JP6974981B2 - Method for producing salt, resist composition and resist pattern - Google Patents

Description

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

特許文献２には、下記式で表される塩を酸発生剤として含有するレジスト組成物が記載されている。

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

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

Japanese Unexamined Patent Publication No. 2008-13551 Japanese Unexamined Patent Publication No. 2014-115319

In the resist composition containing the above salt, the CD uniformity (CDU) of the obtained resist pattern may not always be satisfactory.

［式（Ｉ）中、
Ｑ^１、Ｑ^２、Ｑ^１’及びＱ^２’は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^ｂ１及びＬ^ｂ１’は、それぞれ独立に、炭素数１〜２４の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子はフッ素原子又はヒドロキシ基で置換されていてもよい。
Ｘ^１は、塩基解離性基を有する２価の基を表す。
Ｚ１^＋及びＺ１’^＋は、それぞれ独立に、有機カチオンを表す。］
［２］塩基解離性基を有する２価の基が、式（Ｂａ）で表される部分構造又は式（Ｂｂ）で表される部分構造を有する基である［１］記載の塩。

［式（Ｂａ）及び式（Ｂｂ）中、
Ｌ¹及びＬ^２は、フッ素原子を有する炭素数１〜６のアルカンジイル基を表す。
Ｒ²⁵及びＲ²⁶は、それぞれ独立に、水素原子、フッ素原子又はフッ素原子を有する炭素数１〜６のアルキル基を表す。
＊は、Ｌ^ｂ１又はＬ^ｂ１’との結合手を表す。］
［３］塩基解離性基を有する２価の基が、式（Ｂａ１）で表される２価の基又は式（Ｂｂ１）で表される２価の基である［１］又は［２］記載の塩。

［式（Ｂａ１）及び式（Ｂｂ１）中、
Ｌ¹及びＬ^２は、フッ素原子を有する炭素数１〜６のアルカンジイル基を表す。
Ｒ²⁵、Ｒ²⁶、Ｒ^25’及びＲ^26’は、それぞれ独立に、水素原子、フッ素原子又はフッ素原子を有する炭素数１〜６のアルキル基を表す。
＊１は、Ｌ^ｂ１との結合手を表し、＊２はＬ^ｂ１’との結合手を表す。］
［４］Ｌ^ｂ１及びＬ^ｂ１’が、それぞれ独立して、以下で表される基である［１］〜［３］のいずれかに記載の塩。

（＊は、−Ｃ（Ｑ^１）（Ｑ^２）−又は−Ｃ（Ｑ^１’）（Ｑ^２’）−の炭素原子との結合手を表す。ｍ、ｎ、ｍ’及びｎ’は、それぞれ独立に、０又は１を表す。）
［５］［１］〜［４］のいずれかに記載の塩を含有する酸発生剤。
［６］［５］に記載の酸発生剤と酸不安定基を有する樹脂とを含有するレジスト組成物。
［７］さらに、酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩を含有する［６］に記載のレジスト組成物。
［８］（１）［６］又は［７］に記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In formula (I),
^{Q 1, Q 2, Q 1} ' and Q ^2' each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 and ^{L b1 'each} independently represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, -CH ₂ contained in the saturated hydrocarbon group - is replaced by -O- or -CO- The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
X ¹ represents a divalent group having a base dissociative group.
Z1 ⁺ and Z1' ⁺ each independently represent an organic cation. ]
[2] The salt according to [1], wherein the divalent group having a base dissociative group is a group having a partial structure represented by the formula (Ba) or a partial structure represented by the formula (Bb).

[In the formula (Ba) and the formula (Bb),
L ¹ and L ² represent an alkanediyl group having 1 to 6 carbon atoms having a fluorine atom.
R ²⁵ and R ²⁶ independently represent an alkyl group having 1 to 6 carbon atoms having a hydrogen atom, a fluorine atom, or a fluorine atom.
* Represents a bond with ^{L b1} or L ^b1'. ]
[3] The divalent group having a base dissociative group is a divalent group represented by the formula (Ba1) or a divalent group represented by the formula (Bb1) [1] or [2]. Salt.

[In the formula (Ba1) and the formula (Bb1),
L ¹ and L ² represent an alkanediyl group having 1 to 6 carbon atoms having a fluorine atom.
^{R 25, R 26, R 25} ' and R ^26' each independently represent an alkyl group having 1 to 6 carbon atoms having a hydrogen atom, a fluorine atom or a fluorine atom.
* 1 ^{represents a bond with L b1} and * 2 represents a bond with L ^b1' . ]
[4] The salt according to any one of [1] to [3], wherein ^{L b1} and L ^{b1'are independent groups represented by the following.}

(* Represents a bond with a carbon atom of -C (Q ¹ ) (Q ² )-or -C (Q ^1' ) (Q ^2' )-. M, n, m'and n'are. Represents 0 or 1 independently.)
[5] An acid generator containing the salt according to any one of [1] to [4].
[6] A resist composition containing the acid generator according to [5] and a resin having an acid unstable group.
[7] The resist composition according to [6], which further contains a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.
[8] (1) A step of applying the resist composition according to [6] or [7] onto a substrate,
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) A method for producing a resist pattern, which comprises a step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

Provided are a salt capable of producing a resist pattern having good CD uniformity (CDU) and a resist composition containing the salt.

As used herein, the term "(meth) acrylic monomer" means at least one of the monomers having a structure of _{"CH 2} = CH-CO-" or "CH ₂ = C (CH _{3) -CO-".} do. Similarly, "(meth) acrylate" and "(meth) acrylic acid" mean "at least one of acrylate and methacrylate" and "at least one of acrylic acid and methacrylic acid", respectively. In addition, any of the groups described in the present specification that can have both a linear structure and a branched structure may be used. If a steric isomer is present, it includes all steric isomers.
In the present specification, the "solid content of the resist composition" means the total amount of the components excluding the solvent (E) described later from the total amount of the resist composition.

［式（Ｉ）中、
Ｑ^１、Ｑ^２、Ｑ^１’及びＱ^２’は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^ｂ１及びＬ^ｂ１’は、それぞれ独立に、炭素数１〜２４の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子はフッ素原子又はヒドロキシ基で置換されていてもよい。
Ｘ^１は、塩基解離性基を有する２価の基を表す。
Ｚ１^＋及びＺ１’^＋は、それぞれ独立に、有機カチオンを表す。］ <Salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)")>
The salt of the present invention is represented by the formula (I). The salt (I) produces an acid by the action of light.

[In formula (I),
^{Q 1, Q 2, Q 1} ' and Q ^2' each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 and ^{L b1 'each} independently represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, -CH ₂ contained in the saturated hydrocarbon group - is replaced by -O- or -CO- The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
X ¹ represents a divalent group having a base dissociative group.
Z1 ⁺ and Z1' ⁺ each independently represent an organic cation. ]

The perfluoroalkyl group represented by ^{Q 1, Q 2, Q 1} ' and Q ^2', a trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, a perfluoro sec- butyl group, Examples thereof include a perfluorotert-butyl group, a perfluoropentyl group and a perfluorohexyl group.
^{Q 1, Q 2, Q 1} ' and Q ^2' each independently is preferably a fluorine atom or a trifluoromethyl ^{group, Q 1, Q 2, Q 1} ' and Q ^2' is a fluorine atom Is more preferable.

Examples of the divalent saturated hydrocarbon group represented by L ^b1 and L ^b1' include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and examples of these groups can be mentioned. A combination of two or more of them may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-Diyl group, Octane-1,8-Diyl group, Nonan-1,9-Diyl group, Decane-1,10-Diyl group, Undecan-1,11-Diyl group, Dodecan-1,12-Diyl group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group. Alcandiyl group;
Etan-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc. Valuable alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. The group etc. can be mentioned.

［式（ｂ１−１）中、
Ｌ^ｂ２は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ３は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
ただし、Ｌ^ｂ２とＬ^ｂ３との炭素数合計は、２２以下である。
式（ｂ１−２）中、
Ｌ^ｂ４は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ５は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
ただし、Ｌ^ｂ４とＬ^ｂ５との炭素数合計は、２２以下である。
式（ｂ１−３）中、
Ｌ^ｂ６は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｌ^ｂ７は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
ただし、Ｌ^ｂ６とＬ^ｂ７との炭素数合計は、２３以下である。］ _{Examples of the group in which −CH 2} − contained in the divalent saturated hydrocarbon group of L ^b1 and L ^{b1 ′} is replaced with −O− or −CO− are the groups of the formulas (b1-1) to (b1-3). ) Can be mentioned. Formula (b1-1) ~ formula (b1-3) and in specific examples below, * represents a bond to ^{X 1.}

[In equation (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated hydrocarbon group may be substituted. _{-CH 2-} contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms of ^{L b2} and L ^{b3 is 22 or less.}
In equation (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated hydrocarbon group may be substituted. _{-CH 2-} contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms of ^{L b4} and L ^{b5 is 22 or less.}
In equation (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated hydrocarbon group may be substituted. _{-CH 2-} contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms of ^{L b6} and L ^{b7 is 23 or less.} ]

In the formulas (b1-1) to (b1-3), when -CH _2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before the replacement is the saturated hydrocarbon. The number of carbon atoms in the hydrogen group.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of ^{L b1.}

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. _{-CH 2-} contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.
-CH ₂ contained in the divalent saturated hydrocarbon group of L ^b1 and ^{L b1 '-} as has been replaced by -O- or -CO- group, with group represented by the formula (b1-1) or the formula (b1-3) The group represented is preferred.

［式（ｂ１−４）中、
Ｌ^ｂ８は、単結合又は炭素数１〜２２の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
式（ｂ１−５）中、
Ｌ^ｂ９は、炭素数１〜２０の２価の飽和炭化水素基を表す。
Ｌ^ｂ１０は、単結合又は炭素数１〜１９の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。ただし、Ｌ^ｂ９及びＬ^ｂ１０の合計炭素数は２０以下である。
式（ｂ１−６）中、
Ｌ^ｂ１１は、炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^ｂ１２は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。ただし、Ｌ^ｂ１１及びＬ^ｂ１２の合計炭素数は２１以下である。
式（ｂ１−７）中、
Ｌ^ｂ１３は、炭素数１〜１９の２価の飽和炭化水素基を表す。
Ｌ^ｂ１４は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１５は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。ただし、Ｌ^ｂ１３〜Ｌ^ｂ１５の合計炭素数は１９以下である。
式（ｂ１−８）中、
Ｌ^ｂ１６は、炭素数１〜１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１７は、炭素数１〜１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１８は、単結合又は炭素数１〜１７の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。ただし、Ｌ^ｂ１６〜Ｌ^ｂ１８の合計炭素数は１９以下である。］ Examples of the formula (b1-1) include groups represented by the formulas (b1-4) to (b1-8).

