JP6142602B2 - Resist composition and method for producing resist pattern - Google Patents

Description

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

（式中、Ｒ¹、Ｒ^a、Ｒ^b、Ｒ^c、Ｒ^d、Ｒ^e、Ｒ^f及びＲ^gは、同一又は異なって、水素原子又はメチル基を示し、Ｘ¹、Ｘ²及びＸ³は−ＣＨ₂−又は−ＣＯ−Ｏ−を示す。Ｘ¹、Ｘ²及びＸ³のうち少なくとも１つは−ＣＯ−Ｏ−である。ｍ、ｐ及びｑはそれぞれ０〜２の整数を示す）で表されるモノマー単位から選択された少なくとも１種のモノマー単位を含むフォトレジスト用高分子化合物が記載されており、当該文献には、かかる樹脂と酸発生剤とを含有するレジスト組成物、該レジスト組成物を用いるレジストパターンの製造方法も記載されている。 Patent Document 1 discloses the following formulas (Ia) and (Ib)

(Wherein R ¹ , R ^a , R ^b , R ^c , R ^d , R ^e , R ^f and R ^g are the same or different and represent a hydrogen atom or a methyl group, and X ¹ , X ² and X ³ Represents —CH ₂ — or —CO—O—, wherein at least one of X ¹ , X ² and X ³ is —CO—O—, and m, p and q each represents an integer of 0 to 2. ), A polymer compound for photoresist containing at least one monomer unit selected from the monomer units represented by formula (1) is described, and in the document, a resist composition containing such a resin and an acid generator, A method for producing a resist pattern using the resist composition is also described.

JP 2001-240625 A

  An object of the present invention is to provide a resist composition capable of producing a resist pattern having a low line edge roughness (LER).

［式（Ｉ）中、
Ｒ^１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。
Ａ^１は、単結合、^＊−Ａ^２−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−Ａ^３−ＣＯ−Ｏ−又は^＊−Ａ^２−Ｏ−ＣＯ−Ａ^３−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ^２及びＡ^３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。］
（Ｂ）酸発生剤；
（Ｄ）式（II）で表される化合物

［式（II）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、それぞれ独立に、炭素数１〜１２の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０〜４の整数を表し、ｍ’が２以上の場合、複数のＲ^Ｄ１は同一又は互いに相異なり、ｎ’が２以上の場合、複数のＲ^Ｄ２は同一又は互いに相異なる。］
〔２〕前記（Ａ）は、
前記第１構造単位と前記第２構造単位との含有比率が、［第１構造単位］／［第２構造単位］で表して、５／９５〜８０／２０の範囲の樹脂である〔１〕記載のレジスト組成物。
〔３〕前記（Ａ）は、
酸の作用により分解し、ネガ型現像液に対する溶解性が減少する特性を有する樹脂である〔１〕又は〔２〕記載のレジスト組成物。
〔４〕 ネガ型現像液は酢酸ブチル又は２−ヘプタノンである〔３〕記載のレジスト組成物。
〔５〕前記（Ｂ）が、式（Ｂ１）で表される酸発生剤である〔１〕〜〔４〕のいずれか１つに記載のレジスト組成物。

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜２４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き換わっていてもよく、該飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基、水素原子又はフッ素原子を表し、該脂環式炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］
〔６〕さらに溶剤を含有する〔１〕〜〔５〕のいずれか１つに記載のレジスト組成物。
〔７〕（１）〔１〕〜〔６〕のいずれか１つ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）組成物層を露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程
を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A resist composition containing the following (A), (B) and (D).
(A) a resin having a first structural unit represented by formula (I) and a second structural unit containing an acid labile group;

[In the formula (I),
R ¹ represents a C 1-6 alkyl group, a hydrogen atom or a halogen atom which may have a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O— or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]
(B) an acid generator;
(D) Compound represented by formula (II)

[In the formula (II),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represents an integer of 0 to 4. When m ′ is 2 or more, a plurality of R ^D1 are the same or different from each other, and when n ′ is 2 or more, a plurality of R ^D2 Are the same or different from each other. ]
[2] (A)
The content ratio of the first structural unit to the second structural unit is represented by [first structural unit] / [second structural unit] and is a resin in the range of 5/95 to 80/20 [1]. The resist composition as described.
[3] (A)
[1] or [2] The resist composition according to [1] or [2], which is a resin that has the property of being decomposed by the action of an acid to reduce solubility in a negative developer.
[4] The resist composition according to [3], wherein the negative developer is butyl acetate or 2-heptanone.
[5] The resist composition according to any one of [1] to [4], wherein (B) is an acid generator represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, and methylene constituting the saturated hydrocarbon group The group may be replaced by an oxygen atom or a carbonyl group.
Y represents an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, a hydrogen atom or a fluorine atom, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Z ⁺ represents an organic cation. ]
[6] The resist composition according to any one of [1] to [5], further containing a solvent.
[7] (1) A step of applying the resist composition according to any one of [1] to [6] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

  According to the resist composition of the present invention, a resist pattern having low line edge roughness (LER) can be produced.

In the present specification, "(meth) acrylic monomer" means at least one monomer having a "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- " structure of To do. Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

  The resist composition of the present invention (hereinafter sometimes referred to as “the present resist composition”) contains the above-mentioned (A), (B) and (D). Moreover, when using this resist composition for the manufacturing method of the resist pattern mentioned later, it is preferable to contain a solvent further. Hereinafter, each of (A), (B) and (D), and the solvent contained in the resist composition is referred to as “resin (A)”, “acid generator (B)”, “compound (D)”. And “solvent (E)”, and specific examples and preferred examples thereof will be described.

［式（Ｉ）中、
Ｒ^１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。
Ａ^１は、単結合、^＊−Ａ^２−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−、^＊−Ａ^２−ＣＯ−Ｏ−Ａ^３−ＣＯ−Ｏ−又は^＊−Ａ^２−Ｏ−ＣＯ−Ａ^３−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ａ^２及びＡ^３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。］ <Resin (A)>
The resin (A) has a first structural unit represented by the formula (I) and a second structural unit containing an acid labile group.

[In the formula (I),
R ¹ represents a C 1-6 alkyl group, a hydrogen atom or a halogen atom which may have a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O— or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]

In R ¹ of formula (I), examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group represented by R ¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. Preferably, it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom represented by R ¹ include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluoro tert-butyl group, perfluoro group. Examples include a pentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.
R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom, a methyl group or an ethyl group.

Examples of the alkanediyl group represented by A ² and A ³ include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane- 1,5-diyl group and hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane -1,4-diyl group, 2-methylbutane-1,4-diyl group and the like.
A ¹ is preferably a single bond or ^* -A ² —CO—O—, and more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—O—.

Specific examples of the first structural unit are shown below.

In the structural units represented by formula (aa-1) to formula (aa-6), the structural unit in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom may also be given as specific examples of the first structural unit. it can.

［式（Ｉ’）中、Ｒ^１及びＡ^１は上記と同じ意味を表す。］ The first structural unit is derived from a compound represented by the formula (I ′) (hereinafter sometimes referred to as “compound (I ′)”).

[In formula (I ′), R ¹ and A ¹ represent the same meaning as described above. ]

［式中、Ｒ^１は上記と同じ意味を表す。］ For example, compound (I ′) [compound represented by formula (I′-1), wherein A ¹ is * —CH ₂ —CO—O— (* represents a bond to —CO—O—). ] Can be obtained by reacting a compound represented by the formula (I′-1-a) with a compound represented by the formula (I′-1-b) in a solvent.
Here, methylene chloride, tetrahydrofuran, acetonitrile, and the like are preferably used as the solvent.

