JP6354445B2 - Radiation sensitive resin composition, resist pattern forming method, acid diffusion controller and compound - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition, a resist pattern forming method, an acid diffusion controller and a compound.

  Radiation sensitive resin compositions used for fine processing by lithography are far ultraviolet rays such as KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm) and extreme ultraviolet light (EUV: Extreme Ultraviolet, wavelength 13.5 nm). The acid is generated in the exposed area by irradiation with a charged particle beam such as an electron beam, and a chemical reaction using this acid as a catalyst causes a difference in the dissolution rate in the developer between the exposed area and the unexposed area. A 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 has not only excellent resolution of the resist pattern to be formed and rectangularity of the cross-sectional shape, but also LWR (Line Width Roughness) performance, CDU (Critical Dimension Uniformity) performance. In addition, it is required to obtain a high-accuracy pattern with a high yield, with excellent depth of focus, exposure margin, and MEEF (Mask Error Enhancement Factor) performance. Further, the radiation sensitive resin composition is also required to have good storage stability. In response to these requirements, the types, molecular structures, and the like of the acid generators, acid diffusion controllers and other components used in the radiation-sensitive resin composition have been studied in detail. Among such acid diffusion controllers, an onium salt compound composed of a radiolytic onium cation and a weak acid anion loses the acid trapping function in the exposed part and exhibits the acid trapping function only in the unexposed part. It can be improved (see JP-A-11-125907, JP-A-8-146610 and JP-A-2000-298347).

  However, at present, when the miniaturization of resist patterns is progressing to a level of a line width of 45 nm or less, the required level of the performance is further increased, and the conventional radiation-sensitive resin composition satisfies these requirements. I can't.

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

  The present invention has been made based on the circumstances as described above, and its purpose is to ensure good storage stability, LWR performance, CDU performance, resolution, cross-sectional rectangularity, depth of focus, exposure. An object of the present invention is to provide a radiation-sensitive resin composition having excellent margin and MEEF performance (hereinafter also referred to as “LWR performance”).

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”). A radiation-sensitive acid generator (hereinafter also referred to as “[B] acid generator”), a compound comprising a radiolytic onium cation and a counter anion (hereinafter also referred to as “[C] compound”), and a solvent ( Hereinafter referred to as “[D] solvent”), and the counter anion has two or more carbonyl groups and —N ⁻ — adjacent to one of the carbonyl groups. These are radiation-sensitive resin compositions in which they are bonded via a single bond, a substituted or unsubstituted alkanediyl group having 1 or 2 carbon atoms, or a substituted or unsubstituted 1,2-benzenediyl group.

  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.

（式（１）中、Ｒ^１は、単結合、置換若しくは非置換のメタンジイル基、置換若しくは非置換のエタンジイル基、又は置換若しくは非置換の１，２−ベンゼンジイル基である。Ｒ^２及びＲ^３は、それぞれ独立して、炭素数１〜３０の１価の有機基である。ｎは、１以上３以下の整数である。ｎが２以上の場合、複数のＲ^１は同一でも異なっていてもよい。Ｍ^＋は、１価の放射線分解性オニウムカチオンである。但し、Ｒ^１、Ｒ^２及びＲ^３のうちの２つ以上は、これらの結合により環員数５〜３０の環構造を形成してもよい。） Yet another invention made to solve the above problems is an acid diffusion controller comprising a compound represented by the following formula (1).

(In Formula (1), R ¹ is a single bond, a substituted or unsubstituted methanediyl group, a substituted or unsubstituted ethanediyl group, or a substituted or unsubstituted 1,2-benzenediyl group. R ² and R ³ is each independently a monovalent organic group having 1 to 30 carbon atoms, n is an integer of 1 to 3, and when n is 2 or more, a plurality of R ¹ are the same or different. M ⁺ is a monovalent radiolytic onium cation, provided that two or more of R ¹ , R ² and R ³ form a ring structure having 5 to 30 ring members by these bonds. It may be formed.)

  Yet another invention made to solve the above problems is a compound represented by the above formula (1).

  Here, the “organic group” refers to a group containing at least one carbon atom. The “hydrocarbon group” includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. This “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. The term “alicyclic hydrocarbon group” refers to a hydrocarbon group that includes only an alicyclic structure as a ring structure and does not include an aromatic ring structure, and includes a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic group. Includes both hydrocarbon groups. However, it is not necessary to be composed only of the alicyclic structure, and a part thereof may include a chain structure. “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.

  According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, while maintaining good storage stability, it exhibits excellent depth of focus, exposure margin and MEEF performance, LWR performance, CDU performance, solution It is possible to form a resist pattern that is excellent in image quality and rectangular cross-sectional shape. The acid diffusion controller of the present invention can be suitably used as a component of the radiation sensitive resin composition. The compound of the present invention can be suitably used as the acid diffusion controller. Therefore, they can be suitably used for pattern formation in semiconductor device manufacturing or the like where further miniaturization is expected.

<Radiation sensitive resin composition>
The radiation sensitive resin composition contains a [A] polymer, a [B] acid generator, a [C] compound, and a [D] solvent. The radiation-sensitive resin composition may contain [E] fluorine atom-containing polymer and [F] uneven distribution accelerator as suitable components. Furthermore, the said radiation sensitive resin composition may contain the other arbitrary component in the range which does not impair the effect of this invention. 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 part is dissociated by the acid generated from the [B] acid generator and the like by irradiation with radiation, and the exposed part and the unexposed part As a result, 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 usually a base polymer in the radiation-sensitive resin composition. The “base polymer” refers to a polymer that is a main component of the polymers constituting the resist pattern, and preferably occupies 50% by mass or more, more preferably 60% by mass or more.

  [A] In addition to the structural unit (I), the polymer [A] is at least one selected from the group consisting of a structural unit represented by the formula (3-1) described later and a structural unit represented by (3-2). Species (hereinafter also referred to as “structural unit (II)”), structural unit represented by formula (4) described later (hereinafter also referred to as “structural unit (III)”), and structural units (I) to (III) Other structural units other than) may be included. [A] The polymer may have one or more of these structural units. 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 structural unit (2-2). And a structural unit (hereinafter also referred to as “structural unit (I-2)”).

In the formula (2-1), ^{R 6} is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid dissociable group.
In the above formula (2-2), ^{R 7} is a hydrogen atom or a methyl group. Y ² is a monovalent acid dissociable group.

R ⁶ 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 (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 hydrocarbon group having 1 to 20 carbon atoms, or a ring member having 3 to 20 ring atoms together with the carbon atoms to which these groups are combined with each other. Represents an alicyclic structure.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and 3 to 20 carbon atoms. Monovalent alicyclic hydrocarbon groups, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, and the like.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include:
Alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl and n-pentyl;
Alkenyl groups such as ethenyl group, propenyl group, butenyl group, pentenyl group;
Examples thereof 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 more preferable, a methyl group, an ethyl group, and an i-propyl group are further preferable, and an ethyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include:
A monocyclic cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl 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;
Examples thereof include polycyclic cycloalkenyl groups such as norbornenyl group and 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 include:
Aryl groups such as phenyl, tolyl, xylyl, naphthyl and anthryl;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, and naphthylmethyl group.

  Among these, an aryl group is preferable, an aryl group having 6 to 10 carbon atoms is preferable, a phenyl group and a naphthyl group are more preferable, and a phenyl group is more preferable.

Examples of the alicyclic structure having 3 to 20 ring members constituted by combining these groups with each other include:
Monocyclic cycloalkane structures such as cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, cyclooctane structure;
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 pentane structure, a cyclohexane structure, a cyclooctane structure, a norbornane structure, and an adamantane structure are more preferable, and a cyclopentane structure and an adamantane structure are particularly preferable.

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. It is preferable to represent an alicyclic structure having 3 to 20 ring members constituted together with atoms, R ^e1 is an alkyl group having 1 to 10 carbon atoms, and R ^e2 and R ^e3 are combined with each other and bonded to each other It is more preferable to represent a cycloalkane structure having 3 to 20 ring members, and R ^e1 is an alkyl group having 1 to 4 carbon atoms, and R ^e2 and R ^e3 are combined with each other and bonded to each other. It is more preferable to represent a monocyclic cycloalkane structure having 5 to 8 ring members or a polycyclic cycloalkane structure having 7 to 12 ring members.

R ⁷ is preferably a hydrogen atom from the viewpoint of copolymerizability of the monomer that gives 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 hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxy group having 1 to 20 carbon atoms. It is a hydrocarbon group. However, R ^e4 , R ^e5 and R ^e6 are not simultaneously hydrogen atoms.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and 3 to 20 carbon atoms. Monovalent alicyclic hydrocarbon groups, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, and the like.

A monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms and a carbon number of 6 to 20 represented by R ^e4 , R ^e5 and R ^e6 . Examples of the monovalent aromatic hydrocarbon group include the same groups as those exemplified above as R ^e1 , R ^e2 and R ^e3 .

Among these, as R ^e4 , R ^e5 and R ^e6 , a chain hydrocarbon group and an alicyclic hydrocarbon group are preferable, an alkyl group and a cycloalkyl group are more preferable, and an alkyl group having 1 to 4 carbon atoms. A monocyclic cycloalkyl group and a polycyclic cycloalkyl group are more preferable, and a methyl group, an ethyl group, an n-propyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are particularly preferable.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms represented by the above R ^e4 , R ^e5 and R ^e6 include, for example, a monovalent oxy chain hydrocarbon group having 1 to 20 carbon atoms and 3 carbon atoms. -20 monovalent oxyalicyclic hydrocarbon groups, monovalent oxyaromatic hydrocarbon groups having 6 to 20 carbon atoms, and the like.

Examples of the monovalent oxy-chain hydrocarbon group having 1 to 20 carbon atoms include:
Alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, sec-butoxy group, t-butoxy group and n-pentyloxy group;
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 include:
A monocyclic cycloalkyloxy group such as a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a 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 monovalent oxyaromatic hydrocarbon group having 6 to 20 carbon atoms include:
Aryloxy groups such as phenoxy group, tolyloxy group, naphthyloxy group;
Examples thereof include aralkyloxy groups such as benzyloxy group, phenethyloxy group and naphthylmethoxy group.

