JP6695155B2 - Resin, resist composition, and method for producing resist pattern - Google Patents

Description

  The present invention relates to a resin, a resist composition, and a method for producing a resist pattern.

Patent Document 1 describes a resin composed of structural units derived from the following compounds.

Patent Document 2 describes a resin composed of a combination of the following structural units.

JP, 07-62027, A JP, 2011-170284, A

  In a resist composition using a resin composed of a structural unit derived from the above compound, the line edge roughness may not always be satisfied.

The present invention includes the following inventions.
[1] A resin having a structural unit having a cyclic —O—SO—O— structure and a structural unit having an acid labile group.
[2] The resin according to [1], wherein the structural unit having a cyclic —O—SO—O— structure is a structural unit derived from the compound represented by formula (I).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
X ^I1 represents a trivalent hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced with —O—, —NH— or —CO—, The hydrogen atom contained in the hydrocarbon group may be replaced with a hydroxy group.
A ¹ represents a single bond, alkanediyl group having 1 to 6 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms.
A ³ and A ⁴ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1. ]
[3] The resin according to [2], wherein A ¹ is an alkanediyl group having 1 to 6 carbon atoms or ^* -A ² —X ¹ -A ⁴ —.
[4] The resin according to [2] or [3], wherein A ² is an alkanediyl group having 1 to 6 carbon atoms.
[5] The resin according to any one of [2] to [4], wherein X ¹ and X ² are each independently —O—, —CO—O— or —O—CO—.
[6] The resin according to any one of [2] to [5], wherein A ¹ is a methylene group.
[7] The resin according to any one of [1] to [6], wherein the structural unit having an acid labile group is a structural unit represented by formula (a1-1) or formula (a1-2).
[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. ]
[8] The resin according to any one of [1] to [7], further including a structural unit having a hydroxy group.
[9] The resin according to [8], wherein the structural unit having a hydroxy group is a structural unit derived from the compound represented by formula (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. ]
[10] The resin according to any one of [1] to [9], further including a structural unit having a lactone ring.
[11] The structural unit having a lactone ring is selected from the group consisting of structural units represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). The resin according to [10], which is at least one kind.
[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 -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * 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 -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * 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.
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. ]
[12] A resist composition containing the resin according to any one of [1] to [ 11 ] and an acid generator.
[13] The resist composition according to [12], further containing a resin containing a structural unit having a fluorine atom.
[14] The resist composition according to [12] or [13], further containing a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[15] (1) A step of applying the resist composition according to any one of [12] to [14] 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.

  By using the resist composition containing the resin of the present invention, a resist pattern can be manufactured with good line edge roughness.

  In the present specification, unless otherwise specified, in the description of the structural formula of the compound, groups such as “aliphatic hydrocarbon group” which can be linear or branched include both of them, and The “cyclic hydrocarbon group” means a group in which a number of hydrogen atoms corresponding to the valence is removed from the alicyclic hydrocarbon ring. 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" and "(meth) acrylic acid" mean "at least one of acrylate and methacrylate" and "at least one of acrylic acid and methacrylic acid", respectively.

<Resin (A)>
The resin of the present invention includes a structural unit having a cyclic —O—SO—O— structure (hereinafter sometimes referred to as “structural unit (x)”) and a structural unit having an acid labile group (hereinafter referred to as “structural unit (a1 ) ”In some cases) (hereinafter sometimes referred to as“ resin (A) ”).
The resin (A) further includes a structural unit having no acid labile group such as a structural unit having a hydroxy group, a structural unit having a lactone ring (hereinafter sometimes referred to as “structural unit (s)”), It may contain a structural unit (hereinafter sometimes referred to as “structural unit (t)”) and / or a structural unit well known in the art.

<Structural unit (x)>
The structural unit (x) has a structure having —O—SO—O— as an atom constituting the ring. The cyclic -O-SO-O- structure may be monocyclic or polycyclic. In the case of polycyclic, it may be a condensed ring, a spiro ring, a bridged ring, a ring assembly, or a combination thereof. Among them, in the polycyclic type, a condensed ring is preferable. The cyclic -O-SO-O- structure may have a hetero atom as an atom constituting the ring, in addition to the -O-SO-O- bond. Examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom.
The number of carbon atoms in the cyclic -O-SO-O- structure is preferably 2-18, more preferably 2-12. In other words, the cyclic -O-SO-O- structure is preferably a 5-membered ring to a 12-membered ring, more preferably a 5-membered ring to an 8-membered ring, and still more preferably a 5-membered ring.
As a cyclic -O-SO-O- structure, the structure represented by Formula (x1) -Formula (x15) is mentioned, for example, The structure represented by Formula (x1) or Formula (x2) is preferable. The structure represented by formula (x1) is more preferable. * Represents a bond.

