CN112946999A

CN112946999A - Method for forming photoresist pattern

Info

Publication number: CN112946999A
Application number: CN202011423854.2A
Authority: CN
Inventors: 角田力太; 柳楠熙; 染谷康夫
Original assignee: Tokyo Ohka Kogyo Co Ltd
Current assignee: Tokyo Ohka Kogyo Co Ltd
Priority date: 2019-12-10
Filing date: 2020-12-08
Publication date: 2021-06-11
Also published as: JP2021092779A; KR20210072970A

Abstract

A photoresist pattern forming method, comprising: (i) a step of forming a photoresist film on the support using the photoresist composition; (ii) exposing the photoresist film; and (iii) a step of developing the exposed photoresist film to form a photoresist pattern, wherein the resist composition contains: a resin (A) whose solubility in a developer is changed by the action of an acid, an acid generator (B) which generates an acid upon exposure, a base (D1) which is photodegradable, a solvent (S), and a compound (X) represented by the following formula (X-1), wherein the amount of the solvent remaining in the photoresist film formed in the step (i) is 910ppm or more, wherein R is an amount of a solvent having a solubility in a developer of 910ppm or more¹～R⁴Is hydroxyl or C1-5 alkyl, R⁵And R⁶Hydrogen, C1-5 alkyl or by hydroxyAn alkyl group having 1 to 10 carbon atoms which is substituted with a substituent.

Description

Method for forming photoresist pattern

Technical Field

The present invention relates to a photoresist pattern forming method.

Background

In the photolithography technique, for example, the following steps are performed: a photoresist film made of a resist material is formed on a substrate, and the photoresist film is selectively exposed to light and subjected to a development process, thereby forming a photoresist pattern having a predetermined shape on the photoresist film. A resist material in which an exposed portion of the photoresist film is changed to a characteristic of dissolving in a developer is called a positive type, and a resist material in which an exposed portion of the photoresist film is changed to a characteristic of not dissolving in a developer is called a negative type.

In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, miniaturization of patterns has been advanced due to advances in photolithography technology. As a method for miniaturization, generally, the exposure light source is shortened in wavelength (increased in energy). Specifically, ultraviolet rays typified by g-rays and i-rays have been used, and a KrF excimer laser (eximer laser) or an ArF excimer laser is now used for mass production of semiconductor devices. Further, studies have been conducted on EUV (extreme ultraviolet), EB (electron beam), X-ray, and the like, which have a shorter wavelength (higher energy) than these excimer lasers.

In the progress of further progress in the lithography technology, expansion of the application field, and the like, improvement of various lithography characteristics such as high sensitivity, improvement of resolution, and improvement of roughness is required for formation of a photoresist pattern.

As a photoresist composition for forming a photoresist film, a photoresist composition containing a resin component whose solubility in a developer changes by the action of an acid and an acid generator component that generates an acid upon exposure is generally used. The photoresist composition may contain a nitrogen-containing compound as an acid diffusion controlling agent component for trapping an acid generated by exposure, and when a photodegradable base-form acid diffusion controlling agent that loses the acid diffusion controlling property by decomposition by exposure is used, the resolution can be improved as compared with a conventional amine-type acid diffusion controlling agent, but when a photodegradable base is used as an acid diffusion controlling agent in a KrF negative photoresist, there is a problem that it is difficult to maintain the shape while maintaining the high resolution.

On the other hand, it is pointed out that thinning along with the miniaturization of the resist causes problems such as an increase in line edge roughness of the film and a reduction in pattern film, and it is known that an appropriate amount of solvent needs to be left in the film in order to reduce the line edge roughness (see patent document 1). However, an effective method for controlling the amount of residual solvent in the film or the relationship between the amount of residual solvent in the film and other characteristics of the resist is not sufficiently known.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 4857208

Disclosure of Invention

Technical problem to be solved by the invention

The present invention has been made in view of the above circumstances, and provides a method for forming a photoresist pattern, which can form a pattern having a good shape while maintaining a high resolution.

Solution for solving the above technical problem

In order to achieve the above object, the present invention employs the following configurations. The present inventors have found through studies that the above-described technical problems can be solved by the following photoresist pattern forming method, and have completed the present invention.

A photoresist pattern forming method, comprising:

(i) a step of forming a photoresist film on the support using the photoresist composition;

(ii) exposing the photoresist film; and

(iii) a step of forming a photoresist pattern by developing the exposed photoresist film, the method for forming a photoresist pattern being characterized in that,

the photoresist composition contains: a resin (A) whose solubility in a developer is changed by the action of an acid, an acid generator (B) which generates an acid upon exposure, a base (D1) which is photodegradable, a solvent (S), and a compound (X) represented by the following formula (X-1),

[ solution 1]

[ in the formula, R¹～R⁴Each independently is hydroxyl or alkyl with 1-5 carbon atoms, R⁵And R⁶Each independently hydrogen, an alkyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 10 carbon atoms substituted with a hydroxyl group, a, b, c and d each independently is an integer of 0 to 3, and e and f each independently is an integer of 1 to 2.]

The amount of the solvent remaining in the photoresist film formed in the step (i) is 910ppm or more.

Effects of the invention

The photoresist pattern obtained by the photoresist pattern forming method of the present invention can form a pattern of a good shape while maintaining high resolution.

Detailed Description

In the description of the present invention and the scope of the present claims, "aliphatic" refers to a relative concept with respect to aromatic groups and is defined to mean groups, compounds, and the like that are not aromatic.

Unless otherwise specified, "alkyl" includes straight-chain, branched-chain and cyclic 1-valent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.

Unless otherwise specified, "alkylene" includes linear, branched and cyclic 2-valent saturated hydrocarbon groups.

The "haloalkyl group" is a group in which a part or all of hydrogen atoms of an alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

"fluoroalkyl" or "fluoroalkylene" refers to a group in which a part or all of the hydrogen atoms of an alkyl group or alkylene group are replaced with fluorine atoms.

The "structural unit" refers to a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).

The "structural unit derived from an acrylate" means a structural unit in which an ethylenic double bond of an acrylate is cleaved.

"acrylate" is acrylic acid (CH)₂CH — COOH) in which a hydrogen atom at the carboxyl terminal is substituted with an organic group.

The hydrogen atom bonded to the carbon atom in the α -position of the acrylate may be substituted with a substituent. A substituent (R) for substituting the hydrogen atom bonded to the carbon atom at the alpha position^α0) Examples of the atom or group other than hydrogen atom include alkyl groups having 1 to 5 carbon atoms and halogenated alkyl groups having 1 to 5 carbon atoms. The carbon atom at the α -position of the acrylic ester is a carbon atom to which a carbonyl group of acrylic acid is bonded unless otherwise specified.

Hereinafter, an acrylate in which a hydrogen atom bonded to a carbon atom at the α -position is substituted with a substituent may be referred to as an α -substituted acrylate. Further, the acrylate and the α -substituted acrylate may be collectively referred to as "(α -substituted) acrylate".

The "structural unit derived from hydroxystyrene or a hydroxystyrene derivative" means a structural unit in which an olefinic double bond of hydroxystyrene or a hydroxystyrene derivative is cleaved.

The term "hydroxystyrene derivative" is intended to encompass compounds in which the hydrogen atom at the α -position of hydroxystyrene is substituted with another substituent such as an alkyl group or a haloalkyl group, and derivatives thereof. Examples of the derivatives thereof include compounds in which a hydrogen atom at the α -position is substituted with a substituent, and a hydrogen atom of a hydroxyl group of hydroxystyrene is substituted with an organic group; and a compound in which a substituent other than a hydroxyl group is bonded to a benzene ring of hydroxystyrene in which a hydrogen atom at the α -position may be substituted with a substituent. In addition, the α -position (carbon atom at α -position) of hydroxystyrene means a carbon atom to which a benzene ring is bonded unless otherwise specified.

Examples of the substituent for substituting the hydrogen atom at the α -position of hydroxystyrene may include the same ones as those exemplified as the substituent at the α -position in the above-mentioned α -substituted acrylate.

The "structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative" refers to a structural unit in which an ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative is cleaved.

The term "vinylbenzoic acid derivative" is a concept including compounds in which the hydrogen atom at the α -position of vinylbenzoic acid is substituted with another substituent such as an alkyl group or a haloalkyl group, and derivatives thereof. Examples of the derivatives thereof include compounds in which a hydrogen atom at the α -position is substituted with a substituent, and a hydrogen atom of the carboxyl group of vinylbenzoic acid is substituted with an organic group; and a compound in which a substituent other than a hydroxyl group and a carboxyl group is bonded to a benzene ring of vinylbenzoic acid in which a hydrogen atom at the α -position may be substituted with a substituent. In addition, the α -position (carbon atom at α -position) of vinylbenzoic acid means a carbon atom to which a benzene ring is bonded unless otherwise specified.

The "styrene derivative" refers to a compound in which a hydrogen atom at the α -position of styrene is substituted with another substituent such as an alkyl group or a haloalkyl group, or a compound in which a hydrogen atom of a phenyl group of styrene is substituted with a substituent such as a lower alkyl group having 1 to 5 carbon atoms.

The "structural unit derived from styrene" and the "structural unit derived from a styrene derivative" mean a structural unit in which an ethylenic double bond of styrene or a styrene derivative is cleaved.

The alkyl group as the substituent at the α -position is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl) and the like are mentioned.

The "alkyl group as a substituent at the α -position" may specifically be a group obtained by substituting a part or all of hydrogen atoms of the "alkyl group as a substituent at the α -position" with a halogen atom. The halogen atom may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and a fluorine atom is particularly preferable.

The hydroxyalkyl group as the substituent at the α -position may specifically be one obtained by substituting a part or all of hydrogen atoms of the "alkyl group as the substituent at the α -position" with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

The term "may have a substituent" includes the case where a hydrogen atom (-H) is substituted with a group having a valence of 1, and the case where a methylene group (-CH) is substituted₂-) two cases substituted with a 2-valent group.

"exposure" is a concept including irradiation of all radiation.

Method for forming photoresist pattern

The method for forming a photoresist pattern of the present invention comprises:

(ii) exposing the photoresist film; and

(iii) and forming a photoresist pattern by developing the exposed photoresist film.

In the above-mentioned method for forming a photoresist pattern, a specific photoresist composition according to the present invention is selected and used in the step (i).

Step (i): first, a specific photoresist composition described later is applied to a support by a spin coater or the like, and a photoresist film is formed by a pre-bake (PAB) treatment at a temperature of 80 to 150 ℃, preferably 80 to 120 ℃ (more preferably 100 ℃) for 40 to 120 seconds, preferably 50 to 100 seconds (more preferably 60 seconds).

Step (ii): next, the photoresist film is selectively exposed to light through a mask (mask pattern) having a predetermined pattern formed thereon using, for example, an exposure apparatus, and then baked (Post exposure bake, PEB) at a temperature of, for example, 80 to 150 ℃, preferably 90 to 130 ℃ for 40 to 120 seconds, preferably 60 to 100 seconds.

Step (iii): next, the exposed photoresist film is subjected to a development process. The development treatment is performed using an alkaline developer in the case of an alkaline development process, and is performed using an organic solvent-containing developer (organic developer) in the case of a solvent development process. After the development treatment, a rinsing treatment is preferably performed. The rinsing treatment is preferably a water rinsing using pure water in the case of an alkaline development process, and a rinsing liquid containing an organic solvent in the case of a solvent development process. In the case of the solvent development process, after the development treatment or the rinsing treatment, a treatment of removing the developing solution or the rinsing solution attached to the pattern by the supercritical fluid may be performed.

Drying is performed after the development treatment or after the rinsing treatment. Further, a baking treatment (post-baking) may be performed after the above-described developing treatment according to circumstances.

Thus, a photoresist pattern can be formed.

The support is not particularly limited, and conventionally known supports can be used, and examples thereof include a substrate for electronic components, a support having a predetermined wiring pattern formed thereon, and the like. More specifically, the substrate may be a silicon wafer, a substrate made of metal such as copper, chromium, iron, or aluminum, or a glass substrate. As a material of the wiring pattern, for example, copper, aluminum, nickel, gold, or the like can be used.

The support may be one in which an inorganic and/or organic film is provided on the substrate as described above. As the inorganic film, an inorganic anti-reflection film (inorganic BARC) may be mentioned. Examples of the organic film include organic films such as an organic anti-reflection film (organic BARC) and an underlying organic film in a multilayer resist method. Here, the multilayer resist method is a method in which at least 1 additional organic film (lower organic film) and at least 1 additional resist film (upper resist film) are provided on a substrate, and patterning of the lower organic film is performed using a resist pattern formed on the upper resist film as a mask, and a pattern having a high aspect ratio can be formed. That is, according to the multilayer resist method, since a desired thickness can be secured by the lower organic film, the resist film can be thinned, and a fine pattern having a high aspect ratio can be formed. Among the multilayer resist methods, there is basically a method (2-layer resist method) which adopts a two-layer structure of an upper resist film and a lower organic film; and a method (3-layer resist method) using a multilayer structure of three or more layers in which one or more intermediate layers (such as a metal thin film) are provided between an upper resist film and a lower organic film.