  Among these, an aryloxy group is preferable and a phenoxy group is more preferable.

As the group represented by the above formula (Y-2), R ^e4 is a hydrogen atom and R ^e5 and R ^e6 are monovalent chain hydrocarbon groups, R ^e4 is a hydrogen atom, and R ^e5 is monovalent. A group in which R ^e6 is a monovalent alicyclic hydrocarbon group, a group in which R ^e4 , R ^e5 and R ^e6 are a monovalent chain hydrocarbon group, R ^e4 and R ^e5 are A group in which a monovalent chain hydrocarbon group and R ^e6 is a monovalent oxy chain hydrocarbon group is preferable, a group in which R ^e4 is a hydrogen atom, R ^e5 and R ^e6 are alkyl groups, and R ^e4 is a hydrogen atom R ^e5 is an alkyl group and R ^e6 is a cycloalkyl group, R ^e4 , R ^e5 and R ^e6 are alkyl groups, R ^e4 and R ^e5 are alkyl groups, and R ^e6 is an alkoxy group. more ^{preferably, R e4} are hydrogen ^{atoms, R e5} is an alkyl group and ^{R e} There is a more preferred cycloalkyl group, 1- (cyclohexyl) ethyl group is particularly preferred.

As the structural unit (I), for example,
As the structural unit (I-1), structural units represented by the following formulas (2-1-1) to (2-1-7)
Examples of the structural unit (I-2) include structural units represented by the following formulas (2-2-1) to (2-2-3).

In the formulas (2-1-1) to (2-1-7), R ⁶ has the same meaning as the formula (2-1). R ^e1 , R ^e2 and R ^e3 have the same ^{meaning as} in the above formula (Y-1). Each r is independently an integer of 1 to 3.
In the formulas (2-2-1) to (2-2-3), R ⁷ has the same meaning as the formula (2-2).

  As the structural unit (I), in the above formulas (2-1-2), (2-1-3), (2-1-4), (2-1-5) and (2-2-3) The structural unit represented is preferably a structural unit containing a cyclopentane structure, a structural unit containing a cyclohexane structure, a structural unit containing an adamantane structure is more preferred, and a structural unit derived from 1-ethyl-1-cyclopentyl (meth) acrylate, Structural units derived from 2-methyl-2-adamantyl (meth) acrylate, structural units derived from 2-ethyl-2-adamantyl (meth) acrylate, derived from adamantane-1-yl-2-propyl (meth) acrylate Structural unit, structural unit derived from cyclohexyl-2-propyl (meth) acrylate, derived from 2-ethyl-tetracyclododecyl (meth) acrylate Concrete units, 1 structural unit derived from (cyclohexyl) ethoxy styrene is more preferable.

  As a content rate of structural unit (I), 10 mol%-70 mol% are preferable with respect to all the structural units which comprise a [A] polymer, 20 mol%-60 mol% are more preferable, 30 mol% -55 mol% is further more preferable, and 35 mol%-50 mol% is especially preferable. By making the content rate of structural unit (I) into the said range, the said radiation sensitive resin composition can further improve LWR performance etc.

[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 dispersibility of the [B] acid generator and / or the [C] compound in the [A] polymer can be improved. 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 8} represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. E ¹ is a single bond, —COO— or CO—O— (CH ₂ ) _i . i is an integer of 1-6. R ⁹ is a non-acid dissociable group containing a polar group.
In said formula (3-2), R < ^{8 '>} 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. s is an integer of 1 to 3. When s is 2 or more, the plurality of R ^a and R ^b may be the same or different. R ^9a and R ^9b are each independently a hydrogen atom, a fluorine atom, a hydroxy group or a monovalent organic group, or the number of ring members composed of these groups together with the carbon atom to which these groups are combined and bonded to each other Represents a ring structure of ˜30.

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

E ¹ is preferably —COO— 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 ⁹ that includes a polar group include monovalent groups (a) such as a hydroxy group, a carboxy group, a cyano group, a sulfo group, and a mercapto group; Examples thereof include a carbonyl group, -O-, -S-, and a divalent group (b) formed by combining these.

Examples of the non-acid-dissociable and polar group-containing group represented by R ⁹ include, for example, a part or all of the hydrogen atoms of a monovalent hydrocarbon group having 1 to 20 carbon atoms as the monovalent group ( a group substituted with a), a group containing the divalent group (b) between some or all of the carbon-carbons of a monovalent hydrocarbon group having 1 to 20 carbon atoms, monovalent having 1 to 20 carbon atoms A part or all of the hydrogen atoms of the hydrocarbon group is substituted with the monovalent group (a), and a group containing the divalent group (b) between some or all of the carbon-carbons. Can be mentioned.

Examples of the monovalent 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 R ⁹ 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 the lactone structure include a butyrolactone-yl group, a norbornane lactone-yl group, and a 5-oxo-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-yl group. It is done.
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), the R ^{8 ′} is preferably a hydrogen atom from the viewpoint of copolymerization of the monomer that gives the structural unit (II-2).

Examples of the monovalent organic group represented by R ^a , R ^b , R ^9a, and R ^9b include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, and a part of hydrogen atoms that the hydrocarbon group has. Or a group in which all the substituents are substituted, carbon-carbon of these groups -CO-, -CS-, -O-, -S- or -NR'-, or a combination of two or more thereof And groups containing the above groups. R ′ is a hydrogen atom or a monovalent organic group.

Examples of the ring structure having 3 to 30 ring members composed of the carbon atoms to which R ^9a and R ^9b are combined and bonded to each other include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a norbornane structure, an adamantane Examples thereof include alicyclic structures such as structures; aliphatic heterocyclic structures such as oxacyclopentane structures, thiacyclopentane structures, and azacyclopentane structures.

  As s, 1 or 2 is preferable and 1 is more preferable.

As the structural unit (II), for example,
As the structural unit (II-1), structural units represented by the following formulas (3-1-1) to (3-1-11) (hereinafter referred to as “structural units (II-1-1) to (II-1-)”. 11) "))
As the structural unit (II-2), structural units represented by the following formulas (3-2-1) and (3-2-2) (hereinafter referred to as “structural units (II-2-1) and (II-2-2)”) 2) ")) and the like.

In the above formulas (3-1-1) to (3-1-11), R ⁸ has the same meaning as the above formula (3-1).
In the formulas (3-2-1) and (3-2-2), R ^{8 ′} has the same meaning as the formula (3-2).

  Among these, the structural unit (II-1) is preferable, and the structural units (II-1-1), (II-1-2), (II-1-3), (II-1-8), (II -1-11) is more preferable.

  As a content rate of structural unit (II), 0 mol%-80 mol% are preferable with respect to all the structural units which comprise a [A] polymer, 10 mol%-70 mol% are more preferable, 30 mol% -60 mol% is more preferable. By making the content rate of structural unit (II) into the said range, the dispersibility in the [A] polymer of a [B] acid generator and a [C] compound improves more, As a result, the said radiation sensitive resin The LWR performance and the like of the composition 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 10} is a hydrogen atom or a methyl group. R ¹¹ is a monovalent organic group having 1 to 20 carbon atoms. p is an integer of 0-3. If R ¹¹ is plural, plural R ¹¹ may be the same or different. q is an integer of 1 to 3. However, p and q satisfy p + q ≦ 5.

R ¹⁰ is preferably a hydrogen atom from the viewpoint of copolymerizability of the monomer that gives the structural unit (III).

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹¹ include a monovalent hydrocarbon group having 1 to 20 carbon atoms and a part or all of the hydrogen atoms possessed by the hydrocarbon group. A group substituted by a substituent, a carbon-carbon-CO-, -CS-, -O-, -S- or -NR "-group between these groups, or a combination of two or more thereof. And R ″ is a hydrogen atom or a monovalent organic group.
Among these, a monovalent chain hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is more preferable.

  As said p, the integer of 0-2 is preferable, 0 or 1 is more preferable, and 0 is further more preferable.

  The q is preferably 1 or 2, and more preferably 1.

  Examples of the structural unit (III) include structural units represented by the following formulas (4-1) to (4-4) (hereinafter also referred to as “structural units (III-1) to (III-4)”). Etc.

In the above formulas (4-1) to (4-4), R ¹⁰ has the same meaning as the above formula (4).

  Among these, the structural units (III-1) and (III-2) are preferable, and the structural unit (III-1) is more preferable.

  As a content rate of structural unit (III), 0 mol%-90 mol% are preferable with respect to all the structural units which comprise a [A] polymer, 30 mol%-80 mol% are more preferable, 50 mol% More preferred is ˜75 mol%. 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) was polymerized using a monomer obtained by substituting the hydrogen atom of the OH group of hydroxystyrene with a t-butyl group, and the resulting polymer was hydrolyzed in the presence of a base such as an amine. It can be formed by performing a decomposition reaction 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 the said other 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] The content of the polymer is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 85% by mass or more with respect to the total solid content of the radiation-sensitive resin composition.

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized according to a conventional method such as radical polymerization. For example, 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, a solution containing a monomer and a solution containing a radical initiator A method of performing a polymerization reaction by dropping each into a solution containing a reaction solvent or a monomer, a plurality of types of solutions containing each monomer and a solution containing a radical initiator separately from each other It is preferable to synthesize by a method in which a polymerization reaction is performed by dropping into a solution containing a body, a method in which a solution containing a monomer and a radical initiator is polymerized in a solventless or reaction solvent.

  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. Usually, it is 30 degreeC-150 degreeC, 40 degreeC-150 degreeC is preferable, and 50 degreeC-140 degreeC is more preferable. Although dripping time changes with conditions, such as reaction temperature, the kind of initiator, and the monomer made to react, it is 30 minutes-8 hours normally, 45 minutes-6 hours are preferable, and 1 hour-5 hours are more preferable. Also, the total reaction time including the dropping time varies depending on the conditions as in the dropping time, but is usually 30 minutes to 12 hours, preferably 45 minutes to 12 hours, and more preferably 1 to 10 hours.

