JP5783012B2 - Resist composition and method for producing resist pattern - Google Patents

Description

  The present invention relates to a resist composition and a method for producing a resist pattern using the resist composition.

  In the production of a resist pattern using a resist composition, a coating film obtained by coating the resist composition on a substrate is irradiated with far ultraviolet light or an electron beam, and a portion of the coating film irradiated with far ultraviolet light or an electron beam ( The exposed portion) generates an acid, and the acid-catalyzed reaction changes the solubility of the exposed portion and the unexposed portion (the portion of the coating film not irradiated with far ultraviolet light) in the developer. Is done by.

Such a resist composition is insoluble or hardly soluble in an alkaline aqueous solution and a compound that generates an acid (acid generator) upon receiving energy from irradiation with far ultraviolet light or an electron beam. A soluble resin and a solvent are contained. For example, Patent Document 1 describes a resist composition containing only a sulfonylimide compound having a sulfonium cation shown below as an acid generator. However, Patent Document 1 does not describe a resist composition containing such a sulfonylimide compound and an acid generator other than the sulfonylimide compound.

JP 2010-8912 A

  In the production of a resist pattern using a resist composition, it is required that the cross-sectional shape of the obtained resist pattern is closer to a rectangle, and development residue (scum) is less generated.

  As a result of intensive studies, the present inventors have found that a novel resist composition containing a specific sulfonylimide compound and a specific acid generator sufficiently reduces the occurrence of scum and provides a resist pattern with an excellent cross-sectional shape. And found the present invention. That is, the present invention includes the following inventions.

［式（Ｉ）中、
環Ｘは、環を構成する原子として４級窒素原子を１つ含む、５員環又は６員環の複素環を表す。
ｎは１〜３の整数を表す。
Ｒ^３は、置換基を有していてもよい炭素数１〜１２のアルキル基、置換基を有していてもよい炭素数３〜２４の脂環式飽和炭化水素基又は置換基を有していてもよい炭素数２〜１２のアルケニル基を表す。ｎが２以上である場合、複数存在するＲ^３は互いに同一又は相異なる。
Ｒ^４及びＲ^５は、それぞれ独立に、フッ素原子を有する炭素数１〜４のアルキル基ｗｐ表す。］
（Ｄ）溶剤
〔２〕前記（Ｅ）は、
Ｒ^４及びＲ^５が、それぞれ独立に、炭素数１〜４のペルフルオロアルキル基の前記式（Ｉ）で表される化合物を含む前記〔１〕記載のレジスト組成物。
〔３〕前記（Ｂ）が、式（Ｂ１）で表される酸発生剤である前記〔１〕又は〔２〕記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ^１及びＱ^２は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜１７の２価の脂肪族飽和炭化水素基を表し、該２価の脂肪族飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の１価の脂肪族炭化水素基を表し、該１価の脂肪族炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ+は、スルホニウムカチオン又はヨードニウムカチオンを表す。］
〔４〕前記式（Ｂ１）のＬ^b1が、式（ｂ１−１）で表される基である前記〔３〕記載のレジスト組成物。

［式（ｂ１−１）中、
Ｌ^b2は、単結合又は炭素数１〜１５のアルカンジイル基を表す。
左側の＊は、Ｃ（Ｑ¹）（Ｑ²）の炭素原子と結合する結合手であり、右側の＊は、Ｙと
結合する結合手である。］
〔５〕前記式（Ｂ１）のＹが、置換基を有していてもよい炭素数３〜１８の１価の脂環式炭化水素基である前記〔３〕又は〔４〕記載のレジスト組成物。
〔６〕さらに、以下の（Ｇ）を含有する前記〔１〕〜〔５〕のいずれか記載のレジスト組成物。
（Ｇ）式（ｂ）で表される化合物；

（式（ｂ）中、
Ｒ^g1、Ｒ^g2、Ｒ^g3及びＲ^g4はそれぞれ独立に、炭素数１〜６のアルキル基を表す。
Ａ^１は、置換基を有していてもよい炭素数３〜３６の脂環式炭化水素基、置換基を有していてもよい炭素数６〜２０の芳香族炭化水素基又は置換基を有していてもよい炭素数５〜２０の複素環基を表す。）
〔７〕（１）前記〔１〕〜〔６〕のいずれか記載のレジスト組成物を基板上に塗布する
工程；
（２）塗布後の組成物から溶剤を除去して組成物層を形成する工程；
（３）組成物層を露光する工程；
（４）露光後の組成物層を加熱する工程；及び
（５）加熱後の組成物層を現像する工程
を含むレジストパターンの製造方法。 [1] A resist composition containing the following (A), (B), (E) and (D).
(A) a resin that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid;
(B) an acid generator comprising a sulfonium salt or an iodonium salt;
(E) a compound of formula (I);

[In the formula (I),
Ring X represents a 5-membered or 6-membered heterocyclic ring containing one quaternary nitrogen atom as an atom constituting the ring.
n represents an integer of 1 to 3.
R ³ has an optionally substituted alkyl group having 1 to 12 carbon atoms, an optionally substituted alicyclic saturated hydrocarbon group having 3 to 24 carbon atoms, or a substituent. An alkenyl group having 2 to 12 carbon atoms which may be present. When n is 2 or more, a plurality of R ³ are the same or different from each other.
R ⁴ and R ⁵ each independently represent a C 1-4 alkyl group having a fluorine atom. ]
(D) Solvent [2] (E)
The resist composition according to [1], wherein R ⁴ and R ⁵ each independently contains a compound represented by the formula (I) of a perfluoroalkyl group having 1 to 4 carbon atoms.
[3] The resist composition according to [1] or [2], wherein (B) is an acid generator represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. .
Y represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and the methylene group constituting the monovalent aliphatic hydrocarbon group includes an oxygen atom, a sulfonyl group Alternatively, it may be replaced with a carbonyl group.
Z + represents a sulfonium cation or an iodonium cation. ]
[4] The resist composition according to [3], wherein L ^{b1 in the} formula (B1) is a group represented by the formula (b1-1).

[In the formula (b1-1),
L ^b2 represents a single bond or an alkanediyl group having 1 to 15 carbon atoms.
The * on the left side is a bond that bonds to the carbon atom of C (Q ¹ ) (Q ² ), and the * on the right side is a bond that bonds to Y. ]
[5] The resist composition according to [3] or [4], wherein Y in the formula (B1) is a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. object.
[6] The resist composition according to any one of [1] to [5], further comprising the following (G):
(G) a compound represented by formula (b);

(In the formula (b),
R ^g1 , R ^g2 , R ^g3 and R ^g4 each independently represents an alkyl group having 1 to 6 carbon atoms.
A ¹ represents an alicyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms or a substituent which may have a substituent. The C5-C20 heterocyclic group which you may have is represented. )
[7] (1) The resist composition according to any one of [1] to [6] is applied onto a substrate.
Process;
(2) A step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer;
(4) A step of heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising a step of developing the composition layer after heating.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of a scum is reduced and the novel resist composition which can manufacture a resist pattern of a favorable shape can be provided.

1A and 1B are diagrams schematically showing the cross-sectional shape of a resist pattern, where FIG. 1A shows a good cross-sectional shape, and FIG. 1B shows a cross-sectional shape whose top shape is T-shaped.

  The resist composition of the present invention (hereinafter sometimes referred to as “the present resist composition”) comprises the above-mentioned (A) resin (hereinafter sometimes referred to as “resin (A)”), (B) an acid generator ( Hereinafter, in some cases, referred to as “acid generator (B)”, (D) solvent (hereinafter, sometimes referred to as “solvent (D)”), and (E) a compound represented by formula (I) (hereinafter, referred to as “solvent (D)”). In some cases, it is referred to as “compound (E)”) as an essential component. Hereinafter, each of the constituent components of the resist composition will be described, and a method for preparing the resist composition containing them and a method for producing a resist pattern using the resist composition will be described.

  In describing the compound (E), which is a constituent component of the resist composition, functional groups (groups) may be exemplified in various compounds shown in the present specification, but common groups are defined here. Keep it. In such a definition, the numerical value attached to “C” indicates the number of carbon atoms of each group.

  In the present specification, the “hydrocarbon group” refers to an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group is further classified into a chain type and an alicyclic type. Unless otherwise defined, the term “aliphatic hydrocarbon group” in the present specification includes an aliphatic hydrocarbon group in which a chain and alicyclic aliphatic hydrocarbon group are combined.

Of the chain aliphatic hydrocarbon groups (chain hydrocarbon groups), monovalent ones are typically alkyl groups. Examples of the alkyl group include a methyl group (C ₁ ), an ethyl group (C ₂ ), a propyl group (C ₃ ), a butyl group (C ₄ ), a pentyl group (C ₅ ), a hexyl group (C ₆ ), and a heptyl group. (C ₇ ), octyl group (C ₈ ), decyl group (C ₁₀ ), dodecyl group (C ₁₂ ), hexadecyl group (C ₁₄ ), pentadecyl group (C ₁₅ ), hexyldecyl group (C ₁₆ ), heptadecyl group (C ₁₇ ), octadecyl group (C ₁₈ ) and the like may be mentioned, and these may be linear or branched. Unless particularly limited, this chain hydrocarbon group may contain a carbon-carbon double bond in a part of the alkyl groups exemplified herein, but does not have such a carbon-carbon double bond, etc. A chain hydrocarbon group (aliphatic saturated hydrocarbon group), particularly an alkyl group is preferred. The divalent chain hydrocarbon group typically corresponds to an alkanediyl group obtained by removing one hydrogen atom from the alkyl group shown here.

A chain hydrocarbon group that partially contains a carbon-carbon double bond is typically an alkenyl group that contains one carbon-carbon double bond. Examples of the alkenyl group include an ethenyl group (C ₂ ), a propenyl group (C ₃ ), a butenyl group (C ₄ ), a pentenyl group (C ₅ ), a hexenyl group (C ₆ ), a heptenyl group (C ₇ ), and an octenyl group. (C ₈ ), decenyl group (C ₁₀ ), dodecenyl group (C ₁₂ ) and the like may be mentioned, and these may be linear or branched.

などが挙げられる。 Of the alicyclic aliphatic hydrocarbon groups (alicyclic hydrocarbon groups), monovalent ones are typically groups in which one hydrogen atom has been removed from the alicyclic hydrocarbon. The alicyclic hydrocarbon group may be an unsaturated alicyclic hydrocarbon group containing about one carbon-carbon unsaturated bond, or may be a saturated alicyclic hydrocarbon group containing no such carbon-carbon unsaturated bond. The alicyclic hydrocarbon group referred to in the present specification is preferably saturated. The alicyclic hydrocarbon group may be monocyclic or polycyclic. Here, an alicyclic hydrocarbon group will be illustrated by illustrating an alicyclic hydrocarbon before removing a hydrogen atom. Monocyclic alicyclic hydrocarbons are typically cycloalkanes, specific examples of which are:
Cyclopropane (C ₃ ) represented by the formula (KA-1),
Cyclobutane (C ₄ ) represented by the formula (KA-2),
Cyclopentane (C ₅ ) represented by the formula (KA-3),
Cyclohexane (C ₆ ) represented by the formula (KA-4),
Formula cycloheptane represented by _{(KA-5) (C 7} ),
Cyclooctane (C ₈ ) represented by the formula (KA-6), and
Cyclododecane (C ₁₂ ) represented by the formula (KA-7)

Etc.

