JP7270347B2 - Resist pattern forming method - Google Patents

Description

The present invention relates to a resist pattern forming method.

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 and electron beams through a mask having a predetermined pattern. and a developing process to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to dissolve in a developer is called a positive type, and a resist material in which an exposed portion changes to a property that does not dissolve in a developer is called a negative type.
2. Description of the Related Art In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, advances in lithography technology have led to rapid miniaturization of patterns.
As a technique for pattern miniaturization, generally, the wavelength of the exposure light source is shortened (the energy is increased). Specifically, conventionally, ultraviolet rays typified by g-rays and i-rays have been used, but at present, mass production of semiconductor devices using KrF excimer lasers and ArF excimer lasers has started. Electron beams, EUV (extreme ultraviolet rays), X-rays, and the like, which have shorter wavelengths (higher energy) than these excimer lasers, are also being studied.
Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions.
As a resist material that satisfies such requirements, a chemically amplified resist composition containing a base component whose solubility in an alkaline developer changes under the action of acid and an acid generator component that generates acid upon exposure is used. It is

As one method for further improving resolution, a liquid (immersion medium) with a higher refractive index than air is placed between the objective lens of the exposure machine and the sample for exposure (immersion exposure). lithography, so-called liquid immersion lithography (hereinafter sometimes referred to as "immersion exposure"). According to immersion exposure, even if a light source with the same exposure wavelength is used, it is possible to achieve the same high resolution as when a light source with a shorter wavelength is used or when a high NA lens is used. It is said that there is no decrease. Also, immersion exposure can be performed using an existing exposure apparatus. Therefore, immersion exposure has been widely used in recent years because it can realize formation of a resist pattern with low cost, high resolution, and excellent depth of focus. It is said that immersion exposure is effective in forming all kinds of pattern shapes, and that it can be combined with super-resolution techniques such as a phase shift method and a modified illumination method. At present, as the immersion exposure technique, a technique using an ArF excimer laser as a light source is being actively studied. As the immersion medium, water is mainly considered.
It has been proposed to add a fluorine atom-containing compound to the resist composition used for such immersion exposure. For example, Patent Document 1 discloses, as a fluorine atom-containing compound added to a resist composition, a fluorine-containing polymer compound having a structural unit having a fluorine atom and a structural unit derived from (meth)acrylic acid. ing.

JP 2011-13569 A

In the immersion lithography described above, a resist material is required that has properties compatible with the immersion lithography technique in addition to the usual lithography properties (sensitivity, resolution, etching resistance, etc.). For example, in immersion exposure, when the resist film and the immersion solvent come into contact with each other, substances in the resist film are eluted into the immersion solvent (substance elution). Substance elution causes phenomena such as deterioration of the resist layer and change in the refractive index of the immersion solvent, thereby deteriorating the lithography properties. Since the amount of substance elution is affected by the properties of the resist film surface (for example, hydrophilicity, hydrophobicity, etc.), the substance elution can be reduced by, for example, increasing the hydrophobicity of the resist film surface.

By increasing the hydrophobicity of the resist film surface in this way, it is believed that the problems specific to the immersion exposure technology, such as the reduction of substance elution and the improvement of water followability, can be solved.
However, even if the resist film is simply hydrophobized, it has an adverse effect on lithography characteristics and the like. For example, when the hydrophobicity of the resist film increases, there is a problem that defects tend to occur in the resist film after alkali development. In particular, when a pattern is formed using an alkali development process, defects are likely to occur in unexposed areas of the resist film.
Here, the term "defect" refers to general defects detected when a resist pattern after development is observed from directly above, for example, using a surface defect observation apparatus (trade name "KLA") manufactured by KLA-Tencor. These defects include, for example, scum (resist residue) after development, bubbles, dust, and other foreign matter and deposits adhering to the resist pattern surface, bridging between line patterns, and filling of contact hole pattern holes. This refers to defects related to the pattern shape such as , uneven color of the pattern, and the like.
In the resist composition described in Patent Document 1 and the like, the water repellency of the resist film during exposure is enhanced by the fluorine-containing polymer compound during exposure, and the hydrophilic groups are formed during development to make the resist film hydrophilic. We are trying to reduce defects by improving the performance.
However, the conventional resist composition as described in Patent Document 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, it is an object of the present invention to provide a resist pattern forming method capable of reducing the occurrence of defects in unexposed portions of a resist film and forming a resist pattern with a favorable shape.

In the formation of a resist pattern, when the hydrophobicity of the resist film surface increases, there is a problem in terms of resolution, such as difficulty in wetting the resist film with an alkaline developer.
In order to improve the wettability of the alkaline developer with respect to the resist film, a method of adding a surfactant to the alkaline developer has been devised.
However, although the resolution is improved, there is a problem that defects having a size of 0.1 μm or more are likely to occur in the unexposed area of the resist film after development.
Through investigation, the present inventors have found that the above problems can be solved by adopting an acid generator having a specific structure in a resist composition, and completed the present invention.

That is, one aspect of the present invention includes the step (i) of forming a resist film on a support using a resist composition, the step (ii) of exposing the resist film, and the step (ii) of exposing the resist film after the exposure. and developing with an alkaline developer containing a nonionic surfactant to form a resist pattern (iii), wherein the resist composition dissolves in the alkaline developer by the action of an acid. It contains a substrate component (A) whose properties change and an acid generator component (B) that generates an acid upon exposure, and the acid generator component (B) is represented by the following general formula (b1-1): It is a resist pattern formation method including the compound (B1) obtained.

［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, a 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 portion of the resist film, and to form a resist pattern with a favorable shape.

In the present specification and claims, "aliphatic" is defined relative to aromatic to mean groups, compounds, etc. that do not possess aromatic character.
"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.
Unless otherwise specified, the "alkylene group" includes straight-chain, branched-chain and cyclic divalent saturated hydrocarbon groups.
A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group are substituted with halogen atoms, and the halogen atoms include fluorine, chlorine, bromine and iodine atoms.
A "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of an alkyl group or alkylene group have been substituted with fluorine atoms.
A "structural unit" means a monomer unit (monomeric unit) that constitutes a polymer compound (resin, polymer, copolymer).
When describing “optionally having a substituent” or “optionally having a substituent”, when a hydrogen atom (—H) is substituted with a monovalent group, or when a methylene group (—CH ₂ -) is substituted with a divalent group.
“Exposure” is a concept that includes irradiation of radiation in general.

A “structural unit derived from an acrylic ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylic ester.
“Acrylic acid ester” is a compound in which the terminal hydrogen atom of the carboxy group of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the acrylic acid ester, the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. The substituent (R ^α0 ) substituting the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms, a halogenated group having 1 to 5 carbon atoms, An alkyl group and the like can be mentioned. In addition, itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α-hydroxy acrylic esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a modified hydroxyl group thereof are also available. shall include Unless otherwise specified, the α-position carbon atom of the acrylic acid ester means the carbon atom to which the carbonyl group of acrylic acid is bonded.
Hereinafter, an acrylic acid ester in which the hydrogen atom bonded to the α-position carbon atom is substituted with a substituent may be referred to as an α-substituted acrylic acid ester. In addition, acrylic acid esters and α-substituted acrylic acid esters may be collectively referred to as "(α-substituted) acrylic acid esters".

A “structural unit derived from acrylamide” means a structural unit formed by cleavage of an ethylenic double bond of acrylamide.
In acrylamide, a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and one or both hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. Unless otherwise specified, the α-position carbon atom of acrylamide is the carbon atom to which the carbonyl group of acrylamide is bonded.
The substituent for substituting the hydrogen atom bonded to the carbon atom at the α-position of acrylamide is the same as the substituent at the α-position (substituent (R ^α0 )) in the α-substituted acrylic acid ester. mentioned.

A “structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene. A “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 hydroxystyrene in which the α-position hydrogen atom is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. Derivatives thereof include those obtained by substituting the hydrogen atom of the hydroxyl group of hydroxystyrene with an organic group; Examples include those in which a substituent other than a hydroxyl group is bonded to the benzene ring of good hydroxystyrene. In addition, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents at the α-position in the α-substituted acrylic acid ester.

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

"Styrene derivative" is a concept including those in which the α-position hydrogen atom of styrene is substituted with other substituents such as alkyl groups and halogenated alkyl groups, and derivatives thereof. Derivatives thereof include those in which a substituent is bonded to the benzene ring of hydroxystyrene in which the α-position hydrogen atom may be substituted by a substituent. In addition, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.
A "structural unit derived from styrene" and a "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 α-position substituent is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group , n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Further, the halogenated alkyl group as a substituent at the α-position specifically includes a group in which some or all of the hydrogen atoms in the above "alkyl group as a substituent at the α-position" are substituted with halogen atoms. be done. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred.
Further, the hydroxyalkyl group as the α-position substituent specifically includes a group in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the α-position substituent” are substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1-5, most preferably 1.

In the present specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms and may have enantiomers or diastereomers. In that case, one chemical formula represents those isomers. Those isomers may be used singly or as a mixture.

[Resist pattern forming method]
In one aspect of the present invention, using a resist composition, the step (i) of forming a resist film on a support, the step (ii) of exposing the resist film, and the step (ii) of exposing the resist film to a nonionic interface A resist pattern forming method comprising a step (iii) of forming a resist pattern by developing with an alkaline developer containing an activator. The resist composition used contains a base component (A) whose solubility in an alkaline developer changes under the action of an acid and an acid generator component (B) which generates an acid upon exposure. The acid generator component (B) here contains the compound (B1) described below.
One embodiment of such a resist pattern forming method includes, for example, a resist pattern forming method performed as follows.

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

Step (ii):
Next, the resist film is subjected to selective exposure such as exposure through a mask having a predetermined pattern (mask pattern) using, for example, an exposure apparatus.
After that, baking (post-exposure baking (PEB)) treatment is performed at a temperature condition 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 alkaline developer containing a nonionic surfactant to form a resist pattern.

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

The support is not particularly limited, and a conventionally known one can be used. Examples thereof include a substrate for electronic parts and a substrate having a predetermined wiring pattern formed thereon. More specifically, silicon wafers, metal substrates such as copper, chromium, iron, and aluminum substrates, glass substrates, and the like can be used. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be one in which an inorganic and/or organic film is provided on the substrate as described above. Inorganic films include inorganic antireflection coatings (inorganic BARC). Examples of organic films include organic antireflection coatings (organic BARC) and organic films such as a lower layer organic film in a multilayer resist method.
Here, the multi-layer resist method means that at least one layer of organic film (lower layer organic film) and at least one layer of resist film (upper layer resist film) are provided on a substrate, and a resist pattern formed on the upper layer resist film is used as a mask. It is a method of patterning a lower layer organic film, and is said to be capable of forming a pattern with a high aspect ratio. That is, according to the multi-layer resist method, since the required thickness can be secured by the underlying organic film, the resist film can be made thinner, and fine patterns 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 (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) and a method of forming a multi-layered structure of three or more layers (metal thin film, etc.).