  Examples of the radical initiator used in the polymerization include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), and 2,2′-azobis. (2-cyclopropylpropionitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate), dimethyl 2,2'-azobis Azo radical initiators such as isobutyrate; 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 weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is preferably 1,000 to 50,000, more preferably 2,000 to 40,000, and more preferably 3,000 to 3,000. 30,000 is more preferable, and 5,000 to 20,000 is particularly preferable. [A] When 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 lowered. [A] When the Mw of the polymer exceeds the above upper limit, the developability of the radiation sensitive resin composition may be deteriorated.

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

Mw and Mn of the polymer in this specification are values measured using gel permeation chromatography (GPC) under the following conditions.
GPC column: 2 "G2000HXL" from Tosoh Corporation, 1 "G3000HXL", 1 "G4000HXL" Column temperature: 40 ° C
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<[B] Acid generator>
[B] The acid generator is a substance that generates an acid upon exposure (except for those corresponding to the [C] compound. The [B] acid generator generates an acid stronger than the acid generated from the [C] compound. Occur). Since the acid-dissociable group of the [A] polymer or the like is dissociated by the generated acid to generate a carboxy group or the like, and the solubility of these polymers in the developer changes, the radiation-sensitive resin composition From this, a resist pattern can be formed. The content form of the [B] acid generator in the radiation-sensitive resin composition may be a low molecular compound form (hereinafter referred to as “[B] acid generator” as appropriate), as described later. It may be a form incorporated as a part or both of these forms.

  [B] Examples of the acid generator include onium salt compounds, N-sulfonyloxyimide compounds, halogen-containing compounds, diazoketone compounds, and the like.

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

  [B] Specific examples of the acid generator include compounds described in paragraphs [0080] to [0113] of JP-A-2009-134088.

  [B] The acid generator is preferably a compound represented by the following formula (5). [B] By making the acid generator a compound represented by the following formula (5), [A] the diffusion length of the acid generated by exposure in the resist film due to the interaction with the polar structure of the polymer, etc. As a result, the LWR performance and the like of the radiation sensitive resin composition can be further improved.

In the above formula (5), R ^a1 is a monovalent group containing an alicyclic structure having 6 or more ring members or a monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members. R ^a2 is a fluorinated alkanediyl group having 1 to 10 carbon atoms. M ⁺ is a monovalent radiolytic onium cation.

The “number of ring members” in R ^a1 means the number of atoms constituting the ring of the alicyclic structure and the aliphatic heterocyclic structure, and in the case of the polycyclic alicyclic structure and the polycyclic aliphatic heterocyclic structure, The number of atoms that make up a polycycle.

Examples of the monovalent group containing an alicyclic structure having 6 or more ring members represented by R ^a1 above include:
A monocyclic cycloalkyl group such as a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a cyclododecyl group;
A monocyclic cycloalkenyl group such as a cyclooctenyl group and a cyclodecenyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group;
Examples thereof include polycyclic cycloalkenyl groups such as norbornenyl group and tricyclodecenyl group.

Examples of the monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members represented by R ^a1 above include:
A group containing a lactone structure such as a norbornanelactone-yl group;
A group containing a sultone structure such as a norbornane sultone-yl group;
An oxygen atom-containing heterocyclic group such as an oxacycloheptyl group and an oxanorbornyl group;
A nitrogen atom-containing heterocyclic group such as an azacyclohexyl group, an azacycloheptyl group, a diazabicyclooctane-yl group;
And sulfur atom-containing heterocyclic groups such as a thiacycloheptyl group and a thianorbornyl group.

The number of ring members of the group represented by R ^a1 is preferably 8 or more, more preferably 9 to 15 and even more preferably 10 to 13 from the viewpoint that the diffusion length of the acid described above becomes more appropriate.

Among these, a monovalent group including an alicyclic structure having 9 or more ring members and a monovalent group including an aliphatic heterocyclic structure having 9 or more ring members are preferable, and an adamantyl group, a hydroxyadamantyl group, norbornanelactone-yl. The group, 5-oxo-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-yl group is more preferable, and an adamantyl group is further preferable.

Examples of the fluorinated alkanediyl group having 1 to 10 carbon atoms represented by R ^a2 include one or more hydrogen atoms of an alkanediyl group having 1 to 10 carbon atoms such as a methanediyl group, an ethanediyl group, and a propanediyl group. And a group in which is substituted with a fluorine atom. Among these, SO ₃ ^- fluorinated alkane diyl group which has a fluorine atom to carbon atom is bonded to adjacent groups are preferred, SO ₃ ^- 2 fluorine atoms to the carbon atom adjacent to the group is attached More preferred are fluorinated alkanediyl groups, 1,1-difluoromethanediyl group, 1,1-difluoroethanediyl group, 1,1,3,3,3-pentafluoro-1,2-propanediyl group, 1,1 1,2,2-tetrafluoroethanediyl group, 1,1,2,2-tetrafluorobutanediyl group, and 1,1,2,2-tetrafluorohexanediyl group are more preferable.

Examples of the monovalent radiolytic onium cation represented by M ⁺ include the same cations as those exemplified as the radiolytic onium cation possessed by the [C] compound described later. Among these, a sulfonium cation is preferable, and a triphenylsulfonium cation is more preferable.

  [B] Examples of the acid generator include compounds represented by the following formulas (5-1) to (5-13) (hereinafter also referred to as “compounds (5-1) to (5-13)”). Can be mentioned.

In the above formulas (5-1) to (5-13), M ⁺ has the same meaning as the above formula (5).

  Among these, the compound (5-1), the compound (5-2), the compound (5-12), and the compound (5-13) are preferable.

  Moreover, as the [B] acid generator, a polymer in which the structure of the above formula (5) such as a polymer having a structural unit represented by the following formula (5-14) is incorporated as a part of the polymer is also available. preferable.

In the above formula (5-14), R ″ represents a hydrogen atom or a methyl group. M ⁺ has the same meaning as in the above formula (5).

  [B] As the content of the acid generator, when the [B] acid generator is a [B] acid generator, from the viewpoint of improving the sensitivity and developability of the radiation-sensitive resin composition, [A] 0.1 mass part-30 mass parts are preferable with respect to 100 mass parts of unification, 0.5 mass part-20 mass parts are more preferable, 1 mass part-15 mass parts are more preferable, 3 mass parts-15 mass parts Part is particularly preferred. [B] When the acid generator is incorporated as a part of the polymer, from the viewpoint of improving the sensitivity and developability of the radiation-sensitive resin composition, [A] with respect to all structural units constituting the polymer. 1 mol% to 30 mol% is preferable, 2 mol% to 20 mol% is more preferable, and 3 mol% to 10 mol% is more preferable. [B] 1 type (s) or 2 or more types can be used for an acid generator.

<[C] Compound>
The compound [C] comprises a radiolytic onium cation and a counter anion, and the counter anion has two or more carbonyl groups and —N ⁻ — adjacent to one of the carbonyl groups, The carbonyl group is a compound in which a single bond, a substituted or unsubstituted alkanediyl group having 1 or 2 carbon atoms, or a substituted or unsubstituted 1,2-benzenediyl group is bonded.
The radiation-sensitive resin composition contains a [C] compound in addition to the [A] polymer and the [B] acid generator, thereby ensuring excellent storage stability and excellent LWR performance and the like. .

The compound [C] exhibits an acid trapping function by N ^{− in} the unexposed area, but in the exposed area, protons generated from M ⁺ by exposure bind to N ⁻ to NH. Therefore, the acid-trapping function is lowered by exposure, that is, the [C] compound functions as a radiation-sensitive acid diffusion controller. However, the [C] compound shall not fall under the above [B] acid generator.

The reason why the radiation-sensitive resin composition contains the [C] compound to achieve the above effect is not necessarily clear, but can be inferred as follows, for example. That is, in the [C] compound, a nitrogen atom is an anion, a carbonyl group is bonded to this, and a single bond, an alkanediyl group having 1 or 2 carbon atoms, or a 1,2-benzenediyl group is relatively short. It has one of the other carbonyl groups through the R ¹ group. Therefore, the [C] compound is considered to have a higher basicity than the conventional acid diffusion controller containing a sulfonate anion and the like, and the acid trapping function is enhanced, and the quench contrast between the exposed and unexposed areas is increased. Can be high. As a result, it is considered that the LWR performance and the like of the radiation sensitive resin composition are improved. On the other hand, since the basicity of the [C] compound is suppressed to an appropriate height by the above-described specific structure, it is considered that the radiation-sensitive resin composition can ensure good storage stability.

  [C] As the compound, a compound represented by the following formula (1) is preferable. The said radiation sensitive resin composition can improve LWR performance etc. more by using the compound represented by following formula (1) as a [C] compound. Moreover, such a [C] compound is excellent also in synthetic | combination ease.

In the above formula (1), R ¹ is a single bond, a substituted or unsubstituted methanediyl group, a substituted or unsubstituted ethanediyl group, or a substituted or unsubstituted 1,2-benzenediyl group. R ² and R ³ are each independently a monovalent organic group having 1 to 30 carbon atoms. n is an integer of 1 or more and 3 or less. When n is 2 or more, the plurality of R ¹ may be the same or different. M ⁺ is a monovalent radiolytic onium cation. However, two or more of R ¹ , R ² and R ³ may form a ring structure having 5 to 30 ring members by these bonds.

Examples of the substituent that the methanediyl group, ethanediyl group and 1,2-benzenediyl group of R ¹ may have include, for example, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, a hydroxy group, a carboxy group, Group, 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.

More specifically, as R ¹ , for example, groups represented by the following formulas (C ₁ -1) to (C ₁ -10) (hereinafter referred to as “groups (C ₁ -1) to (C ₁ -10)”. ) ")) And the like.

