JP2009300950A - Resist composition for liquid immersion lithography and resist pattern forming method using the same, and fluorine-containing polymer compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition suitable for liquid immersion lithography, a resist pattern forming method using the resist composition, and a fluorine-containing polymer compound useful as an additive used in the resist composition. <P>SOLUTION: The resist composition for liquid immersion lithography comprises a fluorine-containing polymer compound (C) which contains a group represented by general formula (c0-0) in a side chain and exhibits degradability in an alkali developer, a base component (A) whose solubility in an alkali developer changes under the action of an acid (other than the fluorine-containing polymer compound (C)), and an acid generator component (B) which generates an acid upon exposure to light. In the formula, R<SP>6</SP>is a hydrogen atom or a monovalent hydrocarbon group; q is an integer of 0-2; and g is an integer of 1-4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid immersion lithography resist composition containing a fluorine-containing polymer compound, a resist pattern forming method using the immersion exposure resist composition, and a fluorine-containing polymer compound.

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 radiation 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.
Along with the miniaturization of semiconductor elements, the wavelength of an exposure light source has been shortened and the projection lens has a high numerical aperture (high NA). Currently, an exposure of NA = 0.84 using an ArF excimer laser having a wavelength of 193 nm as a light source. A machine has been developed. Along with the shortening of the wavelength of the exposure light source, the resist material is required to be improved in lithography characteristics such as sensitivity to the exposure light source and resolution capable of reproducing a pattern with a fine dimension. As a resist material that satisfies such requirements, a chemically amplified resist containing a base resin 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.
Currently, as a base resin of a chemically amplified resist used in ArF excimer laser lithography and the like, a resin having a structural unit derived from (meth) acrylic acid ester in the main chain because of its excellent transparency near 193 nm ( Acrylic resin) is generally used.
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 one of the techniques for further improving the resolution, exposure (immersion exposure) is performed by interposing a liquid (immersion medium) having a higher refractive index than air between the objective lens of the exposure machine and the sample. A so-called immersion lithography (hereinafter referred to as “immersion exposure”) is known (for example, see Non-Patent Document 1).
According to immersion exposure, even when a light source having the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and the depth of focus can be reduced. It is said that there is no decline. Moreover, immersion exposure can be performed using an existing exposure apparatus. For this reason, immersion exposure is expected to be able to form resist patterns with low cost, high resolution, and excellent depth of focus. In particular, in terms of lithography characteristics such as resolution, the semiconductor industry is attracting a great deal of attention.
Immersion exposure is effective in the formation of all pattern shapes, and can be combined with super-resolution techniques such as the phase shift method and the modified illumination method that are currently being studied. Currently, as an immersion exposure technique, a technique mainly using an ArF excimer laser as a light source is being actively researched. Currently, water is mainly studied as an immersion medium.

In recent years, with respect to fluorine-containing compounds, attention has been paid to characteristics such as water repellency and transparency, and research and development in various fields has been actively conducted. For example, in the field of resist materials, acid instabilities such as methoxymethyl group, tert-butyl group, and tert-butyloxycarbonyl group are added to fluorine-containing polymer compounds for use as the base resin of positive chemically amplified resists. Introducing groups. However, when such a fluorine-based polymer compound is used as a base resin of a positive resist composition, there are disadvantages such as generation of a large amount of outgas after exposure and insufficient resistance to dry etching gas (etching resistance). is there.
Recently, a fluorine-containing polymer compound having an acid labile group containing a cyclic hydrocarbon group has been reported as a fluorine-containing polymer compound having excellent etching resistance (see, for example, Non-Patent Document 2). In addition, in a resist composition for immersion exposure, a method using a fluorine-containing polymer compound has been reported in order to impart water repellency to a resist film (for example, see Non-Patent Document 3).
Proceedings of SPIE, 5754, 119-128 (2005). Proceedings of SPIE, 4690, 76-83 (2002). Journal of Photopolymer Science and Technology (Journal of Photopolymer. Sci. Technol. Vol. 19, No. 4, P565-568, 2006), Vol. 19, No. 4, 565-568 (2006)

  In immersion exposure, in addition to normal lithography characteristics (sensitivity, resolution, etching resistance, etc.), a resist material having characteristics corresponding to the immersion exposure technique is required. For example, in immersion exposure, when the resist film and the immersion solvent come into contact with each other, elution of the substance in the resist film into the immersion solvent (substance elution) occurs. Substance elution causes phenomena such as alteration of the resist layer and change in the refractive index of the immersion solvent, thereby deteriorating the lithography properties. Since the amount of this substance elution is affected by the characteristics (for example, hydrophilicity / hydrophobicity) of the resist film surface, for example, the elution of the substance can be reduced by increasing the hydrophobicity of the resist film surface. In the case where the immersion medium is water, when immersion exposure is performed using a scanning immersion exposure machine as described in Non-Patent Document 1, the immersion medium follows the movement of the lens. Therefore, the water following ability to move is required. If the water followability is low, the exposure speed is lowered, and there is a concern that the productivity may be affected. This water followability is considered to be improved by increasing the hydrophobicity of the resist film.

Thus, it is considered that by increasing the hydrophobicity of the resist film surface, it is possible to solve problems peculiar to the immersion exposure technology, such as reduction of substance elution and improvement of water followability. However, even if the resist film is simply hydrophobized, there is an adverse effect on lithography characteristics and the like. For example, when the hydrophobicity of the resist film increases, there is a problem that a defect is likely to occur in the resist film after alkali development. In particular, in the case of a positive resist composition, defects are likely to occur in unexposed areas.
The “defect” is a general defect detected when a developed resist film is observed from directly above, for example, by a surface defect observation apparatus (trade name “KLA”) manufactured by KLA Tencor. Examples of the defects include scum, bubbles, dust, bridges (bridge structures between resist patterns), color unevenness, precipitates, and residues after development.
It is presumed that these problems can be solved if the material has characteristics that are hydrophobic during immersion exposure and hydrophilic during development. However, at present, materials with such characteristics are hardly known.

  The present invention has been made in view of the above circumstances, and is useful as a resist composition suitable for immersion exposure, a resist pattern forming method using the resist composition, and an additive used in the resist composition. It is an object of the present invention to provide a fluorinated polymer compound.

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

  That is, the first aspect of the present invention includes a fluorine-containing polymer compound (C) containing a group represented by the following general formula (c0-0) in the side chain and exhibiting decomposability to an alkaline developer, A base component (A) whose solubility in an alkaline developer is changed by the action of an acid (except for those corresponding to the fluorine-containing polymer compound (C)), and an acid generator that generates an acid upon exposure. A resist composition for immersion exposure comprising a component (B).

［式（ｃ０−０）中、Ｒ^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。］

[In Formula (c0-0), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ]

  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 for immersion exposure according to the first aspect, a step of subjecting the resist film to immersion exposure, and the resist film. Is a resist pattern forming method including a step of forming a resist pattern by alkali development.

  The third aspect of the present invention is a fluorine-containing polymer compound containing a group represented by the following general formula (c0-0) in the side chain.

［式（ｃ０−０）中、Ｒ^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。］

[In Formula (c0-0), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ]

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.
The “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, it is possible to provide a resist composition suitable for immersion exposure, a resist pattern forming method using the resist composition, and a fluorine-containing polymer compound useful as an additive used in the resist composition.

≪Resist composition for immersion exposure≫
The resist composition for immersion exposure according to the first aspect of the present invention comprises a group represented by the general formula (c0-0) in the side chain, and is highly fluorine-containing and decomposable with respect to an alkaline developer. Molecular compound (C) (hereinafter referred to as “component (C)”) and base component (A) whose solubility in an alkaline developer is changed by the action of an acid (however, those corresponding to component (C) above) (Hereinafter referred to as “component (A)”) and an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”).

<(C) component>
In the present invention, the component (C) is a fluorine-containing polymer compound containing a group represented by the general formula (c0-0) in the side chain and exhibiting decomposability to an alkaline developer.
In the present specification and claims, the phrase “degradable with respect to an alkali developer” means that it is decomposed by the action of an alkali developer (preferably 2.38% by mass of tetramethylammonium at 23 ° C. (Decomposes by the action of an aqueous hydroxide (TMAH) solution), which means that the solubility in an alkaline developer is increased.
The component (C) has a fluorine atom and is hardly soluble in an alkali developer before decomposition, and the group represented by the general formula (c0-0) is decomposed by the action of the alkali developer. (Hydrolysis) to open the ring to produce a hydrophilic group [carboxy group: —C (═O) —OH], which increases the solubility in an alkali developer.
Therefore, in the resist composition for immersion exposure according to the present invention, by containing the component (C), in the formation of the resist pattern, the resist pattern is hydrophobic during immersion exposure and hydrophilic during alkali development. A resist film can be formed.

In the general formula (c0-0), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group.
In R ⁶ , the hydrocarbon group is not particularly limited, and is preferably an aliphatic hydrocarbon group. Among these, an alkyl group is more preferable because of its good decomposability with respect to an alkaline developer. Such an alkyl group is preferably a lower alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, specifically a methyl group, an ethyl group, a propyl group, an isopropyl group, or n-butyl. Group, or tert-butyl group.
Among the above, R ⁶ is preferably a hydrogen atom.
In the general formula (c0-0), q is an integer of 0 to 2.
In said general formula (c0-0), g is an integer of 1-4, 1-2 are preferable and 1 is especially preferable.

  As the component (C), for example, a polymer compound containing a group represented by the following general formula (c0-0-1) in the side chain is preferable because it has good lithography properties.

［式（ｃ０−０−１）中、Ｒ^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。］

[In Formula (c0-0-1), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ]

In the general formula (c0-0-1), R ⁶ , q and g are the same as R ⁶ , q and g in the general formula (c0-0), respectively.

  In the group represented by the general formula (c0-0-1), a lactone ring is decomposed (hydrolyzed) by the action of an alkali developer, and a carbonyloxy group (—C (═O) —O— in the lactone ring is formed. ) And the carbon atom on the lactone ring bonded to the oxygen atom, the lactone ring is opened and the solubility in an alkali developer is further increased. .

The main chain in the component (C) is not particularly limited. For example, the main chain is a cyclic structural unit (hereinafter referred to as “main chain cyclic structural unit”), a structural unit derived from an acrylate ester. Are mentioned as preferred. Among these, a structural unit derived from an acrylate ester is preferable.
Here, in the present specification, the “main chain cyclic structural unit” has a monocyclic or polycyclic ring structure, and at least one, preferably two or more carbons on the ring of the ring structure. A structural unit in which atoms constitute the main chain.
In the present specification and claims, the “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 not only acrylic acid esters in which a hydrogen atom is bonded to the α-position carbon atom, but also those in which a substituent (an atom or group other than a hydrogen atom) is bonded to the α-position carbon atom. 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 part or all of the hydrogen atoms in 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.

