JP4661397B2 - Radiation sensitive resin composition - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition. More specifically, various radiations such as far ultraviolet rays such as KrF excimer laser and ArF excimer laser, charged particle beams such as electron beams, and X-rays such as synchrotron radiation are used. The present invention relates to a radiation-sensitive resin composition that can be suitably used as a chemically amplified resist useful for microfabrication.

In the field of microfabrication represented by the manufacture of integrated circuit elements, in order to obtain a higher degree of integration, recently, a lithography technique capable of microfabrication at a level of 0.10 μm or less is required.
Therefore, in order to enable fine processing at the sub-quarter micron level, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, an X-ray, an electron beam, and the like. ) Or ArF excimer laser (wavelength 193 nm) has been attracting attention.
As a radiation-sensitive resin composition suitable for irradiation with such an excimer laser, a component having an acid-dissociable functional group and a component that generates an acid upon irradiation with radiation (hereinafter referred to as “exposure”) (hereinafter referred to as “ Many compositions (hereinafter referred to as “chemically amplified radiation-sensitive compositions”) utilizing the chemical amplification effect of “acid generator” are proposed.
As the chemically amplified radiation-sensitive composition, for example, a composition containing a polymer having a t-butyl ester group of carboxylic acid or a t-butyl carbonate group of phenol and an acid generator is disclosed. (Patent Document 1). In this composition, the t-butyl ester group or t-butyl carbonate group present in the polymer is dissociated by the action of an acid generated by exposure, and the polymer is an acidic group consisting of a carboxyl group or a phenolic hydroxyl group. As a result, a phenomenon that the exposed region of the resist film becomes easily soluble in an alkali developer is utilized.

  By the way, most of the conventional chemically amplified radiation-sensitive compositions are based on phenolic resins. When such resins are included, if far ultraviolet rays are used as radiation, aromatic rings in the resin are used. Since the far ultraviolet rays are absorbed due to the above, there is a disadvantage that the exposed far ultraviolet rays cannot sufficiently reach the lower layer portion of the resist film. Therefore, the amount of exposure is large in the upper layer part of the resist film and smaller in the lower layer part, and the resist pattern after development becomes thin in the upper part and becomes thicker in the lower part, so that sufficient resolution cannot be obtained. There was a problem. In addition, when the resist pattern after development has a trapezoidal shape, a desired dimensional accuracy cannot be achieved in the next step, that is, etching or ion implantation, which is a problem. In addition, if the shape of the upper portion of the resist pattern is not rectangular, there is a problem that the resist disappearance rate by dry etching increases, and it becomes difficult to control the etching conditions.

  On the other hand, the shape of the resist pattern can be improved by increasing the radiation transmittance of the resist film. For example, (meth) acrylate resins typified by polymethyl methacrylate are highly transparent to far ultraviolet rays and are very preferable from the viewpoint of radiation transmittance. For example, chemical amplification using methacrylate resins A type radiation sensitive resin composition is disclosed (Patent Document 2). However, although this composition is excellent in terms of microfabrication performance, it does not have an aromatic ring and thus has a drawback of low dry etching resistance. In this case as well, it is difficult to perform highly accurate etching. Therefore, it cannot be said that it has both transparency to radiation and dry etching resistance.

In addition, for a resist composed of a chemically amplified radiation-sensitive resin composition, as one of the measures for improving dry etching resistance without impairing transparency to radiation, the resin component in the composition is replaced with an aromatic ring. A method for introducing an aliphatic ring is known. For example, a chemically amplified radiation-sensitive resin composition using a (meth) acrylate-based resin having an aliphatic ring has been proposed (Patent Document 3).
However, in this composition, as the acid-dissociable functional group of the resin component, a group that is relatively easily dissociated by a conventional acid (for example, an acetal functional group such as a tetrahydropyranyl group) or an acid is relatively hardly dissociated Group (for example, t-butyl functional group such as t-butyl ester group and t-butyl carbonate group) is used, and in the case of the former resin component having an acid dissociable functional group, the basic physical properties of the resist, particularly Although the sensitivity and pattern shape are good, there are difficulties in storage stability as a composition, and the latter resin component having an acid dissociable functional group, on the contrary, has good storage stability. There is a problem that physical properties, particularly sensitivity and pattern shape are impaired. Furthermore, since an aliphatic ring is introduced into the resin component in the composition, there is a problem that the hydrophobicity of the resin itself becomes very high and the adhesion to the substrate is deteriorated.
Therefore, from the viewpoint of technological development that can cope with the progress of miniaturization in semiconductor elements, in the chemically amplified radiation-sensitive composition that can be applied to short-wavelength radiation typified by far ultraviolet rays, the transparency to radiation is high, In addition, development of a new resin component having a fluorinated alkyl group with excellent basic physical properties as a resist at the alpha carbon atom is underway (Patent Document 4).

  However, in the case of a (meth) acrylate-based resin having an aliphatic ring with excellent transparency to radiation, the carboxyl group generated by dissociation is excellent in alkali solubility, but is excellent in hydrophilicity and therefore easily swells in a developer. There is a problem that the line edge roughness (LER) becomes large.

JP-B-2-27660 JP-A-4-226461 JP-A-7-234511 JP 2002-72484 A

  The present invention was made in order to cope with such problems, and is highly transparent to radiation, and excellent in basic physical properties as a resist such as sensitivity, resolution, dry etching resistance, and low development defects. It aims at providing the radiation sensitive resin composition with a favorable pattern shape with small LER.

（式中、Ｒ¹は水素原子、メチル基、エチル基、炭素数１〜４のヒドロキシアルキル基、または炭素数１〜４のパーフルオロアルキル基を表し、Ａは単結合または２価の有機基を表し、
該２価の有機基は−（ＣＯ）−Ａ'−、−（ＣＯ）−Ｏ−Ａ'−、または、−Ｏ−（ＣＯ）−Ａ'−であり、Ａ'側が硫黄原子に結合し、
前記Ａ'は置換もしくは非置換の２価の炭化水素基を表し、この２価の炭化水素基は、メチレン基、炭素数２〜８のアルキレン基、炭素数３〜１０のシクロアルキレン基、炭素数６〜１４のアリーレン基、または、有橋脂環式炭化水素基を表し、ただし前記２価の有機基が−（ＣＯ）−Ｏ−Ａ'−の場合、このＡ'には１つの炭素原子に２つの結合手がある２価の有機基を含まず、
前記Ａ'の置換基として、メチレン基および炭素数２〜８のアルキレン基に対する置換基がヒドロキシル基、カルボキシル基、シアノ基、炭素数１〜４のアルコキシル基、炭素数２〜５のアルキルカルボニルオキシ基、炭素数２〜５のアルコキシカルボニル基、炭素数３〜６のアルコキシカルボニルアルコキシ基、またはハロゲン原子の１個以上あるいは１種以上であり、
炭素数３〜１０のシクロアルキレン基、または炭素数６〜１４のアリーレン基に対する置換基がヒドロキシル基、カルボキシル基、炭素数１〜４のアルキル基、炭素数１〜４のヒドロキシアルキル基、炭素数１〜４のアルコキシル基、シアノ基、炭素数２〜５のシアノアルキル基、炭素数２〜５のアルキルカルボニルオキシ基、炭素数２〜５のアルコキシカルボニル基、炭素数３〜６のアルコキシカルボニルアルコキシ基、ハロゲン原子、または炭素数１〜４のアルオロアルキル基の１個以上あるいは１種以上であり、
Ｒ²は、相互に独立に炭素数１〜４の直鎖状もしくは分岐状のアルキル基または炭素数４〜２０の１価の脂環式炭化水素基もしくはその置換誘導体を表すか、あるいは何れか２つのＲ²が相互に結合して、それぞれが結合している炭素原子とともに炭素数４〜２０の２価の脂環式炭化水素基もしくはその置換誘導体を形成し、残りの１つのＲ²が炭素数１〜４の直鎖状もしくは分岐状のアルキル基または炭素数４〜２０の１価の脂環式炭化水素基もしくはその置換誘導体を表す。）
また、本発明の感放射線性樹脂組成物は、酸拡散制御剤を更に含有することを特徴とする。 The radiation-sensitive resin composition of the present invention is a radiation-sensitive resin composition containing an acid-dissociable group-containing resin that is hardly soluble or insoluble in alkali and easily alkali-soluble by the action of an acid, and an acid generator. The acid-dissociable group-containing resin contains a repeating unit represented by the following formula (1).

