JP2020042108A - Resist pattern forming method - Google Patents

Abstract

To provide a resist pattern forming method by which generation of a defect in an unexposed portion of a resist film can be reduced and a resist pattern having a good profile can be formed.SOLUTION: The resist pattern forming method includes: a step of forming a resist film on a support by using a resist composition; a step of exposing the resist film; and a step of developing the exposed resist film with an alkali developer solution containing a nonionic surfactant to form a resist pattern. The resist composition comprises a base material component and a compound (B1) represented by general formula (b1-1) as an acid generator component. In the formula, Rrepresents a polycyclic aliphatic hydrocarbon group; Ris a fluorine atom or the like; Yrepresents a single bond or the like; Vrepresents a single bond or the like; m represents an integer of 1 or more; and M'represents an m-valent onium cation. [Chem 1]SELECTED DRAWING: None

Description

  The present invention relates to a method for forming a resist pattern.

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 in which a predetermined pattern is formed. And performing a developing process to form a resist pattern having a predetermined shape on the resist film.
A resist material whose exposed part changes to a property of dissolving in a developing solution is called a positive type, and a resist material whose exposed part changes to a property of not dissolving in a developing solution is called a negative type.
2. Description of the Related Art In recent years, in the production of semiconductor devices and liquid crystal display devices, finer patterns have been rapidly advanced due to advances in lithography technology.
In general, as a method of miniaturizing a pattern, a shorter wavelength (higher energy) of an exposure light source is used. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but now, mass production of semiconductor devices using a KrF excimer laser or an ArF excimer laser has started. In addition, electron beams having a shorter wavelength (higher energy) than these excimer lasers, EUV (extreme ultraviolet rays), X-rays, and the like have been studied.
The resist material is required to have lithography characteristics such as sensitivity to the exposure light source and resolution for reproducing a pattern having a fine dimension.
As a resist material satisfying such requirements, a chemically amplified resist composition containing a base component whose solubility in an alkali developing solution is changed by the action of an acid and an acid generator component that generates an acid upon exposure is used. Have been.

As one method 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 device and the sample. , A so-called liquid immersion lithography (hereinafter sometimes referred to as "liquid immersion exposure") is known. According to the immersion exposure, the same high resolution can be achieved even when a light source having the same exposure wavelength is used and a light source having a shorter wavelength or a high NA lens is used. It is said that there is no decline. Further, the liquid immersion exposure can be performed using an existing exposure apparatus. Therefore, liquid immersion exposure has been used in recent years because it can realize formation of a resist pattern that is low in cost, has high resolution, and has an excellent depth of focus. It is said that immersion exposure is effective in forming any pattern shape and can be combined with a super-resolution technique such as a phase shift method and a modified illumination method. Currently, as an immersion exposure technique, a technique using an ArF excimer laser as a light source is actively studied. As the immersion medium, water is mainly studied.
It has been proposed to add a compound containing a fluorine atom to a resist composition used for such immersion exposure. For example, Patent Document 1 discloses, as a compound containing a fluorine atom to be added to a resist composition, a fluorine-containing polymer compound having a constituent unit having a fluorine atom and a constituent unit derived from (meth) acrylic acid. ing.

JP 2011-13569 A

  In the above immersion exposure, a resist material having characteristics corresponding to the immersion exposure technology in addition to ordinary lithography characteristics (sensitivity, resolution, etching resistance, etc.) is required. For example, in immersion exposure, when a resist film comes into contact with an immersion solvent, elution of a substance in the resist film into the immersion solvent (substance elution) occurs. The elution of the substance causes phenomena such as deterioration of the resist layer and a change in the refractive index of the immersion solvent, and deteriorates the lithography characteristics. Since the amount of this substance elution is affected by the characteristics (eg, hydrophilicity / hydrophobicity) of the resist film surface, the elution of the substance can be reduced, for example, by increasing the hydrophobicity of the resist film surface.

As described above, by increasing the hydrophobicity of the resist film surface, it is considered that problems specific to the immersion lithography technique, such as reduction of elution of a substance and improvement of water followability, can be solved.
However, even if the resist film is simply made hydrophobic, adverse effects on lithography characteristics and the like are observed. For example, when the hydrophobicity of the resist film is increased, there is a problem that a defect (defect) easily occurs in the resist film after alkali development. In particular, when a pattern is formed using an alkali developing process, defects are likely to occur in an unexposed portion of the resist film.
Here, the “defect” refers to, for example, all defects detected when a developed resist pattern is observed from directly above by a surface defect observation device (trade name “KLA”) manufactured by KLA Tencor. The defects include, for example, defects such as scum (resist residue), bubbles, dusts, etc., on the resist pattern surface after development, bridges between line patterns, and hole filling of contact hole patterns. And the like regarding the pattern shape, and uneven color of the pattern.
In the resist composition described in Patent Document 1 and the like, at the time of exposure, a fluorine-containing polymer compound increases the water repellency of the resist film at the time of exposure, and at the time of development, a hydrophilic group is formed so that the hydrophilicity of the resist film is increased. The aim is to reduce defects by increasing the quality.
However, the conventional resist composition described in Patent Literature 1 has a problem that the effect of reducing defects may not be sufficiently exhibited depending on the type of developer used.
In view of the above circumstances, an object of the present invention is to provide a resist pattern forming method capable of reducing the occurrence of defects in an unexposed portion of a resist film and forming a resist pattern having a good shape.

In the formation of a resist pattern, if the hydrophobicity of the surface of the resist film is increased, there is a problem in terms of resolution, for example, the alkali developer becomes less likely to wet the resist film.
On the other hand, in order to enhance the wettability of the alkaline developer to the resist film, a method of adding a surfactant to the alkaline developer has been considered.
However, although the resolution is improved, there is a problem that a defect having a size of 0.1 μm or more tends to occur in an unexposed portion of the developed resist film.
The present inventors have studied and found that the above problems can be solved by employing an acid generator having a specific structure in a resist composition, and have completed the present invention.

  That is, one embodiment of the present invention provides a step (i) of forming a resist film on a support using a resist composition, a step (ii) of exposing the resist film, and a step of exposing the resist film after the exposure. Forming a resist pattern by developing with an alkali developer containing a nonionic surfactant, wherein the resist composition is dissolved in the alkali developer by the action of an acid. A base component (A) whose acidity changes and an acid generator component (B) that generates an acid upon exposure, wherein the acid generator component (B) is represented by the following general formula (b1-1). A resist pattern forming method containing the compound (B1) to be formed.

［式中、Ｒ_０ ^１０１は多環式脂肪族炭化水素基である。但し、多環式脂肪族炭化水素基の水素原子が置換基で置換されていてもよい。Ｒ^１０２はフッ素原子又は炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合、又は酸素原子を含む２価の連結基である。Ｖ^１０１は単結合、アルキレン基又はフッ素化アルキレン基である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[In the formula, R ₀ ¹⁰¹ is a polycyclic aliphatic hydrocarbon group. However, the hydrogen atom of the polycyclic aliphatic hydrocarbon group may be substituted with a substituent. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ]

  According to the resist pattern forming method of the present invention, it is possible to reduce the occurrence of defects in the unexposed portions of the resist film and to form a resist pattern having a good shape.

In the present specification and claims, the term "aliphatic" is a concept relative to aromatics, and is defined as meaning a group, compound, or the like having no aromaticity.
“Alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
The “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of an 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.
The “fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or an alkylene group have been substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
Be referred to as a "may have a substituent" or "may have a substituent", the case of replacing a hydrogen atom (-H) a monovalent group, a methylene group (-CH ₂ -) Is substituted with a divalent group.
“Exposure” is a concept including radiation irradiation in general.

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 ester” is a compound in which the hydrogen atom at the carboxy group end of acrylic acid (CH ₂ ＣＨCH—COOH) is substituted with an organic group.
In the acrylic ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R ^α0 ) for substituting a hydrogen atom bonded to the carbon atom at the α-position is an atom or a group other than a hydrogen atom, for example, an alkyl group having 1 to 5 carbon atoms or a halogenated group having 1 to 5 carbon atoms. And an alkyl group. Further, itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α-hydroxyacryl esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group obtained by modifying the hydroxyl group thereof are also included. Shall be included. The carbon atom at the α-position of the acrylate ester is a carbon atom to which the carbonyl group of the acrylic acid is bonded, unless otherwise specified.
Hereinafter, an acrylate in which a hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate. Further, the acrylate and the α-substituted acrylate may be collectively referred to as “(α-substituted) acrylate”.

"Structural unit derived from acrylamide" means a structural unit formed by cleavage of an ethylenic double bond of acrylamide.
In acrylamide, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and one or both of the hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. The carbon atom at the α-position of acrylamide is a carbon atom to which a carbonyl group of acrylamide is bonded, unless otherwise specified.
Examples of the substituent that replaces the hydrogen atom bonded to the carbon atom at the α-position of acrylamide include the same substituents as those described above as the substituent at the α-position (substituent (R ^α0 )) in the α-substituted acrylate ester. No.

"Structural unit derived from hydroxystyrene" means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene. The “structural unit derived from a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. These derivatives include those obtained by substituting the hydrogen atom of the hydroxyl group of hydroxystyrene with an organic group, wherein the hydrogen atom at the α-position may be substituted with a substituent; Examples thereof include those in which a substituent other than a hydroxyl group is bonded to the benzene ring of good hydroxystyrene. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded, unless otherwise specified.
Examples of the substituent that substitutes the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those described as the substituent at the α-position in the α-substituted acrylate.

“Structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative” means a structural unit formed by cleavage of an ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative.
The “vinyl benzoic acid derivative” is a concept including those in which the α-position hydrogen atom of vinyl benzoic acid is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. These derivatives include those in which the hydrogen atom of the carboxy group of vinylbenzoic acid, in which the hydrogen atom at the α-position may be substituted with a substituent, is substituted with an organic group; And those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of the vinyl benzoic acid which may be used. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded, unless otherwise specified.

The term “styrene derivative” is a concept including those in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. Examples of such derivatives include those in which a substituent is bonded to a benzene ring of hydroxystyrene, in which a hydrogen atom at the α-position may be substituted. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded, unless otherwise specified.
“Structural unit derived from styrene” and “structural unit derived from a styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, specifically, an alkyl group having 1 to 5 carbon atoms (a methyl group, an ethyl group, a propyl group, an isopropyl group). , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Examples of the halogenated alkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the above “alkyl group as a substituent at the α-position” are substituted with a halogen atom. Can be 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.
Specific examples of the hydroxyalkyl group as the substituent at the α-position include a group in which part or all of the hydrogen atoms of the above “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably from 1 to 5, and most preferably 1.

  In the present specification and claims, depending on the structure represented by the chemical formula, an asymmetric carbon may exist, and an enantiomer or a diastereoisomer may exist. In that case, these isomers are represented by one chemical formula. These isomers may be used alone or as a mixture.

[Resist pattern forming method]
One embodiment of the present invention provides a step (i) of forming a resist film on a support using a resist composition, a step (ii) of exposing the resist film, and forming the resist film after the exposure on a nonionic interface. A resist pattern forming method including a step (iii) of forming a resist pattern by developing with an alkali developing solution containing an activator. The resist composition contains a base component (A) whose solubility in an alkali developing solution is changed by the action of an acid and an acid generator component (B) which generates an acid upon exposure. The acid generator component (B) here includes a compound (B1) described later.
As one embodiment of such a method for forming a resist pattern, for example, a method for forming a resist pattern performed as follows is exemplified.

Step (i):
First, a specific resist composition described later is applied on a support with a spinner or the like, and is baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150 ° C., preferably 100 to 150 ° C. (more preferably, 100 to 150 ° C.). The resist film is formed under a temperature condition of more than 100 ° C. and 150 ° C. or less) for 40 to 120 seconds, preferably 60 to 120 seconds.

Step (ii):
Next, the resist film is selectively exposed by, for example, exposure through a mask (mask pattern) on which a predetermined pattern is formed using an exposure apparatus or the like.
Thereafter, a bake (post-exposure bake (PEB)) treatment is performed at a temperature of, for example, 80 to 150 ° C., preferably 90 to 130 ° C. for 40 to 120 seconds, preferably 60 to 100 seconds.

Step (iii):
Next, the exposed resist film is developed with an alkali developing solution containing a nonionic surfactant to form a resist pattern.

After the development processing, a rinsing processing is preferably performed. The rinsing treatment is preferably a water rinse using pure water.
After the development processing or the rinsing processing, drying is performed. In some cases, a bake treatment (post-bake) may be performed after the development processing.
Thus, a resist pattern can be formed.

The support is not particularly limited, and a conventionally known support can be used. Examples thereof include a substrate for an electronic component and a support on which a predetermined wiring pattern is formed. More specifically, a silicon wafer, a substrate made of metal such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material of the wiring pattern, for example, copper, aluminum, nickel, gold, or the like can be used.
Further, as the support, a substrate provided with an inorganic and / or organic film on the above-described substrate may be used. Examples of the inorganic film include an inorganic anti-reflection film (inorganic BARC). Examples of the organic film include an organic film such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method means that at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and a 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 having a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be ensured by the lower organic film, so that the resist film can be made thinner and a fine pattern with a high aspect ratio can be formed.
The multilayer resist method basically includes a method of forming a two-layer structure of an upper resist film and a lower organic film (a two-layer resist method), and a method of forming one or more intermediate layers between the upper resist film and the lower organic film. (Three-layer resist method) having a multilayer structure of three or more layers provided with (a metal thin film or the like).

Wavelength used for the exposure is not particularly limited, ArF excimer laser, KrF excimer laser, _{F 2} excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays It can be performed using radiation.

The method of exposing the resist film may be ordinary exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion exposure (Liquid Immersion Lithography).
In the immersion exposure, the space between the resist film and the lowermost lens of the exposure apparatus is filled in advance with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state. Exposure method.
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 to be exposed is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Liquids and the like are mentioned, 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.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all of the 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, the perfluoroalkyl ether compound includes perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.), and the perfluoroalkylamine compound includes perfluorotributylamine ( (Boiling point: 174 ° C.).
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility and the like.

In the step (iii), an alkali developer containing a nonionic surfactant is used as a developer. For example, examples of the developer include a 0.1 to 10% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) containing a nonionic surfactant.
Further, as the nonionic surfactant contained in the alkali developer, a known nonionic surfactant can be blended. Specifically, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether Sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, and other sorbitan fatty acid esters; and polyoxyethylene sorbitan Monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate DOO, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan tristearate; acetylene glycol, acetylene such as oxyethylene adducts of acetylene glycol, and the like.

  The blending amount of the nonionic surfactant is usually preferably from 0.001 to 5% by mass, more preferably from 0.005 to 2% by mass, and further preferably from 0.01 to 0.5% by mass, based on the total amount of the developer. preferable.

  The development processing can be carried out by a known development method, for example, a method of dipping a support in a developer for a certain time (dip method), a method in which the developer is raised on the surface of the support by surface tension, and then stopped for a certain time. Method (paddle method), method of spraying a developer on the surface of a support (spray method), application of developer while scanning a developer application nozzle at a constant speed on a support rotating at a constant speed Continued method (dynamic dispensing method) and the like.

