Resist composition and resist pattern forming method

Abstract

A resist composition which generates an acid by exposure and whose solubility to a developer is changed by the action of the acid, contains: a base material component (A) whose solubility to a developer is changed by the action of the acid; and an ionic liquid (Z), the solid content concentration of the resist composition being 25 mass% or more.

Description

TECHNICAL FIELD

[0001] The present application relates to a resist composition and a resist pattern forming method.

[0002] This application is based on Japanese Patent Application No. 2019-217161 filed on November 29, 2019, and Japanese Patent Application No. 2020-156373 filed on September 17, 2020, in the State of Japan, and this content is hereby incorporated by reference into this application. BACKGROUND

[0003] In the photolithography technique, a process is performed in which, for example, a resist film composed of a resist material is formed on a substrate, the resist film is selectively exposed, and development processing is performed, thereby forming a resist pattern of a prescribed shape in the resist film. A resist material in which the exposed portion of the resist film changes to a property of dissolving in a developer is called a positive type, and a resist material in which the exposed portion of the resist film changes to a property of not dissolving in a developer is called a negative type.

[0004] In recent years, in the production of semiconductor elements and liquid crystal display elements, due to the progress of the photolithography technique, the miniaturization of patterns has rapidly advanced. As a method of miniaturization, in general, shortening of the wavelength (high energy) of the exposure light source is performed. Specifically, although ultraviolet rays typified by g-rays and i-rays were used in the past, now, KrF excimer laser or ArF excimer laser is used to perform mass production of semiconductor elements. In addition, research is also being conducted on EUV (extreme ultraviolet rays), EB (electron beams), X-rays, and the like, which have a shorter (higher energy) wavelength than these excimer lasers.

[0005] With respect to the resist material, sensitivity with respect to these exposure light sources, resolution of reproducible fine-sized patterns, and the like are required as lithography characteristics.

[0006] As a resist material satisfying such requirements, a chemical amplification type resist composition containing a base material component whose solubility in a developer changes due to the action of an acid, and an acid generator component which generates an acid by exposure has been used in the past.

[0007] For example, in the case where the above-mentioned developer is an alkali developer (alkali development process), as a chemical amplification type resist composition of the positive type, a composition containing a resin component (base resin) whose solubility in an alkali developer increases due to the action of an acid, and an acid generator component is generally used. A resist film formed using the resist composition, if selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component at the exposed portion, the polarity of the base resin increases due to the action of the acid, and the exposed portion of the resist film becomes soluble with respect to the alkali developer. Therefore, by performing alkali development, a non-exposed portion of the resist film remains as a positive pattern.

[0008] On the other hand, in the case where such a chemically amplified resist composition is applied to a solvent developing process using a developing solution containing an organic solvent (organic developing solution), if the polarity of the base resin increases, the solubility to the organic developing solution relatively decreases, and thus the unexposed portions of the resist film are dissolved and removed by the organic developing solution, and a negative resist pattern in which the exposed portions of the resist film remain as a pattern is formed. The solvent developing process in which such a negative resist pattern is formed is sometimes referred to as a negative developing process.

[0009] Hitherto, as the base resin of a chemically amplified resist composition, for example, for a KrF excimer laser (248 nm), a polyhydroxystyrene (PHS) having high transparency or a resin in which the hydroxyl group of the PHS is protected by a dissolution inhibiting group having acid dissociability (PHS-based resin) is used. Or for example, for an ArF excimer laser (193 nm), a resin in which the hydroxyl group of the carboxyl group of (meth)acrylic acid is protected by a dissolution inhibiting group having acid dissociability ((meth)acrylic acid-based resin) is used (for example, refer to Patent Document 1).

[0010] As the dissolution inhibiting group having acid dissociability, a so-called acetal group such as a chain ether group represented by 1-ethoxyethyl or a cyclic ether group represented by tetrahydropyranyl, a tertiary alkyl group represented by a tert-butyl group, a tertiary alkoxycarbonyl group represented by a tert-butoxycarbonyl group, and the like are mainly used.

[0011] Further, as the acid generator component used in a chemically amplified resist composition, various acid generator components have been proposed hitherto, and onium salt-based acid generators such as iodonium salts or sulfonium salts, sulfonic acid oxime ester-based acid generators, diazomethane-based acid generators, nitrobenzyl sulfonic acid salt-based acid generators, imino sulfonic acid salt-based acid generators, disulfone-based acid generators, and the like are known.

[0012] Among them, onium salt-based acid generators are generally used, and onium salt-based acid generators having a triphenyl sulfonium or the like onium ion in the cation portion are mainly used. In the anion portion of the onium salt-based acid generators, an alkyl sulfonic acid ion or a fluoroalkyl sulfonic acid ion in which a part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms, and the like are generally used.

[0013] However, at present, with the high integration of LSIs and the high speed of communication, an increase in memory capacity is required, and further miniaturization of patterns is rapidly progressing. However, in photolithography using electron rays or EUV, although the formation of a fine pattern of several tens of nanometers is targeted, there are still many technical problems in which productivity is low, and there are limitations in the technology of fine processing.

[0014] In response to this, in addition to miniaturization, development of three-dimensional structure devices in which memory is increased by stacking cells and laminating is being promoted.

[0015] Prior Art Documents

[0016] Patent Documents

[0017] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-241385 SUMMARY

[0018] PROBLEMS TO BE SOLVED BY THE INVENTION

[0019] In the production of the three-dimensional structure device, there is a process of forming a thick resist film of, for example, 5 μm or more on the surface of a workpiece, forming a resist pattern, and performing etching or the like. In the case where a chemically amplified resist composition is used, there is a problem that the thicker the resist film, the more difficult it is to maintain the sensitivity at the time of exposure, the resolution at the time of development is lowered, and it is difficult to obtain a desired resist pattern shape. Further, there is a problem that the thicker the resist film, the more likely it is to cause cracks in the resist pattern.

[0020] The present invention has been achieved in view of the above-described circumstances, and a technical problem thereof is to provide a resist composition capable of forming a thick resist film and less likely to cause cracks, and having good sensitivity, and a resist pattern forming method using the same.

[0021] Approach for solving the above-described technical problem

[0022] In order to solve the above-described technical problem, the present invention adopts the following configuration.

[0023] That is, the first aspect of the present invention is a resist composition which generates an acid by exposure and whose solubility to a developer changes due to the action of the acid, characterized by containing a base material component (A) whose solubility to a developer changes due to the action of the acid and an ionic liquid (Z), and the solid content concentration of the resist composition is 25% by mass or more.

[0024] The second aspect of the present invention is a resist pattern forming method characterized by having a process of forming a resist film using the resist composition of the first aspect on a support; a process of exposing the resist film; and a process of developing the exposed resist film to form a resist pattern.

[0025] EFFECT OF THE INVENTION

[0026] According to the present invention, it is possible to provide a resist composition capable of forming a thick resist film and less likely to cause cracks, and having good sensitivity, and a resist pattern forming method using the same. DETAILED DESCRIPTION

[0027] In the present specification and the present claims, "aliphatic" is a relative concept with respect to aromatic, and is defined as a group, compound, etc. that does not have aromaticity.

[0028] Unless otherwise specified, "alkyl" includes a 1-valent saturated hydrocarbon group of a linear, branched, and cyclic shape. The same applies to the alkyl group in an alkoxy group.

[0029] Unless otherwise specified, "alkylene" includes a 2-valent saturated hydrocarbon group of a linear, branched, and cyclic shape.

[0030] "Alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group are substituted with halogen atoms. As the halogen atoms, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom can be exemplified.

[0031] "Fluoroalkyl group" or "fluoroalkylene group" is a group in which some or all of the hydrogen atoms of an alkyl group or an alkylene group are substituted with fluorine atoms.

[0032] "Structural unit" refers to a monomeric unit (monomer unit) that constitutes a high molecular compound (resin, polymer, copolymer).

[0033] In the case where it is described as "may have a substituent" or "may have a substituent", both the case where a monovalent group is substituted for a hydrogen atom (-H) and the case where a divalent group is substituted for a methylene group (-CH2-) are included.

[0034] "Exposure" is a concept that includes irradiation of all types of radiation.

[0035] "Base material component" refers to an organic compound having a film-forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. By making the molecular weight of the organic compound 500 or more, the film-forming ability is improved, and in addition, a nanoscale resist pattern is easily formed. The organic compound used as the base material component is roughly classified into a non-polymer and a polymer. As the non-polymer, a non-polymer having a molecular weight of 500 or more and less than 4000 is generally used. Hereinafter, in the case where "low molecular compound" is mentioned, a non-polymer having a molecular weight of 500 or more and less than 4000 is meant. As the polymer, a polymer having a molecular weight of 1000 or more is generally used. Hereinafter, in the case where "resin", "high molecular compound", or "polymer" is mentioned, a polymer having a molecular weight of 1000 or more is meant. As the molecular weight of the polymer, a weight average molecular weight based on polystyrene conversion by GPC (gel permeation chromatography) is used.

[0036] "Structural unit derived from an acrylate ester" refers to a structural unit constituted by cleavage of the ethylenic double bond of an acrylate ester.

[0037] "Acrylate" is a compound in which the hydrogen atom at the carboxyl end of acrylic acid (CH2=CH-COOH) is substituted with an organic group.

[0038] The hydrogen atom bonded to the carbon atom at the α-position of the acrylate can be substituted with a substituent. The substituent (R α0 ) that substitutes the hydrogen atom bonded to the carbon atom at the α-position is an atom or group other than a hydrogen atom, and examples include an alkyl group having a carbon number of 1 to 5, a haloalkyl group having a carbon number of 1 to 5, and the like. In addition, it also includes itaconic acid diester in which the substituent (R α0 ) is substituted with a substituent containing an ester bond, α-hydroxy acrylate in which the substituent (R α0 ) is substituted with a hydroxyalkyl group or a group that modifies the hydroxy group. In addition, unless otherwise specified, the carbon atom at the α-position of the acrylate refers to the carbon atom bonded to the carbonyl group of the acrylic acid.

[0039] Hereinafter, the acrylate in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent will be sometimes referred to as α-substituted acrylate. In addition, the acrylate and the α-substituted acrylate will be sometimes collectively referred to as "(α-substituted) acrylate".

[0040] "Structural unit derived from hydroxystyrene" refers to a structural unit formed by cleavage of the olefinic double bond of hydroxystyrene. "Structural unit derived from hydroxystyrene derivative" refers to a structural unit formed by cleavage of the olefinic double bond of hydroxystyrene derivative.

[0041] "Hydroxystyrene derivative" refers to a concept including a compound in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group, a haloalkyl group, and the like, and derivatives thereof. As the derivatives thereof, examples include a compound in which the hydrogen atom of the hydroxy group of hydroxystyrene is substituted with an organic group, a compound in which a substituent other than a hydroxy group is bonded to the benzene ring of hydroxystyrene in which the hydrogen atom at the α-position can be substituted with a substituent, and the like. In addition, unless otherwise specified, the α-position (carbon atom at the α-position) refers to the carbon atom bonded to the benzene ring.

[0042] As the substituent that substitutes the hydrogen atom at the α-position of the substituted hydroxystyrene, the same groups as those exemplified as the substituent at the α-position in the α-substituted acrylate can be exemplified.

[0043] "Structural unit derived from vinylbenzoic acid or vinylbenzoic acid derivative" refers to a structural unit formed by cleavage of the olefinic double bond of vinylbenzoic acid or vinylbenzoic acid derivative.

[0044] The "vinylbenzoic acid derivative" refers to a concept including a compound in which the hydrogen atom at the α-position of vinylbenzoic acid is substituted with an alkyl group, a halogenated alkyl group, or another substituent, and derivatives thereof. As the derivatives thereof, a compound in which the hydrogen atom at the α-position is substituted with a substituent, a compound in which the hydrogen atom of the carboxyl group of vinylbenzoic acid is substituted with an organic group, a compound in which a substituent other than a hydroxyl group and a carboxyl group is bonded to the benzene ring of vinylbenzoic acid in which the hydrogen atom at the α-position is substituted with a substituent, and the like can be exemplified. In addition, unless otherwise specified, the α-position (carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded.

[0045] The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specifically, an alkyl group having a carbon number of 1 to 5 (methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group), and the like can be exemplified.

[0046] In addition, the halogenated alkyl group as the substituent at the α-position can specifically exemplify a group in which a part or all of the hydrogen atoms of the "alkyl group as the substituent at the α-position" described above are substituted with a halogen atom. As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like can be exemplified, and a fluorine atom is particularly preferred.

[0047] In addition, the hydroxyalkyl group as the substituent at the α-position can specifically exemplify a group in which a part or all of the hydrogen atoms of the "alkyl group as the substituent at the α-position" described above are substituted with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0048] In the present specification and the present claims, depending on the structure represented by the chemical formula, there is a structure of an asymmetric carbon, and a structure of an enantiomer or a diastereomer can exist. In this case, one chemical formula represents these isomers typically. These isomers can be used individually, or can be used as a mixture.

[0049] (R) Resist composition

[0050] The resist composition of the first aspect of the present application is a resist composition in which the solubility to a developer is changed by acid generated by exposure and the action of acid, and contains a base material component (A) in which the solubility to a developer is changed by acid (hereinafter also referred to as "(A) component"), and an ionic liquid (Z) (hereinafter also referred to as "(Z) component"). The solid component concentration of the resist composition of the present embodiment is 25% by mass or more.

[0051] If the above-described resist composition is used to form a resist film, a thick film resist film (for example, a film thickness of 5 μm or more) can be formed.

[0052] If the above-described resist composition is used to form a resist film, and the resist film is subjected to selective exposure, an acid is generated in the exposed portion of the resist film, the solubility of the (A) component to a developer is changed by the action of the acid, on the other hand, in the unexposed portion of the resist film, the solubility of the (A) component to a developer does not change, and thus a difference in the solubility to a developer is generated between the exposed portion and the unexposed portion of the resist film. Therefore, if the resist film is developed, in the case where the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed, and thus a positive resist pattern is formed, in the case where the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed, and thus a negative resist pattern is formed.

[0053] In the present specification, a resist composition in which the exposed portion of a resist film is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition in which the unexposed portion of a resist film is dissolved and removed to form a negative resist pattern is referred to as a negative resist composition. The resist composition of the present embodiment can be either a positive resist composition or a negative resist composition. In addition, the resist composition of the present embodiment can be applied to an alkali developing process in which an alkali developer is used in a developing treatment at the time of resist pattern formation, or can be applied to a solvent developing process in which a developer containing an organic solvent (organic developer) is used in the developing treatment.

[0054] The resist composition of the present embodiment has an acid-generating ability by which an acid is generated by exposure, and can be either a (A) component that generates an acid by exposure or an additive component that generates an acid by exposure, which is mixed separately from the (A) component.

[0055] Specifically, the resist composition of the present embodiment (1) can further contain an acid-generating agent component (B) that generates an acid by exposure (hereinafter referred to as a "(B) component"); (2) can be a (A) component that is a component that generates an acid by exposure; (3) can be a (A) component that is a component that generates an acid by exposure and further contains a (B) component. That is, in the cases of the above-described (2) and (3), the (A) component is a "base material component that generates an acid by exposure and in which the solubility to a developer is changed by the action of the acid". In the case where the (A) component is a base material component that generates an acid by exposure and in which the solubility to a developer is changed by the action of the acid, the (A1) component described later is preferably a high molecular compound that generates an acid by exposure and in which the solubility to a developer is changed by the action of the acid. As such a high molecular compound, a resin having a structural unit that generates an acid by exposure can be used. As the structural unit that generates an acid by exposure, a publicly known structural unit can be used. Among them, the resist composition of the present embodiment is preferably the resist composition of the above-described (1).

[0056] <(A) component>

[0057] In the resist composition of the present embodiment, it is preferable that the (A) component contain a resin component (Al) whose solubility in a developer changes due to the action of an acid (hereinafter also referred to as "(Al) component"). By using the (Al) component, since the polarity of the base material component changes before and after exposure, a good developing contrast can be obtained not only in an alkaline developing process but also in a solvent developing process.

[0058] As the (A) component, at least the (Al) component is used, and other high molecular compounds and / or low molecular compounds can be used together with the (Al) component.

[0059] In the case of applying an alkaline developing process, the base material component containing the (Al) component is insoluble in an alkaline developer before exposure, and, for example, if an acid is generated from the (B) component by exposure, the polarity thereof increases due to the action of the acid, and thus the solubility in the alkaline developer increases. Therefore, in the formation of a resist pattern, if the resist film obtained by applying the resist composition on a support is selectively exposed, the solubility of the exposed part of the resist film in the alkaline developer changes from insolubility to solubility, and, on the other hand, since the unexposed part of the resist film remains insoluble in the alkaline developer without change, a positive resist pattern can be formed by performing an alkaline development.

[0060] On the other hand, in the case of applying a solvent developing process, the base material component containing the (Al) component has a high solubility in an organic developer before exposure, and, for example, if an acid is generated from the (B) component by exposure, the polarity thereof increases due to the action of the acid, and thus the solubility in the organic developer decreases. Therefore, in the formation of a resist pattern, if the resist film obtained by applying the resist composition on a support is selectively exposed, the solubility of the exposed part of the resist film in the organic developer changes from solubility to insolubility, and, on the other hand, since the unexposed part of the resist film remains soluble without change, by performing development with an organic developer, a contrast can be produced between the exposed part and the unexposed part, and thus a negative resist pattern can be formed.

[0061] In the resist composition of the present embodiment, one kind of the (A) component can be used alone, or two or more kinds of the (A) component can be used in combination.

[0062] • Regarding the (Al) component

[0063] The (Al) component is a resin component whose solubility in a developer changes due to the action of an acid. As the (Al) component, it is preferable to have a structural unit (al) containing an acid-decomposable group whose polarity increases due to the action of an acid.

[0064] The (Al) component can have other structural units in addition to the structural unit (al) as needed.

[0065] Structural unit (a1)

[0066] The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases due to the action of an acid.

[0067] The "acid-decomposable group" is a group having an acid-decomposability that at least a part of the bond in the structure of the acid-decomposable group can be cleaved by the action of an acid.

[0068] As the acid-decomposable group whose polarity increases due to the action of an acid, for example, a group that generates a polar group by the action of an acid can be exemplified.

[0069] As the polar group, for example, a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group (-SO3H), and the like can be exemplified. Among these, a polar group containing -OH in the structure (hereinafter also referred to as "polar group containing OH") is preferred, a carboxyl group or a hydroxyl group is more preferred, and a carboxyl group is particularly preferred.

[0070] As the acid-decomposable group, more specifically, a group in which the polar group is protected by an acid dissociation group (for example, a group in which the hydrogen atom of the polar group containing OH is protected by an acid dissociation group) can be exemplified.

[0071] Here, the "acid dissociation group" means either (i) a group having an acid dissociation property that the bond between the acid dissociation group and the atom adjacent to the acid dissociation group can be cleaved by the action of an acid; or (ii) a group in which, after a part of the bond is cleaved by the action of an acid, a decarboxylation reaction further occurs, whereby the bond between the acid dissociation group and the atom adjacent to the acid dissociation group can be cleaved.

[0072] The acid dissociation group constituting the acid-decomposable group must be a group having a polarity lower than that of the polar group generated by the dissociation of the acid dissociation group, and thus, when the acid dissociation group is dissociated by the action of an acid, a polar group having a higher polarity than that of the acid dissociation group is generated, and thus the polarity increases. As a result, the polarity of the (Al) component as a whole increases. By the increase in the polarity, the solubility to the developer changes relatively, and in the case where the developer is an alkali developer, the solubility increases, and in the case where the developer is an organic developer, the solubility decreases.

[0073] As the acid dissociation group, a group proposed so far as an acid dissociation group for a base resin for a chemically amplified resist composition can be exemplified.

[0074] As the group exemplified as the acid-dissociable group of the base resin for the chemically amplified resist composition, specifically, the "acetal type acid-dissociable group", the "tertiary alkyl ester type acid-dissociable group", and the "tertiary alkoxycarbonyl type acid-dissociable group" described below can be exemplified.

[0075] Acetal type acid-dissociable group:

[0076] As the acid-dissociable group for protecting the carboxyl group or the hydroxyl group in the polar group, for example, the acid-dissociable group represented by the following general formula (al-r-l) (hereinafter also referred to as "acetal type acid-dissociable group") can be exemplified.

[0077] [Chemical 1]

[0078]

[0079] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. Ra' 3 is a hydrocarbon group, Ra' 3 may be bonded to any one of Ra' 1 , Ra' 2 to form a ring.]

[0080] In the formula (al-r-l), it is preferable that at least one of Ra' 1 and Ra' 2 be a hydrogen atom, and more preferable that both be hydrogen atoms.

[0081] In the case where Ra' 1 or Ra' 2 is an alkyl group, as the alkyl group, the same alkyl group as exemplified above in the description on the α-substituted acrylic acid ester as the substituent which can be bonded to the carbon atom at the α-position can be exemplified, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group can be preferably exemplified. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like can be exemplified, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0082] In the formula (al-r-l), as the hydrocarbon group of Ra' 3 , a linear or branched alkyl group, or a cyclic hydrocarbon group can be exemplified.

[0083] The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and further preferably 1 or 2 carbon atoms. Specifically, a methyl group, an ethyl group, a n-propyl group, a n-butyl group, a n-pentyl group, and the like can be exemplified. Among them, a methyl group, an ethyl group, or a n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0084] The number of carbons of the branched alkyl group is preferably 3 to 10, and more preferably 3 to 5. Specifically, examples include isopropyl, isobutyl, t-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, and the like, with isopropyl being preferred.

[0085] Ra' is a hydrocarbon group, and 3 In the case where Ra' is a cyclic hydrocarbon group, the hydrocarbon group can be an aliphatic hydrocarbon group, or an aromatic hydrocarbon group, and in addition, can be a polycyclic group, or a monocyclic group.

[0086] As the aliphatic hydrocarbon group of the monocyclic group, a group obtained by removing one hydrogen atom from a monocyclic alkane is preferred. As the monocyclic alkane, a monocyclic alkane having a carbon number of 3 to 6 is preferred, and specifically, examples include cyclopentane, cyclohexane, and the like.

[0087] As the aliphatic hydrocarbon group of the polycyclic group, a group obtained by removing one hydrogen atom from a polycyclic alkane is preferred, and as the polycyclic alkane, a polycyclic alkane having a carbon number of 7 to 12 is preferred, and specifically, examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0088] Ra' is a hydrocarbon group, and 3 In the case where the cyclic hydrocarbon group of Ra' is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0089] The aromatic ring is not particularly limited in the case where it is a cyclic conjugated system having 4n+2 π electrons, and can be monocyclic, or polycyclic. The number of carbons of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12.

[0090] As the aromatic ring, specifically, examples include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, phenanthrene, and the like; and aromatic heterocyclic rings obtained by substituting a part of the carbon atoms constituting the aromatic hydrocarbon ring with a hetero atom. As the hetero atom in the aromatic heterocyclic ring, examples include oxygen atoms, sulfur atoms, nitrogen atoms, and the like. As the aromatic heterocyclic ring, specifically, examples include pyridine rings, thiophene rings, and the like.

