JP6569221B2 - Radiation sensitive resin composition, resist pattern forming method, radiation sensitive acid generator and compound - Google Patents

Description

  The present invention relates to a radiation sensitive resin composition, a resist pattern forming method, a radiation sensitive acid generator and a compound.

  A resist pattern forming method by photolithography is used for forming structures of various electronic devices such as semiconductor devices and liquid crystal devices. For this resist pattern formation, for example, a radiation sensitive resin composition or the like is used. The radiation sensitive resin composition generates an acid in the exposed area by irradiation with radiation such as deep ultraviolet rays and electron beams, and the catalytic action of this acid causes a difference in the dissolution rate in the developer between the exposed area and the unexposed area. The resist pattern is formed on the substrate.

  At present, miniaturization of the resist pattern processing technique is being attempted by using a laser beam having a shorter wavelength, an electron beam, an immersion exposure apparatus, or the like. Accordingly, the radiation-sensitive resin composition is required to improve resolution and rectangularity of the cross-sectional shape of the resist pattern. In response to this requirement, the types and molecular structures of the polymer, acid generator, and other components used in the composition have been studied in detail, and further their combinations have been studied in detail (Japanese Patent Laid-Open No. 11-125907). JP-A-8-146610 and JP-A-2000-298347).

  Under such circumstances, recently, it is required to form a resist pattern having a line width of 50 nm or less. The requirements for the resolution and the rectangular shape of the cross-sectional shape are further increased, and a high-accuracy pattern is achieved by being excellent in LWR (Line Width Roughness) performance and CDU (Critical Dimension Uniformity) performance that show variations in the line width of the resist pattern. In addition, it is also required to improve the process stability and the MEEF (Mask Error Enhancement Factor) performance and sensitivity, which are indices indicating the depth of focus, the exposure margin, and the mask error tolerance. However, the above conventional radiation-sensitive resin composition cannot satisfy these requirements.

Japanese Patent Laid-Open No. 11-125907 JP-A-8-146610 JP 2000-298347 A

  The present invention has been made on the basis of the circumstances as described above, and the purpose thereof is LWR performance, CDU performance, resolution, rectangularity of a cross-sectional shape, depth of focus, exposure margin, MEEF performance and sensitivity ( Hereinafter, the radiation-sensitive resin composition excellent in “LWR performance and the like”) is provided.

  The invention made to solve the above problems is a polymer having a structural unit containing an acid-dissociable group (hereinafter also referred to as “structural unit (I)”) (hereinafter also referred to as “[A] polymer”). And a radiation sensitive acid generator (hereinafter also referred to as “[B] acid generator”), wherein the radiation sensitive acid generator contains a compound represented by the following formula (A): It is a resin composition.

（式（Ａ）中、Ｒ^ｘは、環員数３〜２０の２価の脂環式炭化水素基、上記脂環式炭化水素基の炭素−炭素間に−Ｏ−、−ＣＯＯ−、−ＯＣＯＯ−、−Ｓ−、−ＳＯ_２Ｏ−、−ＮＨＣＯＯ−、−ＳｉＲ^Ｓ _２−若しくはこれらの組み合わせを含む脂肪族複素環基、又は上記脂環式炭化水素基及び上記脂肪族複素環基が有する水素原子の一部若しくは全部を−ＯＨ、−ＣＮ、炭素数１〜２０の１価の炭化水素基、炭素数１〜２０の１価のオキシ炭化水素基、ハロゲン原子若しくはこれらの組み合わせで置換した基であり、Ｒ^ｔ及びＲ^ｙは、上記脂環式炭化水素基及び上記脂肪族複素環基の環構造上の同一炭素原子に結合するか又は互いに隣接する２つの炭素原子にそれぞれ結合している。Ｒ^Ｓは、水素原子、炭素数１〜２０の１価の炭化水素基又は炭素数１〜２０の１価のオキシ炭化水素基である。Ｒ^ｔは、炭素原子である。Ｒ^ｙは、炭素数１〜３０の１価の有機基である。ｋは、１〜３の整数である。ｋが２以上の場合、複数のＲ^ｘは同一でも異なっていてもよく、複数のＲ^ｙは同一でも異なっていてもよい。Ｒ^Ｆ１、Ｒ^Ｆ２及びＲ^Ｆ３は、それぞれ独立して、水素原子、フッ素原子、炭素数１〜２０のアルキル基又は炭素数１〜２０のフッ素化アルキル基である。ｉは、０〜９の整数である。但し、ｉが０の場合、ｋは１又は２である。ｉが２以上の場合、複数のＲ^Ｆ１は同一でも異なっていてもよく、複数のＲ^Ｆ２は同一でも異なっていてもよい。Ｒ^Ｆ３が複数の場合、複数のＲ^Ｆ３は同一でも異なっていてもよい。但し、１若しくは複数のＲ^Ｆ１、１若しくは複数のＲ^Ｆ２及び１若しくは複数のＲ^Ｆ３のうちの少なくともいずれかはフッ素原子又はパーフルオロアルキル基である。Ｍ^＋は、１価の感放射線性オニウムカチオンである。）

(In the formula (A), R ^x represents a divalent alicyclic hydrocarbon group having 3 to 20 ring members, and —O—, —COO—, and —OCOO between the carbon and carbon of the alicyclic hydrocarbon group. _{-, - S -, - SO} 2 O -, - NHCOO -, - SiR S 2 - or aliphatic heterocyclic group, or an alicyclic hydrocarbon group and the aliphatic heterocyclic group having a combination thereof Some or all of the hydrogen atoms are substituted with —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a combination thereof. R ^t and R ^y are bonded to the same carbon atom on the ring structure of the alicyclic hydrocarbon group and the aliphatic heterocyclic group, or bonded to two carbon atoms adjacent to each other. are .R ^S is a hydrogen atom, a monovalent hydrocarbon having 1 to 20 carbon atoms .K or a is .R ^t monovalent oxy hydrocarbon group having 1 to 20 carbon atoms, a carbon atom .R ^y is a monovalent organic group having 1 to 30 carbon atoms, 1 to 3 When k is 2 or more, the plurality of R ^x may be the same or different, and the plurality of R ^y may be the same or different.R ^F1 , R ^F2 and R ^F3 are independent of each other. A hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group having 1 to 20 carbon atoms, i is an integer of 0 to 9, provided that i is 0, k If it .i is 2 or more is 1 or 2, the plurality of R ^F1 may be the same or different, when a plurality of R ^F2 may be the same or different .R ^F3 is plural, a plurality of R ^F3 may be the same or different, provided that one or more R ^F1 , one or more And at least one of R ^F2 and one or more R ^F3 is a fluorine atom or a perfluoroalkyl group, and M ⁺ is a monovalent radiation-sensitive onium cation.)

  Another invention made in order to solve the above-mentioned problems comprises a step of forming a resist film, a step of exposing the resist film, and a step of developing the exposed resist film, It is the resist pattern formation method formed with a conductive resin composition.

  Yet another invention made to solve the above problems is a radiation-sensitive acid generator comprising the compound represented by the above formula (A).

  Yet another invention made to solve the above problems is a compound represented by the above formula (A).

  Here, the “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic structure and not containing an aromatic ring structure, and includes a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic hydrocarbon. Includes both groups. The “aliphatic heterocyclic group” refers to a group that does not include an aromatic ring structure but includes only a ring structure that includes a carbon atom and atoms other than carbon atoms as ring-constituting atoms. The “hydrocarbon group” includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The “hydrocarbon group” may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The “chain hydrocarbon group” refers to a hydrocarbon group that does not include a cyclic structure but includes only a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. “Aromatic hydrocarbon group” refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic structure. “Organic group” refers to a group containing at least one carbon atom.

  According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, while exhibiting excellent depth of focus, exposure margin, MEEF performance, and sensitivity, LWR performance, CDU performance, resolution, and rectangular shape in cross section A resist pattern having excellent properties can be formed. The radiation sensitive acid generator of this invention can be used suitably as a component of the said radiation sensitive resin composition. The compound of the present invention can be suitably used as the radiation sensitive acid generator. Therefore, these can be suitably used for manufacturing processes of semiconductor devices, for which miniaturization is expected to progress further in the future.

<Radiation sensitive resin composition>
The radiation sensitive resin composition contains a [A] polymer and a [B] acid generator. In addition, the radiation-sensitive resin composition has, as a suitable component, an acid generator other than the above [B] acid generator (hereinafter also referred to as “[B ′] other acid generator”), [D]. It may contain a nitrogen atom-containing compound (hereinafter also referred to as “[D] compound”), [E] fluorine atom-containing polymer and [F] solvent, and within the range not impairing the effects of the present invention. An optional component may be contained. Hereinafter, each component will be described.

<[A] polymer>
[A] The polymer is a polymer having the structural unit (I). According to the radiation-sensitive resin composition, the acid-dissociable group of the [A] polymer in the exposed portion is dissociated by the acid generated from the [B] acid generator or the like upon irradiation with radiation, so that the exposed portion and the unexposed portion are exposed. And a difference in solubility in the developer occurs, and as a result, a resist pattern can be formed. The “acid-dissociable group” refers to a group that replaces a hydrogen atom such as a carboxy group or a hydroxy group and dissociates by the action of an acid. [A] The polymer is at least selected from the group consisting of a structural unit represented by the following formula (3-1) and a structural unit represented by (3-2), in addition to the structural unit (I). One type (hereinafter also referred to as “structural unit (II)”), a structural unit represented by the following formula (4) (hereinafter also referred to as “structural unit (III)”), and the structural unit (I) to You may have other structural units other than (III). [A] The polymer may have one or more of each structural unit. Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit containing an acid dissociable group. Examples of the structural unit (I) include a structural unit represented by the following formula (2-1) (hereinafter also referred to as “structural unit (I-1)”) and a structure represented by the following formula (2-2). A unit (hereinafter also referred to as “structural unit (I-2)”).

In the formula (2-1), ^{R 8} represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid dissociable group.
In said formula (2-2), R < ⁸ '> is a hydrogen atom or a methyl group. Y ² is a monovalent acid dissociable group.

R ⁸ is preferably a hydrogen atom and a methyl group, more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit (I-1).

The monovalent acid-dissociable group represented by Y ^1, preferably a group represented by the following formula (Y-1).

In the above formula (Y-1), R ^e1 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^e2 and R ^e3 are each independently a monovalent chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or these groups are An alicyclic structure having 3 to 20 ring members composed of carbon atoms bonded to each other and bonded thereto is represented.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^e1 include a chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. And an aromatic hydrocarbon group having 6 to 20 carbon atoms.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and n-butyl. Group, alkyl group such as i-butyl group, sec-butyl group, t-butyl group and n-pentyl group;
Alkenyl groups such as ethenyl group, propenyl group, butenyl group, pentenyl group;
Examples include alkynyl groups such as ethynyl group, propynyl group, butynyl group, and pentynyl group.
Among these, an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is preferable, a methyl group, an ethyl group, and an i-propyl group are more preferable, and an ethyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. A monocyclic cycloalkyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group;
A monocyclic cycloalkenyl group such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group;
And polycyclic cycloalkenyl groups such as a norbornenyl group and a tricyclodecenyl group.
Among these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are more preferable.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R ^e1 include phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group, methylnaphthyl group, anthryl group, and methylanthryl. Aryl groups such as groups;
Examples include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, and anthrylmethyl group.

Examples of the alicyclic structure having 3 to 20 ring members constituted by carbon atoms to which R ^e2 and R ^e3 are combined and bonded to each other include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cyclooctane structure, etc. A monocyclic cycloalkane structure of
Polycyclic cycloalkane structures such as norbornane structure, adamantane structure, tricyclodecane structure and tetracyclododecane structure;
Monocyclic cycloalkene structures such as cyclopropene structure, cyclobutene structure, cyclopentene structure, cyclohexene structure, cyclooctene structure;
Examples thereof include polycyclic cycloalkene structures such as a norbornene structure, a tricyclodecene structure, and a tetracyclododecene structure.
Among these, a monocyclic cycloalkane structure and a polycyclic cycloalkane structure are preferable, a monocyclic cycloalkane structure having 5 to 8 carbon atoms and a polycyclic cycloalkane structure having 7 to 12 carbon atoms are more preferable, A cyclopentane structure, a cyclohexane structure, a cyclooctane structure, a norbornane structure and an adamantane structure are more preferred, and a cyclopentane structure and an adamantane structure are particularly preferred.

The group represented by the formula (Y-1) is a carbon in which R ^e1 is a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, and R ^e2 and R ^e3 are combined with each other. An alicyclic structure having 3 to 20 ring members constituted with atoms, R ^e1 is a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and R ^e2 and R ^e3 are 1 to C 1 carbon atoms. 10 is preferably a monovalent chain hydrocarbon group, R ^e1 is an alkyl group having 1 to 10 carbon atoms, and R ^e2 and R ^e3 are combined with each other and configured with a carbon atom to which they are bonded. More preferably, it represents a cycloalkane structure having 3 to 20 ring members, R ^e1 is a cycloalkyl group having 3 to 20 carbon atoms, and R ^e2 and R ^e3 are alkyl groups having 1 to 10 carbon atoms, R ^e1 is an alkyl group having 1 to 4 carbon atoms. And represents a monocyclic cycloalkane structure having 5 to 8 ring members or a polycyclic cycloalkane structure having 7 to 12 ring members, which is composed of carbon atoms to which R ^e2 and R ^e3 are combined with each other. More preferable are 1-ethyl-1-cyclopentyl group, 2-ethyl-2-adamantyl group, 2-methyl-2-adamantyl group and 2-adamantyl-2-propyl group.

R ⁸ ′ is preferably a hydrogen atom from the viewpoint of the copolymerizability of the monomer giving the structural unit (I-2).

The monovalent acid-dissociable group represented by Y ^2, preferably a group represented by the following formula (Y-2).

In the above formula (Y-2), R ^e4 , R ^e5 and R ^e6 are each independently a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, or a monovalent group having 3 to 20 carbon atoms. These are alicyclic hydrocarbon groups, oxy-chain hydrocarbon groups having 1 to 20 carbon atoms, or oxyalicyclic hydrocarbon groups having 3 to 20 carbon atoms. However, R ^e4 , R ^e5 and R ^e6 are not simultaneously hydrogen atoms.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include groups similar to those exemplified as R ^e1 , R ^e2 and R ^e3. Can be mentioned.
Among these, an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is preferable, a methyl group, an ethyl group, and an n-propyl group are more preferable, and a methyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include the same groups as those exemplified as R ^e1 , R ^e2 and R ^e3. Is mentioned.
Among these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are more preferable.

Examples of the monovalent oxy-chain hydrocarbon group having 1 to 20 carbon atoms represented by the above R ^e4 , R ^e5 and R ^e6 include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n- Alkoxy groups such as butoxy, i-butoxy, sec-butoxy, t-butoxy and n-pentyloxy;
Alkenyloxy groups such as ethenyloxy group, propenyloxy group, butenyloxy group, pentenyloxy group;
Examples include alkynyloxy groups such as ethynyloxy group, propynyloxy group, butynyloxy group, and pentynyloxy group.
Among these, an alkoxy group is preferable, an alkoxy group having 1 to 4 carbon atoms is preferable, and a methoxy group, an ethoxy group, and an n-propoxy group are more preferable.

Examples of the monovalent oxyalicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include, for example, a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, and a cyclohexyloxy group. A monocyclic cycloalkyloxy group such as cyclooctyloxy group;
A polycyclic cycloalkyloxy group such as a norbornyloxy group, an adamantyloxy group, a tricyclodecyloxy group, a tetracyclododecyloxy group;
A monocyclic cycloalkenyloxy group such as a cyclopropenyloxy group, a cyclobutenyloxy group, a cyclopentenyloxy group, a cyclohexenyloxy group;
Examples thereof include polycyclic cycloalkenyloxy groups such as norbornenyloxy group and tricyclodecenyloxy group.
Among these, a monocyclic cycloalkyloxy group and a polycyclic cycloalkyloxy group are preferable, and a cyclopentyloxy group, a cyclohexyloxy group, a norbornyloxy group, and an adamantyloxy group are more preferable.

Examples of the group represented by the formula (Y-2) include a group in which R ^e4 , R ^e5 and R ^e6 are monovalent chain hydrocarbon groups, and R ^e4 and R ^e5 are monovalent chain hydrocarbon groups. And R ^e6 is a monovalent oxy chain hydrocarbon group, R ^e4 is a monovalent chain hydrocarbon group, and R ^e5 and R ^e6 are monovalent oxy chain hydrocarbon groups, A group in which R ^e4 , R ^e5 and R ^e6 are alkyl groups, a group in which R ^e4 and R ^e5 are alkyl groups and R ^e6 is an alkoxy group, and a group in which R ^e4 is an alkyl group and R ^e5 and R ^e6 are alkoxy groups ^Are more preferable, and groups in which R ^e4 , R ^e5 and R ^e6 are alkyl groups are more preferable, and a t-butyl group, a t-pentyl group, a t-hexyl group, and a t-heptyl group are particularly preferable.

Examples of the structural unit (I) include structural units represented by the following formulas (2-1-1) to (2-1-8) as the structural unit (I-1);
Examples of the structural unit (I-2) include structural units represented by the following formulas (2-2-1) to (2-2-3).

In the above formulas (2-1-1) to (2-1-8), R ⁸ has the same meaning as the above formula (2-1). R ^e1 , R ^e2 and R ^e3 have the same ^{meaning as} in the above formula (Y-1). j is an integer of 1 to 3 independently.
In the above formulas (2-2-1) to (2-2-3), R ⁸ ′ has the same meaning as the above formula (2-2).

