JP5504819B2 - Chemically amplified photoresist composition - Google Patents

Description

  The present invention relates to a chemically amplified photoresist composition used for semiconductor microfabrication, and a pattern forming method using the chemically amplified photoresist composition.

また、樹脂として下記に示すモノマーＡ、モノマーＢ、モノマーＣ及びモノマーＤを、３５：１２：２３：３０のモル比で仕込み、重合させてなる樹脂１０部と、酸発生剤としてトリフェニルスルホニウム１−（（３−ヒドロキシアダマンチル）メトキシカルボニル）ジフルオロメタンスルホナート又は１−（２−オキソ−２−フェニルエチル）テトラヒドロチオフェニウム １−アダマンチルメトキシカルボニルジフルオロメタンスルホナート０．５部と、クエンチャーとして２，６−ジイソプロピルアニリン０．０６５部と、溶剤とからなる化学増幅型フォトレジスト組成物が提案されている（特許文献２）。

更に、樹脂として下記に示すモノマーＦ、モノマーＥ、モノマーＢ、モノマーＣ及びモノマーＤを、３４：８：８：３４：１６のモル比で仕込み、重合させてなる樹脂１０部と、酸発生剤としてトリフェニルスルホニウム ４−オキソ−１−アダマンチルオキシカルボニルジフルオロメタンスルホナート０．４部及び１−（２−オキソ−２−フェニルエチル）テトラヒドロチオフェニウム １−アダマンチルメトキシカルボニルジフルオロメタンスルホナート０．３部と、クエンチャーとして２，６−ジイソプロピルアニリン０．０６５部と、溶剤とからなる化学増幅型フォトレジスト組成物が提案されている（特許文献３）。

As a chemically amplified photoresist composition, for example, 10 parts of a resin prepared by polymerizing monomers A, B, and D shown below as a resin in a molar ratio of 50:25:25, and an acid generator Chemically amplified photoresist composition comprising 0.27 part of triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate, 0.0325 part of 2,6-diisopropylaniline as a quencher, and a solvent. The thing is proposed (patent document 1).

Further, 10 parts of a resin prepared by charging and polymerizing monomers A, B, C, and D shown below as a resin in a molar ratio of 35: 12: 23: 30, and triphenylsulfonium 1 as an acid generator -((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate or 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate 0.5 part, and as a quencher A chemically amplified photoresist composition comprising 0.065 parts of 2,6-diisopropylaniline and a solvent has been proposed (Patent Document 2).

Furthermore, 10 parts of resin prepared by polymerizing monomers F, monomer E, monomer B, monomer C and monomer D shown below as a resin in a molar ratio of 34: 8: 8: 34: 16, and an acid generator As 0.4 parts triphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate and 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate 0.3 A chemically amplified photoresist composition has been proposed that comprises a solvent, 0.065 parts of 2,6-diisopropylaniline as a quencher, and a solvent (Patent Document 3).

JP 2006-257078 A JP 2008-170983 A JP 2008-209917 A

  In the conventional chemical amplification type positive resist composition, there is a case where it is not always possible to form a pattern having good resolution, good line edge roughness, and good pattern collapse resistance.

［式（Ｉ）及び式（ＩＩ）中、Ｑ^１及びＱ²は、互いに独立に、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。
Ｘ^１及びＸ^２は、互いに独立に、単結合又は−［ＣＨ_２］_ｋ−を表し、該−［ＣＨ_２］_ｋ−に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
ｋは、１〜８の整数を表す。
Ｙ^１は、炭素数３〜３６の飽和環状炭化水素基を表し、該飽和環状炭化水素基に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基又は炭素数６〜１２のアリール基で置換されていてもよく、該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
Ｙ^２は、Ｙ^１と同じ骨格の飽和環状炭化水素基を表し、該飽和環状炭化水素基に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基又は炭素数６〜１２のアリール基で置換されていてもよく、該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
Ｚ^＋は、式（ＩＸａ）又は式（ＩＸｂ）で表されるカチオンを表す。］

［式（ＩＸａ）中、Ｐ^１〜Ｐ^３は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表す。］

［式（ＩＸｂ）中、Ｐ^１０〜Ｐ^２１は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表す。
Ｂ^１は、−Ｓ−又は−Ｏ−を表す。
ｍは、０又は１を表す。］ The present invention includes the following inventions.
1. Containing an acid generator represented by formula (I) and a resin comprising a structural unit represented by formula (II),
The content of the acid generator represented by the formula (I) is 45 to 100% by weight with respect to the total amount of the acid generator,
The content of the structural unit represented by the formula (II) in the resin is 35 to 70 mol% with respect to the total structural unit of the resin,
The content of the structural unit having a saturated cyclic hydrocarbon group in the resin is 50 to 70 mol% with respect to the total structural unit of the resin,
A chemically amplified photoresist composition, wherein the resin is a resin having four or more different structural units.

[In Formula (I) and Formula (II), Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
X ¹ and X ² each independently represent a single bond or — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — is replaced with —CO— or —O—. It may be.
k represents an integer of 1 to 8.
Y ¹ represents a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Y ² represents a saturated cyclic hydrocarbon group having the same skeleton as Y ^1, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Z ⁺ represents a cation represented by the formula (IXa) or the formula (IXb). ]

[In Formula (IXa), P ^{1 to} P ³ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ]

[In Formula (IXb), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
B ¹ represents -S- or -O-.
m represents 0 or 1. ]

2. Y ¹ represents an adamantyl group or a cyclohexyl group, and a hydrogen atom contained in the adamantyl group and the cyclohexyl group may be substituted with a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The composition according to claim 1, wherein —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced by —CO— or —O—.

3. The resin containing the structural unit represented by the formula (II) is a resin having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution and capable of dissolving in an alkaline aqueous solution by acting with an acid. 3. The composition according to item 2 or 2.

4). Item 4. The composition according to any one of Items 1 to 3, comprising another resin different from the resin including the structural unit represented by Formula (II).

5. The composition according to any one of Items 1 to 4, wherein the content of the acid generator is 1 to 20 parts by mass with respect to 100 parts by mass of the resin including the structural unit represented by the formula (II).

6). 6. A pattern forming method including a step of applying the composition according to any one of 1 to 5 on a substrate to form a resist film, a step of exposing the resist film, and a step of developing the resist film after exposure.

  According to the chemically amplified photoresist composition of the present invention, a pattern having good resolution, good line edge roughness, and good pattern collapse resistance can be formed.

［式（Ｉ）及び式（ＩＩ）中、Ｑ^１及びＱ²は、互いに独立に、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。
Ｘ^１及びＸ^２は、互いに独立に、単結合又は−［ＣＨ_２］_ｋ−を表し、該−［ＣＨ_２］_ｋ−に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
ｋは、１〜８の整数を表す。
Ｙ^１は、炭素数３〜３６の飽和環状炭化水素基を表し、該飽和環状炭化水素基に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基又は炭素数６〜１２のアリール基で置換されていてもよく、該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
Ｙ^２は、Ｙ^１と同じ骨格の飽和環状炭化水素基を表し、該飽和環状炭化水素基に含まれる水素原子は、水酸基、炭素数１〜１２のアルキル基又は炭素数６〜１２のアリール基で置換されていてもよく、該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−ＣＯ−又は−Ｏ−で置き換わっていてもよい。
Ｚ^＋は、式（ＩＸａ）又は式（ＩＸｂ）で表されるカチオンを表す。］

［式（ＩＸａ）中、Ｐ^１〜Ｐ^３は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表す。］

［式（ＩＸｂ）中、Ｐ^１０〜Ｐ^２１は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表す。
Ｂ^１は、−Ｓ−又は−Ｏ−を表す。
ｍは、０又は１を表す。］ The chemically amplified photoresist composition of the present invention (hereinafter sometimes referred to as “resist composition”) comprises a resin comprising an acid generator represented by formula (I) and a structural unit represented by formula (II). And the content of the acid generator represented by the formula (I) is 45 to 100% by weight based on the total amount of the acid generator, and the resin contains the structural unit represented by the formula (II) The amount is 35 to 70 mol% with respect to the total structural unit of the resin, and the content of the structural unit having a saturated cyclic hydrocarbon group in the resin is 50 to 70 mol% with respect to the total structural unit of the resin. Yes, the resin is a resin having four or more different structural units.

[In Formula (I) and Formula (II), Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
X ¹ and X ² each independently represent a single bond or — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — is replaced with —CO— or —O—. It may be.
k represents an integer of 1 to 8.
Y ¹ represents a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Y ² represents a saturated cyclic hydrocarbon group having the same skeleton as Y ^1, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Z ⁺ represents a cation represented by the formula (IXa) or the formula (IXb). ]

[In Formula (IXa), P ^{1 to} P ³ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ]

[In Formula (IXb), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
B ¹ represents -S- or -O-.
m represents 0 or 1. ]

Y ¹ preferably represents an adamantyl group or a cyclohexyl group, and a hydrogen atom contained in the adamantyl group and the cyclohexyl group is substituted with a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Alternatively, —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced by —CO— or —O—.

