Radiosensitive linear components, pattern formation methods and photodegradable alkalis

Abstract

This invention provides a radiosensitive linear composition exhibiting high sensitivity and good storage stability, as well as excellent LWR performance, CDU performance, and pattern rectangularity. The radiosensitive linear composition contains a polymer with an acid-dissociable group and a compound (Q) represented by formula (1). In formula (1), L... 1 is an ester group, -CO-NR 3-, (thio)ether group or sulfonyl group, L 2 represents a single bond or a divalent linker.

Description

Technical Field

[0001] This invention relates to a radiosensitive linear composition, a patterning method, and a photodegradable alkali. Prior Technology

[0002] In the formation of fine circuits in semiconductor devices, photolithography using a resist composition is employed. A representative procedure in photolithography involves first exposing a resist film (hereinafter also referred to as a "resist film") with a dielectric mask pattern to radiation. Through a chemical reaction involving acids generated by the exposure, a difference in solubility of the resist film in the developer is created between the exposed and unexposed areas. Next, the resist film is brought into contact with the developer to form a resist pattern on a substrate.

[0003] For example, Patent Document 1 discloses an anti-corrosion composition containing a resin with an acid-instable group and an onium salt containing a thioxanthate-type strontium cation and a sulfonic acid anion with a specific structure as an acid generator. [Existing Technical Documents] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2014-167611 Summary of the Invention

[0005] [The problem that the invention aims to solve]

[0006] In photolithography using resist compositions, pattern miniaturization is advanced by utilizing short-wavelength radiation such as ArF excimer lasers, or by using liquid immersion lithography (LII LITHO), where exposure is performed in a state where the space between the lens and the resist film is filled with a liquid medium in the exposure apparatus. Furthermore, as a next-generation technology, lithography using even shorter wavelength radiation such as electron beams, X-rays, and extreme ultraviolet (EUV) is being researched. Efforts towards this next-generation technology require performance equal to or better than previous methods in areas such as the radiation sensitivity of the resist composition, line width roughness (LWR) as an indicator of linewidth deviation in the resist pattern, critical dimension uniformity (CDU) as an indicator of linewidth or aperture uniformity, and pattern rectangularity as an indicator of the rectangularity of the resist pattern's cross-sectional shape.

[0007] When the radiosensitive linear acid generator incorporated into the resist composition is prone to deterioration, the sensitivity or lithography performance may decrease during long-term storage of the resist composition. Therefore, good storage stability of the resist composition is also required.

[0008] The present invention was made in view of the aforementioned issues, and its main objective is to provide a radiosensitive linear composition and a patterning method that exhibit high sensitivity, good storage stability, and excellent LWR performance, CDU performance, and pattern rectangularity. [Methods for solving problems]

[0009] The inventors, through repeated research to solve this problem, discovered that the problem could be solved by using onium salt compounds with a specific structure, thus completing this invention. Specifically, this invention provides the following methods.

[0010] In one embodiment of the present invention, a radiosensitive linear composition is provided, comprising a polymer having an acid-dissociable group and a compound (Q) represented by the following formula (1).

[0011] [Chemistry 1] (In formula (1), L1 is an ester group, -CO-NR 3-, (thio)ether group, or sulfonyl group; when L1 is an ester group, (thio)ether group, or sulfonyl group, R1, R2, and R3 satisfy the following (i) or (ii); when L1 is -CO-NR 3-, R1, R2, and R3 satisfy the following (i), (ii), or (iii); (i) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 via a carbon atom; R2 is a substituted or unsubstituted divalent hydrocarbon group; wherein R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (ii) R1 and R2 represent groups comprising an aliphatic heterocyclic structure formed by mutual bonding and together with the bonded L1 groups; wherein R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (iii) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 via a carbon atom; R2 and R3 represent aliphatic heterocyclic structures formed by mutual bonding and together with L1; wherein the aliphatic heterocyclic structure does not have fluorine atoms; R4 is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group with 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, or a nitro group; R5 is a monovalent hydrocarbon group with 1 to 20 carbon atoms, a monovalent halide hydrocarbon group with 1 to 20 carbon atoms, or a halogen atom, or represents an alicyclic structure formed by two R5s bonded together with the bonded carbon atoms. L2 is a single bond or a divalent linker; n1 and n2 are independent integers from 1 to 4; n3 is an integer from 0 to 5; when n3 is 2 or more, multiple R5s may be the same or different; multiple R4s may be the same or different.