[Wherein R ¹ represents the same meaning as described above. ]

［式中、Ｒ^１は上記と同じ意味を表す。］
また、この反応においては、ジシクロヘキシルカルボジイミドなどの縮合触媒を用いることもできる。 The compound represented by the formula (I′-1-a) is obtained by reacting the compound represented by the formula (I′-1-c) with the compound represented by the formula (I′-1-d). Can be obtained. This reaction is preferably carried out in the presence of a solvent such as methylene chloride, tetrahydrofuran and acetonitrile.

[Wherein R ¹ represents the same meaning as described above. ]
In this reaction, a condensation catalyst such as dicyclohexylcarbodiimide can also be used.

Examples of the compound represented by the formula (I′-1-c) include compounds represented below. The compound represented by the formula (I′-1-c) and the compound represented by the formula (I′-1-d) can be easily obtained from the market.

なお、式（ａａ’−１）〜式（ａａ’−６）でそれぞれ表される化合物（Ｉ’）において、Ｒ^１に相当するメチル基が水素原子に置き換わった構造単位も、化合物（Ｉ’）の具体例として挙げることができる。 If a compound in which * —CH ₂ —CO—OH is replaced by * —A ¹ —OH in the formula (I′-1-c) is used instead of the compound represented by the formula (I′-1-c), Various compounds (I ′) can be obtained by the method for producing a compound represented by the above formula (I′-1).
Here, specific examples of the compound (I ′) are shown below.

In addition, in the compound (I ′) represented by each of the formulas (aa′-1) to (aa′-6), the structural unit in which the methyl group corresponding to R ¹ is replaced with a hydrogen atom is also represented by the compound (I ′ ).

  The content rate of the 1st structural unit in resin (A) is the range of 1-80 mol% with respect to all the structural units (100 mol%) of resin (A), and is the range of 2-75 mol%. And preferably in the range of 3 to 70 mol%, more preferably in the range of 5 to 65 mol%.

［式（１）中、
Ｒ^a1、Ｒ^a２及びＲ^a3は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。＊は結合手を表す。］

［式（２）中、
Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１〜１２の１価の炭化水素基を表し、Ｒ^a3’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。該１価の炭化水素基及び該２価の炭化水素基を構成するメチレン基は、酸素原子又は硫黄原子に置き換わってもよい。＊は結合手を表す。］ Next, the second structural unit will be described.
The second structural unit is a structural unit having an acid labile group. A structural unit having an acid labile group (hereinafter sometimes referred to as “acid labile structural unit”) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “acid labile monomer (a1)”). .
Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

[In Formula (1),
R ^a1 , R ^a2 and R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a1 and R ^a2 are bonded to each other to form carbon A divalent hydrocarbon group of 2 to 20 is formed. * Represents a bond. ]

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

アルキル基で置換された脂環式炭化水素基としては、例えば、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等が挙げられる。
式（１）においては、Ｒ^a1、Ｒ^a２及びＲ^a3で表される該脂環式炭化水素基の炭素数は、好ましくは３〜１６の範囲である。 ^Examples of the alkyl group represented by R ^a1 , R ^a2 and R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group is an alkyl group. May be substituted. In this case, the carbon number of the alicyclic hydrocarbon group is 20 or less including the carbon number of the alkyl group.
Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond).

Examples of the alicyclic hydrocarbon group substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
In the formula (1), the carbon number of the alicyclic hydrocarbon group represented by R ^a1 , R ^a2 and R ^a3 is preferably in the range of 3 to 16.

［各式中、Ｒ^a3及び＊は、上記と同じ意味を表す。］ When R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group, examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) include the following groups. The carbon number of the divalent hydrocarbon group is preferably in the range of 3-12. * Represents a bond with -O-.

[In each formula, R ^a3 and * represent the same meaning as described above. ]

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (a group in which R ^a1 , R ^a2 and R ^a3 are alkyl groups in the formula (1), preferably tert-butoxycarbonyl). Group), 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantane) -1-yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the hydrocarbon group represented by R ^{a1 ′} , R ^{a2 ′} and R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Examples of the alkyl group and alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
Examples of the divalent hydrocarbon group formed by combining R ^{a2 ′} and R ^{a3 ′} include a divalent aliphatic hydrocarbon group.

In Formula (2), it is preferable that at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.
Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

  The second structural unit is a monomer having an acid labile group [hereinafter referred to as “monomer (a1)” in some cases. ] Is derived from. The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

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

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表し、ｋ１は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手を表す。
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^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ１’は０〜３の整数を表す。］ Among the second structural units, the structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as “structural unit (a1-1)”) or the structural unit represented by the formula (a1-2) ( Hereinafter, the “structural unit (a1-2)” is sometimes preferable. The resin (A) having the second structural unit may have a single structural unit (a1-1) or a plurality of structural units (a1-2). You may have by seed | species, you may have multiple types, and you may have combining the structural unit (a1-1) and the structural unit (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents a carbonyl group It represents a bond with (—CO—).
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n1 ′ represents an integer of 0 to 3. ]

ｍ１は、好ましくは０〜３の整数、より好ましくは０又は１である。
ｎ１は、好ましくは０〜３の整数、より好ましくは０又は１である。
ｎ１’は好ましくは０又は１である。 L ^a1 and L ^a2 are preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k1 —CO—O—, wherein k1 is an integer of 1 to 4, more preferably an oxygen atom. or * -O-CH ₂ -CO-O- and, still more preferably an oxygen atom.
R ^a4 and R ^a5 are preferably methyl groups.
The alkyl group represented by R ^a6 and R ^a7 preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group represented by R ^a6 and R ^a7 may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an alkyl group. May be. In this case, the carbon number of the alicyclic hydrocarbon group is 10 or less including the carbon number of the alkyl group. Specific examples include the same groups as the alicyclic hydrocarbon groups represented by R ^a1 , R ^a2 and R ^a3 in formula (1).

m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the structural unit (a1-1), the following formula (a1-1-1), formula (a1-1-2), formula (a1-1-3), formula (a1-1-4), formula ( a1-1-5), the formula (a1-1-6), the formula (a1-1-7), and the structural unit represented by the formula (a1-1-8) are preferable, and the formula (a1-1-1) is preferable. ) To (a1-1-4) are more preferred.

  Examples of the monomer capable of deriving the structural unit (a1-1) include those described in JP-A No. 2010-204646.

On the other hand, as the structural unit (a1-2), for example, the formula (a1-2-1), the formula (a1-2-2), the formula (a1-2-3), the formula (a1-2-4), Formula (a1-2-5), Formula (a1-2-6), Formula (a1-2-7), Formula (a1-2-8), Formula (a1-2-9), Formula (a1-2) -10), structural units represented by formula (a1-2-11) or formula (a1-2-12), respectively. Among these, the structural unit represented by the formula (a1-2-3), the formula (a1-2-4), the formula (a1-2-9), or the formula (a1-2-10) is preferable. The structural unit represented by (a1-2-3) or formula (a1-2-9) is more preferable.

  Examples of the monomer (a1) capable of deriving the structural unit (a1-2) include 1-ethylcyclopentan-1-yl (meth) acrylate, 1-ethylcyclohexane-1-yl (meth) acrylate, and 1-ethyl. Examples include cycloheptan-1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, and 1-isopropylcyclopentan-1-yl (meth) acrylate.

