JP2012155314A - Resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new positive resist composition containing a resin having a specified structural unit.SOLUTION: The positive resist composition contains a resin having a structural unit expressed by formula (I) and an acid generator. In the formula, Rand Reach represent an aliphatic hydrocarbon group, or Rand Rare bonded with each other to form a ring together with a carbon atom to which they are bonded; Rrepresents an alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom; Trepresents a divalent aliphatic saturated hydrocarbon group or the like; and m represents an integer of 0 or 1.

Description

  The present invention relates to a positive resist composition. More specifically, the present invention relates to a positive resist composition containing a resin having a specific structural unit.

しかし、同文献には該化合物を重合させた樹脂を含有するポジ型レジスト組成物は記載されていない。 Patent Document 1 describes a compound shown below and an ultraviolet curable composition containing the compound.

However, this document does not describe a positive resist composition containing a resin obtained by polymerizing the compound.

JP 2004-59435 A

  The present invention provides a novel positive resist composition containing a resin having a specific structural unit.

［式（Ｉ）中、
Ｒ^１及びＲ^２は、それぞれ独立に、炭素数１〜６の脂肪族炭化水素基を表すか、又はＲ^１及びＲ^２が互いに結合し、それらが結合している炭素原子とともに炭素数５〜２０の環を形成する。
Ｒ^３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。
Ｔ^１は、炭素数１〜１７の２価の脂肪族飽和炭化水素基又は式（ａ−１）

（式（ａ−１）中、
ｓは０又は１の整数を表す。
Ｘ¹⁰及びＸ^1１は、それぞれ独立に、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ¹⁰、Ａ^1１及びＡ¹²は、それぞれ独立に、置換基を有していてもよい脂肪族炭化水素基を表し、Ｘ¹⁰、Ｘ¹¹、Ａ¹⁰、Ａ¹¹及びＡ¹²の炭素数の合計は１７以下である。）
で表される基を表す。
ｍは０又は１の整数を表す。］
〔２〕前記樹脂が、前記式（Ｉ）のＲ^１及びＲ^２が、互いに結合してシクロヘキサン環を形成する構造単位を有する前記〔１〕記載のポジ型レジスト組成物。
〔３〕前記樹脂が、アルカリ水溶液に不溶又は難溶であり、酸の作用によりアルカリ水溶液に溶解し得る樹脂である前記〔１〕又は〔２〕記載のポジ型レジスト組成物。
〔４〕さらに、塩基性化合物を含有する前記〔１〕〜〔３〕のいずれか記載のポジ型レジスト組成物。
〔５〕さらに、溶剤（Ｄ）を含む前記〔１〕〜〔４〕のいずれか記載のポジ型レジスト組成物。
〔６〕（１）前記〔１〕〜〔５〕のいずれか記載のポジ型レジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光機を用いて露光する工程、
（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、現像装置を用いて現像する工程を含むパターン形成方法。 The present invention includes the following inventions.
[1] A positive resist composition containing a resin having a structural unit represented by formula (I) and an acid generator.

[In the formula (I),
R ¹ and R ² each independently represent an aliphatic hydrocarbon group having 1 to 6 carbon atoms, or R ¹ and R ² are bonded to each other, and together with the carbon atom to which they are bonded, 20 rings are formed.
R ³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
T ¹ is a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms or the formula (a-1)

(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represents an aliphatic hydrocarbon group which may have a substituent, and the total number of carbon atoms of X ¹⁰ , X ¹¹ , A ¹⁰ , A ¹¹ and A ¹² Is 17 or less. )
Represents a group represented by
m represents an integer of 0 or 1. ]
[2] The positive resist composition according to [1], wherein the resin has a structural unit in which R ¹ and R ^{2 in} the formula (I) are bonded to each other to form a cyclohexane ring.
[3] The positive resist composition according to [1] or [2], wherein the resin is 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.
[4] The positive resist composition as described in any one of [1] to [3], further containing a basic compound.
[5] The positive resist composition as described in any one of [1] to [4], further including a solvent (D).
[6] (1) A step of applying the positive resist composition according to any one of [1] to [5] 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 pattern forming method including a step of heating the composition layer after exposure, and (5) a step of developing the heated composition layer using a developing device.

  According to the present invention, a novel positive resist composition can be provided.

<This resist composition>
This resist composition is a novel positive resist composition characterized by containing the resin (A) having the structural unit (I). By including the resin (A), the present resist composition exhibits an effect that a resist pattern having excellent line edge roughness can be produced.
In addition to the resin (A), the resist composition contains an acid generator (B).
Further, the resist composition preferably contains a solvent (D), and if necessary, a basic compound called a quencher in the art (hereinafter, sometimes referred to as “basic compound (C)”). And other additives.

  In the present specification, unless otherwise specified, the following examples of substituents are applied to any chemical structural formula having the same substituents while appropriately selecting the number of carbon atoms. Those which can be linear, branched or cyclic include any of them, and they may be mixed. When stereoisomers exist, all stereoisomers are included. * Represents a bond. In the following examples of substituents, the numerical value attached to “C” indicates the number of carbon atoms of each group.

  In the present specification, the “hydrocarbon group” includes 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), the monovalent one is typically an alkyl group. Examples of the alkyl group include a methyl group (C ₁ ), an ethyl group (C ₂ ), Propyl group (C ₃ ), butyl group (C ₄ ), pentyl group (C ₅ ), hexyl group (C ₆ ), 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 ), etc. It 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. Of these, a chain hydrocarbon group, particularly a saturated alkyl group, is preferred. The divalent chain hydrocarbon group corresponds to an alkanediyl group obtained by removing one hydrogen atom from the alkyl group shown here.

Monovalent alicyclic aliphatic hydrocarbon groups (hereinafter sometimes referred to as “alicyclic hydrocarbon groups”) typically remove one hydrogen atom from an alicyclic hydrocarbon. It is a group. The alicyclic hydrocarbon group may be an unsaturated alicyclic hydrocarbon group containing about one carbon-carbon unsaturated bond, or 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 formula (KA-1), cyclobutane (C ₄ ) represented by formula (KA-2), cyclopentane (C ₅ ) represented by formula (KA-3), Cyclohexane (C ₆ ) represented by formula (KA-4), cycloheptane (C ₇ ) represented by formula (KA-5), cyclooctane (C ₈ ) represented by formula (KA-6), And cyclododecane (C ₁₂ ) represented by the formula (KA-7).

なお、ここに示した脂環式炭化水素を「式（ＫＡ−１）〜式（ＫＡ−２２）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−２２）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:
Bicyclo [2.2.1] heptane represented by formula (KA-8) (hereinafter sometimes referred to as “norbornane”) (C ₇ ),
Adamantane (C ₁₀ ) represented by formula (KA-9), alicyclic hydrocarbon (C ₁₀ ) represented by formula (KA- ₁₀ ), alicyclic hydrocarbon represented by formula (KA-11) (C ₁₄ ), an alicyclic hydrocarbon (C ₁₇ ) represented by the formula (KA-12), an alicyclic hydrocarbon (C ₁₀ ) represented by the formula (KA-13), and a formula (KA-14). Alicyclic hydrocarbon (C ₁₁ ), alicyclic hydrocarbon (C ₁₅ ) represented by formula (KA- ₁₅ ), alicyclic hydrocarbon (C ₁₂ ) represented by formula (KA-16), formula ( alicyclic hydrocarbon represented by _{KA-17) (C 14)} , alicyclic hydrocarbon (C ₁₅ represented by the formula (KA-18)), an alicyclic hydrocarbon represented by formula (KA-19) (C _17), alicyclic hydrocarbon represented by the formula _{(KA-20) (C 9} ), alicyclic hydrocarbons represented by the formula _{(KA-21) (C 8} ) and formula (KA And alicyclic hydrocarbons (C ₁₀₎ represented by 22) and the like.

In addition, the alicyclic hydrocarbon shown here may be called "the alicyclic hydrocarbon of a formula (KA-1)-a formula (KA-22)."
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-22).