  The rinsing treatment (rinsing treatment) using the rinsing liquid can be performed by a known rinsing method. Examples of the rinsing method include a method of continuously applying a rinsing liquid onto a support rotating at a constant speed (rotation coating method), a method of dipping the support in the rinsing liquid for a fixed time (dipping method), A method of spraying a rinsing liquid on the surface of the support (spraying method) is exemplified.

(Resist composition)
In the above-described resist pattern forming method of the present embodiment, a specific resist composition is used in the step (i).

The resist composition according to the present embodiment includes a base component (A) whose solubility in an alkali developing solution is changed by the action of an acid (hereinafter also referred to as a “(A) component”), and an acid generator that generates an acid upon exposure. Component (B) (hereinafter also referred to as “component (B)”), wherein the component (B) is a compound (B1) represented by the following general formula (b1-1) (hereinafter referred to as “component (B1) ").
When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated in an exposed portion, and the action of the acid causes the solubility of the component (A) in an alkali developing solution. On the other hand, since the solubility of the component (A) in the alkali developing solution does not change in the unexposed portion, there is a difference in the solubility in the developing solution between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, a resist pattern is formed.

For example, when a base component (A-1) which is hardly soluble in an alkali developer and whose polarity is increased by the action of an acid (hereinafter, referred to as “component (A-1)”) is used as the component (A), When an acid is generated by exposure, the exposed part of the resist film changes from poorly soluble to soluble in an alkali developing solution, while the unexposed part of the resist film does not change while being hardly soluble in alkali. As a result, a positive resist pattern is formed.
On the other hand, when the base component (A-2) (hereinafter also referred to as “component (A-2)”) soluble in an alkali developer is used as the component (A), and a crosslinking agent component is further added. When an acid is generated by exposure to light, the acid acts to cause cross-linking between the component (A-2) and the cross-linking agent component. As a result, the solubility in an alkali developing solution decreases. As a result, the exposed portion of the resist film turns to be slightly soluble in the alkali developing solution, while the unexposed portion of the resist film remains soluble in the alkali developing solution. A pattern is formed.

The resist composition has an acid generating ability to generate an acid upon exposure, and in addition to the component (B), the component (A) may generate an acid upon exposure.
When the component (A) generates an acid upon exposure, the component (A) is a “base component that generates an acid upon exposure and changes the solubility in a developer by the action of an acid”.
When the component (A) generates an acid upon exposure and is a base component whose solubility in a developer changes due to the action of the acid, the component (A1) described later generates an acid upon exposure, and It is preferable to use a polymer compound whose solubility in a developing solution is changed by the action of an acid. Examples of such a polymer compound include a resin having a structural unit that generates an acid upon exposure. Known monomers can be used as the monomer for deriving the structural unit that generates an acid upon exposure.

<(A) component>
The component (A) of the resist composition in the present embodiment is a base component whose solubility in a developer changes due to the action of an acid.
In the present invention, the “base component” is an organic compound having a film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved, and in addition, a nano-level resist pattern is easily formed.
Organic compounds used as the base component are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, a “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1,000 or more are usually used. Hereinafter, “resin”, “polymer compound” or “polymer” refers to a polymer having a molecular weight of 1,000 or more.
As the molecular weight of the polymer, a weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) is used.

As described above, when the resist composition according to the present embodiment is a “negative resist composition for an alkali development process” that forms a negative resist pattern in an alkali development process, the component (A-2) and the crosslinking agent component are used as described above. Is used.
As the preferable component (A-2), a resin soluble in an alkali developing solution (hereinafter referred to as "alkali-soluble resin") is used.
Examples of the alkali-soluble resin include α- (hydroxyalkyl) acrylic acid or an alkyl ester of α- (hydroxyalkyl) acrylic acid (preferably having 1 to 5 carbon atoms) disclosed in JP-A-2000-206694. A resin having a constitutional unit derived from at least one selected from alkyl esters); a hydrogen atom bonded to a carbon atom at the α-position having a sulfonamide group, which is disclosed in US Pat. No. 6,949,325, is substituted with a substituent. Acrylic resin or polycycloolefin resin which may be used; US Pat. No. 6,949,325, JP-A-2005-336452, JP-A-2006-317803, contains a fluorinated alcohol, and has an α-position. A hydrogen atom bonded to a carbon atom may be substituted with a substituent Acrylic resin; disclosed in Japanese 2006-259582 discloses, polycycloolefin resins having fluorinated alcohol is preferred because it can form a resist pattern with minimal swelling.
The α- (hydroxyalkyl) acrylic acid is one of acrylic acids in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. One or both of acrylic acid having an atom bonded thereto and α-hydroxyalkyl acrylic acid having a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) bonded to the carbon atom at the α-position .
As the cross-linking agent component, for example, it is preferable to use an amino-based cross-linking agent such as glycoluril having a methylol group or an alkoxymethyl group, or a melamine-based cross-linking agent because a good resist pattern with little swelling is easily formed. . The compounding amount of the crosslinking agent component is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

When the resist composition in the present embodiment is a “positive resist composition for an alkali development process” that forms a positive resist pattern in an alkali development process, the component (A-1) is used as described above.
As the component (A), the component (A-1) is preferably used.

As the component (A) of the resist composition in the present embodiment, one type may be used alone, or two or more types may be used in combination.
When the component (A) is the component (A-1), the component (A-1) preferably includes a resin component (A1) (hereinafter, also referred to as “component (A1)”).

-About the component (A1) The component (A1) is a resin component, and preferably contains a polymer compound having a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid.
As the component (A1), a component having a structural unit (a2) including a lactone-containing cyclic group, a —SO ₂ —-containing cyclic group, or a carbonate-containing cyclic group in addition to the structural unit (a1) is also preferable. .
As the component (A1), in addition to the structural unit (a1), a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (provided that the structural unit (a1) or the structural unit (a2) Are also preferred.
The component (A1) may have a structural unit other than the structural unit (a1), the structural unit (a2), and the structural unit (a3).

{Structural unit (a1)}
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
An “acid-decomposable group” is an acid-decomposable group capable of cleaving at least a part of the bond of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity is increased by the action of an acid include a group which is decomposed by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H) and the like. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar group") is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

Here, the “acid dissociable group” refers to (i) a group having an acid dissociable property in which a bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid; Or (ii) after a partial bond is cleaved by the action of an acid, a further decarboxylation reaction occurs, whereby the bond between the acid dissociable group and an atom adjacent to the acid dissociable group is cleaved. Group to be obtained.
The acid-dissociable group that constitutes the acid-decomposable group needs to be a group having a polarity lower than that of a polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a higher polarity than the acid-dissociable group is generated, and the polarity increases. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer relatively changes. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility increases. Decrease.

Examples of the acid dissociable group include those that have been proposed as an acid dissociable group of a base resin for a chemically amplified resist composition.
Specific examples of the acid-dissociable group of the base resin for the chemically amplified resist composition include “acetal-type acid-dissociable groups” and “tertiary alkyl ester-type acid-dissociable groups” described below. Groups "and" tertiary alkyloxycarbonyl acid dissociable groups ".

Acetal-type acid dissociable group:
Among the polar groups, examples of the acid dissociable group that protects a carboxy group or a hydroxyl group include, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as an “acetal-type acid dissociable group”). In some cases).

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基である。Ｒａ’^３は炭化水素基であって、Ｒａ’^３は、Ｒａ’^１、Ｒａ’^２のいずれかと結合して環を形成してもよい。］

[In the formula, Ra ′ ¹ and Ra ′ ² are a hydrogen atom or an alkyl group. Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ may be bonded to any of Ra ′ ¹ and Ra ′ ² to form a ring. ]

In formula (a1-r-1), at least one of Ra ′ ¹ and Ra ′ ² is preferably a hydrogen atom, and more preferably both are hydrogen atoms.
When Ra ′ ¹ or Ra ′ ² is an alkyl group, examples of the alkyl group include the alkyl groups mentioned as the substituents that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate. The same is mentioned, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferably exemplified. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like are exemplified. More preferred is a methyl group.

In formula (a1-r-1), examples of the hydrocarbon group of Ra ′ ³ include a linear or branched alkyl group and a cyclic hydrocarbon group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably has 1 to 4 carbon atoms, and still more preferably has 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

  The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferable.

When Ra ′ ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms. Include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When the cyclic hydrocarbon group of Ra ′ ³ is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.
Specific examples of the aromatic ring include an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. No. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.
Specific examples of the aromatic hydrocarbon group for Ra ′ ³ include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or the aromatic heterocyclic ring (aryl group or heteroaryl group); A group in which one hydrogen atom has been removed from an aromatic compound (eg, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms in the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (eg, a benzyl group) Phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom. preferable.

The cyclic hydrocarbon group for Ra ′ ³ may have a substituent. Examples of the substituent group, ^{e.g., -R P1, -R P2 -O-} R P1, -R P2 -CO-R P1, -R P2 -CO-OR P1, -R P2 -O-CO-R P1, -R ^{P2 -OH,} (collectively hereinafter these substituents also referred to as ^{"Ra 05".) -R} P2 -CN or ^-R P2 -COOH and the like.
Here, ^RP1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic having 6 to 30 carbon atoms. Is a group hydrocarbon group. ^RP2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent chain having 6 to 30 carbon atoms. Is an aromatic hydrocarbon group. However, part or all of the hydrogen atoms of the chain saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group and the aromatic hydrocarbon group of R ^P1 and R ^P2 may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the above-described substituents alone, or may have one or more of the above-described substituents.
Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. .
Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group. Monocyclic aliphatic saturated hydrocarbon group; bicyclo [2.2.2] octanyl group, tricyclo [5.2.1.02,6] decanyl group, tricyclo [3.3.1.13,7] decanyl group And polycycloaliphatic saturated hydrocarbon groups such as tetracyclo [6.2.1.13, 6.02,7] dodecanyl group and adamantyl group.
Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

When Ra ′ ³ is bonded to any of Ra ′ ¹ and Ra ′ ² to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

Tertiary alkyl ester type acid dissociable group:
Among the polar groups, examples of the acid dissociable group that protects the carboxy group include an acid dissociable group represented by the following general formula (a1-r-2).
In addition, what is comprised by an alkyl group among the acid dissociable groups represented by the following formula (a1-r-2) may be hereinafter referred to as a "tertiary alkyl ester type acid dissociable group" for convenience. .

［式中、Ｒａ’^４〜Ｒａ’^６はそれぞれ炭化水素基であって、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。］

[In the formula, Ra ′ ^{4 to} Ra ′ ⁶ each represent a hydrocarbon group, and Ra ′ ⁵ and Ra ′ ⁶ may combine with each other to form a ring. ]

Examples of the hydrocarbon group of Ra ′ ⁴ include a linear or branched alkyl group, a chain or cyclic alkenyl group, and a cyclic hydrocarbon group.
Linear or branched alkyl group in ra ^'4, cyclic hydrocarbon group (monocyclic aliphatic hydrocarbon group is a group, a polycyclic aliphatic hydrocarbon group is a group, aromatic hydrocarbon group ) Is the same as Ra ′ ³ above.
The chain or cyclic alkenyl group in Ra ′ ⁴ is preferably an alkenyl group having 2 to 10 carbon atoms.
Examples of the hydrocarbon group of Ra ′ ⁵ and Ra ′ ⁶ include the same as those of the above-mentioned Ra ′ ³ .

When Ra ′ ⁵ and Ra ′ ⁶ are bonded to each other to form a ring, a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2) And a group represented by the following general formula (a1-r2-3).
On the other hand, when Ra ′ ^{4 to} Ra ′ ⁶ are not bonded to each other and are independent hydrocarbon groups, a group represented by the following general formula (a1-r2-4) is preferably exemplified.

［式（ａ１−ｒ２−１）中、Ｒａ’^１０は、炭素数１〜１０のアルキル基、又は下記一般式（ａ１−ｒ２−ｒ１）で表される基を示す。Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基を示す。式（ａ１−ｒ２−２）中、Ｙａは炭素原子である。Ｘａは、Ｙａと共に環状の炭化水素基を形成する基である。この環状の炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ^０１〜Ｒａ^０３は、それぞれ独立して、水素原子、炭素数１〜１０の１価の鎖状飽和炭化水素基又は炭素数３〜２０の１価の脂肪族環状飽和炭化水素基である。この鎖状飽和炭化水素基及び脂肪族環状飽和炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ^０１〜Ｒａ^０３の２つ以上が互いに結合して環状構造を形成していてもよい。式（ａ１−ｒ２−３）中、Ｙａａは炭素原子である。Ｘａａは、Ｙａａと共に脂肪族環式基を形成する基である。Ｒａ^０４は、置換基を有していてもよい芳香族炭化水素基である。式（ａ１−ｒ２−４）中、Ｒａ’^１２及びＲａ’^１３は、それぞれ独立に、炭素数１〜１０の１価の鎖状飽和炭化水素基又は水素原子である。この鎖状飽和炭化水素基が有する水素原子の一部又は全部は置換されていてもよい。Ｒａ’^１４は、置換基を有していてもよい炭化水素基である。＊は結合手を示す（以下同じ）。］

[In the formula (a1-r2-1), Ra ′ ¹⁰ represents an alkyl group having 1 to 10 carbon atoms or a group represented by the following general formula (a1-r2-r1). Ra ′ ¹¹ represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ra ′ ¹⁰ is bonded. In the formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group with Ya. Some or all of the hydrogen atoms of the cyclic hydrocarbon group may be substituted. Ra ^{01 to} Ra ⁰³ are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms contained in the chain saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra ^{01 to} Ra ⁰³ may be bonded to each other to form a cyclic structure. In the formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra ⁰⁴ is an aromatic hydrocarbon group which may have a substituent. In the formula (a1-r2-4), Ra ′ ¹² and Ra ′ ¹³ are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms of the chain saturated hydrocarbon group may be substituted. Ra ′ ¹⁴ is a hydrocarbon group which may have a substituent. * Indicates a bond (the same applies hereinafter). ]

［式中、Ｙａ^０は、第４級炭素原子である。Ｒａ^０３１、Ｒａ^０３２及びＲａ^０３３は、それぞれ独立に、置換基を有していてもよい炭化水素基である。但し、Ｒａ^０３１、Ｒａ^０３２及びＲａ^０３３のうちの１つ以上は、少なくとも一つの極性基を有する炭化水素基である。］

[Wherein, Ya ⁰ is a quaternary carbon atom. Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group which may have a substituent. However, at least one of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least one polar group. ]

In the above formula (a1-r2-1), the alkyl group having 1 to ¹⁰ carbon atoms of Ra ′ ¹⁰ is a straight-chain or branched alkyl group of Ra ′ ³ in formula (a1-r-1). The groups mentioned are preferred. Ra ′ ¹⁰ is preferably an alkyl group having 1 to 5 carbon atoms.

In the formula (a1-r2-r1), Ya ⁰ is a quaternary carbon atom. That is, there are four adjacent carbon atoms bonded to Ya ⁰ (carbon atoms).

In the formula (a1-r2-r1), Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ each independently include a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group.