(In the formula, R ¹ represents a hydrogen atom, a methyl group, an ethyl group, a hydroxyalkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group having 1 to 4 carbon atoms, and A is a single bond or a divalent organic group. Represents
The divalent organic group is — (CO) —A′—, — (CO) —OA′—, or —O— (CO) —A′—, and the A ′ side is bonded to a sulfur atom. ,
A ′ represents a substituted or unsubstituted divalent hydrocarbon group, and the divalent hydrocarbon group includes a methylene group, an alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, and carbon. Represents an arylene group of 6 to 14 or a bridged alicyclic hydrocarbon group, provided that when the divalent organic group is — (CO) —O—A′—, this A ′ has one carbon. Does not contain a divalent organic group with two bonds in the atom,
As the substituent for A ′, a substituent for a methylene group and an alkylene group having 2 to 8 carbon atoms is a hydroxyl group, a carboxyl group, a cyano group, an alkoxyl group having 1 to 4 carbon atoms, or an alkylcarbonyloxy having 2 to 5 carbon atoms. A group, an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkoxycarbonylalkoxy group having 3 to 6 carbon atoms, or one or more kinds of halogen atoms,
The substituent for the cycloalkylene group having 3 to 10 carbon atoms or the arylene group having 6 to 14 carbon atoms is a hydroxyl group, a carboxyl group, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, or a carbon number 1-4 alkoxyl group, cyano group, C2-C5 cyanoalkyl group, C2-C5 alkylcarbonyloxy group, C2-C5 alkoxycarbonyl group, C3-C6 alkoxycarbonylalkoxy One or more or one or more of a group, a halogen atom, or a C 1-4 alkyloalkyl group,
R ² represents each independently a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted derivative thereof, or Two R ² are bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a substituted derivative thereof together with the carbon atom to which each R ² is bonded, and the remaining one R ² is A linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted derivative thereof is represented. )
Moreover, the radiation sensitive resin composition of this invention is characterized by further containing an acid diffusion control agent.

  Since the radiation-sensitive resin composition of the present invention contains a repeating unit represented by the formula (1), the acid-dissociable group-containing resin that is hardly soluble or insoluble in alkali and easily soluble in alkali by the action of an acid. Since the transparency to radiation is high, the resolution is high, the sensitivity and the pattern shape are excellent, and the LER is particularly good. Therefore, it is useful as a chemically amplified resist sensitive to far ultraviolet rays typified by actinic rays, for example, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and the like. It is extremely suitable for the production of

In the radiation-sensitive resin composition of the present invention, the acidic group generated by the action of an acid is a -SH group, and the repeating unit that generates the -SH group is represented by the above formula (1).
The substituent R ¹ constituting the formula (1) is ^one selected from a hydrogen atom, a methyl group, an ethyl group, a hydroxyalkyl group having 1 to 4 carbon atoms, and a perfluoroalkyl group having 1 to 4 carbon atoms. . Examples of the hydroxyalkyl group having 1 to 4 carbon atoms include a hydroxymethyl group and a 2-hydroxyethyl group. Examples of the perfluoroalkyl group having 1 to 4 carbon atoms include a monofluoromethyl group, a difluoromethyl group, and a trifluoromethyl group. Of these, a hydrogen atom, a methyl group, a trifluoromethyl group, and a hydroxymethyl group are preferable.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ² in the formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, 2 -Methylpropyl group, 1-methylpropyl group, t-butyl group and the like can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, and the like are preferable.
In addition, the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms of R ² and any two R ² bonded together to form a carbon atom having 4 to 20 carbon atoms formed together with the bonded carbon atoms. Examples of the divalent alicyclic hydrocarbon group include groups derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; adamantane, bicyclo [2.2.1] heptane, and tricyclo [ 5.2.1.0 ^2,6 ] decane, tetracyclo [6.2.1.1 ^3,6 . [0 ^2,7 ] groups derived from bridged hydrocarbons such as dodecane.
Of these monovalent alicyclic hydrocarbon groups and divalent alicyclic hydrocarbon groups, groups derived from cyclopentane, cyclohexane, adamantane, bicyclo [2.2.1] heptane and the like are preferable.
Examples of the substituent in the substituted derivative of the monovalent or divalent alicyclic hydrocarbon group include, for example, hydroxyl group; carboxyl group; oxo group (that is, ═O group); hydroxymethyl group, 1-hydroxyethyl Group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group and the like. Hydroxyalkyl group of 1 to 4 carbon atoms such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group Alkoxyl group; cyano group; carbon such as cyanomethyl group, 2-cyanomethyl group, 3-cyanopropyl group, 4-cyanobutyl group Group having 2 to 5 of substituents such as a cyano group one or more or one or more can be mentioned. Of these substituents, a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, a cyanomethyl group, and the like are preferable. One or more or one or more of these substituents may be present in each substituted derivative.

  Specific examples include t-butyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 2-methyladamantan-2-yl group, 2-ethyladamantane-2. -Yl group, 2-methylbicyclo [2.2.1] heptan-2-yl group, 2-ethylbicyclo [2.2.1] heptan-2-yl group, 1-methyl-1- (adamantane-1 -Yl) ethyl group, 1-methyl-1- (bicyclo [2.2.1] heptan-2-yl) ethyl group and the like are preferable.

In the formula (1), A represents a single bond or a divalent organic group. A single bond is a case where the sulfur atom represented by formula (1) is directly bonded to the carbon atom of the main chain.
Preferred examples of the divalent organic group include-(CO) -A'-,-(CO) -OA'-, and -O- (CO) -A'-, and the A 'side is a sulfur atom. To join.
Examples of A ′ include a substituted or unsubstituted divalent hydrocarbon group, and a divalent group having a hetero atom in the main chain of A ′.
Examples of the divalent hydrocarbon group include methylene group; carbon number such as 1,1-ethylene group, 1,2-ethylene group, propylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, and the like. An alkylene group having 2 to 8 carbon atoms; a cycloalkylene group having 3 to 10 carbon atoms such as a 1,3-cyclopentylene group, a 1,3-cyclohexylene group and a 1,4-cyclohexylene group; a 1,3-phenylene group; An arylene group having 6 to 14 carbon atoms such as 1,4-phenylene group, methyl-1,4-phenylene group, 1,4-phenylenemethylene group, norbornylene group, tricyclodecanylene group, tetracyclododecylene group, Examples thereof include bridged alicyclic hydrocarbon groups such as adamantylene group, methyladamantylene group, ethyladamantylene group, and n-butyladamantylene group. .
In the present invention, when A is — (CO) —OA′—, the A ′ is a divalent divalent having two bonds in one carbon atom such as a methylene group and a 1,1-ethylene group. Does not contain organic groups.

  Among the substituents for the divalent hydrocarbon group represented by A ′, for the methylene group and the alkylene group, for example, a hydroxyl group, a carboxyl group, a cyano group, an alkoxyl group having 1 to 4 carbon atoms, and a carbon number One or more or one or more of a 2 to 5 alkylcarbonyloxy group, a C2 to C5 alkoxycarbonyl group, a C3 to C6 alkoxycarbonylalkoxy group, a halogen atom and the like can be exemplified.

  Among the substituents for the divalent hydrocarbon group represented by A ′, those for the cycloalkylene group and the arylene group include, for example, a hydroxyl group, a carboxyl group, an oxo group (═O), and those having 1 to 4 carbon atoms. Alkyl group, hydroxyalkyl group having 1 to 4 carbon atoms, alkoxyl group having 1 to 4 carbon atoms, cyano group, cyanoalkyl group having 2 to 5 carbon atoms, alkylcarbonyloxy group having 2 to 5 carbon atoms, 2 to 2 carbon atoms 1 or more types, such as a 5 alkoxycarbonyl group, a C3-C6 alkoxycarbonylalkoxy group, a halogen atom, a C1-C4 fluoroalkyl group, etc. can be mentioned.

  Examples of the divalent group having a hetero atom in the main chain represented by A ′ include a group in which one bond of the above substituted or unsubstituted divalent hydrocarbon group is bonded to —O—, Alternatively, a group in which one bond of an unsubstituted divalent hydrocarbon group is bonded to —S—, —CO—, —COO—, —NR—, —NRCO—, and the like can be given. However, each R bonded to the nitrogen atom is independently a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted monovalent group having 3 to 20 carbon atoms. An alicyclic hydrocarbon group or a linear or branched alkenyl group having 2 to 20 carbon atoms is shown.

  In Formula (1), specific examples of preferable A include a methylene group, 1,2-ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, difluoromethylene group, 1,4-cyclohexylene group. 1,4-phenylene group, 1,4-phenylenemethylene group, fluoro-1,4-phenylene group, 1,1,2,2-tetrafluoropentamethylene group and the like.

式（２）において、Ｒ¹、Ｒ²、およびＡ’は式（１）におけるＲ¹、Ｒ²、およびＡ’と同一である。
好ましい単量体の例を以下に示す。

As a monomer which produces | generates the repeating unit represented by Formula (1), the monomer represented by Formula (2) is preferable.

In the formula (2), R ^1, R ^2, and A 'are R ^1, R ^2, and A in the formula (1)' is the same as.
Examples of preferred monomers are shown below.

The monomer represented by the formula (2) can be synthesized by the following synthesis method using, for example, a thiol compound having a carboxyl group as a starting material.

