JP2012203401A - Radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition that satisfies fundamental characteristics such as sensitivity, with excellent MEEF (mask error enhancement factor) and LWR (line-width roughness).SOLUTION: A radiation-sensitive resin composition contains a polymer having a structural unit (I) represented by a following formula (1) and a triphenyl sulfonium salt-based radiation-sensitive acid generator.

Description

  The present invention relates to a radiation sensitive resin composition.

  Lithography using a short wavelength exposure light source typified by a KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm) in order to obtain a higher degree of integration in the field of microfabrication for manufacturing integrated circuit elements, etc. Technology is being developed. Resist materials suitable for these exposure light sources are required to have high sensitivity, high resolution, etc., and usually contain chemical components containing an acid-dissociable group and an acid generator that generates acid upon irradiation with radiation. An amplification type radiation sensitive resin composition is used (see Japanese Patent Application Laid-Open No. 59-45439).

  The component having an acid-dissociable group basically has a structure in which a part of the alkali-soluble portion of the alkali-soluble polymer compound is protected with an appropriate acid-dissociable group. It is important in adjusting the function as a radiation resin composition. As components having an existing acid dissociable group, those having an adamantane structure or the like (see JP-A-9-73173), those having a tetrahydropyranyl group (see JP-A-5-88367), high polarity Those having a heterocyclic group (see JP 2010-191221 A) and the like are known. However, the conventional radiation-sensitive resin composition containing these acid-dissociable group-containing components satisfies the basic characteristics such as sensitivity, but does not always have the lithography characteristics required for forming a finer pattern. Not satisfied.

  In particular, when a finer resist pattern is formed using a conventional radiation-sensitive resin composition, it is appropriate that the acid diffusion distance (hereinafter also referred to as “diffusion length”) in the resist film is somewhat short. It is assumed that there is a sufficient lithography performance such as MEEF (Mask Error Enhancement Factor) and LWR (Line Width Roughness), which are indicators indicating the mask error tolerance, due to an inappropriate diffusion length. It is the present condition that we cannot be satisfied with.

  In view of such circumstances, the radiation-sensitive resin composition for forming a finer resist pattern is desired not only to improve basic characteristics such as sensitivity but also to improve lithography performance such as MEEF and LWR. Yes.

JP 59-45439 A JP-A-9-73173 Japanese Patent Laid-Open No. 5-88367 JP 2010-191221 A

  The present invention has been made based on the above circumstances, and its purpose is to provide a radiation-sensitive resin composition that sufficiently satisfies basic characteristics such as sensitivity and is excellent in lithography performance represented by MEEF and LWR. Is to provide.

（式（１）中、Ｒ^１は、水素原子、フッ素原子、メチル基又はトリフルオロメチル基である。Ａ及びＢは、それぞれ独立して、硫黄原子又は酸素原子である。ｎは０〜２の整数である。Ｒ^２〜Ｒ^１０は、それぞれ独立して、水素原子、炭素数１〜６の直鎖状若しくは分岐状のアルキル基又は炭素数３〜６のシクロアルキル基である。但し、Ｒ^２〜Ｒ^１０のうちのいずれか２つが互いに結合して、それぞれが結合する炭素原子と共に炭素数５〜８の環構造を形成していてもよい。ｎが２の場合、複数のＲ^９及びＲ^１０は、それぞれ同一でも異なっていてもよい。）

（式（２）中、Ｒ^１１は、環構造を含む１価の有機基である。Ｒ^１２は、フッ素化メチレン基又は炭素数２〜１０のフッ素化アルキレン基である。但し、ＳＯ_３ ⁻に直接結合する上記フッ素化アルキレン基の炭素原子はフッ素原子を少なくとも１つ有する。Ｘ^＋は、オニウムカチオンである。） The invention made to solve the above problems is
[A] A polymer having a structural unit (I) represented by the following formula (1) (hereinafter, also referred to as “[A] polymer”), and [B] a radiation sensitive compound represented by the following formula (2). Acid generator (hereinafter also referred to as “[B] acid generator”)
Is a radiation-sensitive resin composition.

(In Formula (1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A and B are each independently a sulfur atom or an oxygen atom. N is 0-2. R ^{2 to} R ¹⁰ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms, provided that Any two of R ^{2 to} R ¹⁰ may be bonded to each other to form a ring structure having 5 to 8 carbon atoms together with the carbon atoms to which each is bonded, and when n is 2, a plurality of R ⁹ And R ¹⁰ may be the same or different.

(In formula (2), R ¹¹ is a monovalent organic group containing a ring structure. R ¹² is a fluorinated methylene group or a fluorinated alkylene group having 2 to 10 carbon atoms, provided that SO ₃ ^— (The carbon atom of the fluorinated alkylene group directly bonded to the above has at least one fluorine atom, and X ⁺ is an onium cation.)

  The radiation-sensitive resin composition of the present invention contains a [B] acid generator, and an acid is generated from the [B] acid generator upon exposure. The [A] polymer is represented by the above formula (1). Since it has a highly polar acid-dissociable group containing two heteroatoms, the interaction with the acid is enhanced, and the diffusion of the acid can be suppressed. Moreover, since the said [B] acid generator is a bulky structure containing the ring structure represented by the said Formula (2), the said radiation sensitive resin composition increases interaction with a [A] polymer. , Acid diffusion can be more effectively suppressed. As a result, dissociation of the acid dissociable group in the unexposed part is suppressed, and according to the radiation sensitive resin composition, a resist pattern excellent in MEEF and LWR can be formed.

（式（３）中、Ｒ^１３〜Ｒ^１５は、それぞれ独立して水素原子、ハロゲン原子、ヒドロキシル基、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、炭素数３〜１２のシクロアルキル基、炭素数１〜１０のアルコキシ基、−Ｓ−Ｒ^１６基又はヘテロ原子を２つ以上有する基である。Ｒ^１６は、アルキル基又はアリール基である。但し、上記アルキル基、シクロアルキル基、アルコキシ基及びアリール基が有する水素原子の一部又は全部は置換されていてもよい。） The X ⁺ is preferably represented by the following formula (3).

(In formula (3), R ^{13 to} R ¹⁵ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a cyclohexane having 3 to 12 carbon atoms. An alkyl group, an alkoxy group having 1 to 10 carbon atoms, an —S—R ¹⁶ group, or a group having two or more heteroatoms, wherein R ¹⁶ is an alkyl group or an aryl group, provided that the above alkyl group or cycloalkyl group; Part or all of the hydrogen atoms of the group, alkoxy group and aryl group may be substituted.)

  Thus, by making the onium cation of the [B] acid generator have the above specific structure, diffusion of the generated acid can be further suppressed. As a result, the radiation sensitive resin composition can form an excellent resist pattern by MEEF and LWR.

The ring structure contained in R ¹¹ is preferably a polycyclic alicyclic group having 6 to 20 carbon atoms or a polycyclic heterocyclic group having 6 to 20 nuclear atoms. In this way, the anion portion of the [B] acid generator has the bulky polycyclic group, so that acid diffusion can be further suppressed. As a result, the radiation sensitive resin composition can form an excellent resist pattern by MEEF and LWR.

It is preferable that n is 0 and R ^{2 to} R ⁸ are hydrogen atoms. Thus, by making the structural unit (I) contained in the [A] polymer into the specific structure having a high polarity, the interaction with the acid generated from the [B] acid generator is further enhanced, and the diffusion of the acid is reduced. More control. Thereby, the said radiation sensitive resin composition can form the resist pattern which is excellent by MEEF and LWR.

（式（４）中、Ｒ^１７は、水素原子、フッ素原子、メチル基又はトリフルオロメチル基である。Ｒ^１８〜Ｒ^２０は、それぞれ独立して、炭素数１〜４の直鎖状若しくは分岐状のアルキル基、炭素数４〜２０の脂環式基又は炭素数６〜２０の芳香族炭化水素基である。但し、Ｒ^１８及びＲ^１９が互いに結合して、それぞれが結合している炭素原子と共に脂環式基を形成していてもよい。また、上記アルキル基、脂環式基及び芳香族炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。） [A] It is preferable that the polymer further has a structural unit (II) represented by the following formula (4).