In the present specification, the aromatic hydrocarbon group is a monovalent aromatic hydrocarbon group, typically an aryl group. Specific examples include a phenyl group (C ₆ ), a naphthyl group (C ₁₀ ), an anthryl group (C ₁₄ ), a biphenyl group (C ₁₂ ), a phenanthryl group (C ₁₄ ), and a fluorenyl group (C ₁₃ ). .

  The aliphatic hydrocarbon group may have a substituent. Representative 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 ). The alkoxy group may be linear or branched.
Examples of the acyl group include acetyl group (C ₂ ), propionyl group (C ₃ ), butyryl group (C ₄ ), valeryl group (C ₅ ), hexanoyl group (C ₆ ), heptanoyl group (C ₇ ), octanoyl group ( C _8), decanoyl group (C ₁₀₎ and dodecanoyl groups (C ₁₂₎ which is an alkyl group and a carbonyl group, such as bonded, which aryl group and a carbonyl group such as benzoyl group (C ₇₎ is bonded Is mentioned. Among the 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.

<Resin (A)>
The resin (A) has the structural unit (I). The present resist composition containing such a resin (A) exhibits an effect that a resist pattern having excellent line edge roughness (hereinafter abbreviated as “LER” in some cases) can be produced.

The aliphatic hydrocarbon group for R ¹ and R ² is typically an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group include those already exemplified in the range of 1 to 6 carbon atoms.
The structural unit (I) in which R ¹ and R ² are bonded to each other and forms a ring with the carbon atom to which they are bonded is also a resist composition containing a resin having the structural unit (I). This is preferable in that an excellent LER resist pattern can be produced.
The ring formed by combining R ¹ and R ² with each other is preferably the above-described alicyclic hydrocarbon group, more preferably a saturated alicyclic hydrocarbon group, among which a cycloheptane ring, A cyclohexane ring and an adamantane ring are preferable, and a cyclohexane ring is more preferable.

The halogen atom of R ³ includes those already exemplified. Of the “alkyl group having 1 to 6 carbon atoms which may have a halogen atom”, the alkyl group is as described for R ^{1 and the} like. A group in which some or all of the hydrogen atoms contained in the alkyl group are substituted with halogen atoms corresponds to a C 1-6 alkyl group having a halogen atom. Among the alkyl groups having a halogen atom, an alkyl group having a fluorine atom is preferable, and a perfluoroalkyl group in which all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms is more preferable. Examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Can be mentioned.

T ¹ represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms or a group represented by the formula (a-1) (hereinafter sometimes referred to as “group (a-1)”). . The aliphatic saturated hydrocarbon group is typically an alkanediyl group or an alicyclic hydrocarbon group, or a combination thereof. The alkanediyl group and the alicyclic hydrocarbon group include those already exemplified in the range of 17 or less carbon atoms. Each of the alkanediyl group and the alicyclic hydrocarbon group can be selected so that the aliphatic hydrocarbon group which is a combination of the alkanediyl group and the alicyclic hydrocarbon group has 17 or less carbon atoms.

The group (a-1) includes an atom or an atomic group such as an oxygen atom, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group, as in X ¹⁰ and X ¹¹ . Here, a specific example is shown about group (a-1).

などが挙げられる（＊は結合手を表す）。 As the group (a-1) having an oxygen atom,

(* Represents a bond).

などが挙げられる（＊は結合手を表す）。 As the group (a-1) having a carbonyl group,

(* Represents a bond).

などが挙げられる（＊は結合手を表す）。 As the group (a-1) having a carbonyloxy group,

(* Represents a bond).

などが挙げられる（＊は結合手を表す）。 As the group (a-1) having an oxycarbonyl group,

(* Represents a bond).

［Ｔ¹¹は、炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。］
Ｔ¹¹は、−ＣＨ_２−、−（ＣＨ_２）_２−、−（ＣＨ_２）_４−、−（ＣＨ_２）_８−、−（ＣＨ_２）_１２−などである。 Specific examples of the group (a-1) have been described above. In view of the ease of production of the compound that derives the structural unit (I) (the description of the compound will be described later), a group containing a carbonyl group (A-1) is preferable, and the group (a-1) containing this carbonyl group is represented by the following formula (T1-A). Note that * is a bond.

[T ¹¹ represents a C 1-16 divalent aliphatic saturated hydrocarbon group. ]
T ¹¹ is —CH ₂ —, — (CH ₂ ) ₂ —, — (CH ₂ ) ₄ —, — (CH ₂ ) ₈ —, — (CH ₂ ) ₁₂ — and the like.

以上の式（Ｉ−１）〜式（Ｉ−８）のいずれかで表される構造単位（Ｉ）の具体例において、以下に示す部分構造Ａを、以下に示す部分構造Ｍに置き換えたものも構造単位（Ｉ）の具体例として挙げることができる。

Here, specific examples of the structural unit (I) are given.

In the specific example of the structural unit (I) represented by any of the above formulas (I-1) to (I-8), the partial structure A shown below is replaced with the partial structure M shown below. Can also be mentioned as specific examples of the structural unit (I).

  Among the specific examples of the structural unit (I), any one of the formula (I-1), the formula (I-2), the formula (I-5), the formula (I-6), and the formula (I-8) The structural unit (I) represented by the formula (I-2), the formula (I-6) and the formula (I-8) is more preferred.

（式（Ｉａ）中の符号はいずれも、上記と同じ意味を表す。） The structural unit (I) is derived from a compound represented by the following formula (Ia) (hereinafter sometimes referred to as “compound (Ia)”).

(All symbols in formula (Ia) have the same meaning as described above.)

（式（Ｉｂ）中の符号はいずれも、上記と同じ意味を表す。） Compound (Ia) can be easily produced by referring to the method described in Patent Document 1.
First, from the corresponding carbonyl group-containing compound (R ¹ —CO—R ² ) and glycerin by the method described in Patent Document 1, a compound represented by the following formula (Ib) (hereinafter, “compound (Ib ) ").

(All symbols in formula (Ib) have the same meaning as described above.)

式（Ｉｃ）で表される化合物（以下、場合により「化合物（Ｉｃ）」という。）において、Ｒ^３は前記と同義であり、Ｘはメチル基やエチル基などの低級アルコキシ基である。化合物（Ｉｃ）は所望のＲ^３の種類に応じ、公知の製造方法により製造したり、市場から容易に入手できる市販品を選択したりすれば、容易に入手できる。該市販品としては、（メタ）アクリル酸メチルや（メタ）アクリル酸エチルなどがある。かかる反応は溶媒の存在下又は不在下、適当なエステル交換触媒を用いることで容易に進行する。該エステル交換触媒としては、遷移金属化合物及びアルカリ（土類）金属アルコラートなどが挙げられる。また、かかる反応は適当な重合禁止剤の存在下で行うことが望ましい。この反応条件の詳細は、前記特許文献１に記載されている。 The production of compound (Ia) when m is 0 is represented by the following reaction formula.

In the compound represented by the formula (Ic) (hereinafter sometimes referred to as “compound (Ic)”), R ³ is as defined above, and X is a lower alkoxy group such as a methyl group or an ethyl group. Compound (Ic) can be easily obtained by producing it by a known production method or selecting a commercially available product that can be easily obtained from the market according to the desired type of R ³ . Examples of the commercially available products include methyl (meth) acrylate and ethyl (meth) acrylate. Such a reaction proceeds easily by using an appropriate transesterification catalyst in the presence or absence of a solvent. Examples of the transesterification catalyst include transition metal compounds and alkali (earth) metal alcoholates. Further, such a reaction is desirably performed in the presence of a suitable polymerization inhibitor. Details of the reaction conditions are described in Patent Document 1.

式（Ｉｄ）で表される化合物（以下、場合により「化合物（Ｉｄ）」という。）のＸは化合物（Ｉｃ）の場合と同じであり、かかる化合物（Ｉｄ）は公知の方法により製造することができる。また、化合物（Ｉｄ）と化合物（Ｉｂ）とから、化合物（Ｉａ）を製造する際の反応条件は、化合物（Ｉｃ）と化合物（Ｉｂ）との反応と同じ条件が採用される。 On the other hand, when the compound (Ia) when m is 1 is exemplified by the case where T ¹ is a group represented by the preferred formula (TA-1), it is represented by the following reaction formula.