  Examples of the anion moiety of the acid generator represented by the formula (I) (hereinafter sometimes referred to as “acid generator (A)”) include, for example, the following formula (IA), formula (IB), and formula (IC): And an anion represented by the formula (ID).

[In formula (IA), formula (IB), formula (IC) and formula (ID), Q ¹ , Q ² and Y ¹ represent the same as those in formula (I).
X ¹¹ represents an alkylene group having 1 to 15 carbon atoms.
X ¹² represents an alkylene group having 1 to 16 carbon atoms. ]

Furthermore, Y ¹ is an anion having an alkyl group having 1 to 12 carbon atoms as a substituent, Y ¹ is an anion having a hydroxyl group as a substituent (excluding those having a lactone structure), and Y ¹ is an anion having a lactone structure. Part, Y ¹ is an anion part having a ketone structure, Y ¹ is an anion part having an aryl group having 6 to 12 carbon atoms as a substituent.

  Examples of the anion moiety represented by the formula (IA) include the followings.

In the formula (IA), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent in formula (IA) include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (IA) include the following.

Specific examples of the anion moiety in which Y ¹ has a ketone structure in formula (IA) include the following.

  In the formula (IA), specific examples of the anion moiety having an aryl group having 6 to 12 carbon atoms as a substituent include the following.

  Examples of the anion moiety represented by the formula (IB) include the following.

In the formula (IB), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent in formula (IB) include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (IB) include the following.

Specific examples of the anion moiety in which Y ¹ has a ketone structure in formula (IB) include the following.

In the formula (IB), specific examples of the anion moiety in which Y ¹ has an aryl group having 6 to 12 carbon atoms as a substituent include the following.

  Specific examples of the anion moiety represented by the formula (IC) include the following.

In the formula (IC), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent in formula (IC) include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (IC) include the following.

Specific examples of the anion moiety in which Y ¹ has a ketone structure in formula (IC) include the following.

In the formula (IC), specific examples of the anion moiety in which Y ¹ has an aryl group having 6 to 12 carbon atoms as a substituent include the following.

  As an anion part represented by a formula (ID), the following are mentioned, for example.

In the formula (ID), specific examples of the anion moiety in which Y ¹ has an alkyl group having 1 to 12 carbon atoms as a substituent include the following.

In the formula (ID), specific examples of the anion moiety in which Y ¹ has a hydroxyl group as a substituent include the following.

Specific examples of the anion moiety in which Y ¹ has a lactone structure in formula (ID) include the following.

In the formula (ID), specific examples of the anion moiety in which Y ¹ has an aryl group having 6 to 12 carbon atoms as a substituent include the following.

Z ⁺ in formula (I) is a cation represented by formula (IXa) or formula (IXb).

[In Formula (IXa), P ^{1 to} P ³ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ]

[In Formula (IXb), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
B ¹ represents -S- or -O-.
m represents 0 or 1. ]

Examples of the alkyl group having 1 to 12 carbon atoms 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, 2 -An ethylhexyl group etc. are mentioned.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group and the like.

  Specific examples of the cation represented by the formula (IXa) include the followings.

  Specific examples of the cation represented by the formula (IXb) include the followings.

  Said anions and cations can be combined.

When such an acid generator (A) is used, it may be used alone or a plurality of types may be used simultaneously. Moreover, you may use together acid generators other than an acid generator (A).
Examples of the acid generator represented by formula (I) used in the present invention include formula (Xa), formula (Xb), formula (Xc), formula (Xd), formula (Xe), formula (Xf), Formula (Xg), Formula (Xh), Formula (Xi), Formula (Xj), Formula (Xk), or Formula (Xl), Formula (Xm), Formula (Xn), Formula (Xo), or the like An acid generator is preferably mentioned.

[In formulas (Xa) to (Xi), P ^{1 to} P ³ represent the same meaning as in formula (IXa).
P ^{10 to} P ²¹ and B ¹ represent the same meaning as in formula (IXb).
Q ¹ and Q ² represent the same as in formula (I).
X ¹¹ represents the same as in formula (IA). ]

Examples of the method for producing the acid generator (A) represented by the formula (I) include a salt represented by the formula (1) and an onium salt represented by the formula (3), for example, acetonitrile, In an inert solvent such as water or methanol, the acid generator (A) is obtained as a salt by stirring and reacting in a temperature range of about 0 to 150 ° C., preferably in a temperature range of about 0 to 100 ° C. The method etc. are mentioned.
The usage-amount of the onium salt of Formula (3) is about 0.5-2 mol normally with respect to 1 mol of salts represented by Formula (1). The salt may be taken out by recrystallization or may be purified by washing with water.

[In formula (1), Q ¹ , Q ² , X ¹ and Y ¹ represent the same meaning as in formula (I).
M represents Li, Na, K, or Ag.
In formula (3), Z ⁺ represents the same meaning as in formula (I).
Z ¹⁻ represents F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ , or ClO ₄ ⁻ . ]

  As a manufacturing method of the salt represented by Formula (1) used for the said manufacture, first, esterifying alcohol represented by Formula (4) and carboxylic acid represented by Formula (6), for example. The method of making it react and obtaining the salt represented by Formula (1) is mentioned.

[In formula (4), Q ¹ , Q ² , X ¹ and Y ¹ represent the same meaning as in formula (I).
In formula (6), M represents the same meaning as in formula (1). ]

  As another method, for example, an esterification reaction of an alcohol represented by the formula (4) and a carboxylic acid represented by the formula (7), followed by hydrolysis with MOH and a salt represented by the formula (1) The method of obtaining is also mentioned.

[In formula (4), X ¹ and Y ¹ represent the same meaning as in formula (I).
In formula (7), Q ¹ and Q ² represent the same meaning as in formula (I). ]

  The esterification reaction is usually stirred in an aprotic solvent such as dichloroethane, toluene, ethylbenzene, monochlorobenzene, acetonitrile, etc. in a temperature range of about 20 to 200 ° C., preferably in a temperature range of about 50 to 150 ° C. You can do it. In the esterification reaction, an organic acid such as p-toluenesulfonic acid and / or an inorganic acid such as sulfuric acid may be added as an acid catalyst.

  Further, the esterification reaction may be carried out while dehydrating, such as by using a Dean Stark apparatus.

  The amount of the carboxylic acid represented by the formula (6) in the esterification reaction is usually about 0.2 to 3 mol, preferably 0.5 to 1 mol with respect to 1 mol of the alcohol represented by the formula (4). About 2 moles. The amount of the acid catalyst used in the esterification reaction may be a catalytic amount or an amount corresponding to a solvent, and is usually about 0.001 to 5 mol.

  The resist composition of the present invention contains a resin having a structural unit represented by the formula (II) (hereinafter sometimes referred to as “resin (B)”). In the resin (B), the content of the structural unit represented by the formula (II) is 35 to 70 mol% with respect to all the structural units of the resin, and the content of the structural unit having a saturated cyclic hydrocarbon group is The resin has 50 to 70 mol% with respect to all the structural units of the resin and has four or more different structural units.

  Specific examples of the structural unit represented by the formula (II) include isobornyl ester, 2-alkyl-2-adamantyl ester, and 1- (1-adamantyl) -1-alkylalkyl ester. Examples include esters containing a saturated cyclic hydrocarbon group.

  Among these, the structural unit represented by the formula (IIa) or the formula (IIb) is preferable.

[In Formula (IIa) and Formula (IIb), R ¹ and X ² represent the same meaning as in Formula (II).
R ² represents an alkyl group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 10 carbon atoms.
R ³ represents a methyl group.
n represents an integer of 0 to 14.
R ⁴ and R ⁵ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms that may contain a hetero atom, or R ⁴ and R ⁵ are bonded to each other to form a ring. In that case, a hetero atom may be included. R ⁴ and R ⁵ are bonded to each other to represent a direct bond between the carbon atom to which R ⁴ is bonded and the carbon atom to which R ⁵ is bonded, or the carbon atom to which R ⁴ is bonded and R ⁵ are bonded to each other. A double bond may be formed with the carbon atom.
m represents an integer of 1 to 3. ]

  Specific examples of the monomer for deriving the structural unit represented by the formula (IIa) include the following.

  Specific examples of the monomer for deriving the structural unit represented by the formula (IIb) include the following.

  Among these, for example, (meth) acrylic acid 2-ethyl-2-adamantyl, (meth) acrylic acid 2-isopropyl-2-adamantyl, or methacrylic acid 1- (2-methyl-2-adamantyloxycarbonyl) methyl, etc. Preferable examples can be given.

  The structural unit represented by the formula (II) may have a hydroxyl group (excluding the OH group in the carboxyl group) in the side chain.

  Examples of the structural unit having a hydroxyl group (excluding the OH group in the carboxyl group) in the side chain include, for example, various esters of carboxylic acid, specifically, cyclic alkyl esters represented by, for example, cyclopentyl ester and cyclohexyl ester. A structure in which a part of a polycyclic ester such as norbornyl ester, 1-adamantyl ester, or 2-adamantyl ester is substituted with a hydroxyl group.