[0091] Ra' is a hydrocarbon group, and 3The aromatic hydrocarbon group or the aromatic heterocyclic group in the above-mentioned "aromatic hydrocarbon group or aromatic heterocyclic group" can be exemplified by a group obtained by removing one hydrogen atom from the above-mentioned aromatic hydrocarbon ring or aromatic heterocyclic ring (an aryl group or a heteroaryl group), a group obtained by removing one hydrogen atom from an aromatic compound having two or more aromatic rings (e.g., a biphenyl group, a fluorene group, etc.), a group obtained by substituting one hydrogen atom of the above-mentioned aromatic hydrocarbon ring or aromatic heterocyclic ring with an alkylene group (e.g., a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, an aralkyl group having 6 to 30 carbon atoms, etc.), and the like. The number of carbon atoms of the alkylene group bonded to the above-mentioned aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably from 1 to 4, more preferably from 1 to 2, and particularly preferably 1.

[0092] Ra' 3 The cyclic hydrocarbon group in the above-mentioned "cyclic hydrocarbon group" can have a substituent. As the substituent, for example, -R P1 , -R P2 , -R P1 , -R P2 , -R P1 , -R P2 , -R P1 , -R P2 , -R P1 , -R P2 , -R P2 , -R P2 , -R 05 , etc. can be exemplified.

[0093] Here, R P1 is a monovalent chain saturated hydrocarbon group having from 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having from 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having from 6 to 30 carbon atoms. In addition, R P2 is a single bond, a divalent chain saturated hydrocarbon group having from 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having from 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having from 6 to 30 carbon atoms. Of these, a part or all of the hydrogen atoms of the chain saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group of R P1 and R P2 may be substituted with fluorine atoms. The above-mentioned aliphatic cyclic hydrocarbon group can have one of the above-mentioned substituents alone, or a plurality of the above-mentioned substituents each having one or more.

[0094] As the monovalent chain saturated hydrocarbon group having from 1 to 10 carbon atoms, for example, 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 decyl group, etc. can be exemplified.

[0095] Examples of monocyclic aliphatic cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl, etc.; and bicyclic [2.2.2]octyl, tricyclic [5.2.1.02, 6]decyl, tricyclic [3.3.1.13, 7]decyl, tetracyclic [6.2.1.13, 6.02, 7]dodecyl, adamantyl, etc.

[0096] Examples of monovalent aromatic hydrocarbon groups with 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from the aromatic hydrocarbon rings of benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0097] In Ra' 3 With Ra' 1 Ra' 2 When a ring is formed by bonding any one of the elements, the cyclic group is preferably a four- to seven-membered ring, more preferably a four- to six-membered ring. Specific examples of this cyclic group include tetrahydropyranyl and tetrahydrofuranyl.

[0098] Tertiary alkyl ester type acid dissociable groups:

[0099] As an acid-dissociating group that protects the carboxyl group in the above-mentioned polar groups, examples of acid-dissociating groups represented by the following general formula (a1-r-2) can be cited.

[0100] In addition, for ease of explanation, the alkyl group in the acid dissociation group represented by the following formula (a1-r-2) will be referred to as the "tertiary alkyl ester type acid dissociation group".

[0101]

Chemistry 2

[0102]

[0103] [In the formula, Ra'] 4 ~Ra' 6 They are hydrocarbon groups, Ra' 5 Ra' 6 They can bond together to form a ring.

[0104] As Ra' 4 The hydrocarbon group can be exemplified by straight-chain or branched alkyl groups, chain or cyclic alkenyl groups, or cyclic hydrocarbon groups.

[0105] Ra' 4 The linear or branched alkyl groups and cyclic hydrocarbon groups (aliphatic hydrocarbon groups as monocyclic groups, aliphatic hydrocarbon groups as polycyclic groups, and aromatic hydrocarbon groups) in Ra' can be exemplified by those described above. 3 The same group.

[0106] As Ra' 4 The chain or cyclic alkenyl group in it is preferably an alkenyl group with 2 to 10 carbon atoms.

[0107] As Ra' 5 Ra' 6 Hydrocarbon groups, for example, can be related to the above Ra' 3 The same hydrocarbon group.

[0108] In Ra' 5 With Ra' 6 When the groups are bonded together to form a ring, examples of groups represented by the following general formula (a1-r2-1), the following general formula (a1-r2-2), and the following general formula (a1-r2-3) can be preferably cited.

[0109] On the other hand, in Ra' 4 ~Ra' 6 In the case where the hydrocarbon groups are independent and not bonded to each other, groups represented by the following general formula (a1-r2-4) can be preferably cited.

[0110]

Transformation 3

[0111]

[0112] In the formula (a1-r2-1), Ra' 10 This refers to an alkyl group having 1 to 10 carbon atoms, or a group represented by the following general formula (a1-r2-r1). Ra' 11 Indicates Ra' 10 The bonded carbon atoms together form an aliphatic cyclic group. In formula (a1-r2-2), Ya is a carbon atom. Xa is the group that forms a cyclic hydrocarbon group with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group can be substituted. Ra 01 ~Ra 03 Each is independently composed of a hydrogen atom and a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Ra 01 ~Ra 03 Two or more atoms can bond together to form a ring structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group with Yaa. Ra 04 It is an aromatic hydrocarbon group that can have substituents. In formula (a1-r2-4), Ra' 12 and Ra' 13 Each is independently a monovalent chain-like saturated hydrocarbon group or a hydrogen atom having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra'14 This refers to a hydrocarbon group that can have substituents. * indicates a bond.

[0113]

Chemistry 4

[0114]

[0115] [In the formula, Ya 0 It is a quaternary carbon atom. Ra 031 Ra 032 and Ra 033 Each is an independent hydrocarbon group that can have substituents. Among them, Ra 031 Ra 032 and Ra 033 One or more of them are hydrocarbon groups having at least one polar group.

[0116] In the above formula (a1-r2-1), Ra' 10 The alkyl group having 1 to 10 carbon atoms is preferably Ra' in formula (a1-r-1). 3 Examples of alkyl groups, whether linear or branched. Ra' 10 Alkyl groups with 1 to 5 carbon atoms are preferred.

[0117] In the formula (a1-r2-r1), Ya 0 It is a quaternary carbon atom. That is, it is related to Ya. 0 The carbon atom is bonded to four adjacent carbon atoms.

[0118] In the formula (a1-r2-r1), Ra 031 Ra 032 and Ra 033 Each can be an independent hydrocarbon group that may have substituents. As Ra 031 Ra 032 and Ra 033 The hydrocarbon groups in the text can be exemplified independently as straight-chain or branched alkyl groups, chain or cyclic alkenyl groups, or cyclic hydrocarbon groups.

[0119] Ra 031 Ra 032 and Ra 033 The linear alkyl group in the form preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, examples include methyl, ethyl, n-propyl, n-butyl, and n-pentyl. Among these, methyl, ethyl, or n-butyl is preferred, and methyl or ethyl is more preferred.

[0120] Ra 031 Ra 032 and Ra 033The number of carbons of the branched alkyl group in Ra, Ra, and Ra is preferably 3 to 10, more preferably 3 to 5. Specifically, isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, and the like can be given, with isopropyl being preferred.

[0121] Ra 031 , Ra 032 , and Ra 033 The chain or cyclic alkenyl group in Ra, Ra, and Ra is preferably an alkenyl group having 2 to 10 carbons.

[0122] The cyclic hydrocarbon group in Ra 031 , Ra 032 , and Ra 033 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and in addition, can be a polycyclic group or a monocyclic group.

[0123] As the aliphatic hydrocarbon group of the monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbons is preferred, and specifically, cyclopentane, cyclohexane, and the like can be given.

[0124] As the aliphatic hydrocarbon group of the polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbons is preferred, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like can be given.

[0125] Ra 031 , Ra 032 , and Ra 033The aromatic hydrocarbon group in the above-mentioned Ra, Rb, and Rc is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and can be monocyclic or polycyclic. The number of carbons of the aromatic ring is preferably from 5 to 30, more preferably from 5 to 20, further preferably from 6 to 15, and particularly preferably from 6 to 12. As the aromatic ring, specifically, aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom can be exemplified. As the hetero atom in the aromatic heterocyclic ring, oxygen atom, sulfur atom, nitrogen atom, and the like can be exemplified. As the aromatic heterocyclic ring, specifically, pyridine ring, thiophene ring, and the like can be exemplified. As the aromatic hydrocarbon group, specifically, groups (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or the aromatic heterocyclic ring; groups obtained by removing one hydrogen atom from an aromatic compound (for example, biphenyl, fluorene, and the like) having two or more aromatic rings; groups (for example, aralkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and the like) in which one hydrogen atom of the aromatic hydrocarbon ring or the aromatic heterocyclic ring is substituted with an alkylene group; and the like can be exemplified. The number of carbons of the alkylene group bonded to the aromatic hydrocarbon ring or the aromatic heterocyclic ring is preferably from 1 to 4, more preferably from 1 to 2, and particularly preferably 1.

[0126] The above-mentioned hydrocarbon group represented by Ra 031 , Rb 032 , and Rc 033 may be substituted. As the substituent, for example, hydroxyl group, carboxyl group, halogen atom (fluorine atom, chlorine atom, bromine atom, and the like), alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, and the like), alkoxycarbonyl group, and the like can be exemplified.

[0127] Among the above-mentioned, the hydrocarbon group represented by Ra 031 , Rb 032 , and Rc 033 may have a substituent. The hydrocarbon group having a substituent is preferably a linear or branched alkyl group having a substituent, and more preferably a linear alkyl group having a substituent.

[0128] Among the above-mentioned, one or more of the hydrocarbon groups represented by Ra 031 , Rb 032 , and Rc 033 are a hydrocarbon group having a polar group.

[0129] The "hydrocarbon group having a polar group" means a hydrocarbon group in which a methylene group (-CH2-) constituting the hydrocarbon group is substituted with a polar group or a hydrocarbon group in which at least one hydrogen atom constituting the hydrocarbon group is substituted with a polar group.

[0130] As the "hydrocarbon group having a polar group", a functional group represented by the following general formula (al-pl) is preferable.

[0131] [Chem. 5]

[0132]

[0133] [In the formula, Ra 07 represents a divalent hydrocarbon group having a carbon number of 2 to 12. Ra 08 represents a divalent linking group containing a hetero atom. Ra 06 represents a monovalent hydrocarbon group having a carbon number of 1 to 12. n p0 is an integer of 1 to 6.

[0134] In the formula (a1-p1), Ra 07 represents a divalent hydrocarbon group having a carbon number of 2 to 12. Ra 07 having a carbon number of 2 to 12, preferably 2 to 8, more preferably 2 to 6, further preferably 2 to 4, particularly preferably 2.

[0135] Ra 07 The hydrocarbon group in Ra

[0136] As Ra 07 , for example, the following can be exemplified: a linear alkane diyl group such as ethene-1, 3-diyl, butane-1, 4-diyl, pentane-1, 5-diyl, hexane-1, 6-diyl, heptane-1, 7-diyl, octane-1, 8-diyl, nonane-1, 9-diyl, decane-1, 10-diyl, undecane-1, 11-diyl, dodecane-1, 12-diyl, and the like; a branched alkane diyl group such as propane-1, 2-diyl, 1-methylbutane-1, 3-diyl, 2-methylpropane-1, 3-diyl, pentane-1, 4-diyl, 2-methylbutane-1, 4-diyl, and the like; a cyclic alkane diyl group such as cyclobutane-1, 3-diyl, cyclopentane-1, 3-diyl, cyclohexane-1, 4-diyl, cyclooctane-1, 5-diyl, and the like; a polycyclic divalent alicyclic hydrocarbon group such as norbornane-1, 4-diyl, norbornane-2, 5-diyl, adamantane-1, 5-diyl, adamantane-2, 6-diyl, and the like.

[0137] Among the above, an alkane diyl group is preferred, and a linear alkane diyl group is more preferred.

[0138] In the formula (a1-p1), Ra 08 represents a divalent linking group containing a hetero atom.

[0139] As Ra 08-O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H can also be substituted by an alkyl group, an acyl group, or the like), -S-, -S(=O)2-, -S(=O)2-O-, or the like can be exemplified.

[0140] Of the above, from the viewpoint of solubility in a developer, -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O- are preferred, and -O-, -C(=O)- are particularly preferred.

[0141] In the formula (a1-p1), Ra 06 represents a monovalent hydrocarbon group having a carbon number of 1 to 12. Ra 06 The carbon number of Ra is preferably 1 to 12, and from the viewpoint of solubility in a developer, the carbon number is preferably 1 to 8, more preferably 1 to 5, further preferably 1 to 3, particularly preferably 1 or 2, and most preferably 1.

[0142] Ra 06 The hydrocarbon group in Ra can be exemplified by a chain hydrocarbon group, a cyclic hydrocarbon group, or a hydrocarbon group obtained by combining a chain and a cycle.

[0143] As the chain hydrocarbon group, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, a 2-ethylhexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, or the like can be exemplified.

[0144] The cyclic hydrocarbon group can be an alicyclic hydrocarbon group or an aromatic hydrocarbon group.

[0145] As the alicyclic hydrocarbon group, either a monocyclic or a polycyclic one can be used, and as the monocyclic alicyclic hydrocarbon group, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, or the like can be exemplified. As the polycyclic alicyclic hydrocarbon group, for example, a decalinyl group, an adamantyl group, a (2-alkyladamant-2) group, a (1-(adamant-1-yl)alkane-1) group, a norbornyl group, a methyl-norbornyl group, an isobornyl group, or the like can be exemplified.

[0146] As the aromatic hydrocarbon group, for example, a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-t-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like can be exemplified.

[0147] As Ra 06 From the viewpoint of solubility in a developer, a chain hydrocarbon group is preferred, and an alkyl group is more preferred, and a straight-chain alkyl group is further preferred.

[0148] In the formula (al-pl), n p0 is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, further preferably 1.

[0149] Specific examples of the hydrocarbon group having at least a polar group are shown below.

[0150] In the following formula, * is a bond to a quaternary carbon atom (Ya 0 ).

[0151]

Chemical 6

[0152]

[0153] In the formula (al-r2-r1), Ra 031 , Ra 032 , and Ra 033 , the number of the hydrocarbon group having at least a polar group is preferably 1 or more, and is appropriately determined in consideration of solubility to a developing solution at the time of resist pattern formation, for example, preferably 1 or 2 of Ra 031 , Ra 032 , and Ra 033 have at least a polar group, particularly preferably 1 has at least a polar group.

[0154] The hydrocarbon group having at least a polar group can have a substituent other than the polar group. As the substituent, for example, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a halogenated alkyl group having a carbon number of 1 to 5 can be exemplified.

[0155] In the formula (al-r2-1), Ra" 11 (the carbon atom to which Ra' 10 is bonded forms an alicyclic ring together) is preferably a group exemplified as the alicyclic hydrocarbon group of Ra' 3 in the formula (al-r-1).

[0156] In the formula (al-r2-2), as the cyclic hydrocarbon group formed together with Xaand Ya, a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) of Ra' 3 in the formula (al-r-1) can be exemplified.

[0157] The cyclic hydrocarbon group formed together with Xaand Ya can have a substituent. As the substituent, the same groups as those which the cyclic hydrocarbon group of Ra' 3 in the above can have can be exemplified.

[0158] In the formula (al-r2-2), as Ra 01~Ra 03 It is a monovalent chain saturated hydrocarbon group with 1 to 10 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, etc.

[0159] As Ra 01 ~Ra 03 The carbon number in the group is 3 to 20. Examples of monocyclic aliphatic cyclic saturated hydrocarbon groups include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl, etc.; and bicyclic [2.2.2]octyl, tricyclic [5.2.1.02, 6]decyl, tricyclic [3.3.1.13, 7]decyl, tetracyclic [6.2.1.13, 6.02, 7]dodecyl, adamantyl, etc.

[0160] From the perspective of easily synthesizing monolithic compounds from which the structural unit (a1) can be derived, Ra 01 ~Ra 03 Preferably, it is a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom, methyl, or ethyl, and particularly preferably a hydrogen atom.

[0161] As mentioned above, Ra 01 ~Ra 03 The substituents represented by the chain-like saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group can be exemplified by those related to the Ra group described above. 05 The same group.

[0162] As through Ra 01 ~Ra 03 A group consisting of two or more mutually bonded to form a cyclic structure and containing a carbon-carbon double bond, such as cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, cyclopenteneylene, and cyclohexeneylene. From the viewpoint of easily synthesizing monolithic compounds from which the structural unit (a1) is derived, cyclopentenyl, cyclohexenyl, and cyclopenteneylene are preferred.

[0163] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa and Yaa together is preferably Ra' in formula (a1-r-1). 3 Examples of groups are aliphatic hydrocarbon groups, either monocyclic or polycyclic.

[0164] In equation (a1-r2-3), Ra is used as... 04 The aromatic hydrocarbon group in [the text] can be exemplified by groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra... 04Preferably, the group is one obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably one obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, further preferably one obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably one obtained by removing one or more hydrogen atoms from benzene or naphthalene, most preferably one obtained by removing one or more hydrogen atoms from benzene.

[0165] Ra in the formula (a1-r2-3) is 04 As the substituent group, for example, a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), an alkoxycarbonyl group, etc. can be exemplified.

[0166] Ra in the formula (a1-r2-4) is 12 and Ra in the formula (a1-r2-4) is 13 each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. As the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra 12 and Ra 13 in the formula (a1-r2-3), the same group as the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the above-mentioned Ra 01 to Ra 03 in the formula (a1-r2-3) can be exemplified. A part or all of the hydrogen atoms possessed by the chain saturated hydrocarbon group can be substituted.

[0167] Ra in the formula (a1-r2-4) is 12 and Ra in the formula (a1-r2-4) is 13 Preferably, the group is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, further preferably a methyl group, an ethyl group, particularly preferably a methyl group.

[0168] In the case where the chain saturated hydrocarbon group represented by Ra 12 and Ra 13 in the formula (a1-r2-4) is substituted, as the substituent group, for example, the same group as the above-mentioned Ra 05 can be exemplified.

[0169] Ra in the formula (a1-r2-4) is 14 a hydrocarbon group which can have a substituent group. As the hydrocarbon group in Ra 14 in the formula (a1-r2-4), a straight-chain or branched-chain alkyl group, or a cyclic hydrocarbon group can be exemplified.

[0170] The carbon number of the straight-chain alkyl group in Ra 14 in the formula (a1-r2-4) is preferably 1 to 5, more preferably 1 to 4, further preferably 1 or 2. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. can be exemplified. Among them, a methyl group, an ethyl group or an n-butyl group is preferred, more preferably a methyl group or an ethyl group.

[0171] Ra' 14 The number of carbon atoms in the branched alkyl group in Ra 14 is preferably from 3 to 10, more preferably from 3 to 5. Specifically, examples include isopropyl, isobutyl, t-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, and the like, with isopropyl being preferred.

[0172] In the case where Ra 14 is a cyclic hydrocarbon group, the hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and in addition, can be a polycyclic group or a monocyclic group.

[0173] As the aliphatic hydrocarbon group of the monocyclic group, a group obtained by removing one hydrogen atom from a monocyclic alkane is preferred. As the monocyclic alkane, a monocyclic alkane having a carbon number of from 3 to 6 is preferred, and specifically, examples include cyclopentane, cyclohexane, and the like.

[0174] As the aliphatic hydrocarbon group of the polycyclic group, a group obtained by removing one hydrogen atom from a polycyclic alkane is preferred, and as the polycyclic alkane, a polycyclic alkane having a carbon number of from 7 to 12 is preferred, and specifically, examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0175] As the aromatic hydrocarbon group in Ra 14 , the same groups as the aromatic hydrocarbon group in Ra 04 can be given. Of these, Ra 14 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having a carbon number of from 6 to 15, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene, or phenanthrene, further preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene, and most preferably a group obtained by removing one or more hydrogen atoms from naphthalene.

[0176] As the substituent group that Ra 14 may have, the same groups as the substituent group that Ra 04 may have can be given.

[0177] In the case where Ra 14 in the formula (al-r2-4) is a naphthyl group, the position bonded to the tertiary carbon atom in the formula (al-r2-4) can be any one of the 1-position or the 2-position of the naphthyl group.

[0178] In the case where Ra 14 in the formula (al-r2-4) is an anthryl group, the position bonded to the tertiary carbon atom in the formula (al-r2-4) can be any one of the 1-position, the 2-position, or the 9-position of the anthryl group.

[0179] Specific examples of the group represented by the formula (al-r2-l) are given below.

[0180] [Chem. 7]

[0181]

[0182] [Chem. 8]

[0183]

[0184] [Chem. 9]

[0185]

[0186] The following illustrates specific examples of the group represented by the formula (al-r2-2).

[0187] [Chem. 10]

[0188]

[0189] [Chem. 11]

[0190]

[0191] [Chem. 12]

[0192]

[0193] The following illustrates specific examples of the group represented by the formula (al-r2-3).

[0194] [Chem. 13]

[0195]

[0196] The following illustrates specific examples of the group represented by the formula (al-r2-4).

[0197] [Chem. 14]

[0198]

[0199] Tertiary alkoxycarbonyl acid dissociation group:

[0200] As the acid dissociation group for protecting the hydroxyl group in the polar group, for example, the acid dissociation group represented by the following general formula (al-r-3) (hereinafter also referred to as "tertiary alkoxycarbonyl acid dissociation group" for convenience of explanation) can be exemplified.

[0201] [Chem. 15]

[0202]

[0203] [In the formula, Ra' 7 ~ Ra' 9 are each an alkyl group.

[0204] In formula (a1-r-3), Ra 7 ~Ra 9 Each of R and R is preferably an alkyl group having a carbon number of 1 to 5, more preferably an alkyl group having a carbon number of 1 to 3.

[0205] Further, the total carbon number of each alkyl group is preferably 3 to 7, more preferably a carbon number of 3 to 5, and most preferably a carbon number of 3 to 4.

[0206] As the structural unit (a1), from the viewpoint of suppressing the decrease in light transmittance in a thick film resist film, it is preferable to contain an acid dissociation group represented by the general formula (a1-r-2), and more preferable to contain an acid dissociation group represented by the general formula (a1-r2-4). In the general formula (a1-r2-4), Ra 12 and Ra 13 Each of R and R is preferably an alkyl group having a carbon number of 1 to 5, more preferably an alkyl group having a carbon number of 1 to 3, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group. In the general formula (a1-r2-4), Ra 14 is preferably an alkyl group having a carbon number of 1 to 5, more preferably an alkyl group having a carbon number of 1 to 3, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

[0207] As the structural unit (a1), examples include a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at an α-position can be substituted with a substituent; a structural unit derived from an acrylamide; a structural unit in which at least a part of hydrogen atoms in a hydroxyl group of a structural unit derived from a hydroxyl styrene or a hydroxyl styrene derivative is protected with a substituent containing the acid dissociation group; a structural unit in which at least a part of hydrogen atoms in -C(=O)-OH of a structural unit derived from a vinylbenzoic acid or a vinylbenzoic acid derivative is protected with a substituent containing the acid dissociation group; and the like.

