JP5070801B2 - Salt for acid generator of chemically amplified resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a salt functioning as an acid-generating agent affording a chemically amplified resist composition that exhibits improved LER and forms a pattern of a good shape. <P>SOLUTION: The salt is for example a salt (B1) illustrated in the figure and is manufactured by causing a specific ester compound to react with a specific compound as illustrated in the figure. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a salt used as an acid generator contained in a chemically amplified resist composition used in a chemically amplified resist composition used for semiconductor microfabrication.

A chemically amplified resist composition used for microfabrication of a semiconductor using a lithography technique contains an acid generator composed of a salt.
In semiconductor microfabrication, it is desirable to improve the line edge roughness (LER) at a high resolution and to form a pattern having a good pattern shape. As a chemically amplified resist composition, the line edge roughness (LER) is improved. Therefore, there is a demand for a pattern capable of forming a pattern having a good pattern shape.

  Recently, a chemically amplified resist composition comprising triphenylsulfonium 1-adamantanemethoxycarbonyldifluoromethanesulfonate (salt) and p-tolyldiphenylsulfonium perfluorooctanesulfonate (salt) as an acid generator has been proposed. However, there has been a demand for a salt serving as an acid generator that provides a chemically amplified resist composition that can further improve line edge roughness (LER) and can form a pattern having a good pattern shape (for example, Patent Documents). 1).

Japanese Patent Laid-Open No. 2004-4561

  An object of the present invention is to provide a salt serving as an acid generator that provides a chemically amplified resist composition having improved line edge roughness (LER) and capable of forming a pattern having a good pattern shape.

  Therefore, in order to solve the above-mentioned problems, the present inventors have intensively studied a salt used as an acid generator contained in a chemically amplified resist composition, and as a result, a specific salt having a cyclic ester residue. However, it has been found that it becomes an acid generator that provides a chemically amplified resist composition capable of forming a pattern having a good pattern shape with improved line edge roughness (LER), and has led to the completion of the present invention. .

（式（Ｉ）中、Ｑ¹、Ｑ²は互いに独立にフッ素原子又は炭素数１〜６のペルフルオロアルキル基を表し、環Ｘは炭素数１０〜３０の３環以上の多環式炭化水素基を表す。ｎは１〜１２の整数を表し、式中の環Ｘ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１〜４のペルフルオロアルキル基又はシアノ基の一つ以上を置換基として含んでいてもよい。Ａ⁺は式（IIａ）、式（IIｂ）又は式（IIｃ）のいずれかで示されるカチオンからなる群から選ばれる少なくとも１種のカチオンを表す。）

（式（IIａ）中、Ｐ¹、Ｐ²は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表し、該アルキル基及び該アルコキシ基は、直鎖でも分岐していてもよい。）

（式（IIｂ）中、Ｐ³、Ｐ⁴は、互いに独立に、炭素数１〜１２のアルキル基又は炭素数３〜１２のシクロアルキル基を表し、該アルキル基は、直鎖でも分岐していてもよい。又はＰ³とＰ⁴とが結合して炭素数３〜１２の２価の炭化水素基を表す。Ｐ⁵は水素原子を表し、Ｐ⁶は炭素数１〜１２のアルキル基、炭素数３〜１２のシクロアルキル基もしくは置換されていてもよい芳香環基を表すか、又はＰ⁵とＰ⁶が結合して炭素数３〜１２の２価の炭化水素基を表す。ここで、２価の炭化水素基に含まれる炭素原子は、いずれも、カルボニル基、酸素原子、硫黄原子に置換されていてもよい。）

（式（IIｃ）中、Ｐ⁷〜Ｐ¹⁸は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表し、該アルキル基及び該アルコキシ基は、直鎖でも分岐していてもよい。Ｂは、硫黄原子又は酸素原子を表す。ｍは、０又は１を表す。） That is, the present invention provides a salt represented by the formula (I).

(In the formula ^{(I), Q 1, Q} 2 independently represents a fluorine atom or perfluoroalkyl group having 1 to 6 carbon atoms with each other ring X polycyclic hydrocarbon group having 3 or more rings having 10 to 30 carbon atoms N represents an integer of 1 to 12, and the ring X in the formula is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, or a cyano group. One or more substituents may be contained, and A ⁺ represents at least one cation selected from the group consisting of cations represented by any one of formulas (IIa), (IIb), and (IIc). .)

(In formula (IIa), P ¹ and P ² each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, and the alkyl group and the alkoxy group May be linear or branched.)

(In Formula (IIb), P ³ and P ⁴ each independently represent a C 1-12 alkyl group or a C 3-12 cycloalkyl group, and the alkyl group is branched even in a straight chain. Or P ³ and P ⁴ may be bonded to each other to represent a divalent hydrocarbon group having 3 to 12 carbon atoms, P ⁵ represents a hydrogen atom, P ⁶ represents an alkyl group having 1 to 12 carbon atoms, A cycloalkyl group having 3 to 12 carbon atoms or an optionally substituted aromatic ring group is represented, or P ⁵ and P ⁶ are combined to represent a divalent hydrocarbon group having 3 to 12 carbon atoms. Any carbon atom contained in the divalent hydrocarbon group may be substituted with a carbonyl group, an oxygen atom, or a sulfur atom.)

(In formula (IIc), P ^{7 to} P ¹⁸ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, and the alkyl group and the alkoxy group May be linear or branched, B represents a sulfur atom or an oxygen atom, and m represents 0 or 1.)

  Moreover, this invention provides the acid generator which uses the salt shown by Formula (I) as an active ingredient.

（式（Ｖ）中、Ｑ¹、Ｑ²は互いに独立にフッ素原子又は炭素数１〜６のペルフルオロアルキル基を表し、環Ｘは炭素数１０〜３０の３環以上の多環式炭化水素基を表す。ｎは１〜１２の整数を表し、式中の環Ｘ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１〜４のペルフルオロアルキル基又はシアノ基の一つ以上を置換基として含んでいてもよい。Ｍは、Ｌｉ、Ｎａ、Ｋ又はＡｇを表す。） The present invention also provides an ester form represented by the formula (V), which is a synthetic intermediate of the salt represented by the formula (I).

(In the formula ^{(V), Q 1, Q} 2 independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms from each other, the ring X is a polycyclic hydrocarbon group having 3 or more rings having 10 to 30 carbon atoms N represents an integer of 1 to 12, and the ring X in the formula is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, or a cyano group. One or more may be contained as a substituent, and M represents Li, Na, K, or Ag.)

（式（ＶI）中、環Ｘは炭素数６〜３０の３環以上の多環式炭化水素基を表し、環Ｘ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１〜４のペルフルオロアルキル基又はシアノ基の一つ以上を置換基として含んでいてもよい。ｎは１〜１２の整数を表す。）
式（ＶＩＩ）で示されるカルボン酸とをエステル化反応させることを特徴とする式（Ｖ）で示されるエステル体の製造方法を提供する。

（式（ＶII）中、Ｑ¹、Ｑ²は互いに独立にフッ素原子又は炭素数１〜６のペルフルオロアルキル基を表し、Ｍは、前記と同じ意味を表す。） The present invention also provides an alcohol represented by the formula (VI):

(In the formula (VI), ring X represents a polycyclic hydrocarbon group having 3 or more rings having 6 to 30 carbon atoms, ring X is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, (One or more of a C1-C4 perfluoroalkyl group or a cyano group may be contained as a substituent. N represents the integer of 1-12.)
Provided is a method for producing an ester form represented by formula (V), which comprises esterifying a carboxylic acid represented by formula (VII).

(In formula (VII), Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group, and M represents the same meaning as described above.)

（式中、Ａ⁺は、前記と同じ意味を表し、ＺはＦ、Ｃｌ、Ｂｒ、Ｉ、ＢＦ₄、ＡｓＦ₆、ＳｂＦ₆、ＰＦ₆又はＣｌＯ₄を表す。） Moreover, this invention provides the manufacturing method of the salt shown by the formula (I) characterized by making the ester body shown by a formula (V), and the compound shown by a formula (VIII) react.

(In the formula, A ⁺ represents the same meaning as described above, and Z represents F, Cl, Br, I, BF ₄ , AsF ₆ , SbF ₆ , PF ₆ or ClO _4. )

  The present invention also provides a resin composition comprising an acid generator containing a salt represented by formula (I) as an active ingredient and a resin, the resin having an acid-labile group, and an alkaline aqueous solution. Provided is a resin composition characterized in that it is an insoluble or hardly soluble resin, and the resin that has reacted with an acid is a resin that can be dissolved in an alkaline aqueous solution.

