JP6459266B2 - Radiation sensitive resin composition, resist pattern forming method, radiation sensitive acid generator and compound - Google Patents

Description

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

  Radiation-sensitive resin compositions used for microfabrication by lithography generate acids in exposed areas by irradiation with electromagnetic waves such as far ultraviolet rays such as ArF excimer laser light and KrF excimer laser light, and charged particle beams such as electron beams. The 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, thereby forming a resist pattern on the substrate.

  Such a radiation-sensitive resin composition is required to improve resolution and rectangularity of the cross-sectional shape of the resist pattern as processing technology becomes finer. In response to this requirement, the types and molecular structures of polymers, acid generators and other components used in the composition have been studied, and further their combinations have been studied in detail (Japanese Patent Application Laid-Open No. 11-125907, special features). (See Kaihei 8-146610 and JP-A 2000-298347).

  However, at present, when the miniaturization of the resist pattern has progressed to a level of a line width of 50 nm or less, the resolution and the rectangular shape of the cross-sectional shape of the resist pattern are not sufficiently satisfied. In addition, the MEEF (Mask Error Enhancement Factor) performance, LWR (Line Width Roughness) performance, CD (Critical Dimension) uniformity, focus depth and exposure margin, which are lithography performance, are disadvantageous in the above conventional acid generators.

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 exhibits excellent MEEF performance, depth of focus and exposure margin, and excellent LWR performance, CD uniformity, resolution, and cross-sectional shape. It aims at providing the radiation sensitive resin composition which can form the resist pattern which has rectangularity.

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 “[A] polymer”),
A compound comprising a radiolytic onium cation and a counter anion (hereinafter also referred to as “[B] compound”), and a solvent (hereinafter also referred to as “[G] solvent”)
Containing
The counter anion has two or more carbonyl groups;
It is a radiation sensitive resin composition in which the carbonyl groups are bonded via a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms.

The resist pattern forming method of the present invention comprises:
Forming a resist film;
A step of exposing the resist film, and a step of developing the exposed resist film,
The resist film is formed from the radiation sensitive resin composition.

（式（１−１）中、Ａは、炭素数１〜３０の１価の有機基である。Ｅ⁻は、ＳＯ_３ ⁻又はＣＯＯ⁻である。Ｘ^＋は、１価の放射線分解性オニウムカチオンである。Ｌは、単結合又は酸素原子である。Ｒ^１は、単結合又は炭素数１〜１０の置換又は非置換のアルカンジイル基である。Ｒ^２は、炭素数１〜２０の２価の有機基である。ｋは、１以上３以下の整数である。ｋ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。）

（式（１−２）中、Ａは、炭素数１〜３０の１価の有機基である。Ｅ⁻は、ＳＯ_３ ⁻又はＣＯＯ⁻である。Ｘ^＋は、１価の放射線分解性オニウムカチオンである。Ｒ^１は、単結合又は炭素数１〜１０の置換又は非置換のアルカンジイル基である。ｉは、０以上２以下の整数である。Ｒ^ｘは、炭素数１〜１０の置換又は非置換のアルカンジイル基である。Ｒ^０は、単結合又は炭素数１〜１９の２価の有機基である。ｉが２の場合、複数のＲ^１は、同一でも異なっていてもよい。）

（式（１−３）中、Ａは、炭素数１〜３０の１価の有機基である。Ｘ^＋は、１価の放射線分解性オニウムカチオンである。Ｒ^１は、炭素数１〜１０の置換又は非置換のアルカンジイル基である。） The radiation sensitive acid generator of the present invention comprises a compound represented by the following formula (1-1), the following formula (1-2), or the following formula (1-3).

(In the formula (1-1), A is a monovalent organic group having 1 to 30 carbon atoms .E ^- is SO ₃ ^- or COO ^- and it .X ⁺ represents a monovalent radiolytic onium L is a single bond or an oxygen atom, R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, R ² is 2 having 1 to 20 carbon atoms (K is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ may be the same or different.)

(In the formula (1-2), A is a monovalent organic group having 1 to 30 carbon atoms .E ^- is SO ₃ ^- or COO ^- and it .X ⁺ represents a monovalent radiolytic onium R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, i is an integer of 0 to 2, and R ^x is 1 to 10 carbon atoms. A substituted or unsubstituted alkanediyl group, R ⁰ is a single bond or a divalent organic group having 1 to 19 carbon atoms, and when i is 2, a plurality of R ¹ may be the same or different. Good.)

(In the formula (1-3), A is a is .X ⁺ is a monovalent organic group having 1 to 30 carbon atoms, .R ¹ is a monovalent radiolytic onium cation is from 1 to 10 carbon atoms Substituted or unsubstituted alkanediyl groups.)

（式（１−１）中、Ａは、炭素数１〜３０の１価の有機基である。Ｅ⁻は、ＳＯ_３ ⁻又はＣＯＯ⁻である。Ｘ^＋は、１価の放射線分解性オニウムカチオンである。Ｌは、単結合又は酸素原子である。Ｒ^１は、単結合又は炭素数１〜１０の置換又は非置換のアルカンジイル基である。Ｒ^２は、炭素数１〜２０の２価の有機基である。ｋは、１以上３以下の整数である。ｋ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。）

（式（１−２）中、Ａは、炭素数１〜３０の１価の有機基である。Ｅ⁻は、ＳＯ_３ ⁻又はＣＯＯ⁻である。Ｘ^＋は、１価の放射線分解性オニウムカチオンである。Ｒ^１は、単結合又は炭素数１〜１０の置換又は非置換のアルカンジイル基である。ｉは、０以上２以下の整数である。Ｒ^ｘは、炭素数１〜１０の置換又は非置換のアルカンジイル基である。Ｒ^０は、単結合又は炭素数１〜１９の２価の有機基である。ｉが２の場合、複数のＲ^１は、同一でも異なっていてもよい。）

（式（１−３）中、Ａは、炭素数１〜３０の１価の有機基である。Ｘ^＋は、１価の放射線分解性オニウムカチオンである。Ｒ^１は、炭素数１〜１０の置換又は非置換のアルカンジイル基である。） The compound of the present invention is a compound represented by the following formula (1-1), the following formula (1-2), or the following formula (1-3).

(In the formula (1-1), A is a monovalent organic group having 1 to 30 carbon atoms .E ^- is SO ₃ ^- or COO ^- and it .X ⁺ represents a monovalent radiolytic onium L is a single bond or an oxygen atom, R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, R ² is 2 having 1 to 20 carbon atoms (K is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ may be the same or different.)

(In the formula (1-2), A is a monovalent organic group having 1 to 30 carbon atoms .E ^- is SO ₃ ^- or COO ^- and it .X ⁺ represents a monovalent radiolytic onium R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, i is an integer of 0 to 2, and R ^x is 1 to 10 carbon atoms. A substituted or unsubstituted alkanediyl group, R ⁰ is a single bond or a divalent organic group having 1 to 19 carbon atoms, and when i is 2, a plurality of R ¹ may be the same or different. Good.)

(In the formula (1-3), A is a is .X ⁺ is a monovalent organic group having 1 to 30 carbon atoms, .R ¹ is a monovalent radiolytic onium cation is from 1 to 10 carbon atoms Substituted or unsubstituted alkanediyl groups.)

  Here, the “organic group” refers to a group containing at least one carbon atom.

  According to the radiation sensitive resin composition and the resist pattern forming method of the present invention, excellent MEEF performance, depth of focus and exposure margin are exhibited, and excellent LWR performance, CD uniformity, resolution, and cross-sectional shape are exhibited. A resist pattern having rectangularity can be formed. Accordingly, these can be suitably used for semiconductor device processing processes and the like that are expected to be further miniaturized in the future.

<Radiation sensitive resin composition>
The radiation sensitive resin composition contains a [A] polymer, a [B] compound, and a [G] solvent. In addition, the radiation-sensitive resin composition has, as a suitable component, a sulfonate compound that generates an acid upon irradiation with radiation other than the [B] compound (hereinafter also referred to as “[C] other acid generator”), [B ] Containing an acid diffusion controller other than the compound (hereinafter also referred to as “[D] other acid diffusion controller”) and a fluorine atom-containing polymer (hereinafter also referred to as “[E] fluorine atom-containing polymer”). In the range which does not impair the effect of this invention, the other arbitrary component may be contained. Hereinafter, each component will be described.

