JP5481046B2 - Resist composition, resist pattern forming method, novel compound and acid generator - Google Patents

Description

  The present invention relates to a resist composition, a method for forming a resist pattern using the resist composition, a novel compound useful as an acid generator for the resist composition, and an acid generator.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
As a resist material satisfying such requirements, a chemically amplified resist composition containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. ing.
For example, as a positive chemically amplified resist composition, a composition containing a resin component (base resin) whose solubility in an alkaline developer is increased by the action of an acid and an acid generator component is generally used. Yes. When such a resist film formed using the resist composition is selectively exposed at the time of forming the resist pattern, an acid is generated from the acid generator in the exposed portion, and the alkali developer of the resin component is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer.

Currently, as a resist base resin used in ArF excimer laser lithography and the like, a resin having a constitutional unit derived from (meth) acrylic acid ester (acrylic resin) because of its excellent transparency near 193 nm ) Etc. are generally used (see, for example, Patent Document 1).
Here, “(meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position. “(Meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

As the acid generator used in the chemically amplified resist composition, various kinds of acid generators have been proposed so far, for example, onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, Diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known.
Currently, an onium salt acid generator having an onium ion such as triphenylsulfonium in the cation moiety is used as the acid generator. As the anion moiety of the onium salt acid generator, an alkyl sulfonate ion or a fluorinated alkyl sulfonate ion in which part or all of the hydrogen atoms of the alkyl group are substituted with a fluorine atom is generally used ( For example, see Patent Document 2).
JP 2003-241385 A Japanese Patent Laid-Open No. 2005-37888

As further advances in lithography technology and miniaturization of resist patterns continue in the future, there is a further demand for resist materials to form resist patterns with higher resolution while maintaining good lithography characteristics. It is growing.
For example, lithography with an electron beam or EUV is aimed at forming a fine pattern of several tens of nanometers. Thus, the smaller the resist pattern dimension is, the more important it is that the resist composition is highly sensitive to the exposure light source. It becomes. However, in the resist composition containing the conventional onium salt acid generator as described above, the sensitivity to an exposure light source such as EUV is not sufficiently high, and desired resolution and lithography characteristics can be obtained. It is difficult and further improvement is demanded.

  The present invention has been made in view of the above circumstances, and is a novel compound useful as an acid generator for a resist composition, an acid generator using the compound, and a resist composition containing the acid generator And a resist pattern forming method using the resist composition.

  In order to solve the above problems, the present invention employs the following configuration.

  That is, the first aspect of the present invention is a resist composition comprising a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure. The acid generator component (B) is a resist composition containing an acid generator (B1) composed of a compound represented by the following general formula (b1-1).

［式中、Ｚは単結合又は２価の連結基であり；Ｒ^１１”〜Ｒ^１３”はそれぞれ独立してフッ素化アルキル基を表し、ｒ_１〜ｒ_３はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_２＋ｒ_３は０とならない。Ｒ^１４”〜Ｒ^１６”はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、ヒドロキシ基、ヒドロキシアルキル基又はハロゲン原子を表し、ｒ_４〜ｒ_６はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_４は５以下であり、ｒ_２＋ｒ_５およびｒ_３＋ｒ_６はそれぞれ４以下である。Ｒ^１１”〜Ｒ^１６”のうち、いずれか２つが相互に結合して環を形成してもよい。複数のＲ^１１”〜Ｒ^１６”が存在する場合、それぞれのＲ^１１”〜Ｒ^１６”は同じであっても異なっていてもよい。Ｘ⁻はアニオンである。］

Wherein Z is a single bond or a divalent linking group; R ¹¹ ″ to R ¹³ ″ each independently represents a fluorinated alkyl group , and r _{1 to} r ₃ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₂ + r ₃ is not 0. R ¹⁴ ″ to R ¹⁶ ″ each independently represents an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxy group, hydroxyalkyl group or halogen atom, and r _{4 to} r ₆ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₄ is 5 or less, and r ₂ + r ₅ and r ₃ + r ₆ are 4 or less, respectively. Any two of R ¹¹ ″ to R ¹⁶ ″ may be bonded to each other to form a ring. When a plurality of R ¹¹ ″ to R ¹⁶ ″ are present, each R ¹¹ ″ to R ¹⁶ ″ may be the same or different. X ⁻ is an anion. ]

  According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the resist composition of the first aspect, a step of exposing the resist film, and an alkali development of the resist film. A resist pattern forming method including a step of forming a resist pattern.

  A third aspect of the present invention is a compound represented by the following general formula (b1-1).

［式中、Ｚは単結合又は２価の連結基であり；Ｒ^１１”〜Ｒ^１３”はそれぞれ独立してフッ素化アルキル基を表し、ｒ_１〜ｒ_３はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_２＋ｒ_３は０とならない。Ｒ^１４”〜Ｒ^１６”はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、ヒドロキシ基、ヒドロキシアルキル基又はハロゲン原子を表し、ｒ_４〜ｒ_６はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_４は５以下であり、ｒ_２＋ｒ_５およびｒ_３＋ｒ_６はそれぞれ４以下である。Ｒ^１１”〜Ｒ^１６”のうち、いずれか２つが相互に結合して環を形成してもよい。複数のＲ^１１”〜Ｒ^１６”が存在する場合、それぞれのＲ^１１”〜Ｒ^１６”は同じであっても異なっていてもよい。Ｘ⁻はアニオンである。］

Wherein Z is a single bond or a divalent linking group; R ¹¹ ″ to R ¹³ ″ each independently represents a fluorinated alkyl group , and r _{1 to} r ₃ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₂ + r ₃ is not 0. R ¹⁴ ″ to R ¹⁶ ″ each independently represents an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxy group, hydroxyalkyl group or halogen atom, and r _{4 to} r ₆ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₄ is 5 or less, and r ₂ + r ₅ and r ₃ + r ₆ are 4 or less, respectively. Any two of R ¹¹ ″ to R ¹⁶ ″ may be bonded to each other to form a ring. When a plurality of R ¹¹ ″ to R ¹⁶ ″ are present, each R ¹¹ ″ to R ¹⁶ ″ may be the same or different. X ⁻ is an anion. ]

  A fourth aspect of the present invention is an acid generator comprising the compound of the third aspect.

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Further, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, a novel compound useful as an acid generator for a resist composition, an acid generator using the compound, a resist composition containing the acid generator, and a resist using the resist composition A pattern forming method can be provided.

≪Resist composition≫
The resist composition according to the first aspect of the present invention comprises a base component (A) (hereinafter referred to as “component (A)”) whose solubility in an alkaline developer is changed by the action of an acid, and an acid upon exposure. Contains the generated acid generator component (B) (hereinafter referred to as “component (B)”).
When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkali developer changes, the solubility of the unexposed portion in the alkali developer does not change. However, in the case of the negative type, the unexposed portion is dissolved and removed to form a resist pattern.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more includes a low molecular weight organic compound having a molecular weight of 500 or more and less than 2000 (hereinafter referred to as “low molecular compound”) and a high molecular weight resin having a molecular weight of 2000 or more (polymer material). Broadly divided. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer, copolymer), a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”. Hereinafter, the term “resin” refers to a resin having a molecular weight of 2000 or more.
As the component (A), a resin whose alkali solubility is changed by the action of an acid can be used, and a low molecular weight material whose alkali solubility is changed by the action of an acid can also be used.

When the resist composition of the present invention is a “negative resist composition”, a base component that is soluble in an alkali developer is used as the component (A), and the negative resist composition further includes a crosslinking agent. Blended.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the base material component and the crosslinking agent, resulting in poor solubility in an alkali developer. To do. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the negative resist composition on a support is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while not yet exposed. Since the exposed portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is usually used.
Examples of the alkali-soluble resin include a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid, and JP-A-2005-336442. Alternatively, a resin having a fluorinated alcohol disclosed in JP-A-2006-259582 is preferable because it can form a good resist pattern with little swelling. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a “positive resist composition”, the component (A) is a base material component (hereinafter referred to as “(A ′) component”) whose solubility in an alkali developer is increased by the action of an acid. Is used).
The component (A ′) is hardly soluble in an alkali developer before exposure. When an acid is generated from the component (B) by exposure, the solubility in the alkali developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the support is selectively exposed, the exposed portion becomes insoluble to soluble in an alkaline developer. On the other hand, since the unexposed portion remains hardly soluble in alkali and does not change, a resist pattern can be formed by alkali development.

In the resist composition of the present invention, the component (A) is preferably a base material component ((A ′) component) whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition of the present invention is preferably a positive resist composition.
The component (A ′) may be a resin component (A1) (hereinafter sometimes referred to as “component (A1)”) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound component (A2) (hereinafter sometimes referred to as “component (A2)”) whose solubility in an alkali developer increases, or a mixture thereof.