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

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

［式（ｂ１−９）中、
Ｌ^ｂ１９は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２０は、単結合又は炭素数１〜２３の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。ただし、Ｌ^ｂ１９及びＬ^ｂ２０の合計炭素数は２３以下である。
式（ｂ１−１０）中、
Ｌ^ｂ２１は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２２は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^ｂ２３は、単結合又は炭素数１〜２１の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。ただし、Ｌ^ｂ２１〜Ｌ^ｂ２３の合計炭素数は２１以下である。
式（ｂ１−１１）中、
Ｌ^ｂ２４は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ２５は、炭素数１〜２１の２価の飽和炭化水素基を表す。
Ｌ^ｂ２６は、単結合又は炭素数１〜２０の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^ｂ２４〜Ｌ^ｂ２６の合計炭素数は２１以下である。］ Examples of the formula (b1-3) include groups represented by the formulas (b1-9) to (b1-11), respectively.

[In equation (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is replaced with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. May be. _{-CH 2-} contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be replaced with a hydroxy group. However, the total carbon number of ^{L b19} and L ^{b20 is 23 or less.}
In equation (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is replaced with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. It may have been. _{-CH 2-} contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be replaced with a hydroxy group. However, the total carbon number of ^{L b21 to} L ^{b23 is 21 or less.}
In equation (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group is replaced with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. It may have been. _{-CH 2-} contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be replaced with a hydroxy group.
^However, the total number of carbon atoms of L b24 ^{~L b26} is 21 or less. ]

In formulas (b1-9) to (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms of the alkylcarbonyloxy group and the ester bond The number of carbon atoms of the divalent saturated hydrocarbon group is taken including the number of CO and O in it.

Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, an adamantylcarbonyloxy group and the like.

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

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

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

Examples of the group represented by the formula (b1-7) include the following.

Examples of the group represented by the formula (b1-8) include the following.

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

Examples of the group represented by the formula (b1-9) include the following.

Examples of the group represented by the formula (b1-10) include the following.

Examples of the group represented by the formula (b1-11) include the following.

（＊は、−Ｃ（Ｑ^１）（Ｑ^２）−又は−Ｃ（Ｑ^１’）（Ｑ^２’）−の炭素原子との結合手を表す。ｍ、ｎ、ｍ’及びｎ’は、それぞれ独立に、０又は１を表す。） Among them, ^{it is preferable that L b1} and L ^b1'are independent groups represented by the following.

(* Represents a bond with a carbon atom of -C (Q ¹ ) (Q ² )-or -C (Q ^1' ) (Q ^2' )-. M, n, m'and n'are. Represents 0 or 1 independently.)

［式（Ｂａ）及び式（Ｂｂ）中、
Ｌ¹及びＬ^２は、フッ素原子を有する炭素数１〜６のアルカンジイル基を表す。
Ｒ²⁵及びＲ²⁶は、それぞれ独立に、水素原子、フッ素原子又はフッ素原子を有する炭素数１〜６のアルキル基を表す。
＊は、Ｌ^ｂ１又はＬ^ｂ１’との結合手を表す。］ The ^{base dissociable group contained in X 1} means a group having a leaving group, and the leaving group is removed by contact with an alkali to form a hydrophilic group (for example, a hydroxy group or a carboxy group). do.
The divalent group having a base dissociative group is preferably a group having a partial structure represented by the formula (Ba) or a partial structure represented by the formula (Bb).

[In the formula (Ba) and the formula (Bb),
L ¹ and L ² represent an alkanediyl group having 1 to 6 carbon atoms having a fluorine atom.
R ²⁵ and R ²⁶ independently represent an alkyl group having 1 to 6 carbon atoms having a hydrogen atom, a fluorine atom, or a fluorine atom.
* Represents a bond with ^{L b1} or L ^b1'. ]

The ^{alkanediyl group having 1 to 6 carbon atoms having a fluorine atom represented by L 1} and L ² is, for example, a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, and the like. Perfluoropropane-1,2-diyl group, perfluoropropane-2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, Perfluoropentane-1,5-diyl group, perfluoropentane-2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, Perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, Perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like, and have 1 to 4 carbon atoms. It is preferably a perfluoroalkanediyl group.

The ^{alkyl group having a fluorine atom represented by R 25} and R ²⁶ is, for example, 1,1,1-trifluoroethyl group, perfluoroethyl group, 1,1,1,2,2-pentafluoropropyl group, 2 -Trifluoromethyl-1,1,1-trifluoroethyl group, perfluoropropyl group, 1,1,1,2,2,3,3-peptafluorobutyl group, perfluorobutyl group, 1,1,1, Examples thereof include 2,2,3,3,4,4-nonafluoropentyl group, perfluoropentyl group, perfluorohexyl group and the like, and a perfluoroalkyl group having 1 to 6 carbon atoms is preferable.
It is preferable that R ²⁵ and R ²⁶ are independently hydrogen atoms or fluorine atoms, respectively.

For example, the partial structure represented by the formula (Ba) is decomposed by the action of an alkali to generate a hydroxy group. Further, the partial structure represented by the formula (Bb) is decomposed by the action of an alkali to generate a carboxy group. As the alkali, tetramethylammonium hydroxide is preferable.
The cleavage of the base dissociative group in the salt (I) can be confirmed according to the method described in JP2013-041269. Note that cleavage means that the bond is cleaved and separated into a plurality of molecules, and does not include a ring-opening reaction.

［式（Ｂａ１）及び式（Ｂｂ１）中、
Ｌ¹及びＬ^２は、フッ素原子を有する炭素数１〜６のアルカンジイル基を表す。
Ｒ²⁵、Ｒ²⁶、Ｒ^25’及びＲ^26’は、それぞれ独立に、水素原子、フッ素原子又はフッ素原子を有する炭素数１〜６のアルキル基を表す。
＊１は、Ｌ^ｂ１との結合手を表し、＊２はＬ^ｂ１’との結合手を表す。］
Ｒ^25’及びＲ^26’は、上述したＲ²⁵及びＲ²⁶で挙げた基と同様の基が挙げられる。 The divalent group having a base dissociative group is preferably a divalent group represented by the formula (Ba1) or a divalent group represented by the formula (Bb1).

[In the formula (Ba1) and the formula (Bb1),
L ¹ and L ² represent an alkanediyl group having 1 to 6 carbon atoms having a fluorine atom.
^{R 25, R 26, R 25} ' and R ^26' each independently represent an alkyl group having 1 to 6 carbon atoms having a hydrogen atom, a fluorine atom or a fluorine atom.
* 1 ^{represents a bond with L b1} and * 2 represents a bond with L ^b1' . ]
As R ^25'and R ^26' , the same groups as those mentioned in R ²⁵ and R ^{26 described above can be mentioned.}

Specific examples of the anion constituting the salt (I) include the following.

［式（ｂ２−１）〜式（ｂ２−４）において、
Ｒ^ｂ４〜Ｒ^ｂ６は、それぞれ独立に、炭素数１〜３０の脂肪族炭化水素基、炭素数３〜３６の脂環式炭化水素基又は炭素数６〜３６の芳香族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子は、ヒドロキシ基、炭素数１〜１２のアルコキシ基、炭素数３〜１２の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、炭素数１〜１８の脂肪族炭化水素基、炭素数２〜４のアルキルカルボニル基又はグリシジルオキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基又は炭素数１〜１２のアルコキシ基で置換されていてもよい。
Ｒ^ｂ４とＲ^ｂ５とは、それらが結合する硫黄原子とともに環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ−又は−ＣＯ−に置き換わってもよい。
Ｒ^ｂ７及びＲ^ｂ８は、それぞれ独立に、ヒドロキシ基、炭素数１〜１２の脂肪族炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に、０〜５のいずれかの整数を表す。
ｍ２が２以上のとき、複数のＲ^ｂ７は同一であっても異なってもよく、ｎ２が２以上のとき、複数のＲ^ｂ８は同一であっても異なってもよい。
Ｒ^ｂ９及びＲ^ｂ１０は、それぞれ独立に、炭素数１〜３６の脂肪族炭化水素基又は炭素数３〜３６の脂環式炭化水素基を表す。
Ｒ^ｂ９とＲ^ｂ１０とは、それらが結合する硫黄原子とともに環を形成してもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ−又は−ＣＯ−に置き換わってもよい。
Ｒ^ｂ１１は、水素原子、炭素数１〜３６の脂肪族炭化水素基、炭素数３〜３６の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表す。
Ｒ^ｂ１２は、炭素数１〜１２の脂肪族炭化水素基、炭素数３〜１８の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表し、該脂肪族炭化水素に含まれる水素原子は、炭素数６〜１８の芳香族炭化水素基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１〜１２のアルコキシ基又は炭素数１〜１２のアルキルカルボニルオキシ基で置換されていてもよい。
Ｒ^ｂ１１とＲ^ｂ１２とは、一緒になってそれらが結合する−ＣＨ−ＣＯ−を含む環を形成していてもよく、該環に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ−又は−ＣＯ−に置き換わってもよい。
Ｒ^ｂ１３〜Ｒ^ｂ１８は、それぞれ独立に、ヒドロキシ基、炭素数１〜１２の脂肪族炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
Ｌ^ｂ３１は、−Ｓ−又は−Ｏ−を表す。
ｏ２、ｐ２、ｓ２、及びｔ２は、それぞれ独立に、０〜５のいずれかの整数を表す。
ｑ２及びｒ２は、それぞれ独立に、０〜４のいずれかの整数を表す。
ｕ２は、０又は１を表す。
ｏ２が２以上のとき、複数のＲ^ｂ１３は同一であっても異なってもよく、ｐ２が２以上のとき、複数のＲ^ｂ１４は同一であっても異なってもよく、ｑ２が２以上のとき、複数のＲ^ｂ１５は同一であっても異なってもよく、ｒ２が２以上のとき、複数のＲ^ｂ１６は同一であっても異なってもよく、ｓ２が２以上のとき、複数のＲ^ｂ１７は同一であっても異なってもよく、ｔ２が２以上のとき、複数のＲ^ｂ１８は同一であっても異なってもよい。］ The cation in the salt (I) is preferably an organic cation. Examples of the organic cation include an organic onium cation, an organic sulfonium cation, an organic iodine cation, an organic ammonium cation, a benzothiazolium cation, an organic phosphonium cation and the like. Among these, organic sulfonium cations and organic iodonium cations are preferable, and aryl sulfonium cations are more preferable.
Among them, a cation represented by any of the formulas (b2-1) to (b2-4) (hereinafter, may be referred to as “cation (b2-1)” or the like depending on the formula number) is preferable.