  When the resin (A) has the structural unit (a1-1) and / or the structural unit (a1-2) as the second structural unit, the total content ratio thereof is the total structural unit of the resin (A) (100 The range of 10 to 95 mol% is preferable, the range of 15 to 90 mol% is more preferable, the range of 20 to 85 mol% is more preferable, and the range of 35 to 80 mol% is particularly preferable. However, it is preferable that the total content ratio of the structural unit (a1-1) and / or the structural unit (a1-2) is determined in consideration of the content ratio of the first structural unit and the second structural unit described later. . Moreover, when it has the 2nd structural unit which has an adamantyl group as a 2nd structural unit, Especially preferably, when it has a structural unit (a1-1), the sum total (100 mol%) of the 2nd structural unit in resin (A). ), The second structural unit having an adamantyl group is preferably 15 mol% or more. In such a content ratio, the resin (A) having the second structural unit having an adamantyl group tends to have good dry etching resistance of a resist pattern produced from the resist composition containing the resin (A). There is. In addition, in order to make the total content rate of a structural unit (a1-1) and / or a structural unit (a1-2) into the above-mentioned range, when manufacturing resin (A), it is with respect to the usage-amount of all monomers. The amount of the monomer (a1) used to derive the structural unit (a1-1) and / or the structural unit (a1-2) may be adjusted.

  Among the second structural units of the resin (A), the preferred structural unit (a1-1) and structural unit (a1-2) have been described in detail. Among these, the structural unit (a1-1) is the resin (A). Is particularly preferable.

  The resin (A) may have a second structural unit other than the structural unit (a1-1) and the structural unit (a1-2). Hereinafter, the second structural unit other than the structural unit (a1-1) and the structural unit (a1-2) will be described by showing a monomer (a1) that derives the second structural unit.

式（ａ１−５）中、
Ｒ³¹は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｌ^１、Ｌ^２及びＬ^３は、酸素原子、硫黄原子又は^＊−Ｏ−（ＣＨ₂）_k４−ＣＯ−Ｏ−で表される基を表す。ここで、ｋ４は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手である。
Ｚ^１は、単結合又は炭素数１〜６のアルカンジイル基であり、該アルカンジイル基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ｓ１及びｓ１’は、それぞれ独立して、０〜４の整数を表す。 As the second structural unit, the resin (A) is, for example, a monomer represented by the formula (a1-5) which is a (meth) acrylic monomer having an acid labile group (2) (hereinafter, “monomer (a1 −5) ”) may be included in the second structural unit.

In formula (a1-5),
R ³¹ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
L ¹ , L ² and L ³ represent an oxygen atom, a sulfur atom or a group represented by ^* —O— (CH ₂ ) _k4 —CO—O—. Here, k4 represents an integer of 1 to 7, and * is a bond with a carbonyl group (—CO—).
Z ¹ is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group may be replaced with an oxygen atom or a carbonyl group.
s1 and s1 ′ each independently represents an integer of 0 to 4.

R ³¹ in formula (a1-5) is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group.
L ¹ is preferably an oxygen atom.
One of L ² and L ³ is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ¹ is preferably a single bond or —CH ₂ —CO—O—.

Examples of the monomer (a1-5) include the following monomers.

  When the resin (A) has the second structural unit derived from the monomer (a1-5), the content ratio is preferably in the range of 1 to 50 mol% with respect to all the structural units of the resin (A). The range of 3-45 mol% is more preferable, and the range of 5-40 mol% is more preferable.

In the resin (A), the second structural unit is decomposed by the action of an acid, and is converted into a resin having a different solubility in a developer used in a method for producing a resist pattern described later.
When the developer is a general-purpose alkaline aqueous solution, the resin (A) subjected to the action of an acid tends to increase the solubility in the alkaline aqueous solution. On the other hand, when the developer is a negative developer such as a developer composed of an organic solvent, the resin (A) subjected to the action of an acid tends to decrease the solubility in the negative developer.
As will be described later in the description of the method for producing a resist pattern, the present resist composition has an effect of producing an excellent LER resist pattern. It is particularly preferable that the resin (A) has a property of being decomposed by the action of an acid (hereinafter, sometimes referred to as “acid action property”).

The content ratio (molar ratio) of the first structural unit and the second structural unit in the resin (A) is expressed by [content of first structural unit] / [content of second structural unit], and is 5 to 80 / It is preferably 95 to 20 (that is, 5/95 to 80/20), and more preferably 5 to 75/95 to 25 (that is, 5/95 to 75/25. This content ratio will be described later. In the production of the resin (A), the ratio of the compound (I ′) for deriving the first structural unit and the monomer (a1) for deriving the second structural unit can be adjusted. (A) particularly preferably has acid action characteristics, and the content ratio (molar ratio) of the first structural unit and the second structural unit may be determined so as to have such acid action characteristics. preferable.

  As described above, the resin (A) has the first structural unit and the second structural unit, but other than these, the structural unit having no acid labile group (hereinafter referred to as “acid-stable structural unit”). And a monomer capable of deriving the acid stable structural unit is referred to as “acid stable monomer”). In the resin (A), the acid stable structural unit may have only one type, or may have a plurality of types.

  When the resin (A) has an acid stable structural unit, the content ratio of the acid stable structural unit may be determined based on the content ratio of the first structural unit and the content ratio of the second structural unit. More specifically, the ratio between the content ratio of each of the first structural unit and the second structural unit and the content ratio of the acid-stable structural unit is [content of the first structural unit] / [content of the second structural unit]. Amount] / [content of acid stable structural unit], preferably (5-80 mol%) / (20-92 mol%) / (3-75 mol%), more preferably (5- 75 mol%) / (25-92 mol%) / (3-70 mol%).

  The acid stable structural unit is preferably an acid stable structural unit having a hydroxy group or a lactone ring. Resin (A) has a coating film formed by applying the present resist composition to a substrate or a composition layer obtained from the coating film in the production of a resist pattern described later by the action of the first structural unit. However, if it further has an acid stable structural unit having a hydroxy group or a lactone ring, the adhesion is further improved. Here, the acid stable structural unit having a hydroxy group is hereinafter referred to as “acid stable structural unit (a2)”, and the acid stable structural unit having a lactone ring is sometimes referred to as “acid stable structural unit (a3)”. I will say. The acid stable structural unit (a3) here does not include the first structural unit. First, the acid stable structural unit (a2) and the acid stable structural unit (a3) suitable as the acid stable structural unit will be described with specific examples.

  When the acid stable structural unit (a2) is introduced into the resin (A), a suitable acid stable structural unit (a2) can be selected depending on the type of exposure source used in the production of the resist pattern described later. That is, when this resist composition is exposed using a short-wavelength ArF excimer laser (wavelength: 193 nm) as an exposure source, it is represented by the formula (a2-1) described later as an acid stable structural unit (a2). It is preferable to introduce an acid stable structural unit into the resin (A). Further, the present resist composition is exposed using a KrF excimer laser (wavelength: 248 nm) as an exposure source, or exposure using a high energy beam such as an electron beam or EUV light as an exposure source. In the specification, it is referred to as “exposure”, and the electron beam is also considered as one of “exposure sources”.) When used for acid stable structural unit (a2), an acid stable structural unit having a phenolic hydroxy group is used. It may be introduced. The acid-stable structural unit (a2) of the resin (A) can be selected depending on the exposure source when producing the resist pattern, but when the resin (A) has the acid-stable structural unit (a2), The acid stable structural unit (a2) may be a single species or a plurality of species.

式（ａ２−１）中、
Ｌ^a3は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−（ｋ２は１〜７の整数を表し、＊はカルボニル基（−ＣＯ−）との結合手を表す。）で表される基を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 A preferable acid stable structural unit (a2) in the case of using ArF excimer laser (wavelength: 193 nm) exposure for the resist composition is represented by the following formula (a2-1) (hereinafter, “acid stable structural unit ( a2-1) ”).