(In Formula (4), R ¹⁷ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^{18 to} R ²⁰ are each independently a linear or branched group having 1 to 4 carbon atoms. In the form of an alkyl group, an alicyclic group having 4 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, provided that R ¹⁸ and R ¹⁹ are bonded to each other, and the carbon to which each is bonded. An alicyclic group may be formed together with atoms, and a part or all of the hydrogen atoms of the alkyl group, alicyclic group and aromatic hydrocarbon group may be substituted.)

  As described above, the polymer [A] further includes the structural unit (II) having the acid dissociable group having the specific structure, whereby the pattern forming property of the radiation sensitive resin composition is improved, and the MEEF and LWR An excellent resist pattern can be formed.

（式（５）中、Ｒ^２１〜Ｒ^２３は、それぞれ独立して水素原子、ハロゲン原子、ヒドロキシル基、炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、炭素数３〜１２のシクロアルキル基、炭素数１〜１０のアルコキシ基、−Ｓ−Ｒ^２４基又はヘテロ原子を２つ以上有する基である。Ｒ^２４は、アルキル基又はアリール基である。但し、上記アルキル基、シクロアルキル基、アルコキシ基及びアリール基が有する水素原子の一部又は全部は置換されていてもよい。Ｍ⁻は、ＯＨ⁻、Ｒ^ｍＣＯＯ⁻又はＲ^ｍ−ＳＯ_３ ⁻である。Ｒ^ｍは、アルキル基、アリール基又はアラルキル基である。但し、上記アルキル基、アリール基及びアラルキル基が有する水素原子の一部又は全部は置換されていてもよい。また、Ｍ⁻がＲ^ｍ−ＳＯ_３ ⁻の場合、ＳＯ_３ ⁻がフッ素原子を有する炭素原子と直接結合する場合はない。） The radiation-sensitive resin composition preferably further contains [C] a compound represented by the following formula (5) (hereinafter also referred to as “[C] compound”).

(In formula (5), R ^{21 to} R ²³ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a cyclohexane having 3 to 12 carbon atoms. An alkyl group, an alkoxy group having 1 to 10 carbon atoms, an —S—R ²⁴ group, or a group having two or more heteroatoms, wherein R ²⁴ is an alkyl group or an aryl group, provided that the alkyl group or cycloalkyl group described above; Some or all of the hydrogen atoms of the group, alkoxy group and aryl group may be substituted, M ⁻ is OH ⁻ , R ^m COO ^— or R ^m —SO ₃ ^—, where R ^m is alkyl. group, an aryl group or an aralkyl group provided that the alkyl group, a part or all of the hydrogen atom of the aryl group and aralkyl group may be substituted also, M ^-.. is R ^m -SO ₃ For, SO ₃ ^- is not when bound directly to a carbon atom having a fluorine atom).

  The compound [C] has an action of controlling the diffusion phenomenon in the resist coating film of the acid generated from the [B] acid generator by exposure and suppressing undesirable chemical reactions in the unexposed areas. Therefore, the radiation sensitive resin composition contains the [C] compound in addition to the [A] polymer and [B] acid generator, thereby further shortening the acid diffusion length and further suppressing the acid diffusion. it can. Thereby, the said radiation sensitive resin composition can form the resist pattern which is excellent by MEEF and LWR.

[A] The polymer may further have at least one structural unit (III) selected from the group consisting of a structural unit containing a lactone structure, a structural unit containing a cyclic carbonate structure, and a structural unit containing a sultone structure. preferable. [A] When a polymer has such a structural unit, the adhesiveness to the board | substrate of the resist film obtained from the said radiation sensitive resin composition can be improved.

  The “radiation” in the “radiation sensitive resin composition” in the present specification is a concept including visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, EUV, and the like.

  The radiation sensitive resin composition of the present invention can form a resist pattern excellent in MEEF and LWR while having basic performance such as sensitivity. Therefore, the radiation-sensitive resin composition can form a fine pattern with high accuracy and stability, and can be suitably used for manufacturing semiconductor devices where further miniaturization is expected in the future.

<Radiation sensitive resin composition>
The radiation sensitive resin composition of the present invention contains a [A] polymer and a [B] acid generator. The radiation sensitive resin composition preferably contains a [C] compound. Furthermore, the said radiation sensitive resin composition may contain the other arbitrary component, unless the effect of this invention is impaired. Hereinafter, each component will be described in detail.

<[A] polymer>
[A] The polymer contains the structural unit (I) represented by the above formula (1) as an essential component as a structural unit having an acid-dissociable group. Moreover, it has structural unit (III) containing the structural unit (II) represented by the above-mentioned formula (3) mentioned later, a lactone structure, etc. as a suitable component. Since the radiation-sensitive resin composition has the structural units (I) and (II), the acid-dissociable group is dissociated using the acid generated from the [B] acid generator as a catalyst, and the dissolution rate in the developer is increased. Change to form a resist pattern. Furthermore, when [A] polymer further has structural unit (III), the adhesiveness to the board | substrate of the resist film obtained from the said radiation sensitive resin composition can be improved. Moreover, as long as the effect of this invention is not prevented, other structural units, such as structural unit (IV) mentioned later, may be included. Hereinafter, each structural unit will be described in detail.

[Structural unit (I)]
The structural unit (I) is represented by the above formula (1). In said formula (1), R < ¹ > is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A and B are each independently a sulfur atom or an oxygen atom. n is an integer of 0-2. R ^{2 to} R ¹⁰ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms. However, any two of R ^{2 to} R ¹⁰ may be bonded to each other to form a ring structure having 5 to 8 carbon atoms together with the carbon atoms to which they are bonded. When n is 2, the plurality of R ⁹ and R ¹⁰ may be the same or different.

Examples of the linear or branched alkyl group having 1 to 6 carbon atoms represented by R ^{2 to} R ¹⁰ include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i- A butyl group etc. are mentioned. Of these, a methyl group and an ethyl group are preferred.

Examples of the cycloalkyl group having 3 to 6 carbon atoms represented by R ^{2 to} R ¹⁰ include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Among the R ^{2 to} R ¹⁰ , any two are bonded to each other, and the ring structure having 5 to 8 carbon atoms formed together with the carbon atoms to which they are bonded includes, for example, a cyclopentane ring, a cyclohexane ring, and a cyclooctane. A ring etc. are mentioned. Of these, a cyclopentane ring and a cyclohexane ring are preferred.

It is preferable that n is 0 and R ^{2 to} R ¹⁰ are hydrogen atoms. By making the structural unit (I) the specific structure having a high polarity, diffusion of the generated acid can be further suppressed. As a result, the radiation sensitive resin composition can form an excellent resist pattern by MEEF and LWR.

  Specific examples of the structural unit (I) include structural units represented by the following formulas (1-a) to (1-h).

In the above formulas (1-a) to (1-h), R ¹ , A, B and n are as defined in the above formula (1). p is an integer of 1 to 4.

  Among these, the structural unit represented by the above formula (1-a) is preferable. Examples of the structural unit represented by the formula (1-a) include a structural unit represented by the following formula.

In the above formula, ^{R 1} is as defined in the above formula (1).

  [A] The content ratio of the structural unit (I) in the polymer is preferably 2 mol% to 60 mol%, and preferably 5 mol% to 40 mol% with respect to all the structural units constituting the [A] polymer. More preferably, 5 mol% to 30 mol% is more preferable. By making the content rate of structural unit (I) into the said range, the effect of this invention is played without fail. In addition, the [A] polymer may contain 2 or more types of structural units (I).

  Examples of the monomer that provides the structural unit (I) include monomers represented by the following formulas.