[In equations (b2-1) to (b2-4),
R ^{b4 to} R ^b6 independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. It may be substituted, and the hydrogen atom contained in the alicyclic hydrocarbon group is a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms or a glycidyloxy group. It may be substituted, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may form a ring together with the sulfur atom to which they are bonded, and -CH _2- contained in the ring may be replaced with -O-, -SO- or -CO-. ..
R ^b7 and R ^b8 independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
When m2 is 2 or more, the plurality of R ^b7s may be the same or different, and when n2 is 2 or more, the plurality of R ^b8s may be the same or different.
R ^b9 and R ^b10 independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may form a ring together with the sulfur atom to which they are bonded, and -CH _2- contained in the ring may be replaced with -O-, -SO- or -CO-. ..
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and is contained in the aliphatic hydrocarbon group. The hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be an alkoxy group having 1 to 12 carbon atoms or 1 to 12 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
The R ^b11 and ^{R b12,} together may form a ring containing a -CH-CO- which they are bond, _-CH 2 contained in the ring - is, -O -, - SO- Alternatively, it may be replaced with −CO−.
R ^{b13 to} R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents -S- or -O-.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, the plurality of R ^b13s may be the same or different, when p2 is 2 or more, the plurality of R ^b14s may be the same or different, and when q2 is 2 or more. , The plurality of R ^b15s may be the same or different, and when r2 is 2 or more, the plurality of R ^b16s may be the same or different, and when s2 is 2 or more, the plurality of R ^b17s are. It may be the same or different, and when t2 is 2 or more, the plurality of R ^b18s may be the same or different. ]

中でも、Ｒ^ｂ９〜Ｒ^ｂ１２の脂環式炭化水素基の炭素数は、好ましくは３〜１８であり、より好ましくは４〜１２である。 The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group.
The chain hydrocarbon group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group and a 2-ethylhexyl group. Alkyl group of. Among them, ^{the aliphatic hydrocarbon group of R b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be either a monocyclic group or a polycyclic group, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a cycloheptyl. Examples thereof include a cycloalkyl group such as a group, a cyclooctyl group and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups.

Among them, ^{the alicyclic hydrocarbon groups of R b9 to} R ^b12 preferably have 3 to 18 carbon atoms, and more preferably 4 to 12 carbon atoms.

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

Examples of the aromatic hydrocarbon group include phenyl group, trill group, xsilyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, p-cyclohexylphenyl group and p-adamantylphenyl group. , Biphenylyl group, naphthyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and other aryl groups.
When the aromatic hydrocarbon group contains an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, the aliphatic hydrocarbon group having 1 to 18 carbon atoms or the alicyclic hydrocarbon group having 3 to 18 carbon atoms may be used. preferable.
Examples of the aromatic hydrocarbon group in which the hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group and the like.
Examples of the aliphatic hydrocarbon group in which the hydrogen atom is substituted with an aromatic hydrocarbon group include an aralkyl group such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group and a naphthylethyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, and a tert-butylcarbonyloxy group. Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group.

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

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

Among the cations (b2-1) to cations (b2-4), cations (b2-1) are preferable.
Examples of the cation (b2-1) include the following cations.

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

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

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

Examples of the salt (I) include salts in which the above-mentioned anions and organic cations are combined. These anions and cations can be combined arbitrarily. Specific examples of the salt (I) are shown in Table 1.

In Table 1, each reference numeral represents a reference numeral assigned to the above-mentioned structure representing an anion or cation. For example, the salt (I-1) is a salt composed of an anion represented by the formula (I-a-1) and a cation represented by the formula (b2-c-1) / formula (b2-c-1). , The salt shown below.

Among them, the salt (I) is salt (I-1), salt (I-2), salt (I-3), salt (I-4), salt (I-5), salt (I-6). , Salt (I-7), Salt (I-8), Salt (I-21), Salt (I-22), Salt (I-25), Salt (I-26), Salt (I-27), Salt (I-28), salt (I-29), salt (I-30), salt (I-31), salt (I-32), salt (I-33), salt (I-34), salt (I-47), salt (I-48), salt (I-51), salt (I-52), salt (I-53), salt (I-54), salt (I-55), salt ( I-56), salt (I-57), salt (I-58), salt (I-59), salt (I-60), salt (I-73), salt (I-74), salt (I) -77), salt (I-78), salt (I-79), salt (I-80), salt (I-81), salt (I-82), salt (I-83), salt (I-) 84), salt (I-85), salt (I-86), salt (I-99), salt (I-100), salt (I-103), salt (I-104), salt (I-105) ), Salt (I-106), Salt (I-107), Salt (I-108), Salt (I-109), Salt (I-110), Salt (I-111), Salt (I-112) , Salt (I-125), Salt (I-126), Salt (I-129), Salt (I-130), Salt (I-131), Salt (I-132), Salt (I-133), Salt (I-134), salt (I-135), salt (I-136), salt (I-137), salt (I-138), salt (I-151), salt (I-152), salt (I-155), salt (I-156), salt (I-157), salt (I-158), salt (I-159), salt (I-160), salt (I-161), salt ( I-162), salt (I-163), salt (I-164), salt (I-177), salt (I-178), salt (I-181) and salt (I-182) are preferred.

（式中、Ｌ^ｂ１、Ｌ^ｂ１’、Ｌ^１、Ｑ¹、Ｑ²、Ｑ^１’、Ｑ^２’、Ｚ１^＋及びＺ１’^＋は上記と同じ意味を表す。）
溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
塩基触媒としては、トリエチルアミン、ピリジン、モルホリン、ピペリジン、Ｎ−メチルピペリジン、Ｎ，Ｎ−ジメチルアミノピリジン、Ｎ−メチルピロリジン等が挙げられる。
反応温度は通常１５℃〜８０℃であり、反応時間は通常０．５時間〜２４時間である。 <Manufacturing method of salt (I)>
The ^{salt (I1) on which X 1} is a divalent group represented by the formula (Ba1) is a salt represented by the formula (I1-a) and a salt represented by the formula (I1-a'). , Can be produced by reacting the compound represented by the formula (I1-b) in a solvent under a basic catalyst.

(In the formula, L ^b1 , L ^b1' , L ¹ , Q ¹ , Q ² , Q ^1' , Q ^2' , Z1 ⁺ and Z1' ⁺ have the same meanings as above.)
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the base catalyst include triethylamine, pyridine, morpholine, piperidine, N-methylpiperidine, N, N-dimethylaminopyridine, N-methylpyrrolidine and the like.
The reaction temperature is usually 15 ° C to 80 ° C, and the reaction time is usually 0.5 to 24 hours.

式（Ｉ１−ｂ）で表される化合物としては、下記式で表される塩等が挙げられる。

Examples of the salt represented by the formula (I1-a) include salts represented by the following formula.

Examples of the compound represented by the formula (I1-b) include salts represented by the following formula.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
溶媒としては、クロロホルム、アセトニトリル等が挙げられる。
塩基触媒としては、トリエチルアミン、ピリジン、モルホリン、ピペリジン、Ｎ−メチルピペリジン、Ｎ，Ｎ−ジメチルアミノピリジン、Ｎ−メチルピロリジン等が挙げられる。
反応温度は通常１５℃〜８０℃であり、反応時間は通常０．５時間〜２４時間である。 The ^{salt (I2) in which X 1} is a divalent group represented by the formula (Bb1) is a salt represented by the formula (I2-a) and a salt represented by the formula (I2-a'). , Can be produced by reacting with the compound represented by the formula (I2-b) in a solvent under a basic catalyst.

(In the formula, all the symbols have the same meanings as described above.)
Examples of the solvent include chloroform, acetonitrile and the like.
Examples of the base catalyst include triethylamine, pyridine, morpholine, piperidine, N-methylpiperidine, N, N-dimethylaminopyridine, N-methylpyrrolidine and the like.
The reaction temperature is usually 15 ° C to 80 ° C, and the reaction time is usually 0.5 to 24 hours.

式（Ｉ２−ｂ）で表される化合物としては、下記式で表される塩等が挙げられる。

Examples of the salt represented by the formula (I2-a) include salts represented by the following formula.

Examples of the compound represented by the formula (I2-b) include salts represented by the following formula.

[Acid generator]
The acid generator of the present invention comprises a salt (I). The acid generator of the present invention may contain two or more kinds of salts (I).
In addition to the salt (I), the acid generator of the present invention may contain an acid generator known in the resist field (hereinafter, may be referred to as "acid generator (B)").
When the acid generator of the present invention contains a salt (I) and an acid generator (B), the ratio of the contents of the salt (I) to the acid generator (B) (mass ratio; salt (I): acid. The generator (B)) is usually 1:99 to 99: 1, preferably 2:98 to 98: 2, more preferably 5:95 to 95: 5, and even more preferably 10:90 to 90:10. be.

[Resist composition]
The resist composition of the present invention contains a resin having an acid unstable group (hereinafter, may be referred to as "resin (A)") and a salt (I). Here, the "acid-unstable group" means a group having a leaving group, and the leaving group is removed by contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group).
The resist composition further preferably contains a quencher (hereinafter, may be referred to as “quencher (C)”) and a solvent (hereinafter, may be referred to as “solvent (E)”).