The wavelength used for exposure is not particularly limited, and includes ArF excimer laser, KrF excimer laser, _F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, soft X-rays, and the like. It can be done with radiation.

The exposure method of the resist film may be normal exposure (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography.
In immersion exposure, the space between the resist film and the lowest lens of the exposure device is filled in advance with a solvent (immersion medium) having a refractive index greater than that of air, and exposure (immersion exposure) is performed in this state. exposure method.
As the liquid immersion medium, a solvent having a refractive index higher than that of air and lower than that 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 higher than that of air and lower than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents.
Specific examples _of fluorine-based inert liquids include fluorine _- based compounds such _{as C3HCl2F5} , _{C4F9OCH3 , C4F9OC2H5 , and C5H3F7} as _{main components .} Examples include liquids, and those having a boiling point of 70 to 180°C are preferable, and those of 80 to 160°C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point within the above range because the medium used for liquid immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.
Further, specifically, the perfluoroalkyl ether compound includes perfluoro(2-butyl-tetrahydrofuran) (boiling point 102° C.), and the perfluoroalkylamine compound includes perfluorotributylamine ( boiling point 174°C).
Water is preferably used as the immersion medium from the viewpoints of cost, safety, environmental concerns, versatility, and the like.

An alkali developer containing a nonionic surfactant is used as the developer in the step (iii). For example, the developer includes a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution containing a nonionic surfactant.
Further, as the nonionic surfactant contained in the alkaline 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, polyoxyethylene oleyl ether; polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether polyoxyethylene alkyl allyl ethers such as; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate; and polyoxyethylene sorbitan Polyoxyethylene sorbitan fatty acid esters such as monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate; acetylene glycol, acetylene glycol Examples include acetylenes such as oxyethylene adducts.

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

The development treatment can be carried out by a known development method, for example, a method of immersing the support in a developer for a certain period of time (dip method), or a method in which the developer is piled up on the surface of the support by surface tension and remains stationary for a certain period of time. method (paddle method), method of spraying the developer onto the surface of the support (spray method), and application of the developer while scanning the developer dispensing nozzle at a constant speed onto the support rotating at a constant speed. A continuous method (dynamic dispensing method) and the like can be mentioned.

Rinsing treatment (cleaning treatment) using a rinse liquid can be performed by a known rinsing method. The rinsing method includes, for example, a method of continuously applying the rinse solution onto the support rotating at a constant speed (rotation coating method), a method of immersing the support in the rinse solution for a given period of time (dip method), A method of spraying a rinsing liquid onto the support surface (spray method) and the like can be mentioned.

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

The resist composition of the present embodiment comprises a base component (A) (hereinafter also referred to as "(A) component") whose solubility in an alkaline developer changes under the action of acid, and an acid generator that generates acid upon exposure. A compound (B1) (hereinafter referred to as "(B1) component ”).
When a resist film is formed using such a resist composition and the resist film is selectively exposed to light, an acid is generated in the exposed portion, and the action of the acid reduces the solubility of the component (A) in an alkaline developer. changes, while the solubility of the component (A) in an alkaline developer does not change in the unexposed areas. Therefore, when the resist film is developed, a resist pattern is formed.

For example, when a substrate component (A-1) (hereinafter referred to as "(A-1) component"), which is sparingly soluble in an alkaline developer and increases in polarity by the action of an acid, is used as the component (A). When acid is generated by exposure, the exposed portion of the resist film changes from poorly soluble to soluble in an alkaline developer, while the unexposed portion of the resist film remains poorly soluble in alkali. Thus, a positive resist pattern is formed.
On the other hand, when a base component (A-2) soluble in an alkaline developer (hereinafter also referred to as "(A-2) component") is used as the component (A), and a cross-linking agent component is added. When an acid is generated by exposure, the acid acts to cause cross-linking between the component (A-2) and the cross-linking agent component, resulting in a decrease in solubility in an alkaline developer. Therefore, the exposed portion of the resist film becomes insoluble in the alkaline developer, while the unexposed portion of the resist film remains soluble in the alkaline developer. A pattern is formed.

The resist composition has the ability to generate an acid upon exposure, and in addition to the component (B), the component (A) may also generate an acid upon exposure.
When the component (A) generates an acid upon exposure, this component (A) is a "base component that generates an acid upon exposure and changes its solubility in a developer by the action of the acid".
When the component (A) is a substrate component that generates an acid upon exposure and changes its solubility in a developer by the action of the acid, the component (A1) described later generates an acid upon exposure and It is preferably a polymer compound whose solubility in a developer is changed by the action of an acid. Examples of such polymer compounds include resins having structural units that generate acid upon exposure. A known monomer can be used as a monomer that induces a structural unit that generates an acid upon exposure.

<(A) Component>
The (A) component of the resist composition in this embodiment is a base component whose solubility in a developer changes under the action of acid.
In the present invention, the "substrate component" is an organic compound having film-forming ability, preferably an organic compound having a molecular weight of 500 or more. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved, and in addition, it becomes easy to form a nano-level resist pattern.
The organic compounds used as the base component are roughly classified into non-polymers and polymers.
As the non-polymer, one having a molecular weight of 500 or more and less than 4000 is usually used. Hereinafter, the term "low-molecular-weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4,000.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, "resin", "polymer compound" or "polymer" refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-equivalent weight-average molecular weight obtained by GPC (gel permeation chromatography) is used.

When the resist composition in the present embodiment is a "negative resist composition for an alkali development process" that forms a negative resist pattern in an alkali development process, as described above, the component (A-2) and the cross-linking agent component is used.
As the (A-2) component, a resin soluble in an alkaline developer (hereinafter referred to as "alkali-soluble resin") is preferably used.
Examples of alkali-soluble resins include α-(hydroxyalkyl)acrylic acid or alkyl esters of α-(hydroxyalkyl)acrylic acid (preferably having 1 to 5 carbon atoms) disclosed in JP-A-2000-206694. A resin having a structural unit derived from at least one selected from alkyl esters); the hydrogen atom bonded to the α-position carbon atom having a sulfonamide group, which is disclosed in U.S. Pat. No. 6,949,325, is substituted with a substituent acrylic resin or polycycloolefin resin that may be used; Acrylic resins in which hydrogen atoms bonded to carbon atoms may be substituted with substituents; It is preferable because a resist pattern can be formed.
In the α-(hydroxyalkyl)acrylic acid, among the acrylic acids in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, hydrogen is attached to the carbon atom at the α-position to which the carboxy group is bonded. one or both of acrylic acid to which an atom is bonded and α-hydroxyalkyl acrylic acid to which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is 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, since a good resist pattern with little swelling is easily formed. . The amount of the cross-linking agent component to be blended 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 this embodiment is a "positive resist composition for an alkali development process" that forms a positive resist pattern in an alkali development process, component (A-1) is used as described above.
Component (A) is preferably component (A-1).

The (A) component of the resist composition in this embodiment may be used singly or in combination of two or more.
When the (A) component is the (A-1) component, the (A-1) component preferably contains a resin component (A1) (hereinafter also referred to as “(A1) component”).

• 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 under the action of an acid.
As the component (A1), in addition to the structural unit (a1), those having a structural unit (a2) containing a lactone-containing cyclic group, a —SO ₂ —-containing cyclic group or a carbonate-containing cyclic group are also preferred. .
Further, as the (A1) component, 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) (except where applicable) are also preferred.
In addition, the component (A1) may have structural units other than the structural unit (a1), the structural unit (a2), and the structural unit (a3).

<<Constituent unit (a1)>>
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases under the action of acid.
An "acid-decomposable group" is a group having acid-decomposability such that at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid.
The acid-decomposable group whose polarity is increased by the action of an acid includes, for example, a group that is decomposed by the action of an acid to form a polar group.
Polar groups include, for example, a carboxy group, a hydroxyl group, an amino group, and a sulfo group (--SO ₃ H). Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferred, a carboxy group or a hydroxyl group is more preferred, and a carboxy group is particularly preferred.
More specifically, the acid-decomposable group includes a group in which the polar group is protected with an acid-labile group (for example, a group in which the hydrogen atom of the OH-containing polar group is protected with an acid-labile group).

The term "acid-dissociable group" as used herein means (i) a group having acid-dissociable properties in which the 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 some bonds are cleaved by the action of an acid, decarboxylation further occurs to cleave the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group; It refers to both the group to obtain.
The acid-labile group that constitutes the acid-labile group must be a group with a lower polarity than the polar group generated by the dissociation of the acid-labile group, so that the acid-labile group can be decomposed by the action of an acid. When is dissociated, a polar group having a higher polarity than the acid-dissociable group is generated and the polarity is increased. 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 acid-dissociable groups include those that have hitherto been proposed as acid-dissociable groups for base resins for chemically amplified resist compositions.
Specific examples of acid-dissociable groups proposed as base resins for chemically amplified resist compositions include "acetal-type acid-dissociable groups" and "tertiary alkyl ester-type acid-dissociable groups" described below. group" and "tertiary alkyloxycarbonyl acid dissociable group".

Acetal-type acid-labile group:
Examples of the acid-dissociable group protecting the carboxy group or hydroxyl group among the polar groups include acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter referred to as "acetal-type acid-dissociable groups" There is a thing.) is mentioned.

［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 hydrogen atoms or alkyl groups. Ra' ³ is a hydrocarbon group, and Ra' ³ may combine with either Ra' ¹ or 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, 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 exemplified as the substituents that may be bonded to the α-position carbon atom in the explanation of the α-substituted acrylic acid ester. The same groups can be mentioned, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More 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, and a neopentyl group, and a methyl group or an ethyl group is More preferred, and a methyl group is particularly preferred.

In formula (a1-r-1), examples of the hydrocarbon group for Ra' ³ include linear or branched alkyl groups and cyclic hydrocarbon groups.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group and the like. 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 chain alkyl group preferably has 3 to 10 carbon atoms, 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, with an isopropyl group being preferred.

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 a monocyclic aliphatic hydrocarbon 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.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When the cyclic hydrocarbon group for 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 aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.
Specifically, the aromatic hydrocarbon group for Ra' ³ is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); A group obtained by removing one hydrogen atom from an aromatic compound containing (e.g., biphenyl, fluorene, etc.); , phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly 1. preferable.