[Structural unit (II)]
[A] The polymer preferably has the structural unit (II) represented by the above formula (4). [A] When the polymer further has a structural unit (II) having an acid-dissociable group having the above specific structure, the radiation-sensitive resin composition has improved pattern-forming properties and is superior in MEEF and LWR. A pattern can be formed.

In the formula (4), R ¹⁷ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^{18 to} R ²⁰ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms, an alicyclic group having 4 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms. It is. However, R ¹⁸ and R ¹⁹ may be bonded to each other to form an alicyclic group together with the carbon atom to which each is bonded. Moreover, one part or all part of the hydrogen atom which the said alkyl group, alicyclic group, and aromatic hydrocarbon group have may be substituted.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms represented by R ^{18 to} R ²⁰ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and i- Examples thereof include a butyl group, a tert-butyl group, a 2-methylpropyl group, and a 1-methylpropyl group.

The alicyclic group having 4 to 20 carbon atoms represented by the above R ^{18 to} R ²⁰ , and R ¹⁸ and R ¹⁹ may be bonded to each other and may be formed together with the carbon atoms to which each is bonded. Examples of the group include a polycyclic alicyclic group having a bridged skeleton such as an adamantane skeleton and a norbornane skeleton; and a monocyclic alicyclic group having a cycloalkane skeleton such as cyclopentane and cyclohexane. In addition, these groups may be substituted with one or more linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms, for example.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R ^{18 to} R ²⁰ include benzene, naphthalene, phenanthrene, anthracene, tetracene, pentacene, pyrene, picene, toluene, xylene, ethylbenzene, mesitylene, cumene, and the like. And a group obtained by removing one hydrogen atom from an aromatic hydrocarbon group.

  As the structural unit (II), a structural unit represented by the following formula is preferred.

In the above formula, R ²⁵ has the same meaning as the above formula (3). R ²⁶ is an alkyl group having 1 to 4 carbon atoms. m is an integer of 1-6.

  Among these, more preferred structural units include structural units represented by the following formulas (2-1) to (2-20).

In the above formula, R ²⁵ has the same meaning as the above formula (3).

  Among these, the structural units represented by the above formulas (2-2), (2-3), and (2-13) are more preferable.

  [A] In the polymer, the content ratio of the structural unit (II) is preferably 5% by mole to 80% by mole, and preferably 10% by mole to 80% by mole with respect to all the structural units constituting the [A] polymer. Is more preferable, and 20 mol% to 70 mol% is particularly preferable. By making the content rate of structural unit (II) into the said range, the lithography performance of the resist pattern obtained improves more. In addition, the [A] polymer may have 2 or more types of structural units (II).

Examples of the monomer that gives the structural unit (II) include (meth) acrylic acid-bicyclo [2.2.1] hept-2-yl ester, (meth) acrylic acid-bicyclo [2.2.2] octa. 2-yl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] dec-7-yl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 Deca-1-yl ester, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] dec-2-yl ester, and the like.

[Structural unit (III)]
[A] The polymer may further have at least one structural unit (III) selected from the group consisting of a structural unit containing a lactone structure, a structural unit containing a cyclic carbonate structure, and a structural unit containing a sultone structure. preferable. By having the structural unit (III), the adhesion of the resist film to the substrate can be improved.

  Examples of the structural unit (III) include a structural unit represented by the following formula.

In the above formula, R ²⁷ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ²⁸ is a hydrogen atom or a methyl group. R ²⁹ is a hydrogen atom or a methoxy group. Z ¹ is a single bond or a methylene group. Z ² is a methylene group or an oxygen atom. a and b are 0 or 1;

  Of these, the structural unit (III) is preferably a structural unit represented by the following formula.

In the above formula, R ³⁰ is a hydrogen atom or a methyl group.

  In the [A] polymer, the content ratio of the structural unit (III) is preferably 0 mol% to 70 mol%, and preferably 20 mol% to 60 mol% with respect to all the structural units constituting the [A] polymer. Is more preferable. By making the content rate of structural unit (III) into the said range, the adhesiveness of a resist and a board | substrate can be improved. On the other hand, when it exceeds 70 mol%, a good pattern may not be obtained.

  Examples of the monomer that gives the structural unit (III) include monomers described in International Publication No. 2007/116664 pamphlet.

[Structural unit (IV)]
[A] The polymer may contain a structural unit having a hydrophilic functional group (hereinafter also referred to as “structural unit (IV)”). [A] When the polymer further contains the structural unit (IV), the lithography performance of the resist pattern can be further improved.

  Examples of the structural unit (IV) include structural units represented by the following formula.

In the above formula, R ³¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  [A] The content ratio of the structural unit (IV) in the polymer is preferably 0 mol% to 30 mol%, more preferably 5 mol% to 20 mol%, based on all structural units constituting the [A] polymer. preferable. [A] The polymer may have two or more structural units (IV).

<[A] Polymer Synthesis Method>
[A] The polymer can be produced, for example, by polymerizing a monomer corresponding to each predetermined structural unit in a suitable solvent using a radical polymerization initiator. For example, a method of dropping a solution containing a monomer and a radical initiator into a reaction solvent or a solution containing the monomer to cause a polymerization reaction, a solution containing the monomer, and a solution containing the radical initiator Separately, a method of dropping a reaction solvent or a monomer-containing solution into a polymerization reaction, a plurality of types of solutions containing each monomer, and a solution containing a radical initiator, It is preferable to synthesize by a method such as a method of dropping it into a reaction solvent or a solution containing a monomer to cause a polymerization reaction.

  What is necessary is just to determine the reaction temperature in these methods suitably with initiator seed | species. Usually, it is 30 degreeC-180 degreeC, 40 degreeC-160 degreeC is preferable, and 50 degreeC-140 degreeC is more preferable. The dropping time varies depending on the reaction temperature, the type of initiator, the monomer to be reacted, etc., but is usually 30 minutes to 8 hours, preferably 45 minutes to 6 hours, and more preferably 1 hour to 5 hours. . Further, the total reaction time including the dropping time varies depending on the conditions similarly to the dropping time, but is usually 30 minutes to 8 hours, preferably 45 minutes to 7 hours, and more preferably 1 hour to 6 hours.

  Examples of the radical initiator used for the polymerization include azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), and 2,2′-azobis (2-cyclopropyl). Propionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylpropionitrile), and the like. Two or more of these initiators may be mixed and used.

  The polymerization solvent is not limited as long as it is a solvent other than a solvent that inhibits polymerization (nitrobenzene having a polymerization inhibiting effect, mercapto compound having a chain transfer effect, etc.) and can dissolve the monomer. Examples of the polymerization solvent include alcohol solvents, ketone solvents, amide solvents, ester / lactone solvents, nitrile solvents, and mixed solvents thereof. These solvents can be used alone or in combination of two or more.

  The resin obtained by the polymerization reaction is preferably recovered by a reprecipitation method. That is, after completion of the polymerization reaction, the target resin is recovered as a powder by introducing the polymerization solution into a reprecipitation solvent. As the reprecipitation solvent, alcohols or alkanes can be used alone or in admixture of two or more. In addition to the reprecipitation method, the resin can be recovered by removing low-molecular components such as monomers and oligomers by a liquid separation operation, a column operation, an ultrafiltration operation, or the like.

  [A] The weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is not particularly limited, but is preferably 1,000 or more and 500,000 or less, more preferably 2,000 or more and 400,000 or less. preferable. In addition, when the Mw of the [A] polymer is less than 1,000, the heat resistance when used as a resist tends to decrease. On the other hand, when the Mw of the [A] polymer exceeds 500,000, the developability when used as a resist tends to be lowered.

  [A] The ratio (Mw / Mn) of Mw to the number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer is usually from 1 to 5, preferably from 1 to 3, more preferably from 1 to 2. preferable. By setting Mw / Mn in such a range, the photoresist film has excellent resolution performance.