<[A] polymer>
[A] The polymer is a polymer having a structural unit containing an acid dissociable group. 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] compound or the like, and the exposed part and the unexposed part against the developer. A difference occurs in solubility, 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 not particularly limited as long as it has an acid dissociable group. The acid dissociable group may be present anywhere in the main chain, side chain, terminal, etc. of the [A] polymer. [A] In addition to the structural unit having an acid dissociable group (hereinafter, also referred to as “structural unit (I)”), the polymer is represented by the following formula (5-1) and the following formula (5-2). At least one selected from the group consisting of the structural units represented (hereinafter also referred to as “structural units (II)”), a structural unit represented by the following formula (6) (hereinafter referred to as “structural units (III)”) And other structural units other than the above structural units (I) to (III). [A] The polymer may have one or more of each structural unit. Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit containing an acid dissociable group. Examples of the structural unit (I) include a structural unit represented by the following formula (3-1) (hereinafter, also referred to as “structural unit (I-1)”), and a structural unit (3-2) below. And a structural unit (hereinafter also referred to as “structural unit (I-2)”).

In the formula (3-1), ^{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 (3-2), ^{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 chain hydrocarbon group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ^e2 and R ^e3 are each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or these groups. Represents an alicyclic structure having 3 to 20 ring carbon atoms that is configured together with the carbon atoms to which they are bonded to each other.

Examples of the monovalent chain hydrocarbon group having 1 to 10 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include, for example,
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 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 represented by R ^e1 , R ^e2 and R ^e3 include, for example,
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;
And polycyclic cycloalkenyl groups such as a norbornenyl group and a tricyclodecenyl group.

  Among these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are more preferable.

Examples of the 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 carbon atoms.

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 chain hydrocarbon group having 1 to 20 carbon atoms, or a monovalent group having 3 to 20 carbon atoms. Or an alicyclic hydrocarbon group having 1 to 20 carbon atoms or an oxyalicyclic hydrocarbon group having 1 to 20 carbon atoms. However, R ^e4 , R ^e5 and R ^e6 are not simultaneously hydrogen atoms.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include, for example,
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 include alkynyl groups such as ethynyl group, propynyl group, butynyl group, and pentynyl group.

  Among these, an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is preferable, a methyl group, an ethyl group, and an n-propyl group are more preferable, and a methyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include the same groups as those exemplified as R ^e1 , R ^e2 and R ^e3. Etc.

  Among these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are more preferable.

Examples of the monovalent oxy-chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include, for example,
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 represented by the R ^e4 , R ^e5 and R ^e6 include, for example,
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 group represented by the formula (Y-2) include a group in which R ^e4 , R ^e5 and R ^e6 are monovalent chain hydrocarbon groups, and R ^e4 and R ^e5 are monovalent chain hydrocarbon groups. And R ^e6 is a monovalent oxy chain hydrocarbon group, R ^e4 is a monovalent chain hydrocarbon group, and R ^e5 and R ^e6 are monovalent oxy chain hydrocarbon groups, A group in which R ^e4 , R ^e5 and R ^e6 are alkyl groups, a group in which R ^e4 and R ^e5 are alkyl groups and R ^e6 is an alkoxy group, a group in which R ^e4 is an alkyl group and R ^e5 and R ^e6 are alkoxy groups ^Are more preferable, R ^e4 , R ^e5 and R ^e6 are more preferably an alkyl group, and a t-butyl group, a t-pentyl group, a t-hexyl group, and a t-heptyl group are particularly preferable.

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

In the formulas (3-1-1) to (3-1-7), R ⁶ has the same meaning as the formula (3-1). 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 above formulas (3-2-1) to (3-2-3), R ⁷ has the same meaning as the above formula (3-2).

  As the structural unit (I), the structural unit (I-1) is preferable, the structural unit represented by the above formula (3-1-2), the structural unit represented by the above formula (3-1-3), The structural unit represented by the above formula (3-1-4) and the structural unit represented by the above formula (3-1-5) are more preferable, and the structural unit containing a cyclopentane structure and the structural unit containing an adamantane structure are More preferred are structural units containing a 1-ethyl-1-cyclopentyl group, a 2-ethyl-2-adamantyl group, and a 2-methyl-2-adamantyl group.

  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 setting the content ratio of the structural unit (I) within the above range, the LWR performance, CD uniformity, resolution, rectangular shape of the cross-sectional shape, MEEF performance, depth of focus and exposure margin of the radiation-sensitive resin composition. (Hereinafter also referred to as “LWR performance”) is more excellent.

[Structural unit (II)]
The structural unit (II) includes a structural unit represented by the following formula (5-1) (hereinafter also referred to as “structural unit (II-1)”) and a structural unit represented by the following formula (5-2) ( 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] compound and [C] other acid generators in the [A] polymer can be improved. As a result, the radiation sensitive resin composition is more excellent in 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 above formula (5-1), ^{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 (5-2), 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 R ^9a and R ^9b are combined with each other and configured with a carbon atom to which they are bonded. A ring structure having 3 to 30 ring members is represented.

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

As the ^{E 1,} from the viewpoint of copolymerizability of the monomer giving the structural unit (II-1), CO- O is preferred.

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 a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and carbon. Examples thereof include monovalent aromatic hydrocarbon groups of several 6 to 20.
Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include the same groups as those exemplified as R ^e4 , R ^e5 and R ^e6 in the above formula (Y-2).
Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include the same groups as those exemplified as R ^e1 , R ^e2 and R ^e3 in the above formula (Y-1).
Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, a methylnaphthyl group, an anthryl group, and a methylanthryl group;
Examples include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, and anthrylmethyl group.

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),
R ^{8 ′} is preferably a hydrogen atom from the viewpoint of the copolymerizability of the monomer giving the structural unit (II-2).

Examples of the monovalent organic group represented by R ^a , R ^b , R ^9a and R ^9b include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent chain having 3 to 20 carbon atoms. An alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a group in which some or all of the hydrogen atoms of these groups are substituted with a substituent, and the carbon-carbon gap of these groups In addition, CO, CS, O, S, or NR ′, or a group including a group in which two or more of these are combined is exemplified. R ′ is a hydrogen atom or a monovalent organic group.

Examples of the ring structure having 3 to 30 ring members formed by combining R ^9a and R ^9b together with the carbon atom to which they are bonded include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a norbornane structure, Examples thereof include alicyclic structures such as an adamantane structure; aliphatic heterocyclic structures such as an oxacyclopentane structure, a thiacyclopentane structure, and an azacyclopentane structure.

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

As the structural unit (II), for example,
Structural units represented by the following formulas (5-1-1) to (5-1-11) as the structural unit (II-1);
Examples of the structural unit (II-2) include structural units represented by the following formulas (5-2-1) and (5-2-2).

In the above formulas (5-1-1) to (5-1-11), R ⁸ has the same meaning as the above formula (5-1).
In the formulas (5-2-1) and (5-2-2), R ^{8 ′} has the same meaning as the formula (5-2).

  Among these, structural units represented by the above formulas (5-1-1), (5-1-3), (5-1-8) and (5-1-11) are preferable.

  As a content rate of structural unit (II), 0 mol%-70 mol% are preferable with respect to all the structural units which comprise a [A] polymer, 10 mol%-60 mol% are more preferable, 20 mol% More preferred is ˜50 mol%. By making the content rate of structural unit (II) into the said range, the dispersibility in the [A] polymer of a [B] compound or [C] other acid generator improves more, As a result, the said radiation sensitivity The LWR performance and the like of the conductive resin composition are more excellent.

[Structural unit (III)]
The structural unit (III) is a structural unit represented by the following formula (6). When KrF excimer laser light, EUV, electron beam or the like is used as radiation to be irradiated, the radiation-sensitive resin composition increases the sensitivity by including the structural unit (III) in the [A] polymer. be able to.

In said formula (6), 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 chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic group having 3 to 20 carbon atoms. A hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a group in which some or all of the hydrogen atoms of these groups are substituted with a substituent, and carbon-carbon between these groups , CS, O, S, or NR ″, or a group including a group in which two or more of these are combined. 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 (6-1) to (6-4).

In the above formulas (6-1) to (6-4), R ¹⁰ has the same meaning as the above formula (6).

  Among these, structural units represented by the above formulas (6-1) and (6-2) are preferable, and a structural unit represented by the above formula (6-1) 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) is obtained by polymerizing a monomer obtained by substituting the hydrogen atom of the OH group of hydroxystyrene with a t-butyl group and the like, and then subjecting the obtained polymer to a hydrolysis reaction in the presence of an amine. Or the like.

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

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized according to a conventional method such as radical polymerization. For example, 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 polystyrene-equivalent number average molecular weight (Mw) by GPC of the polymer is preferably 1 to 5, more preferably 1 to 3, and 1 to 2.5. Further preferred.

  [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 based on the total solid content in the radiation-sensitive resin composition.

<[B] Compound>
[B] The compound is a compound comprising a radiolytic onium cation and a counter anion, wherein the counter anion has two or more carbonyl groups, and the carbonyl groups are single bonds or carbon atoms of 1 to 10 It is a compound that binds via a substituted or unsubstituted alkanediyl group. The said radiation sensitive resin composition is excellent in LWR performance etc. by containing a [B] compound.