The cyclic -O-SO-O- structure may have a substituent. Examples of such a substituent include a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alkylcarbonyloxy group having 2 to 18 carbon atoms, an arylcarbonyloxy group having 7 to 18 carbon atoms, and an alkyl group having 2 to 18 carbon atoms. Examples thereof include an alkoxycarbonyloxy group, an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a hydroxyalkyl group having 1 to 12 carbon atoms, which is included in the alkoxy group having 1 to 12 carbon atoms. The —CH ₂ — may be replaced with —O—.
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. The alkoxy group of 6 is mentioned, and a methoxy group is more preferable.
Examples of the alkylcarbonyloxy group include 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 pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group, preferably an alkylcarbonyloxy group having 2 to 12 carbon atoms, and more preferably a methylcarbonyloxy group. Can be mentioned.
Examples of the arylcarbonyloxy group include a phenylcarbonyloxy group and a tosylcarbonyloxy group, preferably an arylcarbonyloxy group having a carbon number of 7 to 12, and more preferably a phenylcarbonyloxy group.
As the alkoxycarbonyloxy group, a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, an isopropoxycarbonyloxy group, an n-butoxycarbonyloxy group, a sec-butoxycarbonyloxy group, a tert-butoxycarbonyloxy group. , A pentyloxycarbonyloxy group, a hexyloxycarbonyloxy group, an octyloxycarbonyloxy group, a 2-ethylhexyloxycarbonyloxy group, and the like, preferably an alkyloxycarbonyloxy group having 2 to 8 carbon atoms, and more preferably Is a tert-butyloxycarbonyloxy group.
Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group. Groups, etc., and preferably an alkyl group having 1 to 6 carbon atoms.
Examples of the alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecanyl group, adamantyl group, norbornyl group and the like. An alkyl group is mentioned, Preferably it is a C5-C10 cycloalkyl group.
Examples of the hydroxyalkyl group include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, a hydroxyhexyl group and the like, and a hydroxyalkyl group having 1 to 6 carbon atoms is preferable.

Examples of the cyclic -O-SO-O- structure having a substituent include the following structures.
Among them, the substituent of the cyclic -O-SO-O- structure is preferably a hydroxy group.

  The structural unit having a cyclic —O—SO—O— structure preferably further contains a structure derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group and a methacryloyloxy group, and preferably a vinyl group, an acryloyloxy group or a methacryloyloxy group.

The structural unit (x) is preferably a structural unit derived from the compound represented by the formula (I) (hereinafter sometimes referred to as “structural unit (I)”).
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
X ^I1 represents a trivalent hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the hydrocarbon group may be replaced with —O—, —NH— or —CO—, The hydrogen atom contained in the hydrocarbon group may be replaced with a hydroxy group.
A ¹ represents a single bond, alkanediyl group having 1 to 6 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms.
A ³ and A ⁴ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1. ]

Examples of the trivalent hydrocarbon group for X ^I1 include an alkane, an alicyclic hydrocarbon, an aromatic hydrocarbon, or a group formed by combining these, from which three hydrogen atoms have been removed.
Examples of the trivalent alkane (alkanetriyl) include methanetriyl group, ethanetriyl group, n-propanetriyl group, isopropanetriyl group, n-butanetriyl group, sec-butanetriyl group, tert-butanetriyl group, pentanetriyl group, Examples thereof include a hexanetriyl group, a heptanetriyl group, a 2-ethanetriyl group, an octanetriyl group, a nonanenothiyl group, a decantriyl group, an undecanetriyl group and a dodecanetriyl group.
The trivalent alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropanetriyl group, cyclobutanetriyl group and cyclopentanetriyl group. Cycloalkanetriyl groups such as yl group, cyclohexanetriyl group, methylcyclohexanetriyl group, dimethylcyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cycloheptanetriyl group and cyclodecanetriyl group Is mentioned. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthalenetriyl group, an adamantanetriyl group, a 2-alkyladamantan-2-triyll group, and a 1- (adamantan-1-yl) alkane-1-triyl group. , Norbornanetriyl group, methylnorbornanetriyl group, isobornanetriyl group and the like.
Examples of the trivalent aromatic hydrocarbon group include a benzenetriyl group and a naphthalenetriyl group.
Examples of the group formed by combining an alkane, an alicyclic hydrocarbon and an aromatic hydrocarbon include -alkane-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkane, -alkane-aromatic carbon Hydrogen, -alicyclic hydrocarbon-aromatic hydrocarbon, -aromatic hydrocarbon group-alicyclic hydrocarbon group, a group in which two more hydrogen atoms have been removed from an aralkyl group are mentioned, and further hydrogen atom from benzyl. Examples thereof include a group obtained by removing two hydrogen atoms and a group obtained by further removing two hydrogen atoms from a phenethyl group.