[0208] As the structural unit (a1), among the above structural units, a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at an α-position can be substituted with a substituent is preferable. As a preferable specific example of the structural unit (a1), a structural unit represented by the general formula (a1-1) or (a1-2) below can be exemplified.

[0209]

Chemical Formula 16

[0210]

[0211] (In the formula, R is a hydrogen atom, an alkyl group having a carbon number of 1 to 5, or a halogenated alkyl group having a carbon number of 1 to 5. Va 1 is a divalent hydrocarbon group which can have an ether bond. n a1 is an integer of 0 to 2. Ra 1It is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). Wa 1 For n a2 +1 valence hydrocarbon group, n a2 Ra is an integer from 1 to 3. 2 These are acid-dissociable groups represented by the above general formulas (a1-r-1) or (a1-r-3).

[0212] In formula (a1-1), R is preferably a straight-chain or branched alkyl group with 1 to 5 carbon atoms, and examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. The halogenated alkyl group with 1 to 5 carbon atoms is a group obtained by substituting some or all of the hydrogen atoms of the alkyl group with 1 to 5 carbon atoms with halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., and fluorine atoms are particularly preferred.

[0213] 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. From the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferred.

[0214] In the formula (a1-1), Va 1 The divalent hydrocarbon group in it can be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0215] As Va 1 The aliphatic hydrocarbon group of the divalent hydrocarbon group can be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group, but it is usually preferred to be a saturated aliphatic hydrocarbon group.

[0216] More specifically, examples of this aliphatic hydrocarbon group include straight-chain or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing rings in their structure.

[0217] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As a linear aliphatic hydrocarbon group, a linear alkylene group is preferred; specifically, examples include methylene [-CH2-], ethylene [-(CH2)2-], propylene [-(CH2)3-], butylene [-(CH2)4-], and pentylene [-(CH2)5-].

[0218] The number of carbons of the branched aliphatic hydrocarbon group is preferably from 2 to 10, more preferably from 3 to 6, further preferably 3 or 4, most preferably 3. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, examples include alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, and the like; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, and the like; alkyl propylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-, and the like; alkyl butylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and the like; and the like. As the alkyl group in the alkyl alkylene group, a linear alkyl group having from 1 to 5 carbons is preferable.

[0219] As the ring-containing aliphatic hydrocarbon group in the structure, examples 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 at the terminal of a linear or branched aliphatic hydrocarbon group; a group in which an alicyclic hydrocarbon group is interposed between linear or branched aliphatic hydrocarbon groups; and the like. As the linear or branched aliphatic hydrocarbon group, the same groups as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group are preferable.

[0220] The number of carbons of the alicyclic hydrocarbon group is preferably from 3 to 20, more preferably from 3 to 12.

[0221] The alicyclic hydrocarbon group can be either a polycyclic or monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing 2 hydrogen atoms from a monocyclic alkane is preferable, and as the monocyclic alkane, a monocyclic alkane having from 3 to 6 carbons is preferable, and specifically, examples include cyclopentane, cyclohexane, and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing 2 hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having from 7 to 12 carbons is preferable, and specifically, examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0222] As the divalent hydrocarbon group in Va 1 The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.

[0223] The number of carbon atoms in the aforementioned 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 12. This number of carbon atoms does not include the number of carbon atoms in the substituents. Examples of aromatic rings in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles obtained by replacing a portion of the carbon atoms constituting the aromatic hydrocarbon ring with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms.

[0224] Specifically, examples of this aromatic hydrocarbon group include groups (arylenes) obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring; groups (aryl groups) obtained by replacing one hydrogen atom of one hydrogen atom of one hydrogen atom of an aryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring with an alkylene group (for example, groups obtained by further removing one hydrogen atom from an aryl group in aralkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The alkylene group (the alkyl chain in the aralkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2, and particularly preferably 1.

[0225] In the aforementioned formula (a1-1), Ra 1 It is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0226] In the formula (a1-1), n a1 n is an integer between 0 and 2. a1 Preferably 0 or 1, more preferably 0.

[0227] In the aforementioned formula (a1-2), Wa 1 n a2 The +1 valence hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. This aliphatic hydrocarbon group represents a hydrocarbon group that is not aromatic, and can be saturated or unsaturated, but is generally preferred to be saturated. Examples of the aliphatic hydrocarbon group include straight-chain or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in their structure, or groups formed by combining straight-chain or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in their structure. The n... a2 The +1 valence is preferably 2 to 4 valences, and more preferably 2 or 3 valences.

[0228] In the aforementioned formula (a1-2), Ra 2 It is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0229] The following shows specific examples of structural units represented by the aforementioned equation (a1-1). In the following equations, R α It represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0230] [Chem. 17]

[0231]

[0232] [Chem. 18]

[0233]

[0234] [Chem. 19]

[0235]

[0236] [Chem. 20]

[0237]

[0238] [Chem. 21]

[0239]

[0240] [Chem. 22]

[0241]

[0242] [Chem. 23]

[0243]

[0244] [Chem. 24]

[0245]

[0246] [Chem. 25]

[0247]

[0248] [Chem. 26]

[0249]

[0250] [Chem. 27]

[0251]

[0252] The following shows specific examples of structural units represented by the formula (a1-2).

[0253] [Chem. 28]

[0254]

[0255] The structural unit (a1) possessed by the component (A1) can be one or two or more.

[0256] As a structural unit (a1), from the viewpoint of easily further improving the characteristics (sensitivity, shape, etc.) in photolithography using electron beams or EUV, it is more preferable to be a structural unit represented by the above formula (a1-1).

[0257] Among them, as a structural unit (a1), it is particularly preferred to include a structural unit represented by the following general formula (a1-1-1).

[0258]

Chemistry 29

[0259]

[0260] [In the formula, Ra] 1” These are acid-dissociable groups represented by the general formulas (a1-r2-1), (a1-r2-3), or (a1-r2-4).

[0261] In the formula (a1-1-1), R and Va 1 and n a1 With R and Va in the above formula (a1-1) 1 and n a1 same.

[0262] The acid-dissociative groups represented by the general formulas (a1-r2-1), (a1-r2-3), or (a1-r2-4) are explained as above. From the viewpoint of maintaining transparency in thick resist films, Ra 1 "Preferably, the acid-dissociable group is represented by the general formula (a1-r2-4). Ra' in the general formula (a1-r2-4)" 12 Ra' 13 and Ra' 14 The preferred examples are as described above.

[0263] The proportion of structural unit (a1) in component (A1) relative to the total (100 mol%) of all structural units constituting component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, even more preferably 15 to 70 mol%, and particularly preferably 20 to 60 mol%.

[0264] By setting the proportion of the structural unit (a1) above the lower limit of the preferred range, photolithographic characteristics such as sensitivity, resolution, and roughness are improved. On the other hand, if it is below the upper limit of the preferred range, a balance with other structural units can be achieved, resulting in good photolithographic characteristics.

[0265] Other Structural Units

[0266] In addition to the above-mentioned structural unit (a1), component (A1) may also have other structural units as needed.

[0267] As other structural units, for example, there can be mentioned structural unit (a2) containing a lactone ring-containing cyclic group, a -SO2- containing cyclic group, a carbonate ring-containing cyclic group; structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group; structural unit (a4) containing an acid non-dissociative aliphatic cyclic group; structural unit (a10) represented by the following general formula (a10-1); structural unit (st) derived from styrene or a derivative thereof; and the like.

[0268] Regarding the structural unit (a2):

[0269] The (Al) component can further have, in addition to the structural unit (al), a structural unit (a2) containing a lactone ring-containing cyclic group, a -SO2- containing cyclic group, or a carbonate ring-containing cyclic group (wherein the structural unit belonging to the structural unit (al) is excluded).

[0270] In the case where the (Al) component is used for the formation of a resist film, the lactone ring-containing cyclic group, the -SO2- containing cyclic group, or the carbonate ring-containing cyclic group of the structural unit (a2) is effective in improving the adhesion of the resist film to a substrate. Further, by having the structural unit (a2), for example, by the effects of appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to a substrate, appropriately adjusting the solubility at the time of development, and the like, the lithography characteristics and the like become good.

[0271] The "lactone ring-containing cyclic group" means a cyclic group containing a -O-C(=O)- containing ring (lactone ring) in the ring skeleton. The lactone ring is noted as the first ring, and is referred to as a monocyclic group in the case where only the lactone ring is present, and is referred to as a polycyclic group regardless of the structure in the case where other ring structures are also present. The lactone ring-containing cyclic group can be a monocyclic group or a polycyclic group.

[0272] As the lactone ring-containing cyclic group in the structural unit (a2), there is no particular limitation, and any lactone ring-containing cyclic group can be used. Specifically, there can be mentioned groups represented by the following general formulae (a2-r-1) to (a2-r-7), respectively.

[0273]

Chemical Formula 30

[0274]

[0275] [In the formula, Ra 21 are each independently 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, an alkyl group, a lactone ring-containing cyclic group, a carbonate ring-containing cyclic group, or a -SO2- containing cyclic group; A" is an alkylene group having a carbon number of 1 to 5 which can contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, n' is an integer of 0 to 2, and m' is 0 or 1.]

[0276] In the general formulas (a2-r-1) to (a2-r-7), Ra' is used as... 21 The alkyl group in the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms. This alkyl group is preferably straight-chain or branched. Specifically, examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, and hexyl. Among these, methyl or ethyl is preferred, and methyl is particularly preferred.

[0277] As Ra' 21 The alkoxy group in the formula is preferably an alkoxy group having 1 to 6 carbon atoms. This alkoxy group is preferably linear or branched. Specifically, examples can be given as Ra'. 21 The alkyl group in the example is a group formed by attaching an alkyl group to an oxygen atom (-O-).

[0278] As Ra' 21 The halogen atoms in the atom can be fluorine, chlorine, bromine, iodine, etc., with fluorine atoms being preferred.

[0279] As Ra' 21 The haloalkyl group in it can be exemplified by Ra' 21 A group obtained by replacing some or all of the hydrogen atoms of the alkyl group with the halogen atom. The alkyl group is preferably a fluoroalkyl group, and particularly preferably a perfluoroalkyl group.

[0280] Ra' 21 In -COOR” and -OC(=O)R”, R” can be a hydrogen atom, alkyl group, lactone cyclic group, carbonate cyclic group or -SO2- cyclic group.

[0281] The alkyl group in "R" can be any of the following: linear, branched, or cyclic, and the number of carbon atoms is preferably 1 to 15.

[0282] When R” is a straight-chain or branched alkyl group, it is preferred to have 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably methyl or ethyl.

[0283] When R” is a cyclic alkyl group, the number of carbon atoms is preferably 3 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specifically, examples include groups obtained by removing one or more hydrogen atoms from monocyclic alkanes that can be substituted with or not substituted with fluorine atoms or fluoroalkyl groups; and groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as bicyclic alkanes, tricyclic alkanes, and tetracyclic alkanes. More specifically, examples include groups obtained by removing one or more hydrogen atoms from monocyclic alkanes such as cyclopentane and cyclohexane; and groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclic decane, and tetracyclic dodecane.

[0284] As the lactone ring-containing cyclic group in R", the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) can be exemplified.

[0285] As the carbonate ring-containing cyclic group in R", the same groups as those described later can be exemplified, and specifically, the groups represented by the general formulae (ax3-r-1) to (ax3-r-3) can be exemplified.

[0286] As the -SO2- containing cyclic group in R", the same groups as those described later can be exemplified, and specifically, the groups represented by the general formulae (a5-r-1) to (a5-r-4) can be exemplified.

[0287] As the hydroxyalkyl group in Ra' 21 , a hydroxyalkyl group having a carbon number of 1 to 6 is preferred, and specifically, the group in which at least one hydrogen atom of the alkyl group in Ra' 21 is substituted with a hydroxy group can be exemplified.

[0288] In the general formulae (a2-r-2), (a2-r-3), (a2-r-5), as the alkylene group having a carbon number of 1 to 5 in A", a linear or branched alkylene group is preferred, and methylene, ethylene, n-propylene, iso-propylene, and the like can be exemplified. In the case where the alkylene group contains an oxygen atom or a sulfur atom, as specific examples thereof, the group in which the terminal or the carbon atom of the alkylene group is intervened with -O- or -S- can be exemplified, and for example, -O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, and the like can be exemplified. As A", an alkylene group having a carbon number of 1 to 5 or -O- is preferred, an alkylene group having a carbon number of 1 to 5 is more preferred, and methylene is most preferred.

[0289] Specific examples of the groups represented by the general formulae (a2-r-1) to (a2-r-7) are exemplified below.

[0290] [Chem. 31]

[0291]

[0292] [Chem. 32]

[0293]

[0294] "SO2-containing cyclic group" means a cyclic group having a ring containing -SO2- in its ring skeleton, and specifically, a cyclic group in which the sulfur atom (S) in -SO2- forms part of the ring skeleton of the cyclic group. The ring containing -SO2- is counted as the first ring in the ring skeleton, and is referred to as a monocyclic group in the case of having only this ring, and as a polycyclic group regardless of its structure in the case of having other ring structures as well. The SO2-containing cyclic group can be either a monocyclic group or a polycyclic group.

[0295] The SO2-containing cyclic group is particularly preferably a cyclic group having a ring containing -O-SO2- in its ring skeleton, i.e., a cyclic group having a sultone ring containing -O-S- in -O-SO2- as part of the ring skeleton.

[0296] As the SO2-containing cyclic group, more specifically, there can be mentioned groups represented by the following general formulae (a5-r-1) to (a5-r-4), respectively.

[0297] [Chem. 33]

[0298]

[0299] [In the formula, Ra' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxy group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an SO2-containing cyclic group; A" is an alkylene group having a carbon number of 1 to 5 which can contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer of 0 to 2.]

[0300] In the general formulae (a5-r-1) to (a5-r-2), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3), and (a2-r-5).

[0301] As the alkyl group, alkoxy group, halogen atom, haloalkyl group, -COOR", -OC(=O)R", hydroxyalkyl group, and cyano group in Ra' 51 , there can be mentioned the same groups as those exemplified in the description of Ra' 21 in the general formulae (a2-r-1) to (a2-r-7).

[0302] Specific examples of groups represented by the general formulae (a5-r-1) to (a5-r-4), respectively, are shown below. "Ac" in the formula means an acetyl group.

[0303] [Chem. 34]

[0304]

[0305] [Chem. 35]

[0306]

[0307] [Chem. 36]

[0308]

[0309] "Carbonate ring-containing cyclic group" means a cyclic group having -O-C(=O)-O- containing ring (carbonate ring) in its ring skeleton. The carbonate ring is noted as the first ring, and is referred to as a monocyclic group in the case of having only the carbonate ring, and as a polycyclic group in the case of having other ring structure(s) in addition to the carbonate ring, regardless of the structure thereof. The carbonate ring-containing cyclic group can be either a monocyclic group or a polycyclic group.

[0310] As the carbonate ring-containing cyclic group, there is no particular limitation, and any carbonate ring-containing cyclic group can be used. Specifically, there can be mentioned groups represented by the following general formulae (ax3-r-1) to (ax3-r-3), respectively.

[0311] [Chem. 37]

[0312]

[0313] [In the formula, Ra' x31 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxy group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone ring-containing cyclic group, a carbonate ring-containing cyclic group or a -SO2- containing cyclic group; A" is an alkylene group having a carbon number of 1 to 5 which can contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, p' is an integer of 0 to 3, and q' is 0 or 1.]

[0314] In the general formulae (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5).

[0315] As the alkyl group, alkoxy group, halogen atom, haloalkyl group, -COOR", -OC(=O)R", hydroxyalkyl group in Ra' 31 , there can be mentioned the same groups as those exemplified in the description of Ra' 21 in the general formulae (a2-r-1) to (a2-r-7), respectively.

[0316] Specific examples of the groups represented by the general formulae (ax3-r-1) to (ax3-r-3), respectively, are exemplified below.

[0317] [Chem. 38]

[0318]

[0319] As a structural unit (a2), preferably an acrylate-derived structural unit in which the hydrogen atom bonded to the carbon atom at the α position can be replaced by a substituent.

[0320] The structural unit (a2) is preferably represented by the following general formula (a2-1).

[0321]

Chemistry 39

[0322]

[0323] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a haloalkyl group having 1 to 5 carbon atoms. Ya] 21 It is a single bond or a divalent linker. La 21 The denoted as -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. Specifically, in La... 21 In the case of -O-, Ya 21 It can't be -CO-. Ra 21 It may contain a lactone cyclic group, a carbonate cyclic group, or a -SO2- cyclic group.

[0324] In the aforementioned formula (a2-1), R is the same as described above. 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. From the perspective of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

[0325] In the aforementioned formula (a2-1), Ya is... 21 The divalent linking group is not particularly limited, but can preferably be a divalent hydrocarbon group that has a substituent, a divalent linking group containing a heteroatom, etc.

[0326] • Divalent hydrocarbon groups that may have substituents:

[0327] In Ya 21 In the case of a divalent hydrocarbon group that may have substituents, the hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0328] ··Ya 21 aliphatic hydrocarbon groups

[0329] Aliphatic hydrocarbon groups refer to hydrocarbon groups that do not possess aromaticity. These aliphatic hydrocarbon groups can be saturated or unsaturated, but are generally preferred to be saturated. Examples of such aliphatic hydrocarbon groups include straight-chain or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing rings in their structure.

[0330] ...straight-chain or branched aliphatic hydrocarbon groups

[0331] The number of carbon atoms of the linear aliphatic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3.

[0332] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, methylene [-CH2-], ethylene [- (CH2)2-], propylene [- (CH2)3-], butylene [- (CH2)4-], pentylene [- (CH2)5-], and the like can be exemplified.

[0333] 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.

[0334] As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, alkylmethylene groups such as -CH (CH3) -, -CH (CH2CH3) -, -C (CH3)2-, -C (CH3) (CH2CH3) -, -C (CH3) (CH2CH2CH3) -, -C (CH2CH3)2-, and the like; alkylethylene groups such as -CH (CH3) CH2-, -CH (CH3) CH (CH3) -, -C (CH3)2CH2-, -CH (CH2CH3) CH2-, -C (CH2CH3)2CH2-, and the like; alkylpropylene groups such as -CH (CH3) CH2CH2-, -CH2CH (CH3) CH2-, and the like; alkylbutylene groups such as -CH (CH3) CH2CH2CH2-, -CH2CH (CH3) CH2CH2-, and the like; and the like can be exemplified. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0335] The linear or branched aliphatic hydrocarbon group can have a substituent or can not have a substituent. As the substituent, a fluorine atom, a fluoroalkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, and the like can be exemplified.

[0336] Aliphatic hydrocarbon group having a ring in the structure

[0337] As the aliphatic hydrocarbon group having a ring in the structure, a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which can have a substituent, a group obtained by bonding the cyclic aliphatic hydrocarbon group to the end of a linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed between linear or branched aliphatic hydrocarbon groups, and the like can be exemplified. As the linear or branched aliphatic hydrocarbon group, the same aliphatic hydrocarbon group as described above can be exemplified.

[0338] The number of carbon atoms of the cyclic aliphatic hydrocarbon group is preferably 3 to 20, and more preferably 3 to 12.

[0339] The cyclic aliphatic hydrocarbon group can be a polycyclic group or a monocyclic group. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferable, and specifically, cyclopentane, cyclohexane and the like can be given. As the polycyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferable, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be given.

[0340] The cyclic aliphatic hydrocarbon group can have a substituent or can not have a substituent. As the substituent, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group and the like can be given.

[0341] As the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and more preferably, a methyl group, an ethyl group, a propyl group, an n-butyl group, a t-butyl group.

[0342] As the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, and more preferably, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a t-butoxy group, and further preferably, a methoxy group, an ethoxy group.

[0343] As the substituent, a halogen atom can be given a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and preferably, a fluorine atom.

[0344] As the substituent, a halogenated alkyl group can be given a group obtained by substituting a part or all of the hydrogen atoms of the alkyl group with the halogen atom.

[0345] A part of the carbon atoms constituting the ring structure of the cyclic aliphatic hydrocarbon group can also be substituted with a heteroatom-containing substituent. As the heteroatom-containing substituent, -0-, -C(=0)-0-, -S-, -S(=0)2-, -S(=0)2-0- are preferable.

[0346] • • Ya 21 aromatic hydrocarbon group in the formula (1)

[0347] The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0348] The aromatic ring, if it is a cyclic conjugated system having 4n+2 π electrons, is not particularly limited, and can be monocyclic or polycyclic. The number of carbons of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Among the number of carbons, the number of carbons in the substituent is not included.

[0349] Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles formed by replacing a portion of the carbon atoms in the aforementioned aromatic hydrocarbon rings with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0350] Specifically, examples of aromatic hydrocarbon groups include groups (aryl or heteroaryl) obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring or aromatic heterocycle; groups obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups obtained by substituting one hydrogen atom of an aryl or heteroaryl group obtained by removing one hydrogen atom from an aryl group (e.g., a group obtained by further removing one hydrogen atom from an aryl group among aryl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The alkylene group bonded to the aryl or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0351] In the aromatic hydrocarbon group, the hydrogen atoms present in the aromatic hydrocarbon group may also be replaced by substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be replaced by substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, haloalkyl groups, and hydroxyl groups.

[0352] The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably methyl, ethyl, propyl, n-butyl, or tert-butyl.

[0353] The alkoxy, halogen atom, and haloalkyl groups that are said to be substituents can be exemplified as substituents that replace the hydrogen atoms of the cyclic aliphatic hydrocarbon group.

[0354] • Divalent linking groups containing heteroatoms:

[0355] In Ya 21 In the case of a divalent linking group containing a heteroatom, examples of such linking groups include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H can be substituted by alkyl, acyl, or other substituents), -S-, -S(=O)2-, -S(=O)2-O-, and those with the general formula -Y 21 -OY 22 -、-Y 21 -O-、-Y 21 -C(=O)-O-、-C(=O)-OY 21-, -Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 - represents a group [in the formula, Y 21 and Y 22 are each independently a divalent hydrocarbon group which can have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3] and the like as preferred groups.

[0356] In the case where the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=O)-, the H thereof can be substituted with an alkyl group, an acyl group, or the like. The carbon number of this substituent (alkyl group, acyl group, or the like) is preferably 1 to 10, further preferably 1 to 8, and particularly preferably 1 to 5.

[0357] General formula -Y 21 -O-Y 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 - represents a group [in the formula, Y 21 and Y 22 are each independently a divalent hydrocarbon group which can have a substituent. As this divalent hydrocarbon group, the same groups as those exemplified in the explanation of the divalent linking group in the general formula -Ya 21

[0358] As Y 21 , a linear aliphatic hydrocarbon group is preferred, a linear alkylene group is more preferred, a linear alkylene group having a carbon number of 1 to 5 is further preferred, and methylene or ethylene is particularly preferred.