  The reason why the radiation-sensitive resin composition exhibits the above effect by including the [B] compound having the specific structure can be inferred as follows, for example. That is, the counter anion of the [B] compound has a specific structure in which two or more carbonyl groups are located in the vicinity of each other. Therefore, the interaction between the acid generated by exposure of protons generated by exposure to the counter anion of the [B] compound and the [A] polymer in the resist film is enhanced, and the diffusion length of the acid is appropriately controlled. It is conceivable that acid diffusion can be suppressed uniformly by being uniformly distributed in the resist film.

  [B] As the compound, a compound represented by the following formula (1-1) is preferable. The said radiation sensitive resin composition is more excellent in LWR performance etc. by containing the [B] compound represented by a following formula (1-1).

In said formula (1-1), A is a C1-C30 monovalent organic group. E ⁻ is SO ₃ ^— or COO ^— . X ⁺ is a monovalent radiolytic onium cation. L is a single bond or an oxygen atom. R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms. R ² is a divalent organic group having 1 to 20 carbon atoms. k is an integer of 1 to 3. When k is 2 or more, the plurality of R ¹ may be the same or different.

  As L in the formula (1-1), an oxygen atom is preferable. The said radiation sensitive resin composition is further excellent in LWR performance etc. by containing the [B] compound of such a specific structure.

  [B] As the compound, a compound represented by the following formula (1-2) is also preferable. The said radiation sensitive resin composition is more excellent in LWR performance etc. by containing the [B] compound represented by following formula (1-2).

In said formula (1-2), A is a C1-C30 monovalent organic group. E ⁻ is SO ₃ ^— or COO ^— . X ⁺ is a monovalent radiolytic onium cation. R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms. i is an integer of 0 or more and 2 or less. R ^x is a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms. R ⁰ is a single bond or a divalent organic group having 1 to 19 carbon atoms. When i is 2, the plurality of R ¹ may be the same or different.

  [B] As the compound, a compound represented by the following formula (1-3) is also preferable. The said radiation sensitive resin composition is more excellent in LWR performance etc. by containing the [B] compound represented by a following formula (1-3).

In said formula (1-3), A is a C1-C30 monovalent organic group. X ⁺ is a monovalent radiolytic onium cation. R ¹ is a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms.

[B] As the compound, in the formula (1-1) or (1-2), E ⁻ is SO ₃ ^— , and a fluorine atom or a fluorinated alkyl group is bonded to a carbon atom adjacent to E ^−. Compound (hereinafter also referred to as “[B1] compound”), or a compound represented by the above formula (1-3), E ⁻ is SO ₃ ^— , and a fluorine atom is bonded to a carbon atom adjacent to E ⁻ Or a compound in which E ⁻ is COO ⁻ (hereinafter, also referred to as “[B2] compound”). The [B1] compound functions as an acid generator, and the [B2] compound functions as an acid diffusion controller, or functions as an acid generator when the PEB temperature is relatively high.

  Examples of the monovalent organic group having 1 to 30 carbon atoms represented by A include a monovalent hydrocarbon group having 1 to 30 carbon atoms, and -O at the end of the hydrocarbon group between carbon and carbon or on the bond side. And groups containing a heteroatom-containing group such as-, -S-, -N-, -CO-, and -COO-.

  Among these, A is -NRR, -OR or -R, and R is a substituted or unsubstituted chain hydrocarbon group having 1 to 10 carbon atoms, a substituted or unsubstituted ring member having 3 to 30 ring members. An alicyclic hydrocarbon group, an aliphatic heterocyclic group having 3 to 30 ring members, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring members are preferable.

  Moreover, as said A, the group containing -COO- between carbon-carbon of the said substituted or unsubstituted alicyclic hydrocarbon group of 3-30 ring members is also preferable. In -NRR, two Rs may be the same or different.

  Examples of the chain hydrocarbon group include a methyl group, an ethyl group, a propyl group, and a butyl group.

Examples of the alicyclic hydrocarbon group 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 aliphatic heterocyclic group 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;
Nitrogen atom-containing heterocyclic groups such as azacycloheptyl group and diazabicyclooctane-yl group;
And sulfur atom-containing heterocyclic groups such as a thiacycloheptyl group and a thianorbornyl group.

Examples of the aromatic hydrocarbon group include:
An aryl group such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, and a naphthyl group; and an aralkyl group such as a benzyl group and a phenethyl group.

  Examples of the substituent that may substitute the hydrogen atom of the chain hydrocarbon group, alicyclic hydrocarbon group or aromatic hydrocarbon group include an alkyl group, an alkoxy group, an aryloxy group, an acyl group, an acyloxy group, Examples thereof include a hydroxy group, a carboxy group, an amino group, a cyano group, a nitro group, and a sulfonamide group. Among these, a C1-C5 linear or branched alkyl group, a phenoxy group, and a hydroxy group are preferable.

  Among these, A is preferably a cycloalkyl group, a group having a lactone structure, a cycloalkyloxy group, a cycloalkylamino group, a cycloalkylsulfanyl group, a hydroxyaryloxy group, or an aryloxyalkyl group.

As E ⁻ , SO ₃ ^— is preferable.

  As k in the formula (1-1), 1 and 2 are preferable, and 1 is more preferable. However, when k is 3, four or more of —C (O) — are not continuously bonded.

Among the substituted or unsubstituted alkanediyl groups having 1 to 10 carbon atoms of R ¹ , examples of the unsubstituted alkanediyl group include alkanediyl groups having 1 to 10 carbon atoms such as methanediyl group, ethanediyl group, and propanediyl group. Is mentioned. Of these, methanediyl group and propane-2,2-diyl group are preferable. The substituted alkanediyl group includes a group in which some or all of the hydrogen atoms bonded to the same carbon atom of the alkanediyl group are substituted with a divalent organic group, or a hydrogen atom bonded to a different carbon atom of the alkanediyl group. And a group in which a part or all of is substituted with a monovalent group. As the divalent organic group for substituting the same carbon atom of the alkanediyl group, a divalent organic group having a lactone structure, a divalent organic group having a cyclic carbonate structure, and a divalent organic group having a sultone structure are preferable. A valerolactone-diyl group is more preferable. Moreover, as a monovalent group which substitutes a part or all of the hydrogen atom couple | bonded with the different carbon atom of alkanediyl group, a fluorine atom and a fluorinated alkyl group are preferable, and a fluorine atom is more preferable.

R ¹ is also preferably a single bond.

Examples of the divalent organic group having 1 to 20 carbon atoms represented by R ² in the formula (1-1) include a group represented by the following formula (2) and a group represented by the following formula (2 ′). Etc. Of these, a group represented by the following formula (2) is preferable.

In the above formula (2), R ³ and R ⁴ are each independently a hydrogen atom or a monovalent organic group. Rf ¹ and Rf ² are each independently a fluorine atom or a fluorinated alkyl group. n is an integer of 1-6. m is an integer of 0 or more and 6 or less. * 1 shows the site | part couple | bonded with L or an oxygen atom.

In said formula (2 '), ^Ry is a C2-C10 substituted or unsubstituted alkanediyl group. Rf ¹ and Rf ² are each independently a fluorine atom or a fluorinated alkyl group. n is an integer of 1-6. m is an integer of 0 or more and 6 or less. * 1 shows the site | part couple | bonded with L or an oxygen atom.

Examples of the monovalent organic group represented by R ³ and R ⁴ include a chain hydrocarbon group.

R ³ and R ⁴ are preferably a hydrogen atom.

Among the substituted or unsubstituted alkanediyl groups having 2 to 10 carbon atoms represented by R ^y , examples of the unsubstituted alkanediyl group include alkanes having 1 to 10 carbon atoms such as ethanediyl group and propanediyl group. A diyl group is mentioned. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, nitro group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, Examples include an acyloxy group.

  In the above formulas (2) and (2 '), n is preferably 2 or more and 4 or less.

The fluorinated alkyl group represented by Rf ¹ and Rf ² in the above formulas (2) and (2 ′) is preferably a trifluoromethyl group.

  In the above formulas (2) and (2 ′), m is preferably 0 or more and 2 or less.

  In the above formula (1-2), i is preferably 0.

Among the substituted or unsubstituted alkanediyl groups having 1 to 10 carbon atoms represented by R ^x in the above formula (1-2), examples of the unsubstituted alkanediyl group include a methanediyl group, an ethanediyl group, and propanediyl. C1-C10 alkanediyl groups, such as group, are mentioned. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, nitro group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, Examples include an acyloxy group.

Of these, R ^x is preferably a methanediyl group.

Examples of the divalent organic group having 1 to 19 carbon atoms of R ⁰ in the above formula (1-2) include the same groups as those exemplified for R ² in the above formula (1-1).