  As the structural unit (I), the structural unit (I-1) is preferable, and the above formulas (2-1-2), (2-1-3), (2-1-5) and (2-1-6) are preferable. ) Is more preferred, a group containing a cyclopentane structure and a group containing an adamantane structure are more preferred, and a structural unit derived from 1-ethyl-1-cyclopentyl (meth) acrylate, 2-ethyl-2- Particularly preferred are structural units derived from adamantyl (meth) acrylate, structural units derived from 2-methyl-2-adamantyl (meth) acrylate, and structural units derived from 2-adamantyl-2-propyl (meth) acrylate.

  As a minimum of the content rate of structural unit (I), 10 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 20 mol% is more preferable, 25 mol% is further more preferable, 30 mol% % Is particularly preferred. Moreover, as an upper limit of the said content rate, 90 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 70 mol% is more preferable, and 60 mol% is further more preferable. By making the content rate of structural unit (I) into the said range, the LWR performance of the said radiation sensitive resin composition etc. can be improved more.

[Structural unit (II)]
The structural unit (II) includes a structural unit represented by the following formula (3-1) (hereinafter also referred to as “structural unit (II-1)”) and a structural unit represented by the following formula (3-2) ( Hereinafter, it is at least one selected from the group consisting of “structural unit (II-2)”. When the [A] polymer has the structural unit (II), the [B] acid generator can improve the dispersibility in the [A] polymer. As a result, the radiation sensitive resin composition can further improve the LWR performance and the like. Moreover, the adhesiveness to the board | substrate of the resist pattern formed from the said radiation sensitive resin composition can be improved.

In the formula ^{(3-1), R 14} is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. E ¹ is a single bond, —CO—O—, —CO—NH—, or —CO—O— (CH ₂ ) _i —CO—O—. i is an integer of 1-6. R ¹⁵ is a non-acid dissociable group containing a polar group.
In said formula (3-2), R < ¹⁴ '> is a hydrogen atom or a methyl group. R ^a and R ^b are each independently a hydrogen atom, a fluorine atom, a hydroxy group, or a monovalent organic group. u is an integer of 1 to 3. When u is 2 or more, the plurality of R ^a may be the same or different, and the plurality of R ^b may be the same or different. R ^15a and R ^15b are each independently a hydrogen atom, a fluorine atom, a hydroxy group, or a monovalent organic group.

In the structural unit (II-1),
R ¹⁴ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of the copolymerizability of the monomer that gives the structural unit (II-1).

E ¹ is preferably —CO—O— from the viewpoint of the copolymerizability of the monomer that gives the structural unit (II-1).

Examples of the polar group in the non-acid dissociable group represented by R ¹⁵ and containing a polar group include monovalent groups such as a hydroxy group, a carboxy group, a cyano group, a sulfo group, a mercapto group, and an amino group (a ); A carbonyl group, —O—, —S—, —NR′—a divalent group (b) formed by combining these, and the like. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms.

Examples of the group containing a non-acid dissociable and polar group represented by R ¹⁵ include, for example, a part or all of the hydrogen atoms contained in a monovalent hydrocarbon group having 1 to 20 carbon atoms as the monovalent group (a ), A group containing the above divalent group (b) between some or all of the carbon-carbons of the monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent group having 1 to 20 carbon atoms. Examples include a group in which part or all of the hydrogen atoms of the hydrocarbon group are substituted with the monovalent group (a) and the divalent group (b) is contained between some or all of the carbon-carbons. It is done.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and the number of carbon atoms. Examples thereof include 6-20 monovalent aromatic hydrocarbon groups.
Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include groups similar to those exemplified as R ^e1 , R ^e2 and R ^e3 in the above formula (Y-1).
Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include the same groups as those exemplified as R ^e1 , R ^e2 and R ^e3 in the above formula (Y-1).
Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include the same groups as those exemplified as R ^e1 in the above formula (Y-1).

Examples of R ¹⁵ include a group having a lactone structure, a group having a cyclic carbonate structure, a group having a sultone structure, and a group having a hydroxy group.

Examples of the group having a lactone structure include a butyrolactone-yl group, a norbornanelactone-yl group, and a 5-oxo-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-yl group. .
Examples of the group having a cyclic carbonate structure include an ethylene carbonate-ylmethyl group.
Examples of the group having a sultone structure include groups having a sultone structure such as a propane sultone-yl group and a norbornane sultone-yl group.
Examples of the group having a hydroxy group include a hydroxyadamantyl group, a dihydroxyadamantyl group, a trihydroxyadamantyl group, and a hydroxyethyl group.

In the structural unit (II-2),
As R ¹⁴ ′, a hydrogen atom is preferable from the viewpoint of the copolymerizability of the monomer giving the structural unit (II-2).

Examples of the monovalent organic group represented by R ^a , R ^b , R ^15a and R ^15b include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and monovalent fat having 3 to 20 carbon atoms. A cyclic hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a group in which part or all of the hydrogen atoms of these groups are substituted with a substituent, and between these carbon-carbon groups. , —CO—, —CS—, —O—, —S—, or —NR ″ — or a group containing a combination of two or more thereof. R ″ represents a hydrogen atom or a monovalent group. Is an organic group.

  u is preferably 1 or 2, and more preferably 1.

Examples of the structural unit (II) include structural units represented by the following formulas (3-1-1) to (3-1-14) as the structural unit (II-1);
Examples of the structural unit (II-2) include a structural unit represented by the following formula (3-2-1), a structural unit represented by (3-2-2), and the like.

In the formulas (3-1-1) to (3-1-14), R ¹⁴ has the same meaning as the formula (3-1).
In the above formulas (3-2-1) and (3-2-2), R ¹⁴ ′ has the same meaning as in the above formula (3-2).

  Among these, structural units represented by the above formulas (3-1-1), (3-1-3), (3-1-5) and (3-1-12) are preferable.

  [A] When the polymer contains the structural unit (II), the lower limit of the content ratio of the structural unit (II) is 0.5 mol% with respect to all the structural units constituting the [A] polymer. Preferably, 1 mol% is more preferable, 20 mol% is further more preferable, and 35 mol% is especially preferable. Moreover, as an upper limit of the said content rate, 90 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 80 mol% is more preferable, and 70 mol% is further more preferable. By making the content rate of structural unit (II) into the said range, the dispersibility in the [A] polymer of an [B] acid generator improves more, As a result, the LWR performance of the said radiation sensitive resin composition Etc. can be further improved.

[Structural unit (III)]
The structural unit (III) is a structural unit represented by the following formula (4). When KrF excimer laser light, EUV, electron beam, or the like is used as the radiation to be irradiated, the radiation sensitive resin composition increases the sensitivity because the polymer [A] has the structural unit (III). Can do.

In the formula ^{(4), R 15} is hydrogen atom or a methyl group. R ¹⁶ is a monovalent organic group having 1 to 20 carbon atoms. v is an integer of 0-3. If R ¹⁶ is plural, plural R ⁸ may be the same or different. w is an integer of 1 to 3. However, v + w is 5 or less.

R ¹⁵ is preferably a hydrogen atom from the viewpoint of the copolymerizability of the monomer giving the structural unit (III).

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹⁶ include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic carbon group having 3 to 20 carbon atoms. A hydrogen group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a group in which part or all of the hydrogen atoms of these groups are substituted with a substituent, and carbon-carbon between these groups -, -CS-, -O-, -S- or -NR "-or a group containing a combination of two or more of these. R" is a hydrogen atom or a monovalent organic group. It is. Among these, a monovalent chain hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is more preferable.

  v is preferably an integer of 0 to 2, more preferably 0 and 1, and still more preferably 0.

  As w, 1 and 2 are preferable and 1 is more preferable.

  Examples of the structural unit (III) include structural units represented by the following formulas (4-1) to (4-4).

In the above formulas (4-1) to (4-4), R ¹⁵ has the same meaning as the above formula (4).

  Among these, the structural unit represented by the above formula (4-1) and the structural unit represented by (4-2) are preferable, and the structural unit represented by the above formula (4-1) is more preferable.

  [A] When the polymer contains the structural unit (III), the lower limit of the proportion of the structural unit (III) is preferably 1 mol% with respect to all the structural units constituting the [A] polymer, 10 mol% is more preferable, 30 mol% is further more preferable, and 50 mol% is especially preferable. Moreover, as an upper limit of the said content rate, 90 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 80 mol% is more preferable, and 75 mol% is further more preferable. By making the content rate of structural unit (III) into the said range, the said radiation sensitive resin composition can improve a sensitivity more.

  The structural unit (III) is obtained by polymerizing a monomer obtained by substituting the hydrogen atom of the —OH group of hydroxystyrene with an acetyl group, and then subjecting the obtained polymer to a hydrolysis reaction in the presence of an amine. Or the like.

[Other structural units]
[A] The polymer may have other structural units other than the structural units (I) to (III). Examples of the other structural unit include a structural unit derived from a (meth) acrylic acid ester containing a non-dissociable monovalent alicyclic hydrocarbon group. As a content rate of another structural unit, 20 mol% or less is preferable with respect to all the structural units which comprise a [A] polymer, and 10 mol% or less is more preferable.

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized according to a conventional method such as radical polymerization. For example, (1) a method in which a solution containing a monomer and a radical initiator is dropped into a reaction solvent or a solution containing a monomer to cause a polymerization reaction, (2) a solution containing the monomer and a radical initiator A method in which a polymerization reaction is carried out by dropping each of the contained solutions into a reaction solvent or a monomer-containing solution, and (3) a plurality of types of solutions containing each monomer and a solution containing a radical initiator, A method in which a polymerization reaction is carried out by dropping each of the compounds in a solution containing a reaction solvent or a monomer, (4) a method in which a solution containing a monomer and a radical initiator is polymerized in a solvent-free or reaction solvent, etc. It is preferable to synthesize.

  In addition, when the monomer solution is dropped and reacted with respect to the monomer solution, the monomer amount in the dropped monomer solution is 30 mol with respect to the total amount of monomers used for polymerization. % Or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more.

  What is necessary is just to determine the reaction temperature in these methods suitably with initiator seed | species. As a minimum of reaction temperature, 30 ° C is preferred, 40 ° C is more preferred, and 50 ° C is still more preferred. Moreover, as an upper limit of reaction temperature, 150 degreeC is preferable and 140 degreeC is more preferable. The dropping time varies depending on the reaction temperature, the type of initiator, the monomer to be reacted, and the like. As a minimum of dropping time, 30 minutes are preferred, 45 minutes are more preferred, and 1 hour is still more preferred. Moreover, as an upper limit of dripping time, 8 hours are preferable, 6 hours are more preferable, and 5 hours are further more preferable. Furthermore, the total reaction time including the dropping time also varies depending on the conditions as well as the dropping time. As a minimum of total reaction time, 30 minutes are preferred, 45 minutes are more preferred, and 1 hour is still more preferred. Further, the upper limit of the total reaction time is preferably 12 hours, more preferably 10 hours.

Examples of the radical initiator used in the polymerization include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis ( 2-cyclopropylpropionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate), dimethyl 2,2′-azobisiso Azo radical initiators such as butyrate;
And peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and the like. Of these, AIBN and dimethyl 2,2′-azobis (2-methylpropionate) are preferred. In addition, you may use a radical initiator individually or in combination of 2 or more types.

  As a reaction solvent, any solvent other than a solvent that inhibits polymerization (nitrobenzene having a polymerization inhibiting effect, mercapto compound having a chain transfer effect, etc.) and capable of dissolving the monomer may be used. it can. Examples thereof include alcohols, ethers, ketones, amides, esters / lactones, nitriles, and mixed solvents thereof. These solvents may be used alone or in combination of two or more.

  The polymer obtained by the polymerization reaction is preferably recovered by a reprecipitation method. That is, after the polymerization reaction is completed, the polymer is recovered as a powder by introducing the polymerization solution into a reprecipitation solvent. As the reprecipitation solvent, alcohols or alkanes may be used alone or in combination of two or more. In addition to the reprecipitation method, the polymer 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 lower limit of the weight average molecular weight (Mw) in terms of polystyrene by GPC (Gel Permeation Chromatography) of the polymer is preferably 1,000, more preferably 2,000, still more preferably 3,000, and 5,000 Particularly preferred. Moreover, as an upper limit of the said polystyrene conversion weight average molecular weight (Mw), 50,000 are preferable, 40,000 are more preferable, 30,000 is further more preferable, 20,000 is especially preferable. [A] If the Mw of the polymer is less than the lower limit, the heat resistance of the resist pattern formed from the radiation-sensitive resin composition may be reduced. [A] If the Mw of the polymer exceeds the above upper limit, the developability of the radiation-sensitive resin composition may be deteriorated.

  [A] The lower limit of the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer (Mw / Mn, dispersity) is preferably 1. The upper limit of the Mw ratio (Mw / Mn, degree of dispersion) is preferably 5, more preferably 3, and even more preferably 2.5.

  [A] The lower limit of the content of the polymer is preferably 70% by mass, more preferably 80% by mass, and still more preferably 85% by mass with respect to the total solid content in the radiation-sensitive resin composition.

<[B] Acid generator>
[B] The acid generator includes a compound represented by the following formula (A) (hereinafter also referred to as “compound (A)”). The said radiation sensitive resin composition is excellent in LWR performance etc. by containing a [B] acid generator with a [A] polymer.

In the above formula (A), R ^x is a divalent alicyclic hydrocarbon group having 3 to 20 ring members, and —O—, —COO—, and —OCOO between the carbon and carbon of the alicyclic hydrocarbon group. _{-, - S -, - SO} 2 O -, - NHCOO -, - SiR S 2 - or aliphatic heterocyclic group, or an alicyclic hydrocarbon group and the aliphatic heterocyclic group having a combination thereof Some or all of the hydrogen atoms are substituted with —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a combination thereof. R ^t and R ^y are bonded to the same carbon atom on the ring structure of the alicyclic hydrocarbon group and the aliphatic heterocyclic group, or bonded to two carbon atoms adjacent to each other. Yes. R ^S is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms. R ^t is a carbon atom. R ^y is a monovalent organic group having 1 to 30 carbon atoms. k is an integer of 1 to 3. When k is 2 or more, the plurality of R ^x may be the same or different, and the plurality of R ^y may be the same or different. R ^F1 , R ^F2 and R ^F3 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group having 1 to 20 carbon atoms. i is an integer of 0-9. However, when i is 0, k is 1 or 2. When i is 2 or more, the plurality of R ^F1 may be the same or different, and the plurality of R ^F2 may be the same or different. If R ^F3 is plural, the plurality of R ^F3 may be the same or different. However, at least one of one or more R ^F1 , one or more R ^F2 and one or more R ^F3 is a fluorine atom or a perfluoroalkyl group. M ⁺ is a monovalent radiation-sensitive onium cation.

In the compound (A), the anion —SO ₃ ^— is changed to SO ₃ H in the exposed portion to generate sulfonic acid. The radiation sensitive resin composition is an acid generator that generates an acid stronger than the acid generated by the compound (A) in addition to, for example, the [B] acid generator (for example, [B′1] other acid generator described later, etc.) In the unexposed area, the [B] acid generator functions as a trap for the acid generated from the acid generator. The radiation-sensitive resin composition generates an acid generator that generates a weaker acid than the acid generated by the compound (A) in addition to, for example, the [B] acid generator (for example, [B′2] other acid generator described later, etc.) In the exposed area, the [B] acid generator functions as a substance that generates an acid that acts to dissociate the acid-dissociable group of the [A] polymer by irradiation with radiation. Demonstrate.

The reason why the radiation-sensitive resin composition exhibits the above-described effect by including the [B] acid generator is not necessarily clear, but can be inferred as follows, for example. That is, since the [B] acid generator does not contain a polar group such as a carbonyl group between SO ₃ ⁻ and the bulky alicyclic structure, it has a rigid structure. Excellent resistance. Therefore, the [B] acid generator has moderate rigidity and moderate bulk, and as a result, the diffusion of acid generated from the [B] acid generator is moderately shortened. Furthermore, since the [B] acid generator has the above structure, it is excellent in transparency and sensitivity. As a result, the LWR performance and the like of the radiation sensitive resin composition can be improved.

Examples of the divalent alicyclic hydrocarbon group having 3 to 20 ring members represented by R ^x include monocyclic cycloalkanes such as cyclopentane-1,1-diyl group and cyclohexane-1,1-diyl group. -1,1-diyl group;
Monocyclic cycloalkene-1,1-diyl groups such as cyclopentene-1,1-diyl group, cyclohexene-1,1-diyl group;
Polycyclic cycloalkane-1,1-diyl groups such as norbornane-1,1-diyl group and tricyclodecane-1,1-diyl group;
A polycyclic cycloalkene-1,1-diyl group such as a norbornene-1,1-diyl group;
Monocyclic cycloalkane-1,2-diyl groups such as cyclopentane-1,2-diyl group and cyclohexane-1,2-diyl group;
Monocyclic cycloalkene-1,2-diyl groups such as cyclopentene-1,2-diyl group, cyclohexene-1,2-diyl group;
A polycyclic cycloalkane-1,2-diyl group such as a norbornane-1,2-diyl group and a tricyclodecane-1,2-diyl group;
And polycyclic cycloalkene-1,2-diyl groups such as norbornene-1,2-diyl group.