[0012] In another embodiment of the present invention, a pattern forming method is provided, comprising: a step of coating the radiosensitive linear composition onto a substrate to form a resist film; a step of exposing the resist film; and a step of developing the exposed resist film.

[0013] In another embodiment of the present invention, a photodegradable alkali represented by formula (1) is provided. [The effects of the invention]

[0014] The radiosensitive linear composition of the present invention, comprising a polymer having an acid-dissociable group and a compound (Q) represented by formula (1), exhibits high sensitivity and good storage stability, while demonstrating excellent LWR performance, CDU performance, and pattern rectangularity when forming resist patterns. Furthermore, by using the radiosensitive linear composition of the present invention, the pattern forming method of the present invention enables further refinement and improvement in the precision and quality of fine resist patterns. Simple Explanation of the Diagram

[0015] none Implementation

[0016] The following provides a detailed description of matters related to the implementation of this disclosure. Furthermore, in this specification, the numerical range recorded using "~" means that the values ​​recorded before and after "~" are included as lower and upper limits.

[0017] Radioactive linear components The radiosensitive linear resin composition disclosed herein (hereinafter, also referred to as "this composition") contains a polymer having an acid-dissociable group (hereinafter, also referred to as "polymer (A)") and a compound (Q) having a specific structure. Furthermore, this composition may also contain any other arbitrary components, provided that the effects of this disclosure are not impaired. Each component is described in detail below.

[0018] Furthermore, in this specification, "hydrocarbon group" refers to a group comprising chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. "Chain hydrocarbon group" refers to a straight-chain hydrocarbon group or a branched-chain hydrocarbon group that contains only a chain structure and no cyclic structure. Chain hydrocarbon groups may be saturated or unsaturated. "Alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. Alicyclic hydrocarbon groups do not necessarily need to contain only an alicyclic hydrocarbon structure; they may also have a chain structure in a portion thereof. "Aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure. Aromatic hydrocarbon groups do not necessarily need to contain only an aromatic ring structure; they may also contain a chain structure or an alicyclic hydrocarbon structure in a portion thereof. "Organic group" refers to a group of atoms formed by removing any hydrogen atoms from a carbon-containing compound (i.e., an organic compound). "(Meth)acrylic acid" refers to a group comprising "acrylic acid" and "methacrylic acid". "(Thio)ether" refers to a group comprising "ether" and "thioether".

[0019] <Polymer (A)> The acid-dissociative groups in polymer (A) are groups that substitute for the hydrogen atoms of acid groups (such as carboxyl, phenolic hydroxyl, alcoholic hydroxyl, sulfonyl, etc.), and are dissociated by the action of acid. By incorporating polymers with acid-dissociative groups into a radiosensitive linear composition, the acid-dissociative groups dissociate to generate acid groups through a chemical reaction involving the acid generated by exposure, thereby altering the polymer's solubility in the developer. As a result, this composition can be endowed with excellent photolithography properties.