  Furthermore, the present invention provides a chemically amplified resist composition comprising the resin composition and a basic organic compound.

  By using the salt of the present invention as an acid generator, a line edge roughness (LER) is improved, and a chemically amplified resist composition capable of producing a pattern having a good pattern shape can be produced. The present invention is extremely useful industrially.

ここで、式（Ｉ）中、Ｑ¹、Ｑ²は互いに独立にフッ素原子又は炭素数１〜６のペルフルオロアルキル基を表し、環Ｘは炭素数１０〜３０の３環以上の多環式炭化水素基を表す。ｎは１〜１２の整数を表し、式中の環Ｘ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１〜４のペルフルオロアルキル基又はシアノ基の一つ以上を置換基として含んでいてもよい。Ａ⁺は式（IIａ）、式（IIｂ）又は式（IIｃ）のいずれかで示されるカチオンからなる群から選ばれる少なくとも１種のカチオンを表す。

式（IIａ）中、Ｐ¹、Ｐ²は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表し、該アルキル基及び該アルコキシ基は、直鎖でも分岐していてもよい。該アルキル基の具体例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、sec−ブチル基、tert−ブチル基、ペンチル基、ヘキシル基、オクチル基、２−エチルヘキシル基などが挙げられ、アルコキシ基の例としては、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基、ヘキシルオキシ基、オクチルオキシ基、２−エチルヘキシルオキシ基などが挙げられる。

式（IIｂ）中、Ｐ³、Ｐ⁴は、互いに独立に、炭素数１〜１２のアルキル基又は炭素数３〜１２のシクロアルキル基を表し、該アルキル基は、直鎖でも分岐していてもよい。該アルキル基の具体例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、sec−ブチル基、tert−ブチル基、ペンチル基、ヘキシル基、オクチル基、２−エチルヘキシル基などが挙げられる。該シクロアルキル基としては、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロヘキシル基、シクロヘプチル基、シクロデシル基などが挙げられる。また、Ｐ³とＰ⁴とが結合して、アルキレン基などの炭素数３〜１２の２価の炭化水素基であってもよい。Ｐ⁵は水素原子を表し、Ｐ⁶は炭素数１〜１２のアルキル基、炭素数３〜１２のシクロアルキル基、またはフェニル基、ベンジル基などの置換されていてもよい芳香環基を表すか、Ｐ⁵とＰ⁶とが結合して、アルキレンなどの炭素数３〜１２の２価の炭化水素基を表す。Ｐ⁶がアルキル基の場合、該アルキル基の具体例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、sec−ブチル基、tert−ブチル基、ペンチル基、ヘキシル基、オクチル基、２−エチルヘキシル基などが挙げられる。Ｐ⁶がシクロアルキル基の場合、該シクロアルキル基としては、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロヘキシル基、シクロヘプチル基、シクロデシル基などが挙げられる。ここで、式（IIｂ）における２価の炭化水素基に含まれる炭素原子は、いずれも、カルボニル基、酸素原子、硫黄原子に置換されていてもよい。

式（IIｃ）中、Ｐ⁷〜Ｐ¹⁸は、互いに独立に、水素原子、水酸基、炭素数１〜１２のアルキル基又は炭素数１〜１２のアルコキシ基を表し、該アルキル基及び該アルコキシ基は、式（IIａ）のアルキル基及びアルコキシ基と同じ意味を表す。Ｂは、硫黄原子又は酸素原子を表す。ｍは、０又は１を表す。 The salt of the present invention is represented by the formula (I).

Here, in the formula (I), Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group, and the ring X is a polycyclic carbon atom having 3 or more rings having 10 to 30 carbon atoms. Represents a hydrogen group. n represents an integer of 1 to 12, and the ring X in the formula is one or more of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, or a cyano group. May be included as a substituent. A ⁺ represents at least one cation selected from the group consisting of cations represented by any one of formula (IIa), formula (IIb) and formula (IIc).

In Formula (IIa), P ¹ and P ² each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the alkyl group and the alkoxy group are They may be linear or branched. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl. Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group and the like.

In formula (IIb), P ³ and P ⁴ each independently represent an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, and the alkyl group is branched even in a straight chain. Also good. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl. Group and the like. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclodecyl group. Further, by bonding the P ³ and P ^4, it may be a divalent hydrocarbon group having 3 to 12 carbon atoms such as an alkylene group. P ⁵ represents a hydrogen atom, and P ⁶ represents an optionally substituted aromatic ring group such as an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a phenyl group or a benzyl group. P ⁵ and P ⁶ are combined to represent a C 3-12 divalent hydrocarbon group such as alkylene. When P ⁶ is an alkyl group, specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group. Group, octyl group, 2-ethylhexyl group and the like. When P ⁶ is a cycloalkyl group, examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclodecyl group. Here, any carbon atom contained in the divalent hydrocarbon group in formula (IIb) may be substituted with a carbonyl group, an oxygen atom, or a sulfur atom.

In formula (IIc), P ^{7 to} P ¹⁸ each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, and the alkyl group and the alkoxy group are Represents the same meaning as the alkyl group and alkoxy group of formula (IIa). B represents a sulfur atom or an oxygen atom. m represents 0 or 1.

Moreover, as the ring X of the formula (I), a monovalent residue of the compound represented by the formula (IIIa) or the formula (IIIb) is preferable.

In formula (IIIa) and formula (IIIb), X ¹ and X ² each independently represents an alkylene group or an oxygen atom, and X ² may be non-bonded. The ring in the formula may contain one or more of a C 1-6 alkyl group, a C 1-6 alkoxy group, a C 1-4 perfluoroalkyl group or a cyano group as a substituent.
Examples of the compound represented by the formula (IIIa) and the formula (IIIb) include compounds represented by the following formulae.

  n is preferably an integer of 1 to 6, and more preferably 1 or 2.

Specific examples of the anion moiety of the salt represented by the formula (I) include anions represented by the following formula.

Specific examples of the cation A ^{+ represented by} the formula (IIa) include cations represented by the following formula.

Specific examples of the cation A ^{+ represented by} the formula (IIb) include cations represented by the following formula.

Specific examples of the cation A ^{+ represented by} the formula (IIc) include cations represented by the following formula.

（式（IIｄ）中、Ｐ¹⁹、Ｐ²⁰は、互いに独立に、炭素数１〜６のアルキル基又は炭素数３〜６のシクロアルキル基を表し、該アルキル基は、直鎖でも分岐していてもよい。又はＰ¹⁹とＰ²⁰とが結合して炭素数３〜６の２価の炭化水素基を表す。Ｐ²¹は水素原子を表し、Ｐ²²は炭素数１〜６のアルキル基、炭素数３〜６のシクロアルキル基もしくは置換されていてもよい芳香環基を表すか、又はＰ²¹とＰ²²が結合して炭素数３〜６の２価の炭化水素基を表す。ここで、２価の炭化水素基に含まれる炭素原子は、いずれも、カルボニル基、酸素原子、硫黄原子に置換されていてもよい。） As A ⁺ , a cation represented by the formula (IId) is preferable because of easy production.

(In Formula (IId), P ¹⁹ and P ²⁰ each independently represent a C 1-6 alkyl group or a C 3-6 cycloalkyl group, and the alkyl group is branched even in a straight chain. Or P ¹⁹ and P ²⁰ are combined to represent a divalent hydrocarbon group having 3 to 6 carbon atoms, P ²¹ represents a hydrogen atom, P ²² represents an alkyl group having 1 to 6 carbon atoms, It represents a cycloalkyl group having 3 to 6 carbon atoms or an optionally substituted aromatic ring group, or P ²¹ and P ²² are bonded to each other to represent a divalent hydrocarbon group having 3 to 6 carbon atoms. Any carbon atom contained in the divalent hydrocarbon group may be substituted with a carbonyl group, an oxygen atom, or a sulfur atom.)

（式中、Ｐ¹⁹〜Ｐ²²は前記と同じ意味を表す。） Among the salts represented by the formula (I) of the present invention, among them, the salt represented by the formula (IV) is an acid that provides a chemically amplified resist composition having improved line edge roughness (LER) and an excellent pattern shape. It is more preferable because it becomes a generator.

(Wherein, P ¹⁹ to P ²² are as defined above.)