In the above formulas (C ₁ -1) to (C ₁ -10), * and ** represent a bond.

As R ¹ , since the basicity tends to be adjusted to a more appropriate height, a single bond, groups (C ₁ -1) to (C ₁ -3), (C ₁ -5), (C _1-6) is preferably a single bond.

Examples of the monovalent organic group having 1 to 30 carbon atoms represented by R ² and R ³ include, for example, a monovalent hydrocarbon group having 1 to 30 carbon atoms, a carbon-carbon bond or a bond of this hydrocarbon group. A group (q) containing a divalent heteroatom-containing group at the terminal on the side, a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group and group (q) with a monovalent heteroatom-containing group, etc. Can be mentioned.

  Examples of the monovalent hydrocarbon group having 1 to 30 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:
Alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group and butynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include:
A monocyclic cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group;
A monocyclic cycloalkenyl group such as a cyclobutenyl group, a cyclopentenyl group, or a cyclohexenyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group;
And polycyclic cycloalkenyl groups such as a norbornenyl group, a tricyclodecenyl group, and a tetracyclododecenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include:
Aryl groups such as phenyl, tolyl, xylyl, naphthyl and anthryl;
Examples include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and the like.

  Examples of the heteroatoms possessed by the monovalent and divalent heteroatom-containing groups include halogen atoms such as oxygen atoms, sulfur atoms, nitrogen atoms, silicon atoms, phosphorus atoms, fluorine atoms, chlorine atoms, and bromine atoms. . Among these, an oxygen atom, a sulfur atom, a nitrogen atom and a halogen atom are preferable, and an oxygen atom and a fluorine atom are more preferable.

Examples of the divalent heteroatom-containing group include —O—, —CO—, —CO—CO—, —CS—, —NR′—, —SO ₂ —, —SO ₃ —, and combinations thereof. Etc. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

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

More specifically, as R ² and R ³ , for example, groups represented by the following formulas (C ₂ -1) to (C ₂ -21) (hereinafter referred to as “groups (C ₂ -1) to (C ₂ -21), "also referred to), and the like.

In the formula _{(C 2 -1) ~ (C} 2 -21), * represents a bond.

Among them, the examples of ^{R 2,} based on _{(C 2 -1) ~ (C} 2 -10) is preferably the group _{(C 2 -1) ~ (C} 2 -3), (C 2 -5), _{(C 2 -7), (C} 2 -9), (C 2 -10) is more preferable.
As the ^{R 3,} is preferably a group _{(C 2 -11) ~ (C} 2 -21), group _{(C 2 -11), (C} 2 -12), (C 2 -14), (C 2 -15 _{), (C 2 -17) ~} (C 2 -19), (C 2 -21) is more preferable.

R ² is —COR ⁴ , —SO ₂ R ^4, or —SO ₃ R ⁴ from the viewpoint that the basicity can be adjusted to a more appropriate height, and this R ⁴ is 1 having 1 to 20 carbon atoms. A valent organic group is preferred.
Examples of the monovalent organic group for R ⁴ include those having 1 to 20 carbon atoms among the groups exemplified as the monovalent organic groups for R ² and R ³ .

It is also preferred that at least one of R ² and R ³ contains a fluorine atom. By doing so, the basicity tends to be adjusted to a more appropriate height.

Examples of the ring structure that two or more of R ¹ , R ² and R ³ may form include, for example:
Monocyclic cycloalkane structures such as cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, cyclooctane structure;
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;
Polycyclic cycloalkene structures such as norbornene structure, tricyclodecene structure, tetracyclododecene structure;
Oxacycloalkane structures such as oxacyclopentane structure, oxacyclohexane structure, oxanorbornane structure;
Azacycloalkane structures such as azacyclopentane structure, azacyclohexane structure, azanorbornane structure;
Examples include thiacycloalkane structures such as a thiacyclopentane structure, a thiacyclohexane structure, and a thianorbornane structure.

It is also preferable that R ¹ in the above formula (1) is a single bond, and R ² is a monovalent fluorinated hydrocarbon group having 1 to 30 carbon atoms. Also in this case, the basicity tends to be adjusted to a more appropriate height.

  As n in the formula (1), 1 or 2 is preferable, and 1 is more preferable. By setting n to the above value, the [C] compound is more excellent in the ease of synthesis.

Examples of the monovalent radiolytic onium cation represented by M ⁺ include a sulfonium cation and an iodonium cation.

  Examples of the sulfonium cation include a cation represented by the following formula (Q-1), a cation represented by the following formula (Q-2), and the like. Examples of the iodonium cation include the following formula (Q-3). And cations represented.

In the above formula (Q-1), R ^b1 , R ^b2 and R ^b3 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, substituted or unsubstituted. aromatic hydrocarbon group having 6 to 12 carbon atoms, a or a -OSO ₂ -R ^P or _-SO 2 -R ^Q, or two or more are combined with each other configured ring of these groups . R ^P and R ^Q are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k1, k2 and k3 are each independently an integer of 0 to 5. R ^b1 to R ^b3 and when ^{R P} and ^{R Q} are a plurality each of the plurality of ^R b1 ^{to R b3} and ^{R P} and ^{R Q} may be the same as or different from each other.
In the above formula (Q-2), R ^c1 is a substituted or unsubstituted linear or branched alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon having 6 to 8 carbon atoms. It is a group. k4 is an integer of 0 to 7. If R ^c1 is plural, the plurality of R ^c1 may be the same or different, and a plurality of R ^c1 may represent a constructed ring aligned with each other. R ^c2 is a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0-6. If R ^c2 is plural, the plurality of R ^c2 may be the same or different, a plurality of R ^c2 may represent configured ring aligned with each other. t is an integer of 0-3.
In the above formula (Q-3), R ^d1 and R ^d2 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted carbon number of 6 12 aromatic hydrocarbon group, or an -OSO ₂ -R ^R or _-SO 2 -R ^S, or two or more are combined with each other configured ring of these groups. R ^R and R ^S are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k6 and k7 are each independently an integer of 0 to 5. R ^{d1, R} d2, ^R when ^R and ^{R S} is plural respective plurality of ^{R d1,} R d2, ^{R R} and ^{R S} may have respectively the same or different.

Examples of the unsubstituted linear alkyl group represented by R ^{b1 to} R ^b3 , R ^c1 , R ^c2 , R ^d1 and R ^d2 include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group. Etc. Examples of the unsubstituted branched alkyl group represented by R ^{b1 to} R ^b3 , R ^c1 , R ^c2 , R ^d1 and R ^d2 include i-propyl group, i-butyl group, sec-butyl group, t -A butyl group etc. are mentioned. Examples of the unsubstituted aromatic hydrocarbon group represented by R ^{b1 to} R ^b3 , R ^d1, and R ^d2 include aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group, and naphthyl group; benzyl group, And aralkyl groups such as phenethyl group. Examples of the unsubstituted aromatic hydrocarbon group represented by R ^c1 and R ^c2 include a phenyl group, a tolyl group, and a benzyl group.

  Examples of the substituent that may substitute the hydrogen atom of the alkyl group and aromatic hydrocarbon group include the same groups as those exemplified as the substituent that L may have. .

R ^{b1 to} R ^b3 , R ^c1 , R ^c2 , R ^d1 and R ^d2 include an unsubstituted linear or branched alkyl group, a fluorinated alkyl group, and an unsubstituted monovalent aromatic hydrocarbon group. _{^{, -OSO 2 -R T, -SO 2}} -R T is preferably a fluorinated alkyl group, more preferably a monovalent aromatic hydrocarbon group unsubstituted, more preferably a fluorinated alkyl group. R ^T is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

  As k1, k2, and k3 in the formula (Q-1), integers of 0 to 2 are preferable, 0 or 1 is more preferable, and 0 is more preferable. As k4 in the above formula (Q-2), an integer of 0 to 2 is preferable, 0 or 1 is more preferable, and 1 is more preferable. k5 is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0. As k6 and k7 in the formula (Q-3), an integer of 0 to 2 is preferable, 0 or 1 is more preferable, and 0 is more preferable.

  Examples of the sulfonium cation include cations represented by the following formulas (i-1) to (i-23), cations represented by the following formulas (i′-1) to (i′-4), and the like. .

  Among these, the cation represented by the above formula (i-1), the cation represented by the above formulas (i-21) to (i-23), and the cation represented by the above formula (i′-2). Is preferred.

  Examples of the iodonium cation include cations represented by the following formulas (ii-1) to (ii-25).

  Among these, a cation represented by the above formula (ii-1) is preferable.

  Examples of the [C] compound include compounds represented by the following formulas (C-1) to (C-17).

In the above formulas (C-1) to (C-17), M ⁺ is a monovalent radiolytic onium cation.

  Among these, the compounds represented by the above formulas (C-1) to (C-11) are preferable.

  The compound [C] can be synthesized according to the following scheme, for example, when n in the above formula (1) is 1 (a compound represented by the following formula (1 ′)).

In the above scheme, R ¹ is a single bond, a substituted or unsubstituted methanediyl group, a substituted or unsubstituted ethanediyl group, or a substituted or unsubstituted 1,2-benzenediyl group. R ² and R ³ are each independently a monovalent organic group having 1 to 30 carbon atoms. M ⁺ is a monovalent radiolytic onium cation. However, two or more of R ¹ , R ² and R ³ may form a ring structure having 5 to 30 ring members by these bonds. X is a halogen atom. Y ⁻ is a monovalent anion.

By reacting the compound represented by the above formula (a) and the acid halide represented by the above formula (b) in a solvent such as tetrahydrofuran in the presence of a base such as pyridine, the above formula (c) ) Is obtained. The obtained compound (c), in a solvent such as dichloromethane, is reacted with a base such as sodium hydroxide, N ^- after obtaining salt, the N ^- salt and, M ⁺ Y ^- represented by radiolysis in The compound represented by the above formula (1 ′) can be obtained by reacting the active onium salt with, for example, a solvent of dichloromethane / water.