[0020] The polymer (A) is preferably a structural unit containing an acid-dissociable group (hereinafter also referred to as "structural unit (I)"). Examples of structural units (I) include: structural units in which the hydrogen atoms of the carboxyl group are substituted or unsubstituted tertiary hydrocarbon groups, structural units in which the hydrogen atoms of the phenolic hydroxyl group are substituted or unsubstituted tertiary hydrocarbon groups, structural units in which the acetal structure is formed, etc. From the viewpoint of improving the rectangularity of the pattern of the composition, structural unit (I) is preferably a structural unit in which the hydrogen atoms of the carboxyl group are substituted or unsubstituted tertiary hydrocarbon groups, and more specifically, is the structural unit represented by the following formula (3) (hereinafter also referred to as "structural unit (I-1)"). [Chemistry 2] (In formula (3), R11 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or an alkoxyalkyl group; Q1 is a single bond or a substituted or unsubstituted divalent hydrocarbon group; R12 is a substituted or unsubstituted monovalent hydrocarbon group with 1 to 20 carbon atoms; R13 and R14 are independently monovalent chain hydrocarbon groups with 1 to 10 carbon atoms or monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, or represent a divalent alicyclic hydrocarbon group with 3 to 20 carbon atoms formed by the combination of R13 and R14 and the carbon atoms bonded to R13 and R14.)

[0021] In formula (3), from the viewpoint of providing the copolymerization of the monolithic structural unit (I-1), R 11 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. The divalent hydrocarbon group represented by Q 1 is preferably a divalent aromatic ring group, and more preferably an extended phenyl or extended naphthyl group. In the case that Q 1 is a substituted divalent hydrocarbon group, halogen atoms (fluorine atoms, etc.) can be listed as substituents. Q 1 is preferably a single bond.

[0022] Examples of monovalent hydrocarbon groups with 1 to 20 carbon atoms represented by R 12 include: monovalent chain hydrocarbon groups with 1 to 10 carbon atoms, monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups with 6 to 20 carbon atoms. When R 12 is a substituted monovalent hydrocarbon group, examples of substituents include halogen atoms (fluorine atoms, etc.) and alkoxy groups.

[0023] Examples of monovalent chain hydrocarbon groups with 1 to 10 carbon atoms represented by R 12 to R 14 include: straight-chain or branched saturated hydrocarbon groups with 1 to 10 carbon atoms, and straight-chain or branched unsaturated hydrocarbon groups with 1 to 10 carbon atoms. Among these, the monovalent chain hydrocarbon groups with 1 to 10 carbon atoms represented by R 12 to R 14 are preferably straight-chain or branched saturated hydrocarbon groups with 1 to 10 carbon atoms.

[0024] Examples of monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, represented by R 12 to R 14, include: groups obtained by removing one hydrogen atom from a monocyclic saturated alicyclic hydrocarbon with 3 to 20 carbon atoms, a monocyclic unsaturated alicyclic hydrocarbon, or an alicyclic polycyclic hydrocarbon. Specific examples of these alicyclic hydrocarbons include monocyclic saturated alicyclic hydrocarbons such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; monocyclic unsaturated alicyclic hydrocarbons such as cyclopentene, cyclohexene, cycloheptene, cyclooctene, and cyclodecene; and polycyclic alicyclic hydrocarbons such as bicyclic [2.2.1]heptane (norbornene), bicyclic [2.2.2]octane, tricyclic [3.3.1.1 3,7]decane (adamantane), and tetracyclic [6.2.1.1 3,6.0 2,7]dodecane.

[0025] As a monovalent aromatic hydrocarbon group with 6 to 20 carbon atoms represented by R 12, examples include: groups formed by removing one hydrogen atom from the aromatic rings of benzene, naphthalene, anthracene, indene, and fluorene.

[0026] From the viewpoint of fully removing developing residue and increasing the dissolution contrast difference between the exposed and unexposed areas relative to the developing solution, R 12 is preferably a monovalent hydrocarbon group with 1 to 8 carbons, more preferably a straight-chain or branched monovalent saturated hydrocarbon group with 1 to 8 carbons, or a monovalent alicyclic hydrocarbon group with 3 to 8 carbons.

