Radiation-sensitive composition, resist pattern forming method, and radiation-sensitive acid generator

Abstract

A radiation-sensitive composition containing a polymer having an acid-dissociable group and a compound represented by formula (1). L1 represents a group having a (thio) acetal ring, or the like; and W1 represents a single bond or a (b + 1)-valent organic group having 1-40 carbon atoms. R1, R2, and R3 are each independently a hydrogen atom, a C1-10 hydrocarbon group, a fluorine atom, or a fluoroalkyl group. And Rf represents a fluorine atom or a fluoroalkyl group. And a represents an integer of 0-8. And b is an integer of 1-4. And d is 1 or 2. When a is 2 or more, the plurality of R1s are the same or different, and the plurality of R2s are the same or different. When d is 2, the plurality of W1 are the same or different, and the plurality of b are the same or different. M < + > is a monovalent cation. # imgabs0 #

Description

Technical Field

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002] This application claims priority based on Japanese Patent Application No. 2022-119054 filed on Jul. 26, 2022, the entire content of which is incorporated herein by reference.

[0003] The present invention relates to a radiation-sensitive composition, a resist pattern forming method and a radiation-sensitive acid generator. Background Art

[0004] In the formation of fine circuits in semiconductor components, photolithography using radiation-sensitive compositions is used. As a representative sequence of photolithography, first, a film formed of a radiation-sensitive composition (hereinafter, also referred to as a "resist film") is irradiated with radiation through a shielding pattern, and a chemical reaction involving an acid generated by radiation irradiation is used to cause a difference in dissolution rate relative to a developer between the exposed portion and the unexposed portion in the resist film. Then, the exposed resist film is brought into contact with a developer, thereby dissolving the exposed portion or the unexposed portion in the developer. Thus, a resist pattern is formed on a substrate.

[0005] In the circuit formation of semiconductor devices using photolithography technology, in order to form a finer resist pattern, various studies have been conducted on radiation-sensitive acid generators as one of the main components of radiation-sensitive compositions (for example, refer to Patent Documents 1 and 2). Patent Document 1 discloses a radiation-sensitive composition containing a salt including an anion having a spiro structure of a (thio)acetal ring and a saturated ring, and a salt of a cation as an acid generator. In addition, Patent Document 2 discloses a radiation-sensitive composition containing a salt including an anion having a spiro structure of a (thio)acetal lactone ring and an alicyclic hydrocarbon, and a salt of a cation as an acid generator.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-37837

[0009] Patent Document 2: Japanese Patent Application Publication No. 2018-135321 Summary of the invention

[0010] Problems to be solved by the invention

[0011] In photolithography using radiation-sensitive compositions, the miniaturization of patterns is promoted by using short-wavelength radiation such as ArF excimer lasers, or by using a liquid immersion exposure method (liquid immersion lithography) in which exposure is performed in a state where the space between the lens and the resist film of the exposure device is filled with a liquid medium. In addition, as a next-generation technology, lithography using radiation with shorter wavelengths such as electron beams, X-rays, and extreme ultraviolet (EUV) is also being studied. In efforts toward such next-generation technologies, performance that exceeds previous performance is required in terms of radiation sensitivity of radiation-sensitive compositions, line width roughness (LWR) performance as an indicator of deviation in line width of resist patterns, shape properties of resist patterns (e.g., rectangularity of the cross-sectional shape of the resist pattern, etc.), and reduction of development defects.

[0012] The present disclosure has been made in view of the above problems, and one object thereof is to provide a radiation-sensitive composition, a pattern forming method, and a radiation-sensitive acid generator that exhibit high sensitivity, are excellent in LWR performance and pattern shape, and have few development defects.

[0013] Means of solving problems

[0014] The present inventors have made extensive research to solve the problem and have found that the problem can be solved by using an onium salt compound having a specific structure. Specifically, the present disclosure provides the following means.

[0015] The present disclosure provides, in one embodiment, a radiation-sensitive composition comprising: a polymer having an acid-dissociable group; and a compound represented by the following formula (1).

[0016] [Chemistry 1]

[0017]

[0018] (In formula (1), L 1 A group having a (thio)acetal ring in which two oxygens, two sulfurs, or one oxygen and one sulfur are bonded to the same carbon through two methylene groups of a monocyclic saturated aliphatic hydrocarbon ring being substituted with (thio)ether bonds, or a group represented by the following formula (L-2);

[0019] [Chemistry 2]

[0020]

[0021] (In formula (L-2), L 2 is a bridged alicyclic group having 7 or more carbon atoms; 3is a single bond, oxygen atom, sulfur atom or -SO2-; d is 1 or 2; "* 3 " indicates that 1 or carboxyl bond)

[0022] W 1 is a single bond or a (b+1)-valent organic group having 1 to 40 carbon atoms; R 1 , R 2 and R 3 are independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a fluorine atom or a fluoroalkyl group; R f is a fluorine atom or a fluoroalkyl group; a is an integer from 0 to 8; b is an integer from 1 to 4; d is 1 or 2; wherein, 1 When a is 2 or more, the plurality of R 1 Same or different, multiple R 2 The same or different; when d is 2, multiple W 1 The same or different, multiple b are the same or different; M + is a monovalent cation)

[0023] In another embodiment, the present disclosure provides a resist pattern forming method, which includes: applying the radiation-sensitive composition on a substrate to form a resist film; exposing the resist film; and developing the exposed resist film.

[0024] In another embodiment, the present disclosure provides a radiation-sensitive acid generator represented by the formula (1).

[0025] Effects of the Invention

[0026] The radiation-sensitive linear composition disclosed herein can show high sensitivity, can show excellent LWR performance and pattern shape when the resist pattern is formed, and can reduce development defects by including a polymer having an acid dissociative group and a compound represented by the formula (1) together. In addition, by the resist pattern forming method disclosed herein, since the radiation-sensitive linear composition disclosed herein is used, a resist pattern with excellent LWR performance and pattern shape and few development defects can be obtained. Therefore, further high precision and high quality of fine resist patterns can be achieved. In addition, by the radiation-sensitive linear acid generator disclosed herein, a resist pattern with high sensitivity, excellent LWR performance and pattern shape when the resist pattern is formed, and few development defects can be formed. DETAILED DESCRIPTION

[0027] Hereinafter, matters related to the implementation of the present disclosure will be described in detail. In addition, in this specification, the numerical range described using "to" means that the numerical values ​​described before and after "to" are included as the lower limit and the upper limit.

[0028] 《Radiosensitive composite material》

[0029] The radiation-sensitive composition disclosed herein (hereinafter, also referred to as "the present composition") contains: a polymer having an acid dissociable group (hereinafter, also referred to as "polymer (A)"), and a compound having a specific anionic structure (hereinafter, also referred to as "compound (B)"). In addition, the present composition may also contain other arbitrary components within the scope that does not impair the effects of the present disclosure. Each component is described in detail below.

[0030] Furthermore, in this specification, the so-called "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The so-called "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group that does not contain a cyclic structure but only consists of a chain structure. Among them, the chain hydrocarbon group may be saturated or unsaturated. The so-called "alicyclic hydrocarbon group" refers to a hydrocarbon group that only contains alicyclic hydrocarbon structures as a ring structure and does not contain aromatic ring structures. Among them, the alicyclic hydrocarbon group does not need to be composed only of the structure of alicyclic hydrocarbons, and also includes those having a chain structure in a part thereof. The so-called "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. Among them, the aromatic hydrocarbon group does not need to be composed only of the aromatic ring structure, and may also contain a chain structure or an alicyclic hydrocarbon structure in a part thereof. The so-called "organic group" refers to an atomic group formed by removing any hydrogen atom from a carbon-containing compound (i.e., an organic compound). "(Meth)acrylic acid" is a term that includes "acrylic acid" and "methacrylic acid". “(Thio)ether” is a term including “ether” and “thioether”. “(Thio)acetal” is a term including “acetal” and “thioacetal”.

[0031] <Polymer (A)>

[0032] The acid-dissociable group possessed by the polymer (A) is a group that replaces the hydrogen atom possessed by the acid group (e.g., carboxyl group, phenolic hydroxyl group, alcoholic hydroxyl group, sulfonic group, etc.), and is a group that dissociates by the action of an acid. By blending a polymer having an acid-dissociable group into a radiation-sensitive composition, the acid-dissociable group dissociates to generate a carboxyl group by utilizing a chemical reaction involving an acid generated by irradiating the radiation-sensitive composition with radiation, and the solubility of the polymer in a developer can be changed. As a result, the present composition can be endowed with good lithographic properties.

[0033] The polymer (A) preferably contains a structural unit having an acid dissociable group (hereinafter, also referred to as "structural unit (I)"). Examples of structural unit (I) include: a structural unit having a structure in which a hydrogen atom of a carboxyl group is substituted by a substituted or unsubstituted tertiary hydrocarbon group, a structural unit having a structure in which a hydrogen atom of a phenolic hydroxyl group is substituted by a substituted or unsubstituted tertiary hydrocarbon group, and a structural unit having an acetal structure. From the viewpoint of improving the pattern shape of the present composition, structural unit (I) is preferably a structural unit having a structure in which a hydrogen atom of a carboxyl group is substituted by a substituted or unsubstituted tertiary hydrocarbon group, and specifically, preferably a structural unit represented by the following formula (2) (hereinafter, also referred to as "structural unit (I-1)").

[0034] [Chemistry 3]

[0035]

[0036] (In formula (2), R 11 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or an alkoxyalkyl group; 1 is a single bond or a substituted or unsubstituted divalent hydrocarbon group; R 12 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms; R 13 and R 14 are independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R 13 and R 14 Combined with R 13 and R 14 The carbon atoms to which the bond is attached together constitute a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms)

[0037] In formula (2), from the viewpoint of improving the copolymerizability of the monomer of the structural unit (I-1), R 11 It is preferably a hydrogen atom or a methyl group, and more preferably a methyl group. 1 The divalent hydrocarbon group represented by is preferably a divalent aromatic ring group, preferably a phenylene group or a naphthylene group. 1 In the case of a substituted divalent hydrocarbon group, examples of the substituent include a halogen atom (such as a fluorine atom) and the like.

[0038] As R 12 Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms. 12 In the case of a substituted monovalent hydrocarbon group, examples of the substituent include a halogen atom (such as a fluorine atom) and an alkoxy group.

[0039] As R 12 ~R14 The monovalent chain hydrocarbon group having 1 to 10 carbon atoms represented by , includes a linear or branched saturated hydrocarbon group having 1 to 10 carbon atoms, and a linear or branched unsaturated hydrocarbon group having 1 to 10 carbon atoms. 12 ~R 14 The monovalent chain hydrocarbon group having 1 to 10 carbon atoms represented is preferably a linear or branched saturated hydrocarbon group having 1 to 10 carbon atoms.

[0040] As R 12 ~R 14 The monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by the alicyclic hydrocarbon group may be a group obtained by removing one hydrogen atom from a monocyclic saturated alicyclic hydrocarbon, an unsaturated alicyclic hydrocarbon, or an alicyclic polycyclic hydrocarbon having 3 to 20 carbon atoms. Specific examples of the alicyclic hydrocarbons include cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane as monocyclic saturated alicyclic hydrocarbons; cyclopentene, cyclohexene, cycloheptene, cyclooctene, and cyclodecene as monocyclic unsaturated alicyclic hydrocarbons; and bicyclo[2.2.1]heptane (norbornane), bicyclo[2.2.2]octane, tricyclo[3.3.1.1 3,7 ]Decane (adamantane), tetracyclo[6.2.1.1 3,6 .0 2,7 ]Dodecane, etc.

[0041] As R 12 Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic ring of benzene, naphthalene, anthracene, indene, fluorene, and the like.

[0042] From the viewpoint of sufficiently removing the development residue and increasing the difference in dissolution contrast between the exposed portion and the unexposed portion with respect to the developer, R 12 It is preferably a monovalent substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, and more preferably a linear or branched monovalent saturated hydrocarbon group having 1 to 8 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 8 carbon atoms.

[0043] As R 13 and R 14 Combined with R 13 and R 14 The divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms formed by the carbon atoms to which the bonding is combined may be a group formed by removing two hydrogen atoms from the same carbon atom constituting a carbon ring of a monocyclic or polycyclic aliphatic hydrocarbon having the above carbon number. 13 and R 14 The divalent alicyclic hydrocarbon groups formed by bonding with each other may be monocyclic hydrocarbon groups or polycyclic hydrocarbon groups. 13 and R 14When the divalent alicyclic hydrocarbon groups formed by bonding to each other are polycyclic hydrocarbon groups, the polycyclic hydrocarbon groups may be bridged alicyclic hydrocarbon groups or condensed alicyclic hydrocarbon groups. In addition, the polycyclic hydrocarbon groups may be saturated hydrocarbon groups or unsaturated hydrocarbon groups. Saturated hydrocarbon groups are preferred.

[0044] Here, the term "bridged alicyclic hydrocarbon" refers to a polycyclic alicyclic hydrocarbon in which two non-adjacent carbon atoms in the carbon atoms constituting the alicyclic ring are bonded via a bond chain containing one or more carbon atoms. The term "condensed alicyclic hydrocarbon" refers to a polycyclic alicyclic hydrocarbon in which a plurality of alicyclic rings share a common edge (a bond between two adjacent carbon atoms). Specific examples of bridged alicyclic hydrocarbons include bicyclo[2.2.1]heptane (norbornane), bicyclo[2.2.2]octane, tricyclo[3.3.1.1 3,7 ]Decane (adamantane), tetracyclo[6.2.1.1 3,6 .0 2,7 ] dodecane, etc. Specific examples of the condensed alicyclic hydrocarbons include decahydronaphthalene, octahydronaphthalene, etc.

[0045] The saturated hydrocarbon group in the monocyclic alicyclic hydrocarbon group is preferably a cyclopentanediyl group, a cyclohexanediyl group, a cycloheptanediyl group or a cyclooctanediyl group. The unsaturated hydrocarbon group is preferably a cyclopentenyl group, a cyclohexenyl group, a cycloheptenediyl group or a cyclooctenediyl group. The polycyclic alicyclic hydrocarbon group is preferably a bridged aliphatic saturated hydrocarbon group, and more preferably a bicyclo[2.2.1]heptane-2,2-diyl group (norbornane-2,2-diyl group), a bicyclo[2.2.2]octane-2,2-diyl group, a tetracyclo[6.2.1.1 3,6 .0 2,7 ] dodecanediyl, or tricyclic [3.3.1.1 3,7 ]Decan-2,2-diyl (adamantane-2,2-diyl).

[0046] The polymer (A) particularly preferably contains a structural unit represented by the following formula (3) because the difference in dissolution rate between the exposed portion and the unexposed portion in the developer can be increased, thereby enabling formation of a finer pattern.

[0047] [Chemistry 4]

[0048]

[0049] (In formula (3), R 11 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or an alkoxyalkyl group; 1 is a single bond or a substituted or unsubstituted divalent hydrocarbon group; R 15 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms; R 16 and R 17are independently a monovalent chain hydrocarbon group having 1 to 8 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, or R 16 and R 17 Combined with R 16 and R 17 The carbon atoms to which the bond is attached together constitute a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms)

[0050] In formula (3), from the viewpoint of improving the copolymerizability of the monomers of the structural unit represented by formula (3), R 11 It is preferably a hydrogen atom or a methyl group, and more preferably a methyl group. 1 Specific examples and preferred examples include the following as Q in formula (2): 1 The groups exemplified are the same groups.

[0051] As R 15 , R 16 and R 17 As a specific example, R in the formula (2) can be cited. 12 , R 13 and R 14 Examples of corresponding carbon numbers in the description of . 15 It is preferably a linear or branched monovalent saturated hydrocarbon group having 1 to 5 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 8 carbon atoms, and more preferably a linear or branched monovalent saturated hydrocarbon group having 1 to 3 carbon atoms, or a monovalent monocyclic aliphatic hydrocarbon group having 3 to 5 carbon atoms. 16 and R 17 Preferably, it is a linear or branched monovalent chain saturated hydrocarbon group having 1 to 4 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, or R 16 and R 17 Combined with R 16 and R 17 The carbon atoms to which the bond is attached together constitute a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms.

[0052] Regarding the structural unit represented by the formula (3), among the above, it is particularly preferred that: R 15 and R 16 is an alkyl group having 1 to 4 carbon atoms, and R 17 is a cycloalkyl group having 3 to 8 carbon atoms, a norbornyl group or an adamantyl group, or R 15 is an alkyl group having 1 to 4 carbon atoms, and R 16 and R 17 For R 16 and R 17 The carbon atoms bonded to each other together with the bonded carbon atoms form a cycloalkanediyl group, a norbornanediyl group or an adamantanediyl group having 3 to 8 carbon atoms.

[0053] Specific examples of the structural unit (I) include structural units represented by the following formulae (2-1) to (2-7).

[0054] [Chemistry 5]

[0055]

[0056] (In formula (2-1) to formula (2-7), R 11 ~R 14 has the same meaning as in formula (2); i and j are each independently an integer of 0 to 4; h and g are each independently 0 or 1)

[0057] In formula (2-1) to formula (2-7), i and j are preferably 1 or 2, and more preferably 1. h and g are preferably 1. 12 Preferably it is methyl, ethyl or isopropyl. 13 and R 14 Preferred is methyl or ethyl.