（式（Ｖ）中、Ｑ¹、Ｑ²は互いに独立にフッ素原子又は炭素数１〜６のペルフルオロアルキル基を表し、環Ｘは炭素数１０〜３０の３環以上の多環式炭化水素基を表す。ｎは１〜１２の整数を表し、式中の環Ｘ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１〜４のペルフルオロアルキル基又はシアノ基の一つ以上を置換基として含んでいてもよい。Ｍは、Ｌｉ、Ｎａ、Ｋ又はＡｇを表す。）
式（ＶIII）で示されるオニウム塩とを、

（式中、Ａ⁺は、前記と同じ意味を表し、ＺはＦ、Ｃｌ、Ｂｒ、Ｉ、ＢＦ₄、ＡｓＦ₆、ＳｂＦ₆、ＰＦ₆又はＣｌＯ₄を表す。）
例えば、アセトニトリル、水、メタノール、クロロホルム、塩化メチレン等の不活性溶媒中にて、０℃〜１５０℃程度の温度範囲、好ましくは０℃〜１００℃程度の温度範囲にて攪拌して反応させて、式（Ｉ）で示される塩を得る方法などが挙げられる。
ここで、Ｑ¹、Ｑ²としてはそれぞれ独立にフッ素原子または−ＣＦ₃である場合が好ましく、フッ素原子である場合がさらに好ましい。 Examples of the production method of the formula (I) include an ester form represented by the formula (V) and

(In the formula ^{(V), Q 1, Q} 2 independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms from each other, the ring X is a polycyclic hydrocarbon group having 3 or more rings having 10 to 30 carbon atoms N represents an integer of 1 to 12, and the ring X in the formula is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, or a cyano group. One or more may be contained as a substituent, and M represents Li, Na, K, or Ag.)
An onium salt represented by the formula (VIII):

(In the formula, A ⁺ represents the same meaning as described above, and Z represents F, Cl, Br, I, BF ₄ , AsF ₆ , SbF ₆ , PF ₆ or ClO _4. )
For example, in an inert solvent such as acetonitrile, water, methanol, chloroform, and methylene chloride, the reaction is performed with stirring in a temperature range of about 0 ° C. to 150 ° C., preferably in a temperature range of about 0 ° C. to 100 ° C. And a method for obtaining a salt represented by the formula (I).
Here, Q ¹ and Q ² are preferably each independently a fluorine atom or —CF ₃ , and more preferably a fluorine atom.

  Moreover, the illustration and the preferable range of X in Formula (V) are the same as the above. n is preferably an integer of 1 to 6, and more preferably 1 or 2.

  The amount of the onium salt of the formula (VIII) is usually about 0.5 to 2 mol with respect to 1 mol of the ester compound represented by the formula (V). The salt (I) may be taken out by recrystallization or may be purified by washing with water.

（式（ＶI）中、環Ｘは炭素数１０〜３０の３環以上の多環式炭化水素基を表し、環Ｘ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１〜４のペルフルオロアルキル基又はシアノ基の一つ以上を置換基として含んでいてもよい。ｎは１〜１２の整数を表す。）
で示されるアルコールと、式（ＶII）

（式（ＶII）中、Ｑ¹、Ｑ²は互いに独立にフッ素原子又は炭素数１〜６のペルフルオロアルキル基を表し、Ｍは、前記と同じ意味を表す。）
で示されるカルボン酸とをエステル化反応させて、式（Ｖ）で示されるエステル体を得る方法などが挙げられる。
ここで、Ｑ¹、Ｑ²としてはそれぞれ独立にフッ素原子または−ＣＦ₃である場合が好ましく、フッ素原子である場合がさらに好ましい。 As a manufacturing method of the ester body shown by Formula (V) used for manufacture of the salt shown by Formula (I), for example, first, Formula (VI)

(In the formula (VI), ring X represents a polycyclic hydrocarbon group having 3 or more rings having 10 to 30 carbon atoms, ring X is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, (One or more of a C1-C4 perfluoroalkyl group or a cyano group may be contained as a substituent. N represents the integer of 1-12.)
An alcohol represented by formula (VII)

(In formula (VII), Q ¹ and Q ² each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group, and M represents the same meaning as described above.)
And a method of obtaining an ester form represented by the formula (V) by esterifying the carboxylic acid represented by formula (V).
Here, Q ¹ and Q ² are preferably each independently a fluorine atom or —CF ₃ , and more preferably a fluorine atom.

The esterification reaction is usually performed in an aprotic solvent such as dichloroethane, toluene, ethylbenzene, monochlorobenzene, acetonitrile, N, N-dimethylformamide, etc. in a temperature range of about 20 ° C. to 200 ° C., preferably 50 ° C. What is necessary is just to stir in the temperature range of about -150 degreeC. In the esterification reaction, an organic acid such as p-toluenesulfonic acid and / or an inorganic acid such as sulfuric acid is usually added as an acid catalyst. Alternatively, 1,1′-carbonyldiimidazole, N, N′-dicyclohexylcarbodiimide or the like may be added as a dehydrating agent.
The esterification reaction using an acid catalyst is preferably carried out while dehydrating using a Dean Stark apparatus or the like because the reaction time tends to be shortened.

  The amount of the carboxylic acid represented by the formula (VII) in the esterification reaction is about 0.2 to 3 mol, preferably about 0.5 to 2 mol, per 1 mol of the alcohol represented by the formula (VI). It is. The acid catalyst in the esterification reaction may be a catalytic amount or an amount corresponding to a solvent with respect to 1 mol of the alcohol represented by the formula (VI), and is usually about 0.001 mol to 5 mol. The dehydrating agent in the esterification reaction is about 0.2 to 5 mol, preferably about 0.5 to 3 mol, per 1 mol of the alcohol represented by the formula (VI).

  The resin composition of the present invention is a resin composition containing a salt represented by the formula (I) and a resin, and the resin has an acid-labile group and is insoluble or hardly soluble in an alkaline aqueous solution. This resin is a resin that can be dissolved in an alkaline aqueous solution.

  The salt represented by the formula (I) is used as an acid generator, and the acid generated by exposure is cleaved by catalytically acting on a group in the resin which is unstable to the acid, and the resin. Becomes soluble in an alkaline aqueous solution. Such a resin composition is suitable as a chemically amplified positive resist composition.

Examples of the acid labile group include a group having an alkyl ester in which the α position of the ether bond is a quaternary carbon atom, a group having a carboxylic acid ester such as an alicyclic ester, and the α position of the ether bond in a quaternary carbon atom. And a group having a lactone ring.
Here, the quaternary carbon atom means a carbon atom bonded to a substituent other than a hydrogen atom and not bonded to hydrogen, and an acid labile group is a carbon at the α-position of an ether bond. It is preferred that the atom is a quaternary carbon atom bonded to three carbon atoms.

To illustrate a group having a carboxylic acid ester which is one of the acid labile group as R ester of -COOR, (-. The COO-C (CH ₃₎ referred in ₃ form a tert- butyl ester), tert An alkyl ester in which the α-position of the ether bond represented by butyl ester is a quaternary carbon atom; methoxymethyl ester, ethoxymethyl ester, 1-ethoxyethyl ester, 1-isobutoxyethyl ester, 1-isopropoxyethyl ester, 1-ethoxypropyl ester, 1- (2-methoxyethoxy) ethyl ester, 1- (2-acetoxyethoxy) ethyl ester, 1- [2- (1-adamantyloxy) ethoxy] ethyl ester, 1- [2- ( 1-adamantanecarbonyloxy) ethoxy] ethyl ester, tetrahi Acetal type esters such as dro-2-furyl ester and tetrahydro-2-pyranyl ester; isobornyl ester and 1-alkyl cycloalkyl ester, 2-alkyl-2-adamantyl ester, 1- (1-adamantyl) -1- An alicyclic ester in which the α-position of the ether bond is a quaternary carbon atom, such as an alkylalkyl ester.

  Examples of the group having a carboxylic acid ester include a group having a (meth) acrylic acid ester, a norbornene carboxylic acid ester, a tricyclodecene carboxylic acid ester, and a tetracyclodecene carboxylic acid ester.

The resin of the resin composition of the present invention can be produced by addition polymerization of a monomer having an acid labile group and an olefinic double bond.
Such monomers include bulky groups such as alicyclic structures such as 2-alkyl-2-adamantyl groups and 1- (1-adamantyl) -1-alkylalkyl groups as acid labile groups. Monomers are preferred because the resolution of the resulting resist tends to be excellent.
Specific examples of the monomer containing a bulky group include 2-alkyl-2-adamantyl (meth) acrylate, 1- (1-adamantyl) -1-alkylalkyl (meth) acrylate, and 5-norbornene-2. -2-alkyl-2-adamantyl carboxylate, 1- (1-adamantyl) -1-alkylalkyl 5-norbornene-2-carboxylate, 2-alkyl-2-adamantyl α-chloroacrylate, α-chloroacrylic acid 1- (1-adamantyl) -1-alkylalkyl and the like.