[(A1) component]
As the component (A1), resin components (base resins) that are usually used as base components for chemically amplified resists can be used singly or in combination of two or more.
In the present invention, the component (A1) preferably has a structural unit (a1) derived from hydroxystyrene.
Moreover, as (A1) component, what has the structural unit induced | guided | derived from an acrylate ester is also preferable. Among the structural units derived from acrylates, as the component (A1), those having a structural unit (a2) represented by general formula (a2-1) or (a2-2) described later are preferable.

Here, in the present specification and claims, “hydroxystyrene” means hydroxystyrene, and those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group, and those The concept includes derivatives.
Note that the α-position (α-position carbon atom) of a structural unit derived from hydroxystyrene is a carbon atom to which a benzene ring is bonded, unless otherwise specified.
The “structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene.
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include a lower alkyl group and a halogenated lower alkyl group.
Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
In the acrylate ester, as the lower alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, Examples include lower linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated lower alkyl group include groups in which some or all of the hydrogen atoms of the above-mentioned “lower alkyl group as a substituent at the α-position” are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. In view of industrial availability, a hydrogen atom or a methyl group is most preferable.

Structural Unit (a1) The structural unit (a1) is a structural unit derived from hydroxystyrene.
When the component (A1) has the structural unit (a1), dry etching resistance is improved in addition to the effects of the present invention. Furthermore, the structural unit (a1) also has the advantage that the raw material hydroxystyrene is readily available and is inexpensive.

  Preferred examples of the structural unit (a1) include structural units represented by general formula (a1-1) shown below.

［式（ａ１−１）中、Ｒ’は水素原子または低級アルキル基であり；Ｒ^６は低級アルキル基であり；ｐは１〜３の整数であり；ｑは０〜２の整数である。］

[In Formula (a1-1), R ′ represents a hydrogen atom or a lower alkyl group; R ⁶ represents a lower alkyl group; p represents an integer of 1 to 3; and q represents an integer of 0 to 2. ]

In the general formula (a1-1), the lower alkyl group for R ′ is an alkyl group having 1 to 5 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, and an n-butyl group. , An isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, or a linear alkyl group such as a methyl group is preferred.
R ′ is preferably a hydrogen atom or a lower alkyl group, particularly preferably a hydrogen atom or a methyl group.

p is an integer of 1 to 3, preferably 1.
The bonding position of the hydroxyl group may be any of the o-position, m-position and p-position of the phenyl group. When p is 1, the p-position is preferred because it is readily available and inexpensive. When p is 2 or 3, arbitrary substitution positions can be combined.

q is an integer of 0-2. Among these, q is preferably 0 or 1, and is preferably 0 industrially.
As the lower alkyl group for R ^{6, the same as} the lower alkyl group for R ′ can be exemplified.
When q is 1, the substitution position of R ⁶ may be any of the o-position, m-position, and p-position. When q is 2, arbitrary substitution positions can be combined. The plurality of R ⁶ may be the same or different.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a1) in the component (A1) is preferably 50 to 90 mol%, preferably 55 to 85 mol%, based on the total of all structural units constituting the component (A1). More preferably, it is more preferably 60 to 80 mol%. When it is at least the lower limit of the range, moderate alkali solubility is obtained, and the effect of containing the structural unit (a1) is sufficiently obtained. When the amount is not more than the upper limit of the range, the balance with other structural units is good.

Structural Unit (a2) The structural unit (a2) is a structural unit represented by the following general formula (a2-1) or (a2-2).

［式（ａ２−１）中、Ｒは水素原子、炭素数１〜５の低級アルキル基又は炭素数１〜５のハロゲン化低級アルキル基であり；Ｒ^１およびＲ^２はそれぞれ独立して水素原子又は炭素数１〜５の低級アルキル基であり；Ｙ^１は炭素数１〜５の低級アルキル基又は１価の脂肪族環式基であり；ｎ_２１は０〜３の整数である。式（ａ２−２）中、Ｒは前記と同じであり；Ｒ^３およびＲ^４はそれぞれ独立して水素原子又は炭素数１〜５の低級アルキル基であり；Ｒ^５はアルキレン基又は２価の脂肪族環式基であり；Ｙ^２は炭素数１〜５の低級アルキル基又は１価の脂肪族環式基であり；ｎ_２２は０〜３の整数である。］

[In formula (a2-1), R is a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms or a halogenated lower alkyl group having 1 to 5 carbon atoms; R ¹ and R ² are each independently a hydrogen atom; Or a lower alkyl group having 1 to 5 carbon atoms; Y ¹ is a lower alkyl group having 1 to 5 carbon atoms or a monovalent aliphatic cyclic group; and n ₂₁ is an integer of 0 to 3. In formula (a2-2), R is the same as above; R ³ and R ⁴ are each independently a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms; R ⁵ is an alkylene group or a divalent group. An aliphatic cyclic group; Y ² is a lower alkyl group having 1 to 5 carbon atoms or a monovalent aliphatic cyclic group; and n ₂₂ is an integer of 0 to 3. ]

Hereinafter, the structural unit represented by the general formula (a2-1) is referred to as a structural unit (a2-1). Moreover, the structural unit represented by the general formula (a2-2) is referred to as a structural unit (a2-2).
A group represented by the formula —C (R ¹ ) (R ² ) —O— (CH ₂ ) _n21 —Y ¹ in the general formula (a2-1), and a formula —C (R in the general formula (a2-2); ³ ) The group represented by (R ⁴ ) —O— (CH ₂ ) _n22 —Y ² is a so-called “acetal type acid dissociable, dissolution inhibiting group”.
The structural unit (a2-1) and the structural unit (a2-2) have a structure in which the acetal type acid dissociable, dissolution inhibiting group is bonded to an oxygen atom at the terminal of a carbonyloxy group (—C (═O) —O—). In common. In such a structure, when an acid is generated from the component (B) by exposure, the bond between the acid dissociable, dissolution inhibiting group and the oxygen atom at the terminal of the carbonyloxy group is broken by the action of the acid.
Here, in the present specification and claims, the term “acid dissociation” means that it can be dissociated from the component (A1) by the action of an acid generated from the component (B) during exposure.
The “dissolution-inhibiting group” has an alkali dissolution inhibiting property that renders the entire component (A1) insoluble in an alkali developer before dissociation, and after dissociation, the entire component (A1) is soluble in an alkali developer. It means that it is a group to change to.
Therefore, the component (A1) having the structural unit (a2) is insoluble in an alkali developer before exposure, and when the acid generated from the component (B) by exposure acts, the acetal type acid dissociation property The dissolution inhibiting group is dissociated, whereby the solubility of the entire component (A1) in the alkali developer is increased and the alkali-insoluble is changed to alkali-soluble. Therefore, when a resist film obtained by using a positive resist composition is selectively exposed in the formation of a resist pattern, the exposed portion turns alkali-soluble, while the unexposed portion remains alkali-insoluble. Therefore, alkali development can be performed.

In general formula (a2-1), R represents a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a halogenated lower alkyl group having 1 to 5 carbon atoms.
As the lower alkyl group for R, the same as the lower alkyl group for R ′ in formula (a1-1) can be mentioned.
R is preferably a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group, and particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.

In the general formula (a2-1), R ¹ and R ² are each independently a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. Examples of the lower alkyl group for R ¹ and R ² include the same as the lower alkyl group for R ′ in the general formula (a1-1). From the viewpoint of industrial availability, a methyl group or an ethyl group may be used. preferable.
Since R ¹ and R ² are excellent in the effects of the present invention, at least one of them is preferably a hydrogen atom, and more preferably both are hydrogen atoms.
n ₂₁ is an integer of 0 to 3, preferably 0 or 1, and most preferably 0.

In general formula (a2-1), Y ¹ represents a lower alkyl group having 1 to 5 carbon atoms or a monovalent aliphatic cyclic group.
As the lower alkyl group for Y ^{1, the same as} the lower alkyl group for R ′ in general formula (a1-1) above can be used.
The monovalent aliphatic cyclic group for Y ¹ is appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in many resist resins for ArF excimer lasers. be able to.
Here, in the claims and the specification, the “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The aliphatic cyclic group for Y ¹ may or may not have a substituent.
Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a hydrophilic group, and the like. Examples of the hydrophilic group include an oxygen atom (═O), —COOR ″ (R ″ is an alkyl group), an alcoholic hydroxyl group, —OR ″ (R ″ is the same as described above), an imino group, an amino group, and the like. In view of easy availability, an oxygen atom (═O) or an alcoholic hydroxyl group is preferred.
The structure of the basic ring (basic ring) excluding the substituent in the aliphatic cyclic group may be a ring consisting of carbon and hydrogen (hydrocarbon ring), and the carbon atoms constituting the hydrocarbon ring A heterocyclic ring partially substituted with a hetero atom such as a sulfur atom, an oxygen atom, or a nitrogen atom may be used. For the effect of the present invention, the basic ring in Y ¹ is preferably a hydrocarbon ring.
As the hydrocarbon ring, a resist resin for ArF excimer laser, KrF excimer laser, etc. can be used by appropriately selecting from among many proposed resins. Specifically, monocycloalkane or bicyclo Examples include polycycloalkanes such as alkanes, tricycloalkanes, and tetracycloalkanes. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, norbornene, methylnorbornane, ethylnorbornane, methylnorbornene, ethylnorbornene, isobornane, tricyclodecane, and tetracyclododecane. Among these, cyclohexane, cyclopentane, adamantane, norbornane, norbornene, methylnorbornane, ethylnorbornane, methylnorbornene, ethylnorbornene, and tetracyclododecane are industrially preferable, and adamantane is more preferable.