  In addition, Mw and Mn of this specification use a GPC column (Tosoh, G2000HXL, G3000HXL, G4000HXL), flow rate of 1.0 ml / min, elution solvent tetrahydrofuran, column temperature of 40 ° C. It is a value measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under conditions.

<[B] Acid generator>
[B] The acid generator is a radiation-sensitive acid generator represented by the above formula (2). [B] The acid generator generates acid in the exposure step, and the acid dissociates the acid dissociable group present in the [A] polymer. As a result, the [A] polymer becomes hardly soluble in the developer. [B] Since the acid generator has a bulky structure including the ring structure represented by the above formula (2), the interaction with the polymer component is increased. Can be effectively suppressed. As a result, dissociation of the acid dissociable group in the unexposed area is suppressed, and when the radiation sensitive resin composition is used, a resist pattern excellent in MEEF and LWR can be formed. In addition, as a containing form of the [B] acid generator in the said radiation sensitive resin composition, even if it is the aspect of a compound as mentioned later (henceforth this aspect is also called "[B] acid generator"), it is a polymer. It may be an embodiment incorporated as a part of or both of these embodiments.

[B] The acid generator is composed of an anion represented by R ¹¹ —R ¹² —SO ₃ ^— and an onium cation represented by X ⁺ as represented by the above formula (2).

In the above formula (2), R ¹¹ is a monovalent organic group containing a ring structure. R ¹² is a fluorinated alkylene group having 1 to 10 carbon atoms. X ⁺ is an onium cation.

Examples of the ring structure in the monovalent organic group including the ring structure represented by R ¹¹ include alicyclic groups, aromatic rings, and heterocyclic groups.

Examples of the alicyclic group include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, methylcyclohexane, ethylcyclohexane, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclopentadiene, cyclohexane Monocyclic alicyclic groups such as hexadiene, cyclooctadiene, cyclodecadiene;
Bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [3.3.1.1 ^3,7 ] decane, Tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane, norbornane, adamantane, bicyclo [2.2.1] heptene, bicyclo [2.2.2] octene, tricyclo [5.2.1.0 ^2,6 ] decene, tricyclo [3. 3.1.1 ^3,7 ] decene, tetracyclo [6.2.1.1 ^3,6 . And polycyclic alicyclic groups such as 0 ^2,7 ] dodecene.

  Examples of the aromatic ring include benzene, naphthalene, phenanthrene, anthracene, tetracene, pentacene, pyrene, picene, toluene, xylene, ethylbenzene, mesitylene, cumene, and the like.

Examples of the heterocyclic group include a lactone group, a pyrrole ring group, a furan ring group, a thiophene ring group, a pyrazole ring group, an isoxazole ring group, an isothiazole ring group, a pyridine ring group, an imidazole ring group, a thiazole ring group, and a pyrimidine ring. A monocyclic heterocyclic group such as a group, pyridazine ring group, oxazole ring group, piperidine ring group, piperazine ring group, pyrazine ring group, pyran ring group;
Norbornane lactone group, indole ring group, quinoline ring group, isoquinoline ring group, quinazoline ring group, benzofuran ring group, benzothiophene ring group, cinnoline ring group, carbazole ring group, benzoisoxazole ring group, benzothiazole ring group, benzo Examples thereof include polycyclic heterocyclic groups such as isothiazole ring group, benzoxazole ring group, benzimidazole ring group, purine ring group, and indazole ring group.

  Among these, a polycyclic alicyclic group having 6 to 20 carbon atoms and a polycyclic heterocyclic group having 6 to 20 nuclear atoms are preferable, and norbornane, adamantane and norbornane lactone rings are more preferable. [B] Since the anion portion of the acid generator has these bulky groups, acid diffusion can be further suppressed. As a result, the radiation sensitive resin composition can form an excellent resist pattern by MEEF and LWR.

The monovalent organic group containing the ring structure represented by R ¹¹ can contain one or more of the ring structures. The monovalent organic group containing a ring structure in which the R ¹¹ represents, the ring consisting only of groups, and the ring structure, chain hydrocarbon group having 1 to 10 carbon atoms, an ether group, an ester group, And a group in which one or more groups selected from the group consisting of a carbonyl group, an imino group, and an amide group are combined.

The fluorinated methylene group represented by R ¹² and the fluorinated alkylene group having 2 to 10 carbon atoms are preferably groups represented by the following formula (6).

In said formula (6), m is an integer of 1-10. R ^f1 and R ^f2 are each independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 4 carbon atoms. However, when m is 2 or more, the plurality of R ^f1 and R ^f2 may be the same or different. R ^f1 or R ^f2 of the carbon atom directly bonded to SO ₃ ^— is a fluorine atom. * Is SO ₃ ^- is a site that binds to.

Examples of the fluorinated alkyl group having 1 to 4 carbon atoms represented by R ^f1 and R ^f2 include a fluorinated methyl group, a fluorinated ethyl group, a fluorinated n-propyl group, a fluorinated i-propyl group, and a fluorinated group. Examples thereof include an n-butyl group and a fluorinated t-butyl group.

  The m is preferably an integer of 2 to 6.

R ^f1 and R ^f2 are preferably a hydrogen atom and a fluorine atom.

Examples of the anion represented by R ¹¹ —R ¹² —SO ₃ ^— include anions represented by the following formulas.

  Of these, (2-4), (2-5), (2-6) and (2-13) are preferred.

In the above formula (2), examples of the onium cation represented by X ⁺ include a sulfonium cation, a thiophenium cation, an ammonium cation, a phosphonium cation, an iodonium cation, and a pyridinium cation. Among these, a sulfonium cation and a thiophenium cation are preferable, and a cation represented by the above formula (3) is more preferable. [B] By making the onium cation of the acid generator have the specific structure represented by the above (3), the diffusion of the generated acid can be further suppressed. As a result, the radiation sensitive resin composition can form an excellent resist pattern by MEEF and LWR.

In the above formula (3), R ^{13 to} R ¹⁵ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a cyclohexane having 3 to 12 carbon atoms. An alkyl group, an alkoxy group having 1 to 10 carbon atoms, an —S—R ¹⁶ group, or a group having two or more heteroatoms. R ¹⁶ is an alkyl group or an aryl group. However, one part or all part of the hydrogen atom which the said alkyl group, cycloalkyl group, alkoxy group, and aryl group have may be substituted.

Examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R ^{13 to} R ¹⁵ include, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i- Examples include butyl, n-hexyl group, i-hexyl group and the like.

As a C3-C12 cycloalkyl group which said R < ¹³ > -R < ¹⁵ > represents, a cyclopropyl group, a cyclobutyl group, a cyclohexyl group etc. are mentioned, for example.

As a C1-C10 alkoxy group which said R < ¹³ > -R < ¹⁵ > represents, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group etc. are mentioned, for example.

Examples of the alkyl group represented ^{R 16} groups, for example the ^R 13 ^{to R 15} is from 1 to 10 carbon atoms representing straight or exemplified same groups as branched alkyl group, the ^R 13 ^{to R 15} And the same groups as those exemplified as the cycloalkyl group having 3 to 12 carbon atoms represented by

Examples of the aryl group represented by the R ¹⁶ group include a phenyl group and a naphthyl group.

  Examples of the hetero atom include an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom.

The onium cation represented by X ⁺ is particularly preferably a triphenylsulfonium cation.

  These [B] acid generators may be used in combination of two or more. [C] The amount used when the acid generator is an “agent” is the [A] polymer 100 from the viewpoint of ensuring the sensitivity and developability of the resist coating film formed from the radiation-sensitive resin composition. 0.1 parts by mass or more and 25 parts by mass or less are preferable, and 1 part by mass or more and 20 parts by mass or less are more preferable with respect to parts by mass.