The monovalent radiolytic onium cation represented by X ⁺ is a cation that is decomposed by the action of radiation. In the exposed portion, sulfonic acid is generated from protons generated by the decomposition of the radiolytic onium cation and the sulfonate anion of the [B] compound. Examples of the monovalent radiolytic onium cation represented by X ⁺ include a sulfonium cation, a tetrahydrothiophenium cation, and an iodonium cation. Among these, a sulfonium cation represented by the following formula (X-0), a sulfonium cation represented by the following formula (X-1), and an iodonium cation represented by the following formula (X-2) are preferable.

In the formula (X-0), R ^{b4 to} R ^b6 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or 10 to 10 carbon atoms. 36 aromatic hydrocarbon groups may be represented, or R ^b4 and R ^b5 may be combined to form a 3-membered to 12-membered ring containing a sulfur atom. The hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group is substituted with a halogen atom, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, or an alkoxy group having 1 to 12 carbon atoms.

Examples of the aliphatic hydrocarbon group in the above formula (X-0) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Group, octyl group, 2-ethylhexyl group and the like. As carbon number of the aliphatic hydrocarbon group of R ^{< b4} > -R ^{< b6>} , 1-12 are preferable. Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.

Examples of the aliphatic hydrocarbon group in the above formula (X-0) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Group, octyl group, 2-ethylhexyl group and the like. As carbon number of the aliphatic hydrocarbon group of R ^{< b4} > -R ^{< b6>} , 1-12 are preferable. Examples of the aliphatic hydrocarbon group in which a hydrogen atom is substituted with an alicyclic hydrocarbon group include a 1- (adamantan-1-yl) alkane-1-yl group.

  The alicyclic hydrocarbon group in the above formula (X-0) may be monocyclic or polycyclic, and the hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an alkyl group. Also good. In this case, the alicyclic hydrocarbon group has 20 or less carbon atoms including the carbon number of the alkyl group. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, and a norbornyl group.

  Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an alkyl group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group, and an isobornyl group. It is done.

  Examples of the aromatic hydrocarbon group in the above formula (X-0) include a naphthyl group and a phenanthryl group.

  Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include 4-methoxynaphthyl group and 4-nbutoxynaphthyl. Examples of the alkyl group in which a hydrogen atom is substituted with an aromatic hydrocarbon group, that is, an aralkyl group, include a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. In addition, when an alkyl group or an alicyclic hydrocarbon group is contained in an aromatic hydrocarbon group, a C1-C12 alkyl group and a C3-C18 alicyclic hydrocarbon group are preferable.

  Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group and the like.

  Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

  Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, and a tert-butylcarbonyloxy group. Pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.

The ring containing a sulfur atom that R ^b4 and R ^b5 may form together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. If it contains one or more sulfur atoms, it may further contain one or more sulfur atoms and / or one or more oxygen atoms. As said ring, a C3-C18 ring is preferable and a C4-C18 ring is more preferable.

In the above formula (X-1), R ¹⁵ , R ¹⁶ and R ¹⁷ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, substituted or unsubstituted carbon. number 6-12 aromatic hydrocarbon group, or an _OSO 2 -R ^D or _SO 2 -R ^E, or represent two or more are combined with each other configured ring of these groups. R ^D and R ^E 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. k, m, and n are each independently an integer of 0 to 5. When R ¹⁵ to R ¹⁷ and ^{R D} and ^{R E} are a plurality each of a plurality of ^R 15 ^{to R 17} and ^{R D} and ^{R E} may be the same as or different from each other.
In the formula (X-2), R ¹⁸ and R ¹⁹ are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted carbon number of 6 to 12 aromatic hydrocarbon group, or an _OSO 2 -R ^F or _SO 2 -R ^G, or represent two or more are combined with each other configured ring of these groups. R ^F and R ^G 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. i and j are each independently an integer of 0 to 5. ^{R 18,} R 19, R ^F and optionally ^{R G} is plural respective plurality of ^{R 18, R 19, R F} and ^{R G} may have each the same or different.

Examples of the unsubstituted linear alkyl group represented by R ^{15 to} R ¹⁹ include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group.
Examples of the unsubstituted branched alkyl group represented by R ^{15 to} R ¹⁹ include an i-propyl group, an i-butyl group, a sec-butyl group, and a t-butyl group.
Examples of the unsubstituted aromatic hydrocarbon group represented by R ^{15 to} R ¹⁹ include aryl groups such as phenyl group and naphthyl group; aralkyl groups such as benzyl group and phenethyl group.

Examples of the substituent that may substitute the hydrogen atom of the alkyl group and aromatic hydrocarbon group include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxy group, a carboxy group, and a cyano group. 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.

As the ^R 15 ^{to R 19,} unsubstituted, straight or branched alkyl group, a fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon _{^{group, OSO 2 -R D, SO 2}} -R E Are preferable, a fluorinated alkyl group and an unsubstituted monovalent aromatic hydrocarbon group are more preferable, and a fluorinated alkyl group is more preferable. R ″ is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

As k, m, and n in the formula (X-1), integers of 0 to 2 are preferable, 0 or 1 is more preferable, and 0 is more preferable.
As i and j in the said Formula (X-2), the integer of 0-2 is preferable, 0 or 1 is more preferable, and 0 is further more preferable.

  Examples of the sulfonium cation include cations represented by the following formulas (b1-1) to (b1-10). Examples of the iodonium cation include cations represented by the following formulas (b2-1) to (b2-12).

  Of these, the triphenylsulfonium cation represented by the above formula (b1-1) is preferable.

  The above onium cation is described in, for example, Advances in Polymer Science, Vol. 62, p. It can be produced according to the general method described in 1-48 (1984).

  [B] Compounds include the following formulas (1-1-1) to (1-1-17), formulas (1-2-1) to (1-2-3), and formulas (1-3-1). ) And (1-3-2) are preferred.

Formulas (1-1-1) to (1-1-17), Formulas (1-2-1) to (1-2-3), and Formulas (1-3-1) to (1-3-2) ), X ⁺ has the same ^{meaning as} in the above formulas (1-1), (1-2) and (1-3).

<Synthesis of [B] Compound>
[B] Among the compounds, for example, when synthesizing a compound in which E ⁻ in the above formula (1-1) is SO ₃ ^— , the compound has the following first step, the following second step, and the following third step. Can be synthesized by the synthesis method shown in the following reaction scheme.
The organic halide represented by the following formula (ia) and the dithionite represented by D ₂ S ₂ O ₄ are reacted to obtain a sulfite represented by the following formula (ib). 1 step;
A second step of reacting a sulfite represented by the following formula (ib) with a hydrogen peroxide aqueous solution to obtain a sulfonate represented by the following formula (ic);
The third step of reacting the sulfonate represented by the following formula (ic) with the onium salt represented by XY

In the above formulas (ia), (ib), and (ic), A, R ¹ , R ² , k, and X ⁺ are as defined in the above formula (1-1). Z is a halogen atom. D is an alkali metal. Y ⁻ is a monovalent anion.

In the formula (1-1), E ^- is possible and if it is, that by also similar to that described above wherein the compound represented by the above formula (1-2), to synthesize a [B] compounds ^- is COO it can.

  As a content of the [B] compound, when the [B] compound is a [B1] compound that functions as an acid generator, 0.5 to 30 parts by mass with respect to 100 parts by mass of the [A] polymer. Is preferred, 1 to 20 parts by mass is more preferred, 2.5 to 15 parts by mass is further preferred, and 5 to 10 parts by mass is particularly preferred.

  On the other hand, when the [B] compound is the [B2] compound that functions as an acid diffusion controller, the content of the [B] compound is preferably 30 parts by mass or less with respect to 100 parts by mass of the [A] polymer. 0.1 parts by mass to 20 parts by mass is more preferable, and 0.5 parts by mass to 10 parts by mass is more preferable.

<[G] solvent>
The “[G] solvent” is a component for dissolving or dispersing the [A] polymer, compound and optional component. [G] Examples of the solvent include alcohol solvents, ketone solvents, amide solvents, ether solvents, ester solvents, and the like. [G] You may use a solvent individually by 1 type or in combination of 2 or more types.

As an alcohol solvent, for example,
As monoalcohol solvents, methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec -Pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-he Data decyl alcohol, furfuryl alcohol, phenol, cyclohexanol, methyl cyclohexanol, 3,3,5-trimethyl cyclohexanol, benzyl alcohol, diacetone alcohol and the like;
As polyhydric alcohol solvents, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2 , 4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol and the like;
As polyhydric alcohol partial ether solvents, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethyl Butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol Mono butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, and the like.

Examples of the ketone solvent include:
As chain ketone solvents, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n- Hexyl ketone, di-iso-butyl ketone, trimethylnonanone, 2,4-pentanedione, acetonyl acetone, diacetone alcohol, acetophenone, etc .;
Examples of the cyclic ketone solvent include cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and methylcyclohexanone.