[0058] Relative to all the structural units constituting the polymer (A), the content ratio of the structural unit (I) is preferably 10 mol% or more, more preferably 25 mol% or more, and further preferably 35 mol% or more. In addition, relative to all the structural units constituting the polymer (A), the content ratio of the structural unit (I) is preferably 80 mol% or less, more preferably 70 mol% or less, and further preferably 65 mol% or less. By setting the content ratio of the structural unit (I) to the range, the LWR performance of the present composition, or the critical dimension consistency (Critical Dimension Uniformity, CDU) performance and pattern shape as an indicator of uniformity of line width or hole diameter can be further improved.

[0059] When the polymer (A) contains the structural unit represented by the formula (3) as the structural unit (I), the content ratio of the structural unit represented by the formula (3) relative to all the structural units constituting the polymer (A) is preferably 10 mol% or more, more preferably 30 mol% or more, and further preferably 50 mol% or more. By setting the content ratio of the structural unit represented by the formula (3) to the above range, the difference in the dissolution rate of the exposed part and the unexposed part in the developer can be increased, so that a finer pattern can be formed. Furthermore, the polymer (A) may have only one structural unit (I), or may contain two or more in combination.

[0060] [Other structural units]

[0061] The polymer (A) may further contain a structural unit different from the structural unit (I) (hereinafter also referred to as "other structural unit") together with the structural unit (I). Examples of the other structural unit include the following structural unit (II) and structural unit (III).

[0062] Structural unit (II)

[0063] The polymer (A) may further include a structural unit having a polar group (hereinafter, also referred to as "structural unit (II)"). By including the structural unit (II) in the polymer (A), the solubility of the polymer (A) in the developer can be more easily adjusted, and the improvement of the micro-photographic performance such as resolution can be achieved. As structural unit (II), there can be listed: a structural unit including at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure and a sultone structure (hereinafter, also referred to as "structural unit (II-1)"), and a structural unit having a monovalent polar group (hereinafter, also referred to as "structural unit (II-2)").

[0064] Structural unit (II-1)

[0065] By introducing the structural unit (II-1) into the polymer (A), the solubility of the polymer (A) in the developer can be adjusted, or the adhesion of the resist film can be improved, or the etching resistance can be further improved. As the structural unit (II-1), for example, the structural units represented by the following formulas (4-1) to (4-10) can be listed.

[0066] [Chemistry 6]

[0067]

[0068] (In formula (4-1) to formula (4-10), R L1 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or an alkoxyalkyl group; R L2 and R L3 are independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a hydroxyl group, a hydroxymethyl group or a dimethylamino group; R L4 and R L5 are independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a hydroxyl group, a hydroxymethyl group or a dimethylamino group, or R L4 and R L5 Combined with R L4 and R L5 The carbon atoms to which the bond is attached together form a divalent alicyclic hydrocarbon group having 3 to 8 carbon atoms; L 5 is a single bond or a divalent linking group; X is an oxygen atom or a methylene group; p is an integer from 0 to 3; q is an integer from 1 to 3)

[0069] As R L4 and R L5 Combined with R L4 and R L5 The carbon atoms to which the carbon atoms are bonded together constitute a divalent alicyclic hydrocarbon group having 3 to 8 carbon atoms, and examples thereof include R in the above formula (2): 13 and R 14 The carbon number of the alicyclic hydrocarbon group is 3 to 8. One or more hydrogen atoms on the alicyclic hydrocarbon group may be substituted with a hydroxyl group.

[0070] As L 5 Examples of the divalent linking group include a linear or branched divalent chain hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, or a group comprising one or more of these hydrocarbon groups and at least one of -CO-, -O-, -NH- and -S-.

[0071] The structural unit (II-1) is preferably a structural unit represented by formula (4-2), formula (4-4), formula (4-6), formula (4-7) or formula (4-10) among formulas (4-1) to (4-10).

[0072] When the polymer (A) has the structural unit (II-1), the content ratio of the structural unit (II-1) is preferably 80 mol% or less, more preferably 70 mol% or less, and further preferably 65 mol% or less relative to all the structural units constituting the polymer (A). In addition, when the polymer (A) has the structural unit (II-1), the content ratio of the structural unit (II-1) is preferably 2 mol% or more, more preferably 5 mol% or more, and further preferably 10 mol% or more relative to all the structural units constituting the polymer (A). By setting the content ratio of the structural unit (II-1) to the above range, the microscopic performance such as resolution in the present composition can be further improved.

[0073] Structural unit (II-2)

[0074] The structural unit (II-2) can also be introduced into the polymer (A) to adjust the solubility of the polymer (A) in the developer, thereby improving the micro-photographic properties such as the resolution of the present composition. As the polar group possessed by the structural unit (II-2), for example, hydroxyl, carboxyl, cyano, nitro, sulfonamide, etc. can be listed. Among these, hydroxyl and carboxyl are preferred, and hydroxyl (especially alcoholic hydroxyl) is more preferred. Furthermore, the structural unit (II-2) is a structural unit different from the structural unit having a phenolic hydroxyl group described below (structural unit (III)).

[0075] Here, in this specification, the so-called "phenolic hydroxyl group" refers to a group in which a hydroxyl group is directly bonded to an aromatic hydrocarbon structure. The so-called "alcoholic hydroxyl group" refers to a group in which a hydroxyl group is directly bonded to an aliphatic hydrocarbon structure. In the alcoholic hydroxyl group, the aliphatic hydrocarbon structure to which the hydroxyl group is bonded may be a chain hydrocarbon group or an alicyclic hydrocarbon group.

[0076] Examples of the structural unit (II-2) include structural units represented by the following formulae. However, the structural unit (II-2) is not limited thereto.

[0077] [Chemistry 7]

[0078]

[0079]

[0080] (Where R A is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or an alkoxyalkyl group)

[0081] When the polymer (A) contains the structural unit (II-2), the content ratio of the structural unit (II-2) is preferably 2 mol% or more, more preferably 5 mol% or more, relative to all the structural units constituting the polymer (A). In addition, the content ratio of the structural unit (II-2) is preferably 30 mol% or less, more preferably 25 mol% or less, relative to all the structural units constituting the polymer (A). By setting the content ratio of the structural unit (II-2) to the above range, the micro-imaging performance such as resolution in the present composition can be further improved.

[0082] Structural unit (III)

[0083] The polymer (A) may further include a structural unit having a phenolic hydroxyl group (hereinafter, also referred to as "structural unit (III)"). The inclusion of structural unit (III) in the polymer (A) can improve etching resistance and improve the difference in developer solubility (dissolution contrast) between the exposed portion and the unexposed portion, which is preferred in terms of the above aspects.

[0084] In particular, in pattern formation using exposure with radiation having a wavelength of 50 nm or less, such as electron beams or EUV, the polymer (A) having the structural unit (III) can be preferably used. When used in pattern formation using exposure with radiation having a wavelength of 50 nm or less, the polymer (A) preferably has the structural unit (III).

[0085] The structural unit (III) is not particularly limited as long as it contains a phenolic hydroxyl group. Specific examples of the structural unit (III) include structural units derived from hydroxystyrene or a derivative thereof, and structural units derived from a (meth)acrylic acid compound having a hydroxybenzene structure.

[0086] When obtaining a polymer having the structural unit (III) as the polymer (A), the polymer (A) may be provided with the structural unit (III) by carrying out polymerization in a state where the phenolic hydroxyl group is protected by an alkali dissociable group or the like during polymerization, and then hydrolyzing and deprotecting the phenolic hydroxyl group. The structural unit that provides the structural unit (III) by hydrolysis is preferably at least one selected from the group consisting of the structural unit represented by the following formula (5-1) and the structural unit represented by the following formula (5-2).

[0087] [Chemistry 8]

[0088]

[0089] (In formula (5-1) and formula (5-2), R P1 A is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or an alkoxyalkyl group; 3 is a substituted or unsubstituted divalent aromatic ring group; R P2 is a monovalent hydrocarbon group or alkoxy group having 1 to 20 carbon atoms)

[0090] A 3 The aromatic ring group represented is a group obtained by removing two hydrogen atoms from a substituted or unsubstituted aromatic ring. The aromatic ring is preferably a hydrocarbon ring, for example, aromatic hydrocarbon rings such as benzene, naphthalene, and anthracene. 3 It is preferably a group obtained by removing two hydrogen atoms from a ring part of substituted or unsubstituted benzene or naphthalene, and more preferably a substituted or unsubstituted phenylene group. Examples of the substituent include halogen atoms such as a fluorine atom.

[0091] As R P2 The monovalent hydrocarbon group having 1 to 20 carbon atoms represented by can be exemplified as R in the structural unit (I): 12 The alkoxy group is exemplified by a monovalent hydrocarbon group having 1 to 20 carbon atoms. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a tert-butoxy group. P2 Preferred are alkyl or alkoxy groups among these, and among them, methyl or tert-butoxy groups are preferred.

[0092] In the case of obtaining a radiation-sensitive composition for exposure to radiation having a wavelength of 50 nm or less, the content of the structural unit (III) in the polymer (A) is preferably 15 mol% or more, more preferably 20 mol% or more, relative to all the structural units constituting the polymer (A). In addition, the content of the structural unit (III) in the polymer (A) is preferably 65 mol% or less, more preferably 60 mol% or less, relative to all the structural units constituting the polymer (A).

[0093] Synthesis of polymer (A)

[0094] The polymer (A) can be synthesized, for example, by polymerizing monomers providing each structural unit in an appropriate solvent using a radical polymerization initiator or the like.

[0095] As free radical polymerization initiators, there can be listed: azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyric acid dimethyl ester and other azo-based free radical initiators; benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide and other peroxide-based free radical initiators, etc. Among these, AIBN and 2,2'-azobisisobutyric acid dimethyl ester are preferred, and AIBN is more preferred. These free radical initiators can be used alone or in combination of two or more.

[0096] Examples of the solvent used for the polymerization include alkanes, cycloalkanes, aromatic hydrocarbons, halogenated hydrocarbons, saturated carboxylic acid esters, ketones, ethers, and alcohols. As specific examples of these, as alkanes, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, etc. can be listed; as cycloalkanes, cyclohexane, cycloheptane, cyclooctane, decahydronaphthalene, norbornane, etc. can be listed; as aromatic hydrocarbons, benzene, toluene, xylene, ethylbenzene, cumene, etc. can be listed; as halogenated hydrocarbons, chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene, etc. can be listed; as saturated carboxylic acid esters, ethyl acetate, n-butyl acetate, isobutyl acetate, methyl propionate, etc. can be listed; as ketones, acetone, methyl ethyl ketone, 4-methyl-2-pentanone, 2-heptanone, etc. can be listed; as ethers, tetrahydrofuran, dimethoxyethanes, diethoxyethanes, etc. can be listed; as alcohols, methanol, ethanol, 1-propanol, 2-propanol, 4-methyl-2-pentanol, etc. can be listed. The solvent used in the polymerization may be used alone or in combination of two or more.

[0097] The reaction temperature during the polymerization is usually 40 to 150° C., preferably 50 to 120° C. The reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.

[0098] The weight average molecular weight (Mw) of the polymer (A) obtained by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 or more, more preferably 2,000 or more, further preferably 3,000 or more, and further preferably 4,000 or more. In addition, the Mw of the polymer (A) is preferably 50,000 or less, more preferably 30,000 or less, further preferably 20,000 or less, and further preferably 15,000 or less. By setting the Mw of the polymer (A) to the range, it is suitable in terms of improving the coating properties of the present composition, improving the heat resistance of the obtained resist film, and fully suppressing the development defects.

[0099] The ratio (Mw / Mn) of the Mw of the polymer (A) to the polystyrene-equivalent number average molecular weight (Mn) obtained by GPC is preferably 5.0 or less, more preferably 3.0 or less, and still more preferably 2.0 or less. Mw / Mn is usually 1.0 or more.

[0100] In the present composition, relative to the total amount of solid components contained in the present composition (that is, the total mass of components other than the solvent components contained in the present composition), the content ratio of polymer (A) is preferably 70% by mass or more, more preferably 75% by mass or more, and further preferably 80% by mass or more. In addition, relative to the total amount of solid components contained in the present composition, the content ratio of polymer (A) is preferably 99% by mass or less, more preferably 98% by mass or less, and further preferably 95% by mass or less. Furthermore, polymer (A) is preferably a base resin constituting the present composition. In this specification, so-called "base resin" refers to a polymer component accounting for more than 50% by mass in the total amount of solid components contained in the present composition. The present composition may include only one polymer (A) or may include two or more.

[0101] <Compound (B)>

[0102] The compound (B) is a compound represented by the following formula (1).

[0103] [Chemistry 9]

[0104]

[0105] (In formula (1), L 1A group having a (thio)acetal ring in which two oxygens, two sulfurs, or one oxygen and one sulfur are bonded to the same carbon through two methylene groups of a monocyclic saturated aliphatic hydrocarbon ring being substituted with (thio)ether bonds, or a group represented by the following formula (L-2);

[0106] [Chemistry 10]

[0107]

[0108] (In formula (L-2), L 2 is a bridged alicyclic group having 7 or more carbon atoms; 3 is a single bond, oxygen atom, sulfur atom or -SO2-; d is 1 or 2; "* 3 " indicates that 1 or carboxyl bond)

[0109] W 1 is a single bond or a (b+1)-valent organic group having 1 to 40 carbon atoms; R 1 , R 2 and R 3 are independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a fluorine atom or a fluoroalkyl group; R f is a fluorine atom or a fluoroalkyl group; a is an integer from 0 to 8; b is an integer from 1 to 4; d is 1 or 2; wherein, 1 When a is 2 or more, the plurality of R 1 Same or different, multiple R 2 The same or different; when d is 2, multiple W 1 The same or different, multiple b are the same or different; M + is a monovalent cation)

[0110] Compound (B) can function as a radiation-sensitive acid generator. A radiation-sensitive acid generator (hereinafter, also referred to as "acid generator") is a substance that generates an acid in a radiation-sensitive composition by irradiating radiation to the composition. The acid generator is typically an onium salt comprising a radiation-sensitive onium cation and an organic anion, preferably a compound that induces the dissociation of an acid-dissociable group under normal conditions by generating a strong acid such as sulfonic acid, imidic acid, or methylated acid. Furthermore, the "normal conditions" described here refer to conditions of post-exposure baking (PEB) at 110°C for 60 seconds. It is preferred that compound (B) and polymer (A) are formulated into the present composition together, and the acid generated from compound (B) is used to dissociate the acid-dissociable group of polymer (A) to generate an acid group, thereby making the dissolution rate of polymer (A) in the developer different between the exposed part and the unexposed part.

[0111] By including compound (B) as an acid generator in the present composition, the diffusion length of the acid generated by exposure to the present composition can be appropriately shortened. Thus, by the present composition, a resist film showing high sensitivity and excellent micro-image characteristics such as LWR performance or CDU performance and pattern rectangularity can be formed. In addition, the remaining insoluble components in the pattern after development can be reduced, thereby reducing development defects.

[0112] In the formula (1), L 1 The group represented has a (thio)acetal ring, or is a group represented by the formula (L-2). Here, the so-called (thio)acetal ring refers to a ring structure including a ring in which two oxygens, two sulfurs, or one oxygen and one sulfur are bonded to the same carbon by replacing two methylene groups constituting a monocyclic saturated aliphatic hydrocarbon ring (for example, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, etc.) with (thio)ether bonds (hereinafter also referred to as "(thio)acetal ring"). Furthermore, the (thio)acetal ring does not include a ring having heteroatoms other than oxygen and sulfur in the ring skeleton, or a ring having carbon directly bonded to a heteroatom (for example, carbon bonded to a pendant oxy group) in the ring skeleton. Therefore, for example, a ring having an ester bond (-C(=O)-O-) in the ring skeleton does not correspond to a "(thio)acetal ring".

[0113] The number of ring members of the (thio)acetal ring is preferably 5 to 18, more preferably 5 to 10, and even more preferably 5 or 6. The cyclic (thio)acetal structure may have a structure in which the carboxyl group in the formula (1) is directly bonded to the ring portion (i.e., the (thio)acetal ring), or may have a structure in which other substituents other than the carboxyl group are bonded to the (thio)acetal ring. Examples of the other substituents include substituted or unsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms, and among these, monovalent chain hydrocarbon groups having 1 to 10 carbon atoms are preferred, and alkyl groups having 1 to 3 carbon atoms are more preferred.

[0114] Yu L 1 In the case of a group having a (thio)acetal ring, L 1 As long as it has a cyclic (thio)acetal structure. 1 It may be a compound having both a (thio)acetal ring and a divalent linking group, and bonded to the group "-C(R 1 )(R 2 )-" or "-C(R f )(R 3 )-”. In addition, L 1 The (thio)acetal ring may be a single ring or a part of a ring constituting a polycyclic structure. 1 When the (thio)acetal ring possessed by L is a part of a ring constituting a polycyclic structure, L 1The (thio)acetal ring in may be a part of a ring constituting a condensed ring structure condensed with other rings, or may be a part of a ring constituting a spiro ring structure sharing carbon with other rings. 1 When the (thio)acetal ring in is a part of a ring constituting a condensed ring structure condensed with another ring, the other ring may be a monocyclic alicyclic ring or an aromatic ring, or a bridged alicyclic ring. 1 In the case where the (thio) acetal ring is a part of a ring constituting a spirocyclic structure sharing carbon with other rings, the other ring may be a monocyclic alicyclic ring or an aromatic ring, or a bridged alicyclic ring. The ring forming a polycyclic structure together with the (thio) acetal ring may also have a substituent. Examples of the substituent include: a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a hydroxyl group, a carboxyl group, a cyano group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkyloxycarbonyl group, a cycloalkylcarbonyloxy group, etc.