The linear alkyl group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
In Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ , the branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferable.
The chain or cyclic alkenyl group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is preferably an alkenyl group having 2 to 10 carbon atoms.

The cyclic hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms. Include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. No. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or the aromatic heterocycle (aryl group or heteroaryl group); an aromatic group containing two or more aromatic rings. A group in which one hydrogen atom has been removed from a compound (eg, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms in the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (eg, a benzyl group, a phenethyl group) , 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or the aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 or 2, and particularly preferably 1.

When the hydrocarbon groups represented by Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are substituted, examples of the substituent include a hydroxy group, a carboxy group, and a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.). ), An alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group), and an alkyloxycarbonyl group.

Among the above, the hydrocarbon group which may have a substituent in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is preferably a linear or branched alkyl group which may have a substituent, Linear alkyl groups are more preferred.

However, at least one of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least a polar group.
The “hydrocarbon group having a polar group” refers to a group in which a methylene group (—CH ₂ —) constituting a hydrocarbon group is substituted with a polar group, or at least one hydrogen atom constituting a hydrocarbon group is substituted. Any of those substituted with a polar group is included.
As the “hydrocarbon group having a polar group”, a functional group represented by the following general formula (a1-p1) is preferable.

［式中、Ｒａ^０７は、炭素数２〜１２の２価の炭化水素基を表す。Ｒａ^０８は、ヘテロ原子を含む２価の連結基を表す。Ｒａ^０６は、炭素数１〜１２の１価の炭化水素基を表す。ｎ_ｐ０は、１〜６の整数である。］

[In the formula, Ra ⁰⁷ represents a divalent hydrocarbon group having 2 to 12 carbon atoms. Ra ⁰⁸ represents a divalent linking group containing a hetero atom. Ra ⁰⁶ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. n _p0 is an integer of 1 to 6. ]

In the formula (a1-p1), Ra ⁰⁷ represents a divalent hydrocarbon group having 2 to 12 carbon atoms.
The number of carbon atoms of ra ⁰⁷ is 2 to 12, 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, 2 carbon atoms being particularly preferred.
The hydrocarbon group in Ra ⁰⁷ is preferably a chain or cyclic aliphatic hydrocarbon group, and more preferably a chain hydrocarbon group.
Ra ⁰⁷ includes, for example, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1, 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc. Linear alkanediyl group; propane-1,2-diyl group, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, pentane-1,4-diyl group, 2 Branched alkanediyl groups such as -methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1 , 5-di A cycloalkanediyl group such as an yl group; a polycyclic group such as a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, and an adamantane-2,6-diyl group. And a divalent alicyclic hydrocarbon group.
Among the above, an alkanediyl group is preferred, and a linear alkanediyl group is more preferred.

In the formula (a1-p1), Ra ⁰⁸ represents a divalent linking group containing a hetero atom.
Examples of Ra ⁰⁸ include -O-, -C (= O) -O-, -C (= O)-, -OC (= O) -O-, and -C (= O) -NH-. , -NH-, -NH-C (= 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- and the like.
Among these, -O-, -C (= O) -O-, -C (= O)-, -OC (= O) -O- are preferable from the viewpoint of solubility in a developer, and- O- and -C (= O)-are particularly preferred.

In the formula (a1-p1), Ra ⁰⁶ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms.
Ra ⁰⁶ has 1 to 12 carbon atoms, and preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, further preferably 1 to 3 carbon atoms, and more preferably 1 to 12 carbon atoms from the viewpoint of solubility in a developer. 1 or 2 is particularly preferred, and 1 is most preferred.

Examples of the hydrocarbon group in Ra ⁰⁶ include a chain hydrocarbon group or a cyclic hydrocarbon group, or a hydrocarbon group combining a chain and a ring.
Examples of the chain hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, and a -Heptyl group, 2-ethylhexyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group and the like.

The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and methyl. And cycloalkyl groups such as a cyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, and norbornyl. Group, methylnorbornyl group, isobornyl group and the like.
Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, and a mesityl group. , A biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, and the like.

Ra ⁰⁶ is preferably a chain hydrocarbon group, more preferably an alkyl group, and even more preferably a straight chain alkyl group, from the viewpoint of solubility in a developing solution.

In the formula (a1-p1), n _p0 is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, and still more preferably 1.

Specific examples of the hydrocarbon group having at least a polar group are shown below.
In the following formulas, * is a bond bonded to a quaternary carbon atom (Ya ⁰ ).

In the formula (a1-r2-r1), among Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ , the number of at least one hydrocarbon group having a polar group is one or more. ^May be appropriately determined in consideration of the solubility of the compound, for example, it is preferably one or two of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ , and particularly preferably one.

  The hydrocarbon group having at least a polar group may have a substituent other than the polar group. Examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom and the like) and a halogenated alkyl group having 1 to 5 carbon atoms.

In the formula (a1-r2-1), Ra ′ ¹¹ (the aliphatic cyclic group formed together with the carbon atom to which Ra ′ ¹⁰ is bonded) is a monocyclic group of Ra ′ ³ in the formula (a1-r-1) Alternatively, the groups exemplified as the aliphatic hydrocarbon group which is a polycyclic group are preferable.

In the formula (a1-r2-2), examples of the cyclic hydrocarbon group formed by Xa with Ya include a cyclic monovalent hydrocarbon group (aliphatic) in Ra ′ ³ in the formula (a1-r-1). (Hydrocarbon group) from which one or more hydrogen atoms have been further removed.
The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the same substituents as those that the cyclic hydrocarbon group of Ra ′ ³ may have.
In the formula (a1-r2-2), examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ^{01 to} Ra ⁰³ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Group, hexyl group, heptyl group, octyl group, decyl group and the like.
Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in Ra ^{01 to} Ra ⁰³ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl. Monocyclic aliphatic saturated hydrocarbon groups such as a cycloalkyl group and a cyclododecyl group; bicyclo [2.2.2] octanyl group, tricyclo [5.2.1.02,6] decanyl group, tricyclo [3.3.1] .13,7] decanyl group, tetracyclo [6.2.1.13, 6.02,7] dodecanyl group, adamantyl group and other polycyclic aliphatic saturated hydrocarbon groups.
Among them, Ra ^{01 to} Ra ⁰³ are preferably a hydrogen atom and a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, from the viewpoint of ease of synthesis of a monomer compound for deriving the structural unit (a1). Among them, a hydrogen atom, a methyl group and an ethyl group are more preferred, and a hydrogen atom is particularly preferred.

Examples of the substituent of the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by Ra ^{01 to} Ra ⁰³ include the same groups as those of Ra ⁰⁵ described above.

Examples of the group containing a carbon-carbon double bond generated by bonding two or more of Ra ^{01 to} Ra ⁰³ to each other to form a cyclic structure include, for example, a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, and methyl A cyclohexenyl group, a cyclopentylideneethenyl group, a cyclohexylideneethenyl group and the like. Among these, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferable from the viewpoint of easy synthesis of a monomer compound for deriving the structural unit (a1).

In the formula (a1-r2-3), the aliphatic cyclic group formed by Xaa with Yaa is an aliphatic hydrocarbon group represented by the monocyclic group or the polycyclic group of Ra ′ ³ in the formula (a1-r-1). The groups mentioned as the hydrogen group are preferred.
In formula (a1-r2-3), examples of the aromatic hydrocarbon group for Ra ⁰⁴ include groups in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra ⁰⁴ is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, and more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene. A group in which one or more hydrogen atoms have been removed from benzene, naphthalene or anthracene is more preferred, a group in which one or more hydrogen atoms have been removed from benzene or naphthalene is particularly preferred, and a group in which one or more hydrogen atoms have been removed from benzene is the most preferred. preferable.

Examples of the substituent which Ra ^{04 in} formula (a1-r2-3) may have include a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, Bromine atom), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and the like), an alkyloxycarbonyl group, and the like.

In the formula (a1-r2-4), Ra ′ ¹² and Ra ′ ¹³ are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. The monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ′ ¹² and Ra ′ ^{13 includes} the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ⁰¹ to Ra ⁰³ described above. Examples are the same as the groups. Some or all of the hydrogen atoms of the chain saturated hydrocarbon group may be substituted.
Among Ra ′ ¹² and Ra ′ ¹³ , among them, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group and an ethyl group are further preferable, and a methyl group is particularly preferable. preferable.
When the chain saturated hydrocarbon groups represented by Ra ′ ¹² and Ra ′ ¹³ are substituted, examples of the substituent include the same groups as in Ra ⁰⁵ described above.

In the formula (a1-r2-4), Ra ′ ¹⁴ is a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group for Ra ′ ¹⁴ include a linear or branched alkyl group and a cyclic hydrocarbon group.

The linear alkyl group for Ra ′ ¹⁴ preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

The branched alkyl group in Ra ′ ¹⁴ preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and an isopropyl group is preferable.

When Ra ′ ¹⁴ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms. Include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

Examples of the aromatic hydrocarbon group for Ra ′ ¹⁴ include the same as the aromatic hydrocarbon group for Ra ⁰⁴ . Above all, Ra ′ ¹⁴ is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, and more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene. Preferably, a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene is more preferable, a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene is particularly preferable, and a group obtained by removing one or more hydrogen atoms from naphthalene is preferable. Most preferred.
Examples of the substituent that Ra ′ ¹⁴ may have include the same substituents that Ra ⁰⁴ may have.

When Ra ′ ^{14 in the} formula (a1-r2-4) is a naphthyl group, the position bonding to the tertiary carbon atom in the formula (a1-r2-4) is 1- or 2-position of the naphthyl group. Either one may be used.
When Ra ′ ^{14 in the} formula (a1-r2-4) is an anthryl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be the first, second, or the anthryl group. Any of the ninth position may be used.

  Specific examples of the group represented by the formula (a1-r2-1) are shown below.

  Specific examples of the group represented by the formula (a1-r2-2) are shown below.

  Specific examples of the group represented by the formula (a1-r2-3) are shown below.

  Specific examples of the group represented by the formula (a1-r2-4) are shown below.

Tertiary alkyloxycarbonyl acid dissociable group:
Among the polar groups, examples of the acid dissociable group that protects a hydroxyl group include, for example, an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as a “tertiary alkyloxycarbonyl acid dissociable group for convenience”). ").

［式中、Ｒａ’^７〜Ｒａ’^９はそれぞれアルキル基である。］

[In the formula, Ra ′ ^{7 to} Ra ′ ⁹ each represent an alkyl group. ]

In the formula (a1-r-3), Ra ′ ^{7 to} Ra ′ ⁹ are each preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.
Further, the total carbon number of each alkyl group is preferably 3 to 7, more preferably 3 to 5 carbon atoms, and most preferably 3 to 4 carbon atoms.

  As the structural unit (a1), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, a structural unit derived from acrylamide, hydroxystyrene or hydroxystyrene At least a part of the hydrogen atom in the hydroxyl group of the structural unit derived from the styrene derivative is protected by a substituent containing the acid-decomposable group, the structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative- Examples include a structural unit in which at least a part of a hydrogen atom in C (） O) —OH is protected by a substituent containing the acid-decomposable group.

As the structural unit (a1), among the above, a structural unit derived from an acrylate ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferable.
Preferred specific examples of the structural unit (a1) include a structural unit represented by the following general formula (a1-1) or (a1-2).

［式中、Ｒは、水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１は、エーテル結合を有していてもよい２価の炭化水素基である。ｎ_ａ１は、０〜２の整数である。Ｒａ^１は、上記の一般式（ａ１−ｒ−１）又は（ａ１−ｒ−２）で表される酸解離性基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１〜３の整数であり、Ｒａ^２は上記の一般式（ａ１−ｒ−１）又は（ａ１−ｒ−３）で表される酸解離性基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group which may have an ether bond. _na1 is an integer of 0-2. Ra ¹ is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). Wa ¹ is a _n a2 +1 monovalent hydrocarbon _{group, n a2} is an integer from 1 to 3, Ra ² is represented by the above general formula (a1-r-1) or (a1-r-3) Acid dissociable group. ]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group or an ethyl group. Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the aforementioned alkyl group having 1 to 5 carbon atoms have been 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.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group in terms of industrial availability.

In the formula (a1-1), the divalent hydrocarbon group for Va ¹ may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group as a divalent hydrocarbon group in Va ¹ 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 and an aliphatic hydrocarbon group having a ring in the structure.

The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
As the linear aliphatic hydrocarbon group, preferably a linear alkylene group, and specific examples include a methylene group _[-CH 2 -], an ethylene group _{[- (CH 2) 2 -} ], trimethylene [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) and a linear or branched alicyclic hydrocarbon group. Examples thereof include a group bonded to the terminal of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group as a divalent hydrocarbon group in Va ¹ is a hydrocarbon group having an aromatic ring.
Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. . However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and a part of the carbon atoms constituting the aromatic hydrocarbon ring is heterocyclic. Examples include an aromatic heterocycle substituted with an atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (aryl group) ) Is a group in which one of the hydrogen atoms is replaced by an alkylene group (for example, arylalkyl such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group and 2-naphthylethyl group) A group in which one hydrogen atom has been further removed from the aryl group in the group). The carbon number of the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the formula (a1-1), Ra ¹ is an acid dissociable group represented by the formula (a1-r-1) or (a1-r-2).

In the formula (a1-2), n _{a2 +1} monovalent hydrocarbon group for Wa ¹ may be an aliphatic hydrocarbon group may be an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. As the aliphatic hydrocarbon group, a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group Examples thereof include a group obtained by combining with an aliphatic hydrocarbon group containing a ring in the structure.
The _na2 + 1 valence is preferably 2-4, more preferably 2 or 3.

In the formula (a1-2), Ra ² is an acid dissociable group represented by the general formula (a1-r-1) or (a1-r-3).

Specific examples of the structural unit represented by the formula (a1-1) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  Specific examples of the structural unit represented by the formula (a1-2) are shown below.

The structural unit (a1) contained in the component (A1) may be one type, or two or more types.
As the structural unit (a1), a structural unit represented by the formula (a1-1) is more preferable.
Among them, the structural unit (a1) particularly preferably includes a structural unit represented by the following general formula (a1-1-1).

［式中、Ｒａ^１”は、一般式（ａ１−ｒ２−１）で表される酸解離性基である。］

[In the formula, Ra ¹ ″ is an acid dissociable group represented by the general formula (a1-r2-1).]

In the formula (a1-1-1), R, Va ¹ and _{n a1} is, R in the formula (a1-1), the same as Va ¹ and _{n a1.}
The description of the acid dissociable group represented by the general formula (a1-r2-1) is as described above.

The proportion of the structural unit (a1) in the component (A1) is preferably from 5 to 80 mol%, more preferably from 10 to 75 mol%, based on the total (100 mol%) of all the structural units constituting the component (A1). More preferably, 20 to 60 mol% is further preferable.
By setting the ratio of the structural unit (a1) to be equal to or more than the lower limit of the preferable range, lithography characteristics such as sensitivity, resolution, and roughness are improved. On the other hand, when the content is not more than the upper limit of the above preferable range, balance with other constituent units can be obtained, and various lithography characteristics are improved.