As the amide solvent, for example,
Examples of chain amide solvents include N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide and the like;
Examples of the cyclic amide solvent include N-methylpyrrolidone and N, N′-dimethylimidazolidinone.

As the ether solvent, for example,
Examples of chain ether solvents include diethyl ether, dipropyl ether, dibutyl ether, diphenyl ether and the like;
Examples of cyclic ether solvents include tetrahydrofuran and tetrahydropyran.

As the ester solvent, for example,
As acetate solvents, methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-acetic acid 3- Methoxybutyl, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, glycol diacetate, methoxytriglycol acetate, etc .;
As an acetic ester solvent of a polyhydric alcohol partial ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, etc .;
Examples of carbonate solvents include dimethyl carbonate and diethyl carbonate;
Other carboxylic acid ester solvents include methyl acetoacetate, ethyl acetoacetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, lactic acid Examples thereof include ethyl, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, and diethyl phthalate.

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

<[C] acid generator>
[C] The acid generator is an acid generator other than the above-mentioned [B] compound, and is a sulfonate compound that generates an acid upon irradiation with radiation. According to the [C] acid generator, for example, when the structural unit containing an acid dissociable group of the [A] polymer is the structural unit (I-1), the acid generated from the acid generator is It becomes a catalyst and can dissociate acid dissociable groups. As a result, the sensitivity of the radiation sensitive resin composition can be increased. [C] You may use an acid generator individually by 1 type or in combination of 2 or more types.

  [C] Examples of the acid generator include onium salt compounds such as sulfonium salts, tetrahydrothiophenium salts, and iodonium salts.

  Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, cyclohexyl 2-oxocyclohexylmethylsulfonium trifluoromethanesulfonate, dicyclohexyl 2 -Oxocyclohexylsulfonium trifluoromethanesulfonate, 2-oxocyclohexyldimethylsulfonium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate, triphenylsulfonium 2- (adamantan-1-yl) -1,1-difluoroethane- 1-sulfonate, triphenylsulfonate Arm 4- (adamantan-1-yl-carbonyloxy) -1,1,2,2-tetrafluoro-1-sulfonate, and the like.

  Examples of the tetrahydrothiophenium salt include 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium nonafluoro-n-butanesulfonate, 4-hydroxy-1 -Naphtyltetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium nonafluoro-n-butane Sulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydro Ofenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium Examples include perfluoro-n-octane sulfonate.

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

  Among these, onium salt compounds are preferable, sulfonium salts are more preferable, and triphenylsulfonium 2- (adamantan-1-ylcarbonyloxy) -1,1,2,2-tetrafluorobutane-1-sulfonate is more preferable. .

  [C] The content of the acid generator is 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer [A] from the viewpoint of sensitivity and developability of the radiation-sensitive resin composition. Preferably, 1 part by mass to 20 parts by mass is more preferable, and 3 parts by mass to 10 parts by mass are more preferable. [C] When content of an acid generator is less than the said minimum, it exists in the tendency for the sensitivity and developability of the said radiation sensitive resin composition to fall. [C] When the content of the acid generator exceeds the above upper limit, the radiation-sensitive resin composition tends to be less transparent with respect to radiation, making it difficult to obtain a rectangular resist pattern.

<[D] Acid diffusion controller>
[D] The acid diffusion controller controls the diffusion phenomenon in the resist film of the acid generated from the [B] compound or [C] acid generator by exposure, and has an effect of suppressing undesired chemical reactions in the unexposed areas. . The content form of the acid diffusion controller in the radiation-sensitive resin composition may be a compound form as described later (hereinafter, this aspect is also referred to as “[D] acid diffusion controller”) or a part of the polymer. It is possible to use both of these embodiments.

  [D] Examples of the acid diffusion controller 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 amide group-containing compounds include Nt-butoxycarbonyl group-containing amino compounds, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, Examples thereof include 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.

  [D] The acid diffusion controller may be used alone or in combination of two or more. [D] The content of the acid diffusion controller is preferably less than 15 parts by mass with respect to 100 parts by mass of the [A] polymer. [D] By making content of an acid diffusion control agent into the said range, the LWR performance of the said radiation sensitive resin composition etc. can be improved further.

<[E] Fluorine atom-containing polymer>
[E] The fluorine atom-containing polymer is a polymer containing a fluorine atom, and is a polymer different from the above-mentioned [A] polymer. According to the radiation sensitive resin composition, in addition to the [A] polymer, the [E] fluorine atom-containing polymer is formed on the surface layer of the resist film by further containing the [E] fluorine atom-containing polymer. 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 monomers that give 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. Examples include ester compounds in which the side chain is a fluorinated alkyl group or a derivative thereof, and one or more olefin side chains (sites not including a double bond) being a fluorinated alkyl group 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. Such as a fluorinated alkyl group or its derivative ester compound, or 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 by the derivative, a hydrogen atom bonded to a double bond of one or more alicyclic olefin compounds is substituted with a fluorinated alkyl group such as a trifluoromethyl group, and the side chain is a fluorinated alkyl group And those which are derivatives thereof. In addition, an alicyclic olefin compound shows the compound in which a part of ring is a double bond.

  [E] The fluorine atom-containing polymer is a structural unit represented by the following formula (7) (hereinafter also referred to as “structural unit (f1)” and / or a structural unit represented by the following formula (8) (hereinafter, 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 (7).

In the above formula (7), R ^f3 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^f4 is a 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 (7-1) and (7-2) are preferable.

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

  Among these, the structural unit represented by the formula (7-1) is more 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 (8).

In the above formula (8), R ^f5 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^f6 is a (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.

In the above formula (8), examples of the (r + 1) -valent linking group represented by R ^f6 include a linear or branched hydrocarbon group having 1 to 30 carbon atoms and an alicyclic group having 3 to 30 carbon atoms. One or more groups selected from the group consisting of a formula hydrocarbon group, an 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 combination of these. The (r + 1) -valent linking group may have a substituent.

  Examples of the linear or branched hydrocarbon group having 1 to 30 carbon atoms include hydrocarbon groups such as methane, ethane, propane, butane, pentane, hexane, heptane, decane, icosane, and triacontane (r + 1). ) Groups from which a single hydrogen atom is removed.

Examples of the alicyclic hydrocarbon group having 3 to 30 carbon atoms include:
As monocyclic saturated hydrocarbons, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, methylcyclohexane, ethylcyclohexane, etc .;
As monocyclic unsaturated hydrocarbons, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclodecene, cyclopentadiene, cyclohexadiene, cyclooctadiene, cyclodecadiene, etc .;
As polycyclic saturated hydrocarbons, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [3.3.1]. ^.1,3,7 ] decane, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecane, adamantane, etc .;
As polycyclic unsaturated hydrocarbons, bicyclo [2.2.1] heptene, bicyclo [2.2.2] octene, tricyclo [5.2.1.0 ^2,6 ] decene, tricyclo [3.3. 1.1 ^3,7 ] decene, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] dodecene and the like, and (r + 1) hydrogen atoms are removed.

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

In the formula (8), the divalent linking group having a fluorine atom represented by X ^1, include a divalent linear hydrocarbon group having 1 to 20 carbon atoms having a fluorine atom. Examples of X ¹ include groups represented by the following formulas (X1-1) to (X1-6).

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

In the above formula (8), examples of the monovalent organic group represented by R ^f7 include a linear or branched hydrocarbon group having 1 to 30 carbon atoms and an alicyclic carbonization having 3 to 30 carbon atoms. A hydrogen group, an aromatic hydrocarbon group having 6 to 30 carbon atoms, or 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. Examples include a combined group.

  Examples of the structural unit (f2) include structural units represented by the following formulas (8-1) and (8-2).

In the above formula (8-1), R ^f6 is a divalent linear or branched saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, or cyclic saturated or unsaturated group having 3 to 20 carbon atoms. It is a hydrocarbon group. R ^f5 , X ¹ and R ^f7 have the same ^{meaning as} in the above formula (8).

In the formula ^{(8-2), R f5, X} 1, R f7 and o are as defined in the above formula (8). However, when k is 2 or 3, the plurality of X ¹ and R ^f7 may be the same or different.

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

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

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

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

  As a 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 “other structural units” other than the structural unit (f1) and the structural unit (f2). Examples of other structural units include the structural unit (I) of [A] polymer.

  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. More preferred is mol% to 70 mol%.

  [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] When the content of the fluorine atom-containing polymer exceeds the above upper limit, the water repellency of the resist film surface becomes too high, and development failure may occur.

[E] The fluorine atom content of the fluorine atom-containing polymer is preferably larger than the fluorine atom content of the [A] polymer. [E] When the fluorine atom content in the fluorine atom-containing polymer is larger than that of the [A] polymer, it is formed by the radiation sensitive resin composition containing the [A] polymer and the [E] fluorine atom-containing polymer. Further, the water repellency of the 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 and Mn of the fluorine atom-containing polymer is preferably 1 to 5, and more preferably 1 to 3.