X of the compound represented by the formula (Id) (hereinafter sometimes referred to as “compound (Id)”) is the same as that of the compound (Ic), and the compound (Id) should be produced by a known method. Can do. The reaction conditions for producing compound (Ia) from compound (Id) and compound (Ib) are the same as those for the reaction between compound (Ic) and compound (Ib).

Specific examples of compound (Ia) are as follows.

  The content ratio of the structural unit (I) in the resin (A) is usually in the range of 10 to 95 mol%, preferably 15 to 90 mol%, based on the total structural units (100 mol%) of the resin (A). More preferably, it is the range of 20-85 mol%.

  The resin contained in the resist composition needs to function as a positive resist by the action of an acid from the acid generator contained in the resist composition. Such a resin is insoluble or hardly soluble in an aqueous alkali solution and has a characteristic that it can be dissolved in an aqueous alkaline solution by the action of an acid (hereinafter, sometimes referred to as “acid action characteristic”). Even if the resin (A) having the structural unit (I) has acid action characteristics, the resin (A) itself does not have acid action characteristics and has acid action characteristics separately from the resin (A). Resin may be contained in the resist composition, but if the resin (A) itself has acid action characteristics, the preparation of the resist composition becomes easier and production management of the resist composition is possible. Is also preferable.

The resin (A) having acid action characteristics has an acid labile group (hereinafter sometimes referred to as “acid labile group”). The structural unit (I) may also have an acid labile group depending on the type of T ¹ , but preferably a structural unit having an acid labile group is used as a resin separately from the structural unit (I). When (A) has, since manufacture of resin (A) itself becomes still easier, it is preferable.
An acid labile group refers to 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). Hereinafter, the structural unit containing the acid labile group is sometimes referred to as “structural unit (a1)”.

式（１）中、Ｒ^a1、Ｒ^a2及びＲ^a3は、それぞれ独立に、炭素数１〜８の脂肪族炭化水素基を表すか、Ｒ^a1及びＲ^a2が結合して、そ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。Ｒ^a1及びＲ^a2が結合して形成される環及び該脂肪族炭化水素基に含まれるメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよい。＊は結合手を表す。 <Acid labile group>
The acid labile group in the case where the hydrophilic group is a carboxy group is such that the hydrogen atom of the carboxy group is replaced with an organic residue, and the carbon atom of the organic residue bonded to —O— of the carboxy group is tertiary. Examples include groups that are carbon atoms. Among such acid labile groups, preferred acid labile groups are, for example, groups represented by the following formula (1) (hereinafter sometimes referred to as “acid labile groups (1)”).

In formula (1), R ^a1 , R ^a2 and R ^a3 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms, or R ^a1 and R ^a2 are bonded to each other, and the carbon to which they are bonded. A ring having 3 to 20 carbon atoms is formed together with the atoms. The ring formed by combining R ^a1 and R ^a2 and the methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group. * Represents a bond.

The aliphatic hydrocarbon group for R ^{a1 to} R ^a3 is preferably an alkyl group or an alicyclic hydrocarbon group. Examples of the alkyl group include those already exemplified in the range of 1 to 8 carbon atoms. The alicyclic hydrocarbon group also includes those already exemplified in the range of 8 or less carbon atoms.

The combination of R ^a1 and R ^a2 to form a ring means that the group represented by —C (R ^a1 ) (R ^a2 ) (R ^a3 ) is any of the groups shown below. The number of carbon atoms in such a ring is preferably in the range of 3-12.

As the acid labile group (1), a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are all alkyl groups, one of these alkyl groups is tert-butyl A 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are bonded to each other to form an adamantane ring together with the carbon atom to which they are bonded), and R ^a3 Is a group in which R ¹ is an alkyl group) and 1- (adamantan-1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group) ) And the like.

式（２）中、Ｒ^b1及びＲ^b2は、それぞれ独立に、水素原子又は炭素数１〜２０の炭化水素基を表し、Ｒ^b3は、炭素数１〜２０の炭化水素基を表すか、或いは、Ｒ^b2及びＲ^b3が結合して、それらが各々結合する炭素原子及び酸素原子とともに炭素数３〜２０の環を形成する。該炭化水素基がメチレン基を含む場合、そのメチレン基は、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよく、Ｒ^b2及びＲ^b3が結合して形成される環に含まれるメチレン基も、酸素原子、硫黄原子又はカルボニル基に置き換わっていてもよい。＊は結合手を表す。 On the other hand, examples of the acid labile group in the case where the hydrophilic group is a hydroxy group include those in which a hydrogen atom of the hydroxy group is replaced with an organic residue to become a group containing an acetal structure or a ketal structure. Among such acid labile groups, a preferred acid labile group is, for example, a group represented by the following formula (2) (hereinafter sometimes referred to as “acid labile group (2)”).

In formula (2), R ^b1 and R ^b2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ^b3 represents a hydrocarbon group having 1 to 20 carbon atoms, or , R ^b2 and R ^b3 are combined to form a ring having 3 to 20 carbon atoms together with the carbon atom and oxygen atom to which they are bonded. When the hydrocarbon group contains a methylene group, the methylene group may be replaced by an oxygen atom, a sulfur atom or a carbonyl group, and the methylene group contained in the ring formed by combining R ^b2 and R ^b3 is also , Oxygen atom, sulfur atom or carbonyl group may be substituted. * Represents a bond.

The hydrocarbon group of R ^{b1 to} R ^b3 may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and specific examples thereof include those already exemplified in the range having 20 or less carbon atoms. Of ^b1 and ^Rb2 , at least one is preferably a hydrogen atom.

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

The structural unit (a1) is preferably derived from a monomer having an acid labile group and a carbon-carbon double bond, more preferably a (meth) acrylic monomer having an acid labile group Is derived from
The structural unit (a1) preferably has an acid labile group (1) or an acid labile group (2), and may have both of these acid labile groups. More preferred is the structural unit (a1) having an acid labile group (1).

  Of the structural unit (a1) having an acid labile group (1), a group having an aliphatic ring structure having 5 to 20 carbon atoms is preferred. The resin (A) having a structural unit (a1) having a sterically bulky aliphatic ring structure is more favorable when a resist pattern is produced using the present resist composition containing the resin (A). A resist pattern can be manufactured with a high resolution.

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及び＊は上記と同じ意味を表す。）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。
ｎ１’は０〜５の整数を表す。 Among the structural units (a1) having an aliphatic labile acid labile group (1), the structural unit represented by the formula (a1-1) (hereinafter referred to as “structural unit (a1-1)” in some cases). ) And the structural unit represented by formula (a1-2) (hereinafter sometimes referred to as “structural unit (a1-2)”). Resin (A) which has an acid labile group may have these individually, and may have 2 or more types.

In 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). To express.
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 and * represent the same meaning as described 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.
n1 ′ represents an integer of 0 to 5.

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 represented by R ^a6 and R ^a7 , an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms is preferable. 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.
n1 ′ is preferably an integer of 0 to 3, more preferably 0 or 1.

Here, specific examples of the structural unit (a1-1) are given.

式（ａ１−１−１）〜式（ａ１−１−３８）のいずれかで表される構造単位（ａ１−１）の具体例において、上述の部分構造Ｍを部分構造Ａに置き換えたものも構造単位（ａ１−１）の具体例として挙げることができる。

In the specific example of the structural unit (a1-1) represented by any one of the formulas (a1-1-1) to (a1-1-38), the partial structure M described above may be replaced with the partial structure A. Specific examples of the structural unit (a1-1) can be given.