  In particular, when 2-alkyl-2-adamantyl (meth) acrylate or 2-alkyl-2-adamantyl α-chloroacrylate is used as a monomer, it is preferable because the resolution of the resulting resist tends to be excellent.

  Specifically, as 2-alkyl-2-adamantyl (meth) acrylate, for example, 2-methyl-2-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-acrylate Examples thereof include adamantyl, 2-ethyl-2-adamantyl methacrylate, 2-n-butyl-2-adamantyl acrylate, and the like. Examples of α-chloroacrylic acid 2-alkyl-2-adamantyl include α-chloroacrylic acid. Examples include 2-methyl-2-adamantyl and 2-ethyl-2-adamantyl α-chloroacrylate.

  Among these, when 2-ethyl-2-adamantyl (meth) acrylate or 2-isopropyl-2-adamantyl (meth) acrylate is used, the resulting resist tends to have excellent sensitivity and heat resistance. preferable.

  (Meth) acrylic acid 2-alkyl-2-adamantyl can be usually produced by a reaction of 2-alkyl-2-adamantanol or a metal salt thereof with acrylic acid halide or methacrylic acid halide.

The resin used in the present invention may contain a structural unit derived from an acid-stable monomer in addition to a structural unit derived from a monomer having an acid-labile group. Here, the structure derived from an acid-stable monomer means a structure that is not cleaved by the salt (I) of the present invention.
Specifically, a structural unit derived from a monomer having a free carboxylic acid group such as acrylic acid or methacrylic acid, or a structural unit derived from an aliphatic unsaturated dicarboxylic anhydride such as maleic anhydride or itaconic anhydride , Structural units derived from 2-norbornene, structural units derived from (meth) acrylonitrile, (meth) acrylic acid wherein the α-position of the ether bond is a secondary or tertiary carbon atom alkyl ester or 1-adamantyl ester Structural units derived from esters, structural units derived from styrenic monomers such as p- or m-hydroxystyrene, and structures derived from (meth) acryloyloxy-γ-butyrolactone in which the lactone ring may be substituted with an alkyl group Examples include units. The 1-adamantyl ester is a quaternary carbon atom at the α-position of the ether bond, but is a group that is stable to acids, and a hydroxyl group or the like may be bonded to the 1-adamantyl ester.

  Specific acid-stable monomers include 3-hydroxy-1-adamantyl (meth) acrylate, (meth) acrylic acid 3, 5-dihydroxy-1-adamantyl, α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, formulas (a) and (b), hydroxystyrene, norbornene (c) and other alicyclic compounds having an olefinic double bond in the molecule, maleic anhydride (d) Examples thereof include aliphatic unsaturated dicarboxylic acid anhydrides, itaconic anhydride (e) and the like.

  Among these, in particular, a structural unit derived from a styrenic monomer such as p- or m-hydroxystyrene, a structural unit derived from 3-hydroxy-1-adamantyl (meth) acrylate, and (meth) acrylic acid 3, 5 A resist obtained from a resin comprising a structural unit derived from dihydroxy-1-adamantyl, a structure derived from a monomer represented by formula (a), and a structural unit derived from a monomer represented by formula (b) This is preferable because the adhesion and the resolution of the resist tend to be improved.

（式中、Ｒ¹及びＲ²は、互いに独立に、水素原子又はメチル基を表し、Ｒ³及びＲ⁴は、互いに独立に水素原子、メチル基、トリフルオロメチル基又はハロゲン原子を表し、ｐ及びｑは、互いに独立に１〜３の整数を表す。ｐが２または３のときには、Ｒ³は互いに異なる基であってもよく、ｑが２または３のときには、Ｒ⁴は互いに異なる基であってもよい。）

(In the formula, R ¹ and R ² each independently represent a hydrogen atom or a methyl group; R ³ and R ⁴ each independently represent a hydrogen atom, a methyl group, a trifluoromethyl group, or a halogen atom; And q each independently represents an integer of 1 to 3. When p is 2 or 3, R ³ may be a different group, and when q is 2 or 3, R ⁴ is a different group. May be.)

  Monomers such as (meth) acrylic acid 3-hydroxy-1-adamantyl and (meth) acrylic acid 3,5-dihydroxy-1-adamantyl are commercially available. For example, the corresponding hydroxyadamantane is converted to (meth) acrylic acid or It can also be produced by reacting with the halide.

  In addition, a monomer such as (meth) acryloyloxy-γ-butyrolactone is obtained by reacting α- or β-bromo-γ-butyrolactone, in which the lactone ring may be substituted with an alkyl group, with acrylic acid or methacrylic acid, or lactone It can be produced by reacting an α- or β-hydroxy-γ-butyrolactone whose ring may be substituted with an alkyl group with an acrylic acid halide or a methacrylic acid halide.

  Specific examples of the monomer that gives the structural unit represented by formula (a) or formula (b) include (meth) acrylic acid esters of alicyclic lactones having a hydroxyl group such as the following, and mixtures thereof. It is done. These esters can be produced, for example, by reacting an alicyclic lactone having a corresponding hydroxyl group with (meth) acrylic acids (for example, JP-A No. 2000-26446).

  Here, as (meth) acryloyloxy-γ-butyrolactone, for example, α-acryloyloxy-γ-butyrolactone, α-methacryloyloxy-γ-butyrolactone, α-acryloyloxy-β, β-dimethyl-γ-butyrolactone, α- Methacryloyloxy-β, β-dimethyl-γ-butyrolactone, α-acryloyloxy-α-methyl-γ-butyrolactone, α-methacryloyloxy-α-methyl-γ-butyrolactone, β-acryloyloxy-γ-butyrolactone, β- Examples include methacryloyloxy-γ-butyrolactone, β-methacryloyloxy-α-methyl-γ-butyrolactone, and the like.

  In the case of KrF excimer laser exposure, sufficient transmittance can be obtained even if a structural unit derived from a styrene monomer such as p- or m-hydroxystyrene is used as the structural unit of the resin. Such a copolymer resin can be obtained by radically polymerizing the corresponding (meth) acrylic acid ester monomer, acetoxystyrene, and styrene and then deacetylating with an acid.

  Moreover, since the resin containing a structural unit derived from 2-norbornene has an alicyclic skeleton directly in the main chain, it has a sturdy structure and exhibits excellent dry etching resistance. The structural unit derived from 2-norbornene can be introduced into the main chain by radical polymerization using, in addition to the corresponding 2-norbornene, an aliphatic unsaturated dicarboxylic anhydride such as maleic anhydride or itaconic anhydride. Therefore, the one formed by opening the double bond of the norbornene structure can be represented by the formula (c), and the one formed by opening the double bond of maleic anhydride and itaconic anhydride is respectively It can represent with Formula (d) and Formula (e).

Here, R ⁵ and R ⁶ in the formula (c) are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a carboxyl group, a cyano group, or —COOU (U is an alcohol residue). Or R ⁵ and R ⁶ are bonded to each other to represent a carboxylic acid anhydride residue represented by —C (═O) OC (═O) —.
When R ⁵ and / or R ⁶ is a group —COOU, the carboxyl group is an ester, and examples of the alcohol residue corresponding to U include optionally substituted 1 to 8 carbon atoms. A degree of alkyl group, 2-oxooxolan-3- or -4-yl group and the like can be mentioned. Here, in the alkyl group, a hydroxyl group, an alicyclic hydrocarbon residue, or the like may be bonded as a substituent.
Specific examples of R ⁵ and / or R ⁶ being an alkyl group include a methyl group, an ethyl group, a propyl group, and the like. Specific examples of an alkyl having a hydroxyl group bonded thereto include a hydroxymethyl group, 2-hydroxy An ethyl group etc. are mentioned.

As described above, specific examples of the norbornene structure represented by the formula (c), which is a monomer that gives a stable structural unit to an acid, include the following compounds.
2-norbornene,
2-hydroxy-5-norbornene,
5-norbornene-2-carboxylic acid,
Methyl 5-norbornene-2-carboxylate,
2-hydroxy-1-ethyl 5-norbornene-2-carboxylate,
5-norbornene-2-methanol,
5-norbornene-2,3-dicarboxylic anhydride.