<[F] Localization promoter>
The uneven distribution accelerator (hereinafter, also referred to as “[F] uneven distribution accelerator”) is a component that segregates the [E] fluorine atom-containing polymer more efficiently on the resist film surface. 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, and nitrile compounds. [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.

  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>
In addition to the components [A] to [G], the radiation-sensitive resin composition includes other optional components such as a surfactant, an alicyclic skeleton-containing compound, and a sensitizer as long as the effects of the present invention are not impaired. Can be contained. Two or more kinds of other optional components may be used in combination. Further, the content of other optional components can be appropriately determined according to the purpose.

<Method for preparing radiation-sensitive resin composition>
The radiation-sensitive resin composition comprises a [A] polymer, a [B] compound, a [G] solvent and, if necessary, a [C] acid generator, a [D] acid diffusion controller, and [E] a fluorine atom. Each arbitrary component such as a polymer can be prepared by mixing at a predetermined ratio.

  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%-10 mass% are further more preferable.

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

[Resist film forming step]
In this step, a resist film is formed using the above-described radiation-sensitive resin composition of the present invention. Although it does not specifically limit as a coating method, For example, appropriate coating means, such as spin coating, cast coating, roll coating, can be employ | adopted. Examples of the substrate include a silicon wafer and a wafer coated with aluminum. Specifically, after applying the composition so that the resulting resist film has a predetermined thickness, the solvent in the coating film is volatilized by pre-baking (PB) as necessary. As a film thickness of a coating film, 10 nm-500 nm are preferable. As temperature of PB, it is 60 to 140 degreeC normally, and 80 to 120 degreeC is preferable. The PB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.

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

  Moreover, it is preferable to perform post-exposure baking (PEB) after exposure. By performing PEB, the dissociation reaction of the acid dissociable group in the exposed portion of the resist film can be smoothly advanced. As temperature of PEB, it is 50 to 180 degreeC normally, and 80 to 130 degreeC is preferable. The PEB time is usually 5 to 600 seconds, preferably 10 to 300 seconds.

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

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

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

As the organic solvent developer, for example,
Examples of alcohol solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol and the like;
Examples of ether solvents include diethyl ether, dipropyl ether, dibutyl ether, tetrahydrofuran, dioxane, diphenyl ether, anisole and the like;
Examples of ketone solvents include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl amylkenton, and methyl-n-butyl ketone.
Examples of amide solvents include N, N′-dimethylimidazolidinone, N-methylformamide, N, N-dimethylformamide and the like;
Examples of ester solvents include diethyl carbonate, methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, and n-butyl acetate.

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

  The radiation sensitive acid generator of this invention consists of a compound represented by the said Formula (1-1), the said Formula (1-2), or the said Formula (1-3). Since the said radiation sensitive acid generator consists of a compound which has the said structure, it is used suitably as a radiation sensitive acid generator.

<Compound>
The compound of the present invention is represented by the above formula (1-1), the above formula (1-2) or the above formula (1-3). Since the said compound has the said structure, it can be conveniently used as a compound which comprises the said radiation sensitive acid generator.

  The radiation-sensitive acid generator and the compound are described in the section of the [B] 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)]
Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) using Tosoh Corporation GPC columns (G2000HXL: 2, G3000HXL: 1, G4000HXL: 1) under the following conditions. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Column temperature: 40 ° C
Detector: Differential refractometer Standard material: Monodisperse polystyrene

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

<Synthesis of [B] Compound>
[Example 1] (Synthesis of Compound (B-1))
122 g (0.80 mol) of adamantanol A, 97.1 g (0.96 mol) of triethylamine and 800 g of acetonitrile were added to a 3 L eggplant-shaped flask and cooled to 0 ° C. in an ice bath. 120 g (0.88 mol) of acid chloride B was added dropwise thereto. After completion of dropping, the mixture was stirred at room temperature for 7 hours. After replacing the solvent with ethyl acetate, the salt was removed by celite filtration. After washing with water, the organic phase was dried over anhydrous sodium sulfate and the solvent was distilled off. By purification by column chromatography, 181 g of ethyl ester C was obtained (yield 90%).

  To a 200 mL eggplant-shaped flask, 15 g (59.5 mmol) of the ethyl ester obtained above was added and dissolved in 100 g of tetrahydrofuran. 34.2 g (71.3 mmol) of 5 mass% lithium hydroxide aqueous solution was dripped there. After stirring at room temperature for 10 hours, concentrated hydrochloric acid equivalent to lithium hydroxide was added and stirred at room temperature for 20 minutes. The organic phase was recovered and dried over anhydrous sodium sulfate, and then the solvent was distilled off to obtain 13.0 g of carboxylic acid D (yield 98%).

  To a 100 mL eggplant type flask, 3.30 g (14.7 mmol) of the carboxylic acid D obtained above was added and dissolved in 15 g of acetonitrile. To this, 5.07 g (44.1 mmol) of dichloromethyl methyl ether was slowly added dropwise, followed by heating and stirring at 60 ° C. for 10 hours. After removing the solvent and excess dichloromethyl methyl ether, 10 mL of acetonitrile was added and cooled to 0 ° C. in an ice bath (E). A solution in which 3.51 g (14.7 mmol) of 4-bromo-3,3,4,4-tetrafluorobutan-1-ol and 1.78 g (17.6 mmol) of triethylamine were dissolved in 30 mL of acetonitrile. Was slowly added dropwise. After completion of dropping, the mixture was stirred at room temperature for 10 hours. After replacing the solvent with ethyl acetate, the salt was removed by celite filtration. After washing with water, the organic phase was dried over anhydrous sodium sulfate and the solvent was distilled off. By purification by column chromatography, 4.89 g of ester F was obtained (yield 75%).

  In a 200 mL eggplant-shaped flask, 3.18 g (7.37 mmol) of ester F and 30 g of acetonitrile were added and dissolved. A solution prepared by dissolving 1.86 g (22.1 mmol) of sodium bicarbonate and 2.57 g (14.7 mmol) of sodium dithionesan in 30 g of water was added at once, and then at 65 ° C. for 4 hours. Stir with heating. After cooling to room temperature, it was washed twice with an aqueous sodium thiosulfate solution (G). The organic layer was collected, 2.51 g (22.1 mmol) of 30% aqueous hydrogen peroxide was added, and the mixture was heated and stirred at 55 ° C. for 6 hours. After cooling to room temperature, excess hydrogen peroxide was quenched with aqueous sodium sulfite (H). The organic layer was collected and the solvent was distilled off. Then, 2.20 g (7.37 mmol) of triphenylsulfonium chloride, 50 g of dichloromethane and 25 g of water were added and stirred at room temperature for 10 hours. The organic layer was washed 6 times with water, and then the solvent was distilled off to obtain 4.45 g of a compound represented by the following formula (B-1) (hereinafter also referred to as “compound (B-1)”). Rate 87%). The scheme of compound synthesis (B-1) is shown below.

[Examples 2 to 16] (Synthesis of Compound (B-2) to Compound (B-22))
The compounds represented by the following formulas (B-2) to (B-22) were synthesized in the same manner as in Example 1 except that the precursor was appropriately selected.

<Synthesis of [A] polymer and [E] fluorine atom-containing polymer>
The monomer used for the synthesis | combination of each polymer in each Example and a comparative example is shown below.

[Synthesis Example 1] (Synthesis of polymer (A-1))
Compound (M-6) 7.97 g (35 mol%), compound (M-7) 7.44 g (45 mol%) and compound (M-8) 4.49 g (20 mol%) into 2-butanone 40 g It melt | dissolved and AIBN 0.80g (5 mol% with respect to all the monomers) was added as an initiator, and the monomer solution was prepared. Next, a 100 mL three-necked flask charged with 20 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. The polymerization solution cooled in 400 g of methanol was added, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 80 g of methanol, filtered, and dried at 50 ° C. for 17 hours to synthesize a white 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-6), (M-7), and (M-8) was 34.3 mol%, 45.1 mol%, and 20 respectively. It was 6 mol%.

[Synthesis Example 2] (Synthesis of polymer (A-2))
6.88 g (40 mol%) of compound (M-1), 2.30 g (10 mol%) of compound (M-9) and 10.83 g (50 mol%) of compound (M-2) were converted to 40 g of 2-butanone. After dissolution, 0.72 g of AIBN (5 mol% based on the total monomers) was added as an initiator to prepare a monomer solution. Next, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. The polymerization solution cooled in 400 g of methanol was added, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 80 g of methanol, filtered, and dried at 50 ° C. for 17 hours to synthesize a white powdery polymer (A-2) (14.9 g, yield 75). %). Mw of the polymer (A-2) was 7,500, and Mw / Mn was 1.55. As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M-1), (M-9) and (M-2) was 40.1 mol%, 10.1 mol% and 9 respectively. It was 8 mol%.