Preferred examples of the group represented by the formula —C (R ¹ ) (R ² ) —O— (CH ₂ ) _n21 —Y ¹ include groups represented by the following formulas (11) to (22). As mentioned.

In the general formula (a2-2), R is the same as above, R ³ and R ⁴ are each independently a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and Y ² is 1 to 1 carbon atoms. 5 is a lower alkyl group or a monovalent aliphatic cyclic group, and n ₂₂ is an integer of 0 to 3.
Examples of R, R ³ , R ⁴ , n ₂₂ and Y ² are the same as R, R ¹ , R ² , n ₂₁ and Y ¹ in general formula (a2-1).
In general formula (a2-2), R ⁵ represents an alkylene group or a divalent aliphatic cyclic group.
When R ⁵ is an alkylene group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 1 to 3 carbon atoms. Most preferably it is.
When R ⁵ is an aliphatic cyclic group, the aliphatic cyclic group may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the aliphatic cyclic group for R ⁵ is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The aliphatic cyclic group for R ⁵ is preferably a polycyclic group.
Specific examples of the aliphatic cyclic group for R ⁵ include, for example, a monocycloalkane or bicycloalkane which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated lower alkyl group. And groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as tricycloalkane or tetracycloalkane. Specifically, two hydrogen atoms are removed from a group obtained by removing two or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane, or from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include groups that have been removed.
As the aliphatic cyclic group for R ⁵ , a group represented by general formula (y-1) shown below is particularly desirable.

［式（ｙ−１）中、ｍは０または１であり、好ましくは１である。］

[In the formula (y-1), m is 0 or 1, preferably 1. ]

Specific examples of the structural unit (a2-1) represented by the general formula (a2-1) include structural units represented by the following formulas (a2-1-1) to (a2-1-21). It is done.
Specific examples of the structural unit (a2-2) represented by the general formula (a2-2) include structural units represented by the following formulas (a2-2-1) to (a2-2-15). It is done.
In the following formulae, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  As the structural unit (a2), the structural unit (a2-1) is more preferable because the effects of the present invention are more excellent. Among these, at least one structural unit selected from structural units represented by the above formula (a2-1-6), formula (a2-1-7) and formula (a2-1-8) is particularly preferable. The structural unit represented by formula (a2-1-6) is most preferable.

As the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a2) in the component (A1) is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, with respect to the total of all structural units constituting the component (A1). More preferred is mol%. When it is at least the lower limit of the range, a pattern can be obtained when the resist composition is used, and when it is at most the upper limit, the balance with other structural units is good.

-About other structural units The component (A1) may further have a structural unit (a4) derived from styrene in addition to the structural units (a1) and (a2).
In the present invention, the structural unit (a4) is not essential, but when it is contained, the solubility in an alkali developer can be adjusted. Moreover, since dry etching tolerance improves, it is preferable.
In this specification, “styrene” is a concept including styrene and those in which the α-position hydrogen atom of styrene is substituted with another substituent such as an alkyl group.
“Structural unit derived from styrene” means a structural unit formed by cleavage of an ethylenic double bond of styrene. In styrene, the hydrogen atom of the phenyl group may be substituted with a substituent such as an alkyl group having 1 to 5 carbon atoms.
Preferred examples of the structural unit (a4) include structural units represented by general formula (a4-1) shown below.

［式（ａ４−１）中、Ｒ’は前記と同じであり；Ｒ^７は炭素数１〜５の低級アルキル基であり；ｒは０〜３の整数である。］

[In formula (a4-1), R ′ is the same as above; R ⁷ is a lower alkyl group having 1 to 5 carbon atoms; and r is an integer of 0 to 3. ]

In the general formula (a4-1), examples of R ′ and R ⁷ are the same as R ′ and R ⁶ in the formula (a1-1).
r is an integer of 0 to 3, preferably 0 or 1, and industrially particularly preferably 0.
When r is 1, the substitution position of R ⁷ may be any of the o-position, m-position and p-position of the phenyl group.
When r is 2 or 3, any substitution position can be combined. The plurality of R ⁷ may be the same or different.

As the structural unit (a4), one type may be used alone, or two or more types may be used in combination.
When the component (A1) has the structural unit (a4), the proportion of the structural unit (a4) in the component (A1) is 1 to 20 mol% with respect to the total of all the structural units constituting the component (A1). Preferably, 3-15 mol% is more preferable, and 5-15 mol% is further more preferable. The effect by having a structural unit (a4) is high as it is more than the lower limit of this range, and the balance with another structural unit is favorable as it is below an upper limit.

The component (A1) may contain other structural units (a5) other than the structural units (a1), (a2), and (a4) as long as the effects of the present invention are not impaired.
The structural unit (a5) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1), (a2), and (a4) described above, and is a non-acid-dissociable aliphatic polycycle. A structural unit derived from an acrylate ester containing a formula group, a structural unit derived from an acrylate ester containing a lactone-containing cyclic group, or a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group The hydrogen atom of the phenolic hydroxyl group in the structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group or the structural unit (a1) is substituted with an acid dissociable, dissolution inhibiting group or an acid dissociable, dissolution inhibiting group-containing group. Used for resist resins such as ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). And any of the multitude of conventionally available.
In this specification, the “acid-dissociable, dissolution-inhibiting group-containing group” means a group composed of an acid-dissociable, dissolution-inhibiting group and a group or atom that is not dissociated by an acid.

In the present invention, suitable examples of the component (A1) include, for example, a polymer having the structural unit (a1), a polymer having the structural unit (a2), or the structural unit (a1) and the structural unit (a2). And those having a structural unit (a1) and a structural unit (a2) are more preferred, and a copolymer having a structural unit (a1) and a structural unit (a2) is particularly preferred.
Specifically, as the component (A1), for example, a copolymer comprising the structural unit (a1) and the structural unit (a2), and comprising the structural unit (a1), the structural unit (a2), and the structural unit (a4). A copolymer etc. can be illustrated.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
As the component (A1), one containing a copolymer having two types of structural units represented by the following general formula (A1-11) is particularly preferable.

［式（Ａ１−１１）中、Ｒ’およびＲは前記と同じであり；ｎ_１５は０又は１である。］

[In formula (A1-11), R ′ and R are the same as defined above; n ₁₅ is 0 or 1; ]

In formula (A1-11), R ′ is preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.
R is preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.
n ₁₅ is particularly preferably 0.
The bonding position between adamantane and —CH ₂ —O— (CH ₂ ) _n15 — is preferably the 1- or 2-position of adamantane, and more preferably the 2-position.

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom has an LWR (line width roughness: a phenomenon in which the line width of a line pattern becomes nonuniform). Effective for reduction. Further, it is effective for reducing development defects and LER (line edge roughness: uneven unevenness of line side walls).

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 5000. 20000 is most preferred. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.2 to 2 .5 is most preferred. Mn represents a number average molecular weight.

[(A2) component]
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 2000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. Specifically, a compound in which a part of hydrogen atoms of a hydroxyl group of a compound having a plurality of phenol skeletons is substituted with the acid dissociable, dissolution inhibiting group can be mentioned.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

(A) A component may be used individually by 1 type and may use 2 or more types together.
Among the above, the component (A) preferably contains the component (A1).
In the resist composition of the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<(B) component>
In the resist composition of the present invention, the component (B) contains an acid generator (B1) (hereinafter referred to as “component (B1)”) composed of a compound represented by the following general formula (b1-1).