The alicyclic hydrocarbon group represented by R ^x is preferably a monocyclic cycloalkanediyl group, a monocyclic cycloalkenediyl group, a polycyclic cycloalkanediyl group or a polycyclic cycloalkenediyl group, and a cyclopentanediyl group. , Cyclohexanediyl group, cyclohexenediyl group, norbornanediyl group and norbornenediyl group are more preferable, and cyclopentanediyl group, cyclohexanediyl group, norbornanediyl group and norbornenediyl group are more preferable.

The carbon of the alicyclic hydrocarbon group represented by ^{R x} - -O between carbon -, - COO -, - OCOO -, - S -, - SO 2 O -, - NHCOO -, - SiR S 2 - Or as an aliphatic heterocyclic group containing these combinations, for example, cyclic ether structures such as an oxacyclohexane structure;
Lactone structures such as butyrolactone structure, valerolactone structure, cyclohexanelactone structure, norbornane lactone structure;
Cyclic carbonate structures such as ethylene carbonate structures;
Cyclic ketone structures such as oxocyclohexane structures;
Cyclic sulfide structures such as thiacyclohexane structures;
Sultone structures such as norbornane sultone structures;
Cyclic urethane structures such as oxazolidinone structures;
And a group containing a cyclic silyl structure such as a cyclic siloxane structure.

The aliphatic heterocyclic group represented by R ^x is preferably a group containing a cyclic ether structure, a lactone structure, a cyclic carbonate structure and a sultone structure, and includes an oxacyclohexane structure, an oxanorbornane structure, a butyrolactone structure, a norbornanelactone structure, ethylene A group containing a carbonate structure, a thianorbornane structure and a norbornane sultone structure is more preferred, and a group containing an oxacyclohexane structure, an oxanorbornane structure, a butyrolactone structure and a thianorbornane structure is more preferred.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group represented by R ^x include, for example, 1 carbon atom. -20 linear or branched chain hydrocarbon group, C3-C20 alicyclic hydrocarbon group, C6-C20 aromatic hydrocarbon group, etc. are mentioned.

  Examples of the chain hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a pentyl group; an alkenyl group such as an ethenyl group, a propenyl group, a butenyl group and a pentenyl group; an ethynyl group and a propynyl group Alkynyl groups such as butynyl group and pentynyl group.

  Examples of the alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group; and a wide variety such as a norbornyl group, an adamantyl group, a tricyclodecyl group, and a tetracyclododecyl group. Ring cycloalkyl groups; monocyclic cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl; polycyclic cycloalkenyl groups such as norbornenyl and tricyclodecenyl .

  Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group and anthryl group; aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group and anthrylmethyl group. It is done.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group represented by R ^x include, for example, a methoxy group Primary or secondary alkoxy groups such as ethoxy group, n-propoxy group, i-propoxy group and n-butoxy group; cycloalkyloxy groups such as cyclopentyloxy group and cyclohexyloxy group; phenoxy group and benzyloxy group And oxyaromatic hydrocarbon groups.

Examples of the halogen atom that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by R ^x include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. It is done.

Examples of the group that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by R ^x include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. And an cycloalkyl group such as a cyclopentyl group and a cyclohexyl group are preferred. Among these, a cyclohexyl group and a methyl group are more preferable.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^S include the same groups as the monovalent hydrocarbon group having 1 to 20 carbon atoms exemplified as the substituent in R ^x . Can be mentioned.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms represented by ^RS include the same groups as the monovalent hydrocarbon group having 1 to 20 carbon atoms exemplified as the substituent in ^Rx, and the like. Is mentioned.

R ^t is a carbon atom bonded to the carbon atom to which R ^x , R ^F3 and R ^F1 and R ^F2 are bonded. When k is 3, it is bonded to the carbon atom to which R ^x and R ^F1 and R ^F2 are bonded. Carbon atom.

Examples of the monovalent organic group having 1 to 30 carbon atoms represented by R ^y include, for example, a monovalent hydrocarbon group having 1 to 30 carbon atoms, a carbon-carbon boundary of this hydrocarbon group, or a terminal on the bond side. And a group (g) containing a divalent heteroatom-containing group, a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group and group (g) with a monovalent heteroatom-containing group, and the like.

  Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms include a linear or branched chain hydrocarbon group having 1 to 30 carbon atoms and an alicyclic hydrocarbon group having 3 to 30 carbon atoms. And an aromatic hydrocarbon group having 6 to 30 carbon atoms.

As said ^Ry , a C1-C30 linear or branched chain hydrocarbon group and a C3-C30 alicyclic hydrocarbon group are preferable.

  Examples of the hetero atom contained in the monovalent and divalent heteroatom-containing group include an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, and a phosphorus atom. In these, an oxygen atom, a sulfur atom, and a nitrogen atom are preferable, and an oxygen atom is more preferable.

  Examples of the divalent heteroatom-containing group include —O—, —CO—, —CS—, —NR′—, and a combination thereof. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms.

  Examples of the monovalent heteroatom-containing group include a hydroxy group, a carboxy group, a sulfanyl group (—SH), an amino group, and a cyano group.

R ^y is preferably a group (g), more preferably —O—, —CO—, —NR′— or a combination thereof as a heteroatom, —O—, —CO— or a combination thereof. Is more preferable.

  As k, 1 and 2 are preferable.

As a C1-C20 alkyl group represented by said R ^<F1> , R ^<F2> and R ^<F3 >, a methyl group, an ethyl group, a propyl group, a butyl group etc. are mentioned, for example.

As a C1-C20 fluorinated alkyl group represented by said R ^<F1> , R ^<F2> and R ^<F3 >, a trifluoromethyl group, a trifluoroethyl group etc. are mentioned, for example.

  Among these, a hydrogen atom, a fluorine atom, a methyl group and a trifluoromethyl group are preferable, and a hydrogen atom, a trifluoromethyl group and a fluorine atom are more preferable.

It is preferable that at least one of R ^F1, R ^F2 and R ^F3 is attached to a carbon atom adjacent is a fluorine atom or a perfluoroalkyl group, SO ₃ ^{- -} SO ₃ binds to a carbon atom adjacent to the More preferably, both R ^F1 and R ^F2 or a plurality of R ^F3 are a fluorine atom or a perfluoroalkyl group, and both R ^F1 and R ^F2 or a plurality of R ^F3 bonded to a carbon atom adjacent to SO ₃ ^- are used. Is more preferably a fluorine atom.

  i is preferably an integer of 0 to 4, more preferably 0 to 2, and still more preferably 0 and 1.

The monovalent radiation-sensitive onium cation represented by M ⁺ is a cation that is decomposed by the action of radiation. In the exposed portion, sulfonic acid is generated from protons generated by the decomposition of the radiation-sensitive onium cation and the sulfonate anion of the compound (A). For example, examples of the monovalent radiation-sensitive onium cation represented by M ⁺ include elements such as S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, Te, and Bi. And radiation sensitive onium cations. Examples of the cation containing S (sulfur) as an element include a sulfonium cation and a tetrahydrothiophenium cation. Examples of the cation containing I (iodine) as an element include an iodonium cation. Among these, a sulfonium cation represented by the following formula (X-1) and an iodonium cation represented by the following formula (X-2) are preferable, and a sulfonium cation represented by the following formula (X-1) is more preferable. preferable.

In the above formula (X-1), R ⁹ , R ¹⁰ and R ¹¹ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted ring. monovalent aromatic hydrocarbon group Number 6 to 12, -OSO ₂ -R ^a or _-SO 2 -R ^B or where the ring structure formed by two or more binding of these groups Represent. R ^A and R ^B are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted monovalent alicyclic group having 5 to 25 ring members. It is a hydrocarbon group or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 12 ring members. p, q, and r are each independently an integer of 0-5. When there are a plurality of R ^{9 to} R ¹¹ , R ^A and R ^B , the plurality of R ⁹ may be the same or different, the plurality of R ¹⁰ may be the same or different, and the plurality of R ¹¹ may be the same The plurality of R ^A may be the same or different, and the plurality of R ^B may be the same or different.

In the formula (X-2), R ¹² and R ¹³ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted ring member having 6 to 6 members. monovalent aromatic hydrocarbon group of 12, representing the cyclic structure formed by two or more binding of either a -OSO ₂ -R ^C or _-SO 2 -R ^D, or their groups. R ^C and R ^D are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted monovalent alicyclic group having 5 to 25 ring members. It is a hydrocarbon group or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 12 ring members. s and t are each independently an integer of 0 to 5. When there are a plurality of R ¹² , R ¹³ , R ^C and R ^D , the plurality of R ¹² may be the same or different, the plurality of R ¹³ may be the same or different, and the plurality of R ^C may be the same They may be different, and the plurality of ^RDs may be the same or different.

Examples of the unsubstituted linear alkyl group represented by R ^{9 to} R ¹³ include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group.

As an unsubstituted branched alkyl group represented by said R < ⁹ > -R < ¹³ >, i-propyl group, i-butyl group, sec-butyl group, t-butyl group etc. are mentioned, for example.

Examples of the unsubstituted aromatic hydrocarbon group represented by R ^{9 to} R ¹³ include aryl groups such as phenyl group and naphthyl group; aralkyl groups such as benzyl group and phenethyl group.

  Examples of the substituent that may be substituted for the hydrogen atom of the alkyl group and aromatic hydrocarbon group include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxy group, a carboxy group, and a cyano group. Nitro group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, acyloxy group and the like. Among these, a halogen atom is preferable and a fluorine atom is more preferable.

Examples of R ^{9 to} R ¹³ include an unsubstituted linear or branched alkyl group, a fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, —OSO ₂ —R ″ and —SO ₂ —. R ″ is preferable, a fluorinated alkyl group and an unsubstituted monovalent aromatic hydrocarbon group are more preferable, and a fluorinated alkyl group is more preferable. R ″ is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

As p, q, and r in the formula (X-1), integers of 0 to 2 are preferable, 0 and 1 are more preferable, and 0 is more preferable.
As s and t in the formula (X-2), integers of 0 to 2 are preferable, 0 and 1 are more preferable, and 0 is more preferable.

  Examples of the compound (A) include the following compound (1) and compound (1 ′).

[Compound (1)]
The compound (1) is represented by the following formula (1).

In the above formula (1), R ^t , R ^y , R ^F1 , R ^F2 , R ^F3 , k, i and M ⁺ are as defined in the above formula (A). R ¹ is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, and -O-, -COO-,-between the carbon and carbon of the alicyclic hydrocarbon group. _{OCOO -, - S -, -} SO 2 O -, - NHCOO -, - SiR S 2 - or aliphatic heterocyclic group, or an alicyclic hydrocarbon group and the aliphatic heterocyclic group comprising a combination thereof A part or all of hydrogen atoms thereof are substituted with —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a combination thereof. It is a group constituting the group. R ^S is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms.

Examples of the divalent alicyclic hydrocarbon group having 3 to 20 ring members constituted by R ¹ and the carbon atom to which the group is bonded include, for example, the divalent alicyclic hydrocarbon having 3 to 20 ring members exemplified as R ^x above. Examples thereof include the same groups as the cyclic hydrocarbon group. Among these, cyclopentane-1,2-diyl group, cyclohexane-1,2-diyl group, cyclohexene-1,2-diyl group, norbornane-1,2-diyl group, tricyclodecane-1,2-diyl group And norbornene-1,2-diyl group is preferable, and cyclohexane-1,2-diyl group, norbornane-1,2-diyl group, tricyclodecane-1,2-diyl group and norbornene-1,2-diyl group are preferable. More preferred.

Carbon atoms in the alicyclic hydrocarbon group represented by ^{R 1} - -O between carbon -, - COO -, - OCOO -, - S -, - SO 2 O -, - NHCOO -, - SiR S 2 Examples of the aliphatic heterocyclic group containing-or a combination thereof include the same groups as the aliphatic heterocyclic group exemplified as R ^x above. Among these, a group containing —O—, —COO—, —S— and a combination thereof is preferable, and a group containing —O— and —S— is more preferable.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group represented by R ¹ include the R ^x Groups similar to those exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms for substituting part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by Can be mentioned. Of these, alkyl groups such as methyl group, ethyl group, propyl group, butyl group and pentyl group and cycloalkyl groups such as cyclopentyl group and cyclohexyl group are preferable. Among these, a cyclohexane group and a methyl group are more preferable.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group represented by R ¹ include, for example, R ^{The same} groups as those exemplified as the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms for substituting part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by ^x Etc.

Examples of the halogen atom that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by R ¹ include, for example, the alicyclic hydrocarbon group represented by R ^x above. And groups similar to those exemplified as the halogen atom for substituting part or all of the hydrogen atoms of the aliphatic heterocyclic group.

[Compound (1-1)]
Examples of the compound (1) include compounds represented by the following formula (1-1) (hereinafter also referred to as “compound (1-1)”).

In said formula (1-1), R ^{< t >} , R ^{< F1 >} , R ^{< F2 >} , R ^{< F3 >} , i, and M ^<+> are synonymous with said formula (1). R ^h represents a carbon atom to which this group is bonded together with a divalent alicyclic hydrocarbon group having 3 to 20 ring members or a part or all of the hydrogen atoms of the alicyclic hydrocarbon group having 1 to 20 carbon atoms. A group constituting a group substituted with a monovalent hydrocarbon group. R ² is a hydrogen atom or a monovalent organic group having 1 to 29 carbon atoms. X is —O— or —NR ³ —. R ³ is a hydrogen atom or a monovalent organic group having 1 to 29 carbon atoms. Y is a single bond or a divalent chain hydrocarbon group having 1 to 10 carbon atoms.

Compound (1-1), the ^{R y} of the compound (1) is obtained by a ^{-Y-CO-X-R 2} . By including the polar group in this way, the compound (1-1) has an appropriate polarity, and the diffusion of the acid generated from the compound can be shortened more appropriately. As a result, the LWR performance and the like of the radiation sensitive resin composition are further improved.

Examples of the divalent alicyclic hydrocarbon group having 3 to 20 ring members constituted by the R ^h and the carbon atom to which the group is bonded include, for example, the divalent alicyclic hydrocarbon having 3 to 20 ring members exemplified as the above R ^x. Examples thereof include the same groups as the cyclic hydrocarbon group. Among these, cyclopentane-1,2-diyl group, cyclohexane-1,2-diyl group, cyclohexene-1,2-diyl group, norbornane-1,2-diyl group, tricyclodecane-1,2-diyl group And norbornene-1,2-diyl group is preferable, and cyclohexane-1,2-diyl group, norbornane-1,2-diyl group, tricyclodecane-1,2-diyl group and norbornene-1,2-diyl group are preferable. More preferred.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group represented by R ^h include, for example, the alicyclic represented by R ^x above. The group similar to the group illustrated as a C1-C20 monovalent hydrocarbon group which substitutes a part or all of the hydrogen atom which a formula hydrocarbon group has is mentioned. Of these, alkyl groups such as methyl group, ethyl group, propyl group, butyl group and pentyl group and cycloalkyl groups such as cyclopentyl group and cyclohexyl group are preferable. Among these, a cyclohexyl group and a methyl group are more preferable.

Examples of the monovalent organic group having 1 to 29 carbon atoms represented by R ² and R ³ include those having 1 to 29 carbon atoms among the monovalent organic groups having 1 to 30 carbon atoms exemplified as R ^y. Etc.

Among these, R ² is preferably a monovalent chain hydrocarbon group or a monovalent alicyclic hydrocarbon group, more preferably an alkyl group, a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. Preferably, an alkyl group having 1 to 5 carbon atoms and a monocyclic cycloalkyl group having 3 to 8 carbon atoms are more preferable, a methyl group, an ethyl group, a propyl group, and a cyclohexyl group are particularly preferable, and an ethyl group is further particularly preferable.

R ³ is preferably a hydrogen atom.

  X is preferably -O-.

The divalent chain hydrocarbon group having 1 to 10 carbon atoms represented by Y is, for example, a group obtained by removing one hydrogen atom from the chain hydrocarbon group exemplified as R ² and R ³ above. And groups having 1 to 10 carbon atoms.

  Among these, a single bond, a methanediyl group, and an ethanediyl group are preferable, a single bond and a methanediyl group are more preferable, and a single bond is more preferable.

[Compounds (1-a) to (1-d)]
Examples of the compound (1-1) include a compound represented by the following formula (1-a) (hereinafter also referred to as “compound (1-a)”), a compound represented by the following formula (1-b) ( Hereinafter, also referred to as “compound (1-b)”, a compound represented by the following formula (1-c) (hereinafter also referred to as “compound (1-c)”), and represented by the following formula (1-d). (Hereinafter also referred to as “compound (1-d)”) and the like.

In the above formulas (1-a) to (1-d), R ^t , R ² , X, Y, R ^F1 , R ^F2 , R ^F3 , i and M ⁺ are as defined in the above formula (1-1). is there. R ^{4 to} R ⁷ are each independently an alkyl group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 ring members. m is an integer of 1-10. a is an integer of 0 to (2m + 2). When a is 2 or more, the plurality of R ⁴ may be the same or different. b is an integer of 0-8. When b is 2 or more, the plurality of R ⁵ may be the same or different. c is an integer of 0-8. When c is 2 or more, the plurality of R ⁶ may be the same or different. d is an integer of 0-6. When d is 2 or more, the plurality of R ⁷ may be the same or different. Each A is independently —CH ₂ —, —CH ₂ CH ₂ —, —O— or —S—.