In the resist composition of the present invention, the content of the salt (I) is preferably 1 to 40% by mass, more preferably 2 to 35% by mass with respect to the resin (A).

<Acid generator (B)>
The acid generator is classified into a nonionic type and an ionic type, and any of the acid generator (B) may be used. Nonionic acid generators include organic halides and sulfonate esters (eg 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonates), sulfones (eg, disulfones, ketosulfones, sulfonyldiazomethanes) and the like. Examples of the ionic acid generator include an ionic acid generator composed of a combination of a known cation and a known anion, and an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt) is represented. It is a target. Examples of the onium salt anion include a sulfonic acid anion, a sulfonylimide anion, and a sulfonylmethide anion.

Examples of the acid generator (B) include JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, and Japanese Patent Publication No. 63-163452. Kaisho 62-153853, JP-A-63-146029, US Patent No. 3,779,778, US Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. The compound that generates an acid by radiation, the acid generator described in JP2013-68914A, JP2013-3155A, JP2013-11905, and the like can be used. Further, a compound produced by a known method may be used.

［式（Ｂ１）中、
Ｑ^１１及びＱ^１２は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^Ｂ１は、炭素数１〜２４の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］ Examples of the acid generator (B) include organic sulfonates and the like, preferably a fluorine-containing acid generator, and more preferably an acid generator represented by the formula (B1) (hereinafter, "acid generator (hereinafter" acid generator (B)). B1) "may be mentioned).

[In formula (B1),
Q ¹¹ and ^{Q 12} each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^B1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, -CH ₂ contained in a saturated hydrocarbon group of the divalent - may be replaced by -O- or -CO-, The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and is contained in the alicyclic hydrocarbon group. CH ₂ - is, -O -, - SO ₂ - or -CO- may be replaced with.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl group Q ¹¹ and Q ^12, include the same groups as those listed in the perfluoroalkyl group represented by Q ¹ and Q ^2.
Independently, Q ¹¹ and Q ¹² are preferably a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom. It is more preferable that both Q ¹¹ and Q ^{12 are fluorine atoms.}

Examples of the divalent saturated hydrocarbon group of L ^B1, include the same groups as the divalent saturated hydrocarbon group represented by L ^b1.
-CH ₂ contained in the divalent saturated hydrocarbon group of L ^B1 - as has been replaced by -O- or -CO- group, any of the above-mentioned formula (b1-1) ~ formula (b1-3) Examples are similar to the group represented by. * Represents a bond with Y.

The alicyclic hydrocarbon group represented by Y may be a monocyclic ring, a polycyclic ring, or a spiro ring. Examples of the alicyclic hydrocarbon group represented by Y include groups represented by the formulas (Y1) to (Y38).
_{When -CH 2-} contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -SO _2- or -CO-, the number may be one or two or more. ..

Among them, a group represented by any one of the formula (Y1) to the formula (Y20), the formula (Y30) or the formula (Y31) is preferably mentioned, and more preferably the formula (Y11), the formula (Y15) and the formula (Y31). Examples include groups represented by Y16), formula (Y19), formula (Y30) or formula (Y31), and more preferably groups represented by formula (Y11), formula (Y15) or formula (Y30). Be done.

As the substituent of the alicyclic hydrocarbon group of Y, a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms which may have a hydroxy group, and an alicyclic hydrocarbon group having 3 to 16 carbon atoms are used. , An alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group or-(CH ₂ ) _ja. during ^{_{'-O-CO-R b1'}} group (wherein, R ^{b1 'is} an alkyl group having 1 to 16 carbon atoms, an aromatic alicyclic hydrocarbon group or a C6-18 3 to 16 carbon atoms carbide It represents a hydrogen group. Ja'represents an integer from 0 to 4) and the like.

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

Examples of Y include the following.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and more preferably an adamantyl group which may have a substituent (constituting these groups). -CH _2- may be replaced with -O-, -SO _2- or -CO-), more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group or a group represented by the following. ..

Examples of the salt anion represented by the formula (B1) include formulas (B1-A-1) to (B1-A-55). Anions represented by the formulas (B1-A-1) to (B1-A-55) [hereinafter, may be referred to as "anions (B1-A-1)" depending on the formula number. ] Are preferable, and the formulas (B1-A-1) to (B1-A-4), formulas (B1-A-9), formulas (B1-A-10), and formulas (B1-A-24) to formulas (B1-A-24) to formulas are preferable. (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-55). Anions are more preferred.

ここでＲ^ｉ２〜Ｒ^ｉ７は、例えば、炭素数１〜４のアルキル基、好ましくはメチル基又はエチル基である。
Ｒ^ｉ８は、例えば、炭素数１〜１２の脂肪族炭化水素基であり、好ましくは炭素数１〜４のアルキル基、炭素数５〜１２の脂環式炭化水素基又はこれらを組合せることにより形成される基であり、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。
Ｌ^４４は、単結合又は炭素数１〜４のアルカンジイル基である。
Ｑ^１１及びＱ^１２は、上記と同じである。

Here, R ^{i2 to} R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group.
R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. It is a group formed, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
L ⁴⁴ is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ¹¹ and ^{Q 12} are the same as above.

Examples of the anion in the salt represented by the formula (B1) include anions represented by the formulas (Ia-1) to (Ia-34).

Ｚ^＋の有機カチオンとしては、塩（Ｉ）における有機カチオンで例示したものと同様のものが挙げられる。

Examples of the organic cation of Z ⁺ include the same as those exemplified for the organic cation in the salt (I).

Specific examples of the acid generator (B) include salts represented by any of the formulas (B1-1) to (B1-48). Among them, those containing an aryl sulfonium cation are preferable, and formulas (B1-1) to (B1-3), formulas (B1-5) to (B1-7), formulas (B1-11) to formulas (B1-14). ), Formula (B1-17), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-48). Salt is more preferred.

The acid generator (B) may contain one kind alone or two or more kinds.
The content of the acid generator (B) is preferably 1 to 40% by mass, more preferably 3 to 35% by mass, based on the resin (A).
When the acid generator (B) is contained, the total content of the salt (I) and the acid generator (B) is preferably 1.5 parts by mass or more with respect to 100 parts by mass of the resin (A). (More preferably 3 parts by mass or more), preferably 40 parts by mass or less (more preferably 35 parts by mass or less). The acid generator (B) may contain two or more kinds.

<Resin (A)>
The resin (A) has a structural unit having an acid unstable group (hereinafter, may be referred to as “structural unit (a1)”). It is preferable that the resin (A) further contains a structural unit other than the structural unit (a1). The structural unit other than the structural unit (a1) includes a structural unit having no acid unstable group (hereinafter, may be referred to as “structural unit (s)”), a structural unit (a1), and a structural unit other than the structural unit (s). Examples thereof include structural units (hereinafter, may be referred to as “structural unit (t)”) and other structural units derived from monomers known in the art.

［式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、置換基を有していてもよい炭素数１〜８のアルキル基又は置換基を有していてもよい炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合してそれらが結合する炭素原子とともに炭素数３〜２０の非芳香族炭化水素環を形成する。
ｍａ及びｎａは、それぞれ独立に０又は１を表し、ｍａ及びｎａのうち少なくとも一方は１である。
＊は結合手を表す。］

［式（２）中、Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^a3’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合してそれらが結合する炭素原子及びＸとともに炭素数３〜２０の複素環を形成し、該炭化水素基及び該複素環に含まれる−ＣＨ₂−は、−Ｏ−又は−Ｓ−で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
ｎａ’は、０又は１を表す。
＊は結合手を表す。］ <Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid unstable group (hereinafter, may be referred to as “monomer (a1)”).
The acid unstable group contained in the resin (A) is preferably a group represented by the formula (1) and / or a group represented by the formula (2).

[In the formula (1), R ^{a1 to} R ^a3 independently have an alkyl group having 1 to 8 carbon atoms which may have a substituent or an alkyl group having 3 to 20 carbon atoms which may have a substituent. Representing the alicyclic hydrocarbon group of, R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
ma and na independently represent 0 or 1, respectively, and at least one of ma and na is 1.
* Represents a bond. ]

[In the formula (2), R ^a1'and R ^a2' each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^a3' represents a hydrocarbon group having 1 to 20 carbon atoms. Represented, R ^a2'and R ^a3' are bonded to each other to form a heterocycle having 3 to 20 carbon atoms together with the carbon atom and X to which they are bonded, and are contained in the hydrocarbon group and the heterocycle-CH ₂ -May be replaced by -O- or -S-.
X represents an oxygen atom or a sulfur atom.
na'represents 0 or 1.
* Represents a bond. ]

置換基を有していてもよい炭素数１〜８のアルキル基の置換基としては、炭素数３〜２０の脂環式炭化水素基が挙げられる。
置換基を有していてもよい炭素数３〜２０の脂環式炭化水素基の置換基としては、炭素数１〜８のアルキル基が挙げられる。より具体的にはメチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等が挙げられる。
好ましくは、ｍａは０であり、ｎａは１である。 ^Examples of the alkyl group of R ^{a1 to} R a3 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group and the like.
The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 may be either a monocyclic type or a polycyclic type. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* indicates a bond). The alicyclic hydrocarbon group of R ^{a1 to} R ^a3 is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms.

Examples of the substituent of the alkyl group having 1 to 8 carbon atoms which may have a substituent include an alicyclic hydrocarbon group having 3 to 20 carbon atoms.
Examples of the substituent of the alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent include an alkyl group having 1 to 8 carbon atoms. More specifically, a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornylethyl group and the like can be mentioned.
Preferably, ma is 0 and na is 1.

^{Examples of -C (R a1} ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R a ² are bonded to each other to form a non-aromatic hydrocarbon ring include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Specific examples of the group represented by the formula (1) include the following groups. * Represents a bond.

Ｒ^a1’及びＲ^a2’のうち、少なくとも１つは水素原子であることが好ましい。 Examples of the hydrocarbon group R ^{a1 '~R a3',} an alkyl group, an alicyclic hydrocarbon group, and a group formed by combining an aromatic hydrocarbon group and thereof.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same as above.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, trill group, xylyl group, cumenyl group, mesityl group and biphenyl. Examples thereof include an aryl group such as a group, a phenanthryl group, a 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl.
^{Examples of} the heterocycle in which R ^{a2'and R a3'} are bonded to each other and formed together with the carbon atom and X to which they are bonded include the following rings. * Represents a bond.