  Among these, the structural unit represented by the formula (III) can be exemplified.

[In the formula (III), R ³¹ represents a hydrogen atom or a methyl group.
R ⁶ and R ⁷ each independently represent a hydrogen atom, a methyl group or a hydroxyl group.
R ⁸ represents a methyl group.
n ′ represents an integer of 0 to 10.
Z ″ represents a single bond or — [CH ₂ ] _k1 —, and —CH ₂ — contained in — [CH ₂ ] _k1 — may be replaced by —CO— or —O—.
k1 represents an integer of 1 to 8. ]

  Specific examples of the monomer for deriving the structural unit represented by the formula (III) include the following.

  Among these, for example, (meth) acrylic acid 3-hydroxy-1-adamantyl, (meth) acrylic acid 3, 5-dihydroxy-1-adamantyl, methacrylic acid 1- (3-hydroxy-1-adamantyloxycarbonyl) methyl Preferred examples include 1- (3,5-dihydroxy-1-adamantyloxycarbonyl) methyl methacrylate and the like.

  As a structural unit represented by Formula (II), you may have a lactone structure in a side chain, for example. Specific examples include a compound having a β-butyrolactone structure, a compound having a γ-butyrolactone structure, and a compound having a lactone structure added to a cycloalkyl skeleton or a norbornane skeleton.

  Among these, for example, a structural unit represented by any one of the formula (IVa), the formula (IVb), and the formula (IVc) can be preferably exemplified.

[In Formula (IVa) to Formula (IVc), R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁹ represents a hydrogen atom or a methyl group.
l represents an integer of 1 to 5. When l is 2 or more, the plurality of R ⁹ may be the same as or different from each other.
R ¹⁰ and R ¹¹ each independently represent a carboxyl group, a cyano group, or a hydrocarbon group having 1 to 4 carbon atoms.
l ′ represents an integer of 0 to 3. When l ′ is 2 or more, the plurality of R ¹⁰ and R ¹¹ may be the same as or different from each other.
Z ″ represents the same meaning as in formula (III). ]

  Specific examples of the monomer for deriving the structural unit represented by the formula (IVa) include the following.

  Specific examples of the monomer for deriving the structural unit represented by the formula (IVb) include the following.

  Specific examples of the monomer for deriving the structural unit represented by the formula (IVc) include the following.

  Among these, for example, (meth) acrylic acid hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yl, (meth) acrylic acid tetrahydro-2-oxo-3-furyl, Preferred examples include resins obtained from 2- (5-oxo-4-oxatricyclo [4.2.1.03.7] nonan-2-yloxy) -2-oxoethyl (meth) acrylate.

In the resin (B), one type or two or more types of structural units represented by the formula (II) may be contained.
The resin (B) may have a structural unit other than the structural unit represented by the formula (II). Examples of the structural unit other than the structural unit represented by the formula (II) include a structural unit derived from 2-norbornene. 2-norbornene may be introduced into the main chain during polymerization by radical polymerization using, for example, an aliphatic unsaturated dicarboxylic acid anhydride such as maleic anhydride or itaconic anhydride in addition to the corresponding 2-norbornene. Good. The structural unit derived from 2-norbornene is formed by opening a double bond of the norbornene structure and can be represented by the formula (d). The structural unit derived from maleic anhydride and itaconic anhydride is formed by opening a double bond of maleic anhydride and itaconic anhydride, and can be represented by the formulas (e) and (f), respectively.

Here, R ²⁵ and R ²⁶ in the formula (d) are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a carboxyl group, a cyano group, or —COOU (U is an alcohol residue). R ²⁵ and R ²⁶ represent a carboxylic acid anhydride residue represented by —C (═O) OC (═O) —.
The —COOU is a carboxyl group converted to an ester, and examples of the alcohol residue corresponding to U include an optionally substituted alkyl group having 1 to 8 carbon atoms, 2-oxooxolane-3 A-or -4-yl group etc. can be mentioned. Here, as a substituent of the alkyl group, a hydroxyl group or a saturated cyclic hydrocarbon residue having 3 to 36 carbon atoms may be bonded.
Examples of the alkyl group in R ²⁵ and R ²⁶ include a methyl group, an ethyl group, and a propyl group. Examples of the alkyl group to which a hydroxyl group is bonded include a hydroxymethyl group and a 2-hydroxyethyl group.

Specific examples of the monomer that leads to the norbornene structure represented by the formula (d) include the following.
2-norbornene,
2-hydroxy-5-norbornene,
5-norbornene-2-carboxylic acid,
Methyl 5-norbornene-2-carboxylate,
2-hydroxy-1-ethyl 5-norbornene-2-carboxylate,
5-norbornene-2-methanol,
5-norbornene-2,3-dicarboxylic anhydride.

  In addition, about U of —COOU in the formula (d), an acid-labile group such as an ester containing a saturated cyclic hydrocarbon group in which the carbon atom bonded to —O— of the carboxyl group is a quaternary carbon atom. If present, it is a structural unit having an acid labile group even though it has a norbornene structure. Examples of the monomer containing a norbornene structure and an acid labile group include, for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5- 1-methylcyclohexyl norbornene-2-carboxylate, 2-methyl-2-adamantyl 5-norbornene-2-carboxylate, 2-ethyl-2-adamantyl 5-norbornene-2-carboxylate, 5-norbornene-2-carboxyl Acid 1- (4-methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1 -(4-oxocyclohexyl) ethyl, 5-norbornene-2-carboxylic acid 1- (1 Adamantyl) -1-methylethyl and the like.

The acid generator (A) represented by the formula (I) and the resin (B) having the structural unit represented by the formula (II) have a common partial structure in the structure. Specifically, Y ¹ in formula (I) and Y ² in formula (II) are rings having the same skeleton. Since the rings have the same skeleton, the compatibility between the resin and the acid generator is improved, and the diffusion of the acid is reduced. Therefore, a chemically amplified photoresist composition containing the resin and the acid generator. When forming a pattern using, an effect that an excellent pattern can be formed is shown.
A ring in which a hydrogen atom contained in the ring is substituted is included in a ring having the same skeleton regardless of the type of the substituent.
A ring in which —CH ₂ — contained in a ring is replaced with another skeleton is not included in a ring of the same skeleton.

Content of the structural unit represented by Formula (II) in resin is 35-70 mol% with respect to all the structural units of resin, Preferably it is 50-70 mol%.
Furthermore, content of the structural unit which has a saturated cyclic hydrocarbon group in resin is 50-70 mol% with respect to all the structural units of resin, Preferably, it is 50-65 mol%.

The resin (B) is preferably a resin having four or more different structural units.
The resin (B) is preferably a resin that has an acid labile group, is insoluble or hardly soluble in an aqueous alkali solution, and can dissolve in an aqueous alkali solution by acting with an acid.
Such resin (B) may be used alone or in combination of two or more. Moreover, you may use together resin other than resin (B).

  In producing the resist composition of the present invention, a basic compound, preferably a basic nitrogen-containing organic compound, particularly preferably an amine or ammonium salt can be contained together with the resin and the acid generator. By adding a basic compound as a quencher, it is possible to improve the performance degradation due to the deactivation of the acid accompanying the holding after exposure. As a basic compound used for a quencher, the following are mentioned, for example.

In the formula, T ¹ , T ¹² and T ⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. The hydrogen atom of the alkyl group, the hydrogen atom of the cycloalkyl group, or the hydrogen atom of the aryl group may be substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The hydrogen atom of the amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.

T ^{13 to} T ¹⁵ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Represents. The hydrogen atom of the alkyl group, the hydrogen atom of the cycloalkyl group, the hydrogen atom of the aryl group, or the hydrogen atom of the alkoxy group is independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. May be. The hydrogen atom of the amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.

T ⁶ represents an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms. The hydrogen atom of the alkyl group or the hydrogen atom of the cycloalkyl group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The hydrogen atom of the amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.

A represents an alkylene group having 1 to 6 carbon atoms, a carbonyl group, an imino group, a sulfide group, or a disulfide group.
In addition, any of T ^{1 to} T ⁷ that can take both a linear structure and a branched structure may be used.

  Specific examples of such compounds include hexylamine, heptylamine, octylamine, nonylamine, decylamine, aniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, 1- or 2-naphthylamine. , Ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3 '-Diethyldiphenylmethane, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, N-methylaniline, piperidine, diphenylamine, triethylamine, trimethylamine, tripropylamine, tripropylamine Tylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine Methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, N, N-dimethylaniline, 2,6-isopropylaniline, imidazole, Gin, 4-methylpyridine, 4-methylimidazole, bipyridine, 2,2'-dipyridylamine, di-2-pyridyl ketone, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ) Ethane, 1,3-di (4-pyridyl) propane, 1,2-bis (2-pyridyl) ethylene, 1,2-bis (4-pyridyl) ethylene, 1,2-bis (4-pyridyloxy) Ethane, 4,4′-dipyridyl sulfide, 4,4′-dipyridyl disulfide, 1,2-bis (4-pyridyl) ethylene, 2,2′-dipiconylamine, 3,3′-dipiconylamine, tetramethyl Ammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetra-n-hexylammonium hydroxide, tet Examples include la-n-octylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethylammonium hydroxide, and choline.