  As the structural unit (a1-1), a structural unit (a1-1) represented by any one of the formula (a1-1-1), the formula (a1-1-2) and the formula (a1-1-3) And those obtained by substituting the partial structure M of the structural unit (a1-1) with the partial structure A, and are preferably represented by the formula (a1-1-1), the formula (a1-1-2) and the formula (a1-1). -3) is more preferable, and the structural unit (a1-) represented by either the formula (a1-1-1) or the formula (a1-1-2) is more preferable. 1) is more preferable. In addition, the resin (A) having these preferred structural units (a1-1) is obtained by producing 2-methyladamantan-2-yl (meth) acrylate, 2-ethyladamantan-2-yl when producing the resin (A). Ir (meth) acrylate or 2-isopropyladamantan-2-yl (meth) acrylate or the like may be used as a raw material (monomer) for production. These monomers are described in, for example, Japanese Patent Application Laid-Open No. 2010-204646.

式（ａ１−２−１）〜式（ａ１−２−１２）のいずれかで表される構造単位（ａ１−２）の具体例において、構造単位（ａ１−１）の具体例と同様に、部分構造Ｍを部分構造Ａに置き換えたものも構造単位（ａ１−２）の具体例として挙げることができる。 Next, specific examples of the structural unit (a1-2) are shown.

In the specific example of the structural unit (a1-2) represented by any one of the formulas (a1-2-1) to (a1-2-12), as in the specific example of the structural unit (a1-1), What substituted the partial structure M by the partial structure A can also be mentioned as a specific example of a structural unit (a1-2).

  Among them, the structural unit (a1-2-1), the formula (a1-2-2), the formula (a1-2-4), and the formula (a1-2-5) represented by any one of the formulas (a1-2-1), (a1-2-2), (a1-2-5) 2) Alternatively, those in which the partial structure M of these structural units (a1-2) is replaced by the partial structure A are preferred, and any one of the formulas (a1-2-4) and (a1-2-4) Or a structural unit in which the partial structure M of the structural unit (a1-2) is replaced by the partial structure A is more preferable. In order to produce the resin (A) having such a structural unit (a1-2), 1-ethylcyclohexane-1-yl (meth) acrylate or the like may be used as a monomer.

When the resin (A) having the structural unit (a1-1) and / or the structural unit (a1-2) is produced, when the total structural unit of the resin (A) is 100 mol%, the structural unit (a1- 1) and / or the total content of the structural unit (a1-2) is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, still more preferably in the range of 20 to 85 mol%, The range of 25-60 mol% is more preferable.
In order to make the total content of the structural unit (a1-1) and / or the structural unit (a1-2) within such a range, when the resin (A) is produced, 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). Specifically, the amount of monomer used to derive the structural unit (a1-1) and the structural unit (a1-2) relative to the total monomer amount (100 mol%) to produce the resin (A) is: Each is preferably in the range of 10 to 95 mol%, more preferably in the range of 15 to 90 mol%, still more preferably in the range of 20 to 85 mol%, and in the range of 25 to 60 mol%. Even more preferred.

  When the structural unit (a1) includes a structural unit having an adamantane ring, particularly the structural unit (a1-1), the ratio of the structural unit (a1-1) to the total amount (100 mol%) of the structural unit (a1) Is preferably 15 mol% or more. 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 more favorable.

<Acid stable structural unit>
As the resin (A), in addition to the structural unit (a) and the structural unit (a1), the resin (A) has a structural unit having no acid labile group (hereinafter sometimes referred to as “acid-stable structural unit”). It is preferable.

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%.
The structural unit (I) of the resin (A) is determined as to whether the structural unit (I) corresponds to a structural unit having an acid labile group. The above-mentioned [structural unit (a1)] / [acid-stable structural unit] ratio may be obtained by including it in a1) or the acid-stable structural unit.

  As the acid stable structural unit, a structural unit having a hydroxy group or a lactone ring is preferable. 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.

<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 hydroxy group into the resin (A). On the other hand, 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 the acid stable structural unit (a2). It is preferable to introduce into the resin (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).

  As the acid stable structural unit (a2), an acid stable structural unit (a2-0) and an acid stable structural unit (a2-1) are preferable. In the following description, the monomer that derives the acid stable structural unit (a2) is referred to as “acid stable monomer (a2)”, and the monomer that derives the acid stable structural unit (a3) is referred to as “acid stable monomer (a3)”. That's it.

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。 <Acid stable structural unit (a2-1)>
Examples of the acid stable structural unit (a2-1) include a structural unit 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.

式（ａ２−１−１）〜式（ａ２−１−１７）のいずれかで表される酸安定構造単位（ａ２−１）の具体例において、構造単位（ａ１−１）の具体例と同様に、部分構造Ｍを部分構造Ａに置き換えたものも酸安定構造単位（ａ２−１）の具体例として挙げることができる。

In the specific example of the acid stable structural unit (a2-1) represented by any one of the formula (a2-1-1) to the formula (a2-1-17), the same as the specific example of the structural unit (a1-1) In addition, those in which the partial structure M is replaced with the partial structure A can also be given as specific examples of the acid stable structural unit (a2-1).

  Among the exemplified acid stable structural units (a2-1), those represented by formula (a2-1-1), formula (a2-1-2), formula (a2-1-13) and formula (a2-1-15) The acid-stable structural unit (a2-1) represented by any of these, and those in which the partial structure M of these acid-stable structural units (a2-1) is replaced by the partial structure A are preferred, and the formula (a2-1-1) ), An acid stable structural unit (a2-1) represented by any one of formula (a2-1-2), formula (a2-1-13) and formula (a2-1-15) is more preferred. Resin (A) which has these acid stable structural units (a2-1) is 3-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate or (meth) What is necessary is just to use acrylic acid 1- (3,5-dihydroxyadamantane-1-yloxycarbonyl) methyl etc. as a monomer for resin (A) manufacture.

  When the resin (A) has an acid stable structural unit (a2-1), the content ratio is preferably in the range of 3 to 45 mol% with respect to all the structural units (100 mol%) of the resin (A). The range of 5-40 mol% is more preferable, and the range of 5-35 mol% is 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。 <Acid stable structural unit (a2-0)>
Examples of the acid stable structural unit (a2) include those 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 and a halogen atom having 1 to 6 halogen atoms carbon atoms which may have a R ^a30 are the same as those exemplified in R ^a32 of formula (a1-4). Among these, R ^a30 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group and an ethyl group, and further preferably a methyl group.
As the alkyl group for R ^a31 , an alkyl group having 1 to 4 carbon atoms is preferable, an alkyl group having 1 or 2 carbon atoms is more preferable, and a methyl group is further preferable.
Examples of the alkoxy group for R ^a31 include those already exemplified. 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 further preferably a methoxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

ここに例示する具体例において、ベンゼン環に結合しているメチル基やエチル基を、Ｒ^a31として例示したその他の置換基に置き換えたものも、酸安定モノマー（ａ２−０）の具体例である。 Examples of the acid stable structural unit (a2-0) include a monomer for deriving the following acid stable structural unit (a2-0) (hereinafter sometimes referred to as “acid stable monomer (a2-0)”).

In the specific examples illustrated here, those in which the methyl group or ethyl group bonded to the benzene ring is replaced with other substituents exemplified as R ^a31 are also specific examples of the acid stable monomer (a2-0). .

  When the resin (A) is produced using such an acid stable monomer (a2-0), the phenolic hydroxy group in the acid stable monomer (a2-0) is protected with an appropriate protecting group. Monomers can also be used. For example, a phenolic hydroxy group protected with a protecting group capable of leaving with a base or an acid is deprotected by contact with the base or acid, so that the precursor structural unit of the acid stable structural unit (a2-0) By deprotecting, an acid stable structural unit (a2-0) is obtained. However, since the resin (A) has the structural unit (a1) having an acid labile group as described above, the precursor structural unit in which the phenolic hydroxy group is protected with an appropriate protecting group is deprotected. In this case, it is preferable to deprotect by contact with a base so that the acid labile group of the structural unit (a1) is not significantly impaired. As the protecting group to be deprotected by contact with a base, for example, an acetyl group, a benzoyl group and the like are preferable. Examples of the base include 4-dimethylaminopyridine and triethylamine.

  Among the examples of the acid stable monomer (a2-0), 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferable. Of course, when the resin (A) is produced using 4-hydroxystyrene or 4-hydroxy-α-methylstyrene, it is necessary to use those obtained by protecting the phenolic hydroxy group in these with a suitable protecting group. preferable.