The cyclic hydrocarbon group for Ra' ³ may have a substituent. Examples of this substituent include -R ^P1 , -R ^P2 -OR P1 , -R ^P2 -CO-R ^P1 , -R ^P2 -CO-OR ^P1 , -R ^{P2 -O} -CO-R ^P1 , -R ^P2 -OH, -R ^P2 -CN or -R ^P2 -COOH (hereinafter, these substituents are collectively referred to as "Ra ⁰⁵ "), and the like.
Here, R ^P1 is a monovalent chain 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 group having 6 to 30 carbon atoms. is a group hydrocarbon group. R ^P2 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 divalent hydrocarbon group having 6 to 30 carbon atoms. is an aromatic hydrocarbon group. However, some or all of the hydrogen atoms of the chain saturated hydrocarbon groups, aliphatic cyclic saturated hydrocarbon groups and aromatic hydrocarbon groups 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 substituents, or may have one or more of each of a plurality of the above substituents.
Examples of monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and decyl group. .
Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group and the like. 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 , tetracyclo[6.2.1.13,6.02,7]dodecanyl group and polycyclic aliphatic saturated hydrocarbon group such as adamantyl group.
Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

When Ra' ³ combines with either Ra' ¹ or 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 above polar groups, the acid-dissociable group protecting the carboxy group includes, for example, an acid-dissociable group represented by the following general formula (a1-r-2).
Among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may hereinafter be referred to as "tertiary alkyl ester-type acid-dissociable groups" 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, each of Ra' ⁴ to Ra' ⁶ is a hydrocarbon group, and Ra' ⁵ and Ra' ⁶ may combine with each other to form a ring. ]

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

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) or 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, groups represented by the following general formula (a1-r2-4) are suitable.

［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 attached. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms of this cyclic hydrocarbon group may be substituted. Ra ⁰¹ to Ra ⁰³ are each independently a hydrogen atom, a monovalent chain 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 in this chain saturated hydrocarbon group and aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra ⁰¹ to Ra ⁰³ may combine with each other to form a cyclic structure. In 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 optionally substituted aromatic hydrocarbon group. In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted. Ra' ¹⁴ is a hydrocarbon group optionally having a substituent. * indicates a bond (same below). ]

［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。］

[In the formula, Ya ⁰ is a quaternary carbon atom. Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group optionally having a substituent. However, one or more 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 for Ra' ¹⁰ is the linear or branched alkyl group for 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 carbon atoms next to Ya ⁰ (carbon atom).

In the formula (a1-r2-r1), Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are each independently a hydrocarbon group which may have a substituent. The hydrocarbon groups for 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 for Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group and the like. 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 ⁰³¹ , Ra ⁰³² and Ra ⁰³³ preferably has 3 to 10 carbon atoms, 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, with an isopropyl group being preferred.
The chain or cyclic alkenyl group for 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 a monocyclic aliphatic hydrocarbon 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.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically includes 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 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 aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specifically, the aromatic hydrocarbon group includes a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); A group obtained by removing one hydrogen atom from a compound (e.g., biphenyl, fluorene, etc.); A group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., benzyl group, phenethyl group , 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl group such as 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

When the hydrocarbon groups represented by the above Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are substituted, the substituents include, for example, a hydroxy group, a carboxy group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc. ), alkoxy groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl groups, and the like.

Among the above, the optionally substituted hydrocarbon group in Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is preferably an optionally substituted linear or branched alkyl group, A straight-chain alkyl group is more preferred.

However, one or more of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ is a hydrocarbon group having at least a polar group.
The term “hydrocarbon group having a polar group” means a hydrocarbon group in which a methylene group (—CH ₂ —) constituting the hydrocarbon group is substituted with a polar group, or at least one hydrogen atom constituting the hydrocarbon group is Any one substituted on a polar group is included.
As such a “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 heteroatom. Ra ⁰⁶ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. n _p0 is an integer from 1-6. ]

In the formula (a1-p1), Ra ⁰⁷ represents a divalent hydrocarbon group having 2 to 12 carbon atoms.
Ra ⁰⁷ has 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 2 carbon atoms.
The hydrocarbon group for Ra ⁰⁷ is preferably a chain or cyclic aliphatic hydrocarbon group, more preferably a chain hydrocarbon group.
Examples of Ra ⁰⁷ include 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; cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, cyclooctane-1 Cycloalkanediyl groups such as ,5-diyl group; A cyclic divalent alicyclic hydrocarbon group and the like are included.
Among the above, an alkanediyl group is preferred, and a linear alkanediyl group is more preferred.

In the above formula (a1-p1), Ra ⁰⁸ represents a divalent linking group containing a heteroatom.
Examples of Ra ⁰⁸ include -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 -, - and S(=O) ₂ -O-.
Among these, -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O- are preferred from the viewpoint of solubility in the 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, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, even more preferably 1 to 3 carbon atoms, from the viewpoint of solubility in a developer. 1 or 2 are particularly preferred, and 1 is most preferred.

The hydrocarbon group for Ra ⁰⁶ may be a chain hydrocarbon group, a cyclic hydrocarbon group, or a hydrocarbon group combining a chain and a cyclic hydrocarbon group.
Chain hydrocarbon groups include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n -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. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methyl Cycloalkyl groups such as cyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group and cyclodecyl group can be mentioned. Polycyclic alicyclic hydrocarbon groups include, for example, decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1-(adamantan-1-yl)alkane-1-yl group, norbornyl group, methylnorbornyl group, isobornyl group, and the like.
Examples of aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl and mesityl groups. , biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and the like.

From the viewpoint of solubility in a developer, Ra ⁰⁶ is preferably a chain hydrocarbon group, more preferably an alkyl group, and still more preferably a linear alkyl group.

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 that binds to the quaternary carbon atom (Ya ⁰ ).

In the above formula (a1-r2-r1), among Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ , the number of hydrocarbon groups having at least a polar group is one or more. For example, one or two of Ra ⁰³¹ , Ra ⁰³² and Ra ⁰³³ are preferable, and one is particularly preferable.

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

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

In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes a cyclic ^monovalent hydrocarbon group (aliphatic (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 this substituent include those similar to the substituents that the cyclic hydrocarbon group in the above Ra' ³ may have.
In formula (a1-r2-2), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra ⁰¹ to Ra ⁰³ includes, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group and the like.
Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms in Ra ⁰¹ to Ra ⁰³ include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclodecyl. monocyclic aliphatic saturated hydrocarbon groups such as 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, and polycyclic aliphatic saturated hydrocarbon groups such as adamantyl group.
Among them, Ra ⁰¹ to Ra ⁰³ are preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, from the viewpoint of facilitating the synthesis of the monomer compound from which the structural unit (a1) is derived. Among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

Examples of substituents possessed by the chain saturated hydrocarbon groups or aliphatic cyclic saturated hydrocarbon groups represented by Ra ⁰¹ to Ra ⁰³ include the same groups as those for Ra ⁰⁵ above.

Examples of the group containing a carbon-carbon double bond produced by forming a cyclic structure by bonding two or more of Ra ⁰¹ to Ra ⁰³ to each other include, for example, a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methyl A cyclohexenyl group, a cyclopentylideneethenyl group, a cyclohexylideneethenyl group and the like can be mentioned. Among these, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis of the monomer compound from which the structural unit (a1) is derived.

In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is a monocyclic group or polycyclic group of Ra' ³ in formula (a1-r-1). The groups mentioned as hydrogen groups are preferred.
In formula (a1-r2-3), examples of the aromatic hydrocarbon group for Ra ⁰⁴ include groups obtained by removing one or more hydrogen atoms 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, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene. 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 benzene or naphthalene is particularly preferable, and a group obtained by removing one or more hydrogen atoms from benzene is most preferable. preferable.

Examples of substituents that Ra ⁰⁴ in formula (a1-r2-3) may have include methyl group, ethyl group, propyl group, hydroxy group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), alkoxy groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), alkyloxycarbonyl groups, and the like.

In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain 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 for Ra' ¹² and Ra' ¹³ includes the monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms for Ra ⁰¹ to Ra ⁰³ above. The same as the group can be mentioned. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted.
Ra' ¹² and Ra' ¹³ are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and particularly a methyl group. preferable.
When the chain saturated hydrocarbon groups represented by Ra' ¹² and Ra' ¹³ are substituted, examples of the substituent include groups similar to those of Ra ⁰⁵ above.

In formula (a1-r2-4), Ra' ¹⁴ is a hydrocarbon group which may have a substituent. The hydrocarbon group for Ra' ¹⁴ includes linear or branched alkyl groups and cyclic hydrocarbon groups.

The linear alkyl group for Ra' ¹⁴ preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group and the like. 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 for Ra' ¹⁴ preferably has 3 to 10 carbon atoms, 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, with an isopropyl group being preferred.

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 a monocyclic aliphatic hydrocarbon 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.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

Examples of the aromatic hydrocarbon group for ^Ra'14 include those similar to the aromatic hydrocarbon group for ^Ra04 . Among them, 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 preferred, a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene is particularly preferred, and a group obtained by removing one or more hydrogen atoms from naphthalene is Most preferred.
Examples of the substituent that Ra' ¹⁴ may have include the same substituents that Ra ⁰⁴ may have.

When Ra' ¹⁴ in formula (a1-r2-4) is a naphthyl group, the position bonding to the tertiary carbon atom in formula (a1-r2-4) is the 1- or 2-position of the naphthyl group. Either can be used.
When Ra' ¹⁴ in formula (a1-r2-4) is an anthryl group, the position bonding to the tertiary carbon atom in formula (a1-r2-4) is the 1-position, 2-position, or Any of the ninth positions 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, the acid-dissociable group that protects the hydroxyl group includes, for example, an acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as "tertiary alkyloxycarbonyl acid-dissociable group ) can be mentioned.

［式中、Ｒａ’^７～Ｒａ’^９はそれぞれアルキル基である。］

[In the formula, each of Ra' ⁷ to Ra' ⁹ is an alkyl group. ]

In formula (a1-r-3), each of Ra' ⁷ to Ra' ⁹ is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms.
The total carbon number of each alkyl group is preferably 3-7, more preferably 3-5, and most preferably 3-4.

As the structural unit (a1), a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, a structural unit derived from acrylamide, hydroxystyrene or hydroxy - of structural units derived from vinyl benzoic acid or vinyl benzoic acid derivatives, wherein at least part of the hydrogen atoms in the hydroxyl groups of structural units derived from styrene derivatives are protected by substituents containing the acid-decomposable groups Structural units in which at least part of the hydrogen atoms in C(=O)--OH are protected by a substituent containing the acid-decomposable group are exemplified.

As the structural unit (a1), among the above, a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent is preferable.
Preferred specific examples of such a structural unit (a1) include structural units 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 optionally having an ether bond. n _a1 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 an n _a2 + monovalent hydrocarbon group, n _a2 is an integer of 1 to 3, and Ra ² is represented by the above general formula (a1-r-1) or (a1-r-3) is an acid-dissociable group. ]

In the above formula (a1-1), the alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and 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. A halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred.
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 view of industrial availability.

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

The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specifically, the aliphatic hydrocarbon group includes a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, and the like.

The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, a methylene group [ _--CH.sub.2-- ], an ethylene group [--( _CH.sub.2 ) _.sub.2-- ], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -] and the like.
The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) _2- , -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups;- 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ — and —CH ₂ CH(CH ₃ )CH ₂ CH ₂ —. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

The aliphatic hydrocarbon group containing a ring in the structure includes an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group intervenes 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 or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, 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. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group as the divalent hydrocarbon group for 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 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most 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 aromatic rings possessed by aromatic hydrocarbon groups include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; Atom-substituted heteroaromatic rings and the like are included. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like.
Specifically, the aromatic hydrocarbon group includes a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group ) in which one of the hydrogen atoms is substituted with an alkylene group (e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl such as 2-naphthylethyl group group obtained by removing one hydrogen atom from the aryl group in the group), and the like. 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.