  As the component (C), specifically, a polymer having a structural unit (c0) represented by the following general formula (c0-1) is preferable.

［式（ｃ０−１）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^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。］

[In Formula (c0-1), 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 ⁶ is a hydrogen atom or a monovalent hydrocarbon; Q is an integer of 0 to 2, and g is an integer of 1 to 4. ]

Structural Unit (c0) In the general formula (c0-1), 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.
Examples of the lower alkyl group or halogenated lower alkyl group for R include the same as the lower alkyl group or halogenated lower alkyl group which may be bonded to the α-position of the acrylate ester.
In the general formula (c0-1), R ⁶ , q and g are the same as R ⁶ , q and g in the general formula (c0-0), respectively.
As described above, the structural unit (c0) may have increased solubility in an alkaline developer, and the lactone ring may be dissociated from the structural unit (c0) by the action of an acid. When such a thing is used, the solubility with respect to an alkali developing solution will increase more, and a lithography characteristic will improve.

  Specific examples of the structural unit represented by the general formula (c0-1) are shown below.

In the component (C), as the structural unit (c0), one type may be used alone, or two or more types may be used in combination.
In the component (C), the proportion of the structural unit (c0) is preferably 10 to 90 mol%, more preferably 10 to 70 mol%, more preferably 10 to 50 mol based on the total of all the structural units constituting the component (C). Mole% is particularly preferred. When the proportion of the structural unit (c0) is equal to or higher than the lower limit of the above range, the property of becoming hydrophilic during alkali development is further improved in the formation of a resist pattern. Further, the lithography characteristics are further improved. If it is less than or equal to the upper limit of the range, it is possible to balance with other structural units.

  In the present invention, the component (C) is a copolymer having the following structural unit (c1) in addition to the structural unit (c0), that is, a structural unit represented by the following general formula (c0-1). It is preferable that it is a high molecular compound which has (c0) and the structural unit (c1) represented by the following general formula (c1-1).

［式（ｃ０−１）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^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。式（ｃ１−１）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；Ｑ^０は単結合又は二価の連結基であり、Ｒ^２はフッ素原子を有する有機基である。複数のＲはそれぞれ同じであっても異なっていてもよい。］

[In Formula (c0-1), 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 ⁶ is a hydrogen atom or a monovalent hydrocarbon; Q is an integer of 0 to 2, and g is an integer of 1 to 4. In formula (c1-1), 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; Q ⁰ is a single bond or a divalent linking group. R ² is an organic group having a fluorine atom. A plurality of R may be the same or different. ]

In the general formula (c0-1), R, R ⁶ , q, and g are all the same as described above.

Structural Unit (c1) In the general formula (c1-1), 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, and the above formula The same thing as R in (c0-1) is mentioned.
In the general formula (c1-1), Q ⁰ is a single bond or a divalent linking group.
The divalent linking group for Q ⁰ is preferably a divalent organic group having no acid-dissociable site. For example, a hydrocarbon group which may have a substituent, or a group containing a hetero atom is included. It is mentioned as a suitable thing.
Here, the “acid dissociable site” refers to a site in the organic group that is dissociated by the action of an acid generated by exposure.

(Hydrocarbon group which may have a substituent)
In Q ⁰ , the hydrocarbon group “has a substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Such an aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

  More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, particularly preferably 1 to 3, and 1 Most preferred.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], Tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —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 - _{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 Alkylethylene groups such as CH ₃ ) CH ₂ —; alkyltrimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH _{2 CH 2 CH 2 -, - CH} 2 CH (CH 3) CH 2 CH 2 - , etc. And alkyl alkylene groups such as Le Kill tetramethylene group. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like (straight chain or branched chain) aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include 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.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the chain aliphatic aliphatic hydrocarbon group described above. Examples include a group bonded to the terminal of an aromatic hydrocarbon group or interposed in the middle of a chain aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon 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, and an oxygen atom (= O).

Examples of the aromatic hydrocarbon group include aromatics of monovalent aromatic hydrocarbon groups such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A divalent aromatic hydrocarbon group obtained by removing one hydrogen atom from the hydrocarbon nucleus;
An aromatic hydrocarbon group in which a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom;
Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc. Aromatic hydrocarbon groups and the like removed.
Among them, the divalent aromatic hydrocarbon group is preferable, and an aromatic hydrocarbon group in which one hydrogen atom is further removed from a phenyl group, and an aromatic hydrocarbon group in which one hydrogen atom is further removed from a naphthyl group are particularly preferable. preferable.
The carbon number of 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 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, and an oxygen atom (= O).

Among the above, the hydrocarbon group which may have a substituent is preferably a linear, branched or cyclic aliphatic hydrocarbon group, or a divalent aromatic hydrocarbon group, more preferably a methylene group. , An ethylene group, —CH (CH ₃ ) —, a group obtained by further removing one hydrogen atom from a tetracyclododecanyl group, and an aromatic hydrocarbon group obtained by further removing one hydrogen atom from a phenyl group are particularly preferred.

(Groups containing heteroatoms)
A heteroatom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
Examples of the group containing a hetero atom include -O-, -C (= O)-, -C (= O) -O-, carbonate bond (-O-C (= O) -O-), -NH. —, —NR ⁰⁴ (R ⁰⁴ is an alkyl group) —, —NH—C (═O) —, ═N—, or “one or more of these groups” and a divalent hydrocarbon group A combination etc. are mentioned.
Examples of the divalent hydrocarbon group include the same hydrocarbon groups that may have a substituent as described above, and a linear or branched aliphatic hydrocarbon group is preferable.
Among these, as the group containing a hetero atom, a combination of the “one or more of these groups” and a divalent hydrocarbon group is more preferable. Species or a combination of two or more ”and the aliphatic hydrocarbon group, and a combination of the aliphatic hydrocarbon group and the“ one or more of these groups ”and the aliphatic hydrocarbon group is particularly preferable. .

Among these, as Q ⁰ , a group containing a single bond or a hetero atom is more preferable, and a combination of a single bond or the above “one or more of these groups” and the aliphatic hydrocarbon group is particularly preferable. .

In the general formula (c1-1), R ² is an organic group having a fluorine atom.
Here, the “organic group having a fluorine atom” refers to a group in which part or all of the hydrogen atoms in the organic group are substituted with fluorine atoms.
Suitable examples of R ² include a fluorinated hydrocarbon group and an acid dissociable group which may have a substituent.

(Fluorinated hydrocarbon group which may have a substituent)
Preferred examples of the fluorinated hydrocarbon group for R ² include a fluorinated hydrocarbon group that may or may not have a substituent. Of these, a fluorinated saturated hydrocarbon group or a fluorinated unsaturated hydrocarbon group is preferable, and a fluorinated saturated hydrocarbon group is particularly preferable.
R ² may be linear, branched or cyclic, and is preferably linear or branched.
In R ² , the number of carbon atoms is preferably 1-20, more preferably 1-15, particularly preferably 1-10, and most preferably 1-5.
Further, in the organic group having a fluorine atom of R ² , 25% or more of hydrogen atoms in the organic group are preferably fluorinated, more preferably 50% or more are fluorinated, and 60% or more. It is particularly preferable that is fluorinated since the hydrophobicity of the resist film during immersion exposure is increased.

(Acid dissociable group)
The acid dissociable group for R ² is not particularly limited as long as it is an organic group that can be dissociated by the action of an acid, and is a cyclic or chain tertiary alkyl ester type acid dissociable group; an alkoxyalkyl group And acetal type acid dissociable groups. Among these, R ² is preferably a tertiary alkyl ester type acid dissociable group, and more preferably a structural unit represented by the following general formula (IV-1).

［式（ＩＶ−１）中、複数のＲ^２０１はそれぞれ同じであっても異なっていてもよく、少なくとも１つは炭素数１〜４の直鎖状もしくは分岐鎖状のアルキル基であり；残りの２つのＲ^２０１は、それぞれ独立して炭素数１〜４の直鎖状もしくは分岐鎖状のアルキル基、または炭素数４〜２０の１価の脂肪族環式基であるか、あるいは、前記残りの２つのＲ^２０１は相互に結合して、それぞれが結合している炭素原子と共に炭素数４〜２０の２価の脂肪族環式基を形成している。］

[In the formula (IV-1), a plurality of R ²⁰¹ may be the same or different, and at least one is a linear or branched alkyl group having 1 to 4 carbon atoms; two of R ²⁰¹ of are either each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent aliphatic cyclic group having 4 to 20 carbon atoms, or wherein The remaining two R ²⁰¹ are bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atom to which each of R ²⁰¹ is bonded. ]

In the general formula (IV-1), examples of the aliphatic cyclic group represented by R ²⁰¹ include one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Excluded groups and the like. Specific examples thereof include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. More specifically, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like can be given.
Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.

As the acid dissociable group represented by the general formula (IV-1), a plurality of R ²⁰¹ are each independently a linear or branched alkyl group having 1 to 4 carbon atoms. Examples thereof include a butyl group, a tert-pentyl group, and a tert-hexyl group.

As the acid dissociable group represented by the general formula (IV-1), at least one of the plurality of R ^{201 is} a linear or branched alkyl group having 1 to 4 carbon atoms, and the remaining two R ²⁰¹ Are each independently a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent aliphatic cyclic group having 4 to 20 carbon atoms, such as 1- (1-adamantyl) ) -1-methylethyl group, 1- (1-adamantyl) -1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1 -(1-cyclopentyl) -1-methylethyl group, 1- (1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1- Methylpentyl 1- (1-cyclohexyl) -1-methylethyl group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl)- 1-methylpentyl group, etc. are mentioned.

As the acid dissociable group represented by formula (IV-1), among the plurality of ^{R 201,} 1 single ^{R 201} is a straight-chain or branched alkyl group having 1 to 4 carbon atoms, the two Examples of the group in which R ²⁰¹ is bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atom to which each is bonded include a 2-methyl-2-adamantyl group, 2-alkyl-2-adamantyl group such as 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, 1-ethyl 1-alkyl-1-cycloalkyl groups such as a -1-cyclohexyl group.
Among these, as the acid dissociable group represented by the general formula (IV-1), among the plurality of R ²⁰¹ , one R ²⁰¹ is a linear or branched alkyl group having 1 to 4 carbon atoms. In which two R ²⁰¹ 's are bonded to each other to form a divalent aliphatic cyclic group having 4 to 20 carbon atoms together with the carbon atoms to which they are bonded, particularly 2-methyl A 2-adamantyl group is preferred.

Moreover, as long as the group represented by general formula (IV-1) can function as an acid dissociable group, each R ²⁰¹ may have a substituent. Examples of the substituent include a halogen atom such as a fluorine atom.