などが挙げられる。なお、ここに示した脂環式炭化水素を「式（ＫＡ−１）〜式（ＫＡ−１２）の脂環式炭化水素」ということがある。
２価の脂環式炭化水素基とは、式（ＫＡ−１）〜式（ＫＡ−１２）の脂環式炭化水素から水素原子を２個取り去った基が該当する。 Examples of polycyclic alicyclic hydrocarbons include:
Norbornene (C ₇ ) represented by the formula (KA-8),
Adamantane (C ₁₀ ) represented by the formula (KA-9),
An alicyclic hydrocarbon (C ₁₀ ) represented by the formula (KA- ₁₀ ),
An alicyclic hydrocarbon (C ₁₄ ) represented by the formula (KA-11),
An alicyclic hydrocarbon (C ₁₇ ) represented by the formula (KA-12),

Etc. In addition, the alicyclic hydrocarbon shown here may be called "the alicyclic hydrocarbon of Formula (KA-1)-Formula (KA-12)."
The divalent alicyclic hydrocarbon group corresponds to a group in which two hydrogen atoms are removed from the alicyclic hydrocarbon of the formula (KA-1) to the formula (KA-12).

In the present specification, the aromatic hydrocarbon group is a monovalent or divalent aromatic hydrocarbon group, typically an aryl group or an arylene group. Specifically, the monovalent aromatic hydrocarbon group, that is, the aryl group includes a phenyl group (C ₆ ), a naphthyl group (C ₁₀ ), an antonyl group (C ₁₄ ), a biphenyl group (C ₁₂ ), phenanthryl. Examples thereof include a group (C ₁₄ ) and a fluorenyl group (C ₁₃ ). The divalent aromatic hydrocarbon group, that is, the arylene group, corresponds to a group obtained by further removing one hydrogen atom from the aryl group shown here.

  The aliphatic hydrocarbon group may have a substituent. Such substituents are defined each time, and here, representative examples of the substituents are given. Examples of the substituent include a halogen atom, an alkoxy group, an acyl group, an aryl group, an aralkyl group, and an aryloxy group.

The halogen atom is a fluorine atom, a chlorine atom, a bromine atom and an iodine atom unless otherwise specified.
Examples of alkoxy groups include methoxy group (C ₁ ), ethoxy group (C ₂ ), propoxy group (C ₃ ), butoxy group (C ₄ ), pentyloxy group (C ₅ ), hexyloxy group (C ₆ ), heptyl Examples thereof include an oxy group (C ₇ ), an octyloxy group (C ₈ ), a decyloxy group (C ₁₀ ), and a dodecyloxy group (C ₁₂ ), and these alkoxy groups may be linear or branched.
Specific examples of the acyl group include an acetyl group (C ₂ ), a propionyl group (C ₃ ), a butyryl group (C ₄ ), a valyl group (C ₅ ), a hexylcarbonyl group (C ₆ ), and a heptylcarbonyl group (C ₇ ). In addition to those in which an alkyl group such as an octylcarbonyl group (C ₈ ), a decylcarbonyl group (C ₁₀ ), and a dodecylcarbonyl group (C ₁₂ ) is bonded to a carbonyl group, an aryl such as a benzoyl group (C ₇ ) And those in which a group and a carbonyl group are bonded. Among these acyl groups, an alkyl group and a carbonyl group bonded to each other may be linear or branched.
Specific examples of the aryl group are the same as those exemplified as the aryl group of the above-mentioned aromatic hydrocarbon group, and specific examples of the aryloxy group are those in which the aryl group and an oxygen atom are bonded.
Specific examples of the aralkyl group include a benzyl group (C ₇ ), a phenethyl group (C ₈ ), a phenylpropyl group (C ₉ ), a naphthylmethyl group (C ₁₁ ), and a naphthylethyl group (C ₁₂ ).

  The aromatic hydrocarbon group may also have a substituent. Although such a substituent is defined each time, a halogen atom, an alkoxy group, an acyl group, an alkyl group, and an aryloxy group can be mentioned. Among these, the alkyl group is the same as those exemplified as the chain aliphatic hydrocarbon group, and among the substituents optionally present in the aromatic hydrocarbon group, those other than the alkyl group are aliphatic hydrocarbon groups. The same thing as what was illustrated as a substituent of is included.

<Compound (E)>
As described above, the compound (E) is represented by the formula (I). The ring X of the formula (I) is a 5-membered or 6-membered heterocyclic ring containing one quaternary nitrogen atom as an atom constituting the ring (ring-constituting atom), and the heterocyclic ring is aromatic Or non-aromatic. Note that the non-aromatic heterocycle is preferably a saturated heterocycle having no unsaturated bond in the bond constituting the ring. Moreover, as long as this heterocyclic ring has one quaternary nitrogen atom in a ring structural atom, you may have hetero atoms other than the said quaternary nitrogen atom as a ring structural atom.

  Specific examples of the 5-membered aromatic heterocycle include oxazole ring, thiazole ring, imidazole ring, pyrazole ring, isoxazole ring, thiadiazole ring, oxadiazole ring, and triazole ring. In which one nitrogen atom is a quaternary nitrogen atom. Among these, preferably a ring in which one nitrogen atom among the ring constituent atoms of the oxazole ring, thiazole ring and imidazole ring, more preferably the oxazole ring and imidazole ring, particularly preferably the imidazole ring is a quaternary nitrogen atom. Is mentioned. On the other hand, specific examples of the 6-membered aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, and a triazine ring, in which one of the ring constituent atoms is a quaternary nitrogen atom. Is mentioned. Among these, Preferably, the ring whose one of the ring member atoms of a pyridine ring is a quaternary nitrogen atom is mentioned. Specific examples of a non-aromatic 5-membered or 6-membered saturated heterocyclic ring include a pyrrolidine ring, a piperidine ring, a morpholine ring, etc., wherein one nitrogen atom in the ring is a quaternary nitrogen atom. A certain ring can be mentioned. Among these, a ring in which one nitrogen atom among the ring constituent atoms of the pyrrolidine ring is a quaternary nitrogen atom is preferable.

Next, R ³ in the formula (I) will be described. One of R ³ is a monovalent group bonded to a quaternary nitrogen atom that is a ring-constituting atom of X, and may have an alkyl group that may have a substituent or a substituent. An alicyclic saturated hydrocarbon group or an alkenyl group which may have a substituent. Examples of the alkyl group include those already exemplified in the range of 1 to 12 carbon atoms. The alicyclic saturated hydrocarbon group also includes those already exemplified in the range of 3 to 24 carbon atoms and no carbon-carbon unsaturated bond. The alkenyl group includes those already exemplified within the range of 2 to 12 carbon atoms. The alkyl group, aliphatic saturated hydrocarbon group and alkenyl group shown here may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a carboxyl group, an alkoxy group (preferably a methoxy group and an ethoxy group), an aryl group (preferably a phenyl group and a toluyl group), an aralkyl group (preferably, Benzyl group), aryloxy group (preferably phenoxy group etc.), alkylthio group (preferably methylthio group and ethylthio group etc.), carboxyalkyl group (preferably 2-carboxyethyl group etc.), alkoxycarbonyl group ( Preferably, ethoxycarbonyl group and the like, carbonate ester group (preferably ethoxycarbonyloxy group and the like), acyl group (preferably acetyl group, propionyl group, benzoyl group and the like), sulfonyl group (preferably methanesulfonyl group and Benzenesulfoni Group), acyloxy group (preferably acetoxy group and benzoyloxy group etc.), sulfonyloxy group (preferably methanesulfonyloxy group and toluenesulfonyloxy group etc.), phosphonyl group (preferably diethylphosphonyl group etc.) Amide group (preferably acetylamino group and benzoylamino group), carbamoyl group (preferably N, N-dimethylcarbamoyl group etc.) and heterocyclic group (preferably pyridyl group, imidazolyl group and furanyl group etc.) In view of ease of production of the compound (E), R ³ represents an alkyl group having no substituent, an alicyclic saturated hydrocarbon group having no substituent or a substituent. An alkenyl group which does not have is preferable. N which is the number of substitutions of R ³ is in the range of 1 to 3, preferably 2 or 3, and more preferably 2. When n is 2 or more, the plurality of R ³ are the same or different from each other.

Here, specific examples of cations constituting the compound (E) (hereinafter sometimes referred to as “cations (E)”) will be given.

Next, the anion constituting the compound (E) (hereinafter sometimes referred to as “anion (E)”) will be described with specific examples. The alkyl group having a fluorine atom of R ⁴ and R ⁵ may be either linear or branched, but is preferably linear. This “alkyl group having a fluorine atom” corresponds to one in which at least one of hydrogen atoms contained in the alkyl group having 1 to 4 carbon atoms already exemplified is substituted with a fluorine atom, and other hydrogen atoms are It may be substituted with an atom or substituent other than a fluorine atom. More specifically, it corresponds to those in which at least one hydrogen atom contained in an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group and a tert-butyl group is substituted with a fluorine atom. To do. The fluorination rate of the alkyl group having a fluorine atom is preferably 40 to 100%, more preferably 80 to 100%, and particularly preferably 85 to 100%. The fluorination rate here refers to the ratio (%) of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms contained in R ⁴ and R ⁵ . Examples of this atom or substituent include an alkoxy group, a halogen atom (excluding a fluorine atom), a hydroxy group, and an acyl group.
The alkoxy group preferably has 1 to 5 carbon atoms, and specific examples of the alkoxy group include those already exemplified in the range of 1 to 5 carbon atoms, and a methoxy group and an ethoxy group are particularly preferable.
As the halogen atom, any of those already exemplified other than the fluorine atom may be used. So far, specific examples of R ⁴ and R ⁵ have been described, and among these, R ⁴ and R ⁵ are each independently a perfluoroalkyl group, particularly preferably a perfluoromethyl group or a perfluoroethyl group (E ) Is particularly preferable because the occurrence of scum is sufficiently reduced and the present resist composition capable of producing a resist pattern with a better cross-sectional shape can be easily obtained.

More specifically, examples of suitable anions constituting the compound (E) are as follows.

  For example, the compound (E) can be arbitrarily combined with the exemplified cation (E) and anion (E), and here, preferred combinations thereof are shown. The combinations are, for example, those shown in Table 1. In Table 1, the cation (E) represented by the formula (E-C-1) is represented as “(E-C-1)” according to the formula number, and the formula (EA The anion (E) represented by -1) is represented as “(EA-1)” or the like according to the formula number.

Compound (E) can be produced by a known production method or the like, or a commercially available product available from the market can also be used.
Among the specific examples of the compound (E) shown in Table 1, 1-butyl-3-methylpyridinium bis (trifluoromethylsulfonyl) imide [(E-1)], 1-butyl-1-methylpyrrolidinium Bis (trifluoromethylsulfonyl) imide [(E-4)] is more preferable. These are more preferable compounds (E) from the viewpoint that commercial products can be easily obtained from the market.