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

In the formula (a1-2), the n _a2 +1 valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and 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 Groups combined with an aliphatic hydrocarbon group containing a ring in the structure can be mentioned.
The n _a2 +1 valence is preferably 2 to 4 valences, more preferably 2 or 3 valences.

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

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

Specific examples of the structural unit represented by 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 above formula (a1-1) is more preferable.
Among these, as the structural unit (a1), one containing a structural unit represented by the following general formula (a1-1-1) is particularly preferable.

［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 formula (a1-1-1), R, Va ¹ and n _a1 are the same as R, Va ¹ and n _a1 in formula (a1-1).
The explanation of the acid dissociable group represented by general formula (a1-r2-1) is as described above.

The ratio of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol%, preferably 10 to 75 mol%, relative to the total (100 mol%) of all structural units constituting the component (A1). More preferably, 20 to 60 mol % is even more preferable.
By setting the proportion of the structural unit (a1) to be at least the lower limit of the preferred range, lithography properties such as sensitivity, resolution, and improvement in roughness are improved. On the other hand, if it is at most the upper limit of the above preferable range, the balance with other structural units can be achieved, and various lithography properties will be improved.

<<Constituent unit (a2)>>
In addition to the structural unit (a1), the component (A1) further comprises a structural unit (a2) containing a lactone-containing cyclic group, a —SO ₂ —-containing cyclic group or a carbonate-containing cyclic group (with the proviso that the structural unit ( a1) is preferable.
The lactone-containing cyclic group, —SO ₂ —-containing cyclic group, or carbonate-containing cyclic group of the structural unit (a2) contributes to the adhesion of the resist film to the substrate when the component (A1) is used to form the resist film. It is an effective one in terms of enhancing sexuality. 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 enhanced, the solubility during development is appropriately adjusted, the etching resistance is improved, and the like. Due to the effect of , lithography properties and the like are improved.

A “lactone-containing cyclic group” refers to a cyclic group containing a ring containing —O—C(=O)— in its ring skeleton (lactone ring). A lactone ring is counted as the first ring, and a group containing only a lactone ring is called a monocyclic group, and a group containing other ring structures is called a polycyclic group regardless of the structure. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
Any lactone-containing cyclic group in the structural unit (a2) can be used without particular limitation. Specific examples include groups represented by general formulas (a2-r-1) to (a2-r-7) below.

［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。］

[In the formula, each 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; Yes; 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; A″ is an oxygen atom (—O—) or a sulfur atom (— S—), an alkylene group having 1 to 5 carbon atoms, 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 methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred.
As the alkoxy group for Ra' ²¹ , an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specific examples include groups in which the alkyl group exemplified as the alkyl group for Ra' ²¹ and an oxygen atom (--O--) are linked.
The halogen atom for Ra' ²¹ includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferred.
Examples of the halogenated alkyl group for Ra' ²¹ include groups in which part or all of the hydrogen atoms of the alkyl group for Ra' ²¹ are substituted with the above-described 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 either a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ -containing cyclic group. 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. or a group obtained by removing one or more hydrogen atoms from monocycloalkane which may or may not be substituted with a fluorinated alkyl group; polycycloalkane such as bicycloalkane, tricycloalkane and tetracycloalkane Examples include groups obtained by removing one or more hydrogen atoms from, etc. More specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; Examples include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as cyclodecane and tetracyclododecane.
As the lactone-containing cyclic group for R″, the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7) can be mentioned.
The carbonate-containing cyclic group for R" is the same as the carbonate-containing cyclic group described later, and specifically groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. is mentioned.
The —SO ₂ -containing cyclic group in R″ is the same as the —SO ₂ -containing cyclic group described later, and specifically, general formulas (a5-r-1) to (a5-r-4) The group represented respectively by is mentioned.
The hydroxyalkyl group for Ra' ²¹ preferably has 1 to 6 carbon atoms, and specific examples include groups in which at least one hydrogen atom of the alkyl group for Ra' ²¹ is substituted with a hydroxyl group. .

In the general formulas (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A″ is a linear or branched An alkylene group is preferred, and includes 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 include the terminal of the alkylene group or the carbon Groups having -O- or -S- interposed between atoms, such as -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH _A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

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

“—SO ₂ —containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in its ring skeleton, and specifically, the sulfur atom (S) in —SO ₂ — is A cyclic group that forms part of the ring skeleton of a cyclic group. A ring containing —SO ₂ — in its ring skeleton is counted as the first ring, and if it contains only this ring, it is a monocyclic group, and if it has another ring structure, it is a polycyclic group regardless of its structure. called. The —SO ₂ —containing cyclic group may be a monocyclic group or a polycyclic group.
A —SO ₂ —containing cyclic group is particularly a cyclic group containing —O—SO ₂ — in its ring skeleton, ie, —O—S— in —O—SO ₂ — forms part of the ring skeleton. Preferred are cyclic groups containing a forming sultone ring.
More specific examples of the —SO ₂ —containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) below.

［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。］

[In the formula, each 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; Yes; 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; A″ is a carbon optionally containing an oxygen atom or a sulfur atom It is an alkylene group of numbers 1-5, an oxygen atom or a sulfur atom, and n' is an integer of 0-2. ]

In the general formulas (a5-r-1) to (a5-r-2), A″ is the general formulas (a2-r-2), (a2-r-3), (a2-r-5) It is the same as A” in the middle.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group in Ra' ⁵¹ are represented by the general formulas (a2-r-1) to ( Examples are the same as those mentioned in the description of Ra' ²¹ in a2-r-7).
Specific examples of groups represented by general formulas (a5-r-1) to (a5-r-4) are shown below. "Ac" in the formula represents an acetyl group.

A “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C(═O)—O— in its ring skeleton. The carbonate ring is counted as the first ring, and the group containing only the carbonate ring is called a monocyclic group, and the group containing other ring structures is called a polycyclic group regardless of the structure. A carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
Any carbonate ring-containing cyclic group can be used without particular limitation. Specific examples include groups represented by general formulas (ax3-r-1) to (ax3-r-3) below.

［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, each ^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; Yes; 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; A″ is a carbon optionally containing an oxygen atom or a sulfur atom 1 to 5 alkylene groups, oxygen atoms or sulfur atoms, 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″ is the general formulas (a2-r-2), (a2-r-3), (a2-r-5) It is the same as A” in the middle.
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group in Ra' ³¹ are represented by the general formulas (a2-r-1) to ( Examples are the same as those mentioned in the description of Ra' ²¹ in a2-r-7).
Specific examples of groups represented by general formulas (ax3-r-1) to (ax3-r-3) are shown below.

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

［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 is not -CO-. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or a —SO ₂ —-containing cyclic group. ]

In formula (a2-1), R is the same as defined above. 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 is particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.

In the above formula (a2-1), the divalent linking group for Ya ²¹ is not particularly limited, but is an optionally substituted divalent hydrocarbon group, a divalent linking group containing a hetero atom. etc. are preferably exemplified. The description of the optionally substituted divalent hydrocarbon group and heteroatom-containing divalent linking group for Ya ²¹ is the same as for Ya ^x1 in the above general formula (a10-1). The same applies to the divalent hydrocarbon group optionally having a group and the divalent linking group containing a heteroatom.
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 formula (a2-1) above, Ra ²¹ is a lactone-containing cyclic group, —SO ₂ —-containing cyclic group or carbonate-containing cyclic group.
The lactone-containing cyclic group, —SO ₂ —-containing cyclic group, and carbonate-containing cyclic group for Ra ²¹ are represented by the above-described general formulas (a2-r-1) to (a2-r-7), respectively. groups, groups represented by general formulas (a5-r-1) to (a5-r-4), groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively are preferably mentioned.
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 -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 group represented by lc-6-1), (r-sl-1-1) and (r-sl-1-18) is more preferred.

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 proportion of the structural unit (a2) is 20 to 70 mol% with respect to the total (100 mol%) of all structural units constituting the component (A1). and more preferably 40 to 60 mol %.
By setting the ratio of the structural unit (a2) to a preferable lower limit or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and when the ratio is equal to or less than the upper limit, balance with other structural units is achieved. and various lithographic properties are improved.

<<Structural unit (a3)>>
In addition to the structural unit (a1), the component (A1) further includes a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (provided that the structural unit (a1) and the structural unit (a2) are ) is preferred. The (A1) component has the structural unit (a3), so that, for example, the acid diffusion length is appropriately adjusted, the adhesion of the resist film to the substrate is enhanced, the solubility during development is appropriately adjusted, and the etching resistance is improved. The lithographic properties and the like are improved due to the effect of improving the properties.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a portion of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, and the like, with the hydroxyl group being particularly preferred.
Examples of the aliphatic hydrocarbon group include linear or branched hydrocarbon groups (preferably alkylene groups) having 1 to 10 carbon atoms and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be either a monocyclic group or a polycyclic group, and can be appropriately selected from a number of groups proposed for use in resins for ArF excimer laser resist compositions, for example. The cyclic group is preferably a polycyclic group, more preferably having 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a portion of the hydrogen atoms of the alkyl group is substituted with fluorine atoms is more preferred. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, 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 Industrially preferred.

Any structural unit (a3) can be used without particular limitation as long as it contains a polar group-containing aliphatic hydrocarbon group.
The structural unit (a3) is a structural unit derived from an acrylic ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent and includes a polar group-containing aliphatic hydrocarbon group. A building block is preferred.
As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, it is derived from hydroxyethyl ester of acrylic acid. are preferred.
Further, as the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), -2) and structural units represented by formula (a3-3) are preferred.

［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 the 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, l is an integer of 1 to 5 and s is an integer from 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, more preferably 1. When j is 2, hydroxyl groups are preferably bonded to the 3- and 5-positions of the adamantyl group. When j is 1, a hydroxyl group is preferably bonded to the 3-position of the adamantyl group.
j is preferably 1, and particularly preferably a hydroxyl group is bonded to the 3-position of the adamantyl group.

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

In formula (a3-3), t' is preferably 1. l is preferably one. Preferably, s is 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxyl group of acrylic acid. The fluorinated alkyl alcohol is preferably attached to the 5- or 6-position of the norbornyl group.

The structural unit (a3) contained in the component (A1) may be of one type or two or more types.
When the component (A1) has a structural unit (a3), it is preferably 1 to 40 mol%, more preferably 10 to 30 mol%, based on the total of all structural units constituting the component (A1). 20 to 30 mol % is more preferable.
By setting the ratio of the structural unit (a3) to the lower limit of the preferred range or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and the ratio is the upper limit of the preferred range or less. , can be balanced with other structural units, and various lithographic properties are improved.