Below, the suitable specific example of a structural unit (c1) is illustrated.
Hereinafter, the case where R ² in the general formula (c1-1) is “an optionally substituted fluorinated hydrocarbon group” is referred to as a structural unit (c11).
The case where R ² in the general formula (c1-1) is an “acid-dissociable group” is referred to as a structural unit (c12).

-About structural unit (c11) As a preferable specific example of structural unit (c11), the structural unit represented by the following general formula (c11-1) or formula (c11-2) is mentioned.

［式中、Ｒはそれぞれ独立して水素原子、低級アルキル基、又はハロゲン化低級アルキル基であり；Ｘは酸解離性部位を有さない二価の有機基であり、Ａ_ａｒｙｌは置換基を有していてもよい芳香族環式基であり、Ｘ_０１は単結合又は二価の連結基であり；Ｒ^２１は、それぞれ独立して、置換基を有していてもよいフッ素化炭化水素基である。］

[In the formula, each R is independently a hydrogen atom, a lower alkyl group, or a halogenated lower alkyl group; X is a divalent organic group having no acid-dissociable site, and A _aryl is a substituent. Is an aromatic cyclic group which may have, X ₀₁ is a single bond or a divalent linking group; R ²¹ is independently a fluorinated hydrocarbon which may have a substituent. It is a group. ]

In general formula (c11-1) or (c11-2), R is the same as described above, and more preferably a hydrogen atom or a methyl group.
Examples of the fluorinated hydrocarbon group for R ²¹ include the same as those exemplified in the description of the fluorinated hydrocarbon group for R ² above, more preferably a fluorinated hydrocarbon group having 1 to 5 carbon atoms, Most preferred are CH ₂ —CF ₂ —CF ₃ , —CH (CF ₃ ) ₂ , —CH ₂ —CH ₂ —CF ₂ —CF ₂ —CF ₂ —CF ₃ .

In the general formula (c11-1), X is a divalent organic group having no acid dissociable portion.
Preferred examples of X include the above-described hydrocarbon groups that may have a substituent and groups containing a hetero atom.

In the general formula (c11-2), A _aryl represents an aromatic cyclic group which may have a substituent. Specific examples of A _aryl include a group obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring which may have a substituent.
The ring skeleton of the aromatic cyclic group in A _aryl preferably has 6 to 15 carbon atoms, and examples thereof include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Among these, a benzene ring or a naphthalene ring is particularly preferable.
In A _aryl , examples of the substituent that the aromatic cyclic group may have include a halogen atom, an alkyl group, an alkoxy group, a halogenated lower alkyl group, and an oxygen atom (═O). Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. The substituent that the aromatic cyclic group of A _aryl may have is preferably a fluorine atom.
The aromatic cyclic group of A _aryl may have no substituent, may have a substituent, and preferably has no substituent.
In A _aryl , when the aromatic cyclic group has a substituent, the number of substituents may be one, two or more, and one or two. Is preferable, and one is more preferable.

In general formula (c11-2), X ₀₁ represents a single bond or a divalent linking group. Examples of the divalent linking group include an alkylene group having 1 to 10 carbon atoms, —O—, —C (═O) —, —C (═O) —O—, and a carbonate bond (—O—C (═O). -O-), -NH-C (= O)-, or a combination thereof may be mentioned, and a combination of -O- and an alkylene group having 1 to 12 carbon atoms is most preferable.
Examples of the alkylene group having 1 to 12 carbon atoms include linear, branched or cyclic alkylene groups, linear or branched alkylene groups having 1 to 5 carbon atoms, and 4 to 12 carbon atoms. A cyclic alkylene group is preferred.
X ₀₁ is preferably a single bond, — (R ⁷ ) _a0 —O— [C (═O)] _b0 —R ⁸ —, or —C (═O) —O—R ⁹ —.
R ⁷ , R ⁸ , and R ⁹ are each independently a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and a linear or branched alkylene group having 1 to 5 carbon atoms. A cyclic alkylene group having 4 to 10 carbon atoms is preferred.
a0 is 0 or an integer of 1 to 5.
b0 is an integer of 0 or 1.

  Preferred examples of the structural unit (c11) include those represented by the following general formulas (c11-1-1) to (c11-1-5) or (c11-2-1) to (c11-2-4). The structural unit is given.

In the general formulas (c11-1-1) to (c11-1-5) or (c11-2-1) to (c11-2-4),
R is as defined above;
R ²¹ is the same as the fluorinated hydrocarbon group which may have a substituent of R ²¹ ;
R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a lower alkyl group;
a1 to a3, a5, a7, a9 and a11 to a13 each independently represent an integer of 1 to 5;
a4, a6, a8 and a10 each independently represents 0 or an integer of 1 to 5;
b1 to b5 are each independently an integer of 0 or 1;
R ⁵ is a substituent,
e represents an integer of 0 to 2;
A ₁ is a cyclic alkylene group having 4 to 20 carbon atoms.

In the general formula (c11-1-1), examples of the lower alkyl group for R ⁵¹ and R ⁵² include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most preferable. preferable. In the present invention, it is preferable that at least one of R ⁵¹ and R ⁵² is a hydrogen atom.
In the general formula (c11-1-1), a1 is preferably 1 to 3, and more preferably 1 or 2.
In general formula (c11-1-2), a2 and a3 are each independently preferably 1 to 3, and more preferably 1 or 2. b1 is 0 or 1.
In the general formula (c11-1-3), a4 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a5 is preferably 1 to 3, and more preferably 1 or 2. Examples of the substituent for R ⁵ include a halogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, a halogenated lower alkyl group, and an oxygen atom (═O). Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. e is preferably 0 or 1, and particularly preferably 0 from an industrial viewpoint. b2 is preferably 0.
In general formula (c11-1-4), a6 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a7 is preferably 1 to 3, and more preferably 1 or 2. b3 is preferably 0. R ⁵ and e are the same as defined above.
In General Formula (c11-1-5), A ₁ is a cyclic alkylene group having 4 to 20 carbon atoms, preferably a cyclic alkylene group having 5 to 15 carbon atoms, and a cyclic alkylene group having 6 to 12 carbon atoms. Groups are more preferred. Specific examples include those exemplified for the “cyclic aliphatic hydrocarbon group” in the hydrocarbon group which may have a substituent described above.
In the general formula (c11-2-1), a8 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a9 is preferably 1 to 3, and more preferably 1 or 2. b4 is preferably 0. R ⁵ and e are the same as defined above.
In the general formula (c11-2-2), a10 is preferably 0 or 1 to 3, more preferably 0 or 1 to 2, and most preferably 0 or 1. a11 is preferably 1 to 3, and more preferably 1 or 2. b5 is preferably 0. R ⁵ and e are the same as defined above.
In the general formula (c11-2-3), a12 is preferably 1 to 3, and more preferably 1 or 2. R ⁵ and e are the same as defined above.
In the general formula (c11-2-4), a13 is preferably 1 to 3, and more preferably 1 or 2. R ⁵ and e are the same as defined above.

  Specific examples of the structural units represented by general formulas (c11-1-1) to (c11-1-5) and general formulas (c11-2-1) to (c11-2-4) are shown below. .

  The structural unit (c11) is composed of structural units represented by the general formulas (c11-1-1) to (c11-1-5) and (c11-2-1) to (c11-2-4). Preferably, at least one selected from the group is represented by the general formulas (c11-1-1) to (c11-1-5), (c11-2-1) and (c11-2-2) At least one selected from the group consisting of units is more preferable, and a group consisting of structural units represented by the general formulas (c11-1-1), (c11-1-5) and (c11-2-2) At least one selected from is particularly preferred.

In the component (C), as the structural unit (c11), one type may be used alone, or two or more types may be used in combination.
In the component (C), the proportion of the structural unit (c11) is preferably from 10 to 90 mol%, more preferably from 20 to 90 mol%, more preferably from 30 to 90, based on the total of all the structural units constituting the component (C). Mole% is particularly preferred. When the proportion of the structural unit (c11) is not less than the lower limit of the above range, the characteristics that become hydrophobic during immersion exposure are further improved in the formation of the resist pattern. If it is less than or equal to the upper limit of the range, it is possible to balance with other structural units.

-About structural unit (c12) As a preferable specific example of structural unit (c12), the structural unit represented by the following general formula (c12-1) is mentioned.

［式（ｃ１２−１）中、Ｒはそれぞれ独立して水素原子、低級アルキル基、又はハロゲン化低級アルキル基であり；Ｑ^０’は単結合又は二価の連結基であり、Ｒ^２２は酸解離性基である。］

[In formula (c12-1), each R is independently a hydrogen atom, a lower alkyl group, or a halogenated lower alkyl group; Q ⁰ ′ is a single bond or a divalent linking group, and R ²² is an acid. It is a dissociable group. ]

In general formula (c12-1), R is the same as defined above, and more preferably a hydrogen atom or a methyl group.
Examples of the acid dissociable group for R ²² include the same groups as those exemplified above in the description of the acid dissociable group for R ² .

In the general formula (c12-1), examples of the structural unit in which Q ⁰ ′ is a single bond include structural units represented by the following general formulas (c12-1-1) to (c12-1-12). It is mentioned as a suitable thing.
In the general formula (c12-1), when Q ⁰ ′ is a divalent linking group, the divalent linking group is the same as X _{01 in the} formula (c11-2) or a divalent fragrance. Group hydrocarbon groups. As a bivalent aromatic hydrocarbon group, a C6-C20 aromatic hydrocarbon group is mentioned, The group remove | excluding two hydrogen atoms from benzene, naphthalene, and anthracene is mentioned.
In the structural unit (c12), as Q ⁰ ′, a single bond or —C (═O) —O—R ^c — [R ^c is a straight chain having 1 to 10 carbon atoms which may contain an oxygen atom or It is a branched alkylene group. The alkylene group may be fluorinated. It is preferable that it is a single bond.
In the general formula (c12-1), examples of the structural unit in which Q ⁰ ′ is —C (═O) —O—R ^c — include, for example, the following general formulas (c12-1-13) to (c12-1) The structural unit represented by -24) is preferable.
However, R in the following general formula is the same as the above R, and is preferably a hydrogen atom or a methyl group.

  The structural unit (c12) is preferably at least one selected from the group consisting of structural units represented by the general formulas (c12-1-1) to (c12-1-24). -1-1) to (c12-1-12), at least one selected from the group consisting of structural units represented by (c12-1-1) is more preferable. The structural unit represented by the formula is particularly preferred.