The wavelength used for exposure is not particularly limited, and can be performed using radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, and the like. The resist pattern forming method according to the present invention is particularly preferable when KrF excimer laser light is irradiated to the resist film in the step (ii).

The resist film may be exposed to normal light in an inert gas such as air or nitrogen (dry exposure) or may be subjected to Liquid Immersion exposure (Liquid Immersion Lithography).

The immersion exposure is an exposure method in which a space between the resist film and the lens at the lowermost position of the exposure apparatus is filled with a solvent (immersion medium) having a refractive index larger than that of air in advance, and exposure is performed in this state (immersion exposure). The liquid immersion medium is preferably a solvent having a refractive index higher than that of air and lower than that of the resist film to be exposed. The refractive index of the solvent is not particularly limited 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, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent. Specific example of the fluorine-based inert liquid is C₃HCl₂F₅、C₄F₉OCH₃、C₄F₉OC₂H₅、C₅H₃F₇And liquids containing a fluorine-based compound as a main component, preferably a liquid having a boiling point of 70 to 180 ℃, and more preferably a liquid having a boiling point of 80 to 160 ℃. When the fluorine-based inert liquid has a boiling point in the above range, it is preferable because the medium used in the immersion liquid can be removed by a simple method after the end of exposure. The fluorine-based inert liquid is particularly preferably a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group have been replaced with fluorine atoms. The perfluoroalkyl compound may, specifically, be a perfluoroalkyl ether compound or a perfluoroalkyl compoundA fluoroalkyl amine compound. Further, the perfluoroalkyl ether compound may, for example, be perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ℃ C.), and the perfluoroalkyl amine compound may, for example, be perfluorotributylamine (boiling point: 174 ℃ C.). As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

The alkaline developer used for the development treatment in the alkaline development process may, for example, be a 0.1 to 10 mass% aqueous tetramethylammonium hydroxide (TMAH) solution.

The organic solvent contained in the organic developer used for the development treatment in the solvent development process may be selected from known organic solvents as long as it is an organic solvent capable of dissolving the component (a) (component (a) before exposure) described later. The details associated with the solvent are set forth in the following description of the resist composition.

The developing treatment may be carried out by a known developing method, and examples thereof include a method of immersing the support in a developer for a certain period of time (immersion method), a method of supporting the developer on the surface of the support by surface tension and standing for a certain period of time (stirring (paddle) method), a method of spraying the developer on the surface of the support (spray method), and a method of continuously applying the developer to the support rotating at a certain speed while scanning a developer applying nozzle at a certain speed (dynamic dispensing method).

As the organic solvent contained in the rinse liquid used in the rinse treatment after the development treatment in the solvent development process, for example, an organic solvent that is difficult to dissolve the resist pattern among the organic solvents exemplified as the organic solvents used in the organic developer can be appropriately selected and used. The rinse liquid may be mixed with known additives as needed. Examples of the additive include surfactants. The surfactant is preferably a nonionic surfactant, more preferably a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant. When a surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, based on the total amount of the rinsing liquid.

The rinsing process (cleaning process) using the rinsing liquid can be performed by a known rinsing method. Examples of the rinsing treatment include a method of continuously applying a rinsing liquid to a support rotating at a constant speed (spin coating method), a method of immersing the support in a rinsing liquid for a constant period of time (immersion method), and a method of spraying a rinsing liquid onto the surface of the support (spray method).

Photoresist composition

In the above-described method for forming a photoresist pattern of the present invention, a specific photoresist composition is used in the step (i). The specific photoresist composition according to the present invention is a photoresist composition which generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, and contains a resin (a) whose solubility in a developer changes by the action of the acid, an acid generator (B) which generates an acid upon exposure, a photodegradable base (D1), a solvent (S), and a compound (X).

The photoresist composition according to the present invention contains a base component (a) (hereinafter, resin (a)) whose solubility in a developer changes by the action of an acid.

< resin (A) >

In the present invention, the photoresist composition contains a resin (a) (hereinafter also referred to as "component (a)") whose solubility in a developer changes by the action of an acid. The component (a) of the present invention is soluble in a solvent (S) described later, and is not particularly limited as long as it can be used in a photolithography step. Particularly preferred is a resin whose solubility in a developer can be changed by the action of an acid. When a resin whose solubility in a developer can be changed by the action of an acid is blended with an acid generator (B) described later into a photoresist composition, and then the formed film is selectively exposed to light, the exposed portion or the unexposed portion of the film can be selectively made soluble to an alkali. In this case, the selectively exposed film is brought into contact with an alkaline developer to remove the exposed portions or the unexposed portions, thereby forming a pattern having a desired shape.

In the present invention, the resin (a) contains the following resin (a1) (hereinafter also referred to as "(a 1) component").

The resin (A1) preferably contains a structural unit (a10) represented by the general formula (a10-1) described later and a structural unit (a) derived from styrene^st) The resin of (4).

(structural Unit (a10))

The structural unit (a10) is represented by the following formula (a 10-1).

[ solution 2]

[ wherein 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^x1Is a single bond or a 2-valent linking group, Wa^x1Is (n)_ax1+1) valent aromatic hydrocarbon radicals, n_ax1Is an integer of 1 to 3.]

In the formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.

The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, it may, for example, be 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 or a neopentyl group.

The haloalkyl group having 1 to 5 carbon atoms as R is a group in which a part or all of hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. The halogen atom may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and a fluorine atom is particularly preferable. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluoroalkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group from the viewpoint of easy industrial availability.

In the above formula (a10-1), Ya^x1Is a single bond or a 2-valent linking group.

As Ya^x1The linking group having a valence of 2 in (1) is preferably a 2-valent hydrocarbon group which may have a substituent or a 2-valent linking group containing a hetero atom.

2-valent hydrocarbon group which may have a substituent: at Ya^x1When the hydrocarbon group is a 2-valent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

At Ya^x1In the above description, the aliphatic hydrocarbon group means a hydrocarbon group having no aromatic character. The aliphatic hydrocarbon group may be either saturated or unsaturated, and is preferably saturated.

Examples of the aliphatic hydrocarbon group include a straight-chain or branched-chain aliphatic hydrocarbon group, and an aliphatic hydrocarbon group having a ring in the structure.

The number of carbon atoms of the linear or branched aliphatic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3.

The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specifically, it may, for example, be methylene [ -CH ]₂-]Ethylene [ - (CH)₂)₂-]Propylene [ - (CH)₂)₃-]Butylene [ - (CH)₂)₄-]- (CH) pentylene [ - (CH)₂)₅-]And the like.

The number of carbon atoms of the branched aliphatic hydrocarbon group is preferably 2 to 10, more preferably 3 to 6, further preferably 3 or 4, and most preferably 3.

The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically may, for example, be-CH (CH)₃)-、-CH(CH₂CH₃)-、-C(CH₃)₂-、-C(CH₃)(CH₂CH₃)-、-C(CH₃)(CH₂CH₂CH₃)-、-C(CH₂CH₃)₂-isoalkylmethylene; -CH (CH)₃)CH₂-、-CH(CH₃)CH(CH₃)-、-C(CH₃)₂CH₂-、-CH(CH₂CH₃)CH₂-、-C(CH₂CH₃)₂-CH₂-isoalkylethylene; -CH (CH)₃)CH₂CH₂-、-CH₂CH(CH₃)CH₂-isoalkylpropylene; -CH (CH)₃)CH₂CH₂CH₂-、-CH₂CH(CH₃)CH₂CH₂An alkylalkylene group such as an alkylbutylene group, etc. The alkyl group in the alkyl alkylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms.

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

Examples of the aliphatic hydrocarbon group having a ring in the above structure include an alicyclic hydrocarbon group (a group obtained by removing 2 hydrogen atoms from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed between linear or branched aliphatic hydrocarbon groups. Examples of the linear or branched aliphatic hydrocarbon group may include the same aliphatic hydrocarbon groups as described above.

The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.

The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing 2 hydrogen atoms from a monocyclic hydrocarbon. The monocyclic hydrocarbon is preferably a monocyclic hydrocarbon having 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane, or the like may be mentioned. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing 2 hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably a C7-12 polycycloalkane, and specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

The alicyclic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, and a carbonyl 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. 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 isopropoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methyl groupOxy and ethoxy. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable. Examples of the "haloalkyl" group as the substituent may include a group in which a part or all of hydrogen atoms of the alkyl group are substituted with the halogen atom. A part of carbon atoms constituting the ring structure of the cyclic aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom. As the heteroatom-containing substituent, preferred are — O-, -C (═ O) -O-, -S (═ O)₂-、-S(＝O)₂-O-。

Ya^x1The aromatic hydrocarbon group of (2) is a hydrocarbon group having at least 1 aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n +2 pi electrons, and may be a polycyclic or monocyclic ring. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Wherein the number of carbons does not include the number of carbons in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom.

Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group (arylene group or heteroarylene group) obtained by removing 2 hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring; a group obtained by removing 2 hydrogen atoms from an aromatic compound containing 2 or more aromatic rings (for example, biphenyl, fluorene, or the like); and a group (aryl or heteroaryl) obtained by removing 1 hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring, wherein 1 hydrogen atom is substituted with an alkylene group (for example, a group obtained by removing 1 hydrogen atom from an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.), and the like. The number of carbon atoms of the alkylene group bonded to the aryl or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

The aromatic hydrocarbon group may be substituted for a hydrogen atom by 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 haloalkyl 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" and "halogen" and "haloalkyl" as the substituent include those exemplified as substituents for substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

Heteroatom-containing 2-valent linking group: at Ya^x1In the case of a heteroatom-containing 2-valent linking group, examples of the linking group include-O-, -C (═ O) -, -O-C (═ O) -O-, -C (═ O) -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-, of the formula-Y²¹-O-Y²²-、-Y²¹-O-、-Y²¹-C(＝O)-O-、-C(＝O)-O-Y²¹-、-[Y²¹-C(＝O)-O]_m”-Y²²-、-Y²¹-O-C(＝O)-Y²²-or-Y²¹-S(＝O)₂-O-Y²²A group represented by (wherein Y is)²¹And Y²²Each independently represents a 2-valent hydrocarbon group which may have a substituent, O represents an oxygen atom, and m' represents an integer of 0 to 3.]Etc. as preferred groups.

In the case where the heteroatom-containing 2-valent linking group is — C (═ O) -NH-, -C (═ O) -NH-C (═ O) -, -NH-C (═ NH) -, the H may be substituted with a substituent such as an alkyl group, an acyl group, or the like. The carbon number of the substituent (such as an alkyl group or an acyl group) is preferably 1 to 10, more preferably 1 to 8, and particularly preferably 1 to 5. General formula-Y²¹-O-Y²²-、-Y²¹-O-、-Y²¹-C(＝O)-O-、-C(＝O)-O-Y²¹-、-[Y²¹-C(＝O)-O]_m”-Y²²-、-Y²¹-O-C(＝O)-Y²²-or-Y²¹-S(＝O)₂-O-Y²²In (Y)²¹And Y²²Each independently is a 2-valent hydrocarbon group which may have a substituent. The 2-valent hydrocarbon group may, for example, be a group (a 2-valent hydrocarbon group which may have a substituent) exemplified in the description of the 2-valent linking group. As Y²¹The aliphatic hydrocarbon group is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. As Y²²The aliphatic hydrocarbon group is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Is represented by the formula- [ Y ]²¹-C(＝O)-O]_m”-Y²²In the group represented by (A), m' is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, as represented by the formula- [ Y ]²¹-C(＝O)-O]_m”-Y²²A group represented by the formula-Y is particularly preferred²¹-C(＝O)-O-Y²²-a group represented by (a). Among them, the formula- (CH) is preferred₂)_a’-C(＝O)-O-(CH₂)_b’-a group represented by (a). In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

As Ya^x1Preferably a single bond, an ester bond [ -C (═ O) -O-]An ether bond (-O-) -, -C (-O) -NH-, a linear or branched alkylene group, or a combination thereof, and among them, a single bond is particularly preferable.

In the formula (a10-1), Wa^x1Is (n)_ax1+1) a valent aromatic hydrocarbon radical.

As Wa^x1Examples of the aromatic hydrocarbon group in (1) include a group obtained by removing (n) from an aromatic ring_ax1+1) hydrogen atoms. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n +2 pi electrons, and may be monocyclic or polycyclic.

The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, phenanthrene, and the like; and an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

In the formula (a10-1), n_ax1Is 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, R^αRepresents a hydrogen atom, a methyl group or a trifluoromethyl group.

