixture was further stirred at 23 ° C. for 18 hours. And concentrated. Chloroform (100 parts) and ion-exchanged water (35 parts) were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, and the organic layer was separated. 35 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred to remove the supernatant. By concentrating the obtained residue, 10.98 parts of the salt represented by the formula (I-2) was obtained.

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 453.1

Example 3: Synthesis of salt represented by formula (I-3)
13.25 parts of the compound represented by the formula (I-3-a) and 40 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. 11.63 parts of the compound represented by the formula (I-3-b) was added to the obtained mixed solution, and the mixture was further stirred at 40 ° C. for 1 hour. A mixed solution of 16.13 parts of the compound represented by the formula (I-3-c) and 20 parts of acetonitrile was added to the obtained reaction mass, and the mixture was further stirred at 23 ° C. for 3 hours. The obtained reaction product was concentrated, and the concentrated mass was separated by a column (Kanto Kagaku Silica Gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 1/2) to obtain a formula ( 10.22 parts of the compound represented by I-3-d) was obtained.

9.98 parts of the salt represented by the formula (I-3-e) and 50 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the obtained mixed solution, 4.04 parts of the compound represented by the formula (I-3-b) was added, and the mixture was further stirred at 70 ° C. for 2 hours to give the compound represented by the formula (I-3-f). A solution containing the desired salt was obtained.

To the obtained solution containing the salt represented by the formula (I-3-f), 6.04 parts of the compound represented by the formula (I-3-d) was added, and the mixture was further stirred at 23 ° C. for 18 hours. And concentrated. Chloroform (100 parts) and ion-exchanged water (35 parts) were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, and the organic layer was separated. 35 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred to remove the supernatant. By concentrating the obtained residue, 11.12 parts of the salt represented by the formula (I-3) was obtained.

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 451.1

Example 4: Synthesis of salt represented by formula (I-4)
8.90 parts of the compound represented by the formula (I-3-d), 7.30 parts of the compound represented by the formula (I-4-a) and 50 parts of 1,2-dichloroethane are added, and the mixture is added at 23 ° C. Stir for 30 minutes. 0.10 parts of p-toluenesulfonic acid was added to the obtained mixed solution, and the mixture was refluxed and stirred at 100 ° C. for 1 hour. The obtained reaction product was concentrated, and the concentrated mass was separated by a column (Kanto Kagaku Silica Gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 1/2) to obtain a formula ( 2.89 parts of the compound represented by I-4-b) was obtained.

1.00 parts of the salt represented by the formula (I-4-c) and 20 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. 0.41 parts of the compound represented by the formula (I-4-d) was added to the obtained mixed solution, and the mixture was further stirred at 70 ° C. for 2 hours to give the compound represented by the formula (I-4-f). A solution containing the desired salt was obtained.

0.90 parts of the compound represented by the formula (I-4-b) was added to the obtained solution containing the salt represented by the formula (I-4-f), and the mixture was further stirred at 23 ° C. for 18 hours. And concentrated. Chloroform (100 parts) and ion-exchanged water (35 parts) were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, and the organic layer was separated. 35 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 10 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23 ° C. for 30 minutes, and filtered to obtain a salt of the formula (I-4) 0 .92 parts were obtained.

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 595.1

Example 5: Synthesis of salt represented by formula (I-13)
2.50 parts of the compound represented by the formula (I-12-a) and 25 parts of pyridine were added, and the mixture was stirred at 23 ° C for 30 minutes. To the resulting mixed solutions was added 3.10 parts of the compound represented by the formula (I-13-b), and the mixture was further stirred at 23 ° C. for 18 hours. 30 parts of ion-exchanged water and 50 parts of ethyl acetate were added to the obtained reaction product, and the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and separated. 20 parts of ion-exchanged water was added to the collected organic layer, the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and liquid-separated to wash the organic layer. This water washing operation was repeated 3 times. The collected organic layer was concentrated, and the concentrated mass was collected by column (Kanto Kagaku Silica Gel 60N (spherical, neutral) 100-210 μm developing solvent: n-heptane / ethyl acetate = 9/1) to obtain the compound of formula (I Thus, 2.22 parts of the compound represented by -13-c) was obtained.

1.00 parts of salts represented by the formula (I-13-e) and 50 parts of acetonitrile were added, and the mixture was stirred at 23 ° C for 30 minutes. 0.41 parts of the compound represented by the formula (I-13-b) was added to the obtained mixed solution, and the mixture was further stirred at 70 ° C. for 2 hours to give the compound represented by the formula (I-13-f). A solution containing the desired salt was obtained.