In the component (C), as the structural unit (c12), one type may be used alone, or two or more types may be used in combination.
In the component (C), the proportion of the structural unit (c12) is preferably smaller than the proportion of the structural unit (c0). For example, the proportion of the structural unit (c12) is preferably 10 to 90 mol%, more preferably 30 to 90 mol%, particularly 50 to 90 mol%, based on the total of all structural units constituting the component (C). preferable. When the proportion of the structural unit (c12) is not less than the lower limit of the above range, the characteristics that become hydrophobic during immersion exposure are further improved in the formation of the resist pattern. Further, the lithography characteristics are further improved. If it is less than or equal to the upper limit of the range, it is possible to balance with other structural units.

-Constituent Unit (c3) Component (C) may contain constituent units (c3) other than the constituent unit (c0) and constituent unit (c1) as long as the effects of the present invention are not impaired. .
The structural unit (c3) is not particularly limited as long as it is another structural unit that is not classified into the above structural units (c0) and (c1). For example, a structural unit having a carboxy group is preferable.
Specific examples of the structural unit (c3) include structural units represented by general formula (c3-1), formula (c3-2), or formula (c3-3) shown below.

［式中、Ｒは水素原子、炭素原子数１〜５の低級アルキル基、又は炭素原子数１〜５のハロゲン化低級アルキル基であり；Ｑ^１’は単結合又は二価の連結基である。Ａ^０１およびＢ^０１はそれぞれ独立して置換基を有していてもよい２価の炭化水素基であり、Ｑ^１は酸素原子を含む２価の連結基であり、ｒは０又は１の整数であり；Ａ_ａｒｙｌは置換基を有していてもよい芳香族環式基であり、Ｘ_０２は単結合、−（Ｒ^７）_ａ０−Ｏ−［Ｃ（＝Ｏ）］_ｂ０−Ｒ^８−、又は−Ｃ（＝Ｏ）−Ｏ−Ｒ^９−である。］

[Wherein, 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; Q ¹ ′ is a single bond or a divalent linking group. . A ⁰¹ and B ⁰¹ are each independently a divalent hydrocarbon group which may have a substituent, Q ¹ is a divalent linking group containing an oxygen atom, and r is an integer of 0 or 1 A _aryl is an aromatic cyclic group which may have a substituent, X ₀₂ is a single bond, — (R ⁷ ) _a0 —O— [C (═O)] _b0 —R ⁸ —. Or —C (═O) —O—R ⁹ —. ]

In the general formula (c3-1), R and Q ¹ ′ are the same as R and Q ⁰ in the formula (c1-1), respectively.

In general formula (c3-2), R is the same as defined above.
In formula (c3-2), A ⁰¹ is a hydrocarbon group or a divalent to have a substituent, a straight-chain alkylene group, a branched alkylene group, cyclic alkylene group In the description of Q ⁰ , an aromatic hydrocarbon group is preferable, an ethylene group, —CH (CH ₃ ) —, a group obtained by further removing one hydrogen atom from a tetracyclododecanyl group, and a hydrogen atom from a phenyl group. Aromatic hydrocarbon groups with one removed are particularly preferred.
In the general formula (c3-2), B ⁰¹ is a divalent hydrocarbon group which may have a substituent, and is preferably a linear alkylene group or a branched alkylene group, and a methylene group. An ethylene group is particularly preferred.
In general formula (c3-2), Q ¹ represents a divalent linking group containing an oxygen atom, and represents —O—, —C (═O) —, —C (═O) —O—, —O. —C (═O) —, carbonate bond (—O—C (═O) —O—), —NH—C (═O) — are preferred, —O—, —C (═O) —O—, -O-C (= O)-is particularly preferred.
In the general formula (c3-2), r is an integer of 0 or 1.

In the general formula (c3-3), R, A _aryl , X ₀₂ , R ⁷ , a0, b0, R ⁸ and R ⁹ are all R, A _aryl , X ₀₁ in the formula (c11-2). is the same as ^{R 7, a0, b0, R} 8 and ^{R 9.}

Specific examples of the structural units represented by the general formulas (c3-1) to (c3-3) are shown below.
In general formulas (c3-1) to (c3-3), R is the same as described above, and is preferably a hydrogen atom or a methyl group.

The structural unit (c3) is preferably at least one selected from the group consisting of structural units represented by the general formulas (c3-1), (c3-2) and (c3-3). The structural unit represented by (c3-1) is particularly preferable.
More specifically, as the structural unit (c3), the general formulas (c3-1-1), (c3-2-1) to (c3-2-6), and (c3-3-1) to (c3) At least one selected from the group consisting of structural units represented by 3-3) is more preferred, and the structural unit represented by the general formula (c3-1-1) is most preferred.

In the component (C), as the structural unit (c3), one type may be used alone, or two or more types may be used in combination.
In the component (C), the proportion of the structural unit (c3) is preferably 1 to 25 mol%, more preferably 5 to 20 mol%, based on the total of all the structural units constituting the component (C), and 10 to 20 Mole% is particularly preferred.

In the present invention, the component (C) is preferably a polymer having the structural unit (c0), and more preferably a polymer compound having the structural unit (c0) and the structural unit (c1).
Specifically, as the component (C), a polymer comprising the structural unit (c0); a copolymer comprising the structural units (c0) and (c1); from the structural units (c0), (c1) and (c3) And the like are preferable.
Specific examples of such a copolymer include a copolymer composed of the structural units (c0) and (c11) and a copolymer composed of the structural units (c0) and (c12).
The component (C) is preferably a random copolymer.

The mass average molecular weight (Mw) of the component (C) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 2000 to 50000, more preferably 3000 to 30000, most preferably 4000 to 25000. preferable. 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 (C) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.

  The component (C) described above can be suitably used as an additive for a resist composition for immersion exposure.

As the component (C), the above fluorine-containing polymer compound may be used alone or in combination of two or more.
The content of the component (C) in the resist composition for immersion exposure according to the present invention is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 40 parts by mass with respect to 100 parts by mass of the component (A). 0.5 to 30 parts by mass is particularly preferable, and 1 to 15 parts by mass is most preferable.
The hydrophobicity of the resist film formed using the resist composition for immersion exposure is improved by setting it to the lower limit value or more of the above range, and the hydrophobicity suitable for immersion exposure is obtained. The hydrophilicity of the resist film due to contact with the developer becomes higher. When it is at most the upper limit value, the lithography properties are improved.

<(A) component>
In the present invention, the component (A) is a base material component whose solubility in an alkali developer is changed by the action of an acid.
However, the component (A) does not include those corresponding to the fluorine-containing polymer compound (C).
As the component (A), organic compounds that are usually used as base components for chemically amplified resists can be used alone 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 used as the substrate component is a low molecular weight organic compound (low molecular material) having a molecular weight of 500 or more and less than 2000 and a high molecular weight organic compound (polymer material) having a molecular weight of 2000 or more. It is divided roughly. As the low molecular weight material, a non-polymer is usually used. Resin (polymer, copolymer) is used as the polymer material, and the “molecular weight” is a polystyrene-reduced mass average molecular weight measured by GPC (gel permeation chromatography). 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 for immersion exposure according to the present invention is a “negative resist composition”, a base material component that is soluble in an alkali developer is used as the component (A), and the negative resist composition is further crosslinked. An agent is blended.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause cross-linking between the base component and the cross-linking agent, resulting in poor solubility in an alkali developer. To do. Therefore, in the formation of the resist pattern, when the resist film obtained by coating the negative resist composition on the substrate is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while unexposed. Since the 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.
As the alkali-soluble resin, 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 is a good resist with little swelling. A pattern can be formed, which is preferable. Note that 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 for immersion exposure of the present invention is a “positive resist composition”, as the component (A), a base material component whose solubility in an alkaline 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 substrate is selectively exposed, the exposed portion changes from poorly soluble 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 for immersion exposure according to the present invention, the component (A) is preferably a base material component whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition for immersion exposure according to 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 weight material (A2) (hereinafter also referred to as “component (A2)”) whose solubility in a 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 alone or in combination of two or more.
In the present invention, the component (A1) preferably contains a structural unit derived from an acrylate ester.
Especially, it is preferable that (A1) component has a structural unit (a1) induced | guided | derived from the acrylate ester containing an acid dissociable dissolution inhibiting group especially.
In addition to the structural unit (a1), the component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) is derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2). It is preferable to have a structural unit (a3).

Constituent Unit (a1) The acid dissociable, dissolution inhibiting group in the constituent unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) insoluble in an alkaline developer before dissociation, It dissociates to increase the solubility of the entire component (A1) in an alkaline developer, and what has been proposed as an acid dissociable, dissolution inhibiting group for a base resin for a chemically amplified resist is used. be able to. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. .

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.

“Aliphatic branched” means having a branched structure having no aromaticity.
The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” 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.
As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group. .

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) 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, and an oxygen atom (= O).
The basic ring structure excluding the substituent of the “aliphatic cyclic group” 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” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. And groups obtained by removing one or more hydrogen atoms from a polycycloalkane. More specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .

  Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 -Adamantyl group, 2-ethyl-2-adamantyl group, etc. are mentioned. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) An aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecanyl group, or a tetracyclododecanyl group, and a branched alkylene group having a tertiary carbon atom bonded thereto. Groups.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１５、Ｒ^１６はアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁵ and R ¹⁶ may be alkyl groups (both linear and branched, preferably 1 to 5 carbon atoms). Is). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the lower alkyl group or halogenated lower alkyl group of R is a lower alkyl group or halogenated lower alkyl which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.

The “acetal-type acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, this acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級アルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the lower alkyl group for R ¹ ′ and R ² ′ include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

Wherein, ^{R 1} ', n, Y are as defined above. ]

Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状もしくは分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include groups excluding hydrogen atoms. Specific examples thereof include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ And may be combined.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4-7 membered ring, and more preferably a 4-6 membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents a divalent linking group. ]

In general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group that may be bonded to the α-position of the acrylate ester. .
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. And tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).

Examples of the divalent linking group for Y ² include an alkylene group, a divalent aliphatic cyclic group, and a divalent linking group containing a hetero atom.
As the aliphatic cyclic group, those similar to the description of the “aliphatic cyclic group” can be used except that a group in which two or more hydrogen atoms are removed is used.
When Y ² 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 Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .
When Y ² is a divalent linking group containing a hetero atom, examples of the divalent linking group containing a hetero 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 or an acyl group), —S—. , —S (═O) ₂ —, —S (═O) ₂ —O—, “—AO (oxygen atom) —B— (wherein A and B each independently have a substituent) A divalent hydrocarbon group that may be present.) ”And the like.

When Y ² is —NH—, the substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. It is particularly preferred that
When Y ² is “A—O—B”, A and B are each independently a divalent hydrocarbon group which may have a substituent.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.

  The hydrocarbon group in A may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.