[ solution 3]

(A1) The constituent unit (a10) of component (a) may be 1 or 2 or more.

Among the above, the structural unit (a10) is preferably a structural unit having a hydroxystyrene skeleton, and particularly preferably a structural unit represented by the following general formula (a 10-1-0).

[ solution 4]

[ in the formula, R^stRepresents a hydrogen atom or a methyl group. m is₀₁Represents an integer of 1 to 3.]

(A1) The proportion of the structural unit (a10) in component (a) is preferably 55 to 95 mol%, more preferably 60 to 90 mol%, and particularly preferably 65 to 85 mol%, based on the total (100 mol%) of all the structural units constituting component (a 1).

When the ratio of the structural unit (a10) is equal to or higher than the lower limit of the preferable range, sensitivity, development characteristics, the effect of suppressing the occurrence of defects, and the like are further improved, and when the ratio is equal to or lower than the upper limit of the preferable range, the lithography characteristics such as dimensional uniformity are further improved.

(structural Unit (a)^st))

(A1) Component (a) may further have a structural unit derived from styrene^st). Structural unit (a)^st) The "structural unit derived from styrene" in (1) means a structural unit comprising styrene and a styrene derivative (excluding hydroxystyrene) in which an olefinic double bond is cleaved.

The "styrene derivative" herein refers to a compound in which a hydrogen atom bonded to the α -position of styrene is substituted with another substituent such as a halogen atom, an alkyl group, or a halogenated alkyl group, and a compound in which a hydrogen atom of a phenyl group of styrene is substituted with a substituent such as a lower alkyl group having 1 to 5 carbon atoms.

Examples of the halogen atom include a chlorine atom, a fluorine atom and a bromine atom, and a fluorine atom is preferable.

Unless otherwise specified, "α -position of styrene" refers to a carbon atom to which a benzene ring is bonded.

As a structural unit (a)^st) The structural unit contained in the compound represented by the following general formula (a) can be preferably exemplified^stStructural unit (a) represented by-1)^st1)。

[ solution 5]

[ wherein R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; r²Represents an alkyl group having 1 to 5 carbon atoms; q represents 0 or an integer of 1 to 2.]

R may be the same group as R of the general formula (a 10-1).

q is 0 or an integer of 1 to 2. Among them, q is preferably 0 or 1, and particularly preferably 0 industrially.

In the case where q is 1, R²The substitution position(s) of (b) may be any of ortho (o-position), meta (m-position), and para (p-position), and when q is 2, any substitution position(s) may be combined.

As a structural unit (a)^st) The number of the compounds may be 1 or 2 or more.

Component (A1) contains a structural unit (a)^st) In the case of (a), the structural unit (a)^st) The proportion of (c) is preferably 1 to 25 mol%, more preferably 5 to 25 mol%, most preferably 10 to 25 mol% based on the total structural units constituting the component (a 1). When the amount is within this range, the effect of heat resistance is high when the photoresist composition is produced, and the balance with other structural units is good.

The component (A1) may contain the above-mentioned essential structural unit (a10) and structural unit (a) within a range not to impair the effects of the present invention^st) Other structural units than the above.

The above-mentioned structural unit may be any one not classified into the above-mentioned essential structural unit (a10) and the structural unit (a)^st) The other structural units are not particularly limited, and various structural units conventionally known as those used for photoresist resins for KrF excimer lasers, ArF excimer lasers, and the like can be used.

In the present invention, the component (a1) may further include the following structural units: a structural unit (a 1)', which contains an acid-decomposable group having an increased polarity by the action of an acid; structural unit (a 2)', containing a lactone-containing cyclic group, a carbonate-containing cyclic group or an-SO-containing group₂-a cyclic group (wherein the structural unit belonging to the above structural unit (a 1)' is excluded); a structural unit (a3) ', which contains a polar group-containing aliphatic hydrocarbon group (excluding the structural units belonging to the structural units (a1) ', (a2) '); the structural unit (a 4)', which contains an acid non-dissociable cyclic group.

(structural unit (a 1)')

The structural unit (a 1)' is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.

The "acid-decomposable group" is an acid-decomposable group having a structure in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid.

Examples of the acid-decomposable group having an increased polarity by the action of an acid include groups which are decomposed by the action of an acid to form a polar group.

Examples of the polar group include a carboxyl group, a hydroxyl group, an amino group and a sulfonic acid group (-SO)₃H) And the like. Among these, a sulfonic acid group or a polar group having — OH in the structure (hereinafter, sometimes referred to as "OH-containing polar group") is preferable, a sulfonic acid group, a carboxyl group, or a hydroxyl group is preferable, and a carboxyl group or a hydroxyl group is particularly preferable.

More specifically, the acid-decomposable group may, for example, be a group in which the above-mentioned polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

Here, the "acid-dissociable group" refers to both of the following:

(i) an acid-dissociable group in which a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group is cleavable by an acid, or

(ii) A group in which a part of the bonds are cleaved by the action of an acid and then decarboxylation reaction is further caused, whereby the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved.

The acid-dissociable group constituting the acid-dissociable group must be a group having a polarity lower than that of the polar group generated by dissociation of the acid-dissociable group, and thus when the acid-dissociable group dissociates by the action of an acid, a polar group having a polarity higher than that of the acid-dissociable group is generated and the polarity increases. As a result, the polarity of the entire component (a1) increases. The polarity increases to relatively change the solubility in the developer, and the solubility decreases when the developer is an organic developer.

The acid-dissociable group is not particularly limited, and those proposed as the acid-dissociable group of the base resin for the photoresist can be used.

Examples of the acid-dissociable group that protects the carboxyl group or the hydroxyl group of the polar group include acid-dissociable groups represented by the following formula (a 1-r-1)' (hereinafter, for convenience, may also be referred to as "acetal-type acid-dissociable groups").

[ solution 6]

[ wherein, Ra'¹、Ra’²Represents a hydrogen atom or an alkyl group, Ra'³Represents a hydrocarbon group, Ra'³May be substituted with Ra'¹、Ra’²Any of which is bonded to form a ring. Denotes the bonding site.]

In the formula (a1-r-1) 'as Ra'¹、Ra’²Examples of the "alkyl" group include the same ones as those exemplified as the alkyl group which may be bonded to the carbon atom at the α -position in the description of the α -substituted acrylate, and methyl or ethyl is preferred, and methyl is most preferred.

As Ra'³The hydrocarbon group of (a) is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and further preferably a linear or branched alkyl group, and specifically, it may, for example, be a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a1, 1-dimethylethyl group, a1, 1-diethylpropyl group, a2, 2-dimethylpropyl group, or a2, 2-dimethylbutyl group.

In Ra'³When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be aliphatic or aromatic, or may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing 1 hydrogen atom from a monocyclic hydrocarbon. The monocycloalkane is preferably a monocycloalkane having 3 to 8 carbon atoms, and specifically, cyclopentane, cyclohexane, cyclooctane and the like are mentioned. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing 1 hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably a C7-12 polycycloalkane, and specifically, examples thereof includeAdamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

In Ra'³In the case of an aromatic hydrocarbon group, the aromatic ring contained may specifically be an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene, or the like; and aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the aromatic hydrocarbon group include a group (aryl group) obtained by removing 1 hydrogen atom from the aromatic hydrocarbon ring; and a group in which 1 hydrogen atom of the aryl group is substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

Ra’³And Ra'¹、Ra’²In the case where any one of these groups is bonded to form a ring, the cyclic group is preferably a four-to seven-membered ring, and more preferably a four-to six-membered ring. Specific examples of the cyclic group include tetrahydropyranyl group and tetrahydrofuranyl group.

Examples of the acid-dissociable group for protecting the carboxyl group in the polar group include an acid-dissociable group represented by the following formula (a1-r-2) '(a group consisting of an alkyl group in the acid-dissociable group represented by the following formula (a 1-r-2)' may be referred to as a "tertiary alkyl ester-type acid-dissociable group" for convenience).

[ solution 7]

[ wherein, Ra'⁴～Ra’⁶Is hydrocarbyl, Ra'⁵、Ra’⁶May be bonded to each other to form a ring.

Denotes the bonding site. ]

As Ra'⁴～Ra’⁶The hydrocarbyl group of (A) may, for example, be represented by the formula Ra'³The same hydrocarbon group. Ra'⁴Preferably an alkyl group having 1 to 5 carbon atoms. In Ra'⁵And Ra'⁶Examples of the "ring" may include those represented by the following formula (a1-r 2-1)'.

On the other hand, in Ra'⁴～Ra’⁶Examples of the "hydrocarbyl group" may include groups represented by the following formula (a1-r 2-2)'.

[ solution 8]

[ wherein, Ra'¹⁰Represents an alkyl group having 1 to 10 carbon atoms, Ra'¹¹Is represented by and Ra'¹⁰The bonded carbon atoms together form a radical of an aliphatic cyclic group, Ra'¹²～Ra’¹⁴Each independently represents a hydrocarbon group. Denotes the bonding site.]

Ra 'of formula (a1-r 2-1)'¹⁰The alkyl group having 1 to 10 carbon atoms in (a1-r-1) 'is preferably Ra'³Examples of the "alkyl" may include linear and branched alkyl. Ra 'of formula (a1-r 2-1)'¹¹The alicyclic group of formula (a) is preferably Ra 'in the formula (a 1-r-1)'³The cyclic alkyl group of (a).

Ra 'of formula (a1-r 2-2)'¹²And Ra'¹⁴Each independently preferably an alkyl group having 1 to 10 carbon atoms, and the alkyl group is more preferably Ra 'in the formula (a 1-r-1)'³The group exemplified as the linear or branched alkyl group of (2) is more preferably a linear alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.

Ra 'of formula (a1-r 2-2)'¹³Preferably Ra 'in the formula (a 1-r-1)'.³Examples of the hydrocarbon group of (1) include linear, branched or cyclic alkyl groups. Of these, Ra 'is more preferable'³The cyclic alkyl group of (1).

Specific examples of the above formula (a1-r 2-1)' are shown below. Denotes the bonding site.

[ solution 9]

Specific examples of the above formula (a1-r 2-2)' are shown below. Denotes the bonding site.

[ solution 10]

Examples of the acid-dissociable group that protects the hydroxyl group of the polar group include acid-dissociable groups represented by the following formula (a 1-r-3)' (hereinafter, for convenience of explanation, also referred to as "tertiary alkoxycarbonyl acid-dissociable groups").

[ solution 11]

[ wherein, Ra'⁷～Ra’⁹Represents an alkyl group. Denotes the bonding site.]

Of formula (a1-r-3) 'wherein Ra'⁷～Ra’⁹Each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms.

In addition, the total carbon number of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

Examples of the structural unit (a 1)': a structural unit derived from an acrylate in which a hydrogen atom bonded to the carbon atom at the α -position is substituted with a substituent, and containing an acid-decomposable group whose polarity is increased by the action of an acid; a structural unit in which at least a part of hydrogen atoms in hydroxyl groups of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group; and a structural unit in which at least a part of hydrogen atoms in-C (═ O) -OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative is protected with a substituent containing the acid-decomposable group.

As the structural unit (a 1)', among the above structural units, preferred is a structural unit derived from an acrylate in which a hydrogen atom bonded to a carbon atom at the α -position may be substituted with a substituent.

As the structural unit (a1) ', a structural unit represented by the following formula (a1-1) ' or (a1-2) ' is preferable.

[ solution 12]

[ wherein 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 (Va)¹Is a 2-valent hydrocarbon group which may have an ether bond, an urethane bond or an amide bond, n_a1Is 0 to 2, Ra¹Is an acid-dissociable group represented by the formulae (a1-r-1) '- (a 1-r-2)'. Wa¹Is n_a2A hydrocarbon radical having a valence of +1, n_a2Is 1 to 3, Ra²Is an acid-dissociable group represented by the formula (a1-r-1) 'or (a 1-r-3)'.]

In the above formula (a 1-1)', the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, it may, for example, be 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 or a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part or all of hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. The halogen atom may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and a fluorine atom is particularly preferable.

R' is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluoroalkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group from the viewpoint of easy industrial availability.

Va¹The hydrocarbon group (b) may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromatic character. As Va¹The aliphatic hydrocarbon group of the 2-valent hydrocarbon group in (A) may be saturated or unsaturated, and a saturated aliphatic hydrocarbon group is generally preferred.

More specifically, the aliphatic hydrocarbon group may, for example, be a straight-chain or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group having a ring in the structure.

Further, as Va¹Examples thereof include groups in which the above-mentioned 2-valent hydrocarbon group is bonded via an ether bond, a urethane bond or an amide bond.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.

Said Va¹The aromatic hydrocarbon group as the 2-valent hydrocarbon group in (1) 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. Wherein the number of carbons does not include the number of carbons in the substituent.