[0115] From the viewpoint of ease of synthesis, L 1 The (thio)acetal ring is preferably an acetal ring in which both of the methylene groups constituting the monocyclic saturated aliphatic hydrocarbon ring are substituted with ether bonds.

[0116] Yu L 1 When L is a group represented by the formula (L-2), 2 The bridged alicyclic group with a carbon number of 7 or more represented may be an alicyclic hydrocarbon group or an aliphatic heterocyclic group. Here, the so-called "bridged alicyclic group" refers to an n-valent group (n is an integer greater than 1) after removing n hydrogen atoms from a polycyclic alicyclic hydrocarbon or an aliphatic heterocycle bonded by a bond chain containing one or more atoms between two non-adjacent carbon atoms in the carbon atoms constituting the alicyclic hydrocarbon or aliphatic heterocycle. The bridged alicyclic group may also have a substituent in the ring portion. The carbon number of the ring (bridged alicyclic hydrocarbon or bridged aliphatic heterocycle) possessed by the bridged alicyclic group is preferably greater than 7, and more preferably greater than 8. In addition, the carbon number of the ring possessed by the bridged alicyclic group is, for example, less than 20.

[0117] About L 2 Specific examples of the ring possessed by the bridged cyclic alicyclic group represented by include, as bridged cyclic alicyclic hydrocarbons, bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, tricyclo[3.3.1.1 3,7 ]Decane, tetracyclo[6.2.1.1 3,6 .0 2,7 ] dodecane, etc.; as bridged aliphatic heterocyclic rings, 7-oxabicyclo [2.2.1] heptane, 7-azabicyclo [2.2.1] heptane, 9-oxatetracyclo [6.2.1.1 3,6 .0 2,7 ] dodecane, etc. 2When the bridged alicyclic ring represented by the above-mentioned has a substituent based on the ring part, examples of the substituent include the same groups as those exemplified as the substituents that the ring forming the polycyclic structure together with the (thio)acetal ring may have.

[0118] X 3 It is a single bond, an oxygen atom, a sulfur atom or -SO2-. Among these, a single bond or an oxygen atom is preferred from the viewpoint of ease of synthesis.

[0119] W 1 The (b+1)-valent organic group having 1 to 40 carbon atoms represented may be a group having only a chain structure or a group having a cyclic structure. Examples of the (b+1)-valent organic group include a substituted or unsubstituted (b+1)-valent hydrocarbon group having 1 to 40 carbon atoms, a (b+1)-valent group in which any methylene group in a substituted or unsubstituted hydrocarbon group is substituted with -O-, -CO- or -COO-, a (b+1)-valent group having an aliphatic heterocyclic structure having 3 to 40 carbon atoms (except for a cyclic (thio)acetal structure), and a (b+1)-valent group having an aromatic heterocyclic structure having 4 to 40 carbon atoms.

[0120] Yu W 1 In the case of a (b+1)-valent hydrocarbon group, examples of the hydrocarbon group include: a (b+1)-valent chain hydrocarbon group having 1 to 40 carbon atoms, a (b+1)-valent alicyclic hydrocarbon group having 3 to 40 carbon atoms, and a (b+1)-valent aromatic hydrocarbon group having 6 to 40 carbon atoms. Specific examples of these include R in the formula (2): 12 The monovalent hydrocarbon group exemplified in the description of further removing b hydrogen atoms, etc. 1 The (b+1)-valent hydrocarbon group represented by is preferably a (b+1)-valent chain hydrocarbon group having 1 to 6 carbon atoms, a (b+1)-valent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a (b+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms. From the viewpoint of suppressing the diffusion of acid generated by exposure or the viewpoint of suppressing the occurrence of development defects, among these, W 1 The (b+1)-valent hydrocarbon group represented is more preferably a (b+1)-valent alicyclic hydrocarbon group having 3 to 20 carbon atoms or a (b+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, further preferably a (b+1)-valent polycyclic alicyclic hydrocarbon group having 7 to 20 carbon atoms or a (b+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms, further preferably a (b+1)-valent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0121] Yu W 1 In the case of a substituted (b+1)-valent hydrocarbon group, examples of the substituent include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a hydroxyl group, a cyano group, an alkoxy group, and an alkoxycarbonyl group.

[0122] Yu W 1 In the case of a (b+1)-valent group having an aliphatic heterocyclic structure, W 1 The aliphatic heterocyclic structure may include a cyclic ether structure (excluding a cyclic (thio)acetal structure), a lactone structure, a cyclic carbonate structure, a sultone structure, a thioxane structure, etc. The aliphatic heterocyclic structure may be a monocyclic structure or a polycyclic structure, and may also be a bridged ring structure, a condensed ring structure, or a spiro ring structure. 1 The aliphatic heterocyclic structure represented may be a combination of two or more of a bridged ring structure, a condensed ring structure, and a spiro ring structure.

[0123] From the viewpoint of suppressing the diffusion of the acid derived from the compound (B) and improving the quality of the resist pattern, and from the viewpoint of improving the transparency of the resist film and improving the hydrophobicity of the film to further increase the difference in the dissolution rate of the exposed portion and the unexposed portion with respect to the developer, W 1 The (b+1)-valent organic group represented by is preferably a (b+1)-valent group having a cyclic structure. 1 The (b+1)-valent organic group represented preferably has an alicyclic hydrocarbon structure, an aliphatic heterocyclic structure, an aromatic hydrocarbon structure or an aromatic heterocyclic structure, and more preferably has an alicyclic hydrocarbon structure, an aliphatic heterocyclic structure or an aromatic hydrocarbon structure.

[0124] As W 1 Specific examples of the (b+1)-valent organic group represented by the formula (a) are groups having an alicyclic hydrocarbon structure, and examples thereof include groups having a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, a cyclooctane structure, a cyclopentene structure, a cyclohexene structure, a bicyclo[2.2.1]heptane structure, a bicyclo[2.2.2]octane structure, a tricyclo[3.3.1.1 3,7 ]Decane structure, tetracyclic [6.2.1.1 3,6 .0 2,7 ] a group having a dodecane structure, a decahydronaphthalene structure or an octahydronaphthalene structure.

[0125] As W 1 Specific examples of the (b+1)-valent organic group represented as a group having an aliphatic heterocyclic structure include a group having a lactone structure, a cyclic carbonate structure, a sultone structure, or a thioxane structure.

[0126] As W 1 Specific examples of the (b+1)-valent organic group represented as a group having an aromatic hydrocarbon structure include a group having a benzene ring structure, a naphthalene ring structure, an indene ring structure, an anthracene ring structure, a phenanthrene ring structure or a fluorene ring structure.

[0127] As W 1Specific examples of the (b+1)-valent organic group represented as a group having an aromatic heterocyclic structure include a group having a furan structure or a thiophene structure.

[0128] In the above, W 1 The (b+1)-valent organic group represented by is more preferably a bridged aliphatic saturated hydrocarbon structure, a bridged aliphatic heterocyclic structure or an aromatic hydrocarbon structure, and more preferably an aromatic hydrocarbon structure. 1 It is preferred that the polyol contains no fluorine atoms.

[0129] In the formula (1), L 1 Partial structure of the bond "-W 1 -(COOH) b "One or more W 1 In the case of a (b+1)-valent organic group having 1 to 40 carbon atoms, it is preferred that W 1 is a group having a ring structure, and one or more carboxyl groups are directly bonded to W 1 In this case, W 1 The ring in is preferably an alicyclic hydrocarbon ring, an aliphatic heterocyclic ring or an aromatic hydrocarbon ring, more preferably a bridged aliphatic saturated hydrocarbon ring, a bridged aliphatic heterocyclic ring or an aromatic hydrocarbon ring, and further preferably an aromatic hydrocarbon ring. Specific examples of these rings are as described above.

[0130] In the formula (1), L 1 Partial structure of the bond "-W 1 -(COOH) b "One or more W 1 is a single bond, and L 1 In the case of a group having a (thio)acetal ring, L is preferably 1 With L 1 The (thio)acetal ring in the x ”), and in the ring R x Or a carboxyl group is bonded to the (thio)acetal ring. x It is preferably an aliphatic hydrocarbon ring, an aromatic hydrocarbon ring or an aliphatic heterocyclic ring, which may be a monocyclic ring or a polycyclic ring. x In the case of multiple rings, ring R x It may be a ring having any of a bridged ring structure, a condensed ring structure, and a spiro ring structure. x In the case of multiple rings, ring R x It may also be a combination of two or more of a bridged ring structure, a condensed ring structure and a spiro ring structure.

[0131] As ring R xSpecific examples include: monocyclic aliphatic hydrocarbon rings such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclopentene, cyclohexene, cycloheptene, cyclooctene and cyclodecene; bicyclo[2.2.1]heptane (norbornane), bicyclo[2.2.2]octane, tricyclo[3.3.1.1 3,7 ]Decane (adamantane), tetracyclo[6.2.1.1 3,6 .0 2,7 ] Polycyclic aliphatic hydrocarbon rings such as dodecane, decahydronaphthalene and octahydronaphthalene; polycyclic saturated heterocyclic rings having a lactone structure, a cyclic carbonate structure, a sultone structure or a thioxane structure; polycyclic aromatic hydrocarbon rings such as a naphthalene ring, an indene ring, anthracene ring, a phenanthrene ring and a fluorene ring.

[0132] From the viewpoint of suppressing the diffusion of the acid generated by exposure, the 1 Partial structure of the bond "-W 1 -(COOH) b "One or more W 1 In the case of a single bond, L 1 The ring R x It is preferably a polycyclic aliphatic hydrocarbon ring, a polycyclic saturated heterocyclic ring or a polycyclic aromatic hydrocarbon ring, more preferably a bridged aliphatic saturated hydrocarbon ring, a bridged aliphatic heterocyclic ring or a polycyclic aromatic hydrocarbon ring, and further preferably a bridged aliphatic saturated hydrocarbon ring. 1 Partial structure of the bond "-W 1 -(COOH) b "One or more of the W 1 is a single bond, and the carboxyl group is bonded to L 1 In the case of the ring in the embodiment, it is preferable that the ring R x There is a carboxyl group directly bonded to it.

[0133] Furthermore, Ring R x It may have a substituent other than a carboxyl group. Examples of the substituent include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a hydroxyl group, a cyano group, an alkoxy group, and an alkoxycarbonyl group.

[0134] In the formula (1), L 1 In the case of a group having a (thio)acetal ring, L 1 The orientation of the (thio)acetal ring is not particularly limited. 1 The (thio)acetal ring may have two oxygens, two sulfurs, or one oxygen and one sulfur bonded to a carbon located at the "-SO3 - " side, or the reverse side. From the perspective of ease of synthesis, L 1The (thio)acetal ring preferably has two oxygens, two sulfurs, or one oxygen and one sulfur bonded to the carbon located at the position adjacent to "-SO3 - "The opposite side (i.e., W in the formula (1) 1 Specifically, in L 1 In the case of a group having a (thio)acetal ring, L 1 Preferably, it is a group represented by the following formula (L-1). 1 With X 2 The bonded carbon is "a carbon bonded to two oxygens, two sulfurs, or one oxygen and one sulfur" in the (thio)acetal ring.

[0135] [Chemistry 11]

[0136]

[0137] (In formula (L-1), X 1 and X 2 are independently an oxygen atom or a sulfur atom; R 41 is a single bond or an alkanediyl group having 1 to 10 carbon atoms; r is 1 or 2; when r is 1, 44 and R 45 , R 44 is a single bond, R 45 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, or represents R 44 and R 45 Combined with each other and with the carbon atoms to which they are bonded and the (thio)acetal ring in formula (L-1) to form a spiro ring structure; when r is 2, R 44 is a single bond; wherein, in the formula (1), 1 Partial structure of the bond "-W 1 -(COOH) b "W" 1 In the partial structure with a single bond, b is 1; R 42 , R 43 , Y 1 and Y 2 Satisfies (i), (ii) or (iii) below;

[0138] (i)R 42 is an alkanediyl group having 1 to 10 carbon atoms; R 43 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; 1 is a single bond or a divalent linking group; Y 2 is a single bond;

[0139] (ii) R 42 and Y 1represents a ring structure that is combined with each other and forms a condensed ring structure together with the carbon atoms to which they are bonded and the (thio)acetal ring in formula (L-1); R 43 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; 2 It is a single bond or a divalent linking group;

[0140] (iii) R 43 and Y 1 represents a ring structure that is combined with each other and forms a spiro ring structure together with the carbon atoms to which they are bonded and the (thio)acetal ring in formula (L-1); R 42 is an alkanediyl group having 1 to 10 carbon atoms; 2 It is a single bond or a divalent linking group;

[0141] "* 1 " represents the same as W in the formula (1) 1 or carboxyl bond; "*" indicates a bond)

[0142] In the formula (L-1), X 1 and X 2 Preferably, they are all oxygen atoms or all sulfur atoms, and more preferably, they are all oxygen atoms.

[0143] R 41 The alkanediyl group having 1 to 10 carbon atoms may be linear or branched. From the viewpoint of ease of synthesis, the alkanediyl group preferably has 1 to 3 carbon atoms, and more preferably is a methylene group.

[0144] R 41 It is preferably a single bond or a linear or branched alkanediyl group having 1 to 3 carbon atoms, and more preferably a single bond or a methylene group.

[0145] About R 44 and R 45 , in represents R 44 and R 45 In the case of a ring structure that is bonded to each other and forms a spiro ring structure together with the carbon atoms to which these are bonded and the (thio)acetal ring, specific examples of the ring that forms a spiro ring structure together with the (thio)acetal ring include ring R x The rings exemplified in the description of . 44 and R 45 The spiro ring structure bonded to each other and formed together with the (thio)acetal ring preferably has a bridged aliphatic saturated hydrocarbon ring, a bridged aliphatic heterocycle or a polycyclic aromatic hydrocarbon ring, more preferably has a bridged aliphatic saturated hydrocarbon ring or a bridged aliphatic heterocycle, and further preferably has a bridged aliphatic saturated hydrocarbon ring.

[0146] Yu R 45 In the case of a monovalent hydrocarbon group having 1 to 10 carbon atoms, specific examples of the monovalent hydrocarbon group include the following:12 The same groups as those exemplified for the corresponding carbon numbers in the monovalent hydrocarbon groups exemplified in the description of 45 The monovalent hydrocarbon group having 1 to 10 carbon atoms represented is preferably a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 10 carbon atoms, more preferably a linear or branched saturated chain hydrocarbon group having 1 to 4 carbon atoms, or a monocyclic aliphatic hydrocarbon group having 3 to 8 carbon atoms, and further preferably an alkyl group having 1 to 3 carbon atoms.

[0147] Yu R 42 , R 43 , Y 1 and Y 2 When (i) is satisfied, R 42 The alkanediyl group having 1 to 10 carbon atoms represented by may be linear or branched. 42 An alkanediyl group having 1 to 3 carbon atoms is preferred, and a methylene group is more preferred.

[0148] Yu Y 1 When the group represented by is a divalent linking group, examples of the divalent linking group include a carbonyl group, a carbonyloxy group, a 2 -R 20 -O-,* 2 -R 20 -CO-,* 2 -R 20 -CO-O-,* 2 -R 20 -O-CO-(where R 20 is an alkanediyl group having 1 to 3 carbon atoms, "* 2 " indicates that the 41 , R 42 and R 43 From the viewpoint of suppressing the diffusion of the acid generated by the exposure to the present composition and the viewpoint of the ease of synthesis, Y 1 It is preferably a single bond, a carbonyl group, a carbonyloxy group or -CH2-O-CO-, and more preferably a single bond.

[0149] As R 43 Specific examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by include the following: 12 The same groups as those exemplified for the corresponding carbon numbers in the monovalent hydrocarbon groups exemplified in the description of . 43 It is preferably a hydrogen atom, a linear or branched saturated hydrocarbon group having 1 to 4 carbon atoms, or a monocyclic aliphatic hydrocarbon group having 3 to 8 carbon atoms.

[0150] Yu R 42 , R 43 , Y 1and Y 2 When the above (ii) is satisfied, R 42 and Y 1 Specific examples of the rings that are bonded to each other and form a condensed ring structure together with the carbon atoms to which they are bonded and the (thio)acetal ring include ring R x The rings exemplified in the description of . 42 and Y 1 The condensed ring structure formed by bonding to each other preferably has a bridged aliphatic saturated hydrocarbon ring, a bridged aliphatic heterocycle, or a polycyclic aromatic hydrocarbon ring, and more preferably has a bridged aliphatic saturated hydrocarbon ring or a bridged aliphatic heterocycle.

[0151] About R 43 Specific examples and preferred examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms are the same as those described in the above (i).

[0152] About Y 2 Specific examples and preferred examples when the group represented by is a divalent linking group are the same as those of Y 1 The description of the specific examples and preferred examples is the same.