<Resin (A)>
As described above, the resin (A) contained in the resist composition is insoluble or hardly soluble in an alkaline aqueous solution, and can be dissolved in an alkaline aqueous solution by the action of an acid (hereinafter, sometimes referred to as “acid action characteristic”). ). By containing this resin (A), this resist composition can manufacture a resist pattern by the effect | action of the acid generate | occur | produced from the acid generator (B) mentioned later. Note that “can be dissolved in an alkaline aqueous solution by the action of an acid” means “insoluble or hardly soluble in an alkaline aqueous solution before contact with an acid, but soluble in an alkaline aqueous solution after contact with an acid”. Means.

  The resin (A) having acid action characteristics has an acid labile group (hereinafter, sometimes referred to as “acid labile group”) in its molecule. Such a resin (A) is a monomer having an acid labile group (hereinafter, this monomer is sometimes referred to as “monomer (a1)”, and the structural unit derived from the monomer (a1) is referred to as “structural unit (a1)”. Can be produced by polymerization. In producing the resin (A) having acid action characteristics, the monomer (a1) may be used alone, or two or more kinds may be used in combination.

［式（１）中、
Ｒ^a1、Ｒ^ａ２及びＲ^a3（Ｒ^a1〜Ｒ^a3）は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合して、これらが結合する炭素原子とともに炭素数３〜２０の環を形成する。＊は結合手を表す。］

［式（２）中、
Ｒ^a1'及びＲ^a2'は、それぞれ独立に、水素原子又は炭素数１〜１２の１価の炭化水素基を表し、Ｒ^a3'は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2'及びＲ^a3'は互いに結合して、これらが結合する炭素原子とともに炭素数３〜２０の環を形成する。該１価の炭化水素基及び該２価の炭化水素基を構成するメチレン基は、酸素原子又は硫黄原子に置き換わってもよい。＊は結合手を表す。］ <Acid labile group>
The “acid labile group” means a group that cleaves a leaving group upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). Examples of the acid labile group include a group represented by the formula (1) (acid labile group (1)) and a group represented by the formula (2) (acid labile group (2)). .

[In Formula (1),
Or which R ^{a1, R a2} and a R ^a3 (R ^a1 ~R ^a3) each independently represents an alicyclic hydrocarbon group of the alkyl group or 3 to 20 carbon atoms having 1 to 8 carbon atoms, R ^a1 and R ^a2 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. * Represents a bond. ]

[In Formula (2),
R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^{a3 ′ a2 ′} and R ^{a3 ′} are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. The monovalent hydrocarbon group and the methylene group constituting the divalent hydrocarbon group may be replaced with an oxygen atom or a sulfur atom. * Represents a bond. ]

The alkyl group and alicyclic hydrocarbon group of R ^{a1 to} R ^a3 of the acid labile group (1) include those already exemplified in the range of 1 to 20 carbon atoms. However, carbon number of this alicyclic hydrocarbon group becomes like this. Preferably it is the range of 3-16.

The case where R ^a1 and R ^a2 are bonded to each other to form a ring is when the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) is any of the following groups: is there. The number of carbon atoms in the ring formed by combining R ^a1 and R ^a2 is preferably in the range of 3-12.

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

Examples of the R ^{a1 ′} and R ^{a2 ′} hydrocarbon groups of the acid labile group (2) include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Among these groups, the same groups are included in the range having 20 or less carbon atoms. However, at least one of R ^{a1 ′} and R ^{a2 ′} is preferably a hydrogen atom.

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

  The monomer (a1) having an acid labile group [preferably an acid labile group (1) and / or an acid labile group (2)] preferably has an acid labile group and a carbon-carbon double bond. More preferably, it is a (meth) acrylic monomer having an acid labile group.

  Of the (meth) acrylic monomers having an acid labile group, the monomer (a1) having an alicyclic hydrocarbon group having 5 to 20 carbon atoms is preferred. Since the resin (A) obtained using such a monomer (a1) has a bulky structure such as an alicyclic hydrocarbon group, the resist composition containing the resin (A) The resolution tends to be better.

［式（ａ１−１）中、
Ｌ^a1は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−（ｋ１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。）で表される基を表す。
Ｒ^a4は、水素原子又はメチル基を表す。
Ｒ^a6は、炭素数１〜１０の脂肪族炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
式（ａ１−２）中、
Ｌ^a2は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−（ｋ１は前記と同義である。）で表される基を表す。
Ｒ^a5は、水素原子又はメチル基を表す。
Ｒ^a7は、炭素数１〜１０の脂肪族炭化水素基を表す。
ｎ１は０〜１０の整数を表す。］ <Preferred structural unit (a1)>
A suitable resin (A) obtained using the monomer (a1) having such an alicyclic hydrocarbon group will be described in more detail. Among the resins (A), a structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as “structural unit (a1-1)”) or a structural unit represented by the formula (a1-2) A resin having (hereinafter, referred to as “structural unit (a1-2)” in some cases) is preferable. Such resin (A) may have the structural unit (a1-1) as a single species, may have a plurality of types, or may have the structural unit (a1-2) as a single species. In addition, a plurality of types may be included, and the structural unit (a1-1) and the structural unit (a1-2) may be combined.

[In the formula (a1-1),
L ^a1 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O— (k1 represents an integer of 1 to 7, and * represents a bond to a carbonyl group). Represent.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
m1 represents the integer of 0-14.
In formula (a1-2),
L ^a2 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O— (k1 is as defined above).
R ^a5 represents a hydrogen atom or a methyl group.
R ^a7 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.
n1 represents an integer of 0 to 10. ]

L ^a1 and L ^a2 are preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, wherein k1 is an integer of 1 to 4, more preferably an oxygen atom. or * -O-CH ₂ -CO-O- and, still more preferably an oxygen atom.
R ^a4 and R ^a5 are preferably methyl groups.
Of the aliphatic hydrocarbon groups of R ^a6 and R ^a7 , preferably an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and within the range of the upper limit of the carbon number, Includes the same as those already exemplified. The aliphatic hydrocarbon groups for R ^a6 and R ^a7 are each independently preferably an alkyl group having 8 or less carbon atoms or an alicyclic hydrocarbon group having 8 or less carbon atoms, more preferably an alkyl group having 6 or less carbon atoms. Or it is an alicyclic hydrocarbon group having 6 or less carbon atoms.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the monomer (a1) capable of deriving the structural unit (a1-1) include those described in JP-A No. 2010-204646. Among the structural units (a1-1) derived from these, the following formula (a1-1-1), formula (a1-1-2), formula (a1-1-3), formula (a1-1-4) ), Formula (a1-1-5), formula (a1-1-6), formula (a1-1-7) and formula (a1-1-8) [formula (a1-1-1) to formula (a1) −1-8)] is preferable, and the structural unit (a1-1) represented by each of the formula (a1-1-1) to the formula (a1-1-4) is preferable. Is more preferable.

  Examples of the monomer represented by the formula (a1-1) include monomers described in JP 2010-204646 A. Monomers respectively represented by the following formulas (a1-1-1) to (a1-1-8) are preferred, and monomers represented by the following formulas (a1-1-1) to (a1-1-4) are respectively preferred. More preferred.

  On the other hand, examples of the monomer (a1) capable of deriving the structural unit (a1-2) include 1-ethyl-1-cyclopentyl (meth) acrylate, 1-ethyl-1-cyclohexyl (meth) acrylate, and 1-ethyl- Examples include 1-cycloheptyl (meth) acrylate, 1-methyl-1-cyclopentyl (meth) acrylate, and 1-isopropyl-1-cyclopentyl (meth) acrylate.

As the structural unit (a1-2), the following formula (a1-2-1), formula (a1-2-2), formula (a1-2-3), formula (a1-2-4), formula (a1) -2-5) and Formula (a1-2-6) [Formula (a1-2-1) to Formula (a1-2-6)] are preferable. Among these, the structural unit (a1-2) represented by the formula (a1-2-3) or (a1-2-4) is more preferable, and is represented by the formula (a1-2-3). The structural unit (a1-2) is more preferable.

  When the resin (A) has the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is based on the total structural unit (100 mol%) of the resin (A). The range of 10 to 95 mol% is preferable, the range of 15 to 90 mol% is more preferable, the range of 20 to 85 mol% is more preferable, and the range of 20 to 60 mol% is particularly preferable. When the structural unit (a1) has a structural unit (a1) having an adamantyl group (particularly preferably, the structural unit (a1-1)), the total of the structural units (a1) in the resin (A) The structural unit (a1) having an adamantyl group is preferably 15 mol% or more with respect to (100 mol%). With such a content ratio, the resin (A) having the structural unit (a1) having an adamantyl group tends to have good dry etching resistance of a resist pattern produced from the resist composition containing the resin (A). There is. In addition, in order to make the total content rate of a structural unit (a1-1) and / or a structural unit (a1-2) into the above-mentioned range, when manufacturing resin (A), it is with respect to the usage-amount of all monomers. What is necessary is just to adjust the usage-amount of the monomer which induces | guides | derives a structural unit (a1-1) and / or a structural unit (a1-2).

  The structural unit (a1-1) and the structural unit (a1-2), which are preferable structural units (a1), have been described above. However, the resin (A) has a structural unit (a1) other than these. May be. Hereinafter, the structural unit (a1) other than the structural unit (a1-1) and the structural unit (a1-2) will be described with reference to a monomer that derives the structural unit (a1).

［式（ａ１−３）中、
Ｒ^a9は、水素原子、置換基（例えばヒドロキシ基）を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基、又は−ＣＯＯＲ^a13で表される基を表し、Ｒ^a13は、炭素数１〜８の脂肪族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子はヒドロキシ基などで置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。Ｒ^a10、Ｒ^a11及びＲ^a12は、それぞれ独立に、炭素数１〜１２の脂肪族炭化水素基を表すか、或いはＲ^a10及びＲ^a11は互いに結合して環を形成している。該脂肪族炭化水素基及に含まれる水素原子はヒドロキシ基などで置換されていてもよく、該脂肪族炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ The resin (A) may have a structural unit (a1) derived from a monomer represented by the following formula (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”). Good. In the resin (A) having the structural unit (a1) derived from the monomer (a1-3), the structural unit (a1) contains a rigid norbornane ring in the main chain of the resin (A). This resist composition containing such a resin (A) tends to be able to produce a resist pattern having excellent dry etching resistance.

[In the formula (a1-3),
R ^a9 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a substituent (for example, a hydroxy group), a carboxy group, a cyano group, or a group represented by —COOR ^a13. , R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and constitutes the aliphatic hydrocarbon group The methylene group may be replaced by an oxygen atom or a carbonyl group. R ^a10 , R ^a11 and R ^a12 each independently represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or R ^a10 and R ^a11 are bonded to each other to form a ring. The hydrogen atom contained in the aliphatic hydrocarbon group may be substituted with a hydroxy group or the like, and the methylene group constituting the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. ]

The aliphatic hydrocarbon group which may have a substituent of R ^a9 is typically an alkyl group which may have a substituent, and among these alkyl groups, an alkyl having no substituent The group includes those already exemplified in the range of 1 to 8 carbon atoms. Examples of the substituent, particularly the aliphatic hydrocarbon group (alkyl group) having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group.