[0359] As Y 22 , a linear aliphatic hydrocarbon group or a branched aliphatic hydrocarbon group is preferred, methylene, ethylene, or alkylmethylene is more preferred. The alkyl group in the alkylmethylene is preferably a linear alkyl group having a carbon number of 1 to 5, more preferably a linear alkyl group having a carbon number of 1 to 3, and most preferably a methyl group.

[0360] ​a group represented by the formula: -Y 21 -C(=O)-O] m” -Y 22 In the group represented by the formula: -Y 21 -C(=O)-O] m” -Y 22 In the group represented by the formula: -Y 21 -C(=O)-O-Y 22 -C(=O)-O-Y a’ -C(=O)-O-(CH2) b’ -C(=O)-O-(CH2) 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, 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, further preferably 1 or 2, most preferably 1.

[0361] Among the above, as Ya 21 , preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0362] In the formula (a2-1), Ra 21 is a lactone ring-containing cyclic group, an -SO2- containing cyclic group, or a carbonate ring-containing cyclic group.

[0363] As the lactone ring-containing cyclic group, the -SO2- containing cyclic group, and the carbonate ring-containing cyclic group in Ra 21 , the above-mentioned groups represented by the general formulae (a2-r-1) to (a2-r-7), the groups represented by the general formulae (a5-r-1) to (a5-r-4), and the groups represented by the general formulae (ax3-r-1) to (ax3-r-3), respectively, can be preferably exemplified.

[0364] Among them, preferably a lactone ring-containing cyclic group or an -SO2- containing cyclic group, more preferably a group represented by the general formula (a2-r-1), (a2-r-2), (a2-r-6), or (a5-r-1), respectively. Specifically, more preferably any one of the groups represented by the chemical formulae (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1), (r-sl-1-18), respectively.

[0365] The structural unit (a2) possessed by the component (A1) can be one or two or more.

[0366] In the case where the (Al) component has the structural unit (a2), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 60 mol%, further preferably 20 to 55 mol%, particularly preferably 30 to 50 mol%, relative to the total (100 mol%) of all the structural units constituting the (Al) component.

[0367] If the proportion of the structural unit (a2) is above the lower limit of the preferable range, the effect of the structural unit (a2) can be sufficiently obtained by the above-mentioned effects, and if it is below the upper limit, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0368] Regarding the structural unit (a3):

[0369] The (Al) component can further have, in addition to the structural unit (al), a structural unit (a3) containing a polar-group-containing aliphatic hydrocarbon group (wherein the structural unit is not included in the structural unit (al) or the structural unit (a2)). By having the structural unit (a3) in the (Al) component, the hydrophilicity of the (A) component is increased, thereby contributing to an improvement in resolution. Furthermore, the acid diffusion length can be appropriately adjusted.

[0370] As the polar group, a hydroxy group, a cyano group, a carboxyl group, a hydroxyalkyl group in which a part of the hydrogen atoms of an alkyl group is substituted with a fluorine atom, or the like can be exemplified, and a hydroxy group is particularly preferable.

[0371] As the aliphatic hydrocarbon group, a linear or branched hydrocarbon group (preferably an alkylene group) having a carbon number of 1 to 10, a cyclic aliphatic hydrocarbon group (cyclic group) can be exemplified. As the cyclic group, a monocyclic group or a polycyclic group can be used, and for example, in a resin for an ArF excimer laser resist composition, a cyclic group mentioned several times above can be appropriately selected and used.

[0372] In the case where the cyclic group is a monocyclic group, a carbon number of 3 to 10 is more preferable. Among them, a structural unit derived from an acrylic ester containing an aliphatic monocyclic group having a hydroxy group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which a part of the hydrogen atoms of an alkyl group is substituted with a fluorine atom is more preferable. As the monocyclic group, a group obtained by removing two or more hydrogen atoms from a monocycloalkane can be exemplified. Specifically, a group obtained by removing two or more hydrogen atoms from a monocycloalkane such as cyclopentane, cyclohexane, cyclooctane, or the like can be exemplified. Among these monocyclic groups, a group obtained by removing two or more hydrogen atoms from cyclopentane, a group obtained by removing two or more hydrogen atoms from cyclohexane are industrially preferable.

[0373] In the case where the cyclic group is a polycyclic group, the number of carbon atoms of the polycyclic group is more preferably from 7 to 30. Among them, more preferred is a structural unit derived from an acrylate ester containing an aliphatic polycyclic group having a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group of a hydroxyl group, a cyano group, a carboxyl group, or an alkyl group is substituted with a fluorine atom. As the polycyclic group, a group obtained by removing two or more hydrogen atoms from a bicycloalkane, a tricycloalkane, a tetracycloalkane, or the like can be exemplified. Specifically, a group obtained by removing two or more hydrogen atoms from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like can be exemplified. Among these polycyclic groups, a group obtained by removing two or more hydrogen atoms from adamantane; a group obtained by removing two or more hydrogen atoms from norbornane; and a group obtained by removing two or more hydrogen atoms from tetracyclododecane are industrially preferred.

[0374] As the structural unit (a3), there is no particular limitation as long as it contains an aliphatic hydrocarbon group containing a polar group, and any structural unit can be used.

[0375] As the structural unit (a3), it is preferred to be a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at an α position can be substituted with a substituent, and a structural unit containing an aliphatic hydrocarbon group containing a polar group.

[0376] As the structural unit (a3), when the aliphatic hydrocarbon group containing a polar group is a linear or branched hydrocarbon group having a carbon number of 1 to 10, it is preferred to be a structural unit derived from a hydroxyethyl ester of acrylic acid.

[0377] Further, as the structural unit (a3), when the aliphatic hydrocarbon group containing a polar group is a polycyclic group, a structural unit represented by formula (a3-1) below, a structural unit represented by formula (a3-2) below, and a structural unit represented by formula (a3-3) below can be preferably exemplified; and when it is a monocyclic group, a structural unit represented by formula (a3-4) below can be preferably exemplified.

[0378] [Chemical formula 40]

[0379]

[0380] [In the formula, R is the same as described above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, 1 is an integer of 0 to 5, and s is an integer of 1 to 3.]

[0381] In formula (a3-1), j is preferably 1 or 2, and further preferably 1. In the case where j is 2, it is preferred that the hydroxyl group is bonded to the 3- and 5-positions of the adamantyl group. In the case where j is 1, it is preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group. j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0382] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0383] In formula (a3-3), t' is preferably 1. 1 is preferably 1. s is preferably 1. Preferably, they are bonded to the terminal of the carboxyl group of acrylic acid with 2-norbornyl or 3-norbornyl. The fluoroalkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0384] In formula (a3-4), t' is preferably 1 or 2. 1 is preferably 0 or 1. s is preferably 1. The fluoroalkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0385] The structural unit (a3) possessed by the (Al) component can be one or two or more.

[0386] In the case where the (Al) component has the structural unit (a3), the proportion of the structural unit (a3) is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and further preferably 5 to 20 mol%, relative to the total (100 mol%) of all the structural units constituting the (Al) component.

[0387] By making the proportion of the structural unit (a3) be the preferable lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained by the above-mentioned effect, and if it is the preferable upper limit value or less, a balance with other structural units can be obtained, and various lithography characteristics become good.

[0388] Regarding the structural unit (a4):

[0389] The (Al) component can further have, in addition to the structural unit (al), a structural unit (a4) containing an aliphatic cyclic group which is not dissociated by an acid.

[0390] By making the (Al) component have the structural unit (a4), the dry etching resistance of the resist pattern formed is improved. Furthermore, the hydrophobicity of the (A) component is improved. In particular, in the case of a solvent developing process, the improvement in hydrophobicity contributes to the improvement in resolution, resist pattern shape, and the like.

[0391] The "cyclic group which is not dissociated by an acid" in the structural unit (a4) is a cyclic group which, when an acid is generated in the resist composition by exposure (for example, when an acid is generated from a structural unit which generates an acid by exposure or the (B) component), is not dissociated even under the action of the acid and remains directly in the structural unit.

[0392] As the structural unit (a4), for example, a structural unit derived from an acrylic acid ester containing an aliphatic ring group which is not dissociated by an acid, and the like are preferred. The ring group can use various groups known in the past as a group for a resin component of a resist composition for an ArF excimer laser, a KrF excimer laser (preferably a KrF excimer laser), and the like.

[0393] The ring group is particularly preferably at least one selected from the group consisting of tricyclodecyl group, adamantyl group, tetracyclododecyl group, isobornyl group, norbornyl group from the viewpoint of industrial availability and the like. These polycyclic ring groups can have a linear or branched alkyl group having a carbon number of 1 to 5 as a substituent.

[0394] As the structural unit (a4), specifically, structural units represented by the following general formulae (a4-1) to (a4-7), respectively, can be exemplified.

[0395] [Chem. 41]

[0396]

[0397] [Note that, R α The same as above.

[0398] The structural unit (a4) possessed by the (Al) component can be one or two or more.

[0399] In the case where the (Al) component has the structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 40 mol%, and more preferably 5 to 20 mol% with respect to the total (100 mol%) of all the structural units constituting the (Al) component.

[0400] By setting the proportion of the structural unit (a4) to be more than the lower limit of the preferred range, the effect of containing the structural unit (a4) can be sufficiently obtained, and on the other hand, by setting it to be less than the upper limit of the preferred range, a balance with other structural units can be easily obtained.

[0401] Regarding the structural unit (a10):

[0402] The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0403] [Chem. 42]

[0404]

[0405] [Note that, R is a hydrogen atom, an alkyl group having a carbon number of 1 to 5, or a halogenated alkyl group having a carbon number of 1 to 5. Ya x1 is a single bond or a divalent linking group. Wa x1 is (n ax1+1) valent aromatic hydrocarbon group. n ax1 is an integer of 1 or more.

[0406] In the formula (a10-1), R is a hydrogen atom, an alkyl group having a carbon number of 1 to 5, or a halogenated alkyl group having a carbon number of 1 to 5.

[0407] The alkyl group having a carbon number of 1 to 5 in R is preferably a linear or branched alkyl group having a carbon number of 1 to 5, and specifically, examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like.

[0408] The halogenated alkyl group having a carbon number of 1 to 5 in R is a group in which a part or all of the hydrogen atoms of the alkyl group having a carbon number of 1 to 5 are substituted with halogen atoms. As the halogen atoms, examples include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, and a fluorine atom is particularly preferred.

[0409] R is preferably a hydrogen atom, an alkyl group having a carbon number of 1 to 5, or a fluorinated alkyl group having a carbon number of 1 to 5, and from the viewpoint of industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is further preferred, and a methyl group is particularly preferred.

[0410] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group.

[0411] In the formula, as the divalent linking group in Ya x1 there is no particular limitation, and as preferred linking groups, examples include a divalent hydrocarbon group which can have a substituent, a heteroatom-containing divalent linking group, and the like.

[0412] • a divalent hydrocarbon group which can have a substituent:

[0413] In the case where Ya x1 is a divalent hydrocarbon group which can have a substituent, the hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0414] • an aliphatic hydrocarbon group in Ya x1

[0415] The aliphatic hydrocarbon group indicates a hydrocarbon group which does not have aromaticity. The aliphatic hydrocarbon group can be saturated or unsaturated, and is generally preferably saturated. As the aliphatic hydrocarbon group, examples include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure, and the like.

[0416] • a linear or branched aliphatic hydrocarbon group

[0417] ​The number of carbon atoms of the straight-chain aliphatic hydrocarbon group is preferably from 1 to 10, more preferably from 1 to 6, further preferably from 1 to 4, and most preferably from 1 to 3.

[0418] As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, methylene [-CH2-], ethylene [- (CH2)2-], propylene [- (CH2)3-], butylene [- (CH2)4-], pentylene [- (CH2)5-], and the like can be exemplified.

[0419] The number of carbon atoms of the branched aliphatic hydrocarbon group is preferably from 2 to 10, more preferably from 3 to 6, further preferably 3 or 4, and most preferably 3.

[0420] As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, alkylmethylene groups such as -CH (CH3) -, -CH (CH2CH3) -, -C (CH3)2-, -C (CH3) (CH2CH3) -, -C (CH3) (CH2CH2CH3) -, -C (CH2CH3)2-, and the like; alkylethylene groups such as -CH (CH3) CH2-, -CH (CH3) CH (CH3) -, -C (CH3)2CH2-, -CH (CH2CH3) CH2-, -C (CH2CH3)2CH2-, and the like; alkylpropylene groups such as -CH (CH3) CH2CH2-, -CH2CH (CH3) CH2-, and the like; alkylbutylene groups such as -CH (CH3) CH2CH2CH2-, -CH2CH (CH3) CH2CH2-, and the like; and the like can be exemplified. As the alkyl group in the alkylalkylene group, a straight-chain alkyl group having a number of carbon atoms of from 1 to 5 is preferable.

[0421] The straight-chain or branched aliphatic hydrocarbon group can have a substituent or can not have a substituent. As the substituent, a fluorine atom, a fluoroalkyl group having a number of carbon atoms of from 1 to 5 substituted with a fluorine atom, a carbonyl group, and the like can be exemplified.

[0422] Aliphatic hydrocarbon group having a ring in the structure

[0423] As the aliphatic hydrocarbon group having a ring in the structure, a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which can have a substituent, a group obtained by bonding the cyclic aliphatic hydrocarbon group to the end of a straight-chain or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed between straight-chain or branched aliphatic hydrocarbon groups, and the like can be exemplified. As the straight-chain or branched aliphatic hydrocarbon group, the same aliphatic hydrocarbon groups as described above can be exemplified.

[0424] The number of carbon atoms of the cyclic aliphatic hydrocarbon group is preferably from 3 to 20, and more preferably from 3 to 12.

[0425] The cyclic aliphatic hydrocarbon group can be a polycyclic group or a monocyclic group. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferable, and specifically, cyclopentane, cyclohexane and the like can be given. As the polycyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferable, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be given.

[0426] The cyclic aliphatic hydrocarbon group can have a substituent or can not have a substituent. As the substituent, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group and the like can be given.

[0427] As the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and more preferably, a methyl group, an ethyl group, a propyl group, an n-butyl group, a t-butyl group.

[0428] As the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, and more preferably, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a t-butoxy group, and further preferably, a methoxy group, an ethoxy group.

[0429] As the substituent, a halogen atom can be given a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and preferably, a fluorine atom.

[0430] As the substituent, a halogenated alkyl group can be given a group obtained by substituting a part or all of the hydrogen atoms of the alkyl group with the halogen atom.

[0431] A part of the carbon atoms constituting the ring structure of the cyclic aliphatic hydrocarbon group can also be substituted with a heteroatom-containing substituent. As the heteroatom-containing substituent, -0-, -C(=0)-0-, -S-, -S(=0)2-, -S(=0)2-0- are preferable.

[0432] The aromatic hydrocarbon group in the formula (1) is a hydrocarbon group having at least one aromatic ring. x1

[0433] The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0434] The aromatic ring, if it is a cyclic conjugated system having 4n+2 π electrons, is not particularly limited, and can be monocyclic or polycyclic. The number of carbons of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Among the number of carbons, the number of carbons in the substituent is not included.

[0435] ​Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles formed by replacing a portion of the carbon atoms in the aforementioned aromatic hydrocarbon rings with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings.

[0436] Specifically, examples of aromatic hydrocarbon groups include groups (aryl or heteroaryl) obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring or aromatic heterocycle; groups obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups obtained by substituting one hydrogen atom of an aryl or heteroaryl group obtained by removing one hydrogen atom from an aryl group (e.g., a group obtained by further removing one hydrogen atom from an aryl group among aryl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The alkylene group bonded to the aryl or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0437] In the aromatic hydrocarbon group, the hydrogen atoms present in the aromatic hydrocarbon group may also be replaced by substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be replaced by substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, haloalkyl groups, and hydroxyl groups.

[0438] The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably methyl, ethyl, propyl, n-butyl, or tert-butyl.

[0439] The alkoxy, halogen atom, and haloalkyl groups that are said to be substituents can be exemplified as substituents that replace the hydrogen atoms of the cyclic aliphatic hydrocarbon group.

[0440] • Divalent linking groups containing heteroatoms:

[0441] In Ya x1 In the case of a divalent linking group containing a heteroatom, examples of such linking groups include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H can be substituted by alkyl, acyl, or other substituents), -S-, -S(=O)2-, -S(=O)2-O-, and those with the general formula -Y 21 -OY 22 -、-Y 21 -O-、-Y 21 -C(=O)-O-、-C(=O)-OY 21-、-[Y 21 -C(=O)-O] m” -Y 22 -、-Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 - represents a group [where Y is a group that represents ... 21 and Y 22 Preferred groups include divalent hydrocarbon groups that can be independently substituted, where O is an oxygen atom and m" is an integer from 0 to 3.

[0442] When the divalent linking group containing heteroatoms is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, its H can be replaced by substituents such as alkyl or acyl groups. The number of carbon atoms in the substituent (alkyl, acyl, etc.) is preferably 1 to 10, more preferably 1 to 8, and particularly preferably 1 to 5.

[0443] General formula -Y 21 -OY 22 -、-Y 21 -O-、-Y 21 -C(=O)-O-、-C(=O)-OY 21 -、-[Y 21 -C(=O)-O] m” -Y 22 -、-Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22 Each is independently a divalent hydrocarbon group that may have substituents. Examples of such divalent hydrocarbon groups include those related to Ya. x1 The same groups (which may be divalent hydrocarbon groups with substituents) are listed in the description of the divalent linking groups.

[0444] As Y 21 Preferably, it is a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkylene group, even more preferably a straight-chain alkylene group with 1 to 5 carbon atoms, and particularly preferably methylene or ethylene.

[0445] As Y 22 Preferably, the alkyl group is a straight-chain or branched aliphatic hydrocarbon group, more preferably methylene, ethylene, or alkylmethylene. The alkyl group in the alkylmethylene group is preferably a straight-chain alkyl group with 1 to 5 carbon atoms, more preferably a straight-chain alkyl group with 1 to 3 carbon atoms, and most preferably methyl.

[0446] a group represented by the formula: -Y 21 -C(=O)-O] m” -Y 22 In the group represented by the formula: -Y 21 -C(=O)-O] m” -Y 22 In the group represented by the formula: -Y 21 -C(=O)-O-Y 22 In the group represented by the formula: -Y a’ -C(=O)-O-(CH2) b’ -C(=O)-O-(CH2) 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, 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, further preferably 1 or 2, most preferably 1.

[0447] Among the above, as Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, more preferably a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], further preferably a single bond.

[0448] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group having (n ax1 +1) valences.

[0449] As the aromatic hydrocarbon group in Wa x1 , a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic ring can be exemplified. The aromatic ring herein is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and can be monocyclic or polycyclic. The carbon number of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, particularly preferably 6 to 12. As the aromatic ring, specifically, an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, phenanthrene, etc.; an aromatic heterocycle obtained by substituting a part of carbon atoms constituting the aromatic hydrocarbon ring with a hetero atom, etc. can be exemplified. As the hetero atom in the aromatic heterocycle, an oxygen atom, a sulfur atom, a nitrogen atom, etc. can be exemplified. As the aromatic heterocycle, specifically, a pyridine ring, a thiophene ring, etc. can be exemplified.

[0450] Further, as the aromatic hydrocarbon group in Wa x1 , a group obtained by removing (nax1 A group obtained by adding 1+ hydrogen atoms.

[0451] In the above, as Wa x1 Preferably, it is removed from benzene, naphthalene, anthracene, or biphenyl (n ax1 A group obtained by removing (n) hydrogen atoms is more preferably derived from benzene or naphthalene. ax1 The group obtained by removing (n) hydrogen atoms is further preferably derived from benzene. ax1 A group obtained by adding 1+ hydrogen atoms.

[0452] Wa x1 The aromatic hydrocarbon group in the form may or may not have substituents, preferably without substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and haloalkyl groups. Examples of alkyl, alkoxy, halogen atoms, and haloalkyl groups that can be used as substituents include those used as Ya. x1 The cyclic aliphatic hydrocarbon group substituents in the example are the same groups as those listed. In Wa x1 To remove (n) from the aromatic ring ax1 In the case of a group obtained by adding (+1) hydrogen atoms, the substituent is a substitution that removes (n) hydrogen atoms from the aromatic ring. ax1 The substituent is a group containing hydrogen atoms in a group obtained by adding (+1) hydrogen atoms. The substituent is preferably a straight-chain or branched alkyl group having 1 to 5 carbon atoms, more preferably a straight-chain or branched alkyl group having 1 to 3 carbon atoms, further preferably methyl or ethyl, and particularly preferably methyl.

[0453] In the aforementioned formula (a10-1), n ax1 The integer is 1 or higher, preferably an integer from 1 to 10, more preferably an integer from 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2. Wherein, n ax1 The preferred value is 1.

[0454] The following shows a specific example of a structural unit (a10) represented by the aforementioned formula (a10-1). In the following formulas, R α It represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0455]

Chemistry 43

[0456]

[0457]

Chemistry 44

[0458]

[0459]

Chemistry 45

[0460]

[0461]

[0462]

[0463] The structural unit (a10) possessed by the (Al) component can be one or two or more.

[0464] In the case where the (Al) component has the structural unit (a10), the proportion of the structural unit (a10) in the (Al) component is preferably 5 to 80 mol%, more preferably 5 to 75 mol%, and further preferably 10 to 70 mol%, relative to the total (100 mol%) of all the structural units constituting the (Al) component.

[0465] By setting the proportion of the structural unit (a10) to be the lower limit value or more, it is easier to improve the sensitivity. On the other hand, by setting it to be the upper limit value or less, it is easier to achieve a balance with other structural units.

[0466] Regarding the structural unit (st):

[0467] The structural unit (st) is a structural unit derived from styrene or a styrene derivative. The "structural unit derived from styrene" means a structural unit constituted by cleavage of the olefinic double bond of styrene. The "structural unit derived from a styrene derivative" means a structural unit constituted by cleavage of the olefinic double bond of a styrene derivative.

[0468] The "styrene derivative" means a compound in which at least a part of the hydrogen atoms of styrene is substituted with a substituent. As the styrene derivative, for example, a compound in which the hydrogen atom at the α-position of styrene is substituted with a substituent, a compound in which one or more hydrogen atoms of the benzene ring of styrene is substituted with a substituent, a compound in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms of the benzene ring are substituted with a substituent, and the like can be exemplified.

[0469] As the substituent substituting the hydrogen atom at the α-position of the substituted styrene, an alkyl group having a carbon number of 1 to 5 or a halogenated alkyl group having a carbon number of 1 to 5 can be exemplified.

[0470] As the alkyl group having a carbon number of 1 to 5, a linear or branched alkyl group having a carbon number of 1 to 5 is preferable, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like can be exemplified.

[0471] The halogenated alkyl group having a carbon number of 1 to 5 is a group in which a part or all of the hydrogen atoms of the alkyl group having a carbon number of 1 to 5 are substituted with a halogen atom. As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like can be exemplified, and a fluorine atom is particularly preferable.