{Structural unit (a2)}
The component (A1) includes, in addition to the structural unit (a1), a structural unit (a2) containing a lactone-containing cyclic group, a —SO ₂ —-containing cyclic group, or a carbonate-containing cyclic group (provided that the structural unit ( a1) are preferred.
Lactone-containing cyclic group of the structural unit (a2), -SO 2 _- containing cyclic group or a carbonate-containing cyclic group, when used for forming a resist film (A1) component, the adhesion of the resist film and the substrate It is effective in enhancing the performance. Further, by having the structural unit (a2), for example, the acid diffusion length is appropriately adjusted, the adhesion of the resist film to the substrate is increased, the solubility during development is appropriately adjusted, the etching resistance is improved, and the like. The effects described above improve the lithography characteristics and the like.

“Lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —OC (＝ O) — in the ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is used, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone-containing cyclic group in the structural unit (a2) is not particularly limited, and any one can be used. Specific examples include groups represented by the following general formulas (a2-r-1) to (a2-r-7).

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基であり；Ａ”は酸素原子（−Ｏ−）もしくは硫黄原子（−Ｓ−）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り、ｎ’は０〜２の整数であり、ｍ’は０または１である。］

[Wherein, Ra ′ ²¹ is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (＝ O) R ″, a hydroxyalkyl group or a cyano group. There; R "represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 _- be-containing cyclic group; A" represents an oxygen atom (-O-) or a sulfur atom (- It is an alkylene group having 1 to 5 carbon atoms, which may contain S-), an oxygen atom or a sulfur atom, n 'is an integer of 0 to 2, and m' is 0 or 1. ]

In the general formulas (a2-r-1) to (a2-r-7), the alkyl group for Ra ′ ²¹ is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group in Ra ′ ²¹ is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned as the alkyl group in Ra ′ ²¹ and an oxygen atom (—O—) are linked to each other is exemplified.
Examples of the halogen atom in Ra ′ ²¹ 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 for ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In —COOR ″ and —OC (＝ O) R ″ in Ra ′ ²¹ , R ″ is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO ₂ —containing cyclic group. It is.
The alkyl group for R "may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
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 have been removed from a monocycloalkane which may or may not be substituted with a fluorinated alkyl group; polycycloalkanes such as bicycloalkane, tricycloalkane and tetracycloalkane A group obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; more specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane and cyclohexane; Groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as cyclodecane and tetracyclododecane; That.
Examples of the lactone-containing cyclic group for R ″ include the same groups as the groups represented by formulas (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group for R ″ is the same as the carbonate-containing cyclic group described below, and specifically includes groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. Is mentioned.
The containing cyclic group, -SO ₂ below - - -SO ₂ in R "are the same as containing cyclic group, specifically the general formula (a5-r-1) ~ (a5-r-4) And the groups represented by
The hydroxyalkyl group in Ra ′ ²¹ preferably has 1 to 6 carbon atoms, and specifically includes a group in which at least one hydrogen atom of the alkyl group in Ra ′ ²¹ has been substituted with a hydroxyl group. .

In the general formulas (a2-r-2), (a2-r-3) and (a2-r-5), as the alkylene group having 1 to 5 carbon atoms in A ″, a linear or branched alkylene group may be used. An alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a terminal of the alkylene group or a carbon atom. between atoms -O- or -S- can be mentioned a group intervening, for example, _{-O-CH 2 -, - CH} 2 -O-CH 2 -, - S-CH 2 -, - CH 2 -S-CH ₂ - such as .A "which include, an alkylene group or -O- is preferable of 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

  Specific examples of the groups represented by formulas (a2-r-1) to (a2-r-7) are shown below.

And _- "-SO 2 containing cyclic group", -SO 2 _- within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO 2 _- sulfur atom (S) is in A cyclic group that forms part of the cyclic skeleton of the cyclic group. The ring containing -SO _{2-in the} ring skeleton is counted as the first ring, and if the ring alone is a monocyclic group, and if it has another ring structure, it is a polycyclic group regardless of the structure. Called. The —SO ₂ —-containing cyclic group may be a monocyclic group or a polycyclic group.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed.
More specifically, examples of the —SO ₂ —-containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基であり；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り、ｎ’は０〜２の整数である。］

[Wherein, Ra ′ ⁵¹ is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (＝ O) R ″, a hydroxyalkyl group or a cyano group. There; R "represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 _- be-containing cyclic group; a" good carbon may contain an oxygen atom or a sulfur atom It is an alkylene group of the formulas 1 to 5, an oxygen atom or a sulfur atom, and n 'is an integer of 0 to 2. ]

In the general formulas (a5-r-1) to (a5-r-2), A ″ represents the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). It is the same as A ″ in FIG.
Alkyl group in ra ^'51, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR ", - OC (= O) R", The hydroxyalkyl group, each of the general formulas (a2-r-1) ~ ( The same as those described in the description of Ra ′ ^{21 in} a2-r-7) can be given.
Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are shown below. “Ac” in the formula represents an acetyl group.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —OC (＝ O) —O— in its ring skeleton. The carbonate ring is counted as the first ring, and a carbonate ring alone is referred to as a monocyclic group, and a compound having another ring structure is referred to as a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
As the carbonate ring-containing cyclic group, any one can be used without particular limitation. Specific examples include groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子、アルキル基、ラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基であり；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り、ｐ’は０〜３の整数であり、ｑ’は０または１である。］

^Wherein Ra ′ ^x31 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (＝ O) R ″, a hydroxyalkyl group or a cyano group. There; R "represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 _- be-containing cyclic group; a" good carbon may contain an oxygen atom or a sulfur atom It is an alkylene group of the formulas 1 to 5, an oxygen atom or a sulfur atom, p 'is an integer of 0 to 3, and q' is 0 or 1. ]

In the general formulas (ax3-r-2) to (ax3-r-3), A ″ represents the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). It is the same as A ″ in FIG.
Alkyl group in ra ^'31, an alkoxy group, a halogen atom, a halogenated alkyl group, -COOR ", - OC (= O) R", The hydroxyalkyl group, each of the general formulas (a2-r-1) ~ ( The same as those described in the description of Ra ′ ^{21 in} a2-r-7) can be given.
Specific examples of the groups represented by formulas (ax3-r-1) to (ax3-r-3) are shown below.

As the structural unit (a2), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferable.
Such a structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｙａ^２１は単結合または２価の連結基である。Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が−Ｏ−の場合、Ｙａ^２１は−ＣＯ−にはならない。Ｒａ^２１はラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ²¹ is a single bond or a divalent linking group. La ²¹ is -O-, -COO-, -CON (R ')-, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La ²¹ is -O-, Ya ²¹ does not become -CO-. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO ₂ -containing cyclic group. ]

  In the formula (a2-1), R is the same as described above. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly preferable in terms of industrial availability.

In the formula (a2-1), the divalent linking group of Ya ²¹ is not particularly limited, but may be a divalent hydrocarbon group which may have a substituent, or a divalent linking group containing a hetero atom. And the like. The description of the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom in Ya ²¹ is the same as the substitution in Ya ^x1 in the general formula (a10-1). This is the same as the description of the divalent hydrocarbon group which may have a group and the divalent linking group containing a hetero atom.
Ya ²¹ is preferably a single bond, an ester bond [—C (＝ O) —O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. .

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, a —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, -SO ₂ -containing cyclic group, and carbonate-containing cyclic group in Ra ²¹ are respectively represented by the aforementioned general formulas (a2-r-1) to (a2-r-7). Groups represented by general formulas (a5-r-1) to (a5-r-4), and groups represented by general formulas (ax3-r-1) to (ax3-r-3) Are preferred.
Among them, a lactone-containing cyclic group or a —SO ₂ -containing cyclic group is preferable, and the general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r) Groups represented by -1) are more preferred. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r- Any of the groups represented by (lc-6-1), (r-sl-1-1), and (r-sl-1-18) is more preferable.

The structural unit (a2) contained in the component (A1) may be one type, or two or more types.
When the component (A1) has the structural unit (a2), the ratio of the structural unit (a2) is from 20 to 70 mol% based on the total (100 mol%) of all the structural units constituting the component (A1). And more preferably 40 to 60 mol%.
When the proportion of the structural unit (a2) is at least the preferred lower limit, the effect of including the structural unit (a2) can be sufficiently obtained, and when the proportion is at most the upper limit, balance with other structural units is maintained. And various lithography characteristics are improved.

{Structural unit (a3)}
The component (A1) includes, in addition to the structural unit (a1), a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (provided that the structural unit (a1) and the structural unit (a2) are included). Are preferred. When the component (A1) has the structural unit (a3), for example, the acid diffusion length is appropriately adjusted, the adhesion of the resist film to the substrate is increased, the solubility during development is appropriately adjusted, and the etching resistance is improved. By such effects as improvement, lithography characteristics and the like are improved.

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, and 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 cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and may be appropriately selected from, for example, those proposed for a resin for a resist composition for an ArF excimer laser. The cyclic group is preferably a polycyclic group, and more 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 preferred. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from bicycloalkane, tricycloalkane, tetracycloalkane, and the like. Specific examples include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, a group obtained by removing two or more hydrogen atoms from adamantane, a group obtained by removing two or more hydrogen atoms from norbornane, and a group obtained by removing two or more hydrogen atoms from tetracyclododecane are given below. Industrially preferred.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any unit can be used.
The structural unit (a3) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group. Structural units are preferred.
As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a straight-chain or branched-chain hydrocarbon group having 1 to 10 carbon atoms, it is derived from hydroxyethyl ester of acrylic acid. Preferred are the structural units.
Further, as the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1); Preferred are the structural unit represented by -2) and the structural unit represented by formula (a3-3).

［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 described 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 1 is an integer of 1 to 5 And s is an integer of 1 to 3. ]

In the 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 3- and 5-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 particularly preferably a group in which a hydroxyl group is bonded to the 3-position of an adamantyl group.

  In the formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

  In the formula (a3-3), t ′ is preferably 1. 1 is preferably 1. s is preferably 1. It is preferable that a 2-norbornyl group or a 3-norbornyl group is bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded at the 5- or 6-position of the norbornyl group.

The structural unit (a3) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a3), it is preferably 1 to 40 mol%, more preferably 10 to 30 mol%, based on the total of all the structural units constituting the component (A1). 20 to 30 mol% is more preferred.
When the proportion of the structural unit (a3) is equal to or more than the lower limit of the preferable range, the effect of including the structural unit (a3) is sufficiently obtained, and is equal to or less than the upper limit of the preferable range. Balance with other constituent units, and various lithography characteristics can be improved.

≪Other constituent units≫
The component (A1) may have another structural unit other than the structural unit (a1), the structural unit (a2), and the structural unit (a3) described above.
Other structural units include, for example, a structural unit (a10) containing a hydroxystyrene skeleton described below, a structural unit (a9) represented by the general formula (a9-1), and a structural unit derived from styrene (however, the structural unit (Excluding those corresponding to (a10)), and a structural unit (a4) containing an acid-non-dissociable aliphatic cyclic group.

<< Structural unit containing hydroxystyrene skeleton (a10) >>
The component (A1) preferably has a structural unit (a10) having a hydroxystyrene skeleton in addition to the structural unit (a1).
As such a structural unit (a10), for example, a structural unit represented by the following general formula (a10-1) is preferably mentioned.

［式中、Ｒは、水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｙａ^ｘ１は、単結合又は２価の連結基である。Ｗａ^ｘ１は、（ｎ_ａｘ１＋１）価の芳香族炭化水素基である。ｎ_ａｘ１は、１〜３の整数である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is an (n _ax1 +1) valent aromatic hydrocarbon group. _nax1 is an integer of 1 to 3. ]

In the formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, and an n- Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group of 1 to 5 carbon atoms for R is a group in which part or all of the hydrogen atoms of the aforementioned alkyl group of 1 to 5 carbon atoms have been 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.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group in terms of industrial availability.

In the formula (A10-1), ^{Ya x1} is a single bond or a divalent linking group.
Examples of the divalent linking group for Ya ^x1, for example, a substituted divalent hydrocarbon group which may have a divalent linking group containing a hetero atom as preferred.

A divalent hydrocarbon group which may have a substituent:
When ^Yax1 is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

· Aliphatic hydrocarbon group and the aliphatic hydrocarbon group for Ya ^x1 means a hydrocarbon group that has no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and the like.

... A linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, Numbers 1 to 4 are more preferred, and carbon numbers 1 to 3 are most preferred.
As the linear aliphatic hydrocarbon group, preferably a linear alkylene group, and specific examples include a methylene group _[-CH 2 -], an ethylene group _{[- (CH 2) 2 -} ], trimethylene [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

  The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and a carbonyl group substituted with a fluorine atom.

... Aliphatic hydrocarbon group containing a ring in the structure As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (A group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, Groups in which an aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as described above.
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 alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable. As the polycycloalkane, a group having 7 to 12 carbon atoms is preferable. Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be mentioned.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable.
As the alkoxy group as the substituent, 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, and a tert-butoxy group are more preferable. Most preferred are a methoxy group and an ethoxy group.
Examples of the halogen atom as the substituent 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 include groups in which part or all of the hydrogen atoms of the aforementioned alkyl group have been substituted with the aforementioned halogen atoms.
In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing a hetero atom, -O-, -C (= O) -O-, -S-, -S (= O) _2- , and -S (= O) _2- O- are preferable.

··· Aromatic hydrocarbon group in Ya ^x1 The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. No. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.
Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or the aromatic heterocyclic ring (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings A group in which two hydrogen atoms have been removed from (for example, biphenyl, fluorene, etc.); one of the hydrogen atoms in a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) One of which is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc. A group from which one atom has been further removed). The alkylene group bonded to the aryl or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable.
Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

A divalent linking group containing a hetero atom:
When ^Yax1 is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C (= O) -O-, -C (= O)-, and -OC. (= O) -O-, -C (= O) -NH-, -NH-, -NH-C (= 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-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 - ^{C (= O) -O -,} - C (= O) -O-Y 21 -, - [Y 21 -C (= O) -O] m "-Y 22 -, - Y 21 -O-C ( ＯO) —Y ²² — or —Y ²¹ —S (ＯO) ₂ —O—Y ²² — wherein Y ²¹ and Y ²² each independently have a substituent. Is a divalent hydrocarbon group, It is an oxygen atom, m "is an integer of 0 to 3. And the like.
The divalent linking group containing a hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH )-, H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (such as an alkyl group or an acyl group) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - C (= O) -O-Y 21 -, - [Y 21 - _{^{C (= O) -O] m}} "-Y 22 -, - Y 21 -O-C (= O) -Y 22 - or _{^{-Y 21 -S (= O) 2}} -O-Y 22 - in, Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, and examples of the divalent hydrocarbon group include those described above as the divalent linking group. (Divalent hydrocarbon group which may have a substituent).
As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable. preferable.
As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group, or an alkylmethylene group is more preferable. 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.
Formula _{^{- [Y 21 -C (= O}} ) -O] m "-Y 22 - In the group represented by, m" is an integer of 0 to 3, preferably an integer of 0 to 2, 0 Alternatively, 1 is more preferable, and 1 is particularly preferable. In other words, the formula ^- Examples of the group represented by the formula ^{-Y 21 -C (= O) -O} -Y 22 - - [Y 21 -C (= O) -O] m "-Y 22 represented by group is particularly preferred among them, the formula _{-. (CH 2) a '} -C (= O) -O- (CH 2) b' -. in the group represented by the formula in the formula, a 'is from 1 to 10 And an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10 and 1 to 8 An integer is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is more preferable, and 1 is most preferable.