As a C1-C10 alkyl group represented by said R < ⁴ > -R < ⁷ >, a C1-C10 thing etc. are mentioned among the groups illustrated as said R ^{< F1>} and R ^<F2>, for example. Among these, a C1-C5 alkyl group is preferable, a methyl group, an ethyl group, and a propyl group are more preferable, a methyl group and an ethyl group are further more preferable, and a methyl group is especially preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by ^R 4 to R ^7, and a monovalent alicyclic hydrocarbon group exemplified C3-20 as the ^{R e1} The same group etc. are mentioned. Among these, a cyclopentyl group and a cyclohexyl group are preferable, and a cyclohexyl group is more preferable.

  As m in said formula (1-a), the integer of 2-8 is preferable, the integer of 3-6 is more preferable, 4 and 5 are further more preferable, and 4 is especially preferable.

  As a to d in the above formulas (1-a) to (1-d), an integer of 0 to 3 is preferable, 0 to 2 is more preferable, 0 and 1 are further preferable, and 0 is particularly preferable.

As A, —CH ₂ —, —O—, and —S— are preferable.

  Examples of the compound (1-a) include compounds represented by the following formulas (1-a-1) to (1-a-8) (hereinafter referred to as “compounds (1-a-1) to (1-a)”. -8) "), and the compound (1-b) is, for example, a compound represented by the following formulas (1-b-1) to (1-b-9) (hereinafter referred to as" compound (1-b) "). -1) to (1-b-9) ”) and the compound (1-c) is, for example, a compound represented by the following formula (1-c-1) to (1-c-15) ( Hereinafter, examples of the compound (1-d-1) to (1-d-) include compounds (1-c-1) to (1-c-15)) and the compound (1-d). 5) (hereinafter also referred to as “compounds (1-d-1) to (1-d-5)”) and the like.

Formulas (1-a-1) to (1-a-8), Formulas (1-b-1) to (1-b-9), Formulas (1-c-1) to (1-c-15) ) And formulas (1-d-1) to (1-d-5), M ⁺ is a monovalent radiation-sensitive onium cation.

  Among these, compounds (1-a-1) to (1-a-5), compounds (1-b-1) to (1-b-9), compounds (1-c-1), (1 -C-3), (1-c-5) to (1-c-15) and compounds (1-d-1) to (1-d-5) are preferred, and the compound (1-a-1), The compounds (1-c-3), (1-c-5) to (1-c-15) and the compound (1-d-2) are more preferable.

[Compound (1-1-a)]
The compound (1-1) is also represented by the following formula (1-1-a) (hereinafter also referred to as “compound (1-1-a)”). Examples of the compound (1-1-a) include the following compound (1-a ′), the following compound (1-b ′), the following compound (1-c ′), and the following compound (1-d ′). Can be mentioned.

In the formula (1-1-a), M ⁺ has the same meaning as the formula (A). R ^ha represents a carbon atom to which this group is bonded together with a divalent alicyclic hydrocarbon group having 3 to 20 ring members or a part or all of the hydrogen atoms of the alicyclic hydrocarbon group having 1 to 20 carbon atoms. A group constituting a group substituted with a monovalent hydrocarbon group. R ^2a is a hydrogen atom or a monovalent organic group having 1 to 29 carbon atoms. R ^f1 and R ^f2 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or a fluorinated alkyl group having 1 to 20 carbon atoms. n is an integer of 1-10. When n is 2 or more, the plurality of R ^f1 may be the same or different, and the plurality of R ^f2 may be the same or different. However, at least one of one or more R ^f1 and one or more R ^f2 is a fluorine atom or a perfluoroalkyl group. X ′ is —O— or —NR ^3a —. R ^3a is a hydrogen atom or a monovalent organic group having 1 to 29 carbon atoms. Y ′ is a single bond or a divalent chain hydrocarbon group having 1 to 10 carbon atoms.

Examples of the divalent alicyclic hydrocarbon group having 3 to 20 ring members formed by the R ^ha and the carbon atom to which the group is bonded include, for example, two bonds exemplified as R ^x forming a ring structure. Examples thereof include groups similar to the divalent alicyclic hydrocarbon group having 3 to 20 ring members present on the adjacent carbon atom. Among these, cyclopentane-1,2-diyl group, cyclohexane-1,2-diyl group, cyclohexene-1,2-diyl group, norbornane-1,2-diyl group, tricyclodecane-1,2-diyl Group and norbornene-1,2-diyl group are preferred, cyclohexane-1,2-diyl group, norbornane-1,2-diyl group, tricyclodecane-1,2-diyl group and norbornene-1,2-diyl group Is more preferable.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group represented by R ^ha include, for example, the alicyclic represented by R ^x above. The group similar to the group illustrated as a C1-C20 monovalent hydrocarbon group which substitutes a part or all of the hydrogen atom which a formula hydrocarbon group has is mentioned. Of these, alkyl groups such as methyl group, ethyl group, propyl group, butyl group and pentyl group and cycloalkyl groups such as cyclopentyl group and cyclohexyl group are preferable. Among these, a cyclohexyl group and a methyl group are more preferable.

As C1-C29 monovalent organic group represented by said R ^<2a> and R < ^3a >, C1-C29 among C1-C30 monovalent organic groups illustrated as said ^Ry, for example. And the like. Among these, R ^2a is preferably a monovalent chain hydrocarbon group or a monovalent alicyclic hydrocarbon group, more preferably an alkyl group, a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. Preferably, an alkyl group having 1 to 5 carbon atoms and a monocyclic cycloalkyl group having 3 to 8 carbon atoms are more preferable, a methyl group, an ethyl group, a propyl group, and a cyclohexyl group are particularly preferable, and an ethyl group is further particularly preferable.

R ^3a is preferably a hydrogen atom.

  X ′ is preferably —O—.

Examples of the divalent chain hydrocarbon group having 1 to 10 carbon atoms represented by Y ′ above include carbons among groups in which one hydrogen atom is removed from the chain hydrocarbon group exemplified as R ^y above. Examples are groups of 1 to 10.

  Among these, a single bond, a methanediyl group, and an ethanediyl group are preferable, a single bond and a methanediyl group are more preferable, and a single bond is more preferable.

Examples of the alkyl group having 1 to 20 carbon atoms represented by R ^f1 and R ^f2 include the same groups as the alkyl groups exemplified as R ^F1 and R ^F2 .

Examples of the fluorinated alkyl group having 1 to 20 carbon atoms represented by R ^f1 and R ^f2 include groups similar to the fluorinated alkyl groups exemplified as R ^F1 and R ^F2 .

Among these, R ^f1 and R ^f2 are preferably a hydrogen atom, a fluorine atom, a methyl group and a trifluoromethyl group, more preferably a hydrogen atom, a trifluoromethyl group and a fluorine atom.

It is preferable that at least one of R ^f1 and R ^f2 bonded to a carbon atom adjacent to SO ₃ ^— is a fluorine atom or a perfluoroalkyl group, and R ^f1 bonded to a carbon atom adjacent to SO ₃ ^— and It is more preferable that both R ^f2 are a fluorine atom or a perfluoroalkyl group, and it is more preferable that both R ^f1 and R ^f2 bonded to the carbon atom adjacent to SO ₃ ^— are a fluorine atom.

  n is preferably an integer of 1 to 5, more preferably 1 to 3, and still more preferably 1 and 2.

[Compounds (1-a ′) to (1-d ′)]
The compound (1-a ′) is represented by the following formula (1-a ′), the compound (1-b ′) is represented by the following formula (1-b ′), and the compound (1-c ′) Is represented by the following formula (1-c ′), and the compound (1-d ′) is represented by the following formula (1-d ′).

In the above formulas (1-a ′) to (1-d ′), R ^2a , X ′, Y ′, R ^f1 , R ^f2 , n and M ⁺ are as defined in the above formula (1-1-a). is there. R ^{4a to} R ^7a are each independently an alkyl group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 ring members. m ′ is an integer of 1 to 10. a ′ is an integer of 0 to (2m ′ + 2). When a ′ is 2 or more, the plurality of R ^4a may be the same or different. b 'is an integer of 0-8. When b ′ is 2 or more, the plurality of R ^5a may be the same or different. c 'is an integer of 0-8. When c ′ is 2 or more, the plurality of R ^6a may be the same or different. d 'is an integer of 0-6. When d ′ is 2 or more, the plurality of R ^7a may be the same or different. A ′ is independently —CH ₂ —, —CH ₂ CH ₂ —, —O— or —S—.

As a C1-C10 alkyl group represented by said R < ^4a > -R < ^7a >, a C1-C10 thing etc. are mentioned among the groups illustrated as said R ^{< F1>} and R ^<F2>, for example. Among these, a C1-C5 alkyl group is preferable, a methyl group, an ethyl group, and a propyl group are more preferable, a methyl group and an ethyl group are further more preferable, and a methyl group is especially preferable.

As C3-C20 monovalent alicyclic hydrocarbon group represented by said R < ^4a > -R < ^7a >, C3-C20 monovalent alicyclic hydrocarbon group illustrated as said R ^<e1 > and The same group etc. are mentioned. Among these, a cyclopentyl group and a cyclohexyl group are preferable, and a cyclohexyl group is more preferable.

  In the above formula (1-a ′), m ′ is preferably an integer of 2 to 8, more preferably an integer of 3 to 6, further preferably 4 and 5, and particularly preferably 4.

  As a'-d 'in said formula (1-a')-(1-d '), the integer of 0-3 is preferable, 0-2 are more preferable, 0 and 1 are further more preferable, and 0 is especially preferable. .

As A ′, —CH ₂ —, —O—, and —S— are preferable.

  Examples of the compound (1-a ′) include compounds represented by the above formulas (1-a-1) to (1-a-8), and examples of the compound (1-b ′) include those represented by the formula (1- Examples of the compound represented by 1-b-1) to (1-b-9) and the compound (1-c ′) include, for example, the above formulas (1-c-1) to (1-c-15). Examples of the compound represented by the formula and the compound (1-d ′) include compounds represented by the above formulas (1-d-1) to (1-d-5).

  Among these, compounds (1-a-1) to (1-a-5), compounds (1-b-1) to (1-b-9), compounds (1-c-1), (1 -C-3), (1-c-5) to (1-c-15) and compounds (1-d-1) to (1-d-5) are preferred, and the compound (1-a-1), The compounds (1-c-3), (1-c-5) to (1-c-15) and the compound (1-d-2) are more preferable.

[Compound (1 ′)]
The compound (1 ′) is represented by the following formula (1 ′).

In the above formula (1 ′), R ^t , R ^y , R ^F1 , R ^F2 , R ^F3 , k, i and M ⁺ are as defined in the above formula (A). R ¹ ′ is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, —O—, —COO— between the carbon and carbon of the alicyclic hydrocarbon group, An aliphatic heterocyclic group containing —OCOO—, —S—, —SO ₂ O—, —NHCOO—, —SiR ^S ₂ — or a combination thereof, or the above alicyclic hydrocarbon group and the above aliphatic heterocyclic group. A part or all of the hydrogen atoms possessed by —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a combination thereof. It is a group constituting a substituted group. R ^S is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms.

Examples of the divalent alicyclic hydrocarbon group having 3 to 20 ring members formed by the above R ¹ ′ and the carbon atom to which the group is bonded include a divalent alicyclic hydrocarbon having 3 to 20 ring members exemplified as R ^x. Examples thereof include the same groups as the cyclic hydrocarbon group. Among these, cyclopentane-1,1-diyl group, cyclohexane-1,1-diyl group, cyclopentene-1,1-diyl group, cyclohexene-1,1-diyl group, norbornane-1,1-diyl group and A norbornene-1,1-diyl group is preferable, and a cyclopentane-1,1-diyl group and a cyclohexane-1,1-diyl group are more preferable.

Carbon atoms in the alicyclic hydrocarbon group represented by ^{R 1} '- -O between carbon -, - COO -, - OCOO -, - S -, - SO 2 O -, - NHCOO -, - SiR S Examples of the aliphatic heterocyclic group containing ₂ or a combination thereof include the same groups as the aliphatic heterocyclic groups exemplified as R ^x above. Among these, a group containing —O—, —COO—, —S— and a combination thereof is preferable, and a group containing —O— and —COO— is more preferable.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by R ¹ ′ include, for example, R groups similar to those exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms for substituting part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by ^x , and the like Is mentioned.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group represented by R ¹ ′ include, for example, The same groups as those exemplified as the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms for substituting part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by R ^x Groups and the like.

Examples of the halogen atom that substitutes part or all of the hydrogen atoms of the alicyclic hydrocarbon group and aliphatic heterocyclic group represented by R ¹ ′ include, for example, the alicyclic hydrocarbon represented by R ^x above. Examples thereof include the same groups as those exemplified as the halogen atom for substituting part or all of the hydrogen atoms of the group and the aliphatic heterocyclic group.

[Compound (1′-a) and Compound (1′-b)]
As the compound (1 ′), for example, a compound represented by the compound (1′-a) (hereinafter also referred to as “compound (1′-a)”) or a compound represented by the compound (1′-b) ( Hereinafter, also referred to as “compound (1′-b)”) and the like.

In the formulas (1′-a) and (1′-b), R ^t , R ¹ ′, R ^F1 , R ^F2 , R ^F3 , k, i, and M ⁺ are the same as those in the above formula (1 ′). . R ² ′ is independently a monovalent organic group having 1 to 29 carbon atoms.

Compound (1′-a) is obtained by changing R ^y of compound (1 ′) to —OCO—R ² ′, and Compound (1′-b) is obtained by changing R ^y of compound (1 ′), -O-R ² '. By including -OCO- or -O- having polarity as described above, the compound (1′-a) and the compound (1′-b) have appropriate polarity, and the diffusion of the acid generated from the compound is prevented. Can be made reasonably short. As a result, the LWR performance and the like of the radiation sensitive resin composition are further improved.

Examples of the monovalent organic group having 1 to 29 carbon atoms represented by R ² ′ include those having 1 to 29 carbon atoms among the monovalent organic groups having 1 to 30 carbon atoms exemplified as R ^y. Can be mentioned. Examples of R ² ′ include a chain hydrocarbon group having 1 to 29 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 29 carbon atoms, an aliphatic heterocyclic group, and an aromatic group having 6 to 29 carbon atoms. Is preferably a chain hydrocarbon group having 1 to 29 carbon atoms, an alicyclic hydrocarbon group having 3 to 29 carbon atoms and an alicyclic hydrocarbon group substituted with an adamantane-2,2-dioxy group Is more preferable.

  Examples of the compound (1′-a) include compounds represented by the following formulas (1′-a-1) to (1′-a-7) (hereinafter referred to as “compound (1′-a-1) — (Also referred to as (1′-a-7) ”), examples of the compound (1′-b) include compounds represented by the following formulas (1′-b-1) to (1′-b-10) ( Hereinafter, “compounds (1′-b-1) to (1′-b-10)”) and the like may be mentioned. As another example, the compound (1 ′) is, for example, a compound represented by the following formula (1′-c-1) to (1′-c-5) (hereinafter, “compound (1′-c-1)”. To (1′-c-5) ”).

The above formulas (1′-a-1) to (1′-a-7), formulas (1′-b-1) to (1′-b-10) and formulas (1′-c-1) to ( In 1′-c-5), M ⁺ is a monovalent radiation-sensitive onium cation.

  Among these, the compounds (1′-a-1) to (1′-a-4), the compounds (1′-b-1) to (1′-b-6) and the compound (1′-c— 1) to (1′-c-5) are preferable, and the compound (1′-a-1), the compound (1′-a-4), the compound (1′-b-3), and (1′-b—) are preferable. 6), compounds (1′-c-2) and (1′-c-5) are more preferred.

The compound (A) can be synthesized by a method represented by the following reaction scheme. That is,
(A) a step of reacting the following compound (ia) with an alkali metal dithionite represented by E ₂ S ₂ O ₄ to obtain a sulfinate represented by the following formula (ib),
(B) a step of reacting the sulfinate (ib) with hydrogen peroxide to obtain a sulfonate represented by the following formula (ic); and (C) the sulfonate (i- c) and an onium salt represented by M ⁺ Y ^— can be synthesized by a method for synthesizing a compound.

In the above formula scheme, R ^x represents a divalent alicyclic hydrocarbon group having 3 to 20 ring members, and —O—, —COO—, —OCOO— between carbon and carbon of the alicyclic hydrocarbon group, _{-S -, - SO 2 O -} , - NHCOO -, - SiR S 2 - or aliphatic heterocyclic group, or an alicyclic hydrocarbon group and a hydrogen atom of the above aliphatic heterocyclic group comprising a combination thereof A group in which a part or all of is substituted with —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a combination thereof. R ^t and R ^y are bonded to the same carbon atom on the ring structure of the alicyclic hydrocarbon group and the aliphatic heterocyclic group, or bonded to two carbon atoms adjacent to each other. R ^S is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms. R ^t is a carbon atom. R ^y is a monovalent organic group having 1 to 30 carbon atoms. k is an integer of 1 to 3. When k is 2 or more, the plurality of R ^x may be the same or different, and the plurality of R ^y may be the same or different. R ^F1 , R ^F2 and R ^F3 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group having 1 to 20 carbon atoms. i is an integer of 0-9. However, when i is 0, k is 1 or 2. When i is 2 or more, the plurality of R ^F1 may be the same or different, and the plurality of R ^F2 may be the same or different. If R ^F3 is plural, the plurality of R ^F3 may be the same or different. However, at least one of one or more R ^F1 , one or more R ^F2 and one or more R ^F3 is a fluorine atom or a perfluoroalkyl group. M ⁺ is a monovalent radiation-sensitive onium cation. Z is a halogen atom. E ⁺ is an alkali metal ion. Y ⁻ is a monovalent anion.