The acid-dissociable group-containing resin of the present invention is a resin containing a repeating unit represented by the formula (1). The resin of the present invention is preferably copolymerized with a conventionally known repeating unit having an acid dissociable group.
The conventionally known acid-dissociable group is a group in which a hydrogen atom in an acidic group such as a phenolic hydroxyl group, a carboxyl group, or a sulfonic acid group is substituted, and means a group that dissociates in the presence of an acid.
Examples of such an acid dissociable group include a substituted methyl group, a 1-substituted ethyl group, a 1-substituted-n-propyl group, a 1-branched alkyl group, an alkoxycarbonyl group, and a cyclic acid dissociable group. It is done.

式（３）において、Ｒ³は相互に独立に炭素数１〜４の直鎖状もしくは分岐状のアルキル基または炭素数４〜２０の１価の脂環式炭化水素基もしくはその置換誘導体を表すか、あるいは何れか２つのＲ³が相互に結合して、それぞれが結合している炭素原子とともに炭素数４〜２０の２価の脂環式炭化水素基もしくはその置換誘導体を形成し、残りの１つのＲ³が炭素数１〜４の直鎖状もしくは分岐状のアルキル基または炭素数４〜２０の１価の脂環式炭化水素基もしくはその置換誘導体を表す。 Moreover, the group represented by Formula (3) can be used as an acid dissociable group.

In Formula (3), R ³ independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted derivative thereof. Or any two R ³ 's bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a substituted derivative thereof together with the carbon atoms to which each is bonded, One R ³ represents a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted derivative thereof.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ³ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, Examples thereof include 1-methylpropyl group and t-butyl group. Of these alkyl groups, a methyl group, an ethyl group, and the like are preferable.
In addition, the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms of R ³ and any two R ³ bonded together to form a carbon atom having 4 to 20 carbon atoms formed together with the bonded carbon atoms. Examples of the divalent alicyclic hydrocarbon group include groups derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; adamantane, bicyclo [2.2.1] heptane, and tricyclo [ 5.2.1.0 ^2,6 ] decane, tetracyclo [6.2.1.1 ^3,6 . [0 ^2,7 ] groups derived from bridged hydrocarbons such as dodecane.
Of these monovalent alicyclic hydrocarbon groups and divalent alicyclic hydrocarbon groups, groups derived from cyclopentane, cyclohexane, adamantane, bicyclo [2.2.1] heptane and the like are preferable.
Examples of the substituent in the substituted derivative of the monovalent or divalent alicyclic hydrocarbon group include, for example, the divalent linear or branched hydrocarbon group of R ³ and a divalent alicyclic group. The substituent similar to what was illustrated about the substituent with respect to a hydrocarbon can be mentioned.
Of these substituents, a hydroxyl group, a carboxyl group, a hydroxymethyl group, a cyano group, a cyanomethyl group, and the like are preferable. One or more or one or more of these substituents may be present in each substituted derivative.

In the formula (3), examples of the structure corresponding to —C (R ³ ) ₃ include t-butyl group, 2-methyl-2-butyl group, 2-ethyl-2-butyl group, and 3-methyl-3. -Trialkylmethyl groups such as butyl group, 3-ethyl-3-butyl group, 3-methyl-3-pentyl group;
1-alkylcyclopentyl group, 1-ethylcyclopentyl group, 1-n-propylcyclopentyl group, 1-alkylcyclohexyl group such as 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-n-propylcyclohexyl group;
2-methyladamantan-2-yl group, 2-methyl-3-hydroxyadamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-ethyl-3-hydroxyadamantan-2-yl group, 2- n-propyladamantan-2-yl group, 2-n-butyladamantan-2-yl group, 2-methoxymethyladamantan-2-yl group, 2-methoxymethyl-3-hydroxyadamantan-2-yl group, 2- Ethoxymethyladamantan-2-yl group, 2-n-propoxymethyladamantan-2-yl group, 2-methylbicyclo [2.2.1] heptan-2-yl group, 2-methyl-5-hydroxybicyclo [2] 2.1] heptan-2-yl group, 2-methyl-6-hydroxybicyclo [2.2.1] heptan-2-yl group, 2-methyl-5- Anobicyclo [2.2.1] heptan-2-yl group, 2-methyl-6-cyanobicyclo [2.2.1] heptan-2-yl group, 2-ethylbicyclo [2.2.1] heptane- 2-yl group, 2-ethyl-5-hydroxybicyclo [2.2.1] heptan-2-yl group, 2-ethyl-6-hydroxybicyclo [2.2.1] heptan-2-yl group, 4 -Methyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] -4-yl group, 4-methyl-9-hydroxytetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 4-methyl-10-hydroxytetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 4-methyl-9-cyanotetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 4-methyl-10-cyanotetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 4-ethyltetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 4-ethyl-9-hydroxytetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 4-ethyl-10-hydroxytetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl group, 8-methyltricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8-methyl-4-hydroxytricyclo [5.2. 1.0 ^2,6 ] decan-8-yl group, 8-methyl-4-cyanotricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, 8-ethyltricyclo [5. 2.1.0 ^2,6 ] Decan-8-yl group, 8-ethyl-4-hydroxytricyclo [5.2.1.0 ^2,6 ] decan-8-yl group, etc. A hydrocarbon group;

1-methyl-1-cyclopentylethyl group, 1-methyl-1- (2-hydroxycyclopentyl) ethyl group, 1-methyl-1- (3-hydroxycyclopentyl) ethyl group, 1-methyl-1-cyclohexylethyl group, 1-methyl-1- (3-hydroxycyclohexyl) ethyl group, 1-methyl-1- (4-hydroxycyclohexyl) ethyl group, 1-methyl-1-cycloheptylethyl group, 1-methyl-1- (3- Dialkyl-cycloalkylmethyl groups such as hydroxycycloheptyl) ethyl group, 1-methyl-1- (4-hydroxycycloheptyl) ethyl group; 1-methyl-1- (adamantan-1-yl) ethyl group, 1 -Methyl-1- (3-hydroxyadamantan-1-yl) ethyl group, 1-methyl-1- (bicyclo [2.2.1] Tan-2-yl) ethyl group, 1-methyl-1- (5-hydroxybicyclo [2.2.1] heptan-2-yl) ethyl group, 1-methyl-1- (6-hydroxybicyclo [2. 2.1] Heptan-2-yl) ethyl group, 1-methyl-1- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] dodecan-4-yl) ethyl group, 1-methyl -1- (9-hydroxy tetracyclo [6.2.1.1 ^3,6 .0 ^2,7] dodecane-4-yl) ethyl group, 1-methyl-1- (10-hydroxy-tetracyclo [6. 2.1.1 ^3,6 .0 ^2,7 ] dodecan-4-yl) ethyl group, 1-methyl-1- (tricyclo [5.2.1.0 ^2,6 ] decan-8-yl) ethyl group, 1-methyl-1- (4-hydroxy-tricyclo [5.2.1.0 ^2,6] decan-8-yl) Al or ethyl group A substituted or bridged hydrocarbon group-substituted methyl group; 1,1-dicyclopentylethyl group, 1,1-di (2-hydroxycyclopentyl) ethyl group, 1,1-di (3-hydroxycyclopentyl) ethyl group, 1,1-dicyclohexylethyl group, 1,1-di (3-hydroxycyclohexyl) ethyl group, 1,1-di (4-hydroxycyclohexyl) ethyl group, 1,1-dicycloheptylethyl group, 1,1-di Alkyl-dicycloalkylmethyl groups such as (3-hydroxycycloheptyl) ethyl group and 1,1-di (4-hydroxycycloheptyl) ethyl group; 1,1-di (adamantan-1-yl) ethyl group 1,1-di (3-hydroxyadamantan-1-yl) ethyl group, 1,1-di (bicyclo [2.2.1] heptan-2-yl) ethyl group, 1-di (5-hydroxybicyclo [2.2.1] heptan-2-yl) ethyl group, 1,1-di (6-hydroxybicyclo [2.2.1] heptan-2-yl) ethyl group, 1,1-di (tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecan-4-yl) ethyl group, 1,1-di (9-hydroxytetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] dodecan-4-yl) ethyl group 1,1-di (10-hydroxytetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] dodecan-4-yl) ethyl group, 1,1-di (tricyclo [5.2. 1.0 ^2,6 ] decan-8-yl) ethyl group, alkyl such as 1,1-di (4-hydroxytricyclo [5.2.1.0 ^2,6 ] decan-8-yl) ethyl group Substitution / di (bridged hydrocarbon group) substitution methyl group etc. can be mentioned.

Among these structures corresponding to —C (R ³ ) ₃ , in particular, t-butyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 2-methyl Adamantane-2-yl group, 2-ethyladamantan-2-yl group, 2-methylbicyclo [2.2.1] heptan-2-yl group, 2-ethylbicyclo [2.2.1] heptane-2- An yl group, a 1-methyl-1- (adamantan-1-yl) ethyl group, a 1-methyl-1- (bicyclo [2.2.1] heptan-2-yl) ethyl group and the like are preferable.