  Furthermore, a hindered amine compound having a piperidine skeleton as disclosed in JP-A-11-52575 can be used as a quencher.

  More preferable quenchers include compounds represented by the formula (XII). Specifically, for example, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-trifluoromethyl-phenyltrimethylammonium hydroxide, etc. Can be mentioned.

  The resist composition of the present invention may generally contain a resin in the range of about 80 to 99% by weight and an acid generator in the range of about 1 to 20% by weight based on the total solid content.

  Further, when the resist composition of the present invention contains a basic compound as a quencher, the content of the basic compound is usually 0.01 to 5% by weight based on the total solid content of the resist composition of the present invention. The range of the degree.

  The resist composition of the present invention can further contain small amounts of various additives such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, dyes and the like as necessary.

  The resist composition of the present invention is usually applied to a substrate such as a silicon wafer in a state where each of the above components is dissolved in a solvent according to a method that is usually used industrially such as spin coating. The solvent used here may be any solvent that dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after the solvent evaporates, and a solvent generally used in this field is used. Yes.

  Examples of the solvent include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate, esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate, acetone, methyl Examples thereof include ketones such as isobutyl ketone, 2-heptanone and cyclohexanone, cyclic esters such as γ-butyrolactone, and propylene glycol monomethyl ether. These solvents can be used alone or in combination of two or more.

The resist film coated and dried on the substrate is subjected to an exposure process for patterning, followed by a heat treatment for promoting a deprotecting group reaction, and then developed with an alkali developer. The alkaline developer used here can be various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline) can be used. Can be mentioned.
Since the resist composition of the present invention has an excellent exposure margin and can be suitably used for immersion lithography and double imaging, the present invention is industrially useful.

  Hereinafter, the present invention will be described in detail by way of examples. In Examples and Comparative Examples, “%” and “part” representing content or use amount are based on mass unless otherwise specified.

  The weight average molecular weight of the resin is a value determined by gel permeation chromatography.

Apparatus: HLC-8120GPC (manufactured by Tosoh Corporation)
Column: 3 TSKgel Multipore HXL-M + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μL
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

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

(Synthesis of acid generator A1)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 150 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.4 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.7%). To 1.9 parts (purity 62.7%) of difluorosulfoacetic acid sodium salt and 9.5 parts of N, N-dimethylformamide, 1.0 part of 1,1′-carbonyldiimidazole was added for 2 hours. A mixture was prepared by stirring.
On the other hand, 0.2 part of sodium hydride was added to 1.1 parts of 3-hydroxyadamantyl methanol and 5.5 parts of N, N-dimethylformamide, and stirred for 2 hours. To this solution was added the above mixture. After the resulting mixture was stirred for 15 hours, the resulting solution containing difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt was used as it was in the next reaction. To the obtained solution containing difluorosulfoacetate-3-hydroxy-1-adamantylmethyl ester sodium salt, 17.2 parts of chloroform and 2.9 parts of 14.8% aqueous triphenylsulfonium chloride were added. After stirring for 15 hours, the organic layer was recovered by liquid separation. Subsequently, the remaining aqueous layer was extracted with 6.5 parts of chloroform to recover the organic layer. Further, the above extraction operation was repeated on the remaining aqueous layer, and the organic layer was further recovered. The organic layers were combined, washed with ion-exchanged water, and then the obtained organic layer was concentrated. To the concentrate, 5.0 parts of tert-butyl methyl ether was added, stirred and filtered to give triphenylsulfonium 1-((3-hydroxyadamantyl) methoxycarbonyl) difluoromethanesulfonate (A1) as a white solid. Two parts were obtained.

(Synthesis of acid generator A2)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.8 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.6%). To a mixture of 5.0 parts (purity 62.6%) of the obtained sodium difluorosulfoacetate, 2.6 parts of 4-oxo-1-adamantanol and 100 parts of ethylbenzene, 0.8 part of concentrated sulfuric acid was added, Heated to reflux for hours. The obtained mixture was cooled and then filtered, and the filtration residue was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of purity analysis by ¹ H-NMR, the purity was 35.6%. 16 parts of acetonitrile and 16 parts of ion-exchanged water were added to 5.4 parts (purity 35.6%) of the obtained difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. To the obtained mixture, 1.7 parts of triphenylsulfonium chloride, 5 parts of acetonitrile, and 5 parts of ion-exchanged water were added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting mixture was extracted with 142 parts of chloroform to recover the organic layer. The collected organic layer was washed with ion-exchanged water, and then the obtained organic layer was concentrated. The concentrate was repulped with 24 parts of tert-butyl methyl ether to obtain 1.7 parts of triphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (A2) as a white solid.

(Synthesis of acid generator A3)
To 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 300 parts of ion-exchanged water, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetic acid sodium salt (content of 63.5% because inorganic salts were not removed). To a mixture of the obtained sodium difluorosulfoacetate salt 39.4 parts (content 63.5%), 1-adamantane methanol 21.0 parts and dichloroethane 200 parts, p-toluenesulfonic acid (p-TsOH) 24.0 was added. Was added and this was heated to reflux for 7 hours. Thereafter, the mixture was concentrated to distill off dichloroethane, 250 parts of tert-butyl methyl ether was added to the concentrated residue, repulped and filtered. To the residue, 250 parts of acetonitrile was added and stirred, followed by filtration. The obtained filtrate was concentrated to obtain 32.8 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt. To a solution obtained by dissolving 32.8 parts of the obtained difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt in 100 parts of ion-exchanged water, a solution of 28.3 parts of triphenylsulfonium chloride and 140 parts of methanol was added. Added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting concentrate was extracted twice with 200 parts of chloroform. The recovered organic layers obtained by the extraction twice were combined, and the washing operation using ion-exchanged water was repeated until the organic layer became neutral, and then the obtained organic layer was concentrated. To the concentrated solution, 300 parts of tert-butyl methyl ether was added, stirred, and then filtered to collect a white precipitate, which was dried under reduced pressure to give triphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfone as white crystals. Nate (A3) 39.7 parts was obtained.

(Synthesis of acid generator A4)
To 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 300 parts of ion-exchanged water, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. This was refluxed at 100 ° C. for 2.5 hours, cooled, and then neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.8%). To a mixture of the obtained difluorosulfoacetic acid sodium salt 123.3 parts (purity 62.8%), 1-adamantane methanol 65.7 parts and dichloroethane 600 parts, p-toluenesulfonic acid (p-TsOH) 75.1 parts. And heated at reflux for 12 hours. Thereafter, the mixture was concentrated to distill off dichloroethane, and 400 parts of tert-butyl methyl ether was added to the concentrated residue, followed by repulping and filtration. 400 parts of acetonitrile was added to the residue, and after stirring, filtration was repeated twice and concentrated to obtain 99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt.
Next, 150 parts of 2-bromoacetophenone was dissolved in 375 parts of acetone, and 66.5 parts of tetrahydrothiophene was added dropwise thereto. After stirring the resulting mixture at room temperature for 24 hours, the white precipitate formed was collected by filtration, washed with acetone, and then dried to give 1- (2-oxo-2-phenyl) as white crystals. 207.9 parts of ethyl) tetrahydrothiophenium bromide were obtained.
99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt obtained above was dissolved in 298 parts of acetonitrile. To the obtained solution, 79.5 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide obtained above and 159 parts of ion-exchanged water were added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting concentrate was extracted twice with 500 parts of chloroform. The organic layers recovered by the two extractions were combined, washed with ion-exchanged water, and the obtained organic layer was concentrated. To the concentrate, 250 parts of tert-butyl methyl ether was added, stirred, and then filtered to collect a white precipitate, which was dried under reduced pressure to give 1- (2-oxo-2-phenylethyl as white crystals. ) 116.9 parts of tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (A4) were obtained.

(Synthesis of acid generator A5)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 164.8 parts of difluorosulfoacetate sodium salt (containing inorganic salt, purity 62.6%). To 5.0 parts of the obtained sodium difluorosulfoacetate (purity 62.8%), 2.6 parts of 4-oxo-1-adamantanol and 100 parts of ethylbenzene, 0.8 part of concentrated sulfuric acid was added, Heated to reflux for hours. The obtained mixture was cooled and then filtered, and the filtration residue was washed with tert-butyl methyl ether to obtain 5.5 parts of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of purity analysis by ¹ H-NMR, the purity was 35.6%. 30 parts of acetonitrile and 20 parts of ion-exchanged water were added to 10.0 parts (purity 55.2%) of the obtained difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. To this, 5.0 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide, 10 parts of acetonitrile and 5 parts of ion-exchanged water were added. The resulting mixture was stirred for 15 hours and then concentrated, and the resulting concentrate was extracted with 98 parts of chloroform. The organic layer recovered by the extraction was washed with ion-exchanged water, and the obtained organic layer was concentrated. The concentrate is repulped with 70 parts of ethyl acetate to give 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (A5) 5.2 as a white solid. Got a part.