[0153] Yu R 42 , R 43 , Y 1 and Y 2 When the above (iii) is satisfied, R 43 and Y 1 Specific examples of the rings that are bonded to each other and form a spiro ring structure together with the carbon atoms and the (thio)acetal ring to which they are bonded include ring R x The rings exemplified in the description of . 43 and Y 1 The spiro ring structure bonded to each other and formed together with the (thio)acetal ring preferably has a bridged aliphatic saturated hydrocarbon ring, a bridged aliphatic heterocycle or a polycyclic aromatic hydrocarbon ring, and more preferably has a bridged aliphatic saturated hydrocarbon ring or a bridged aliphatic heterocycle.

[0154] R 42 The alkanediyl group having 1 to 10 carbon atoms may be linear or branched. 42 An alkanediyl group having 1 to 3 carbon atoms is preferred, and a methylene group is more preferred.

[0155] About Y 2 Specific examples and preferred examples when the group represented by is a divalent linking group are the same as those of Y 1 The description of the specific examples and preferred examples is the same.

[0156] As L in the formula (1) 1 Partial structure of the bond "-W 1 -(COOH) b”, in the case of having W 1 In the case of a partial structure of a (b+1)-valent organic group, "-W 1 -(COOH) b The b carboxyl groups in " can be bonded to W 1 In terms of further improving the effect of suppressing development defects, the L 1 In the case of a group having a (thio)acetal ring, W 1 Partial structure of an organic group with a valence of (b+1) "-W 1 -(COOH) b "One or more of the b carboxyl groups in the 1 More preferably, all b carboxyl groups are bonded to W 1 In addition, as L in the formula (1), 1 Partial structure of the bond "-W 1 -(COOH) b ”, in the case of having W 1 is a partial structure of a single bond, and L 1 In the case of a group having a (thio)acetal ring, "-W 1 -(COOH) b The b carboxyl groups in " are bonded to L 1 Ring R x Or on the (thio)acetal ring.

[0157] That is, in L 1 In the case of a group having a (thio)acetal ring, the compound (B) is preferably a group having L in the formula (1). 1 Partial structure of the bond "-W 1 -(COOH) b "One or more of the following necessary conditions (I) or (II) are satisfied.

[0158] (I) in the formula (1) 1 Partial structure of the bond "-W 1 -(COOH) b "In more than one of the 1 is a group having a ring structure, one or more carboxyl groups are bonded to W 1 On the ring in.

[0159] (II) in the formula (1) 1 Partial structure of the bond "-W 1 -(COOH) b "In more than one of the 1 is a single bond, L in the formula (1) 1 With L 1The (thio)acetal rings in the x , and in the ring R x Or a carboxyl group is bonded to the (thio)acetal ring.

[0160] When compound (B) satisfies the necessary condition (I), W bonded to the carboxyl group is 1 The ring in the formula (1) is preferably an aliphatic hydrocarbon ring, an aliphatic heterocyclic ring or an aromatic ring, and more preferably a bridged aliphatic saturated hydrocarbon ring, a bridged aliphatic heterocyclic ring or an aromatic ring. Among these, from the viewpoint of improving the effect of suppressing development defects, it is preferred that at least one of the carboxyl groups in the formula (1) is bonded to W 1 More preferably, all the carboxyl groups in formula (1) are bonded to W 1 The aromatic ring to which the carboxyl group in formula (1) is bonded is preferably an aromatic hydrocarbon ring. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring, and are preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.

[0161] When compound (B) satisfies requirement (II), L bonded to the carboxyl group 1 Ring R x Preferred specific examples include W 1 When the ring R is a single bond x those illustrated in the description.

[0162] Yu L 1 When W is a group represented by the formula (L-2), 1 It is preferably a single bond or a substituted or unsubstituted chain hydrocarbon group, more preferably a single bond, an alkanediyl group having 1 to 3 carbon atoms, or a fluoroalkanediyl group having 1 to 3 carbon atoms, and still more preferably a single bond.

[0163] Furthermore, it is considered that the compound (B) has the same 1 or L 1 The bonded carboxyl group improves the solubility of compound (B) relative to the alkaline developer, thereby reducing the insoluble components in the exposed part. As a result, it is believed that the LWR performance and development defect suppression performance of the present composition can be optimized. It is believed that, especially in the case where the carboxyl group possessed by compound (B) is directly bonded to the ring, the degree of freedom of the carboxyl group becomes smaller, thereby suppressing the aggregation of compound (B), further reducing the insoluble components remaining after development, and further improving the suppression effect of development defects. In addition, it is believed that when the present composition is applied to a negative type, the dissolution suppression effect relative to the organic solvent developer is improved, thereby optimizing the CDU performance.

[0164] As R 1 , R 2 or R 3The monovalent hydrocarbon group represented by can be exemplified by the same group as R in the formula (2) 12 The same groups as those exemplified for the corresponding carbon numbers in the monovalent hydrocarbon groups exemplified in the description of . 1 , R 2 or R 3 The monovalent hydrocarbon group having 1 to 10 carbon atoms represented is preferably a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms, further preferably an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group, an ethyl group or an isopropyl group.

[0165] As R 1 , R 2 , R 3 or R f The fluoroalkyl group represented by may be a linear or branched fluoroalkyl group having 1 to 10 carbon atoms. Specific examples thereof include trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, 2,2,3,3,3-pentafluoropropyl, 1,1,1,3,3,3-hexafluoropropyl, heptafluoro-n-propyl, heptafluoro-isopropyl, nonafluoro-n-butyl, nonafluoro-isobutyl, nonafluoro-tert-butyl, 2,2,3,3,4,4,5,5-octafluoro-n-pentyl, tridecafluoro-n-hexyl, and 5,5,5-trifluoro-1,1-diethylpentyl. 1 , R 2 , R 3 and R f The fluoroalkyl group represented is preferably a linear or branched fluoroalkyl group having 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.

[0166] R 1 and R 2 It is preferably a hydrogen atom, a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom, a fluorine atom or a trifluoromethyl group. 3 and R f Preferably, both of them are fluorine atoms or trifluoroalkyl groups. 3 and R f Both are fluorine atoms or trifluoromethyl groups, and preferably R 3 and R f Both are fluorine atoms. From the viewpoint of suppressing diffusion of an acid generated by exposure to the present composition, a is preferably 0 to 5, more preferably 0 to 3, and still more preferably 0 or 1. b is preferably 1 or 2.

[0167] About cations

[0168] In the formula (1), M + As a monovalent cation. +The monovalent cation represented by M includes, for example, sulfonium cation, iodonium cation, quaternary ammonium cation, etc. In terms of forming a high-quality resist film with high LWR performance or CDU performance, among these, M + Preferably, it is a sulfonium cation or an iodonium cation. Specific examples of sulfonium cations include cations represented by the following formula (X-1), formula (X-2), formula (X-3) or formula (X-4). Specific examples of iodonium cations include cations represented by the following formula (X-5) or formula (X-6).

[0169] [Chemistry 12]

[0170]

[0171] In formula (X-1), R a1 , R a2 and R a3 are independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, an alkoxy group, an alkylcarbonyloxy group or a cycloalkylcarbonyloxy group, a monocyclic or polycyclic cycloalkyl group having 3 to 12 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, a hydroxyl group, a halogen atom, -OSO2-R P 、-SO2-R Q 、-SR T , or R a1 , R a2 and R a3 The ring structure may contain heteroatoms (oxygen atoms or sulfur atoms, etc.) between the carbon-carbon bonds forming the skeleton. P , R Q and R T are independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted monovalent alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms. k1, k2 and k3 are independently an integer of 0 to 5. a1 ~R a3 and R P , R Q and R T In the case of multiple R a1 ~R a3 and R P , R Q and R T The same or different from each other. a1 , R a2 and R a3 In the case of having a substituent, the substituent may be a hydroxyl group, a halogen atom, a carboxyl group, a protected hydroxyl group, a protected carboxyl group, -OSO2-R P 、-SO2-RQ 、-SR T .

[0172] In formula (X-2), R b1 It is a substituted or unsubstituted alkyl or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted acyl group having 2 to 8 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 8 carbon atoms, a halogen atom or a hydroxyl group. k is 0 or 1. k When it is 0, k4 is an integer from 0 to 4. k When is 1, k4 is an integer from 0 to 7. b1 In the case of multiple R b1 Same or different, multiple R b1 It can also represent a ring structure formed by combining with each other. b2 L is a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 or 7 carbon atoms. C is a single bond or a divalent linking group. k5 is an integer from 0 to 4. b2 In the case of multiple R b2 Same or different, in addition, multiple R b2 It can also represent a ring structure formed by mutual bonding. q is an integer of 0 to 3. + The ring structure may contain heteroatoms (oxygen atoms or sulfur atoms, etc.) between the carbon-carbon bonds forming the skeleton.

[0173] In formula (X-3), R c1 , R c2 and R c3 Each is independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms.

[0174] In formula (X-4), R g1 It is a substituted or unsubstituted alkyl or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted acyl group having 2 to 8 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, or a hydroxyl group. k2 is 0 or 1. k2 When k10 is 0, it is an integer from 0 to 4. k2 When is 1, k10 is an integer from 0 to 7. g1 In the case of multiple R g1 Same or different, in addition, multiple R g1 It can also represent a ring structure formed by combining with each other. g2 and R g3are independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, an alkoxy group or an alkoxycarbonyloxy group, a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a hydroxyl group, a halogen atom, or R g2 and R g3 k11 and k12 are independently integers of 0 to 4. g2 and R g3 In the case of multiple R g2 and R g3 Same as or different from each other.

[0175] In formula (X-5), R d1 and R d2 are independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, an alkoxy group or an alkoxycarbonyl group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a halogen atom, a halogenated alkyl group having 1 to 4 carbon atoms, a nitro group, or a ring structure formed by combining two or more of these groups. k6 and k7 are independently an integer of 0 to 5. d1 and R d2 In the case of multiple R d1 and R d2 Same as or different from each other.

[0176] In formula (X-6), R e1 and R e2 Each of k8 and k9 is independently an integer of 0 to 4. e1 and R e2 In the case of multiple R e1 and R e2 Same as or different from each other.

[0177] As M + Specific examples of the sulfonium cation and iodonium cation represented by include structures represented by the following formulae, etc. However, the present invention is not limited to these specific examples.

[0178] [Chemistry 13]

[0179]

[0180]

[0181] [Chemistry 14]

[0182]

[0183] [Chemistry 15]

[0184]

[0185]

[0186] [Chemistry 16]

[0187]

[0188] Among these, the compound (B) is preferably a sulfonium salt, and more preferably a triarylsulfonium salt. As the compound (B), one kind may be used alone, or two or more kinds may be used in combination.

[0189] Specific examples of the compound (B) include compounds represented by the following formula (1-1) to formula (1-65).

[0190] [Chemistry 17]

[0191]

[0192]

[0193] [Chemistry 18]

[0194]

[0195] [Chemistry 19]

[0196]

[0197]

[0198]

[0199]

[0200]

[0201] [Chemistry 21]

[0202]

[0203] [Chemistry 22]

[0204]

[0205] (In formula (1-1) to formula (1-66), M + is a monovalent cation)

[0206] Relative to 100 parts by mass of polymer (A), the content ratio of compound (B) in the present composition is preferably 0.5 parts by mass or more, more preferably 1 parts by mass or more, and more preferably 3 parts by mass or more. In addition, relative to 100 parts by mass of polymer (A), the content ratio of compound (B) is preferably 45 parts by mass or less, more preferably 35 parts by mass or less, and more preferably 25 parts by mass or less. By setting the content ratio of compound (B) to the range, the sensitivity of the present composition can be improved, and LWR performance, CDU performance and pattern shape can be excellent, and development defects can be reduced. Furthermore, as compound (B), one can be used alone or two or more can be used in combination.

[0207] Synthesis of compound (B)

[0208] Compound (B) can be synthesized by appropriately combining general methods of organic chemistry as shown in the examples described below. 1 In the case of having a (thio)acetal ring, the synthesis can be carried out as follows: synthesizing a compound having a partial structure of "-(CR 1 R 2 ) a -CR f R 3 -X 5 " diol (wherein X 5 is a halogen atom), and then, the diol and the 1 or L 1 A carboxyl group-containing compound of the corresponding structure is reacted in a suitable solvent and optionally in the presence of a catalyst, and the obtained intermediate product is then hydrolyzed and then reacted with sulfonium chloride, sulfonium bromide, etc. which provide an onium cation portion.

[0209] Alternatively, the synthesis can be carried out in the following manner: synthesizing a cyclic (thio)acetal structure and a partial structure "-(CR 1 R 2 ) a -CR f R 3 -X 5 " is a halogenated compound, which is hydrolyzed, and then reacted with sulfonium chloride, sulfonium bromide, etc. that provide an onium cation portion, so that the onium salt thus obtained and the onium salt having W 1 or L 1 The corresponding carboxyl group-containing compound is reacted in a suitable solvent and optionally in the presence of a catalyst. The synthesis method of compound (B) is not limited to the above method.

[0210] <Other ingredients>

[0211] The present composition may also contain polymer (A) and compound (B) together with components different from polymer (A) and compound (B) (hereinafter, also referred to as "other components"). Examples of other components that the present composition may contain include acid diffusion controllers, solvents, and high fluorine content polymers.

[0212] (Acid Diffusion Controller)

[0213] The acid diffusion control agent is deployed in the present composition for the following purpose: the acid generated by the acid generator by exposure is suppressed from diffusing in the resist film, thereby suppressing the chemical reaction caused by the acid in the unexposed portion. By deploying the acid diffusion control agent in the present composition, the micro-image characteristics of the present composition can be further improved, which is suitable in terms of the above aspect. Furthermore, the line width change of the resist pattern caused by the change of the placement time from exposure to development treatment can be suppressed, so that a radiation-sensitive linear composition with excellent process stability can be obtained.

[0214] As the acid diffusion control agent, for example, a nitrogen-containing compound or a photodegradable base can be cited. As the photodegradable base, a compound that generates an acid weaker than the acid generated from the self-compound (B) (i.e., an acid with low acidity) by exposure can be used, for example, a compound that generates a weak acid (preferably a carboxylic acid), a sulfonic acid or a sulfonamide by exposure can be cited. The acidity can be evaluated by the acid dissociation constant (pKa). The acid dissociation constant of the acid generated by the photodegradable base is usually -3 or more, preferably -1≦pKa≦7, and more preferably 0≦pKa≦5.

[0215] Nitrogen compounds

[0216] Examples of nitrogen-containing compounds include compounds represented by the following formula (6) (hereinafter, also referred to as “nitrogen-containing compounds (6A)”), compounds having two nitrogen atoms (hereinafter, also referred to as “nitrogen-containing compounds (6B)”), compounds having three nitrogen atoms (hereinafter, also referred to as “nitrogen-containing compounds (6C)”), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, nitrogen-containing compounds having acid-dissociable groups, and the like.

[0217] [Chemistry 23]

[0218]

[0219] (In formula (6), R 51 , R 52 and R 53 are independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group)

[0220] Specific examples of the nitrogen-containing compound include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and tri-n-pentylamine; and aromatic amines such as aniline and 2,6-diisopropylaniline.

[0221] Examples of the nitrogen-containing compound (6B) include ethylenediamine and N,N,N',N'-tetramethylethylenediamine.

[0222] Examples of the nitrogen-containing compound (6C) include polyamine compounds such as polyethyleneimine and polyallylamine; and polymers such as dimethylaminoethylacrylamide.

[0223] Examples of the amide group-containing compound include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, and N-methylpyrrolidone.

[0224] Examples of the urea compound include urea, methyl urea, 1,1-dimethyl urea, 1,3-dimethyl urea, 1,1,3,3-tetramethyl urea, 1,3-diphenyl urea, and tributylthiourea.

[0225] Examples of the nitrogen-containing heterocyclic compound include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N-(undec-1-ylcarbonyloxyethyl)morpholine; pyrazines, and pyrazoles.

[0226] Examples of the nitrogen-containing compound having an acid-dissociable group include N-tert-butoxycarbonylpiperidine, N-tert-butoxycarbonylimidazole, N-tert-butoxycarbonylbenzimidazole, N-tert-butoxycarbonyl-2-phenylbenzimidazole, N-(tert-butoxycarbonyl)di-n-octylamine, N-(tert-butoxycarbonyl)diethanolamine, N-(tert-butoxycarbonyl)dicyclohexylamine, N-(tert-butoxycarbonyl)diphenylamine, N-tert-butoxycarbonyl-4-hydroxypiperidine, and N-tert-pentyloxycarbonyl-4-hydroxypiperidine.

[0227] Photodegradable base

[0228] The photodegradable base is a compound that generates an acid by irradiation with radiation. The acid generated by the photodegradable base is an acid that does not induce the dissociation of the acid dissociable group under normal conditions. As the photodegradable base, an onium salt that generates a carboxylic acid, a sulfonic acid, or a sulfonamide by irradiation with radiation can be preferably used.

[0229] When the present composition contains an acid generator and a photodegradable base, the photodegradable base is a component that generates an acid weaker than the acid generated by the acid generator by exposure. The degree of acidity can be evaluated by the acid dissociation constant (pKa). The acid dissociation constant (pKa) of the acid generated by the photodegradable base is preferably -3 or more, more preferably -1≦pKa≦7, and further preferably 0≦pKa≦5.