[Synthesis Example 3] (Synthesis of Polymer (A-3))
Compound (M-1) 3.43 g (20 mol%), Compound (M-11) 3.59 g (15 mol%), Compound (M-10) 7.83 g (40 mol%) and Compound (M-8) ) 5.16 g (25 mol%) was dissolved in 40 g of 2-butanone, and 0.72 g of AIBN (5 mol% based on the total monomers) was added as an initiator to prepare a monomer solution. Next, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. The polymerization solution cooled in 400 g of methanol was added, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 80 g of methanol, filtered, and dried at 50 ° C. for 17 hours to synthesize a white powdery polymer (A-3) (15.3 g, yield 77). %). Mw of the polymer (A-3) was 7,200, and Mw / Mn was 1.53. As a result of ¹³ C-NMR analysis, the content ratios of structural units derived from (M-1), (M-11), (M-10), and (M-8) were 19.5 mol% and 15 respectively. It was 0.5 mol%, 40.1 mol% and 24.9 mol%.

[Synthesis Example 4] (Synthesis of Polymer (A-4))
Dissolve 55.0 g (65 mol%) of compound (M-5) and 45.0 g (35 mol%) of compound (M-3), 4 g of AIBN as an initiator, and 1 g of t-dodecyl mercaptan in 100 g of propylene glycol monomethyl ether Then, the reaction temperature was maintained at 70 ° C. in a nitrogen atmosphere, and copolymerization was performed for 16 hours. After completion of the polymerization reaction, the polymer solution was dropped into 1,000 g of n-hexane to solidify and purify the polymer. Next, 150 g of propylene glycol monomethyl ether was added to the polymer again, and then 150 g of methanol, 34 g of triethylamine and 6 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. After completion of the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting polymer was dissolved in 150 g of acetone, then dropped into 2,000 g of water and solidified, and the resulting white powder was filtered and filtered at 50 ° C. It was made to dry for a period of time to obtain a white powdery polymer (A-4) (65.7 g, yield 77%). Mw of the polymer (A-4) was 7,500, and Mw / Mn was 1.90. As a result of ¹³ C-NMR analysis, the content of each structural unit derived from p-hydroxystyrene and (M-3) was 65.4 mol% and 34.6 mol%, respectively.

[Synthesis Example 5] (Synthesis of Polymer (E-1))
79.9 g (70 mol%) of the compound (M-1) and 20.91 g (30 mol%) of the compound (M-4) were dissolved in 100 g of 2-butanone, and dimethyl 2,2′-azo was used as an initiator. A monomer solution was prepared by dissolving 4.77 g of bisisobutyrate. Next, a 1,000 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 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 solution was cooled with water and cooled to 30 ° C. or lower. The reaction solution was transferred to a 2 L separatory funnel, and then the polymerization solution was uniformly diluted with 150 g of n-hexane, and 600 g of methanol was added and mixed.
Next, 30 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution containing the polymer (E-1) as a solid content (yield 60%). Mw of the polymer (E-1) was 7,200, and Mw / Mn was 2.00. As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M-1) and (M-4) was 71.1 mol% and 28.9 mol%, respectively.

<Preparation of radiation-sensitive resin composition>
The component used for preparation of each radiation sensitive resin composition is shown below.

[[C] acid generator]
Compound represented by the following formula (C-1)

[[D] acid diffusion controller]
Compounds represented by the following formulas (D-1) and (D-2)

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

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

[Example 17] (Preparation of radiation-sensitive resin composition (J-1))
[A] 100 parts by mass of (A-1) as a polymer, [D] 2.3 parts by mass of (D-1) as an acid diffusion controller, and (B-1) 8.5 as a [B] compound [E] (E-1) 3 parts by mass as a fluorine atom-containing polymer, [G] 2,240 parts by mass and (G-2) 960 parts by mass as a solvent, F] A radiation-sensitive resin composition (J-1) was prepared by mixing 30 parts by mass of (F-1) as an uneven distribution accelerator and filtering through a 0.2 μm membrane filter.

[Examples 18 to 48 and Comparative Examples 1 to 6]
Except having used the [A]-[D] component of the kind and content shown in the following Table 1, it operated similarly to Example 17 and each radiation sensitive resin composition (J-2)-(J- 32) and (CJ-1) to (CJ-6) were prepared.

<Formation of resist pattern (1)>
On the surface of a 12-inch silicon wafer, using a spin coater (“CLEAN TRACK ACT12” manufactured by Tokyo Electron Ltd.), a composition for forming a lower antireflection film (“ARC66” manufactured by Brewer Science Inc.) was applied. A lower antireflection film with a thickness of 105 nm was formed by heating at 60 ° C. for 60 seconds. On the lower antireflection film, each of the prepared radiation sensitive resin compositions was applied using the spin coater, and PB was performed at 90 ° C. for 60 seconds. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with a film thickness of 90 nm. Next, this resist film is 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 Corporation). The film was exposed through a 40 nm line and space (1L1S) mask pattern. After the exposure, PEB was performed at 90 ° C. for 60 seconds. Thereafter, alkali development was performed using a 2.38% by mass TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern. When this resist pattern was formed, the exposure amount formed in a one-to-one line and space with a line width of 40 nm formed through a one-to-one line and space mask with a target dimension of 40 nm was defined as the optimum exposure amount.

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

<Evaluation>
About the resist pattern formed using each said radiation sensitive resin composition, LWR performance, resolution, cross-sectional shape, depth of focus, exposure margin, CD uniformity, and MEEF were evaluated in accordance with the following method. The results are shown in Table 2. A scanning electron microscope (“S-9380” manufactured by Hitachi High-Technologies Corporation) was used for measuring the resist pattern.

[LWR performance]
The resist pattern 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. LWR performance (nm) indicates that the smaller the value, the better. When the value of LWR performance is compared with the judgment standard, LWR performance improvement of 10% or more (meaning that the value of LWR performance is 0.9 times or less) is “good” and less than 10% Those with improved LWR performance were evaluated as “bad”.

[Resolution]
The dimension of the minimum resist pattern that can be resolved at the optimum exposure amount is defined as the resolution. The smaller the value, the better the resolution (nm). At this time, when the resolution is compared with the determination standard, a resolution improvement of 10% or more (which means that the numerical value of the resolution is 0.9 times or less) is “good” "And those with a resolution improvement of less than 10% were evaluated as" bad ".

[Rectangularity of the cross-sectional shape]
The cross-sectional shape of the resist pattern resolved at the optimum exposure dose was observed, and the line width Lb in the middle of the resist pattern and the line width La at the top of the film were measured. At this time, the rectangularity of the cross-sectional shape was evaluated as “good” when it was within the range of 0.9 ≦ La / Lb ≦ 1.1, and “bad” when it was out of the above range.

[Depth of focus]
In the resist pattern resolved at the above optimum exposure amount, the dimension when the focus is changed in the depth direction is observed, and the depth direction in which the pattern dimension falls within 90% to 110% of the standard without any bridge or residue. The margin of focus was taken as the depth of focus. The depth of focus (nm) indicates that the larger the value, the better. Depth of focus is “good” when 10% or more of the depth of focus is improved (meaning that the value of the depth of focus is 1.1 times or more) when compared with the criterion. Those with improved depth of focus were evaluated as “bad”.

[Exposure margin]
The above-mentioned optimum range of exposure amount when the pattern dimension resolved when using a 40 nm line and space (1L / 1S) resist pattern forming mask pattern is within ± 10% of the mask design dimension The ratio to the exposure amount was defined as the exposure margin (EL performance) (%). The larger the value of the exposure margin, the smaller the change amount of the patterning performance with respect to the change of the exposure amount. The exposure margin was evaluated as “good” when 18% or more and “bad” when less than 18%.

[CD uniformity]
The formed resist pattern was observed from above the pattern using the scanning electron microscope. The line width was measured at 20 points in the range of 400 nm, the average value was measured at a total of 500 points, and a 3-sigma value was obtained from the distribution of the measured values, and this was defined as CD uniformity (nm). The smaller the value of CD uniformity, the better the variation in line width over a long period. The CD uniformity was evaluated as “good” when it was 1.5 nm or less, and “bad” when it exceeded 1.5.

[MEEF]
Using the scanning electron microscope, five types of mask sizes (38.0 nmLine / 80 nmPitch, 39.0 nmLine / 80 nmPitch,
The line width of the resist pattern resolved by 40.0 nmLine / 80 nmPitch, 41.0 nmLine / 80 nmPitch, 42.0 nmLine / 80 nmPitch) was measured. The obtained measurement values were plotted with the horizontal axis as the mask size and the vertical axis as the line width formed with each mask size, and the slope of the approximate straight line calculated by the least square method was obtained, and this slope was defined as MEEF performance. The MEEF performance indicates that the closer the value is to 1, the better. The MEEF performance was evaluated as “good” when 4.7 or lower and “bad” when 4.7 or higher.