上記各式においてＲ⁴は水素原子、メチル基、エチル基、炭素数１〜４のヒドロキシアルキル基、または炭素数１〜４のパーフルオロアルキル基を表し、特に水素原子、メチル基、またはトリフルオロメチル基が好ましい。 In the acid-dissociable group-containing resin of the present invention, the repeating unit having an acid-dissociable group is a monomer of the acrylic acid derivative having the acid-dissociable group in the side chain in the monomer represented by the formula (2). The polymer can be introduced into the polymer by polymerization.
The monomer of an acrylic acid derivative suitable for this invention is illustrated as a formula (3-1)-a formula (3-6) below.

In the above formulas, R ⁴ represents a hydrogen atom, a methyl group, an ethyl group, a hydroxyalkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group having 1 to 4 carbon atoms, particularly a hydrogen atom, a methyl group, or trifluoro A methyl group is preferred.

上記式においてＲ⁵は、水素原子、メチル基、またはトリフルオロメチル基を表し、Ｒ⁶は置換基を表す。
ラクトン骨格として５−オキソ−４−オキサトリシクロ［４．２．１．０^3,7］ノナンを有する脂環式炭化水素基を側鎖の一部に有する。またこのラクトン骨格は、Ｒ⁶で表される、炭素数１〜４の直鎖状または分岐状のアルキル基、アルコキシ基、またはフッ素化アルキル基で置換されていてもよい。
炭素数１〜４の直鎖状または分岐状のアルキル基としては、例えば、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、２−メチルプロピル基、１−メチルプロピル基、ｔ−ブチル基等が挙げられ、炭素数１〜４の直鎖状または分岐状のアルコキシ基としては、メトキシ基、エトキシ基、ｎ−プロポキシ基、ｉ−プロポキシ基、ｎ−ブトキシ基、２−メチルプロポキシ基、１−メチルプロポキシ基、ｔ−ブトキシ基等が挙げられる。炭素数１〜４の直鎖状あるいは分岐状のフッ素化アルキル基としては、上記アルキル基の水素の一部または全部をフッ素原子で置換した基が挙げられる。
上記ラクトンユニット含有繰り返し単位は、該ラクトンユニットを側鎖に有するアクリル酸誘導体を単量体として用いて重合させることにより重合体中に導入できる。 The acid-dissociable group-containing resin of the present invention can contain a lactone unit-containing repeating unit represented by the following formula (4) together with a repeating unit having an acid-dissociable group.

In the above formula, R ⁵ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ⁶ represents a substituent.
It has an alicyclic hydrocarbon group having 5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonane as a lactone skeleton in a part of the side chain. The lactone skeleton may be substituted with a linear or branched alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a fluorinated alkyl group represented by R ⁶ .
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, and 1-methyl group. Examples thereof include a propyl group and a t-butyl group. Examples of the linear or branched alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and an n-butoxy group. , 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group and the like. Examples of the linear or branched fluorinated alkyl group having 1 to 4 carbon atoms include groups in which part or all of the hydrogen atoms in the alkyl group have been substituted with fluorine atoms.
The said lactone unit containing repeating unit can be introduce | transduced in a polymer by making it polymerize using the acrylic acid derivative which has this lactone unit in a side chain as a monomer.

式（５）において、Ｒ⁷は水素原子またはメチル基を表し、ｐは１〜３の整数である。繰り返し単位（５）は、（メタ）アクリル酸ヒドロキシ置換−１−アダマンチルに由来する繰り返し単位である。 The acid-dissociable group-containing resin of the present invention can further contain a unit represented by the following formula (5) as another repeating unit. When the acid-dissociable group-containing resin contains the repeating unit represented by the formula (5), the dry etching resistance of the resist obtained from the radiation-sensitive resin composition of the present invention is further improved. The smoothness of the subsequent resist surface becomes extremely excellent, and the acid generated by exposure diffuses moderately, so that the resolution is further improved.

In Formula (5), R ⁷ represents a hydrogen atom or a methyl group, and p is an integer of 1 to 3. The repeating unit (5) is a repeating unit derived from hydroxy-substituted-1-adamantyl (meth) acrylate.

式（５）において、Ｒ⁷は水素原子またはメチル基である。 As the repeating unit represented by the formula (5), a unit represented by the following formula (5-1) is particularly preferable.

In the formula (5), R ⁷ is a hydrogen atom or a methyl group.

The acid-dissociable group-containing resin of the present invention includes a repeating unit having an acid-dissociable group (hereinafter referred to as repeating unit I), a lactone unit-containing repeating unit (hereinafter referred to as repeating unit II), and / or (meth). It is preferable to include a repeating unit derived from hydroxy-substituted -1-adamantyl acrylate (hereinafter referred to as repeating unit III), and the ratio of the repeating unit I is 5 to 80 mol% with respect to the whole polymer, preferably 10 to 70 mol%, repeating unit II is 5 to 60 mol%, preferably 10 to 55 mol%, and repeating unit III is 0 to 50 mol%, preferably 5 to 40 mol%.
When the repeating unit I is less than 5 mol%, the resolution is insufficient, and when it exceeds 80 mol%, the etching resistance is insufficient. If the repeating unit II is less than 5 mol%, the resolution is insufficient, and if it exceeds 60 mol%, the solubility in the solvent decreases. When the repeating unit III exceeds 50 mol%, the resolution is insufficient.
The repeating unit I may be a repeating unit having an acid dissociable group represented by the formula (1) (hereinafter referred to as repeating unit Ia) alone. Preferably, the ratio (molar ratio) between the repeating unit Ia and the above-mentioned conventionally known repeating unit having an acid dissociable group (hereinafter referred to as repeating unit Ib) is the repeating unit Ia / repeating unit Ib = (1 to 100). ) / (0 to 99), particularly preferably repeating unit Ia / repeating unit Ib = (10 to 75) / (25 to 90).

The acid-dissociable group-containing resin of the present invention can be variously selected according to the type of radiation used. For example, the resin containing the repeating unit I, the repeating unit II, and the repeating unit III can be used as an acid-dissociable group-containing resin suitable for a radiation-sensitive resin composition using an ArF excimer laser. The resin may be suitably used in KrF excimer laser, F ₂ excimer laser radiation-sensitive resin composition using other radiation such as electron beams.

The acid-dissociable group-containing resin of the present invention can be usually produced by radical polymerization. In addition to the radical polymerization initiator, a chain transfer agent can be used as necessary.
Examples of the radical polymerization initiator that can be used in the present invention include a thermal polymerization initiator, a redox polymerization initiator, and a photopolymerization initiator. Examples thereof include polymerization initiators such as peroxides and azo compounds. Although not particularly limited, specific radical polymerization initiators include t-butyl hydroperoxide, t-butyl perbenzoate, benzoyl peroxide, 2,2′-azobis (2,4-dimethylvaleronitrile), 2, Examples include 2′-azobisisobutyronitrile (AIBN), 1,1′-azobis (cyclohexanecarbonitrile), dimethyl-2,2′-azobisisobutyrate (MAIB), and the like.

The polymerization operation can be synthesized by a usual method such as batch polymerization or dropping polymerization. For example, an acid-dissociable group-containing resin can be obtained by dissolving a necessary monomer amount in an organic solvent and polymerizing in the presence of a radical polymerization initiator.
As the polymerization solvent, an organic solvent capable of dissolving the monomer and the radical polymerization initiator is used. Examples of the organic solvent include ketone solvents, ether solvents, aprotic polar solvents, ester solvents, aromatic solvents, and linear or cyclic aliphatic solvents. Examples of the ketone solvent include methyl ethyl ketone and acetone. Examples of ether solvents include alkoxyalkyl ethers such as methoxymethyl ether, ethyl ether, tetrahydrofuran, and 1,4-dioxane. Examples of the aprotic polar solvent include dimethylformamide and dimethyl sulfoxide. Examples of ester solvents include alkyl acetates such as ethyl acetate and methyl acetate. Aromatic solvents include alkylaryl solvents such as toluene, xylene, and halogenated aromatic solvents such as chlorobenzene. Examples of the aliphatic solvent include hexane and cyclohexane.
The polymerization temperature is 20 to 120 ° C, preferably 50 to 110 ° C, more preferably 60 to 100 ° C. Although polymerization may be performed even in a normal air atmosphere, polymerization in an inert gas atmosphere such as nitrogen or argon is preferable. The molecular weight of the polymer can be adjusted by controlling the monomer amount, the polymerization initiator amount, and the chain transfer agent amount.
The polymerization time is generally 0.5 to 144 hours, preferably 1 to 72 hours, more preferably 2 to 24 hours.

The acid-dissociable group-containing resin of the present invention has a polystyrene-reduced weight average molecular weight (hereinafter also referred to as “Mw”) measured by gel permeation chromatography (GPC) of 2000 to 100,000, preferably 2000 to 60,000. Especially preferably, it is 2000-40,000. The ratio (Mw / Mn) between Mw and the polystyrene-equivalent number average molecular weight (hereinafter also referred to as “Mn”) measured by GPC is usually 1 to 5.
The acid-dissociable group-containing resin of the present invention can be used as a resin component constituting a radiation-sensitive resin composition that is insoluble in alkali or hardly soluble in alkali and easily soluble in alkali by the action of an acid.