［式中、Ｚは単結合又は２価の連結基であり；Ｒ^１１”〜Ｒ^１３”はそれぞれ独立してフッ素原子を有する有機基を表し、ｒ_１〜ｒ_３はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_２＋ｒ_３は０とならない。Ｒ^１４”〜Ｒ^１６”はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、ヒドロキシ基、ヒドロキシアルキル基又はハロゲン原子を表し、ｒ_４〜ｒ_６はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_４は５以下であり、ｒ_２＋ｒ_５およびｒ_３＋ｒ_６はそれぞれ４以下である。Ｒ^１１”〜Ｒ^１６”のうち、いずれか２つが相互に結合して環を形成してもよい。複数のＲ^１１”〜Ｒ^１６”が存在する場合、それぞれのＲ^１１”〜Ｒ^１６”は同じであっても異なっていてもよい。Ｘ⁻はアニオンである。］

[Wherein, Z is a single bond or a divalent linking group; R ¹¹ ″ to R ¹³ ″ each independently represents an organic group having a fluorine atom, and r _{1 to} r ₃ each independently represents 0 to It is an integer of 3. However, r ₁ + r ₂ + r ₃ is not 0. R ¹⁴ ″ to R ¹⁶ ″ each independently represents an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxy group, hydroxyalkyl group or halogen atom, and r _{4 to} r ₆ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₄ is 5 or less, and r ₂ + r ₅ and r ₃ + r ₆ are 4 or less, respectively. Any two of R ¹¹ ″ to R ¹⁶ ″ may be bonded to each other to form a ring. When a plurality of R ¹¹ ″ to R ¹⁶ ″ are present, each R ¹¹ ″ to R ¹⁶ ″ may be the same or different. X ⁻ is an anion. ]

-About the cation part of (B1) component In said general formula (b1-1), Z is a single bond or a bivalent coupling group.
As a bivalent coupling group in Z, a C15 or less thing is preferable and a C10 or less thing is more preferable.
Specific examples of the linking group include an alkylene group, an arylene group, a carbonyl group, a sulfonyl group, a carbonyloxy group, a carbonylamino group, a sulfonylamide group, an ether group, a thioether group, an amino group, a disulfide group, an acyl group, Alkylsulfonyl group, —CH═CH—, —C≡C—, aminocarbonylamino group, aminosulfonylamino group and the like can be mentioned.
The linking group may have a substituent. The phrase “having a substituent” for the linking group means that, in the linking group having a hydrogen atom, part or all of the hydrogen atom is substituted with an atom or group other than a hydrogen atom.
Examples of the substituent that the linking group may have include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
In such a substituent, examples of the alkoxy group include an alkoxy group having 1 to 5 carbon atoms, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are preferable. .
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

  Among these, Z is preferably a single bond, an alkylene group, a carbonyl group, a sulfonyl group, an ester group, an ether group or a thioether group, more preferably a single bond, an alkylene group, a carbonyl group or a sulfonyl group, and a carbonyl group. Most preferred.

In the general formula (b1-1), R ¹¹ ″ to R ¹³ ″ each independently represents an organic group having a fluorine atom.
In the present specification and claims, the “organic group” refers to a group containing at least one carbon atom.
The organic group having a fluorine atom of R ¹¹ ″ to R ¹³ ″ may be linear, branched or cyclic, and is preferably linear or branched.
The organic group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and most preferably 1 to 5 carbon atoms.
The organic group is preferably 30% or more, more preferably 60% or more, and more preferably 80% or more because the sensitivity to the exposure light source when the resist composition is used is further increased. It is particularly preferred.
The “fluorination rate” is the ratio of the number of fluorine atoms substituted by fluorination to the total number of hydrogen atoms in the alkyl group before fluorination, ie, the total of hydrogen atoms and fluorine atoms in the organic group. The number (%) of (the number of fluorine atoms) to the number (the same applies hereinafter).

As R ¹¹ ″ to R ¹³ ″, a fluorinated hydrocarbon group which may have a substituent is preferable because it is easily available and sensitivity to an exposure light source when a resist composition is further increased. .
In the fluorinated hydrocarbon group, the hydrocarbon group (non-fluorinated) may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an aliphatic hydrocarbon group. It is preferable.
The aliphatic hydrocarbon group is a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be either saturated or unsaturated, and is usually preferably saturated.
That is, R ¹¹ ″ to R ¹³ ″ are preferably a fluorinated saturated hydrocarbon group or a fluorinated unsaturated hydrocarbon group, and particularly preferably a fluorinated saturated hydrocarbon group, that is, a fluorinated alkyl group. .
Examples of the fluorinated alkyl group include groups in which part or all of the hydrogen atoms of the unsubstituted alkyl group (which does not have a substituent described below) are substituted with fluorine atoms. The fluorinated alkyl group may be a group in which some of the hydrogen atoms of the unsubstituted alkyl group are substituted with fluorine atoms, or a group in which all of the hydrogen atoms of the unsubstituted alkyl group are substituted with fluorine atoms ( Perfluoroalkyl group).

The unsubstituted alkyl group may be linear, branched or cyclic, and may be a combination of a linear or branched alkyl group and a cyclic alkyl group. .
As an unsubstituted linear alkyl group, C1-C10 is preferable and C1-C8 is more preferable. Specifically, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n- A decanyl group etc. are mentioned, A methyl group and an ethyl group are preferable and a methyl group is the most preferable.
As an unsubstituted branched alkyl group, C3-C10 is preferable and C3-C8 is more preferable. As the branched alkyl group, a tertiary alkyl group is preferable.
Examples of the unsubstituted cyclic alkyl group include groups in which one hydrogen atom has been removed from a monocycloalkane or a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include monocycloalkyl groups such as cyclopentyl group and cyclohexyl group; polycycloalkyl groups such as adamantyl group, norbornyl group, isobornyl group, tricyclodecanyl group, and tetracyclododecanyl group.
The combination of an unsubstituted linear or branched alkyl group and a cyclic alkyl group includes a group in which a cyclic alkyl group is bonded as a substituent to a linear or branched alkyl group, or a cyclic alkyl And a group in which a linear or branched alkyl group is bonded to the group as a substituent.

  Examples of the substituent that the fluorinated hydrocarbon group may have include an alkyl group having 1 to 5 carbon atoms.

In R ¹¹ ″ to R ¹³ ″, the fluorinated alkyl group is preferably a linear or branched fluorinated alkyl group, and particularly preferably a perfluoroalkyl group.

In the general formula (b1-1), R ¹⁴ ″ to R ¹⁶ ″ each independently represents an alkyl group, an acetyl group, an alkoxy group, a carboxy group, a hydroxy group, a hydroxyalkyl group, or a halogen atom.
In R ¹⁴ ″ to R ¹⁶ ″, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, or an isopropyl group. It is preferably a group, an n-butyl group or a tert-butyl group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.

Any two of R ¹¹ ″ to R ¹⁶ ″ may be bonded to each other to form a ring.
In such a case, examples of a combination that forms a ring include a combination of R ¹¹ ″ and R ¹² ″, and a combination of R ¹¹ ″ and R ¹³ ″.
Specific examples of the ring formed include, for example, a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, Thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring , Isoquinoline ring, carbazole ring, phenanthridine ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring and the like.

In the general formula (b1-1), r _{1 to} r ₃ are each independently an integer of 0 to 3.
r _{1 to} r ₃ are preferably each independently 0 or 1.
However, r ₁ + r ₂ + r ₃ is not 0. That is, the cation part of the component (B1) necessarily has an organic group having a fluorine atom. Thereby, the sensitivity with respect to the exposure light source at the time of setting it as a resist composition increases more.
_Further, r 4 ~r ₆ are each independently represents an integer of 0 to 3.
r ₄ is preferably 0 to 2, more preferably 0 or 1, and particularly preferably 0.
r ₅ and r ₆ are each independently preferably 0 or 1, more preferably 0.
However, r ₁ + r ₄ is 5 or less, and r ₂ + r ₅ and r ₃ + r ₆ are 4 or less, respectively.
When the symbols r _{1 to} r ₆ attached to R ¹¹ ″ to R ¹⁶ ″ are integers of 2 or more, that is, when a plurality of R ¹¹ ″ to R ¹⁶ ″ are present, R ¹¹ ″ to R ¹⁶ ″ are Each may be the same or different.

-About the anion part of (B1) component In the said general formula (b1-1), X < ^- > is an anion.
The anion of X ⁻ is not particularly limited, and for example, what is known as an anion portion of an onium salt acid generator can be used as appropriate.
X ^- is, for example, the general formula "R ^{14 SO} 3 _- ^{(R 14} is substituted or linear also, branched or cyclic alkyl group, a halogenated alkyl group, an aryl group, Or an alkenyl group)) ”.

In the general formula “R ¹⁴ SO ₃ ⁻ ”, R ¹⁴ represents a linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group which may have a substituent. Represent.

The linear or branched alkyl group as R ¹⁴ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. preferable.
The cyclic alkyl group as R ¹⁴ preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.