Of R ^{a1 'and} R ^a2', it is preferable that at least one is a hydrogen atom.

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

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

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

［式（ａ１−０）、式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a01、Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ１−ＣＯ−Ｏ−を表し、ｋ１は１〜７のいずれかの整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組み合わせた基を表す。
Ｒ^ａ６及びＲ^ａ７は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合せることにより形成される基を表す。
ｍ１は０〜１４のいずれかの整数を表す。
ｎ１は０〜１０のいずれかの整数を表す。
ｎ１’は０〜３のいずれかの整数を表す。］ The structural unit derived from the (meth) acrylic monomer having a group represented by the formula (1) is preferably a structural unit represented by the formula (a1-0) (hereinafter referred to as a structural unit (a1-0)). In some cases), a structural unit represented by the formula (a1-1) (hereinafter, may be referred to as a structural unit (a1-1)) or a structural unit represented by the formula (a1-2) (hereinafter, referred to as a structural unit). It may be referred to as a structural unit (a1-2)). These may be used alone or in combination of two or more.

[In the formula (a1-0), the formula (a1-1) and the formula (a1-2),
L ^{a01, L a1} and ^{L a2} each independently, -O- or _{^{* -O- (CH 2) k1 -CO}} -O- the stands, k1 represents an integer of 1-7, and * Represents a bond with −CO−.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these groups.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining them.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1'represents an integer of 0 to 3. ]

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
L ^{a01, L a1} and ^{L a2} are preferably oxygen atom or _{* -O- (CH 2) k01 -CO} -O- and is (however, k01 is preferably either 1 to 4 integer, more preferably Is 1), more preferably an oxygen atom.
The alkyl groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 , the alicyclic hydrocarbon group and the group combining these are the same as the groups listed in ^{R a1 to} R ^{a3 of the formula (1).} The group is mentioned.
The alkyl groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 preferably have 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
The alicyclic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 have preferably 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of these alkyl groups and the alicyclic hydrocarbon group.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.
m1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, and more preferably 0 or 1.
n1'is preferably 0 or 1.

The structural unit (a1-0), for example, the formula (a1-0-1) ~ expression methyl group hydrogen atoms corresponding to the structural units and ^{R a01} represented by any one of (a1-0-12) Examples thereof include the replaced structural units, and structural units represented by any of the formulas (a1-0-1) to (a1-0-10) are preferable.

Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. Among them, the structural unit represented by any of the formulas (a1-1-1) to (a1-1-8) is preferable, and any of the formulas (a1-1-1) to (a1-1-4) is preferable. The structural unit represented by is more preferable.

The structural unit (a1-2) includes a structural unit represented by any of the formulas (a1-2-1) to (a1-2-6) and a methyl group corresponding to ^{R a01} , R ^a4 , and R ^a5. The structural unit in which is replaced with a hydrogen atom is mentioned, and the formula (a1-2-2) and the formula (a1-2-5) are preferable.

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

式（ａ１−５）中、
Ｒ^a8は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^a1は、単結合又は＊−（ＣＨ₂）_h3−ＣＯ−Ｌ⁵⁴−を表し、ｈ３は１〜４のいずれかの整数を表し、＊は、Ｌ⁵¹との結合手を表す。
Ｌ⁵¹、Ｌ⁵²、Ｌ⁵³及びＬ⁵⁴は、それぞれ独立に、−Ｏ−又は−Ｓ−を表す。
ｓ１は、１〜３のいずれかの整数を表す。
ｓ１’は、０〜３のいずれかの整数を表す。 The structural unit derived from the (meth) acrylic monomer having a group represented by the formula (2) is a structural unit represented by the formula (a1-5) (hereinafter referred to as “structural unit (a1-5)”). There is).

In equation (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms, which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * − (CH ₂ ) _h3 −CO−L ⁵⁴ −, h3 represents an integer of 1 to 4, and * represents a bond with ^{L 51.}
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ independently represent -O- or -S-, respectively.
s1 represents any integer of 1 to 3.
s1'represents an integer of 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Alkyl groups having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group and a trifluoromethyl group. The group is mentioned.
In the formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
Of L ⁵² and L ⁵³ , it is preferable that one is −O− and the other is −S−.
1 is preferable for s1.
s1'is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * -CH _2- CO-O-.

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

When the resin (A) has a structural unit (a1-5), the content thereof is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on all the structural units of the resin (A). , 5-40 mol% is more preferred.

Moreover, the following structural unit is also mentioned as a structural unit (a1).

樹脂（Ａ）が上記構造単位を含む場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１０〜９５モル％が好ましく、１５〜９０モル％がより好ましく、２０〜８５モル％がさらに好ましい。

When the resin (A) contains the above structural units, the content thereof is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, and 20 to 85 mol% with respect to all the structural units of the resin (A). % Is more preferable.

The structural unit (a1) having an acid unstable group in the resin (A) includes a structural unit (a1-0), a structural unit (a1-1), a structural unit (a1-2), and a structural unit (a1-5). ) Is preferred, at least two or more are more preferred, and combinations of structural units (a1-1) and structural units (a1-2), structural units (a1-1) and structural units (a1-1) The combination of a1-5) is even more preferable. The structural unit (a1) preferably includes the structural unit (a1-1).

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no acid unstable group (hereinafter, may be referred to as “monomer (s)”). As the monomer for deriving the structural unit (s), a monomer having no acid unstable group known in the resist field can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid unstable group is preferable. A structure having a hydroxy group and no acid unstable group (hereinafter sometimes referred to as "structural unit (a2)") and / or having a lactone ring and no acid unstable group. If a resin having a unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

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

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７のいずれかの整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０のいずれかの整数を表す。 Examples of the structural unit (a2) having an alcoholic hydroxy group include structural units represented by the formula (a2-1) (hereinafter, may be referred to as “structural unit (a2-1)”).

In equation (a2-1),
L ^a3 represents −O− or ^* −O− (CH ₂ ) _k2 −CO−O−.
k2 represents any integer from 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 independently represent a hydrogen atom, a methyl group or a hydroxy group, respectively.
o1 represents any integer from 0 to 10.

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

Examples of the structural unit (a2-1) include structural units derived from the monomers described in JP-A-2010-204646. The structural unit represented by any of the formulas (a2-1-1) to (a2-1-6) is preferable, and any of the formulas (a2-1-1) to (a2-1-4) is preferable. The structural unit represented is more preferable, and the structural unit represented by the formula (a2-1-1) or the formula (a2-1-3) is further preferable.

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

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocyclic ring such as β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a fused ring of a monocyclic lactone ring and another ring. But it may be. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure can be mentioned.

［式（ａ３−１）、式（ａ３−２）、式（ａ３−３）及び式（ａ３−４）中、
Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、−Ｏ−又は^＊−Ｏ−（ＣＨ_２）_ｋ３−ＣＯ−Ｏ−（ｋ３は１〜７のいずれかの整数を表す。）で表される基を表す。
Ｌ^ａ７は、−Ｏ−、^＊−Ｏ−Ｌ^ａ８−Ｏ−、^＊−Ｏ−Ｌ^ａ８−ＣＯ−Ｏ−、^＊−Ｏ−Ｌ^ａ８−ＣＯ−Ｏ−Ｌ^ａ９−ＣＯ−Ｏ−又は^＊−Ｏ−Ｌ^ａ８−Ｏ−ＣＯ−Ｌ^ａ９−Ｏ−を表す。
Ｌ^ａ８及びＬ^ａ９は、それぞれ独立に、炭素数１〜６のアルカンジイル基を表す。
＊はカルボニル基との結合手を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、水素原子又はメチル基を表す。
Ｒ^ａ２４は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^ａ２１は炭素数１〜４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５のいずれかの整数を表す。
ｑ１は、０〜３のいずれかの整数を表す。
ｒ１は、０〜３のいずれかの整数を表す。
ｗ１は、０〜８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なってもよい。］ The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) or the formula (a3-4). One of these may be contained alone, or two or more thereof may be contained.

[In the formula (a3-1), the formula (a3-2), the formula (a3-3) and the formula (a3-4),
L ^a4 , ^{La 5} and ^{La 6} represent a group represented by -O- or ^* -O- (CH ₂ ) _k3 -CO-O- (k3 represents an integer of 1 to 7). ..
L ^a7 is -O-, ^* -O-L ^a8- O-, ^* -O-L ^a8- CO-O-, ^* -O-L ^a8- CO-O-L ^a9- CO-O- or ^* Represents −O−L ^a8 −O−CO−L ^a9 −O−.
L ^a8 and ^{La 9} each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* Represents a bond with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 represent a hydrogen atom or a methyl group.
R ^a24 represents an alkyl group having 1 to 6 carbon atoms, which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer from 0 to 5.
q1 represents any integer from 0 to 3.
r1 represents any integer from 0 to 3.
w1 represents any integer from 0 to 8.
When p1, q1, r1 and / or w1 is 2 or more, the plurality of R ^a21 , R ^a22 , R ^a23 and / or R ^a25 may be the same or different from each other. ]

Examples of the aliphatic hydrocarbon group of R ^a21 , R ^a22 , R ^a23 and R ^a25 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group and a tert-butyl group. Alkyl groups can be mentioned.
^{Examples of the halogen atom of Ra24} include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
^Examples of the alkyl group of R a24 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group and an n-hexyl group. An alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.
^{Alkyl groups having a halogen atom of Ra24} include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro. Examples thereof include a hexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

The ^{alkanediyl groups of La8} and ^La9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group and pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples thereof include 4-diyl group and 2-methylbutane-1,4-diyl group.

In the formula (a3-1) ~ formula ^(a3-3), L a4 ^{~L a6} are each independently preferably -O- or, k3 is a integer of 1 to 4 * -O- ( CH ₂ ) _{A group represented by k3-} CO-O-, more preferably -O- and * -O-CH _2- CO-O-, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently, preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are independently, preferably an integer of 0 to 2, and more preferably 0 or 1.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） In the formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, more preferably a hydrogen atom or a methyl group Is.
^Ra25 is preferably a carboxy group, a cyano group or a methyl group.
L ^a7 is preferably -O- or ^{* -O-L} a8 ^-CO-O-, more preferably an _{-O -, - O-CH 2} -CO-O- or _-O-C 2 _{H 4} - It is CO-O-.
The formula (a3-4) is particularly preferably the formula (a3-4)'.