The aliphatic hydrocarbon group for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 2 to 5, and most preferably 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], Tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —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 - _{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 Alkylethylene groups such as CH ₃ ) CH ₂ —; alkyltrimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH _{2 CH 2 CH 2 -, - CH} 2 CH (CH 3) CH 2 CH 2 - , etc. And alkyl alkylene groups such as Le Kill tetramethylene group. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include 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.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. Examples include a group bonded to the terminal of an aromatic hydrocarbon group or interposed in the middle of a chain aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon 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, and an oxygen atom (= O).

  A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 2 to 5 carbon atoms, and most preferably an ethylene group.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups as those described above for A.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an alkylmethylene group.
The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２は２価の連結基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n represents an integer of 0 to 3] Y ² represents a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

Wherein, X 'include the same tertiary alkyl ester-type acid dissociable, dissolution inhibiting groups as those described above for X ^{1.
R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable, dissolution inhibiting group" described above ^{(p1) ', R 2'} , n, Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).

  Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

Among the above, the structural unit represented by the general formula (a1-1) is preferable, and specifically, the formulas (a1-1-1) to (a1-1-7) and (a1-1-36) to It is more preferable to use at least one selected from the group consisting of structural units represented by (a1-1-42).
Furthermore, the structural unit (a1) is represented by the following general formula (a1-1-01) that includes the structural units represented by formula (a1-1-1) to formula (a1-1-5). And those represented by the following general formula (a1-1-02) including the structural units represented by formulas (a1-1-36) to (a1-1-42) are also preferable.

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す。）

(Wherein R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, and h represents an integer of 1 to 3).

In general formula (a1-1-01), R is the same as defined above.
The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably a methyl group.
In general formula (a1-1-02), R is the same as defined above.
The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, and more preferably 25 to 50 mol% with respect to all the structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

Structural Unit (a2) The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.

As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from a monocyclic lactone such as γ-butyrolactone or mevalonic lactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.

  More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｒ’は水素原子、低級アルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、前記Ｒ”は水素原子、または炭素数１〜１５の直鎖状、分岐鎖状もしくは環状のアルキル基であり、ｍは０または１の整数であり、Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, or —COOR ″, and the above R ″ is A hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, m is an integer of 0 or 1, and A ″ is a carbon which may contain an oxygen atom or a sulfur atom. It is an alkylene group of formula 1 to 5, an oxygen atom or a sulfur atom.

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a1).
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms are removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Specific examples of the alkylene group having 1 to 5 carbon atoms that may contain an oxygen atom or sulfur atom of A ″ include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, —O—CH ₂ —. _{, -CH 2 -O-CH 2 -} , - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to (a2) -3) At least 1 sort (s) selected from the group which consists of a structural unit represented by 3) is more preferable. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-2-9), (a2-2-10) ), (A2-3-1), (a2-3-2), (a2-3-9) and (a2-3-10) at least one selected from the group consisting of structural units It is particularly preferable to use it.

As the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all the structural units constituting the component (A1). 50 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

Structural Unit (a3) The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A1) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the following formula (a3-2), and the following formula The structural unit represented by (a3-3) is preferable.

（式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。）

Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5. And s is an integer of 1 to 3.)

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3-position of the adamantyl group is particularly preferred.
In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and more preferably 5 to 25 mol% with respect to all the structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) is sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

-About structural unit (a4) (A1) component may contain other structural units (a4) other than the said structural units (a1)-(a3) in the range which does not impair the effect of this invention.
The structural unit (a4) is not particularly limited as long as it is another structural unit not classified into the above structural units (a1) to (a3), and for ArF excimer laser, for KrF excimer laser (preferably ArF excimer) A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

  When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) in the component (A1) is 1 to 30 with respect to the total of all the structural units constituting the component (A1). Mol% is preferable and 10 to 20 mol% is more preferable.

  In the present invention, the component (A1) preferably contains a copolymer having the structural units (a1), (a2) and (a3). Examples of the copolymer include copolymers composed of the structural units (a1), (a2) and (a3), copolymers composed of the structural units (a1), (a2), (a3) and (a4). Can be mentioned.

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 the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

The mass average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of the component (A1) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. 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) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows 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.

In the resist composition for immersion exposure according to the present invention, as the component (A), one type may be used alone, or two or more types may be used in combination.
Among these, the component (A) is preferably a base material component whose solubility in an alkaline developer is increased by the action of an acid, and particularly preferably the component (A1).
In the resist composition for immersion exposure according to the present invention, the content of the component (A) may be adjusted according to the thickness of the resist film to be formed.

<(B) component>
(B) It does not specifically limit as a component, What has been proposed as an acid generator for chemical amplification type resists until now 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；複数のＲ^４”は、それぞれ独立して、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表し；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 of them may be bonded to each other to form a ring together with the sulfur atom in the formula; a plurality of R ⁴ ″ each independently represents an alkyl group which may have a substituent, an alkyl halide; A group, an aryl group, or an alkenyl group; at least one of R ¹ ″ to 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 be substituted with a group, a halogen atom, a hydroxyl group or the like, or may not be substituted. 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, Most preferred is a tert-butoxy group.
The alkoxy group that may be substituted for the hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may substitute 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 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 those described above for R ¹ ″ to R ³ ″.

In formula (b-1), R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
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 preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.

Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. It is preferable that it is 50 to 100%, and 100% is the most preferable. The higher the halogenation rate, the more preferable the strength of the acid.

The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.

In the above R ⁴ ″, “optionally substituted” means one of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, ^wherein: X ^{05 -Q} 05 - ^{[wherein, Q 05} represents a divalent linking group containing an oxygen ^atom, a ^{X 05} is a substituent It is a hydrocarbon group that may have. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described as the halogen atom and alkyl group in the halogenated alkyl group in R ⁴ ″.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

X ⁰⁵ -Q ⁰⁵ - In the group represented ^{by, Q 05} represents a divalent linking group containing an oxygen atom.
Q ⁰⁵ may contain atoms other than oxygen atoms. 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 - such as an alkyl trimethylene group; Te Ramechiren 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 ⁰⁵ 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.

X ^{05 -Q} 05 ^- In the group represented by the formula, the hydrocarbon group for X ⁰⁵ may be an aromatic hydrocarbon group may be 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 carbon number of 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 ⁰⁵ may be either a saturated aliphatic hydrocarbon group, or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In ^X05 , 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.
As the "hetero atom" in X ^05, not particularly limited as long as it is an atom other than carbon and hydrogen atoms, for example 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 that substitutes 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.

The aliphatic hydrocarbon group for X ^05, a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group or cyclic aliphatic hydrocarbon group, ( Aliphatic cyclic groups) are preferred.
In ^X05 , 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.
In ^X05 , 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.

In ^X05 , the unsaturated hydrocarbon group preferably has 2 to 10 carbon atoms, preferably 2 to 5, more preferably 2 to 4, and particularly preferably 3. 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.

In ^X05 , the aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is 3 to 30, preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms have been removed from a monocycloalkane; a group in which one or more hydrogen atoms have been 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; 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 groups obtained by removing one or more hydrogen atoms from adamantane are most preferred.
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, each of the alkylene groups in Q ″, R ⁹⁴ and R ⁹⁵ is preferably a linear or branched alkylene group, and the alkylene group has 1 to 5 carbon atoms and 1 to 3 carbon atoms. It is 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.

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 ⁰⁵ 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, the above (L2) to (L5), (S3) to (S4), and the like.

In the present invention, R ⁴ ″ preferably has X ⁰⁵ -Q ^05- as a substituent. In this case, R ⁴ ″ has X ⁰⁵ -Q ⁰⁵ -Y ^05- [wherein Q ⁰⁵ and X ⁰⁵ is the same as above, and Y ⁰⁵ is 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 particularly preferable.

X ⁰⁵ -Q ⁰⁵ -Y ⁰⁵ - In the group represented ^by, as the alkylene group for ^{Y 05,} include the same ones having 1 to 4 carbon atoms of the alkylene group mentioned in the ^{Q 05.}
Examples of the fluorinated alkylene group for Y ⁰⁵ include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
Specific examples _{^{Y 05, -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 ⁰⁵ is particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. When the carbon atom bonded to the adjacent sulfur atom of Y ⁰⁵ is fluorinated, the component (B), an acid having strong acidity is generated upon exposure, the generated. Thereby, the resist pattern shape becomes better, and the lithography characteristics are further improved.
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 -, - CH 2 CF 2 - or _CH 2 _CF 2 CF ₂ - is preferable, _{-CF 2} -, - CF 2 CF ₂ —, —CH ₂ CF ₂ —, —CF ₂ CF ₂ CF ₂ — or CH ₂ CF ₂ CF ₂ — is more preferred, and —CF ₂ —, —CF ₂ CF ₂ — or —CF ₂ CF ₂ CF ₂ is preferred. - it is particularly preferable, -CF ₂ - is most preferred.

The fluorinated alkylene group for Y ⁰⁵ may have a substituent.
The term “having a substituent” for the fluorinated alkylene group means that part or all of the hydrogen atom or fluorine atom in the fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. To do.
Examples of the substituent that the 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.

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. All of R ⁵ ″ to R ⁶ ″ are preferably 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 all of R ⁵ ″ to R ⁶ ″ are 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 the formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethanesulfonate or nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, tri (4-methylphenyl) sulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or the same 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) phenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-phenyltetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate 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.

  Moreover, the onium salt which replaced the anion part of these onium salts with alkyl sulfonates, such as methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, can also be used.

  Moreover, the onium salt which replaced the anion part of these onium salts by the anion part represented by either of following formula (b1-1)-(b1-7) can also be used.

［式中、ｐ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、ｔ１〜ｔ２はそれぞれ独立に１〜３の整数であり、ｄは１〜２０の整数であり、Ｒ^２０”は置換基であり、ｎ１１〜ｎ１５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〜ｗ６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, p is an integer of 1 to 3, q1 to q2 are each independently an integer of 1 to 5, t1 to t2 are each independently an integer of 1 to 3, and d is 1 to 20] R ²⁰ ″ is a substituent, n11 to n15 are each independently 0 or 1, v1 to v5 are each independently an integer of 0 to 3, and w1 to w6 are each independently 0 to 0. Is an integer of 3, and Q ″ is the same as described above. ]

Examples of the substituent for R ²⁰ ″ are the same as those described above for X ⁰⁵ as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have. Things.
^"If reference numeral of (W1 to W6) is an integer of 2 or more, plural R ²⁰ in the ^compound" R ²⁰ may be each the same or different.

  Moreover, as an onium salt type | system | group acid generator, the anion part in the said general formula (b-1) or (b-2) is changed into the anion represented by the following general formula (b-3) or (b-4). A substituted onium salt acid generator can also be used (the cation moiety is the same as the cation moiety of the acid generator represented by formula (b-1) or (b-2)).