The Ya ^x1, single bond, an ester bond [-C (= O) -O-] , an ether bond (-O -), - C ( = O) -NH-, linear or branched alkylene group Or a combination thereof, and a single bond is particularly preferable.

In the formula (A10-1), ^{Wa x1} _{is (n} ax1 +1) valent aromatic hydrocarbon group.
The aromatic hydrocarbon group for Wa ^x1, include groups obtained by removing from an aromatic ring of the _(n ax1 +1) number of hydrogen atoms. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. No. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

In the formula (a10-1), n _ax1 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

Hereinafter, specific examples of the structural unit represented by Formula (a10-1) will be shown.
In the following formula, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a10) contained in the component (A1) may be one type, or two or more types.
In the component (A1), the proportion of the structural unit (a10) is, for example, 0 to 80 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1), and is 10 to 80 mol%. Mol% is preferable, 20 to 70 mol% is more preferable, and 30 to 60 mol% is particularly preferable.
By setting the ratio of the structural unit (a10) to be equal to or more than the lower limit of the preferable range, lithography characteristics such as sensitivity, resolution, and roughness are improved. On the other hand, when the content is not more than the upper limit of the above preferable range, balance with other constituent units can be obtained, and various lithography characteristics are improved.

Structural unit (a9):
The structural unit (a9) is a structural unit represented by the following general formula (a9-1).

［式中、Ｒは、水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｙａ^９１は、単結合又は２価の連結基である。Ｙａ^９２は、２価の連結基である。Ｒ^９１は、置換基を有していてもよい炭化水素基である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ⁹¹ is a single bond or a divalent linking group. Ya ⁹² is a divalent linking group. R ⁹¹ is a hydrocarbon group which may have a substituent. ]

In the formula (a9-1), R is the same as described above.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly preferable in terms of industrial availability.

In the formula (a9-1), examples of the divalent linking group in Ya ⁹¹ include the same as the above-described divalent linking group in Ya ^x1 in the general formula (a10-1). Among them, Ya ⁹¹ is preferably a single bond.

In the formula (A9-1), the divalent linking group for ^{Ya 92} may include the same divalent linking group ^{Ya x1} in general formula (A10-1).
In the divalent linking group for Ya ^92, the divalent hydrocarbon group which may have a substituent is preferably a linear or branched aliphatic hydrocarbon group.
In the divalent linking group of Ya ^92, the divalent linking group containing a hetero atom includes -O-, -C (= O) -O-, -C (= O)-, -OC. (= O) -O-, -C (= O) -NH-, -NH-, -NH-C (= 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 -, - C (= S) -, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 ^{-O -, - Y 21 -C (} = O) -O -, - C (= O) -O - Y 21, [Y 21 -C (= O) -O] m '-Y 22 - or - ^{Y 21 -O-C (= O} ) -Y 22 - group represented by ^{[wherein, Y 21} and ^{Y 22} are each independently of the bivalent which may have a substituent hydrocarbon group , O is an oxygen atom, and m ′ is 0-3 It is an integer. And the like. Especially, -C (= O)-and -C (= S)-are preferable.

In the formula (a9-1), examples of the hydrocarbon group for R ⁹¹ include an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, and an aralkyl group.
The alkyl group for R ⁹¹ preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 4 carbon atoms, and may be linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group and the like are preferred.
The monovalent alicyclic hydrocarbon group for R ⁹¹ preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, and may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclobutane, cyclopentane, cyclohexane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms. Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be mentioned.
The aryl group for R ⁹¹ preferably has 6 to 18 carbon atoms, more preferably has 6 to 10 carbon atoms, and particularly preferably has a phenyl group.
The aralkyl group for R ^91, an alkylene group and the aralkyl group is preferably a bound "aryl group for R ⁹¹ ', an alkylene group and aryl group in the" R ⁹¹ having 1 to 6 carbon atoms having 1 to 8 carbon atoms more preferably an aralkyl group "and is bonded, particularly preferably an aralkyl group in which an aryl group" and is bonded in the alkylene group and the "R ⁹¹ having 1 to 4 carbon atoms.
In the hydrocarbon group for R ^91, it is preferable that part or all of the hydrogen atoms of the hydrocarbon group be substituted with fluorine atoms, and that 30 to 100% of the hydrogen atoms of the hydrocarbon group be substituted with fluorine atoms. Is more preferable. Among them, a perfluoroalkyl group in which all of the hydrogen atoms of the above-described alkyl group are substituted with fluorine atoms is particularly preferable.

The hydrocarbon group for R ⁹¹ may have a substituent. Examples of the substituent include a halogen atom, an oxo group (＝ O), a hydroxy group (—OH), an amino group (—NH ₂ ), and —SO ₂ —NH ₂ . Further, a part of carbon atoms constituting the hydrocarbon group may be substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -NH-, -N =, -C (= O) -O-, -S-, -S (= O) _2- , -S (= O ) ₂ -O-.
In R ⁹¹ , examples of the hydrocarbon group having a substituent include the lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7).

In R ⁹¹ , ^examples of the hydrocarbon group having a substituent include a —SO ₂ —-containing cyclic group represented by each of the general formulas (a5-r-1) to (a5-r-4); Examples include a substituted aryl group represented by a chemical formula, a monovalent heterocyclic group, and the like.

  Among the structural units (a9), a structural unit represented by the following general formula (a9-1-1) is preferable.

［式中、Ｒは前記と同様であり、Ｙａ^９１は単結合または２価の連結基であり、Ｒ^９１は置換基を有していてもよい炭化水素基であり、Ｒ^９２は酸素原子又は硫黄原子である。］

[Wherein, R is the same as described above, Ya ⁹¹ is a single bond or a divalent linking group, R ⁹¹ is a hydrocarbon group which may have a substituent, and R ⁹² is an oxygen atom or It is a sulfur atom. ]

In the general formula (a9-1-1), the description of Ya ⁹¹ , R ⁹¹ , and R is the same as described above. R ⁹² is an oxygen atom or a sulfur atom.

Hereinafter, specific examples of the structural unit represented by Formula (a9-1) or General Formula (a9-1-1) are shown. In the following formula, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a9) contained in the component (A1) may be one type, or two or more types.
When the component (A1) has the structural unit (a9), the ratio of the structural unit (a9) is 1 to 40 mol% based on the total (100 mol%) of all the structural units constituting the component (A1). Is preferably 3 to 30 mol%, more preferably 5 to 25 mol%, and particularly preferably 10 to 20 mol%.
When the proportion of the structural unit (a9) is at least the lower limit of the preferred range, for example, the acid diffusion length is appropriately adjusted, the adhesion of the resist film to the substrate is increased, and the solubility during development is appropriately adjusted. And the effects of improving the etching resistance can be obtained. When the content is not more than the upper limit of the preferable range described above, balance with other constituent units can be obtained, and various lithography characteristics can be improved.

Structural unit (a4):
The structural unit (a4) is a structural unit containing an acid non-dissociable cyclic group. When the component (A1) has the structural unit (a4), the dry etching resistance of the formed photosensitive resin pattern is improved. Further, the hydrophobicity of the component (A1) increases.
The “acid non-dissociable cyclic group” in the structural unit (a4) is, when an acid is generated from the component (B) described below by exposure, without dissociation even when the acid acts, in the structural unit as it is. Is the remaining cyclic group.

  As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid non-dissociable aliphatic cyclic group is preferable. Examples of the cyclic group include the same as those exemplified in the case of the structural unit (a1), such as an ArF excimer laser, a KrF excimer laser (preferably an ArF excimer laser), and the like. Many conventionally known ones can be used as the resin component of the resist composition. In particular, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable from the viewpoint 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 having the structures of the following general formulas (a4-1) to (a4-7).

［式中、Ｒ^αは、水素原子、メチル基またはトリフルオロメチル基を示す。］

[In the formula, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. ]

The structural unit (a4) contained in the component (A1) may be one type, or two or more types.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% based on the total of all the structural units constituting the component (A1), More preferably, it is 10 to 20 mol%.

As the component (A1) contained in the resist composition, one type may be used alone, or two or more types may be used in combination.
The component (A1) preferably contains a polymer compound (A1-1) having a structural unit (a1) (hereinafter, also referred to as “component (A1-1)”).
Preferred examples of the component (A1-1) include, for example, a polymer compound having a repeating structure of the structural unit (a1) and the structural unit (a2).
In addition to the combination of the above-mentioned two constitutional units, as the third or more than three constitutional units, the constitutional units described above may be appropriately combined according to a desired effect. The third structural unit is preferably a structural unit (a3).

As the component (A1), a monomer for deriving each structural unit is dissolved in a polymerization solvent, and a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (eg, V-601) is added thereto. It can be produced by adding an agent and polymerizing. Alternatively, the component (A1) includes a monomer for deriving the structural unit (a1), and a precursor monomer for deriving a structural unit other than the structural unit (a1) (a monomer having a protected functional group), if necessary. Is dissolved in a polymerization solvent, a radical polymerization initiator as described above is added thereto, polymerization is performed, and then a deprotection reaction is performed. At the time of polymerization, for _example, by using a combination of chain transfer agent such as _{HS-CH 2 -CH 2 -CH 2} -C (CF 3) 2 -OH, -C terminated _(CF 3) _{A 2-} OH group may be introduced. As described above, a copolymer in which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is introduced can reduce development defects and LER (line edge roughness: unevenness of line side walls). It is effective in reducing the amount of slag.

The weight average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, but is preferably from 1,000 to 50,000, more preferably from 2,000 to 30,000, and preferably from 3,000 to 3,000. 20,000 is more preferred.
When the Mw of the component (A1) is less than or equal to the preferred upper limit of this range, there is sufficient solubility in a resist solvent to be used as a resist. The cross-sectional shape of the resist pattern is good.
The degree of dispersion (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.1 to 2.0. . Mn indicates a number average molecular weight.

Component (A2) The resist composition according to the present embodiment includes, as the component (A), a base component (hereinafter referred to as “(A2) ) Component).
The component (A2) is not particularly limited, and may be arbitrarily selected from many conventionally known base components for a chemically amplified resist composition.
As the component (A2), one type of a high molecular compound or a low molecular compound may be used alone, or two or more types may be used in combination.

  The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and preferably 100% by mass, based on the total mass of the component (A). It may be. When the proportion is 25% by mass or more, a resist pattern excellent in various lithography characteristics such as high sensitivity, resolution, and improvement in roughness is easily formed.

  In the resist composition of the present embodiment, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<(B) component>
The component (B) of the resist composition according to this embodiment includes a compound (B1) represented by the following general formula (b1-1) (hereinafter, also referred to as “component (B1)”).

［式中、Ｒ_０ ^１０１は多環式脂肪族炭化水素基である。但し、多環式脂肪族炭化水素基の水素原子が置換基で置換されていてもよい。Ｒ^１０２はフッ素原子又は炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合、又は酸素原子を含む２価の連結基である。Ｖ^１０１は単結合、アルキレン基又はフッ素化アルキレン基である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[In the formula, R ₀ ¹⁰¹ is a polycyclic aliphatic hydrocarbon group. However, the hydrogen atom of the polycyclic aliphatic hydrocarbon group may be substituted with a substituent. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ]

<< anion part >>
In the formula (b1-1), R ₀ ¹⁰¹ is a polycyclic aliphatic hydrocarbon group. However, the hydrogen atom of the polycyclic aliphatic hydrocarbon group may be substituted with a substituent.

  As the polycyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, examples of the polycycloalkane include a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and a fused ring such as a cyclic group having a steroid skeleton. And polycycloalkanes having a polycyclic skeleton. Among them, a polycycloalkane having a bridged ring polycyclic skeleton is preferable. Preferable specific examples of the polycyclic aliphatic hydrocarbon group include an adamantyl group.

  When the hydrogen atom of the polycyclic aliphatic hydrocarbon group is substituted, examples of the substituent include a hydroxy group, a carboxy group, a halogen atom (such as a fluorine atom, a chlorine atom, and a bromine atom), and an alkoxy group. (A methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), and an alkyloxycarbonyl group. As the substituent, a hydroxy group is preferable among them because the occurrence of defects in the unexposed portion of the resist film is more easily suppressed. A plurality of hydrogen atoms of the polycyclic aliphatic hydrocarbon group may be each independently substituted with the above substituents and the like.

In the formula (b1-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of the atom other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.
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 oxycarbonyl group (—O—C (ＯO—). )-), Non-hydrocarbon such as amide bond (-C (= O) -NH-), carbonyl group (-C (= O)-), carbonate bond (-OC (= O) -O-) System oxygen atom-containing linking group; a combination of the non-hydrocarbon oxygen atom-containing linking group with an alkylene group. A sulfonyl group (—SO ₂ —) may be further connected to this combination. Examples of such a divalent linking group containing an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-7).

［式中、Ｖ’^１０１は単結合または炭素数１〜５のアルキレン基であり、Ｖ’^１０２は炭素数１〜３０の２価の飽和炭化水素基である。］

[Wherein, V ' ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms. ]

The divalent saturated hydrocarbon group for V ′ ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and an alkylene group having 1 to 5 carbon atoms. Is more preferable.

The alkylene group in V ′ ¹⁰¹ and V ′ ¹⁰² may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group.
As the alkylene group for V ^'101 and V' ^102, specifically, 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 ) An alkylethylene group such as CH _2- ; a 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 - and the like alkyl trimethylene group; tetramethylene _{[-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; pentamethylene group _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 -] , and the like.

As Y ¹⁰¹ , a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable.

In Formula (b1-1), V ¹⁰¹ represents a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group for V ¹⁰¹ preferably have 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group for V ¹⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group for V ¹⁰¹ have been substituted with fluorine atoms. Above all, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms, and more preferably a fluorinated alkylene group having 1 to 4 carbon atoms.

In the formula (b1-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Among them, a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms is preferable, and a fluorine atom is more preferable.

  Specific examples of the anion portion of the component (b1-1) include, for example, anions represented by the following formulas (an-b-1) to (an-b-3).

｛Cation section｝
In the formula (b1-1), m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation, and a sulfonium cation and an iodonium cation are preferably exemplified. For example, the following general formula (ca-1) ) To (ca-4).