  When the resin (A) has an acid stable structural unit (a2-0), the content is preferably in the range of 5 to 95 mol% with respect to all the structural units (100 mol%) of the resin (A). The range of 10-80 mol% is more preferable, and the range of 15-80 mol% is more preferable.

<Acid stable structural unit (a3)>
The lactone ring possessed by the acid stable structural unit (a3) may be monocyclic such as β-propiolactone ring, γ-butyrolactone ring and δ-valerolactone ring, 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 formula (a3-1) is sometimes referred to as “acid-stable structural unit (a3-1)”, and what is represented by formula (a3-2) is sometimes referred to as “acid”. It is referred to as “stable structural unit (a3-2)”, and the one represented by the formula (a3-3) is sometimes 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), examples of L ^{a4 to} L ^a6 include 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.

Examples of the acid stable structural unit (a3-1) having a γ-butyrolactone ring include the following.

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

式（ａ３−１−１）〜式（ａ３−１−１１）のいずれかで表される酸安定構造単位（ａ３−１）、式（ａ３−２−１）〜式（ａ３−２−１１）のいずれかで表される酸安定構造単位（ａ３−２）及び式（ａ３−３−１）〜式（ａ３−３−６）のいずれかで表される酸安定構造単位（ａ３−３）において、構造単位（ａ１−１）の具体例と同様に、部分構造Ｍを部分構造Ａに置き換えたものも、各々酸安定構造単位（ａ３−１）、酸安定構造単位（ａ３−２）及び酸安定構造単位（ａ３−３）の具体例として挙げることができる。また、この例示において、ラクトン環が有する置換基（Ｒ^a21〜Ｒ^a23）としてメチル基を有するものも例示したが、このメチル基を上述のような基に置き換えたものも、酸安定構造単位（ａ３）の具体例として挙げられる。 Examples of the acid stable structural unit (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring include the following.

The acid stable structural unit (a3-1) represented by any one of formula (a3-1-1) to formula (a3-1-11), formula (a3-2-1) to formula (a3-2-11) The acid stable structural unit (a3-2) represented by any one of the formula (a3-3-1) and the acid stable structural unit (a3-3) represented by any one of the formulas (a3-3-1) to (a3-3-6) ), In the same manner as in the specific examples of the structural unit (a1-1), those in which the partial structure M is replaced with the partial structure A are the acid stable structural unit (a3-1) and the acid stable structural unit (a3-2). And specific examples of the acid stable structural unit (a3-3). Moreover, in this illustration, those having a methyl group as an example of the substituent (R ^{a21 to} R ^a23 ) of the lactone ring are also exemplified, but those in which this methyl group is replaced with the above-described groups are also acid stable structural units ( Specific examples of a3) are mentioned.

Among the acid stable structural units (a3), α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, α- (meth) acryloyloxy-β, β-dimethyl-γ-butyrolactone, α -(Meth) acryloyloxy-α-methyl-γ-butyrolactone, β- (meth) acryloyloxy-α-methyl-γ-butyrolactone, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1 .0 ^3,7] nonane-2-yl, (meth) acrylic acid 2- tetrahydro-2-oxo-3-furyl, and (meth) acrylic acid (5-oxo-4-oxa-tricyclo [4.2.1 .0 ^3,7] nonane-2-yloxy) -2-oxoethyl acid derived from such stable structural unit (a3) is preferable.

The resin (A) has an acid stable structural unit (a3) selected from the group consisting of an acid stable structural unit (a3-1), an acid stable structural unit (a3-2), and an acid stable structural unit (a3-3). In this case, the total content is preferably in the range of 5 to 70 mol%, more preferably in the range of 10 to 65 mol%, and more preferably 10 to 60 mol, based on the total structural unit (100 mol%) of the resin (A). % Is more preferable, the range of 15 to 55 mol% is particularly preferable, and the range of 15 to 50 mol% is more preferable.
The content ratio of each of the acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit (a3-3) is the total structural unit (100 mol%) of the resin (A). Is preferably in the range of 5-70 mol%, more preferably in the range of 10-65 mol%, still more preferably in the range of 10-60 mol%, particularly preferably in the range of 15-55 mol%. A range of mol% is more preferred.

<Other structural units>
The resin (A) may have other than the above-described structural units as long as the object of the present invention is not significantly impaired.

<Method for producing resin (A)>
Resin (A) was obtained by copolymerizing compound (Ia) [monomer deriving structural unit (I)], monomer deriving structural unit (a1), more preferably a monomer deriving an acid stable structural unit. More preferably, the monomer for deriving the structural unit (a1-1) and / or the structural unit (a1-2), the acid stable structural unit (a2) and / or the acid stable structural unit (a3) are derived. Copolymerized with a monomer.
The resin (A) further preferably has a structural unit (a1-1) having an adamantyl group as the structural unit (a1). As the acid stable structural unit (a2), it is preferable to use a structural unit (a2-1) having a hydroxyadamantyl group. The acid stable structural unit (a3) includes at least an acid stable structural unit (a3-1) having a γ-butyrolactone ring and an acid stable structural unit (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring. It is preferable to have one. 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 (more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 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)>
The acid generator is classified into a nonionic type and an ionic type. The acid generator (B) contained in the resist composition may be a nonionic acid generator, an ionic acid generator, or a combination thereof. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates), sulfones (e.g. disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, or an iodonium salt). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

Examples of the acid generator (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712. The compound which generate | occur | produces an acid by the radiation as described in No. etc. can be used.
Moreover, what was manufactured by the well-known method can be utilized for an acid generator (B).

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、置換基を有していてもよい炭素数１〜１７の２価の脂肪族炭化水素基を表す。該脂肪族炭化水素基に含まれるメチレン基は、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メチレン基は、酸素原子、カルボニル基又はスルホニル基に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。 The acid generator (B) contained in the resist composition is preferably an acid generator represented by the following formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). In the following description, among the acid generators (B1), Z ⁺ having a positive charge is referred to as “organic cation”, and a negative charge obtained by removing the organic cation is referred to as “sulfonate anion”. There is.

In formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a C 1-17 divalent aliphatic hydrocarbon group which may have a substituent. The methylene group contained in the aliphatic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted aliphatic hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the aliphatic hydrocarbon group is replaced with an oxygen atom, a carbonyl group or a sulfonyl group. May be.
Z ⁺ represents an organic cation.

The perfluoroalkyl group of Q ¹ and Q ^{2 corresponds} to an alkyl group having 1 to 6 carbon atoms, in which all of the hydrogen atoms contained in the alkyl group are replaced with fluorine atoms, among the already exemplified alkyl groups. .
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-22). Group.

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価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２価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２価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２価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２価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２価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２価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。 Examples of the methylene group contained in the aliphatic hydrocarbon group in L ^b1 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) [Hereinafter expressed as Formula (b1-1) to Formula (b1-6). ] The group shown by either of these is mentioned. Incidentally, the formula (b1-1) ~ formula (b1-6) is coupled to the left and right have been described in accordance with the formula (B1), the left bond * is a ^{C (Q 1) (Q 2} ) The right hand * 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 a C 1-15 divalent aliphatic hydrocarbon group, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b3 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms, and the aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group.
L ^b4 represents a divalent 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 a divalent 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 a divalent 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 a divalent 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 a divalent 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.

L ^b1 is preferably a group represented by any one of formulas (b1-1) to (b1-4), and more preferably any one of formulas (b1-1) to (b1-3). It is a group represented.
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.

  Here, the specific example of group represented by either of preferable formula (b1-1)-a formula (b1-3) is given. The definition of * is as described above.

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.

The aliphatic hydrocarbon group for L ^b1 may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, and a glycidyloxy group. Can be mentioned. Specific examples of the aromatic hydrocarbon group, the aralkyl group, and the acyl group are as described above.