<[C] Compound>
The radiation sensitive resin composition may further contain a [C] compound. The compound [C] has an action of controlling the diffusion phenomenon in the resist coating film of the acid generated from the [B] acid generator by exposure and suppressing an undesirable chemical reaction in the unexposed area. Therefore, the radiation sensitive resin composition contains the [C] compound in addition to the [A] polymer and [B] acid generator, thereby further shortening the acid diffusion length and further suppressing the acid diffusion. it can. As a result, the radiation sensitive resin composition can form a resist pattern excellent in MEEF and LWR.

The compound [C] is represented by the above formula (5). In Formula (5), R ^{21 to} R ²³ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a hydroxyl group. M ⁻ is OH ⁻ , R ²⁴ COO ^— or R ²⁴ —SO ₃ ^— . R ²⁴ is an alkyl group, an aryl group, or an aralkyl group. However, one part or all part of the hydrogen atom which the said alkyl group, an aryl group, and an aralkyl group have may be substituted. When M ⁻ is R ²⁴ —SO ₃ ^— , SO ₃ ^— is not directly bonded to a carbon atom having a fluorine atom.

Examples of the halogen atom represented by R ^{21 to} R ²³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkyl group represented by R ^{21 to} R ²³ include chain alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and an i-butyl group;
Examples thereof include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a norbornyl group.

Examples of the alkoxy group represented by R ^{21 to} R ²³ include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

Examples of the alkyl group represented by R ²⁴ include the same groups as those exemplified as the alkyl group represented by R ^{21 to} R ²³ .

  As a preferable [C] compound, the compound represented by a following formula is mentioned.

  Among these, the compounds represented by the above formulas (C-1) and (C-2) are preferable. [C] By using the above preferable compound as the compound, it functions more highly as an acid diffusion controlling agent and can further suppress acid diffusion. As a result, the radiation sensitive resin composition is superior to MEEF and LWR.

  These [C] compounds may be used alone or in combination of two or more. As the usage-amount of the [C] compound in the said radiation sensitive resin composition, 0.1 to 20 mass parts is preferable with respect to 100 mass parts of [A] polymers, and 1 to 15 mass parts is preferable. The following is more preferable. When the amount of the [C] compound used is less than 0.1 parts by mass, the effects of the present invention may not be fully exerted, such as inconvenience that reduction of MEEF is not achieved. On the other hand, when the amount exceeds 15 parts by mass, shape deterioration due to a decrease in sensitivity of the radiation-sensitive resin composition and a decrease in resist transmittance may be observed.

<Solvent>
The radiation sensitive resin composition usually contains a solvent. Examples of the solvent include alcohol solvents, ketone solvents, amide solvents, ether solvents, ester solvents, and mixed solvents thereof. Two or more of these solvents may be used in combination.

Examples of alcohol solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , Sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec -Monoalcohol solvents such as heptadecyl alcohol, furfuryl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2 -Polyhydric alcohol solvents such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, dipropylene glycol monoethyl ether, polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether.

  Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n- Ketones such as hexyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone A solvent is mentioned.

  Examples of the amide solvents include N, N′-dimethylimidazolidinone, N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide, N-methylpyrrolidone and the like can be mentioned.

  Examples of the ester solvents include diethyl carbonate, propylene carbonate, methyl acetate, ethyl acetate, γ-valerolactone, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, acetic acid. n-pentyl, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, acetoacetate Ethyl acetate ethylene glycol monomethyl ether, acetate ethylene glycol monoethyl ether, acetate diethylene glycol monomethyl ether, acetate diethylene glycol monoethyl ether, acetate diethylene glycol mono-n-butyl Ether ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriacetate Glycol, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, Examples thereof include dimethyl phthalate and diethyl phthalate.

Examples of other solvents include n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane, Aliphatic hydrocarbon solvents such as methylcyclohexane;
Fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene and n-amylnaphthalene Group hydrocarbon solvents;
And halogen-containing solvents such as dichloromethane, chloroform, chlorofluorocarbon, chlorobenzene, and dichlorobenzene.

  Of these solvents, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, and cyclohexanone are preferred.

<Other optional components>
In the range which does not impair the effect of this invention, the said radiation sensitive resin composition is [D] fluorine atom containing polymer, [B] acid generators other than an acid generator, an alicyclic skeleton compound, surfactant, Other optional components such as a sensitizer can be contained. Hereinafter, these optional components will be described in detail. Such other optional components can be used alone or in admixture of two or more. Moreover, the compounding quantity of another arbitrary component can be suitably determined according to the objective.

[Fluorine atom-containing polymer]
The said radiation sensitive resin composition may contain the polymer whose fluorine atom content rate is higher than [A] polymer. When the radiation sensitive resin composition contains a [D] fluorine atom-containing polymer, when the resist film is formed, due to the oil repellency characteristics of the [D] fluorine atom-containing polymer in the film, Since the distribution tends to be unevenly distributed in the vicinity of the resist film surface, it is possible to suppress the elution of the acid generator, the acid diffusion controller, and the like during the immersion exposure into the immersion medium. Further, due to the water repellency characteristics of the [D] fluorine atom-containing polymer, the advancing contact angle between the resist film and the immersion medium can be controlled within a desired range, and the occurrence of bubble defects can be suppressed. Furthermore, the receding contact angle between the resist film and the immersion medium is increased, and high-speed scanning exposure is possible without leaving water droplets. Thus, when the said radiation sensitive resin composition contains a [D] fluorine atom containing polymer, the resist coating film suitable for an immersion exposure method can be formed.

  The [D] fluorine-containing polymer is not particularly limited as long as it has a fluorine atom, but it is essential that the fluorine atom content (mass%) is higher than that of the [A] polymer. [A] When the fluorine atom content is higher than that of the polymer, the degree of uneven distribution described above is further increased, and characteristics such as water repellency and elution suppression of the resulting resist coating film are improved.

  The [D] fluorine atom-containing polymer in the present invention is formed by polymerizing one or more monomers containing fluorine atoms in the structure.

  As a monomer that gives a polymer containing a fluorine atom in its structure, a monomer containing a fluorine atom in the main chain, a monomer containing a fluorine atom in the side chain, and a fluorine atom in the main chain and the side chain Monomer.

  Examples of monomers that give a polymer containing a fluorine atom in the main chain include α-fluoroacrylate compounds, α-trifluoromethyl acrylate compounds, β-fluoroacrylate compounds, β-trifluoromethyl acrylate compounds, α, β- Examples thereof include a fluoroacrylate compound, an α, β-trifluoromethyl acrylate compound, a compound in which hydrogen at one or more vinyl sites is substituted with fluorine or a trifluoromethyl group, and the like.

  As the monomer that gives a polymer containing a fluorine atom in the side chain, for example, the side chain of an alicyclic olefin compound such as norbornene is fluorine or a fluoroalkyl group or a derivative thereof, a fluoroalkyl group of acrylic acid or methacrylic acid, Examples of the ester compound of the derivative include a fluorine atom or a fluoroalkyl group in which the side chain of one or more olefins (site not including a double bond) or a derivative thereof is used.

  Examples of the monomer that gives a polymer containing fluorine atoms in the main chain and the side chain include α-fluoroacrylic acid, β-fluoroacrylic acid, α, β-fluoroacrylic acid, α-trifluoromethylacrylic acid, Ester compounds of fluoroalkyl groups such as β-trifluoromethylacrylic acid and α, β-trifluoromethylacrylic acid and derivatives thereof, and hydrogen in one or more kinds of vinyl sites are substituted with fluorine atoms or trifluoromethyl groups A compound in which the side chain of a compound is substituted with a fluorine atom or a fluoroalkyl group or a derivative thereof, and hydrogen bonded to a double bond of one or more alicyclic olefin compounds is substituted with a fluorine atom or a trifluoromethyl group. And the side chain is a fluoroalkyl group or a derivative thereof. In addition, this alicyclic olefin compound shows the compound in which a part of ring is a double bond.

  [D] The structural unit possessed by the fluorine atom-containing polymer includes a structural unit represented by the following formula (hereinafter also referred to as “structural unit (V)”).