The halogenated alkyl group as R ¹⁴ is one in which part or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms, and the alkyl group is preferably a lower alkyl group having 1 to 5 carbon atoms, Among them, a linear or branched alkyl group is more preferable, and it is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a tert-pentyl group, or an isopentyl group. Further preferred. And the halogen atom by which a hydrogen atom is substituted includes a fluorine atom, a chlorine atom, an iodine atom, a bromine atom and the like. In the halogenated alkyl group, it is preferable that 50 to 100% of the total number of hydrogen atoms in the alkyl group (alkyl group before halogenation) is substituted with a halogen atom, and all the hydrogen atoms are substituted with a halogen atom. More preferably.
Here, the halogenated alkyl group is preferably a fluorinated alkyl group. The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
Further, the fluorination rate of the fluorinated alkyl group is preferably 10 to 100%, more preferably 50 to 100%, and in particular, when all the hydrogen atoms are substituted with fluorine atoms, the strength of the acid is increased. preferable.
Specific examples of such a preferred fluorinated alkyl group include a trifluoromethyl group, a heptafluoro-n-propyl group, and a nonafluoro-n-butyl group.

The aryl group as R ¹⁴ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group as R ¹⁴ is preferably an alkenyl group having 2 to 10 carbon atoms.

In R ¹⁴ , “may have a substituent” means a part of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. Or it means that all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ¹⁴ may be one, or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, a formula: X ¹ -Q ^1- [where Q ¹ is a divalent linking group containing an oxygen atom, and X ¹ represents a substituent. It is a C3-C30 hydrocarbon group which may have. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described above for R ¹⁴ as the halogen atom and alkyl group in the halogenated alkyl group.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

In the group represented by X ¹ -Q ^1- , Q ¹ is a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) — , R ^{91 to} R ⁹³ are each independently an alkylene group.) And the like.
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —, Alkylethylene groups such as —CH (CH ₂ CH ₃ ) CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} - alkyl trimethylene group and the like; Toramechiren group _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; penta And methylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond, and in particular, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by X ¹ -Q ^1- , the hydrocarbon group of X ¹ may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X ¹ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X ¹ , the aliphatic hydrocarbon group may be a group in which a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom, and hydrogen constituting the aliphatic hydrocarbon group A part or all of the atoms may be substituted with a substituent containing a hetero atom.
The “heteroatom” in X ¹ is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include the following formulas (L1) to (L5), (S1) to (S4), and the like.

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, and R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

In the present invention, X ¹ is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, (L2) to (L5), (S3) to (S4), and the like.

Among the above, R ¹⁴ preferably has a halogenated alkyl group or X ¹ -Q ^1- as a substituent.
In the case of having X ¹ -Q ^1- as a substituent, R ¹⁴ is X ¹ -Q ¹ -Y ^3- [wherein Q ¹ and X ¹ are the same as above, and Y ³ has a substituent. Or an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] Is preferable.
In the group represented by X ¹ -Q ¹ -Y ^3- , examples of the alkylene group for Y ³ include the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^3, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ³ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

R ¹⁴ is ^X 1 ^-Q 1 -Y ³ - is a group represented by ^R 14 -SO ₃ ^- Examples of the anions, for example represented by the following formula (b1) ~ (b7).

［式中、ｔは１〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｒ７は０〜３の整数であり、ｊは１〜２０の整数であり、Ｒ^８は置換基であり、ｍ１〜ｍ５はそれぞれ独立に０または１であり、ｖ１〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein, t is an integer of 1 to 3, q1 to q2 are each independently an integer of 1 to 5, r7 is an integer of 0 to 3, j is an integer of 1 to 20, R ⁸ is a substituent, m1 to m5 are each independently 0 or 1, v1 to v5 are each independently an integer of 0 to 3, w1 to w5 are each independently an integer of 0 to 3, Q ″ is the same as above.]

As the substituent for R ^8, the same as those mentioned as the substituents that the aliphatic hydrocarbon group may have and the substituents that the aromatic hydrocarbon group may have in X ¹ above. Is mentioned.
Code (r7, w1 to w5) attached to R ⁸ when it is an integer of 2 or more, plural R ⁸ in the compound may be the same, respectively, it may be different.

In addition, in the general formula (b1-1), X ⁻ includes, for example, an anion represented by the following general formula (b-3) and an anion represented by the following general formula (b-4).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

In the general formula (b-3), X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group preferably has 2 carbon atoms. -6, more preferably 3-5 carbon atoms, most preferably 3 carbon atoms.
In the general formula (b-4), Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. Carbon number becomes like this. Preferably it is 1-10, More preferably, it is C1-C7, Most preferably, it is C1-C3.
The number of carbon atoms of the X ″ alkylene group or the number of carbon atoms of the Y ″ and Z ″ alkyl groups is preferably as small as possible because the solubility in a resist solvent is good within the above-mentioned range of carbon numbers.
Further, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, the strength of the acid increases as the number of hydrogen atoms substituted by fluorine atoms increases, and high-energy light or electron beam of 200 nm or less This is preferable because the transparency to the surface is improved.
The fluorination rate of the alkylene group or alkyl group is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkylene group or a perfluoroalkylene group in which all hydrogen atoms are substituted with fluorine atoms. A fluoroalkyl group;

In the general formula (b1-1), X ⁻ may be a halogen anion.
Here, examples of the halogen anion include fluoride ion, chloride ion, bromide ion, and iodide ion.

Among the above, X ⁻ in the general formula (b1-1) is preferably an anion represented by the general formula “R ¹⁴ SO ₃ ⁻ ”, and R ¹⁴ is represented by X ¹ -Q ¹ -Y ³ —. And those represented by the above formulas (b1) to (b7), those in which R ¹⁴ is a halogenated alkyl group, more preferably those in which R ¹⁴ is a halogenated alkyl group.

  Preferred specific examples of the component (B1) are listed below.

As the component (B1), one type may be used alone, or two or more types may be used in combination.
The content ratio of the component (B1) is preferably in the range of 0.5 to 60 parts by mass, more preferably in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the component (A). It is particularly preferable that the amount be in the range of 2 to 45 parts by mass. The sensitivity with respect to the exposure light source at the time of setting it as a resist composition as the content rate of (B1) component is more than the lower limit of the said range increases more. It is preferable for it to be not more than the upper limit of the above range, since a uniform solution can be obtained and the storage stability becomes good.

  In the resist composition of the present invention, the content ratio of the component (B1) in the component (B) is preferably 40% by mass or more, more preferably 70% by mass or more, and even 100% by mass. Good. Most preferably, it is 100 mass%. When the content ratio of the component (B1) is not less than the lower limit of the above range, the sensitivity to the exposure light source when using the resist composition is further increased.

[(B2) component]
In the resist composition of the present invention, in addition to the component (B1), the component (B) contains an acid generator other than the component (B1) (hereinafter referred to as “component (B2)”) as necessary. You may contain.
The component (B2) is not particularly limited as long as it does not correspond to the component (B1), and any of those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、直鎖状、分岐鎖状若しくは環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ¹ ″ to R ³ ″ in formula (b-1), Any two may be bonded together to form a ring with the sulfur atom in the formula; R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group; R ¹ At least one of “˜R ³ ” represents an aryl group, and at least one of R ⁵ ”to R ⁶ ” represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.
The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom, a hydroxyl group or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, A tert-butoxy group is particularly preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, R ¹ ″ to R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

When any two of R ¹ ″ to R ³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring including the sulfur atom is formed. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as R ¹ ″ to R ³ ″.

In addition, R ¹ ″ to R ³ ″ in the formula (b-1) may have a substituent represented by the following formula (b).

［式（ｂ）中、Ｒ^５２は鎖状又は環状の炭化水素基を表し、ｆは０又は１を表し、ｇは０又は１を表す。］

[In the formula (b), R ⁵² represents a chain or cyclic hydrocarbon group, f represents 0 or 1, and g represents 0 or 1. ]

In the formula (b), R ⁵² represents a chain or cyclic hydrocarbon group.
In R ⁵² , the hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.

Examples of the aliphatic hydrocarbon group represented by R ⁵² include a linear, branched or cyclic saturated hydrocarbon group having 1 to 15 carbon atoms, or a linear or branched non-carbon group having 2 to 5 carbon atoms. A saturated hydrocarbon group is mentioned.
The aliphatic hydrocarbon group for R ⁵² may be an acid dissociable group. Examples of the acid dissociable group include those conventionally proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists, such as tertiary alkyl ester type acid dissociable, dissolution inhibiting groups, And acetal type acid dissociable, dissolution inhibiting groups.

In R ⁵² , the linear or branched saturated hydrocarbon group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a hydroxyl group, an oxygen atom (═O), a cyano group, and a carboxy group.