［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

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 has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
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, and the alkyl group has 1 to 10 carbon atoms, Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, 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 with 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 proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

  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. 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 “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 or a fluorinated alkyl group having 1 to 4 carbon atoms which has no substituent.

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 of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and 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 a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. 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 18] to [Chemical 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.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, as the component (B), it is preferable to use an onium salt acid generator having a fluorinated alkyl sulfonate ion which may have a substituent as an anion part.
0.5-30 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component in the resist composition for immersion exposure of this invention, 1-10 mass parts is more preferable. 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.

<Optional component>
[(D) component]
In the resist composition for immersion exposure according to the present invention, a nitrogen-containing organic compound component (D) (hereinafter referred to as “(D) component” is further added as an optional component in order to improve the resist pattern shape, the stability over time. It is preferable to contain.
Since a wide variety of component (D) has already been proposed, any known one can be used. Among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are used. preferable. Here, the 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, and the like; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a C5-C10 trialkylamine is preferable and tri-n-pentylamine is more 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 more preferable to use an alkylamine as the component (D), and it is particularly preferable to use a trialkylamine having 5 to 10 carbon atoms.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

[(E) component]
In the resist composition for immersion exposure according to the present invention, an organic carboxylic acid, a phosphorus oxoacid and a phosphorus oxoacid and At least one compound (E) selected from the group consisting of derivatives thereof (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 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.
In the present invention, it is particularly preferable to use an organic carboxylic acid as the component (E), and it is most preferable to use salicylic acid.
(E) A component is used in 0.01-5.0 mass parts normally with respect to 100 mass parts of (A) component.

  The resist composition for immersion exposure according to the present invention further contains miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants for improving coating properties, and dissolution inhibition. An agent, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

[(S) component]
The resist composition for immersion exposure according to the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes 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; many such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol Monohydric alcohols: compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate or dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or the compound having an 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.
Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), ethyl lactate (EL), and γ-butyrolactone 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 and is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. It is used in a range of 2 to 20% by mass, preferably 5 to 15% by mass.

  The dissolution of the material in the component (S) can be carried out, for example, by simply mixing and stirring the above-mentioned components by a usual method, and if necessary, a disperser such as a dissolver, a homogenizer, or a three roll mill. You may use and disperse and mix. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

The resist composition for immersion exposure according to the first aspect of the present invention has good lithography characteristics and characteristics suitable for immersion exposure, which are characteristics required for a resist composition used for immersion exposure ( Therefore, it can be suitably used for immersion exposure.
That is, the resist film formed using the resist composition for immersion exposure according to the present invention contains the above component (C) (the fluorine-containing polymer compound according to the third aspect of the present invention described later).
Since the component (C) has a fluorine atom since it has a high hydrophobicity, the component (C) has a group represented by the general formula (c0-0), thereby increasing hydrophilicity under basic conditions. Have properties. This is because the lactone ring is decomposed (hydrolyzed) and opened by the action of a base (alkaline developer) to generate a hydrophilic group [carboxy group: —C (═O) —OH].
Therefore, the resist film formed using the resist composition for immersion exposure according to the present invention in which the component (C) is blended with the component (A) and the component (B) is contacted with an alkali developer (for example, While having a high hydrophobicity during immersion exposure, the hydrophilicity is increased by contact with an alkaline developer.
Thus, since the hydrophobicity at the time of immersion exposure is high, the resist film formed using the resist composition for immersion exposure according to the present invention has a scanning type as described in Non-Patent Document 1. It is very excellent in water followability required when immersion exposure is performed using an immersion exposure machine.
Moreover, since hydrophilicity increases at the time of alkali development, according to the resist composition for immersion exposure of the present invention, defects in immersion exposure can be effectively reduced. That is, in the immersion exposure, when immersion exposure is performed on the resist film, the solubility of the exposed portion in the alkaline developer changes. For example, in the case of the positive type, the solubility of the exposed portion in the alkaline developer increases, and in the case of the negative type, the solubility of the exposed portion in the alkaline developer decreases. Then, by performing alkali development, in the case of the positive type, the exposed portion is removed, and in the case of the negative type, the unexposed portion is removed to form a resist pattern.
At this time, the surface of the resist film where the radiation is not irradiated by immersion exposure (for example, the unexposed portion in the case of a positive type) is subjected to a defect (watermark defect) due to the influence of an immersion medium such as water after alkali development. However, the resist film formed by using the resist composition for immersion exposure according to the present invention has increased hydrophilicity during alkali development, so that the occurrence of defects can be reduced.

Moreover, by using the resist composition for immersion exposure of the present invention, substance elution from the resist film during immersion exposure can be suppressed.
That is, as described above, the immersion exposure is performed by exposing the portion between the lens and the resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen, at a time higher than the refractive index of air. This is a method including a step of performing exposure (immersion exposure) in a state filled with a solvent (immersion medium) having a large refractive index. In immersion exposure, when the resist film and the immersion solvent come into contact with each other, elution (substance elution) of substances ((B) component, (D) component, etc.) in the resist film into the immersion solvent occurs. Substance elution causes phenomena such as alteration of the resist layer and change in the refractive index of the immersion solvent, thereby deteriorating the lithography properties.
The amount of this substance elution is affected by the characteristics of the resist film surface (for example, hydrophilicity / hydrophobicity). Therefore, it is estimated that the amount of substance elution is reduced by increasing the hydrophobicity of the resist film surface, for example.
Since the resist film formed using the resist composition for immersion exposure according to the present invention contains a component (C) having a fluorine atom, exposure and alkali development are performed as compared with the case where the component (C) is not included. High hydrophobicity before performing. Therefore, according to the resist composition for immersion exposure of the present invention, substance elution during immersion exposure can be suppressed.
Since elution of the substance can be suppressed, the use of the resist composition for immersion exposure according to the present invention can suppress the alteration of the resist film and the change in the refractive index of the immersion solvent in the immersion exposure. A resist pattern having a good shape and the like can be formed by suppressing fluctuations in the refractive index of the immersion solvent. Further, the contamination of the lens of the exposure apparatus can be reduced, and therefore, it is not necessary to take protective measures against these, and it is possible to contribute to the simplification of the process and the exposure apparatus.
In addition, since the resist film formed from the resist composition for immersion exposure according to the present invention hardly swells with water, a fine resist pattern can be formed with high accuracy.
Furthermore, the resist composition for immersion exposure of the present invention has good lithography properties such as sensitivity, resolution and etching resistance, and forms a resist pattern without any practical problems when used as a resist in immersion exposure. it can. For example, by using the resist composition for immersion exposure according to the present invention, a fine resist pattern having a dimension of 100 nm or less can be formed.

The hydrophobicity of the resist film includes the contact angle with water, for example, the static contact angle (the angle formed by the surface of the water droplet on the resist film in the horizontal state and the resist film surface), and the dynamic contact angle (the tilted resist film). The contact angle when the water droplet starts to fall (fall angle), the contact angle (advance angle) at the end point in front of the drop direction, the contact angle (retreat angle) at the end point behind the fall direction). It can be evaluated by measuring. For example, the higher the hydrophobicity of the resist film, the larger the static contact angle, the advancing angle, and the receding angle, while the smaller the falling angle.
Here, as shown in FIG. 1, when the plane 2 on which the droplet 1 is placed is gradually tilted, the advancing angle starts to move (drop) on the plane 2 when the plane 1 is gradually inclined. Is the angle θ ₁ formed by the surface of the droplet at the lower end 1 a of the droplet 1 and the plane 2. At this time (when the droplet 1 starts to move (drop) on the plane 2), an angle θ2 formed by the droplet surface at the upper end 1b of the droplet 1 and the plane ₂ is a receding angle, The inclination angle θ _{3 of the} plane 2 is the falling angle.
In this specification, the advancing angle, the receding angle, and the falling angle are measured as follows.
First, a resist composition solution is spin-coated on a silicon substrate, and then heated at 110 ° C. for 60 seconds to form a resist film.
Next, with respect to the resist film, DROP MASTER-700 (product name, manufactured by Kyowa Interface Science Co., Ltd.), AUTO SLIDING ANGLE: SA-30DM (product name, manufactured by Kyowa Interface Science Co., Ltd.), AUTO DISPENSER: AD-31 ( It can be measured using a commercially available measuring device such as a product name (manufactured by Kyowa Interface Science Co., Ltd.).

In the resist composition for immersion exposure according to the present invention, it is preferable that the measured value of the receding angle before exposure and alkali development in a resist film obtained using the resist composition is 60 degrees or more, and 60 to 100 It is more preferable that the angle is 60 ° to 90 °. When the receding angle is greater than or equal to the lower limit value, the substance elution suppression effect during immersion exposure is improved. The reason for this is not clear, but one of the main factors may be related to the hydrophobicity of the resist film. In other words, since the aqueous immersion medium is an aqueous medium such as water, it is highly hydrophobic, so that the immersion medium is quickly removed from the resist film surface when the immersion medium is removed after immersion exposure. It is presumed that the fact that it can be removed is affected. Further, when the receding angle is not more than the upper limit value, the lithography characteristics and the like are good.
For the same reason, the resist composition for immersion exposure of the present invention has a measured value of a static contact angle of 70 degrees or more before performing exposure and alkali development in a resist film obtained using the resist composition. It is preferably 70 to 99 degrees, more preferably 75 to 90 degrees.
In the resist composition for immersion exposure according to the present invention, it is preferable that the measured value of the falling angle before exposure and alkali development in a resist film obtained using the resist composition is 36 degrees or less. It is more preferably ˜36 degrees, particularly preferably 10 to 30 degrees, and most preferably 14 to 27 degrees. When the falling angle is less than or equal to the upper limit value, the substance elution suppression effect during immersion exposure is improved. Further, when the sliding angle is at least the lower limit value, the lithography properties and the like are good.
The above-mentioned various angles (dynamic contact angle (advance angle, receding angle, sliding angle, etc.), static contact angle) are determined depending on the composition of the resist composition for immersion exposure, for example, the type and composition of component (C). The amount can be adjusted by adjusting the type of component (A). For example, as the content of the component (C) increases, the hydrophobicity of the resulting resist composition increases, the advancing angle, the receding angle, and the static contact angle increase, and the sliding angle decreases.

As described above, the resist composition for immersion exposure according to the present invention sufficiently has various properties required for resist materials in immersion exposure, and can be suitably used for immersion exposure.
The component (C) is useful as an additive used in a resist composition for immersion exposure.

≪Resist pattern formation method≫
The resist pattern forming method according to the second aspect of the present invention comprises a step of forming a resist film on a support using the resist composition for immersion exposure according to the first aspect of the present invention, It includes a step of immersion exposure and a step of alkali developing the resist film to form a resist pattern.