In the formula (c), R ⁵ and / or R ⁶ —COOU U is an acid-labile group such as an alicyclic ester group in which the α-position of the ether bond is a quaternary carbon atom. Although it has a norbornene structure, it is a structural unit having an acid labile group. Examples of the monomer containing a norbornene structure and an acid labile group include, for example, 5-norbornene-2-carboxylic acid-t-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, and 5-norbornene. 2-carboxylate 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl, 5-norbornene-2-carboxylic acid 1- (4-methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-Oxocyclohexyl) ethyl, 5-norbornene-2-carboxylic acid 1- (1-adama) Chill) -1-methylethyl and the like.

  The resin used in the resin composition of the present invention varies depending on the type of radiation used for patterning exposure and the type of acid labile group, but is usually derived from a monomer having an acid labile group in the resin. The content of the structural unit is adjusted to a range of 10 to 80 mol%.

  And as a structural unit derived from a monomer having an acid labile group, in particular, 2-alkyl-2-adamantyl (meth) acrylate and 1- (1-adamantyl) -1-alkylalkyl (meth) acrylate When the derived structural unit is included, if the structural unit is 15 mol% or more of the total structural units constituting the resin, the resin has a rugged structure because of the alicyclic group, and the resist has a dry etching resistance. Is advantageous.

  In addition, when using an alicyclic compound having an olefinic double bond in the molecule and an aliphatic unsaturated dicarboxylic acid anhydride as monomers, these tend to be difficult to undergo addition polymerization. These are preferably used in excess.

  Further, as the monomer used, monomers having the same olefinic double bond but different acid labile groups may be used in combination, or monomers having the same acid labile group but different olefinic double bonds may be used. You may use together, and you may use together the monomer from which the combination of an acid labile group and an olefinic double bond differs.

  The chemically amplified resist composition of the present invention preferably contains a basic compound, more preferably a basic nitrogen-containing organic compound, particularly preferably an amine or ammonium salt. By adding a basic compound as a quencher, it is possible to improve the performance degradation due to the deactivation of the acid accompanying the holding after exposure. Specific examples of the basic compound used for the quencher include those represented by the following formulas.

In the formula, R ¹¹ and R ¹² each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. The alkyl group preferably has about 1 to 6 carbon atoms, the cycloalkyl group preferably has about 5 to 10 carbon atoms, and the aryl group preferably has about 6 to 10 carbon atoms. Of carbon atoms. Further, at least one hydrogen atom on the alkyl group, cycloalkyl group or aryl group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. Good. At least one hydrogen atom on the amino group may be independently substituted with an alkyl group having 1 to 4 carbon atoms.

R ¹³ , R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an alkoxy group. The alkyl group preferably has about 1 to 6 carbon atoms, the cycloalkyl group preferably has about 5 to 10 carbon atoms, and the aryl group preferably has 6 to 10 carbon atoms. The alkoxy group preferably has 1 to 6 carbon atoms.
Further, at least one hydrogen atom on the alkyl group, cycloalkyl group, aryl group, or alkoxy group is independently a hydroxyl group, an amino group, or an alkoxy group having about 1 to 6 carbon atoms. May be substituted. At least one of the hydrogen atoms on the amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.

R ¹⁶ represents an alkyl group or a cycloalkyl group. The alkyl group preferably has about 1 to 6 carbon atoms, and the cycloalkyl group preferably has about 5 to 10 carbon atoms. Furthermore, at least one hydrogen atom on the alkyl group or cycloalkyl group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. At least one of the hydrogen atoms on the amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.

R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²⁰ each independently represents an alkyl group, a cycloalkyl group or an aryl group. The alkyl group preferably has about 1 to 6 carbon atoms, the cycloalkyl group preferably has about 5 to 10 carbon atoms, and the aryl group preferably has 6 to 10 carbon atoms. Has about carbon atoms. Furthermore, at least one hydrogen atom on the alkyl group, cycloalkyl group or aryl group may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. . At least one of the hydrogen atoms on the amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.

W represents an alkylene group, a carbonyl group, an imino group, a sulfide group or a disulfide group. The alkylene group preferably has about 2 to 6 carbon atoms.
Further, in R ^{11 to} R ²⁰ , any of those that can take both a linear structure and a branched structure may be used.

  Specific examples of such compounds include hexylamine, heptylamine, octylamine, nonylamine, decylamine, aniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, 1- or 2-naphthylamine, and ethylenediamine. Tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'- Diethyldiphenylmethane, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, N-methylaniline, piperidine, diphenylamine, triethylamine, trimethylamine, tripropylamine, tributylamine , Tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine Methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, N, N-dimethylaniline, 2,6-isopropylaniline, imidazole, pyridine, -Methylpyridine, 4-methylimidazole, bipyridine, 2,2'-dipyridylamine, di-2-pyridyl ketone, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,3-di (4-pyridyl) propane, 1,2-bis (2-pyridyl) ethylene, 1,2-bis (4-pyridyl) ethylene, 1,2-bis (4-pyridyloxy) ethane, 4 , 4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 1,2-bis (4-pyridyl) ethylene, 2,2'-dipicolylamine, 3,3'-dipicolylamine, tetramethylammonium hydroxide Tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetra-n-hexylammonium hydroxide, tetra-n- Examples include octylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-trifluoromethylphenyltrimethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide (common name: choline), and the like.

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

The resin composition of the present invention preferably contains about 80 to 99.9% by weight of the resin and about 0.1 to 20% by weight of the acid generator based on the total solid content.
Further, when a basic compound that is a quencher is used as the chemically amplified resist composition, it is preferably contained in a range of about 0.01 to 1% by weight based on the total solid content of the resist composition.
The resist composition can further contain small amounts of various additives such as sensitizers, dissolution inhibitors, other resins, surfactants, stabilizers, and dyes as necessary.

  The resist composition of the present invention is usually used as a resist solution composition in a state in which each of the above components is dissolved in a solvent, and is usually used in industrial processes such as spin coating on a substrate such as a silicon wafer. Applied according to The solvent used here may be any solvent that dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after the solvent evaporates, and is usually used industrially in this field. Solvents can be used.

  For example, 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, esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate And ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone, and cyclic esters such as γ-butyrolactone. These solvents can be used alone or in combination of two or more.

  The resist film coated and dried on the substrate is subjected to an exposure process for patterning, followed by a heat treatment for promoting a deprotecting group reaction, and then developed with an alkali developer. The alkaline developer used here may be various alkaline aqueous solutions used in this field, but in general, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (common name: choline). Is often used.

EXAMPLES Next, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples.
In Examples and Comparative Examples, “%” and “part” representing content or use amount are based on weight unless otherwise specified. Further, the weight average molecular weight is a value obtained by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation, column is TSKgel Multipore HXL-M3, solvent is tetrahydrofuran) using polystyrene as a standard product.
The structure of the compound was confirmed by NMR (JEOL GX-270 type or EX-270 type) and mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type). .

Synthesis Example of Acid Generator 1: Synthesis of 1- (3,3-dimethyl-2-oxobutyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B1) (1) Difluoro (fluorosulfonyl) acetic acid To 200 parts of methyl ester and 300 parts of ion-exchanged water, 460 parts of a 30% aqueous sodium hydroxide solution was added dropwise in an ice bath. The mixture was refluxed at 100 ° C. for 2.5 hours, cooled, and neutralized with 175 parts of concentrated hydrochloric acid. The obtained solution was concentrated to obtain 328.19 parts of sodium difluorosulfoacetate (containing inorganic salt, purity 62.8%).
(2) 123.3 parts of difluorosulfoacetic acid sodium salt (purity 62.8%), 65.7 parts of 1-adamantane methanol and 600 parts of dichloroethane were charged, and 75.1 parts of p-toluenesulfonic acid (p-TsOH) was added. In addition, the mixture was heated to reflux for 12 hours. Thereafter, the mixture was concentrated to distill off dichloroethane, 400 parts of tert-butyl methyl ether was added, filtered after repulping. After adding and stirring 400 parts of acetonitrile to the residue, filtration was repeated twice and concentrated to obtain 99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.51 (d, 6H); 1.62 (dd, 6H); 1.92 (s, 3H); 3.80 (s, 2H)