Specific examples of the aromatic ring included in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene, and the like; and an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the aromatic hydrocarbon group include a group (arylene group) obtained by removing 2 hydrogen atoms from the aromatic hydrocarbon ring; a group (aryl group) obtained by removing 1 hydrogen atom from the aromatic hydrocarbon ring, wherein 1 hydrogen atom is substituted with an alkylene group (for example, a group obtained by removing 1 hydrogen atom from an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl) and the like. The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the formula (a 1-2)', Wa¹N in (1)_a2The +1 valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group represents a hydrocarbon group having no aromatic character, and may be saturated or unsaturated, and is preferably saturated in general. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, a ring-containing aliphatic hydrocarbon group in the structure, and a combination of a linear or branched aliphatic hydrocarbon group and a ring-containing aliphatic hydrocarbon group in the structure, and specifically, the aliphatic hydrocarbon group may include a group obtained by combining the above-mentioned linear or branched aliphatic hydrocarbon group with Va of the formula (a 1-1)'¹The same groups.

N is_a2The +1 valence is preferably 2 to 4 valence, more preferably 2 valence or 3 valence.

As the above formula (a1-2) ', a structural unit represented by the following formula (a 1-2-01)' is particularly preferable.

[ solution 13]

In the formula (a 1-2-01)', Ra²An acid-dissociable group represented by the formula (a1-r-1) 'or (a 1-r-3)'. n is_a2Is an integer of 1 to 3, preferably 1 or 2, more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, more preferably 1. R' is the same as described above.

Specific examples of the above formulae (a1-1) 'and (a 1-2)' are shown below. In the following formulae, R^αRepresents a hydrogen atom, a methyl group or a trifluoromethyl group.

[ solution 14]

When the component (a1) has the structural unit (a1) ', the proportion of the structural unit (a 1)' in the component (a1) is preferably 3 to 25 mol%, more preferably 5 to 20 mol%, based on the total of all the structural units constituting the component (a 1). When the ratio is not less than the lower limit, the sensitivity, resolution, LWR and other lithographic characteristics are improved. Further, by setting the above ratio to an upper limit or lower, balance with other constituent units can be achieved.

(structural unit (a 2)')

In the present invention, the component (A1) may contain a structural unit (a 2)' having a structure containing-SO₂A cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these.

Of the structural unit (a 2)' contains-SO₂The cyclic group, the lactone ring-containing group, the carbonate ring-containing group, or a heterocyclic group other than these groups is effective in improving adhesion of the photoresist film to the support.

Further, the structural unit (a 1)' has an-SO-containing group in its structure₂In the case of a cyclic group, a lactone ring-containing group, a carbonate ring-containing group, or a heterocyclic group other than these, the structural unit also belongs to the structural unit (a2) ', but such a structural unit is made to be a structural unit belonging to the structural unit (a1) ' but not to the structural unit (a2) '.

The structural unit (a2) 'is preferably a structural unit represented by the following formula (a 2-1)'.

[ solution 15]

[ wherein 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 ], Ya²¹Is a single bond or a 2-valent linking group, La²¹is-O-, -COO-, -CON (R ') -, -OCO-, -CONHCO-or-CONHCS-, and R' represents a hydrogen atom or a methyl group. Wherein, in La²¹In the case of-O-, Ya²¹Will not be-CO-. Ra²¹Is containing-SO₂A cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these.]

In the above formula (a 2-1)', Ra²¹Preferably contains-SO₂-a cyclic group, a lactone-containing cyclic group, a heterocyclic group or a carbonate-containing cyclic group.

"contains-SO₂The term "cyclic group" means a group containing-SO in its ring skeleton₂The cyclic group of the ring of (A) is, in particular, -SO₂The sulfur atom (S) in (E) forms a cyclic group which is part of the ring skeleton of the cyclic group. Will contain-SO in the ring skeleton₂The ring of (a) is counted as the first ring, and is called a monocyclic group in the case of only the ring, and is called a polycyclic group regardless of the structure in the case of having other ring structures. containing-SO₂The cyclic group may be a monocyclic group or a polycyclic group.

containing-SO₂The cyclic group is particularly preferably one having-O-SO in the ring skeleton₂Cyclic radicals of (i) containing-O-SO₂-O-S-in (a) -forms the cyclic group of the sultone ring forming part of the ring backbone. As containing-SO₂Examples of the "cyclic group" may include, more specifically, groups represented by the following formulae (a5-r-1) '- (a 5-r-4)'.

[ solution 16]

[ wherein, Ra'⁵¹Each independently is hydrogen atom, alkyl, alkoxyA group, a halogen atom, a haloalkyl group, a hydroxyl group, -COOR ", -OC (═ O) R", a hydroxyalkyl group, or a cyano group; r' is a hydrogen atom or an alkyl group; a 'is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, and n' is an integer of 0 to 2. Denotes the bonding site.]

In the above-mentioned formulas (a5-r-1) '- (a 5-r-4)', A 'is the same as A' in the formulas (a2-r-1) '- (a 2-r-7)', which will be described later. As Ra'⁵¹The alkyl group, alkoxy group, halogen atom, haloalkyl group, -COOR ", -OC (═ O) R", hydroxyalkyl group in (A) 2-R-1 ' to (a2-R-7) ' mentioned later and Ra '²¹The same is true.

Specific examples of the groups represented by the formulae (a5-r-1) '- (a 5-r-4)' will be described below. "Ac" in the formula represents an acetyl group. Denotes the bonding site.

[ solution 17]

In the present invention, the structural unit (a 2)' contains a group containing-SO₂In the case of cyclic radicals, containing-SO₂The cyclic acrylate monomer is not particularly limited if the logP value is less than 1.2, but among the above, the group represented by the formula (a 5-r-1)' is preferable, at least 1 selected from the group consisting of the groups represented by any one of the formulae (r-sl-1-1), (r-sl-1-18), (r-sl-3-1) and (r-sl-4-1) is more preferable, and the group represented by the formula (r-sl-1-1) is most preferable.

The "lactone ring-containing group" refers to a cyclic group containing a ring containing — O — C (═ O) - (lactone ring) in its ring skeleton. The lactone ring is referred to as the first ring, and when the lactone ring is present alone, the lactone ring is referred to as a monocyclic group, and when the lactone ring has another ring structure, the lactone ring is referred to as a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

The lactone ring-containing group is not particularly limited, and any lactone ring-containing group can be used. Specifically, the groups may be represented by the following formulae (a2-r-1) '- (a 2-r-7)'. Denotes the bonding site.

[ solution 18]

[ wherein, Ra'²¹Each independently is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, -COOR ", -OC (═ O) R", a hydroxyalkyl group or a cyano group; r' is a hydrogen atom or an alkyl group; a ' is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, n ' is an integer of 0 to 2, and m ' is 0 or 1.]

In the formulae (a2-r-1) ' - (a2-r-7) ', A ' is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom or a sulfur atom. The alkylene group having 1 to 5 carbon atoms in a ″ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group having-O-or-S-interposed between the terminal or carbon atom of the alkylene group, and examples thereof include-O-CH₂-、-CH₂-O-CH₂-、-S-CH₂-、-CH₂-S-CH₂-and the like. 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. Ra'²¹Each independently is an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, -COOR ", -OC (═ O) R", a hydroxyalkyl group, or a cyano group.

As Ra'²¹The alkyl group in (1) is preferably an alkyl group having 1 to 5 carbon atoms.

As Ra'²¹The alkoxy group in (1) is preferably an alkoxy group having 1 to 5 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Ra 'may be mentioned'²¹Alkyl group exemplified by alkyl group of (1) and oxy groupA group formed by connecting (O-) molecules.

As Ra'²¹The halogen atom in (2) may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and preferably a fluorine atom.

As Ra'²¹The haloalkyl group in (1) may be represented by the formula Ra'²¹Wherein a part or all of hydrogen atoms of the alkyl group in (1) are substituted by the halogen atom. The haloalkyl group is preferably a fluoroalkyl group, and particularly preferably a perfluoroalkyl group.

Specific examples of the groups represented by the formulae (a2-r-1) '- (a 2-r-7)' will be described below. Denotes the bonding site.

[ solution 19]

In the present invention, the structural unit (a2) ' is preferably a group represented by the above-mentioned formula (a2-r-1) ' or (a2-r-2) ' respectively, more preferably a group represented by the above-mentioned formula (r-lc-1-1) or (r-lc-2-7) respectively.

The "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 referred to as the first ring, and when only the carbonate ring is present, the carbonate ring is referred to as a monocyclic group, and when the carbonate ring has another ring structure, the carbonate ring is referred to as a polycyclic group regardless of the structure. The cyclic group containing carbonate may be a monocyclic group or a polycyclic group.

Specifically, the groups may be represented by the following formulae (ax3-r-1) '- (ax 3-r-3)'. Denotes the bonding site.

[ solution 20]

[ wherein, Ra'^x31Each independently is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, -COOR ", -OC (═ O) R", a hydroxyalkyl group or a cyano group; r' is a hydrogen atom or an alkyl group; a 'is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, and q' is 0 or 1.]

Specific examples of A "in the above-mentioned formulas (ax3-r-1) '- (ax 3-r-3)' are the same as A" in the above-mentioned formulas (a2-r-1) '- (a 2-r-7)'. As Ra'^x31Examples of the alkyl group, alkoxy group, halogen atom, haloalkyl group, -COOR ", -OC (═ O) R", and hydroxyalkyl group in (A2-R-1) ' - (A2-R-7) ', respectively, include Ra '²¹The same groups as those exemplified in the description of (1) above.

Specific examples of the groups represented by the formulae (ax3-r-1) '- (ax 3-r-3)' are shown below. Denotes the bonding site.

[ solution 21]

The "heterocyclic group" is a cyclic group containing 1 or more atoms other than carbon in addition to carbon, and examples thereof include heterocyclic groups and nitrogen-containing heterocyclic groups exemplified in the following (r-hr-1) to (r-hr-16). Examples of the nitrogen-containing heterocyclic group include cycloalkyl groups having 3 to 8 carbon atoms which may be substituted with 1 or 2 oxo groups. Examples of the cycloalkyl group include 2, 5-dioxapyrrolidine and 2, 6-dioxapiperidine, which are suitable examples. Denotes the bonding site.

[ solution 22]

Specific examples of the structural unit (a 2)' having a lactone ring-containing group are described below. In the following formulae, R^αIs hydrogen atom, methyl or trifluoromethyl.

[ solution 23]

The structural unit (a 2)' may be 1 type or 2 or more types.

When the component (a1) has the structural unit (a2) ', the proportion of the structural unit (a 2)' is preferably 1 to 80 mol%, more preferably 3 to 70 mol%, further preferably 5 to 65 mol%, and particularly preferably 10 to 60 mol%, based on the total of all structural units constituting the component (a 1). By setting the lower limit or more, the effect of containing the structural unit (a 2)' can be sufficiently obtained, and by setting the upper limit or less, balance with other structural units can be obtained, and various lithographic characteristics and pattern shapes can be improved.

(structural unit (a 3)')

The structural unit (a3) ' is a structural unit containing a polar group-containing aliphatic hydrocarbon group (excluding the structural units belonging to the structural units (a1) ', (a2) ').

In the case where the (a1) 'component has the structural unit (A3)', it is considered that the hydrophilicity of the (a1) component is improved, contributing to the improvement of resolution.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxyl group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom, and a hydroxyl group is particularly preferable.

Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group (preferably an alkylene group) having 1 to 10 carbon atoms and a cyclic aliphatic hydrocarbon group (a cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected from cyclic groups which have been mentioned many times among resins for photoresist compositions for ArF excimer lasers, for example. The cyclic group is preferably a polycyclic group, and more preferably has 7 to 30 carbon atoms.

Among these, a structural unit derived from an acrylate containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups obtained by removing 2 or more hydrogen atoms from a bicycloalkane, tricycloalkane, tetracycloalkane, or the like. Specifically, the compound may be a compound obtained by removing 2 or more hydrogen atoms from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like. Among these polycyclic groups, industrially preferred are groups obtained by removing 2 or more hydrogen atoms from adamantane, groups obtained by removing 2 or more hydrogen atoms from norbornane, and groups obtained by removing 2 or more hydrogen atoms from tetracyclododecane.

The structural unit (a 3)' is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit can be used.

As the structural unit (a 3)', preferred is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α -position may be substituted with a substituent, and is a structural unit containing an aliphatic hydrocarbon group containing a polar group.

The structural unit (a3) 'is preferably a structural unit derived from hydroxyethyl acrylate 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, and is preferably a structural unit represented by the following formula (a 3-1)' to the formula (a3-5) 'when the hydrocarbon group is a polycyclic group, more preferably a structural unit represented by the following formula (a 3-1)'.

[ solution 24]

[ wherein R 'is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 1 to 5, and s is an integer of 1 to 3. ]

In the formula (a 3-1)', j is preferably 1 or 2, more preferably 1. In the case where j is 2, it is preferable that hydroxyl groups are 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 the formula (a 3-2)', k is preferably 1. Preferably, the cyano group is bonded to the 5-or 6-position of the norbornyl group.