(In the formula, ^Ra24 and ^La7 have the same meanings as above.)

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

In the structural units represented by the following formulas (a3-4-1) to (a3-4-12), ^{the compound in which the methyl group corresponding to R a24} is replaced with a hydrogen atom is also a structural unit (a3-4). ) Can be mentioned as a specific example.

When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). , More preferably 10-60 mol%.
Further, the contents of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) and the structural unit (a3-4) are the respective contents with respect to all the structural units of the resin (A). Therefore, 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is further preferable.

<Other structural units (t)>
The structural unit (t) includes a structural unit (hereinafter, sometimes referred to as “structural unit (a4)”) and a non-structural unit which may have a halogen atom in addition to the structural unit (a2) and the structural unit (a3). Examples thereof include a structural unit having a desorbed hydrocarbon group (hereinafter, may be referred to as “structural unit (a5)”).

［式（ａ４−０）中、
Ｒ⁵は、水素原子又はメチル基を表す。
Ｌ⁴は、単結合又は炭素数１〜４の脂肪族飽和炭化水素基を表す。
Ｌ³は、炭素数１〜８のペルフルオロアルカンジイル基又は炭素数３〜１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ⁶は、水素原子又はフッ素原子を表す。］ Examples of the structural unit (a4) include a structural unit represented by the formula (a4-0).

[In equation (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ⁴ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the aliphatic saturated hydrocarbon group of L ⁴ include a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and an ethane-1,1-. Branched alkanediyl groups such as diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group. The group is mentioned.

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

L ⁴ is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group.
L ³ is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

The structural unit (a4-0), a methyl group have structural units replaced by a hydrogen atom corresponding to R ⁵ in the structural unit and the following structural units shown below.

［式（ａ４−１）中、
Ｒ^a41は、水素原子又はメチル基を表す。
Ｒ^a42は、置換基を有していてもよい炭素数１〜２０の炭化水素基を表し、該炭化水素基に含まれる−ＣＨ₂−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよい。
Ａ^a41は、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−ｇ１）で表される基を表す。ただし、Ａ^ａ４１及びＲ^ａ４２のうち少なくとも１つは、置換基としてハロゲン原子（好ましくはフッ素原子）を有する。

〔式（ａ−ｇ１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ａ^a43は、単結合又は置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ｘ^a41及びＸ^a42は、それぞれ独立に、−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−を表す。
ただし、Ａ^a42、Ａ^a43、Ａ^a44、Ｘ^a41及びＸ^a42の炭素数の合計は７以下である。〕
＊は結合手であり、右側の＊が−Ｏ−ＣＯ−Ｒ^a42との結合手である。］ Examples of the structural unit (a4) include a structural unit represented by the formula (a4-1).

[In equation (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and −CH ₂ − contained in the hydrocarbon group may be replaced with −O− or −CO−. good.
A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by the formula (a-g1). However, ^{at least one of Aa41} and ^Ra42 has a halogen atom (preferably a fluorine atom) as a substituent.

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

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

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニリル基、フェナントリル基及びフルオレニル基が挙げられる。 Chain-type aliphatic hydrocarbon groups include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and n-decyl. Examples include a group, an n-dodecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group and an n-octadecyl group. Cyclic aliphatic hydrocarbon groups include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* is a bond). Examples thereof include polycyclic alicyclic hydrocarbon groups such as).

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

［式（ａ−ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a45は、少なくとも１つのハロゲン原子を有する炭素数１〜１７の脂肪族炭化水素基を表す。
＊は結合手を表す。］ ^As the hydrocarbon group of R a42, a chain type or a cyclic type aliphatic hydrocarbon group and a group formed by combining these groups are preferable, and a chain type may have a carbon-carbon unsaturated bond, but a chain type. And cyclic aliphatic saturated hydrocarbon groups and groups formed by combining them are more preferable.
Examples of R a42 include a halogen atom or a group represented by the formula ( ^{ag3) as a substituent.} Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.
* Represents a bond. ]

Examples of the aliphatic hydrocarbon group of A ^{a45 include} the same groups as those exemplified in ^{R a42.}
R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (ag3). ..
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and further preferably having a carbon number of carbons. It is a perfluoroalkyl group of 1 to 6, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.
When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (ag3), the aliphatic hydrocarbon includes the number of carbon atoms contained in the group represented by the formula (ag3). The total carbon number of the group is preferably 15 or less, more preferably 12 or less. When the group represented by the formula (ag3) is used as a substituent, the number thereof is preferably one.

［式（ａ−ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。
Ｘ^a44は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。
＊はカルボニル基との結合手を表す。］ Aliphatic hydrocarbons having a group represented by the formula (ag3) are more preferably a group represented by the formula (ag2).

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

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

A more preferable structure of the partial structure represented by * -A ^a46- X ^a44- A ^a47 (* is a bond with a carbonyl group) is the following structure.

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

^{The aliphatic hydrocarbon groups of A a42} , A ^a43 and A ^{a44 in} the group (a-g1) may have a carbon-carbon unsaturated bond, but are chain-type and cyclic-type aliphatic saturated hydrocarbon groups. In addition, a group formed by combining these is preferable. The aliphatic saturated hydrocarbon group is formed by combining a linear or branched alkyl group and a monocyclic or polycyclic alicyclic hydrocarbon group, and an alkyl group and an alicyclic hydrocarbon group. Examples include aliphatic hydrocarbon groups. Specifically, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, Examples thereof include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent of the aliphatic hydrocarbon group of A a42, A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

^{Examples of the group (ag1) in} which X a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following groups. In the following examples, * and ** represent the bond, respectively, and ** is the bond with -O-CO-R ^a42 .

［式（ａ４−２）中、
Ｒ^f1は、水素原子又はメチル基を表す。
Ａ^f1は、炭素数１〜６のアルカンジイル基を表す。
Ｒ^f2は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ As the structural unit represented by the formula (a4-1), the structural unit represented by the formula (a4-2) is preferable.

[In the formula (a4-2),
R ^f1 represents a hydrogen atom or a methyl group.
A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.
R ^f2 represents a hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom. ]

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

Hydrocarbon groups of R ^f2 include chain and cyclic aliphatic hydrocarbon groups and aromatic hydrocarbon groups, as well as groups formed by combining them. As the aliphatic hydrocarbon group, an alkyl group (straight or branched) and an alicyclic hydrocarbon group are preferable.
Alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2 -Examples include ethylhexyl groups.
The alicyclic hydrocarbon group may be either a monocyclic group or a polycyclic group, and the monocyclic alicyclic hydrocarbon group includes a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group and a methylcyclohexyl group. , Cycloalkyl groups such as dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkyl group, a norbornyl group, and a methylnorbornyl group. Examples include groups and isobornyl groups.

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

^{As A f1} in the formula (a4-2), an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.
As R ^f2 , an alkyl fluoride group having 1 to 6 carbon atoms is preferable.

Examples of the structural unit represented by the formula (a4-2) include the structural unit shown below and the structural unit in which the ^{methyl group corresponding to R f1} in the following structural unit is replaced with a hydrogen atom.

Examples of the structural unit (a4) include the structural unit shown below and the structural unit in which the ^{methyl group corresponding to R f11} in the following structural unit is replaced with a hydrogen atom.

When the resin (A) has a structural unit (a4), the content thereof is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and 3) with respect to all the structural units of the resin (A). 10 mol% is more preferable.

［式（ａ５−１）中、
Ｒ⁵¹は、水素原子又はメチル基を表す。
Ｒ⁵²は、炭素数３〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる水素原子は炭素数１〜８の脂肪族炭化水素基又はヒドロキシ基で置換されていてもよい。但し、Ｌ⁵⁵との結合位置にある炭素原子に結合する水素原子は、炭素数１〜８の脂肪族炭化水素基で置換されない。
Ｌ⁵⁵は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。］ <Structural unit (a5)>
Examples of the non-eliminating hydrocarbon group of the structural unit (a5) include a group having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably contains a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1).

[In equation (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a hydroxy group. May be. However, ^{the hydrogen atom bonded to the carbon atom at the bond position with L 55} is not replaced by the aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ − contained in the saturated hydrocarbon group may be replaced with −O− or −CO−. ]

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

Examples of the divalent saturated hydrocarbon group of L ⁵⁵ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent aliphatic saturated hydrocarbon group is preferable. ..
Examples of the divalent aliphatic saturated hydrocarbon group include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanjiyl group and a pentandiyl group.
The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cycloalkanediyl group such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantandiyl group and a norbornanediyl group.

式（Ｌ１−１）中、
Ｘ^x1は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ｌ^x1は、炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１６以下である。
式（Ｌ１−２）中、
Ｌ^x3は、炭素数１〜１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x4は、単結合又は炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x3及びＬ^x4の合計炭素数は、１７以下である。
式（Ｌ１−３）中、
Ｌ^x5は、炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x6及びＬ^x7は、それぞれ独立に、単結合又は炭素数１〜１４の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x5、Ｌ^x6及びＬ^x7の合計炭素数は、１５以下である。
式（Ｌ１−４）中、
Ｌ^x8及びＬ^x9は、単結合又は炭素数１〜１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^x1は、炭素数３〜１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^x8、Ｌ^x9及びＷ^x1の合計炭素数は、１５以下である。 Examples of the group in which −CH ₂ − contained in the saturated hydrocarbon group is replaced with −O− or −CO− include groups represented by the formulas (L1-1) to (L1-4). In the following formula, * represents a bond with an oxygen atom.