In the step (A), the compound (ia) and the alkali metal dithionite represented by E ₂ S ₂ O ₄ are reacted in an organic solvent in the presence of a base such as sodium hydrogen carbonate. Thus, the sulfinate (ib) is obtained.

  In the step (B), the sulfinate (ic) is obtained by reacting the sulfinate (ib) with hydrogen peroxide.

Subsequently, in the step (C), the compound (A) is reacted with the sulfonate (ic) and the onium salt represented by M ⁺ Y ⁻ in a solvent such as dichloromethane / water. ) Is obtained. The produced compound (A) can be isolated by purification by solvent washing, recrystallization or the like.

  [B] The lower limit of the content of the acid generator is preferably 0.2 parts by weight, more preferably 0.5 parts by weight, and even more preferably 1 part by weight with respect to 100 parts by weight of the polymer [A]. 2 parts by mass is particularly preferred. Moreover, as an upper limit of content, 30 mass parts is preferable with respect to 100 mass parts of [A] polymers, 20 mass parts is more preferable, 15 mass parts is further more preferable, and 10 mass parts is especially preferable. [B] By making content of an acid generator into the said range, the LWR performance of the said radiation sensitive resin composition etc. can be improved more. [B] The acid generator may contain an acid generator other than the compound (A). [B] As a minimum of the content rate of compound (A) in an acid generator, 50 mass% is preferred, 70 mass% is more preferred, and 90 mass% is still more preferred. Moreover, as an upper limit of the said content rate, 100 mass% is preferable. [B] The acid generators may be used alone or in combination of two or more.

<[B ′] Other acid generator>
[B ′] The other acid generator is a radiation sensitive acid generator other than the [B] acid generator. [B ′] Other acid generators include, for example, a radiation-sensitive onium cation and an anion having SO ₃ ^— and having two fluorine atoms bonded to the carbon atom adjacent to this SO ₃ ^—. compound (hereinafter, also referred to as "[B'1] other acid generator"), a radiation-sensitive onium cation, SO ₃ ^- this SO ₃ has a ^- hydrogen atom to a carbon atom adjacent to, 1 to carbon atoms A compound comprising an anion to which a 20 alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms is bonded, a compound comprising a radiation-sensitive onium cation and an anion having COO ⁻ (hereinafter referred to as “[B '2] Other acid generators ”, [B′1] other acid generators and [B′2] radiation sensitive acid generators other than other acid generators (hereinafter referred to as“ [B′3 And other acid generators ”). [B′1] According to another acid generator, the acid generated by exposure dissociates the acid dissociable group of the [A] polymer, and as a result, the solubility of the [A] polymer in the developer is increased. The resist pattern can be changed. [B′2] Other acid generators exhibit a high acid scavenging function due to the basicity of SO ₃ ^— or COO ^— in the unexposed area, but the SO generated by the proton generated in the exposed area. _{Since 3} ⁻ becomes SO ₃ H and COO ⁻ becomes COOH, and its acid trapping function is lowered, it functions as an acid diffusion control agent. [B ′] Other acid generators may be used alone or in combination of two or more.

  Examples of [B′1] other acid generators and [B′2] other acid generators include onium salt compounds such as sulfonium salts, tetrahydrothiophenium salts, and iodonium salts. [B′1] Other acid generator and [B′2] other acid generator are preferably those having a monovalent radiation-sensitive onium cation and a monovalent anion.

  [B′3] Examples of other acid generators include N-sulfonyloxyimide compounds, oxime sulfonate compounds, halogen-containing compounds, diazoketone compounds, and the like.

  [B′1] Examples of the sulfonium salts that can be used as other acid generators include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, and triphenylsulfonium perfluoro-n-octanesulfonate. Cyclohexyl 2-oxocyclohexylmethylsulfonium trifluoromethanesulfonate, dicyclohexyl 2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate, triphenylsulfonium 2- (Adamantan-1-yl) -1,1-difluoro Tan-1-sulfonate, triphenylsulfonium 4- (adamantan-1-ylcarbonyloxy) -1,1,2,2-tetrafluorobutane-1-sulfonate, triphenylsulfonium 2- (adamantan-1-ylcarbonyloxy) ) -1,1,3,3,3-pentafluoropropane-1-sulfonate, triphenylsulfonium norbornane sultone-2-yloxycarbonyldifluoromethanesulfonate, triphenylsulfonium 3- (piperidin-1-ylsulfonyl) -1 1,2,2,3,3-hexafluoropropane-1-sulfonate and the like.

  Examples of the tetrahydrothiophenium salt that can be used as the other acid generator [B′1] include 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-hydroxy-1-naphthyltetrahydrothio. Phenium nonafluoro-n-butanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (1 -Naphthylacetomethyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 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.

  [B′1] Examples of the iodonium salt that can be used as another acid generator include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, and bis. (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, etc. Can be mentioned.

  [B′1] Among these acid generators, among these, onium salt compounds are preferred, sulfonium salts are more preferred, triphenylsulfonium salts are more preferred, and triphenylsulfonium 2- (adamantan-1-ylcarbonyl). Oxy) -1,1,3,3,3-pentafluoropropane-1-sulfonate, triphenylsulfonium norbornane sultone-2-yloxycarbonyldifluoromethanesulfonate and triphenylsulfonium 3- (piperidin-1-ylsulfonyl)- 1,1,2,2,3,3-hexafluoropropane-1-sulfonate is particularly preferred.

  [B′2] Examples of the sulfonium salt that can be used as another acid generator include triphenylsulfonium salicylate, triphenylsulfonium 10-camphorsalicylate, and the like.

  [B′2] Examples of the tetrahydrothiophenium salts that can be used as other acid generators include 4-hydroxy-1-naphthyltetrahydrothiophenium salicylate and 4-hydroxy-1-naphthyltetrahydrothiophene. Nium 10-camphorsulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium salicylate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium 10-camphorsulfonate, 1- (3,5-dimethyl- 4-hydroxyphenyl) tetrahydrothiophenium salicylate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 10-camphorsulfonate, and the like.

  [B′2] Examples of the iodonium salt that can be used as other acid generators include diphenyliodonium salicylate, diphenyliodonium 10-camphorsulfonate, bis (4-t-butylphenyl) iodonium salicylate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate and the like.

  [B'2] Other acid generators are preferably onium salt compounds, more preferably sulfonium salts, more preferably triphenylsulfonium salts, and particularly preferably triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate. .

[B′3] Other acid generators include, for example, N-sulfonyloxyimide compounds such as N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyl. Examples include imide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide.

  When the radiation sensitive resin composition contains [B ′] other acid generator, from the viewpoint of sensitivity and developability of the radiation sensitive resin composition, content of [B ′] other acid generator. Is preferably 0.5 parts by weight, more preferably 1 part by weight, and still more preferably 2 parts by weight with respect to 100 parts by weight of the [A] polymer. Moreover, as an upper limit of the said content, 30 mass parts is preferable with respect to 100 mass parts of [A] polymers, 20 mass parts is more preferable, and 10 mass parts is further more preferable.

<[D] Compound>
[D] A compound is a compound containing a nitrogen atom. The [D] compound can moderately shorten the diffusion of the acid generated from the [B] acid generator and [B ′] other acid generators. The said radiation sensitive resin composition can improve LWR performance etc. more by further containing a [D] compound. [D] You may use a compound individually by 1 type or in combination of 2 or more types.

  Examples of the compound [D] include amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

  Examples of the amine compound include mono (cyclo) alkylamines such as n-pentylamine and cyclohexylamine; di (cyclo) alkylamines such as di-n-pentylamine and dicyclohexylamine; tri-n-pentylamine and tricyclohexyl. Tri (cyclo) alkylamines such as amines; substituted alkylanilines such as 2,6-dii-propylaniline and 2,6-din-propylaniline or derivatives thereof; ethylenediamine, N, N, N ′, N ′ -Tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4-aminophenyl) Lopan, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2 -(4-hydroxyphenyl) propane, 1,4-bis (1- (4-aminophenyl) -1-methylethyl) benzene, 1,3-bis (1- (4-aminophenyl) -1-methylethyl ) Benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″ N ″ -pentamethyldiethylenetriamine and the like can be mentioned.

  Examples of the amide group-containing compound include Nt-butoxycarbonyl group-containing amino compounds such as Nt-butoxycarbonyl-4-hydroxypiperidine; Nt such as Nt-amyloxycarbonyl-4-hydroxypiperidine. -Amyloxycarbonyl group-containing amino compound; formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N -Acetyl-1-adamantylamine, isocyanuric acid tris (2-hydroxyethyl) and the like.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tri-n-butylthiourea. Etc.

  Examples of the nitrogen-containing heterocyclic compound include imidazoles such as 2-phenylimidazole; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidineethanol, 3-piperidino-1,2- Propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4- And diazabicyclo [2.2.2] octane, N- (undecan-1-ylcarbonyloxyethyl) morpholine, and the like.

  Of these, nitrogen-containing heterocyclic compounds and amine compounds are preferable, and N- (undecan-1-ylcarbonyloxyethyl) morpholine, 2,6-di-propylaniline, and tri-n-pentylamine are more preferable.

  When the said radiation sensitive resin composition contains a [D] compound, as a minimum of content of a [D] compound, 0.1 mass part is preferable with respect to 100 mass parts of [A] polymers, 0 More preferably, 5 parts by mass. Moreover, as an upper limit of the said content, 30 mass parts is preferable with respect to 100 mass parts of [A] polymers, 20 mass parts is more preferable, and 10 mass parts is further more preferable. [D] By making content of a compound into the said range, the LWR performance of the said radiation sensitive resin composition etc. can be improved further.

<[E] Fluorine atom-containing polymer>
[E] A fluorine atom containing polymer is a polymer containing a fluorine atom. The radiation sensitive resin composition further contains [E] fluorine atom-containing polymer in addition to [A] polymer, so that [E] fluorine atom-containing polymer is unevenly distributed on the surface layer of the resist film to be formed. As a result, the hydrophobicity of the resist film surface can be improved. As a result, when performing immersion exposure, etc., the substance elution suppression from the resist film is excellent, and the receding contact angle between the resist film and the immersion liquid can be sufficiently increased, enabling faster scanning. Become.

  [E] The fluorine atom-containing polymer is not particularly limited, but (1) the polymer itself is insoluble in the developer and becomes alkali-soluble by the action of acid, and (2) itself is soluble in the developer. A polymer whose alkali solubility is increased by the action of an acid; (3) a polymer which is itself insoluble in a developer and becomes alkali-soluble by the action of an alkali; and (4) itself is soluble in a developer. And polymers whose alkali solubility is increased by the action of alkali.

[E] As an aspect of the fluorine atom-containing polymer, for example, a structure in which a fluorinated alkyl group is bonded to the main chain;
A structure in which a fluorinated alkyl group is bonded to the side chain;
Examples include a structure in which a fluorinated alkyl group is bonded to the main chain and the side chain.

  As a monomer that gives a structure in which a fluorinated alkyl group is bonded to the main chain, for example, an α-trifluoromethyl acrylate compound, a β-trifluoromethyl acrylate compound, an α, β-trifluoromethyl acrylate compound, one or more types And compounds in which the hydrogen atom of the vinyl moiety is substituted with a fluorinated alkyl group such as a trifluoromethyl group.

  Examples of the monomer that gives a structure in which a fluorinated alkyl group is bonded to the side chain include those in which the side chain of an alicyclic olefin compound such as norbornene is a fluorinated alkyl group or a derivative thereof, acrylic acid or methacrylic acid. An ester compound in which the side chain is a fluorinated alkyl group or a derivative group thereof, and a compound in which the side chain of one or more olefins (site not including a double bond) is a fluorinated alkyl group or a derivative group thereof can be used.

  Examples of the monomer that gives a structure in which a fluorinated alkyl group is bonded to the main chain and the side chain include α-trifluoromethylacrylic acid, β-trifluoromethylacrylic acid, α, β-trifluoromethylacrylic acid, and the like. An ester compound in which the side chain is a fluorinated alkyl group or a derivative thereof, and the side chain of a compound in which one or more vinyl moiety hydrogen atoms are substituted with a fluorinated alkyl group such as a trifluoromethyl group Or substituted with a derivative thereof, a hydrogen atom bonded to a double bond of one or more alicyclic olefin compounds is replaced with a fluorinated alkyl group such as a trifluoromethyl group, and the side chain is fluorinated Examples thereof include alkyl groups and derivatives thereof. In addition, an alicyclic olefin compound shows the compound in which a part of ring is a double bond.

  [E] As the fluorine atom-containing polymer, a structural unit represented by the following formula (7) (hereinafter also referred to as “structural unit (f1)”) and / or a structural unit represented by the following formula (8) ( Hereinafter, it is also preferable to have “structural unit (f2)”. [E] The fluorine atom-containing polymer may have other structural units other than the structural unit (f1) and the structural unit (f2). In addition, the [E] fluorine atom containing polymer may contain 1 type, or 2 or more types of each structural unit. Hereinafter, each structural unit will be described in detail.

[Structural unit (f1)]
The structural unit (f1) is a structural unit represented by the following formula (7).

In the above formula (7), R ^f3 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^f4 is a substituted or unsubstituted monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms or a substituted or unsubstituted monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms. .

  Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms include a fluoromethyl group, a trifluoromethyl group, a trifluoroethyl group, a pentafluoro-n-propyl group, and a hexafluoro-i-propyl group. And nonafluoro-n-butyl group.

  Examples of the monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms include a fluorocyclopentyl group, a difluorocyclopentyl group, a cyclopentyl difluoropropyl group, a perfluorocyclohexyl group, a cyclohexyl difluoromethyl group, and a perfluorocycloheptyl group. Etc.

  Examples of the monomer that gives the structural unit (f1) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, perfluoro n-propyl ( (Meth) acrylate, perfluoro i-propyl (meth) acrylate, perfluoro n-butyl (meth) acrylate, perfluoro i-butyl (meth) acrylate, perfluoro t-butyl (meth) acrylate, perfluorocyclohexyl (meth) Acrylate, 2- (1,1,1,3,3,3-hexafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) pentyl ( (Meth) acrylate, 1- (2,2,3,3,4,4,5,5-octafluoro) hex (Meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4, 4,4-Heptafluoro) penta (meth) acrylate, 1- (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10- Heptadecafluoro) decyl (meth) acrylate, 1- (5-trifluoromethyl-3,3,4,4,5,6,6,6-octafluoro) hexyl (meth) acrylate and the like.

  As the structural unit (f1), a structural unit represented by the following formula (7-1) and a structural unit represented by (7-2) are preferable.

In the formulas (7-1) and (7-2), R ^f3 has the same ^meaning as the formula (7).

  Among these, the structural unit represented by the formula (7-1) is preferable.

  As a minimum of the content rate of a structural unit (f1), 10 mol% is preferable with respect to all the structural units which comprise a [E] fluorine atom containing polymer, and 20 mol% is more preferable. Moreover, as an upper limit of the said content rate, 70 mol% is preferable with respect to all the structural units which comprise a [E] fluorine atom containing polymer, and 50 mol% is more preferable.

[Structural unit (f2)]
The structural unit (f2) is a structural unit represented by the following formula (8).

In the above formula (8), R ^f5 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^f6 is a (y + 1) -valent linking group. X ¹ is a divalent linking group having a fluorine atom. R ^f7 is a hydrogen atom or a monovalent organic group. y is an integer of 1-3. However, when y is 2 or 3, the plurality of X ¹ may be the same or different, and the plurality of R ^f7 may be the same or different.

Examples of the (y + 1) -valent linking group represented by R ^f6 include a linear or branched hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and the number of carbon atoms. 6-30 aromatic hydrocarbon groups, or these groups combined with one or more groups selected from the group consisting of oxygen atom, sulfur atom, ether group, ester group, carbonyl group, imino group and amide group Groups. The (y + 1) -valent linking group may have a substituent.

  Examples of the linear or branched hydrocarbon group having 1 to 30 carbon atoms include hydrocarbon groups such as methane, ethane, propane, butane, pentane, hexane, heptane, decane, icosane and triacontane (y + 1). And a group excluding individual hydrogen atoms.

Examples of the alicyclic hydrocarbon group having 3 to 30 carbon atoms include, as monocyclic saturated hydrocarbons, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, methylcyclohexane, ethylcyclohexane, and the like;
As monocyclic unsaturated hydrocarbons, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene, etc .;
As polycyclic saturated hydrocarbons, 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, adamantane, etc .;
As polycyclic unsaturated hydrocarbons, 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 . 0 ^2,7 ] dodecene and the like, and (y + 1) hydrogen atoms are removed.

  Examples of the aromatic hydrocarbon group having 6 to 30 carbon atoms include aromatic hydrocarbon groups such as benzene, naphthalene, phenanthrene, anthracene, tetracene, pentacene, pyrene, picene, toluene, xylene, ethylbenzene, mesitylene, cumene ( and y + 1) groups excluding hydrogen atoms.

Examples of the divalent linking group having a fluorine atom represented by X ¹ include a C 1-20 divalent chain hydrocarbon group having a fluorine atom. Examples of the divalent chain hydrocarbon group include groups represented by the following formulas (X1-1) to (X1-6).