0.47 parts of the compound represented by the formula (I-13-c) was added to the obtained solution containing the salt represented by the formula (I-13-f), and the mixture was further stirred at 23 ° C. for 18 hours. And concentrated. 20 parts of chloroform and 10 parts of ion-exchanged water were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. 10 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This operation was repeated 3 times. The obtained organic layer was concentrated, 10 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred, and the supernatant was removed. The obtained residue was concentrated to obtain 1.01 part of the salt represented by the formula (I-13).

MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 385.1

Example 6: Synthesis of salt represented by formula (I-103)
2.21 parts of lithium aluminum hydride was added to 10 parts of tetrahydrofuran at 5 ° C., and the mixture was stirred at 5 ° C. for 30 minutes. Thereafter, a mixed solution of 8.22 parts of the compound represented by the formula (I-103-a) and 30 parts of tetrahydrofuran was added dropwise thereto over 1 hour, and the mixture was further stirred at 23 ° C. for 18 hours. The obtained reaction product was charged with 30 parts of 1N hydrochloric acid and concentrated. To the collected concentrate, 82 parts of acetonitrile was added, stirred, filtered, and the obtained filtrate was concentrated to obtain 6.28 parts of a compound represented by the formula (I-103-b).
10.04 parts of the compound represented by the formula (I-3-d) and 50 parts of acetonitrile were added, and the mixture was stirred at 23 ° C. for 30 minutes. To the resulting mixed solutions was added 5.82 parts of the compound represented by the formula (I-103-c), and the mixture was further stirred at 40 ° C. for 1 hour. A mixed solution of 3.14 parts of the compound represented by the formula (I-103-b) and 6.60 parts of acetonitrile was added to the obtained reaction mass, and the mixture was further stirred at 23 ° C. for 16 hours. The obtained reaction product was filtered, and the obtained filtrate was concentrated to obtain 9.42 parts of the compound represented by the formula (I-103-e).
50 parts of the compound represented by the formula (I-103-f), 10.33 parts of the compound represented by the formula (I-103-g) and 350 parts of chloroform were charged, and the mixture was stirred at 23 ° C. for 30 minutes. Then, 0.20 parts of copper (II) acetate was charged therein, refluxed at 80 ° C. for 2 hours, and concentrated. To the collected concentrate, 440 parts of tert-butyl methyl ether was added, stirred and filtered to obtain 32.96 parts of the salt represented by the formula (I-103-h).
6.35 parts of the compound represented by the formula (I-103-e), 5.95 parts of the compound represented by the formula (I-103-h), 10 parts of acetonitrile, 32 parts of chloroform and 5% oxalic acid aqueous solution 15 0.72 parts was added, and the mixture was stirred at 23 ° C. for 2 hours. The obtained reaction solution was separated. To the collected organic layer, 11 parts of a 5% oxalic acid aqueous solution was added, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. This washing operation was repeated 3 times. To the collected organic layer was added 11 parts of a 5% sodium hydrogen carbonate aqueous solution, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This washing operation was repeated twice. 11 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. This water washing operation was repeated 3 times. The obtained organic layer was concentrated, 10 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred and the supernatant was removed. The resulting residue was concentrated to obtain 4.24 parts of the compound represented by the formula (I-103).
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 481.1

Example 7: Synthesis of salt represented by formula (I-104)
2.16 parts of the compound represented by the formula (I-103), 0.73 part of the compound represented by the formula (I-104-a) and 10 parts of 1,2-dichloroethane are added, and the mixture is added at 23 ° C. for 30 minutes. It was stirred.
0.01 part of p-toluenesulfonic acid was added to the obtained mixed solution, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 30 parts of chloroform and 10 parts of a 5% sodium hydrogen carbonate aqueous solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. The recovered organic layer was charged with 10 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to collect the organic layer. This washing operation was repeated 7 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 10 parts of acetonitrile was added to the obtained concentrate to dissolve and concentrate. To the recovered concentrate, 10 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was concentrated to obtain 1.88 parts of a compound represented by the formula (I-104).
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 625.2

Example 8: Synthesis of salt represented by formula (I-58)
9.39 parts of the salt represented by the formula (I-58-a) and 50 parts of acetonitrile were added, and the mixture was stirred at 23 ° C for 30 minutes. To the obtained mixed solution, 4.04 parts of the compound represented by the formula (I-58-b) was added, and the mixture was further stirred at 70 ° C. for 2 hours to give the compound represented by the formula (I-58-c). A solution containing the desired salt was obtained.