[0472] ​As the substituent of the hydrogen atom at the α-position of the substituted styrene, an alkyl group having 1 to 5 carbon atoms or a fluoroalkyl group having 1 to 5 carbon atoms is preferred, an alkyl group having 1 to 3 carbon atoms or a fluoroalkyl group having 1 to 3 carbon atoms is more preferred, and a methyl group is further preferred from the viewpoint of industrial availability.

[0473] As the substituent of the hydrogen atom of the benzene ring of the substituted styrene, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, or the like can be exemplified.

[0474] As the alkyl group of the substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a t-butyl group is more preferred.

[0475] As the alkoxy group of the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a t-butoxy group is more preferred, and a methoxy group or an ethoxy group is further preferred.

[0476] As the halogen atom of the substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like can be exemplified, and a fluorine atom is preferred.

[0477] As the haloalkyl group of the substituent, a group in which a part or all of the hydrogen atoms of the alkyl group are substituted with the halogen atom can be exemplified.

[0478] As the substituent of the hydrogen atom of the benzene ring of the substituted styrene, an alkyl group having 1 to 5 carbon atoms is preferred, a methyl group or an ethyl group is more preferred, and a methyl group is further preferred.

[0479] As the structural unit (st), a structural unit derived from a styrene, or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of the styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a haloalkyl group having 1 to 5 carbon atoms is preferred, a structural unit derived from a styrene or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of the styrene is substituted with a methyl group is more preferred, and a structural unit derived from a styrene is further preferred.

[0480] The structural unit (st) possessed by the (Al) component can be one or two or more.

[0481] In the case where the (Al) component has the structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol%, and more preferably 3 to 20 mol%, relative to the total (100 mol%) of all the structural units constituting the (Al) component.

[0482] The (Al) component contained in the resist composition can be used alone or two or more can be used in combination.

[0483] In the resist composition of the present embodiment, the (Al) component can exemplify a high molecular compound having a repeating structure of structural unit (al).

[0484] As a preferred (Al) component, a high molecular compound having a repeating structure of structural unit (al) and other structural unit can be exemplified. As the other structural unit, structural unit (a10) or structural unit (st) or the like can be exemplified.

[0485] In addition to the combination of the above 2 kinds of structural units, the above-described structural units can be further combined as a third or 3 or more kinds of structural units as appropriate to meet a desired effect. As a combination of 3 or more kinds of structural units, a combination of structural unit (al) and structural unit (a10) and structural unit (st) or the like can be exemplified.

[0486] As a preferred example of the (Al) component, a high molecular compound having a repeating structure of structural unit (al) and structural unit (a10); a high molecular compound having a repeating structure of structural unit (al) and structural unit (st); or a high molecular compound having a repeating structure of structural unit (al), structural unit (a10) and structural unit (st) can be exemplified.

[0487] The (Al) component can be produced by dissolving monomers from which the respective structural units are derived in a polymerization solvent, to which a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (e.g., V-601 or the like) or the like is added, and performing polymerization.

[0488] Alternatively, the (Al) component can be produced by dissolving monomers from which structural unit (al) is derived and monomers from which structural units other than structural unit (al) are derived as necessary in a polymerization solvent, adding a radical polymerization initiator as described above, and performing polymerization, followed by a deprotection reaction.

[0489] Further, at the time of polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH can be used in combination, whereby a -C(CF3)2-OH group can be introduced at the terminal. A copolymer of a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is effective for reduction of development defects and reduction of LER (line edge roughness: unevenness of the line side wall).

[0490] The weight average molecular weight (Mw) of the (Al) component (polystyrene conversion basis based on gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1000 to 50000, more preferably 2000 to 30000, and further preferably 3000 to 20000.

[0491] If the Mw of the (Al) component is below the preferable upper limit of the range, sufficient solubility against a resist solvent is obtained for use as a resist, and if it is above the preferable lower limit of the range, dry etching resistance and a good resist pattern cross-sectional shape are obtained.

[0492] The molecular weight distribution coefficient (Mw / Mn) of the (Al) component is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. In addition, Mn represents the number average molecular weight.

[0493] • Regarding the base component other than the (Al) component

[0494] In the resist composition of the present embodiment, as the (A) component, a base component other than the (Al) component, which changes in solubility to a developer due to the action of an acid, can be used in combination. The base component other than the (Al) component is not particularly limited, and can be arbitrarily selected from among a variety of compounds known as a base component for a chemically amplified resist composition in the past, and one kind of a high molecular compound or a low molecular compound can be used alone or two or more kinds can be used in combination.

[0495] The proportion of the (Al) component in the (A) component with respect to the total mass of the (A) component is preferably 25% by mass or more, more preferably 50% by mass or more, and further preferably 75% by mass or more, and can be 100% by mass. If the proportion is 25% by mass or more, it becomes easy to form a resist pattern excellent in various lithography properties.

[0496] In the resist composition of the present embodiment, the content of the (A) component is preferably 20% by mass or more with respect to the total mass (100% by mass) of the resist composition. By making the content of the (A) component 20% by mass or more, it becomes easy to form a resist film of a thick film (for example, 5 μm or more in film thickness). The upper limit of the content of the (A) component is not particularly limited as long as it is a concentration at which a resist film can be formed, and for example, it can be 50% by mass or less. The content of the (A) component is preferably 20 to 50% by mass, more preferably 22 to 50% by mass, and further preferably 25 to 50% by mass.

[0497] <(Z) component>

[0498] The (Z) component is an ionic liquid.

[0499] The ionic liquid refers to a salt existing in a liquid state. The ionic liquid is composed of a cationic portion and an anionic portion, and the electrostatic interaction between these ions is weak, and it is a salt that is difficult to crystallize. The ionic liquid has a melting point of 100°C or lower, and further has the following characteristics 1) to 5).

[0500] Characteristics 1) extremely low vapor pressure, 2) non-flammability over a wide temperature range, 3) liquid state over a wide temperature range, 4) large change in density, and 5) controllable polarity.

[0501] Further, in the present embodiment, the ionic liquid is preferably non-polymerizable.

[0502] The weight average molecular weight (Mw) of the ionic liquid is preferably 1000 or less, more preferably 750 or less, and further preferably 500 or less.

[0503] • the cationic portion of the (Z) component

[0504] The cationic portion of the (Z) component is not particularly limited, but from the aspect of more easily obtaining the effect of improving the phase separation performance, the dipole moment of the cationic portion is preferably 3 debye or more, more preferably 3.2 to 15 debye, and further preferably 3.4 to 12 debye.

[0505] The "dipole moment of the cationic portion" is a parameter that indicates the polarity (electric charge bias) of the cationic portion in a given amount. 1 debye (D) is defined as 1 x 10 -18 esu-cm. In the present specification, the dipole moment of the cationic portion is indicated as a value simulated by CAChe. For example, it is measured by using CAChe Work System Pro Version 6.1.12.33 and performing structure optimization using MM geometry (MM2), PM3 geometry.

[0506] As the cation having a dipole moment of 3 debye or more, for example, imidazolium ions, pyrrolidinium ions, piperidinium ions, ammonium ions, sulfonium ions, and phosphonium (phosphonium) ions can be preferably exemplified.

[0507] That is, as the preferred (Z) component, for example, imidazolium salts, pyrrolidinium salts, piperidinium salts, ammonium salts, sulfonium salts, or phosphonium salts, and the like can be exemplified. Among these salts, from the aspect of more easily improving the phase separation performance, the cationic portion thereof is preferably a cation having a substituent. Among these, a cation including an alkyl group having a carbon number of 1 or more that can have a substituent, or a cation including a polar group is preferred. The alkyl group having a carbon number of 1 or more included in the cation is preferably an alkyl group having a carbon number of 1 to 12, and more preferably an alkyl group having a carbon number of 1 to 6. The alkyl group can be a linear alkyl group or a branched alkyl group, and is preferably a linear alkyl group. As the substituent that the alkyl group having a carbon number of 2 or more can have, a hydroxyl group, a vinyl group, an allyl group, and the like can be exemplified. In addition, the alkyl group having a carbon number of 1 or more preferably does not have a substituent. As the polar group included in the cation, for example, a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, and the like can be exemplified.

[0508] As the cationic component of the more preferred (Z) component, mention can be made of cations represented by the general formulae (z-ca-1) to (z-ca-5) below.

[0509] [Chem. 47]

[0510]

[0511] [In the formula, Rz c1 ~Rz c6 are each independently an alkyl group having a carbon number of 1 to 12. Rz c7 ~Rz c9 are each independently an aryl group which can have a substituent. Rz c10 ~Rz c13 are each independently a linear alkyl group having a carbon number of 1 to 20.

[0512] In the formula (z-ca-1), Rz c1 and Rz c2 are each independently an alkyl group having a carbon number of 1 to 12, preferably a linear or branched alkyl group having a carbon number of 1 to 12, more preferably a linear alkyl group having a carbon number of 1 to 12, further preferably a linear alkyl group having a carbon number of 1 to 6. Among them, Rz c1 is particularly preferably a methyl group or an ethyl group, and Rz c2 is a linear alkyl group having a carbon number of 1 to 4.

[0513] In the formula (z-ca-2), Rz c3 and Rz c4 are each independently an alkyl group having a carbon number of 1 to 12, preferably a linear or branched alkyl group having a carbon number of 1 to 12, more preferably a linear alkyl group having a carbon number of 1 to 12, further preferably a linear alkyl group having a carbon number of 1 to 6. Among them, Rz c3 is particularly preferably a methyl group or an ethyl group, and Rz c4 is a linear alkyl group having a carbon number of 1 to 4.

[0514] In the formula (z-ca-3), Rz c5 and Rz c6 are each independently an alkyl group having a carbon number of 1 to 12, preferably a linear or branched alkyl group having a carbon number of 1 to 12, more preferably a linear alkyl group having a carbon number of 1 to 12, further preferably a linear alkyl group having a carbon number of 1 to 6. Among them, Rz c5 is particularly preferably a linear alkyl group having a carbon number of 1 to 6, and Rz c6 is a linear alkyl group having a carbon number of 1 to 4.

[0515] In the formula (z-ca-4), Rz c7 ~Rz c9Each independently is an aryl group which can have a substituent, preferably a phenyl group or a naphthyl group, more preferably a phenyl group.

[0516] Rz c7 Rz c9 The aryl group in Rzmay have a substituent, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, a group represented by the following general formulae (ca-r-1) to (ca-r-7), respectively, and the like.

[0517] In the formula (z-ca-5), Rz c10 Rz c13 Each independently is a linear alkyl group having a carbon number of 1 to 20, preferably a linear alkyl group having a carbon number of 3 to 18, more preferably a linear alkyl group having a carbon number of 4 to 16, further preferably a linear alkyl group having a carbon number of 5 to 15.

[0518] • Anionic portion of the (Z) component

[0519] The anionic portion of the (Z) component is not particularly limited, and examples include anions represented by any one of the following general formulae (z-an-1) to (z-an-5).

[0520] [Chemical Formula 48]

[0521]

[0522] [In the formula (z-an-1), Rz a1 represents an aromatic hydrocarbon group which can have a substituent, an aliphatic cyclic group which can have a substituent, or a chain hydrocarbon group which can have a substituent. In the formula (z-an-2), Rz a2 represents an alkyl group having a carbon number of 1 to 5 which can be substituted with a fluorine atom. k is an integer of 1 to 4, 1 is an integer of 0 to 3, and k + 1 = 4. In the formula (z-an-3), Rz a3 represents an alkyl group having a carbon number of 1 to 5 which can be substituted with a fluorine atom. m is an integer of 1 to 6, n is an integer of 0 to 5, and m + n = 6.

[0523] [Chemical Formula 49]

[0524]

[0525] [In the formula (z-an-4), X" represents an alkylene group having a carbon number of 2 to 6 in which at least one hydrogen atom is substituted with a fluorine atom. In the formula (z-an-5), Y" and Z" each independently represent an alkyl group having a carbon number of 1 to 10 in which at least one hydrogen atom is substituted with a fluorine atom.]

[0526] In the formula (z-an-1), Rz a1represents an aromatic hydrocarbon group which can have a substituent, an alicyclic group which can have a substituent, or a chain hydrocarbon group which can have a substituent.

[0527] In the formula (z-an-1), Rz a1 In the case of the aromatic hydrocarbon group which can have a substituent, as the aromatic ring included in R, specifically, there can be mentioned an aromatic hydrocarbon ring of benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene, etc.; an aromatic heterocyclic ring in which a part of carbon atoms constituting the aromatic hydrocarbon ring is replaced with a hetero atom, etc. As the hetero atom in the aromatic heterocyclic ring, there can be mentioned an oxygen atom, a sulfur atom, a nitrogen atom, etc.

[0528] As the aromatic hydrocarbon group, specifically, there can be mentioned a group in which one hydrogen atom is removed from the aromatic hydrocarbon ring (an aryl group), a group in which one hydrogen atom of the aryl group is replaced with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc., an aralkyl group), etc. The number of carbon atoms of the alkylene group (alkyl chain in the aralkyl group) is preferably 1 to 4, more preferably 1 to 2, particularly preferably 1.

[0529] As the aromatic hydrocarbon group of R, a phenyl group or a naphthyl group is preferred, and a phenyl group is more preferred.

[0530] In the formula (z-an-1), Rz a1 In the case of the alicyclic group which can have a substituent, it can be either a polycyclic ring or a monocyclic ring. As the alicyclic group of the monocyclic ring, a group in which one hydrogen atom is removed from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 8 carbon atoms is preferred, and specifically, there can be mentioned cyclopentane, cyclohexane, cyclooctane, etc. As the alicyclic group of the polycyclic ring, a group in which one hydrogen atom is removed from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred, and specifically, there can be mentioned adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0531] Among them, as the alicyclic group, more preferably, it is a group in which one or more hydrogen atoms are removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0532] In the formula (z-an-1), as Rz a1chain hydrocarbon group, preferably a chain alkyl group. As the chain alkyl group, a straight chain alkyl group having 1 to 10 carbon atoms, specifically, 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, and the like; a branched chain alkyl group having 1 to 10 carbon atoms, specifically, a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 4-methylpentyl group, and the like can be exemplified. The chain alkyl group is more preferably a straight chain alkyl group having 1 to 6 carbon atoms, and further preferably a straight chain alkyl group having 1 to 3 carbon atoms. In addition, a straight chain alkyl group is preferred.

[0533] In the formula (z-an-1), Rz a1 The aromatic hydrocarbon group, the aliphatic cyclic group, or the chain hydrocarbon group in the formula (z-an-1) can have a substituent, and a hydroxyl group, an alkyl group, a fluorine atom or a fluoroalkyl group, a triphenylphosphonium group, and the like can be exemplified.

[0534] In the formula (z-an-1), Rz a1 A methyl group, a trifluoromethyl group, a p-tolyl group, or a propyl triphenylphosphonium group is preferred.

[0535] In the formula (z-an-2), Rz a2 represents an alkyl group having 1 to 5 carbon atoms which can be substituted with a fluorine atom.

[0536] k is an integer of 1 to 4, preferably an integer of 3 to 4, and most preferably 4.

[0537] l is an integer of 0 to 3, preferably an integer of 0 to 2, and most preferably 0. In the case where l is 2 or more, the plurality of Rz a2 may be the same as or different from each other, but are preferably the same as each other.

[0538] In the formula (z-an-3), Rz a3 represents an alkyl group having 1 to 5 carbon atoms which can be substituted with a fluorine atom.

[0539] m is an integer of 1 to 6, preferably an integer of 3 to 6, and most preferably 6.

[0540] n is an integer of 0 to 5, preferably an integer of 0 to 3, and most preferably 0. In the case where n is 2 or more, the plurality of Rz a3 may be the same as or different from each other, but are preferably the same as each other.

[0541] In the formula (z-an-4), X" represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom. The alkylene group herein can be straight chain or branched chain, has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, and most preferably 3 carbon atoms.

[0542] In the formula (z-an-5), Y" and Z" each independently represent an alkyl group having 1 to 10 carbons in which at least one hydrogen atom is substituted with a fluorine atom. The alkyl group can be linear or branched, and has 1 to 10 carbons, preferably 1 to 7 carbons, and more preferably 1 to 3 carbons. In the formula (z-an-5), it is particularly preferred that Y" and Z" each be a trifluoromethyl group.

[0543] The carbon number of the alkylene group of X", or the carbon number of each of the alkyl groups of Y" and Z" is preferably smaller within the above range for the reason that the solubility in an organic solvent ingredient is also good, and the like.

[0544] Further, the number of hydrogen atoms substituted with a fluorine atom in the alkylene group of X", or each of the alkyl groups of Y" and Z" is preferably larger for the reason that the strength of the acid becomes stronger, and the like. The fluorination rate of the alkylene group or the alkyl group is preferably 70 to 100%, further preferably 90 to 100%, and most preferably a perfluoroalkylene group or a perfluoroalkyl group in which all hydrogen atoms are substituted with a fluorine atom.

[0545] As the anion part of the (Z) component, it is preferred that the anion part be represented by any one of the formulas (z-an-1) to (z-an-5), and more preferably be represented by the general formula (z-an-1), (z-an-2), (z-an-3), or (z-an-5).

[0546] As the (Z) component, it is preferred that the compound be represented by any one of the following general formulas (z-1) to (z-5).

[0547] [Formula 50]

[0548]

[0549] [Formula 1] Rz c1 ~ Rz c6 each independently represent an alkyl group having 1 to 12 carbons. Xz1 - ~ Xz5 - each independently represent an anion represented by any one of the general formulas (z-an-1) to (z-an-5).

[0550] In the formulas (z-1) to (z-3), Rz c1 ~ Rz c6 are the same groups as Rz c1 ~ Rz c6 in the formulas (z-ca-1) to (z-ca-3).

[0551] In the formula (z-1), Xz1 - is preferably an anion represented by the formula (z-an-5).

[0552] In the formula (z-2), Xz2 - Preferably, the anion is represented by the formula (z-an-5).

[0553] In the formula (z-3), Xz3 - Preferably, the anion is represented by the formula (z-an-2).

[0554] In the formula (z-4), Xz4 - Preferably, the anion is represented by the formula (z-an-5).

[0555] In the formula (z-5), Xz5 - Preferably, the anion is represented by the formula (z-an-5).

[0556] The following compounds (IL) are exemplified as specific examples, but are not limited to these.

[0557] [Chemical Formula 51]

[0558]

[0559] [Chemical Formula 52]

[0560]

[0561] [Chemical Formula 53]

[0562]

[0563] In the resist composition of the present embodiment, one kind of the (Z) component can be used alone, or two or more kinds of the (Z) components can be used in combination.

[0564] In the resist composition of the present embodiment, the content of the (Z) component is preferably more than 0 parts by mass and less than 25 parts by mass, more preferably 0.1 to 20 parts by mass, further preferably 0.5 to 15 parts by mass, and particularly preferably 3 to 12 parts by mass, relative to 100 parts by mass of the (A) component.

[0565] By making the content of the (Z) component be the lower limit value or more of the range, it becomes easier to improve the sensitivity while it also becomes easier to suppress the generation of cracks at the time of resist pattern formation. On the other hand, by making the content of the (Z) component be the upper limit value or less of the range, it is easy to obtain a resist pattern of good shape.

[0566] <Other Components>

[0567] ​The resist composition of the present embodiment can further contain other components in addition to the above-mentioned (A) component and (Z) component. As the other components, for example, the following (B) component, (D) component, (E) component, (F) component, (S) component, and the like can be exemplified.

[0568] The acid generator component (B)

[0569] The resist composition of the present embodiment can further contain an acid generator component (B) (hereinafter referred to as "(B) component") which generates an acid by exposure in addition to the (A) component and the (Z) component.

[0570] The (B) component is not particularly limited, and an acid generator hitherto proposed as an acid generator for a chemically amplified resist composition can be used.

[0571] As such an acid generator, various acid generators such as iodonium salts, sulfonium salts, and the like, sulfonic acid oxime ester-based acid generators, diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyl diazomethane-based acid generators and poly(bis sulfonyl) diazomethane-based acid generators, nitrobenzyl sulfonic acid salt-based acid generators, imino sulfonic acid salt-based acid generators, disulfone-based acid generators, and the like can be exemplified.

[0572] As the (B) component, a compound (B1) consisting of an onium salt (hereinafter referred to as "(B1) component") is preferably contained.

[0573] • (B1) Component

[0574] As the (B1) component, for example, a compound represented by general formula (b-1) (hereinafter also referred to as "(b-1) component"), a compound represented by general formula (b-2) (hereinafter also referred to as "(b-2) component"), or a compound represented by general formula (b-3) (hereinafter also referred to as "(b-3) component") described below can be exemplified.

[0575] [Formula 54]

[0576]

[0577] [Formula 54] 101 and R 104 ~R 108 are each independently a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent. R 104 and R 105 may be bonded to each other to form a ring structure. R 102 is a fluoroalkyl group having a carbon number of 1 to 5 or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 ~V 103each independently is a single bond, alkylene, or fluoroalkylene. L 101 ~L 102 each independently is a single bond or an oxygen atom. L 103 ~L 105 each independently is a single bond, -CO-, or -SO2-. m is an integer of 1 or more, M m+ is an onium cation of valence m.

[0578] {anion portion}

[0579] • anion in component (b-1)

[0580] In formula (b-1), R 101 is a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent.

[0581] cyclic group which can have a substituent:

[0582] The cyclic group is preferably a cyclic hydrocarbon group, which can be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group which does not have aromaticity. In addition, the aliphatic hydrocarbon group can be saturated or unsaturated, and is usually preferably saturated.

[0583] R 101 The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The number of carbons 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. Among these, the number of carbons does not include the number of carbons in a substituent.

[0584] As the aromatic ring possessed by the aromatic hydrocarbon group in R 101 , specifically, there can be mentioned benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocycle in which a part of carbon atoms constituting these aromatic rings is substituted with a heteroatom, and the like. As the heteroatom in the aromatic heterocycle, there can be mentioned an oxygen atom, a sulfur atom, a nitrogen atom, and the like.

[0585] As the aromatic hydrocarbon group in R 101 , specifically, there can be mentioned a group in which one hydrogen atom is removed from the aromatic ring (aryl group: for example, phenyl, naphthyl, and the like), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, and the like aralkyl group, and the like). The number of carbons of the alkylene group (alkyl chain in the aralkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0586] R 101 The cyclic aliphatic hydrocarbon group in R

[0587] As the alicyclic hydrocarbon group, a cycloaliphatic hydrocarbon group (a group obtained by removing one hydrogen atom from an alicyclic hydrocarbon ring), a group obtained by bonding the terminal of a straight-chain or branched-chain aliphatic hydrocarbon group to a cycloaliphatic hydrocarbon group, a group in which a cycloaliphatic hydrocarbon group is interposed in a straight-chain or branched-chain aliphatic hydrocarbon group, and the like can be exemplified.

[0588] The carbon number of the alicyclic hydrocarbon group is preferably from 3 to 20, more preferably from 3 to 12.