In formula (a2-1),
L ^a3 is an oxygen atom or ^* —O— (CH ₂ ) _k2 —CO—O— (k2 represents an integer of 1 to 7, and * represents a bond to a carbonyl group (—CO—)). Represents the group represented.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

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

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

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

  When the resin (A) has an acid stable structural unit (a2-1), the content ratio is preferably in the range of 1 to 45 mol%, and 1 to 40 mol% with respect to all the structural units of the resin (A). The range of 1 to 35 mol% is more preferable, the range of 1 to 20 mol% is still more preferable.

Next, the acid stable structural unit (a3) having a lactone ring will be described.
The lactone ring of the acid stable structural unit (a3) is not particularly limited as long as it is other than the adamantane ring-like lactone ring of the first structural unit. For example, β-propiolactone ring, γ-butyrolactone ring and A monocyclic ring such as a δ-valerolactone ring or a condensed ring of a monocyclic lactone ring and another ring may be used.

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a21は炭素数１〜４のアルキル基を表し、ｐ１が２以上の場合、複数のＲ^a21は互いに同一でも異なっていてもよい。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
ｑ１は、０〜３の整数を表す。
Ｒ^a22は、カルボキシ基、シアノ基又は炭素数１〜４のアルキル基を表し、ｑ１が２以上の場合、複数のＲ^a22は互いに同一でも異なっていてもよい。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
ｒ１は、０〜３の整数を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４のアルキル基を表し、ｒ１が２以上の場合、複数のＲ^a23は互いに同一でも異なっていてもよい。］ The acid stable structural unit (a3) is preferably one represented by the following formula (a3-1), formula (a3-2) or formula (a3-3). Resin (A1) may have only 1 type in these, and may have 2 or more types. In the following description, what is represented by the formula (a3-1) is referred to as “acid-stable structural unit (a3-1)”, and what is represented by the formula (a3-2) is “acid-stable structural unit ( a3-2) ”, and the compound represented by formula (a3-3) is referred to as“ acid-stable structural unit (a3-3) ”.

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

In Formula (a3-1) to Formula (a3-3), L ^a4 , L ^a5, and L ^a6 are the same as those described for L ^a3 in Formula (a2-1).
L ^a4 , L ^a5 and L ^a6 are each independently preferably an oxygen atom or a group represented by * —O— (CH ₂ ) _k3 —CO—O—, wherein k3 is an integer of 1 to 4. An atom and * —O—CH ₂ —CO—O— are more preferable, and an oxygen atom is more preferable.
R ^a18 , L ^a19 , L ^a20 and R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are preferably integers of 0 to 2, more preferably 0 or 1. When p1 is 2, two R ^a21 may be the same as or different from each other. When q1 is 2, two R ^a22 may be the same as or different from each other, and r1 is 2. Two R ^a23 may be the same or different from each other.

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

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

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

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

  The acid stable structural unit (a3-1), the acid stable structural unit (a3-2), and the acid stable structural unit (a3-3) can be derived from an acid stable monomer described in JP 2010-204646 A. Among the specific examples of the acid stable structural unit (a3), the formula (a3-1-1), the formula (a3-1-2), the formula (a3-2-3), and the formula (a3-2-4) Are more preferable, and the acid stable structural unit (a3) represented by the formula (a3-1-1) or the formula (a3-2-3) is more preferable. In addition, when resin (A) has an acid stable structural unit (a3), this acid stable structural unit (a3) may be single type, or may be multiple types.

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

The acid-stable structural unit that the resin (A) optionally has, preferably the acid-stable structural unit (a2) and the acid-stable structural unit (a3), the specific examples and the content ratio in the resin (A) are described. The content of the acid stable structural unit is particularly preferably determined so as not to significantly impair the acid action characteristics of the resin (A).
The resin (A) has acid-stable structural units other than the acid-stable structural unit (a2) and the acid-stable structural unit (a3) as long as the acid action characteristics of the resin (A) are not significantly impaired. You may do it.

Resin (A) comprises compound (I ′) for deriving the first structural unit and monomer (a1) for deriving the second structural unit, more preferably compound (I ′), monomer (a1) and And an acid-stable monomer, and more preferably, the compound (I ′) and the monomer (a1) for deriving the structural unit (a1-1) and / or the structural unit (a1-2) The acid stable structural unit (a2) and / or the acid stable monomer for deriving the acid stable structural unit (a3) are copolymerized.
The resin (A) more preferably has a structural unit (a1-1) having an adamantyl group as the second structural unit. The resin (A) can be produced by subjecting the monomer as described above to a known polymerization method (for example, radical polymerization method) and copolymerizing it.

  The weight average molecular weight of the resin (A) is preferably 2,500 or more and 50,000 or less, more preferably 3,000 or more and 30,000 or less, and further preferably 4,000 or more and 15,000 or less. In addition, the weight average molecular weight here is calculated | required as a conversion value of a standard polystyrene reference | standard by gel permeation chromatography analysis. Detailed analysis conditions for this analysis are described in the Examples of the present application.

  The resist composition contains the resin (A) as a resin component, but the resin component may contain a resin other than the resin (A). Examples of the resin other than the resin (A) include resins known in the resist field, such as a resin obtained by removing the first structural unit from the resin (A).

  In the present resist composition, the content ratio of the resin component is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the present resist composition. As described above, the resin component may contain a resin other than the resin (A), but the resin (A) is preferably 50% by mass or more based on the total amount of the resin component, and 70 More preferably, it is more than mass%, and it is especially preferable that the resin component consists essentially of the resin (A). In the present specification, the “solid content” means the total of the resist composition components excluding the solvent (E) described later. The solid content and the content ratio of the resin component to the solid content can be measured by a known analysis means such as liquid chromatography or gas chromatography, for example.

<Acid generator (B)>
In the resist field, acid generators are usually classified into nonionic and ionic, but the acid generator (B) contained in the resist composition may be a nonionic acid generator, An ionic acid generator or a combination thereof may be used. Examples of the nonionic acid generator include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4). -Sulfonate), and sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. Examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts) and the like. Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, and JP-A 63-163452. JP-A-62-153853, JP-A-63-146029, US Pat. No. 3,779,778, US Pat. No. 3,849,137, German Patent 3914407, European Patent 126, Compounds that generate an acid by radiation, such as those described in No. 712, can also be used.

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、炭素数１〜２４、好ましくは１〜１７、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で置換されていてもよく、該飽和炭化水素基を構成するメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基、水素原子又はフッ素原子を表し、該脂環式炭化水素基を構成するメチレン基は、酸素原子、スルホニル基又はカルボニル基に置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］
かかる酸発生剤（Ｂ１）を含有する本レジスト組成物は、後述のレジストパターンの製造方法により、一層優れたＬＥＲのレジストパターンを製造できる。 The acid generator (B) is preferably a fluorine-containing acid generator, more preferably an acid generator represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”). .

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, preferably 1 to 17 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, The methylene group constituting the saturated hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
Y represents an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, a hydrogen atom or a fluorine atom, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Z ⁺ represents an organic cation. ]
This resist composition containing such an acid generator (B1) can produce a more excellent LER resist pattern by the method for producing a resist pattern described later.

Examples of the perfluoroalkyl group represented by Q ¹ and Q ² include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluorotert-butyl group, perfluoropentyl. Group, perfluorohexyl group and the like.
As the acid generator (B1) contained in the resist composition, Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom acid generator (B1). Q ¹ and Q ² An acid generator (B1) in which both are fluorine atoms is more preferred.