［式中、Ｒ^２０１〜Ｒ^２０７及びＲ^２１１〜Ｒ^２１２はそれぞれ独立に、置換基を有してもよいアリール基、置換基を有してもよいアルキル基、又は置換基を有してもよいアルケニル基を表す。Ｒ^２０１〜Ｒ^２０３、Ｒ^２０６〜Ｒ^２０７、Ｒ^２１１〜Ｒ^２１２はそれぞれ、相互に結合して式中のイオウ原子と共に環を形成していてもよい。Ｒ^２０８〜Ｒ^２０９は、それぞれ独立に、水素原子もしくは炭素数１〜５のアルキル基を表すか、又は相互に結合して式中のイオウ原子と共に環を形成していてもよい。Ｒ^２１０は、置換基を有してもよいアリール基、置換基を有してもよいアルキル基、置換基を有してもよいアルケニル基、又は置換基を有してもよい−ＳＯ_２−含有環式基である。Ｌ^２０１は、−Ｃ（＝Ｏ）−又は−Ｃ（＝Ｏ）−Ｏ−を表す。複数のＹ^２０１はそれぞれ独立に、アリーレン基、アルキレン基又はアルケニレン基を表す。ｘは、１又は２である。Ｗ^２０１は、（ｘ＋１）価の連結基を表す。］

[Wherein, R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² each independently represent an aryl group which may have a substituent, an alkyl group which may have a substituent, or a group which may have a substituent. Represents a good alkenyl group. R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ , and R ^{211 to} R ²¹² may be mutually bonded to form a ring together with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group of 1 to 5 carbon atoms, or may form a ring with each other bonded to the sulfur atom in the formula. R ²¹⁰ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or —SO ₂ — which may have a substituent. It is a cyclic group containing. L ²⁰¹ represents -C (= O)-or -C (= O) -O-. A plurality of Y ²⁰¹ each independently represent an arylene group, an alkylene group or an alkenylene group. x is 1 or 2. W ²⁰¹ represents a (x + 1) -valent linking group. ]

Examples of the aryl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² include an aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² is a chain or cyclic alkyl group, and preferably has 1 to 30 carbon atoms.
The alkenyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² preferably has 2 to 10 carbon atoms.
Examples of the substituent that R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and the following general groups. Examples include groups represented by formulas (ca-r-1) to (ca-r-7).

［式中、Ｒ’^２０１は、それぞれ独立に、水素原子、置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。］

[Wherein, R ′ ²⁰¹ independently has a hydrogen atom, a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent. A chain alkenyl group which may be substituted. ]

R ′ ^{201 is} a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

Cyclic group optionally having substituent (s):
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and usually preferably is saturated.

The aromatic hydrocarbon group for R ′ ²⁰¹ 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, particularly preferably 6 to 15, and most preferably 6 to 10. However, the carbon number does not include the carbon number in the substituent.
As the aromatic ring of the aromatic hydrocarbon group for R ′ ²⁰¹ , specifically, benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of the carbon atoms constituting these aromatic rings is substituted with a hetero atom. Aromatic heterocycles and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Specific examples of the aromatic hydrocarbon group for R ′ ²⁰¹ include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, a phenyl group and a naphthyl group), and one of the hydrogen atoms of the aromatic ring. Groups substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 2-naphthylethyl group); . The carbon number of the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

Examples of the cyclic aliphatic hydrocarbon group for R ′ ²⁰¹ include an aliphatic hydrocarbon group having a ring in the structure.
Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring) and a linear or branched alicyclic hydrocarbon group. Examples thereof include a group bonded to the terminal of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, as the polycycloalkane, a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane; a condensed ring system such as a cyclic group having a steroid skeleton The polycycloalkane having a polycyclic skeleton is more preferable.

Chain alkyl group which may have a substituent:
The linear alkyl group for R ′ ²⁰¹ may be linear or branched.
The linear 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, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henycosyl group, docosyl group and the like.
The branched 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 thereof include a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

Chain-like alkenyl group which may have a substituent:
The chain alkenyl group for R ′ ²⁰¹ may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, more preferably 2 to 4, 3 is particularly preferred. Examples of the linear alkenyl group include a vinyl group, a propenyl group (an allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
Among the above, the linear alkenyl group is preferably a linear alkenyl group, more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.

'The substituent in chain alkyl group or alkenyl group of ^201, for example, an alkoxy group, a halogen atom, a halogenated alkyl group, hydroxy group, a carbonyl group, a nitro group, an amino group, the R' R cyclic in ²⁰¹ And the like.

When R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ , and R ^{211 to} R ²¹² are mutually bonded to form a ring together with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom, or a nitrogen atom; carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. May be bonded via a functional group of As the ring formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring including a sulfur atom, and particularly preferably a 5- to 7-membered ring. preferable. Specific examples of the ring formed include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thiantrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxatiin ring, and a tetrahydro ring. A thiophenium ring, a tetrahydrothiopyranium ring and the like.

R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group of 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, if the alkyl group, bonded to each other A ring may be formed.

R ²¹⁰ may have an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. —SO ₂ —-containing cyclic group.
^Examples of the aryl group for R ²¹⁰ include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group for R ²¹⁰ is a chain or cyclic alkyl group, and preferably has 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms. Table is preferably the general formula (a5-r-1) The content cyclic group, - at R ^210, which may have -SO ₂ substituents "- containing polycyclic group - SO _2" Are more preferred.

Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group.
^Examples of the arylene group for Y ²⁰¹ include groups in which one hydrogen atom has been removed from the aryl group for R ²¹⁰ described above.
Examples of the alkylene group and alkenylene group for Y ²⁰¹ include groups in which one hydrogen atom has been removed from the groups exemplified as the chain alkyl group and chain alkenyl group for R ′ ²⁰¹ described above.

In the formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x + 1) -valent, that is, a divalent or trivalent linking group.
As the divalent linking group for W ^{201, a} divalent hydrocarbon group which may have a substituent is preferable, and has the same substituent as Ya ²¹ in the above general formula (a2-1). And a divalent hydrocarbon group which may be used. The divalent linking group in W ²⁰¹ may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferred.
^Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. No. As the trivalent linking group for W ²⁰¹ , a group in which two carbonyl groups are bonded to an arylene group is preferable.

Specific examples of suitable cations represented by the above formula (ca-1) include the following chemical formulas (ca-1-1) to (ca-1-78), (ca-1-101) to (ca- And cations represented by 1-149).
In the following chemical formula, g1 represents the number of repetitions, and g1 is an integer of 1 to 5. g2 represents the number of repetitions, and g2 is an integer of 0 to 20. g3 represents the number of repetitions, and g3 is an integer of 0 to 20.

［式中、Ｒ”^２０１は水素原子又は置換基である。該置換基としては、上記Ｒ^２０１〜Ｒ^２０７およびＲ^２１１〜Ｒ^２１２が有してもよい置換基として挙げた、アルキル基、ハロゲン原子、ハロゲン化アルキル基、カルボニル基、シアノ基、アミノ基、アリール基、一般式（ｃａ−ｒ−１）〜（ｃａ−ｒ−７）でそれぞれ表される基が挙げられる。］

[Wherein, R ″ ²⁰¹ is a hydrogen atom or a substituent. Examples of the substituent include the alkyl groups and halogens described as the substituents that R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² may have. Atoms, halogenated alkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by general formulas (ca-r-1) to (ca-r-7).]

  Specific examples of suitable cations represented by the formula (ca-2) include cations represented by the following formulas (ca-2-1) to (ca-2-2), diphenyliodonium cations, and bis ( 4-tert-butylphenyl) iodonium cation.

  Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-7).

  Specific examples of suitable cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

Among the above, the cation part ((M ^{m +} ) _{1 / m} ) is preferably a cation represented by the general formula (ca-1), and is represented by the chemical formulas (ca-1-1) to (ca-1-78), ( Cations represented by (ca-1-101) to (ca-1-149) are more preferred.

  Among the above, the component (B1) is more preferably a compound (B11) represented by the following formula (b1-1-1).

［式中、Ｒ_０ ^２０１はヒドロキシ基を有する多環式脂肪族炭化水素基である。Ｒ^１０２はフッ素原子又は炭素数１〜５のフッ素化アルキル基である。Ｖ_０ ^１０１は炭素数１〜４のフッ素化アルキレン基である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[Wherein, R ₀ ²⁰¹ is a polycyclic aliphatic hydrocarbon group having a hydroxy group. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. V ₀ ¹⁰¹ is a fluorinated alkylene group having 1 to 4 carbon atoms. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ]

In Formula (b1-1-1), R ₀ ²⁰¹ is a polycyclic aliphatic hydrocarbon group having a hydroxy group. A plurality of hydrogen atoms of the polycyclic aliphatic hydrocarbon group may be substituted with a hydroxy group.
The polycyclic aliphatic hydrocarbon group is the same as described for R ₀ ¹⁰¹ in formula (b1-1).

In Formula (b1-1-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, and is the same as the content described in Formula (b1-1).
In formula (b1-1-1), V ₀ ¹⁰¹ represents a fluorinated alkylene group having 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group for V ₀ ¹⁰¹ include groups in which part or all of the hydrogen atoms of an alkylene group have been substituted with fluorine atoms. Of these, a group in which part of the hydrogen atoms of an alkylene group has been substituted with fluorine atoms is preferred. The number of fluorine atoms in the fluorinated alkylene group of V ₀ ¹⁰¹ is preferably from 1 to 6, more preferably from 1 to 3, and even more preferably 2 or 3.

In the formula (b1-1-1), M ′ ^{m +} is the same as the content described in the formula (b1-1).

  Preferable specific examples of the component (B1) of the resist composition in the present embodiment are shown below, but the invention is not limited thereto.

  As the component (B1) of the resist composition in the present embodiment, one type may be used alone, or two or more types may be used in combination.

The content of the component (B1) in the resist composition according to the present embodiment is preferably 50 parts by mass or less, more preferably 1 to 40 parts by mass, and more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the component (A). More preferred.
When the content of the component (B1) is equal to or more than the above lower limit, in forming a resist pattern, sensitivity, resolution performance, LWR (line-wise roughness) reduction, lithography characteristics such as shape, and occurrence of defects in an unexposed portion of the resist film. Is further improved.
When the content of the component (B1) is equal to or less than the above upper limit, a uniform solution is easily obtained when each component is dissolved in an organic solvent, and the storage stability as a resist composition is further improved.

In the resist composition, the ratio of the component (B1) is, for example, 50% by mass or more, and preferably 70% by mass, of the entire acid generator component (B) that generates an acid acting on the component (A). % Or more, and more preferably 95% by mass or more. In addition, it may be 100% by mass.
When the proportion of the component (B1) is equal to or more than the lower limit of the preferable range, the occurrence of defects in the unexposed portion of the resist film can be further reduced.

<Optional components>
The resist composition according to the exemplary embodiment may further contain components (arbitrary components) other than the above-described components (A) and (B1).
Examples of such optional components include the following components (B2), (D), (E), (F), and (S).

<< component (B2) >>
The resist composition according to the present embodiment may contain an acid generator component other than the above-mentioned component (B1) (hereinafter, referred to as “component (B2)”) as long as the effects of the present invention are not impaired.
The component (B2) is not particularly limited, and those which have been proposed as an acid generator for a chemically amplified resist composition can be used.
Examples of such an acid generator include onium salt-based acid generators such as iodonium salts and sulfonium salts; oxime sulfonate-based acid generators; and diazomethane-based acids such as bisalkyl or bisarylsulfonyldiazomethanes and poly (bissulfonyl) diazomethanes. Acid generators: various types such as a nitrobenzylsulfonate-based acid generator, an iminosulfonate-based acid generator, and a disulfone-based acid generator are exemplified.

  Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter, also referred to as “component (b-1) component”) and a general formula (b-2) A compound (hereinafter also referred to as “component (b-2)”) or a compound represented by the general formula (b-3) (hereinafter also referred to as “(b-3) component”) may be used. The component (b-1) does not include the compound corresponding to the component (B1) described above.

［式中、Ｒ^１０１、Ｒ^１０４〜Ｒ^１０８はそれぞれ独立に、置換基を有してもよい環式基、置換基を有してもよい鎖状のアルキル基、又は置換基を有してもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０２はフッ素原子又は炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合、又は酸素原子を含む２価の連結基である。Ｖ^１０１〜Ｖ^１０３はそれぞれ独立に単結合、アルキレン基又はフッ素化アルキレン基である。Ｌ^１０１〜Ｌ^１０２はそれぞれ独立に単結合又は酸素原子である。Ｌ^１０３〜Ｌ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[Wherein, R ¹⁰¹ , R ^{104 to} R ¹⁰⁸ each independently represent a cyclic group optionally having a substituent, a chain-like alkyl group optionally having a substituent, or a substituent. Is a good chain alkenyl group. R ¹⁰⁴ and R ¹⁰⁵ may be mutually bonded to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ^{101 to} V ¹⁰³ each independently represent a single bond, an alkylene group or a fluorinated alkylene group. L ^{101 to} L ¹⁰² are each independently a single bond or an oxygen atom. L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ]

<< anion part >>
-Anion part of component (b-1) In formula (b-1), R ¹⁰¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group which may have a group.

Cyclic group which may have a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and usually preferably is saturated.

The aromatic hydrocarbon group for R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and particularly preferably 6 to 15 carbon atoms. Most preferably, it has 6 to 12 carbon atoms. However, the carbon number does not include the carbon number in the substituent.
As the aromatic ring of the aromatic hydrocarbon group for R ¹⁰¹ , specifically, benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of the carbon atoms constituting these aromatic rings is substituted with a hetero atom And an aromatic heterocycle. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like. The aromatic ring of the aromatic hydrocarbon group for R ¹⁰¹ preferably does not contain a hetero atom from the viewpoint of compatibility with the component (A), and an aromatic ring such as benzene, fluorene, naphthalene, anthracene, phenanthrene, and biphenyl is preferred. Is preferred.
Specific examples of the aromatic hydrocarbon group for R ¹⁰¹ include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and one of the hydrogen atoms in the aromatic ring is an alkylene. And a group substituted with a group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 2-naphthylethyl group). The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aliphatic hydrocarbon group having a ring in the structure.
Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring) and a linear or branched alicyclic hydrocarbon group. Examples thereof include a group bonded to the terminal of a chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
Examples of the alicyclic hydrocarbon group include a monocyclic alicyclic hydrocarbon group, and a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.

Of these, as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ , a group in which one or more hydrogen atoms have been removed from monocycloalkane or polycycloalkane is preferable, and a group in which one hydrogen atom has been removed from monocycloalkane is more preferable. A group in which one hydrogen atom has been removed from cyclopentane or cyclohexane is particularly preferred.

The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. Is more preferable, and a carbon number of 1-3 is most preferable. As the linear aliphatic hydrocarbon group, preferably a linear alkylene group, and specific examples include a methylene group _[-CH 2 -], an ethylene group _{[- (CH 2) 2 -} ], trimethylene [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and 3 or 4 carbon atoms. Are more preferable, and carbon number 3 is the most preferable. As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Examples of the substituent in the cyclic group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, and a carbonyl group.
As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable.
As the alkoxy group as a substituent, 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, and a tert-butoxy group are more preferable. And ethoxy groups are most preferred.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms, for example, a part or all of hydrogen atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group The group substituted by the halogen atom is exemplified.
A carbonyl group as a substituent is a group that substitutes a methylene group (—CH ₂ —) constituting a cyclic hydrocarbon group.
Among them, an alkyl group, a halogen atom, a halogenated alkyl group and the like are preferable as the substituent in the cyclic group of R ¹⁰¹ from the viewpoint of compatibility with the component (A), and an alkyl group is more preferable.