(Synthesis of acid generator A6)
To 100 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 250 parts of ion-exchanged water, 230 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 88 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 158.4 parts of sodium difluorosulfoacetate (containing inorganic salt, purity: 65.1%). 31.26 parts of p-toluenesulfonic acid was added to 50.0 parts (purity 65.1%) of difluorosulfoacetic acid sodium salt, 18.76 parts of cyclohexylmethanol and 377 parts of dichloroethane, and this was heated to reflux for 6 hours. did. Then, after concentrating the obtained mixture and distilling dichloroethane off, 200 parts of n-heptane was added thereto, followed by repulping and filtration. 200 parts of acetonitrile was added to the obtained filtration residue and stirred, followed by filtration. The collected filtrate was concentrated to obtain 39.03 parts of difluorosulfoacetic acid-1-cyclohexylmethyl ester sodium salt. The obtained 39.03 parts of difluorosulfoacetic acid-1-cyclohexylmethyl ester sodium salt was dissolved in 195.2 parts of ion-exchanged water. To this solution, 39.64 parts of triphenylsulfonium chloride and 196.4 parts of ion-exchanged water were added, and 500 parts of acetonitrile was further added. The resulting mixture was stirred for 15 hours, then concentrated, and the resulting concentrate was extracted twice with 250 parts of chloroform. The organic layers recovered by the two extractions were combined, washed with ion-exchanged water, and the obtained organic layer was concentrated. The concentrate was repulped with 200 parts of tert-butyl methyl ether to obtain 40.16 parts of triphenylsulfonium (1-cyclohexylmethoxycarbonyl) difluoromethanesulfonate difluoromethanesulfonate (A6) as a white solid.

(Synthesis of acid generator A7)
5.0 parts of difluorosulfoacetate-4-oxo-1-adamantyl ester sodium salt synthesized by a synthesis method according to the synthesis method described in “Synthesis of acid generator A1” (content: 49.1%) ) Was added 50.0 parts of chloroform. 42.0 parts (concentration 5.0%) of an aqueous methyldiphenylsulfonium chloride solution was added to the resulting mixture. The resulting mixture was stirred for 15 hours and then separated to recover the organic layer. Next, the remaining aqueous layer was extracted with 25.0 parts of chloroform to recover the organic layer. The two organic layers were combined, washed repeatedly with ion exchange water until neutral, and the resulting organic layer was concentrated. To the concentrate was added 29.6 parts of tert-butyl methyl ether, and the mixture was stirred and decanted. 16.6 parts of ethyl acetate was added to the residue, stirred and decanted to give 1.6 parts of methyldiphenylsulfonium 4-oxo-1-adamantyloxycarbonyldifluoromethanesulfonate (A7) as a pale yellow liquid. Obtained.

(Synthesis of acid generator A8)
Dissolve 5.0 parts of thioanisole in 15.0 parts of acetonitrile, add 8.35 parts of silver (I) perchlorate, and add 11.4 parts of a solution of 5.71 parts of methyl iodide to acetonitrile. And stirred for 24 hours. The precipitated solid was removed by filtration, and the filtrate was concentrated to remove acetonitrile. To the concentrate was added 36.8 parts of tert-butyl methyl ether, and the mixture was stirred and then filtered to obtain 8.22 parts of dimethylphenylsulfonium perchlorate as white crystals.
Chloroform 35.9 parts was added to 5.98 parts of difluorosulfoacetate-1-adamantyl methyl ester sodium salt synthesized according to the synthesis method described below in the synthesis method described in “Synthesis of acid generator A6”. . To the obtained mixture, 4.23 parts of dimethylphenylsulfonium perchlorate obtained above and 12.7 parts of ion-exchanged water were added. The resulting mixture was stirred for 4 hours and then separated to recover the organic layer. Next, the remaining aqueous layer was extracted with 23.9 parts of chloroform to recover the organic layer. The collected organic layers were combined and repeatedly washed with ion exchange water until neutral, and the resulting organic layer was concentrated. The concentrate was added with 31.8 parts of tert-butyl methyl ether, stirred, and filtered to obtain 5.38 parts of dimethylphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (A8) as a white solid. .

(Synthesis of acid generator A9)
To 200 parts of difluoro (fluorosulfonyl) acetic acid methyl ester and 300 parts of ion-exchanged water, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The resulting mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of difluorosulfoacetic acid sodium salt (content was 62.8% because inorganic salts were not removed). To 5.0 parts (content 62.8%) of difluorosulfoacetic acid sodium salt, 2.6 parts of 4-oxo-1-adamantanol and 100 parts of ethylbenzene, 0.8 part of concentrated sulfuric acid was added. Heated to reflux for 30 hours. The resulting mixture was cooled and then filtered, and the filter residue was washed with tert-butyl methyl ether to obtain 5.5 parts of a mixture containing difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt. As a result of analysis by ¹ H-NMR, since the inorganic salt was not removed, the content of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt was 57.6%. To 4.3 parts (content 57.6%) of difluorosulfoacetic acid-4-oxo-1-adamantyl ester sodium salt obtained, 43.0 parts of chloroform was added. To the obtained mixture, 2.2 parts of a sulfonium salt having the following structure and 11.7 parts of ion-exchanged water were added. The obtained mixture was stirred for 15 hours and then separated, and washing with ion-exchanged water was repeated until the collected organic layer became neutral, and the obtained organic layer was concentrated.

To the concentrate was added 15.0 parts of tert-butyl methyl ether, and the mixture was stirred and decanted. The residue was dried to obtain 2.3 parts of compound (A9) as a white solid.

(Synthesis of acid generator A10)
10.4 parts of lithium aluminum hydride and 120 parts of anhydrous tetrahydrofuran were charged and stirred at 23 ° C. for 30 minutes. Next, a solution obtained by dissolving 62.2 parts of sodium ethyldifluorosulfoacetate in 900 parts of anhydrous THF was added dropwise under ice cooling, and the mixture was stirred at 23 ° C. for 5 hours. To the reaction mass, 50.0 parts of ethyl acetate and 50.00 parts of 6N hydrochloric acid were added, followed by liquid separation. After concentration of the organic layer, separation of the column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) was performed to obtain 84.7 g of sodium salt of 2,2-difluoro-2-sulfoethanol. (Purity 60%).
Further, 4.5 parts of 4-oxo-1-adamantanecarboxylic acid and 90 parts of anhydrous THF were added and dissolved by stirring at room temperature for 30 minutes. To this solution, a mixed solution of 3.77 parts of carbonyldiimidazole and 45 parts of anhydrous THF was added dropwise at room temperature, followed by stirring at 23 ° C. for 4 hours. The obtained reaction solution was added dropwise at 54 ° C. to 60 ° C. for 30 minutes while mixing 7.87 parts (purity 60%) of sodium salt of 2,2-difluoro-2-sulfoethanol and 50 parts of anhydrous THF. The reaction solution was heated at 65 ° C. for 18 hours, cooled and then filtered. The obtained filtrate was concentrated, and the concentrate was fractionated into a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain sodium 4-oxo-1-adamantylcarbonyloxymethyldifluoromethanesulfone. 4.97 parts of narate (yield 59%) were obtained.
Next, 1.0 part of sodium 4-oxo-1-adamantylcarbonyloxymethyldifluoromethanesulfonate and 20 parts of chloroform were charged, stirred at 23 ° C. for 30 minutes, and further triphenylsulfonium chloride (13.1% aqueous solution). Three parts were added at 23 ° C. After stirring at room temperature for 12 hours, liquid separation was performed. 10 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added, stirred at 23 ° C. for 30 minutes, filtered, and the filtrate was concentrated to obtain 1.36 parts of compound (A10).

(Synthesis of acid generator A11)
3.51 parts of 3-hydroxy-1-adamantanecarboxylic acid and 75 parts of anhydrous THF were charged and stirred at 23 ° C. for 30 minutes. Next, a mixed solution of 2.89 parts of carbonyldiimidazole and 50 parts of anhydrous THF was added dropwise at 23 ° C., and the mixture was stirred at 23 ° C. for 4 hours. The obtained reaction solution was dropped into a mixed solution of 2,2-difluoro-2-sulfoethanol sodium salt 6.04 parts (purity 60%) and anhydrous THF 50 parts at 54-60 ° C. over 25 minutes, Heated at 65 ° C. for 18 hours, cooled and filtered. The obtained filtrate was concentrated, and the concentrate was fractionated into a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain sodium 3-hydroxy-1-adamantylcarbonyloxymethyldifluoromethanesulfone. 2.99 parts of nat were obtained.
Sodium 3-hydroxy-1-adamantylcarbonyloxymethyldifluoromethanesulfonate (1.0 part) and chloroform (30 parts) were charged and stirred at 23 ° C. for 30 minutes. Subsequently, 6.3 parts of triphenylsulfonium chloride (13.1% aqueous solution) were stirred at 23 ° C. for 12 hours, and then separated. 10 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added, stirred at 23 ° C. for 30 minutes, filtered, and the filtrate was concentrated to obtain 1.6 parts of compound (A11).