  As can be seen from the results in Table 2, the radiation-sensitive resin composition of the present invention, when used for ArF exposure, in both alkaline development and organic solvent development, LWR performance, resolution, cross-sectional shape, depth of focus, While the exposure margin, CD uniformity, and MEEF were good, in the comparative example, each characteristic was inferior to the examples.

[Preparation of radiation-sensitive resin composition for electron beam exposure]
[Example 49]
[A] 100 parts by mass of (A-4) as a polymer, [D] 3.6 parts by mass of (D-1) as another acid diffusion controller, (B-1) 20 as a [B] compound Radiation sensitivity is obtained by mixing 4 parts by mass and (G-1) 4,280 parts by mass and (G-2) 1,830 parts by mass as a [G] solvent and filtering through a 0.2 μm membrane filter. A resin composition (J-27) was prepared.

[Examples 50 to 73 and Comparative Examples 7 and 8]
Except having used each component of the kind and content shown in the following Table 3, it operated similarly to Example 49, the radiation sensitive resin composition (J-33)-(J-57), and (CJ-7) And (CJ-8) were prepared.

<Formation of resist pattern (3)>
Using a spin coater (“CLEAN TRACK ACT8” from Tokyo Electron Ltd.) on the surface of an 8-inch silicon wafer, each radiation-sensitive resin composition shown in Table 3 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 using a simple electron beam drawing apparatus (“HL800D”, Hitachi, Ltd., output: 50 KeV, current density: 5.0 A / cm ² ). After irradiation, PEB was performed at 120 ° C. for 60 seconds. Thereafter, development was performed at 23 ° C. for 30 seconds using a 2.38 mass% TMAH aqueous solution, washed with water, and dried to form a positive resist pattern. Each formed resist pattern was evaluated in the same manner as described above. The evaluation results are shown in Table 4.

  As can be seen from the results in Table 4, when the radiation sensitive resin composition of the present invention is used for alkali development in electron beam exposure, LWR performance, resolution, cross-sectional shape, depth of focus, exposure margin and CD uniformity. While the properties were good, in the comparative example, each characteristic was poor compared to the examples.

  According to the radiation sensitive resin composition and the resist pattern forming method of the present invention, excellent MEEF performance, depth of focus and exposure margin are exhibited, and excellent LWR performance, CD uniformity, resolution, and cross-sectional shape are exhibited. A resist pattern having rectangularity can be formed. Accordingly, these can be suitably used for semiconductor device processing processes and the like that are expected to be further miniaturized in the future.

Claims (15)

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

(In the formula (1-1), A is a is .E monovalent organic group having 1 to 30 carbon atoms ^- is C OO ^- a .X ⁺ is a monovalent radiolytic onium cation L is a single bond or an oxygen atom R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms R ² is a divalent organic having 1 to 20 carbon atoms K is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ may be the same or different .   The radiation sensitive resin composition according to claim 1, wherein L in the formula (1-1) is an oxygen atom. A polymer having a structural unit containing an acid dissociable group,
The radiation sensitive resin composition containing the compound represented by a following formula (1-2), and a solvent.

(In the formula (1-2), A is a monovalent organic group having 1 to 30 carbon atoms .E ^- is SO ₃ ^- or COO ^- and it .X ⁺ represents a monovalent radiolytic onium R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, i is an integer of 0 to 2, and R ^x is 1 to 10 carbon atoms. A substituted or unsubstituted alkanediyl group, R ⁰ is a single bond or a divalent organic group having 1 to 19 carbon atoms, and when i is 2, a plurality of R ¹ may be the same or different. Good.) A polymer having a structural unit containing an acid dissociable group,
The radiation sensitive resin composition containing the compound represented by a following formula (1-3), and a solvent.

(In the formula (1-3), A is a is .X ⁺ is a monovalent organic group having 1 to 30 carbon atoms, .R ¹ is a monovalent radiolytic onium cation is from 1 to 10 carbon atoms Substituted or unsubstituted alkanediyl groups.) The radiation sensitive resin composition according to claim 1 or 2, wherein R ² in the formula (1-1) is represented by the following formula (2).

(In Formula (2), R ³ and R ⁴ are each independently a hydrogen atom or a monovalent organic group. Rf ¹ and Rf ² are each independently a fluorine atom or a fluorinated alkyl group. N is an integer of 1 or more and 6 or less, m is an integer of 0 or more and 6 or less, * 1 represents a site bonded to L or an oxygen atom. The radiation sensitive resin composition according to claim 1 or 2, wherein R ² in the formula (1-1) is represented by the following formula (2 ').

(In formula (2 ′), R ^y is a substituted or unsubstituted alkanediyl group having 2 to 10 carbon atoms. Rf ¹ and Rf ² are each independently a fluorine atom or a fluorinated alkyl group. N is an integer of 1 or more and 6 or less, m is an integer of 0 or more and 6 or less, and * 1 represents a site bonded to L or an oxygen atom.   The radiation sensitive resin composition according to claim 1 or 2, wherein k in the formula (1-1) is 1. The R ¹ in the formula (1-1) or the formula (1-2) is a single bond, and 4 or more of —C (O) — are not continuously bonded. The radiation sensitive resin composition described in 1. R ¹ in the formula (1-1), the formula (1-2) or the formula (1-3) is a substituted or unsubstituted alkanediyl group, and the alkanediyl group is a methanediyl group. The radiation sensitive resin composition of any one of Claim 4.   A in the above formula (1-1), the above formula (1-2) or the above formula (1-3) is —OR or —R, and R is a monovalent alicyclic carbonization having 3 to 30 ring members. The sensation according to any one of claims 1 to 4, which is a hydrogen group, a monovalent aliphatic heterocyclic group having 3 to 30 ring members, or a monovalent aromatic hydrocarbon group having 6 to 30 ring members. Radiation resin composition. The radiation sensitive resin composition according to any one of claims 1 to 10, wherein the structural unit is represented by the following formula (3).

(In Formula (3), R ⁵ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid-dissociable group represented by the following Formula (Y-1). is there.)

(In formula (Y-1), R ^e1 is a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ^e2 and R ^e3 are Each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or these groups are combined with each other and bonded to each other. (Represents an alicyclic structure having 3 to 20 ring members and a carbon atom.)   The radiation-sensitive resin composition according to any one of claims 1 to 11, wherein the radiation-decomposable 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 1-12. A radiation-sensitive acid generator comprising a compound represented by the following formula (1-1), the following formula (1-2), or the following formula (1-3).

(In the formula (1-1), A is a is .E monovalent organic group having 1 to 30 carbon atoms ^- is C OO ^- a .X ⁺ is a monovalent radiolytic onium cation L is a single bond or an oxygen atom R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms R ² is a divalent organic having 1 to 20 carbon atoms K is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ may be the same or different .

(In the formula (1-2), A is a monovalent organic group having 1 to 30 carbon atoms .E ^- is SO ₃ ^- or COO ^- and it .X ⁺ represents a monovalent radiolytic onium R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, i is an integer of 0 to 2, and R ^x is 1 to 10 carbon atoms. A substituted or unsubstituted alkanediyl group, R ⁰ is a single bond or a divalent organic group having 1 to 19 carbon atoms, and when i is 2, a plurality of R ¹ may be the same or different. Good.)

(In the formula (1-3), A is a is .X ⁺ is a monovalent organic group having 1 to 30 carbon atoms, .R ¹ is a monovalent radiolytic onium cation is from 1 to 10 carbon atoms Substituted or unsubstituted alkanediyl groups.) A compound represented by the following formula (1-1), the following formula (1-2) or the following formula (1-3).

(In the formula (1-1), A is a is .E monovalent organic group having 1 to 30 carbon atoms ^- is C OO ^- a .X ⁺ is a monovalent radiolytic onium cation L is a single bond or an oxygen atom R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms R ² is a divalent organic having 1 to 20 carbon atoms K is an integer of 1 to 3. When k is 2 or more, a plurality of R ¹ may be the same or different .

(In the formula (1-2), A is a monovalent organic group having 1 to 30 carbon atoms .E ^- is SO ₃ ^- or COO ^- and it .X ⁺ represents a monovalent radiolytic onium R ¹ is a single bond or a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, i is an integer of 0 to 2, and R ^x is 1 to 10 carbon atoms. A substituted or unsubstituted alkanediyl group, R ⁰ is a single bond or a divalent organic group having 1 to 19 carbon atoms, and when i is 2, a plurality of R ¹ may be the same or different. Good.)

(In the formula (1-3), A is a is .X ⁺ is a monovalent organic group having 1 to 30 carbon atoms, .R ¹ is a monovalent radiolytic onium cation is from 1 to 10 carbon atoms Substituted or unsubstituted alkanediyl groups.)