Chain alkyl group which may have a substituent:
The chain alkyl group for R ¹⁰¹ may be linear or branched.
The linear 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, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henycosyl group, docosyl group and the like.
The branched 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, 1,1-dimethylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-methylbutyl group Examples include an ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

Chain-like alkenyl group which may have a substituent:
The chain alkenyl group for R ¹⁰¹ may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably has 2 to 5 carbon atoms, and has 2 to 4 carbon atoms. More preferably, carbon number 3 is particularly preferable. Examples of the linear alkenyl group include a vinyl group, a propenyl group (an allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
Among the above, the linear alkenyl group is preferably a linear alkenyl group, more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. Group, an amino group, the cyclic group for R ^{101 and} the like.
Among them, as the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ , from the viewpoint of compatibility with the component (A), a halogen atom, a halogenated alkyl group, or a group described as the cyclic group for R ¹⁰¹ above And the like, and the groups exemplified as the cyclic group for R ¹⁰¹ are more preferred.

Among the above, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, a group in which one or more hydrogen atoms have been removed from a phenyl group, a naphthyl group, or a polycycloalkane; the general formulas (a2-r-1), (a2-r-3) to (a2-r) Lactone-containing cyclic group represented by each of formulas (7-7); -SO ₂ -containing cyclic groups represented by formulas (a5-r-1) to (a5-r-4);

In the formula (b-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of the atom other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.
Examples of such a divalent linking group containing an oxygen atom include linking groups represented by the above general formulas (y-al-1) to (y-al-8).
Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and is represented by any of the above general formulas (y-al-1) to (y-al-5). Are more preferred.

In the formula (b-1), V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group for V ¹⁰¹ preferably have 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group for V ¹⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group for V ¹⁰¹ have been substituted with fluorine atoms. Among them, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

In the formula (b-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

(B-1) Specific examples of the anion moiety of the component, for example, if the Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion can be exemplified; Y ¹⁰¹ is In the case of a divalent linking group containing an oxygen atom, an anion represented by any of the following formulas (an1) to (an3) may be mentioned.

［式中、Ｒ”^１０１は、置換基を有してもよい脂肪族環式基、上記の化学式（ｒ−ｈｒ−１）〜（ｒ−ｈｒ−６）でそれぞれ表される１価の複素環式基、又は置換基を有してもよい鎖状のアルキル基である。Ｒ”^１０２は、置換基を有してもよい脂肪族環式基、前記一般式（ａ２−ｒ−１）、（ａ２−ｒ−３）〜（ａ２−ｒ−７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５−ｒ−１）〜（ａ５−ｒ−４）でそれぞれ表される−ＳＯ_２−含有環式基である。Ｒ”^１０３は、置換基を有してもよい芳香族環式基、置換基を有してもよい脂肪族環式基、又は置換基を有してもよい鎖状のアルケニル基である。Ｖ”^１０１は、炭素数１〜４のアルキレン基、又は炭素数１〜４のフッ素化アルキレン基である。Ｒ^１０２は、フッ素原子又は炭素数１〜５のフッ素化アルキル基である。ｖ”はそれぞれ独立に０〜３の整数であり、ｑ”はそれぞれ独立に１〜２０の整数であり、ｎ”は０または１である。］

[Wherein, R ″ ¹⁰¹ is an aliphatic cyclic group which may have a substituent, and a monovalent complex represented by each of the above-mentioned chemical formulas (r-hr-1) to (r-hr-6). R ″ ¹⁰² is a cyclic group or a chain-like alkyl group which may have a substituent, and R ″ ¹⁰² is an aliphatic cyclic group which may have a substituent, and has the general formula (a2-r-1) , A lactone-containing cyclic group represented by (a2-r-3) to (a2-r-7), or a lactone-containing cyclic group represented by each of the general formulas (a5-r-1) to (a5-r-4). that -SO ₂ - containing cyclic group. R ″ ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. V ″ ¹⁰¹ is an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group having 1 to 4 carbon atoms. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. v "is independently an integer of 0 to 3, q" is independently an integer of 1 to 20, and n "is 0 or 1.]

The aliphatic cyclic group which may have a substituent of R ″ ¹⁰¹ , R ″ ¹⁰² and R ″ ¹⁰³ is a group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in the formula (b-1). The substituent is preferably the same as the substituent which may substitute the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in the formula (b-1).

The aromatic cyclic group which may have a substituent for R ″ ¹⁰³ may be the group exemplified as the aromatic hydrocarbon group for the cyclic hydrocarbon group for R ¹⁰¹ in the formula (b-1). The substituent is preferably the same as the substituent which may substitute the aromatic hydrocarbon group for R ¹⁰¹ in the formula (b-1).

R in ^"Good chain alkyl group which may have a substituent at ^101, the formula (b-1) is preferably ^.R a group exemplified as chain alkyl group in ^{R 101 in" 103} The chain alkenyl group which may have a substituent is preferably the group exemplified as the chain alkenyl group for R ¹⁰¹ in the formula (b-1).

-Anion part of component (b-2) In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ are each independently a cyclic group which may have a substituent, or a chain which may have a substituent. An alkyl group or a chain alkenyl group which may have a substituent, and a cyclic group which may have a substituent and a substituent in R ¹⁰¹ in the formula (b-1), Examples thereof include the same as a chain-like alkyl group which may have a group or a chain-like alkenyl group which may have a substituent. Further, R ¹⁰⁴ and R ¹⁰⁵ may be mutually bonded to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a linear alkyl group which may have a substituent, and are preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. Is more preferred.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The smaller the number of carbon atoms in the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is, the better the solubility in resist solvents is within the above-mentioned number of carbon atoms. In the chain alkyl group of R ¹⁰⁴ and R ^105, the larger the number of hydrogen atoms substituted with fluorine atoms, the higher the strength of the acid, which is preferable. The ratio of fluorine atoms in the chain 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. Perfluoroalkyl group.
In Formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and are the same as V ¹⁰¹ in Formula (b-1), respectively. No.
In the formula (b-2), L ¹⁰¹ and L ¹⁰² are each independently a single bond or an oxygen atom.

· (B-3) component of Anion formula ^{(b-3), R 106} ~R 108 are each independently an optionally substituted cyclic group, an optionally substituted chain An alkyl group or a chain-like alkenyl group which may have a substituent, and a cyclic group or a substituent which may have a substituent in R ¹⁰¹ in the formula (b-1). Examples thereof include the same as a chain-like alkyl group which may have a group or a chain-like alkenyl group which may have a substituent.
L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —.

｛Cation section｝
In the formulas (b-1), (b-2) and (b-3), m is an integer of 1 or more, and M ′ ^{m +} is an onium cation having a valence of m, preferably a sulfonium cation or an iodonium cation. Examples thereof include organic cations represented by the above formulas (ca-1-1) to (ca-1-78) and (ca-1-101) to (ca-1-149).

In formulas (b-1), (b-2) and (b-3), M ′ ^{m +} represents a diphenyliodonium cation, a bis (4-tert-butylphenyl) iodonium cation, or the above formula (ca-3) Cations represented by -1) to (ca-3-6), and cations represented by the above formulas (ca-4-1) to (ca-4-2).

Among the above, the cation part [(M ′ ^{m +} ) _{1 / m} ] has the formula (ca-1-1) to (ca-1-78), (ca-1-101) to (ca-1-149). The organic cations represented by the following organic cations are more preferred.

In the resist composition of the present embodiment, as the component (B2), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (B2), the content of the component (B2) in the resist composition is preferably 50 parts by mass or less, and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the component (A). Is more preferable, and 5 to 30 parts by mass is further preferable.
When the resist composition contains the component (B2), the content of the component (B2) in the entire acid generator component (B) that generates an acid acting on the component (A) in the resist composition Is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 0% by mass or more and 5% by mass or less.
By setting the content of the component (B2) in the above range, pattern formation is sufficiently performed.

≪ (D) component≫
The resist composition in this embodiment may further contain an acid diffusion controller component (hereinafter, referred to as “component (D)”) in addition to the components (A) and (B). The component (D) functions as a quencher (acid diffusion controller) for trapping an acid generated by exposure in the resist composition.
As the component (D), for example, a nitrogen-containing organic compound (D1) (hereinafter referred to as a “component (D1)”, a photo-degradable base (D2) which is decomposed by exposure not corresponding to the component (D1) and loses acid diffusion controllability. ) (Hereinafter referred to as “component (D2)”).
By using the resist composition containing the component (D), the contrast between the exposed and unexposed portions of the resist film can be further improved when forming a resist pattern.

-Regarding the component (D1) The component (D1) is a base component, and is a nitrogen-containing organic compound component that acts as an acid diffusion controller in the resist composition.

  The component (D1) is not particularly limited as long as it acts as an acid diffusion controller, and examples thereof include aliphatic amines and aromatic amines.

Among the aliphatic amines, secondary aliphatic amines and tertiary aliphatic amines are preferable.
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 in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms (an alkylamine or an alkyl alcohol amine) or a cyclic amine.
Specific examples of the alkylamine and the alkyl alcoholamine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; diethylamine, di-n-propylamine, Dialkylamines such as -n-heptylamine, di-n-octylamine and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine and tri-n-hexylamine Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine and tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine; Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among them, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Examples of the cyclic amine include a heterocyclic compound containing a nitrogen atom as a hetero atom. The heterocyclic compound may be a monocyclic compound (aliphatic monocyclic amine) or a polycyclic compound (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, one having 6 to 10 carbon atoms is preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene and 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane and the like.

  Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, and tris {2- (1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxyethoxy) ) Ethoxy [ethyl] amine], triethanolamine triacetate and the like, with triethanolamine triacetate being preferred.

  Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, aniline compounds, N-tert-butoxycarbonylpyrrolidine and the like.

As the component (D1), one type may be used alone, or two or more types may be used in combination.
Among the above, the component (D1) is preferably an aromatic amine, and more preferably an aniline compound. Examples of the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, and N, N-dihexylaniline.

-Component (D2) The component (D2) is not particularly limited as long as it is decomposed by exposure and loses acid diffusion controllability, and a compound represented by the following general formula (d2-1) (hereinafter "(( a compound represented by the following general formula (d2-2) (hereinafter, referred to as a “component (d2-2) component”) and a compound represented by the following general formula (d2-3) (Hereinafter referred to as “(d2-3) component”.) At least one compound selected from the group consisting of is preferred.
The components (d2-1) to (d2-3) decompose in the exposed part of the resist film and lose the acid diffusion controllability (basicity), so that they do not act as a quencher, and the quencher does not act in the unexposed part of the resist film. Act as

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有してもよい環式基、置換基を有してもよい鎖状のアルキル基、又は置換基を有してもよい鎖状のアルケニル基である。但し、一般式（ｄ２−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子にはフッ素原子が結合していないものとする。Ｙｄ^１は単結合又は２価の連結基である。ｍは１以上の整数であって、Ｍ’^ｍ＋はそれぞれ独立にｍ価のオニウムカチオンである。］

[Wherein, Rd ^{1 to} Rd ⁴ are a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. It is. However, in the general formula (d2-2) Rd ² in, the carbon atom adjacent to the S atom and which is a fluorine atom not bonded. Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and M ′ ^{m +} is each independently an m-valent onium cation. ]

{(D2-1) component}
-Anion part In formula (d2-1), Rd ¹ may have a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent. A chain alkenyl group, each of which is the same as R ¹⁰¹ in the above formula (b-1);
Among these, as Rd ¹ , an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain form which may have a substituent Alkyl groups are preferred. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, and the above general formulas (a2-r-1) to (a2-r-7). ), An ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, the substituent may be via an alkylene group. In this case, the substituent is represented by any of the above formulas (y-al-1) to (y-al-5). Are preferred.
Preferable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (for example, a polycyclic structure composed of a ring structure of a bicyclooctane skeleton and another ring structure). Can be
The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, Linear alkyl groups such as nonyl group and decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl And a branched alkyl group such as a 2-ethylbutyl group, a 2-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and 1 to 8. To 4 are more preferred. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than the fluorine atom include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms, and Rd ¹ represents a hydrogen atom constituting the linear alkyl group. It is particularly preferable that all of them are fluorinated alkyl groups (linear perfluoroalkyl groups) substituted by fluorine atoms.

  Preferred specific examples of the anion part of the component (d2-1) are shown below.

-Cation part In formula (d2-1), M'm ⁺ is an m-valent onium cation.
As the onium cation of M ′ ^{m +} , those similar to the cations represented by the aforementioned general formulas (ca-1) to (ca-4) are preferably exemplified, and represented by the aforementioned general formula (ca-1). The cations represented by the formulas (ca-1-1) to (ca-1-78) and (ca-1-101) to (ca-1-149) are more preferable.
As the component (d2-1), one type may be used alone, or two or more types may be used in combination.

{(D2-2) component}
Anion formula (d2-2), Rd ^2, the substituents cyclic group which may have a may have a substituent which may chain having alkyl group, or a substituent It is a chain alkenyl group, and includes the same groups as R ¹⁰¹ in the formula (b-1).
However, in Rd ^2, the carbon atom adjacent to the S atom fluorine atom is assumed unbound (non-fluorinated). Thereby, the anion of the component (d2-2) becomes an appropriate weak acid anion, and the quenching ability as the component (D2) is improved.
Rd ² is preferably a chain-like alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like (which may have a substituent); Is more preferably a group from which the hydrogen atom has been removed.
The hydrocarbon group for Rd ² may have a substituent, and examples of the substituent include the hydrocarbon group for Rd ¹ in the formula (d2-1) (an aromatic hydrocarbon group, an aliphatic cyclic group, a chain). And the same substituents as the substituents that the alkyl group may have.

  Preferred specific examples of the anion part of the component (d2-2) are shown below.

-Cation part In formula (d2-2), M'm ⁺ is an onium cation of m valence, and is the same as M'm ⁺ in the above formula (d2-1).
As the component (d2-2), one type may be used alone, or two or more types may be used in combination.

{(D2-3) component}
During Anion formula (d2-3), Rd ³ is an optionally substituted cyclic group, an alkyl group which may chain have a substituent or may chains may have a substituent A alkenyl group having the same meaning as R ¹⁰¹ or the like in the formula (b-1), and a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group Is preferred. Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group for Rd ¹ is more preferable.

In the formula (d2-3), Rd ⁴ represents a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear group which may have a substituent. It is an alkenyl group, and examples thereof include the same ones as R ¹⁰¹ in the above formula (b-1).
Among them, an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group which may have a substituent are preferable.
The alkyl group for Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atoms of the alkyl group for Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group for Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, and an n- Butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

Examples of the alkenyl group for Rd ⁴ include those similar to R ¹⁰¹ and the like in the formula (b-1), and are preferably a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, or a 2-methylpropenyl group. . These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

Examples of the cyclic group for Rd ⁴ include the same groups as R ¹⁰¹ in the formula (b-1), and cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. And an alicyclic group obtained by removing one or more hydrogen atoms from, or an aromatic group such as a phenyl group and a naphthyl group. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, so that lithography characteristics are improved.