(3) 70.2 parts of tetrahydrothiophene was dissolved in 750 parts of acetone, and 150 parts of 1-bromo-3,3-dimethyl-2-butanone was added dropwise. After stirring at room temperature for 24 hours, the obtained white precipitate was filtered, washed with acetone, and dried to obtain 161.3 parts of 1- (3,3-dimethyl-2-oxobutyl) tetrahydrothiophenium bromide as white crystals. Got.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.14 (s, 9H); 2.08-2.30 (m, 4H); 3.37-3 .58 (m, 4H); 5.03 (s, 2H)

(4) 5.0 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt obtained in (2) above was charged and dissolved in 50 parts of ion-exchanged water. To this solution, 3.86 parts of 1- (3,3-dimethyl-2-oxobutyl) tetrahydrothiophenium bromide obtained in (3) above and 19.3 parts of ion-exchanged water were added, and 50 parts of acetonitrile were added. Was added to obtain a completely dissolved system. After stirring for 15 hours, the mixture was concentrated and extracted twice with 100 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. 1- (3,3-Dimethyl-2-oxobutyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate was added as white crystals by filtering and drying the filtrate after adding 100 parts of tert-butyl methyl ether and stirring. 4.93 parts of (B1) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.15 (s, 9H) 1.52 (d, 6H); 1.63 (dd, 6H); 1 .93 (s, 3H); 2.01-2.30 (m, 4H); 3.28-3.56 (m, 4H); 3.82 (s, 2H); 4.85 (s, 2H) )
MS (ESI (+) Spectrum): M + 187.2 (C ₁₀ H ₁₉ OS ⁺ = 187.12)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Synthesis Example of Acid Generator 2: Synthesis of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B2) (1) 150 parts of 2-bromoacetophenone It melt | dissolved in 375 parts of acetone, and 66.5 parts of tetrahydrothiophene were dripped. After stirring at room temperature for 24 hours, the obtained white precipitate was filtered, washed with acetone, and dried to obtain 207.9 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide as white crystals. It was.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.13-2.36 (m, 4H); 3.50-3.67 (m, 4H); 5 .41 (s, 2H); 7.63 (t, 2H); 7.78 (t, 1H); 8.02 (d, 2H)

(2) 99.5 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt obtained in (2) of acid generator synthesis example (acid generator synthesis example 1) of acid generator B1 was charged and 298 parts of acetonitrile. Dissolved in. To this solution, 79.5 parts of 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium bromide obtained in (1) above and 159 parts of ion-exchanged water were added. After stirring for 15 hours, the mixture was concentrated and extracted twice with 500 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated liquid was added with 250 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2-phenylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (white crystals). 116.9 parts of B2) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.50 (d, 6H); 1.62 (dd, 6H); 1.92 (s, 3H); 2.13-2.32 (m, 4H); 3.45-3.63 (m, 4H); 3.80 (s, 2H); 5.30 (s, 2H); 7.62 (t, 2H); 7.76 (t, 1H); 8.00 (d, 2H)
MS (ESI (+) Spectrum): M + 207.0 (C ₁₂ H ₁₅ OS ⁺ = 207.08)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Acid Generator Synthesis Example 3: Synthesis of 1- (2-oxo-2- (4′-methylphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B3) (1) 2 -50 parts of bromo-4'-methylacetophenone was dissolved in 150 parts of acetone, and 21 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the resulting white precipitate was filtered, washed with acetone, and dried to give 1- (2-oxo-2- (4′-methylphenylethyl)) tetrahydrothiophenium bromide as white crystals. 65 parts were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.18-2.30 (m, 4H); 2.42 (s, 3H); 3.48-3 .62 (m, 4H); 5.32 (s, 2H); 7.44 (d, 2H, J = 8.1 Hz); 7.91 (d, 2H, J = 8.2 Hz)

(2) 3.05 parts of difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt obtained in (2) of acid generator synthesis example (acid generator synthesis example 1) of acid generator B1 was charged with acetonitrile 15.5. Dissolved in 3 parts. To this solution, 2.61 parts of 1- (2-oxo-2- (4′-methylphenylethyl)) tetrahydrothiophenium bromide obtained in (1) above and 13.1 parts of ion-exchanged water were added. did. After stirring for 15 hours, the mixture was concentrated and extracted twice with 50 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated solution was added with 30 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2- (4′-methylphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxy as white crystals. 3.44 parts of carbonyl difluoromethanesulfonate (B3) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.51 (d, 6H); 1.63 (dd, 6H); 1.93 (s, 3H); 2.13-2.30 (m, 4H); 2.42 (s, 3H); 3.45-3.64 (m, 4H); 3.81 (s, 2H); 5.28 (s, 2H); 7.43 (d, 2H); 7.91 (d, 2H)
MS (ESI (+) Spectrum): M + 221.2 (C ₁₃ H ₁₇ OS ⁺ = 221.10)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Synthesis Example of Acid Generator 4: Synthesis of 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B4) (1) 2 -50 parts of bromo-4'-methoxyacetophenone was dissolved in 150 parts of acetone, and 19 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the resulting white precipitate was filtered, washed with acetone, and dried to give 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium bromide as white crystals. 63 parts were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.14-2.34 (m, 4H); 3.48-3.65 (m, 4H); 3 .89 (s, 3H); 5.39 (s, 2H); 7.15 (d, 2H, J = 8.9 Hz); 8.00 (d, 2H, J = 8.9 Hz)

(2) 3.05 parts of difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt obtained in (2) of acid generator synthesis example (acid generator synthesis example 1) of acid generator B1 was charged with acetonitrile 15.5. Dissolved in 3 parts. To this solution, 2.61 parts of 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium bromide obtained in (1) above and 13.1 parts of ion-exchanged water were added. did. After stirring for 15 hours, the mixture was concentrated and extracted twice with 50 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated solution was added with 30 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2- (4′-methoxyphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxy as white crystals. 3.44 parts of carbonyldifluoromethanesulfonate (B4) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.52 (d, 6H); 1.63 (dd, 6H); 1.93 (s, 3H); 2.12-2.30 (m, 4H); 3.43-3.60 (m, 4H); 3.81 (s, 2H); 3.88 (s, 3H); 5.26 (s, 2H); 7.15 (d, 2H); 7.98 (d, 2H)
MS (ESI (+) Spectrum) : M + 237.2 (C 13 H 17 O 2 S + = 237.09)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Acid Generator Synthesis Example 5: Synthesis of 1- (2-oxo-2- (4′-nitrophenylethyl)) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B5) (1) 2 -50 parts of bromo-4'-nitroacetophenone was dissolved in 150 parts of acetone, and 18 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the resulting white precipitate was filtered, washed with acetone, and dried to give 1- (2-oxo-2- (4′-nitrophenylethyl)) tetrahydrothiophenium bromide as white crystals. 66 parts were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.21-2.29 (m, 4H); 3.59-3.63 (m, 4H); 5 .41 (s, 2H); 8.24 (d, 2H, J = 8.9 Hz); 8.45 (d, 2H, J = 8.9 Hz)

(2) 3.05 parts of difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt obtained in (2) of acid generator synthesis example (acid generator synthesis example 1) of acid generator B1 was charged with acetonitrile 15.5. Dissolved in 3 parts. To this solution, 2.88 parts of 1- (2-oxo-2- (4′-nitrophenylethyl)) tetrahydrothiophenium bromide obtained in (1) above and 14.4 parts of ion-exchanged water were added. did. After stirring for 15 hours, the mixture was concentrated and extracted twice with 50 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated liquid was added with 30 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2- (4′-nitrophenylethyl)) tetrahydrothiophenium 1-adamantylmethoxy as white crystals. 4.26 parts of carbonyldifluoromethanesulfonate (B5) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.52 (d, 6H); 1.63 (dd, 6H); 1.93 (s, 3H); 2.18-2.31 (m, 4H); 3.50-3.66 (m, 4H); 3.81 (s, 2H); 5.34 (s, 2H); 8.22 (d, 2H); 8.45 (d, 2H)
MS (ESI (+) Spectrum): M + 252.0 (C ₁₂ H ₁₄ NO ₃ S ⁺ = 252.07)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Acid Generator Synthesis Example 6: Synthesis of 1- (2-oxo-2- (4′-cyclohexylphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B6) (1) 4 50 parts of '-cyclohexylacetophenone was dissolved in 250 parts of chloroform, cooled to 0 ° C., and 40 parts of bromine was added dropwise. After the reaction, 5% NaHSO ₃ water washing, 2% K ₂ CO ₃ water washing and water washing were performed, and then the organic layer was concentrated to obtain 60 parts of a bromoacetophenone body.
(2) 53 parts of bromoacetophenone was dissolved in 265 parts of acetone, and 17 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the resulting white precipitate was filtered, washed with acetone, and dried to give 1- (2-oxo-2- (4′-cyclohexylphenylethyl)) tetrahydrothiophenium bromide as white crystals. 44 parts were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.22-1.52 (m, 5H); 1.70-1.81 (m, 5H); 2 .16-2.31 (m, 4H); 2.60-2.67 (m, 1H); 3.50-3.63 (m, 4H); 5.39 (s, 2H); 7.47 (D, 2H, J = 8.3 Hz); 7.94 (d, 2H, J = 8.4 Hz)