The aliphatic hydrocarbon groups of R ^{a10 to} R ^a12 are also typically alkyl groups, and specific examples thereof are the same as those of R ^a9 . The ring formed by combining R ^a10 and R ^a11 together with the carbon atom to which they are bonded includes a cyclohexyl ring and an adamantyl ring.

As a monomer (a1-3), what was described in Unexamined-Japanese-Patent No. 2010-204646 is used, for example. Among these, the monomers (a1-3-1), (a1-3-3), (a1-3-3) and (a1-3-4) represented by the following formulas (a1-3-1), 3) is preferable, and the monomer (a1-3) represented by the formula (a1-3-2) or (a1-3-4) is more preferable, and the monomer represented by the formula (a1-3-2) (A1-3) is more preferable.

  When the resin (A) has a structural unit derived from the monomer (a1-3), the content is preferably in the range of 10 to 95 mol% with respect to the total structural unit of the resin (A). The range of 90 mol% is more preferable, and the range of 20 to 85 mol% is more preferable.

［式（ａ１−４）中、
Ｒ¹⁰は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
ｌ^ａは０〜４の整数を表す。
Ｒ¹¹は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表し、ｌ^ａが２以上である場合、複数のＲ¹¹は互いに同一であっ
ても異なってもよい。
Ｒ¹²及びＲ¹³はそれぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^a2は、置換基を有していてもよい炭素数１〜１７の脂肪族炭化水素基又は単結合を表し、該脂肪族炭化水素基を構成するメチレン基は、酸素原子、硫黄原子、カルボニル基、スルホニル基又は−Ｎ（Ｒ^ｃ）−（ただし、Ｒ^ｃは、水素原子又は炭素数１〜６のアルキル基を表す）で表される基に置き換わっていてもよい。
Ｙ^a3は、置換基を有していてもよい炭素数１〜１８の炭化水素基を表す。］ Further, the resin (A) may have a structural unit (a1) derived from a monomer represented by the following formula (a1-4) (hereinafter sometimes referred to as “monomer (a1-4)”). Good.

[In the formula (a1-4),
R ¹⁰ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
l ^a represents an integer of 0 to 4;
R ¹¹ 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 acryloyl group, or methacryloyl. In the case where l ^a is 2 or more, a plurality of R ¹¹ may be the same as or different from each other.
R ¹² and R ¹³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents an ^optionally substituted aliphatic hydrocarbon group having 1 to 17 carbon atoms or a single bond, and the methylene group constituting the aliphatic hydrocarbon group includes an oxygen atom, a sulfur atom, a carbonyl A group, a sulfonyl group, or a group represented by —N (R ^c ) — (wherein R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) may be substituted.
Y ^a3 represents an ^optionally substituted hydrocarbon group having 1 to 18 carbon atoms. ]

Among “an alkyl group having 1 to 6 carbon atoms which may have a halogen atom”, the alkyl group includes those already exemplified in the range of 1 to 6 carbon atoms. As the alkyl group having a halogen atom, an alkyl group having a fluorine atom is preferable. Group, perfluoropentyl group, perfluorohexyl group and the like. Among these, as R < ¹⁰ >, a C1-C4 alkyl group is preferable, a methyl group and an ethyl group are more preferable, and a methyl group is especially preferable.
The alkoxy group of R ¹¹ includes those already exemplified in the range of 1 to 6 carbon atoms. Among them, an alkoxy group having 1 to 4 carbon atoms is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is particularly preferable. .
The acyl group and acyloxy group of R ¹¹ include those already exemplified in the range of 2 to 4 carbon atoms.
The hydrocarbon groups of R ¹² and R ¹³ are those having 1 to 12 carbon atoms, and the hydrocarbon group of Y ^a3 is the aliphatic hydrocarbon group exemplified above in the range of 1 to 18 carbon atoms. Contains any of the aromatic hydrocarbon groups.
The aliphatic hydrocarbon group of X ^a2 is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, or a divalent group in which a chain hydrocarbon group and an alicyclic hydrocarbon group are combined. And groups obtained by appropriately combining the groups already exemplified in the range of 1 to 17 carbon atoms.

As a monomer (a1-4), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. The following formula (a1-4-1), formula (a1-4-2), formula (a1-4-3), formula (a1-4-4), formula (a1-4-5), formula (a1) -4-6) and any one of the monomers represented by formula (a1-4-7) [formula (a1-4-1) to formula (a1-4-7)], respectively, are preferred, The monomer represented by each of 4-1)-Formula (a1-4-5) is more preferable.

  When the resin (A) has a structural unit derived from the monomer (a1-4), the content is preferably in the range of 10 to 95 mol% with respect to the total structural unit of the resin (A). The range of mol% is more preferable, and the range of 20 to 85 mol% is particularly preferable.

<Acid stable structural unit>
Resin (A) is a structural unit not having an acid labile group in addition to a structural unit (a1) having an acid labile group (hereinafter, sometimes referred to as “acid stable structural unit”). The derivatizable monomer is preferably referred to as “acid-stable monomer”). In the resin (A), the acid stable structural unit may have only one type, or may have a plurality of types.

  When the resin (A) has an acid stable structural unit, the content ratio of the acid stable structural unit may be determined based on the content ratio of the structural unit (a1). The ratio of the content ratio of the structural unit (a1) and the content ratio of the acid-stable structural unit is represented by [structural unit (a1)] / [acid-stable structural unit], and preferably 10 to 80 mol% / 90 to It is 20 mol%, More preferably, it is 20-60 mol% / 80-40 mol%. If it does in this way, there exists a tendency for the dry etching tolerance of the resist pattern obtained from this resist composition containing resin (A) to become still better.

Next, a preferable thing is demonstrated among an acid stable structural unit.
The acid stable structural unit is preferably a structural unit having a hydroxy group or a lactone ring. An acid stable structural unit having a hydroxy group (hereinafter referred to as “acid stable structural unit (a2)”) and / or an acid stable structural unit having a lactone ring (hereinafter referred to as “acid stable structural unit (a3)”). When the present resist composition containing the resin (A) is applied to a substrate, the resin (A) having the coating film formed on the substrate or the composition layer obtained from the coating film is between the substrate It becomes easy to develop excellent adhesion, and this resist composition can produce a resist pattern with good resolution. In addition, the manufacturing method of the resist pattern using this resist composition here is mentioned later. First, the acid stable structural unit (a2) and the acid stable structural unit (a3) suitable as the acid stable structural unit will be described with specific examples.

<Acid stable structural unit (a2)>
When the acid-stable structural unit (a2) is introduced into the resin (A), a suitable acid-stable structure is used depending on the type of exposure source when producing a resist pattern from the resist composition containing the resin (A). The unit (a2) can be selected. That is, when this resist composition is used for exposure using a KrF excimer laser (wavelength: 248 nm) as an exposure source, or exposure using a high energy beam such as an electron beam or EUV light as an exposure source, an acid stable structural unit ( As a2), it is preferable to introduce an acid stable structural unit (a2-0) having a phenolic hydroxyl group into the resin (A). When using exposure using a short wavelength ArF excimer laser (wavelength: 193 nm) as an exposure source, an acid stable structural unit represented by the formula (a2-1) described later is used as a resin ( It is preferable to introduce into A). Thus, each of the acid stable structural units (a2) possessed by the resin (A) can be selected according to the exposure source used for producing the resist pattern, but the acid stable structural units possessed by the resin (A) ( a2) may have only one type of acid stable structural unit (a2) suitable for the type of exposure source, and two or more types of acid stable structural unit (a2) suitable for the type of exposure source. Or an acid stable structural unit (a2) suitable for the type of exposure source and a combination of other acid stable structural units (a2).

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表す。）を表し、＊はカルボニル基（−ＣＯ−）との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 One specific example of the acid stable structural unit (a2) is one represented by the following formula (a2-1) (hereinafter sometimes referred to as “acid stable structural unit (a2-1)”).

In formula (a2-1),
L ^a3 represents an oxygen atom or ^* —O— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7), and * represents a bond with a carbonyl group (—CO—). Represent.
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.

L ^a3 is preferably an oxygen atom or a group represented by —O— (CH ₂ ) _k2 —CO—O—, wherein k2 is an integer of 1 to 4, more preferably an oxygen atom or — O—CH ₂ —CO—O—, more preferably an oxygen atom.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As an acid stable structural unit (a2-1), the following are mentioned, for example.

  As described above, the exemplified acid stable structural unit (a2-1) is derived from, for example, an acid stable monomer described in JP 2010-204646 A. Among these, acid stable structural units (a2) represented by formula (a2-1-1), formula (a2-1-2), formula (a2-1-3) and formula (a2-1-4), respectively. -1) is more preferable, and the acid stable structural unit (a2-1) represented by the formula (a2-1-1) or (a2-1-3) is more preferable.

  When the resin (A) has the acid stable structural unit (a2-1), the content ratio thereof is in the range of 3 to 45 mol% with respect to all the structural units (100 mol%) of the resin (A). Preferably, the range of 5-40 mol% is more preferable, and the range of 5-35 mol% is further more preferable.

式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は同一でも異なっていてもよい。 Next, the acid stable structural unit which has a phenolic hydroxyl group among the acid stable structural units which have a hydroxy group is demonstrated. The acid stable structural unit is preferably one represented by the following formula (a2-0) (hereinafter sometimes referred to as “acid stable structural unit (a2-0)”).

In formula (a2-0),
R ^a30 represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or 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 acryloyl group, or methacryloyl. Represents a group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 may be the same or different.

Specific examples of the “alkyl group having 1 to 6 carbon atoms” in the “alkyl group having 1 to 6 carbon atoms which may have a halogen atom” for R ^a30 include those already exemplified in this range. . The “C 1-6 alkyl group having a halogen atom” is one in which at least a part of the hydrogen atoms contained in the C 1-6 alkyl group is substituted with a halogen atom. The specific example of the halogen atom is as already described. Among these, R ^a30 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
Specific examples of the alkoxy group of R ^a31 include those already exemplified in the range of 1 to 6 carbon atoms. Among these, R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and particularly preferably a methoxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

Among the acid stable structural units (a2-0), in the following formula (a2-0-1), formula (a2-0-2), formula (a2-0-3) and formula (a2-0-4) Those represented respectively are preferred. The monomer (a1) capable of deriving such a structural unit is described in, for example, JP 2010-204634 A.

  Acid-stable monomer capable of deriving acid-stable structural unit (a2-0) such as p-hydroxystyrene and p-hydroxy-α-methylstyrene [hereinafter referred to as “acid-stable monomer (a2)” in some cases. ] In the production of the resin (A), the acid stable structural unit (a2-0) represented by the formula (a2-0-1) or the formula (a2-0-2) is converted into the resin (A). After the phenolic hydroxyl group in the acid-stable monomer (a2) is protected with a protecting group such as an acetyl group to form a protected acid-stable monomer (a2), this protected acid stable Resin (A) can also be manufactured using a monomer (a2). A resin (A) having an acid-stable structural unit (a2-0) can be produced by deprotecting a resin having a structural unit derived from the protected acid-stable monomer (a2) and removing the protecting group. . However, when carrying out the deprotection treatment, it is necessary to carry out the deprotection treatment without significantly damaging the other structural unit (a1).