[0230] The photodegradable base has alkalinity in the unexposed part and thus exhibits an acid diffusion inhibitory effect, but in the exposed part, the protons generated by the decomposition of the cations and the anions generate a weak acid, so the acid diffusion inhibitory effect is reduced. Therefore, in the resist film containing the photodegradable base, in the exposed part, the generated acid acts efficiently and the acid dissociable groups in the resist film dissociate, and in the unexposed part, the components in the resist film are not changed by the acid. As a result, the difference in solubility between the exposed part and the unexposed part is more clearly revealed.

[0231] As the photodegradable base, for example, onium salts having a cation structure such as a sulfonium cation structure, an iodonium cation structure, and a quaternary ammonium cation structure can be cited. In terms of maintaining the sensitivity of the present composition at a high level and forming a resist film with higher LWR performance, as the photodegradable base, an onium salt having a sulfonium cation structure or an iodonium cation structure can be preferably used, and specifically, at least one selected from the group consisting of a compound represented by the following formula (7A-1), a compound represented by the following formula (7A-2), a compound represented by the following formula (7B-1), and a compound represented by the following formula (7B-2) can be preferably used.

[0232] [Chemistry 24]

[0233] (J a ) + (E a ) - (7A-1)

[0234] (In formula (7A-1), (J a ) + is a sulfonium cation; (E a ) - OH - , R α -COO - , R α -SO3 - or R α -N - (SO2R f2 ) represents an anion; R αis a monovalent hydrocarbon group, or any methylene group in a monovalent hydrocarbon group is -O-, -CO-, -COO-, -O-CO-O-, -S-, -SO2- or -CONR β -substituted monovalent radical (hereinafter, also referred to as "radical FA"), or a monovalent hydrocarbon radical or a radical F A A monovalent group in which any hydrogen atom is replaced by a fluorine atom, an iodine atom or a hydroxyl group; R β is a hydrogen atom or a monovalent hydrocarbon group; R f2 is a perfluoroalkyl group)

[0235] [Chemistry 25]

[0236]

[0237] (In formula (7A-2), (J b ) + is a group having a sulfonium cation structure; (E b ) - for* 2 -COO - ,* 2 -SO3 - or* 2 -N - (SO2R f2 ); "* 2 " indicates a bonding bond; R f2 is a perfluoroalkyl group; R 31 is a single bond, or a divalent hydrocarbon group, or any methylene group in a divalent hydrocarbon group is -O-, -CO-, -COO-, -O-CO-O-, -S-, -SO2- or -CONR β -substituted divalent group (hereinafter, also referred to as "group F B ”), or a divalent hydrocarbon group or a group F B A divalent group in which any hydrogen atom is replaced by a fluorine atom or a hydroxyl group; R β is a hydrogen atom or a monovalent hydrocarbon group)

[0238] [Chemistry 26]

[0239] (U a )+(Q a ) - (7B-1)

[0240] (In formula (7B-1), (U a ) + is an iodine cation; (Q a ) - OH - , R α -COO - , R α -SO3- or R α -N - (SO2R f2 ) represents an anion; R α are independently a monovalent hydrocarbon group, or any methylene group in a monovalent hydrocarbon group is -O-, -CO-, -COO-, -O-CO-O-, -S-, -SO2- or -CONR β -substituted monovalent radical FA, or a monovalent hydrocarbon radical or a monovalent radical in which any hydrogen atom of radical FA is substituted by a fluorine atom or a hydroxyl group; R β is a hydrogen atom or a monovalent hydrocarbon group; R f2 is a perfluoroalkyl group)

[0241] [Chemistry 27]

[0242]

[0243] (In formula (7B-2), (U b ) + is a group having an iodine cation structure; (Q b ) - for* 2 -COO - ,* 2 -SO3 - or* 2 -N - (SO2R f2 ); "* 2 " indicates a bonding bond; R f2 is a perfluoroalkyl group; R 32 is a single bond, or a divalent hydrocarbon group, or any methylene group in a divalent hydrocarbon group is -O-, -CO-, -COO-, -O-CO-O-, -S-, -SO2- or -CONR β -substituted divalent radical F B , or a divalent hydrocarbon group or a group F B A divalent group in which any hydrogen atom is replaced by a fluorine atom or a hydroxyl group; R β is a hydrogen atom or a monovalent hydrocarbon group)

[0244] In formula (7A-1), (E a ) - The monovalent anion represented by, and (Q a ) - Among the monovalent anions represented by α The monovalent hydrocarbon group represented by may include, for example, a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the like. Specific examples thereof include: 12The groups exemplified are monovalent hydrocarbon groups having 1 to 20 carbon atoms represented by β Examples of the monovalent hydrocarbon group include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms.

[0245] As R f2 Examples of the perfluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a heptafluoro-n-propyl group, a heptafluoro-isopropyl group, a nonafluoro-n-butyl group, a nonafluoro-isobutyl group, and a nonafluoro-t-butyl group.

[0246] As (E a ) - or (Q a ) - Specific examples of the anion represented by include structures represented by the following formulas. However, it is not limited to these specific examples. In the following formula, R 21 and R 22 Each independently represents an alkyl group having 1 to 20 carbon atoms.

[0247] [Chemistry 28]

[0248]

[0249] In formula (7A-1), as (J a ) + The sulfonium cation represented by may be exemplified by the sulfonium cations represented by the above formulae (X-1) to (X-4). a ) + Examples of the iodonium cation represented by include the iodonium cation represented by the above formula (X-5) or formula (X-6).

[0250] In formula (7A-2), (E b ) - And (Q in formula (7B-2) b ) - About R f2 Specific examples of the perfluoroalkyl group represented by include R in formula (7A-1) and formula (7B-1): f2 And the base illustrated.

[0251] As R in formula (7A-2) 31 And R in formula (7B-2) 32 The divalent hydrocarbon group represented by can be exemplified by α A group obtained by removing one hydrogen atom from the groups exemplified as the monovalent hydrocarbon group represented by .

[0252] As "-R" in formula (7A-2) 31-(E b ) - " and "-R in formula (7B-2) 32 -(Q b ) - Specific examples of the partial structure represented by " can be listed as (E a ) - And (Q in formula (7B-1) a ) - A partial structure in which one arbitrary hydrogen atom is removed from the structure exemplified as a specific example of an anion represented by * 2 -COO - ,* 2 -SO3 - ,* 2 -N - (SO2R f2 ).

[0253] As "-(J b ) + Specific examples of the group represented by "-(U" can be listed as a group obtained by removing an arbitrary hydrogen atom from the sulfonium cations represented by the formulae (X-1) to (X-4). b ) + Specific examples of the group represented by " include groups obtained by removing an arbitrary hydrogen atom from the iodonium cation represented by the formula (X-5) or (X-6).

[0254] Specific examples of the photodegradable base include compounds represented by the following formulae, but are not limited to these compounds.

[0255] [Chemistry 29]

[0256]

[0257] [Chemistry 30]

[0258]

[0259] [Chemistry 31]

[0260]

[0261] Among these, the photodegradable base used in the preparation of the present composition is preferably a sulfonium salt, and more preferably a triarylsulfonium salt. In addition, as the photodegradable base, one kind may be used alone or two or more kinds may be used in combination.

[0262] In the case where the present composition contains an acid diffusion controller, the content of the acid diffusion controller in the present composition is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and further preferably 3 parts by mass or more, relative to 100 parts by mass of polymer (A). In addition, the content of the acid diffusion controller is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and further preferably 40 parts by mass or less, relative to 100 parts by mass of polymer (A). By setting the content of the acid diffusion controller to the range, the LWR performance of the present composition can be further improved, which is suitable in terms of the above aspects. As the acid diffusion controller, one may be used alone, or two or more may be used in combination.

[0263] (Solvent)

[0264] The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing the components formulated in the present composition. Examples of the solvent include alcohols, ethers, ketones, amides, esters, hydrocarbons, and the like.

[0265] Examples of alcohols include aliphatic monoalcohols having 1 to 18 carbon atoms, such as 4-methyl-2-pentanol and n-hexanol; alicyclic monoalcohols having 3 to 18 carbon atoms, such as cyclohexanol; polyols having 2 to 18 carbon atoms, such as 1,2-propylene glycol; and partial ethers of polyols having 3 to 19 carbon atoms, such as propylene glycol monomethyl ether. Examples of ethers include dialkyl ethers, such as diethyl ether, dipropyl ether, dibutyl ether, diamyl ether, diisoamyl ether, dihexyl ether, and diheptyl ether; cyclic ethers, such as tetrahydrofuran and tetrahydropyran; and aromatic ring-containing ethers, such as diphenyl ether and anisole.

[0266] Examples of ketones include chain ketones such as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl isobutyl ketone, 2-heptanone, ethyl n-butyl ketone, methyl n-hexyl ketone, diisobutyl ketone, and trimethyl nonanone; cyclic ketones such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and methylcyclohexanone; 2,4-pentanedione, acetonylacetone, acetophenone, and diacetone alcohol; and examples of amides include cyclic amides such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone; chain amides such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.

[0267] Examples of esters include monocarboxylic acid esters such as n-butyl acetate and ethyl lactate; polyol carboxylic acid esters such as propylene glycol acetate; polyol partial ether carboxylic acid esters such as propylene glycol monomethyl ether acetate (propylene glycol monomethyl ether acetate); polycarboxylic acid diesters such as diethyl oxalate; carbonates such as dimethyl carbonate and diethyl carbonate; cyclic esters such as γ-butyrolactone, etc. Examples of hydrocarbons include aliphatic hydrocarbons having 5 to 12 carbon atoms such as n-pentane and n-hexane; and aromatic hydrocarbons having 6 to 16 carbon atoms such as toluene and xylene.

[0268] Among these, the solvent preferably includes at least one selected from the group consisting of esters and ketones, and more preferably includes at least one selected from the group consisting of polyol partial ether carboxylic acid esters and cyclic ketones. As the solvent, one or more types can be used.

[0269] (High fluorine content polymer)

[0270] The high fluorine content polymer (hereinafter, also referred to as "polymer (F)") is a polymer having a higher mass content of fluorine atoms than the polymer (A). When the present composition contains the polymer (F), the polymer (F) can be more preferentially present in the surface layer of the resist film relative to the polymer (A), thereby improving the water repellency of the resist film surface during immersion exposure.

[0271] The fluorine atom content of polymer (F) is not particularly limited as long as it is greater than that of polymer (A). The fluorine atom content of polymer (F) is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 4% by mass or more, and particularly preferably 7% by mass or more. In addition, the fluorine atom content of polymer (F) is preferably 60% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. The fluorine atom content (mass %) of the polymer can be calculated by 13 C-NMR ( 13 C-Nuclear Magnetic Resonance, 13 The structure of the polymer was determined by C-NMR spectroscopy and the like, and the calculation was performed based on the structure.

[0272] As the structural unit containing a fluorine atom (hereinafter, also referred to as "structural unit (f)") possessed by the polymer (F), for example, the structural unit (fa) and the structural unit (fb) shown below can be cited. The polymer (F) may have one of the structural unit (fa) and the structural unit (fb) as the structural unit (f), or may have both the structural unit (fa) and the structural unit (fb).

[0273] Structural unit (fa)

[0274] The structural unit (fa) is a structural unit represented by the following formula (8-1). The fluorine atom content of the polymer (F) can be adjusted by having the structural unit (fa).

[0275] [Chemistry 32]

[0276]

[0277] (In formula (8-1), R C is a hydrogen atom, a fluoro group, a methyl group or a trifluoromethyl group; G is a single bond, an oxygen atom, a sulfur atom, -COO-, -SO2-O-NH-, -CONH- or -O-CO-NH-; R E is a monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms)

[0278] In the formula (8-1), from the viewpoint of providing copolymerizability of the monomer of the structural unit (fa), R C It is preferably a hydrogen atom and a methyl group, and more preferably a methyl group. In addition, from the viewpoint of improving the copolymerizability of the monomer of the structural unit (fa), G is preferably a single bond or -COO-, and more preferably -COO-.

[0279] As R E The monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms represented by may be a group in which a part or all of the hydrogen atoms in a linear or branched alkyl group having 1 to 20 carbon atoms are substituted with fluorine atoms. E The monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by may be a group in which a part or all of the hydrogen atoms in a monocyclic or polycyclic alicyclic hydrocarbon group having 3 to 20 carbon atoms are substituted with fluorine atoms. E It is preferably a monovalent fluorinated chain hydrocarbon group, more preferably a monovalent fluorinated alkyl group, and still more preferably a 2,2,2-trifluoroethyl group, a 1,1,1,3,3,3-hexafluoropropyl group, or a 5,5,5-trifluoro-1,1-diethylpentyl group.

[0280] In the case where polymer (F) has structural unit (fa), relative to all structural units constituting polymer (F), the content ratio of structural unit (fa) is preferably 30 mol% or more, more preferably 40 mol% or more, and further preferably 50 mol% or more. In addition, relative to all structural units constituting polymer (F), the content ratio of structural unit (fa) is preferably 95 mol% or less, more preferably 90 mol% or less, and further preferably 85 mol% or less. By setting the content ratio of structural unit (fa) to the range, the mass content of fluorine atoms of polymer (F) can be adjusted more appropriately, thereby further promoting the partial existence of the surface layer of resist film, thereby further improving the water repellency of resist film during immersion exposure.

[0281] ·Structural unit (fb)

[0282] The structural unit (fb) is a structural unit represented by the following formula (8-2): When the polymer (F) has the structural unit (fb), the solubility in the alkaline developer is improved, thereby further suppressing the occurrence of development defects.

[0283] [Chemistry 33]

[0284]

[0285] (In formula (8-2), R F is a hydrogen atom, a fluoro group, a methyl group or a trifluoromethyl group; R 59 is a (s+1)-valent hydrocarbon group having 1 to 20 carbon atoms, or is R 60 The terminal of the side is bonded with an oxygen atom, a sulfur atom, -NR'-, a carbonyl group, -CO-O- or -CO-NH-; R' is a hydrogen atom or a monovalent organic group; R 60 is a single bond or a divalent organic group having 1 to 20 carbon atoms; X 12 A is a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or a divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms; 11 is an oxygen atom, -NR"-, -CO-O-* or -SO2-O-*; R" is a hydrogen atom or a monovalent hydrocarbon group with 1 to 10 carbon atoms; "*" indicates the same 61 Bonding site of the bond; R 61 is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms; s is an integer of 1 to 3; wherein, when s is 2 or 3, multiple R 60 , X 12 , A 11 and R 61 Same or different)

[0286] The structural unit (fb) is divided into a case where it has an alkali-soluble group and a case where it has a group that dissociates by the action of an alkali and increases solubility in an alkaline developer (hereinafter, also simply referred to as an "alkali-dissociable group").

[0287] When the structural unit (fb) has an alkali-soluble group, R 61 A is a hydrogen atom, 11 is an oxygen atom, -CO-O-* or -SO2-O-*. "*" indicates the same 61 The bonding site. 12 is a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or a divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms. 11 When X is an oxygen atom, 12 For A 11 A fluorinated hydrocarbon group having a fluorine atom or a fluoroalkyl group on the carbon atom to which it is bonded.60 is a single bond or a divalent organic group having 1 to 20 carbon atoms. When s is 2 or 3, multiple R 60 , X 12 , A 11 and R 61 When the structural unit (fb) has an alkali-soluble group, the affinity for an alkaline developer can be increased, thereby suppressing development defects.

[0288] When the structural unit (fb) has a base dissociable group, R 61 A is a monovalent organic group having 1 to 30 carbon atoms, 11 is an oxygen atom, -NR"-, -CO-O-* or -SO2-O-*. "*" indicates the same 61 The bonding site. 12 R is a single bond or a divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms. 60 It is a single bond or a divalent organic group having 1 to 20 carbon atoms. 11 In the case of -CO-O-* or -SO2-O-*, X 12 or R 61 Yu and A 11 The carbon atom to which the bond is made or the carbon atom adjacent to it has a fluorine atom. 11 When X is an oxygen atom, 12 or R 60 is a single bond, R 59 R is a hydrocarbon group having 1 to 20 carbon atoms. 60 The structure with a carbonyl group bonded to the end of the side, R 61 is an organic group having a fluorine atom. When s is 2 or 3, multiple R 60 , X 12 , A 11 and R 61 The structural unit (fb) has an alkali dissociable group, so that the surface of the resist film changes from hydrophobic to hydrophilic in the alkali development process. This can improve the affinity for the developer and more effectively suppress development defects. As the structural unit (fb) having an alkali dissociable group, A is particularly preferred. 11 is -CO-O-*, R 61 or X 12 Alternatively, both of them have fluorine atoms.

[0289] In the case where the polymer (F) has a structural unit (fb), the content of the structural unit (fb) is preferably 40 mol% or more, more preferably 50 mol% or more, and further preferably 60 mol% or more relative to all the structural units constituting the polymer (F). In addition, the content of the structural unit (fb) is preferably 95 mol% or less, more preferably 90 mol% or less, and further preferably 85 mol% or less relative to all the structural units constituting the polymer (F). By setting the content of the structural unit (fb) to the range, the water repellency of the resist film during immersion exposure can be further improved.

[0290] In addition to the structural units (fa) and (fb), the polymer (F) may also contain a structural unit (I) having an acid-dissociable group or a structural unit having an alicyclic hydrocarbon structure represented by the following formula (9) (hereinafter also referred to as "structural unit (G)").

[0291] [Chemistry 34]

[0292]

[0293] (In the formula (9), R G1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R G2 is a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms)

[0294] In the formula (9), R G2 The monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by can be exemplified as R of the formula (3): 13 ~R 15 The groups are exemplified by the monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms represented by .