A preferred example of the method for forming a resist pattern of the present invention is shown below.
First, after applying the resist composition for immersion exposure of the present invention on a support with a spinner or the like, a resist film is formed by performing pre-baking (post-apply baking (PAB) treatment).

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 organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

  After the resist film is formed, an organic antireflection film may be further provided on the resist film to form a three-layer laminate including a support, a resist film, and an antireflection film. The antireflection film provided on the resist film is preferably soluble in an alkali developer.

  The steps so far can be performed using a known method. The operating conditions and the like are preferably set as appropriate according to the composition and characteristics of the resist composition for immersion exposure to be used.

Next, liquid immersion lithography is selectively performed on the resist film obtained above through a desired mask pattern. At this time, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in this state.
The wavelength used for the exposure is not particularly limited, and can be performed using radiation such as an ArF excimer laser, a KrF excimer laser, or an F ₂ laser. The resist composition for immersion exposure of the present invention is particularly effective for a KrF excimer laser or an ArF excimer laser, and is most effective for an ArF excimer laser.

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 formed using the resist composition for immersion exposure of the present invention 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 fluorinated inert liquid include fluorinated compounds 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 main components. 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.).
The resist composition for immersion exposure according to the present invention is not particularly adversely affected by water, and is excellent in lithography properties such as sensitivity and resist pattern shape. Therefore, in the present invention, water is preferably used as the immersion medium. . Water is also preferable from the viewpoints of cost, safety, environmental problems, and versatility.

  Next, after the immersion exposure step is completed, post-exposure heating (post-exposure baking (PEB)) is performed, and subsequently, development processing is performed using an alkaline developer composed of an alkaline aqueous solution. And preferably, water rinsing is performed using pure water. The water rinse is performed, for example, by dropping or spraying water on the surface of the support while rotating the support to wash away the developer on the support and the resist composition for immersion exposure dissolved by the developer. Can be implemented. Then, drying is performed to obtain a resist pattern in which the resist film (the coating film of the resist composition for immersion exposure) is patterned into a shape corresponding to the mask pattern.

≪Fluorine-containing polymer compound≫
The fluorine-containing polymer compound according to the third aspect of the present invention is a polymer compound containing a group represented by the following general formula (c0-0) in the side chain, and the liquid according to the first aspect of the present invention. This is the same as the component (C) in the description of the resist composition for immersion exposure.

［式（ｃ０−０）中、Ｒ^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。］

[In Formula (c0-0), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ]

In the general formula (c0-0), R ⁶ , q and g are the same as R ⁶ , q and g in the description of the component (C), respectively.

  Preferred examples of the fluorine-containing polymer compound of the present invention include polymer compounds containing a group represented by the following general formula (c0-0-1) in the side chain.

［式（ｃ０−０−１）中、Ｒ^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。］

[In Formula (c0-0-1), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ]

In the general formula (c0-0-1), R ⁶ , q and g are the same as R ⁶ , q and g in the general formula (c0-0), respectively.

  Specifically, a polymer having the following structural unit (c0) is preferable as the fluorine-containing polymer compound of the present invention; a copolymer having the following structural unit (c0) and the following structural unit (c1), that is, A polymer compound having the structural unit (c0) represented by the general formula (c0-1) and the structural unit (c1) represented by the following general formula (c1-1) is preferable.

［式（ｃ０−１）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^６は水素原子又は１価の炭化水素基であり、ｑは０〜２の整数であり、ｇは１〜４の整数である。式（ｃ１−１）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；Ｑ^０は単結合又は二価の連結基であり、Ｒ^２はフッ素原子を有する有機基である。複数のＲはそれぞれ同じであっても異なっていてもよい。］

[In Formula (c0-1), 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 ⁶ is a hydrogen atom or a monovalent hydrocarbon; Q is an integer of 0 to 2, and g is an integer of 1 to 4. In formula (c1-1), 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; Q ⁰ is a single bond or a divalent linking group. R ² is an organic group having a fluorine atom. A plurality of R may be the same or different. ]

In the formula, ^{R, R} 6, q and g, and ^{Q 0} and ^{R 2} are each, R in the description of component ^{(C), R} 6, q and g, as well as the same as ^{Q 0} and ^{R 2} is there.

(Method for producing fluorine-containing polymer compound)
As an example, the fluorine-containing polymer compound of the present invention includes a monomer that induces a desired structural unit, for example, a structural unit that includes a group represented by the general formula (c0-0) in the side chain (for example, the structural unit (c0)). ) Etc.) and a monomer deriving a structural unit containing a fluorine atom (for example, the structural unit (c1) etc.), azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (Wako Pure Chemical Industries, Ltd.) It can be obtained by polymerization by a known radical polymerization using a radical polymerization initiator such as V-601).

The above-described fluorine-containing polymer compound according to the third aspect of the present invention is a novel compound that has not been known so far.
Such a fluorine-containing polymer compound is useful as an additive for a resist composition, and a resist composition to which the fluorine-containing polymer compound is added is suitable for immersion exposure.
The resist composition to which the fluorine-containing polymer compound is added is not particularly limited as long as it is used for immersion exposure, but is a base material component whose solubility in an alkaline developer is changed by the action of an acid. And a chemically amplified resist composition containing an acid generator component that generates an acid upon exposure is suitable.
The fluorine-containing polymer compound is particularly useful as an additive used in the resist composition for immersion exposure 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.

<Synthesis of fluorinated polymer compound (C)>
As shown in Examples 1 and 2 below, fluorine-containing polymer compounds were synthesized according to respective synthesis examples.

(Synthesis Example 1: Synthesis Example of Compound (1))
To a THF solution of methacrylic acid in which 30 g (348 mmol) of methacrylic acid was dissolved in 300 ml of THF at 0 ° C. under a nitrogen atmosphere, 61 g (600 mmol) of triethylamine and 64 g (418 mmol) of methyl bromoacetate were added, returned to room temperature, and stirred for 3 hours. did. After confirming the disappearance of the raw material by thin layer chromatography (TLC), the reaction solution was evaporated under reduced pressure. Water was added to the obtained reaction product, and the mixture was extracted 3 times with ethyl acetate. The organic layer was washed twice with water and the solvent was distilled off under reduced pressure to obtain 47 g of Compound (1) -1 as a colorless liquid (yield 85%).
Next, 700 ml of a 2.38 mass% TMAH aqueous solution was added to 700 ml of a THF solution of 30 g (190 mmol) of Compound (1) -1 at 0 ° C. in a nitrogen atmosphere, and the mixture was stirred at room temperature for 3 hours. After confirming the disappearance of the raw material by thin layer chromatography (TLC), the THF solvent was distilled off under reduced pressure. To the resulting aqueous reaction solution, 50 ml of 10N hydrochloric acid was added at 0 ° C. to adjust the acidity, followed by extraction three times with ethyl acetate. The obtained organic layer was washed twice with water, and the solvent was distilled off under reduced pressure to obtain 26 g of Compound (1) -2 as a colorless liquid (yield 95%).
Next, at 0 ° C. under a nitrogen atmosphere, 27 g (177 mmol) of 2,2,3,3,3-pentafluoro-1-propanol, 37 g (195 mmol) of ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride, dimethylaminopyridine (DMAP) ) Compound (1) -2 (17 g, 118 mmol) was added to 0.6 g (5 mmol) in THF (100 ml), and the mixture was returned to room temperature and stirred for 3 hours. After confirming the disappearance of the raw materials by thin layer chromatography (TLC), the reaction solution was cooled to 0 ° C., and water was added to stop the reaction. The organic layer obtained by extraction three times with ethyl acetate was washed twice with water. The crude product obtained by evaporating the solvent under reduced pressure was purified by silica gel filtration (ethyl acetate) to obtain 19 g of Compound (1) as a colorless liquid (yield 58%).

¹ H-NMR of compound (1) was measured. The results are shown below.
Spectral data of compound (1)
¹ H-NMR (CDCl ₃ ) 6.14 (s, 1H, Hb), 5.80 (d, 1H, Hb), 4.90 (s, 4H, Hc, Hd), 1.92 (s, 3H , Ha)

(Synthesis Example 2: Synthesis Example of Compound (3))
(I) Synthesis of 7,7,7-trifluoro-3-ethyl-3-heptanol 1.3 g of magnesium, 1-bromo- 10.0 g of 4,4,4-trifluorobutane and 20 g of tetrahydrofuran were added, and a Grignard reagent was prepared by a conventional method. To the obtained Grignard reagent, a mixed solution of 5.0 g of 3-pentanone and 4 g of tetrahydrofuran was added dropwise at 25 to 35 ° C. over 30 minutes, and further stirred at the same temperature for 1 hour. The reaction mixture was treated by a conventional method, and the obtained organic layer was washed with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure, and 7,7,7-trifluoro-3-ethyl-3-heptanol was pale yellow. 7.9 g was obtained as an oil.

(Ii) Synthesis of 7,7,7-trifluoro-3-ethyl-3-heptyl methacrylate The 7,7,7- obtained above was added to a four-necked flask equipped with a stirrer, thermometer, and dropping funnel. 7.9 g of trifluoro-3-ethyl-3-heptanol, 0.2 g of 4-dimethylaminopyridine, 7.1 g of triethylamine, and 10 g of acetritonyl were added and dissolved by stirring.
To the solution, 6.7 g of methacrylic acid chloride was added dropwise at about 75 ° C. over 30 minutes and further stirred at the same temperature for 2 hours. The reaction solution was cooled to room temperature, washed once with a mixed solution of 8.8 g of potassium carbonate and 100 ml of water, once with 10% by mass brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The concentrate was purified by silica gel column chromatography to obtain 5.7 g of compound (3) (7,7,7-trifluoro-3-ethyl-3-heptyl methacrylate).

¹ H-NMR of compound (3) was measured. The results are shown below.
¹ H-NMR (CDCl ₃ ) δ: 0.82 to 0.87 (tr, 6H, —CH ₃ ), 1.46 to 1.58 (m, 2H, —CH ₂ —), 1.78 to 1 .97 (m, 9H, ═C—CH ₃ , —C—CH ₂ —), 1.98 to 2.16 (m, 2H, CF ₃ CH ₂ —), 5.49 (s, 1H, C = _{CH 2), 6.01 (s,} 1H, C = CH 2)
From the results of the above measurement, it was confirmed to be the compound (3) represented by the following chemical formula.