Examples of X ^I1 include groups in which —O—SO—O— has been removed from the above-described cyclic —O—SO—O— structure. For example, the following groups are preferable. In the following groups, * and ** represent a bond, and either of them may bond to A ¹ or an oxygen atom in the cyclic —O—SO—O— structure.
Among them, the bond represented by ** is preferably the bond with A ¹ .
Incidentally, _-CH 2 contained in trivalent hydrocarbon radical - is, -O -, - NH- or -CO- may be replaced by. For example, when the trivalent hydrocarbon group contains an alkyl group, the alkyl group may be an alkoxy group having 1 to 12 carbon atoms, an alkylcarbonyloxy group having 2 to 18 carbon atoms, or 2 to 2 carbon atoms in addition to the hydroxy group. It may be replaced with an alkoxycarbonyloxy group having 18 carbon atoms or a hydroxyalkyl group having 1 to 12 carbon atoms. Here, -CH ₂ contained in an alkoxy group having 1 to 12 carbon atoms - may be replaced by -O-. When the trivalent hydrocarbon group contains an arylalkyl group, the arylalkyl group may be replaced with an arylcarbonyloxy group having 7 to 18 carbon atoms in addition to the hydroxy group.

Examples of the alkanediyl group of A ¹ , A ³ and A ⁴ include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group and hexane- A linear alkanediyl group such as a 1,6-diyl group, a linear alkanediyl group, and 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). Group, sec-butyl group, tert-butyl group, etc.), ethane-1,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2- Examples include branched alkanediyl groups such as methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2-methylbutane-1,4-diyl group. Be done. The alkanediyl group of A ¹ , A ³ and A ⁴ is preferably an alkanediyl group having 1 to 3 carbon atoms, and particularly, the methylene group is more preferable as the alkanediyl group of A ⁴ .

Examples of the divalent hydrocarbon group of A ² include an alkanediyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group and a group in which these are combined.
As the alkanediyl group, the same groups as those exemplified for A ¹ and the like can be mentioned.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, cyclohexanediyl group. Examples thereof include a cycloalkanediyl group such as a group, a methylcyclohexanediyl group, a dimethylcyclohexanediyl group, a cycloheptanediyl group, a cyclooctanediyl group, a cycloheptanediyl group, and a cyclodecanediyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthalenediyl group, an adamantanediyl group, a 2-alkyladamantan-2-diyl group, a 1- (adamantan-1-yl) alkane-1-diyl group, and norbornane. Examples thereof include a diyl group, a methylnorbornanediyl group and an isobornanediyl group.
Examples of the aromatic hydrocarbon group include a phenylene group and a naphthylene group.
Examples of the group formed by combining an alkanediyl group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group include a group in which one hydrogen atom has been removed from an aralkyl group, and a benzyl group further has a hydrogen atom. And a group obtained by further removing one hydrogen atom from the phenethyl group.
The hydrocarbon group of A ² is preferably a saturated hydrocarbon group, more preferably a saturated hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms and an alkane having 1 to 6 carbon atoms. A diyl group is more preferable, and an adamantanediyl group and an alkanediyl group having 1 to 6 carbon atoms are particularly preferable.

^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - ^{The, * -A 2 -O-, * -A} 2 -CO-O-, * -A 2 -O ^{-CO-O-, * -A 2 -CO} -O-A 4 -, * -A 2 -CO-O-A 4 -, * -A 2 -O-CO-O-A 4 -, * -A ^{2 -O-CO-A 3 -O} -A 4 -, * -A 2 -O-CO-, * -A 2 -O-CO-A 4 -, * -A 2 -CO-O-A 3 - ^{CO-O-, * -A 2 -CO} -O-A 3 -CO-O-A 4 -, * -A 2 -O-CO-A 3 -O-, * -A 2 -O-A 3 - ^{CO-O-, * -A 2 -O} -A 3 -CO-O-A 4 -, * -A 2 -CO-O-A 3 -O-CO-, * -A 2 -O-CO-A ^3- O-CO- is mentioned. Among ^{them, * -A 2 -O-, * -A} 2 -O-CO-, * -A 2 -O-CO-O-, * -A 2 -CO-O-A 4 -, * -A 2 ^{-O-A 3 -CO-O-} A 4 - is preferable. * Represents a bond with an oxygen atom.

The alkanediyl group of A ¹ , A ² , A ³ and A ⁴ is preferably an alkanediyl group having 1 to 3 carbon atoms.
A ¹ is a methylene ^{group, * -A 2 -X 1 -A 4} -, * -A 2 -X 1 -A 3 -X 2 -A 4 -, is preferably a methylene group, -CH ₂ - CO-O-CH ₂ -, adamantanediyl -CO-O-CH ₂ - or head down Tan diyl _{-O-CO-O-CH 2} - , more preferably a methylene group, his head down Tan diyl -CO-O- More preferably, it is CH ₂ — or atamantanediyl-O—CO—O—CH ₂ —.