Examples of the saturated hydrocarbon group represented by L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
Side of alkyl group (particularly alkyl group having 1 to 4 carbon atoms, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, etc.) to linear alkanediyl group Having a chain, for example, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, Branched alkanediyl groups such as 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 Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

各式中、
Ｌ^b2は、単結合又は炭素数１〜２２、好ましくは１〜１５の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１９、好ましくは１〜１２の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜２０、好ましくは１〜１３の飽和炭化水素基を表す。但しＬ^b3及びＬ^b4の合計炭素数の上限は２０、好ましくは１３である。
Ｌ^b５は、単結合又は炭素数１〜２１、好ましくは１〜１４の飽和炭化水素基を表す。
Ｌ^b６は、炭素数１〜２２、好ましくは１〜１５の飽和炭化水素基を表す。但しＬ^b5及びＬ^b6の合計炭素数の上限は２２、好ましくは１５である。
Ｌ^b７は、単結合又は炭素数１〜２２、好ましくは１５の飽和炭化水素基を表す。
Ｌ^b８は、炭素数１〜２３、好ましくは１〜１６の飽和炭化水素基を表す。但しＬ^b７及びＬ^b８の合計炭素数の上限は２３、好ましくは１〜１７である。
Ｌ^b9は、単結合又は炭素数１〜２０、好ましくは１〜１３の飽和炭化水素基を表す。
Ｌ^b10は、炭素数１〜２１、好ましくは１〜１４の飽和炭化水素基を表す。但しＬ^b9及びＬ^b10の合計炭素数の上限は２１、好ましくは１４である。
Ｌ^b11及びＬ^b12は、単結合又は炭素数１〜１８、好ましくは１〜１１の飽和炭化水素基を表す。
Ｌ^b13は、炭素数１〜１９、好ましくは１〜１２の飽和炭化水素基を表す。但しＬ^b11、Ｌ^b12及びＬ^b13の合計炭素数の上限は１９、好ましくは１２である。
Ｌ^b14及びＬ^b15は、それぞれ独立に、単結合又は炭素数１〜２０、好ましくは１〜１３の飽和炭化水素基を表す。
Ｌ^b16は、炭素数１〜２１、好ましくは１〜１４の飽和炭化水素基を表す。但しＬ^b14、Ｌ^b15及びＬ^b16の合計炭素数の上限は２１、好ましくは１４である。 Examples of the methylene group constituting the saturated hydrocarbon group represented by L ^b1 replaced with an oxygen atom or a carbonyl group include the following formulas (b1-1), (b1-2), and (b1 -3), groups represented by formula (b1-4), formula (b1-5), formula (b1-6) and formula (b1-7), respectively. Incidentally, the formula (b1-1) ~ formula represents a bond in (b1-7) * is described in conjunction the right in equation (B1), the left bond is, C (Q ¹⁾ ( Q ² ) is bonded to the carbon atom, and the right bond is bonded to Y. The same applies to specific examples of the following formulas (b1-1) to (b1-7).

In each formula,
L ^b2 represents a single bond or a saturated hydrocarbon group having 1 to 22 carbon atoms, preferably 1 to 15 carbon atoms.
L ^b3 represents a single bond or a saturated hydrocarbon group having 1 to 19 carbon atoms, preferably 1 to 12 carbon atoms.
L ^b4 represents a saturated hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 20, preferably 13.
L ^b5 represents a single bond or a saturated hydrocarbon group having 1 to 21 carbon atoms, preferably 1 to 14 carbon atoms.
L ^b6 represents a saturated hydrocarbon group having 1 to 22 carbon atoms, preferably 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b5 and L ^b6 is 22, preferably 15.
L ^b7 represents a single bond or a saturated hydrocarbon group having 1 to 22 carbon atoms, preferably 15 carbon atoms.
L ^b8 represents a saturated hydrocarbon group having 1 to 23 carbon atoms, preferably 1 to 16 carbon atoms. However, the upper limit of the total carbon number of L ^b7 and L ^b8 is 23, preferably 1-17.
L ^b9 represents a single bond or a saturated hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 13 carbon atoms.
L ^b10 represents a saturated hydrocarbon group having 1 to 21 carbon atoms, preferably 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 21, preferably 14.
L ^b11 and L ^{b12 each} represents a single bond or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 11 carbon atoms.
L ^b13 represents a saturated hydrocarbon group having 1 to 19 carbon atoms, preferably 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b11 , L ^b12 and L ^b13 is 19, preferably 12.
L ^b14 and L ^b15 each independently represent a single bond or a saturated hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 13 carbon atoms.
L ^b16 represents a saturated hydrocarbon group having 1 to 21 carbon atoms, preferably 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 21, preferably 14.

L ^b1 is preferably a group represented by the formula (b1-1), and a group represented by the formula (b1-1) in which L ^b2 is a single bond or an aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms. More preferred.

As ^{L b2, L b3, L b4} , L b5, L b6, L b7, L b8, L b9, L b10, L b11, L b12, L b13, L b14, saturated hydrocarbon group in L ^b15 and L ^b16 Is preferably an alkanediyl group, and the saturated hydrocarbon group in L ^b10 is preferably an alkanediyl group or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, more preferably an alkanediyl group, a cyclohexyl group or an adamantyl group.
L ^b1 is preferably any one of formula (b1-1) to formula (b1-4), more preferably formula (b1-1) or formula (b1-2), and still more preferably formula (b1-1). A divalent group represented by formula (b1-1) in which L ^b2 is a single bond or —CH ₂ —.

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

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

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

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

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

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

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

Specific examples of the group in which the hydrogen atom contained in the saturated hydrocarbon group represented by L ^b1 is substituted with a fluorine atom or a hydroxy group include the following.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y26).

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent of the alicyclic hydrocarbon group include a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and an alkyl group having 3 to 16 carbon atoms. An alicyclic hydrocarbon group, 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 ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or a group having 6 to 18 carbon atoms. Represents an aromatic hydrocarbon group, and j2 represents an integer of 0 to 4).
The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are substituents for Y, may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
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 aromatic hydrocarbon group include those similar to the above.
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 which may have a substituent, more preferably an adamantyl group which may have a substituent (for example, a hydroxy group), or a methylene group is carbonyl. An adamantyl group replaced by a group, more preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group;

Preferable examples of the sulfonate anion constituting the acid generator (B1) include anions represented by formulas (b1-1-1) to (b1-1-9), respectively. In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group). Specific examples of the sulfonate anion include the anions described in JP 2010-204646 A.

Next, the organic cation (cation) constituting the acid generator (B1) will be described. This cation functions as a light absorption part of the acid generator (B1). In the ionic acid generator used in the resist field, various cations used as the light absorption part can be mentioned, and more specifically, Includes organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, organic benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an organic sulfonium cation is more preferable. Specific examples of preferred cations are organic cations represented by the following formulas (b2-1) to (b2-4) [hereinafter referred to as “cation (b2-1)” according to the number of each formula]. , “Cation (b2-2)”, “cation (b2-3)” and “cation (b2-4)”. ].

In formula (b2-1) to formula (b2-4),
R ^b4 , R ^b5 and R ^b6 each independently represent a hydrocarbon group having 1 to 30 carbon atoms, and among these hydrocarbon groups, an alkyl group having 1 to 30 carbon atoms and an oil having 3 to 18 carbon atoms A cyclic hydrocarbon group and an aromatic hydrocarbon group having 6 to 18 carbon atoms are preferred. The alkyl group may have a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon group includes a halogen atom and a carbon number. The aromatic hydrocarbon group may have 2 to 4 acyl groups or glycidyloxy groups, and the aromatic hydrocarbon group is a halogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms, or an alicyclic group having 3 to 18 carbon atoms. You may have a hydrocarbon group or a C1-C12 alkoxy group.
R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.
R ^b9 and R ^b10 each independently represent an alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b9 , R ^b10 and R ^b11 (R ^{b9 to} R ^b11 ) are each independently an alkyl group, preferably a carbon number in the range of 1 to 12, and an alicyclic hydrocarbon group. The number of carbon atoms is preferably in the range of 3-18, more preferably in the range of 4-12.
R ^b12 represents a hydrocarbon group having 1 to 18 carbon atoms. Among these hydrocarbon groups, the aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 1 to 12 carbon atoms. It may have an alkylcarbonyloxy group.
The combination of R ^b9 and R ^b10 and / or the combination of R ^b11 and R ^b12 are independently bonded to each other to form a 3-membered ring to 12-membered ring (preferably a 3-membered ring to 7-membered ring). These 3-membered ring to 12-membered ring (preferably 3-membered ring to 7-membered ring) may be an aliphatic ring or a methylene group constituting the aliphatic ring may be an oxygen atom, a sulfur atom or A ring that replaces a carbonyl group.