  When the resin (A) has an acid stable structural unit (a2-0), the content is preferably in the range of 5 to 90 mol%, and preferably 10 to 85 mol%, based on all units of the resin (A). The range is more preferable, and the range of 15 to 80 mol% is particularly preferable.

<Acid stable structural unit (a3)>
The lactone ring included in the acid stable structural unit (a3) may be monocyclic such as β-propiolactone ring, γ-butyrolactone ring and δ-valerolactone ring, and the monocyclic lactone ring and other rings Or a condensed ring. Among these lactone rings, a γ-butyrolactone ring and a condensed ring of a γ-butyrolactone ring and another ring are preferable.

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表し、ｐ１が２以上の場合、複数のＲ^a21は同一でも異なっていてもよい。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。＊はカルボニル基との結合手を表す。
ｑ１は、０〜３の整数を表す。
Ｒ^a22は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｑ１が２以上の場合、複数のＲ^a22は同一でも異なっていてもよい。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）を表す。＊はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
ｒ１は、０〜３の整数を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表し、ｒ１が２以上の場合、複数のＲ^a23は同一でも異なっていてもよい。］ The acid stable structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A) may have only 1 type among these, and may have 2 or more types. In the following description, what is represented by the formula (a3-1) is referred to as “acid-stable structural unit (a3-1)”, and what is represented by the formula (a3-2) is “acid-stable structural unit ( a3-2) ”, and the compound represented by formula (a3-3) is referred to as“ acid-stable structural unit (a3-3) ”.

[In the formula (a3-1),
L ^a4 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a18 represents a hydrogen atom or a methyl group.
p1 represents an integer of 0 to 5.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when p1 is 2 or more, a plurality of R ^a21 may be the same or different.
In formula (a3-2),
L ^a5 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
q1 represents an integer of 0 to 3.
R ^a22 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and when q1 is 2 or more, a plurality of R ^a22 may be the same or different.
In formula (a3-3),
L ^a6 represents an oxygen atom or ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an integer of 1 to 7). * Represents a bond with a carbonyl group.
R ^a20 represents a hydrogen atom or a methyl group.
r1 represents an integer of 0 to 3.
R ^a23 represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. When r1 is 2 or more, a plurality of R ^a23 may be the same or different. ]

In formula (a3-1) to formula (a3-3), L ^{a4 to} L ^a6 are the same as those described for L ^a3 in formula (a2-1).
L ^{a4 to} L ^a6 are each independently an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O— in which k3 is an integer of 1 to 4, preferably an oxygen atom and * —O—CH ₂ —CO—O— is more preferable, and an oxygen atom is more preferable.
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 preferably integers of 0 to 2, more preferably 0 or 1. When p1 is 2, two R ^a21 may be the same as or different from each other. When q1 is 2, two R ^a22 may be the same as or different from each other, and r1 is 2. Two R ^a23 may be the same or different from each other.

  Hereinafter, preferred examples of the acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit (a3-3) will be shown.

Preferable examples of the acid stable structural unit (a3-1) include the following formula (a3-1-1), formula (a3-1-2), formula (a3-1-3) and formula (a3-1-4). ) Respectively.

Preferable examples of the acid stable structural unit (a3-2) include the following formula (a3-2-1), formula (a3-2-2), formula (a3-2-3) and formula (a3-2-4). ) Respectively.

Preferred examples of the acid stable structural unit (a3-3) include the following formula (a3-3-1), formula (a3-3-2), formula (a3-3-3) and formula (a3-3-4). ) Respectively.

  Examples of the acid stable monomer capable of deriving the acid stable structural unit (a3-3) include those described in JP 2010-204646 A.

  When the resin (A) has an acid stable structural unit (a3-3), the content ratio is preferably in the range of 5 to 70 mol% with respect to all the structural units of the resin (A), 10 to 65 The range of mol% is more preferable, and the range of 10 to 60 mol% is more preferable.

  As described above, the structural unit (a1-1) or the structural unit (a1-2) suitable as the structural unit (a1) of the resin (A), the acid stable structural unit (a2) or the acid stable structure suitable as the acid stable structural unit. Although the unit (a3) has been described in detail, structural units other than these may be included, and examples of the structural unit include structural units well known in the art. Although the resin (A) having an acid labile group in the molecule has been described here, the resist composition contains a resin having no acid labile group in addition to the resin (A). May be.

<Method for producing resin (A)>
The resin (A) is obtained by copolymerizing the monomer (a1) for deriving the structural unit (a1), more preferably the monomer (a1) and an acid stable monomer for deriving the acid stable structural unit. More preferably, the monomer (a1) for deriving the structural unit (a1-1) and / or the structural unit (a1-2), and the acid-stable structural unit (a2) and / or the acid-stable structural unit (a3) are derived. Copolymerized with an acid stable monomer. For example, when the resist composition is used for EUV exposure, the monomer (a1) that induces the structural unit (a1-1) and / or the structural unit (a1-2), and the acid stable structural unit (a2- And an acid-stable monomer derived from 0).
The resin (A) further preferably has a structural unit (a1-1) having an adamantyl group as the structural unit (a1). The resin (A) can be produced by subjecting the monomer as described above to a known polymerization method (for example, radical polymerization method) and polymerizing (copolymerizing) it.

  The weight average molecular weight of the resin (A) is preferably 2,500 or more and 30,000 or less (more preferably 3,000 or more), 30,000 or less (more preferably 15,000 or less, and further preferably 1,000). Hereinafter, particularly preferably 6,000 or less. In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis. Detailed analysis conditions for this analysis are described in the Examples of the present application.

<Acid generator (B)>
Next, the acid generator (B) contained in the resist composition will be described.
The acid generator (B) is an acid generator composed of a sulfonium salt or an iodonium salt, and examples of the anion of the acid generator (B) include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は炭素数１〜１７の２価の脂肪族飽和炭化水素基を表し、前記２価の脂肪族飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の１価の脂肪族炭化水素基を表し、該１価の脂肪族炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ⁺は、スルホニウムカチオン又はヨードニウムカチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably an acid generator represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). is there.

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group. May be.
Y represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and the methylene group constituting the monovalent aliphatic hydrocarbon group includes an oxygen atom, a sulfonyl group Alternatively, it may be replaced with a carbonyl group.
Z ⁺ represents a sulfonium cation or an iodonium cation. ]

Specific examples of the perfluoroalkyl group of Q ¹ and Q ² include those in which all of the hydrogen atoms constituting the alkyl group are replaced by fluorine atoms in the alkyl group having 1 to 6 carbon atoms among the already exemplified alkyl groups. Applicable. Specifically, for example, a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, etc. It is done.
As the acid generator (B1) contained in the resist composition, Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom acid generator (B1). Q ¹ and Q ² An acid generator (B1) in which both are fluorine atoms is more preferred.

Specific examples of the aliphatic hydrocarbon group represented by L ^b1 include the removal of two hydrogen atoms from the alkanediyl group already exemplified and the alicyclic hydrocarbons of the above formulas (KA-1) to (KA-19). Group.

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b3は、単結合又は炭素数１〜１２の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b4は、炭素数１〜１３の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b5は、炭素数１〜１５のの脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b6及びＬ^b7の合計炭素数の上限は１６である。
Ｌ^b8は、炭素数１〜１４の脂肪族炭化水素基を表し、この脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の脂肪族炭化水素基を表し、これらの脂肪族炭化水素基は脂肪族飽和炭化水素基が好ましい。但しＬ^b9及びＬ^b10の合計炭素数の上限は１２である。
本レジスト組成物に用いる酸発生剤としては、これらの中でも、式（ｂ１−１）で表される２価の基をＬ^b1として有する酸発生剤（Ｂ１）が好ましく、Ｌ^b2が単結合又はメチレン基である式（ｂ１−１）で表される２価の基を、Ｌ^b1として有する酸発生剤（Ｂ１）がより好ましい。 Examples of those in which the methylene group constituting the aliphatic hydrocarbon group of L ^b1 is replaced with an oxygen atom or a carbonyl group include the following formulas (b1-1), (b1-2), and (b1-3) ), Formula (b1-4), formula (b1-5), and formula (b1-6) [formula (b1-1) to formula (b1-6)]. In the formulas (b1-1) to (b1-6), “*” indicating a bond is described in accordance with the formula (B1) on the left and right, and the bond on the left is C (Q ¹ ). It is bonded to the carbon atom of (Q ² ), and the right bond is bonded to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or an aliphatic hydrocarbon group having 1 to 15 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b3 represents a single bond or an aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b4 represents an aliphatic hydrocarbon group having 1 to 13 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents an aliphatic hydrocarbon group having 1 to 15 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b6 and L ^b7 each independently represent an aliphatic hydrocarbon group having 1 to 15 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents an aliphatic hydrocarbon group having 1 to 14 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b9 and L ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 11 carbon atoms, and these aliphatic hydrocarbon groups are preferably aliphatic saturated hydrocarbon groups. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 12.
Among these, as the acid generator used in the present resist composition, an acid generator (B1) having a divalent group represented by the formula (b1-1) as L ^b1 is preferable, and L ^b2 is a single bond or The acid generator (B1) having a divalent group represented by the formula (b1-1) which is a methylene group as L ^b1 is more preferable.

L ^b1 is preferably a group represented by formula (b1-1) to formula (b1-4), and more preferably a group represented by formula (b1-1) to formula (b1-3). And particularly preferably a group represented by the formula (b1-1).

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

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

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

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

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

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

As above-mentioned, Y represents the C1-C18 aliphatic hydrocarbon group which may have a substituent. Among these aliphatic hydrocarbon groups, Y is preferably an alkyl group or an alicyclic hydrocarbon group, and is an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, More preferred is an alicyclic hydrocarbon group having 3 to 12 carbon atoms.
When the aliphatic hydrocarbon group of Y has a substituent, the substituent is, for example, a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic having 6 to 18 carbon atoms. Group represented by a group hydrocarbon group, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 (wherein R ^b1 represents a hydrocarbon group having 1 to 16 carbon atoms, j2 represents an integer of 0 to 4, and the like. The aromatic hydrocarbon group and aralkyl group referred to here may further have, for example, an alkyl group, a halogen atom or a hydroxy group.
The methylene group constituting the aliphatic hydrocarbon group for Y may be replaced with a group (divalent group) selected from the group consisting of an oxygen atom, a sulfonyl group and a carbonyl group. Examples of the group in which the methylene group constituting the alicyclic hydrocarbon group is replaced with an oxygen atom, a sulfonyl group or a carbonyl group include, for example, a cyclic ether group (one or two of the methylene groups constituting the alicyclic hydrocarbon group are A group in which an oxygen atom is substituted), a cyclic ketone group (a group in which one or two methylene groups constituting an alicyclic hydrocarbon group are replaced by a carbonyl group), a sultone ring group (which constitutes an alicyclic hydrocarbon group) Two adjacent methylene groups in the methylene group are replaced with oxygen atoms and sulfonyl groups, respectively, and a lactone ring group (two methylene groups adjacent in the methylene group constituting the alicyclic hydrocarbon group, A group in which an oxygen atom and a carbonyl group are substituted, respectively).