In formula (L1-1),
X ^x1 represents a carbonyloxy group or an oxycarbonyl group.
L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
However, the total number of carbon atoms of ^{L x 1} and L ^{x 2 is 16 or less.}
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.
L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.
However, the total number of carbon atoms of ^{L x3} and L ^{x4 is 17 or less.}
In formula (L1-3),
L ^{x 5} represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.
However, the total carbon number of ^{L x5} , L ^x6 and L ^{x7 is 15 or less.}
In equation (L1-4),
L ^x8 and L ^x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^{x 1} represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms.
However, the total carbon number of ^{L x8} , L ^x9 and W ^{x1 is 15 or less.}

L ^{x 1} is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^{x 5} is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group.
W ^{x 1} is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantandiyl group.

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

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

Examples of the group represented by the formula (L1-3) include the divalent group shown below.

Examples of the group represented by the formula (L1-4) include the divalent group shown below.

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

Examples of the structural unit (a5-1) include the structural unit shown below and the structural unit in which the ^{methyl group corresponding to R 51} in the following structural unit is replaced with a hydrogen atom.

When the resin (A) has the structural unit (a5), the content thereof is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and 3) with respect to all the structural units of the resin (A). ~ 15 mol% is more preferred.

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

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer for inducing these structural units. can do. The content of each structural unit of the resin (A) can be adjusted by adjusting the amount of the monomer used for the polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, still more preferable). Is 15,000 or less).

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). Examples of such a resin include a resin consisting of only the structural unit (s), a resin containing the structural unit (a4) (however, the resin does not include the structural unit (a1); hereinafter may be referred to as “resin (X)”) and the like. Can be mentioned. Of these, a resin containing the structural unit (a4) is preferable.
In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol% or more, still more preferably 50 mol% or more, based on all the structural units of the resin (X). ..
Examples of the structural unit that the resin (X) may further include include a structural unit (a2), a structural unit (a3), and a structural unit derived from other known monomers.
The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as that of the resin (A).
When the resist composition contains the resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 2 to 50 parts by mass, and further, with respect to 100 parts by mass of the resin (A). It is preferably 2 to 40 parts by mass, and particularly preferably 3 to 30 parts by mass.

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

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

Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate. Esters; ketones such as acetone, methylisobutylketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. The solvent (E) may contain one kind alone or two or more kinds.

<Quencher (C)>
Examples of the quencher (C) include a salt that generates an acid having a weaker acidity than the acid generated from the acid generator, or a basic nitrogen-containing organic compound.

Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.
Specifically, 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine. , Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, trypentylamine, 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, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino- 3,3'-diethyldiphenylmethane, piperazine, morpholin, piperidine and hindered amine compounds having a piperidine skeleton described in JP-A-11-52575, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1, 2 -Di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethen, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridyl Amine, 2,2'-dipicolylamine, bipyridine and the like can be mentioned, preferably diisopropylaniline, and particularly preferably 2,6-diisopropylaniline.

Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, and 3- (trifluoromethyl) phenyltrimethyl. Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

Examples of the salt that generates an acid having a weaker acidity than the acid generated from the acid generator include a salt (I) and a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B). , Its acidity is indicated by the acid dissociation constant (pKa). The salt that generates an acid having a weaker acidity than the acid generated from the acid generator is usually a salt having an acid dissociation constant of -3 <pKa, preferably -1 <pKa <7. A salt of 0 <pKa <5, more preferably a salt of 0 <pKa <5. Examples of the salt that generates an acid having a weaker acidity than the acid generated from the acid generator include a salt represented by the following formula and a weak acid intramolecular salt represented by the formula (D) described in JP-A-2015-147926. , And JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502 and JP-A-2011-191745.

式（Ｄ）で表される弱酸分子内塩としては、以下の塩が挙げられる。

Examples of the weak acid intramolecular salt represented by the formula (D) include the following salts.

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

<Other ingredients>
If necessary, the resist composition may contain a component other than the above-mentioned components (hereinafter, may be referred to as “other component (F)”). As the other component (F), additives known in the field of resist, for example, a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, a dye and the like can be used.

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

[Manufacturing method of resist pattern]
The method for producing a resist pattern of the present invention is
(1) A step of applying the resist composition of the present invention onto a substrate,
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
It includes (4) a step of heating the composition layer after exposure and (5) a step of developing the composition layer after heating.

The resist composition can be applied onto the substrate by a commonly used device such as a spin coater. Examples of the substrate include an inorganic substrate such as a silicon wafer. Before applying the resist composition, the substrate may be washed, or an antireflection film or the like may be formed on the substrate.

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. The pressure at the time of vacuum drying is preferably about 1~1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. The exposure light source includes a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F ₂ excima laser (wavelength 157 nm) that emits laser light in the ultraviolet region, and a solid-state laser light source (YAG or semiconductor laser). Etc.), and various ones such as those that radiate harmonic laser light in the far ultraviolet region or vacuum ultraviolet region by wavelength conversion, those that irradiate electron beams, super-ultraviolet light (EUV), etc. are used. Can be done. In addition, in this specification, irradiation of these radiations may be generically referred to as "exposure". At the time of exposure, the exposure is usually performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, it may be exposed by direct drawing without using a mask.

The exposed composition layer is heat treated (so-called post-exposure bake) to promote the deprotection reaction at the acid unstable group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.

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

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

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

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

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

The present invention will be described in more detail with reference to examples. In the examples, "%" and "part" indicating the content or the amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh)
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)
The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type). In the following examples, the value of this molecular ion peak is indicated by "MASS".

式（Ｉ−１−ａ）で表される塩１７．１部、式（Ｉ−１−ｂ）で表される化合物３部、クロロホルム１５０部及びピリジン４．３部を混合し、２３℃で２時間攪拌した。得られた反応物に、イオン交換水１００部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：クロロホルム／メタノール＝１／１）分取することにより、式（Ｉ−１）で表される塩４．１７部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：［Ｍ^２−＋Ｈ］⁻ ８８３．１ Example 1: Synthesis of salt represented by formula (I-1)

17.1 part of the salt represented by the formula (I-1-a), 3 parts of the compound represented by the formula (I-1-b), 150 parts of chloroform and 4.3 parts of pyridine are mixed and mixed at 23 ° C. The mixture was stirred for 2 hours. 100 parts of ion-exchanged water was added to the obtained reaction product, stirred at 23 ° C. for 30 minutes, and the liquid was separated to recover the organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is separated by a column (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: chloroform / methanol = 1/1) to formulate (I-1). 4.17 parts of salt represented by is obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
^{MASS (ESI (-) Spectrum)} : [M 2- + H] - 883.1

式（Ｉ−１０５−ａ）で表される塩１６．４部、式（Ｉ−１−ｂ）で表される化合物３部、クロロホルム１５０部及びピリジン４．３部を混合し、２３℃で２時間攪拌した。得られた反応物に、イオン交換水１００部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：クロロホルム／メタノール＝１／１）分取することにより、式（Ｉ−１０５）で表される塩８．４８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２３７．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：［Ｍ^２−＋Ｈ］⁻ ８８３．１ Example 2: Synthesis of salt represented by the formula (I-105)

16.4 parts of the salt represented by the formula (I-105-a), 3 parts of the compound represented by the formula (I-1-b), 150 parts of chloroform and 4.3 parts of pyridine are mixed and mixed at 23 ° C. The mixture was stirred for 2 hours. 100 parts of ion-exchanged water was added to the obtained reaction product, stirred at 23 ° C. for 30 minutes, and the liquid was separated to recover the organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is separated into a column (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: chloroform / methanol = 1/1) to formulate (I-105). 8.48 parts of salt represented by is obtained.
MASS (ESI (+) Spectrum): M ⁺ 237.1
^{MASS (ESI (-) Spectrum)} : [M 2- + H] - 883.1

式（Ｉ−２１−ａ）で表される塩１７．１部、式（Ｉ−１−ｂ）で表される化合物３部、クロロホルム１５０部及びピリジン４．３部を混合し、２３℃で２時間攪拌した。得られた反応物に、イオン交換水１００部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：クロロホルム／メタノール＝１／１）分取することにより、式（Ｉ−２１）で表される塩5.89部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：［Ｍ^２−＋Ｈ］⁻ ８８３．１ Example 3: Synthesis of salt represented by the formula (I-21)

17.1 part of the salt represented by the formula (I-21-a), 3 parts of the compound represented by the formula (I-1-b), 150 parts of chloroform and 4.3 parts of pyridine are mixed and mixed at 23 ° C. The mixture was stirred for 2 hours. 100 parts of ion-exchanged water was added to the obtained reaction product, stirred at 23 ° C. for 30 minutes, and the liquid was separated to recover the organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is separated into a column (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: chloroform / methanol = 1/1) to formulate (I-21). 5.89 parts of salt represented by is obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
^{MASS (ESI (-) Spectrum)} : [M 2- + H] - 883.1

式（Ｉ−１２５−ａ）で表される塩１６．４部、式（Ｉ−１−ｂ）で表される化合物３部、クロロホルム１５０部及びピリジン４．３部を混合し、２３℃で２時間攪拌した。得られた反応物に、イオン交換水１００部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：クロロホルム／メタノール＝１／１）分取することにより、式（Ｉ−１２５）で表される塩１０．２８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２３７．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：［Ｍ^２−＋Ｈ］⁻ ８８３．１ Example 4: Synthesis of salt represented by formula (I-125)

16.4 parts of the salt represented by the formula (I-125-a), 3 parts of the compound represented by the formula (I-1-b), 150 parts of chloroform and 4.3 parts of pyridine are mixed and mixed at 23 ° C. The mixture was stirred for 2 hours. 100 parts of ion-exchanged water was added to the obtained reaction product, stirred at 23 ° C. for 30 minutes, and the liquid was separated to recover the organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is separated by a column (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: chloroform / methanol = 1/1) to formulate (I-125). 10.28 parts of salt represented by is obtained.
MASS (ESI (+) Spectrum): M ⁺ 237.1
^{MASS (ESI (-) Spectrum)} : [M 2- + H] - 883.1

式（Ｉ−３−ａ）で表される塩１７．５部、式（Ｉ−３−ｂ）で表される化合物２．８７部、クロロホルム１５０部及びピリジン４．３部を混合し、２３℃で２時間攪拌した。得られた反応物に、イオン交換水１００部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を５回行った。得られた有機層を濃縮し、濃縮マスをカラム（関東化学 シリカゲル６０Ｎ（球状、中性）１００−２１０μｍ 展開溶媒：クロロホルム／メタノール＝１／１）分取することにより、式（Ｉ−３）で表される塩３．２１部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：［Ｍ^２−＋Ｈ］⁻ ８８３．１ Example 5: Synthesis of salt represented by formula (I-3)

17.5 parts of the salt represented by the formula (I-3-a), 2.87 parts of the compound represented by the formula (I-3-b), 150 parts of chloroform and 4.3 parts of pyridine are mixed and 23. The mixture was stirred at ° C for 2 hours. 100 parts of ion-exchanged water was added to the obtained reaction product, stirred at 23 ° C. for 30 minutes, and the liquid was separated to recover the organic layer. This washing operation was performed 5 times. The obtained organic layer is concentrated, and the concentrated mass is separated by a column (Kanto Chemical silica gel 60N (spherical, neutral) 100-210 μm developing solvent: chloroform / methanol = 1/1) to formulate (I-3). 3.21 parts of salt represented by is obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
^{MASS (ESI (-) Spectrum)} : [M 2- + H] - 883.1

Synthesis of Resin The compounds (monomers) used for the synthesis of the resin (A) are shown below. Hereinafter, these compounds will be referred to as "monomer (a1-1-3)" or the like according to the formula number.