(Synthesis of acid generator A12)
5-hydroxymethyl-2-adamantanone 1.00 part of ethylene ketal, 2.47 parts of pyridine and 5 parts of anhydrous methylene chloride were added and stirred at 23 ° C for 30 minutes. Next, a solution of 2.37 parts of trifluoromethanesulfonic anhydride and 5 parts of methylene chloride was added dropwise under ice cooling, and the mixture was stirred at 3 to 5 ° C. for 2 hours. To the reaction solution, 10 parts of methylene chloride and 10 parts of ion exchange water were added, followed by separation and washing with water. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added, and the mixture was stirred at 23 ° C. for 30 minutes and then filtered. The filtrate was concentrated, and the concentrate was separated into a column (Merck silica gel 60-200 mesh developing solvent: hexane / ethyl acetate = 1/1). By taking, 1.19 parts of 5-trifluoromethanesulfonylmethyl-2-adamantanone ethylene ketal was obtained.
0.2285 parts of sodium hydride and 3 parts of anhydrous dimethyl sulfoxide were added and stirred at 60 ° C. for 30 minutes. Next, 0.62 part of sodium salt of 2,2-difluoro-2-sulfoethanol was added and stirred at 60 ° C. for 1 hour. Further, a solution of 1.00 part of 5-trifluoromethanesulfonylmethyl-2-adamantanone ethylene ketal and 9 parts of anhydrous dimethyl sulfoxide was added dropwise and stirred at 60 ° C. for 5 hours. After cooling, the reaction mass is separated from a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain sodium spiro {adamantane-4,4 ′-[1,3] dioxolane} -1. 0.28 parts of -yl-methoxymethyldifluoromethanesulfonate were obtained. Sodium spiro {adamantane-4,4 ′-[1,3] dioxolane} -1-yl-methoxymethyldifluoromethanesulfonate (0.2 parts) and chloroform (10 parts) were added and stirred at 23 ° C. for 30 minutes. Next, 1.5 parts of triphenylsulfonium chloride (12.8% aqueous solution) was stirred at 23 ° C. for 36 hours, followed by liquid separation. 10 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. Thereafter, 1 part of magnesium sulfate was added and stirred at 23 ° C. for 30 minutes, followed by filtration. The filtrate was concentrated to obtain 0.24 part of compound (A12).

(Synthesis of acid generator A13)
Triphenylsulfonium chloride (14.2% aqueous solution) 573.7 parts and difluorosulfoacetic acid sodium salt (18.0% aqueous solution) 300.0 parts were charged and stirred at 25 ° C. for about 20 hours. The precipitated white solid was separated by filtration, washed with 100 parts of ion-exchanged water, and dried to obtain 88.4 parts of triphenylsulfonium hydroxycarbonyldifluoromethanesulfonate.
9.5 parts of triphenylsulfonium hydroxycarbonyldifluoromethanesulfonate and 47.6 parts of N, N'-dimethylformamide were charged and dissolved, and 3.0 parts of potassium carbonate and 0.9 parts of potassium iodide were added. , And stirred at 50 ° C. for about 1 hour. Thereafter, the mixture was cooled to 40 ° C. and dissolved in 5.0 parts of chloroacetic acid hexahydro-2-oxo-3,5-methano-2H-cyclopenta [b] furan-6-yl and 40 parts of N, N′-dimethylformamide. Was added dropwise and reacted at 40 ° C. for 23 hours. After the reaction, the reaction mixture was cooled, 106 parts of chloroform and 106 parts of ion-exchanged water were added, stirred, allowed to stand, and then separated. The aqueous layer was extracted twice with 106 parts of chloroform, and all the organic layers were combined and washed repeatedly with 106 parts of ion-exchanged water until the aqueous layer became neutral. After adding 3.5 parts of activated carbon to the organic layer and stirring, it was filtered. The filtrate was concentrated, 38 parts of ethyl acetate was added and stirred, and then the supernatant was removed. After adding 38 parts of tert-butyl methyl ether to the residue and stirring, the supernatant was removed. The residue was dissolved in chloroform and then concentrated to obtain 4.3 parts of compound (A13) as an amber oil.

  Then, the synthesis example of resin is described below. The monomers used in the synthesis examples are as follows.

[Synthesis of Resin B1]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 15: 20: 30, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8100 in a yield of 78%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B1. The ratio of the structural unit derived from the monomer having an adamantyl skeleton in the resin B1 is 50 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 50 mol%.

[Synthesis of Resin B2]
Monomer F, monomer E, monomer B, monomer C and monomer D are charged in a molar ratio of 30: 15: 5: 20: 30, and then 1.5 mass times dioxane with respect to the total mass of all monomers. Was added. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 73 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8500 in a yield of 73%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B2. The ratio of the structural unit derived from the monomer having an adamantyl skeleton in the resin B2 is 35 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 50 mol%.

[Synthesis of Resin B3]
Resin B3 was synthesized according to the same synthesis method except that the charging ratio of monomer F, monomer E, monomer B, monomer C and monomer D was changed to a molar ratio of 35: 5: 15: 20: 25 in the synthesis of resin B2. Was synthesized to obtain a copolymer having a weight average molecular weight of about 8600 in a yield of 70%. The ratio of structural units derived from the monomer having an adamantyl skeleton in the resin B3 is 50 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 55 mol%.

[Synthesis of Resin B4]
Monomer F, monomer E, monomer H and monomer C were charged at a molar ratio of 40: 10: 10: 40, and then 1.2 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by performing the operation of pouring into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 7400 in a yield of 74%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B4. The ratio of the structural unit derived from the monomer having an adamantyl skeleton in the resin B4 is 50 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 60 mol%.

[Synthesis of Resin B5]
Monomer A, monomer B and monomer D were charged in a molar ratio of 50:25:25, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8000 in a yield of 60%. This copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B5. The ratio of the structural unit derived from the monomer having an unsubstituted adamantyl skeleton in the resin B5 is 75 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 75 mol%.

[Synthesis of Resin B6]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 15: 15: 35, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent for precipitation three times to obtain a copolymer having a weight average molecular weight of about 8000 in a yield of 72%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B6. The ratio of the structural unit derived from the monomer having an adamantyl skeleton in the resin B6 is 50 mol%. The ratio of the structural unit derived from the monomer having an adamantanone skeleton is 35 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 50 mol%.

[Synthesis of Resin B7]
Monomer A, monomer B, monomer C and monomer D were charged at a molar ratio of 35: 15: 40: 10, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 7800 in a yield of 73%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B7. The ratio of the structural unit derived from the monomer having an adamantyl skeleton in the resin B7 is 50 mol%. The ratio of the structural unit derived from the monomer having a norbornane lactone skeleton is 40 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 50 mol%.

[Synthesis of Resin B8]
Monomer F, monomer E, monomer B, monomer C and monomer D are charged in a molar ratio of 55: 5: 5: 20: 15, and then 1.5 mass times dioxane with respect to the total mass of all monomers. Was added. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8000 in a yield of 70%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B8. The ratio of structural units derived from the monomer having an adamantyl skeleton in the resin B8 is 60 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 65 mol%.

[Synthesis of Resin B9]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 55: 15: 20: 10, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8100 in a yield of 78%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B9. The ratio of structural units derived from the monomer having an adamantyl skeleton in the resin B9 is 70 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 70 mol%.

[Synthesis of Resin B10]
Monomer A, monomer B, monomer C and monomer D were charged in a molar ratio of 35: 12: 23: 30, and then 1.5 mass times dioxane was added to the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8100 in a yield of 78%. The obtained copolymer has a structural unit derived from each monomer of the following formula, and this was designated as resin B10. The ratio of structural units derived from the monomer having an adamantyl skeleton in the resin B10 is 47 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 47 mol%.

〔樹脂Ｂ１１の合成〕
モノマーＦ、モノマーＥ、モノマーＢ、モノマーＣ及びモノマーＤを、モル比３４：８：８：３４：１６の割合で仕込み、次いで、全モノマーの合計質量に対して、１．５質量倍のジオキサンを加えた。得られた混合物に、開始剤としてアゾビスイソブチロニトリルとアゾビス（２，４−ジメチルバレロニトリル）とを全モノマーの合計モル数に対して、それぞれ、１ｍｏｌ％と３ｍｏｌ％との割合で添加し、これを７３℃で約５時間加熱した。その後、反応液を、大量のメタノールと水との混合溶媒に注いで沈殿させる操作を３回行うことにより精製し、重量平均分子量が約７８００の共重合体を収率７３％で得た。得られた共重合体は、次式の各モノマーから導かれる構造単位を有するものであり、これを樹脂Ｂ１１とした。樹脂Ｂ１１におけるアダマンチル骨格を有するモノマーから導かれる構造単位の比率は、４２モル％である。飽和環状炭化水素基を有する構造単位の比率は、５０モル％である。

[Synthesis of Resin B11]
Monomer F, monomer E, monomer B, monomer C and monomer D are charged in a molar ratio of 34: 8: 8: 34: 16, and then 1.5 mass times dioxane with respect to the total mass of all monomers. Was added. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 73 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a large amount of methanol / water mixed solvent and precipitating three times to obtain a copolymer having a weight average molecular weight of about 7800 in a yield of 73%. The obtained copolymer has a structural unit derived from each monomer represented by the following formula, and this was designated as resin B11. The ratio of structural units derived from the monomer having an adamantyl skeleton in the resin B11 is 42 mol%. The ratio of the structural unit having a saturated cyclic hydrocarbon group is 50 mol%.