X ¹ is preferably a group represented by the above formula (X1-1) or a group represented by the formula (X1-2), and more preferably a group represented by the formula (X1-2).

Examples of the monovalent organic group represented by R ^f7 include a linear or branched hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and 6 to 6 carbon atoms. 30 aromatic hydrocarbon groups, or a combination of these groups and one or more groups selected from the group consisting of oxygen, sulfur, ether, ester, carbonyl, imino and amide groups, etc. Is mentioned.

  Examples of the structural unit (f2) include a structural unit represented by the following formula (8-1), a structural unit represented by the following formula (8-2), and the like.

In the above formula (8-1), R ^f6 is a divalent linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms. R ^f5 , X ¹ and R ^f7 have the same ^{meaning as} in the above formula (8).
In the above formula (8-2), R ^f5 , X ¹ , R ^f7 and y are as defined in the above formula (8). However, when y is 2 or 3, the plurality of X ¹ may be the same or different, and the plurality of R ^f7 may be the same or different.

  Examples of the structural unit represented by the above formulas (8-1) and (8-2) include the structural units represented by the following formulas (8-1-1) to (8-1-3), And a structural unit represented by (8-2-1).

In the above formulas (8-1-1) to (8-1-3) and the formula (8-2-1), R ^f5 has the same ^{meaning as} the above formula (8).

  As the structural unit (f2), a structural unit represented by the above formula (8-1) is preferable, and a structural unit represented by the above formula (8-1-3) is more preferable.

  Examples of the monomer that gives the structural unit (f2) include (meth) acrylic acid [2- (1-ethyloxycarbonyl-1,1-difluoro-n-butyl)] ester, (meth) acrylic acid (1, 1,1-trifluoro-2-trifluoromethyl-2-hydroxy-3-propyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4- Butyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-5-pentyl) ester, (meth) acrylic acid 2-{[5- (1 ′, 1 ', 1'-trifluoro-2'-trifluoromethyl-2'-hydroxy) propyl] bicyclo [2.2.1] heptyl} ester and the like. Among these, (meth) acrylic acid [2- (1-ethyloxycarbonyl-1,1-difluoro-n-butyl)] ester is preferable.

  As a minimum of the content rate of a structural unit (f2), 30 mol% is preferable with respect to all the structural units which comprise a [E] fluorine atom containing polymer, and 50 mol% is more preferable. Moreover, as an upper limit of the said content rate, 90 mol% is preferable with respect to all the structural units which comprise a [E] fluorine atom containing polymer, and 80 mol% is more preferable.

[Other structural units]
[E] The fluorine atom-containing polymer may contain other structural units other than the structural unit (f1) and the structural unit (f2). Examples of other structural units include the structural unit (I) of [A] polymer.

  [E] When the fluorine atom-containing polymer contains other structural units, the lower limit of the content ratio of the other structural units is 5 mol with respect to all the structural units constituting the [E] fluorine atom-containing polymer. % Is preferable, 10 mol% is more preferable, and 20 mol% is more preferable. Moreover, as an upper limit of the said content rate, 90 mol% is preferable with respect to all the structural units which comprise a [E] fluorine atom containing polymer, 80 mol% is more preferable, and 70 mol% is further more preferable.

  When the said radiation sensitive resin composition contains a [E] fluorine atom containing polymer, as a minimum of content of a [E] fluorine atom containing polymer, it is 0 with respect to 100 mass parts of [A] polymers. 1 part by mass is preferable, and 1 part by mass is more preferable. Moreover, as an upper limit of the said content, 20 mass parts is preferable with respect to 100 mass parts of [A] polymers, 15 mass parts is more preferable, 10 mass parts is further more preferable, 6 mass parts is especially preferable. [E] If the content of the fluorine atom-containing polymer exceeds the above upper limit, the water repellency of the resist film surface becomes too high and development failure may occur.

[E] The fluorine atom content of the fluorine atom-containing polymer is preferably larger than the fluorine atom content of the [A] polymer. [E] When the fluorine atom content in the fluorine atom-containing polymer is larger than that of the [A] polymer, the [E] fluorine atom-containing polymer can be effectively unevenly distributed on the surface layer of the resist film. The water repellency of the resist film surface formed by the radiation sensitive resin composition containing the A] polymer and the [E] fluorine atom-containing polymer can be further increased. [E] The lower limit of the difference between the fluorine atom content of the fluorine atom-containing polymer and the fluorine atom content of the [A] polymer is preferably 1% by mass, and more preferably 3% by mass. Moreover, as a minimum of the fluorine atom content rate of [E] fluorine atom containing polymer, 1 mass% is preferable, 3 mass% is more preferable, 5 mass% is further more preferable, 10 mass% is especially preferable. The fluorine atom content (% by mass) can be calculated from the structure of the polymer obtained by ¹³ C-NMR.

<[E] Method for Synthesizing Fluorine Atom-Containing Polymer>
[E] A fluorine atom-containing polymer can be produced, for example, by polymerizing a monomer corresponding to each predetermined structural unit in a suitable polymerization solvent using a radical polymerization initiator.

  Examples of the radical polymerization initiator include those similar to the radical polymerization initiator used in the method for synthesizing the [A] polymer. Examples of the polymerization solvent include those similar to the polymerization solvent used in the method for synthesizing the polymer [A].

  As a minimum of reaction temperature in the above-mentioned polymerization, 40 ° C is preferred and 50 ° C is more preferred. Moreover, as an upper limit of the said reaction temperature, 150 degreeC is preferable and 120 degreeC is more preferable. The lower limit of the reaction time is preferably 1 hour. Moreover, as an upper limit of reaction time, 48 hours are preferable and 24 hours are more preferable.

  [E] The lower limit of Mw of the fluorine atom-containing polymer is preferably 1,000, more preferably 2,000, and still more preferably 3,000. Further, the upper limit of the Mw is preferably 50,000, more preferably 30,000, and further preferably 10,000. [E] When Mw of the fluorine atom-containing polymer is less than 1,000, a sufficient receding contact angle may not be obtained. On the other hand, when Mw exceeds 50,000, the developability of the resist tends to decrease.

  [E] The lower limit of the ratio (Mw / Mn) between Mw and Mn of the fluorine atom-containing polymer is preferably 1. Moreover, as an upper limit of the said ratio (Mw / Mn), 5 are preferable and 3 is more preferable.

<[F] solvent>
The radiation-sensitive resin composition may contain a [F] solvent in order to dissolve or disperse the [A] polymer, the [B] acid generator, and other components as necessary. Examples of the [F] solvent include alcohol solvents, ketone solvents, amide solvents, ether solvents, ester solvents, and the like. [F] You may use a solvent individually by 1 type or in combination of 2 or more types.

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, and 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. A chain ketone solvent such as hexyl ketone, di-iso-butyl ketone, trimethylnonanone, 2,4-pentanedione, acetonyl acetone, diacetone alcohol, acetophenone;
Examples thereof include cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and methylcyclohexanone.

Examples of the amide solvent include chain forms such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide. An amide solvent;
Examples thereof include cyclic amide solvents such as N-methylpyrrolidone and N, N′-dimethylimidazolidinone.

Examples of the ether solvent include chain ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, and diphenyl ether;
Examples include cyclic ether solvents such as tetrahydrofuran and tetrahydropyran.

Examples of the ester solvent include methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, and acetic acid. Acetate solvents such as 3-methoxybutyl, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, glycol diacetate, methoxytriglycol acetate;
Acetic acid ethylene glycol monomethyl ether, acetic acid ethylene glycol monoethyl ether, acetic acid diethylene glycol monomethyl ether, acetic acid diethylene glycol monoethyl ether, acetic acid diethylene glycol mono-n-butyl ether, acetic acid propylene glycol monomethyl ether, acetic acid propylene glycol monoethyl ether, acetic acid propylene glycol monopropyl ether Acetate solvents of polyhydric alcohol partial ethers such as ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether;
Carbonate solvents such as dimethyl carbonate and diethyl carbonate;
Methyl acetoacetate, ethyl acetoacetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-lactate And ester solvents of other carboxylic acids such as amyl, diethyl malonate, dimethyl phthalate, and diethyl phthalate.

  Among these, ketone solvents and ester solvents are preferable. As the ketone solvents, cyclic ketone solvents are more preferable, and cyclohexanone is more preferable. As the ester solvent, an acetate solvent of a polyhydric alcohol partial ether is more preferable, and propylene glycol monomethyl ether acetate is more preferable.

<[G] Uneven distribution promoter>
[G] The uneven distribution accelerator can be used to efficiently apply the [E] fluorine atom-containing polymer to the resist film surface when the radiation-sensitive resin composition contains the [E] fluorine atom-containing polymer. This component is unevenly distributed. When the radiation-sensitive resin composition contains [G] an uneven distribution accelerator, the [E] fluorine atom-containing polymer can be effectively unevenly distributed on the resist film surface, and as a result, [E] fluorine The amount of the atom-containing polymer used can be reduced. [G] Examples of the uneven distribution promoter include lactone compounds, carbonate compounds, nitrile compounds, polyhydric alcohols, and the like. You may use an uneven distribution promoter individually by 1 type or in combination of 2 or more types.

  Examples of the lactone compound include γ-butyrolactone, valerolactone, mevalonic lactone, and norbornane lactone.

  Examples of the carbonate compound include propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, and the like.

  Examples of the nitrile compound include succinonitrile.

  Examples of the polyhydric alcohol include glycerin.

  Of these, lactone compounds are preferred, and γ-butyrolactone is more preferred.

  When the said radiation sensitive resin composition contains [G] uneven distribution accelerator, as a minimum of content of [G] uneven distribution accelerator, 5 mass parts with respect to 100 mass parts of [A] polymers Is preferable, 10 masses is more preferable, and 20 mass parts is further more preferable. The upper limit of the content is preferably 300 parts by mass, more preferably 100 parts by mass, and still more preferably 70 parts by mass with respect to 100 parts by mass of the [A] polymer.

<Other optional components>
In addition to the above components [A] to [G], the radiation-sensitive resin composition may include other arbitrary radiation-sensitive acid generators, surfactants, alicyclic skeleton-containing compounds, sensitizers, and the like. It may contain components. Other optional components may be used alone or in combination of two or more. Further, the content of other optional components can be appropriately determined according to the purpose.

<Method for preparing radiation-sensitive resin composition>
The radiation-sensitive resin composition includes [A] polymer, [B] acid generator, [B ′] other acid generator, [D] compound, [E] fluorine atom-containing polymer and [F] It can be prepared by mixing each optional component such as a solvent in a predetermined ratio.

  The lower limit of the solid content concentration of the radiation-sensitive resin composition is preferably 0.1% by mass, more preferably 0.5% by mass, and even more preferably 1% by mass. Moreover, as an upper limit of the said solid content density | concentration, 50 mass% is preferable, 30 mass% is more preferable, and 10 mass% is further more preferable.

<Method for forming resist pattern>
The resist pattern forming method includes a step of forming a resist film (hereinafter also referred to as “resist film forming step”), a step of exposing the resist film (hereinafter also referred to as “exposure step”), and the exposed resist. A step of developing the film (hereinafter also referred to as “developing step”) is provided, and the resist film is formed of the radiation-sensitive resin composition. Hereinafter, each step will be described.

[Resist film forming step]
In this step, a resist film is formed using the above-described radiation-sensitive resin composition of the present invention. Although it does not specifically limit as an application | coating method, For example, appropriate application | coating means, such as spin coating, cast coating, roll coating, can be employ | adopted. Examples of the substrate include a silicon wafer and a wafer coated with aluminum. Specifically, after applying the composition so that the resulting resist film has a predetermined thickness, the solvent in the coating film is volatilized by pre-baking (PB) as necessary. As a minimum of the average film thickness of a coating film, 10 nm is preferable. The upper limit of the average film thickness is preferably 500 nm. As a minimum of the temperature of PB, 60 degreeC is preferable and 80 degreeC is more preferable. Moreover, as an upper limit of the said temperature, 140 degreeC is preferable and 80 degreeC is more preferable. The lower limit of the PB time is preferably 5 seconds, and more preferably 10 seconds. Moreover, as an upper limit of the said time, 600 second is preferable and 300 second is more preferable.

  In the resist pattern molding method, an organic or inorganic antireflection film can be formed on a substrate to be used in order to maximize the potential of the radiation sensitive resin composition. Moreover, in order to prevent the influence of the basic impurity etc. which are contained in environmental atmosphere, a protective film can also be provided, for example on a coating film. When immersion exposure is performed, an immersion protective film may be provided on the resist film, for example, in order to avoid direct contact between the immersion medium and the resist film.

[Exposure process]
In this step, the resist film formed in the resist film forming step is exposed. In some cases, this exposure is performed by irradiating radiation through a mask having a predetermined pattern through an immersion medium such as water. Examples of the radiation include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, EUV (wavelength 13.5 nm), X-rays, and γ-rays; and charging such as electron beams and α-rays, depending on the line width of the target pattern. It is appropriately selected from particle beams and the like. Among these, when the [A] polymer of the radiation sensitive resin composition has the structural unit (I-1), far ultraviolet rays are preferable, ArF excimer laser light (wavelength 193 nm), KrF excimer laser light, and the like. (Wavelength 248 nm) is more preferable, and ArF excimer laser light is more preferable. Moreover, when the [A] polymer of the said radiation sensitive resin composition has a structural unit (I-2) etc., an electron beam and EUV are preferable.

  Moreover, it is preferable to perform PEB (Post Exposure Bake) after exposure. By performing PEB, the dissociation reaction of the acid dissociable group in the exposed portion of the resist film can be smoothly advanced. As a minimum of the temperature of PEB, 50 degreeC is preferable and 80 degreeC is more preferable. Moreover, as an upper limit of the said temperature, 180 degreeC is preferable and 130 degreeC is more preferable. The lower limit of the PEB time is preferably 5 seconds, and more preferably 10 seconds. Moreover, as an upper limit of the said time, 600 second is preferable and 300 second is more preferable.

[Development process]
In this step, the resist film exposed in the exposure step is developed. Examples of the developer used for the development include an alkali developer and an organic solvent developer. Thereby, a predetermined resist pattern is formed.

  Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl Diethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [ 4.3.0] -5-nonene, and an alkaline aqueous solution in which at least one alkaline compound is dissolved.

Examples of the organic solvent developer include alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol and sec-butanol;
Ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, tetrahydrofuran, dioxane, diphenyl ether, anisole;
Ketone solvents such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone;
Amide solvents such as N, N′-dimethylimidazolidinone, N-methylformamide, N, N-dimethylformamide;
Examples include ester solvents such as diethyl carbonate, methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, and n-butyl acetate.

  These developers may be used alone or in combination of two or more. In general, after development, the substrate is washed with water or the like and dried.

<Radiation sensitive acid generator>
The radiation sensitive acid generator of this invention consists of a compound represented by the said Formula (A). Since the said radiation sensitive acid generator has the above-mentioned characteristic, the LWR performance etc. of the radiation sensitive resin composition containing this can be improved.

<Compound>
The compound of the present invention is represented by the above formula (A). Since the said compound has the said structure, it can be used suitably as the said radiation sensitive acid generator.

  The radiation sensitive acid generator and the compound are described in the section of [B] acid generator of the radiation sensitive resin composition described above.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, each measurement in an Example and a comparative example was performed with the following method.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
Using GPC columns (Tosoh "G2000HXL": 2; Tosoh "G3000HXL": 1 Tosoh "G4000HXL": 1), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, sample Concentration: 1.0% by mass, sample injection amount: 100 μL, column temperature: 40 ° C., detector: measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of a differential refractometer. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.

[ ¹³ C-NMR analysis]
Using a nuclear magnetic resonance apparatus (“JNM-ECX400” manufactured by JEOL Ltd.), deuterated chloroform was used as a measurement solvent, and analysis for determining the content ratio (mol%) of each structural unit in each polymer was performed.

<Synthesis of compounds>
[Example 1] (Synthesis of Compound (H-1))
In a 300 mL three-necked flask, 25.4 g (125 mmol) of ethyl bromodifluoroacetate (A) was added, purged with nitrogen, and 120 mL of diethyl ether was added and stirred. At −78 ° C., 25.8 g (138 mmol) of Grignard reagent (B-1) was added dropwise over 20 minutes. After completion of the addition, the mixture was stirred at −78 ° C. for 3 hours. After quenching the reaction by adding 150 mL of 1N hydrochloric acid, the aqueous layer was extracted with 150 mL of diethyl ether three times. The organic layer was dried over magnesium sulfate, the insoluble material was removed by filtration, and the filtrate was concentrated. The concentrated solution was purified by column chromatography to obtain 12.1 g (yield 40%) of compound (C-1).

  Next, 1.20 g (50 mmol) of sodium hydride was placed in a 200 mL three-necked flask, nitrogen substitution was performed, and 100 mL of tetrahydrofuran was added and stirred. After adding 33.6 g (150 mmol) of ethyl diethylphosphonoacetate and 12.1 g (50.0 mmol) of compound (C-1) at 0 ° C., the mixture was stirred at 0 ° C. for 1 hour, and then stirred at room temperature for 3 hours. . After adding 150 mL of saturated ammonium chloride aqueous solution and stirring, the aqueous layer was extracted 3 times with 150 mL of tetrahydrofuran. The organic layer was dried over magnesium sulfate, the insoluble material was removed by filtration, and the filtrate was concentrated. The concentrated solution was purified by column chromatography to obtain 13.2 g (yield 85%) of compound (D-1).