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

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

^Examples of the alkyl group represented by R ^b9 , R ^b10 , R ^b11 and R ^b12 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl. Group, hexyl group, octyl group and 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group represented by R ^{b9 to} R ^b11 include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyladamantan-2-yl group, 1- (1- Adamantyl) alkane-1-yl group and isobornyl group.
^Examples of the aromatic hydrocarbon group represented by R ^b12 include a phenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-cyclohexylphenyl group, and a 4-methoxyphenyl group. A biphenylyl group and a naphthyl group.
A ^combination of an aromatic hydrocarbon group represented by R ^b12 and an alkyl group is typically an aralkyl group.
Examples of the ring formed by combining the combination of R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. Is mentioned.
^Examples of the ring formed by combining the combination of R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Specific examples of the organic cation represented by each of the formulas (b2-1) to (b2-4) include those described in JP 2010-204646 A.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, the cation represented by the formula (b2-1-1) is more preferable, and the triphenylsulfonium cation (formula (b2) -1-1), v2 = w2 = x2 = 0), diphenyltolylsulfonium cation (in formula (b2-1-1), v2 = w2 = 0, x2 = 1, and R ^b21 is a methyl group .) Or tolylsulfonium cation (in formula (b2-1-1), v2 = w2 = x2 = 1, and R ^b19 , R ^b20 and R ^b21 are all methyl groups).

式（ｂ２−１−１）中、
Ｒ^b19、Ｒ^b20及びＲ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）ヒドロキシ基、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基又は炭素数３〜１８の脂環式炭化水素基を表す。また、Ｒ^b19、Ｒ^b20及びＲ^b21から選ばれる２つが一緒になって硫黄原子を含む環を形成してもよい。
ｖ２、ｗ２及びｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。
ｖ２が２以上のとき、複数のＲ^b19は同一又は相異なり、ｗ２が２以上のとき、複数のＲ^b20は同一又は相異なり、ｘ２が２以上のとき、複数のＲ^b21は同一又は相異なる。

In formula (b2-1-1),
R ^b19 , R ^b20 and R ^b21 each independently represent a halogen atom (more preferably a fluorine atom) hydroxy group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an alkyl group having 3 to 18 carbon atoms. Represents an alicyclic hydrocarbon group. Two selected from R ^b19 , R ^b20 and R ^b21 may be combined to form a ring containing a sulfur atom.
v2, w2 and x2 each independently represent an integer of 0 to 5 (preferably 0 or 1).
When v2 is 2 or more, the plurality of R ^b19 are the same or different, when w2 is 2 or more, the plurality of R ^b20 are the same or different, and when x2 is 2 or more, the plurality of R ^b21 are the same or different. .

Among them, R ^b19 , R ^b20 and R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. It is.

  Specific examples of the cation include those described in JP2010-204646A.

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, but preferably the sulfonate anion of any one of the formulas (b1-1-1) to (b1-1-9) and the formula (b2-1-1- The combination of 1) with the organic cation, and the combination of the sulfonate anion of any one of formulas (b1-1-3) to (b1-1-5) with the organic cation of formula (b2-3) Can be mentioned.

  As the acid generator (B1), those represented by the formula (B1-1) to the formula (B1-20) are more preferable, and the formula (B1-1) and the formula (B1- 2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1-11), Formula (B1-12), Formula (B1-13), Formula (B1-14) ), Formula (B1-18), formula (B1-19) or formula (B1-20) is particularly preferable.

The content of the acid generator (B) is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 3 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the resin (A).
The acid generator (B) contained in the resist composition may be a single type or a plurality of types of acid generators, but at least one type of acid generator may be contained even when a plurality of types of acid generators are contained. Is preferably an acid generator (B1), more preferably substantially all of the acid generator (B) is composed of an acid generator (B1).

［式（II）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、それぞれ独立に、炭素数１〜１２の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０〜４の整数を表し、ｍ’が２以上の場合、複数のＲ^Ｄ１は同一又は互いに相異なり、ｎ’が２以上の場合、複数のＲ^Ｄ２は同一又は互いに相異なる。］ <Compound (D)>
As described above, the compound (D) is represented by the formula (II).

[In the formula (II),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represents an integer of 0 to 4. When m ′ is 2 or more, a plurality of R ^D1 are the same or different from each other, and when n ′ is 2 or more, a plurality of R ^D2 Are the same or different from each other. ]

Examples of the hydrocarbon group include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which these are combined, and specifically, R ^a1 in the formula (2). Examples thereof include the same groups as the hydrocarbon groups represented by ^' , R ^a2' and R ^{a3 '} .

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group.
As an alkoxycarbonyl group, the group which the carbonyl group couple | bonded with the said alkoxy group is mentioned, for example.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, and an isobutyryloxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, or a carbon number It is preferably 2 to 5 alkoxycarbonyl group, nitro group or halogen atom.
m ′ and n ′ are each independently preferably an integer of 0 to 3, more preferably an integer of 0 to 2, still more preferably 0 or 1, and particularly preferably 0.

Specific examples of compound (II) are shown below.

  As the compound (D), a commercially available product may be used, or a compound produced by a known production method may be used. Among the compounds (D) shown here, those in which both m and n are 0 are preferred, and specifically represented by the formula (II-a), formula (II-b) and formula (II-c). Are preferred. Among them, the compound represented by the formula (II-a) is preferable because it can be easily obtained from the market, and thus the resist composition can be easily prepared.

  The content ratio of the compound (D) in the resist composition is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass with respect to the solid content of the resist composition. It is particularly preferably about 0.01 to 1% by mass.

<Solvent (E)>
As described above, the resist composition preferably contains a solvent (E), particularly an organic solvent as the solvent (E). The solvent (E) depends on the type and amount of the resin (A) to be used, the type and amount of the acid generator (B), and the resist composition on the substrate in the production of a resist pattern described later. The optimum one can be appropriately selected from the viewpoint that the coating property when coating is good.

  When this resist composition contains a solvent (E), the content ratio is 90 mass% or more with respect to the total amount of this resist composition, for example, Preferably it is 92 mass% or more, More preferably, it is 94 mass% or more. For example, it is 99.9% by mass or less, preferably 99% by mass or less. The content ratio of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and Examples thereof include esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone. A solvent (E) may contain 1 type independently, and may contain 2 or more types.

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition may contain a basic compound (C) called “quencher” in the resist field.
The basic compound (C) is a compound having a property of capturing an acid, particularly a compound having a property of capturing an acid generated from the acid generator (B).

  The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to the formula (C8), more preferably a compound represented by the formula (C1-1).