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

(A1) The constituent unit (a 3)' contained in component (a) may be 1 kind or 2 or more kinds.

When the component (a1) contains the structural unit (A3) ', the proportion of the structural unit (A3)' in the component (a1) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and still more preferably 5 to 25 mol% based on the total of all the structural units constituting the component (a 1).

By setting the proportion of the structural unit (a3) 'to the lower limit or more, the effect of containing the structural unit (a 3)' can be sufficiently obtained, and by setting the proportion to the upper limit or less, balance with other structural units can be easily obtained.

(A1) Component (c) may have the following structural unit (a4) 'in addition to the structural units (a 1)', (a2) ', (a 3)'.

(structural unit (a 4)')

The structural unit (a 4)' is a structural unit containing an acid-non-dissociable cyclic group. When the component (a1) has the structural unit (a 4)', the dry etching resistance of the formed photoresist pattern is improved. In addition, the hydrophobicity of the component (a1) is improved. It is considered that, particularly in the case of organic solvent development, improvement of hydrophobicity contributes to improvement of resolution, photoresist pattern shape, and the like.

The "acid-non-dissociable cyclic group" in the structural unit (a 4)' is a cyclic group that does not dissociate and remains in the structural unit directly even by the action of an acid when the acid is generated from the component (B) described later by exposure.

As the structural unit (a 4)', for example, a structural unit derived from an acrylate containing an acid-non-dissociable alicyclic group or the like is preferable. Examples of the cyclic group include the same groups as those exemplified for the structural unit (a 1)' described above, and various groups known in the art can be used as the groups used in the resin component of a photoresist composition for ArF excimer laser, KrF excimer laser (preferably ArF excimer laser), and the like.

In particular, at least 1 kind selected from the group consisting of tricyclodecyl group, adamantyl group, tetracyclododecyl group, isobornyl group and norbornyl group is preferable in terms of easy industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

As the structural unit (a4) ', specifically, structural units of the following formulae (a4-1) ' - (a4-7) ' can be exemplified.

[ solution 25]

[ in the formula, R^αRepresents a hydrogen atom, a methyl group or a trifluoromethyl group.]

(A1) The constituent unit (a 4)' contained in component (a) may be 1 kind or 2 or more kinds.

When the structural unit (a4) 'is contained in the component (a1), the proportion of the structural unit (a 4)' is preferably 1 to 30 mol%, more preferably 10 to 20 mol%, based on the total of all the structural units constituting the component (a 1).

In the photoresist composition of the present embodiment, 1 kind of the component (a) may be used alone, or 2 or more kinds may be used in combination.

The content of the component (A) in the photoresist composition of the present invention can be adjusted according to the required characteristics of the photoresist to be formed, but is preferably 20 to 100 parts by mass, more preferably 40 to 80 parts by mass, and still more preferably 50 to 70 parts by mass, based on 100 parts by mass of the component (S) described later.

< acid Generator (B) >

The photoresist composition of the present invention contains an acid generator component (hereinafter referred to as "component (B)") in addition to the component (a).

The component (B) is not particularly limited, and those conventionally proposed as acid generators for photoresists can be used.

Examples of the acid generator include onium salt type acid generators such as iodonium salts and sulfonium salts, and oxime sulfonate type acid generators; diazomethane acid generators such as dialkyl or bisarylsulfonyl diazomethane and poly (bissulfonyl) diazomethane; a plurality of acid generators such as nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like. Among them, an onium salt type acid generator is preferably used.

Examples of the onium salt-type acid generator include a compound represented by the following formula (b-1) (hereinafter, also referred to as "component (b-1)"), a compound represented by the following formula (b-2) (hereinafter, also referred to as "component (b-2)"), and a compound represented by the following formula (b-3) (hereinafter, also referred to as "component (b-3)").

[ solution 26]

[ in the formula, R¹⁰¹、R¹⁰⁴And R¹⁰⁵Each independently represents a halogen atom, a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. R¹⁰⁴、R¹⁰⁵May be bonded to each other to form a ring. R¹⁰²Is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. R¹⁰⁶Is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, wherein R is¹⁰⁶Wherein a carbon atom adjacent to the S atom is not bonded with a fluorine atom (fluorine-free substitution). Y is¹⁰¹Is a single bond or a 2-valent linking group comprising an oxygen atom. V¹⁰¹～V¹⁰³Each independently a single bond, alkylene, or fluoroalkylene. L is¹⁰¹～L¹⁰²Each independently a single bond or an oxygen atom. M is an integer of 1 or more, M'^m+Is an onium cation having a valence of m.]

{ anion (anion) part }

The anion part of component (b-1)

In the formula (b-1), R¹⁰¹Is a halogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

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

A cyclic group which may have a substituent:

the cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromatic character. The aliphatic hydrocarbon group may be saturated or unsaturated, and is preferably saturated.

R¹⁰¹The aromatic hydrocarbon group in (1) is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. Wherein the number of carbons does not include the number of carbons in the substituent.

As R¹⁰¹The aromatic ring of the aromatic hydrocarbon group in (3) may, specifically, be benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocycle in which a part of carbon atoms constituting the aromatic ring is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.

As R¹⁰¹Specific examples of the aromatic hydrocarbon group in (1) include a group obtained by removing 1 hydrogen atom from the aromatic ring (an aryl group: e.g., a phenyl group or a naphthyl group), and a group obtained by substituting 1 hydrogen atom of the aromatic ring with an alkylene group (e.g., an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

R¹⁰¹The cyclic aliphatic hydrocarbon group in (2) may be an aliphatic hydrocarbon group having a ring in the structure.

Examples of the aliphatic hydrocarbon group having a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing 1 hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed between linear or branched aliphatic hydrocarbon groups.

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 1 or more hydrogen atoms from a monocycloparaffin. The monocycloalkane is preferably a monocycloalkane having 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane, or the like may be mentioned. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing 1 or more hydrogen atoms from a cycloalkane, and the polycycloalkane is preferably a C7-30 polycycloalkane. Among these, as the polycyclic alkane, polycyclic alkanes having a polycyclic skeleton with a crosslinked ring, such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane, are more preferable; polycyclic alkanes having a polycyclic skeleton of condensed rings, such as cyclic groups having a steroid skeleton.

Wherein, as R¹⁰¹The cyclic aliphatic hydrocarbon group in (1) is preferably a group obtained by removing 1 or more hydrogen atoms from a monocycloalkane or polycycloalkane, more preferably a group obtained by removing 1 hydrogen atom from a polycycloalkane, particularly preferably an adamantyl group or norbornyl group, and most preferably an adamantyl group.

The straight-chain or branched-chain 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, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

As branched aliphaticThe hydrocarbon group is preferably a branched alkylene group, and specifically may be-CH (CH)₃)-、-CH(CH₂CH₃)-、-C(CH₃)₂-、-C(CH₃)(CH₂CH₃)-、-C(CH₃)(CH₂CH₂CH₃)-、-C(CH₂CH₃)₂-isoalkylmethylene; -CH (CH)₃)CH₂-、-CH(CH₃)CH(CH₃)-、-C(CH₃)₂CH₂-、-CH(CH₂CH₃)CH₂-、-C(CH₂CH₃)₂-CH₂-isoalkylethylene; -CH (CH)₃)CH₂CH₂-、-CH₂CH(CH₃)CH₂-isoalkylpropylene; -CH (CH)₃)CH₂CH₂CH₂-、-CH₂CH(CH₃)CH₂CH₂An alkylalkylene group such as an alkylbutylene group, etc. The alkyl group in the alkyl alkylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms.

Furthermore, R¹⁰¹The cyclic hydrocarbon group in (2) may contain a hetero atom like a heterocycle and the like. Specifically, examples thereof include lactone ring-containing groups represented by the above-mentioned formulae (a2-r-1) 'to (a 2-r-7)' and-SO-containing groups represented by the above-mentioned formulae (a5-r-1) 'to (a 5-r-2)'₂A polycyclic group and other heterocyclic groups represented by the following formulae (r-hr-1) to (r-hr-16). Denotes the bonding site.

[ solution 27]

As R¹⁰¹Examples of the substituent in the cyclic group (b) include an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

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, or 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 isopropoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group.

Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.

Examples of the haloalkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, for example, groups in which some or all of hydrogen atoms such as methyl, ethyl, propyl, n-butyl, and tert-butyl are substituted with the above-mentioned halogen atom.

The carbonyl group as the substituent is a methylene group (-CH) substituted for the cyclic hydrocarbon group₂-) of (a) a group of (b).

Chain alkyl groups which may have a substituent:

as R¹⁰¹The chain alkyl group of (b) may be either linear or branched.

The straight-chain 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, examples thereof include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl and docosyl.

The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples thereof include 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl and 4-methylpentyl.

Chain alkenyl groups which may have a substituent:

as R¹⁰¹The chain alkenyl group (b) may be either straight-chain or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include an ethenyl group and a propenyl group (allyl group)Mesityl), and the like. Examples of the branched alkenyl group include a 1-methylethenyl group, a 2-methylethenyl group, a 1-methylpropenyl group and a 2-methylpropenyl group.

Among the above, the linear alkenyl group is preferably a linear alkenyl group, more preferably an ethenyl group or a propenyl group, and particularly preferably an ethenyl group.

As R¹⁰¹Examples of the substituent in the linear alkyl group or the linear alkenyl group of (3) include an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the R¹⁰¹Cyclic group in (1), and the like.

Wherein R is¹⁰¹The cyclic group which may have a substituent and the chain alkyl group which may have a substituent are preferable, the cyclic group which may have a substituent is more preferable, and the cyclic hydrocarbon group which may have a substituent is further preferable.

Among them, preferred are phenyl group, naphthyl group, groups obtained by removing 1 or more hydrogen atoms from cycloalkane, lactone-containing cyclic groups represented by the formulae (a2-r-1) '- (a 2-r-7)' respectively, and-SO-containing groups represented by the formulae (a5-r-1) '- (a 5-r-2)', respectively₂Among these, more preferred are-SO-containing groups represented by the formulae (a5-r-1) '- (a 5-r-2)' described above, each of which is obtained by removing 1 or more hydrogen atoms from a cycloalkane₂-polycyclic radicals.

In the formula (b-1), Y¹⁰¹Is a single bond or a 2-valent linking group comprising an oxygen atom.

At Y¹⁰¹In the case of a 2-valent linking group containing an oxygen atom, Y¹⁰¹Atoms other than oxygen atoms may be contained. Examples of the atom other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

Examples of the 2-valent linking group containing an oxygen atom include non-hydrocarbon oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C (═ O) -O-), an oxycarbonyl (-O-C (═ O) -), an amide bond (-C (═ O) -NH-), a carbonyl (-C (═ O) -), and a carbonate bond (-O-C (═ O) -O-; combinations of the non-hydrocarbon oxygen atom-containing linking groups and alkylene groups, and the like. In this combination, sulfur may be further bondedAcyl (-SO)₂-). Examples of the linking group having a valence of 2 and containing an oxygen atom may include linking groups represented by the following formulae (y-al-1) to (y-al-7).

[ solution 28]

[ in the formula, V'¹⁰¹Is a single bond or C1-5 alkylene group, V'¹⁰²Is a C1-30 saturated hydrocarbon group with a valence of 2.]

V’¹⁰²The 2-valent saturated hydrocarbon group in (1) is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and still more preferably an alkylene group having 1 to 5 carbon atoms.

As V'¹⁰¹And V'¹⁰²The alkylene group in (b) may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group.

As V'¹⁰¹And V'¹⁰²The alkylene group in (1) is specifically exemplified by methylene [ -CH ]₂-]；-CH(CH₃)-、-CH(CH₂CH₃)-、-C(CH₃)₂-、-C(CH₃)(CH₂CH₃)-、-C(CH₃)(CH₂CH₂CH₃)-、-C(CH₂CH₃)₂-isoalkylmethylene; ethylene [ -CH₂CH₂-]；-CH(CH₃)CH₂-、-CH(CH₃)CH(CH₃)-、-C(CH₃)₂CH₂-、-CH(CH₂CH₃)CH₂-isoalkylethylene; propylene (n-propylene) [ -CH₂CH₂CH₂-]；-CH(CH₃)CH₂CH₂-、-CH₂CH(CH₃)CH₂-isoalkylpropylene; butylene [ -CH₂CH₂CH₂CH₂-]；-CH(CH₃)CH₂CH₂CH₂-、-CH₂CH(CH₃)CH₂CH₂-isoalkylbutylene; pentylene radical[-CH₂CH₂CH₂CH₂CH₂-]And the like.