  The ring of the structural unit (I) is preferably a ring represented by the formula (x1) to the formula (x8), more preferably a ring represented by the formula (x1) or the formula (x2), further preferably a formula (x1). It is a ring represented by x1).

Examples of the structural unit (I) include structural units represented below.

  The content of the structural unit (x) in the resin (A) of the present invention, for example, the structural unit (I) is preferably 5 to 40 mol% based on the total of all structural units of the resin of the present invention, It is more preferably 7 to 35 mol%, further preferably 8 to 30 mol%, and particularly preferably 10 to 25 mol%.

The resin (A) of the present invention further has a structural unit having an acid labile group, in addition to the structural unit (x), for example, the structural unit (I).
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

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).
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 R ^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 of 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 is preferable, and a tert-butoxycarbonyl group is preferable). A 2-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- Examples thereof include (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

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 And aryl groups such as a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.
^{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.

  As the (meth) acrylic monomer having an acid labile group, those having an alicyclic hydrocarbon group having preferably 5 to 20 carbon atoms can be mentioned. 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.

  As the structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1), a structural unit represented by the formula (a1-0) or a structure represented by the formula (a1-1) is preferable. A unit or a structural unit represented by formula (a1-2) may 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 , R ^a03, and 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), More preferably, it is an oxygen atom.
Examples of the alkyl group of R ^a02 , R ^a03, and 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 in formula (1).
The alkyl group of R ^a02 , R ^a03 and R ^a04 preferably has 6 or less carbon atoms.
The number of carbon atoms of the alicyclic hydrocarbon group of R ^a02 , R ^a04 and 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 structural unit (a1-0), for example, a structural unit represented by any of the formulas (a1-0-1) to (a1-0-12) is preferable, and the structural units (a1-0-1) to The structural unit represented by any of the formulas (a1-0-10) is more preferred.

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-methylcyclohexan-1-yl (meth). Acrylate, 1-ethylcyclohexan-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 , R ^a11 and 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; R ^a10 and R ^a11 are 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.

Here, 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 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 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} each independently 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 bonded to each other And form a divalent heterocyclic group having 3 to 20 carbon atoms with C—O to which they are bonded, and —CH ₂ — contained in the hydrocarbon group and the divalent heterocyclic group is —O— Alternatively, it may be replaced by -S-. ]

^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. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
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. The group formed is more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. 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 JP 2010-204646 A. 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 52, L ⁵³ and ^{L 54} each independently represents -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 (a) 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). At least one or more selected from the group consisting of), more preferably at least two or more, a combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and the structural unit ( a1-5), structural unit (a1-1) and structural unit (a1-0), structural unit (a1-2) and structural unit (a1-0), structural unit (a1-5) And a combination of structural units (a1-0), a structural unit (a1-0), a combination of structural units (a1-1) and a structural unit (a1-2), a structural unit (a1-0), a structural unit (a1- 1) and the structural unit (a1-5) are more preferable, and the combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and the structural unit (a1-5) Combinations are even more preferred.
The structural unit (a1) preferably includes the structural unit (a1-1).

<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. R ^a30 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.
^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. Of these, 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.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

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, and 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 still more 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 -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * 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, the plurality of R ^a22 may be the same or different.
In formula (a3-3),
L ^a6 represents -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * 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 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.
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. ]

Examples of the aliphatic hydrocarbon group of R ^a21 , R ^a22 and R ^a23 include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. Can be mentioned.
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 each independently preferably -O-, or * -O- (CH ₂ ) in which k3 is an integer of 1 to 4. 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 each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, 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-, and more preferably a single bond, ^* -O-, ^* -O- CH ₂ —CO-. O- or ^* -O -C ₂ H ₄ is -CO-O-.

  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 (a3-1-4), 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%.
Moreover, 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 the total of all structural units of the resin (A). On the other hand, it is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and further preferably 10 to 50 mol%.

<Other structural units (t)>
The structural unit (t) includes, 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 structure having a non-eliminating hydrocarbon group. Examples include a unit (hereinafter sometimes referred to as “structural unit (a5)”) and the like.

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 by —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 an aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a single bond or an 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 chain and cyclic aliphatic saturated hydrocarbon groups 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 a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and an n-decyl group. Group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group. Examples of the cyclic aliphatic hydrocarbon group include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and other cycloalkyl groups; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* is a bond 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.

The hydrocarbon group for R ^a42 is preferably a chain or cyclic aliphatic hydrocarbon group or a group formed by combining these, and may have a carbon-carbon unsaturated bond, And cyclic aliphatic saturated hydrocarbon groups and groups formed by combining these are more preferable.
^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, and a fluorine atom is preferable.
[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 an aliphatic hydrocarbon group which has an alkyl group having a halogen atom and / or a group represented by the formula (a-g3). Is more preferable.
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 an 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 of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and A ^a47 is 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 , A ^a43 and A ^{a44 in} the group (a-g1) may have a carbon-carbon unsaturated bond, but an aliphatic saturated hydrocarbon group is preferable. As the aliphatic saturated hydrocarbon group, an alkyl group (the alkyl group may be linear or branched) and an alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group are combined. And an aliphatic hydrocarbon group formed by the above. 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 , A ^a43 and 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- ^Ra42 .