≪Other structural units≫
The component (A1) may have structural units 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 later, a structural unit (a9) represented by the general formula (a9-1), a structural unit derived from styrene (provided that the structural unit (excluding those corresponding to (a10)), structural units (a4) containing an acid-nondissociable aliphatic cyclic group, and the like.

<<Structural Unit (a10) Containing a Hydroxystyrene Skeleton>>
The component (A1) preferably has a structural unit (a10) containing 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 suitable.

［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 a (n _ax1 +1) valent aromatic hydrocarbon group. n _ax1 is an integer of 1-3. ]

In formula (a10-1) above, 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, methyl group, 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 for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred.
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 view of industrial availability.

In the formula (a10-1), Ya ^x1 is a single bond or a divalent linking group.
As the divalent linking group for Ya ^x1 , for example, a divalent hydrocarbon group optionally having a substituent and a divalent linking group containing a hetero atom are preferred.

- A divalent hydrocarbon group which may have a substituent:
When Ya ^x1 is an optionally substituted divalent hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

Aliphatic Hydrocarbon Group in Ya ^x1 The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing rings in their structures.

... 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, and Numbers 1 to 4 are more preferred, and carbon numbers 1 to 3 are most preferred.
As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, a methylene group [ _--CH.sub.2-- ], an ethylene group [--( _CH.sub.2 ) _.sub.2-- ], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -] and the like.
The branched chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) _2- , -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups;- 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ — and —CH ₂ CH(CH ₃ )CH ₂ CH ₂ —. 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 fluorine-substituted fluorinated alkyl group having 1 to 5 carbon atoms, and a carbonyl group.

... Aliphatic hydrocarbon group containing a ring in its structure The aliphatic hydrocarbon group containing a ring in its structure is 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, the cyclic aliphatic groups in which a group hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include those mentioned above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
A 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. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

A 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, a carbonyl group and the like.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group. A methoxy group and an ethoxy group are most preferred.
The halogen atom as the substituent includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferred.
Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a heteroatom-containing substituent. Preferred heteroatom-containing substituents are -O-, -C(=O)-O-, -S-, -S(=O) ₂ - and -S(=O) ₂ -O-.

Aromatic Hydrocarbon Group for 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 aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.
Specific examples of the aromatic hydrocarbon group include groups obtained by removing two hydrogen atoms from the above aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); aromatic compounds containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (e.g., biphenyl, fluorene, etc.); One of the hydrogen atoms of the group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) A group in which one is substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a hydrogen from an arylalkyl group such as a 2-naphthylethyl group) group from which one atom has been further removed), and the like. The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

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.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
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 bivalent linking group containing a heteroatom:
When Ya ^x1 is a divalent linking group containing a hetero atom, the linking group is preferably -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-, general 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 a group represented by —Y ²¹ —S(=O) ₂ —O—Y ²² — [wherein Y ²¹ and Y ²² each independently have a substituent and is a divalent hydrocarbon group, O is an oxygen atom, and m″ is an integer of 0-3. ] and the like.
The divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH )—, the H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
general formulas -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 -, Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent. (divalent hydrocarbon group optionally having substituent(s)).
Y ²¹ is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkylene group, more preferably a straight-chain alkylene group having 1 to 5 carbon atoms, particularly a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms, more preferably a straight-chain alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula -[Y ²¹ -C(=O)-O] _m″ -Y ²² -, m″ is an integer of 0 to 3, preferably an integer of 0 to 2, and 0 or 1 is more preferred, and 1 is particularly preferred. That is, the group represented by the formula -[Y ²¹ -C(=O)-O] _m″ -Y ²² - is represented by the formula -Y ²¹ -C(=O)-O-Y ²² - is particularly preferred, and among these, a group represented by the formula —(CH ₂ ) _a′ —C(═O)—O—(CH ₂ ) _b′ —, in which a′ is 1 to 10 is an integer of 1 to 8, preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, and 1 to 8 An integer is preferred, an integer from 1 to 5 is more preferred, 1 or 2 is more preferred, and 1 is most preferred.

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

In the formula (a10-1), Wa ^x1 is a (n _ax1 +1)-valent aromatic hydrocarbon group.
Examples of the aromatic hydrocarbon group for Wa ^x1 include groups obtained by removing (n _ax1 +1) hydrogen atoms from an aromatic ring. 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 aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings.

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

Specific examples of the structural unit represented by the general formula (a10-1) are shown below.
In the formula below, 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.
The ratio of the structural unit (a10) in the component (A1) is, for example, 0 to 80 mol%, 10 to 80%, relative to the total (100 mol%) of all structural units constituting the component (A1). mol % is preferred, 20 to 70 mol % is more preferred, and 30 to 60 mol % is particularly preferred.
By setting the proportion of the structural unit (a10) to be at least the lower limit of the preferred range, lithography properties such as sensitivity, resolution, and improvement in roughness are improved. On the other hand, if it is at most the upper limit of the above preferable range, the balance with other structural units can be achieved, and various lithography properties will be improved.

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

［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 optionally having a substituent. ]

In formula (a9-1), R is the same as defined above.
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 is particularly preferably a hydrogen atom or a methyl group in terms of industrial availability.

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

In formula (a9-1), the divalent linking group for Ya ⁹² includes the same divalent linking group for Ya ^x1 in general formula (a10-1) described above.
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 for 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)-, general 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 - a group represented by Y ²¹ -OC(=O)-Y ²² - [wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group optionally having a substituent; , O is an oxygen atom, and m′ is an integer of 0-3. ] and the like. Of these, -C(=O)- and -C(=S)- are preferred.

In the above formula (a9-1), the hydrocarbon group for R ⁹¹ includes an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, an aralkyl group and the like.
The alkyl group for R ⁹¹ preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, even 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. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclobutane, cyclopentane, cyclohexane and the like. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The aryl group for R ⁹¹ preferably has 6 to 18 carbon atoms, more preferably 6 to 10 carbon atoms, and more preferably a phenyl group.
The aralkyl group for R ⁹¹ is preferably an aralkyl group in which an alkylene group having 1 to 8 carbon atoms and the above “aryl group for R ⁹¹ ” are bonded, and an alkylene group having 1 to 6 carbon atoms and the above “aryl group for R ⁹¹ is more preferable, and an aralkyl group in which an alkylene group having 1 to 4 carbon atoms is bonded to the above-mentioned "aryl group for R ⁹¹ " is particularly preferable.
The hydrocarbon group for R ⁹¹ is preferably partially or entirely substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms in the hydrocarbon group are substituted with fluorine atoms. more preferably. Among them, a perfluoroalkyl group in which all the hydrogen atoms of the alkyl group described above are substituted with fluorine atoms is particularly preferable.

The hydrocarbon group for R ⁹¹ may have a substituent. Examples of the substituent include halogen atoms, oxo groups (=O), hydroxy groups (--OH), amino groups (--NH ₂ ), --SO ₂ --NH ₂ and the like. Also, some of the carbon atoms constituting the hydrocarbon group may be substituted with a heteroatom-containing substituent. The heteroatom-containing substituents include -O-, -NH-, -N=, -C(=O)-O-, -S-, -S(=O) ₂ -, -S(=O ) ₂ —O—.
Examples of substituted hydrocarbon groups for R ⁹¹ include lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7).

Further, in R ⁹¹ , the hydrocarbon group having a substituent includes —SO ₂ —containing cyclic groups represented by the above general formulas (a5-r-1) to (a5-r-4), respectively; Also included are substituted aryl groups represented by chemical formulas, monovalent heterocyclic groups, and the like.

Among the structural units (a9), structural units represented by the following general formula (a9-1-1) are preferred.

［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 defined above, Ya ⁹¹ is a single bond or a divalent linking group, R ⁹¹ is an optionally substituted hydrocarbon group, R ⁹² is an oxygen atom or It is a sulfur atom. ]

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

Specific examples of structural units represented by formula (a9-1) or general formula (a9-1-1) are shown below. In the formula below, 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% with respect to 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 %.
By setting the proportion of the structural unit (a9) to be at least the lower limit of the preferred range, for example, the acid diffusion length can be appropriately adjusted, the adhesion of the resist film to the substrate can be increased, and the solubility during development can be appropriately improved. When it is equal to or less than the upper limit of the preferable range, it is possible to balance with other structural units, and various lithography properties are improved.

Structural unit (a4):
The structural unit (a4) is a structural unit containing an acid non-dissociable cyclic group. By including the structural unit (a4) in the component (A1), the dry etching resistance of the formed photosensitive resin pattern is improved. In addition, the hydrophobicity of the component (A1) increases.
The "acid-non-dissociable cyclic group" in the structural unit (a4) does not dissociate even when an acid is generated from the component (B) or the like described later due to exposure to light, and remains in the structural unit without dissociation. is a cyclic group remaining in

As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid-nondissociable aliphatic cyclic group is preferred. Examples of the cyclic group include those exemplified for the structural unit (a1) above, such as for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), and the like. A large number of those conventionally known as those used for the resin component of the resist composition can be used. In particular, at least one group selected from tricyclodecyl, adamantyl, tetracyclododecyl, isobornyl, and norbornyl groups is preferred from the standpoint 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 structures represented by 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% with respect to the total of all structural units constituting the component (A1). It is more preferably 10 to 20 mol %.

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

Such component (A1) is obtained by dissolving a monomer that induces each structural unit in a polymerization solvent, and adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (for example, V-601, etc.) to the polymerization solvent. It can be produced by adding an agent and polymerizing. Alternatively, the component (A1) comprises a monomer that derives the structural unit (a1), and optionally a precursor monomer (monomer with a protected functional group) that derives a structural unit other than the structural unit (a1), is dissolved in a polymerization solvent, a radical polymerization initiator as described above is added thereto for polymerization, and then a deprotection reaction is performed. In the polymerization, for example, a chain transfer agent such as HS--CH ₂ --CH ₂ --CH ₂ --C(CF ₃ ) ₂ --OH may be used in combination to form --C(CF ₃ ) at the terminal. A ₂ -OH group may be introduced. Thus, a copolymer into which a hydroxyalkyl group is introduced, in which a portion of the hydrogen atoms of the alkyl group is substituted with a fluorine atom, reduces development defects and improves LER (line edge roughness: non-uniform irregularities on the side wall of a line). is effective in reducing

The weight average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1000 to 50000, more preferably 2000 to 30000, and 3000 to 20,000 is more preferred.
When the Mw of the component (A1) is less than the preferable upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and when it is more than the preferable lower limit of this range, it has dry etching resistance and The cross-sectional shape of the resist pattern is good.
The dispersity (Mw/Mn) of 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. . In addition, Mn shows a number average molecular weight.

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

The proportion of component (A1) in 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 100% by mass, relative to the total mass of component (A). may be When the proportion is 25% by mass or more, a resist pattern having excellent various lithography properties such as high sensitivity, resolution, and improvement in roughness can be easily formed.

The content of the component (A) in the resist composition of this embodiment may be adjusted according to the resist film thickness to be formed.