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

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

［式（Ｃ１−１）中、
Ｒ^c2及びＲ^c3は、上記と同じ意味を表す。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は同一又は相異なる。］

[In the formula (C1-1),
R ^c2 and R ^c3 represent the same meaning as described above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 are the same or different. ]

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、
Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は同一又は相異なる。］
なお、ここでいうアルカノイル基としては、アセチル基、２−メチルアセチル基、２，２−ジメチルアセチル基、プロピオニル基、ブチリル基、イソブチリル基、ペンタノイル基及び２，２−ジメチルプロピオニル基などである。

[In Formula (C2), Formula (C3) and Formula (C4),
R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different. ]
The alkanoyl group mentioned here includes an acetyl group, a 2-methylacetyl group, a 2,2-dimethylacetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pentanoyl group, and a 2,2-dimethylpropionyl group.

［式（Ｃ５）及び式（Ｃ６）中、
Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｏ３及びｐ３は、それぞれ独立に０〜３の整数を表し、ｏ３が２以上であるとき、複数のＲ^c1４は同一又は相異なり、ｐ３が２以上であるとき、複数のＲ^c15は、同一又は相異なる。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

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

［式（Ｃ７）及び式（Ｃ８）中、
Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上であるとき、複数のＲ^c18は同一又は相異なり、ｒ３が２以上であるとき、複数のＲ^c1９は同一又は相異なり、及びｓ３が２以上であるとき、複数のＲ^c20は同一又は相異なる。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

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

Specific examples of the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group and alkanediyl group in the formulas (C1) to (C8) are those already exemplified in the respective carbon number ranges. including.
Specific examples of the alkanoyl group include the same as those described for R ^c9 in formula (C4).

  Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diiso Ropiruanirin. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide and 2,2′-dipyridylamine, 2,2′-dipycolylamine, bipyridine and the like.

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

  When the basic compound (C) is contained in the resist composition, the content ratio is preferably about 0.01 to 5% by mass, more preferably about 0.005% by mass, based on the solid content of the resist composition. It is about 01 to 3% by mass, particularly preferably about 0.01 to 1% by mass.

<Other components (hereinafter sometimes referred to as “component (F)”)>
The present resist composition may contain a component (F) as necessary. The component (F) includes additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes. When the component (F) is used in the resist composition of the present invention, an appropriate content can be adjusted according to the type of the component (F).

<Preparation of the present resist composition>
This resist composition is a mixture of resin (A), acid generator (B), compound (D) and solvent (E), and basic compound (C) and component (F) used as necessary. Can be prepared. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to solvent (E), such as resin (A) kind, resin (A). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

The method for producing a resist pattern of the present invention (hereinafter sometimes referred to as “the present production method”)
(1) A step of applying the resist composition on a substrate (application step),
(2) A step of drying the composition after coating to form a composition layer (drying step),
(3) Step of exposing the composition layer (exposure step),
(4) Step of heating composition layer after exposure (heating step), and (5) Step of developing composition layer after heating (development step)
including.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus 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.

The composition layer is formed by drying the composition after application. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking) or using a decompression device to form a composition layer from which the solvent has been removed. The temperature in this case is preferably about 50 to 200 ° C. The pressure is preferably about 1 to 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. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do.

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., and the development time is preferably 5 to 300 seconds.
The heated composition layer is usually developed using a developer using a developing device.

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

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent 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 still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.

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

<Application>
The resist composition 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, in particular, ArF excimer. It is suitable as a resist composition for immersion exposure for laser exposure.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified. The weight average molecular weight of the resin (A) is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

式（Ｋ−１）で表される化合物３３．４８部、ジシクロヘキシルカルボジイミド２３．９３部及び塩化メチレン４０．００部を、反応器に仕込み、混合した。得られた混合物を０℃程度まで冷却した後、式（Ｋ−２）で表される化合物１８．８３部を加え、０℃程度のまま、１時間攪拌した。２３℃まで昇温し、さらに３０分間攪拌した。不溶物をろ過して除去し、得られたろ液を濃縮して、式（Ｋ−３）で表される化合物４４．２８部を得た。 Synthesis Example 1 (Synthesis of monomer (M-K))

33.48 parts of the compound represented by the formula (K-1), 23.93 parts of dicyclohexylcarbodiimide and 40.00 parts of methylene chloride were charged into a reactor and mixed. After cooling the obtained mixture to about 0 ° C., 18.83 parts of the compound represented by the formula (K-2) was added, and the mixture was stirred for about 1 hour while maintaining about 0 ° C. The temperature was raised to 23 ° C., and the mixture was further stirred for 30 minutes. Insoluble matters were removed by filtration, and the obtained filtrate was concentrated to obtain 44.28 parts of a compound represented by the formula (K-3).

前記のようにして得られた式（Ｋ−３）で表される化合物１９．４２部、式（Ｋ−４）で表される化合物１８．２２部及びアセトニトリル２００部を、反応器に仕込み、混合した。得られた混合物を５０℃で３時間攪拌した。得られた混合物を濃縮し、クロロホルム３００部及びイオン交換水１５０部を加えた後、分液操作により、有機層を回収した。回収された有機層をイオン交換水１５０部で水洗した後、有機層を濃縮した。濃縮物を、カラム分取（カラム分取条件 固定相：メルク社製シリカゲル６０−２００メッシュ 展開溶媒：酢酸エチル）することにより、式（Ｍ−Ｋ）で表される化合物１２．８９部を得た。
ＭＳ（質量分析）：３０８．１（分子イオンピーク）

A reactor was charged with 19.42 parts of the compound represented by the formula (K-3) obtained as described above, 18.22 parts of the compound represented by the formula (K-4) and 200 parts of acetonitrile. Mixed. The resulting mixture was stirred at 50 ° C. for 3 hours. The obtained mixture was concentrated, 300 parts of chloroform and 150 parts of ion-exchanged water were added, and then the organic layer was recovered by a liquid separation operation. The recovered organic layer was washed with 150 parts of ion exchange water, and then the organic layer was concentrated. The concentrate is subjected to column fractionation (column fractionation conditions stationary phase: silica gel 60-200 mesh manufactured by Merck & Co., Ltd. developing solvent: ethyl acetate) to obtain 12.89 parts of a compound represented by the formula (M-K). It was.
MS (mass spectrometry): 308.1 (molecular ion peak)

以下、これらのモノマーを、その符号に応じて、「モノマー（Ｍ−Ａ）」〜「モノマー（Ｍ−Ｋ）」という。 Synthesis of Resin (A) Compounds (monomers) used in the synthesis of resin (A) are shown below.

Hereinafter, these monomers are referred to as “monomer (MA)” to “monomer (M-K)” depending on the reference numerals.

Synthesis Example 2 [Synthesis of Resin A1]
As a monomer, a monomer (MG), a monomer (ME), a monomer (MB), a monomer (M-H), and a monomer (M-K) are used, and the molar ratio (monomer (MG) : Monomer (ME): Monomer (MB): Monomer (M-H): Monomer (M-K)) were mixed so that the ratio was 32: 7: 8: 43: 10. 1.5 mass times dioxane was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained is again dissolved in dioxane, and a solution obtained by pouring the solution into a methanol / water mixed solvent is precipitated twice, and the resin is filtered twice to perform a reprecipitation operation twice. 6 × 10 ³ resin A1 (copolymer) was obtained with a yield of 80%. This resin A1 has the following structural units.

Synthesis Example 3 [Synthesis of Resin A2]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (M-J), a monomer (MD) and a monomer (M-K) are used, and the molar ratio (monomer (MF)) : Monomer (M-I): monomer (M-J): monomer (MD): monomer (M-K)) were mixed so that 45: 14: 2.5: 22.5: 16, Dioxane of 1.5 mass times the total monomer amount was added to make a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 8 × 10 ³ resin A2 (copolymer) was obtained with a yield of 71%. This resin A2 has the following structural units.