  [C] compounds other than the compound represented by the above formula (1 ') can also be synthesized by the same method as described above.

  As a minimum of content of a [C] compound, 0.1 mass part is preferable with respect to 100 mass parts of [A] polymers, 0.5 mass part is more preferable, 1 mass part is further more preferable. 5 parts by mass is particularly preferred. [C] The upper limit of the content of the compound is preferably 30 parts by mass, more preferably 20 parts by mass, further preferably 10 parts by mass, and particularly preferably 5 parts by mass with respect to 100 parts by mass of the polymer [A]. . By making the content rate of a [C] compound into the said range, the said radiation sensitive resin composition can further improve LWR performance etc., ensuring further favorable storage stability. The radiation-sensitive resin composition may contain one or more [C] compounds.

<[D] solvent>
The radiation-sensitive resin composition usually contains a [D] solvent. [D] The solvent should be a solvent that can dissolve or disperse at least the [A] polymer, the [B] acid generator, the [C] compound, and the [E] fluorine atom-containing polymer contained as necessary. There is no particular limitation. These may use 1 type and may use 2 or more types together.

  [D] Examples of the solvent include alcohol solvents, ether solvents, ketone organic solvents, amide solvents, ester organic solvents, hydrocarbon solvents, and the like.

As an alcohol solvent, for example,
C1-C18 aliphatic monoalcohol solvents such as 4-methyl-2-pentanol and n-hexanol;
An alicyclic monoalcohol solvent having 3 to 18 carbon atoms such as cyclohexanol;
A C2-C18 polyhydric alcohol solvent such as 1,2-propylene glycol;
Examples thereof include C3-C19 polyhydric alcohol partial ether solvents such as propylene glycol monomethyl ether.

As an ether solvent, for example,
Dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether, diheptyl ether;
Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;
And aromatic ring-containing ether solvents such as diphenyl ether and anisole.

Examples of ketone solvents include:
Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-iso-butyl ketone, trimethyl Chain ketone solvents such as Nonanon:
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and methylcyclohexanone:
2,4-pentanedione, acetonylacetone, acetophenone and the like can be mentioned.

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

Examples of ester solvents include:
Monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate;
Polyhydric alcohol carboxylate solvents such as propylene glycol acetate;
Polyhydric alcohol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate;
Polycarboxylic acid diester solvents such as diethyl oxalate;
Examples thereof include carbonate solvents such as dimethyl carbonate and diethyl carbonate.

Examples of the hydrocarbon solvent include
an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms such as n-pentane and n-hexane;
Examples thereof include aromatic hydrocarbon solvents having 6 to 16 carbon atoms such as toluene and xylene.

  Among these, ester solvents and ketone solvents are preferable, polyhydric alcohol partial ether carboxylate solvents and cyclic ketone solvents are more preferable, polyhydric alcohol partial alkyl ether acetates and cycloalkanones are more preferable, and propylene glycol. Monomethyl ether acetate and cyclohexanone are particularly preferred.

<[E] Fluorine atom-containing polymer>
[E] The fluorine atom-containing polymer is a polymer containing a fluorine atom (except for those corresponding to the [A] polymer). When the radiation-sensitive resin composition further contains a [E] fluorine atom-containing polymer in addition to the [A] polymer, the [E] fluorine atom-containing polymer is unevenly distributed in 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] Fluorine atom-containing polymer is not particularly limited, but is itself a polymer that is insoluble in a developer and becomes alkali-soluble by the action of an acid, itself soluble in a developer and alkali-soluble by the action of an acid Polymers that increase in solubility, polymers that are insoluble in the developer and become alkali-soluble by the action of alkali, polymers that are soluble in the developer and increase in alkali-solubility by the action of alkali, and the like .

[E] As an aspect of a 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.

  Examples of the monomer that gives a structure in which a fluorinated alkyl group is bonded to the main chain include, for example, α-trifluoromethyl acrylate compound, β-trifluoromethyl acrylate compound, 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, for example, 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 thereof, and one or more olefin side chains (sites not containing a double bond) are fluorinated alkyl groups or a derivative thereof. .

  Monomers that give a structure in which a fluorinated alkyl group is bonded to the main chain and side chain include, for example, α-trifluoromethylacrylic acid, β-trifluoromethylacrylic acid, α, β-trifluoromethylacrylic acid. Ester compounds in which the side chain is a fluorinated alkyl group or its derivative group, etc., and the side chain of a compound in which the hydrogen atom of one or more vinyl moieties is substituted with a fluorinated alkyl group such as a trifluoromethyl group Substituted with a group or 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 fluorine An alkyl group or a derivative thereof. The alicyclic olefin compound refers to a compound in which a part of the ring is a double bond.

  [E] The fluorine atom-containing polymer is a structural unit represented by the following formula (6) (hereinafter also referred to as “structural unit (f1)” and / or a structural unit represented by the following formula (7) (hereinafter, The [E] fluorine atom-containing polymer has “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 is explained in full detail.

[Structural unit (f1)]
The structural unit (f1) is a structural unit represented by the following formula (6).

In the above formula (6), R ^f3 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^f4 is a C 1-6 linear or branched alkyl group having a fluorine atom or a C 4-20 monovalent alicyclic hydrocarbon group having a fluorine atom. However, one part or all part of the hydrogen atom which the said alkyl group and alicyclic hydrocarbon group have may be substituted.

  As said C1-C6 linear or branched alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group etc. are mentioned, for example.

  Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms include a cyclopentyl group, a cyclopentylpropyl group, a cyclohexyl group, a cyclohexylmethyl group, a cycloheptyl group, a cyclooctyl group, and a cyclooctylmethyl group. It is done.

  Examples of the monomer that gives the structural unit (f1) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, and 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 (meta ) 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) he Sil (meth) acrylate, perfluorocyclohexylmethyl (meth) acrylate, 1- (2,2,3,3,3-pentafluoro) propyl (meth) acrylate, 1- (2,2,3,3,4,4) 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), structural units represented by the following formulas (6-1) and (6-2) are preferable.

In the formulas (6-1) and (6-2), R ^f3 has the same ^meaning as the formula (6).

  Among these, the structural unit represented by the above formula (6-1) is preferable.

  As a content rate of a structural unit (f1), 10 mol%-70 mol% are preferable with respect to all the structural units which comprise a [E] fluorine atom containing polymer, and 20 mol%-50 mol% are more preferable.

[Structural unit (f2)]
The structural unit (f2) is a structural unit represented by the following formula (7).

In the above formula (7), R ^f5 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^f6 is a (r + 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. r is an integer of 1 to 3. However, when r is 2 or 3, the plurality of X ¹ and R ^f7 may be the same or different.

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

  Examples of the (r + 1) -valent linear or branched hydrocarbon group having 1 to 30 carbon atoms include carbonization such as methane, ethane, propane, butane, pentane, hexane, heptane, decane, icosane, and triacontane. And a group obtained by removing (r + 1) hydrogen atoms from a hydrogen group.

Examples of the (r + 1) -valent alicyclic hydrocarbon group having 3 to 30 carbon atoms include:
Monocyclic saturated hydrocarbons such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, methylcyclohexane, ethylcyclohexane;
Monocyclic unsaturated hydrocarbons such as cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene;
Bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [3.3.1.1 ^3,7 ] decane, Tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] polycyclic saturated hydrocarbons such as dodecane and adamantane;
Bicyclo [2.2.1] heptene, bicyclo [2.2.2] octene, tricyclo [5.2.1.0 ^2,6 ] decene, tricyclo [3.3.1.1 ^3,7 ] decene, Tetracyclo [6.2.1.1 ^3,6 . And a group obtained by removing (r + 1) hydrogen atoms from a polycyclic unsaturated hydrocarbon such as 0 ^2,7 ] dodecene.

  Examples of the (r + 1) -valent aromatic hydrocarbon group having 6 to 30 carbon atoms include aromatics such as benzene, naphthalene, phenanthrene, anthracene, tetracene, pentacene, pyrene, picene, toluene, xylene, ethylbenzene, mesitylene, cumene, and the like. And a group obtained by removing (r + 1) hydrogen atoms from the group hydrocarbon group.

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. For example, the following formula (X1-1) Group represented by-(X1-6).

X ¹ is preferably a group represented by the formula (X1-1) and 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 carbon atoms. -30 aromatic hydrocarbon groups, or a group in which these groups are combined with one or more groups selected from the group consisting of an oxygen atom, a sulfur atom, an ether group, an ester group, a carbonyl group and an imino group. It is done.

  Examples of the structural unit (f2) include a structural unit represented by the following formula (7-1), a structural unit represented by the following formula (7-2), and the like.

In the above formulas (7-1) and (7-2), R ^f5 , X ¹ , R ^f7 and r are as defined in the above formula (7).
In the above formula (7-1), R ^f6 is a divalent linear or branched saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, or alicyclic saturation having 3 to 20 carbon atoms. Or it is an unsaturated hydrocarbon group.

  As the structural unit represented by the above formula (7-1), for example, the structural units represented by the following formulas (7-1-1) to (7-1-3) are represented by the above formula (7-2). Examples of the structural unit represented include a structural unit represented by the following formula (7-2-1).

In the above formulas (7-1-1) to (7-1-3) and the formula (7-2-1), R ^f5 has the same meaning as the above formula (7).

  As the structural unit (f2), a structural unit represented by the above formula (7-1) is preferable, and a structural unit represented by the above formula (7-1-3) 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 content rate of a structural unit (f2), 30 mol%-90 mol% are preferable with respect to all the structural units which comprise a [E] fluorine atom containing polymer, and 50 mol%-80 mol% are more preferable.

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

  The content ratio of the other structural units is preferably 5 mol% to 90 mol%, more preferably 10 mol% to 80 mol%, based on all the structural units constituting the [E] fluorine atom-containing polymer. 20 mol%-70 mol% are more preferable.