Synthesis Example 1: Synthesis of resin A1 As a monomer, a monomer (a1-1-3), a monomer (a1-2-9), a monomer (a2-1-3) and a monomer (a3-4-2) are used. The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-4-2)] is 45: 14: 2.5: 38. The mixture was mixed so as to be 5, and propylene glycol monomethyl ether acetate 1.5% by mass of the total amount of monomers was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 1 mol% and 3 mol%, respectively, based on the total amount of monomers, and these were heated at 73 ° C. for about 5 hours. bottom. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin is dissolved again in propylene glycol monomethyl ether acetate, and the obtained solution is poured into a methanol / water mixed solvent to precipitate the resin, and the resin is filtered. A resin A1 having a molecular weight of 7.6 × 10 ³ was obtained in a yield of 68%. This resin A1 has the following structural units.

Synthesis Example 2: Synthesis of resin X1 A monomer (a4-1-7) was used as a monomer, and methyl isobutyl ketone 1.5% by mass of the total amount of the monomer was added to prepare a solution. To this solution, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added in an amount of 0.7 mol% and 2.1 mol%, respectively, based on the total amount of the monomers, and these were added at 75 ° C. It was heated for about 5 hours. The reaction mixture obtained, the resin was precipitated by pouring into a large amount of methanol / water mixed solvent, the resin was filtered, to obtain a resin X1 of weight average molecular weight 1.7 × 10 ⁴ in 77% yield. This resin X1 has the following structural units.

Synthesis Example 3: Synthesis of Resin X2 A monomer (a5-1-1) and a monomer (a4-0-12) are used as the monomer, and the molar ratio thereof [monomer (a5-1-1): monomer (a4-0-). 12)] was mixed so that the ratio was 50:50, and methyl isobutyl ketone 1.2% by mass of the total amount of the monomers was added to prepare a solution. Azobis (2,4-dimethylvaleronitrile) as an initiator was added to this solution in an amount of 3 mol% based on the total amount of monomers, and the mixture was heated at 70 ° C. for about 5 hours. The reaction mixture obtained, the resin was precipitated by pouring into a large amount of methanol / water mixed solvent, the resin was filtered, to obtain a resin X having a weight-average molecular weight 1.0 × 10 ⁴ in 91% yield. This resin X2 has the following structural units.

<Preparation of resist composition>
Each resist composition was prepared by mixing each component and solvent shown in Table 2 and filtering the obtained mixture with a fluororesin filter having a pore size of 0.2 μm.

ＩＸ−１：特開２００８−１３５５１号公報の実施例に従って合成

ＩＸ−２：特開２０１４−１１５６１９号公報の実施例に従って合成

＜クエンチャー（Ｃ）＞
Ｄ１：（東京化成工業（株）製）

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ２６５部
プロピレングリコールモノメチルエーテル ２０部
２−ヘプタノン ２０部
γ−ブチロラクトン ３．５部 <Resin>
A1, X1, X2: Resin A1, Resin X1, Resin X2
<Salt (I)>
I-1: Salt represented by the formula (I-1) I-3: Salt represented by the formula (I-3) I-21: Salt represented by the formula (I-21) I-105: Formula Salt represented by (I-105) I-125: Salt represented by formula (I-125) <acid generator>
B1-21: Salt represented by the formula (B1-21) (synthesized according to an example of JP2012-224611A)
B1-22: Salt represented by the formula (B1-22) (synthesized according to an example of JP2012-224611A)

IX-1: Synthesized according to the examples of JP-A-2008-13551

IX-2: Synthesized according to Examples of Japanese Patent Application Laid-Open No. 2014-115619

<Quencher (C)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene Glycol Monomethyl Ether Acetate 265 Parts Propylene Glycol Monomethyl Ether 20 Parts 2-Heptanone 20 Parts γ-Butyrolactone 3.5 Parts

<Manufacturing of resist pattern and its evaluation>
An organic antireflection film composition (ARC-29; manufactured by Nissan Chemical Industries, Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to cause organic reflection on the wafer with a film thickness of 78 nm. An anti-reflective film was formed. Next, the above resist composition was applied (spin coated) on the organic antireflection film so that the film thickness after drying was 85 nm. After coating, the silicon wafer was prebaked on a direct hot plate at the temperature shown in the “PB” column of Table 2 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 90 nm) was used on a silicon wafer on which a composition layer was formed with an ArF excimer stepper for immersion exposure (XT: 1900Gi; ASML, NA = 1.35, 3/4 Anal XY polarization). / Using a mask for forming a hole diameter (55 nm), the exposure amount was changed stepwise for exposure. Ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed on a hot plate at the temperature listed in the “PEB” column of Table 2 for 60 seconds. Next, the composition layer on this silicon wafer was developed using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution at 23 ° C. for 20 seconds by the dynamic dispensing method to obtain a negative resist pattern. Manufactured.

In the resist pattern obtained after development, the exposure amount having a hole diameter of 50 nm formed by using the mask was defined as the effective sensitivity.

<CD uniformity (CDU) evaluation>
In the effective sensitivity, the hole diameter of the pattern formed by the mask having a hole diameter of 55 nm was measured 24 times for one hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was obtained by measuring the average hole diameter of a pattern formed by a mask with a hole diameter of 55 nm in the same wafer at 400 points as a population.
"A" when the standard deviation is 1.80 nm or less,
When the standard deviation was larger than 1.80 nm, it was judged as "B".
The results are shown in Table 3. The numbers in parentheses indicate the standard deviation (nm).

<Manufacturing of resist pattern and its evaluation>
A composition for an organic antireflection film (ARC-29; manufactured by Nissan Chemical Industries, Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to obtain an organic antireflection film having a thickness of 780 Å. Formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (prebaking) was 85 nm. A silicon wafer coated with a resist composition was prebaked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a resist film (composition layer). A contact hole pattern (hole pitch 150 nm) was used on a silicon wafer on which a resist film was formed with an ArF excimer laser stepper for immersion exposure (XT: 1900Gi; ASML, NA = 1.35, 3/4 Anal XY polarization). / Using a mask for forming (hole diameter 75 nm), the exposure amount was changed stepwise for exposure. Ultrapure water was used as the immersion medium.
After the exposure, the silicon wafer was post-exposure baked on a hot plate at the temperature listed in the "PEB" column of Table 2 for 60 seconds. Next, this silicon wafer was paddle-developed with a 2.38% tetramethylammonium hydroxide aqueous solution for 60 seconds to obtain a resist pattern.

In forming a resist pattern from each resist composition, the exposure amount at which the hole diameter of the pattern formed by the mask having a hole diameter of 75 nm was 55 nm was defined as the effective sensitivity.

The following items were evaluated in the production of the resist pattern as described above.

<CD uniformity (CDU) evaluation>
In the effective sensitivity, the hole diameter of the pattern formed by the mask having a hole diameter of 75 nm was measured 24 times for one hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was obtained by measuring the average hole diameter of a pattern formed with a mask with a hole diameter of 75 nm at 400 points on the same wafer as a population.
"A" when the standard deviation is 2.00 nm or less,
When the standard deviation was larger than 2.00 nm, it was judged as "B".
The results are shown in Table 4. The numbers in parentheses indicate the standard deviation (nm).

The salt of the present invention and the resist composition containing the salt are suitable for microfabrication of semiconductors because the CD uniformity (CDU) of the obtained resist pattern is good, and are extremely useful in industry.

Claims (6)

A salt represented by the formula (I).

[In formula (I),
^{Q 1, Q 2, Q 1} ' and Q ^2' each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 and ^{L b1 'each} independently represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, -CH ₂ contained in the saturated hydrocarbon group - is replaced by -O- or -CO- The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
X ¹ represents a divalent group having a base dissociative group selected from a divalent group represented by the formula (Ba1) and a divalent group represented by the formula (Bb1).

(In the formula (Ba1) and the formula (Bb1),
L ¹ and L ² represent an alkanediyl group having 1 to 6 carbon atoms having a fluorine atom.
^{R 25, R 26, R 25} ' and R ^26' each independently represent an alkyl group having 1 to 6 carbon atoms having a hydrogen atom, a fluorine atom or a fluorine atom.
* 1 ^{represents a bond with L b1} and * 2 represents a bond with L ^b1' . )
Z1 ⁺ and Z1' ⁺ each independently represent a sulfonium cation. ] The salt according to claim 1, wherein L ^b1 and L ^{b1'are independent groups represented by the following.}

(* Represents a bond with a carbon atom of -C (Q ¹ ) (Q ² )-or -C (Q ^1' ) (Q ^2' )-. M, n, m'and n'are. Represents 0 or 1 independently.) The acid generator containing the salt according to claim 1 or 2. A resist composition containing the acid generator according to claim 3 and a resin having an acid unstable group. The resist composition according to claim 4, further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. (1) A step of applying the resist composition according to claim 4 or 5 onto a substrate.
(2) A step of drying the applied composition to form a composition layer,
(3) Step of exposing the composition layer,
(4) A step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating,
A method for manufacturing a resist pattern including.