Synthesis Example 4 [Synthesis of Resin A3]
As a monomer, a monomer (M−F), a monomer (M−I), a monomer (M−J), a monomer (M−D), a monomer (M−H), and a monomer (M−K) are used, and a molar ratio thereof. (Monomer (MF): Monomer (M-I): Monomer (M-J): Monomer (MD): Monomer (M-H): Monomer (M-K))) 45: 14: 2. It mixed so that it might become 5: 17.5: 5: 16, and the dioxane of 1.5 mass times the total monomer amount was added, and it was set as the solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, with respect to the total monomer amount, and these are heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice, and the weight average molecular weight was 8. 3 × 10 ³ resin A3 (copolymer) was obtained with a yield of 69%. This resin A3 has the following structural units.

Synthesis Example 5 [Synthesis of Resin A4]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (M-B), a monomer (MD), and a monomer (M-K) are used, and the molar ratio (monomer (MF)) : Monomer (M-I): monomer (MB): monomer (MD): monomer (M-K)) are mixed so as to be 30: 14: 6: 20: 30, and the total amount of monomers Of 1.5 mass times of dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.9. × 10 ³ of the resin A4 (copolymer) was obtained in 62% yield. This resin A4 has the following structural units and is referred to as resin A4.

Synthesis Example 6 [Synthesis of Resin A5]
As a monomer, a monomer (MF), a monomer (M-I), a monomer (M-J), a monomer (MD) and a monomer (M-K) are used, and the molar ratio (monomer (MF)) : Monomer (M-I): monomer (M-J): monomer (MD): monomer (M-K)) were mixed so as to be 35: 15: 3: 27: 20, and the total amount of monomers Of 1.5 mass times of dioxane was added to make a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 75 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 7.8. × give 10 ^third resin A5 (copolymer) in 66% yield. This resin A5 has the following structural units, and this is designated as resin A5.

Synthesis Example 7 [Synthesis of Resin H1]
As a monomer, a monomer (MA), a monomer (MB), and a monomer (MC) are used, and the molar ratio (monomer (MA): monomer (MB): monomer (MC) ) Was 40:20:40, and 1.5 mass times dioxane of the total monomer amount was added to obtain a solution. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators are added to the solution, respectively, and heated at 78 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The resin thus obtained was dissolved again in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the reprecipitation operation of filtering the resin was performed twice, and the weight average molecular weight 6. 5 × 10 ³ resin H1 (copolymer) was obtained with a yield of 85%. This resin H1 has the following structural units.

<Preparation of resist composition>
Each of the components shown below was dissolved in the following solvent in parts by mass shown in Table 1, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

Each code | symbol shown in Table 1 represents the component shown below.
<Resin>
A1, A2, A3, H1: Resin A1, Resin A2, Resin A3, Resin H1
<Acid generator>
B1: Synthesis according to the example of JP 2010-152341 A

<Basic compound (C): quencher>
C1: 2,6-diisopropylaniline (manufactured by Tokyo Chemical Industry Co., Ltd.)
<Compound (D)>
D1: (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Solvent (E)>
Propylene glycol monomethyl ether acetate 265.0 parts Propylene glycol monomethyl ether 20.0 parts 2-heptanone 20.0 parts γ-butyrolactone 3.5 parts

<Immersion exposure evaluation of resist composition>
(1) Application process By applying a composition for organic antireflection film [ARC-29; manufactured by Nissan Chemical Co., Ltd.] on a 12-inch silicon wafer and baking at 205 ° C. for 60 seconds, An organic antireflection film having a thickness of 780 mm was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) (the film thickness of the composition layer) was 100 nm.
(2) Drying Step After the coating step, the silicon wafer on which the coating film was formed was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature described in the “PB” column of Table 1. Thus, a composition layer was formed on the silicon wafer.
(3) Exposure Step ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annual σ _out = 0.85 on a silicon wafer on which the composition layer is formed.
σ _in = 0.65 XY-pol. Illumination] was performed by using a mask (pitch 240 nm / line 60 nm) for forming a trench pattern (pitch 240 nm / trench 60 nm) while changing the exposure amount stepwise. Note that ultrapure water was used as the immersion medium.
(4) Heating step After exposure, post-exposure baking (PEB) was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 1.
(5) Development process The composition layer on the silicon wafer after the heating process is subjected to paddle development for 20 seconds using butyl acetate (using n-butyl acetate purchased from Tokyo Kasei as it is) as a developer, A pattern was manufactured.

  In each composition layer, an exposure amount at which a trench pattern formed with a mask having a pitch of 240 nm / line of 60 nm becomes 60 nm was defined as effective sensitivity.

<Line edge roughness evaluation (LER)>
The wall surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and the fluctuation width (nm) of the unevenness on the side wall of the resist pattern was obtained. The results are shown in Table 2.

Examples 4 to 6 and Comparative Example 2
The same as each of Examples 1 to 3 and Comparative Example 1, except that the developer used in the development process was changed from n-butyl acetate to 2-heptanone (the one purchased from Kyowa Hakko Co., Ltd. was used as it was). Experiments were performed to determine LER. The results are shown in Table 3.

  In the resist pattern manufacturing of Examples 1 to 6, a resist pattern (negative resist pattern) could be manufactured with a line edge roughness superior to that of Comparative Example 1 and Comparative Example 2.

<Preparation of resist composition>
Each of the components shown below was dissolved in the following solvent in parts by mass shown in Table 3, and further filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a resist composition.

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

  In each of the obtained resist pattern films, an exposure amount at which the 50 nm line and space pattern becomes an exposure amount of 1: 1 was defined as an effective sensitivity.

<Line edge roughness evaluation (LER)>
The wall surface of the resist pattern after the lithography process was observed with a scanning electron microscope, and the fluctuation width (nm) of the unevenness on the side wall of the resist pattern was obtained. The results are shown in Table 4.

  The resist composition of the present invention can be used for fine processing of semiconductors.

Claims (6)

A resist composition containing the following (A), (B) and (D).
(A) A resin having a first structural unit represented by formula (I) and a second structural unit containing an acid labile group ,
The content ratio (molar ratio) between the first structural unit and the second structural unit is represented by [content of first structural unit] / [content of second structural unit]. A range of 44 resins ;

[In the formula (I),
R ¹ represents a C 1-6 alkyl group, a hydrogen atom or a halogen atom which may have a halogen atom.
A ¹ is a single bond, ^* —A ² —O—, ^* —A ² —CO—O—, ^* —A ² —CO—O—A ³ —CO—O— or ^* —A ² —O—CO. -A ³ represents a -O-.
* Represents a bond with -O-.
A ² and A ³ each independently represents an alkanediyl group having 1 to 6 carbon atoms. ]
(B) an acid generator;
(D) Compound represented by formula (II)

[In the formula (II),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represents an integer of 0 to 4. When m ′ is 2 or more, a plurality of R ^D1 are the same or different from each other, and when n ′ is 2 or more, a plurality of R ^D2 Are the same or different from each other. ] Said (A) is
2. The resist composition according to claim 1 , wherein the resist composition is a resin that has the property of being decomposed by the action of an acid and having reduced solubility in a negative developer. Negative developer resist composition according to claim 2, wherein butyl acetate or 2-heptanone. Said (B) is an acid generator represented by Formula (B1), The resist composition of any one of Claims 1-3 .

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group, and methylene constituting the saturated hydrocarbon group The group may be replaced by an oxygen atom or a carbonyl group.
Y represents an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, a hydrogen atom or a fluorine atom, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, A sulfonyl group or a carbonyl group may be substituted.
Z ⁺ represents an organic cation. ] Furthermore, the resist composition of any one of Claims 1-4 containing a solvent. (1) The process of apply | coating the resist composition of any one of Claims 1-5 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer,
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.