上記式（５）において、Ｒ⁹は１価の有機基を表し、Ｒ⁸は２価の有機基を表す。
１価の有機基としては、置換もしくは非置換の直鎖または分岐アルキル基、置換もしくは非置換の環式アルキル基、置換もしくは非置換のアリール基、パーフルオロアルキル基等が、２価の有機基としては、置換もしくは非置換のアルキレン基、置換もしくは非置換のアルケニレン基、置換もしくは非置換のフェニレン基等が挙げられる。 As the radiation-sensitive acid generator (hereinafter referred to as “acid generator”) that can be used together with the acid-dissociable group-containing resin, a conventionally known acid generator can be used. Of these, sulfonimide compounds and onium salt compounds are preferable acid generators.
A sulfonimide compound is represented by the following formula (6), for example.

In the above formula (5), R ⁹ represents a monovalent organic group, and R ⁸ represents a divalent organic group.
Examples of the monovalent organic group include a divalent organic group such as a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted cyclic alkyl group, a substituted or unsubstituted aryl group, and a perfluoroalkyl group. Examples thereof include a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, a substituted or unsubstituted phenylene group, and the like.

  Specific examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide. N- (10-camphorsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyl) Oxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (p-toluenesulfonyloxy) succinimide, N- (p-toluenesulfonyloxy) bicyclo [ 2.2.1] Hept-5-ene-2,3-dicarboximide, N- (4-trifluoromethylbenzene) Sulfonyloxy) succinimide, N- (4-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluorobenzenesulfonyloxy) succinimide, N -(Perfluorobenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluorobutylsulfonyloxy) succinimide, N- (nonafluorobutylsulfonyloxy) Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluorooctanesulfonyloxy) succinimide, N- (perfluorooctanesulfonyloxy) bicyclo [2.2.1] Hept-5-ene-2,3-dicarboximide, N- (benzene Sulfonyloxy) succinimide, N- (benzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (benzenesulfonyloxy) -7-oxabicyclo [2.2. 1] hept-5-ene-2,3-dicarboximide, N-{(5-methyl-5-carboxymethanebicyclo [2.2.1] hept-2-yl) sulfonyloxy} succinimide and the like. .

  Among the sulfonamides, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) succinimide, N -(P-toluenesulfonyloxy) succinimide, N- (nonafluorobutylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (benzenesulfonyloxy) bicyclo [ 2.2.1] Hept-5-ene-2,3-dicarboximide, N-{(5-methyl-5-carboxymethanebicyclo [2.2.1] hept-2-yl) sulfonyloxy} succinimide Is preferred.

Examples of the onium salt compounds include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, ammonium salts, pyridinium salts, and the like.
Examples of the onium salt compound include bis (4-t-butylphenyl) iodonium nonafluorobutanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium perfluorooctanesulfonate, Bis (4-t-butylphenyl) iodonium p-toluenesulfonate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, 4-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium perfluoro Benzene sulfonate, diphenyliodonium nonafluorobutanesulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium perfluorooctanesulfone Diphenyliodonium p-toluenesulfonate, diphenyliodoniumbenzenesulfonate, diphenyliodonium10-camphorsulfonate, diphenyliodonium4-trifluoromethylbenzenesulfonate, diphenyliodonium perfluorobenzenesulfonate, bis (p-fluorophenyl) iodonium trifluoromethanesulfonate Bis (p-fluorophenyl) iodonium nonafluoromethanesulfonate, bis (p-fluorophenyl) iodonium camphorsulfonate, (p-fluorophenyl) (phenyl) iodonium trifluoromethanesulfonate,

  Triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluorooctanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfoniumbenzenesulfonate, triphenylsulfonium 10-camphorsulfonate, triphenylsulfonium 4- Trifluoromethylbenzenesulfonate, triphenylsulfonium perfluorobenzenesulfonate, 4-hydroxyphenyl diphenylsulfonium trifluoromethanesulfonate, tri (p-methoxyphenyl) sulfonium nonafluorobutanesulfonate, tri (p-methoxyphenyl) sulfonium trifluoromethanesulfonate Tri (p-methoxyphenyl) sulfonium perfluorooctane sulfonate, tri (p-methoxyphenyl) sulfonium p-toluenesulfonate, tri (p-methoxyphenyl) sulfonium benzenesulfonate, tri (p-methoxyphenyl) sulfonium 10-camphorsulfonate, Examples include tris (p-fluorophenyl) sulfonium trifluoromethanesulfonate, tris (p-fluorophenyl) sulfonium p-toluenesulfonate, (p-fluorophenyl) diphenylsulfonium trifluoromethanesulfonate, and the like.

  In this invention, the usage-amount of an acid generator becomes like this. Preferably it is 0.1-20 weight part with respect to 100 weight part of resin components, More preferably, it is 0.5-15 weight part. In the present invention, two or more acid generators can be mixed and used.

式中、Ｒ¹⁰は、相互に同一でも異なってもよく、水素原子、アルキル基、アリール基またはアラルキル基を表す（アルキル基、アリール基、アラルキル基等の水素原子が、例えば、ヒドロキシ基など、官能基で置換されている場合を含む）。 The radiation-sensitive resin composition of the present invention can contain an acid diffusion controller and other additives.
The acid diffusion control agent controls the diffusion phenomenon in the resist film of the acid generated from the acid generator by exposure, and has an action of suppressing an undesirable chemical reaction in the non-exposed region. By using such an acid diffusion control agent, the storage stability of the composition is improved, the resolution of the resist is improved, and the change of the line width of the resist pattern due to the fluctuation of PED can be suppressed, thereby stabilizing the process. It is extremely excellent in properties.
As the acid diffusion controller, a nitrogen-containing organic compound whose basicity does not change by exposure or heat treatment in the resist pattern forming step is preferable.
Examples of such nitrogen-containing organic compounds include compounds represented by the following formula (7) (hereinafter referred to as “nitrogen-containing compound (I)”), amide group-containing compounds, nitrogen-containing heterocyclic compounds, and the like. It is done.

In the formula, R ¹⁰ may be the same as or different from each other, and represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group (the hydrogen atom such as an alkyl group, an aryl group or an aralkyl group is, for example, a hydroxy group, Including the case where it is substituted with a functional group).

  Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; di-n-butylamine, di-n- Dialkylamines such as pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine, Trialkylamines such as tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine Aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methyl Examples thereof include aromatic amines such as ruaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, and 1-naphthylamine.

Examples of the amide group-containing compound include formamide, N-methylformamide, N,
N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like can be mentioned.
Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, benzimidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, 2-phenylbenzimidazole; pyridine, 2-methylpyridine, 4-methylpyridine. Pyridine such as 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, acridine In addition to the above, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, etc. It is done.

  A base precursor having an acid dissociable group can also be used as the acid diffusion controller. Specifically, N- (t-butoxycarbonyl) piperidine, N- (t-butoxycarbonyl) imidazole, N- (t-butoxycarbonyl) benzimidazole, N- (t-butoxycarbonyl) 2-phenylbenzimidazole, N -(T-Butoxycarbonyl) dioctylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine and the like can be mentioned.

Of these nitrogen-containing organic compounds, nitrogen-containing compounds (I) and nitrogen-containing heterocyclic compounds are preferred. Further, among the nitrogen-containing compounds (I), trialkylamines are particularly preferable, and among the nitrogen-containing heterocyclic compounds, imidazoles are particularly preferable.
The acid diffusion control agents can be used alone or in admixture of two or more.
The compounding amount of the acid diffusion controller is 15 parts by weight or less, preferably 0.001 to 10 parts by weight, and more preferably 0.005 to 5 parts by weight with respect to 100 parts by weight of the resin. In this case, when the compounding amount of the acid diffusion controller exceeds 15 parts by weight, the sensitivity as a resist and the developability of the exposed part tend to be lowered. If the blending amount of the acid diffusion controller is less than 0.001 part by weight, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

In the radiation sensitive resin composition of the present invention, a surfactant exhibiting an effect of improving the coating property and striation of the composition, the developing property as a resist, and the like can be blended.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, polyethylene glycol dilaurate, and polyethylene glycol distearate. Examples of commercially available products include F-top EF301, EF303, and EF352 (manufactured by Tochem Products), Megafax F171 and F173 (manufactured by Dainippon Ink & Chemicals, Inc.), Florad FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC1 06 (Asahi Glass Co., Ltd.), KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, No. 95 (Kyoeisha Chemical Co., Ltd.) and the like.
The compounding amount of the surfactant is preferably 2 parts by weight or less with respect to 100 parts by weight of the acid dissociable group-containing resin.
Further, other sensitizers can be blended. Examples of preferred sensitizers include carbazoles, benzophenones, rose bengals, anthracenes and the like.
The blending amount of the sensitizer is preferably 50 parts by weight or less with respect to 100 parts by weight of the acid dissociable group-containing resin.