As the cyclic saturated hydrocarbon group, the cyclic saturated hydrocarbon group may be either a polycyclic group or a monocyclic group, and examples thereof include a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Examples include groups in which one hydrogen atom has been removed from a monocycloalkane or polycycloalkane (bicycloalkane, tricycloalkane, tetracycloalkane, etc.). More specifically, one or more hydrogen atoms are removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Group.
The cyclic saturated hydrocarbon group may have a substituent. As the one having the substituent, for example, one in which a part of carbon atoms constituting the ring in the cyclic saturated hydrocarbon group is substituted with a hetero atom (the former) may be used. The hydrogen atom bonded to may be substituted with a substituent (the latter).
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example are the same as those described above as the substituent that the linear or branched saturated hydrocarbon group may have, and an alkyl group. The alkyl group as the substituent is preferably a lower alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group or an ethyl group. The carbon atom constituting the ring to which the alkyl group is bonded is bonded to the terminal of -C (= O)-(O) g- in the substituent represented by the general formula (b1-0). Is preferred.

In R ⁵² , examples of the linear unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group.
Examples of the branched unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
The linear or branched unsaturated hydrocarbon group may have a substituent. Examples of the substituent include the same as those mentioned as the substituent that the linear or branched saturated hydrocarbon group may have.

Examples of the aromatic hydrocarbon group for R ⁵² include the same aromatic hydrocarbon groups as those described above for X ¹ .

Among the above, R ⁵² is preferably a cyclic hydrocarbon group, more preferably a cyclic aliphatic hydrocarbon group, and further preferably a cyclic saturated hydrocarbon group.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group is a cyclic group as indicated by R ¹ ″ and preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and more preferably 6 carbon atoms. Most preferably, it is -10.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Particularly, all the hydrogen atoms are substituted with fluorine atoms. A fluorinated alkyl group (perfluoroalkyl group) is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.
R ⁴ ″ may have a substituent, and examples of the substituent include the same substituents as exemplified in the description of R ¹⁴ above.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that R ⁵ ″ to R ⁶ ″ are all phenyl groups.
"The, ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
Also, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, or anions represented by the above formulas (b1) to (b7) should be used. Can do.

  Moreover, the onium salt type acid generator which replaced the anion part by the anion represented by the said general formula (b-3) or (b-4) in the said general formula (b-1) or (b-2). (The cation moiety is the same as the cation moiety in (b-1) or (b-2)).

  Moreover, the sulfonium salt which has the cation represented by the following general formula (b-5) or (b-6) in a cation part can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^４１〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation represented by the formula (b-5) or (b-6) in the cation part is not particularly limited, and the anion part of the onium salt acid generators proposed so far It may be similar.
Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion represented by the above general formula (b-3) or (b-4), etc. Among them, a fluorinated alkyl sulfonate ion is preferable, and a fluorinated alkyl sulfonate ion having 1 to 4 carbon atoms. Are more preferable, and linear perfluoroalkylsulfonic acid ions having 1 to 4 carbon atoms are particularly preferable, and specific examples thereof include trifluoromethylsulfonic acid ions, heptafluoro-n-propylsulfonic acid ions, and nonafluoro-n-. A butyl sulfonate ion etc. are mentioned.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.

As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent for R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And heteroaryl groups in which some of the carbon atoms constituting the ring of these groups are substituted with heteroatoms such as oxygen, sulfur and nitrogen atoms. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

The alkyl group or halogenated alkyl group having no substituent for R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 85 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

  As the component (B2), one type of acid generator may be used alone, or two or more types may be used in combination.

  1-70 mass parts is preferable with respect to 100 mass parts of (A) component, as for the total content of the (B) component in the resist composition of this invention, 5-60 mass parts is more preferable, 10-50 mass parts Is most preferred. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(D) component>
The resist composition of the present invention preferably further contains a nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have already been proposed. Therefore, it may be used arbitrarily from known ones, and among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-octylamine is most preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
These may be used alone or in combination of two or more.
In the present invention, it is particularly preferable to use a trialkylamine having 5 to 10 carbon atoms as the component (D).
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

<Optional component>
[(E) component]
The resist composition of the present invention comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as “component (E)”) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  The resist composition of the present invention further contains miscible additives as desired, for example, an additional resin for improving the performance of the resist film, a surfactant, a dissolution inhibitor, and a plasticizer for improving coatability. Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

[(S) component]
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter referred to as “(S) component”).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. -20% by mass, preferably 5-15% by mass.

The resist composition of the present invention described above is a novel one that has not been known so far.
According to the resist composition of the present invention, the sensitivity to an exposure light source such as EUV (extreme ultraviolet) is excellent, and high sensitivity can be achieved. Therefore, the resist composition of the present invention is particularly suitable as a resist composition used in a step of exposing a resist film using EUV as an exposure light source.

In recent years, with the progress of miniaturization of resist patterns, for example, in lithography using electron beams or EUV, “higher sensitivity” is one of the characteristics most required for resist materials.
In the resist composition containing the conventional onium salt acid generator as described above, it cannot be said that the sensitivity to an exposure light source such as EUV is sufficiently high, and it is difficult to achieve high sensitivity. However, there is a problem that resolution and lithographic characteristics are liable to be reduced.
The resist composition of this invention contains the acid generator component (B) containing the acid generator (B1) which consists of a compound represented by the said general formula (b1-1). The component (B1) has a specific structure including a benzene ring, and has a structure in which the “organic group having a fluorine atom” is substituted on the benzene ring as a substituent. By having the substituent, it is presumed that the resist composition can be made highly sensitive while maintaining good resolution and lithography properties.

  In the resist composition of the present invention, an exposure light source is obtained by combining the above-described component (A1) having the structural unit (a1) and the structural unit (a2) and the acid generator (B1). High sensitivity is easily obtained. Therefore, the resist composition using both the component (A1) and the acid generator (B1) is particularly suitable for lithography using an electron beam or EUV, and among them, it is suitable for lithography using EUV.

≪Resist pattern formation method≫
The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention, a step of exposing the resist film, And a step of alkali developing the resist film to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Then, after selectively exposing an electron beam (EB) through a desired mask pattern by an electron beam drawing machine or the like, PEB (post-exposure heating) is 40 to 120 at a temperature of 80 to 150 ° C. Second, preferably 60-90 seconds. Subsequently, this is alkali-development-processed using alkaline developing solution, for example, 0.1-10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, Preferably, water rinse is carried out using a pure water, and it dries. In some cases, a baking treatment (post-baking) may be performed after the alkali development treatment. In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).

The wavelength used for exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation.
The resist composition of the present invention is more effective for KrF excimer laser, ArF excimer laser, EB or EUV, and particularly effective for EB or EUV.

The exposure of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure.
In immersion exposure, at the time of exposure, a solvent (having a refractive index larger than the refractive index of air) is formed between a lens and a resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen. Exposure is performed in a state filled with the immersion medium.
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure can be performed through a desired mask pattern (immersion exposure).
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film exposed by the immersion exposure is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).

≪Compound≫
The compound according to the third aspect of the present invention is a compound represented by the following general formula (b1-1), and is contained in the component (B) of the resist composition according to the first aspect of the present invention described above. This is the same as the component (B1).

［式中、Ｚは単結合又は２価の連結基であり；Ｒ^１１”〜Ｒ^１３”はそれぞれ独立してフッ素原子を有する有機基を表し、ｒ_１〜ｒ_３はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_２＋ｒ_３は０とならない。Ｒ^１４”〜Ｒ^１６”はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、ヒドロキシ基、ヒドロキシアルキル基又はハロゲン原子を表し、ｒ_４〜ｒ_６はそれぞれ独立して０〜３の整数である。ただし、ｒ_１＋ｒ_４は５以下であり、ｒ_２＋ｒ_５およびｒ_３＋ｒ_６はそれぞれ４以下である。Ｒ^１１”〜Ｒ^１６”のうち、いずれか２つが相互に結合して環を形成してもよい。複数のＲ^１１”〜Ｒ^１６”が存在する場合、それぞれのＲ^１１”〜Ｒ^１６”は同じであっても異なっていてもよい。Ｘ⁻はアニオンである。］

[Wherein, Z is a single bond or a divalent linking group; R ¹¹ ″ to R ¹³ ″ each independently represents an organic group having a fluorine atom, and r _{1 to} r ₃ each independently represents 0 to It is an integer of 3. However, r ₁ + r ₂ + r ₃ is not 0. R ¹⁴ ″ to R ¹⁶ ″ each independently represents an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxy group, hydroxyalkyl group or halogen atom, and r _{4 to} r ₆ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₄ is 5 or less, and r ₂ + r ₅ and r ₃ + r ₆ are 4 or less, respectively. Any two of R ¹¹ ″ to R ¹⁶ ″ may be bonded to each other to form a ring. When a plurality of R ¹¹ ″ to R ¹⁶ ″ are present, each R ¹¹ ″ to R ¹⁶ ″ may be the same or different. X ⁻ is an anion. ]

  The description about the compound of this invention is the same as the description about the said (B1) component.