これらの中でも、好ましくは式（Ｙ１）〜式（Ｙ１９）でそれぞれ表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１４）、式（Ｙ１５）又は式（Ｙ１９）で表される基であり、さらに好ましくは式（Ｙ１１）又は式（Ｙ１４）で表される基である。 In particular, examples of the alicyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y26).

Among these, Preferably it is group respectively represented by Formula (Y1)-Formula (Y19), More preferably, it represents with Formula (Y11), Formula (Y14), Formula (Y15), or Formula (Y19). A group represented by formula (Y11) or formula (Y14).

Examples of Y include the following.

  As already explained, the alicyclic hydrocarbon group of Y is preferably a group having an adamantane ring as shown in formulas (Y1) and (Y2), and when these have a substituent, Is preferably a hydroxy group or an oxo group. That is, as the alicyclic hydrocarbon group having a substituent, a hydroxyadamantyl group and an oxoadamantyl group are particularly preferable as Y.

Specifically, preferred examples of the sulfonate anion include formula (b1-1-1), formula (b1-1-2), formula (b1-1-3), formula (b1-1-4), formula (B1-1-5), formula (b1-1-6), formula (b1-1-7), formula (b1-1-8) and formula (b1-1-9) [hereinafter referred to as "formula (b1 -1-1) to formula (b1-1-1-9) ". ] The sulfonate anion represented by each can be mentioned. In the sulfonate anion represented by each of the formula (b1-1-1) to the formula (b1-1-1-9), L ^b1 is preferably a group represented by the formula (b1-1).

  Specific examples of the sulfonate anions represented by formula (b1-1-1) to formula (b1-1-9) include sulfonate anions described in JP 2010-204646 A, for example. it can.

Hereinafter, as a preferable sulfonate anion, L ^b1 is a group represented by the formula (b1-1), and Y is an alicyclic hydrocarbon group represented by the formula (Y1) or the formula (Y2). A specific example is given. Examples of the sulfonate anion in which Y is an unsubstituted alicyclic hydrocarbon group include those represented by the following formulas (b1-s-1) to (b1-s-9), respectively.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having a hydroxy group include those represented by the following formulas (b1-s-10) to (b1-s-18), respectively.

Examples of the sulfonate anion in which Y is a cyclic ketone group include those represented by the following formulas (b1-s-19) to (b1-s-29), respectively.

Examples of the sulfonate anion in which Y is an alicyclic hydrocarbon group having an aromatic group include those represented by the following formulas (b1-s-30) to (b1-s-35).

Examples of the sulfonate anion in which Y is the lactone ring group or the sulfonate ring group include those represented by the following formulas (b1-s-36) to (b1-s-41).

Y may be an alkyl group. Examples of such a sulfonate anion include those represented by the following formula (b1-s-42).

The cation (Z ⁺ ) contained in the acid generator (B) is a sulfonium cation or an iodonium cation, preferably a sulfonium cation, more preferably an arylsulfonium cation.

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

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and among these hydrocarbon groups, an alkyl group having 1 to 18 carbon atoms and a fatty acid having 3 to 18 carbon atoms. A cyclic hydrocarbon group and an aromatic hydrocarbon group having 6 to 18 carbon atoms are preferred. The alkyl group may have a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon group includes a halogen atom and a carbon number. It may have 2 to 4 acyl groups or glycidyloxy groups, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, or a saturated cyclic carbonization having 3 to 18 carbon atoms. You may have a hydrogen group or a C1-C12 alkoxy group.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl 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.
R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b9 , R ^b10 and R ^b11 (R ^{b9 to} R ^b11 ) are each independently an aliphatic hydrocarbon group. When the aliphatic hydrocarbon group is an alkyl group, the number of carbon atoms is 1 to 12. Preferably, when the aliphatic hydrocarbon group is an alicyclic hydrocarbon group, the number of carbon atoms is preferably 3-18, and more preferably 4-12.
R ^b12 represents a hydrocarbon group having 1 to 18 carbon atoms. Among these hydrocarbon groups, the aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 1 to 12 carbon atoms. It may have an alkylcarbonyloxy group.
The combination of R ^b9 and R ^b10 and / or the combination of R ^b11 and R ^b12 are independently bonded to each other to form a 3-membered ring to 12-membered ring (preferably a 3-membered ring to 7-membered ring). These 3-membered ring to 12-membered ring (preferably 3-membered ring to 7-membered ring) may be an aliphatic ring or a methylene group constituting the aliphatic ring may be an oxygen atom, a sulfur atom or A ring that replaces a carbonyl group.

^{R b13, R b14, R b15} , R b16, R b17 and R ^b18 (R ^b13 ~R ^b18) are each independently a hydroxy group, an alkyl group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms Represents.
L ^b11 represents an oxygen atom or a sulfur atom.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13 may be the same or different. When p2 is 2 or more, the plurality of R ^b14 are independent, and when s2 is 2 or more, a plurality of R ^{b13 b15} may be the same or different, and when t2 is 2 or more, a plurality of ^Rb18 may be the same or different.

The alkylcarbonyloxy group for R ^b12 is a group in which the acyl group already exemplified and an oxygen atom are bonded.

Preferred examples of the alkyl group ^{represented by} R ^{b9 to} R ^b12 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, a pentyl group, a hexyl group, and an octyl group. And 2-ethylhexyl group.
Preferred examples of the alicyclic hydrocarbon group represented by R ^{b9 to} R ^b11 include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1 -Adamantyl) -1-alkyl group and isobornyl group.
Preferred examples of the aromatic hydrocarbon group for R ^b12 include phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, And biphenylyl and naphthyl groups.
A group in which an aromatic hydrocarbon group of R ^b12 and an alkyl group are bonded is typically an aralkyl group.
Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include, for example, a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Etc.
Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Specific examples of the sulfonium cation and the iodonium cation include those described in JP 2010-204646 A.

式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１８の脂肪族炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
この脂肪族炭化水素基の炭素数は１〜１２であると好ましく、炭素数１〜１２のアルキル基及び炭素数４〜１８の脂環式炭化水素基がより好ましく、さらには置換基として、ハロゲン原子、ヒドロキシ基、炭素数１〜１２のアルコキシ基、炭素数６〜１８の芳香族炭化水素基、炭素数２〜４のアシル基又はグリシジルオキシ基を有していてもよい。
ｖ２、ｗ２及びｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。
ｖ２が２以上のとき、複数のＲ^b19は同一でも異なっていてもよく、ｗ２が２以上のとき、複数のＲ^b20は同一でも異なっていてもよく、ｘ２が２以上のとき、複数のＲ^b21は同一でも異なっていてもよい。
なかでも、Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、好ましくは、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、炭素数１〜１２のアルキル基、又は炭素数１〜１２のアルコキシ基である。 Among the exemplified organic cations, those represented by the formula (b2-1) are preferable, and organic cations represented by the following formula (b2-1-1) [hereinafter referred to as “cation (b2-1-1)” That's it. ], More preferably a triphenylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 0) or a tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = X2 = 1, and R ¹⁹ , R ²⁰ and R ²¹ are all methyl groups).

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.
The aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms and an alicyclic hydrocarbon group having 4 to 18 carbon atoms. You may have an atom, a hydroxy group, a C1-C12 alkoxy group, a C6-C18 aromatic hydrocarbon group, a C2-C4 acyl group, or a glycidyloxy group.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, a plurality of R ^b19 may be the same or different. When w2 is 2 or more, a plurality of R ^b20 may be the same or different. When x2 is 2 or more, a plurality of R ^{b19 b21} may be the same or different.
Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. It is a group.

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anions and cations can be arbitrarily combined. Preferably, any one of the sulfonate anions of the formula (b1-1-1) to the formula (b1-1-9) and the formula (b2-1-1) ) And an organic cation of formula (b1-1-3) to (b1-1-5) and an organic cation of formula (b2-3). It is done.

The acid generator (B1) is preferably a salt represented by each of the formulas (B1-1) to (B1-17), more preferably an acid generator (B1) containing a triphenylsulfonium cation. [Formula (B1-1), Formula (B1-2), Formula (B1-6), Formula (B1-11), Formula (B1-12), Formula (B1-13), and Formula (B1-14) And acid generators (B1) each represented by the formula:

<Basic compound (C)>
The resist composition may contain a basic compound (C) known as a quencher in the resist field. When the basic composition (C) is contained in the resist composition, the content of the basic compound (C) is preferably 200 parts by mass or less with respect to 100 parts by mass of the total content of the compound (E). More preferably, it is 150 parts by mass or less, and more preferably 100 parts by mass or less. When the basic compound (C) is contained, the total content of the basic compound (C) and the compound (E) is preferably 1% by mass or more and 5% by mass in the solid content of the resist composition. Hereinafter, it is more preferably 1.5% by mass or more and 3% by mass or less. In addition, solid content here is mentioned later.

  The basic compound (C) is preferably a basic amine, an ammonium salt or a combination thereof, and the amine and the ammonium salt preferably have no sulfur atom in the molecule. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. Preferred examples of the basic compound (C) include compounds represented by formulas (C1) to (C8), and more preferred examples include compounds represented by formula (C1-1).

［式（Ｃ１）中、
Ｒ^c1、Ｒ^c2及びＲ^c3は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基、炭素数５〜１０の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基、アミノ基又は炭素数１〜６のアルコキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］

[In the formula (C1),
R ^c1 , R ^c2 and R ^c3 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. The hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group, or an alkoxy group having 1 to 6 carbon atoms, and the aromatic hydrocarbon group The hydrogen atom contained is substituted with an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms. It may be. ]

［式（Ｃ１−１）中、
Ｒ^c2及びＲ^c3は、前記と同義である。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は、互いに同一でも異なってもよい。］

[In the formula (C1-1),
R ^c2 and R ^c3 are as defined above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, a plurality of R ^{c4 s} may be the same as or different from each other. ]

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は、互いに同一でも異なってもよい。］

[In Formula (C2), Formula (C3) and Formula (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 are each independently synonymous with R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 may be the same as or different from each other. ]

［式（Ｃ５）及び式（Ｃ６）中、
Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同義である。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同義である。
ｏ３及びｐ３は、それぞれ独立に０〜３の整数を表し、ｏ３が２以上であるとき、複数のＲ^c14は互いに同一でも異なってもよい。ｐ３が２以上であるとき、複数のＲ^c15は互いに同一でも異なってもよい。
Ｌ^c1は、炭素数１〜６のアルキレン基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C5) and Formula (C6),
R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 are each independently synonymous with R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently have the same ^meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3, and when o3 is 2 or more, the plurality of R ^c14 may be the same or different from each other. When p3 is 2 or more, the plurality of R ^c15 may be the same as or different from each other.
L ^c1 represents an alkylene group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

［式（Ｃ７）及び式（Ｃ８）中、
Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同義である。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18は互いに同一でも異なってもよい。ｒ３が２以上であるとき、複数のＲ^c19は互いに同一でも異なってもよい。ｓ３が２以上であるとき、複数のＲ^c20は互いに同一でも異なってもよい。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C7) and Formula (C8),
R ^c18, R ^c19 and R ^c20 in each occurrence independently has the same meaning as R ^c4.
q3, r3 and s3 each independently represents an integer of 0 to 3, and when q3 is 2 or more, the plurality of R ^c18 may be the same or different from each other. When r3 is 2 or more, the plurality of R ^c19 may be the same as or different from each other. When s3 is 2 or more, the plurality of R ^c20 may be the same as or different from each other.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

  Examples of the compound represented by the formula (C1) include 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, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenyl Examples include ethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, and 4,4′-diamino-3,3′-diethyldiphenylmethane. Propyl aniline. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 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′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine and 2,2′-dipiconylamine, bipyridine and the like.