  [E] The content of the fluorine atom-containing polymer is preferably 20 parts by mass or less, more preferably 0.1 parts by mass to 15 parts by mass, and more preferably 1 part by mass to 100 parts by mass of the polymer [A]. 10 parts by mass is more preferable, and 1 part by mass to 6 parts by mass is particularly 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 (% by mass) of the fluorine atom-containing polymer is preferably larger than the fluorine atom content of the [A] polymer. [E] By making the fluorine atom content in the fluorine atom-containing polymer larger than that of the [A] polymer, the radiation sensitive resin composition containing the [A] polymer and the [E] fluorine atom-containing polymer The water repellency of the formed resist film surface can be further increased. [E] 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 or more, and more preferably 3% by mass or more.
[E] The fluorine atom content of the fluorine atom-containing polymer is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, and particularly preferably 10% by mass or more. 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] The fluorine atom-containing polymer can be synthesized, 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. As said polymerization solvent, the thing similar to the polymerization solvent used by the synthesis method of [A] polymer is mentioned, for example.

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

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

  [E] The ratio (Mw / Mn) of Mw to Mn of the fluorine atom-containing polymer is preferably 1 to 5, and more preferably 1 to 3.

<[F] Localization promoter>
[F] The uneven distribution promoter is a component that segregates the [E] fluorine atom-containing polymer on the resist film surface more efficiently. When the radiation-sensitive resin composition contains [F] an uneven distribution accelerator, the [E] fluorine atom-containing polymer can be segregated more effectively on the resist film surface, resulting in [E] fluorine atoms. The amount of the containing polymer used can be reduced. [F] Examples of the uneven distribution promoter include lactone compounds, carbonate compounds, nitrile compounds, polyhydric alcohols, and the like. [F] The uneven distribution promoter may be used alone or in combination of two or more.

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

  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.

  [F] The content of the uneven distribution accelerator is preferably 5 to 300 parts by mass, more preferably 10 to 100 parts by mass, and 20 to 70 parts by mass with respect to 100 parts by mass of the polymer (A). Part by mass is more preferable.

<Other optional components>
The said radiation sensitive resin composition may contain other arbitrary components other than said [A]-[F] component. Examples of the other optional components include acid diffusion controllers other than the [C] compound, surfactants, alicyclic skeleton-containing compounds, and sensitizers. Each of these other optional components may be used alone or in combination of two or more.

[Other acid diffusion controllers]
The said radiation sensitive resin composition may contain other acid diffusion control bodies other than a [C] compound in the range which does not impair the effect of this invention. The other acid diffusion controller controls the diffusion phenomenon of the acid generated from the [B] acid generator in the resist film by exposure. As a result, there is an effect of suppressing an undesirable chemical reaction in the non-exposed region, and the storage stability of the resulting radiation-sensitive resin composition is further improved. Further, the resolution as a resist is further improved, and a change in the line width of the resist pattern due to a change in the holding time from exposure to development processing can be suppressed, and a radiation-sensitive resin composition excellent in process stability can be obtained. . As the inclusion form of the other acid diffusion controller in the radiation sensitive resin composition, a form of a free compound (hereinafter referred to as “other acid diffusion controller” as appropriate) is incorporated as a part of the polymer. Either of these forms may be used.

  Examples of the other acid diffusion control agents 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; di (cyclo) alkylamines; tri (cyclo) alkylamines; substituted alkylanilines or derivatives thereof; ethylenediamine, N, N, N ′, N′-tetra Methylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4 -Aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-amino) Phenyl) -2- (4-hydroxyphenyl) propane, 1, -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.

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

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea and the like. Is mentioned.

  Examples of the nitrogen-containing heterocyclic compound include imidazoles; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 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-diazabicyclo [2.2.2 ] Octane etc. are mentioned.

  The content of the other acid diffusion controller is preferably 15 parts by mass or less with respect to 100 parts by mass of the polymer [A] when the other acid diffusion controller is another acid diffusion controller. Less than the mass part is more preferable. Moreover, as content of said other acid diffusion control agent, 95 mass parts or less are preferable with respect to 100 mass parts of [C] compounds, 50 mass parts or less are more preferable, and 20 mass parts or less are more preferable.

[Surfactant]
Surfactants have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate; commercially available products include “KP341” from Shin-Etsu Chemical Co., Ltd., “Polyflow No.75” and “No.95” from Kyoeisha Chemical Co., Ltd., “F-Top” from Tochem Products EF301, EF303, EF352, DIC's "MegaFuck F171", "F173", Sumitomo 3M's "Florard FC430", "FC431", Asahi Glass Industry's "Asahi Guard AG71""SurflonS-382","SC-101","SC-102","SC-103","SC-104","SC-105","SC-106" Etc. As content of surfactant in the said radiation sensitive resin composition, it is 2 mass parts or less normally with respect to 100 mass parts of [A] polymers.

[Alicyclic skeleton-containing compound]
The alicyclic skeleton-containing compound has the effect of improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.

[Sensitizer]
A sensitizer exhibits the effect | action which increases the production amount of the acid from a [B] acid generator etc., and there exists an effect which improves the "apparent sensitivity" of the said radiation sensitive resin composition.

  Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines and the like. These sensitizers may be used alone or in combination of two or more. As content of the sensitizer in the said radiation sensitive resin composition, it is 2 mass parts or less normally with respect to 100 mass parts of [A] polymers.

<Method for preparing radiation-sensitive resin composition>
The radiation sensitive resin composition includes, for example, [A] polymer, [B] acid generator, [C] compound, [E] fluorine atom-containing polymer and other optional components contained as necessary, and [D] The solvent can be prepared by mixing at a predetermined ratio. The radiation-sensitive resin composition is preferably filtered after mixing with, for example, a filter having a pore size of about 0.2 μm. As solid content concentration of the said radiation sensitive resin composition, 0.1 mass%-50 mass% are preferable, 0.5 mass%-30 mass% are more preferable, 1 mass%-20 mass% are more preferable.

  The radiation-sensitive resin composition can be used for forming a positive pattern using an alkaline developer and for forming a negative pattern using a developer containing an organic solvent. Among these, when used for negative pattern formation using a developer containing an organic solvent, the radiation-sensitive resin composition can exhibit higher resolution.

<Method for forming resist pattern>
The resist pattern forming method is:
A step of forming a resist film (hereinafter also referred to as a “resist film forming step”),
A step of exposing the resist film (hereinafter also referred to as “exposure step”), and a step of developing the exposed resist film (hereinafter also referred to as “development step”).
Is provided.
The said resist film is formed with the said radiation sensitive resin composition mentioned above.

According to the resist pattern forming method, since the radiation sensitive resin composition described above is used, LWR and CDU are small, resolution is high while exhibiting excellent depth of focus, exposure margin and MEEF performance, It is possible to form a resist pattern that is excellent in rectangular shape in cross section.
Hereinafter, each step will be described.

[Resist film forming step]
In this step, a resist film is formed from the radiation sensitive resin composition. Examples of the substrate on which the resist film is formed include a silicon wafer and a wafer coated with aluminum. A resist film is formed by applying the radiation sensitive resin composition on the substrate. Although it does not specifically limit as a coating method of the said radiation sensitive resin composition, For example, it can apply | coat by well-known methods, such as a spin coat method. When applying the radiation-sensitive resin composition, the amount of the radiation-sensitive resin composition to be applied is adjusted so that the formed resist film has a desired thickness. In addition, after apply | coating the said radiation sensitive resin composition on a board | substrate, in order to volatilize a solvent, you may pre-bake (PB). As temperature of PB, 30 to 200 degreeC is preferable and 50 to 150 degreeC is more preferable.

  In order to maximize the potential of the radiation-sensitive resin composition, as disclosed in, for example, Japanese Patent Publication No. 6-12452, Japanese Patent Application Laid-Open No. 59-93448, etc. It is also possible to form an organic or inorganic antireflection film. In order to prevent the influence of basic impurities contained in the ambient atmosphere, a protective film can be provided on the resist film as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598.

[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 with radiation through a mask having a predetermined pattern through an immersion exposure liquid such as water.

  As the immersion exposure liquid, a liquid having a refractive index larger than that of air is usually used. Specific examples include pure water, long-chain or cyclic aliphatic compounds, and the like. In this state through the immersion exposure liquid, that is, in a state where the immersion exposure liquid is filled between the lens and the resist film, the exposure apparatus irradiates radiation and exposes the resist film through a mask having a predetermined pattern. To do.

  Examples of the radiation include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and γ-rays depending on the type of radiation-sensitive acid generator used; Of these, the ultraviolet ray, EUV, and electron beam are preferable, and ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV, electron A line is more preferable, and ArF excimer laser light, EUV, and an electron beam are further preferable. In addition, exposure conditions, such as exposure amount, can be suitably selected according to the compounding composition of the said radiation sensitive resin composition, the kind of additive, etc.

  It is preferable to perform heat treatment (hereinafter also referred to as “post-exposure baking (PEB)”) after exposure. By this PEB, the dissociation reaction of the acid dissociable group in the [A] polymer can be smoothly advanced. Although the heating conditions of PEB are suitably adjusted with the compounding composition of the said radiation sensitive resin composition, 30 to 200 degreeC is preferable and 50 to 170 degreeC 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 aqueous alkali solution (alkaline developer) and a solution containing an organic solvent (organic solvent developer). As a result, 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. In these, a TMAH aqueous solution is preferable and a 2.38 mass% TMAH aqueous solution is more preferable.

  Examples of the organic solvent developer include organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, alcohol solvents, and liquids containing organic solvents. As said organic solvent, the 1 type (s) or 2 or more types of the solvent enumerated as the [D] solvent of the said radiation sensitive resin composition mentioned above are mentioned, for example. Of these, ester solvents and ketone solvents are preferred. As the ester solvent, an acetate solvent is preferable, and n-butyl acetate is more preferable. As the ketone solvent, a chain ketone is preferable, and 2-heptanone is more preferable. As content of the organic solvent in a developing solution, 80 mass% or more is preferable, 90 mass% or more is more preferable, 95 mass% or more is further more preferable, 99 mass% or more is especially preferable. Examples of components other than the organic solvent in the developer include water and silicone oil.