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

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

The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkanes include polycycloalkanes having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; condensed rings such as cyclic groups having a steroid skeleton; and polycycloalkanes having a polycyclic skeleton of the system. Among them, polycycloalkanes having a polycyclic skeleton of a bridged ring system are preferred. A suitable specific example of the polycyclic aliphatic hydrocarbon group is an adamantyl group.

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

In formula (b1-1), Y ¹⁰¹ is a divalent linking group containing a single bond or an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, said Y ¹⁰¹ may contain an atom other than an oxygen atom. Atoms other than an oxygen atom include, for example, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like.
The divalent linking group containing an oxygen atom includes, for example, an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O )-), amide bond (-C(=O)-NH-), carbonyl group (-C(=O)-), carbonate bond (-OC(=O)-O-), etc. and a combination of the non-hydrocarbon oxygen atom-containing linking group and an alkylene group. A sulfonyl group ( _--SO.sub.2-- ) may be further linked to this combination. Such a divalent linking group containing an oxygen atom includes, for example, 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。］

[In the formula, 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 for V' ¹⁰¹ and V' ¹⁰² may be a straight-chain alkylene group or a branched alkylene group, and a straight-chain alkylene group is preferred.
Specific examples of the alkylene group for V' ¹⁰¹ and V' ¹⁰² include a methylene group [-CH ₂ -]; -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups; ethylene groups [-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 ) Alkylethylene groups such as CH ₂ -; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ ) Alkyltrimethylene groups such as CH ₂ -; Tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ Alkyltetramethylene groups such as CH ₂ —; pentamethylene groups [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.

Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond.

In formula (b1-1), 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 in the alkylene group for V ¹⁰¹ are substituted with fluorine atoms. Among them, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms, more preferably a fluorinated alkylene group having 1 to 4 carbon atoms.

In 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 component (b1-1) include anions represented by the following formulas (an-b-1) to (an-b-3).

{cation part}
In formula (b1-1), m is an integer of 1 or more, and ^M'm+ is an m-valent onium cation, preferably a sulfonium cation or an iodonium cation. ) to (ca-4), respectively.

［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 are each independently an aryl group optionally having a substituent, an alkyl group optionally having a substituent, or represents a good alkenyl group. Each of 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 having 1 to 5 carbon atoms, or may combine with each other to form a ring together with the sulfur atom in the formula. R ²¹⁰ is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ₂ — It contains cyclic groups. L ²⁰¹ represents -C(=O)- or -C(=O)-O-. A plurality of Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group. x is 1 or 2; W ²⁰¹ represents a (x+1)-valent linking group. ]

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

［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。］

[In the formula, each R′ ²⁰¹ is independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or a substituted is a chain alkenyl group that may be ]

R′ ²⁰¹ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

Cyclic group optionally having 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. An aliphatic hydrocarbon group means a hydrocarbon group without aromaticity. Also, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably 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 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 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 of the aromatic hydrocarbon group in R′ ²⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or those in which some of the carbon atoms constituting the aromatic ring are substituted with heteroatoms. and aromatic heterocycles. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, 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, a naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring is groups substituted with an alkylene group (for example, arylalkyl groups such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.); . 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.

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

A chain alkyl group optionally having a substituent:
The chain 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 group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group and the like.
The branched-chain 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, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

A chain alkenyl group optionally having a substituent:
The chain alkenyl group for R' ²⁰¹ may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and further preferably 2 to 4 carbon atoms. 3 is particularly preferred. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group and the like.
Among the above, the chain 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 substituents on the linear alkyl group or alkenyl group for ^R'201 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, a carbonyl group, a nitro group, an amino group, and a cyclic group for ^R'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, heteroatoms such as a sulfur atom, an oxygen atom and a nitrogen atom, carbonyl group, -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N(R _N )- (where R _N is an alkyl group having 1 to 5 carbon atoms), etc. may be bonded via the functional group of As the ring to be formed, one ring containing a sulfur atom in the formula in its ring skeleton is preferably a 3- to 10-membered ring including a sulfur atom, particularly a 5- to 7-membered ring. preferable. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiine ring, a tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, and the like are included.

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

R ²¹⁰ is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ₂ —containing cyclic group.
The aryl group for R ²¹⁰ includes an unsubstituted aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms. The —SO ₂ -containing cyclic group optionally having a substituent for R ²¹⁰ is preferably a “—SO ₂ -containing polycyclic group” represented by the above general formula (a5-r-1). is more preferred.

Each Y ²⁰¹ independently represents an arylene group, an alkylene group or an alkenylene group.
Examples of the arylene group for Y ²⁰¹ include groups obtained by removing one hydrogen atom from the above aryl group for R ²¹⁰ .
Examples of the alkylene group and alkenylene group for Y ²⁰¹ include groups obtained by removing one hydrogen atom from the groups exemplified as the chain alkyl group and chain alkenyl group for R' ²⁰¹ above.

In formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x+1)-valent, ie divalent or trivalent linking group.
The divalent linking group for W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and has a substituent similar to Ya ²¹ in the above general formula (a2-1). A divalent hydrocarbon group which may be substituted can be exemplified. The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. The arylene group includes a phenylene group, a naphthylene group and the like, and a phenylene group is particularly preferred.
The trivalent linking group for W ²⁰¹ includes a group obtained by removing one hydrogen atom from the divalent linking group for W ²⁰¹ , a group obtained by further bonding the divalent linking group to the divalent linking group, and the like. mentioned. The trivalent linking group for W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

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

［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。］

[In the formula, R ^{″ 201} is a hydrogen ^atom or a substituent ^. Examples of the substituent include ^the alkyl group, halogen 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, bis( 4-tert-butylphenyl)iodonium cations.

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

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

Among the above, the cation moiety ((M ^m+ ) _1/m ) is preferably a cation represented by general formula (ca-1), and 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。］

[In the formula, 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 hydroxy groups.
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 described in formula (b1-1).
In formula (b1-1-1), V ₀ ¹⁰¹ is a fluorinated alkylene group having 1 to 4 carbon atoms. Examples of the fluorinated alkylene group for V ₀ ¹⁰¹ include groups in which some or all of the hydrogen atoms in an alkylene group are substituted with fluorine atoms. Among them, a group in which a part of hydrogen atoms of an alkylene group is substituted with fluorine atoms is preferable. The number of fluorine atoms in the fluorinated alkylene group of V ₀ ¹⁰¹ is preferably 1 to 6, more preferably 1 to 3, and still more preferably 2 or 3.

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

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

The (B1) component of the resist composition in this embodiment may be used singly or in combination of two or more.

The content of the component (B1) in the resist composition in 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.
If the content of the component (B1) is at least the above lower limit, lithographic properties such as sensitivity, resolution performance, LWR (linewise roughness) reduction, shape, etc., and defects in the unexposed areas of the resist film occur in resist pattern formation. is further improved.
When the content of the component (B1) is not more than the above upper limit, a uniform solution can be easily obtained when each component is dissolved in an organic solvent, and the storage stability of the resist composition is further enhanced.

In the resist composition, the proportion of the component (B1) in the total acid generator component (B) component that generates an acid acting on the component (A) is, for example, 50% by mass or more, preferably 70% by mass. % or more, more preferably 95 mass % or more. In addition, 100 mass % may be sufficient.
When the proportion of component (B1) is at least the lower limit of the preferred range, the occurrence of defects in the unexposed areas of the resist film can be further reduced.

<Optional component>
The resist composition in this embodiment may further contain components (optional components) other than the components (A) and (B1) described above.
Examples of such optional components include components (B2), (D), (E), (F), and (S) shown below.

<<(B2) component>>
The resist composition in the present embodiment may contain an acid generator component (hereinafter referred to as "(B2) component") other than the above-described (B1) component within a range that does not impair the effects of the present invention.
The component (B2) is not particularly limited, and those hitherto proposed as acid generators for chemically amplified resist compositions can be used.
Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators; Acid generators: nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators and the like.

As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), represented by general formula (b-2) A compound (hereinafter also referred to as "(b-2) component") or a compound represented by general formula (b-3) (hereinafter also referred to as "(b-3) component") can be mentioned. The component (b-1) does not contain 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。］

[In the formula, R ¹⁰¹ , R ¹⁰⁴ to R ¹⁰⁸ are each independently an optionally substituted cyclic group, an optionally substituted chain alkyl group, or a substituted is a good chain alkenyl group. R ¹⁰⁴ and R ¹⁰⁵ may combine with each other 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 are each independently 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 portion of component (b-1) In formula (b-1), R ¹⁰¹ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or a substituted It is a chain alkenyl group which may have a group.

Cyclic group optionally having 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. An aliphatic hydrocarbon group means a hydrocarbon group without aromaticity. Also, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably 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, 6 to 12 carbon atoms are most preferred. 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 for R ¹⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a portion of carbon atoms constituting these aromatic rings substituted with heteroatoms. Aromatic heterocycle etc. are mentioned. The heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like. The aromatic ring possessed by the aromatic hydrocarbon group for R ¹⁰¹ preferably does not contain a heteroatom from the viewpoint of compatibility with the component (A). is preferred.
Specific examples of the aromatic hydrocarbon group for R ¹⁰¹ include a group in which one hydrogen atom is 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 alkylene groups substituted with groups (for example, arylalkyl groups 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), and the like. 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.

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

Among them, the cyclic aliphatic hydrocarbon group for R ¹⁰¹ is preferably a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane, more preferably a group obtained by removing one hydrogen atom from monocycloalkane. A group obtained by removing one hydrogen atom 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 preferred, and those with 1 to 3 carbon atoms are most preferred. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, a methylene group [ _--CH.sub.2-- ], an ethylene group [--( _CH.sub.2 ) _.sub.2-- ], a trimethylene group [ -(CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], 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. is more preferred, and one having 3 carbon atoms is most preferred. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) _2- , -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - and other alkylmethylene groups;- 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 Alkylethylene groups such as CH ₃ ) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ ) Examples include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH ₂ — and —CH ₂ CH(CH ₃ )CH ₂ CH ₂ —. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

Examples of substituents on the cyclic group of R ¹⁰¹ include alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, nitro groups, carbonyl groups and the like.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group. Most preferred is the ethoxy group.
A halogen atom as a substituent includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
Halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, tert-butyl, etc., wherein some or all of the hydrogen atoms are Groups substituted with the aforementioned halogen atoms are included.
A carbonyl group as a substituent is a group that substitutes a methylene group ( _--CH.sub.2-- ) constituting a cyclic hydrocarbon group.
Among them, the substituent for the cyclic group of R ¹⁰¹ is preferably an alkyl group, a halogen atom, a halogenated alkyl group, or the like, more preferably an alkyl group, from the viewpoint of compatibility with the component (A).