In the above formula, R ³² is hydrogen, a methyl group or a trifluoromethyl group. Y is a linking group. R ³³ is a linear or branched alkyl group having 1 to 6 carbon atoms containing at least one fluorine atom, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a derivative thereof. .

  Examples of the linking group represented by Y include a single bond, an oxygen atom, a sulfur atom, a carbonyloxy group, an oxycarbonyl group, an amide group, a sulfonylamide group, and a urethane group.

  Examples of the monomer that gives the structural unit (V) include 2- [1- (ethoxycarbonyl) -1,1-difluorobutyl] (meth) acrylic acid ester, trifluoromethyl (meth) acrylic acid ester, 2, 2,2-trifluoroethyl (meth) acrylic acid ester, perfluoroethyl (meth) acrylic acid ester, perfluoro n-propyl (meth) acrylic acid ester, perfluoro i-propyl (meth) acrylic acid ester, perfluoro n-butyl (meth) acrylic acid ester, perfluoro i-butyl (meth) acrylic acid ester, perfluoro t-butyl (meth) acrylic acid ester, 2- (1,1,1,3,3,3-hexa Fluoropropyl) (meth) acrylic acid ester, 1- (2,2,3,3,4,4,5,5-octaful Lopentyl) (meth) acrylic acid ester, perfluorocyclohexylmethyl (meth) acrylic acid ester, 1- (2,2,3,3,3-pentafluoropropyl) (meth) acrylic acid ester, 1- (3,3 , 4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl) (meth) acrylic acid ester, 1- (5-trifluoro) Methyl-3,3,4,4,5,6,6,6-octafluorohexyl) (meth) acrylic acid ester and the like.

  [D] The fluorine atom-containing polymer may contain two or more structural units (V). The content ratio of the structural unit (V) is usually 5 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more when all the structural units in the fluorine atom-containing polymer are 100 mol%. . If the content of the structural unit (V) is less than 5 mol%, a receding contact angle of 70 degrees or more cannot be achieved, or elution of an acid generator or the like from the resist coating film may not be suppressed.

  [D] In addition to the structural unit (V), the fluorine atom-containing polymer may be a structural unit having an acid-dissociable group, a lactone skeleton, a hydroxyl group, a carboxyl, or the like, for example, in order to control the dissolution rate in a developer. One or more “other structural units” such as structural units derived from aromatic compounds can be contained in order to suppress light scattering due to reflection from the light.

  As the other structural unit having an acid dissociable group, a structural unit similar to the structural unit exemplified in the structural unit (II) can be applied. As other structural units containing the lactone skeleton, structural units similar to the structural units exemplified in the structural unit (III) can be applied. As the other structural unit containing a hydroxyl group, a structural unit similar to the structural unit exemplified for the structural unit (IV) can be used.

  As a preferable monomer for generating another structural unit derived from the aromatic compound, for example, styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 4- (2-t-butoxycarbonylethyloxy) styrene 2-hydroxystyrene, 3-hydroxystyrene, 4-hydroxystyrene, 2-hydroxy-α-methylstyrene, 3-hydroxy -Α-methylstyrene, 4-hydroxy-α-methylstyrene, 2-methyl-3-hydroxystyrene, 4-methyl-3-hydroxystyrene, 5-methyl-3-hydroxystyrene, 2-methyl-4-hydroxystyrene 3-methyl-4-hydroxystyrene, 3,4-dihydro Cystyrene, 2,4,6-trihydroxystyrene, 4-t-butoxystyrene, 4-t-butoxy-α-methylstyrene, 4- (2-ethyl-2-propoxy) styrene, 4- (2-ethyl- 2-propoxy) -α-methylstyrene, 4- (1-ethoxyethoxy) styrene, 4- (1-ethoxyethoxy) -α-methylstyrene, phenyl (meth) acrylate, benzyl (meth) acrylate, acenaphthylene, 5-hydroxyacenaphthylene, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-hydroxy-6-vinylnaphthalene, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, 1-naphthylmethyl (meth) acrylate 1-anthryl (meth) acrylate, 2-anthryl (meth) acrylate, 9- Anthryl (meth) acrylate, 9-anthrylmethyl (meth) acrylate, 1-vinylpyrene and the like can be mentioned.

  The content ratio of other structural units is usually 80 mol% or less, preferably 75 mol% or less, more preferably 70 mol%, when all the structural units in the [D] fluorine atom-containing polymer are 100 mol%. It is as follows.

  [D] The Mw of the fluorine atom-containing polymer is preferably 1,000 to 50,000, more preferably 1,000 to 30,000, and particularly preferably 1,000 to 10,000. When the Mw of the fluorine atom-containing polymer is less than 1,000, a sufficient advancing contact angle cannot be obtained. On the other hand, when Mw exceeds 50,000, the developability of the resist tends to decrease. [D] The ratio (Mw / Mn) of Mw and Mn of the fluorine atom-containing polymer is usually 1 to 3, preferably 1 to 2.

  As a content rate of [D] fluorine atom containing polymer in the said radiation sensitive composition, 0-50 mass parts is preferable with respect to 100 mass parts of [A] polymers, 0-20 mass parts is more preferable, 0.5-10 mass parts is especially preferable, and 1-8 mass parts is the most preferable. By making the content rate of the said [D] fluorine atom containing polymer in the said radiation sensitive resin composition into the said range, the water repellency and elution suppression property of the resist coating film surface obtained can be improved more.

[[D] Method for synthesizing fluorine atom-containing polymer]
The [D] fluorine atom-containing polymer can be synthesized, for example, by polymerizing a monomer corresponding to each predetermined structural unit in a suitable solvent using a radical polymerization initiator.

  Examples of the solvent used for the polymerization include the same solvents as those mentioned in the method for synthesizing the polymer [A].

  As reaction temperature in the said superposition | polymerization, 40 to 150 degreeC and 50 to 120 degreeC are preferable normally. The reaction time is usually preferably 1 hour to 48 hours and 1 hour to 24 hours.

[[B] Acid generator other than acid generator]
The radiation-sensitive resin composition may contain an acid generator other than the [B] acid generator as long as the effects of the present invention are not impaired. Examples of such an acid generator include onium salt compounds other than [B] acid generators, sulfonimide compounds, halogen-containing compounds, diazoketone compounds, and the like.

  Examples of the onium salt compound include sulfonium salts (including tetrahydrothiophenium salts), iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

  Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenyl. Sulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4 -Methanesulfonylphenyl di E sulfonyl sulfonium perfluoro -n- octanesulfonate, and the like. Of these, triphenylsulfonium trifluoromethanesulfonate and triphenylsulfonium nonafluoro-n-butanesulfonate are preferable.

  Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nona. Fluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophene 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium par Fluoro-n-oct Sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octane sulfonate and the like. Of these tetrahydrothiophenium salts, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) Tetrahydrothiophenium perfluoro-n-octane sulfonate and 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butane sulfonate are preferred.

  Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4- t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, and the like. Of these iodonium salts, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate is preferred.

  Examples of the sulfonimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [ 2.2.1] Hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3- Dicarboximide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene -2,3-dicarboximide and the like. Of these sulfonimide compounds, N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide is preferred.

  These [B] acid generators other than the acid generator may be used alone or in combination of two or more.

[Alicyclic skeleton compound]
An alicyclic skeleton compound is a component that exhibits an action of further improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. Examples of the alicyclic skeleton compound include adamantane derivatives such as 1-adamantanecarboxylic acid, 2-adamantanone, and 1-adamantanecarboxylic acid t-butyl; deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, Deoxycholic acid esters such as 2-ethoxyethyl deoxycholic acid; Lithocholic acid esters such as tert-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid; 3- [2-hydroxy-2 , 2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nonane, and the like.

[Surfactant]
Surfactants are components that have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. In addition to nonionic surfactants such as stearate, the following trade names are KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFac F171, F173 (above, manufactured by Dainippon Ink & Chemicals), Fluorad FC430, FC431 ( As above, manufactured by Sumitomo 3M, Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, manufactured by Asahi Glass) ) And the like.