[0027] As a divalent alicyclic hydrocarbon group with 3 to 20 carbon atoms, formed by the combination of R13 and R14 and the carbon atoms bonded to R13 and R14, examples can be derived from the group formed by removing two hydrogen atoms from the same carbon atom of the carbon ring of a monocyclic or polycyclic alicyclic hydrocarbon constituting the aforementioned number of carbon atoms. The divalent alicyclic hydrocarbon group formed by the combination of R13 and R14 can be a monocyclic hydrocarbon group or a polycyclic hydrocarbon group. When the divalent alicyclic hydrocarbon group formed by the combination of R13 and R14 is a polycyclic hydrocarbon group, it can be a bridged alicyclic hydrocarbon group or a condensed alicyclic hydrocarbon group. Furthermore, the polycyclic hydrocarbon group can be a saturated hydrocarbon group or an unsaturated hydrocarbon group. A saturated hydrocarbon group is preferred.

[0028] In this specification, "bridged alicyclic hydrocarbon" refers to a polycyclic alicyclic hydrocarbon in which two non-adjacent carbon atoms constituting the alicyclic ring are bonded together by a chain bond containing one or more carbon atoms. "Condensed alicyclic hydrocarbon" refers to a polycyclic alicyclic hydrocarbon in which multiple alicyclic rings share a common edge (a bond between two adjacent carbon atoms). "Spirocyclic hydrocarbon" refers to a polycyclic cyclic hydrocarbon in which two rings share a common atom. Spirocyclic hydrocarbons can be composed of combinations of monocyclic structures, and can also include bridged ring structures or condensed ring structures. "Alicyclic polycyclic hydrocarbons" include bridged alicyclic hydrocarbons, condensed alicyclic hydrocarbons, and spirocyclic hydrocarbons.

[0029] The saturated hydrocarbon group in the monocyclic alicyclic hydrocarbon group (hereinafter also referred to as "monocyclic aliphatic hydrocarbon group") is preferably cyclopentanediyl, cyclohexanediyl, cycloheptanediyl, or cyclooctanediyl, and the unsaturated hydrocarbon group is preferably cyclopentenidyl, cyclohexenidyl, cycloheptenidyl, or cyclooctenidyl. The polycyclic alicyclic hydrocarbon group (hereinafter also referred to as "polycyclic aliphatic hydrocarbon group") is preferably a bridged alicyclic saturated hydrocarbon group, and is preferably a bicyclic [2.2.1]heptane-2,2-diyl (norbornene-2,2-diyl), a bicyclic [2.2.2]octane-2,2-diyl, a tetracyclic [6.2.1.1 3,6.0 2,7]dodecanediyl, or a tricyclic [3.3.1.1 3,7]decane-2,2-diyl (adamantane-2,2-diyl).

[0030] In terms of the ease of adjusting the solubility of polymer (A) in developer, the ease of forming fine patterns, the fact that compounds derived from detached groups are less likely to remain in the film, the ability to suppress roughness degradation, and the ability to suppress uneven dissolution at the interface with developer, polymer (A) preferably contains at least a portion of the structural unit (I) containing the structural unit represented by the following formula (4). [Chemistry 3] (In formula (4), R11 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or an alkoxyalkyl group; Q1 is a single bond or a substituted or unsubstituted divalent hydrocarbon group; R15 is a monovalent hydrocarbon group with 1 to 8 carbon atoms; R16 and R17 are independently monovalent chain hydrocarbon groups with 1 to 8 carbon atoms or monovalent monocyclic aliphatic hydrocarbon groups with 3 to 8 carbon atoms, or represent a divalent monocyclic aliphatic hydrocarbon group with 3 to 8 carbon atoms formed by the combination of R16 and R17 and the carbon atoms bonded to R16 and R17.)

[0031] In equation (4), from the viewpoint of providing the copolymerization of the monolithic structural unit represented by equation (4), R 11 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. Specific and preferred examples of Q 1 can be listed as the same base as that exemplified as Q 1 in equation (3).