The radiation-sensitive resin composition of the present invention is used after being uniformly dissolved in a solvent so that the total solid content is, for example, 0.1 to 50% by weight, preferably 1 to 40% by weight. For example, it is prepared as a composition solution by filtering with a filter having a pore diameter of about 200 nm.
Examples of the solvent used for the preparation of the composition solution include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-n-butyl ether acetate and the like. Glycol monoalkyl ether acetates; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether; propylene glycol dimethyl ether, propylene glycol diethyl Ether, propylene glycol di-n-propyl ether, propylene Propylene glycol dialkyl ethers such as recall di-n-butyl ether; propylene glycol monoalkyl such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-n-butyl ether acetate Ether acetates; lactate esters such as methyl lactate, ethyl lactate, n-propyl lactate, i-propyl lactate; n-amyl formate, i-amyl formate, ethyl acetate, n-propyl acetate, i-propyl acetate, Aliphatic carboxylates such as n-butyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, i-propyl propionate, n-butyl propionate and i-butyl propionate Ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, Methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl Other esters such as butyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate; aromatic hydrocarbons such as toluene, xylene; methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4 Ketones such as heptanone and cyclohexanone; amides such as N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide and N-methylpyrrolidone; lactones such as γ-butyrolactone Can be mentioned.

Among these solvents, propylene glycol monoalkyl ether acetates, 2-heptanone, lactic acid esters, 2-hydroxypropionic acid esters, 3-alkoxypropionic acid esters, etc. have good in-plane uniformity during coating. Is preferable in that.
These solvents can be used alone or in admixture of two or more.

When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution prepared as described above is applied by appropriate coating means such as spin coating, cast coating, roll coating, etc. A resist film is formed by coating on a substrate such as a silicon wafer or a wafer coated with aluminum, and a heat treatment (hereinafter referred to as “PB”) is performed at a temperature of about 70 ° C. to 160 ° C. in some cases. After that, exposure is performed through a predetermined mask pattern. The radiation used in this case depends on the type of the acid generator, for example, far ultraviolet rays such as F ₂ excimer laser (wavelength 157 nm), ArF excimer laser (wavelength 193 nm), KrF excimer laser (wavelength 248 nm), and synchrotron. X-rays such as radiation, and charged particle beams such as electron beams are appropriately selected and used. Moreover, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition, the kind of each additive, etc. In the present invention, far ultraviolet rays such as KrF excimer laser (wavelength 248 nm) are preferably used.

In the present invention, in order to stably form a high-precision fine pattern, it is preferable to perform heat treatment (hereinafter referred to as “PEB”) for 30 seconds or more at a temperature of 70 ° C. to 160 ° C. after exposure. In this case, if the post-exposure baking temperature is less than 70 ° C., there is a possibility that the variation in sensitivity depending on the type of the substrate is widened.
Thereafter, development is performed with an alkali developer at 10 ° C. to 50 ° C., 10 seconds to 200 seconds, preferably 15 ° C. to 30 ° C., 15 seconds to 100 seconds, particularly preferably 20 ° C. to 25 ° C., 15 seconds to 90 seconds. As a result, a predetermined resist pattern is formed.
As the alkaline developer, for example, an alkaline compound such as tetraalkylammonium hydroxide is usually used at a concentration of 1% by weight to 10% by weight, preferably 1% by weight to 5% by weight, particularly preferably 1 to 3% by weight. An alkaline aqueous solution dissolved so as to be used is used.
In addition, a water-soluble organic solvent such as methanol or ethanol or a surfactant can be appropriately added to the developer composed of the alkaline aqueous solution. In forming the resist pattern, a protective film can be provided on the resist film in order to prevent the influence of basic impurities contained in the environmental atmosphere.

３−メルカプトプロピオン酸１２７ｇを反応フラスコ内に入れ、窒素置換を行なった。そして、ｐ−トルエンスルホン酸を１．１ｇ加え、窒素雰囲気下、氷浴中でイソブテン５００ｇをバブリングさせ１時間攪拌した。その後、室温で２時間攪拌した。その後、５％ＮａＨＣＯ₃水溶液２００ｍｌを加え、１時間攪拌後、５００ｍｌ酢酸エチルで抽出し、その酢酸エチル層に蒸留水３００ｍｌを加えて振とうさせ、静置した後、水層を除去した。そして、残った酢酸エチル溶液を無水硫酸マグネシウムで乾燥させてろ過した。その後、エバポレーターを用いて乾燥後の上記酢酸エチル溶液から酢酸エチルを留去し、化合物（ａ−１）を得た。
続いて、リチウムアルミニウムハイドライド９１ｇをテトラヒドロフラン１．５ ｌに溶かし、この溶液を反応フラスコ内に加え、０℃で攪拌し、化合物（ａ−１）をテトラヒドロフラン３００ｍｌに溶かした溶液を滴下した。その後、８０℃で１時間加熱攪拌し、冷却後、飽和炭酸カリウム３０ｍｌを加え、析出した塩を濾過した。濾液を酢酸エチルで抽出し、その酢酸エチル層を５％ＮａＨＣＯ₃水溶液２００ｍｌで洗浄し、蒸留水３００ｍｌを加えて振とうさせ、静置した後、水層を除去した。そして、残った酢酸エチル溶液を無水硫酸マグネシウムで乾燥させてろ過した。その後、エバポレーターを用いて乾燥後の上記酢酸エチル溶液から酢酸エチルを留去し、化合物（ａ−２）を得た。
続いて、得られた化合物（ａ−２）１２４ｇをテトラヒドロフラン１ ｌに溶かし、この溶液を反応フラスコ内に加え、トリエチルアミン２２９ｇ、メタクリル酸クロライド１１８ｇを加え、０℃で１時間攪拌し、その後、水を１ ｌ加え、エバポレーターを用いて反応溶液からテトラヒドロフランを留去し、その後酢酸エチルで抽出し、その酢酸エチル層を５％ＮａＨＣＯ₃水溶液２００ｍｌで洗浄し、蒸留水３００ｍｌを加えて振とうさせ、静置した後、水層を除去した。そして、残った酢酸エチル溶液を無水硫酸マグネシウムで乾燥させてろ過した。その後、エバポレーターを用いて乾燥後の上記酢酸エチル溶液から酢酸エチルを留去し、減圧蒸留を行ない、式（２−２）で表される単量体を得た。以下、この単量体をＥ１−１という。 Synthesis of monomer (E1-1)

127 g of 3-mercaptopropionic acid was placed in the reaction flask and purged with nitrogen. Then, 1.1 g of p-toluenesulfonic acid was added, and 500 g of isobutene was bubbled in an ice bath under a nitrogen atmosphere and stirred for 1 hour. Then, it stirred at room temperature for 2 hours. Thereafter, 200 ml of 5% NaHCO ₃ aqueous solution was added, stirred for 1 hour, extracted with 500 ml of ethyl acetate, 300 ml of distilled water was added to the ethyl acetate layer, shaken, allowed to stand, and then the aqueous layer was removed. The remaining ethyl acetate solution was dried over anhydrous magnesium sulfate and filtered. Then, ethyl acetate was distilled off from the ethyl acetate solution after drying using an evaporator to obtain compound (a-1).
Subsequently, 91 g of lithium aluminum hydride was dissolved in 1.5 l of tetrahydrofuran, this solution was added to the reaction flask, stirred at 0 ° C., and a solution of compound (a-1) dissolved in 300 ml of tetrahydrofuran was added dropwise. Thereafter, the mixture was heated and stirred at 80 ° C. for 1 hour, cooled, 30 ml of saturated potassium carbonate was added, and the precipitated salt was filtered. The filtrate was extracted with ethyl acetate, and the ethyl acetate layer was washed with 200 ml of 5% NaHCO ₃ aqueous solution, added with 300 ml of distilled water, shaken and allowed to stand, and then the aqueous layer was removed. The remaining ethyl acetate solution was dried over anhydrous magnesium sulfate and filtered. Then, ethyl acetate was distilled off from the ethyl acetate solution after drying using an evaporator to obtain compound (a-2).
Subsequently, 124 g of the obtained compound (a-2) was dissolved in 1 l of tetrahydrofuran, this solution was added to the reaction flask, 229 g of triethylamine and 118 g of methacrylic acid chloride were added, and the mixture was stirred at 0 ° C. for 1 hour. 1 l was added, and the tetrahydrofuran was distilled off from the reaction solution using an evaporator, followed by extraction with ethyl acetate. The ethyl acetate layer was washed with 200 ml of 5% NaHCO ₃ aqueous solution, and 300 ml of distilled water was added and shaken. After standing, the aqueous layer was removed. The remaining ethyl acetate solution was dried over anhydrous magnesium sulfate and filtered. Then, ethyl acetate was distilled off from the ethyl acetate solution after drying using an evaporator, and vacuum distillation was performed to obtain a monomer represented by the formula (2-2). Hereinafter, this monomer is referred to as E1-1.

  NMR and mass spectrometry data of the obtained monomer (E1-1) are as follows.