  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.

<Acid diffusion control agent>
The acid diffusion controller of the present invention comprises a compound represented by the above formula (1). The acid diffusion control agent can be suitably used as a component of the radiation sensitive resin composition described above.

<Compound>
The compound of the present invention is a compound represented by the above formula (1). The compound can be suitably used as the acid diffusion controller.
The acid diffusion controller and the compound are described in the section of the [C] compound of the above-mentioned radiation sensitive resin composition.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measuring method of various physical property values is shown below.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
Using GPC columns (two "G2000HXL", one "G3000HXL", one "G4000HXL" from Tosoh Corporation), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran (Wako Pure Chemical Industries), sample concentration: Measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of 1.0 mass%, sample injection amount: 100 μL, column temperature: 40 ° C., detector: 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 (Z-1))
To a 200 mL round-bottom flask, 5.00 g (30.3 mmol) of hexanesulfonamide, 3.60 g (45.5 mmol) of pyridine and 50 mL of tetrahydrofuran were added and stirred while cooling in an ice bath under a nitrogen atmosphere. Thereto, 4.96 g (36.4 mmol) of ethyl chloroglyoxylate was slowly added dropwise. After completion of dropping, the mixture was stirred at 0 ° C. for 1 hour, and then stirred at room temperature for 5 hours. After adding water to stop the reaction, the organic layer was washed twice with an aqueous sodium chloride solution. After distilling off the solvent, purification by column chromatography gave 4.10 g (yield 51%) of a compound represented by the following formula (z-1).
Next, 4.00 g (15.1 mmol) of the compound (z-1) obtained above and 50 mL of tetrahydrofuran were added to a 200 mL round bottom flask and stirred at room temperature. A 5% by mass aqueous solution containing 0.634 g (15.9 mmol) of sodium hydroxide was slowly added dropwise thereto. After completion of dropping, the mixture was stirred at room temperature for 1 hour, and then the solvent was distilled off. Thereto were added 4.51 g (15.1 mmol) of triphenylsulfonium chloride, 70 mL of dichloromethane and 30 mL of water, and the mixture was stirred at room temperature for 8 hours. Next, the organic layer was collected, washed with water three times, and then dried over anhydrous sodium sulfate. After distilling off the solvent, the residue was purified by column chromatography to obtain 6.53 g (yield 82%) of a compound represented by the following formula (Z-1).

[Examples 2 to 11] (Synthesis of compounds (Z-2) to (Z-11))
The precursors were appropriately selected and the same operations as in Example 1 were performed to synthesize compounds represented by the following formulas (Z-2) to (Z-11).

<Synthesis of polymer>
The monomers used in the synthesis of [A] polymer and [E] fluorine atom-containing polymer are shown below.

  The monomers (M-1), (M-5) to (M-7), (M-9), (M-12) and (M-13) are structural units (I) in the [A] polymer. ), Monomer (M-2), (M-3), (M-8), (M-10) and (M-11) are structural units (II) and monomer (M-4). ) Gives structural units (III), respectively. Moreover, the structural unit which has a structure of a radiation sensitive acid generator is integrated in a polymer with a monomer (M-14).

[[A] Synthesis of polymer]
[Synthesis Example 1] (Synthesis of polymer (A-1))
7.97 g (35 mol%) of the compound (M-1), 7.44 g (45 mol%) of the compound (M-2) and 4.49 g (20 mol%) of the compound (M-3) were converted into 40 g of 2-butanone. In addition, 0.80 g of AIBN (5 mol% based on the total amount of monomers) as a radical polymerization initiator was dissolved 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, then heated to 80 ° C. with stirring, and the monomer solution prepared above 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 reaction 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 powder polymer (A-1) (15.2 g, yield 76). %). Mw of the polymer (A-1) was 7,300, and Mw / Mn was 1.53. As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M-1), (M-2) and (M-3) is 34.3 mol%, 45.1 mol%, and It was 20.6 mol%.

[Synthesis Examples 2 to 4, 6 and 7] (Polymers (A-2) to (A-4), (A-6) and (A-7))
Polymers (A-2) to (A-7) were synthesized in the same manner as in Synthesis Example 1 except that the types and amounts of monomers shown in Table 1 were used. The total mass of the monomers used was 20 g. The yield (%) of the synthesized polymer, Mw, Mw / Mn, and the content ratio (mol%) of each structural unit are shown in Table 1 below.

[Synthesis Example 5] (Synthesis of Polymer (A-5))
55.0 g (65 mol%) of the compound (M-4) and 45.0 g (35 mol%) of the compound (M-5), 4 g of AIBN as a radical polymerization initiator, and 1 g of t-dodecyl mercaptan were mixed with propylene glycol monomethyl. After dissolving in 100 g of ether, 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 polymerization reaction 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 again to the polymer obtained above, 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 time and the white powdery polymer (A-5) was obtained (65.7g, yield 77%). Mw of the polymer (A-5) 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 (M-5) was 65.4 mol% and 34.6 mol%, respectively.

[[E] Synthesis of fluorine atom-containing polymer]
[Synthesis Example 8] (Synthesis of polymer (E-1))
82.2 g (70 mol%) of the compound (M-15) and 17.8 g (30 mol%) of the compound (M-12) were dissolved in 200 g of 2-butanone, and 0.46 g of AIBN as a radical polymerization initiator (simple A monomer solution was prepared by adding 1 mol%) to the total amount of the monomer. 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 reaction 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. Thereafter, the solvent was replaced with propylene glycol monomethyl ether acetate to obtain a solution containing 60.1 g of the polymer (E-1) (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 ratio of each structural unit derived from (M-15) and (M-12) was 70.3 mol% and 29.7 mol%, respectively.

<Preparation of radiation-sensitive resin composition>
The [B] acid generator, the [C] compound, the [D] solvent and the [F] uneven distribution accelerator used for the preparation of the radiation sensitive resin composition are shown below.

[[B] acid generator]
Each structural formula is shown below.
B-1: Triphenylsulfonium 2- (adamantan-1-ylcarbonyloxy) -1,1,3,3,3-pentafluoropropane-1-sulfonate B-2: Triphenylsulfonium norbornane sultone-2-yloxy Carbonyl difluoromethanesulfonate B-3: Triphenylsulfonium 3- (piperidin-1-ylsulfonyl) -1,1,2,2,3,3-hexafluoropropane-1-sulfonate B-4: Triphenylsulfonium adamantane- 1-yloxycarbonyldifluoromethanesulfonate

[[C] Compound]
Z-1 to Z-11 used in Examples: Compound (Z-1) to (Z-11) synthesized above
CZ-1 to CZ-4 used in Comparative Examples: Compounds represented by the following formulas (CZ-1) to (CZ-4)

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

[[F] uneven distribution promoter]
F-1: γ-butyrolactone

[Preparation of radiation-sensitive resin composition for ArF exposure]
[Example 12]
[A] 100 parts by mass of (A-1) as a polymer, 8.5 parts by mass of (B-1) as an acid generator [B], 2.3 parts of (Z-1) as a [C] compound Part, (D-1) 2,240 parts by mass and (D-2) 960 parts by weight as solvent, [E] 3 parts by weight (E-1) as fluorine atom-containing polymer, and [F The radiation-sensitive resin composition (J-1) was prepared by mixing 30 parts by mass of (F-1) as an uneven distribution accelerator and filtering with a membrane filter having a pore size of 0.2 μm.

[Examples 13 to 26 and Comparative Examples 1 to 7]
Each radiation-sensitive resin composition was prepared in the same manner as in Example 12 except that the components having the types and contents shown in Table 2 were used.

[Preparation of radiation-sensitive resin composition for electron beam exposure]
[Example 27]
[A] 100 parts by mass of (A-5) as a polymer, [B] 20 parts by mass of (B-1) as an acid generator, 3.6 parts by mass of (Z-1) as a [C] compound, In addition, (D-1) 4,280 parts by mass and (D-2) 1,830 parts by mass as a solvent [D] are mixed and filtered through a membrane filter having a pore size of 0.2 μm to thereby form a radiation sensitive resin composition. (J-16) was prepared.

[Examples 28 to 44 and Comparative Examples 8 to 17]
Each radiation-sensitive resin composition was prepared in the same manner as in Example 27 except that the components having the types and contents shown in Table 3 were used.

<Formation of resist pattern (1)>
A 12-inch silicon wafer surface was coated with a composition for forming a lower antireflection film (“ARC66” from Brewer Science Co., Ltd.) using a spin coater (“CLEAN TRACK ACT12” from Tokyo Electron), and then 205 ° C. Was heated for 60 seconds to form a lower antireflection film having a thickness of 105 nm. On the lower antireflection film, the prepared radiation sensitive resin composition for ArF exposure 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 a film thickness of 90 nm. Next, this resist film was subjected to an optical condition of NA = 1.3 and dipole (Sigma 0.977 / 0.782) using an ArF excimer laser immersion exposure apparatus (“NSR-S610C” manufactured by NIKON). , Exposed through a 40 nm line and space (1L1S) mask pattern. After the exposure, PEB was performed at 90 ° C. for 60 seconds. Thereafter, the resist was alkali-developed using a 2.38 mass% TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern. When forming the resist pattern, the exposure amount formed in a one-to-one line and space with a line width of 40 nm and a line width formed through a one-to-one line and space mask with a target dimension of 40 nm is an optimum exposure amount ( Eop).

<Formation of resist pattern (2)>
In the formation of the resist pattern (1), similar to the formation of the resist pattern (1) except that n-butyl acetate was used instead of the TMAH aqueous solution and the organic solvent was developed and no washing with water was performed. In this way, a negative resist pattern was formed.