[0032] As specific examples of R15, R16, and R17, examples of the corresponding carbon numbers in the description of R12, R13, and R14 in formula (3) can be cited. Among these, R15 is preferably a straight-chain or branched monovalent saturated chain hydrocarbon group with 1 to 5 carbons, or a monovalent alicyclic hydrocarbon group with 3 to 8 carbons, more preferably a straight-chain or branched monovalent saturated chain hydrocarbon group with 1 to 3 carbons, or a monovalent monocyclic aliphatic hydrocarbon group with 3 to 5 carbons. R16 and R17 are preferably straight-chain or branched monovalent chain saturated hydrocarbon groups with 1 to 4 carbons, or represent a divalent monocyclic aliphatic hydrocarbon group with 3 to 8 carbons formed by the combination of R16 and R17 and together with the carbon atoms bonded to R16 and R17.

[0033] The structural unit represented by formula (4) is preferably R15, which is an alkyl group having 1 to 4 carbon atoms, and R16 and R17, which are cycloalkanediols having 3 to 6 carbon atoms formed by the combination of R16 and R17 and together with the carbon atoms of these bonds.

[0034] Furthermore, from the viewpoint of improving etch resistance, polymer (A) may have the structural unit represented by the following formula (5). From the viewpoint of improving the solubility of polymer (A) and suppressing roughness degradation, while improving etch resistance, polymer (A) is preferably having the structural unit represented by the above formula (4) and the structural unit represented by the following formula (5). [Chemistry 4] (In formula (5), R11 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or an alkoxyalkyl group; Q1 is a single bond or a substituted or unsubstituted divalent hydrocarbon group; R18 is a monovalent hydrocarbon group with 1 to 20 carbon atoms; regarding R19 and R20, R19 is a monovalent chain hydrocarbon group with 1 to 10 carbon atoms or a monovalent polycyclic aliphatic hydrocarbon group with 7 to 20 carbon atoms, and R20 is a monovalent polycyclic aliphatic hydrocarbon group with 7 to 20 carbon atoms; or it represents a divalent polycyclic aliphatic hydrocarbon group with 7 to 20 carbon atoms formed by the combination of R19 and R20 and the carbon atoms bonded to R19 and R20.)

[0035] In equation (5), from the viewpoint of providing the copolymerization of the monolithic structural unit represented by equation (5), R 11 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. Specific and preferred examples of Q 1 can be listed as the same base as that exemplified as Q 1 in equation (3).

[0036] As specific examples of R18, R19, and R20, examples of the corresponding carbon numbers in the description of R12, R13, and R14 in formula (3) can be cited. Among these, R18 is preferably a straight-chain or branched monovalent chain hydrocarbon group with 1 to 5 carbons, or a monovalent alicyclic hydrocarbon group with 3 to 10 carbons. R19 and R20 are preferably: R19 is a monovalent chain hydrocarbon group with 1 to 4 carbons, and R20 is a monovalent bridged aliphatic hydrocarbon group with 7 to 15 carbons; or it represents a divalent bridged aliphatic hydrocarbon group with 7 to 15 carbons formed by the combination of R19 and R20 and together with the carbon atoms bonded to R19 and R20.

[0037] The structural unit represented by formula (5) is preferably R18 and R19 being alkyl groups having 1 to 4 carbon atoms, and R20 being a saturated bridged alicyclic hydrocarbon group having 7 to 15 carbon atoms, or R18 being an alkyl group having 1 to 4 carbon atoms, and R19 and R20 being saturated bridged alicyclic hydrocarbon groups having 7 to 15 carbon atoms that are bonded together with each other and together with the bonded carbon atoms.

[0038] As a specific example of structural unit (I), the structural units represented by equations (3-1) to (3-7) can be listed below. [Chemistry 5] (In equations (3-1) to (3-7), R11 to R14 have the same meaning as in equation (3); i and j are independent integers from 0 to 4; h and g are independent integers of 0 or 1.)

[0039] In formulas (3-1) to (3-7), i and j are preferably 1 or 2, more preferably 1. h and g are preferably 1. R 12 is preferably methyl, ethyl or isopropyl. R 13 and R 14 are preferably methyl or ethyl.