Next, 13.2 g (42.5 mmol) of the compound (D-1) was placed in a 200 mL three-necked flask, nitrogen substitution was performed, 100 mL of heptane and 3.09 g (46.8 mmol) of cyclopentadiene were added, and the mixture was refluxed for 8 hours. . After cooling to room temperature, the mixture was concentrated and purified by column chromatography to obtain 14.7 g of Compound (E-1) (yield 92%).
Into a 500 mL three-necked flask, 14.7 g (39.1 mmol) of the compound (E-1) was added, nitrogen substitution was performed, and 200 mL of acetonitrile was added and stirred. A solution prepared by dissolving 9.85 g (117 mmol) of sodium hydrogen carbonate and 13.6 g (78.2 mmol) of sodium dithionesan in 120 g of water was added, and the mixture was stirred at 65 ° C. for 4 hours to give a compound (F-1 ) Was generated. After cooling to room temperature, it was washed twice with 100 mL of saturated aqueous sodium thiosulfate solution. To the organic layer were added 13.3 g (117 mmol) of 30% aqueous hydrogen peroxide solution and 0.903 g (2.74 mmol) of sodium tungstate dihydrate, and the mixture was stirred at 55 ° C. for 6 hours to give compound (G-1). Was generated. After cooling to room temperature, excess hydrogen peroxide was quenched with 150 mL of an aqueous sodium sulfite solution, and the organic layer was recovered. After distilling off the solvent, 11.7 g (39.1 mmol) of triphenylsulfonium chloride, 250 mL of dichloromethane and 125 mL of water were added and stirred at room temperature for 8 hours. The organic layer was washed with water three times, and then the solvent was distilled off to obtain 19.2 g (yield 86%) of compound (H-1).

[Example 2] (Synthesis of Compound (H-2))
To a 50 mL three-necked flask, 70 mg of Pd—C (10%) and 15 mL of ethyl acetate were added to perform hydrogen replacement. 3.77 g (10.0 mmol) of the compound (E-1) obtained by performing the same operation as in Synthesis Example 1 was dissolved in 10 mL of ethyl acetate and added to the flask with a syringe. After stirring at room temperature for 40 hours, Pd—C was removed by Celite filtration and the solvent was distilled off. By purification by column chromatography, 3.30 g (yield 87%) of hydrogenated product (E-2) was obtained.

  Next, 3.30 g (8.70 mmol) of (E-2) obtained above was placed in a 100 mL three-necked flask, purged with nitrogen, and 50 mL of acetonitrile was added and stirred. A solution prepared by dissolving 2.19 g (26.1 mmol) of sodium hydrogen carbonate and 2.68 g (15.4 mmol) of sodium dithionesan in 35 g of water was added, and the mixture was stirred at 65 ° C. for 4 hours to give a compound (F -2). After cooling to room temperature, it was washed twice with 40 mL of a saturated aqueous sodium thiosulfate solution. To the organic layer were added 2.96 g (26.1 mmol) of a 30% by mass aqueous hydrogen peroxide solution and 0.201 g (0.609 mmol) of sodium tungstate dihydrate, and the mixture was stirred at 55 ° C. for 6 hours. -2). After cooling to room temperature, excess hydrogen peroxide was quenched with 40 mL of an aqueous sodium sulfite solution, and the organic layer was recovered. After distilling off the solvent, 2.60 g (8.70 mmol) of triphenylsulfonium chloride, 60 mL of dichloromethane and 30 mL of water were added and stirred at room temperature for 8 hours. The organic layer was washed three times with water, and then the solvent was distilled off to obtain 4.17 g (yield 83%) of compound (H-2).

[Examples 3 to 14] (Synthesis of compounds (H-3) to (H-14))
The precursors were appropriately selected and the same operations as in Example 2 were performed to synthesize compounds represented by the following formulas (H-3) to (H-14).

[Example 15] (Synthesis of Compound (H-15))
Magnesium (21.9 g, 0.9 mol) was placed in a 1 L three-necked flask, the atmosphere was replaced with nitrogen, and 200 mL of diethyl ether was added and stirred. 69.0 g (0.3 mol) of dibromopentane (A-2) was added dropwise over 1 hour, and after completion of the addition, the mixture was refluxed for 2 hours to prepare a Grignard reagent (B-2). After cooling to room temperature, 121.8 g (0.6 mol) of ethyl bromodifluoroacetate was added dropwise over 2 hours. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours. After quenching the reaction by adding 100 mL of saturated aqueous ammonium chloride solution, the organic layer was washed with water three times. Furthermore, it dried with magnesium sulfate and concentrated after removing insoluble matter by filtration. The concentrated liquid was purified by column chromatography to obtain 22.9 g (yield 33%) of compound (C-2).

  Next, 2.44 g (20 mmol) of dimethylaminopyridine and 22.9 g (100 mmol) of dimethylaminopyridine and 22.9 g (100 mmol) of compound (C-2) were placed in a 500 mL three-necked flask, and the atmosphere was replaced with nitrogen. 200 mL of tetrahydrofuran and 15.2 g (150 mmol) of triethylamine were added and stirred. did. After adding 14.7 g (100 mmol) of cyclohexanecarbonyl chloride at 0 ° C., the mixture was stirred at room temperature for 5 hours. After quenching the reaction by adding 150 mL of a saturated aqueous sodium hydrogen carbonate solution, the aqueous layer was extracted 3 times with 150 mL of dichloromethane. The organic layer was dried over sodium sulfate, the insoluble material was removed by filtration, and the mixture was concentrated. The concentrated solution was purified by column chromatography to obtain 21.8 g (yield 64%) of compound (D-2).

  Next, 21.8 g (64.3 mmol) of the compound (D-2) was placed in a 500 mL three-necked flask, nitrogen substitution was performed, and 200 mL of acetonitrile was added and stirred. A solution prepared by dissolving 16.2 g (193 mmol) of sodium hydrogen carbonate and 22.4 g (128 mmol) of sodium dithionesan in 150 g of water was added, and the mixture was stirred at 65 ° C. for 4 hours to give compound (E-3). Generated. After cooling to room temperature, it was washed twice with 100 mL of saturated aqueous sodium thiosulfate solution. To the organic layer were added 21.9 g (193 mmol) of 30% aqueous hydrogen peroxide solution and 1.48 g (4.50 mmol) of sodium tungstate dihydrate, and the mixture was stirred at 55 ° C. for 6 hours to give compound (F-3). Was generated. After cooling to room temperature, excess hydrogen peroxide was quenched with 150 mL of an aqueous sodium sulfite solution, and the organic layer was recovered. After distilling off the solvent, 19.2 g (64.3 mmol) of triphenylsulfonium chloride, 300 mL of dichloromethane and 150 mL of water were added and stirred at room temperature for 8 hours. The organic layer was washed with water three times, dried over magnesium sulfate, insoluble matters were removed by filtration, and the filtrate was concentrated. The concentrated liquid was purified by column chromatography to obtain 17.4 g (yield 45%) of compound (H-15).

[Examples 16 to 20] (Synthesis of compounds (H-16) to (H-20))
The precursors were appropriately selected, and the same operations as in Example 15 were performed to synthesize compounds represented by the following formulas (H-2) to (H-20).

<Synthesis of [A] polymer and [E] polymer>
The monomers used in the synthesis of each polymer in each example and comparative example are shown below.

[Synthesis Example 1] (Synthesis of polymer (A-1))
Compound (M-1) 7.97 g (35 mol%), compound (M-2) 7.44 g (45 mol%) and compound (M-3) 4.49 g (20 mol%) into 2-butanone 40 g After dissolving, 0.80 g of AIBN (5 mol% based on the total amount of compounds) as a radical initiator was added to prepare a monomer solution. Next, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, and 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 polymerization solution cooled in 400 g of methanol was added, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 80 g of methanol, filtered, and dried at 50 ° C. for 17 hours to synthesize a white powdery polymer (A-1) (15.2 g, yield 76). %). Mw of the polymer (A-1) was 7,300, and Mw / Mn was 1.53. Moreover, as a result of ¹³ C-NMR analysis, the content ratios of the structural units derived from the compound (M-1), the compound (M-2), and the compound (M-3) were 34.3 mol% and 45. 1 mol% and 20.6 mol%.

[Synthesis Examples 2 and 3] (Synthesis of Polymers (A-2) and (A-3))
Polymers (A-2) and (A-3) were synthesized by the same operations as in Synthesis Example 1 except that the types and amounts of compounds shown in Table 1 were used.

[Synthesis Example 4] (Synthesis of Polymer (A-4))
Compound (M-4) 55.0 g (65 mol%) and compound (M-5) 45.0 g (35 mol%), 4 g of AIBN as a radical initiator and 1 g of t-dodecyl mercaptan were added to 100 g of propylene glycol monomethyl ether. After dissolution, the reaction temperature was maintained at 70 ° C. in a nitrogen atmosphere and copolymerization was performed for 16 hours. After completion of the polymerization reaction, the polymer solution was dropped into 1,000 g of n-hexane to solidify and purify the polymer. Next, 150 g of propylene glycol monomethyl ether was added to the polymer again, and then 150 g of methanol, 34 g of triethylamine and 6 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. After completion of the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting polymer was dissolved in 150 g of acetone, then dropped into 2,000 g of water and solidified, and the resulting white powder was filtered and filtered at 50 ° C. It was made to dry for a period of time to obtain a white powdery polymer (A-4) (65.7 g, yield 77%). Mw of the polymer (A-4) was 7,500, and Mw / Mn was 1.90. As a result of ¹³ C-NMR analysis, the content of each structural unit derived from p-hydroxystyrene and the compound (M-5) was 65.4 mol% and 34.6 mol%, respectively.

[Synthesis Example 5] (Synthesis of Polymer (E-1))
Compound (M-11) 82.2 g (70 mol%) and compound (M-12) 17.8 g (30 mol%) were dissolved in 200 g of 2-butanone, and 0.46 g of AIBN as a radical initiator was added. A monomer solution was prepared. Next, a 500 mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes, and 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. After replacing the solvent with 400 g of acetonitrile, the operation of adding 100 g of hexane and stirring to recover the acetonitrile layer was repeated three times. By replacing the solvent with propylene glycol monomethyl ether acetate, a solution containing 60.1 g of the polymer (E-1) was obtained (yield 60%). Mw of the polymer (E-1) was 15,000, and Mw / Mn was 1.90. As a result of ¹³ C-NMR analysis, the content of each structural unit derived from the compound (M-11) and the compound (M-12) was 70.3 mol% and 29.7 mol%, respectively.

<Preparation of radiation-sensitive resin composition>
[B] Other acid generators and [C] acid diffusion inhibitors used for the preparation of radiation sensitive resin compositions of the following Examples and Comparative Examples other than the above compounds (H-1) to (H-20) , [D] compound, [F] solvent and [G] uneven distribution promoter are shown below.

[[B] Other acid generators]
The compound represented by a following formula (b'-1).

[[C] acid diffusion controller]
Compounds represented by the following formulas (c′-1) to (c′-2).

[[F] solvent]
f-1: Propylene glycol monomethyl ether acetate f-2: Cyclohexanone

[[G] uneven distribution promoter]
g-1: γ-butyrolactone

[Example 21] (Preparation of radiation-sensitive resin composition (J-1))
[A] 100 parts by mass of (A-1) as a polymer, [C] 2.3 parts by mass of (c′-1) as an acid diffusion controller, [B] (H-1) as an acid generator 8.5 parts by mass, (E-1) 3 parts by mass as a fluorine atom-containing polymer, (F-1) 2,240 parts by mass and (f-2) 960 parts by mass as a [F] solvent In addition, [G] 30 parts by mass of (g-1) as an uneven distribution accelerator was mixed and filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation sensitive resin composition (J-1).

[Examples 22 to 46 and Comparative Examples 1 to 6] (Preparation of radiation-sensitive resin compositions (J-2) to (J-26) and (J-27) to (J-32))
Each radiation-sensitive resin composition was prepared in the same manner as in Example 21 except that the components of the types and contents shown in Table 2 and Table 3 were used.

[Examples 47 to 57 and Comparative Examples 7 to 11] (Preparation of radiation-sensitive resin compositions (J-33) to (J-43) and (J-44) to (J-48))
Each radiation-sensitive resin composition was prepared in the same manner as in Example 21 except that the components having the types and contents shown in Table 4 below were used.

<Formation of resist pattern (1)>
Using a spin coater (CLEAN TRACK ACT12, Tokyo Electron) on a 12-inch silicon wafer surface, a composition for forming an antireflection film (ARC66, Brewer Science) was applied and heated at 205 ° C. for 60 seconds. As a result, a lower antireflection film having an average film thickness of 105 nm was formed. On the lower antireflection film, each of the prepared radiation sensitive resin compositions was applied using the spin coater, and PB was performed at 90 ° C. for 60 seconds. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with an average film thickness of 90 nm. Next, this resist film is 40 nm under an optical condition of NA = 1.3 and dipole (Sigma 0.977 / 0.782) using an ArF excimer laser immersion exposure apparatus (NSR-S610C, NIKON). Exposure was through a line and space (1L1S) mask pattern. After the exposure, PEB was performed at 90 ° C. for 60 seconds. Thereafter, alkali development was performed using a 2.38% by mass TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern. When this resist pattern is formed, the line width formed through a one-to-one line and space mask having a target dimension of 40 nm is defined as an optimum exposure amount. did.

<Formation of resist pattern (2)>
A negative resist pattern was prepared in the same manner as in the above resist pattern formation (1) except that n-butyl acetate was used instead of the TMAH aqueous solution and the organic solvent was developed, and washing with water was not performed. Formed.

<Evaluation>
About each resist pattern formed using said each radiation sensitive resin composition (J-1)-(J-48), it measured according to the following method, and evaluated each radiation sensitive resin composition. The results are shown in Tables 5-8. A scanning electron microscope (Hitachi High-Technologies “CG-4100”) was used for measuring the resist pattern.

[LWR performance]
The resist pattern resolved at the optimum exposure dose was observed from above the pattern using the scanning electron microscope. A total of 50 line widths were measured at arbitrary points, and a 3-sigma value was obtained from the distribution of the measured values, and this was defined as LWR performance. The LWR performance indicates that the smaller the value, the smaller the backlash of the line. The LWR performance was evaluated as “A (good)” when 5.0 nm or less and “B (defective)” when exceeding 5.0 nm.

[Resolution]
The dimension of the minimum resist pattern that can be resolved at the optimum exposure dose was measured, and this measured value was taken as the resolution. The resolution indicates that the smaller the value, the better the pattern can be formed. The resolution was evaluated as “A (good)” when it was 30 nm or less, and “B (defective)” when it exceeded 30 nm.

[Rectangularity of the cross-sectional shape]
The cross-sectional shape of the resist pattern resolved at the optimum exposure dose was observed, and the line width Lb in the middle of the resist pattern in the height direction and the line width La at the top of the resist pattern were measured. The rectangularity of the cross-sectional shape indicates that the closer the value is to 1, the more the resist pattern may be rectangular. The rectangularity of the cross-sectional shape is “A (good)” when 0.90 ≦ (La / Lb) ≦ 1.14, and (La / Lb) <0.90 or 1.14 <(La / Lb). ), It was evaluated as “B (defect)”.

[Depth of focus]
In the resist pattern resolved at the above optimum exposure amount, the dimension when the focus is changed in the depth direction is observed, and the depth direction in which the pattern dimension falls within 90% to 110% of the standard without any bridge or residue. Was measured, and this measured value was defined as the depth of focus. The larger the value of the focal depth, the smaller the variation in the dimension of the pattern obtained when the focal position varies, and the higher the yield during device fabrication. The depth of focus was evaluated as “A (good)” when the depth was 45 nm or more, and “B (defective)” when the depth was less than 45 nm.

[Exposure margin]
In the range of the exposure amount including the optimum exposure amount, the exposure amount was changed every 1 mJ / cm ² to form a resist pattern, and each line width was measured using the scanning electron microscope. From the relationship between the obtained line width and exposure amount, an exposure amount E (44) at which the line width becomes 44 nm and an exposure amount E (36) at which the line width becomes 36 nm are obtained, and exposure margin = (E (36) The exposure margin (%) was calculated from the equation: −E (44)) × 100 / (optimum exposure amount). The larger the value of the exposure margin, the smaller the variation in the dimension of the pattern obtained when the exposure amount fluctuates, and the higher the yield during device fabrication. The exposure margin was evaluated as “A (good)” when 10% or more, and “B (defective)” when less than 10%.

[CDU performance]
The resist pattern resolved at the optimum exposure dose was observed from above the pattern using the scanning electron microscope. The line width is measured at 20 points in the range of 400 nm, the average value is obtained, the average value is measured at a total of 500 points, and the 3 sigma value is obtained from the distribution of the measured values, which is taken as the CDU performance. . The CDU performance indicates that the smaller the value, the smaller the line width variation in a long cycle. The CDU performance was evaluated as “A (good)” when it was 1.5 nm or less, and “B (bad)” when it exceeded 1.5 nm.

[MEEF performance]
In the resist pattern resolved at the optimum exposure amount, the line width of the resist pattern formed using a mask pattern having line widths of 51 nm, 53 nm, 55 nm, 57 nm, and 59 nm is plotted on the vertical axis, and the size of the mask pattern is defined as the vertical axis. The slope of the straight line when plotted on the horizontal axis was calculated and used as the MEEF performance. The MEEF performance indicates that the closer the value is to 1, the better the mask reproducibility. The MEEF performance was evaluated as “A (good)” when 1.30 or less, and “B (defective)” when it exceeded 1.30.