¹ HNMR σ ppm (CD ₃ Cl): 1.25 (9H, s, CH ₃ × 3), 1.94 (3H, s, CH ₃ ), 1.95 to 2.05 (2H, m, CH ₂ ) , 2.61~2.71 (2H, m, CH 2), 4.23 (2H, t, J = 6.3Hz, CH 2), 5.56 (1H, s, CH 2), 6.10 (1H, s, CH ₂₎
MS (FAB) m / z 216 (M +)
Mass spectrometry was carried out using a “JMS-AX505W type mass spectrometer” manufactured by JEOL Ltd. under the following conditions. The obtained result was a parent ion peak of 216, and it was confirmed to be a monomer represented by the formula (2-1).
Emitter current: 5 mA (used gas: Xe)
Acceleration voltage: 3.0 kV
10N MULTI: 1.3
Ionization method: Fast atom bombardment method (FAB)
Detection ion: Cation (+)
Measurement mass range: 20-1500 m / z
Scan: 30 sec
Resolution: 1500
Matrix: 3-nitrobenzyl alcohol

化合物（Ｅ１−１）２．６８ｇ（１４モル％）、化合物（Ｅ１−２）７．４７ｇ（３６モル％）、化合物（Ｅ１−３）９．８４ｇ（５０モル％）を２−ブタノン６０ｇに溶かし、さらにジメチル２，２'−アゾビス（２−メチルプロピオネート）１．０１ｇを投入した単量体溶液を準備し、３０ｇの２−ブタノンを投入した１００ｍｌの三口フラスコを３０分窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、事前に準備した上記単量体溶液を滴下漏斗を用いて３時間かけて滴下した。滴下開始を重合開始時間とし、重合反応を６時間実施した。重合終了後、重合溶液は水冷することにより３０℃以下に冷却し、２０００ｇのメタノールへ投入し、析出した白色粉末をろ別する。
ろ別された白色粉末を２度４００ｇのメタノールにてスラリー上で洗浄した後、ろ別し、５０℃にて１７時間乾燥し、白色粉末の重合体を得た（１６ｇ、収率８０％）。この重合体はＭｗが７，２００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（Ｅ１−１）、化合物（Ｅ１−２）、化合物（Ｅ１−３）で表される繰り返し単位、各繰り返し単位の含有率が１３．２：３５．８：５１．０（モル％）の共重合体であった。この共重合体を樹脂（Ａ−１）とする。 Reference Example 1: Synthesis of acid-dissociable group-containing resin

2.68 g (14 mol%) of compound (E1-1), 7.47 g (36 mol%) of compound (E1-2), and 9.84 g (50 mol%) of compound (E1-3) were converted to 60 g of 2-butanone. Dissolve and prepare a monomer solution charged with 1.01 g of dimethyl 2,2′-azobis (2-methylpropionate), and purge a 100 ml three-necked flask charged with 30 g of 2-butanone with nitrogen for 30 minutes. . After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off.
The filtered white powder was washed twice with 400 g of methanol on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (16 g, yield 80%). . This polymer has Mw of 7,200, and as a result of ¹³ C-NMR analysis, the repeating unit represented by compound (E1-1), compound (E1-2), compound (E1-3), and each repeating unit Was a copolymer having a content of 13.2: 35.8: 51.0 (mol%). This copolymer is referred to as “resin (A-1)”.

化合物（Ｅ２−１、参考例１のＥ１−１と同一化合物）１３．８９ｇ（７０モル％）、化合物（Ｅ２−２）６．１１ｇ（３０モル％）を２−ブタノン３０ｇに溶かし、さらにジメチル２，２'−アゾビス（２−メチルプロピオネート）１．２０ｇを投入した単量体溶液を準備し、１０ｇの２−ブタノンを投入した１００ｍｌの三口フラスコを３０分窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、事前に準備した上記単量体溶液を滴下漏斗を用いて３時間かけて滴下した。滴下開始を重合開始時間とし、重合反応を６時間実施した。重合終了後、重合溶液は水冷することにより３０℃以下に冷却し、２００ｇのメタノールへ投入し、析出した白色粉末をろ別する。
ろ別された白色粉末を２度４００ｇのメタノールにてスラリー上で洗浄した後、ろ別し、５０℃にて１７時間乾燥し、白色粉末の重合体を得た（８ｇ、収率８０％）。この重合体はＭｗが７，５００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（Ｅ２−１）、化合物（Ｅ２−２）で表される繰り返し単位、各繰り返し単位の含有率が６８．９：３１．１（モル％）の共重合体であった。この共重合体を樹脂（Ａ−２）とする。 Reference example 2: Synthesis of acid-dissociable group-containing resin

13.89 g (70 mol%) of the compound (E2-1, the same compound as E1-1 of Reference Example 1) and 6.11 g (30 mol%) of the compound (E2-2) were dissolved in 30 g of 2-butanone, and further dimethyl A monomer solution charged with 1.20 g of 2,2′-azobis (2-methylpropionate) is prepared, and a 100 ml three-necked flask charged with 10 g of 2-butanone is purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or lower, poured into 200 g of methanol, and the precipitated white powder is filtered off.
The filtered white powder was washed twice with 400 g of methanol on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (8 g, yield 80%). . This polymer has Mw of 7,500, and as a result of ¹³ C-NMR analysis, the repeating unit represented by compound (E2-1) and compound (E2-2), and the content of each repeating unit is 68.9. : 31.1 (mol%) copolymer. This copolymer is referred to as “resin (A-2)”.

化合物（Ｅ３−１）７．０９ｇ（４０モル％）、化合物（Ｅ３−２、参考例１のＥ１−１と同一化合物）２．１０ｇ（１０モル％）、化合物（Ｅ３−３）１０．８１ｇ（５０モル％）を２−ブタノン６０ｇに溶かし、さらにジメチル２，２'−アゾビス（２−メチルプロピオネート）１．０１ｇを投入した単量体溶液を準備し、３０ｇの２−ブタノンを投入した１００ｍｌの三口フラスコを３０分窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、事前に準備した上記単量体溶液を滴下漏斗を用いて３時間かけて滴下した。滴下開始を重合開始時間とし、重合反応を６時間実施した。重合終了後、重合溶液は水冷することにより３０℃以下に冷却し、２０００ｇのメタノールへ投入し、析出した白色粉末をろ別する。
ろ別された白色粉末を２度４００ｇのメタノールにてスラリー上で洗浄した後、ろ別し、５０℃にて１７時間乾燥し、白色粉末の重合体を得た（１６ｇ、収率８０％）。この重合体はＭｗが７，２００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（Ｅ３−１）、化合物（Ｅ３−２）、化合物（Ｅ３−３）で表される繰り返し単位、各繰り返し単位の含有率が４３．２：９．８：４７．０（モル％）の共重合体であった。この共重合体を樹脂（Ａ−３）とする。 Reference Example 3: Synthesis of acid-dissociable group-containing resin

Compound (E3-1) 7.09 g (40 mol%), Compound (E3-2, the same compound as E1-1 in Reference Example 1) 2.10 g (10 mol%), Compound (E3-3) 10.81 g (50 mol%) was dissolved in 2-butanone 60 g, and a monomer solution containing 1.01 g of dimethyl 2,2′-azobis (2-methylpropionate) was prepared, and 30 g of 2-butanone was added. The 100 ml three-necked flask is purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off.
The filtered white powder was washed twice with 400 g of methanol on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (16 g, yield 80%). . This polymer has Mw of 7,200, and as a result of ¹³ C-NMR analysis, the repeating unit represented by compound (E3-1), compound (E3-2), compound (E3-3), and each repeating unit Was a copolymer having a content of 43.2: 9.8: 47.0 (mol%). This copolymer is referred to as “resin (A-3)”.

化合物（Ｅ４−１）９．５８ｇ（４５モル％）、化合物（Ｅ４−２、参考例１のＥ１−１と同一化合物）１．８５ｇ（１０モル％）、化合物（Ｅ４−３）８．５７ｇ（４５モル％）を２−ブタノン６０ｇに溶かし、さらにジメチル２，２'−アゾビス（２−メチルプロピオネート）１．０１ｇを投入した単量体溶液を準備し、３０ｇの２−ブタノンを投入した１００ｍｌの三口フラスコを３０分窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、事前に準備した上記単量体溶液を滴下漏斗を用いて３時間かけて滴下した。滴下開始を重合開始時間とし、重合反応を６時間実施した。重合終了後、重合溶液は水冷することにより３０℃以下に冷却し、２０００ｇのメタノールへ投入し、析出した白色粉末をろ別する。
ろ別された白色粉末を２度４００ｇのメタノールにてスラリー上で洗浄した後、ろ別し、５０℃にて１７時間乾燥し、白色粉末の重合体を得た（１６ｇ、収率８０％）。この重合体はＭｗが７，５００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（Ｅ３−１）、化合物（Ｅ３−２）、化合物（Ｅ３−３）で表される繰り返し単位、各繰り返し単位の含有率が４１．８：１０．５：４７．７（モル％）の共重合体であった。この共重合体を樹脂（Ａ−４）とする。 Reference Example 4: Synthesis of acid-dissociable group-containing resin

Compound (E4-1) 9.58 g (45 mol%), Compound (E4-2, the same compound as E1-1 in Reference Example 1) 1.85 g (10 mol%), Compound (E4-3) 8.57 g (45 mol%) was dissolved in 2-butanone 60 g, and a monomer solution containing 1.01 g of dimethyl 2,2′-azobis (2-methylpropionate) was prepared, and 30 g of 2-butanone was added. The 100 ml three-necked flask is purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off.
The filtered white powder was washed twice with 400 g of methanol on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (16 g, yield 80%). . This polymer has Mw of 7,500, and as a result of ¹³ C-NMR analysis, the repeating unit represented by compound (E3-1), compound (E3-2), compound (E3-3), and each repeating unit Was a copolymer having a content of 41.8: 10.5: 47.7 (mol%). This copolymer is referred to as “resin (A-4)”.