Furthermore, V'¹⁰¹Or V'¹⁰²In the alkylene group, a part of methylene groups in the alkylene group may be substituted with a 2-valent alicyclic group having 5 to 10 carbon atoms. The alicyclic group is preferably cyclohexylene, 1, 5-adamantylene or 2, 6-adamantylene.

As Y¹⁰¹The linking group having a valence of 2 comprising an ester bond or the linking group having a valence of 2 comprising an ether bond is preferable, the linking groups represented by the formulae (y-al-1) to (y-al-5) are more preferable, and the linking groups represented by the formulae (y-al-1) to (y-al-3) are even more preferable.

In the formula (b-1), V¹⁰¹Is a single bond, alkylene or fluoroalkylene. V¹⁰¹The alkylene group and the fluoroalkylene group in (1) preferably have 1 to 4 carbon atoms. As V¹⁰¹The fluoroalkylene group in (1) may, for example, be V¹⁰¹Wherein a part or all of hydrogen atoms of the alkylene group in (1) are substituted by fluorine atoms. Wherein, V¹⁰¹Preferably a single bond or a C1-4 fluoroalkylene group.

In the formula (b-1), R¹⁰²Is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. R¹⁰²Preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

Specific examples of the anion portion of the component (b-1) include, for example, those in Y¹⁰¹Examples of the "single bond" may include fluoroalkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutane sulfonate anion; at Y¹⁰¹In the case of a linking group having a valence of 2 and containing an oxygen atom, an anion represented by any one of the following formulae (an-1) to (an-3) may be mentioned.

[ solution 29]

[ in the formula, R "¹⁰¹Is an optionally substituted alicyclic group, or a group represented by the formulae (r-hr-1) to (r-hr-6)A group or a chain alkyl group which may have a substituent; r'¹⁰²Is an alicyclic ring group which may have a substituent, a lactone ring-containing group represented by the formulae (a2-r-1) '- (a 2-r-7)' or an-SO-containing group represented by the formulae (a5-r-1) '- (a 5-r-2)' -, respectively₂-a polycyclic group; r'¹⁰³An aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent; v 'is an integer of 0 to 3, q' is an integer of 1 to 20, t 'is an integer of 1 to 3, and n' is 0 or 1.]

R”¹⁰¹、R”¹⁰²And R "¹⁰³The alicyclic group which may have a substituent(s) is preferably as the R¹⁰¹The cyclic aliphatic hydrocarbon group in (1) is exemplified. The substituent may, for example, be represented by the formula¹⁰¹The same groups as those mentioned above as the substituents which may be substituted for the cyclic aliphatic hydrocarbon group.

R”¹⁰³The aromatic cyclic group which may have a substituent(s) in (1) is preferably the R¹⁰¹Examples of the aromatic hydrocarbon group in the cyclic hydrocarbon group in (1) are given. The substituent may, for example, be represented by the formula¹⁰¹The same groups as those in (1) may be substituted for the aromatic hydrocarbon group.

R”¹⁰¹The chain alkyl group which may have a substituent(s) in (1) is preferably the R group¹⁰¹The chain alkyl group in (1) above. R'¹⁰³The optionally substituted chain alkenyl group in (1) is preferably the R group¹⁰¹The chain alkenyl group in (1) is exemplified.

The anionic moiety of component (b-2)

In the formula (b-2), R¹⁰⁴、R¹⁰⁵Each of which is independently a halogen atom, a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, is exemplified by R in the formula (b-1)¹⁰¹The same groups. Wherein R is¹⁰⁴、R¹⁰⁵May be bonded to each other to form a ring.

R¹⁰⁴、R¹⁰⁵Preferred is a chain alkyl group which may have a substituent, and more preferred isA linear or branched alkyl group or a linear or branched fluoroalkyl group.

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. R is also good in solubility in a solvent for a photoresist¹⁰⁴、R¹⁰⁵The number of carbons of the chain alkyl group(s) in the above range is preferably as small as possible. Furthermore, R¹⁰⁴、R¹⁰⁵The larger the number of hydrogen atoms substituted with fluorine atoms in the chain alkyl group (2) is, the stronger the acid strength is and the transparency to high-energy light of 200nm or less and electron beams is improved, and thus the chain alkyl group 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 a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

In the formula (b-2), V¹⁰²、V¹⁰³Each independently represents a single bond, an alkylene group or a fluoroalkylene group, and is exemplified by V in the formula (b-1)¹⁰¹The same groups.

In the formula (b-2), L¹⁰¹、L¹⁰²Each independently a single bond or an oxygen atom.

The anionic moiety of component (b-3)

In the formula (b-3), R¹⁰⁶Is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, wherein R is¹⁰⁶Wherein a carbon atom adjacent to the S atom is not bonded with a fluorine atom (fluorine-free substitution). R¹⁰⁶Preferred are cyclic groups which may have a substituent and chain-like alkyl groups which may have a substituent.

Preferable specific examples of the anion portion of the component (b-3) include anions of (D1-2-11) to (D1-2-31), and most preferably anions of (D1-2-11), which are preferable specific examples of the anion portion of the component (D1-2) in the component (D) described later.

{ cation (cation) part }

In the formulae (b-1), (b-2) and (b-3), M is an integer of 1 or more and M'^m+Is an m-valent onium cation, and may preferably beAs the sulfonium cation and the iodonium cation, particularly preferred are organic cations represented by the following formulae (ca-1) to (ca-4).

[ solution 30]

[ in the formula, R²⁰¹～R²⁰⁷And R²¹¹～R²¹²Each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, R²⁰¹～R²⁰³、R²⁰⁶～R²⁰⁷、R²¹¹～R²¹²May be bonded to each other to form a ring together with the sulfur atom in the formula. R²⁰⁸～R²⁰⁹Each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R²¹⁰Is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a-SO-containing group which may have a substituent₂-a cyclic radical, L²⁰¹represents-C (═ O) -or-C (═ O) -O-, Y²⁰¹Each independently represents an arylene group, an alkylene group or an alkenylene group, x is 1 or 2, W²⁰¹Represents a (x +1) -valent linking group.]

As R²⁰¹～R²⁰⁷And R²¹¹～R²¹²Examples of the aryl group in (1) include unsubstituted aryl groups having 6 to 20 carbon atoms, and phenyl and naphthyl are preferable.

As R²⁰¹～R²⁰⁷And R²¹¹～R²¹²The alkyl group in (1) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

As R²⁰¹～R²⁰⁷And R²¹¹～R²¹²The alkenyl group in (1) preferably has 2 to 10 carbon atoms.

As R²⁰¹～R²⁰⁷And R²¹⁰～R²¹²Examples of the substituent which may be present include alkyl groups, halogen atoms, haloalkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following formulae (ca-r-1) to (ca-r-7).

[ solution 31]

[ wherein R'²⁰¹Each independently represents a hydrogen atom, a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent.]

R’²⁰¹Examples of the cyclic group which may have a substituent, the chain alkyl group which may have a substituent or the chain alkenyl group which may have a substituent include R in the formula (b-1)¹⁰¹The same groups. Furthermore, as R'²⁰¹Examples of the cyclic group which may have a substituent or the chain alkyl group which may have a substituent may include the same groups as those of the acid-dissociable group in the above-mentioned structural unit (a 1)'.

At R²⁰¹～R²⁰³、R²⁰⁶～R²⁰⁷、R²¹¹～R²¹²When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may be bonded to each other via a heteroatom such as a sulfur atom, an oxygen atom, a nitrogen atom or the like, a carbonyl group, -SO-, -SO₂-、-SO₃-, -COO-, -CONH-or-N (R)_N) - (the R)_NAlkyl group having 1 to 5 carbon atoms) and the like. The ring to be formed is preferably a three-to ten-membered ring, particularly preferably a five-to seven-membered ring, containing the sulfur atom in the formula in the ring skeleton of 1 ring. Specific examples of the ring to be formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

R²⁰⁸～R²⁰⁹Each independently represents 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, in R²⁰⁸～R²⁰⁹In the case of an alkyl group, they may be bonded to each other to form a ring.

R²¹⁰Is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a-SO-containing group which may have a substituent₂-a cyclic group.

As R²¹⁰Examples of the aryl group in (1) include unsubstituted aryl groups having 6 to 20 carbon atoms, and phenyl and naphthyl are preferable.

As R²¹⁰The alkyl group in (1) is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

As R²¹⁰The alkenyl group in (1) is preferably an alkenyl group having 2 to 10 carbon atoms.

As R²¹⁰Wherein the-SO-containing group may have a substituent₂-cyclic group, preferably said "containing-SO₂A polycyclic group ", more preferably a group represented by the formula (a 5-r-1)'.

Y²⁰¹Each independently represents an arylene group, an alkylene group or an alkenylene group.

Y²⁰¹The arylene group in (b) is exemplified by the group represented by R in the formula (b-1)¹⁰¹The aromatic hydrocarbon group in (1) is a group obtained by removing 1 hydrogen atom from an aryl group.

Y²⁰¹The alkylene group and alkenylene group in (a) may be exemplified by those represented by R in the formula (b-1)¹⁰¹The group (b) in (a) is a group obtained by removing 1 hydrogen atom from the group exemplified as the chain alkyl group or the chain alkenyl group.

In the formula (ca-4), x is 1 or 2.

W²⁰¹Is a linking group having a valence of (x +1), i.e., 2 or 3.

As W²⁰¹The 2-valent linking group in (2) is preferably a 2-valent hydrocarbon group which may have a substituent, and can be exemplified by the group Va in the above formula (a 1-1)'¹The same 2-valent hydrocarbon group which may have a substituent. W²⁰¹The 2-valent linking group in (b) may be linear, branched or cyclic, and is preferably cyclic. Among these, a group in which 2 carbonyl groups are combined at both ends of an arylene group is preferable. The arylene group may, for example, be a phenylene group or a naphthylene group, and a phenylene group is particularly preferred.

As W²⁰¹The linking group having a valence of 3 in (1) may, for example, be represented by the formula W²⁰¹Wherein 1 hydrogen atom is removed from the 2-valent linking group, a group obtained by bonding the 2-valent linking group to the 2-valent linking group, and the like. As W²⁰¹The linking group having a valence of 3 in (1) is preferably a group in which 2 carbonyl groups are bonded to an arylene group.

Specific examples of the preferable cation represented by the formula (ca-1) include cations represented by the following formulae (ca-1-1) to (ca-1-67).

[ solution 32]

[ wherein g1, g2 and g3 represent the number of repeats, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20. ]

[ solution 33]

[ in the formula, R "²⁰¹Is a hydrogen atom or a substituent, as the substituent, and as said R²⁰¹～R²⁰⁷And R²¹⁰～R²¹²Examples of the substituent which may be contained are the same ones as those listed above.]

Specific examples of the preferable cation represented by the formula (ca-2) include a diphenyliodonium cation and a bis (4-tert-butylphenyl) iodonium cation.

Specific examples of the preferable cation represented by the formula (ca-3) include cations represented by the following formulae (ca-3-1) to (ca-3-6).

[ chemical 34]

Specific examples of the preferable cation represented by the formula (ca-4) include cations represented by the following formulae (ca-4-1) to (ca-4-2).

[ solution 35]

Of the above, the cation portion [ (M'^m+)_1/m]The cation represented by the formula (ca-1) is preferable, and the cations represented by the formulae (ca-1-1) to (ca-1-67) are more preferable.

As a preferable example of the component (B), a component (B-3) can be mentioned, and particularly, as the component (B-3), a combination of an anion portion represented by (d1-2-11) to (d1-2-31) described later and a cation represented by the above-mentioned formulae (ca-1-1) to (ca-1-16) can be used.

(B) The acid generator may be used alone in 1 kind or in combination of 2 or more kinds.

The content of the component (B) in the photoresist composition is preferably 0.1 to 50 parts by mass, and more preferably 0.1 to 40 parts by mass, based on 100 parts by mass of the component (S) described later.

By setting the content of the component (B) to the above range, pattern formation is sufficiently performed. Further, when the components of the photoresist composition are dissolved in a solvent, a uniform solution is easily obtained, and the storage safety of the photoresist composition is preferable.

< acid diffusion-controlling agent (D) >

The photoresist composition of the present invention contains an acid diffusion controller (D) (hereinafter referred to as "component (D)"). (D) The component (a) is a substance that functions as a quencher (acid diffusion controller) for capturing an acid generated by exposure in the photoresist composition.

The component (D) of the photoresist composition of the present invention may contain a photodegradable base (D1) (hereinafter referred to as a "(D1) component") which is decomposed by exposure to light and loses its acid diffusion controllability, or may further contain a nitrogen-containing organic compound (D2) (hereinafter referred to as a "(D2) component") which is not the (D1) component.

With respect to the (D1) component

When a photoresist pattern is formed by using the photoresist composition containing the component (D1), the contrast between exposed portions and unexposed portions can be improved.