Y in Formula (B1) represents a C 1-18 aliphatic hydrocarbon group which may have a substituent. Among these, Y is preferably an alkyl group and an alicyclic hydrocarbon group, more preferably an alkyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and an alicyclic group having 3 to 12 carbon atoms. A hydrocarbon group of the formula is more preferred.
When the aliphatic hydrocarbon group for Y has a substituent, examples of the substituent include a halogen atom (excluding a fluorine atom), a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, and an alkyl group having 6 to 18 carbon atoms. An aromatic hydrocarbon group, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group or a group represented by — (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 contained in 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 by an oxygen atom, a sulfonyl group or a carbonyl group include, for example, a cyclic ether group (one or two of the methylene groups contained in 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 contained in an alicyclic hydrocarbon group are substituted with a carbonyl group), a sultone ring group (included in an alicyclic hydrocarbon group) Two adjacent methylene groups in the methylene group are groups in which an oxygen atom and a sulfonyl group are substituted, respectively, and a lactone ring group (two methylene groups adjacent to each other among methylene groups contained in the alicyclic hydrocarbon group, A group in which an oxygen atom and a carbonyl group are substituted, respectively).

A preferred group of the alicyclic hydrocarbon group of Y is an alicyclic group represented by any of the following formula (Y1), formula (Y2), formula (Y3), formula (Y4), and formula (Y5). Among them, an alicyclic hydrocarbon group represented by any one of the formula (Y1), the formula (Y2), the formula (Y3) and the formula (Y5) is more preferable, and the formula (Y1) Or the alicyclic hydrocarbon group represented by a formula (Y2) is still more preferable. In addition, the hydrogen atom contained in these alicyclic hydrocarbon groups may be substituted by the substituent.

Examples of the alicyclic hydrocarbon group having a substituent include the following.

  The alicyclic hydrocarbon group of Y is preferably a group having an adamantane ring as shown in the formulas (Y1) and (Y2), and when these have a substituent, the substituent is preferably a hydroxy group . That is, as the alicyclic hydrocarbon group having a substituent, a hydroxyadamantyl group is preferable.

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 (b1-1-9) ". The sulfonate anion represented by this can be mentioned. In the sulfonate anion represented by any one of formulas (b1-1-1) to (b1-1-9), L ^b1 is preferably a group represented by formula (b1-1). R ^b2 and R ^b3 are each independently the same as those exemplified as the substituent that the aliphatic hydrocarbon group of Y may have, and an aliphatic hydrocarbon group having 1 to 4 carbon atoms and A hydroxy group is preferred, and a methyl group and a hydroxy group are more preferred.

  Specific examples of the sulfonate anion represented by any one of the formulas (b1-1-1) to (b1-1-9) include sulfonate anions described in JP 2010-204646 A, for example. be able to.

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 any of the following formulas (b1-s-1) to (b1-s-9).

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

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

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

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

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

Examples of the organic cation (Z ⁺ ) in the acid generator (B1) include organic onium cations such as an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, an organic benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and more preferably, the following formula (b2-1), formula (b2-2), formula (b2-3) and formula (b2-4) [hereinafter, It describes like "Formula (b2-1)-Formula (b2-4)." ] Is an organic cation represented by any of the above.

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent a hydrocarbon group having 1 to 30 carbon atoms, and examples of the hydrocarbon group include an alkyl group having 1 to 30 carbon atoms and an alicyclic ring having 3 to 18 carbon atoms. A formula 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. The aromatic hydrocarbon group 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 are each independently an aliphatic hydrocarbon group, and when the aliphatic hydrocarbon group is an alkyl group, the carbon number thereof is preferably 1 to 12, When the group 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 each independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring). An alicyclic hydrocarbon ring may be formed, and the alicyclic hydrocarbon ring of these 3 to 12-membered rings (preferably 3- to 7-membered rings) is an aliphatic ring or the aliphatic ring A methylene group contained in a group ring is a ring in which an oxygen atom, a sulfur atom or a carbonyl group is replaced.

^{R b13, R b14, R b15} , R b16, R b17 and R ^b18 each independently represent a hydroxy group, an alkyl group or an alkoxy group having 1 to 12 carbon atoms having 1 to 12 carbon atoms.
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 may be the same or different. When s2 is 2 or more, The plurality of R ^b15 may be the same or different, and when t2 is 2 or more, the plurality of R ^b15 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.

^Examples of the alkyl group ^{represented by} R ^{b9 to} R ^b12 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 -An ethylhexyl group etc. are mentioned.
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-alkyladamantan-2-yl group, 1- (adamantane- 1-yl) alkane-1-yl group and isobornyl group.
^As the aromatic hydrocarbon group for R ^b12 , phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl group And a naphthyl group.
^Examples of the ^combination of the aromatic hydrocarbon group of R ^b12 and the alkyl group include an aralkyl group, specifically, a benzyl group and the like.
R ^b9 and R ^b10 may be bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring) containing a sulfur atom, and the methylene group contained in the ring is , Oxygen atom, sulfur atom or carbonyl group may be substituted.
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.
R ^b11 and R ^b12 may be bonded to each other to form a ^3- to 12-membered ring (preferably a ^4- to 7-membered ring) containing —CH—CO—, and are included in the ring. The methylene group may be replaced with an oxygen atom, a sulfur atom or a carbonyl group.
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 organic cation represented by the formulas (b2-1) to (b2-4) include those described in JP2010-204646A.

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。
該脂肪族炭化水素基としては、炭素数は１〜１２の脂肪族炭化水素基が好ましく、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い。該脂肪族炭化水素基は、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ことが好ましい。 Among the exemplified organic cations, the cation (b2-1) is preferable, and an organic cation represented by the following formula (b2-1-1) [hereinafter referred to as “cation (b2-1-1)” in some cases. ], 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 ^b19 , R ^b20 and R ^b21 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.
As this aliphatic hydrocarbon group, a C1-C12 aliphatic hydrocarbon group is preferable, and a C1-C12 alkyl group and a C4-C18 alicyclic hydrocarbon group are more preferable. The aliphatic hydrocarbon group includes, as a substituent, a halogen atom, a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or glycidyloxy. It may have a 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 preferably a group.

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

Moreover, as an organic cation, the following organic cations can also be mentioned as a suitable thing among the organic cations represented by Formula (b2-3).

  The acid generator (B1) is a combination of the above sulfonic acid anion and the above organic cation. These can be arbitrarily combined. The combinations are shown in Table 1. In Table 1, the sulfonate anion represented by the formula (b1-s-1) is represented as “(b1-s-1)” according to the formula number, and the formula (b2-c- The organic cation represented by 1) is represented as “(b2-c-1)” or the like according to the formula number.

  More preferred acid generator (B1) is specifically shown. Such an acid generator (B1) has the following formula (B1-1), formula (B1-2), formula (B1-3), formula (B1-4), formula (B1-5), formula (B) B1-6), formula (B1-7), formula (B1-8), formula (B1-9), formula (B1-10), formula (B1-11), formula (B1-12), formula (B1) −13), Formula (B1-14), Formula (B1-15), Formula (B1-16), and Formula (B1-17). Among them, the acid generator (B) is preferably a salt containing a triphenylsulfonium cation or a salt containing a tolylsulfonium cation, and the acid generator (B1) is preferably the acid generator (B1) or (B1-3). A salt represented by any of the formulas (B1-6), (B1-7), (B1-11), (B1-12), (B1-13) and (B1-14): Is more preferable. Further, as already described, Y is preferably an alicyclic hydrocarbon group which may have a substituent. Therefore, in this respect, formula (B1-2), formula (B1-3), formula (B1 −6), a salt represented by any one of formulas (B1-7) and (B1-11) is more preferable.

  The acid generator (B) may contain an acid generator different from the acid generator (B1). In this case, the content ratio of the acid generator (B1) in the total amount of the acid generator (B) is preferably 70% by mass or more, and more preferably 90% by mass or more. However, the acid generator (B) in the resist composition is more preferably substantially only the acid generator (B1).

<Basic compound (C)>
The resist composition preferably contains a basic compound (C). As mentioned above, the basic compound (C) is called a quencher in this technical field.

［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。］ The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and basic ammonium salts. As the amine, either an aliphatic amine or an aromatic amine may be used. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to a compound represented by the formula (C8), more preferably a compound represented by the formula (C1-1). It is done.