  As is clear from the results of Tables 5 to 8, in each of the examples, the LWR performance, the resolution, the rectangular shape of the cross-sectional shape, the focal depth, the exposure margin, the CDU performance, and the MEEF performance were good. On the other hand, in the comparative example, each characteristic was inferior compared with the Example.

[Example 58] (Preparation of radiation-sensitive resin composition (J-49))
[A] 100 parts by mass of (A-4) as a polymer, [C] 2.3 parts by mass of (c′-1) as an acid diffusion controller, [B] (H-1) as an acid generator By blending 8.5 parts by mass and (f-1) 2,240 parts by mass and (f-2) 1,830 parts by mass as a [F] solvent, and filtering through a membrane filter having a pore size of 0.2 μm, A radiation resin composition (J-49) was prepared.

[Examples 59 to 74 and Comparative Examples 12 and 13] (Preparation of Radiation Sensitive Resin Compositions (J-50) to (J-65) and (J-66) and (J-67))
Each radiation-sensitive resin composition was prepared in the same manner as in Example 58 except that the components having the types and contents shown in Table 9 below were used.

[Examples 75 to 83 and Comparative Examples 14 and 15] (Preparation of Radiation Sensitive Resin Compositions (J-68) to (J-76) and (J-77) and (J-78))
Each radiation-sensitive resin composition was prepared in the same manner as in Example 58 except that the components having the types and contents shown in Table 10 below were used.

<Formation of resist pattern (3)>
Using a spin coater (CLEAN TRACK ACT8, Tokyo Electron) on the surface of an 8-inch silicon wafer, each radiation sensitive resin composition shown in Table 9 and Table 10 was applied, and PB was performed at 90 ° C. for 60 seconds. It was. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with an average film thickness of 50 nm. Next, the resist film was irradiated with an electron beam using a simple electron beam drawing apparatus (Hitachi, Ltd., model “HL800D”, output: 50 KeV, current density: 5.0 A / cm ² ). After irradiation, PEB was performed at 120 ° C. for 60 seconds. Thereafter, development was performed at 23 ° C. for 30 seconds using a 2.38 mass% TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern.

<Formation of resist pattern (4)>
A negative resist pattern was prepared in the same manner as in the above resist pattern formation (3) except that n-butyl acetate was used instead of the TMAH aqueous solution and the organic solvent was developed. Formed.

<Evaluation>
Evaluation similar to the said Example was implemented about the resist pattern formed using each said radiation sensitive resin composition (J-49)-(J-78). The results are shown in Table 11 and Table 12 below.

  As is clear from the results of Table 11 and Table 12, in the examples, all of the LWR performance, resolution, rectangularity of the cross-sectional shape, depth of focus, exposure margin, and CDU performance were good. In the comparative example, each characteristic was inferior to the example.

  According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, while exhibiting excellent depth of focus, exposure margin, MEEF performance, and sensitivity, LWR performance, CDU performance, resolution, and rectangular shape in cross section A resist pattern having excellent properties can be formed. The radiation sensitive acid generator of this invention can be used suitably as a component of the said radiation sensitive resin composition. The compound of the present invention can be suitably used as the radiation sensitive acid generator. Therefore, these can be suitably used for manufacturing processes of semiconductor devices, which are expected to be further miniaturized in the future.

Claims (12)

A polymer having a structural unit containing an acid-dissociable group, and a radiation-sensitive acid generator,
The radiation sensitive resin composition in which the said radiation sensitive acid generator contains the compound represented by following formula (1) .

(In the formula (1) , R ¹ is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, and -O between carbon and carbon of the alicyclic hydrocarbon group. An aliphatic heterocyclic group containing —, —COO—, —OCOO—, —S—, —SO ₂ O—, —NHCOO—, —SiR ^S ₂ —, or a combination thereof, or the above alicyclic hydrocarbon group and Some or all of the hydrogen atoms of the aliphatic heterocyclic group are —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, halogen R ^t and R ^y are groups substituted by an atom or a combination thereof, and R ^t and R ^y are bonded to the same carbon atom on the ring structure of the alicyclic hydrocarbon group and the aliphatic heterocyclic group or adjacent to each other. Bonded to two carbon atoms, R ^S is a hydrogen atom, A monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, R ^t is a carbon atom, and R ^y is a monovalent hydrocarbon having 1 to 30 carbon atoms. K is an integer of 1 to 3. When k is 2 or more, the plurality of R ¹ may be the same or different, and the plurality of R ^y may be the same or different. R ^F1 , R ^F2 and R ^F3 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group having 1 to 20 carbon atoms, i being 0 to 9; Provided that when i is 0, k is 1 or 2. When i is 2 or more, a plurality of R ^F1 may be the same or different, and a plurality of R ^F2 may be the same or different. Again good .R ^F3 is plural, the plurality of R ^F3 may be the same or different. However, 1 Moshiku A is .M ⁺ is at least one fluorine atom or a perfluoroalkyl group of the plurality of R ^F1, one or more of R ^F2 and one or more of R ^F3, a monovalent radiation-sensitive onium cation. ) The radiation sensitive resin composition according to claim 1 , wherein the compound represented by the formula (1) is a compound represented by the following formula (1-1).

(In the formula (1-1), R ^t , R ^F1 , R ^F2 , R ^F3 , i and M ⁺ are the same as those in the formula (1). R ^h is a ring together with the carbon atom to which this group is bonded. Consists of a group having 3 to 20 divalent alicyclic hydrocarbon groups or a group in which part or all of the hydrogen atoms of the alicyclic hydrocarbon group are substituted with monovalent hydrocarbon groups having 1 to 20 carbon atoms. R ² is a hydrogen atom or a monovalent organic group having 1 to 29 carbon atoms, X is —O— or —NR ³ —, R ³ is a hydrogen atom or carbon number 1 Y is a single bond or a divalent chain hydrocarbon group having 1 to 10 carbon atoms. The compound represented by the above formula (1-1) is represented by the compound represented by the following formula (1-a), the compound represented by the following formula (1-b), and the following formula (1-c). The radiation sensitive resin composition according to claim 2, which is a compound represented by formula (1-d):

(In the formulas (1-a) to (1-d), R ^t , R ² , X, Y, R ^F1 , R ^F2 , R ^F3 , i and M ⁺ are the same as those in the above formula (1-1). R ^{4 to} R ⁷ are each independently an alkyl group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 ring members, and m is an integer of 1 to 10. A is an integer of 0 to (2m + 2) When a is 2 or more, a plurality of R ⁴ may be the same or different, b is an integer of 0 to 8. b is 2 or more A plurality of R ⁵ may be the same or different, c is an integer of 0 to 8. When c is 2 or more, a plurality of R ⁶ may be the same or different. If .d is 2 or an integer of 0-6, a plurality of ^{R 7} is optionally be the same or different .A is independently -CH ₂ - or -CH ₂ CH ₂ In is.) A polymer having a structural unit containing an acid dissociable group, and
Radiation sensitive acid generator
Containing
The radiation sensitive resin composition in which the radiation sensitive acid generator contains a compound represented by the following formula (1'-a) or a compound represented by the following formula (1'-b).

(In the formulas (1'-a) and (1'-b), R ¹ 'Is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, and -O-, -COO-, -OCOO between the carbon and carbon of the alicyclic hydrocarbon group. -, -S-, -SO ₂ O-, -NHCOO-, -SiR ^S ₂ -Or an aliphatic heterocyclic group containing a combination thereof, or a part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group are -OH, -CN, C1-20 It is a group constituting a monovalent hydrocarbon group, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a group substituted with a halogen atom or a combination thereof. R ^S Is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms. R ^t Is a carbon atom. R ² 'Is a monovalent organic group having 1 to 29 carbon atoms. k is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ ′ May be the same or different, and a plurality of R ² 'May be the same or different. R ^F1 , R ^F2 And R ^F3 Are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or a fluorinated alkyl group having 1 to 20 carbon atoms. i is an integer of 0-9. However, when i is 0, k is 1 or 2. When i is 2 or more, a plurality of R ^F1 May be the same or different, and a plurality of R ^F2 May be the same or different. R ^F3 When there are multiple, multiple R ^F3 May be the same or different. However, one or more R ^F1 One or more R ^F2 And one or more R ^F3 At least one of these is a fluorine atom or a perfluoroalkyl group. M ⁺ Is a monovalent radiation-sensitive onium cation. ) At least one of R ^F1 , R ^F2 and R ^F3 bonded to the carbon atom adjacent to SO ₃ ^— in the formula (1), the formula (1′-a) or the formula (1′-b) is The radiation-sensitive resin composition according to any one of claims 1 to 4 , which is a fluorine atom or a perfluoroalkyl group. The radiation sensitive resin composition according to any one of claims 1 to 5 , wherein the structural unit containing the acid dissociable group is represented by the following formula (2).

(In formula (2), R ⁸ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid-dissociable group represented by the following formula (Y-1). is there.)

(In formula (Y-1), R ^e1 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^e2 and R ^e3 are each independently a monovalent chain having 1 to 20 carbon atoms. A hydrocarbon group or a monovalent alicyclic hydrocarbon group having 3 to 20 ring members, or an alicyclic structure having 3 to 20 ring members composed of these groups together with the carbon atom to which they are bonded Represents.) The radiation sensitive onium cation of M ^{+ in} the above formula (1), the above formula (1′-a) or the above formula (1′-b) is a cation represented by the following formula (X-1) or the following formula ( The radiation-sensitive resin composition according to any one of claims 1 to 6 , which is a cation represented by X-2).

(In formula (X-1), R ⁹ , R ¹⁰ and R ¹¹ are each independently a substituted or unsubstituted C 1-12 linear or branched alkyl group, substituted or unsubstituted ring. monovalent aromatic hydrocarbon group Number 6 to 12, -OSO ₂ -R ^a or _-SO 2 -R ^B or where the ring structure formed by two or more binding of these groups R ^A and R ^B are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted monovalent fat having 5 to 25 ring members. A cyclic hydrocarbon group or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 12 ring members, and p, q and r are each independently an integer of 0 to 5. R ⁹ to R ^11, when ^{R a} and ^{R B} is plural respective plurality of ^{R 9} is the same However, they may be different, a plurality of R ¹⁰ may be the same or different, a plurality of R ¹¹ may be the same or different, a plurality of R ^A may be the same or different, and a plurality of R ^B May be the same or different.
In Formula (X-2), R ¹² and R ¹³ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted ring number of 6 to 12 monovalent aromatic hydrocarbon group, represents a cyclic structure formed by two or more binding of either a -OSO ₂ -R ^C or _-SO 2 -R ^D, or their groups. R ^C and R ^D are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted monovalent alicyclic group having 5 to 25 ring members. It is a hydrocarbon group or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 12 ring members. s and t are each independently an integer of 0 to 5. When there are a plurality of R ¹² , R ¹³ , R ^C and R ^D , the plurality of R ¹² may be the same or different, the plurality of R ¹³ may be the same or different, and the plurality of R ^C may be the same They may be different, and the plurality of ^RDs may be the same or different. ) Forming a resist film;
A step of exposing the resist film, and a step of developing the exposed resist film,
A resist pattern forming method of forming a radiation-sensitive resin composition according to any one of claims 7 to the resist film from claim 1. The radiation sensitive acid generator which consists of a compound represented by following formula (1) .

(In the formula (1) , R ¹ is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, and -O between carbon and carbon of the alicyclic hydrocarbon group. An aliphatic heterocyclic group containing —, —COO—, —OCOO—, —S—, —SO ₂ O—, —NHCOO—, —SiR ^S ₂ —, or a combination thereof, or the above alicyclic hydrocarbon group and Some or all of the hydrogen atoms of the aliphatic heterocyclic group are —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, halogen R ^t and R ^y are groups substituted by an atom or a combination thereof, and R ^t and R ^y are bonded to the same carbon atom on the ring structure of the alicyclic hydrocarbon group and the aliphatic heterocyclic group or adjacent to each other. Bonded to two carbon atoms, R ^S is a hydrogen atom, A monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, R ^t is a carbon atom, and R ^y is a monovalent hydrocarbon having 1 to 30 carbon atoms. K is an integer of 1 to 3. When k is 2 or more, the plurality of R ¹ may be the same or different, and the plurality of R ^y may be the same or different. R ^F1 , R ^F2 and R ^F3 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group having 1 to 20 carbon atoms, i being 0 to 9; Provided that when i is 0, k is 1 or 2. When i is 2 or more, a plurality of R ^F1 may be the same or different, and a plurality of R ^F2 may be the same or different. Again good .R ^F3 is plural, the plurality of R ^F3 may be the same or different. However, 1 Moshiku A is .M ⁺ is at least one fluorine atom or a perfluoroalkyl group of the plurality of R ^F1, one or more of R ^F2 and one or more of R ^F3, a monovalent radiation-sensitive onium cation. ) A radiation-sensitive acid generator comprising a compound represented by the following formula (1'-a) or a compound represented by the following formula (1'-b).

(In the formulas (1'-a) and (1'-b), R ¹ 'Is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, and -O-, -COO-, -OCOO between the carbon and carbon of the alicyclic hydrocarbon group. -, -S-, -SO ₂ O-, -NHCOO-, -SiR ^S ₂ -Or an aliphatic heterocyclic group containing a combination thereof, or a part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group are -OH, -CN, C1-20 It is a group constituting a monovalent hydrocarbon group, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a group substituted with a halogen atom or a combination thereof. R ^S Is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms. R ^t Is a carbon atom. R ² 'Is a monovalent organic group having 1 to 29 carbon atoms. k is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ ′ May be the same or different, and a plurality of R ² 'May be the same or different. R ^F1 , R ^F2 And R ^F3 Are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or a fluorinated alkyl group having 1 to 20 carbon atoms. i is an integer of 0-9. However, when i is 0, k is 1 or 2. When i is 2 or more, a plurality of R ^F1 May be the same or different, and a plurality of R ^F2 May be the same or different. R ^F3 When there are multiple, multiple R ^F3 May be the same or different. However, one or more R ^F1 One or more R ^F2 And one or more R ^F3 At least one of these is a fluorine atom or a perfluoroalkyl group. M ⁺ Is a monovalent radiation-sensitive onium cation. ) A compound represented by the following formula (1) .

(In the formula (1) , R ¹ is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, and -O between carbon and carbon of the alicyclic hydrocarbon group. An aliphatic heterocyclic group containing —, —COO—, —OCOO—, —S—, —SO ₂ O—, —NHCOO—, —SiR ^S ₂ —, or a combination thereof, or the above alicyclic hydrocarbon group and Some or all of the hydrogen atoms of the aliphatic heterocyclic group are —OH, —CN, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, halogen R ^t and R ^y are groups substituted by an atom or a combination thereof, and R ^t and R ^y are bonded to the same carbon atom on the ring structure of the alicyclic hydrocarbon group and the aliphatic heterocyclic group or adjacent to each other. Bonded to two carbon atoms, R ^S is a hydrogen atom, A monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, R ^t is a carbon atom, and R ^y is a monovalent hydrocarbon having 1 to 30 carbon atoms. K is an integer of 1 to 3. When k is 2 or more, the plurality of R ¹ may be the same or different, and the plurality of R ^y may be the same or different. R ^F1 , R ^F2 and R ^F3 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms or a fluorinated alkyl group having 1 to 20 carbon atoms, i being 0 to 9; Provided that when i is 0, k is 1 or 2. When i is 2 or more, a plurality of R ^F1 may be the same or different, and a plurality of R ^F2 may be the same or different. Again good .R ^F3 is plural, the plurality of R ^F3 may be the same or different. However, 1 Moshiku A is .M ⁺ is at least one fluorine atom or a perfluoroalkyl group of the plurality of R ^F1, one or more of R ^F2 and one or more of R ^F3, a monovalent radiation-sensitive onium cation. ) A compound represented by the following formula (1'-a) or a compound represented by the following formula (1'-b).

(In the formulas (1'-a) and (1'-b), R ¹ 'Is a divalent alicyclic hydrocarbon group having 3 to 20 ring members together with the carbon atom to which this group is bonded, and -O-, -COO-, -OCOO between the carbon and carbon of the alicyclic hydrocarbon group. -, -S-, -SO ₂ O-, -NHCOO-, -SiR ^S ₂ -Or an aliphatic heterocyclic group containing a combination thereof, or a part or all of the hydrogen atoms of the alicyclic hydrocarbon group and the aliphatic heterocyclic group are -OH, -CN, C1-20 It is a group constituting a monovalent hydrocarbon group, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, a group substituted with a halogen atom or a combination thereof. R ^S Is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms. R ^t Is a carbon atom. R ² 'Is a monovalent organic group having 1 to 29 carbon atoms. k is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ ′ May be the same or different, and a plurality of R ² 'May be the same or different. R ^F1 , R ^F2 And R ^F3 Are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms, or a fluorinated alkyl group having 1 to 20 carbon atoms. i is an integer of 0-9. However, when i is 0, k is 1 or 2. When i is 2 or more, a plurality of R ^F1 May be the same or different, and a plurality of R ^F2 May be the same or different. R ^F3 When there are multiple, multiple R ^F3 May be the same or different. However, one or more R ^F1 One or more R ^F2 And one or more R ^F3 At least one of these is a fluorine atom or a perfluoroalkyl group. M ⁺ Is a monovalent radiation-sensitive onium cation. )