(Method for producing compound)
The compound which is the third embodiment of the present invention includes, for example, a compound (i ′) represented by the following general formula (i-0) and a compound (ii ′) represented by the following general formula (ii-0). It can manufacture by making these react.

In the formula (i-0), R ¹¹ ″, R ¹⁴ ″, r ₁ , r ₄ and X ⁻ represent R ¹¹ ″, R ¹⁴ ″, r ₁ , in the general formula (b1-1), respectively. Same as r ₄ and X ⁻ .
In the formula (ii-0), R ¹² ″, R ¹³ ″, R ¹⁵ ″, R ¹⁶ ″, r ₂ , r ₃ , r ₅ and r ₆ are each in the general formula (b1-1). R ¹² ″, R ¹³ ″, R ¹⁵ ″, R ¹⁶ ″, r ₂ , r ₃ , r ₅ and r ₆ are the same.

Compound (i ′) and compound (ii ′) can be reacted, for example, by dissolving these compounds in a solvent such as chlorobenzene and iodobenzene and stirring.
The reaction temperature is preferably about 80 to 130 ° C, more preferably about 90 to 120 ° C.
The reaction time varies depending on the reactivity between the compound (i ′) and the compound (ii ′), the reaction temperature, and the like, but usually 0.5 to 30 hours are preferable, and 1 to 20 hours are more preferable.
The amount of compound (ii ′) used in the above reaction is usually preferably about 0.5 to 2 mol per 1 mol of compound (i ′).
Compound (ii ′) can be appropriately selected from, for example, commercially available products.

The structure of the compound of the present invention obtained as described above includes ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass It can be confirmed by a general organic analysis method such as analysis (MS) method, elemental analysis method or X-ray crystal diffraction method.

  The compound of the present invention described above is a novel compound useful as an acid generator for a resist composition, and can be blended in a resist composition as an acid generator.

≪Acid generator≫
The acid generator which is the 4th aspect of this invention consists of a compound represented by the said general formula (b1-1).
The acid generator is useful as an acid generator for a chemically amplified resist composition, for example, the acid generator component (B) of the resist composition according to the first aspect of the present invention.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

<Base material component (A)>
In Examples 2-3 and Comparative Examples 1-6 and Reference Example 1, the resin (A1-11-1) used as the component (A) was synthesized by the method shown in the synthesis examples below.

[Synthesis Example 1: Synthesis of Resin (A1-11-1)]
Under a nitrogen atmosphere, PGMEA was placed in a flask equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer, and the temperature of the hot water bath was raised to 80 ° C. while stirring. Next, a monomer PGMEA solution charged with 2,2′-azobisisobutyronitrile (AIBN) and monomer (1) / monomer (2) = 3/1 (molar ratio) as a polymerization initiator was prepared. Using a dropping device, the solution was dropped into the flask over 6 hours at a constant speed, and then kept at 80 ° C. for 1 hour. Thereafter, the reaction solution was returned to room temperature. Subsequently, the obtained reaction solution was added dropwise to about 30 times amount of methanol with stirring to obtain a colorless precipitate. The resulting precipitate was filtered off, and the precipitate was washed in about 30 times the amount of methanol used for the monomer used for the polymerization. Then, this precipitate was filtered off and dissolved in THF, and then an 80% by mass hydrazine aqueous solution was added dropwise to the solution, followed by stirring at 25 ° C. for 1 hour. After completion of the reaction, the mixture was dropped into a large amount of water to obtain a precipitate. The precipitate was separated by filtration, washed, and dried under reduced pressure at 50 ° C. for about 40 hours to obtain a resin (A1-11-1).

The structure of the resin (A1-11-1) is shown below.
In addition, the mass average molecular weight (Mw) and dispersity (Mw / Mn) of the following resin (A1-11-1) are also shown. The mass average molecular weight (Mw) and dispersity (Mw / Mn) were determined on a polystyrene conversion basis by gel permeation chromatography (GPC).
The composition ratio was calculated by carbon NMR. In the chemical formula, the symbol attached to the lower right of the structural unit indicates the ratio (mol%) of each structural unit in the copolymer.

［ａ１／ａ２＝７０／３０（モル比）；Ｍｗ１００００、Ｍｗ／Ｍｎ１．８］

[A1 / a2 = 70/30 (molar ratio); Mw10000, Mw / Mn1.8]

<Acid generator component (B)>
In Examples 2-3, the acid generator composed of the compound (b1-1-1) used as the component (B) was synthesized by the method shown in Example 1 below.
In Example 3 and Reference Example 1, the acid generator composed of the compound (X) used as the component (B) was synthesized by the methods shown in Synthesis Examples 2 to 4 below.

[Example 1: Synthesis of compound (b1-1-1)]
Diphenliodonium Perfluorobutanesulfonate (compound (i)) 6.38 g, 2- (trifluoromethyl) thioxanthen-9-one (compound (ii)) 2.80 g and benzoic acid copper (II) 0.087 g It melt | dissolved in 10g and made it react at 110 degreeC for 3 hours. After completion of the reaction, chlorobenzene was distilled off under reduced pressure, and 19.98 g of dichloromethane was added and dissolved therein, followed by washing with diluted ammonia and washing with water. The dichloromethane solution was added dropwise to 99.13 g of n-hexane, and the precipitated powder was filtered and dried to obtain 2.3 g of the target compound (b1-1-1).

The obtained compound (b1-1-1) was analyzed by ¹ H-NMR. The results are shown below.
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 8.76 (s, 1H, ArH), 8.59-8.64 (m, 1H, ArH), 8.42 (t, 2H, ArH) ), 8.03-8.19 (m, 5H, ArH), 7.81 (t, 1H, ArH), 7.69 (t, 2H, ArH).
¹⁹ F-NMR (DMSO, 376 MHz): δ (ppm) = − 62.1, −80.5, −114.9, −121.4, −125.7.
From the results of the above analysis, it was confirmed that the obtained compound (b1-1-1) had a structure represented by the chemical formula showing the compound (b1-1-1) in the above reaction formula.

[Synthesis Example 2: Synthesis of Compound (III)]
Charge compound (II) 4.34g (purity: 94.1%), 2-benzyloxyethanol 3.14g, and toluene 43.4g, and add p-toluenesulfonic acid monohydrate 0.47g. And refluxed at 105 ° C. for 20 hours. The reaction solution was filtered, and 20 g of hexane was added to the filtrate and stirred. Filtration was performed again, and the residue was dried to obtain 1.41 g (yield: 43.1%) of compound (III).

The obtained compound (III) was analyzed by NMR. The results are shown below.
^{1 H-NMR (DMSO-d6,400MHz} ): δ (ppm) = 4.74-4.83 (t, 1H, OH), 4.18-4.22 (t, 2H, H a), 3. 59-3.64 (q, 2H, ^Hb ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.6.
From the results of the above analysis, it was confirmed that the obtained compound (III) had the structure of the chemical formula showing the compound (III) in the above reaction formula.

[Synthesis Example 3: Synthesis of Compound (IV)]
To 1.00 g of compound (III) and 3.00 g of acetonitrile, 0.82 g of 1-adamantanecarbonyl chloride and 0.397 g of triethylamine were added dropwise under ice cooling. After completion of dropping, the mixture was stirred at room temperature for 20 hours and filtered. The filtrate was concentrated to dryness, dissolved in 30 g of dichloromethane and washed with water three times. The organic layer was concentrated and dried to obtain 0.82 g (yield: 41%) of compound (IV).

The obtained compound (IV) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 8.81 (s, 1H, H ^c ), 4.37-4.44 (t, 2H, H ^d ), 4.17-4 .26 (t, 2H, H ^e ), 3.03-3.15 (q, 6H, H ^b ), 1.61-1.98 (m, 15H, Adamantane), 1.10-1.24 ( t, 9H, H ^a ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.61.
From the results of the above analysis, it was confirmed that the obtained compound (IV) had the structure of the chemical formula showing the compound (IV) in the reaction formula.

[Synthesis Example 4-1: Synthesis of Compound (V)]
To 60.75 g of methanesulfonic acid controlled at 20 ° C. or lower, 8.53 g of phosphorus oxide, 8.81 g of 2,5-dimethylphenol, and 12.2 g of diphenyl sulfoxide were added little by little. After aging for 30 minutes while controlling the temperature at 15 to 20 ° C., the temperature was raised to 40 ° C. and aging was performed for 2 hours. Thereafter, the reaction solution was dropped into 109.35 g of pure water cooled to 15 ° C. or lower. After completion of the dropwise addition, 54.68 g of dichloromethane was added, and after stirring, the dichloromethane layer was recovered. A separate container was charged with 386.86 g of hexane at 20 to 25 ° C., and the dichloromethane layer was added dropwise. After completion of the dropwise addition, the mixture was aged at 20 to 25 ° C. for 30 minutes and then filtered to obtain 17.14 g (yield: 70.9%) of the intended compound (V).