[0295] When the polymer (F) contains the structural unit represented by the formula (9), the content ratio of the structural unit is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more relative to all the structural units constituting the polymer (F). In addition, the content ratio of the structural unit represented by the formula (9) is preferably 70 mol% or less, more preferably 60 mol% or less, and further preferably 50 mol% or less relative to all the structural units constituting the polymer (F).

[0296] The Mw of the polymer (F) obtained by GPC is preferably 1,000 or more, more preferably 3,000 or more, and further preferably 4,000 or more. In addition, the Mw of the polymer (F) is preferably 50,000 or less, more preferably 30,000 or less, and further preferably 20,000 or less. The molecular weight distribution (Mw / Mn) represented by the ratio of Mn to Mw obtained by GPC of the polymer (F) is preferably 1 or more and 5 or less, and more preferably 1 or more and 3 or less.

[0297] When the present composition contains a polymer (F), the content of the polymer (F) in the present composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 1 part by mass or more, relative to 100 parts by mass of the polymer (A). In addition, the content of the polymer (F) is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and further preferably 5 parts by mass or less, relative to 100 parts by mass of the polymer (A). Furthermore, the present composition may contain one polymer (F) alone, or may contain two or more in combination.

[0298] ·Other optional ingredients

[0299] The present composition may further contain components different from the polymer (A), compound (B), acid diffusion controller, solvent and polymer (F) (hereinafter, also referred to as "other arbitrary components"). Examples of other arbitrary components include acid generators other than compound (B), surfactants, compounds containing alicyclic skeletons (for example, 1-adamantanyl carboxylic acid, 2-adamantanone, deoxycholic acid tert-butyl ester, etc.), sensitizers, partial presence promoters, etc. The content ratio of other arbitrary components in the present composition can be appropriately selected according to each component within the range that does not impair the effects of the present disclosure.

[0300] Furthermore, when an acid generator other than compound (B) is formulated in the present composition, from the viewpoint of obtaining a radiation-sensitive composition capable of forming a resist pattern showing good sensitivity, excellent LWR performance and pattern shape, and few development defects, the content ratio of the acid generator other than compound (B) relative to the total amount of the acid generator contained in the present composition is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

[0301] <Method for producing radiation-sensitive composition>

[0302] The present composition can be manufactured, for example, by the following manner: with the required ratio, polymer (A) and compound (B), and other optional solvents and other components are mixed, preferably using a filter (for example, a filter with a pore size of about 0.2 μm) etc. to filter the obtained mixture. The solid component concentration of the present composition is preferably more than 0.1% by mass, more preferably more than 0.5% by mass, and then preferably more than 1% by mass. In addition, the solid component concentration of the present composition is preferably less than 50% by mass, more preferably less than 20% by mass, and then preferably less than 5% by mass. By setting the solid component concentration of the present composition to the scope, the coating property can be made good, and the shape of the resist pattern can be made good.

[0303] The present composition thus obtained can be used as a positive pattern forming composition for forming a pattern using an alkaline developer, or as a negative pattern forming composition for forming a pattern using a developer containing an organic solvent. Among these, the present composition is particularly suitable as a positive pattern forming composition using an alkaline developer in that it exhibits high sensitivity and exhibits excellent pattern rectangularity by developing the resist film after exposure.

[0304] 《Resist pattern forming method》

[0305] The resist pattern forming method disclosed herein includes: a process of applying the present composition on one surface of a substrate (hereinafter, also referred to as a "coating process"); a process of exposing the resist film obtained by the coating process (hereinafter, also referred to as an "exposure process"); and a process of developing the exposed resist film (hereinafter, also referred to as a "development process"). Examples of patterns formed by the resist pattern forming method disclosed herein include line and space patterns, hole patterns, and the like. In the resist pattern forming method disclosed herein, since the resist film is formed using the present composition, a resist pattern having good sensitivity and lithography characteristics and few development defects can be formed. Each process is described below.

[0306] [Coating process]

[0307] In the coating process, a resist film is formed on the substrate by applying the composition on one surface of the substrate. As a substrate for forming the resist film, previously known ones can be used, for example, silicon wafers, silicon dioxide, aluminum-coated wafers, etc. In addition, an organic or inorganic anti-reflection film disclosed in, for example, Japanese Patent Publication No. 6-12452 or Japanese Patent Publication No. 59-93448 can also be formed on the substrate for use. As a coating method for the present composition, for example, spin coating (spin coating), cast coating, roller coating, etc. can be listed. Pre-baking (prebake, PB) can also be performed after coating to volatilize the solvent in the coating film. The temperature of PB is preferably above 60°C, more preferably above 80°C. In addition, the temperature of PB is preferably below 140°C, more preferably below 120°C. The time of PB is preferably above 5 seconds, more preferably above 10 seconds. In addition, the time of PB is preferably below 600 seconds, more preferably below 300 seconds. The average thickness of the formed resist film is preferably 10 nm to 1,000 nm, more preferably 20 nm to 500 nm.

[0308] In the case of immersion exposure in the next exposure process, regardless of the presence or absence of hydrophobic polymer additives such as polymer (F) in the present composition, for the purpose of avoiding direct contact between the immersion liquid and the resist film, a liquid immersion protective film that is insoluble in the immersion liquid may also be further provided on the resist film formed by the present composition. As a liquid immersion protective film, a solvent-stripping protective film (for example, with reference to Japanese Patent Laid-Open 2006-227632 Gazette) that is stripped using a solvent before the developing process and a developer stripping protective film (for example, with reference to International Publication No. 2005 / 069076, International Publication No. 2006 / 035790) that is stripped simultaneously with the developing process may also be used. From the viewpoint of output, it is preferred to use a developer stripping liquid immersion protective film.

[0309] [Exposure process]

[0310] In the exposure process, the resist film obtained by the coating process is exposed. The exposure is carried out by irradiating the resist film with radiation through a dielectric mask, optionally through an immersion medium such as water. As radiation, according to the line width of the target pattern, for example, electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and gamma rays can be listed; charged particle beams such as electron beams and α rays, etc. Among these, the radiation irradiated to the resist film formed using the present composition is preferably far ultraviolet light, EUV or electron beam, more preferably ArF excimer laser light (wavelength 193nm), KrF excimer laser light (wavelength 248nm), EUV or electron beam, and further preferably ArF excimer laser light, EUV or electron beam.

[0311] Preferably, a post-exposure bake (PEB) is performed after the exposure, and the dissociation of the acid dissociative group is promoted in the exposed part of the resist film by using the acid generated by the self-radioactive linear acid generator by exposure. By this PEB, the difference in solubility in the developer can be increased between the exposed part and the unexposed part. The temperature of PEB is preferably 50°C or more, more preferably 80°C or more. In addition, the temperature of PEB is preferably 180°C or less, more preferably 130°C or less. The time of PEB is preferably 5 seconds or more, more preferably 10 seconds or more. In addition, the time of PEB is preferably 600 seconds or less, more preferably 300 seconds or less.

[0312] [Development process]

[0313] In the developing step, the exposed resist film is developed using a developer. Thus, a desired resist pattern can be formed. The developer can be an alkaline developer or an organic solvent developer. The developer can be appropriately selected according to the target pattern (positive pattern or negative pattern).

[0314] Examples of the developer used for alkali development include alkaline aqueous solutions containing at least one alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene. Among these, a TMAH aqueous solution is preferred, and a 2.38 mass % TMAH aqueous solution is more preferred.

[0315] As the developer used in the organic solvent development, there can be listed: organic solvents such as hydrocarbons, ethers, esters, ketones, alcohols, or solvents containing the organic solvents. As the organic solvent, for example, one or more of the solvents listed as solvents that can be formulated into the present composition can be listed. Among these, ethers, esters and ketones are preferred. As ethers, glycol ethers are preferred, and ethylene glycol monomethyl ether and propylene glycol monomethyl ether are more preferred. As esters, acetates are preferred, and n-butyl acetate and amyl acetate are more preferred. As ketones, chain ketones are preferred, and 2-heptanone is more preferred. As the content of the organic solvent in the developer, it is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and particularly preferably 99% by mass or more. As components other than the organic solvent in the developer, for example, water, silicone oil, etc. can be listed.

[0316] As the developing method, for example, there can be listed: a method of immersing the substrate in a tank filled with a developer for a fixed time (immersion method); a method of developing by depositing the developer on the substrate surface by using surface tension and letting it stand for a fixed time (puddle method); a method of spraying the developer on the substrate surface (spray method); a method of continuously spraying the developer onto the substrate rotating at a fixed speed while scanning the developer spray nozzle at a fixed speed (dynamic distribution method), etc. After the development, the substrate is generally cleaned with a rinse solution such as water or alcohol and dried.

[0317] Example

[0318] Hereinafter, the present disclosure will be specifically described based on examples, but the present disclosure is not limited to these examples. In addition, "parts" and "%" in the following examples are based on mass unless otherwise specified. The following shows the measurement methods of various physical property values.

[0319] [Weight average molecular weight (Mw), number average molecular weight (Mn) and dispersion (Mw / Mn)]

[0320] The Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard, using GPC columns manufactured by Tosoh Corporation (G2000HXL: two, G3000HXL: one, G4000HXL: one), under the following analytical conditions: flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, sample concentration: 1.0 mass %, sample injection volume: 100 μL, column temperature: 40° C., detector: differential refractometer. In addition, the degree of dispersion (Mw / Mn) was calculated based on the measurement results of Mw and Mn.

[0321] [ 13 C-NMR analysis]

[0322] Polymer 13 C-NMR analysis was performed using a nuclear magnetic resonance apparatus ("JNM-Delta 400" manufactured by JEOL Ltd.).

[0323] The [A] resin, [B] radiation-sensitive acid generator, [C] acid diffusion controller, [E] solvent, and [F] high-fluorine content resin used in the preparation of the radiation-sensitive composition in each example are as follows.

[0324] <[A] Resin and [F] High-fluorine Content Resin>

[0325] ·[A] Synthesis of resin and [F] high fluorine content resin

[0326] The monomers used in the synthesis of each resin and high fluorine content resin are shown below. In the following synthesis examples, unless otherwise specified, "parts by mass" refers to the value when the total mass of the monomers used is set to 100 parts by mass, and "mol %" refers to the value when the total number of moles of the monomers used is set to 100 mol %.

[0327] [Chemistry 35]

[0328]

[0329]

[0330] [Synthesis example 1]

[0331] (Synthesis of Resin (A-1))

[0332] The monomer (M-1), monomer (M-2), monomer (M-5), monomer (M-10) and monomer (M-14) were dissolved in 2-butanone (200 parts by mass) at a molar ratio of 40 / 10 / 20 / 20 / 10 (mol%), and AIBN (azobisisobutyronitrile) (5 mol% relative to the total 100 mol% of the monomers used) was added as an initiator to prepare a monomer solution. 2-Butanone (100 parts by mass) was placed in a reaction container, and after nitrogen flushing for 30 minutes, the temperature in the reaction container was set to 80°C, and the monomer solution was added dropwise over 3 hours while stirring. The start of the addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was water-cooled and cooled to 30°C or less. The cooled polymerization solution was added to methanol (2,000 parts by mass), and the precipitated white powder was separated by filtration. The white powder separated by filtration was washed twice with methanol, separated by filtration, and dried at 50°C for 24 hours to obtain a white powdery resin (A-1) (yield: 85%). The Mw of the resin (A-1) was 7,100, and the Mw / Mn was 1.61. 13 As a result of C-NMR analysis, the contents of the structural units derived from monomer (M-1), monomer (M-2), monomer (M-5), monomer (M-10) and monomer (M-14) were 40.3 mol%, 9.2 mol%, 20.5 mol%, 19.8 mol% and 10.2 mol%, respectively.

[0333] [Synthesis Example 2 to Synthesis Example 13]

[0334] (Synthesis of Resins (A-2) to (A-13))

[0335] Resins (A-2) to (A-13) were synthesized in the same manner as in Synthesis Example 1 except that monomers of the types and blending ratios shown in Table 1 were used. The content ratios (mol %) and physical property values ​​(Mw and Mw / Mn) of the structural units of the obtained resins are shown in Table 1. In Table 1, "-" indicates that the corresponding monomer was not used (the same applies to the following tables).

[0336]

[0337] [Synthesis Example 14]

[0338] (Synthesis of Resin (A-14))

[0339] The monomer (M-1) and the monomer (M-18) were dissolved in 1-methoxy-2-propanol (200 parts by mass) at a molar ratio of 50 / 50 (mol%), and AIBN (5 mol%) was added as an initiator to prepare a monomer solution. 1-methoxy-2-propanol (100 parts by mass) was placed in a reaction vessel, and after nitrogen flushing for 30 minutes, the temperature in the reaction vessel was set to 80°C, and the monomer solution was added dropwise for 3 hours while stirring. The start of the addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was water-cooled and cooled to below 30°C. The cooled polymerization solution was added to hexane (2,000 parts by mass), and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with hexane, separated by filtration, and dissolved in 1-methoxy-2-propanol (300 parts by mass). Then, methanol (500 parts by mass), triethylamine (50 parts by mass) and ultrapure water (10 parts by mass) were added, and a hydrolysis reaction was carried out at 70°C for 6 hours while stirring. After the reaction, the residual solvent was distilled off, and the obtained solid was dissolved in acetone (100 parts by mass), and then added dropwise to water (500 parts by mass) to solidify the resin. The obtained solid was filtered and separated, and dried at 50°C for 13 hours to obtain a white powdery resin (A-14) (yield: 81%). The Mw of the resin (A-14) is 5,500, and the Mw / Mn is 1.62. In addition, 13 As a result of C-NMR analysis, the contents of the structural units derived from the monomer (M-1) and the monomer (M-18) were 50.2 mol % and 49.8 mol %, respectively.

[0340] [Synthesis Example 15 to Synthesis Example 18]

[0341] (Synthesis of Resins (A-15) to (A-18))

[0342] Resins (A-15) to (A-18) were synthesized in the same manner as in Synthesis Example 14 except that monomers of the types and blending ratios shown in Table 2 were used. In addition, in the monomers providing the structural unit (III), all alkali dissociable groups were hydrolyzed to become phenolic hydroxyl groups. The content ratio (mol %) and physical property values ​​(Mw and Mw / Mn) of each structural unit of the obtained resin are shown in Table 2.

[0343]

[0344] [Synthesis Example 19]

[0345] (Synthesis of high fluorine content resin (F-1))

[0346] The monomer (M-1) and the monomer (M-20) were dissolved in 2-butanone (200 parts by mass) at a molar ratio of 20 / 80 (mol%), and AIBN (4 mol%) was added as an initiator to prepare a monomer solution. 2-Butanone (100 parts by mass) was placed in a reaction vessel, and after nitrogen flushing for 30 minutes, the temperature in the reaction vessel was set to 80°C, and the monomer solution was added dropwise for 3 hours while stirring. The start of the addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was water-cooled and cooled to below 30°C. After the solvent was replaced with acetonitrile (400 parts by mass), hexane (100 parts by mass) was added, stirred, and the acetonitrile layer was recovered, and this operation was repeated 3 times. The solvent was replaced with propylene glycol monomethyl ether acetate, thereby obtaining a solution of a high fluorine content resin (F-1) (yield: 75%). The Mw of the high fluorine content resin (F-1) is 6,200, and the Mw / Mn is 1.77. 13 As a result of C-NMR analysis, the contents of the structural units derived from (M-1) and (M-20) were 19.5 mol% and 80.5 mol%, respectively.

[0347] [Synthesis Example 20 to Synthesis Example 23]

[0348] (Synthesis of high fluorine content resin (F-2) to high fluorine content resin (F-5))

[0349] High fluorine content resins (F-2) to (F-5) were synthesized in the same manner as in Synthesis Example 19 except that monomers of the types and blending ratios shown in Table 3 were used. The content ratios (mol %) and physical property values ​​(Mw and Mw / Mn) of the obtained high fluorine content resins are shown in Table 3.

[0350]

[0351] <[B]Radiosensitive acid generator>

[0352] [Synthesis of Radiosensitive Acid Generator (B)]

[0353] [Synthesis Example 24]

[0354] (Synthesis of Compound (B-1))

[0355] Compound (B-1) was synthesized according to the following synthesis scheme.

[0356] [Chemistry 36]

[0357]

[0358] In a reaction vessel, 20.0 mmol of cyclopentadiene and 50 g of methyl chloride were added to 20.0 mmol of 4-bromo-3,3,4,4-tetrafluoro-1-butene, and stirred at room temperature for 3 hours. After dilution with water, methyl chloride was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium chloride solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and purified by column chromatography to obtain an olefin (hereinafter also referred to as "olefin (B-1-a)") with a good yield.

[0359] To the olefin (B-1-a), 40.0 mmol of potassium permanganate and 50 g of acetonitrile were added, and the mixture was stirred at 50°C for 10 hours. Afterwards, a saturated aqueous sodium thiosulfate solution was added to stop the reaction, and then ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium chloride solution, and then washed with water. After drying with sodium sulfate, the solvent was distilled off, and the diol was purified by column chromatography to obtain a diol with a good yield.

[0360] 20.0 mmol of 2-adamantanone-5-carboxylic acid, 2.00 mmol of sulfuric acid and 50 g of dichloromethane were added to the diol and stirred at room temperature for 24 hours. After dilution with water, ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and purified by column chromatography to obtain an acetal body with a good yield.