(Example 1)
Synthesis example of fluorine-containing polymer compound (1):
In a three-necked flask connected with a thermometer and a reflux tube, 4.00 g (14.48 mmol) of the compound (1) and 3.28 g of a 50% PGMEA solution of the following compound (2) (9. as compound (2)). 65 mmol), and 28.68 g of PGMEA was added and dissolved. To this solution, 1.21 mmol of dimethyl azobisisobutyrate (V-601) was added and dissolved as a polymerization initiator.
The reaction solution was heated and stirred at 80 ° C. for 6 hours under a nitrogen atmosphere, and then cooled to room temperature. The obtained reaction polymerization liquid is concentrated under reduced pressure, then dropped into a large amount of a methanol / water mixed solution, and an operation for precipitating the polymer is performed. The precipitated polymer compound is filtered, washed, and dried to be the target product. 3.67 g of fluorine-containing polymer compound (1) was obtained.
With respect to this fluorine-containing polymer compound (1), the mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 13,900, and the molecular weight dispersity (Mw / Mn) was 1.59. Further, the copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m = 57.9 / 42. 1

(Example 2)
Synthesis example of fluorine-containing polymer compound (2):
In a three-necked flask connected with a thermometer and a reflux tube, 3.50 g (13.16 mmol) of the compound (3) and 4.48 g of a 50% PGMEA solution of the following compound (2) (13. as compound (2)). 16 mmol) and 30.29 g of PGMEA was added and dissolved. To this solution, 1.32 mmol of dimethyl azobisisobutyrate (V-601) was added and dissolved as a polymerization initiator.
The reaction solution was heated and stirred at 80 ° C. for 6 hours under a nitrogen atmosphere, and then cooled to room temperature. The obtained reaction polymerization liquid is concentrated under reduced pressure, then dropped into a large amount of a methanol / water mixed solution, and an operation for precipitating the polymer is performed. The precipitated polymer compound is filtered, washed, and dried to be the target product. 1.83 g of fluorine-containing polymer compound (2) was obtained.
With respect to this fluorine-containing polymer compound (2), the mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 6,900, and the molecular weight dispersity (Mw / Mn) was 1.26. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m = 31.9 / 68. 1

<Preparation of resist composition>
(Examples 3 to 4, Comparative Example 1)
The components shown in Table 1 below were mixed and dissolved to prepare a positive resist composition.

In Table 1, each abbreviation indicates the following, and the numerical value in [] is the blending amount (part by mass).
(A) -1: a copolymer of Mw7000 and Mw / Mn1.8 represented by the following chemical formula (A) -1. In the formula, the numerical value on the lower right of () indicates the ratio (mol%) of each structural unit.

(B) -1: (4-methylphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate.
(C) -1: The fluorine-containing polymer compound (1).
(C) -2: The fluorine-containing polymer compound (2).
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME = 6/4 (mass ratio).

<Measurement of contact angle in resist film>
Next, the resist compositions of Examples 3 to 4 and Comparative Example 1 were respectively applied onto an 8-inch silicon wafer subjected to hexamethyldisilazane (HMDS) treatment using a spinner, and 110 ° C. on a hot plate. The resist film having a film thickness of 120 nm was formed by pre-baking for 60 seconds and drying.
Water was dropped on the surface of the resist film (resist film before exposure), and the contact angle (static contact angle) was measured using DROP MASTER-700 (product name, manufactured by Kyowa Interface Science Co., Ltd.). (Measurement of contact angle: 2 μL of water). This measured value was defined as “contact angle before development (°)”.
The wafer after the contact angle measurement was subjected to alkali development treatment for 30 seconds and 60 seconds with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution at 23 ° C., and then using pure water for 15 seconds. After rinsing with water, the contact angle was measured in the same manner as described above. The respective measured values were defined as “contact angle after 30 seconds development (°)” and “contact angle after 60 seconds development (°)”.
Further, in Examples 3 to 4 and Comparative Example 1, the difference between the contact angle before development and the contact angle after 60 seconds development was determined and set as “Δ contact angle (°)”. These results are shown in Table 2.

From the results of Table 2, the resist films formed using the resist compositions of Examples 3 to 4 containing the fluorine-containing polymer compound according to the present invention are all comparisons not containing the fluorine-containing polymer compound. It was confirmed that the contact angle before development was higher than that of the resist film formed using the resist composition of Example 1.
This shows that the hydrophobicity of the resist film is increased by containing the fluorine-containing polymer compound. This is expected to improve both the scan followability and the elution reduction effect during the immersion scan exposure.

In addition, from the results of Table 2, the resist films formed using the resist compositions of Examples 3 to 4 have contact angles after development for 30 seconds and after development for 60 seconds to be contact angles before development. It was confirmed that it was lower than that.
From this, it can be seen that the hydrophilicity of the resist film is increased by the alkali development treatment by containing the fluorine-containing polymer compound. Thereby, it is expected that the effect of reducing the defect due to immersion is improved.

  As described above, the resist film formed using the resist compositions of Examples 3 to 4 is higher in hydrophobicity than the resist film formed using the resist composition of Comparative Example 1 during immersion exposure. It was confirmed that the alkali development has a characteristic that the hydrophilicity is higher than that before the development.

<Measurement of contact angle in a film comprising a fluorine-containing polymer compound>
100 parts by mass of each of the fluorine-containing polymer compound (1) and the fluorine-containing polymer compound (2) are respectively dissolved in 2500 parts by mass of the mixed solvent (S) -2 to prepare a fluorine-containing polymer compound solution. did.
Next, except that the fluorine-containing polymer compound solution was used instead of the resist composition, a contact angle (static contact angle, falling angle, advancing angle) was determined in the same manner as in the above <Measurement of Contact Angle in Resist Film>. , And receding angle) were measured. These results are shown in Table 3.

In the results of Table 3, for example, from the measured values of the static contact angle, both the films made of the fluorine-containing polymer compound (1) and the fluorine-containing polymer compound (2) have measured values before development exceeding 90 °. It was confirmed that the membrane was highly hydrophobic.
In addition, in the films composed of the fluorine-containing polymer compound (1) and the fluorine-containing polymer compound (2), the measured values after 30-second development and after 60-second development are lower than the measured values before development. Therefore, it was confirmed that the hydrophilicity of the film was increased by the alkali development treatment.

<Formation of resist pattern>
Next, an organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds. Then, an organic antireflection film having a film thickness of 89 nm was formed.
Then, each of the resist compositions of Examples 3 to 4 and Comparative Example 1 was applied onto the antireflection film using a spinner, and prebaked (PAB) treatment was performed on a hot plate at 110 ° C. for 60 seconds. By performing and drying, a resist film having a film thickness of 100 nm was formed.
Next, an ArF excimer laser (193 nm) is applied to the resist film through a mask pattern using an ArF immersion exposure apparatus NSR-S609B (Nikon Corporation; NA (numerical aperture) = 1.07, σ0.97). ) Was selectively irradiated. Then, PEB processing is performed at 110 ° C. for 60 seconds, and further development processing is performed for 30 seconds with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution at 23 ° C., and then pure water is used for 30 seconds. Rinse with water and shake off to dry.
As a result, in each example, a line and space pattern having a line width of 55 nm and a pitch of 110 nm was formed on the resist film.

From the above results, it was confirmed that the resist compositions of Examples 3 to 4 according to the present invention were suitable for immersion exposure.
Moreover, it has confirmed that the fluorine-containing polymer compound of Examples 1-2 which concerns on this invention was useful as an additive used for the resist composition for immersion exposure.

It is a figure explaining advancing angle ((theta) ₁ ), receding angle ((theta) ₂ ), and falling angle ((theta) ₃ ).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Droplet, 1a ... Lower end, 1b ... Upper end, 2 ... Plane, [theta] ₁ ... Advance angle, [theta] ₂ ... Receding angle, [theta] ₃ ... Falling angle

Claims (12)

A fluorine-containing polymer compound (C) containing a group represented by the following general formula (c0-0) in the side chain and exhibiting decomposability to an alkaline developer;
A base component (A) whose solubility in an alkaline developer is changed by the action of an acid (excluding those corresponding to the fluorine-containing polymer compound (C));
A resist composition for immersion exposure, comprising an acid generator component (B) that generates an acid upon exposure.

[In Formula (c0-0), R ⁶ is a hydrogen atom or a monovalent hydrocarbon group, q is an integer of 0 to 2, and g is an integer of 1 to 4. ] The resist composition for immersion exposure according to claim 1, wherein the fluorine-containing polymer compound (C) is a polymer compound containing a group represented by the following general formula (c0-0-1) in the side chain.

[In Formula (c0-0-1), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ] The fluorine-containing polymer compound (C) is
A structural unit (c0) represented by the following general formula (c0-1);
The resist composition for immersion exposure according to claim 2, which is a polymer compound having a structural unit (c1) represented by the following general formula (c1-1).

[In Formula (c0-1), 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 ⁶ is a hydrogen atom or a monovalent hydrocarbon; Q is an integer of 0 to 2, and g is an integer of 1 to 4. In formula (c1-1), 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; Q ⁰ is a single bond or a divalent linking group. R ² is an organic group having a fluorine atom. A plurality of R may be the same or different. ]   The resist composition for immersion exposure according to any one of claims 1 to 3, wherein the substrate component (A) is a substrate component whose solubility in an alkaline developer is increased by the action of an acid.   The base material component (A) contains a resin component (A1) whose solubility in an alkaline developer is increased by the action of an acid, and the resin component (A1) contains an acid dissociable, dissolution inhibiting group. The resist composition for immersion exposure according to claim 4, which has a structural unit (a1) derived from   The resist composition for immersion exposure according to claim 5, wherein the resin component (A1) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition for immersion exposure according to claim 5 or 6, wherein the resin component (A1) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.   The resist composition for immersion exposure according to any one of claims 1 to 7, comprising a nitrogen-containing organic compound component (D).   A step of forming a resist film on the support using the resist composition for immersion exposure according to any one of claims 1 to 8, a step of performing immersion exposure of the resist film, and an alkali of the resist film A resist pattern forming method including a step of developing and forming a resist pattern. A fluorine-containing polymer compound containing a group represented by the following general formula (c0-0) in the side chain.

[In Formula (c0-0), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ] The fluorine-containing polymer compound according to claim 10, which is a polymer compound containing a group represented by the following general formula (c0-0-1) in a side chain.

[In Formula (c0-0-1), R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group, q represents an integer of 0 to 2, and g represents an integer of 1 to 4. ] A structural unit (c0) represented by the following general formula (c0-1);
The fluorine-containing polymer compound according to claim 11, which is a polymer compound having a structural unit (c1) represented by the following general formula (c1-1).

[In Formula (c0-1), 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 ⁶ is a hydrogen atom or a monovalent hydrocarbon; Q is an integer of 0 to 2, and g is an integer of 1 to 4. In formula (c1-1), 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; Q ⁰ is a single bond or a divalent linking group. R ² is an organic group having a fluorine atom. A plurality of R may be the same or different. ]

Images