(3) 3.05 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt obtained in (2) of acid generator synthesis example (acid generator synthesis example 1) of acid generator B1 was charged with acetonitrile 15.5. Dissolved in 3 parts. To this solution was added 3.15 parts of 1- (2-oxo-2- (4′-cyclohexylphenylethyl)) tetrahydrothiophenium bromide obtained in (2) above and 15.7 parts of ion-exchanged water. did. After stirring for 15 hours, the mixture was concentrated and extracted twice with 50 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated liquid was added with 30 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2- (4′-cyclohexylphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxy as white crystals. 4.63 parts of carbonyldifluoromethanesulfonate (B6) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.22-1.48 (m, 5H); 1.52 (d, 6H); 1.63 (dd , 6H); 1.77-1.81 (m, 5H); 1.93 (s, 3H); 2.18-2.27 (m, 4H); 2.59-2.67 (m, 1H) 3.44-3.63 (m, 4H); 3.81 (s, 2H); 5.28 (s, 2H); 7.48 (d, 2H); 7.92 (d, 2H)
MS (ESI (+) Spectrum): M + 289.2 (C ₁₈ H ₂₅ OS ⁺ = 289.16)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Acid Generator Synthesis Example 7: Synthesis of 1- (2-oxo-2- (4′-phenylphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B7) (1) 2 -To 50 parts of bromo-4'-phenylacetophenone, 150 parts of acetone and 200 parts of acetonitrile were added and dissolved, and 16 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the resulting white precipitate was filtered, washed with acetone, and dried to give 1- (2-oxo-2- (4′-phenylphenylethyl)) tetrahydrothiophenium bromide as white crystals. 58 parts were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.15-2.33 (m, 4H); 3.52-3.65 (m, 4H); 5 .40 (s, 2H); 7.44-7.57 (m, 3H); 7.81 (dd, 2H, J = 8.4, 1.5 Hz); 7.95 (d, 2H, J = 8.4 Hz); 8.10 (d, 2H, J = 8.4 Hz)

(2) 3.05 parts of difluorosulfoacetic acid-1-adamantyl methyl ester sodium salt obtained in (2) of acid generator synthesis example (acid generator synthesis example 1) of acid generator B1 was charged with acetonitrile 15.5. Dissolved in 3 parts. To this solution was added 3.15 parts of 1- (2-oxo-2- (4′-phenylphenylethyl)) tetrahydrothiophenium bromide obtained in (1) above and 15.7 parts of ion-exchanged water. did. After stirring for 15 hours, the mixture was concentrated and extracted twice with 50 parts of chloroform. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated solution was added with 30 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2- (4′-phenylphenylethyl)) tetrahydrothiophenium 1-adamantylmethoxy as white crystals. 4.63 parts of carbonyldifluoromethanesulfonate (B7) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.51 (d, 6H); 1.63 (dd, 6H); 1.92 (s, 3H); 2.20-2.30 (m, 4H); 3.48-3.66 (m, 4H); 3.81 (s, 2H); 5.35 (s, 2H); 7.44-7. 57 (m, 3H); 7.80 (d, 2H); 7.95 (d, 2H); 8.09 (d, 2H)
MS (ESI (+) Spectrum): M + 283.2 (C ₁₈ H ₁₉ OS ⁺ = 283.12)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Synthesis of acid generator 8: 1- (2-oxo-2-naphthylethyl) tetrahydrothiophenium Synthesis of 1-adamantylmethoxycarbonyldifluoromethanesulfonate (acid generator B8) (1) 2-Bromo-acetylnaphthalene 75 Part was dissolved in 375 parts of acetone, and 27 parts of tetrahydrothiophene was added dropwise. After stirring at room temperature for 24 hours, the obtained white precipitate was filtered, washed with acetone, and dried to obtain 92 parts of 1- (2-oxo-2-naphthylethyl) tetrahydrothiophenium bromide as white crystals.

¹ H-NMR (dimethylsulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 2.20-2.37 (m, 4H); 3.55-3.71 (m, 4H); 5 .57 (s, 2H); 7.67-7.79 (m, 2H); 8.00-8.18 (m, 4H); 8.79 (s, 1H)

(2) 5.00 parts of difluorosulfoacetic acid-1-adamantylmethyl ester sodium salt obtained in (2) of acid generator synthesis example (acid generator synthesis example 1) of acid generator B1 was charged with 50. acetonitrile. Dissolved in 0 parts. To this solution, 4.71 parts of 1- (2-oxo-2-naphthylethyl) tetrahydrothiophenium bromide obtained in (1) above and 23.6 parts of ion-exchanged water were added. After stirring for 15 hours, the mixture was concentrated and extracted once with 100 parts of chloroform and once with 50 parts. The organic layers were combined and washed with ion exchange water, and the resulting organic layer was concentrated. The concentrated solution was added with 50 parts of tert-butyl methyl ether, stirred, filtered, and dried under reduced pressure to give 1- (2-oxo-2-naphthylethyl) tetrahydrothiophenium 1-adamantylmethoxycarbonyldifluoromethanesulfonate (white crystals). 6.09 parts of B8) were obtained.

¹ H-NMR (dimethyl sulfoxide-d ₆ , internal standard substance tetramethylsilane): δ (ppm) 1.51 (d, 6H); 1.63 (dd, 6H); 1.93 (s, 3H); 2.22-2.31 (m, 4H); 3.53-3.66 (m, 4H); 3.81 (s, 2H); 5.46 (s, 2H); 7.67-7. 79 (m, 2H); 7.9-8.17 (m, 4H); 8.73 (s, 1H)
MS (ESI (+) Spectrum): M + 257.0 (C ₁₆ H ₁₇ OS ⁺ = 257.10)
MS (ESI (−) Spectrum): M− 323.0 (C ₁₃ H ₁₇ F ₂ O ₅ S ⁻ = 323.08)

Resin Synthesis Example 1: Synthesis of Resin A1 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, and α-methacryloyloxy-γ-butyrolactone were mixed with 5: 2.5: 2.5. The methyl isobutyl ketone was added 2 times by weight with respect to the total monomer to prepare a solution. Thereto, 2 mol% of azobisisobutyronitrile as an initiator was added with respect to the total amount of monomers and heated at 80 ° C. for about 8 hours. Thereafter, the operation of pouring the reaction solution into a large amount of heptane and precipitating was performed three times for purification. As a result, a copolymer having a weight average molecular weight of about 9200 was obtained. This copolymer has each unit represented by the following formula, and this is designated as resin A1.

  Next, in addition to the resin (A1) obtained in the above resin synthesis example, a resist composition was prepared and evaluated using the raw materials shown below.

酸発生剤Ｂ３：

酸発生剤Ｃ１：

＜クエンチャー＞
クエンチャーＱ１：２，６−ジイソプロピルアニリン
＜溶剤＞
溶剤Ｙ１：
プロピレングリコールモノメチルエーテルアセテート ８０．０部
２−ヘプタノン ２０．０部
γ−ブチロラクトン ３．０部 <Acid generator>
Acid generator B2:

Acid generator B3:

Acid generator C1:

<Quencher>
Quencher Q1: 2,6-diisopropylaniline <solvent>
Solvent Y1:
Propylene glycol monomethyl ether acetate 80.0 parts 2-heptanone 20.0 parts γ-butyrolactone 3.0 parts

Examples 1-2 and Comparative Example 1
The following components were mixed and dissolved, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist solution.