化合物（Ｆ１−１）２４．３１ｇ（５０モル％）、化合物（Ｆ１−２）７．７５ｇ（１５モル％）、化合物（Ｆ１−３）１７．９４ｇ（３５モル％）を２−ブタノン１５０ｇに溶かし、さらにジメチル２，２'−アゾビス（２−メチルプロピオネート）１．０１ｇ単量体溶液を準備し、１００ｇの２−ブタノンを投入した１０００ｍｌの三口フラスコを３０分窒素パージする。窒素パージの後、反応釜を攪拌しながら８０℃に加熱し、事前に準備した上記単量体溶液を滴下漏斗を用いて３時間かけて滴下した。滴下開始を重合開始時間とし、重合反応を６時間実施した。重合終了後、重合溶液は水冷することにより３０℃以下に冷却し、２０００ｇのメタノールへ投入し、析出した白色粉末をろ別する。
ろ別された白色粉末を２度４００ｇのメタノールにてスラリー上で洗浄した後、ろ別し、５０℃にて１７時間乾燥し、白色粉末の重合体を得た（３８ｇ、収率８８％）。この重合体はＭｗが８，２００であり、¹³Ｃ-ＮＭＲ分析の結果、化合物（Ｆ１−１）、化合物（Ｆ１−２）、化合物（Ｆ１−３）で表される繰り返し単位、各繰り返し単位の含有率が５２．１：１３．６：３４．３（モル％）の共重合体であった。この共重合体を樹脂（Ａ'−１）とする。 Reference Example 5: Synthesis of acid-dissociable group-containing resin

Compound (F1-1) 24.31 g (50 mol%), compound (F1-2) 7.75 g (15 mol%), compound (F1-3) 17.94 g (35 mol%) into 2-butanone 150 g Dissolve and prepare a 1.01 g monomer solution of dimethyl 2,2′-azobis (2-methylpropionate), and purge a 1000 ml three-necked flask charged with 100 g of 2-butanone with nitrogen for 30 minutes. After purging with nitrogen, the reaction kettle was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise using a dropping funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution is cooled with water to 30 ° C. or less, put into 2000 g of methanol, and the precipitated white powder is filtered off.
The filtered white powder was washed twice with 400 g of methanol on the slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder polymer (38 g, yield 88%). . This polymer has Mw of 8,200, and as a result of ¹³ C-NMR analysis, the repeating unit represented by compound (F1-1), compound (F1-2), compound (F1-3), and each repeating unit Was a copolymer having a content of 52.1: 13.6: 34.3 (mol%). This copolymer is referred to as “resin (A′-1)”.

Examples 1 to 4 and Comparative Example 1
Each resin obtained in Reference Example 1 to Reference Example 5, the acid generator shown below, and other components were mixed at a ratio shown in Table 1 to obtain a uniform solution, and then a membrane filter having a pore size of 200 nm. It filtered and each radiation sensitive resin composition solution was obtained.
The obtained radiation-sensitive resin composition solution was exposed under the conditions shown in Table 2 and subjected to various evaluations. The evaluation results are shown in Table 2. Here, the part is based on weight unless otherwise specified.
Acid generator (B)
B-1: Triphenylsulfonium nonafluoro-n-butanesulfonate acid diffusion controller (C)
C-1: 2-Phenylbenzimidazole solvent (D)
D-1: Propylene glycol monomethyl ether acetate D-2: Cyclohexanone

Here, each resist was evaluated in the following manner.
(1) Sensitivity:
When performing exposure using an ArF light source, a silicon wafer (ARC29) having an ARC29 film (manufactured by Brewer Science) with a film thickness of 770 angstroms formed on the wafer surface is used, and each composition solution is spin-coated on the substrate. A Nikon ArF excimer laser exposure apparatus (numerical aperture of 0.75) is applied to a resist film having a film thickness of 200 nm formed by applying and PB on a hot plate under the conditions shown in Table 2 through a mask pattern. And exposed. Thereafter, PEB is performed under the conditions shown in Table 2, and then developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 25 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. did. At this time, the exposure amount for forming a line-and-space pattern (1L1S) having a line width of 100 nm with a one-to-one line width was defined as the optimum exposure amount, and this optimum exposure amount was defined as the sensitivity.
(2) Resolution:
The dimension of the smallest line and space pattern that can be resolved at the optimum exposure dose was taken as the resolution.
(3) Pattern profile:
The bottom side dimension L1 and the top and bottom side dimension L2 of the square cross section of the line and space pattern (1L1S) having a line width of 100 nm are measured with a scanning electron microscope, and 0.85 ≦ L2 / L1 ≦ 1 is satisfied, and The case where the pattern profile did not have a tail was regarded as “good”.
(4) Line edge roughness (LER):
A line pattern of a line and space pattern (1L1S) having a designed line width of 100 nm was observed with a scanning electron microscope. FIG. 1 shows a schematic diagram of the pattern (unevenness is exaggerated more than actual). 1A is a plan view, and FIG. 1B is a cross-sectional view of a pattern 2 formed on the silicon wafer 1.
For the shapes observed in each of the examples and comparative examples, the difference ΔCD between the line width at the most marked portion of the unevenness generated along the lateral surface 2a of the line pattern and the designed line width of 100 nm was measured. The measurement was performed at n = 10, and the measurement variation was evaluated at 3σ.

  As shown in each example of Table 2, a radiation-sensitive resin composition excellent in resolution, pattern profile, and line edge roughness (LER) characteristics which are resist basic performances can be obtained.

  Since the radiation-sensitive resin composition of the present invention is excellent in line edge roughness (LER) characteristics, it is extremely useful as a chemically amplified resist for semiconductor device production, which is expected to be further refined from now on.

It is a schematic diagram of the line pattern for LER measurement.

Explanation of symbols

1 Substrate 2 Resist pattern

Claims (3)

A radiation-sensitive resin composition containing an acid-dissociable group-containing resin that is hardly soluble or insoluble in alkali and becomes alkali-soluble by the action of an acid, and an acid generator,
The said acid dissociable group containing resin contains the repeating unit represented by following formula (1) whose acidic group produced | generated by the effect | action of an acid is -SH group, The radiation sensitive resin composition characterized by the above-mentioned.

(In the formula, R ¹ represents a hydrogen atom, a methyl group, an ethyl group, a hydroxyalkyl group having 1 to 4 carbon atoms, or a perfluoroalkyl group having 1 to 4 carbon atoms, and A is a single bond or a divalent organic group. Represents
The divalent organic group is — (CO) —A′—, — (CO) —OA′—, or —O— (CO) —A′—, and the A ′ side is bonded to a sulfur atom. ,
A ′ represents a substituted or unsubstituted divalent hydrocarbon group, and the divalent hydrocarbon group includes a methylene group, an alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, and carbon. Represents an arylene group of 6 to 14 or a bridged alicyclic hydrocarbon group, provided that when the divalent organic group is — (CO) —O—A′—, this A ′ has one carbon. Does not contain a divalent organic group with two bonds in the atom,
As the substituent for A ′, the substituent for the methylene group and the alkylene group having 2 to 8 carbon atoms is a hydroxyl group, a carboxyl group, a cyano group, an alkoxyl group having 1 to 4 carbon atoms, or an alkylcarbonyl having 2 to 5 carbon atoms. An oxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkoxycarbonylalkoxy group having 3 to 6 carbon atoms, or one or more halogen atoms,
The substituent for the cycloalkylene group having 3 to 10 carbon atoms or the arylene group having 6 to 14 carbon atoms is a hydroxyl group, a carboxyl group, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, or a carbon number 1-4 alkoxyl group, cyano group, C2-C5 cyanoalkyl group, C2-C5 alkylcarbonyloxy group, C2-C5 alkoxycarbonyl group, C3-C6 alkoxycarbonylalkoxy One or more or one or more of a group, a halogen atom, or a C 1-4 alkyloalkyl group,
R ² represents each independently a linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted derivative thereof, or Two R ² are bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a substituted derivative thereof together with the carbon atom to which each R ² is bonded, and the remaining one R ² is A linear or branched alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted derivative thereof is represented. )   The radiation sensitive resin composition according to claim 1, wherein A in the formula (1) is represented by-(CO) -OA'-.   The radiation sensitive resin composition according to claim 1, further comprising an acid diffusion controller.

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