[0361] After adding a mixed solution of acetonitrile: water (1:1 (mass ratio)) to the acetal to prepare a 1M solution, 40.0mmol of sodium dithionite and 60.0mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 4 hours. After extraction with acetonitrile and distillation of the solvent, a mixed solution of acetonitrile: water (3:1 (mass ratio)) was added to prepare a 0.5M solution. 60.0mmol of hydrogen peroxide water and 2.00mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. Extraction with acetonitrile and distillation of the solvent were performed to obtain a sodium sulfonate compound. 20.0mmol of triphenylsulfonium bromide was added to the sodium sulfonate compound, and a mixed solution of water: dichloromethane (1:3 (mass ratio)) was added to prepare a 0.5M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain the compound (B-1) represented by the formula (B-1) at a good yield.

[0362] [Synthesis Example 25 to Synthesis Example 32]

[0363] (Synthesis of Compounds (B-2) to (B-9))

[0364] Onium salt compounds represented by the following formula (B-2) to (B-9) were synthesized in the same manner as in Synthesis Example 24 except that the raw materials and precursors were appropriately changed.

[0365] [Chemistry 37]

[0366]

[0367] [Synthesis Example 33]

[0368] (Synthesis of Compound (B-10))

[0369] Compound (B-10) was synthesized according to the following synthesis scheme.

[0370] [Chemistry 38]

[0371]

[0372] 20.0 mmol of 4-bromo-3,3,4,4-tetrafluoro-1-butene, 40.0 mmol of potassium permanganate, and 50 g of acetonitrile were added to the reaction container and stirred at 50°C for 10 hours. After that, a saturated sodium thiosulfate aqueous solution was added to stop the reaction, and then ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and purified by column chromatography to obtain a diol with a good yield.

[0373] 20.0 mmol of 2-adamantanone-5-carboxylic acid, 2.00 mmol of sulfuric acid and 50 g of dichloromethane were added to the diol and stirred at room temperature for 24 hours. After dilution with water, ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and purified by column chromatography to obtain an acetal body with a good yield.

[0374] After adding a mixed solution of acetonitrile: water (1:1 (mass ratio)) to the acetal to prepare a 1M solution, 40.0mmol of sodium dithionite and 60.0mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 4 hours. After extraction with acetonitrile and distillation of the solvent, a mixed solution of acetonitrile: water (3:1 (mass ratio)) was added to prepare a 0.5M solution. 60.0mmol of hydrogen peroxide water and 2.00mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. Extraction with acetonitrile and distillation of the solvent were performed to obtain a sodium sulfonate compound. 20.0mmol of triphenylsulfonium bromide was added to the sodium sulfonate compound, and a mixed solution of water: dichloromethane (1:3 (mass ratio)) was added to prepare a 0.5M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain the compound (B-10) represented by the formula (B-10) in good yield.

[0375] [Synthesis Example 34 and Synthesis Example 35]

[0376] (Synthesis of Compound (B-11) and Compound (B-12))

[0377] Onium salt compounds represented by the following formula (B-11) and formula (B-12) were synthesized in the same manner as in Synthesis Example 33 except that the raw materials and precursors were appropriately changed.

[0378] [Chemistry 39]

[0379]

[0380] [Synthesis Example 36]

[0381] (Synthesis of Compound (B-13))

[0382] Compound (B-13) was synthesized according to the following synthesis scheme.

[0383] [Chemistry 40]

[0384]

[0385] 1,2-isopropylidene glycol 20.0mmol, bromodifluoroacetic acid 20.0mmol, dicyclohexylcarbodiimide 30.0mmol and acetonitrile 50g were added to the reaction container and stirred at room temperature for 4 hours. Thereafter, after dilution with water, ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and refined by column chromatography to obtain an ester with a good yield.

[0386] After adding a mixed solution of acetonitrile: water (1:1 (mass ratio)) to the ester to prepare a 1M solution, 40.0mmol of sodium dithionite and 60.0mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 4 hours. After extraction with acetonitrile and distillation of the solvent, a mixed solution of acetonitrile: water (3:1 (mass ratio)) was added to prepare a 0.5M solution. 60.0mmol of hydrogen peroxide water and 2.00mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. Extraction with acetonitrile and distillation of the solvent were performed to obtain a sodium sulfonate compound. 20.0mmol of triphenylsulfonium bromide was added to the sodium sulfonate compound, and a mixed solution of water: dichloromethane (1:3 (mass ratio)) was added to prepare a 0.5M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain an onium salt in good yield.

[0387] 20.0 mmol of 2-adamantanone-5-carboxylic acid, 2.00 mmol of sulfuric acid and 50 g of dichloroethane were added to the onium salt, and stirred at 70 ° C for 24 hours. Thereafter, after dilution with water, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium chloride solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and refined by column chromatography, thereby obtaining the compound (B-13) represented by the formula (B-13) with a good yield.

[0388] [Synthesis Example 37 to Synthesis Example 40]

[0389] (Synthesis of Compounds (B-14) to (B-17))

[0390] Onium salt compounds represented by the following formula (B-14) to (B-17) were synthesized in the same manner as in Synthesis Example 36 except that the raw materials and precursors were appropriately changed.

[0391] [Chemistry 41]

[0392]

[0393] [Synthesis Example 41]

[0394] (Synthesis of Compound (B-18))

[0395] Compound (B-18) was synthesized according to the following synthesis scheme.

[0396] [Chemistry 42]

[0397]

[0398] 20.0 mmol of glyceric acid, 2.00 mmol of sulfuric acid and 50 g of acetone were added to the reaction vessel and stirred at room temperature for 2 hours. After dilution with water, ethyl acetate was added for extraction and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and purified by column chromatography to obtain an acetal body with a good yield.

[0399] 20.0 mmol of 2-bromo-2,2-difluoroethane-1-ol, 30.0 mmol of dicyclohexylcarbodiimide and 50 g of dichloromethane were added to the acetal, and stirred at room temperature for 4 hours. Thereafter, after dilution with water, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution, and then washed with water. After drying with sodium sulfate, the solvent was distilled off, and refined by column chromatography, thereby obtaining an ester body with a good yield.

[0400] After adding a mixed solution of acetonitrile: water (1:1 (mass ratio)) to the ester to prepare a 1M solution, 40.0mmol of sodium dithionite and 60.0mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 4 hours. After extraction with acetonitrile and distillation of the solvent, a mixed solution of acetonitrile: water (3:1 (mass ratio)) was added to prepare a 0.5M solution. 60.0mmol of hydrogen peroxide water and 2.00mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. Extraction with acetonitrile and distillation of the solvent were performed to obtain a sodium sulfonate compound. 20.0mmol of triphenylsulfonium bromide was added to the sodium sulfonate compound, and a mixed solution of water: dichloromethane (1:3 (mass ratio)) was added to prepare a 0.5M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain an onium salt in good yield.

[0401] 20.0 mmol of 2-adamantanone-5-carboxylic acid, 2.00 mmol of sulfuric acid and 50 g of dichloroethane were added to the onium salt, and stirred at 70 ° C for 20 hours. Thereafter, after dilution with water, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium chloride solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and refined by column chromatography, thereby obtaining the compound (B-18) represented by the formula (B-18) with a good yield.

[0402] [Synthesis Example 42 to Synthesis Example 45]

[0403] (Synthesis of Compounds (B-19) to (B-22))

[0404] Onium salt compounds represented by the following formula (B-19) to (B-22) were synthesized in the same manner as in Synthesis Example 41 except that the raw materials and precursors were appropriately changed.

[0405] [Chemistry 43]

[0406]

[0407] [Synthesis Example 46]

[0408] (Synthesis of Compound (B-23))

[0409] Compound (B-23) was synthesized according to the following synthesis scheme.

[0410] [Chemistry 44]

[0411]

[0412] 20.0 mmol of the olefin (B-1-a), 25.0 mmol of m-chloroperbenzoic acid and 50 g of dichloromethane were added to a reaction container and stirred at room temperature for 4 hours. Afterwards, a saturated aqueous sodium sulfite solution was added to stop the reaction, and then ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium bicarbonate solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and refined by column chromatography to obtain an epoxy body with a good yield.

[0413] To the epoxy body, 20.0 mmol of trimethylsilyl cyanide, 1.00 mmol of N-methylmorpholine-N-oxide and 50 g of dichloromethane were added, and the mixture was stirred at room temperature for 4 hours. Thereafter, 2 M hydrochloric acid was added to stop the reaction, and dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium chloride solution, and then washed with water. After drying with sodium sulfate, the solvent was distilled off, and column chromatography was used for purification, thereby obtaining a cyano body with a good yield.

[0414] 50 g of 5M sodium hydroxide aqueous solution was added to the cyano compound, and the mixture was stirred at 100° C. for 12 hours. After that, 1M hydrochloric acid was added to stop the reaction, and ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was distilled off, and the mixture was purified by column chromatography, thereby obtaining the carboxylic acid compound in good yield.

[0415] After adding a mixed solution of acetonitrile: water (1:1 (mass ratio)) to the carboxylic acid to prepare a 1M solution, 40.0mmol of sodium dithionite and 60.0mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 4 hours. After extraction with acetonitrile and distillation of the solvent, a mixed solution of acetonitrile: water (3:1 (mass ratio)) was added to prepare a 0.5M solution. 60.0mmol of hydrogen peroxide and 2.00mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. Extraction with acetonitrile and distillation of the solvent were performed to obtain a sodium sulfonate compound. 20.0mmol of (4-(tert-butyl)phenyl)diphenylsulfonium bromide was added to the sodium sulfonate compound, and a mixed solution of water: dichloromethane (1:3 (mass ratio)) was added to prepare a 0.5M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain the compound (B-23) represented by the formula (B-23) in good yield.

[0416] [Synthesis Example 47]

[0417] (Synthesis of Compound (B-24))

[0418] Compound (B-24) was synthesized according to the following synthetic scheme.

[0419] [Chemistry 45]

[0420]

[0421] 20.0 mmol of 3-hydroxy-1-adamantanecarboxylic acid, 20.0 mmol of methanol, 30.0 mmol of dicyclohexylcarbodiimide and 50 g of dichloromethane were added to the reaction vessel and stirred at room temperature for 4 hours. After dilution with water, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution and then washed with water. After drying with sodium sulfate, the solvent was distilled off and refined by column chromatography to obtain an ester with a good yield.

[0422] To the ester, 30.0 mmol of methanesulfonyl chloride, 30.0 mmol of triethylamine, and 50 g of dichloromethane were added, and the mixture was stirred at room temperature for 3 hours. Afterwards, a saturated aqueous ammonium chloride solution was added to stop the reaction, and dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium chloride solution, and then washed with water. After drying with sodium sulfate, the solvent was distilled off, and the mixture was purified by column chromatography, thereby obtaining a mesyl body with a good yield.

[0423] 30.0 mmol of 4-bromo-3,3,4,4-tetrafluoro-1-ol, 30.0 mmol of diazabicycloundecene and 50 g of acetonitrile were added to the mesyl body, and stirred at 80°C for 24 hours. Afterwards, a saturated aqueous solution of ammonium chloride was added to stop the reaction, and ethyl acetate was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous solution of sodium chloride and then washed with water. After drying with sodium sulfate, the solvent was distilled off and purified by column chromatography, thereby obtaining an alkoxy body with a good yield.

[0424] After adding a mixed solution of acetonitrile: water (1:1 (mass ratio)) to the alkoxy body to prepare a 1M solution, 40.0mmol of sodium dithionite and 60.0mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 4 hours. After extraction with acetonitrile and distillation of the solvent, a mixed solution of acetonitrile: water (3:1 (mass ratio)) was added to prepare a 0.5M solution. 60.0mmol of hydrogen peroxide water and 2.00mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. Extraction with acetonitrile and distillation of the solvent were performed to obtain a sodium sulfonate compound. 20.0mmol of (4-(tert-butyl)phenyl)diphenylsulfonium bromide was added to the sodium sulfonate compound, and a mixed solution of water: dichloromethane (1:3 (mass ratio)) was added to prepare a 0.5M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain an onium salt in good yield.

[0425] 50 g of 1M sodium hydroxide aqueous solution and 50 g of methanol were added to the onium salt, and stirred at 100° C. for 5 hours. Thereafter, 1M hydrochloric acid was added to stop the reaction, and dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried with sodium sulfate, the solvent was distilled off, and purified by column chromatography, thereby obtaining the compound (B-24) represented by the formula (B-24) with a good yield.

[0426] <Onium salts other than compounds (B-1) to (B-24)>

[0427] bb-1 to bb-7: Compounds represented by the following formulae (bb-1) to (bb-7) (hereinafter, compounds represented by formulae (bb-1) to (bb-7) may be referred to as "compound (bb-1)" to "compound (bb-7)", respectively)

[0428] [Chemistry 46]

[0429]

[0430] <[C] Acid diffusion control agent>

[0431] C-1 to C-8: Compounds represented by the following formulae (C-1) to (C-8) (hereinafter, compounds represented by formulae (C-1) to (C-8) may be referred to as "compound (C-1)" to "compound (C-8)", respectively)

[0432] [Chemistry 47]

[0433]

[0434] <[E]Solvent>

[0435] E-1: Propylene glycol monomethyl ether acetate

[0436] E-2: Propylene glycol monomethyl ether

[0437] E-3: γ-Butyrolactone

[0438] E-4: Ethyl lactate

[0439] <Preparation of positive radiation-sensitive composition for ArF immersion exposure>

[0440] [Example 1]

[0441] 100 parts by mass of (A-1) as the resin [A], 10.0 parts by mass of (B-1) as the radiation-sensitive acid generator [B], 8.0 parts by mass of (C-1) as the acid diffusion controller [C], 3.0 parts by mass of (F-1) as the high fluorine content resin [F] (solid content), and 3,230 parts by mass of a mixed solvent of (E-1) / (E-2) / (E-3) (2,240 / 960 / 30 (parts by mass)) as the solvent [E] were mixed and filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation-sensitive composition (J-1).

[0442] [Example 2 to Example 51 and Comparative Example 1 to Comparative Example 7]

[0443] Radiation-sensitive compositions (J-2) to (J-51) and radiation-sensitive compositions (CJ-1) to (CJ-7) were prepared in the same manner as in Example 1 except that the types and contents of the components shown in Tables 4 and 5 below were used.

[0444]

[0445]

[0446] <Formation of a resist pattern using a positive radiation-sensitive composition for ArF immersion exposure>

[0447] A composition for forming an underlayer film ("ARC66" produced by Brewer Science) was applied to a 12-inch silicon wafer using a spin coater ("CLEAN TRACK ACT12" produced by Tokyo Electron Co., Ltd.), and then heated at 205°C for 60 seconds to form an underlayer film having an average thickness of 100 nm. The positive-type radiation-sensitive composition for ArF immersion exposure prepared as described above was applied to the underlayer film using the spin coater, and prebaked (PB) was performed at 100°C for 60 seconds. Thereafter, the film was cooled at 23°C for 30 seconds to form a resist film having an average thickness of 90 nm. Next, the resist film was exposed using an ArF excimer laser immersion exposure device ("TWINSCAN XT-1900i" manufactured by ASML) under the optical conditions of NA = 1.35 and dipole (σ = 0.9 / 0.7) with a shielding pattern of 40 nm lines and spaces. After exposure, a post-exposure bake (PEB) was performed at 100°C for 60 seconds. Thereafter, a 2.38 mass % TMAH aqueous solution was used as an alkaline developer to perform alkaline development on the resist film, which was then rinsed with water and dried to form a positive resist pattern (55 nm line and space pattern).

[0448] <Evaluation>

[0449] The resist pattern formed using the positive radiation-sensitive composition for ArF immersion exposure was evaluated for sensitivity, LWR performance, pattern rectangularity, and the number of development defects by the following methods. The results are shown in Tables 6 and 7. A scanning electron microscope ("CG-5000" manufactured by Hitachi High-Technologies Co., Ltd.) was used to measure the length of the resist pattern.

[0450] [sensitivity]

[0451] In the formation of a resist pattern using a positive radiation-sensitive composition for ArF immersion exposure, the exposure amount for forming a 55 nm line and space pattern was set as the optimum exposure amount, and the optimum exposure amount was set as the sensitivity (mJ / cm 2 ). Regarding the sensitivity, it is 25mJ / cm 2 The following cases were evaluated as "good", and more than 25mJ / cm 2 In the case of , it is evaluated as "bad".

[0452] [LWR performance]

[0453] The resist pattern of 55nm line and space is formed by irradiating with the optimal exposure amount obtained in the evaluation of the sensitivity. Using the scanning electron microscope, the formed resist pattern is observed from the upper part of the pattern. The deviation of the line width at a total of 500 places is measured, and the 3 sigma value is calculated based on the distribution of the measured values, and the 3 sigma value is used as LWR (nm). The smaller the value of LWR, the smaller the roughness of the line and the better. Regarding the LWR performance, it is evaluated as "good" when it is less than 2.5nm, and it is evaluated as "poor" when it exceeds 2.5nm.