[Sensitizer]
The sensitizer absorbs radiation energy and transmits the energy to the [C] acid generator, thereby increasing the amount of acid produced. It has the effect of improving the “apparent sensitivity”. Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines and the like.

<Method for preparing radiation-sensitive resin composition>
The radiation sensitive resin composition can be prepared, for example, by mixing the [A] polymer, [B] acid generator, [C] compound and other optional components in a predetermined ratio in the above solvent. The solvent is not particularly limited as long as it can dissolve or disperse the [A] polymer, [B] acid generator, [C] compound and other optional components. The radiation-sensitive resin composition is usually dissolved in a solvent so that the total solid content concentration is 1% by mass to 30% by mass, preferably 1.5% by mass to 25% by mass. It is prepared by filtering with a filter of about 0.2 μm.

<Method for forming resist pattern>
Using the radiation-sensitive resin composition of the present invention, for example, a resist pattern can be formed by the following steps.
(1) A step of forming a coating film of the radiation-sensitive resin composition on a substrate (hereinafter also referred to as “step (1)”),
(2) A step of irradiating at least a part of the coating film (hereinafter also referred to as “step (2)”), and (3) a step of developing the coating film irradiated with the radiation (hereinafter referred to as “step”). (Also referred to as (3))
Have Hereinafter, each process is explained in full detail.

  By using the radiation sensitive resin composition, a resist pattern excellent in MEEF and LWR can be formed. Therefore, even with radiation such as KrF excimer laser, ArF excimer laser, EUV, etc., a fine pattern can be formed with high accuracy and stability from the radiation sensitive resin composition, and further miniaturization will progress in the future. It can be suitably used for expected semiconductor device manufacturing.

[Step (1)]
In this step, the radiation-sensitive resin composition or a solution of the radiation-sensitive resin composition obtained by dissolving this in a solvent is applied to a silicon wafer by a coating means such as spin coating, cast coating, and roll coating. In a coating film, it is applied on a substrate such as a wafer coated with silicon dioxide or an antireflection film so as to have a predetermined film thickness, and in some cases, it is usually pre-baked (PB) at a temperature of about 70 ° to 160 ° C. The solvent is volatilized to form a resist film.

[Step (2)]
In this step, the resist film formed in the step (1) is exposed by irradiation with radiation (in some cases through an immersion medium such as water). At this time, radiation is irradiated through a mask having a predetermined pattern. The radiation is appropriately selected from visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams, EUV, etc. according to the line width of the target pattern. Among these, far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) and KrF excimer laser (wavelength 248 nm) are preferable, and light sources capable of forming finer patterns such as EUV (extreme ultraviolet ray, wavelength 13.5 nm) are preferred. Even if it exists, it can be used conveniently. Subsequently, it is preferable to perform post-exposure baking (PEB). This PEB makes it possible to smoothly proceed with elimination of the acid dissociable group of the [A] polymer. The heating condition of PEB can be appropriately selected depending on the composition of the radiation sensitive resin composition, but is usually about 50 ° C to 180 ° C.

[Step (3)]
In this step, a resist pattern is formed by developing the exposed resist film with a developer. After development, it is common to wash with water and dry. As the developer, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyl Dimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3.0] An aqueous alkaline solution in which at least one alkaline compound such as -5-nonene is dissolved is preferable.

  In the case of performing immersion exposure, before the step (2), in order to protect the direct contact between the immersion liquid and the resist film, an immersion liquid insoluble immersion protective film is formed on the resist film. It may be provided. As the protective film for immersion, a solvent-peeling protective film that peels off with a solvent before the step (3) (see, for example, JP-A-2006-227632), a developer that peels off simultaneously with the development in the step (3) Any of peelable protective films (for example, see WO2005-069096, WO2006-035790, etc.) may be used.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Here, the part is based on mass unless otherwise specified. The measurement and evaluation of each physical property value in Examples and Comparative Examples were performed by the following methods.

[Molecular weight (Mw, Mn) measurement method]
The molecular weight (Mw, Mn) of each polymer was measured using a Tosoh GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL), a flow rate of 1.0 mL / min, an elution solvent tetrahydrofuran, and a column temperature of 40 ° C. The measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. Further, the dispersity (Mw / Mn) was calculated from the measurement results of each molecular weight (Mw, Mn).

[ ¹³ C-NMR analysis]
The ¹³ C-NMR analysis of each polymer was measured using a nuclear magnetic resonance apparatus (JNM-ECX400, manufactured by JEOL Ltd.).

[Measurement of amount of low molecular weight component derived from monomer]
Measured by high-performance liquid chromatography (HPLC) using an Intersil ODS-25 μm column (4.6 mmφ × 250 mm) manufactured by GL Sciences under the flow rate of 1.0 mL / min and elution solvent acrylonitrile / 0.1% phosphoric acid aqueous solution. did.

  The structures of monomers used in the synthesis of [A] polymer, polymer for comparative example corresponding to [A] polymer, and [D] fluorine atom-containing polymer are shown below.

<[A] Synthesis of polymer>
[Synthesis Example 1]
2.87 g (10 mol%) of the compound (M-1) giving the structural unit (I), 11.56 g (45 mol%) of the compound (M-3) giving the structural unit (II) and the compound (M- 4) 2.00 g (5 mol%) and 13.57 g (40 mol%) of the above compound (M-6) giving the structural unit (III) are dissolved in 60 g of 2-butanone, and azobisisobutyro Nitrile (AIBN) 2.51 g was added to prepare a monomer solution. A 500 mL three-necked flask containing 30 g of 2-butanone was purged with nitrogen for 30 minutes, then heated to 80 ° C. with stirring, and the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. The cooled polymerization solution was put into 600 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 120 g of methanol and then filtered and dried at 50 ° C. for 17 hours to obtain a white powdery polymer (A-1) (18 g, yield 60%). . Mw of the obtained polymer (A-1) was 4,200, Mw / Mn was 1.46, and the residual ratio of low molecular weight components was 1%. As a result of ¹³ C-NMR analysis, the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-3): the structural unit derived from the compound (M-4): derived from the compound (M-6) The content of the structural unit was 8.3: 44.2: 4.3: 43.2 (mol%).

[Synthesis Examples 2 to 6]
Polymers (A-2) to (A-5) and (a-1) were obtained in the same manner as in Synthesis Example 1 except that a predetermined amount of the monomers listed in Table 1 were blended. In addition, Table 1 shows the Mw, Mw / Mn, yield (%), and the content of the structural unit derived from each monomer in each polymer.

<[D] Synthesis of fluorine atom-containing polymer>
[Synthesis Example 7]
After dissolving 35.83 g (70 mol%) of monomer (M-5) and 14.17 g (30 mol%) of monomer (M-7) in 50 g of 2-butanone, dimethyl 2, 2.17 g (8 mol%) of 2′-azobis (2-methylpropionate) was added to prepare a dissolved monomer solution. Next, 50 g of 2-butanone was charged into a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the flask was heated to 80 ° C. while stirring with a magnetic stirrer. Using a dropping funnel, a monomer solution prepared in advance was added dropwise 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 was cooled to 30 ° C. or less by water cooling. After cooling, the reaction solution, 150 g of hexane, 600 g of methanol, and 30 g of water were poured into a separatory funnel and stirred vigorously, and then allowed to stand. The mixed solution was separated into two layers and allowed to stand for 3 hours, and then the lower layer (resin solution) was collected. The resin solution fractionated using an evaporator was solvent-substituted with a propylene glycol monomethyl ether acetate solution to obtain 159.2 g of a propylene glycol monomethyl ether acetate solution of a copolymer. As a result of obtaining the solid content concentration using a hot plate, the copolymer concentration was 20.1% and the yield was 64%. This copolymer was designated as resin (D-1). This copolymer had Mw of 6,900 and Mw / Mn of 1.34. As a result of ¹³ C-NMR analysis, the content ratio of the repeating unit derived from the compound (M-5): the repeating unit derived from the compound (M-7) was 70.5: 29.5 (mol%).