Examples 1 to 71, Comparative Examples 1 to 33
As shown in Table 1, various chemically amplified photoresist compositions were prepared by filtering a mixture obtained by mixing and dissolving the following components through a fluororesin filter having a pore size of 0.2 μm. did.

<Acid generator>
Acid generator; A1-A9
C1: Triphenylsulfonium pentafluoroethanesulfonate <Resin>
Resin; B1-B5
<Quencher>
Q1: 2,6-diisopropylaniline <solvent>
Propylene glycol monomethyl ether acetate 245 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 Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic antireflective coating having a thickness of 780 mm. Formed. Next, the chemical amplification photoresist composition was spin-coated on the organic antireflection film so that the film thickness after drying was 0.15 μm. After coating the composition, the obtained silicon wafer was pre-baked on a direct hot plate at a temperature described in the “PB” column of Table 1 for 60 seconds. Using the ArF excimer stepper [FPA5000-AS3; manufactured by Canon Inc., NA = 0.75 2 / 3Annular], the exposure amount is stepped on the silicon wafer on which the film of the chemically amplified photoresist composition is thus formed. Line and space patterns were exposed.
After the exposure, the silicon wafer was post-exposure baked for 60 seconds at a temperature described in the “PEB” column of Table 1 on a hot plate. Next, the obtained silicon wafer was subjected to paddle development for 60 seconds with an aqueous 2.38 wt% tetramethylammonium hydroxide solution.
The developed dark field pattern on the organic antireflection film substrate was observed with a scanning electron microscope. The results are shown in Table 3. The dark field pattern referred to here is a pattern obtained by exposure and development through a reticle in which a glass surface (translucent portion) is formed in a line with a chromium layer (light-shielding layer) as a base on the outside, After exposure and development, the resist layer around the line and space pattern is left. The following evaluation was performed on the obtained pattern and the like.

Effective sensitivity: The exposure amount at which a 100 nm line and space pattern is 1: 1 is shown.
Evaluation of resolution: A pattern obtained by exposing a 100 nm line-and-space pattern at an exposure amount of 1: 1 was observed with a scanning electron microscope, and Comparative Example 3 was used as a reference (indicated by Δ). The image was judged as ◯, the case without change as Δ, and the case worsened as X. Comparative Example 3 resolved 90 nm, but was tapered and skirting was observed. When the skirting is improved even at the same resolution, it is indicated as ◯, and when the skirting is deteriorated, it is indicated as x.
Line edge roughness evaluation (LER): The surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and Comparative Example 3 was used as a reference (indicated by Δ). The case where there was no △ was marked as Δ, and the case which was worse than this was marked as ×.
The uneven line width of the side wall was measured, and those having a smaller uneven line width than Comparative Example 3 were marked with ◯, and those having a large uneven line width were marked with x.
Pattern collapse evaluation: The pattern when the 100 nm line-and-space pattern was exposed at an exposure amount of 1: 1 was observed with a scanning electron microscope, and Comparative Example 3 was used as a reference (indicated by Δ). ◯ if the line width is relaxed and the pattern shape is maintained, △ if there is no change, △ if the pattern is undercut, if the pattern is about to fall down due to the line width narrowing What was there was marked with x.

[Table 1]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Resin Acid generator Quencher PB / PEB
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 B1 / 10 part A1 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 2 B1 / 10 part A1 / A2 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 3 B1 / 10 part A1 / A2 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 4 B1 / 10 part A1 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 5 B1 / 10 part A1 / A2 = 0.30 / 0.40 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 6 B1 / 10 part A1 / A2 = 0.25 / 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 7 B1 / 10 part A1 / A3 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 8 B1 / 10 part A1 / A3 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 9 B1 / 10 part A1 / A3 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 10 B1 / 10 part A3 = 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 11 B1 / 10 part A1 / A4 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 12 B1 / 10 part A1 / A4 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 13 B1 / 10 part A1 / A5 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 14 B1 / 10 part A1 / A6 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 15 B1 / 10 part A1 / A7 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 16 B1 / 10 part A1 / A7 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 17 B1 / 10 part A1 / A7 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 18 B1 / 10 part A1 / A7 = 0.30 / 0.40 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 19 B1 / 10 part A1 / A7 = 0.25 / 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 20 B1 / 10 part A1 / A8 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 21 B1 / 10 part A1 / A8 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 22 B1 / 10 part A8 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 23 B1 / 10 part A1 / A9 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 24 B1 / 10 part A1 / A9 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 25 B2 / 10 part A1 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 26 B2 / 10 part A1 / A2 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 27 B2 / 10 part A1 / A2 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 28 B2 / 10 part A1 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 29 B2 / 10 part A1 / A2 = 0.30 / 0.40 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 30 B2 / 10 part A1 / A2 = 0.25 / 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 31 B2 / 10 part A1 / A3 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 32 B2 / 10 part A1 / A3 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 33 B2 / 10 part A1 / A3 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 34 B2 / 10 part A3 = 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 35 B2 / 10 part A1 / A4 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 36 B2 / 10 part A1 / A4 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 37 B2 / 10 part A1 / A5 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 39 B2 / 10 part A1 / A6 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 39 B2 / 10 part A1 / A7 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 40 B2 / 10 part A1 / A7 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 41 B2 / 10 part A1 / A7 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 42 B2 / 10 part A1 / A7 = 0.30 / 0.40 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 43 B2 / 10 part A1 / A7 = 0.25 / 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 44 B2 / 10 part A1 / A8 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 45 B2 / 10 part A1 / A8 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 46 B2 / 10 part A8 = 0.7 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 47 B2 / 10 part A1 / A9 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 48 B2 / 10 part A1 / A9 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 49 B2 / 10 part A1 / A6 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 50 B3 / 10 part A1 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 51 B3 / 10 part A1 / A2 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 52 B3 / 10 part A1 / A2 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 53 B3 / 10 part A1 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 54 B3 / 10 part A1 / A2 = 0.30 / 0.40 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 55 B3 / 10 part A1 / A2 = 0.25 / 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 56 B4 / 10 parts A1 = 0.70 parts Q1 / 0.065 parts 95 ° C / 95 ° C
Example 57 B4 / 10 part A1 / A2 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 58 B4 / 10 part A1 / A2 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 59 B4 / 10 part A1 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 60 B4 / 10 part A1 / A2 = 0.30 / 0.40 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 61 B4 / 10 part A1 / A2 = 0.25 / 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 62 B4 / 10 part A1 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 63 B4 / 10 part A1 / A2 = 0.50 / 0.20 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 64 B4 / 10 part A1 / A2 = 0.40 / 0.30 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 65 B4 / 10 part A1 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 66 B4 / 10 part A1 / A2 = 0.30 / 0.40 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 67 B4 / 10 part A1 / A2 = 0.25 / 0.45 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 68 B6 / 10 parts A1 = 0.70 parts Q1 / 0.065 parts 95 ° C / 95 ° C
Example 69 B6 / 10 part A2 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 70 B6 / 10 part A1 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 71 B7 / 10 part A1 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 72 B7 / 10 part A13 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 73 B7 / 10 part A1 / A13 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 74 B7 / 10 part A1 / A2 / A13 = 0.3 / 0.2 / 0.2 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 75 B6 / 10 part A10 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 76 B6 / 10 part A10 / A1 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 77 B6 / 10 part A12 / A2 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 78 B6 / 10 part A12 / A1 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 79 B8 / 10 part A1 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 80 B9 / 10 part A1 = 0.70 part Q1 / 0.065 part 95 ° C / 95 ° C
Example 81 B1 / 10 part A1 / A11 = 0.35 / 0.35 part Q1 / 0.065 part 95 ° C / 95 ° C
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Comparative Example 1 B5 / 10 part A1 = 0.27 part Q1 / 0.0325 part 130 ° C / 130 ° C
Comparative Example 2 B10 / 10 part A2 = 0.5 part Q1 / 0.065 part 100 ℃ / 105 ℃
Comparative Example 3 B10 / 10 part A1 = 0.51 part Q1 / 0.065 part 100 ° C / 105 ° C
Comparative Example 4 B11 / 10 part A2 / A4 = 0.4 / 0.3 part Q1 / 0.065 part 100 ° C / 95 ° C
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 2]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. (* 1) mol% (* 2) mol% (* 3) wt% (* 4) wt%
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 50 50 100 100
Example 2 50 50 100 71
Example 3 50 50 100 57
Example 4 50 50 100 43
Example 5 50 50 100 36
Example 6 50 50 100 100
Example 7 50 50 100 100
Example 8 50 50 100 100
Example 9 50 50 100 100
Example 10 50 50 100 100
Example 11 50 50 71 100
Example 12 50 50 50 100
Example 13 50 50 71 71
Example 14 50 50 100 71
Example 15 50 50 100 71
Example 16 50 50 100 57
Example 17 50 50 100 50
Example 18 50 50 100 43
Example 19 50 50 100 36
Example 20 50 50 100 100
Example 21 50 50 100 100
Example 22 50 50 100 100
Example 23 50 50 100 71
Example 24 50 50 100 50
Example 25 35 50 100 100
Example 26 35 50 100 71
Example 27 35 50 100 57
Example 28 35 50 100 50
Example 29 35 50 100 43
Example 30 35 50 100 36
Example 31 35 50 100 100
Example 32 35 50 100 100
Example 33 35 50 100 100
Example 34 35 50 100 100
Example 35 35 50 71 100
Example 36 35 50 50 100
Example 37 35 50 100 71
Example 38 35 50 100 71
15 50 100 29
Example 39 35 50 100 71
Example 40 35 50 100 57
Example 41 35 50 100 50
Example 42 35 50 100 43
Example 43 35 50 100 36
Example 44 35 50 100 100
Example 45 35 50 100 100
Example 46 35 50 100 100
Example 47 35 50 100 71
Example 48 35 50 100 50
Example 49 35 50 100 50
15 50 100 50
Example 50 50 55 100 100
Example 51 50 55 100 71
Example 52 50 55 100 57
Example 53 50 55 100 50
Example 54 50 55 100 43
Example 55 50 55 100 36
Example 56 50 60 100 100
Example 57 50 60 100 71
Example 58 50 60 100 57
Example 59 50 60 100 50
Example 60 50 60 100 43
Example 61 50 60 100 36
Example 62 50 60 100 100
Example 63 50 60 100 71
Example 64 50 60 100 57
Example 65 50 60 100 50
Example 66 50 60 100 43
Example 67 50 60 100 36
Example 68 50 50 100 100
Example 69 35 50 100 100
Example 70 50 50 100 50
35 50 100 50
Example 71 50 50 100 100
Example 72 40 50 100 100
Example 73 50 50 100 50
40 50 100 50
Example 74 50 50 100 43
10 50 100 29
40 50 100 29
Example 75 35 50 100 50
Example 76 35 50 100 100
Example 77 35 50 100 50
Example 78 50 50 100 50
Example 79 60 65 100 100
Example 80 70 70 100 100
Example 81 50 50 100 50
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Comparative Example 1 75 75 100 100
Comparative Example 2 47 47 100 0
Comparative Example 3 47 47 100 100
Comparative Example 4 42 50 100 43
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
(* 1) Ring structure: mol% (% by weight) of a structural unit containing a ring structure of the same skeleton as the acid generator
(* 2) Saturated cyclic group: mol% of structural unit containing saturated cyclic group
(* 3) Content of acid generator having a cation represented by formula (IXa) or formula (IXd):% by weight
(* 4) Content of acid generator containing a ring structure of the same skeleton as the resin:% by weight