6.08 parts of the compound represented by the formula (I-2-d) was added to the obtained solution containing the salt represented by the formula (I-58-c), and the mixture was further stirred at 23 ° C. for 18 hours. And concentrated. Chloroform (100 parts) and ion-exchanged water (35 parts) were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, and the organic layer was separated. 35 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred to remove the supernatant. The obtained residue was concentrated to obtain 9.68 parts of the salt represented by the formula (I-58).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 453.1

Example 9: Synthesis of salt represented by formula (I-59)
9.39 parts of the salt represented by the formula (I-59-a) and 50 parts of acetonitrile were added, and the mixture was stirred at 23 ° C for 30 minutes. To the obtained mixed solution, 4.04 parts of the compound represented by the formula (I-59-b) was added, and the mixture was further stirred at 70 ° C. for 2 hours to give the compound represented by the formula (I-59-c). A solution containing the desired salt was obtained.

To the resulting solution containing the salt represented by the formula (I-59-c), 6.04 parts of the compound represented by the formula (I-3-d) was added, and the mixture was further stirred at 23 ° C. for 18 hours. And concentrated. Chloroform (100 parts) and ion-exchanged water (35 parts) were added to the obtained concentrate, and the mixture was stirred at 23 ° C. for 30 minutes, and the organic layer was separated. 35 parts of ion-exchanged water was added to the obtained organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred to remove the supernatant. The obtained residue was concentrated to obtain 10.43 parts of the salt represented by the formula (I-59).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 451.1

Example 10: Synthesis of salt represented by formula (I-60)
2.07 parts of the compound represented by the formula (I-59), 0.73 part of the compound represented by the formula (I-59-a) and 10 parts of 1,2-dichloroethane are added, and the mixture is added at 23 ° C. for 30 minutes. It was stirred.
0.01 part of p-toluenesulfonic acid was added to the obtained mixed solution, and the mixture was refluxed and stirred at 100 ° C. for 3 hours. The obtained reaction product was cooled to 23 ° C., 30 parts of chloroform and 10 parts of a 5% sodium hydrogen carbonate aqueous solution were added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated. The recovered organic layer was charged with 10 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to collect the organic layer. This washing operation was repeated 7 times. The organic layer obtained was charged with 1.00 part of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 10 parts of acetonitrile was added to the obtained concentrate to dissolve and concentrate. To the recovered concentrate, 10 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was concentrated to obtain 1.98 parts of a compound represented by the formula (I-60).
MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 595.1

Synthesis Example 1 [Synthesis of salt represented by formula (B1-21)]
30.00 parts of a compound represented by the formula (B1-21-b) obtained by the method described in JP 2008-209917 A, a salt represented by the formula (B1-21-a) 35.50. Parts, chloroform 100 parts and ion-exchanged water 50 parts were charged, and the mixture was stirred at 23 ° C. for 15 hours.
Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 30 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 100 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23 ° C. for 30 minutes, and filtered to give the salt of the formula (B1-21-c) 48. 57 parts were obtained.

20.00 parts of the salt represented by the formula (B1-21-c), 2.84 parts of the compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged, and the mixture was stirred at 23 ° C for 30 minutes. ..
0.21 part of copper (II) dibenzoate was added to the obtained mixed liquid, and the mixture was further stirred at 100 ° C. for 1 hour. The obtained reaction solution was concentrated, 200 parts of chloroform and 50 parts of ion-exchanged water were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes, separated, and the organic layer was taken out. 50 parts of ion-exchanged water was added to the collected organic layer, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the obtained residue was dissolved in 53.51 parts of acetonitrile and concentrated. Thereafter, 113.05 parts of tert-butyl methyl ether was added, and the mixture was stirred and filtered to obtain 10.47 parts of the salt represented by the formula (B1-21).

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 339.1

Synthesis Example 2 [Synthesis of salt represented by formula (B1-22)]
11.26 parts of the salt represented by the formula (B1-22-a), 10.00 parts of the compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of deionized water were charged, and the temperature was 23 ° C. It was stirred for 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained residue, the mixture was stirred at 23 ° C. for 30 minutes, and filtered to obtain the salt represented by the formula (B1-22-c). Obtained 75 parts.