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 ^f2 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 C 1-18 aliphatic hydrocarbon group 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.
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 an ethylene group is preferred.
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.
The aliphatic hydrocarbon group of A ^f14 is preferably an aliphatic hydrocarbon group having 3 to 12 carbon atoms, and more preferably an aliphatic hydrocarbon group having 3 to 10 carbon atoms. 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 ⁵¹ 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 , L ^x6, and 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) 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).
In the present specification, the weight average molecular weight is a value determined by gel permeation chromatography. Gel permeation chromatography can be measured, for example, under the analysis conditions described in Examples.

<Resist composition>
The resist composition of the present invention contains a resin (A) and an acid generator (hereinafter sometimes referred to as “acid generator (B)”).
The resist composition of the present invention may contain a resin other than the resin (A).
The resist composition of the present invention further comprises a solvent (E) (hereinafter sometimes referred to as “solvent (E)”), a weak acid inner salt (hereinafter sometimes referred to as “weak acid inner salt (D)”), and the like. It preferably contains a quencher (C) such as a salt having a weak acidity (hereinafter sometimes referred to as “quencher (C)”). In particular, it is preferable that the quencher (C) contains a salt having a weak acidity such as a weak acid inner salt (D).

<Resin other than resin (A)>
The resin other than the resin (A) may be any resin that does not contain the structural unit (x). As such a resin, for example, a resin composed of only the structural unit (t) can be mentioned. Among them, a resin containing the structural unit (a4) (however, it does not contain the structural unit (x). Hereinafter, it may be referred to as “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 (a1), structural units (a2), structural units (a3), and structural units derived from other known monomers. The resin (X) is preferably a resin composed of only the structural unit (t), and more preferably a resin composed of the structural unit (a4) and / or the structural unit (a5).

The weight average molecular weight of the resin (X) is preferably 6,000 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 to 100 parts by mass of the resin (A). It is preferably 1 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. 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. 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.

<Acid generator (B)>
As the acid generator, either a nonionic or ionic acid generator may be used. 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, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent 3914407, and European Patent 126,712. Compounds capable of generating an acid by the radiation described in etc. 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 each independently 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 saturated hydrocarbon group. And the number of carbons.
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.

  Especially, the group represented by Formula (b1-1) or Formula (b1-3) is preferable.

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 , L ^b14, and 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 , L ^b17, and 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. You may. 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 , L ^b22, and 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, L ^b24, the total number of carbon atoms of ^{L b25} and ^{L b26} is 21 or less. ]

  In the formulas (b1-9) to (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms in the acyloxy group, The carbon number of the divalent saturated hydrocarbon group including the numbers of CO and O 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).
The group in which —CH ₂ — contained in the monovalent alicyclic hydrocarbon group represented by Y is replaced by —O—, —SO ₂ — or —CO— is represented by formula (Y12) to formula (Y27). And a group represented by.

  Of these, a group represented by any one of formulas (Y1) to (Y19) is preferable, and a group represented by formula (Y11), formula (Y14), formula (Y15), or formula (Y19) is more preferable. And a group represented by formula (Y11) or formula (Y14).

Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, a monovalent n-alicyclic hydrocarbon group having 3 to 16 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. , glycidyloxy group, or _{- (CH 2) ja -O-} CO-R b1 group ^{(wherein, R b1} represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon 3 to 16 carbon atoms 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.
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 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 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 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 halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of Y include the following.

When Y is a methyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y -CH group ₂ - is preferably replaced by -O- or -CO-.

  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 particularly preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

  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-33) [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-33) is more preferable.

R ^{i2 to} R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, and 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. And 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 have the same meanings as described above.

Specific examples of the sulfonate anion in the salt represented by the formula (B1) include anions described in JP2010-204646A.
Preferred sulfonate anions in the salt represented by the formula (B1) include anions represented by formulas (B1a-1) to (B1a-15).

  Among them, anions represented by any of the formulas (B1a-1) to (B1a-3) and the formulas (B1a-7) to (B1a-15) are preferable.

The organic cation of Z ⁺ includes 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, and preferably an organic sulfonium cation or an organic iodonium cation. Yes, 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 each independently 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 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 each independently represent an integer of 0 to 5.
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 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 each independently represent an integer of 0 to 4.
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 carbon number of the monovalent aliphatic hydrocarbon group of R ^{b9 to} R ^b12 is preferably 1 to 12.
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 Alternatively, a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms 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 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. For example, the following rings are mentioned.