[0589] The alicyclic hydrocarbon group can be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocyclic alkane is preferable. As the monocyclic alkane, a monocyclic alkane having a carbon number of from 3 to 6 is preferable, and specifically, cyclopentane, cyclohexane, and the like can be exemplified. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having a carbon number of from 7 to 30 is preferable. Among them, a polycyclic alkane having a cross-linked ring type polycyclic skeleton such as adamantyl, norbornyl, isobornyl, tricyclodecanyl, tetracyclododecane, and the like; a polycyclic alkane having a fused ring type polycyclic skeleton such as a cyclic group having a steroid skeleton.

[0590] Among them, as the alicyclic hydrocarbon group in R 101 , a group obtained by removing one or more hydrogen atoms from a monocyclic alkane or a polycyclic alkane is preferable, a group obtained by removing one hydrogen atom from a polycyclic alkane is more preferable, and adamantyl group, norbornyl group is particularly preferable, and adamantyl group is most preferable.

[0591] The carbon number of the straight-chain aliphatic hydrocarbon group which can be bonded to the alicyclic hydrocarbon group is preferably from 1 to 10, more preferably from 1 to 6, further preferably from 1 to 4, and most preferably from 1 to 3. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specifically, methylene [-CH2-], ethylene [- (CH2)2-], propylene [- (CH2)3-], butylene [- (CH2)4-], pentylene [- (CH2)5-], and the like can be exemplified.

[0592] The branched aliphatic hydrocarbon group that can bond with the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6, further preferably 3 or 4, and most preferably 3. As a branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkylpropylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkyl alkylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms.

[0593] In addition, R 101 The cyclic hydrocarbon group in the formula can contain heteroatoms, just like heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16).

[0594]

Transformation 55

[0595]

[0596] As R 101 Substituents in the cyclic group can include, for example, alkyl, alkoxy, halogen atom, haloalkyl, hydroxy, carbonyl, nitro, etc. The alkyl group used as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably methyl, ethyl, propyl, n-butyl, or tert-butyl.

[0597] The alkoxy group used as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, or tert-butoxy, and most preferably methoxy or ethoxy.

[0598] Examples of halogen atoms that can be used as substituents include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being the preferred option.

[0599] Examples of alkyl halogens that can be used as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, tert-butyl, etc., in which some or all of the hydrogen atoms are replaced by the halogen atom.

[0600] The carbonyl group as a substituent is a group substituting a methylene group (-CH2-) constituting a cyclic hydrocarbon group.

[0601] The chain-like alkyl group which can have a substituent:

[0602] The chain-like alkyl group as R 101 may be either of a straight chain or a branched chain.

[0603] The straight chain alkyl group preferably has a carbon number of 1 to 20, more preferably 1 to 15, and most preferably 1 to 10. Specifically, for example, there can be mentioned methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docosyl, and the like.

[0604] The branched chain alkyl group preferably has a carbon number of 3 to 20, more preferably 3 to 15, and most preferably 3 to 10. Specifically, for example, there can be mentioned 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, and the like.

[0605] The chain-like alkenyl group which can have a substituent:

[0606] The chain-like alkenyl group as R 101 may be either of a straight chain or a branched chain, and preferably has a carbon number of 2 to 10, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. The straight chain alkenyl group, for example, can be mentioned ethenyl, propenyl (allyl), butynyl, and the like. The branched chain alkenyl group, for example, can be mentioned 1-methylethenyl, 2-methylethenyl, 1-methylpropenyl, 2-methylpropenyl, and the like.

[0607] The chain-like alkenyl group, among the above, is preferably a straight chain alkenyl group, more preferably ethenyl, propenyl, and particularly preferably ethenyl.

[0608] The substituent in the chain-like alkyl group or the chain-like alkenyl group as R 101 , for example, can be mentioned alkoxy, a halogen atom, haloalkyl, hydroxy, carbonyl, nitro, amino, a cyclic group in R 101 , and the like.

[0609] Among the above, R 101The cyclic group preferably has a substituent, and more preferably a cyclic hydrocarbon group having a substituent. More specifically, a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, a polycyclic alkane; a cyclic group having a lactone ring represented by the general formula (a2-r-1) to (a2-r-7); a cyclic group having -SO2- represented by the general formula (a5-r-1) to (a5-r-4); and the like are preferable.

[0610] In the formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom.

[0611] In the case where Y 101 is a divalent linking group containing an oxygen atom, the Y 101 may contain an atom other than an oxygen atom. As the atom other than an oxygen atom, for example, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like can be exemplified.

[0612] As the divalent linking group containing an oxygen atom, for example, a non-hydrocarbon divalent linking group containing an oxygen atom such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), a carbonate bond (-O-C(=O)-O-), and the like; a combination of the non-hydrocarbon divalent linking group containing an oxygen atom and an alkylene group; and the like can be exemplified. In the combination, a sulfonyl group (-SO2-) can be further linked. As the above-mentioned divalent linking group containing an oxygen atom, for example, a linking group represented by the general formula (y-al-1) to (y-al-7) can be exemplified.

[0613] [Chem. 56]

[0614]

[0615] [In the formula, V 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, V 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0616] V 102 The divalent saturated hydrocarbon group in V

[0617] As V 101 and V 102 , an alkylene group can be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferable.

[0618] As V 101 and V 102The alkylene groups in this context can specifically include methylene [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; and ethylene [-CH2CH2-]; alkylmethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, and -C(CH3)2CH2-. Alkyl ethylides such as -CH(CH2CH3)CH2-; propylene (n-propylene) [-CH2CH2CH2-]; alkyl propylenes such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; butylides [-CH2CH2CH2CH2-]; alkyl butylides such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; pentylides [-CH2CH2CH2CH2CH2-], etc.

[0619] In addition, V' 101 or V' 102 A portion of the methylene group in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. This aliphatic cyclic group is preferably Ra' from the formula (a1-r-1). 3 The divalent group obtained by further removing one hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), more preferably cyclohexylene, 1,5-adamantylene or 2,6-adamantylene.

[0620] As Y 101 Preferably, the linking group contains a divalent ester bond or a divalent ether bond, and more preferably the linking group represented by the above formulas (y-al-1) to (y-al-5).

[0621] In equation (b-1), V 101 It is a single bond, an alkylene group, or a fluoroalkylene group. V 101 The alkylene or fluoroalkylene groups preferably have 1 to 4 carbon atoms. As V 101 The fluoroalkylene groups in the text can be exemplified by V. 101 A group obtained by replacing some or all of the hydrogen atoms of the alkylene group with fluorine atoms. Wherein, V 101 Preferably, it is a single bond or a fluoroalkylene group having 1 to 4 carbon atoms.

[0622] In equation (b-1), R 102 It is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. R 102 Preferably, it is a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

[0623] As a specific example of the anion section represented by the aforementioned formula (b-1), for example, in Y 101 In the case of a single bond, examples include fluoroalkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion; in Y 101 In the case of a divalent linking group containing an oxygen atom, anions represented by any one of the following formulas (an-1) to (an-3) can be cited.

[0624]

Chemistry 57

[0625]

[0626] [In the formula, R”] 101 It can be an aliphatic cyclic group that may have substituents, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), or a chain alkyl group that may have substituents. R” 102 It can be an aliphatic cyclic group that may have substituents, a lactone-containing cyclic group represented by the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4). R” 103 It can be an aromatic cyclic group that may have substituents, an aliphatic cyclic group that may have substituents, or a chain-like alkenyl group that may have substituents. V” 101 It is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluoroalkylene group having 1 to 4 carbon atoms. R 102 It is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. v” is an independent integer from 0 to 3, q” is an independent integer from 0 to 20, and n” is 0 or 1.

[0627] R” 101 、R” 102 And R” 103 The aliphatic cyclic group that may have substituents is preferably R in formula (b-1). 101 The group exemplified is a cyclic aliphatic hydrocarbon group. Examples of substituents include those related to R in formula (b-1). 101 The same substituents are used for the substituted cyclic aliphatic hydrocarbon groups.

[0628] R” 103 The aromatic cyclic group that may have substituents is preferably R in formula (b-1). 101 The group exemplified is the aromatic hydrocarbon group in the cyclic hydrocarbon group. Examples of substituents include those corresponding to R in formula (b-1). 101 The same substituents that can replace the aromatic hydrocarbon group in the same group.

[0629] R”101 The chain-like alkyl group which can have a substituent in the formula (b-1) is preferably a group exemplified as the chain-like alkyl group in the formula (b-2). 101 The chain-like alkyl group which can have a substituent in the formula (b-1) is preferably a group exemplified as the chain-like alkyl group in the formula (b-2).

[0630] R" 103 The chain-like alkenyl group which can have a substituent in the formula (b-1) is preferably a group exemplified as the chain-like alkenyl group in the formula (b-2). 101 The chain-like alkenyl group which can have a substituent in the formula (b-1) is preferably a group exemplified as the chain-like alkenyl group in the formula (b-2).

[0631] • Anion in the component (b-2)

[0632] In the formula (b-2), R 104 , R 105 are each independently a cyclic group which can have a substituent, a chain-like alkyl group which can have a substituent, or a chain-like alkenyl group which can have a substituent, and the same groups as R 101 in the formula (b-1) can be exemplified. Among them, R 104 , R 105 may be bonded to each other to form a ring.

[0633] R 104 , R 105 are preferably a chain-like alkyl group which can have a substituent, more preferably a straight-chain or branched-chain alkyl group, or a straight-chain or branched-chain fluoroalkyl group.

[0634] The carbon number of the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and further preferably 1 to 3. For the reason that the solubility in a solvent for a resist is also good and the like, the carbon number of the chain-like alkyl group of R 104 , R 105 is more preferably smaller within the above range. Further, the more the number of hydrogen atoms substituted with fluorine atoms in the chain-like alkyl group of R 104 , R 105 is, the stronger the acid strength and the higher the transparency to high-energy light and electron rays of 250 nm or less, and thus it is preferred. The proportion of fluorine atoms in the chain-like alkyl group, that is, the fluorination rate is preferably 70 to 100%, further preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all the hydrogen atoms are substituted with fluorine atoms.

[0635] In the formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluoroalkylene group, and the same groups as V 101 in the formula (b-1) can be exemplified.

[0636] In the formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0637] Anions in component (b-3)

[0638] In equation (b-3), R 106 ~R 108 Each can be independently a cyclic group that may have substituents, a chain alkyl group that may have substituents, or a chain alkenyl group that may have substituents, and examples can be given for R in formula (b-1). 101 The same group.

[0639] In equation (b-3), L 103 ~L 105 Each can be a single bond, -CO-, or -SO2-, respectively.

[0640] Of the above, the anionic portion of component (B) is preferably the anion in component (b-1). More preferably, it is a fluoroalkyl sulfonate anion or an anion represented by any one of the above general formulas (an-1) to (an-3), and even more preferably, it is a fluoroalkyl sulfonate anion or an anion represented by any one of the general formulas (an-1) and (an-2).

[0641] {Cation Section}

[0642] In equations (b-1), (b-2), and (b-3), M' m+ This represents a monium cation with a valence of m. Preferably, it is a sulfonium cation or an iodonium cation.

[0643] m is an integer greater than or equal to 1.

[0644] As a preferred cation portion ((M') m+ ) 1 / m Examples of organic cations can be given by the following general formulas (ca-1) to (ca-4).

[0645]

Transformation 58

[0646]

[0647] [In the formula, R] 201 ~R 207 and R 211 ~R 212 Each can be independently represented by an aryl, alkyl, or alkenyl group, which may have substituents. R 201 ~R 203 R 206 ~R 207 R 211 ~R 212 They can also bond with each other to form a ring together with the sulfur atoms in the formula. R 208 ~R 209 Each can be independently represented by a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R210 is an aryl group which can have a substituent, an alkyl group which can have a substituent, an alkenyl group which can have a substituent, or a -SO2- containing cyclic group which can have a substituent. L 201 represents -C(=O)- or -C(=O)-O-. Y 201 each independently represents an arylene group, an alkylene group or an alkenylene group. x is 1 or 2. W 201 represents a (x+1)-valent linking group.

[0648] In the above general formulae (ca-1) to (ca-4), R 201 ~R 207 and R 211 ~R 212 As the aryl group in R

[0649] As the aryl group in R 201 ~R 207 and R 211 ~R 212 is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms.

[0650] As the alkenyl group in R 201 ~R 207 and R 211 ~R 212 is preferably 2 to 10 carbon atoms.

[0651] As the alkenyl group in R 201 ~R 207 and R 210 ~R 212 which can have a substituent, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, or a group represented by the following general formulae (ca-r-1) to (ca-r-7), respectively.

[0652] [Formula (ca-r-1)]

[0653]

[0654] [Formula (ca-r-2)] [Formula (ca-r-3)] [Formula (ca-r-4)] [Formula (ca-r-5)] [Formula (ca-r-6)] [Formula (ca-r-7)] 201 each independently is a hydrogen atom, a cyclic group which can have a substituent, a linear alkyl group which can have a substituent, or a linear alkenyl group which can have a substituent.

[0655] The cyclic group which can have a substituent is:

[0656] The cyclic group which can have a substituent is preferably a cyclic hydrocarbon group, which can be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. Furthermore, the aliphatic hydrocarbon group can be saturated or unsaturated, and is usually preferably saturated.

[0657] R' 201 The aromatic hydrocarbon group in the form is a hydrocarbon group having an aromatic ring. The number of carbon atoms in this aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. This number of carbon atoms does not include the carbon atoms in the substituents.

[0658] As R' 201 The aromatic rings contained in aromatic hydrocarbon groups can be specifically exemplified by benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles obtained by replacing part of the carbon atoms constituting these aromatic rings with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms.

[0659] As R' 201 The aromatic hydrocarbon group in the aromatic ring can specifically include groups obtained by removing one hydrogen atom from the aromatic ring (aryl: for example, phenyl, naphthyl, etc.), and groups obtained by substituting one hydrogen atom of the aromatic ring with an alkylene group (for example, benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc., aralkyl groups). The alkylene group (the alkyl chain in the aralkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0660] R' 201 Examples of cyclic aliphatic hydrocarbon groups in the structure include aliphatic hydrocarbon groups containing rings.

[0661] Examples of alicyclic hydrocarbon groups containing a ring in the structure include alicyclic hydrocarbon groups (groups obtained by removing one hydrogen atom from an alicyclic hydrocarbon ring); groups obtained by bonding an alicyclic hydrocarbon group to the end of a straight-chain or branched alicyclic hydrocarbon group; and groups in between alicyclic hydrocarbon groups that are intermediate in a straight-chain or branched alicyclic hydrocarbon group.

[0662] The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12.

[0663] The alicyclic hydrocarbon group can be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocyclic alkane is preferable. As the monocyclic alkane, a monocyclic alkane having 3 to 6 carbons is preferable, and specifically, cyclopentane, cyclohexane, and the like can be given. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having 7 to 30 carbons is preferable. Among them, a polycyclic alkane having a polycyclic skeleton of a cross-linked ring group such as adamantyl, norbornyl, isobornyl, tricyclodecanyl, tetracyclododecanyl, and the like; a polycyclic alkane having a polycyclic skeleton of a fused ring group such as a steroid skeleton group, and the like are more preferable.

[0664] Among them, as R' 201 The alicyclic hydrocarbon group can be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocyclic alkane is preferable. As the monocyclic alkane, a monocyclic alkane having 3 to 6 carbons is preferable, and specifically, cyclopentane, cyclohexane, and the like can be given. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having 7 to 30 carbons is preferable. Among them, a polycyclic alkane having a polycyclic skeleton of a cross-linked ring group such as adamantyl, norbornyl, isobornyl, tricyclodecanyl, tetracyclododecanyl, and the like; a polycyclic alkane having a polycyclic skeleton of a fused ring group such as a steroid skeleton group, and the like are more preferable.

[0665] The alicyclic hydrocarbon group can be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocyclic alkane is preferable. As the monocyclic alkane, a monocyclic alkane having 3 to 6 carbons is preferable, and specifically, cyclopentane, cyclohexane, and the like can be given. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having 7 to 30 carbons is preferable. Among them, a polycyclic alkane having a polycyclic skeleton of a cross-linked ring group such as adamantyl, norbornyl, isobornyl, tricyclodecanyl, tetracyclododecanyl, and the like; a polycyclic alkane having a polycyclic skeleton of a fused ring group such as a steroid skeleton group, and the like are more preferable.

[0666] As the alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having 7 to 30 carbons is preferable. Among them, a polycyclic alkane having a polycyclic skeleton of a cross-linked ring group such as adamantyl, norbornyl, isobornyl, tricyclodecanyl, tetracyclododecanyl, and the like; a polycyclic alkane having a polycyclic skeleton of a fused ring group such as a steroid skeleton group, and the like are more preferable.

[0667] As the alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having 7 to 30 carbons is preferable. Among them, a polycyclic alkane having a polycyclic skeleton of a cross-linked ring group such as adamantyl, norbornyl, isobornyl, tricyclodecanyl, tetracyclododecanyl, and the like; a polycyclic alkane having a polycyclic skeleton of a fused ring group such as a steroid skeleton group, and the like are more preferable.

[0668] As the alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferable, and as the polycyclic alkane, a polycyclic alkane having 7 to 30 carbons is preferable. Among them, a polycyclic alkane having a polycyclic skeleton of a cross-linked ring group such as adamantyl, norbornyl, isobornyl, tricyclodecanyl, tetracyclododecanyl, and the like; a polycyclic alkane having a polycyclic skeleton of a fused ring group such as a steroid skeleton group, and the like are more preferable. 201The cyclic hydrocarbon group in the above formula (a2-r-1) to (a2-r-7) can have a hetero atom such as a heterocyclic ring. Specifically, examples include a lactone ring-containing cyclic group represented by the above formula (a2-r-1) to (a2-r-7), an -SO2- containing cyclic group represented by the above formula (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the above formula (r-hr-1) to (r-hr-16).

[0669] R' as R 201 Examples of the substituent in the cyclic group of the above formula (a2-r-1) to (a2-r-7) include an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like.

[0670] 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 t-butyl group.

[0671] The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a t-butoxy group, and most preferably a methoxy group or an ethoxy group.

[0672] The halogen atom as the substituent can include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, and is preferably a fluorine atom.

[0673] The haloalkyl group as the substituent can include an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a t-butyl group, and the like, in which a part or all of the hydrogen atoms are substituted with the halogen atom.

[0674] The carbonyl group as the substituent is a group in which a methylene group (-CH2-) constituting the cyclic hydrocarbon group is substituted.

[0675] The chain-like alkyl group which can have a substituent is:

[0676] R' as R 201 The chain-like alkyl group which can have a substituent is:

[0677] The straight chain-like alkyl group is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and most preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, a heneicosyl group, a docosyl group, and the like.

[0678] As a branched alkyl group, the number of carbon atoms is preferably 3 to 20, more preferably 3 to 15, and most preferably 3 to 10. Specifically, examples 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.

[0679] Alkenyl groups that may have substituents in a chain-like structure:

[0680] As R' 201 The chain-like alkenyl group can be either straight-chain or branched, preferably with 2 to 10 carbon atoms, more preferably with 2 to 5 carbon atoms, even more preferably with 2 to 4 carbon atoms, and particularly preferably with 3 carbon atoms. Examples of straight-chain alkenyl groups include vinyl, allyl, and butynyl. Examples of branched alkenyl groups include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, and 2-methylpropenyl.

[0681] As a chain-like alkenyl group, the linear alkenyl group is preferred, more preferably vinyl or propenyl, and particularly preferably vinyl.

[0682] As R' 201 Substituents in the chain alkyl or chain alkenyl groups, for example, alkoxy, halogen atom, haloalkyl, hydroxyl, carbonyl, nitro, amino, and the above R' 201 Ring-shaped bases, etc.

[0683] R' 201 In addition to the groups described above, cyclic groups that may have substituents, chain-like alkyl groups that may have substituents, or chain-like alkenyl groups that may have substituents can also include groups that are the same as the acid-dissociable groups represented by the above formula (a1-r-2) as cyclic groups that may have substituents or chain-like alkyl groups that may have substituents.

[0684] Among them, R' 201 Preferably, it is a cyclic group that may have substituents, and more preferably a cyclic hydrocarbon group that may have substituents. More specifically, it is preferred, for example, a group obtained by removing one or more hydrogen atoms from phenyl, naphthyl, or polycyclic alkanes; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7); or a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), etc.

[0685] In the above general formulas (ca-1) to (ca-4), in R 201 ~R 203 R 206 ~R 207 R 211~R 212 In the case where they are bonded to each other to form a ring together with the sulfur atom in the formula, they can be bonded via a heteroatom such as a sulfur atom, an oxygen atom, a nitrogen atom, a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(the R N group is an alkyl group having a carbon number of 1 to 5) or the like. As the ring formed, it is preferable that one ring including the sulfur atom in the ring skeleton thereof be a three- to ten-membered ring including the sulfur atom, and particularly preferably a five- to seven-membered ring. As a specific example of the ring formed, for example, a thienyl ring, a thiazolyl ring, a benzothiophenyl ring, a thianthrenyl ring, a dibenzothiophenyl ring, a 9H-thioxanthrenyl ring, a thioxanthonyl ring, a phenoxathiinyl ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, or the like can be exemplified.

[0686] R 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having a carbon number of 1 to 5, preferably a hydrogen atom or an alkyl group having a carbon number of 1 to 3, and in the case where R 208 ~R 209 are alkyl groups, they can be bonded to each other to form a ring.

[0687] R 210 is an aryl group which can have a substituent, an alkyl group which can have a substituent, an alkenyl group which can have a substituent, or an -SO2-containing cyclic group which can have a substituent.

[0688] As the aryl group in R 210 , an unsubstituted aryl group having a carbon number of 6 to 20, preferably a phenyl group or a naphthyl group, can be exemplified.

[0689] As the alkyl group in R 210 , an alkyl group having a carbon number of 1 to 30 which is linear or cyclic is preferable.

[0690] As the alkenyl group in R 210 , an alkenyl group having a carbon number of 2 to 10 is preferable. As the -SO2-containing cyclic group which can have a substituent in R 210 , an -SO2-containing polycyclic group is preferable, and a group represented by the general formula (a5-r-1) is more preferable.

[0691] Y 201 each independently represents an arylene group, an alkylene group, or an alkenylene group.

[0692] Y 201 The arylene group in Y 101 may be exemplified by a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in R 101 in the above-described formula (b-1).

[0693] Y 201The alkylene and alkenylene groups in the above formula (b-1) can be exemplified by R. 101 The group obtained by removing one hydrogen atom from the chain alkyl or chain alkenyl groups exemplified in the text.

[0694] In the formula (ca-4), x is 1 or 2.

[0695] W 201 It is a (x+1) valence, that is, a divalent or trivalent linking group.

[0696] As W 201 The divalent linking group in the formula (a2-1) is preferably a divalent hydrocarbon group that may have substituents, and can be exemplified by Ya in the formula (a2-1) above. 21 Similarly, divalent hydrocarbon groups that can have substituents. W 201 The divalent linking group can be any of the following: linear, branched, or cyclic, preferably cyclic. Preferably, it is a group formed by combining two carbonyl groups at both ends of the arylene group. Examples of arylene groups include phenylene and naphthylene, with phenylene being particularly preferred.