<Formation of resist pattern (3)>
Using a spin coater (“CLEAN TRACK ACT8” manufactured by Tokyo Electron Ltd.) on the surface of an 8-inch silicon wafer, the prepared radiation sensitive resin composition for electron beam exposure 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 a film thickness of 50 nm. Next, the resist film was irradiated with an electron beam by using a simple electron beam drawing apparatus (“HL800D” manufactured by Hitachi, Ltd., output: 50 KeV, current density: 5.0 A / cm ² ). After irradiation, PEB was performed at 120 ° C. for 60 seconds. Thereafter, an alkali development was carried out at 23 ° C. for 30 seconds using a 2.38 mass% TMAH aqueous solution as an alkaline developer, washed with water, and dried to form a positive resist pattern.

<Formation of resist pattern (4)>
In the formation of the resist pattern (3), similar to the formation of the resist pattern (3) except that the organic solvent development was performed using n-butyl acetate instead of the TMAH aqueous solution and the washing with water was not performed. In this way, a negative resist pattern was formed.

<Evaluation>
About the formed resist pattern, each radiation sensitive resin composition was evaluated by measuring according to the following method. A scanning electron microscope (Hitachi High-Technologies “CG-4100”) was used for measuring the resist pattern. The evaluation results are shown in Table 4 and Table 5, respectively.

[LWR performance]
The resist pattern formed by irradiating the exposure amount of Eop 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 (nm). The LWR performance indicates that the smaller the value, the smaller the backlash of the line. The LWR performance can be evaluated as “good” when it is 3.5 nm or less, and “bad” when it exceeds 3.5 nm.

[CDU performance]
The resist pattern formed by irradiating the exposure amount of Eop 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. ). The CDU performance indicates that the smaller the value, the smaller the line width variation in a long cycle. The CDU performance can be evaluated as “good” when it is 1.5 nm or less, and “bad” when it exceeds 1.5 nm.

[Resolution]
The dimension of the minimum resist pattern resolved by irradiating the exposure amount of Eop was measured, and this measured value was defined as resolution (nm). The resolution indicates that the smaller the value, the better the pattern can be formed. The resolution can be evaluated as “good” when it is 35 nm or less, and “bad” when it exceeds 35 nn.

[Rectangularity of the cross-sectional shape]
The cross-sectional shape of the resist pattern resolved by irradiating the exposure amount of Eop is observed, and the line width Lb in the middle in the height direction of the resist pattern and the line width La at the upper part of the resist pattern are measured. La / Lb was calculated and used as an index of rectangularity of the cross-sectional shape. 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 “good” when 0.9 ≦ (La / Lb) ≦ 1.1, and (La / Lb) <0.9 or 1.1 <(La / Lb). The case can be evaluated as “bad”.

[Depth of focus]
In the resist pattern resolved by irradiating the exposure amount of Eop, the dimension when the focus is changed in the depth direction is observed, and the pattern dimension is 90% to 110% of the reference without any bridge or residue. The depth of entry in the depth direction was measured, and this measured value was defined as the depth of focus (nm). The greater the value of the focal depth, the smaller the variation in the dimension of the pattern obtained when the focal position varies, and the better the yield during device fabrication. The depth of focus can be evaluated as “good” when the depth is 100 nm or more, and “bad” when the depth of focus is less than 100 nm.

[Exposure margin]
In the range of the exposure amount including the Eop, the exposure amount was changed every 1 mJ / cm ² to form resist patterns, respectively, and the respective line widths were 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 better the variation in the dimension of the pattern obtained when the amount of exposure varies, and the higher the yield during device fabrication. The exposure margin can be evaluated as “good” when it is 18% or more, and “bad” when it is less than 18%.

[MEEF performance]
In the above Eop, resist pattern line widths resolved at five mask sizes (38.0 nmLine / 80 nmPitch, 39.0 nmLine / 80 nmPitch, 40.0 nmLine / 80 nmPitch, 41.0 nmLine / 80 nmPitch, 42.0 nmLine / 80 nmPitch) Was measured using the scanning electron microscope. The horizontal axis represents the mask size, the vertical axis represents the line width of the resist pattern formed with each mask size, the measured values obtained are plotted, and the slope of the approximate straight line calculated by the least square method is obtained. This slope is the MEEF performance. It was. The MEEF performance indicates that the closer the value is to 1, the better the mask reproducibility. The MEEF performance can be evaluated as “good” when 4.7 or less and “bad” when 4.7 or more.

  As is clear from the results of Tables 4 and 5, the radiation-sensitive resin compositions of the examples were subjected to LWR performance, CDU performance, solution in both ArF exposure and electron beam exposure, and alkaline development and organic solvent development. It is excellent in image quality, cross-sectional rectangularity, depth of focus, exposure margin, and MEEF performance. In the comparative example, each of these characteristics was inferior to the example. Generally, according to electron beam exposure, it is known to show the same tendency as in the case of EUV exposure. Therefore, according to the radiation-sensitive resin composition of the example, even in the case of EUV exposure, It is estimated that the LWR performance is excellent.

<Storage stability>
The prepared radiation sensitive resin compositions (J-1) to (J-11) of Examples 12 to 22 and the radiation sensitive resin composition (CJ-1) of Comparative Example 1 were stored at 35 ° C. for 3 months. After that, the turbidity of the solution was visually confirmed.
As a result, turbidity was not confirmed in the radiation sensitive resin compositions (J-1) to (J-11), but white turbidity was observed in the radiation sensitive resin composition (CJ-1). From the analysis result of GC-MS, the decomposition product derived from the said monomer (M-15) was observed in the radiation sensitive resin composition (CJ-1). In the radiation sensitive resin compositions (J-1) to (J-11), no corresponding decomposition products were observed.

  According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, while maintaining good storage stability, it exhibits excellent depth of focus, exposure margin and MEEF performance, LWR performance, CDU performance, solution It is possible to form a resist pattern that is excellent in image quality and rectangular cross-sectional shape. The acid diffusion controller of the present invention can be suitably used as a component of the radiation sensitive resin composition. The compound of the present invention can be suitably used as the acid diffusion controller. Therefore, they can be suitably used for pattern formation in semiconductor device manufacturing or the like where further miniaturization is expected.

Claims (10)

A polymer having a structural unit containing an acid dissociable group,
Radiation sensitive acid generator,
Containing a compound consisting of a radiolytic onium cation that generates protons by radiation and a counter anion, and a solvent,
The counter anion is a 2 or more carbonyl groups, -N adjacent to one of the carbonyl group - and a, ^-
A radiation-sensitive resin composition in which the carbonyl groups are bonded to each other through a single bond, a substituted or unsubstituted alkanediyl group having 1 or 2 carbon atoms, or a substituted or unsubstituted 1,2-benzenediyl group. The radiation sensitive resin composition according to claim 1, wherein the compound is represented by the following formula (1).

(In Formula (1), R ¹ is a single bond, a substituted or unsubstituted methanediyl group, a substituted or unsubstituted ethanediyl group, or a substituted or unsubstituted 1,2-benzenediyl group. R ² and R ³ is each independently a monovalent organic group having 1 to 30 carbon atoms, n is an integer of 1 to 3, and when n is 2 or more, a plurality of R ¹ are the same or different. M ⁺ is a monovalent radiolytic onium cation that generates a proton by radiation, provided that two or more of R ¹ , R ^2, and R ^{3 have} 5 to 5 ring members due to their bond. 30 ring structures may be formed.) The R ² in the formula (1) is —COR ⁴ , —SO ₂ R ⁴ or —SO ₃ R ⁴ , and this R ⁴ is a monovalent organic group having 1 to 20 carbon atoms. Radiation sensitive resin composition. The radiation sensitive resin composition of Claim 2 or Claim ³ in which at least 1 of R < ² > and R < ³ > in said Formula (1) contains a fluorine atom. The radiation sensitive resin composition according to claim 4, wherein R ¹ in the formula (1) is a single bond, and R ² is a monovalent fluorinated hydrocarbon group having 1 to 30 carbon atoms. The radiation sensitive resin composition according to any one of claims 1 to 5, wherein the structural unit is represented by the following formula (2-1).

(In the formula (2-1), R ⁶ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid dissociation represented by the following formula (Y-1). Group.)

(In Formula (Y-1), R ^e1 is a hydrocarbon group having 1 to 20 carbon atoms. R ^e2 and R ^e3 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms. Or an alicyclic structure having 3 to 20 ring members composed of these groups combined with the carbon atom to which they are bonded.)   The radiation-sensitive resin composition according to any one of claims 1 to 6, wherein the radiolytic onium cation is a sulfonium cation or an iodonium cation. Forming a resist film;
A step of exposing the resist film, and a step of developing the exposed resist film,
The resist pattern formation method which forms the said resist film with the radiation sensitive resin composition of any one of Claims 1-7. An acid diffusion controller comprising a compound represented by the following formula (1).

(In Formula (1), R ¹ is a single bond, a substituted or unsubstituted methanediyl group, a substituted or unsubstituted ethanediyl group, or a substituted or unsubstituted 1,2-benzenediyl group. R ² and R ³ is each independently a monovalent organic group having 1 to 30 carbon atoms, n is an integer of 1 to 3, and when n is 2 or more, a plurality of R ¹ are the same or different. M ⁺ is a monovalent radiolytic onium cation that generates a proton by radiation, provided that two or more of R ¹ , R ^2, and R ^{3 have} 5 to 5 ring members due to their bond. 30 ring structures may be formed.) A compound represented by the following formula (1).

(In Formula (1), R ¹ is a single bond, a substituted or unsubstituted methanediyl group, a substituted or unsubstituted ethanediyl group, or a substituted or unsubstituted 1,2-benzenediyl group. R ² and R ³ is each independently a monovalent organic group having 1 to 30 carbon atoms, n is an integer of 1 to 3, and when n is 2 or more, a plurality of R ¹ are the same or different. M ⁺ is a monovalent radiolytic onium cation that generates a proton by radiation, provided that two or more of R ¹ , R ^2, and R ^{3 have} 5 to 5 ring members due to their bond. 30 ring structures may be formed.)