The obtained compound (V) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 600 MHz): δ (ppm) = 7.61-7.72 (m, 10H, phenyl), 7.14 (s, 2H, H ^c ), 3.12 (s, 3H, H ^b ), 2.22 (s, 6H, H ^a ).
From the results of the above analysis, it was confirmed that the obtained compound (V) had the structure shown below.

[Synthesis Example 4-2: Synthesis of Compound (VI)]
4 g of compound (V) was dissolved in 79.8 g of dichloromethane. After confirming dissolution, 6.87 g of potassium carbonate was added, and 3.42 g of methyl adamantane bromoacetate was added. After reaction for 24 hours under reflux, filtration, washing with water were performed, and crystallization was performed with hexane. The obtained powder was dried under reduced pressure to obtain 3.98 g (yield 66%) of the target compound (VI).

The obtained compound (VI) was analyzed by NMR.
¹ H-NMR (CDCl ₃ , 400 MHz): δ (ppm) = 7.83-7.86 (m, 4H, Phenyl), 7.69-7.78 (m, 6H, Phenyl), 7.51 ( s, 2H, H ^d ), 4.46 (s, 2H, H ^c ), 2.39 (s, 6H, H ^a ), 2.33 (s, 2H, Adamantan), 2.17 (s, 2H) , Adamantane), 1.71-1.98 (m, 11H, Adamantane), 1.68 (s, 3H, ^Hb ), 1.57-1.61 (m, 2H, Adamantane).
From the results of the above analysis, it was confirmed that the obtained compound (VI) had the structure shown below.

[Synthesis Example 4-3: Synthesis of Compound (X)]
After dissolving 4.77 g of compound (VI) in 23.83 g of dichloromethane and 23.83 g of water, 3.22 g of compound (IV) was added. After stirring for 1 hour, the organic layer was recovered by liquid separation treatment, and washed with water 3.84 g three times. The obtained organic layer was concentrated and dried to obtain 4.98 g (yield 87%) of compound (X).

The obtained compound (X) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 7.76-7.88 (m, 10H, Phenyl), 7.62 (s, 2H, Phenyl), 4.64 (s, 2H) , H ^b ), 4.43-4.44 (t, 2H, H ^e ), 4.22-4.23 (t, 2H, H ^d ), 1.51-2.36 (m, 38H, Adamantane + H ^a + ^Hc ).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 106.7.
From the results of the above analysis, it was confirmed that the obtained compound (X) had the structure of the chemical formula showing the compound (X) in the reaction formula.

<Preparation of resist composition>
(Examples 2-3, Comparative Examples 1-6, Reference Example 1)
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: the resin (A1-11-1).
(B) -1: a compound represented by the following chemical formula (b2-1-1).
(B) -2: a compound represented by the following chemical formula (b2-1-2).
(B) -3: a compound represented by the following chemical formula (b2-5-1).
(B) -4: A compound represented by the following chemical formula (b2-5-2).
(B) -5: A compound represented by the following chemical formula (b2-2-1).
(B) -6: A compound represented by the following chemical formula (b2-1-3).

(B) -7: The compound (b1-1-1).
(B) -8: Compound (X).
(D) -1: tri-n-octylamine.
(S) -1: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.

<Formation of resist pattern>
[Sensitivity / Resolution]
The resolution was evaluated using the obtained positive resist composition.
The positive resist composition of each example was uniformly applied using a spinner on an 8-inch silicon substrate that had been subjected to hexamethyldisilazane (HMDS) treatment at 90 ° C. for 30 seconds, and the temperatures shown in Table 2 were obtained. A resist film (film thickness 60 nm) was formed by performing a baking process (PAB) for 60 seconds.
The resist film was drawn (exposed) at an acceleration voltage of 70 keV using an electron beam lithography machine HL-800D (VSB) (manufactured by Hitachi), and baked at a temperature shown in Table 2 for 60 seconds (PEB). And developed for 30 seconds at 23 ° C. using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, rinsing was performed with pure water for 15 seconds to form a line and space (L / S) pattern.
At this time, the exposure amount (Eop; μC / cm ² ) at which a 100 nm L / S pattern was formed at 1: 1 was determined. The results are shown in Table 2.

From the results of Table 2, it was confirmed that the resist composition of Example 2 according to the present invention had a lower Eop value and higher sensitivity than the resist compositions of Comparative Examples 1 to 6, and was excellent in sensitivity. .
Therefore, it was confirmed that the resist composition of Example 2 was suitable as a resist composition used in the step of exposing the resist film using EUV (extreme ultraviolet) as an exposure light source.
Also, from the results of Example 3 and Reference Example 1, it was confirmed that the resist composition of Example 3 containing the acid generator according to the present invention was highly sensitive and excellent in sensitivity.

Claims (9)

A resist composition containing a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The said acid generator component (B) contains the acid generator (B1) which consists of a compound represented by the following general formula (b1-1), The resist composition characterized by the above-mentioned.

Wherein Z is a single bond or a divalent linking group; R ¹¹ ″ to R ¹³ ″ each independently represents a fluorinated alkyl group , and r _{1 to} r ₃ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₂ + r ₃ is not 0. R ¹⁴ ″ to R ¹⁶ ″ each independently represents an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxy group, hydroxyalkyl group or halogen atom, and r _{4 to} r ₆ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₄ is 5 or less, and r ₂ + r ₅ and r ₃ + r ₆ are 4 or less, respectively. Any two of R ¹¹ ″ to R ¹⁶ ″ may be bonded to each other to form a ring. When a plurality of R ¹¹ ″ to R ¹⁶ ″ are present, each R ¹¹ ″ to R ¹⁶ ″ may be the same or different. X ⁻ is an anion. ]   The resist composition according to claim 1, wherein a content ratio of the acid generator (B1) is in a range of 1 to 60 parts by mass with respect to 100 parts by mass of the base material component (A).   The resist composition according to claim 1, wherein the base material component (A) is a base material component whose solubility in an alkaline developer is increased by the action of an acid. The base component (A) contains a resin component (A1) whose solubility in an alkaline developer is increased by the action of an acid,
The resin component (A1) has a structural unit (a1) derived from hydroxystyrene and a structural unit (a2) represented by the following general formula (a2-1) or (a2-2). The resist composition as described.

[In formula (a2-1), R is a hydrogen atom, a lower alkyl group having 1 to 5 carbon atoms or a halogenated lower alkyl group having 1 to 5 carbon atoms; R ¹ and R ² are each independently a hydrogen atom; Or a lower alkyl group having 1 to 5 carbon atoms; Y ¹ is a lower alkyl group having 1 to 5 carbon atoms or a monovalent aliphatic cyclic group; and n ₂₁ is an integer of 0 to 3. In formula (a2-2), R is the same as above; R ³ and R ⁴ are each independently a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms; R ⁵ is an alkylene group or a divalent group. An aliphatic cyclic group; Y ² is a lower alkyl group having 1 to 5 carbon atoms or a monovalent aliphatic cyclic group; and n ₂₂ is an integer of 0 to 3. ]   The resist composition as described in any one of Claims 1-4 containing a nitrogen-containing organic compound component (D).   The resist composition as described in any one of Claims 1-5 used for the process of exposing a resist film using EUV (extreme ultraviolet rays) as an exposure light source.   A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 6, a step of exposing the resist film, and an alkali developing of the resist film to form a resist pattern A resist pattern forming method including a step of forming a film. The compound represented by the following general formula (b1-1).

Wherein Z is a single bond or a divalent linking group; R ¹¹ ″ to R ¹³ ″ each independently represents a fluorinated alkyl group , and r _{1 to} r ₃ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₂ + r ₃ is not 0. R ¹⁴ ″ to R ¹⁶ ″ each independently represents an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxy group, hydroxyalkyl group or halogen atom, and r _{4 to} r ₆ each independently represents 0 to 3 It is an integer. However, r ₁ + r ₄ is 5 or less, and r ₂ + r ₅ and r ₃ + r ₆ are 4 or less, respectively. Any two of R ¹¹ ″ to R ¹⁶ ″ may be bonded to each other to form a ring. When a plurality of R ¹¹ ″ to R ¹⁶ ″ are present, each R ¹¹ ″ to R ¹⁶ ″ may be the same or different. X ⁻ is an anion. ]   An acid generator comprising the compound according to claim 8.