11.71 parts of the salt represented by the formula (B1-22-c), 1.70 parts of the compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was heated at 23 ° C. for 30 minutes. It was stirred. 0.12 parts of copper (II) dibenzoate was added to the obtained mixed liquid, and the mixture was further stirred at 100 ° C. for 30 minutes. The obtained reaction solution was concentrated, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue, the mixture was stirred at 23 ° C. for 30 minutes, and liquid-separated to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C for 30 minutes.
Then, liquid separation was performed and the organic layer was taken out. This water washing operation was repeated 8 times. The obtained organic layer was concentrated, and 50 parts of tert-butyl methyl ether was added to the obtained residue and stirred.
Then, by filtration, 6.84 parts of a salt represented by the formula (B1-22) was obtained.

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

Synthesis of Resin (A) The compound (monomer) used for the synthesis of the resin (A) is shown below. Hereinafter, these compounds are referred to as “monomer (a1-1-2)” and the like according to the formula numbers.

Synthesis Example 3 [Synthesis of Resin A1]
Monomer (a1-1-2), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-1-1) and monomer (a3-2-3) are used in a molar ratio [ Monomer (a1-1-2): Monomer (a1-2-3): Monomer (a2-1-1): Monomer (a3-1-1): Monomer (a3-2-3)] is 30:14. : 6: 20: 30, and the mixture was mixed with propylene glycol monomethyl ether acetate in an amount of 1.5 times by mass based on the total mass of all the monomers. In the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were used as an initiator with respect to the total number of moles of all the monomers, and 1.00 mol% and 3.00 mol%, respectively. Was added. This was polymerized by heating at 73 ° C. for about 5 hours.
The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A1 having a weight average molecular weight of 7.8 × 10 ³ with a yield of 76%. This resin A1 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A2]
As the monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-3) and a monomer (a3-4-2) were used, and the molar ratio [monomer (a1-1 -3): Monomer (a1-2-9): Monomer (a2-1-3): Monomer (a3-4-2)] and mixed so as to be 45: 14: 2.5: 38.5, Propylene glycol monomethyl ether acetate in an amount of 1.5 times the total amount of the monomers was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 1 mol% and 3 mol% based on the total amount of the monomers, respectively, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin A2 having a weight average molecular weight of 7.8 × 10 ³ with a yield of 65%. This resin A2 has the following structural units.

Synthesis Example 5 [Synthesis of Resin X1]
As the monomer, the monomer (a4-1-7) was used, and 1.2 mass times of the total amount of methyl isobutyl ketone was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 0.7 mol% and 2.1 mol% based on the total amount of the monomers, respectively, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was repulped in a methanol / water mixed solvent and filtered to obtain a resin X1 having a weight average molecular weight of 1.7 × 10 ³ with a yield of 76%. This resin X1 has the following structural units.

(Preparation of resist composition)
Each of the components shown below was mixed in the parts by mass shown in Table 2, dissolved in a solvent, and filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin (A)>
A1, A2, X1: Resin A1, Resin A2, Resin X1
<Acid generator (B)>
I-1: Salt represented by formula (I-1) I-2: Salt represented by formula (I-2) I-3: Salt represented by formula (I-3) I-4: Formula Salt represented by (I-4) I-13: Salt represented by formula (I-13) I-58: Salt represented by formula (I-58) I-59: Formula (I-59) Salt represented by formula I-60: salt represented by formula (I-60) I-103: salt represented by formula (I-103) I-104: salt represented by formula (I-104) B1-21: salt represented by formula (B1-21) B1-22: salt represented by formula (B1-22) B1-X1: synthesized according to the examples of JP 2011-16794 A.
B1-X2: Synthesized according to the example of JP2012-252322A
<Quencher (C)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)
<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

<Production of resist pattern and its evaluation>
A silicon wafer is coated with a composition for organic antireflection film (ARC-29; manufactured by Nissan Kagaku Co., Ltd.) and baked at 205 ° C. for 60 seconds to give an organic reflection film having a film thickness of 78 nm on the wafer. The prevention film was formed. Next, the above resist composition was applied (spin-coated) on the organic antireflection film so that the film thickness after drying (prebaking) was 85 nm. After the application, the silicon wafer was prebaked on the direct hot plate at the temperature described in the "PB" column of Table 2 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 100 nm) was formed on a silicon wafer on which the composition layer was formed, using an ArF excimer stepper for immersion exposure (XT: 1900 Gi; ASML, NA = 1.35, 3/4 Annular XY polarized light). / Hole diameter 70 nm) was used, and the exposure amount was changed stepwise using the mask for exposure. Ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was heated (post-exposure bake treatment) on the hot plate at the temperature described in the “PEB” column of Table 2 for 60 seconds. Then, this silicon wafer was subjected to paddle development for 60 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution to obtain a resist pattern.