[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、上記と同じ意味を表す。
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いてもよい。］

[In the formula (C1-1),
R ^c2 and R ^c3 represent the same meaning as described 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と同じ意味を表す。
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は同一でも異なっていてもよい。］
アルカノイル基としては、アセチル基、２−メチルアセチル基、２，２−ジメチルアセチル基、プロピオニル基、ブチリル基、イソブチリル基、ペンタノイル基、２，２−ジメチルプロピオニル基等が挙げられる。

[In Formula (C2), Formula (C3) and Formula (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as 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 or different. ]
Examples of the alkanoyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

［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と同じ意味を表す。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
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は同一でも異なっていてもよく、ｐ３が２以上であるとき、複数のＲ^c15は同一でも異なっていてもよい。
Ｌ^c1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 (C5) and Formula (C6),
R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3. When o3 is 2 or more, the plurality of R ^c14 may be the same or different. When p3 is 2 or more, the plurality of R ^c15 is It may be the same or different.
L ^c1 represents an alkanediyl 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と同じ意味を表す。
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は同一でも異なっていてもよく、ｒ３が２以上であるとき、複数のＲ^c19は同一でも異なっていてもよく、ｓ３が２以上であるとき、複数のＲ^c20は同一でも異なっていてもよい。
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 represent 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, a plurality of R ^c18 may be the same or different. When r3 is 2 or more, a plurality of Rc18 ^c19 may be the same or different, and when s3 is 2 or more, a plurality of ^Rc20 may be the same or different.
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- And diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and the like. Diisopropylaniline are preferred, 2,6-diisopropylaniline are especially preferable.

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, 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, tetra-n-butylammonium salicylate, and choline.

<Solvent (D)>
The solvent (D) contained in the resist composition is used in the production of a resist pattern, which will be described later, according to the type and amount of the resin (A) used and the type and amount of the acid generator (B). From the viewpoint of good coating properties when the resist composition is applied onto the substrate, an optimal one can be selected as appropriate.

  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 and it may use 2 or more types together.

<Other ingredients>
This resist composition may contain components other than the resin (A) and the acid generator (B), the solvent (D) used as necessary, and the basic compound (C) as necessary. Good. This component is sometimes referred to as “component (F)”. Such component (F) is not particularly limited, and includes additives known in the art, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes.

<Preparation of the present resist composition>
This resist composition can be prepared by mixing the resin (A), the acid generator (B), and the basic compound (C), the solvent (D) and the component (F) used as necessary. it can. 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, the solubility with respect to solvent (E), such as resin. What is necessary is just to select mixing time according to mixing temperature, and 0.5 to 24 hours are preferable. The mixing means is not particularly limited, and stirring and mixing can be used.
Thus, after mixing each component, it is preferable to filter using a filter with a pore diameter of about 0.01 to 0.2 μm.

  The content of the resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less with respect to the total mass of the solid content of the resist composition. “Solid content” means the total of components excluding the solvent (D) from the resist composition of the present invention. When content of a solvent (D) is 90 mass%, content of solid content with respect to the resist composition total mass of this invention corresponds to 10 mass%.

  The content of the acid generator (B) in the resist composition is preferably 1 part by mass or more, more preferably 3 parts by mass or more, preferably 100 parts by mass of the total mass of the resin (A). Is 30 parts by mass or less, more preferably 25 parts by mass or less.

  When the basic compound (C) is used in the resist composition, the content is preferably about 0.01 to 1% by mass with respect to the total mass of the solid content of the resist composition.

When the solvent (D) is used in the resist composition, the content can be appropriately adjusted according to the type of the resin (A). The content of the solvent (D) is preferably 90% by mass or more, more preferably 92% by mass or more, still more preferably 94% by mass or more, and preferably 99% by mass with respect to the total mass of the resist composition. It is at most 9 mass%, more preferably at most 99.9 mass%.
When the resist composition contains the solvent (D) at such a content, a thin composition layer having a thickness of about 30 to 300 nm can be formed in the resist pattern manufacturing method described later.

  The content of each of the resin (A), the acid generator (B), the solvent (D), and the basic compound (C) can be controlled by the amount used in preparing the resist composition. After preparing the product, the resist composition of the present invention can be obtained by using a known analysis means such as gas chromatography or liquid chromatography.

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

<Method for producing resist pattern>
The method for producing a resist pattern using the present resist composition is a method for producing a positive resist pattern. Specifically,
(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 heated composition layer using a developing device. 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. In this way, 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 may be washed or an antireflection film may 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 step (2), the resist composition applied on the substrate, that is, the coating film is dried to remove the solvent [solvent (D)]. Such drying is performed by, for example, heating means (so-called pre-baking) using a heating device such as a hot plate, decompression means using a decompression device, or a combination of these means from the coating film to the solvent (D). Is performed by evaporating. The drying conditions can be selected according to the type of the solvent (D) contained in the resist composition. For example, in the case of a hot plate, the surface temperature of the hot plate should be in the range of about 50 to 200 ° C. preferable. 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. By drying the coating film in this manner, 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 (photomask) on which a desired pattern to be finely processed is formed. As an exposure light source of the exposure machine, an ultraviolet light source such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excimer laser (wavelength 157 nm), or a solid-state laser light source (YAG In addition, various lasers such as those that emit laser light from a far ultraviolet region or a vacuum ultraviolet region by converting the wavelength of laser light from a semiconductor laser or the like can be used. The exposure machine may be an immersion exposure machine. Further, the exposure machine may irradiate an electron beam or extreme ultraviolet light (EUV).
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 contained in the composition layer receives exposure energy to generate an acid, and the acid labile group in the resin (A) is deprotected by the action of the generated acid. As a result, a hydrophilic group is formed, and as a result, the resin (A) in the composition layer of the exposed portion becomes soluble in the 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 solubility with respect to aqueous alkali solution will differ significantly between the composition layer in an exposed part, and the composition layer in an unexposed part.

  In the step (4), a heat treatment (so-called post-exposure baking) for further promoting the progress of the deprotecting group reaction that may occur in the exposed portion is performed. Such heat treatment is preferably the heating means using the hot plate shown in the step (2). In addition, when performing hot plate heating in a process (4), about 50-200 degreeC is preferable and the surface temperature of this hot plate has more preferable about 70-150 degreeC.

Step (5) is a step of developing the heated composition layer, and preferably a step of developing the heated composition layer using a developing device. In the step of developing, when the heated composition layer is brought into contact with an alkaline aqueous solution, the exposed composition layer is dissolved and removed in the alkaline aqueous solution, and the unexposed composition layer remains on the substrate. A resist pattern is manufactured on the substrate.
As the alkaline aqueous solution, those known in this technical field called “alkaline developer” 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).

  After development, the manufactured resist pattern is preferably rinsed with ultrapure water or the like, and water remaining on the substrate and the resist pattern is preferably removed.

  According to the resist pattern manufacturing method including the steps (1) to (5) as described above, the resist composition can manufacture an excellent LER resist pattern.

<Application>
This resist composition is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) irradiation, or a resist composition for an EUV exposure machine. .

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, three columns are “TSKgel Multipore HXL-M”, and the solvent is tetrahydrofuran) 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)
The ratio of the structural units in the resin (copolymerization ratio) is determined by quantifying the monomer remaining in the reaction liquid after resin production by high-performance liquid chromatography or gas chromatography, and for each monomer consumed in resin production. Calculated by determining the amount.

The compounds (monomers) used in Examples and Comparative Examples are shown below. Hereinafter, these monomers are referred to as “monomer (a1-1-2)”, “monomer (I)”, etc., depending on the formula number. In addition, a monomer (I1) etc. can be manufactured by the method of patent document 1, for example.