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

［式（ｂ）中、
Ｒ^g1、Ｒ^g2、Ｒ^g3及びＲ^g4はそれぞれ独立に、炭素数１〜６のアルキル基を表す。Ａ^１は、置換基を有していてもよい炭素数３〜３６の脂環式炭化水素基、置換基を有していてもよい炭素数６〜２０の芳香族炭化水素基又は置換基を有していてもよい炭素数５〜２０の複素環基を表す。］ Furthermore, it is also preferable to contain the following (G) in this resist composition. Inclusion of this (G) is expected to increase the sensitivity of the resist composition.
(G) A compound represented by the formula (b) (hereinafter sometimes referred to as “compound (G)”).

[In the formula (b),
R ^g1 , R ^g2 , R ^g3 and R ^g4 each independently represents an alkyl group having 1 to 6 carbon atoms. A ¹ represents an alicyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms or a substituent which may have a substituent. The C5-C20 heterocyclic group which you may have is represented. ]

The alkyl groups of R ^{g1 to} R ^g4 include those already exemplified in the range of 1 to 6 carbon atoms. Specific examples of the cation moiety (ammonium ion) of the compound (G) include those represented by the following formulas (G-C1) to (G-C6).

The alicyclic hydrocarbon group of A ¹ is preferably in the range of 3 to 20 carbon atoms, more preferably in the range of 3 to 12 carbon atoms, and is an adamantanediyl group, cyclohexanediyl group or norbornenediyl group. And more preferred. Such alicyclic hydrocarbon groups include those already exemplified in such a range of carbon number.

The aromatic hydrocarbon group for A ¹ preferably has 6 to 12 carbon atoms, and more preferably a phenylene group. Such aromatic hydrocarbon groups include those already exemplified within the above range of carbon number.

The heterocyclic group for A ¹ may be aromatic or non-aromatic as long as it is in the range of 5 to 20 carbon atoms. Examples of the aromatic heterocyclic group include a pyridinediyl group and a bipyridinediyl group. Non-aromatic heterocyclic groups include pyrrolidinediyl group, pyrazolinediyl group, imidazolinediyl group, isoxazolinediyl group, isothiazolinediyl group, piperidinediyl group, piperazinediyl group, morpholinediyl group, thiomorpholinediyl group, A triazole diyl group, a tetrazole diyl group, etc. are mentioned.

The alicyclic hydrocarbon group, aromatic hydrocarbon group and heterocyclic group of A ¹ may have a substituent, and examples of the substituent include an alkyl group and an acyl group. An alicyclic hydrocarbon group, an aromatic hydrocarbon group and a heterocyclic group having no group are more preferable.

Although A ¹ has been described above, among these, A ¹ is preferably an alicyclic hydrocarbon group or an aromatic hydrocarbon group.

When the anion part (carboxyl ion) of a compound (G) is illustrated, what is represented by the following formula | equation (G-A1)-a formula (G-A5) will be mentioned.

  A suitable compound (G) is prepared by combining the above-described cation moiety (ammonium ion represented by any one of formulas (G-C1) to (G-C6)) and an anion moiety (formula (G-A1) to formula (G). Table 2 shows combinations with any of the carboalkyl ions represented by -A5). In Table 2, a cation moiety represented by the formula (G-C1) is represented as “(G-C1)” according to the formula number, and the anion represented by the formula (G-A1). And the like are represented as “(G-A1)” or the like according to the equation number.

<Solvent (D)>
The solvent (D) contained in the resist composition is a substrate in the production of a resist pattern, which will be described later, according to the type and amount of the resin (A) used, the type and amount of the acid generator (B), and the like. An optimum one can be appropriately selected from the viewpoint that the coating property when the resist composition is applied to the top is improved.

  Examples of suitable solvents (D) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and Examples thereof include esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and cyclic esters such as γ-butyrolactone. Only 1 type may be used for a solvent (D) and it may use 2 or more types together.

<Other ingredients>
The resist composition may contain components other than the compound (E), the resin (A), the acid generator (B), the solvent (D), and the basic compound (C) used as necessary. You may contain. This component is referred to as “component (F)”. Such component (F) is an additive widely used in the present technical field, such as a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye.

<This resist composition and its preparation method>
The resist composition is
(R1) Combination of resin (A), acid generator (B), compound (E) and solvent (D) (R2) resin (A), acid generator (B), compound (E), basic compound ( C)
And a combination of solvent (D) (R3) resin (A), acid generator (B), compound (E), compound (G) and
Combination of solvent (D) (R4) Resin (A), acid generator (B), compound (E), basic compound (C),
It can be prepared by mixing any combination of the combination of the compound (G) and the solvent (D). Furthermore, a component (F) may be mixed as needed. In such mixing, the mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin (A) to be used, the solubility with respect to the solvent (D) of resin (A). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.

  Next, in this resist composition, the compound (E), the resin (A), the acid generator (B) and the solvent (D), and the basic compound (C) and the compound (G) used as necessary A preferable content ratio will be described. In the following description, what removed the solvent (D) from this resist composition may be called "solid content" of this resist composition.

As described above, the content ratio of the solvent (D) can be appropriately adjusted according to the type of the resin (A), but is preferably 90% by mass or more based on the total mass of the resist composition. In addition, in this resist composition whose content rate of a solvent (D) is 90 mass%, content of solid content with respect to this resist composition total mass corresponds to 10 mass%. This resist composition containing the solvent (D) in such a content ratio is suitable as a thin film resist capable of forming a composition layer having a thickness of about 30 to 300 nm, for example, in a method for producing a resist pattern described later. From this viewpoint, the content of the solvent (D) with respect to the total mass of the resist composition is more preferably 92% by mass or more, and still more preferably 94% by mass or more. The upper limit of the content of the solvent (D) is, for example, 99.9% by mass or less, and preferably 99% by mass or less.
The content of the solvent (D) can be controlled by the amount of the solvent (D) used in preparing the resist composition. After preparing the resist composition, the resist composition It can also be obtained by using a known analytical means such as liquid chromatography or gas chromatography.

  A preferable range of the content ratio of the resin (A) to the present resist composition is selected with respect to the total mass of the solid content of the present resist composition. Specifically, the content ratio of the resin (A) with respect to the total mass of the solid content is preferably 80% by mass or more.

  A preferable range of the content of the acid generator (B) in the resist composition is selected with respect to the total mass of the resin (A) contained in the resist composition. Specifically, the acid generator (B) is preferably 1 part by mass or more and more preferably 3 parts by mass or more with respect to 100 parts by mass of the resin (A). The acid generator (B) is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, relative to 100 parts by mass of the resin (A).

  A preferable range of the content of the compound (E) with respect to the resist composition is selected with respect to the total mass of the resin (A) contained in the resist composition. Specifically, the compound (E) is preferably 1 part by mass or more and more preferably 2 parts by mass or more with respect to 100 parts by mass of the resin (A). Further, the compound (E) is preferably 30 parts by mass or less, and more preferably 25 parts by mass or less, relative to 100 parts by mass of the resin (A).

  When the basic compound (C) is used in the resist composition, a preferable range of the content ratio is selected with respect to the total mass of the solid content of the resist composition. Specifically, the content ratio of the basic compound (C) to the total mass of the solid content is preferably about 0.01 to 2.5% by mass.

  When using a compound (G) for this resist composition, the preferable range is selected with respect to the total mass of the solid content of this resist composition. Specifically, the content ratio of the compound (G) with respect to the total mass of the solid content is preferably about 0.01 to 5% by mass.

  The resin composition (A), the acid generator (B), the compound (E), and the suitable content ratios of the basic compound (C) and the compound (G) used as necessary also prepare the resist composition. It can be controlled by the amount of each used. After the present resist composition is prepared, the present resist composition can be obtained by subjecting it to a known analysis means such as gas chromatography or liquid chromatography.

  In addition, when using a component (F) for this resist composition, suitable content can also be adjusted according to the kind of the said component (F).

  Thus, the compound (E), the resin (A), the acid generator (B) and the solvent (D), and the basic compound (C), compound (G) and / or component (F) used as necessary. ) Are mixed at a preferred content, and then the resist composition can be prepared by filtration using a filter having a pore size of about 0.2 μm.

<Method for producing resist pattern>
Specifically showing a method for producing a resist pattern using the present resist composition,
(1) a step of applying the resist composition on a substrate;
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating. Hereinafter, each of the steps shown here is referred to as “step (1)” to “step (5)”.

  Application of the resist composition on the substrate in the step (1) can be performed by a coating apparatus widely used for applying a resist material for semiconductor microfabrication, such as a spin coater. Thus, a coating film made of the present resist composition is formed on the substrate. The film thickness of the coating film can be adjusted by variously adjusting the conditions (coating conditions) of the coating apparatus, and by applying an appropriate preliminary experiment, the coating film can be applied to have a desired film thickness. You can choose the conditions. Various substrates to be subjected to microfabrication can be selected as the substrate before applying the resist composition. The substrate can be washed or an antireflection film can be formed before applying the resist composition. For example, a commercially available composition for an organic antireflection film can be used for forming the antireflection film.

In the step (2), the solvent [solvent (D)] is removed from the resist composition coated on the substrate, that is, the coated film. Such solvent removal is performed, for example, by evaporating the solvent (D) from the coating film by a heating means using a heating device such as a hot plate, a decompression means using a decompression device, or a combination of these means. Is done. The conditions for the heating means and the decompression means are adjusted according to the type of the solvent (D) contained in the resist composition. For example, in the heating means (hot plate heating) using a hot plate, What is necessary is just to make surface temperature into the range of about 50-200 degreeC. In the decompression means, after the substrate on which the coating film is formed is sealed in an appropriate decompressor, the internal pressure of the decompressor may be set to about 1 to 1.0 × 10 ⁵ Pa. Thus, by removing the solvent (D) from the coating film, a composition layer is formed on the substrate.