[Table 3]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Effective sensitivity Resolution LER Pattern collapse tolerance
(mJ / cm2)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 43 ○ ○ △
Example 2 40 ○ ○ ○
Example 3 37 ○ ○ ○
Example 4 35 ○ ○ ○
Example 5 34 △ △ ○
Example 6 33 △ △ ○
Example 7 37 ○ ○ ○
Example 8 34 ○ ○ ○
Example 9 33 ○ ○ ○
Example 10 34 △ ○ ○
Example 11 37 O O O
Example 12 48 ○ ○ ○
Example 13 38 ○ ○ ○
Example 14 35 ○ ○ ○
Example 15 39 ○ ○ ○
Example 16 39 ○ ○ ○
Example 17 37 ○ ○ ○
Example 18 35 △ △ ○
Example 19 34 △ △ ○
Example 20 48 ○ ○ ○
Example 21 52 ○ ○ ○
Example 22 35 ○ △ △
Example 23 40 ○ ○ ○
Example 24 44 ○ ○ ○
Example 25 45 ○ ○ ○
Example 26 43 ○ ○ ○
Example 27 40 ○ ○ ○
Example 28 38 ○ ○ ○
Example 29 36 △ ○ ○
Example 30 34 △ ○ ○
Example 31 39 O O O
Example 32 36 O O O
Example 33 35 O O O
Example 34 35 Δ ○ ○
Example 35 39 O O O
Example 36 49 ○ ○ ○
Example 37 40 O O O
Example 38 37 O O O
Example 39 41 O O O
Example 40 40 ○ ○ ○
Example 41 39 O O O
Example 42 37 △ ○ ○
Example 43 35 △ ○ ○
Example 44 50 ○ ○ ○
Example 45 54 ○ ○ ○
Example 46 37 ○ △ △
Example 47 42 ○ ○ ○
Example 48 45 ○ ○ ○
Example 49 36 ○ ○ ○
Example 50 47 ○ ○ ○
Example 51 45 ○ ○ ○
Example 52 41 O O O
Example 53 39 O O O
Example 54 37 △ ○ ○
Example 55 35 △ ○ ○
Example 56 43 ○ ○ ○
Example 57 41 ○ ○ ○
Example 58 37 O O O
Example 59 35 ○ ○ ○
Example 60 34 △ ○ ○
Example 61 33 △ ○ ○
Example 62 33 ○ ○ ○
Example 63 31 ○ ○ ○
Example 64 27 ○ ○ ○
Example 65 25 ○ ○ ○
Example 66 24 Δ ○ ○
Example 67 24 △ ○ ○
Example 68 44 ○ ○ ○
Example 69 41 △ ○ ○
Example 70 42 ○ ○ ○
Example 71 40 ○ ○ ○
Example 72 38 O O O
Example 73 39 O O O
Example 74 38 ○ ○ ○
Example 75 41 ○ ○ ○
Example 76 43 ○ ○ ○
Example 77 44 △ ○ ○
Example 78 46 ○ ○ ○
Example 79 43 ○ ○ △
Example 80 44 ○ ○ △
Example 81 43 ○ ○ △
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Comparative Example 1 38 × × ×
Comparative Example 2 38 × △ △
Comparative Example 3 44 △ △ △
Comparative Example 4 42 Δ × ×
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  According to the chemically amplified photoresist composition of the present invention, a pattern having good resolution, good line edge roughness, and good pattern collapse resistance can be formed.

Claims (6)

Containing an acid generator represented by formula (I) and a resin comprising a structural unit represented by formula (II),
The content of the acid generator represented by the formula (I) is 45 to 100% by weight with respect to the total amount of the acid generator,
The content of the structural unit represented by the formula (II) in the resin is 35 to 70 mol% with respect to the total structural unit of the resin,
The content of the structural unit having a saturated cyclic hydrocarbon group in the resin is 50 to 70 mol% with respect to the total structural unit of the resin,
A chemically amplified photoresist composition, wherein the resin is a resin having four or more different structural units.

[In Formula (I) and Formula (II), R ¹ represents a hydrogen atom or a methyl group.
Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
X ¹ and X ² each independently represent a single bond or — [CH ₂ ] _k —, and —CH ₂ — contained in — [CH ₂ ] _k — is replaced with —CO— or —O—. It may be.
k represents an integer of 1 to 8.
Y ¹ represents a saturated cyclic hydrocarbon group having 3 to 36 carbon atoms, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Y ² represents a saturated cyclic hydrocarbon group having the same skeleton as Y ^1, and the hydrogen atom contained in the saturated cyclic hydrocarbon group is a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. The —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced with —CO— or —O—.
Z ⁺ represents a cation represented by the formula (IXa) or the formula (IXb). ]

[In Formula (IXa), P ^{1 to} P ³ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ]

[In Formula (IXb), P ^{10 to} P ²¹ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
B ¹ represents -S- or -O-.
m represents 0 or 1. ] Y ¹ represents an adamantyl group or a cyclohexyl group, and a hydrogen atom contained in the adamantyl group and the cyclohexyl group may be substituted with a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. _2. The composition according to claim 1, wherein —CH ₂ — contained in the saturated cyclic hydrocarbon group may be replaced by —CO— or —O—.   The resin containing the structural unit represented by the formula (II) is a resin having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution and capable of dissolving in an alkaline aqueous solution by acting with an acid. Item 3. The composition according to Item 1 or 2.   The composition in any one of Claims 1-3 containing other resin different from resin containing the structural unit represented by Formula (II).   The composition according to any one of claims 1 to 4, wherein the content of the acid generator is 1 to 20 parts by mass with respect to 100 parts by mass of the resin including the structural unit represented by the formula (II).   A pattern forming method comprising a step of applying the composition according to claim 1 on a substrate to form a resist film, a step of exposing the resist film, and a step of developing the resist film after exposure.