[0697] As W 201 The trivalent linker group in W can be exemplified by the following: 201 Groups obtained by removing one hydrogen atom from a divalent linking group, and groups obtained by bonding another divalent linking group to the divalent linking group, etc. As W 201 The trivalent linking group in the group is preferably a group obtained by bonding two carbonyl groups to an arylene group.

[0698] As preferred cations represented by the formula (ca-1), examples can be given of cations represented by the following chemical formulas (ca-1-1) to (ca-1-70).

[0699]

Transformation 60

[0700]

[0701]

Chemistry 61

[0702]

[0703]

Transformation 62

[0704]

[0705] [In the formula, g1, g2, and g3 represent the number of repetitions, where g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[0706]

Transformation 63

[0707]

[0708] [Chem. 64]

[0709]

[0710] [Chem. 65]

[0711]

[0712] [In the formula, R" 201 is a hydrogen atom or a substituent, and as the substituent, the same group as the R 201 ~R 207 and R 210 ~R 212 are the same group.]

[0713] As the preferred cation represented by the formula (ca-2), specifically, diphenyliodonium cation, bis (4-tert-butylphenyl) iodonium cation, and the like can be exemplified.

[0714] As the preferred cation represented by the formula (ca-3), specifically, cations represented by the following formulas (ca-3-1) to (ca-3-6), respectively, can be exemplified.

[0715] [Chem. 66]

[0716]

[0717] As the preferred cation represented by the formula (ca-4), specifically, cations represented by the following formulas (ca-4-1) to (ca-4-2), respectively, can be exemplified.

[0718] [Chem. 67]

[0719]

[0720] Among the above, the cation portion ((M' m+ ) 1 / m ) is preferably a cation represented by the general formula (ca-1). From the viewpoint of maintaining transparency in a thick resist film, in the general formula (ca-1), it is preferred that at least one of R 202 ~R 203 be an alkyl group or an alkenyl group, more preferably that two or more of R 202 ~R 203 be an alkyl group or an alkenyl group, and further preferably that two or more of R 202 ~R 203 be an alkyl group. In R 202 ~R 203When two or more of the groups are alkyl or alkenyl groups, these two groups may also bond to each other to form a ring together with the sulfur atom in the formula. As a cation represented by the general formula (ca-1), it is preferred to be a cation represented by any one of the above formulas (ca-1-55) to (ca-1-68), and more preferably a cation represented by any one of the above formulas (ca-1-63) to (ca-1-68).

[0721] Among them, as component (B1), compounds represented by the following general formula (b1-1) are particularly preferred.

[0722]

Transformation 68

[0723]

[0724] [In the formula, Rb] 201 It is an aryl group that can have substituents. Rb 202 and Rb 203 Each can be independently an alkyl group that may have substituents or an alkenyl group that may have substituents. Rb 202 and Rb 203 They can bond with each other and form a ring together with the sulfur atoms in the formula. R 101 It can be a cyclic group that may have substituents, a chain-like alkyl group that may have substituents, or a chain-like alkenyl group that may have substituents. R 102 It is a fluoroalkyl group or a fluorine atom with 1 to 5 carbon atoms. 101 It is a divalent linking group or single bond containing an oxygen atom. V 101 It is a single bond, an alkylene group, or a fluoroalkylene group.

[0725] In the aforementioned formula (b1-1), Rb 201 The aryl group that may have substituents in the formula (ca-1) is related to R. 201 The aryl groups that can have substituents are the same aryl groups. Among them, as Rb... 201 Phenyl or naphthyl is preferred, and phenyl is more preferred.

[0726] In the above formula (b1-1), Rb 202 and Rb 203 The alkyl group or alkenyl group that may have substituents in the formula (ca-1) is the same as R in the formula (ca-1). 202 and R 203 The alkyl or alkenyl groups that may have substituents are the same group. Wherein, as Rb 202 and Rb 203 Preferably, it is a straight-chain alkyl group with 1 to 5 carbon atoms, more preferably Rb. 202 and Rb 203 They combine with each other to form five-membered or six-membered rings together with the sulfur atoms in the formula.

[0727] In the formula (b1-1), R 101 , R 102 , Y 101 , and V 101 are the same groups as R 101 , R 102 , Y 101 , and V 101 in the formula (b-1).

[0728] • Regarding the (B2) component

[0729] The (B) component can also contain an acid generator component that does not belong to the above (B1) component (hereinafter referred to as "(B2) component"). The (B2) component is not particularly limited as long as it is a component that generates an acid by exposure and does not belong to the above (B1) component, and can be arbitrarily selected from publicly known components. As the (B2) component, for example, sulfonic acid oxime ester-based acid generators; diaalkyl or diaaryl sulfonyl diazomethane-based, poly(bis-sulfonyl) diazomethane-based, and the like can be exemplified. Various acid generators such as nitrobenzyl sulfonate-based acid generators, imino sulfonate-based acid generators, disulfone-based acid generators, and the like can be exemplified.

[0730] In the resist composition of the present embodiment, the (B) component can be used alone in one kind, or two or more kinds can be used in combination.

[0731] In the case where the resist composition contains the (B) component, the content of the (B) component in the resist composition is preferably less than 50 parts by mass, more preferably 0.1 to 40 parts by mass, and further preferably 0.3 to 25 parts by mass, relative to 100 parts by mass of the (A) component.

[0732] By making the content of the (B) component in the above-described preferable range, pattern formation can be sufficiently performed. In addition, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, and the storage stability of the resist composition becomes good, and thus is preferable.

[0733] Base Component (D)

[0734] The resist composition of the present embodiment can further contain, in addition to the (A) component and the (Z) component, a base component that captures an acid generated by exposure, i.e., controls the diffusion of the acid ((D) component). The (D) component is a component that functions as a quencher (acid diffusion controller) that captures an acid generated by exposure in the resist composition.

[0735] As the (D) component, for example, a photodegradable base (D1) (hereinafter referred to as "(D1) component") which loses the acid diffusion controllability by decomposition through exposure, a nitrogen-containing organic compound (D2) (hereinafter referred to as "(D2) component") which does not belong to the (D1) component, and the like can be exemplified. Among them, from the viewpoint of maintaining the sensitivity in a thick resist film, the nitrogen-containing organic compound (D2) ((D2) component) is preferred. In the (D2) component, from the viewpoint of maintaining the transparency in a thick resist film, a chain alkyl amine is preferred.

[0736] • (D1) component

[0737] By providing the resist composition containing the (D1) component, it is possible to further improve the contrast between the exposed part and the unexposed part of the resist film at the time of forming a resist pattern. As the (D1) component, there is no particular limitation if it is a component which loses the acid diffusion controllability by decomposition through exposure, and it is preferably one or more compounds selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1-3) component").

[0738] The (d1-1) to (d1-3) components lose the acid diffusion controllability (basicity) by decomposing in the exposed part of the resist film and thus cannot function as a quencher, but function as a quencher in the unexposed part of the resist film.

[0739] [Formula 69]

[0740]

[0741] [In the formula, Rd 1 ~Rd 4 is a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent. Among them, in the formula (d1-2), Rd 2 is not bonded to a fluorine atom on the carbon atom adjacent to the S atom. Yd 1 is a single bond or a divalent linking group. m is an integer of 1 or more, and M m+ are each independently an organic cation of m valence.]

[0742] {(d1-1) component}

[0743] • Anion part

[0744] In the formula (d1-1), Rd 1 is a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent, and each of R'201 the same group.

[0745] Among these, as Rd 1 , preferably an aromatic hydrocarbon group which can have a substituent, an aliphatic cyclic group which can have a substituent, or a chain alkyl group which can have a substituent. As the substituent which these groups can have, a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluoroalkyl group, a lactone ring-containing cyclic group represented by the above general formulae (a2-r-1) to (a2-r-7) respectively, an ether bond, an ester bond, or a combination thereof can be exemplified. In the case where an ether bond or an ester bond is included as a substituent, a linking group represented by the above formulae (y-al-1) to (y-al-5) respectively is preferred as the substituent in this case.

[0746] As the aromatic hydrocarbon group, a polycyclic structure (a polycyclic structure composed of a bicyclooctane skeleton and a ring structure other than this) including a phenyl group, a naphthyl group, or a bicyclooctane skeleton can be preferably exemplified.

[0747] As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like is more preferred.

[0748] As the chain alkyl group, a straight chain alkyl group having a carbon number of 1 to 10 can be exemplified, specifically, 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, and the like; a branched chain alkyl group such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 4-methylpentyl group, and the like.

[0749] In the case where the chain alkyl group is a fluoroalkyl group having a fluorine atom or a fluoroalkyl group as a substituent, the carbon number of the fluoroalkyl group is preferably 1 to 11, more preferably 1 to 8, and further preferably 1 to 4. The fluoroalkyl group can contain atoms other than a fluorine atom. As the atoms other than a fluorine atom, for example, an oxygen atom, a sulfur atom, a nitrogen atom, and the like can be exemplified.

[0750] As Rd 1 , a fluoroalkyl group in which hydrogen atoms constituting a straight chain alkyl group are substituted with fluorine atoms is preferred, and a fluoroalkyl group in which all hydrogen atoms constituting a straight chain alkyl group are substituted with fluorine atoms (a straight chain perfluoroalkyl group) is particularly preferred.

[0751] Preferred specific examples of the anion portion of the (d1-1) component are shown below.

[0752]

Chemical Formula 70

[0753]

[0754] Cationic part

[0755] In formula (d1-1), M m+ is an organic cation having valence m.

[0756] As the organic cation of M m+ , the same organic cations as those represented by the general formulas (ca-1) to (ca-4), respectively, can be preferably exemplified, and the cation represented by the general formula (ca-1) is more preferable, and the cations represented by the formulas (ca-1-1) to (ca-1-70), respectively, are further preferable.

[0757] The (d1-1) component can be used alone or in combination with two or more.

[0758] {(d1-2) component}

[0759] Anionic part

[0760] In formula (d1-2), Rd 2 is a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent, and the same groups as those of Rd 201 in the formula (d1-1) can be exemplified.

[0761] In formula (d1-2), Rd 2 is a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent, and the same groups as those of Rd 2 in the formula (d1-1) can be exemplified.

[0762] As Rd 2 , a chain alkyl group which can have a substituent or an aliphatic cyclic group which can have a substituent is preferable. As the chain alkyl group, the number of carbons is preferably 1 to 10, and more preferably 3 to 10. As the aliphatic cyclic group, a group (which can have a substituent) obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; a group obtained by removing one or more hydrogen atoms from camphor or the like is more preferable.

[0763] The hydrocarbon group of Rd 2 may have a substituent, and as the substituent, the same groups as those which the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) of Rd 1 in the formula (d1-1) can have can be exemplified.

[0764] Preferred specific examples of the anionic part of the (d1-2) component are shown below.

[0765] [Chemical 71]

[0766]

[0767] Cationic part

[0768] In formula (d1-2), M m+ is an organic cation having valence m, and is the same as M m+ in formula (d1-1).

[0769] The (d1-2) component can be used alone or in combination with two or more.

[0770] (d1-3) component

[0771] Anionic part

[0772] In formula (d1-3), Rd 3 is a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent, and the same groups as R 201 can be exemplified. It is preferably a cyclic group, a chain alkyl group, or a chain alkenyl group containing a fluorine atom. Among them, a fluoroalkyl group is preferred, and a fluoroalkyl group the same as R 1 d

[0773] In formula (d1-3), Rd 4 is a cyclic group which can have a substituent, a chain alkyl group which can have a substituent, or a chain alkenyl group which can have a substituent, and the same groups as R 201 can be exemplified.

[0774] Among them, an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group which can have a substituent are preferred.

[0775] The alkyl group in Rd 4 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like can be exemplified. A part of the hydrogen atoms of the alkyl group of Rd 4 may be substituted with a hydroxyl group, a cyano group, or the like.

[0776] The alkoxy group in Rd 4 is preferably an alkoxy group having 1 to 5 carbon atoms, and as an alkoxy group having 1 to 5 carbon atoms, specifically, a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, a t-butoxy group, and the like can be exemplified. Among them, a methoxy group and an ethoxy group are preferred.

[0777] The alkenyl group in Rd 4 can be exemplified the same as R 201The alkenyl group is preferably vinyl, allyl, 1-methylpropenyl, or 2-methylpropenyl. These groups may further have alkyl groups having 1 to 5 carbon atoms or haloalkyl groups having 1 to 5 carbon atoms as substituents.

[0778] Rd 4 The cyclic base in the example can be exemplified by the R'. 201 The same cyclic group is preferred, preferably an alicyclic group obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornene, isoboronane, tricyclodecane, and tetracyclododecane, or an aromatic group such as phenyl or naphthyl. In Rd 4 In the case of alicyclic groups, the photolithography properties are improved by ensuring good solubility of the resist composition in organic solvents. Furthermore, in Rd... 4 When the resist group is aromatic, the resist composition exhibits excellent light absorption efficiency and good sensitivity and lithographic properties in photolithography using EUV or other light sources.

[0779] In equation (d1-3), Yd 1 It is a single bond or a divalent linker.

[0780] As Yd 1 The divalent linking group in the formula (a2-1) is not particularly limited, and examples include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) that can have substituents, and divalent linking groups containing heteroatoms. Examples of these can be found in relation to Ya in the above formula (a2-1). 21 The description of the divalent linking group is the same as that of the divalent hydrocarbon group that may have substituents and the divalent linking group containing heteroatoms.

[0781] As Yd 1 Preferably, it is a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. As an alkylene group, it is more preferably a straight-chain or branched alkylene group, and even more preferably a methylene or ethylene group.

[0782] The following shows a preferred example of the anionic portion of the (d1-3) component.

[0783]

Chemistry 72

[0784]

[0785]

Transformation 73

[0786]

[0787] • Cation section

[0788] In equation (d1-3), M m+is an organic cation having a valence of m, and is not the same as M in the formula (d1-1) m+ The same organic cation.

[0789] The (d1-3) component can be used alone or in combination with two or more kinds.

[0790] The (D1) component can be used alone or in combination with two or more kinds of the above (d1-1) to (d1-3) components.

[0791] In the case where the resist composition contains the (D1) component, the content of the (D1) component is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and further preferably 5 to 10 parts by mass, relative to 100 parts by mass of the (A) component in the resist composition.

[0792] If the content of the (D1) component is equal to or more than the lower limit of the preferable range, particularly good lithography properties and resist pattern shape are easily obtained. On the other hand, if it is equal to or less than the upper limit of the preferable range, sensitivity is favorably maintained, and throughput is also excellent.

[0793] Method for producing the (D1) component:

[0794] The method for producing the (d1-1) component and the (d1-2) component is not particularly limited, and can be produced by a publicly known method.

[0795] Further, the method for producing the (d1-3) component is not particularly limited, and can be produced, for example, in the same manner as the method described in US 2012-0149916.

[0796] • Regarding the (D2) component

[0797] As the (D) component, it is preferable to contain a nitrogen-containing organic compound component (hereinafter referred to as "(D2) component") which does not belong to the above (D1) component.

[0798] As the (D2) component, there is no particular limitation as long as it functions as an acid diffusion control agent and does not belong to the (D1) component, and any of publicly known components can be used. Among them, it is preferable to be an aliphatic amine, and more particularly preferable to be an aliphatic secondary amine or an aliphatic tertiary amine.

[0799] The aliphatic amine refers to an amine having one or more aliphatic groups, and the aliphatic group preferably has a carbon number of 1 to 12.

[0800] As the aliphatic amine, an amine (alkyl amine or alkyl alcohol amine) in which at least one hydrogen atom of ammonia NH3 is substituted with an alkyl group or a hydroxyalkyl group having a carbon number of 12 or less, or a cyclic amine can be exemplified.

[0801] As specific examples of the alkylamines and the alkylolamines, there can be mentioned monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, etc.; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, dicyclohexylamine, etc.; 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, tri-n-dodecylamine, etc.; alkylolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, etc. Among these, further preferred are trialkylamines having a carbon number of 5 to 10, and particularly preferred are tri-n-pentylamine or tri-n-octylamine.

[0802] As the cyclic amines, for example, there can be mentioned heterocyclic compounds containing a nitrogen atom as a hetero atom. As the heterocyclic compounds, there can be either monocyclic compounds (aliphatic monocyclic amines) or polycyclic compounds (aliphatic polycyclic amines).

[0803] As the aliphatic monocyclic amines, specifically, there can be mentioned piperidine, piperazine, etc. As the aliphatic polycyclic amines, preferred are those having a carbon number of 6 to 10, and specifically, there can be mentioned 1, 5-diazabicyclo [4.3.0] -5-nonene, 1, 8-diazabicyclo [5.4.0] -7-undecene, hexamethylenetetramine, 1, 4-diazabicyclo [2.2.2] octane, etc.

[0804] As other aliphatic amines, there can be mentioned tri (2-methoxy methoxy ethyl) amine, tri {2- (2-methoxy ethoxy) ethyl} amine, tri {2- (2-methoxy ethoxy methoxy) ethyl} amine, tri {2- (1-methoxy ethoxy) ethyl} amine, tri {2- (1-ethoxy ethoxy) ethyl} amine, tri {2- (1-ethoxy propoxy) ethyl} amine, tri [2- {2- (2-hydroxy ethoxy) ethoxy} ethyl] amine, triethanolamine triacetate, etc., and preferred is triethanolamine triacetate.

[0805] Further, as the (D2) component, an aromatic amine can be used.

[0806] As the aromatic amines, there can be mentioned 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2, 6-diisopropylphenylamine, n-tert-butoxycarbonylpyrrolidine, etc.

[0807] As the (D2) component, from the viewpoint of maintaining transparency in the thick film resist, an aliphatic amine is preferred, a chain aliphatic amine is more preferred, and a chain alkyl amine is further preferred. The chain alkyl group possessed by the chain alkyl amine preferably has a carbon number of 5 to 10. Among these, a dialkyl amine or a trialkyl amine having a straight chain alkyl group having a carbon number of 5 to 10 is preferred, and a trialkyl amine is more preferred.

[0808] (D2) component can be used alone or two or more kinds can be used in combination.

[0809] In the case where the resist composition contains the (D2) component, it is generally used in a range of 0.005 to 5 parts by mass with respect to 100 parts by mass of the (A) component in the resist composition. By being set to the above range, the resist pattern shape, standing time stability, and the like are improved.

[0810] "at least one kind of compound (E) selected from the group consisting of organic carboxylic acids and phosphorus-containing oxyacids and derivatives thereof"

[0811] For the purpose of preventing sensitivity deterioration or improving the resist pattern shape, standing time stability, and the like, at least one kind of compound (E) (hereinafter referred to as "(E) component") selected from the group consisting of organic carboxylic acids and phosphorus-containing oxyacids and derivatives thereof can be contained in the resist composition of the present embodiment as an arbitrary component.

[0812] As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, and the like are preferable.

[0813] As the phosphorus-containing oxyacid, phosphoric acid, phosphonic acid, phosphinic acid, and the like can be exemplified, and among these, phosphonic acid is particularly preferable.

[0814] As the derivative of the phosphorus-containing oxyacid, for example, esters and the like obtained by substituting the hydrogen atom of the above oxyacid with a hydrocarbon group can be exemplified, and as the hydrocarbon group, an alkyl group having a carbon number of 1 to 5, an aryl group having a carbon number of 6 to 15, and the like can be exemplified.

[0815] As the derivative of the phosphonic acid, phosphonic acid di-n-butyl ester, diphenyl phosphonate, and the like can be exemplified.

[0816] As the derivative of the phosphonic acid, dimethyl phosphonate, di-n-butyl phosphonate, phenyl phosphonic acid, diphenyl phosphonate, dibenzyl phosphonate, and the like can be exemplified.

[0817] As the derivative of the phosphinic acid, phosphinic acid ester or phenyl phosphinic acid, and the like can be exemplified.

[0818] In the resist composition of the present embodiment, the (E) component can be used alone or two or more kinds can be used in combination.

[0819] In the case where the resist composition contains the (E) component, it is generally used in a range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the (A) component.

[0820] "fluorine additive component (F)"

[0821] In order to impart water resistance to the resist film or to improve photolithography properties, the resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "(F) component").

[0822] As component (F), for example, fluorine-containing polymers described in Japanese Patent Application Publication Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 may be used.

[0823] More specifically, as component (F), examples can be given of polymers having structural units (f1) represented by the following general formula (f1-1). Preferably, such polymers are polymers (homopolymers) consisting solely of structural units (f1) represented by the following formula (f1-1); copolymers of the structural unit (f1) with the structural unit (a1); the structural unit (f1), structural units derived from acrylic acid or methacrylic acid, and copolymers with the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate or a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate.

[0824]

Chemistry 74

[0825]

[0826] [In the formula, R is the same as above, Rf] 102 and Rf 103 Each of the following can be independently represented: a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a haloalkyl group having 1 to 5 carbon atoms. Rf 102 and Rf 103 They can be the same or different. nf 1 Rf is an integer from 1 to 5. 101 [This refers to an organic group containing a fluorine atom.]

[0827] In formula (f1-1), R bonded to the carbon atom at the α position is the same as described above. Preferably, R is a hydrogen atom or a methyl group.

[0828] In equation (f1-1), Rf 102 and Rf 103 Halogen atoms can be exemplified by fluorine, chlorine, bromine, and iodine atoms, with fluorine atoms being particularly preferred. As Rf... 102 and Rf 103 The alkyl group having 1 to 5 carbon atoms can be exemplified by groups having the same alkyl group having 1 to 5 carbon atoms as the aforementioned R, preferably methyl or ethyl. As Rf102 and Rf 103 halogenated alkyl group having a carbon number of 1 to 5, specifically, a group in which a part or all of hydrogen atoms of an alkyl group having a carbon number of 1 to 5 are substituted with a halogen atom can be exemplified. As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like can be exemplified, and a fluorine atom is particularly preferable. Among them, as Rf 102 and Rf 103 a hydrogen atom, a fluorine atom, or an alkyl group having a carbon number of 1 to 5, preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group.

[0829] In formula (f1-1), nf 1 is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

[0830] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom.

[0831] As the hydrocarbon group containing a fluorine atom, any one of a linear shape, a branched shape, or a cyclic shape can be exemplified, and preferably a carbon number of 1 to 20, more preferably a carbon number of 1 to 15, and particularly preferably a carbon number of 1 to 10.

[0832] Further, the hydrocarbon group containing a fluorine atom preferably has 25% or more of hydrogen atoms in the hydrocarbon group fluorinated, more preferably 50% or more of hydrogen atoms fluorinated, and particularly preferably 60% or more of hydrogen atoms fluorinated, from the viewpoint of improving the hydrophobicity of the resist film at the time of immersion exposure.

[0833] Among them, as Rf 101 more preferably a fluorinated hydrocarbon group having a carbon number of 1 to 6, and particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, -CH2-CH2-CF2-CF2-CF2-CF3.

[0834] The weight average molecular weight (Mw) of the (F) component (polystyrene conversion basis based on gel permeation chromatography) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. If it is below the upper limit of the range, it has sufficient solubility against a solvent for a resist for use as a resist, and if it is above the lower limit of the range, the water repellency of the resist film is good.