Step (3) is a step of exposing the composition layer, and preferably the composition layer is exposed using an exposure machine. At this time, exposure is performed through a mask corresponding to a desired pattern to be finely processed. As an exposure light source of the exposure machine, an ultraviolet light emitting device such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), solid laser light source (YAG or Use various types of laser light such as semiconductor lasers that convert wavelength of laser light to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, and those that directly draw with an electron beam (electron beam). it can. The present resist composition is particularly useful for producing a resist pattern by electron beam lithography. Therefore, the exposure light source of the exposure machine is preferably an electron beam. The exposure machine may be an immersion exposure machine (the immersion medium is, for example, ultrapure water).
As described above, by exposing through a mask, an exposed portion (exposed portion) and an unexposed portion (unexposed portion) are generated in the composition layer. In the composition layer of the exposed portion, the acid generator (B) (preferably the acid generator (B1)) contained in the composition layer generates an acid upon receiving exposure energy, and further, by the action of the generated acid, The acid labile group in the resin (A) causes a deprotection reaction, and as a result, the resin (A) in the composition layer of the exposed portion becomes soluble in an alkaline aqueous solution. On the other hand, since the exposure energy is not received in the unexposed area, the resin (A) remains insoluble or hardly soluble in the alkaline aqueous solution. Thus, the composition layer in the exposed portion and the composition layer in the unexposed portion are significantly different in solubility in the alkaline aqueous solution. In addition, although it described about the method of forming an exposure part and an unexposed part in a composition layer by exposing through a mask here, direct writing is performed using an electron beam as an exposure source. Thereby, an exposed part and an unexposed part can also be formed in this composition layer.

  In step (4), a heat treatment for further promoting the progress of the deprotecting group reaction that may occur in the exposed portion is performed. For the heat treatment, a heating means using a hot plate shown in the step (2) is employed. In the hot plate heating in step (4), the surface temperature of the hot plate is preferably about 50 to 200 ° C, more preferably about 70 to 150 ° C.

Step (5) is a step of developing the heated composition layer, and preferably the heated composition layer is developed with a developing device. The development referred to here is by bringing the composition layer after heating into contact with an alkaline aqueous solution, thereby dissolving the exposed composition layer in the alkaline aqueous solution and leaving the unexposed composition layer on the substrate. A resist pattern is manufactured on the substrate.
The alkaline aqueous solution used here is referred to as “alkaline developer”, and those used in this technical field can be used. Examples of the alkaline aqueous solution include an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline).

  The resist pattern manufactured on the substrate as described above is preferably rinsed with ultrapure water or the like to further remove moisture remaining on the substrate and the resist pattern.

  According to the resist pattern manufacturing method including the steps (1) to (5) as described above, the present resist composition can manufacture a resist pattern having a good cross-sectional shape, that is, a substantially rectangular cross-sectional shape. In particular, the resist composition can provide a resist pattern having an extremely excellent cross-sectional shape in the production of a resist pattern by electron beam (EB) drawing or EUV exposure. The mechanism of manifestation of such an effect is not necessarily clear, and is based on the inventors' original knowledge.

<Application>
As described above, the present resist composition is suitable not only as a resist composition for electron beam drawing or EUV exposure, but also as a resist composition for KrF excimer laser exposure and a resist composition for ArF excimer laser exposure. It is also useful.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing content and use amount are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation) using polystyrene as a standard product.
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)

以下、ここに示すモノマーをその式番号に応じて、「モノマー（Ａ−Ｂ）」などという。 Synthesis Example (Synthesis of Resin (A))
Resin (A) was synthesized using the following monomers.

Hereinafter, the monomer shown here is called "monomer (AB)" etc. according to the formula number.

Synthesis Example 1 (Synthesis of Resin A1)
Synthesis Example 1 (Synthesis of Resin A1)
In a four-necked flask equipped with a condenser and a stirrer, 19.59 parts of propylene glycol monomethyl ether acetate was charged, and after the atmosphere was replaced with nitrogen, the temperature was raised to 75 ° C. Using another container, 16.00 parts of monomer (AB), 5.50 parts of monomer (AC), 2.57 parts of monomer (AD), 11.86 parts of monomer (AE), Monomer (AF) 12.21 parts, azobisisobutyronitrile 0.72 parts, 2,2′-azobis (2,4-dimethylvaleronitrile) 3.25 parts and propylene glycol monomethyl ether acetate 57.76 The monomer solution was prepared by mixing the parts. This monomer solution was dropped into propylene glycol monomethyl ether acetate kept at 75 ° C. over 1 hour, and kept at 75 ° C. for 5 hours after the completion of dropping. After cooling, the reaction solution was poured into a mixed solution of 501 parts of methanol and 125 parts of ion-exchanged water to precipitate a polymer, and the precipitated polymer was separated from the reaction solution by filtration. The operation of adding 313 parts of methanol to the separated polymer and stirring, followed by filtration was repeated three times. The finally obtained polymer was dried to obtain 39.10 parts of a resin (this resin is referred to as Resin A1). This resin A1 has the following structural units, and the weight average molecular weight was about 5.8 × 10 ³ .

Synthesis Example 2 (Synthesis of Resin A2)
A 4-necked flask equipped with a condenser and a stirrer was charged with 92.81 parts of 1,4-dioxane, purged with nitrogen, and then heated to 85 ° C. Using another container, 39.06 parts of monomer (AA), 60.00 parts of monomer (AG), 9.22 parts of monomer (AD), 4.06 parts of monomer (AH), A monomer solution was prepared by mixing 26.55 parts of monomer (AE), 11.53 parts of azobisisobutyronitrile and 138.55 parts of 1,4-dioxane. This monomer solution was dropped into 1,4-dioxane kept at 85 ° C. over 1 hour, and after completion of dropping, the monomer solution was kept at 85 ° C. for 6 hours. After cooling, the reaction solution was poured into a mixed solution of 1609 parts of methanol and 402 parts of ion-exchanged water to precipitate a polymer, and the precipitated polymer was separated from the reaction solution by filtration. The separated polymer was dissolved in 464 parts of methyl isobutyl ketone, and 312.46 parts of a 1% aqueous p-toluenesulfonic acid solution was added to the resulting mixture, followed by stirring at room temperature for 6 hours. The water washing operation of adding 309 parts of ion exchanged water to the reaction solution after the reaction and stirring, standing, and separating was repeated three times. The organic layer after washing with water was poured into 2011 parts of n-heptane, and the precipitated resin was filtered. This resin A2 had the following structural units, and its yield was 129.16 parts and its weight average molecular weight was about 5.2 × 10 ³ .

Examples 1-5 and Reference Examples 1-2
The components shown in Table 3 below were mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin (A)>
Resin A1 and Resin A2 obtained in Synthesis Examples 1 and 2
<Acid generator (B)>
Acid generator B1-11

<Compound (G)>
G-17: Tetrabutylammonium 3-hydroxy-2-naphthoic acid

<Compound (E)>
E-1: 1-butyl-3-methylpyridinium bis (trifluoromethylsulfonyl) imide E-4: 1-butyl-1-methylpyrrolidinium bis (trifluoromethylsulfonyl) imide <solvent (D)>
D1:
Propylene glycol monomethyl ether acetate 410.0 parts Propylene glycol monomethyl ether 150.0 parts γ-butyrolactone 5.0 parts

Evaluation of Resist Composition After a silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 ° C. for 60 seconds, the film thickness after drying the resist composition described in Table 3 was 0.04 μm. It spin-coated so that it might become. After applying the resist composition, it was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature described in the “PB” column of Table 3. Each wafer on which the resist film (composition layer) was formed in this manner was subjected to an electron beam drawing machine ["HL-800D 50 keV" manufactured by Hitachi, Ltd. Was exposed. After exposure, post exposure bake (PEB) is performed for 60 seconds on a hot plate at the temperature described in the “PEB” column of Table 3, and then paddle development is performed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution for 60 seconds. Went.

<Shape evaluation>
A 100 nm line and space pattern was observed with a scanning electron microscope. If the cross-sectional shape of the pattern is close to a rectangle and is good (FIG. 1A) is “g” (good), and the top shape is close to a T-shape (FIG. 1B) is “b” ( bad). The results are shown in Table 4. The conceptual diagram of the resist pattern shown in FIG. 1 schematically shows a cross-sectional shape when one line and space pattern is cut. A resist pattern having an excellent cross-sectional shape corresponding to “g” means that when a plurality of cross-sections are observed as described above, all cross-sectional shapes are close to a rectangle and good.

<Evaluation of scum generation>
A 100 nm line and space pattern was observed with a scanning electron microscope. Evaluation was made at two levels, with “g” (good) indicating no scum on the substrate and “b” (bad) indicating scum. The results are shown in Table 4.

  The resist composition of the present invention is extremely useful for semiconductor microfabrication, particularly microfabrication by electron beam lithography or EUV lithography.

Claims (7)

A resist composition containing the following (A), (B), (E) and (D).
(A) a resin that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid;
(B) an acid generator comprising a sulfonium salt or an iodonium salt;
(E) a compound of formula (I);

[In the formula (I),
Ring X represents a 5-membered or 6-membered heterocyclic ring containing one quaternary nitrogen atom as an atom constituting the ring.
n represents an integer of 1 to 3.
R ³ has an optionally substituted alkyl group having 1 to 12 carbon atoms, an optionally substituted alicyclic saturated hydrocarbon group having 3 to 24 carbon atoms, or a substituent. An alkenyl group having 2 to 12 carbon atoms which may be present. When n is 2 or more, a plurality of R ³ are the same or different from each other.
R ⁴ and R ⁵ each independently represents a C 1-4 alkyl group having a fluorine atom. ]
(D) Solvent Said (E) is
2. The resist composition according to claim 1, wherein R ⁴ and R ⁵ each independently contain a compound represented by the formula (I) of a perfluoroalkyl group having 1 to 4 carbon atoms. The resist composition according to claim 1, wherein the (B) is an acid generator represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group. .
Y represents a monovalent aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and the methylene group constituting the monovalent aliphatic hydrocarbon group includes an oxygen atom, a sulfonyl group Alternatively, it may be replaced with a carbonyl group.
Z + represents a sulfonium cation or an iodonium cation. ] The resist composition according to claim 3, wherein L ^{b1 in the} formula (B1) is a group represented by the formula (b1-1).

[In the formula (b1-1),
L ^b2 represents a single bond or an alkanediyl group having 1 to 15 carbon atoms.
The * on the left side is a bond that bonds to the carbon atom of C (Q ¹ ) (Q ² ), and the * on the right side is a bond that bonds to Y. ]   The resist composition according to claim 3 or 4, wherein Y in the formula (B1) is a monovalent alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. Furthermore, the resist composition in any one of Claims 1-5 containing the following (G).
(G) a compound represented by formula (b);

(In the formula (b),
R ^g1 , R ^g2 , R ^g3 and R ^g4 each independently represents an alkyl group having 1 to 6 carbon atoms.
A ¹ represents an alicyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms or a substituent which may have a substituent. The C5-C20 heterocyclic group which you may have is represented. ) (1) The process of apply | coating the resist composition in any one of Claims 1-6 on a board | substrate;
(2) A step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

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