<Preparation of radiation-sensitive resin composition>
[Example 1]
[A] 100 parts by mass of a copolymer (A-1) as a polymer, [B] 11 parts by mass of (B-1) described later as an acid generator, and (C-1) of a compound as described later (C-1) 6.4 parts by mass, [D] copolymer (D-1) 3 parts by mass as a fluorine atom-containing polymer, 1,980 parts by mass of propylene glycol monomethyl ether (E-1) and cyclohexanone (E-2) 848 parts by mass and 200 parts by mass of γ-butyrolactone (F-1) were added and the components were mixed to obtain a uniform solution. Then, the radiation sensitive resin composition was prepared by filtering using a membrane filter with a hole diameter of 200 nm.

[Examples 2 to 9 and Comparative Examples 1 to 3]
Each radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that the types and amounts of each component shown in Table 2 were used.

  The [B] acid generator and the [C] compound used in the preparation of each Example and Comparative Example are as follows.

<[B] Acid generator>
Compound represented by the following formula

<[C] Compound>
Compound represented by the following formula

<Evaluation>
A resist pattern was formed as described below, and various physical properties were evaluated. The results are shown in Table 2.

[Evaluation of sensitivity]
A film with a film thickness of 75 nm is formed from a radiation-sensitive resin composition on a 12-inch silicon wafer on which an underlayer antireflection film (ARC66, Nissan Chemical Co., Ltd.) is formed, and soft baking (SB) is performed at 120 ° C. for 60 seconds. It was. Next, this film was used for pattern formation of 46 nm lines and 92 nm pitches using an ArF excimer laser immersion exposure apparatus (NSR S610C, NIKON) under the conditions of NA = 1.3, ratio = 0.800, Annular. Exposure was through a mask pattern. After the exposure, each radiation-sensitive resin composition was post-baked (PEB) at 100 ° C. for 60 seconds. Thereafter, the resist film was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution, washed with water, and dried to form a positive resist pattern. The exposure amount at which the portion exposed through the mask pattern for pattern formation at this time forms a line having a line width of 46 nm was defined as the optimum exposure amount (Eop). This optimum exposure amount was defined as sensitivity (mJ / cm ² ). Note that a scanning electron microscope (Hitachi High-Technologies Corporation, CG4000) was used for length measurement. If the sensitivity was 50 (mJ / cm ² ) or less, it was judged to be good.

[LWR]
A line having a line width of 46 nm formed by Eop was observed from the upper part of the pattern using a scanning electron microscope (Hitachi High-Technologies Corporation, CG4000), and the line width was measured at arbitrary 10 points. The 3-sigma value (variation) of the measured line width was defined as LWR (nm). When the value of this LWR was 5.8 nm or less, it was evaluated that the formed pattern shape was good.

[MEEF]
Using the mask pattern with the target size of the line width at the 92 nm pitch at the optimal exposure amount of 43 nm, 44 nm, 45 nm, 46 nm, 47 nm, 48 nm, and 49 nm, the LS pattern with the pitch of 92 nm is formed and formed on the resist film. The measured line width was measured with a length measurement SEM (Hitachi, CG4000). At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the line width (nm) formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEEF. The closer the value is to 1, the better the mask reproducibility, and the lower the MEEF value, the lower the mask production cost.

  As is clear from the results shown in Table 2, it was found that the resist pattern formed from the radiation-sensitive resin composition sufficiently satisfies the sensitivity that is a basic characteristic, and is excellent in MEEF and LWR.

  According to the present invention, there is provided a radiation-sensitive resin composition that sufficiently satisfies the sensitivity and the like that are basic characteristics of a radiation-sensitive resin composition for forming a resist film and that can form a resist pattern excellent in MEEF and LWR. Can do. Therefore, even with radiation such as KrF excimer laser, ArF excimer laser, EUV, etc., a fine pattern can be formed with high accuracy and stability from the radiation sensitive resin composition, and further miniaturization will progress in the future. It can be suitably used for expected semiconductor device manufacturing.

Claims (7)

[A] A radiation-sensitive resin composition containing a polymer having a structural unit (I) represented by the following formula (1), and [B] a radiation-sensitive acid generator represented by the following formula (2) .

(In Formula (1), R ¹ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A and B are each independently a sulfur atom or an oxygen atom. N is 0-2. R ^{2 to} R ¹⁰ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms, provided that Any two of R ^{2 to} R ¹⁰ may be bonded to each other to form a ring structure having 5 to 8 carbon atoms together with the carbon atoms to which each is bonded, and when n is 2, a plurality of R ⁹ And R ¹⁰ may be the same or different.

(In formula (2), R ¹¹ is a monovalent organic group containing a ring structure. R ¹² is a fluorinated methylene group or a fluorinated alkylene group having 2 to 10 carbon atoms, provided that SO ₃ ^— (The carbon atom of the fluorinated alkylene group directly bonded to the above has at least one fluorine atom, and X ⁺ is an onium cation.) The radiation sensitive resin composition according to claim 1, wherein the X ⁺ is represented by the following formula (3).

(In formula (3), R ^{13 to} R ¹⁵ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a cyclohexane having 3 to 12 carbon atoms. An alkyl group, an alkoxy group having 1 to 10 carbon atoms, an —S—R ¹⁶ group, or a group having two or more heteroatoms, wherein R ¹⁶ is an alkyl group or an aryl group, provided that the above alkyl group or cycloalkyl group; Part or all of the hydrogen atoms of the group, alkoxy group and aryl group may be substituted.) The radiation-sensitive composition according to claim 1 or 2, wherein the ring structure contained in R ¹¹ is a polycyclic alicyclic group having 6 to 20 carbon atoms or a polycyclic heterocyclic group having 6 to 20 nuclear atoms. Resin composition. The radiation sensitive resin composition according to claim 1, wherein n is 0, and R ^{2 to} R ⁸ are hydrogen atoms. [A] The radiation sensitive resin composition according to any one of claims 1 to 4, wherein the polymer further has a structural unit (II) represented by the following formula (4).

(In Formula (4), R ¹⁷ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^{18 to} R ²⁰ are each independently a linear or branched group having 1 to 4 carbon atoms. In the form of an alkyl group, an alicyclic group having 4 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, provided that R ¹⁸ and R ¹⁹ are bonded to each other, and the carbon to which each is bonded. An alicyclic group may be formed together with atoms, and a part or all of the hydrogen atoms of the alkyl group, alicyclic group and aromatic hydrocarbon group may be substituted.) [C] The radiation sensitive resin composition according to any one of claims 1 to 5, further comprising a compound represented by the following formula (5).

(In formula (5), R ^{21 to} R ²³ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, or a cyclohexane having 3 to 12 carbon atoms. An alkyl group, an alkoxy group having 1 to 10 carbon atoms, an —S—R ²⁴ group, or a group having two or more heteroatoms, wherein R ²⁴ is an alkyl group or an aryl group, provided that the alkyl group or cycloalkyl group described above; Some or all of the hydrogen atoms of the group, alkoxy group and aryl group may be substituted, M ⁻ is OH ⁻ , R ^m COO ^— or R ^m —SO ₃ ^—, where R ^m is alkyl. group, an aryl group or an aralkyl group provided that the alkyl group, a part or all of the hydrogen atom of the aryl group and aralkyl group may be substituted also, M ^-.. is R ^m -SO ₃ For, SO ₃ ^- is not when bound directly to a carbon atom having a fluorine atom).   [A] The polymer further has at least one structural unit (III) selected from the group consisting of a structural unit containing a lactone structure, a structural unit containing a cyclic carbonate structure, and a structural unit containing a sultone structure. The radiation sensitive resin composition of any one of Claims 1-6.