The component (D1) is not particularly limited as long as it is a component which loses acid diffusion controllability by decomposition by exposure to light, and is preferably 1 or more compounds selected from the group consisting of a compound represented by the following formula (D1-1) (hereinafter referred to as a "D1-1 component"), a compound represented by the following formula (D1-2) (hereinafter referred to as a "D1-2 component"), and a compound represented by the following formula (D1-3) (hereinafter referred to as a "D1-3 component").

The components (d1-1) to (d1-3) decompose in the exposed portion of the photoresist film and lose the acid diffusion controllability (basicity), and thus cannot function as a quencher, but function as a quencher in the unexposed portion.

[ solution 36]

[ in the formula, Rd¹～Rd⁴The alkyl group may be a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. Wherein Rd in the formula (d1-2)²To the carbon atom adjacent to the S atom in (1) is not bonded with a fluorine atom. Yd¹Is a single bond or a 2-valent linking group. M is an integer of 1 or more, and M^m+Each independently an m-valent organic cation.]

{ (d1-1) composition }

Anion part

In the formula (d1-1), Rd¹The alkyl group may be a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent.

Among these, as Rd¹Preferred is an aromatic hydrocarbon group which may have a substituent, an alicyclic group which may have a substituent, or a chain alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom and a fluoroalkyl groupA lactone ring-containing group represented by the formulae (a2-r-1) '- (a 2-r-6)', an ether bond, an ester bond or a combination thereof. When an ether bond or an ester bond is contained as a substituent, an alkylene group may be present.

As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.

The alicyclic group is more preferably a group obtained by removing 1 or more hydrogen atoms from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like.

The chain alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms, and specifically, may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, or the like; branched alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl and 4-methylpentyl.

The chain alkyl group may have a fluorine atom or a fluoroalkyl group as a substituent, and the number of carbon atoms in the fluoroalkyl group is preferably 1 to 11, more preferably 1 to 8, and still more preferably 1 to 4. The fluoroalkyl group may contain an atom other than a fluorine atom. Examples of the atom other than the fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

As Rd¹The fluoroalkyl group is preferably a fluoroalkyl group in which a part or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms, and particularly preferably a fluoroalkyl group (linear perfluoroalkyl group) in which all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms.

Preferred specific examples of the anion portion of the component (d1-1) are shown below.

[ solution 37]

Cation part

In the formula (d1-1), M^m+Is m valenceThe organic cation of (1).

As M^m+The organic cation of (2) may preferably be the same as the cations represented by the formulae (ca-1) to (ca-4), more preferably the cation represented by the formula (ca-1), and still more preferably the cations represented by the formulae (ca-1-1) to (ca-1-67).

The component (d1-1) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

{ (d1-2) composition }

Anion part

In the formula (d1-2), Rd²The alkyl group may be a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent.

Wherein, Rd²The carbon atom adjacent to the S atom in (1) is not bonded with a fluorine atom (fluorine-free substitution). Thus, the anion of the component (D1-2) becomes a moderately weak acid anion, and the quenching ability as the component (D) is improved.

As Rd²Preferable is a chain alkyl group which may have a substituent or an alicyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. The alicyclic group is more preferably a group (which may have a substituent) obtained by removing 1 or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; groups obtained by removing 1 or more hydrogen atoms from camphor and the like.

Rd²The hydrocarbon group (C) may have a substituent, and examples of the substituent include Rd of the formula (d1-1)¹The hydrocarbon group (aromatic hydrocarbon group, alicyclic group, or chain alkyl group) in (1) may have the same substituent.

Preferred specific examples of the anion portion of the component (d1-2) are shown below.

[ solution 38]

Cation part

In the formula (d1-2), M^m+An organic cation having a valence of M, is the same as M in said formula (d1-1)^m+The same organic cation.

The component (d1-2) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

{ (d1-3) composition }

Anion part

In the formula (d1-3), Rd³The group is a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, and is preferably a cyclic group, a linear alkyl group, or a linear alkenyl group containing a fluorine atom. Among them, fluoroalkyl group is preferable, and Rd is more preferable¹The fluoroalkyl group of (a) is the same fluoroalkyl group.

In the formula (d1-3), Rd⁴The alkyl group may be a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent.

Among them, preferred are alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups which may have a substituent.

Rd⁴The alkyl group in (b) is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, it may, for example, be a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group or a neopentyl group. Rd⁴A part of the hydrogen atoms of the alkyl group in (b) may be substituted by a hydroxyl group, a cyano group or the like.

Rd⁴The alkoxy group in (3) 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 isopropoxy group, an n-butoxy group and a tert-butoxy group. Among them, methoxy group and ethoxy group are preferable.

Rd⁴The alkenyl group in (1) is preferably vinyl, propenyl (allyl), 1-methylpropenyl or 2-methylpropenyl. These groups may further have an alkyl group having 1 to 5 carbon atoms or a haloalkyl group having 1 to 5 carbon atoms as a substituent.

Rd⁴The cyclic group in (A) is preferably selected from cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetradecaneAlicyclic groups obtained by removing 1 or more hydrogen atoms from cycloalkanes such as cyclododecane, and aromatic groups such as phenyl and naphthyl groups. At Rd⁴In the case of an alicyclic group, the photoresist composition is favorably dissolved in a solvent, whereby the lithographic characteristics are improved. Furthermore, at Rd⁴In the case of an aromatic group, the photoresist composition has excellent light absorption efficiency, sensitivity and lithographic characteristics in lithography using EUV or the like as an exposure light source.

In the formula (d1-3), Yd¹Is a single bond or a 2-valent linking group.

As Yd¹The 2-valent linking group in (2) is not particularly limited, and examples thereof include a 2-valent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) having a substituent, a 2-valent linking group containing a hetero atom, and the like.

As Yd¹Preferably a carbonyl group, ester linkage, amide linkage, alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and still more preferably a methylene group or an ethylene group.

Preferred specific examples of the anion portion of the component (d1-3) are shown below.

[ solution 39]

Cation part

In the formula (d1-3), M^m+Is an organic cation having a valence of M, with M in said formula (d1-1)^m+The same is true.

The component (d1-3) may be used alone in 1 kind or in combination of 2 or more kinds.

(D1) Component (c) may be any of the above-mentioned components (d1-1) to (d1-3), or 2 or more of them may be used in combination.

Among the above, it is preferable to use at least the component (D1-1) as the component (D1).

The content of the component (D1) in the photoresist composition is preferably 0.1 to 5 parts by mass, more preferably 0.1 to 4 parts by mass, and still more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the component (S).

When the content of the (D1) component is not less than the preferable lower limit, particularly good lithographic characteristics and photoresist pattern shape can be easily obtained. On the other hand, if the value is equal to or less than the upper limit, the sensitivity can be maintained well.

(D1) The method for producing the component (A):

the method for producing the component (d1-1) or the component (d1-2) is not particularly limited, and the component (d1-1) can be produced by a known method.

The method for producing the component (d1-3) is not particularly limited, and can be produced, for example, in the same manner as the method described in U.S. patent publication No. US 2012-0149916.

With respect to the (D2) component

The acid diffusion-controlling agent component may further contain a nitrogen-containing organic compound component (hereinafter referred to as "component D2") which is not the component D1.

The component (D2) is not particularly limited as long as it functions as an acid diffusion controller and does not belong to the component (D1), and any known component may be used. Among them, aliphatic amines and aromatic amines are preferable.

The aliphatic amine is an amine having 1 or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.

The aliphatic amine may, for example, be ammonia NH₃An amine (alkylamine or alkylol amine) or a cyclic amine obtained by substituting at least 1 of the hydrogen atoms of (a) a hydrocarbon group having 12 or less carbon atoms or a hydroxyalkyl group.

Specific examples of the alkylamine and the alkylol amine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as 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, and tri-n-dodecylamine; and alkylolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be a monocyclic compound (aliphatic monocyclic amine) or a polycyclic compound (aliphatic polycyclic amine).

Specific examples of the alicyclic monocyclic amine include piperidine and piperazine.

The aliphatic polycyclic amine is preferably one having 6 to 10 carbon atoms, and specifically, it may, for example, be 1, 5-diazabicyclo [4.3.0] -5-nonene, 1, 8-diazabicyclo [5.4.0] -7-undecene, hexamethylenetetramine or 1, 4-diazabicyclo [2.2.2] octane.

Examples of the other aliphatic amine 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, and triethanolamine triacetate is preferable.

As the component (D2), an aromatic amine can be used.

Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2, 6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and 2, 4-diamino-6-phenyl-1, 3, 5-triazine, with N-tert-butoxycarbonylpyrrolidine and 2, 4-diamino-6-phenyl-1, 3, 5-triazine being preferred, and 2, 4-diamino-6-phenyl-1, 3, 5-triazine being more preferred.

(D2) The component (A) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

When the photoresist composition contains the (D2) component, the (D2) component may be used in an amount of 0.005 to 3 parts by mass based on 100 parts by mass of the (S) component. By setting the above range, the shape of the photoresist pattern, the stability with time after exposure, and the like are improved.

< additive (E) >

The photoresist composition of the present invention may contain at least one additive (E) (hereinafter referred to as "(E) component") in order to improve the characteristics of the photoresist composition. (E) The component (B) is different from the components (a) and (B) described above, and is also different from the component (S) described below.

The photoresist composition of the present invention may contain any suitable crosslinking agent (E1) (hereinafter referred to as "(E1) component") capable of crosslinking the resin component (a) in the presence of an acid. Non-limiting examples of the component (E1) include resins containing melamine, methylol, glycoluril (glycouril), polymeric glycoluril, benzoguanamine, urea, hydroxyalkylamide, epoxy and epoxy amine resins, blocked isocyanate, divinyl monomers, and the like, and monomeric melamine such as hexamethoxymethylmelamine, glycoluril derivatives, or aromatic methylol such as 2, 6-bis-methylol-p-cresol can be used.

The component (E1) used in the present invention is preferably a glycoluril derivative, and particularly preferably tetrakis (methoxymethyl) glycoluril, tetrakis (butoxymethyl) glycoluril, or the like.

(E1) The components can be used alone in 1 kind, or can be used in combination in more than 2 kinds. When the photoresist composition contains the component (E1), the content of the component (E1) is preferably 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and still more preferably 5 to 20 parts by mass, based on 100 parts by mass of the component (a).

The photoresist composition of the present invention may contain a compound (E2) having 1 or more polar groups in order to satisfy excellent adhesion. When the photoresist composition contains a compound having 1 or more polar groups, the amount of the solvent remaining in the photoresist layer is reduced when forming a photoresist pattern, and the adhesion between the support and the photoresist pattern is improved.

The polar group of the compound having 1 or more polar groups is preferably selected from the group consisting of a hydroxyl group, an amino group, a mercapto group, a carboxyl group and a sulfonic acid group, more preferably from the group consisting of a hydroxyl group, an amino group and a carboxyl group, and most preferably a hydroxyl group.

From the viewpoint of improving adhesion to the support, the compound having 1 or more polar groups is preferably a compound having a molecular weight of 2,000 or less, more preferably a compound having a molecular weight of 1,500 or less, and still more preferably a compound having a molecular weight of 1,000 or less.

In addition, from the viewpoint of improving the adhesion to the support, the compound having 1 or more polar groups is preferably a compound having 1 or more hydroxyl groups, and in this case, the compound having 1 or more hydroxyl groups is preferably a compound represented by the formula (e-1).

[ solution 40]

A(OH)_p (e-1)

[ in the formula, A is a straight-chain hydrocarbon group having 1-10 carbon atoms or a branched-chain hydrocarbon group having 3-10 carbon atoms, and p is an integer of 1-3. ]

In A in the formula (e-1), the number of carbon atoms in the linear hydrocarbon group is preferably 2 to 8, more preferably 4 to 6.

In A in the formula (e-1), the branched hydrocarbon group preferably has 4 to 8 carbon atoms, more preferably 5 to 6 carbon atoms.

P in the formula (e-1) is preferably 2-3, and more preferably 3.

In addition, in the case where the compound having 1 or more polar groups is a compound having 1 or more amino groups, the compound having 1 or more amino groups is preferably a compound represented by the formula (e-2).

[ solution 41]

B(NH₂)_q (e-2)

[ wherein B is a straight-chain hydrocarbon group having 1 to 10 carbon atoms or a branched-chain hydrocarbon group having 3 to 10 carbon atoms and q is an integer of 1 to 3. ]

In the formula (e-2) B, the number of carbon atoms in the linear hydrocarbon group is preferably 2 to 8, more preferably 4 to 6.

In B in the formula (e-2), the branched hydrocarbon group preferably has 4 to 8 carbon atoms, more preferably 5 to 6 carbon atoms.

Q in the formula (e-2) is preferably 2 to 3, and more preferably 3.

In addition, in the case where the compound having 1 or more polar groups is a compound having 1 or more carboxyl groups, the compound having 1 or more carboxyl groups is preferably a compound represented by the formula (e-3).