Synthesis Example 1 [Synthesis of Resin A1]
As the monomer, the monomer (a1-1-2), the monomer (a1-2-3), the monomer (a2-1-1), the monomer (a3-1-1) and the monomer (I1) are used, and the molar ratio [ Monomer (a1-1-3): Monomer (a1-2-3): Monomer (a2-1-1): Monomer (a3-1-1): Monomer (I1)] is 32: 7: 8: 48: The mixture was mixed so that the total monomer amount was 1.5 mass times of dioxane to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.5. × 10 ³ of the resin A1 (copolymer) was obtained in 68% yield. This resin A1 has the following structural units. The copolymerization ratio of each structural unit is as follows: structural unit (a1-1-2): structural unit (a1-2-3): structural unit (a2-1-1): structural unit (a3-1-1): structure Unit (I1) = 23.7: 8.2: 9.4: 52.6: 6.1 [Note that “structural unit (a1-1-2)” here is monomer (a1- 1-2), which is hereinafter referred to as the type of structural unit according to the monomer formula number].

Synthesis Example 2 [Synthesis of Resin A2]
As the monomer, monomer (a1-1-2), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-2-3), monomer (a3-1-1) and monomer ( I1) and its molar ratio (monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (a3-1) -1): The monomer (I1)) was mixed so as to be 32: 7: 8: 13: 33: 7, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.6. × 10 ³ of the resin A2 (copolymer) was obtained in a yield of 65%. This resin A2 has the following structural units. The copolymerization ratio of each structural unit is as follows: structural unit (a1-1-3): structural unit (a1-2-3): structural unit (a2-1-1): structural unit (a3-2-3): structure Unit (a3-1-1): Structural unit (I1) = 23.8: 8.1: 9.1: 14.2: 37.2: 7.6.

Synthesis Example 3 [Synthesis of Resin A3]
As the monomer, monomer (a1-1-2), monomer (a2-1-1), monomer (a3-1-1) and monomer (I1) are used, and the molar ratio (monomer (a1-1-3): Monomer (a2-1-1): monomer (a3-1-1): monomer (I1)) is mixed so as to be 40: 10: 45: 5, and 1.5 mass times of the total amount of dioxane is added. In addition, a solution was obtained. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.2. × 10 ³ of the resin A3 (copolymer) was obtained in 68% yield. This resin A3 has the following structural units. The copolymerization ratio of each structural unit was as follows: structural unit (a1-1-2): structural unit (a2-1-1): structural unit (a3-1-1): structural unit (I1) = 29.7: 11 2: 53.1: 6.0.

Synthesis Example 4 [Synthesis of Resin A4]
As the monomer, monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1) were used, and the molar ratio (monomer (a1-1-2): monomer (a2-1) -1): The monomer (a3-1-1)) was mixed so as to be 50:25:25, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 80 ° C. for about 8 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 9.2. A × 10 ³ resin A4 (copolymer) was obtained in a yield of 60%. This resin A4 has the following structural units. The copolymerization ratio of each structural unit was as follows: structural unit (a1-1-2): structural unit (a2-1-1): structural unit (a3-1-1) = 42.6: 28.7: 28.7 Met.

Synthesis Example 5 [Synthesis of Resin A5]
As the monomer, monomer (a1-1-2), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-2-3), monomer (a3-1-1) and monomer ( The molar ratio (monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (a3-1) -1): The monomer (I2)) was mixed so as to be 32: 7: 8: 13: 33: 7, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, and this resin was filtered twice. The weight average molecular weight was 7.7. × give 10 ^third resin A5 (copolymer) in 72% yield. This resin A5 has the following structural units. The copolymerization ratio of each structural unit is as follows: structural unit (a1-1-3): structural unit (a1-2-3): structural unit (a2-1-1): structural unit (a3-2-3): structure Unit (a3-1-1): Structural unit (I2) = 23.9: 8.0: 9.1: 14.3: 37.4: 7.3.

Synthesis Example 6 [Synthesis of Resin A6]
As the monomer, monomer (a1-1-2), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-2-3), monomer (a3-1-1) and monomer ( The molar ratio (monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (a3-1) -1): The monomer (I3)) was mixed so as to be 32: 7: 8: 13: 33: 7, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.9. A × 10 ³ resin A6 (copolymer) was obtained in a yield of 70%. This resin A6 has the following structural units. The copolymerization ratio of each structural unit is as follows: structural unit (a1-1-3): structural unit (a1-2-3): structural unit (a2-1-1): structural unit (a3-2-3): structure Unit (a3-1-1): Structural unit (I3) = 23.6: 8.0: 9.0: 14.2: 37.3: 7.9.

Synthesis Example 7 [Synthesis of Resin A7]
As the monomer, monomer (a1-1-2), monomer (a1-2-3), monomer (a2-1-1), monomer (a3-2-3), monomer (a3-1-1) and monomer ( The molar ratio (monomer (a1-1-3): monomer (a1-2-3): monomer (a2-1-1): monomer (a3-2-3): monomer (a3-1) -1): The monomer (I4)) was mixed so as to be 32: 7: 8: 13: 33: 7, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.5. × 10 ³ of the resin A7 (copolymer) was obtained in 69% yield. This resin A7 has the following structural units. The copolymerization ratio of each structural unit is as follows: structural unit (a1-1-3): structural unit (a1-2-3): structural unit (a2-1-1): structural unit (a3-2-3): structure Unit (a3-1-1): Structural unit (I4) = 23.9: 8.1: 9.1: 14.4: 37.6: 6.9.

Examples 1-7 and Comparative Example 1
<Preparation of resist composition>
Resins A1 to A7 obtained in Synthesis Examples 1 to 7;
Acid generators B1 to B2 shown below;
Basic compound C1 shown below;
Each was dissolved in the solvent shown below in parts by mass shown in Table 2, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

Ｂ２：

<Resin>
A1: Resin A1
A2: Resin A2
A3: Resin A3
A4: Resin A4
A5: Resin A5
A6: Resin A6
A7: Resin A7
<Acid generator>
B1:

B2:

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene glycol monomethyl ether acetate 265 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed.
Subsequently, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 85 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature described in the “PB” column of Table 2. Using the ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY deflection] on the wafer on which the resist composition film is formed in this manner, the exposure amount is stepwise. The line and space pattern was subjected to immersion exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking (PEB) was performed on the hot plate at the temperature described in the “PEB” column of Table 2 for 60 seconds.
Further, paddle development was performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution to obtain a resist pattern.
In each resist film, the exposure amount at which the 50 nm line and space pattern becomes an exposure amount of 1: 1 was defined as the effective sensitivity.

Line edge roughness evaluation (LER): The wall surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and the fluctuation width of the unevenness on the side wall of the resist pattern was determined.
The results are shown in Table 3.

  This resist composition is useful for fine processing of semiconductors.

Claims (6)

A positive resist composition comprising a resin having a structural unit represented by formula (I) and an acid generator.

[In the formula (I),
R ¹ and R ² each independently represent an aliphatic hydrocarbon group having 1 to 6 carbon atoms, or R ¹ and R ² are bonded to each other, and together with the carbon atom to which they are bonded, 5 to 20 carbon atoms. Form a ring.
R ³ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
T ¹ represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms or a group represented by the formula (a-1).

(In the formula (a-1),
s represents an integer of 0 or 1.
X ¹⁰ and X ¹¹ each independently represent an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ¹⁰ , A ¹¹ and A ¹² each independently represents an aliphatic hydrocarbon group which may have a substituent, and the total number of carbon atoms of X ¹⁰ , X ¹¹ , A ¹⁰ , A ¹¹ and A ¹² Is 17 or less. )
m represents an integer of 0 or 1. ] The positive resist composition according to claim 1, wherein the resin has a structural unit in which R ¹ and R ^{2 in} the formula (I) are bonded to each other to form a cyclohexane ring.   3. The positive resist composition according to claim 1, wherein the resin is a resin that is insoluble or hardly soluble in an aqueous alkali solution and can be dissolved in an aqueous alkaline solution by the action of an acid.   The positive resist composition according to claim 1, further comprising a basic compound.   The positive resist composition according to claim 1, further comprising a solvent (D). (1) The process of apply | coating the positive resist composition in any one of Claims 1-5 on a board | 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 pattern forming method including a step of heating the composition layer after exposure, and (5) a step of developing the heated composition layer using a developing device.