A 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 group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group and the like.
The branched-chain 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- ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

A chain 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 2 to 5 carbon atoms, and 2 to 4 carbon atoms. More preferably, 3 carbon atoms are particularly preferable. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group and the like.
Among the above, the chain 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 substituents on the chain alkyl or alkenyl group of R ¹⁰¹ include alkoxy groups, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), halogenated alkyl groups, hydroxyl groups, carbonyl groups, nitro groups, amino groups, cyclic groups for R ¹⁰¹ above, and the like.
Among them, from the viewpoint of compatibility with the component (A), the substituents on the chain alkyl group or alkenyl group for R ¹⁰¹ include halogen atoms, halogenated alkyl groups, and the groups listed as the cyclic groups for R ¹⁰¹ above. etc. are preferred, and the groups exemplified as the cyclic group for R ¹⁰¹ are more preferred.

Among the above, R ¹⁰¹ is preferably an optionally substituted cyclic group, more preferably an optionally substituted cyclic hydrocarbon group. More specifically, a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane; -7); and -SO ₂ -containing cyclic groups represented by the above general formulas (a5-r-1) to (a5-r-4).

In formula (b-1) above, Y ¹⁰¹ is a divalent linking group containing a single bond or an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, said Y ¹⁰¹ may contain an atom other than an oxygen atom. Atoms other than an oxygen atom include, for example, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like.
Such a divalent linking group containing an oxygen atom includes, for example, the 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, represented by the above general formulas (y-al-1) to (y-al-5), respectively. is 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 in the alkylene group for V ¹⁰¹ are 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 formula (b-1) above, 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 C 1-5 perfluoroalkyl group, more preferably a fluorine atom.

Specific examples of the anion moiety of component (b-1) include, for example, ^when Y ¹⁰¹ is a single bond, fluorinated alkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; In the case of a divalent linking group containing an oxygen atom, an anion represented by any one of the following formulas (an1) to (an3) can 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 optionally substituted aliphatic cyclic group, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-1) to (r-hr-6) A cyclic group or an optionally substituted chain alkyl group. R″ ¹⁰² is an optionally substituted aliphatic cyclic group, the general formula (a2-r-1) , (a2-r-3) to (a2-r-7) respectively represented by a lactone-containing cyclic group, or the general formulas (a5-r-1) to (a5-r-4) respectively represented by is a —SO ₂ —containing cyclic group. R″ ¹⁰³ is an optionally substituted aromatic cyclic group, an optionally substituted aliphatic cyclic group, or an optionally substituted chain alkenyl group. 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. Each v″ is independently an integer of 0 to 3, each q″ is independently an integer of 1 to 20, and n″ is 0 or 1.]

The optionally substituted aliphatic cyclic groups of R″ ¹⁰¹ , R″ ¹⁰² and R″ ¹⁰³ are the groups exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in the formula (b-1). Examples of the substituent include the same substituents that may substitute the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in the formula (b-1).

The optionally substituted aromatic cyclic group for R″ ¹⁰³ is the group exemplified as the aromatic hydrocarbon group for the cyclic hydrocarbon group for R ¹⁰¹ in the formula (b-1). Preferred examples of the substituent include the same substituents that may substitute the aromatic hydrocarbon group for R ¹⁰¹ in the formula (b-1).

The optionally substituted chain alkyl group ^for R″ ¹⁰¹ is preferably a group exemplified as the chain alkyl group for R ¹⁰¹ in the formula (b-1). The chain alkenyl group which may have a substituent is preferably a group exemplified as the chain alkenyl group for R ¹⁰¹ in the formula (b-1).

Anion portion of component (b-2) In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ are each independently an optionally substituted cyclic group and an optionally substituted chain. a linear alkyl group, or a chain alkenyl group which may have a substituent, respectively, a cyclic group which may have a ^substituent , a substituted Examples thereof include the same as the chain alkyl group optionally having a group or the chain alkenyl group optionally having a substituent. In addition, R ¹⁰⁴ and R ¹⁰⁵ may combine with each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain alkyl group which may have a substituent, and are 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 chain alkyl groups of R ¹⁰⁴ and R ¹⁰⁵ preferably have a smaller number of carbon atoms within the range of the number of carbon atoms described above, for reasons such as good solubility in resist solvents. In addition, in the chain alkyl groups of R ¹⁰⁴ and R ¹⁰⁵ , the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The proportion 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. is a 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, each of which is the same as V ¹⁰¹ in formula (b-1) mentioned.
In formula (b-2), L ¹⁰¹ and L ¹⁰² are each independently a single bond or an oxygen atom.

Anion portion of component (b-3) In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain which may have a substituent a linear alkyl group, or a chain alkenyl group which may have a substituent, ^respectively , a cyclic group which may have a substituent, a substituted Examples thereof include the same as the chain alkyl group optionally having a group or the chain alkenyl group optionally having a substituent.
L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -.

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

M′ ^m+ in formulas (b-1), (b-2) and (b-3) includes diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, -1) to (ca-3-6), and cations represented by the above formulas (ca-4-1) to (ca-4-2).

Among the above, the cation moieties [(M′ ^m+ ) _1/m ] are represented by the formulas (ca-1-1) to (ca-1-78), (ca-1-101) to (ca-1-149) The organic cations respectively represented by the organic cations respectively represented by are more preferable.

In the resist composition of the present embodiment, the component (B2) may be used singly or in combination of two or more.
When the resist composition contains component (B2), the content of component (B2) in the resist composition is preferably 50 parts by mass or less, and 1 to 40 parts by mass, per 100 parts by mass of component (A). is more preferred, and 5 to 30 parts by mass is even more preferred.
When the resist composition contains the component (B2), the content of the component (B2) among the total acid generator components (B) that generate an acid acting on the component (A) in the resist composition is, for example, 50% by mass or less, more preferably 30% by mass or less, and even more preferably 0% by mass or more and 5% by mass or less.
By setting the content of the component (B2) within the above range, pattern formation is sufficiently performed.

<<(D) component>>
The resist composition in the present embodiment may further contain an acid diffusion controller component (hereinafter referred to as "component (D)") in addition to components (A) and (B). Component (D) acts as a quencher (acid diffusion control agent) that traps acid generated by exposure in the resist composition.
Component (D) includes, for example, a nitrogen-containing organic compound (D1) (hereinafter referred to as "(D1) component"), a photodegradable base (D2 ) (hereinafter referred to as “(D2) component”).
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.

- Component (D1) 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.

Component (D1) is not particularly limited as long as it functions 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 preferred.
Aliphatic amines are amines having one or more aliphatic groups, which preferably have 1 to 12 carbon atoms.
Aliphatic amines include amines (alkylamines or alkylalcohol amines) in which at least one hydrogen atom of ammonia _NH3 is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms, or cyclic amines.
Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; - dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, trialkylamine; Alkyl alcohol amines such as isopropanolamine, di-n-octanolamine and tri-n-octanolamine are included. Among these, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Cyclic amines include, for example, heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of aliphatic monocyclic amines include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable, and specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5. 4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane and the like.

Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, 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, etc., and triethanolamine triacetate is preferred.

Aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, aniline compounds, N-tert-butoxycarbonylpyrrolidine and the like.

(D1) component may be used individually by 1 type, and may be used in combination of 2 or more type.
Among the above, the component (D1) is preferably an aromatic amine, more preferably an aniline compound. Examples of aniline compounds include 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, N,N-dihexylaniline and the like.

Regarding the (D2) component The (D2) component is not particularly limited as long as it is decomposed by exposure to lose the acid diffusion controllability, and is a compound represented by the following general formula (d2-1) (hereinafter "( d2-1) component”), compounds represented by the following general formula (d2-2) (hereinafter referred to as “(d2-2) components”), and compounds represented by the following general formula (d2-3) (hereinafter referred to as "component (d2-3)"). One or more compounds selected from the group consisting of are preferred.
Components (d2-1) to (d2-3) do not act as quenchers because they decompose in the exposed areas of the resist film and lose the acid diffusion controllability (basicity), and act as quenchers in the unexposed areas of the resist film. acts 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。］

[In the formula, Rd ¹ to Rd ⁴ are a cyclic group optionally having a substituent, a chain alkyl group optionally having a substituent, or a chain alkenyl group optionally having a substituent is. However, it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom in Rd ² in general formula (d2-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and each ^M'm+ is independently an m-valent onium cation. ]

{(d2-1) component}
Anion portion In formula (d2-1), Rd ¹ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted It is a chain alkenyl group, and includes the same groups as R ¹⁰¹ and the like in formula (b-1) above.
Among these, Rd ¹ is an optionally substituted aromatic hydrocarbon group, an optionally substituted aliphatic cyclic group, or an optionally substituted chain-like Alkyl groups are preferred. Examples of substituents that 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 general formulas (a2-r-1) to (a2-r-7). ), an ether bond, an ester bond, or a combination thereof. When it contains an ether bond or an ester bond as a substituent, it may be via an alkylene group, and the substituents in this case are represented by the above formulas (y-al-1) to (y-al-5), respectively. is preferred.
Preferred 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 consisting of a ring structure of a bicyclooctane skeleton and a ring structure other than this). be done.
More preferably, the aliphatic cyclic group is 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, and specific examples thereof include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, 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 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and other branched alkyl groups.

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 in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and 1 ~4 is more preferred. The fluorinated alkyl group may contain atoms other than fluorine atoms. Atoms other than a fluorine atom include, for example, 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 are substituted with fluorine atoms, and the number of hydrogen atoms constituting the linear alkyl group is preferably A fluorinated alkyl group (straight-chain perfluoroalkyl group) in which all are substituted with fluorine atoms is particularly preferred.

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

Cation Moiety In formula (d2-1), M′ ^m+ is an m-valent onium cation.
As the onium cation of M'm ⁺ , the same cations as those represented by the general formulas (ca-1) to (ca-4) are preferably mentioned, and the onium cation represented by the general formula (ca-1) is are more preferred, and cations represented by the formulas (ca-1-1) to (ca-1-78) and (ca-1-101) to (ca-1-149) are more preferred.
Component (d2-1) may be used alone or in combination of two or more.

{(d2-2) component}
Anion portion In formula (d2-2), Rd ² is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted It is a chain alkenyl group, and examples thereof include those similar to R ¹⁰¹ and the like in the formula (b-1).
However, the carbon atom adjacent to the S atom in Rd ² is not bonded to a fluorine atom (not fluorine-substituted). As a result, the anion of the component (d2-2) becomes a moderately weak acid anion, and the quenching ability of the component (D2) is improved.
Rd ² is preferably an optionally substituted chain alkyl group or an optionally substituted aliphatic cyclic group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. Aliphatic cyclic groups include groups obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like (which may have substituents); is more preferably a group from which a hydrogen atom is removed.
^The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain and the same substituents as those that may be possessed by the alkyl group).

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

Cation Moiety In formula (d2-2), M′ ^m+ is an m-valent onium cation, which is the same as M′ ^m+ in formula (d2-1).
The component (d2-2) may be used singly or in combination of two or more.

{(d2-3) component}
Anion portion In formula (d2-3), Rd ³ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain is a linear alkenyl group, including the same as R ¹⁰¹ in the formula (b-1), and is 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 preferred, and the same fluorinated alkyl group as Rd ¹ is more preferred.