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. 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 monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. 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.

  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 represented by any one of formula (B1a-1) to formula (B1a-3) and formula (B1a-7) to formula (B1a-15) and a formula (B1a-15). b2-1) or the combination with the cation represented by the formula (b2-3).

  Examples of the acid generator (B1) preferably include those represented by formulas (B1-1) to (B1-30), among which formula (B1-1) containing an arylsulfonium cation and formula (B1-1) B1-2), 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), those represented by formula (B1-26) or formula (B1-29), respectively, are particularly preferable.

The content of the acid generator (B1) is preferably 30% by mass or more and 100% by mass or less, more preferably 50% by mass or more and 100% by mass or less, and substantially the acid content based on the total amount of the acid generator (B). More preferably, it is only the generator (B1).
The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass) with respect to 100 parts by mass of the resin (A). Part and below). The resist composition of the present invention may contain one kind of the acid generator (B) alone or may contain plural kinds thereof.

<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.

<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.
Among them, the weak acid inner salt represented by the formula (D) (hereinafter sometimes referred to as “weak acid inner salt (D)”) is preferable.

[In the formula (D),
R ^D1 and R ^D2 are each independently 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 each independently 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 each independently 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 5% by mass. It is 3% by mass.
The quencher (C) may be used alone or in combination of two or more kinds.

<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 comprises a resin (A) and a salt (I), and, if necessary, a resin other than the resin (A), an acid generator (B), a solvent (E), a quencher (C), and others. It can be prepared by mixing the component (F). 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 of 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. The pressure during 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".

Synthesis Example 1: [Synthesis of Compound Represented by Formula (I-2)]
20 parts of the compound represented by the formula (I-2-a) and 240 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Then, 15.10 parts of the compound represented by the formula (I-2-b) was added, and the mixture was stirred at 60 ° C. for 12 hours. 60 parts of ion-exchanged water was added to the obtained reaction product, and the mixture was stirred for 30 minutes and separated to collect an organic layer. This washing operation was repeated 6 times. By concentrating the collected organic layer, 27.00 parts of the compound represented by the formula (I-2-c) was obtained.
10 parts of the compound represented by the formula (I-2-c), 4.19 parts of the compound represented by the formula (I-2-d) and 50 parts of chloroform were charged, the mixture was stirred at 23 ° C. for 30 minutes, and further, The mixture was stirred at 60 ° C for 2 hours. The obtained reaction product was cooled to 23 ° C., 35 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and liquid-separated to wash the organic layer with water. This water washing operation was repeated 4 times. The organic layer after washing with water is concentrated, and the obtained concentrate is subjected to column fractionation (column fractionation condition stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Inc. developing solvent: n-heptane / ethyl acetate = 1/1). Thus, 10.92 parts of the compound represented by the formula (I-2) was obtained.
MS (mass spectrometry): 400.1 (molecular ion peak)

Synthesis Example 2: [Synthesis of Compound Represented by Formula (I-3)]
11.19 parts of the compound represented by formula (I-3-a) and 100 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes to obtain 7.55 parts of the compound represented by formula (I-2-b). By adding and stirring at 60 degreeC for 2 hours, the solution containing the compound represented by a formula (I-3-c) was obtained.
A solution containing the compound represented by formula (I-3-c) was charged with 5.85 parts of the compound represented by formula (I-3-d), stirred at 23 ° C. for 30 minutes, and further 60 ° C. It was stirred for 2 hours. The obtained reaction product was cooled to 23 ° C., 35 parts of ion-exchanged water was added, the mixture was stirred at 23 ° C. for 30 minutes, allowed to stand, and liquid-separated to wash the organic layer with water. This water washing operation was repeated 4 times. The organic layer after washing with water is concentrated, and the obtained concentrate is subjected to column fractionation (column fractionation condition stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Inc. developing solvent: n-heptane / ethyl acetate = 1/1). Thus, 11.22 parts of the compound represented by the formula (I-3) was obtained.
MS (mass spectrometry): 384.1 (molecular ion peak)

Synthesis Example 3 [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. Then, liquid separation was performed 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 then liquid-separated to take out the organic layer. This water washing operation was repeated 5 times. After the obtained organic layer was concentrated, 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 4 [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, and the mixture was stirred at 23 ° C. for 30 minutes. Then, liquid separation was performed and the organic layer was taken out. 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, separated, and the organic layer was taken out. This water washing operation was repeated 8 times. The obtained organic layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained residue, and the mixture was stirred and filtered to obtain 6.84 parts of the salt represented by the formula (B1-22). It was

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.