[0040] The content of structural unit (I) relative to all structural units constituting polymer (A) is preferably 15 mol% or more, more preferably 25 mol% or more, and even more preferably 35 mol% or more. Furthermore, the content of structural unit (I) relative to all structural units constituting polymer (A) is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less. By setting the content of structural unit (I) within the aforementioned range, the LWR performance, CDU performance, and pattern rectangularity of the composition can be further improved. Moreover, polymer (A) may have only one type of structural unit (I), or it may contain two or more types.

[0041] When polymer (A) has the structural unit represented by formula (4) as structural unit (I), the content ratio of the structural unit represented by formula (4) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, relative to all structural units constituting polymer (A). By keeping the content ratio of the structural unit represented by formula (4) within the above range, the solubility of polymer (A) in developer can be easily adjusted, and fine patterns can be easily obtained.

[0042] Furthermore, when polymer (A) has the structural unit represented by formula (5) as structural unit (I), the content ratio of the structural unit represented by formula (5) is preferably 1 mol% or more, more preferably 2 mol% or more, and even more preferably 5 mol% or more, relative to all structural units constituting polymer (A). By setting the content ratio of the structural unit represented by formula (5) within the aforementioned range, the difference in dissolution rate between the exposed and unexposed portions in the developer solution can be sufficiently increased in the resist film obtained using this composition, thereby improving the CDU performance and pattern rectangularity of this composition. Furthermore, when polymer (A) has both the structural unit represented by formula (4) and the structural unit represented by formula (5), the content ratio of the structural unit represented by formula (5) in polymer (A) is preferably 30 mol% or less, more preferably 25 mol% or less, and even more preferably 20 mol% or less, relative to all structural units constituting polymer (A).

[0043] [Other structural units] In addition to structural unit (I), polymer (A) may contain structural units that are different from structural unit (I) (hereinafter also referred to as "other structural units"). Examples of other structural units include structural units (II) and (III).

[0044] • Structural Unit (II) Polymer (A) may further include structural units having polar groups (hereinafter also referred to as "structural unit (II)"). By including structural unit (II) in polymer (A), the solubility of polymer (A) in developer can be more easily adjusted, thereby enabling improvements in lithography properties such as resolution. Examples of structural unit (II) include: structural units comprising at least one selected from the group consisting of lactone structures, cyclic carbonate structures, and sulfonyl lactone structures (hereinafter also referred to as "structural unit (II-1)"), and structural units having monovalent polar groups (hereinafter also referred to as "structural unit (II-2)").

[0045] • Structural Unit (II-1) By introducing structural unit (II-1) into polymer (A), the solubility of polymer (A) in developer can be adjusted, the adhesion of resist film can be improved, or the etching resistance can be further improved. Structural unit (II-1) can be exemplified by the structural units represented by the following formulas (6-1) to (6-9). [Chemistry 6] (In formulas (6-1) to (6-10), RL1 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or an alkoxyalkyl group; RL2 and RL3 are independently hydrogen atoms, alkyl groups with 1 to 4 carbon atoms, cyano groups, trifluoromethyl groups, methoxy groups, methoxycarbonyl groups, hydroxy groups, hydroxymethyl groups, or dimethylamino groups; RL4 and RL5 are independently hydrogen atoms, alkyl groups with 1 to 4 carbon atoms, cyano groups, trifluoromethyl groups, methoxy groups, methoxycarbonyl groups, hydroxy groups, hydroxymethyl groups, or dimethylamino groups, or are 3 to 8 carbon atoms of a divalent alicyclic hydrocarbon group formed by the combination of RL4 and RL5 and the carbon atoms bonded to RL4 and RL5; L5 is a single bond or a divalent linker; 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)

[0046] As a divalent alicyclic hydrocarbon group with 3 to 8 carbon atoms, formed by the combination of RL4 and RL5 and together with the carbon atoms bonded to RL4 and RL5, the groups with 3 to 8 carbon atoms in the description of R13 and R14 in formula (3) can be listed. One or more hydrogen atoms on the alicyclic hydrocarbon group may be substituted with hydroxyl groups.