[0454] [Pattern rectangularity]

[0455] The 55nm line and space resist pattern formed by irradiating the optimal exposure amount obtained in the evaluation of the sensitivity was observed using the scanning electron microscope to evaluate the cross-sectional shape of the line and space pattern. Regarding the rectangularity of the resist pattern, if the ratio of the length of the lower side to the length of the upper side in the cross-sectional shape is greater than 1.00 and less than 1.05, it is evaluated as "A" (extremely good), if it exceeds 1.05 and is less than 1.10, it is evaluated as "B" (good), and if it exceeds 1.10, it is evaluated as "C" (poor).

[0456] [Development Defects]

[0457] The resist film is exposed with the optimal exposure amount to form a line and space pattern with a line width of 55nm as a defect inspection wafer. A defect inspection device ("KLA2810" of KLA-Tencor) is used to measure the number of defects on the defect inspection wafer. Defects with a diameter of less than 50μm are judged as defects originating from the resist film, and their number is calculated. Regarding the number of defects after development, it is evaluated as "good" when the number of defects judged to be derived from the resist film is less than 50, and it is evaluated as "poor" when more than 50.

[0458] [Table 6]

[0459]

[0460] [Table 7]

[0461]

[0462] As is clear from the results of Tables 6 and 7, the radiation-sensitive compositions of Examples 1 to 51, when used for forming a resist pattern by ArF immersion exposure, have good sensitivity, LWR performance, pattern rectangularity, and development defect suppression performance, and have achieved a balance of various properties. In contrast, the radiation-sensitive compositions of Comparative Examples 1 to 7 have various properties inferior to those of the Examples. Therefore, it can be said that when the radiation-sensitive compositions of Examples 1 to 51 are used for ArF immersion exposure, a resist pattern showing high sensitivity, good LWR performance and pattern rectangularity, and few development defects can be formed.

[0463] <Preparation of positive-type radiation-sensitive composition for extreme ultraviolet (EUV) exposure>

[0464] [Example 52]

[0465] 100 parts by mass of (A-14) as the resin [A], 40.0 parts by mass of (B-1) as the radiation-sensitive acid generator [B], 30.0 parts by mass of (C-1) as the acid diffusion controller [C], 6.0 parts by mass of (F-5) as the high fluorine content resin [F] (solid content), and 6,110 parts by mass of a mixed solvent of (E-1) / (E-4) as the solvent [E] (4,280 / 1,830 (parts by mass)) were mixed, and filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation-sensitive composition (J-52).

[0466] [Example 53 to Example 72 and Comparative Example 8 to Comparative Example 12]

[0467] Radiation-sensitive compositions (J-53) to (J-72) and radiation-sensitive compositions (CJ-8) to (CJ-12) were prepared in the same manner as in Example 52 except that the components of the types and contents shown in Table 8 below were used.

[0468]

[0469] <Formation of a resist pattern using a positive radiation-sensitive composition for EUV exposure>

[0470] A composition for forming an underlayer film ("ARC66" produced by Brewer Science) was applied to a 12-inch silicon wafer using a spin coater ("CLEAN TRACK ACT12" produced by Tokyo Electron), and then heated at 205°C for 60 seconds to form an underlayer film having an average thickness of 105 nm. The prepared radiation-sensitive composition for EUV exposure was applied to the underlayer film using the spin coater, and PB was performed at 130°C for 60 seconds. Thereafter, the film was cooled at 23°C for 30 seconds to form a resist film having an average thickness of 55 nm. Next, the resist film was exposed using an EUV exposure device ("NXE3300" produced by ASML) with NA = 0.33, illumination conditions: conventional s = 0.89, and shield: imecDEFECT32FFR02. After exposure, PEB was performed at 120° C. for 60 seconds. Thereafter, the resist film was alkali developed using a 2.38 mass % TMAH aqueous solution as an alkaline developer, and after development, it was washed with water and dried to form a positive resist pattern (25 nm line and space pattern).

[0471] <Evaluation>

[0472] The resist pattern formed using the positive radiation-sensitive composition for EUV exposure was evaluated for sensitivity, LWR performance, pattern rectangularity, and the number of development defects by the following methods. The results are shown in Table 9. A scanning electron microscope ("CG-5000" manufactured by Hitachi High-Technologies Co., Ltd.) was used to measure the length of the resist pattern.

[0473] [sensitivity]

[0474] In the formation of a resist pattern using a positive radiation-sensitive composition for EUV exposure, the exposure amount for forming a 25 nm line and space pattern was set as the optimum exposure amount, and the optimum exposure amount was set as the sensitivity (mJ / cm 2 ). Regarding the sensitivity, it is 40mJ / cm 2 The following cases were evaluated as "good", and more than 40 mJ / cm 2 The case was evaluated as "poor".

[0475] [LWR performance]

[0476] The optimal exposure amount obtained in the evaluation of the sensitivity is irradiated, and the shielding size is adjusted in a manner to form a 25nm line and space pattern to form a resist pattern. Using the scanning electron microscope, the formed resist pattern is observed from the upper part of the pattern. The deviation of the line width at a total of 500 places is measured, and the 3 sigma value is calculated based on the distribution of the measured values, and the 3 sigma value is used as LWR (nm). The smaller the value of LWR, the smaller the shaking of the line and the better. Regarding the LWR performance, it is evaluated as "good" when it is less than 3.0nm, and it is evaluated as "poor" when it exceeds 3.0nm.

[0477] [Pattern rectangularity]

[0478] The 32nm line and space resist pattern formed by irradiating the optimal exposure amount obtained in the evaluation of the sensitivity was observed using the scanning electron microscope to evaluate the cross-sectional shape of the line and space pattern. Regarding the rectangularity of the resist pattern, if the ratio of the length of the lower side to the length of the upper side in the cross-sectional shape is greater than 1.00 and less than 1.05, it is evaluated as "A" (extremely good), if it exceeds 1.05 and is less than 1.10, it is evaluated as "B" (good), and if it exceeds 1.10, it is evaluated as "C" (poor).

[0479] [Development Defects]

[0480] The resist film is exposed with the optimal exposure amount to form a line and space pattern with a line width of 25nm as a defect inspection wafer. A defect inspection device ("KLA2810" of KLA-Tencor) is used to measure the number of defects on the defect inspection wafer. Defects with a diameter of less than 50μm are judged as defects originating from the resist film, and their number is calculated. Regarding the number of defects after development, it is evaluated as "good" when the number of defects judged to be derived from the resist film is less than 50, and it is evaluated as "poor" when more than 50.

[0481] [Table 9]

[0482]

[0483] As is clear from the results of Table 9, the radiation-sensitive compositions of Examples 52 to 72 are good in sensitivity, LWR performance, pattern rectangularity, and development defect suppression performance when used for forming a resist pattern by EUV exposure. In contrast, the radiation-sensitive compositions of Comparative Examples 8 to 12 are inferior in various properties to those of the Examples.

[0484] <Preparation of negative radiation-sensitive composition for ArF immersion exposure, formation and evaluation of resist pattern using the composition>

[0485] [Example 73]

[0486] 100 parts by mass of (A-1) as the resin [A], 12.0 parts by mass of (B-1) as the radiation-sensitive acid generator [B], 6.0 parts by mass of (C-4) as the acid diffusion controller [C], 3.0 parts by mass of (F-4) as the high fluorine content resin [F] (solid content), and 3,230 parts by mass of a mixed solvent of (E-1) / (E-2) / (E-3) (2,240 / 960 / 30 (parts by mass)) as the solvent [E] were mixed and filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation-sensitive composition (J-73).

[0487] A composition for forming an underlayer film ("ARC66" from Brewer Science) was applied to a 12-inch silicon wafer using a spin coater ("CLEAN TRACK ACT12" from Tokyo Electron Co., Ltd.), and then heated at 205°C for 60 seconds to form an underlayer film having an average thickness of 100 nm. The prepared radiation-sensitive composition (J-73) was applied to the underlayer film using the spin coater, and prebaked (PB) was performed at 100°C for 60 seconds. Thereafter, the film was cooled at 23°C for 30 seconds to form a resist film having an average thickness of 90 nm. Next, the resist film was exposed using an ArF excimer laser immersion exposure device (TWINSCAN XT-1900i from ASML) with an optical condition of NA = 1.35, annular (σ = 0.8 / 0.6) and a shielding pattern with a 40nm hole and a 105nm pitch. After exposure, a post-exposure bake (PEB) was performed at 100°C for 60 seconds. Thereafter, the resist film was subjected to organic solvent development using n-butyl acetate as an organic solvent developer and dried to form a negative resist pattern (60nm hole, 120nm pitch).

[0488] The CDU performance of the resist pattern formed using the negative radiation-sensitive composition for ArF immersion exposure was evaluated by the following method. The length of the resist pattern was measured using a scanning electron microscope ("CG-5000" manufactured by Hitachi High-Technologies Co., Ltd.).

[0489] [CDU performance]

[0490] For a resist pattern with 60 nm holes and 120 nm spacing, the scanning electron microscope was used to measure the length of a total of 1,800 points from the top of the pattern. The deviation (3σ) of the size was calculated and used as the CDU performance (nm). The smaller the CDU value, the smaller the deviation of the hole diameter under the long period, which is good.

[0491] Resist patterns using the radiation sensitive composition (J-73) were evaluated as described above. As a result, it was found that the radiation sensitive composition containing the polymer (A) and the compound (B) showed good CDU performance when a negative resist pattern was formed by ArF immersion exposure.

[0492] <Preparation of negative-type radiation-sensitive composition for EUV exposure, formation and evaluation of resist pattern using the composition>

[0493] [Example 74]

[0494] 100 parts by mass of (A-17) as the resin [A], 40.0 parts by mass of (B-6) as the radiation-sensitive acid generator [B], 40.0 parts by mass of (C-2) as the acid diffusion controller [C], 3.0 parts by mass of (F-5) as the high fluorine content resin [F] (solid content), and 6,110 parts by mass of a mixed solvent of (E-1) / (E-4) (4,280 / 1,830 (parts by mass)) as the solvent [E] were mixed, and filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation-sensitive composition (J-74).

[0495] A composition for forming an underlayer film ("ARC66" produced by Brewer Science) was applied to a 12-inch silicon wafer using a spin coater ("CLEAN TRACK ACT12" produced by Tokyo Electron), and then heated at 205°C for 60 seconds to form an underlayer film having an average thickness of 105 nm. The prepared radiation-sensitive composition (J-74) was applied to the underlayer film using the spin coater, and PB was performed at 130°C for 60 seconds. Thereafter, the film was cooled at 23°C for 30 seconds to form a resist film having an average thickness of 55 nm. Next, the resist film was exposed using an EUV exposure device ("NXE3300" produced by ASML) with NA = 0.33, illumination conditions: conventional s = 0.89, and shield: imecDEFECT32FFR02. After exposure, PEB was performed at 120° C. for 60 seconds. Thereafter, the resist film was subjected to organic solvent development using n-butyl acetate as an organic solvent developer and dried to form a negative resist pattern (30 nm holes, 60 nm pitch).

[0496] The CDU performance of the resist pattern using the radiation-sensitive composition (J-74) was evaluated in the same manner as the evaluation of the resist pattern using the negative-type radiation-sensitive composition for ArF immersion exposure. As a result, the radiation-sensitive composition containing the polymer (A) and the compound (B) showed good CDU performance even when a negative-type resist pattern was formed by EUV exposure.

[0497] The radiation-sensitive composition and resist pattern forming method described above have good sensitivity to exposure light, and are excellent in LWR performance, pattern rectangularity, and development defect suppression performance. Therefore, these can be suitably used in the processing of semiconductor devices that are expected to be further miniaturized in the future.

Claims

1. A radiation-sensitive composition comprising: A polymer having an acid-dissociable group, and A compound represented by the following formula (1): In formula (1), L 1 A group having a (thio)acetal ring in which two oxygens, two sulfurs, or one oxygen and one sulfur are bonded to the same carbon through two methylene groups of a monocyclic saturated aliphatic hydrocarbon ring being substituted with (thio)ether bonds, or a group represented by the following formula (L-2); In formula (L-2), L 2 is a bridged alicyclic group having 7 or more carbon atoms; 3 is a single bond, oxygen atom, sulfur atom or -SO2-; d is 1 or 2; "* 3 " indicates that 1 or carboxyl-bonded bonds; W 1 is a single bond or a (b+1)-valent organic group having 1 to 40 carbon atoms; R 1 , R 2 and R 3 are independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a fluorine atom or a fluoroalkyl group; R f is a fluorine atom or a fluoroalkyl group; a is an integer from 0 to 8; b is an integer from 1 to 4; d is 1 or 2; L 1 When a is 2 or more, the plurality of R 1 Same or different, multiple R 2 The same or different; when d is 2, multiple W 1 The same or different, multiple b are the same or different; M + It is a monovalent cation.

2. The radiation-sensitive composition according to claim 1, wherein the L 1 is a group having a (thio)acetal ring and is represented by the following formula (L-1), In formula (L-1), X 1 and X 2 are independently an oxygen atom or a sulfur atom; R 41 is a single bond or an alkanediyl group having 1 to 10 carbon atoms; r is 1 or 2; when r is 1, 44 and R 45 , R 44 is a single bond, R 45 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, or represents R 44 and R 45 The carbon atoms to which they are bonded and the (thio)acetal ring in formula (L-1) form a spirocyclic ring structure; when r is 2, R 44 is a single bond; In the formula (1), L 1 Partial structure of the bond"-W 1 -(COOH) b "W" 1 In the partial structure with a single bond, b is 1; R 42 , R 43 , Y 1 and Y 2 Satisfies (i), (ii) or (iii) below; (i)R 42 is an alkanediyl group having 1 to 10 carbon atoms; R 43 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; 1 is a single bond or a divalent linking group; Y 2 is a single bond; (ii) R 42 and Y 1 represents a ring structure that is combined with each other and forms a condensed ring structure together with the carbon atom to which it is bonded and the (thio)acetal ring in formula (L-1); R 43 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; 2 It is a single bond or a divalent linking group; (iii) R 43 and Y 1 represents a ring structure that is bonded to each other and forms a spiro ring structure together with the carbon atom to which it is bonded and the (thio)acetal ring in formula (L-1); R 42 is an alkanediyl group having 1 to 10 carbon atoms; 2 It is a single bond or a divalent linking group; "* 1 " represents the same as W in the formula (1) 1 Or a bond to a carboxyl group; "*" indicates a bond.

3. The radiation-sensitive composition according to claim 1, wherein the 1 Partial structure of the bond"-W 1 -(COOH) b "In more than one of the 1 is a group having a ring structure, one or more carboxyl groups are bonded to W 1 On the ring in. 4 . The radiation sensitive composition according to claim 3 , wherein one or more carboxyl groups are bonded to an aromatic ring.

5. The radiation-sensitive composition according to claim 1, wherein the 1 Partial structure of the bond"-W 1 -(COOH) b "In more than one of the 1 is a single key, In the formula (1), L 1 is a group having a (thio)acetal ring and having 1 The (thio)acetal rings in the x , In the ring R x Or a carboxyl group is bonded to the (thio)acetal ring.

6. The radiation-sensitive composition according to claim 5, wherein the ring R x is a polycyclic aliphatic hydrocarbon ring, a polycyclic saturated heterocyclic ring or a polycyclic aromatic hydrocarbon ring, In the ring R x A carboxyl group is bonded to the polycyclic aliphatic hydrocarbon ring, polycyclic saturated heterocyclic ring or polycyclic aromatic hydrocarbon ring.

7. The radiation-sensitive composition according to claim 1, wherein the polymer comprises a structural unit represented by the following formula (3): In formula (3), R 11 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group or an alkoxyalkyl group; 1 is a single bond or a substituted or unsubstituted divalent hydrocarbon group; R 15 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms; R 16 and R 17 are independently a monovalent chain hydrocarbon group having 1 to 8 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, or R 16 and R 17 Combined with R 16 and R 17 The carbon atoms to which the bond is attached together constitute a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms. 8 . The radiation-sensitive composition according to claim 1 , further comprising a compound that generates an acid weaker than the acid generated from the compound represented by the formula (1) upon irradiation with radiation.

9. A method for forming a resist pattern, comprising: A step of applying the radiation-sensitive composition according to any one of claims 1 to 8 on a substrate to form a resist film; a step of exposing the resist film to light; and A step of developing the exposed resist film. 10 . The resist pattern forming method according to claim 9 , wherein in the developing step, the exposed resist film is developed using an alkaline developer.

11. A radiation-sensitive linear acid generator represented by the following formula (1): In formula (1), L 1 A group having a (thio)acetal ring in which two oxygens, two sulfurs, or one oxygen and one sulfur are bonded to the same carbon through two methylene groups of a monocyclic saturated aliphatic hydrocarbon ring being substituted with (thio)ether bonds, or a group represented by the following formula (L-2); In formula (L-2), L 2 is a bridged alicyclic group having 7 or more carbon atoms; 3 is a single bond, oxygen atom, sulfur atom or -SO2-; d is 1 or 2; "* 3 " indicates that 1 or carboxyl-bonded bonds; W 1 is a single bond or a (b+1)-valent organic group having 1 to 40 carbon atoms; R 1 , R 2 and R 3 are independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a fluorine atom or a fluoroalkyl group; R f is a fluorine atom or a fluoroalkyl group; a is an integer from 0 to 8; b is an integer from 1 to 4; d is 1 or 2; L 1 When a is 2 or more, the plurality of R 1 Same or different, multiple R 2 The same or different; when d is 2, multiple W 1 The same or different, multiple b are the same or different; M + It is a monovalent cation.

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