  In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask was 55 nm was defined as the effective sensitivity.

<CD uniformity (CDU) evaluation>
In terms of effective sensitivity, the hole diameter of the pattern formed by the mask was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The average hole diameter was measured for 400 holes formed on the same silicon wafer by the mask, and the standard deviation was determined using these as the population.
When the standard deviation is less than 1.85 nm, "◎",
When the standard deviation is 1.85 nm or more and less than 2.00 nm, "○",
The case where the standard deviation was larger than 2.00 nm was judged as "x".
The results are shown in Table 3. Numerical values in parentheses indicate standard deviation (nm).

  INDUSTRIAL APPLICABILITY The resist composition of the present invention is excellent in CD uniformity of the obtained resist pattern, and thus is suitable for fine processing of semiconductors and is extremely useful industrially.

Claims (13)

A salt represented by the formula (I).
[In the formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² are the same or different from each other.
X ¹ represents * -CO-O-, * -O-CO-, * -O-CO-O- or * -O-, and * represents C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² ) is represented.
A ¹ and A ² each independently represent a single bond or * -L ¹ —CO—O— (L ² —CO—O) _g —. * Represents a bond with X ¹ or an oxygen atom.
L ¹ and L ² each independently represent a divalent hydrocarbon group having 1 to 12 carbon atoms.
g represents 0 or 1.
A ³ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms.
R ³ represents an alicyclic hydrocarbon group having 5 to 18 carbon atoms, and the methylene group contained in the alicyclic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. The hydrogen atom contained in the hydrogen group may be substituted with a hydroxy group, or two hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with oxygen atoms, respectively, and the two oxygen atoms and the fluorine atom may be substituted. It may form a ketal structure together with the optionally substituted alkanediyl group having 1 to 8 carbon atoms.
Z ⁺ represents an organic cation. ] X ¹ is, * - CO-O -, * - O-CO- , * -O- and represents, * is ^{C (R 1) (R 2} ) or ^{C (Q 1) (Q 2} ) and the coupling position The salt according to claim 1, which represents The salt according to claim 2, wherein X ¹ is * -CO-O-, and * represents a bonding position with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² ). The salt according to claim 1, wherein A ³ is a single bond. The salt according to claim ^1, wherein A ¹ and A ² are single bonds. R ³ is a cyclohexyl group or an adamantyl group, and the methylene group contained in the cyclohexyl group and the adamantyl group may be replaced with an oxygen atom or a carbonyl group, and a hydrogen atom contained in the cyclohexyl group and the adamantyl group. May be substituted with a hydroxy group, or two hydrogen atoms contained in the cyclohexyl group and the adamantyl group may be substituted with oxygen atoms, and the number of carbon atoms that may have two oxygen atoms and a fluorine atom is 1 The salt according to any one of claims 1 to 5, which may form a ketal ring together with the alkanediyl group of ~ 8.   An acid generator containing the salt according to claim 1.   A resist composition comprising the acid generator according to claim 7 and a resin containing a structural unit having an acid labile group. The resist composition according to claim 8, wherein the structural unit having an acid labile group is at least one selected from the structural unit represented by formula (a1-1) and the structural unit represented by formula (a1-2). object.
[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent -O- or ^* -O- (CH ₂ ) _k1- CO-O-, k1 represents an integer of 1 to 7, and * represents a bond with -CO-. Representing a hand.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents the integer of 0-14.
n1 represents the integer of 0-10.
n1 'represents the integer of 0-3. ] The resist composition according to claim 8 or 9, further comprising an acid generator represented by formula (B1).
[In the formula (B1),
Q ¹ , Q ² and Z ⁺ have the same meanings as described above.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the monovalent alicyclic hydrocarbon group is, -O - - -CH ₂ contained in the hydrogen radical, - SO ₂ - or -CO- may be replaced with. ] The resist composition according to claim 8, further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator represented by formula (B1) .

[In the formula (B1),
Q ¹ , Q ² and Z ⁺ have the same meanings as described above.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the monovalent alicyclic hydrocarbon group is, -O - - -CH ₂ contained in the hydrogen radical, - SO ₂ - or -CO- may be replaced with. ]   The resist composition according to claim 8, further comprising a resin containing a structural unit having a fluorine atom. (1) A step of applying the resist composition according to any one of claims 8 to 12 onto a substrate,
(2) a step of drying the composition after coating to form a composition layer,
(3) exposing the composition layer
A method for producing a resist pattern, comprising: (4) heating the composition layer after exposure, and (5) developing the composition layer after heating.