In formula (d2-3), Rd ⁴ is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain It is an alkenyl group, and examples thereof include those similar to R ¹⁰¹ and the like in the formula (b-1).
Among them, an optionally substituted alkyl group, alkoxy group, alkenyl group, and cyclic group 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 and an isobutyl group. , tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A portion of the hydrogen atoms of the alkyl group of ^Rd4 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, an n- butoxy group and tert-butoxy group. Among them, a methoxy group and an ethoxy group are preferable.

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

Examples of the cyclic group for Rd ⁴ include those similar to R ¹⁰¹ in the formula (b-1), and cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group obtained by removing one or more hydrogen atoms from , or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in good lithography properties.

In formula (d2-3), Yd ¹ is 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 (aliphatic hydrocarbon group, aromatic hydrocarbon group) optionally having a substituent, a bivalent heteroatom-containing and the like. Each of these is a ^divalent hydrocarbon group optionally having a substituent, a heteroatom-containing 2 The same as the valence linking group can be mentioned.
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, more preferably a methylene group or an ethylene group.

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

Cation Moiety In formula (d2-3), M′ ^m+ is an m-valent onium cation, which is the same as M′ ^m+ in formula (d2-1).
Component (d2-3) may be used alone or in combination of two or more.

As the component (D2), any one of the above components (d2-1) to (d2-3) may be used alone, or two or more of them may be used in combination.
When the resist composition contains component (D2), the content of component (D2) in the resist composition is preferably 0.5 to 35 parts by mass, preferably 1 to 35 parts by mass, per 100 parts by mass of 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 properties and resist pattern shape are likely to be obtained. On the other hand, if it is equal to or less than the upper limit, the balance with other components can be achieved, and various lithography properties will be improved.

Method for producing component (D2):
The method for producing the components (d2-1) and (d2-2) is not particularly limited, and they can be produced by known methods.
In addition, the method for producing component (d2-3) is not particularly limited, and for example, it is produced 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, phosphorus oxoacids, and derivatives thereof>>
The resist composition in the present embodiment contains an organic carboxylic acid, an oxoacid of phosphorus, and a derivative thereof as optional components for the purpose of preventing deterioration of sensitivity and improving resist pattern shape, storage stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as "(E) component") can be contained.

Suitable examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid.
Phosphorus oxoacids include phosphoric acid, phosphonic acid, phosphinic acid, etc. Among these, phosphonic acid is particularly preferred.
Examples of the oxoacid derivative of phosphorus include esters obtained by substituting a hydrogen atom of the above oxoacid with a hydrocarbon group. Examples of the hydrocarbon group include alkyl groups having 1 to 5 carbon atoms, 15 aryl groups and the like.
Derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Phosphonic acid derivatives include phosphonic acid esters such as dimethyl phosphonic acid, di-n-butyl phosphonic acid, phenylphosphonic acid, diphenyl phosphonic acid and dibenzyl phosphonic acid.
Phosphinic acid derivatives 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, the component (E) may be used singly or in combination of two or more.
When the resist composition contains component (E), the content of 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 component (A). 0.5 parts by mass is more preferred.
By setting the amount within the above range, the balance with other components can be achieved, and various lithography properties can be improved.

<<(F) component: Fluorine additive component>>
The resist composition in the present embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") in order to impart water repellency to the resist film or improve lithography properties.
As the component (F), for example, JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, JP-A-2011-128226. can be used.
More specific examples of component (F) include polymers having a structural unit (f1) represented by the following formula (f1-1). Examples of this polymer include a polymer (homopolymer) consisting only of a 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) is preferably Here, as the structural unit (a1) to be 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 defined above, 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 formula (f1-1), R bonded to the α-position carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), the halogen atoms of Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, with a fluorine atom being particularly preferred. Examples of the alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include the same alkyl groups having 1 to 5 carbon atoms as the above 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 some or all of the hydrogen atoms in the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. be done. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred. 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 formula (f1-1), nf ¹ is an integer of 0 to 5, preferably an integer of 0 to 3, more preferably 0 or 1.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, 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 1 to 10 carbon atoms are particularly preferred.
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 Fluorination is particularly preferred because the hydrophobicity of the resist film during immersion exposure increases.
Among them, Rf ¹⁰¹ is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, such as a 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 component (F) (polystyrene equivalent by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When the upper limit value of this range or less, there is sufficient solubility in a resist solvent for use as a resist, and when it is more than the lower limit value of this range, dry etching resistance and resist pattern cross-sectional shape are good. .
The dispersity (Mw/Mn) of component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

In the resist composition of this embodiment, the component (F) may be used alone or in combination of two or more.
When the resist composition contains the (F) component, the content of the (F) component is usually used in a proportion of 0.5 to 10 parts by mass per 100 parts by mass of the (A) component.

<<(S) component: organic solvent component>>
The resist composition in the present embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as "(S) component").
As the component (S), any component that can dissolve each component to be used and form a uniform solution can be used. It can be selected and used.
Component (S) includes, 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 and propylene carbonate; ethylene Polyhydric alcohols such as glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, and the polyhydric alcohols Or derivatives of polyhydric alcohols such as compounds having an ether bond such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, etc. or monophenyl ether of compounds having an ester bond [among these , propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, pyruvin Esters such as methyl acid, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene , isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethylsulfoxide (DMSO).
In the resist composition of the present embodiment, the (S) component may be used singly or as a mixed solvent of two or more.
Among them, PGMEA, PGME, γ-butyrolactone, propylene carbonate, EL, and cyclohexanone are preferred.
A mixed solvent obtained by mixing PGMEA and a polar solvent is also preferable. The blending ratio (mass ratio) thereof may be appropriately determined in consideration of compatibility between PGMEA and the polar solvent, etc., 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 a polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. . Further, 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, still more preferably 3:7 to 7: 3. Further, a mixed solvent of PGMEA, PGME and cyclohexanone is also preferred.
Further, 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, as a mixing ratio, the mass ratio of the former to 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 according to the coating film thickness at a concentration that can be applied to the substrate or the like. The component (S) is generally used so that the resist composition has a solid content concentration of 0.1 to 20 mass %, preferably 0.2 to 15 mass %.

The resist composition of the present invention further optionally contains miscible additives such as additional resins, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents to improve the performance of the resist film. , dyes, etc. can be added and contained as appropriate.

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

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

<Preparation of resist composition>
Each component shown in Table 1 was mixed and dissolved to prepare resist compositions (1) to (5).

In Table 1, each abbreviation has the following meaning. The numbers in [ ] are the compounding 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 using a predetermined molar ratio of monomers that induce the structural units constituting the polymer compound. The polymer compound (A)-1 had a weight average molecular weight (Mw) of 7000 in terms of standard polystyrene and a molecular weight distribution (Mw/Mn) of 1.68 as determined by GPC measurement. Copolymer composition ratio determined by ¹³ C-NMR (ratio (molar ratio) of each structural unit in the structural formula is 1/m/n/o = 45/30/15/10.

(B1)-1 to (B1)-3: Acid generators each comprising the following compounds (B1-1) to (B1-3).

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

(D)-1: Acid diffusion control agent 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 obtained by GPC measurement was 23000, and the molecular weight dispersity (Mw/Mn) was 1.40.
(S)-1: Mixed solvent of propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether (mass ratio 60/40).

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

(Examples 2 and 3, Comparative Examples 1 and 2)
A resist pattern was formed in the same manner as in Example 1 above, except that the resist composition (1) in Table 1 was changed to 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.
However, the resist pattern forming method of Examples 1 and 2 is the resist pattern forming method of the reference example.

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

In the resist pattern forming methods of Examples 1 to 3 to which the present invention is applied, the occurrence of defects of 0.1 μm or more in the remaining film portion, which is the 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 Example 3, Example 2, and Example 1.

<Formation of resist pattern (2)>
(Example 4)
An organic antireflection film composition "ARC29A" (trade name, manufactured by Brewer Science Inc.) is applied onto a 12-inch silicon wafer using a spinner, and baked on a hot plate at 205°C for 60 seconds to dry. Thus, an organic antireflection film having a thickness of 89 nm was formed.
The resist composition (3) in Table 1 was applied onto the antireflection film using a coater/developer Lithius (manufactured by Tokyo Electron Ltd.) and prebaked (PAB) on a hot plate at 105° C. for 60 seconds. and dried to form a resist film with a film thickness of 150 nm.
Next, an immersion ArF exposure apparatus NSR-S609B [manufactured by Nikon; NA (numerical aperture) = 1.07, Dipole (in/out = 0.78/0.97) with Polano, Immersion medium: water] was selectively irradiated with an ArF excimer laser (193 nm) through a transmission type phase shift mask.
After that, PEB treatment was performed at 100° C. for 60 seconds.
Then, using a coater/developer Lithius (manufactured by Tokyo Electron Co., Ltd.), at 23 ° C., a 2.38% by mass TMAH aqueous solution (trade name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) containing an acetylene-based activator. Alkaline development was performed for 30 seconds, followed by water rinsing with pure water for 30 seconds, and drying by shaking off.
As a result, a 1:1 line and space (LS) pattern with 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 TMAH aqueous 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 <Formation of resist pattern (2)> was observed using a scanning electron microscope (trade name: SU-8000, manufactured by Hitachi High-Technology Co., Ltd.), 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 was highly rectangular and had a good shape. On the other hand, in the resist pattern forming method of Comparative Example 3 in which the alkaline developer does not contain a nonionic surfactant, there is a problem in terms of resolution, such as difficulty in wetting the resist film with the alkaline developer. 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, the occurrence of defects in the unexposed portion of the resist film can be reduced, and a resist pattern having a favorable shape can be formed. .

Claims (1)

step (i) of forming a resist film on the support using the resist composition;
The step (ii) of exposing the resist film, and the step (iii) of developing the resist film after exposure with an alkaline developer containing a nonionic surfactant to form a resist pattern;
A method of forming a resist pattern, comprising:
The resist composition contains a base component (A) whose solubility in an alkaline developer changes under the action of an acid and an acid generator component (B) which generates an acid upon exposure,
The acid generator component (B) contains a compound (B1) represented by the following general formula (b1-1),
The base component (A) is a polymer compound having a structural unit (a1) containing an acid-decomposable group whose polarity increases under the action of acid,
The weight average molecular weight (Mw) of the polymer compound is 1000 to 50000,
The polymer compound has a molecular weight dispersity of 1.0 to 4.0,
The content of the compound (B1) is 1 to 40 parts by mass with respect to 100 parts by mass of the base component (A),
The method of forming a resist pattern , wherein the nonionic surfactant contains an acetylenic surfactant .

[In the formula, R ₀ ¹⁰¹ is a polycyclic aliphatic hydrocarbon group having a hydroxy group. However, a 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 fluorinated alkylene group. m is an integer of 1 or more, and ^M'm+ is an m-valent onium cation. ]