Example 1 [Synthesis of Resin A1]
As the monomer, the monomer (a1-1-2), the monomer (a1-2-3), the monomer (a2-1-1), the monomer (a3-1-1), the monomer (a3-2-3), and the monomer ( I-1) and its molar ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (a3). -2-3): The monomers (I-1)) were mixed so as to be 30: 14: 6: 20: 20: 10, and propylene glycol monomethyl ether acetate was added in an amount of 1.5 times the total amount of the monomers. It was 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin A1 (copolymer) having a weight average molecular weight of 7.9 × 10 ³ with a yield of 80%. This resin A1 has the following structural units.

Example 2 [Synthesis of Resin A2]
As the monomer, a monomer (a1-1-2), a monomer (a1-2-3), a monomer (a2-1-1), a monomer (a3-2-3) and a monomer (I-1) are used, and their moles are used. The ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (I-1)) is 30:14: The mixture was mixed so as to be 6:22:28, and propylene glycol monomethyl ether acetate in an amount 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin A2 (copolymer) having a weight average molecular weight of 8.1 × 10 ³ with a yield of 84%. This resin A2 has the following structural units.

Example 3 [Synthesis of Resin A3]
As the monomer, a monomer (a1-1-2), a monomer (a1-2-3), a monomer (a2-1-1), a monomer (a3-1-1) and a monomer (I-1) are used, and the mole thereof is used. The ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (I-1)) is 30:14: The mixture was mixed at 6:20:30 and 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin A3 (copolymer) having a weight average molecular weight of 8.3 × 10 ³ with a yield of 81%. This resin A3 has the following structural units.

Example 4 [Synthesis of Resin A4]
As the monomer, a monomer (a1-1-2), a monomer (a1-2-3), a monomer (a2-1-1), a monomer (a3-4-2), and a monomer (I-1) are used, and their moles are used. The ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-4-2): monomer (I-1)) is 30:14: The mixture was mixed at 6:20:30 and 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin A4 (copolymer) having a weight average molecular weight of 7.4 × 10 ³ with a yield of 75%. This resin A4 has the following structural units.

Example 5 [Synthesis of Resin A5]
As the monomer, a monomer (a1-1-2), a monomer (a1-2-7), a monomer (I-1) and a monomer (a3-2-1) were used, and their molar ratios [monomer (a1-1-2 ): Monomer (a1-2-7): Monomer (I-1): Monomer (a3-2-1)] are mixed so as to be 10: 30: 10: 50, and the total amount of the monomers is 1.5 mass. Double the amount of propylene glycol monomethyl ether acetate was added to make 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin A5 (copolymer) having a weight average molecular weight of 7.6 × 10 ³ with a yield of 78%. This resin A5 has the following structural units.

Example 6 [Synthesis of Resin A6]
As the monomer, a monomer (a1-1-2), a monomer (a1-2-3), a monomer (a2-1-1), a monomer (a3-1-1) and a monomer (I-2) are used, and their moles are used. The ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (I-2)) is 30:14: The mixture was mixed at 6:20:30 and 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin A6 (copolymer) having a weight average molecular weight of 7.8 × 10 ³ with a yield of 76%. This resin A6 has the following structural units.

Example 7 [Synthesis of Resin A7]
As the monomer, a monomer (a1-1-2), a monomer (a1-2-3), a monomer (a2-1-1), a monomer (a3-1-1) and a monomer (I-3) are used, and their moles are used. The ratio (monomer (a1-1-2): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-1-1): monomer (I-3)) is 30:14: The mixture was mixed at 6:20:30 and 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin A7 (copolymer) having a weight average molecular weight of 7.9 × 10 ³ with a yield of 72%. This resin A7 has the following structural units.

Synthesis Example 5 [Synthesis of Resin AX-1]
As the monomer, a monomer (a1-1-2), a monomer (a1-2-7), a monomer (IX-1) and a monomer (a3-2-1) were used, and the molar ratio [monomer (a1-1-2 ): Monomer (a1-2-7): Monomer (IX-1): Monomer (a3-2-1)] are mixed so as to be 10: 30: 10: 50, and 1.5 mass of the total amount of monomers. Double the amount of propylene glycol monomethyl ether acetate was added to make 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 monomers, respectively, and these were heated at 75 ° 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 then filtered to obtain a resin AX-1 (copolymer) having a weight average molecular weight of 7.5 × 10 ³ with a yield of 85%. This resin AX-1 has the following structural units.

Synthesis Example 6 [Synthesis of Resin AX-2]
Monomer (I-1) was used as a monomer, and 1.2 mass times of the total amount of propylene glycol monomethyl ether acetate was added to obtain a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 0.5 mol% and 1.5 mol% with respect to the total amount of 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 then filtered to obtain a resin AX-2 having a weight average molecular weight of 2.5 × 10 ^{4 in} a yield of 58%. This resin AX-2 has the following structural units.