[0835] The molecular weight distribution coefficient (Mw / Mn) of the (F) component is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0836] In the resist composition of the present embodiment, the (F) component can be used alone as one kind, or two or more kinds can be used in combination.

[0837] In the case where the resist composition contains the (F) component, the (F) component is generally used at a content of 0.5 to 10 parts by mass per 100 parts by mass of the (A) component.

[0838] "Organic Solvent Component (S)"

[0839] The resist composition of the present embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as "(S) component").

[0840] As the (S) component, any component can be appropriately selected from substances conventionally known as solvents for chemically amplified resist compositions, provided that the component can dissolve each of the components used to form a uniform solution.

[0841] For example, as the (S) component, mention can be made of 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, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; monoalkyl ethers or monophenyl ethers of the polyhydric alcohols or the compounds having an ester bond such as monomethyl ether of propylene glycol monoacetate (PGMEA) or monomethyl ether of propylene glycol (PGME); cyclic ethers such as dioxane; esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, methyl tolyl ether, diphenyl ether, dibenzyl ether, phenyl ethyl ether, butyl phenyl ether, ethyl benzene, diethyl benzene, amyl benzene, cumene, toluene, xylene, isopropyl toluene, mesitylene; and dimethyl sulfoxide (DMSO).

[0842] In the resist composition of the present embodiment, the (S) component can be used alone as one kind or as a mixed solvent of two or more kinds. Of these, at least one selected from the group consisting of PGMEA, PGME, γ-butyrolactone, EL, butyl acetate, and cyclohexanone is preferred, and at least one selected from the group consisting of PGMEA, PGME, and butyl acetate is more preferred.

[0843] Further, as the (S) component, a mixed solvent obtained by mixing PGMEA with a polar solvent is also preferred. The blending ratio (mass ratio) of the mixed solvent can be appropriately determined in consideration of the compatibility of PGMEA with the polar solvent and the like, and is preferably set to a range of 1 : 9 to 9 : 1, and more preferably to a range of 2 : 8 to 8 : 2.

[0844] More specifically, in the case of blending EL, butyl acetate or cyclohexanone as the polar solvent, the mass ratio of PGMEA:EL, butyl acetate or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. Further, in the case of blending PGME as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, further preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA and PGME and butyl acetate is also preferable.

[0845] Further, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mass ratio of the former to the latter is preferably set to 70:30 to 95:5 as the mixing ratio.

[0846] The amount of use of the (S) component is set in such a manner that the solid content concentration of the resist composition is 25% by mass or more. In the present specification, the solid content in the resist composition refers to components other than the (S) component. The solid content concentration of the resist composition is calculated by the following formula.

[0847] Solid content concentration (% by mass) = (total mass of components other than the (S) component) / (total mass of the resist composition) x 100

[0848] For example, in the case where the resist composition is composed of the (A) component, the (Z) component, the (B) component, the (D) component and the (S) component, the solid content concentration (% by mass) = [((A) component + (Z) component + (B) component + (D) component) / ((A) component + (Z) component + (B) component + (D) component) + (S) component] x 100.

[0849] By setting the solid content concentration of the resist composition to 25% by mass or more, in the case where the resist composition is applied to a substrate to form a resist film, a thick resist film (for example, a film thickness of 5 μm or more, preferably 7 μm or more) can be formed. The solid content concentration of the resist composition is not particularly limited as long as it is 25% by mass or more, and can be appropriately determined in accordance with the desired film thickness of the resist film. Generally, the higher the solid content concentration, the thicker the film thickness of the resist film.

[0850] The upper limit of the solid content concentration of the resist composition is not particularly limited as long as it is a concentration at which the solid content can be dissolved. The solid content concentration of the resist composition is, for example, 60% by mass or less, preferably 55% by mass or less, more preferably 50% by mass or less.

[0851] As a range of the solid content concentration of the resist composition, for example, 25 to 60 mass%, 25 to 55 mass%, or 25 to 50 mass% can be exemplified.

[0852] The resist composition of the present embodiment can further contain an additive having a mixed property, such as an additional resin for improving the properties of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an anti-halo agent, a dye, and the like, as appropriate according to the needs.

[0853] The resist composition of the present embodiment can further be subjected to removal of impurities and the like using a polyimide porous membrane, a polyamide-imide porous membrane, or the like after dissolving the above-described resist material in the (S) component. For example, filtration of the resist composition can be performed using a filter composed of a polyimide porous membrane, a filter composed of a polyamide-imide porous membrane, a filter composed of a polyimide porous membrane and a polyamide-imide porous membrane, or the like. As the polyimide porous membrane and the polyamide-imide porous membrane, for example, a substance described in Japanese Patent Application Publication No. 2016-155121 can be exemplified.

[0854] The solid content concentration of the resist composition of the present embodiment described above is 25 mass% or more, and contains the ionic liquid (Z).

[0855] Since the solid content concentration of the resist composition of the present embodiment is 25 mass% or more, if a resist film is formed by applying the resist composition to a substrate, a thick resist film (for example, a film thickness of 5 μm or more) can be formed. In such a thick resist film, cracks are easily generated on the resist pattern. In addition, since light is difficult to reach the bottom, it is difficult to maintain the sensitivity at the time of exposure, and thus it is difficult to form a resist pattern with a good shape.

[0856] In the resist composition of the present embodiment, by containing the ionic liquid (Z), both crack resistance and high sensitivity can be achieved. It is presumed that this is because, by allowing the ionic liquid (Z) to exist in the resist film formed using the resist composition, the stress of the resist film is relaxed.

[0857] (Resist pattern forming method)

[0858] The resist pattern forming method of the second aspect of the present application is a method having the following steps: a step of forming a resist film on a support using the resist composition of the above-described embodiment; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

[0859] As an embodiment of the above-described resist pattern forming method, for example, a resist pattern forming method performed as described below can be exemplified.

[0860] First, the resist composition of the embodiment described above is applied on a support body with a spin coater or the like, and a baking (PAB: Post apply bake) treatment is performed at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably for 60 to 90 seconds to form a resist film.

[0861] Next, for the resist film, selective exposure is performed, for example, using an electron beam drawing device, an EUV exposure device, or the like, by exposure through a mask (mask pattern) that forms a prescribed pattern, or drawing by direct irradiation of electron rays without the mask pattern, and the like, and a baking (PEB: Post exposure bake) treatment is performed at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably for 60 to 90 seconds.

[0862] Next, a developing treatment is performed on the resist film. In the case of an alkali developing process, an alkali developing solution is used, and in the case of a solvent developing process, a developing solution containing an organic solvent (organic developing solution) is used.

[0863] After the developing treatment, a rinsing treatment is preferably performed. In the case of an alkali developing process, water rinsing using pure water is preferably performed, and in the case of a solvent developing process, a rinsing solution containing an organic solvent is preferably used.

[0864] In the case of a solvent developing process, after the developing treatment or the rinsing treatment, a treatment for removing the developing solution or the rinsing solution adhering to the pattern by a supercritical fluid can be performed.

[0865] Drying is performed after the developing treatment or the rinsing treatment. Furthermore, a baking treatment (post-baking) can be performed after the developing treatment described above, as the case can be.

[0866] As described above, a resist pattern can be formed.

[0867] The support body is not particularly limited, and a support body known in the past can be used, and for example, a substrate for electronic parts, a support body on which a prescribed wiring pattern is formed, or the like can be exemplified. More specifically, a silicon wafer, a metal substrate of copper, chromium, iron, aluminum, or the like, or a glass substrate, or the like can be exemplified. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold, or the like can be used.

[0868] Furthermore, as the support body, a support body in which an inorganic and / or organic film is provided on the substrate described above can be used. As the inorganic film, an inorganic anti-reflective film (inorganic BARC) can be exemplified. As the organic film, an organic anti-reflective film (organic BARC), a lower organic film in a multilayer resist method, or the like can be exemplified.

[0869] Here, the multilayer resist method refers to a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and a resist pattern formed in the upper resist film is used as a mask to pattern the lower organic film, and is considered to be capable of forming a pattern with a high aspect ratio. That is, according to the multilayer resist method, the desired thickness can be ensured by the lower organic film, and thus the resist film can be thinned, and a fine pattern with a high aspect ratio can be formed.

[0870] In the multilayer resist method, basically, there are a method using a two-layer structure of an upper resist film and a lower organic film (2-layer resist method), and a method using a multilayer structure of three or more layers in which one or more intermediate layers (metal thin film, etc.) are provided between the upper resist film and the lower organic film (3-layer resist method).

[0871] In the resist pattern forming method of the present embodiment, since the resist composition of the above embodiment is used, a thick resist film can be formed in the process (i). The film thickness of the resist film is preferably 5 μm or more, more preferably 7 μm or more, and further preferably 8 μm or more. The upper limit of the film thickness of the resist film is, for example, 30 μm or less. As the range of the film thickness of the resist film formed in the process (i), for example, 5 to 30 μm can be exemplified, preferably 7 to 20 μm, more preferably 7 to 15 μm, and further preferably 8 to 12 μm. The film thickness of the resist film can be adjusted depending on the solid content concentration of the resist composition used in the process (i). That is, the higher the solid content concentration of the resist composition, the higher the film thickness of the resist film that can be formed.

[0872] The wavelength used in the exposure is not particularly limited, and 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, etc. can be used. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB, or EUV, and is more highly useful for KrF excimer laser or ArF excimer laser, and is particularly highly useful for KrF excimer laser. That is, the resist pattern forming method of the present embodiment is particularly useful in a case where the process of exposing the resist film includes an operation of exposing the resist film to KrF excimer laser.

[0873] The exposure method of the resist film can be a general exposure (dry exposure) performed in air, inert gas such as nitrogen, etc., or can be liquid immersion exposure (Liquid Immersion Lithography).

[0874] Immersion exposure refers to an exposure method in which a space between an antireflective agent film and a lens at the lowermost position of an 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).

[0875] As the immersion medium, a solvent having a refractive index larger than that of air and smaller than that of the exposed antireflective agent film is preferable. The refractive index of the solvent is not particularly limited as long as it is within the above range.

[0876] As the solvent having a refractive index larger than that of air and smaller than that of the antireflective agent film, for example, water, a fluorine-based inert liquid, a silicon-based solvent, a hydrocarbon-based solvent, and the like can be exemplified.

[0877] As a specific example of the fluorine-based inert liquid, a liquid in which a fluorine-based compound such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, C5H3F7, or the like is a main component can be exemplified, and a liquid having a boiling point of 70 to 180°C is preferable, and a liquid having a boiling point of 80 to 160°C is more preferable. If the fluorine-based inert liquid has a boiling point within the above range, removal of the medium for immersion after the exposure can be performed by a simple method, and thus it is preferable.

[0878] As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms is particularly preferable. As the perfluoroalkyl compound, specifically, a perfluoroalkyl ether compound or a perfluoroalkyl amine compound can be exemplified.

[0879] Further, specifically, as the perfluoroalkyl ether compound, perfluoro(2-butyl-tetrahydrofuran) (boiling point: 102°C) can be exemplified, and as the perfluoroalkyl amine compound, perfluorotributyl amine (boiling point: 174°C) can be exemplified.

[0880] As the immersion medium, from the viewpoints of cost, safety, environmental problems, and versatility, it is preferable to use water.

[0881] As the alkaline developer used for the development treatment in the alkaline development process, for example, a 0.1 to 10 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) can be exemplified.

[0882] As the organic solvent contained in the organic developer used for the development treatment in the solvent development process, an organic solvent capable of dissolving the (A) component (the (A) component before exposure) can be appropriately selected from publicly known organic solvents. Specifically, polar solvents such as a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, a nitrile-based solvent, an amide-based solvent, an ether-based solvent, and the like, and a hydrocarbon-based solvent, and the like can be exemplified.

[0883] A ketone solvent is an organic solvent including C-C(=0)-C in the structure. An ester solvent is an organic solvent including C-C(=0)-0-C in the structure. An alcohol solvent is an organic solvent including an alcoholic hydroxyl group in the structure. The "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent including a nitrile group in the structure. An amide solvent is an organic solvent including an amide group in the structure. An ether solvent is an organic solvent including C-O-C in the structure.

[0884] Among the organic solvents, there are also organic solvents including a plurality of functional groups having the characteristics of each of the above-described solvents in the structure, in which case the organic solvent is classified into all the solvent categories having the functional groups possessed. For example, diethylene glycol monomethyl ether is classified into either of the above-described alcohol solvent or ether solvent.

[0885] A hydrocarbon solvent is a hydrocarbon solvent composed of a halogenatable hydrocarbon, having no substituent other than a halogen atom. As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like can be exemplified, and a fluorine atom is preferred.

[0886] As the organic solvent contained in the organic developer, among the above, a polar solvent is preferred, and a ketone solvent, an ester solvent, a nitrile solvent, and the like are preferred.

[0887] As the ketone solvent, for example, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylpropyl ketone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, diaceton, ionone, diaceton alcohol, acetyl carbinol, phenylethyl ketone, methylnaphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), and the like can be exemplified. Among these, as the ketone solvent, methyl amyl ketone (2-heptanone) is preferred.

[0888] As the ester-based solvent, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, and the like can be exemplified. Among these, as the ester-based solvent, butyl acetate is preferred.

[0889] As the nitrile-based solvent, for example, acetonitrile, propionitrile, valeronitrile, butyronitrile, and the like can be exemplified.

[0890] In the organic developer, a known additive can be blended as necessary. As the additive, for example, a surfactant can be exemplified. As the surfactant, there is no particular limitation, and for example, an ionic, non-ionic, fluorine-based and / or silicon-based surfactant, and the like can be used. As the surfactant, a non-ionic surfactant is preferred, and a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant is more preferred.

[0891] In the case where the surfactant is blended, the blending amount thereof 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, relative to the total amount of the organic developer.

[0892] The developing treatment can be performed by a publicly known developing method, for example, a method in which the support is immersed in a developing solution for a certain period of time (immersion method), a method in which a developing solution is carried on the surface of the support by surface tension and left still for a certain period of time (puddle method), a method in which a developing solution is sprayed to the surface of the support (spray method), a method in which a developing solution is continuously applied to a support rotating at a certain speed while a nozzle from which the developing solution is applied is scanned at a certain speed (dynamic dispensing method), and the like.

[0893] As the organic solvent contained in the rinsing solution used for the rinsing treatment after the developing treatment in the solvent developing process, for example, an organic solvent which is difficult to dissolve the resist pattern among the organic solvents exemplified as the organic solvent for the organic developing solution can be appropriately selected. At least one solvent selected from a hydrocarbon-based solvent, a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, an amide-based solvent, and an ether-based solvent is generally used. Among these, at least one selected from a hydrocarbon-based solvent, a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, and an amide-based solvent is preferred, at least one selected from an alcohol-based solvent and an ester-based solvent is more preferred, and an alcohol-based solvent is particularly preferred.

[0894] The alcohol-based solvent used in the rinsing solution is preferably a monohydric alcohol having a carbon number of 6 to 8, and the monohydric alcohol can be any one of a straight chain, a branched chain, or a cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol, and the like can be exemplified. Among these, 1-hexanol, 2-heptanol, 2-hexanol are preferred, and 1-hexanol, 2-hexanol are more preferred.

[0895] These organic solvents can be used alone as any one of them or in combination of two or more. In addition, they can be used in combination with an organic solvent other than the above or water. Among these, if the developing properties are taken into consideration, the amount of water blended in the rinsing solution is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and particularly preferably 3% by mass or less, relative to the total amount of the rinsing solution.

[0896] In the rinsing solution, a publicly known additive can be blended as needed. As the additive, for example, a surfactant can be exemplified. The surfactant can be exemplified as the same surfactants as described above, and a nonionic surfactant is preferred, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferred.

[0897] In the case where a surfactant is blended, the amount of the surfactant blended is generally 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total amount of the rinsing solution.

[0898] The rinsing treatment (cleaning treatment) using the rinsing liquid can be performed by a publicly known rinsing method. As the method of the rinsing treatment, for example, a method in which the rinsing liquid is continuously applied to a support body rotating at a certain speed (spin coating method), a method in which the support body is immersed in the rinsing liquid for a certain time (immersion method), a method in which the rinsing liquid is sprayed to the surface of the support body (spray coating method), and the like can be exemplified.

[0899] According to the resist pattern forming method of the present embodiment described above, since the resist composition of the above-described first aspect is used, high sensitivity can be achieved, and a resist pattern having less cracks can be formed.

[0900] The above-described resist pattern forming method is useful as a method for manufacturing a three-dimensional structure device.

[0901] Examples

[0902] Hereinafter, the present application will be further explained by examples, but the present application is not limited by these examples.

[0903] <Preparation of resist composition>

[0904] (Examples 1 to 12, Comparative Examples 1 and 2)

[0905] Each of the resist compositions of the examples was prepared by mixing and dissolving each of the components shown in Table 1.

[0906] [Table 1]

[0907]

[0908] In Table 1, each of the abbreviations has the following meaning. The values in the brackets are the blending amounts (mass parts). The solid content concentration was calculated by the following formula: solid content concentration (mass %) = [((A) component + (B) component + (D) component + (Z) component) / ((A) component + (B) component + (D) component + (Z) component + (S) component)] x 100.

[0909] (A)-1: A high molecular compound represented by the following Chemical Formula (A-1). The weight average molecular weight (Mw) converted to polystyrene standard measured by GPC was 10,000, and the molecular weight distribution coefficient (Mw / Mn) was 1.4. The copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) measured by C-NMR was 1 / m / n = 60 / 15 / 25. 13 C-NMR was 1 / m / n = 60 / 15 / 25.

[0910] [Chemical 75]

[0911]

[0912] (B)-1: an acid generator consisting of a compound represented by the following formula (B-1).

[0913] (D)-1: a nitrogen-containing organic compound consisting of a compound represented by the following formula (D-1).

[0914]

Chemical 76

[0915]

[0916] (Z)-1: a compound represented by the following formula (IL)-1.

[0917] (Z)-2: a compound represented by the following formula (IL)-3.

[0918] (Z)-3: a compound represented by the following formula (IL)-14.

[0919] (Z)-4: a compound represented by the following formula (IL)-15.

[0920] (Z)-5: a compound represented by the following formula (IL)-16.

[0921] (Z)-6: a compound represented by the following formula (IL)-17.

[0922] (Z)-7: a compound represented by the following formula (IL)-18.

[0923] (Z)-8: a compound represented by the following formula (IL)-19.

[0924] (Z)-9: a compound represented by the following formula (IL)-20.

[0925]

Chemical 77

[0926]

[0927]

Chemical 78

[0928]

[0929] (S)-1: propylene glycol monomethyl ether

[0930] (S)-2: propylene glycol monomethyl ether acetate

[0931] (S)-3: butyl acetate

[0932] Formation of resist pattern

[0933] Step (i):

[0934] On an 8-inch silicon wafer on which a hexamethyldisilazane (HMDS) treatment at 110°C for 60 seconds was performed, each of the resist compositions of Examples was applied using a spinner. A prebake (PAB) treatment at 140°C for 90 seconds was performed on a hot plate to dry, thereby forming a resist film having a thickness of 15 μm.

[0935] Process (ii):

[0936] Next, the resist film was selectively irradiated with KrF excimer laser light (248 nm) via a mask pattern (binary mask) using a KrF exposure device NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.68, σ = 0.40).

[0937] Then, a post-exposure bake (PEB) treatment at 110°C for 90 seconds was performed.

[0938] Process (iii):

[0939] Next, an alkali development was performed at 23°C for 60 seconds using a 2.38 mass% aqueous tetramethylammonium hydroxide (TMAH) solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer.

[0940] Subsequently, a post-bake at 100°C for 60 seconds was performed.

[0941] As a result, an isolated space pattern (hereinafter referred to as "IS pattern") having a space width of 5 μm and a gap of 30 μm was formed.

[0942] [Crack resistance evaluation]

[0943] A silicon wafer on which an IS pattern was formed by the above-described "resist pattern formation" was placed in a chamber of a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation), and a vacuum treatment at a pressure of 0.0001 Pa was performed for 60 seconds. The silicon wafer after the vacuum treatment was observed using an optical microscope, and the number of cracks was counted. The number of cracks was evaluated based on the following evaluation criteria. The results are shown as "cracks" in Table 2.

[0944] Evaluation criteria

[0945] A: 0 cracks

[0946] B: 1 to 5 cracks

[0947] C: 6 or more cracks

[0948] [Sensitivity evaluation]

[0949] The optimum exposure amount Eop (mJ / cm2) for forming an IS pattern having a space width of 5 μm and a gap of 30 μm in the above-mentioned "formation of resist pattern" was found. This is shown as "Eop (mJ / cm2)" in Table 2. 2 ). This is shown as "Eop (mJ / cm 2 )" in Table 2.

[0950] [Table 2]

[0951]

[0952] From the results shown in Table 2, it was confirmed that the crack resistance and sensitivity of the resist compositions of Examples 1 to 12 were both good.

[0953] The above describes preferred embodiments of the present application, but the present application is not limited by these embodiments. Additions, omissions, substitutions and other changes can be made to the constitution within the scope of the gist of the present application. The present application is not limited by the above description, but only by the scope of the appended claims.

Claims

1. A photoresist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, characterized in that, contains: a base material component (A) whose solubility to a developer changes due to an acid; an acid generator component (B); an ionic liquid (Z) having a melting point of 100°C or lower, an anion part of the ionic liquid (Z) is an anion represented by any one of the following general formulae (z-an-1) to (z-an-5), a cation part of the ionic liquid (Z) is a cation represented by any one of the following general formulae (z-ca-1), (z-ca-2), and (z-ca-4), a content of the ionic liquid (Z) is 3 parts by mass or more and less than 25 parts by mass with respect to 100 parts by mass of the base material component (A), a solid component concentration of the resist composition is 25% by mass or more, In formula (z-an-1), Rz a1 represents a chain hydrocarbon group which can have a substituent, in formula (z-an-2), Rz a2 represents an alkyl group having 1 to 5 carbons which can be substituted with a fluorine atom, k is an integer of 1 to 4, 1 is an integer of 0 to 3, and k + 1 = 4, in formula (z-an-3), Rz a3 represents an alkyl group having 1 to 5 carbons which can be substituted with a fluorine atom, m is an integer of 1 to 6, n is an integer of 0 to 5, and m + n = 6, in formula (z-an-4), X" represents an alkylene group having 2 to 6 carbons in which at least one hydrogen atom is substituted with a fluorine atom, in formula (z-an-5), Y" and Z" each independently represent an alkyl group having 1 to 10 carbons in which at least one hydrogen atom is substituted with a fluorine atom, wherein Rz c1 ~Rz c4 are each independently an alkyl group having a carbon number of 1 to 12, Rz c7 ~Rz c9 are each independently an aryl group which can have a substituent.

2. A resist pattern forming method characterized by, has: a step of forming a resist film using the resist composition of claim 1 on a support; a step of exposing the resist film; and a step of forming a resist pattern by developing the exposed resist film.

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