Resin (type and amount are listed in Table 1)
Acid generator (type and amount are listed in Table 1)
Quencher (type and amount are listed in Table 1)
Solvent (type is listed in Table 1)

An organic antireflection film having a thickness of 780 mm is formed by applying “ARC-29A-8”, a composition for organic antireflection film made by Brewer, to a silicon wafer and baking it at 215 ° C. for 60 seconds. Subsequently, the above resist solution was spin-coated thereon so that the film thickness after drying was 0.25 μm. After applying the resist solution, pre-baking was performed on a direct hot plate at a temperature indicated in the column “PB” in Table 1 for 60 seconds. For each wafer on which the resist film was formed in this way, an ArF excimer stepper (“NSR ArF” manufactured by Nikon Corporation, NA = 0.55, 2/3 Annular) was used to change the exposure amount step by step. The space pattern was exposed.
After exposure, post-exposure baking is performed for 60 seconds on the hot plate at the temperature shown in the column of “PEB” in Table 1, and further paddle development is performed for 60 seconds with an aqueous 2.38 wt% tetramethylammonium hydroxide solution. It was.
The dark field pattern after development on the organic antireflection film substrate was observed with a scanning electron microscope. The results are shown in Table 2. The dark field pattern referred to here is obtained by exposure and development through a reticle having a glass surface (translucent portion) formed in a line form on the outside with a chromium layer (light-shielding layer) as a base, and thus exposure development. The rest is a pattern in which the resist layer around the line and space pattern is left.

Resolution: Displayed with the minimum dimension of the line and space pattern separated by the exposure amount of effective sensitivity. Here, the effective sensitivity is indicated by an exposure amount at which a 0.13 μm line and space pattern is 1: 1.
Profile T / B: Displayed as a ratio of the length of the top side (shown as T) and the length of the base side (shown as B) of the 0.13 μm line cross section. The closer to 1, the better the profile.
Line edge roughness (LER): A case where the line edge roughness (LER) is good is indicated by ○, and a case where the line edge roughness (LER) is not good is indicated by ×.

[Table 1]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Resin Acid generator Quencher Solvent PB / PEB
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 A1 / 10 part B2 / 0.69 part Q1 / 0.0325 part Y1 115 ° C / 115 ° C
Example 2 A1 / 10 part B3 / 0.709 part Q1 / 0.0325 part Y1 115 ° C / 115 ° C
───────────────────────────────────────
Comparative Example 1 A1 / 10 part C1 / 0.659 part Q1 / 0.0325 part Y1 115 ° C / 115 ° C
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[Table 2]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example No. Resolution Profile Effective sensitivity LER
(μm) T / B (mJ / cm ² )
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Example 1 0.12 1.00 32.5 ○
Example 2 0.13 1.00 37.5 ○
───────────────────────────────────────
Comparative Example 1 0.13 0.84 25.0
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  In both of the obtained Examples 1 and 2, the LER was improved while maintaining the resolution, and the pattern shape was almost the same on the top side and the bottom side, indicating an excellent pattern shape.

  The salt of the present invention is suitably used as an acid generator for a chemically amplified positive resist composition having improved line edge roughness (LER) and giving an excellent pattern shape. Among them, excimer lasers such as ArF and KrF It can be used as an acid generator for a chemically amplified positive resist composition suitable for lithography and ArF immersion exposure lithography.

Claims (10)

A salt represented by the formula (I):

(In the formula (I), Q ¹ and Q ² represents a fluorine atom, the ring X table to a .n is an integer from 1 to 12 representing a monovalent residue of a compound represented by the formula (IIIa). A ⁺ represents a Kachio emissions of formula (IIb).

(The ring in Formula (IIIa ) contains one or more of a C1-C6 alkyl group, a C1-C6 alkoxy group, a C1-C4 perfluoroalkyl group, or a cyano group as a substituent. May also be.) )

(In the formula (IIb), P ³ and P ⁴ each independently represent an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, and the alkyl group is branched even in a straight chain. Or P ³ and P ⁴ may be bonded to each other to represent a divalent hydrocarbon group having 3 to 12 carbon atoms, P ⁵ represents a hydrogen atom, P ⁶ represents an alkyl group having 1 to 12 carbon atoms, A cycloalkyl group having 3 to 12 carbon atoms or an optionally substituted aromatic ring group is represented, or P ⁵ and P ⁶ are combined to represent a divalent hydrocarbon group having 3 to 12 carbon atoms. And any carbon atom contained in the divalent hydrocarbon group may be substituted with a carbonyl group, an oxygen atom, or a sulfur atom. ) The salt according to claim 1, wherein A ⁺ is a cation represented by the formula (IId).

(Formula (IId) in, P ¹⁹ and P ²⁰ are independently of one another, a cycloalkyl group of 3 to 6 alkyl carbon atoms or 1 to 6 carbon atoms, the alkyl group be a linear or branched chain Or P ¹⁹ and P ²⁰ are combined to represent a divalent hydrocarbon group having 3 to 6 carbon atoms, P ²¹ represents a hydrogen atom, P ²² represents an alkyl group having 1 to 6 carbon atoms, A cycloalkyl group having 3 to 6 carbon atoms or an optionally substituted aromatic ring group is represented, or P ²¹ and P ²² are bonded to each other to represent a divalent hydrocarbon group having 3 to 6 carbon atoms. And any carbon atom contained in the divalent hydrocarbon group may be substituted with a carbonyl group, an oxygen atom, or a sulfur atom.) The salt according to claim 1 or 2 , wherein the salt represented by the formula (I) is a salt represented by the formula (IV).

(In formula (IV), P ^{19 to} P ²² represent the same meaning as described above.) An acid generator comprising the salt according to any one of claims 1 to 3 as an active ingredient. An ester product represented by the formula (V):

(In the formula (V), Q ¹ and Q ² represents a fluorine atom, the ring X table to a .n is an integer from 1 to 12 representing a monovalent residue of a compound represented by the formula (IIIa). M Represents Li, Na, K or Ag.

(The ring in Formula (IIIa ) contains one or more of a C1-C6 alkyl group, a C1-C6 alkoxy group, a C1-C4 perfluoroalkyl group, or a cyano group as a substituent. Good))) An alcohol of the formula (VI),

(In the formula (VI), the ring X Table to. N a monovalent residue of a compound represented by the formula (IIIa) represents an integer of 1 to 12.

(The ring in Formula (IIIa ) contains one or more of a C1-C6 alkyl group, a C1-C6 alkoxy group, a C1-C4 perfluoroalkyl group, or a cyano group as a substituent. Good)))
Formula (VII)

(In formula (VII), Q ¹ and Q ² represent a fluorine atom, and M represents Li, Na, K, or Ag .)
And a carboxylic acid represented by formula (V)

(In formula (V), Q ¹ , Q ² , n and M have the same meaning as described above.)
The manufacturing method of the ester body shown by this. A method for producing a salt represented by formula (I), comprising reacting an ester represented by formula (V) with a compound represented by formula (VIII).

(In formula (V), Q ¹ and Q ² represent a fluorine atom, and ring X represents a monovalent residue of the compound represented by formula (IIIa). N represents an integer of 1 to 12. M represents , Li, Na, K or Ag.

(The ring in Formula (IIIa) contains one or more of a C 1-6 alkyl group, a C 1-6 alkoxy group, a C 1-4 perfluoroalkyl group or a cyano group as a substituent. Good)))

(In the formula, A ⁺ represents a cation represented by the formula (IIb), and Z represents F, Cl, Br, I, BF ₄ , AsF ₆ , SbF ₆ , PF ₆ or ClO ₄ .

(In the formula (IIb), P ³ and P ⁴ each independently represent an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, and the alkyl group is branched even in a straight chain. Or P ³ and P ⁴ may be bonded to each other to represent a divalent hydrocarbon group having 3 to 12 carbon atoms, P ⁵ represents a hydrogen atom, P ⁶ represents an alkyl group having 1 to 12 carbon atoms, A cycloalkyl group having 3 to 12 carbon atoms or an optionally substituted aromatic ring group is represented, or P ⁵ and P ⁶ are combined to represent a divalent hydrocarbon group having 3 to 12 carbon atoms. And any carbon atom contained in the divalent hydrocarbon group may be substituted with a carbonyl group, an oxygen atom, or a sulfur atom.) )

(In formula (I), Q ¹ , Q ² , ring X, n and A ⁺ represent the same meaning as described above.) A resin composition comprising the acid generator according to claim 4 and a resin, wherein the resin has an acid-labile group and is a resin that is insoluble or hardly soluble in an alkaline aqueous solution, and acts with an acid. The resin composition is a resin that is soluble in an alkaline aqueous solution. The resin composition according to claim 8 , wherein the resin is a resin containing a structural unit derived from a monomer having a bulky group and an acid-labile group. A chemically amplified resist composition comprising the resin composition according to claim 8 or 9 and a basic compound.