Synthesis Example 7 [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 the solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in an amount of 0.7 mol% and 2.1 mol% with respect to the total amount of 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 is again dissolved in dioxane, the solution obtained is poured into a methanol / water mixed solvent to precipitate the resin, and the resin is filtered to collect resin X1 having a weight average molecular weight of 1.7 × 10 ^4. The yield was 79%. This resin X1 has the following structural units.

(Preparation of resist composition)
Each of the components shown below was mixed in a mass ratio shown in Table 1 and dissolved in a solvent, and then filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin (A)>
A1 to A5, AX-1, AX-2, X1: Resin A1 to Resin A4, Resin AX-1, Resin AX-1, Resin X1

<Acid generator (B)>
B1-21: salt represented by formula (B1-21) B1-22: salt represented by formula (B1-22) B1-3: synthesized according to the examples of JP 2010-152341 A
<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 12-inch silicon wafer was coated with a composition for organic antireflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] and baked at 205 ° C. for 60 seconds to give a film having a thickness of 78 nm. An organic antireflection film was formed. Then, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (prebaking) was 85 nm.
The obtained silicon wafer was prebaked (PB) for 60 seconds on the direct hot plate at the temperature described in the "PB" column of Table 1. On the wafer thus formed with the resist composition film (composition layer), an ArF excimer stepper for immersion exposure [XT: 1900Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] was used. The line-and-space pattern was subjected to immersion exposure by changing the exposure amount stepwise. Ultrapure water was used as the immersion medium.
After the exposure, post-exposure bake (PEB) was performed for 60 seconds on the hot plate at the temperature shown in the "PEB" column of Table 1, and further for 2.60 seconds with a 2.38 mass% tetramethylammonium hydroxide aqueous solution. Paddle development was performed to obtain a resist pattern.

  In each resist film, the exposure amount at which the 50 nm line-and-space pattern was 1: 1 was defined as the effective sensitivity.

<Line edge roughness evaluation (LER)>
The wall surface of the resist pattern after the lithography process is observed with a scanning electron microscope, and the fluctuation width of the unevenness of the side wall of the resist pattern is
◯ with a thickness of 3.5 nm or less,
Those having a thickness of more than 3.5 nm were marked with x.
The results are shown in Table 2.

  Since the resist composition of the present invention is excellent in the line edge roughness of the obtained resist pattern, it is suitable for fine processing of semiconductors and is extremely useful industrially.

Claims (13)

A structural unit derived from the compound represented by formula (I) ,
Containing a structural unit represented by the formula (a1-1) and at least one structural unit represented by the formula (a1-2) ,
The content of the structural unit derived from the compound represented by the formula (I) is 5 to 40 mol% with respect to the total of all structural units of the resin,
The total content of the structural unit represented by the formula (a1-1) and the structural unit represented by the formula (a1-2) is 15 to 90 mol% with respect to the total of all structural units of the resin. Resin.
[In the formula (I),
R ¹ represents a hydrogen atom or a methyl group.
A ¹ represents a single bond, alkanediyl group having 1 to 6 carbon atoms or ^{* -A 2 -X 1 - (A} 3 -X 2) a - (A 4) b - represents a. * Represents a bond with an oxygen atom.
A ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms.
A ³ and A ⁴ each independently represent an alkanediyl group having 1 to 6 carbon atoms.
X ¹ and X ² each independently represent —O—, —CO—O—, —O—CO— or —O—CO—O—.
a represents 0 or 1.
b represents 0 or 1.
Is. * Represents a bond. ]
[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. ] A ¹ is the number 1-6 alkanediyl group or ^* -A ² -X ¹ -A ⁴ carbon - claim 1, wherein the resin is. A ² is, according to claim 1 or 2 wherein the resin is a alkanediyl group having 1 to 6 carbon atoms. The resin according to claim ^1, wherein X ¹ and X ² are each independently —O—, —CO—O—, or —O—CO—. A ¹ is any description of the resin of claims 1 to 4 is a methylene group. Further, any description of the resin of claim 1-5 comprising a structural unit having a hydroxy group. The resin according to claim 6 , wherein the structural unit having a hydroxy group is a structural unit derived from the compound represented by formula (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. ] Further, according to claim 1-7 or the description of resin containing a structural unit having a lactone ring. The structural unit having a lactone ring is at least one selected from the group consisting of structural units represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). The resin according to claim 8, which is
[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 -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * 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 -O- or _{^{* -O- (CH 2) k3 -CO}} -O- (k3 represents. An integer of 1-7) is represented by the group. * 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.
L ^a7 is a single bond, ^* -O-, ^* -O- ^La8- O-, ^* -O- ^La8- CO-O-, ^* -O- ^La8- CO-O- ^La9- 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. ] Resist composition containing a resin and a photoacid generator according to any one of claims 1-9. The resist composition according to claim 10 , further comprising a resin containing a structural unit having a fluorine atom. The resist composition according to claim 10 , further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. (1) A step of applying the resist composition according to any one of claims 10 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.