Wherein (d2-3), Yd ¹ represents a single bond or a divalent linking group.
The divalent linking group for Yd ¹ is not particularly limited, but may be a divalent hydrocarbon group which may have a substituent (aliphatic hydrocarbon group, aromatic hydrocarbon group), or a divalent group containing a hetero atom. And the like. Each of these, mentioned in the description of the divalent linking group for Ya ^x1 in formula (A10-1), 2 may have a substituent monovalent hydrocarbon group, 2 containing a hetero atom Examples are the same as the valent linking group.
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

  Preferred specific examples of the anion part of the component (d2-3) are shown below.

-Cation part In formula (d2-3), M'm ⁺ is an onium cation of m valence, and is the same as M'm ⁺ in the formula (d2-1).
As the component (d2-3), one type may be used alone, or two or more types may be used in combination.

As the component (D2), any one of the above components (d2-1) to (d2-3) may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (D2), the content of the component (D2) in the resist composition is preferably from 0.5 to 35 parts by mass, and more preferably from 1 to 35 parts by mass, per 100 parts by mass of the component (A). 25 parts by mass is more preferable, 2 to 20 parts by mass is more preferable, and 3 to 15 parts by mass is particularly preferable.
When the content of the component (D2) is at least the preferred lower limit, particularly good lithography characteristics and a resist pattern shape are easily obtained. On the other hand, when the content is equal to or less than the upper limit, it is possible to balance with other components, and various lithography characteristics are improved.

Method for producing component (D2):
The method for producing the components (d2-1) and (d2-2) is not particularly limited, and the components can be produced by a known method.
The method for producing the component (d2-3) is not particularly limited, and is produced, for example, in the same manner as the method described in US2012-0149916.

{Component (E): at least one compound selected from the group consisting of organic carboxylic acids and phosphorus oxo acids and derivatives thereof}
The resist composition according to the present embodiment includes, as optional components, an organic carboxylic acid and an oxo acid of phosphorus and a derivative thereof for the purpose of preventing deterioration in sensitivity, improving the resist pattern shape, and keeping stability over time. At least one compound (E) selected from the group (hereinafter referred to as “component (E)”) can be contained.

Preferred examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid.
Examples of the oxo acid of phosphorus include phosphoric acid, phosphonic acid, and phosphinic acid, and among them, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include, for example, an ester in which a hydrogen atom of the above oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms, and a 6 to 6 carbon atoms. And 15 aryl groups.
Examples of phosphoric acid derivatives include phosphate esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of the phosphonic acid derivative include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate.
Examples of the phosphinic acid derivative include phosphinic acid esters and phenylphosphinic acid.

  Among the above, the component (E) is preferably an organic carboxylic acid, more preferably an aromatic carboxylic acid. Specific examples include benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid.

In the resist composition of the present embodiment, as the component (E), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (E), the content of the component (E) is preferably 0.01 to 5 parts by mass, preferably 0.1 to 1 part by mass, per 100 parts by mass of the component (A). More preferably, it is 0.5 parts by mass.
By setting the content within the above range, balance with other components can be obtained, and various lithography characteristics are improved.

≪ (F) component: fluorine additive component≫
The resist composition in this embodiment may contain a fluorine additive component (hereinafter, referred to as “component (F)”) in order to impart water repellency to the resist film or to improve lithography characteristics.
The component (F) is described in, for example, JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226. Can be used.
More specifically, the component (F) includes a polymer having a structural unit (f1) represented by the following formula (f1-1). Examples of the polymer include a polymer (homopolymer) composed of only the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a4) A copolymer of the structural unit (f1) and the structural unit (a1); a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) It is preferred that Here, as the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate, 1-methyl-1-adamantyl ( Structural units derived from (meth) acrylates are preferred.

［式中、Ｒは前記と同様であり、Ｒｆ^１０２およびＲｆ^１０３はそれぞれ独立して水素原子、ハロゲン原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基を表し、Ｒｆ^１０２およびＲｆ^１０３は同じであっても異なっていてもよい。ｎｆ^１は０〜５の整数であり、Ｒｆ^１０１はフッ素原子を含む有機基である。］

[Wherein, R is the same as described above, and Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Rf ¹⁰² and Rf ¹⁰³ may be the same or different. nf ¹ is an integer of 0 to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom. ]

In the formula (f1-1), R bonded to the carbon atom at the α-position is the same as described above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), examples of the halogen atom for Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ are the same as the alkyl groups having 1 to 5 carbon atoms for R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include groups in which part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Can be 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. Among them, Rf ¹⁰² and Rf ¹⁰³ are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group.

In the formula (f1-1), nf ¹ is an integer of 0 to 5, preferably 0 to 3, and more preferably 0 or 1.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. , And particularly preferably 1 to 10 carbon atoms.
In the hydrocarbon group containing a fluorine atom, 25% or more of the hydrogen atoms in the hydrocarbon group are preferably fluorinated, more preferably 50% or more are fluorinated, and 60% or more are fluorinated. The fluorination is particularly preferable because the hydrophobicity of the resist film at the time of immersion exposure increases.
Among ^these, as ^{Rf 101,} more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, trifluoromethyl _{group, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3 ) ₂ , —CH ₂ —CH ₂ —CF ₃ , —CH ₂ —CH ₂ —CF ₂ —CF ₂ —CF ₂ —CF ₃ are particularly preferred.

The weight average molecular weight (Mw) of the component (F) (based on gel permeation chromatography in terms of polystyrene) is preferably from 1,000 to 50,000, more preferably from 5,000 to 40,000, and most preferably from 10,000 to 30,000. When the content is not more than the upper limit of this range, there is sufficient solubility in a solvent for resist to be used as a resist, and when the content is not less than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good. .
The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.2 to 2.5.

In the resist composition of the present embodiment, as the component (F), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (F), the content of the component (F) is usually 0.5 to 10 parts by mass based on 100 parts by mass of the component (A).

≪ (S) component: organic solvent component≫
The resist composition according to this embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter, referred to as “component (S)”).
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, and any one of conventionally known solvents for a chemically amplified resist composition can be appropriately used. Can be selected and used.
As the component (S), for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone, ethylene carbonate, propylene carbonate; Polyhydric alcohols such as glycol, diethylene glycol, propylene glycol, dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; the polyhydric alcohols Or monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether of the compound having an ester bond. Derivatives of polyhydric alcohols such as compounds having an ether bond such as monoalkyl ether or monophenyl ether [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferable]; Cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; Anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropyl Aromatic solvents such as benzene, toluene, xylene, cymene, and mesitylene; dimethyl sulfoxide (DMSO);
In the resist composition of the present embodiment, the component (S) may be used alone or as a mixed solvent of two or more.
Among them, PGMEA, PGME, γ-butyrolactone, propylene carbonate, EL, and cyclohexanone are preferred.
Further, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferable. The compounding ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, and is 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 or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA: EL or cyclohexanone is preferably from 1: 9 to 9: 1, and more preferably from 2: 8 to 8: 2. . When PGME is blended as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, and still more preferably 3: 7 to 7 :. 3. Further, a mixed solvent of PGMEA, PGME and cyclohexanone is also preferable.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and at least one selected from γ-butyrolactone and propylene carbonate is also preferable. In this case, the mixing ratio of the former and the latter is preferably 60:40 to 99: 1, more preferably 70:30 to 95: 5.
The amount of the component (S) to be used is not particularly limited, and is appropriately set at a concentration applicable to a substrate or the like and in accordance with the thickness of the applied film. Generally, the component (S) is used so that the solid content of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

  The resist composition according to the present embodiment may further contain additives that are optionally miscible, for example, an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, and an antihalation agent. , Dyes and the like can be added and contained as appropriate.

  The resist pattern forming method of forming a resist pattern by developing with an alkali developer containing a nonionic surfactant according to the present embodiment described above uses a specific resist composition, that is, the above-described component (A) and the component (B). And (B) a resist composition containing the component (B1), the occurrence of defects in unexposed portions of the resist film can be reduced, and a resist pattern having a good shape can be formed. be able to.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

<Preparation of resist composition>
The components shown in Table 1 were mixed and dissolved to prepare resist compositions (1) to (5).

  In Table 1, each abbreviation has the following meaning. Numerical values in [] are blending amounts (parts by mass).

(A) -1: a polymer compound represented by the following chemical formula (A-1). This polymer compound (A) -1 was obtained by radical polymerization of a monomer for deriving a structural unit constituting the polymer compound at a predetermined molar ratio. For this polymer compound (A) -1, the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 7000, and the molecular weight dispersity (Mw / Mn) was 1.68. ^The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula is 1 / m / n / o = 45/30/15/10) determined by ¹³ C-NMR.

  (B1) -1 to (B1) -3: acid generators composed of each of the following compounds (B1-1) to (B1-3).

(B2) -1: an acid generator comprising the following compound (B2-1).
(B2) -2: an acid generator comprising the following compound (B2-2).

(D) -1: an acid diffusion controller comprising a compound represented by the following chemical formula (D-1).
(E) -1: a compound represented by the following chemical formula (E-1).
(F) -1: a fluorine-containing polymer compound represented by the following chemical formula (F-1). The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 23000, and the molecular weight dispersity (Mw / Mn) was 1.40.
(S) -1: a mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether (mass ratio 60/40).

<Formation of resist pattern (1)>
(Example 1)
On a 12-inch silicon wafer, an organic anti-reflective coating composition "ARC29A" (trade name, manufactured by Brewer Science) is applied using a spinner, baked on a hot plate at 205 ° C. for 60 seconds, and dried. Thus, an organic antireflection film having a thickness of 89 nm was formed.
The resist composition (1) shown in Table 1 was applied on the antireflection film using a coater / developer Lithius (manufactured by Tokyo Electron Limited) and subjected to a pre-bake (PAB) treatment at 105 ° C. for 60 seconds on a hot plate. By performing and drying, a resist film having a thickness of 150 nm was formed.
Next, an ArF exposure apparatus for liquid immersion NSR-S609B [manufactured by Nikon Corporation; NA (numerical aperture) = 1.07, Dipole (in / out = 0.78 / 0.97) with Polano, An immersion medium: water] was selectively irradiated with an ArF excimer laser (193 nm) via a transmission type phase shift mask.
Thereafter, PEB treatment was performed at 100 ° C. for 60 seconds.
Then, using a coater / developer Lithius (manufactured by Tokyo Electron Ltd.), at 23 ° C., a 2.38 mass% TMAH aqueous solution containing acetylene-based activator (trade name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) Alkaline development was performed for 30 seconds, followed by rinsing with pure water for 30 seconds, followed by shaking off and drying.
As a result, the exposed portions of the resist film were dissolved and removed by the developer, and the unexposed portions remained.

(Examples 2, 3 and Comparative Examples 1, 2)
A resist pattern was formed in the same manner as in Example 1 except that the resist composition (1) in Table 1 was changed to each of the resist compositions (2) to (5). The resist composition (2) was used in Example 2, the resist composition (3) was used in Example 3, the resist composition (4) was used in Comparative Example 1, and the resist composition (5) was used in Comparative Example 2.

<Evaluation of resist pattern (1)>
[Evaluation of defects]
Using the surface defect observation device (manufactured by KLA Tencor, product name: KLA-2371) for the resist pattern formed by the above <Formation of resist pattern (1)>, the residual film portion which is an unexposed portion is 0.1 μm. The number of the above defects was measured.
Defects were evaluated according to the following evaluation criteria, and the evaluation results are shown in Table 2 as "defects".
Evaluation criteria 〇: 100 pieces or less ×: More than 100 pieces

  In the resist pattern forming methods of Examples 1 to 3 to which the present invention is applied, generation of defects of 0.1 μm or more in the remaining film portion which is an unexposed portion is suppressed as compared with the resist pattern forming methods of Comparative Examples 1 and 2. It was confirmed that. Among them, the resist pattern forming method of Example 3 was particularly effective in suppressing the occurrence of defects, and the effect of suppressing the occurrence of defects was high in the order of Examples 3, 2, and 1.

<Formation of resist pattern (2)>
(Example 4)
On a 12-inch silicon wafer, an organic anti-reflective coating composition "ARC29A" (trade name, manufactured by Brewer Science) is applied using a spinner, baked on a hot plate at 205 ° C. for 60 seconds, and dried. Thus, an organic antireflection film having a thickness of 89 nm was formed.
The resist composition (3) shown in Table 1 was applied on the antireflection film using a coater / developer Lithius (manufactured by Tokyo Electron Limited), and prebaked (PAB) at 105 ° C. for 60 seconds on a hot plate. By performing and drying, a resist film having a thickness of 150 nm was formed.
Next, an ArF exposure apparatus for liquid immersion NSR-S609B [manufactured by Nikon Corporation; NA (numerical aperture) = 1.07, Dipole (in / out = 0.78 / 0.97) with Polano, An immersion medium: water] was selectively irradiated with an ArF excimer laser (193 nm) via a transmission type phase shift mask.
Thereafter, PEB treatment was performed at 100 ° C. for 60 seconds.
Then, using a coater / developer Lithius (manufactured by Tokyo Electron Ltd.), at 23 ° C., a 2.38 mass% TMAH aqueous solution containing acetylene-based activator (trade name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) Alkaline development was performed for 30 seconds, followed by rinsing with pure water for 30 seconds, followed by shaking off and drying.
As a result, a 1: 1 line and space (LS) pattern having a line width of 65 nm and a pitch of 130 nm was formed.

(Comparative Example 3)
An LS pattern was formed in the same manner as in Example 4, except that the developer was changed to a 2.38% by mass aqueous TMAH solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.).

<Evaluation of resist pattern (2)>
[Evaluation of resist pattern shape]
The cross-sectional shape of the LS pattern formed by the above <Formation of resist pattern (2)> was observed using a scanning electron microscope (trade name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and the shape was evaluated. .
As a result, according to the resist pattern forming method of Example 4 to which the present invention was applied, the resist pattern had a high rectangularity and a good shape. On the other hand, the resist pattern forming method of Comparative Example 3 in which the alkaline developer does not contain a nonionic surfactant has a problem in terms of resolution, for example, the alkali developer is less likely to wet the resist film. Has become tapered.

  From the above results, it can be confirmed that according to the resist pattern forming method of the example to which the present invention is applied, it is possible to reduce the occurrence of defects in the unexposed portion of the resist film and to form a resist pattern having a good shape. .

Claims (3)

Step (i) of forming a resist film on a support using the resist composition;
Exposing the resist film to light (ii), and developing the exposed resist film with an alkaline developer containing a nonionic surfactant to form a resist pattern (iii);
A method for forming a resist pattern, comprising:
The resist composition contains a base component (A) whose solubility in an alkali developer changes by the action of an acid, and an acid generator component (B) that generates an acid by exposure to light,
A method for forming a resist pattern, wherein the acid generator component (B) contains a compound (B1) represented by the following general formula (b1-1).

[In the formula, R ₀ ¹⁰¹ is a polycyclic aliphatic hydrocarbon group. However, the hydrogen atom of the polycyclic aliphatic hydrocarbon group may be substituted with a substituent. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ] The method according to claim 1, wherein V ¹⁰¹ is a fluorinated alkylene group. The method according to claim 1, wherein R ₀ ¹⁰¹ is a polycyclic aliphatic hydrocarbon group having a hydroxy group. 4.