[ solution 42]

D(COOH)_r (e-3)

[ in the formula, D is a straight chain alkyl group with a carbon number of 1-10 or a branched chain alkyl group with a carbon number of 3-10, and r is an integer of 1-3. ]

In the formula (e-3) D, the number of carbon atoms in the linear hydrocarbon group is preferably 2 to 8, more preferably 4 to 6.

In the formula (e-3) D, the branched hydrocarbon group preferably has 4 to 8 carbon atoms, more preferably 5 to 6 carbon atoms.

R of the formula (e-3) is preferably 2 to 3, and more preferably 3.

(E2) The components can be used alone in 1 kind, or can be used in combination in more than 2 kinds.

When the photoresist composition contains the (E2) component, the content of the (E2) component is preferably 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and still more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the (S) component. By setting the above range, the adhesion of the thick photoresist layer to the support is improved.

< solvent (S) >

The photoresist composition of the present invention can be produced by dissolving a photoresist material in a solvent (S) (hereinafter referred to as "S component").

The component (S) is not particularly limited as long as it is a component capable of dissolving each component used to form a uniform solution, and therefore, any component can be appropriately selected from those conventionally known as solvents for photoresist compositions and used, and can be selected within the range satisfying the conditions of the present invention in which an appropriate amount of residual solvent remains in a resist film before pattern formation.

For example, lactones such as γ -butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1, 2-hexanol, and 1, 3-butanediol; polyhydric alcohol derivatives such as compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, and compounds having an ether bond such as monoalkyl ethers or monophenyl ethers of the polyhydric alcohols or the compounds having an ester bond such as monomethyl ether, monoethyl ether, monopropyl ether, or monobutyl ether; esters such as cyclic ethers like dioxane, methyl lactate, Ethyl Lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic solvents such as anisole, ethylbenzyl ether, methyltolyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, isopropyltoluene, mesitylene, and the like; dimethylsulfoxide (DMSO); propylene carbonate, and the like.

The compound having an ester bond may be a monoacetate or a diacetate represented by the following general formula (s-1).

[ solution 43]

R^s-(O-CO-CH₃)_n1 (s-1)

Wherein n1 is 1 or 2, R^sThe alkyl group may have a substituent group and has 5 to 10 carbon atoms including the carbon atoms of the substituent group.

The R is^sThe substituent of the alkyl group having 5 to 10 carbon atoms which may have a substituent may be a substituent R^sThe substituent for a part or all of hydrogen atoms of the alkyl group of (2) may be R^sA substituent of an alkyl main chain carbon atom of (1).

As a substituent R^sExamples of the substituent for a part or all of hydrogen atoms of the alkyl group of (2) include a lower alkyl group having 1 to 5 carbon atoms, a lower alkoxy group having 1 to 5 carbon atoms, a fluorine atom having 1 to 5 carbon atoms which is substituted with a fluorine atomLower alkyl, oxygen atom (═ O), and the like. Among them, a lower alkoxy group having 1 to 5 carbon atoms is preferable, and methoxy (-OCH) group is more preferable₃)。

As a substituent R^sFor example, a 2-valent linking group preferably containing a heteroatom. Examples of the heteroatom-containing linking group having a valence of 2 include-O-, -C (═ O) -, -O-C (═ O) -O-, "-a-O (oxygen atom) -B- (wherein a and B are each independently a hydrocarbon group having a valence of 2 which may have a substituent)," and the like. Examples of the substituent which said A and B may have include the substituent mentioned for R^sThe substituents for a part or all of the hydrogen atoms of the alkyl group in (1) are the same as the substituents exemplified above.

Examples of the monoacetate or diacetate represented by the general formula (s-1) include 3-methoxybutyl acetate (abbreviated as MBA; boiling point 171 ℃; SP value 871), dipropylene glycol methyl ether acetate (abbreviated as DPMA; boiling point 213 ℃; SP value 871), propylene glycol diacetate (abbreviated as PGDA; boiling point 190 ℃; SP value 960), 1, 3-butanediol diacetate (abbreviated as 1, 3 BGDA; boiling point 232 ℃; SP value 1011), cyclohexanol acetate (abbreviated as CHXA; boiling point 173 ℃; SP value 918), ethylene glycol monobutyl ether acetate (abbreviated as BMGAC; boiling point 188 ℃; SP value 885), diethylene glycol monoethyl ether acetate (abbreviated as EDGAC; boiling point 217 ℃; SP value 901), diethylene glycol monobutyl ether acetate (abbreviated as BDGAC; boiling point 247 ℃; SP value 894), and the like.

As the component (S), DPMA, Propylene Glycol Monomethyl Ether Acetate (PGMEA), Propylene Glycol Monomethyl Ether (PGME), 2-heptanone, 1, 2-hexanediol, 1, 3-butanediol and the like are preferable.

The component (S) may be used alone in 1 kind, or may be used as a mixed solvent of 2 or more kinds. The amount of the component (S) used is not particularly limited, and may be appropriately set according to the coating film thickness at a concentration at which the component (S) can be applied to a support or the like. The (S) component can be used in a range where the solid content concentration of the photoresist composition is 30 to 70 mass%, and more preferably in a range where the solid content concentration is 5 to 20 mass%.

< Compound (X) >

The photoresist composition of the invention at least contains 1 compound (X) represented by the following formula (X-1) in order to improve the characteristics of the photoresist composition.

[ solution 44]

The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and more preferably a linear alkyl group. Specifically, the alkyl group may include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl.

The alkyl group having 1 to 10 carbon atoms which is substituted with a hydroxyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms which is substituted with 1 or more hydroxyl groups, and more preferably a linear alkyl group.

The R is¹And R²、R³And R⁴、R⁵And R⁶The individual radicals in (a) may be identical to one another or different, preferably identical to one another. The numbers of a and b, c and d, e and f may be the same or different, and are preferably the same.

As the compound (X), a compound represented by the following formula is preferable.

[ solution 45]

[ in the formula, R⁵And R⁶And the above-mentionedThe definitions in the formula (x-1) are the same.]

As the compound (X), a compound represented by the following formula is also preferable.

[ solution 46]

[ in the formula, R³And R⁴The same as defined in said formula (x-1).]

Specific examples of the compound (X) are as follows.

[ solution 47]

By using the compound (X), an effect of improving sensitivity can be obtained, and the shape can be maintained while maintaining high resolution.

The component (X) may be used alone in 1 kind, or may be used as a mixture of 2 or more kinds. The content of the component (X) in the photoresist composition is preferably 1 to 25 parts by mass, more preferably 1 to 20 parts by mass, and still more preferably 2 to 15 parts by mass, based on 100 parts by mass of the component (A).

Examples

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

< preparation of Photoresist composition >

The components shown in tables 1 and 2 below were mixed and dissolved to prepare photoresist compositions of the respective examples.

[ TABLE 1]

[ TABLE 2]

In tables 1 and 2, the abbreviations each have the following meanings, and the numerical values in [ ] are the blending amounts (parts by mass).

(A) Composition (I)

And (2) taking x: the ratio of y is a polymer compound (A) -1 comprising the following structural units:

[ solution 48]

(B) Composition (I)

An acid generator represented by the following chemical formula.

[ solution 49]

(D) Composition (I)

An acid diffusion controlling agent represented by the following chemical formula.

[ solution 50]

[ solution 51]

[ solution 52]

[ Hua 53]

(D2) -1: triethylamine (E1) component

[ solution 54]

Tetrakis (methoxymethyl) glycoluril (S) component (S) -1: dipropylene glycol methyl ether acetate (DPMA) (S) -2: 1, 2-hexanediol

(S) -3: 2-heptanone

(S) -4: 1, 3-butanediol

(S) -5: dipropylene glycol methyl ether

(S) -6: gamma-butyrolactone (GBL)

(S) -7: propylene carbonate

(S) -8: propylene Glycol Monomethyl Ether Acetate (PGMEA)

(S) -9: propylene Glycol Monomethyl Ether (PGME)

(X) component

[ solution 55]

2, 2 '-dimethyl-4, 4' - (fluorene-9, 9-diyl) diphenol

[ solution 56]

4, 4' - (9-fluorenylidene) diphenol

[ solution 57]

Bis-phenoxyethanolic fluorenes

[ solution 58]

4, 4' -cyclohexylidenebisphenol

< measurement of amount of residual solvent in film >

The compositions shown in tables 1 and 2 were applied to 8-inch silicon wafers, and then baked at 100 ℃ for 60 seconds to have a film thickness of 300 nm. The photoresist film on the silicon wafer was cut out, and the amount of residual solvent was measured with a GC-flame ionization detector. The values are shown in table 3 below.

[ TABLE 3]

	Amount of solvent remaining in film (ppm)
		Example 1	1040
Example 2	1040
		Example 3	1040
Example 4	1040
		Example 5	1040
Example 6	1040
		Example 7	980
Example 8	960
		Example 9	910
Comparative example 1	1040
		Comparative example 2	900
Comparative example 3	1040
		Comparative example 4	850
Comparative example 5	720
		Comparative example 6	810
Comparative example 7	890

< formation of Photoresist Pattern >

The compositions shown in tables 1 and 2 were applied to a 12-inch silicon wafer using a coater, and then Prebaked (PAB) at 100 ℃ for 60 seconds on a hot plate, followed by drying, thereby forming a photoresist film having a thickness of 300 μm.

Next, the photoresist film was selectively irradiated with KrF excimer laser light (248nm) through a mask pattern (binary mask) by a KrF exposure apparatus NSR-S210D (manufactured by nikon, NA (numerical aperture) 0.82, σ 0.90).

Then, a post-exposure heating (PEB) treatment was performed at 110 ℃ for 90 seconds.

Next, alkaline development was carried out at 23 ℃ for 60 seconds using 2.38 mass% aqueous tetramethylammonium hydroxide (TMAH) solution "NMD-3" (trade name, manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a developer. Then, the film was rinsed with pure water for 30 seconds and dried.

< evaluation of characteristics of Photoresist Pattern >

The characteristics of the photoresist pattern formed as described above were evaluated as described below.

(standing wave value)

The Standing Wave (SW) is a value obtained by digitizing the cross-sectional shape of the formed photoresist pattern, and is preferably closer to 1.0, as expressed by the width (MAX) of the thickest cross-sectional portion/the width (MIN) of the thinnest cross-sectional portion.

(depth of focus (DOF))

In order to form a fine pattern, the depth of focus must be made large.

The photoresist patterns formed from the photoresist compositions of examples 1 to 9 and comparative examples 1 to 7 were observed using a Scanning Electron Microscope (SEM) to determine the SW value and the DOF.

This is shown in table 4 below.

[ TABLE 4]

	SW value	DOF
			Example 1	0.85	450
Example 2	0.74	550
			Example 3	0.82	550
Example 4	0.84	550
			Example 5	0.89	550
Example 6	0.73	450
			Example 7	0.75	500
Example 8	0.59	350
			Example 9	0.55	400
Comparative example 1	0.90	150
			Comparative example 2	0.41	250
Comparative example 3	0.42	250
			Comparative example 4	0.43	250
Comparative example 5	0.32	200
			Comparative example 6	0.36	200
Comparative example 7	0.39	250

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the invention.

Claims

1. A photoresist pattern forming method, comprising:

(ii) exposing the photoresist film; and

(iii) a step of forming a photoresist pattern by developing the exposed photoresist film,

in the formula, R¹～R⁴Each independently is hydroxyl or alkyl with 1-5 carbon atoms, R⁵And R⁶Independently represents hydrogen, an alkyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 10 carbon atoms substituted with a hydroxyl group, a, b, c and d independently represent an integer of 0 to 3, e and f independently represent an integer of 1 to 2,

2. The method of forming a photoresist pattern of claim 1 wherein a, b, c and d are 0, e and f are 1, R⁵And R⁶Are each independently hydrogen or- (CH)₂)_n-OH, wherein n is an integer of 1 to 5.

3. The method of forming a photoresist pattern according to claim 1 or 2, wherein the photodegradable base (D1) is 1 or more compounds selected from the group consisting of compounds represented by the following formula (D1-1), formula (D1-2) and formula (D1-3),

in the formula, Rd¹～Rd⁴Is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent,Or a chain alkenyl group which may have a substituent(s), wherein Rd in the formula (d1-2)²In (2), a carbon atom adjacent to the S atom is not bonded with a fluorine atom, Yd¹Is a single bond or a 2-valent linking group, M is an integer of 1 or more, and M^m+Each independently an m-valent organic cation.

4. The method of forming a photoresist pattern according to claim 1 or 2, wherein the resin (A) whose solubility in a developer is changed by the action of an acid comprises a polymer compound having a structural unit represented by the following formula (a10-1),

wherein 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^x1Is a single bond or a 2-valent linking group, Wa^x1Is (n)_ax1+1) valent aromatic hydrocarbon radicals, n_ax1Is an integer of 1 to 3.