[0047] Examples of divalent linkages represented by L 5 include: straight-chain or branched divalent chain hydrocarbon groups with 1 to 10 carbon atoms, divalent alicyclic hydrocarbon groups with 4 to 12 carbon atoms, or groups consisting of one or more of these hydrocarbon groups and at least one of the groups selected from -CO-, -O-, -NH- and -S-.

[0048] The structural unit (II-1) is preferably the structural unit represented by equation (6-2), (6-4), (6-6), (6-7) or (6-10) in equations (6-1) to (6-10).

[0049] When polymer (A) has structural unit (II-1), the content of structural unit (II-1) relative to all structural units constituting polymer (A) is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less. Furthermore, when polymer (A) has structural unit (II-1), the content of structural unit (II-1) relative to all structural units constituting polymer (A) is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more. By setting the content of structural unit (II-1) within the aforementioned range, the photolithography properties such as resolution of the composition can be further improved.

[0050] • Structural Unit (II-2) Structural unit (II-2) can also be introduced into polymer (A) to adjust the solubility of polymer (A) in developer, thereby improving the photolithography properties of the composition, such as resolution. Examples of polar groups that may be present in structural unit (II-2) include: hydroxyl, carboxyl, cyano, nitro, sulfonamide, etc. Among these, hydroxyl and carboxyl groups are preferred, with hydroxyl (especially alcoholic hydroxyl) being more preferred. Furthermore, structural unit (II-2) is a structural unit different from the structural unit (structural unit (III)) with phenolic hydroxyl groups described below.

[0051] In this specification, "phenolic hydroxyl group" refers to a group in which the hydroxyl group is directly bonded to an aromatic hydrocarbon structure. "Alcoholic hydroxyl group" refers to a group in which the hydroxyl group is directly bonded to an aliphatic hydrocarbon structure. In alcoholic hydroxyl groups, the aliphatic hydrocarbon structure to which the hydroxyl group is bonded can be a chain hydrocarbon group or an alicyclic hydrocarbon group.

[0052] As structural units (II-2), examples include structural units represented by the following formula. However, structural units (II-2) are not limited to these. [Chemistry 7] (In the formula, RA is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or an alkoxyalkyl group)

[0053] When polymer (A) has structural unit (II-2), the content of structural unit (II-2) is preferably 2 mol% or more, more preferably 5 mol% or more, relative to all structural units constituting polymer (A). Furthermore, the content of structural unit (II-2) is preferably 30 mol% or less, more preferably 25 mol% or less, and even more preferably 20 mol% or less, relative to all structural units constituting polymer (A). By setting the content of structural unit (II-2) within the aforementioned range, the photolithography properties such as resolution of the composition can be further improved.

[0054] • Structural Unit (III) Polymer (A) may further include structural units with phenolic hydroxyl groups (hereinafter also referred to as "structural unit (III)"). By having structural unit (III) in polymer (A), it is possible to achieve improved etch resistance and improved difference in developer solubility between exposed and unexposed areas (solution contrast), which is therefore preferable.

[0055] Especially in pattern formation using exposure with radiation of wavelengths below 50 nm, such as electron beams or EUV, polymer (A) having structural unit (III) is preferred. In the case of pattern formation using exposure with radiation of wavelengths below 50 nm, polymer (A) is preferably having structural unit (III).

[0056] Structural unit (III) is not particularly limited as long as it contains a phenolic hydroxyl group. Specific examples of structural unit (III) include structural units derived from hydroxystyrene or its derivatives, and structural units derived from (meth)acrylic acid compounds having a hydroxybenzene structure.

[0057] When obtaining a polymer having structural unit (III) as polymer (A), it is preferable to polymerize with the phenolic hydroxyl groups protected by a base-dissociating group or other protecting group during polymerization, and then deprotect by hydrolysis to obtain structural unit (III). The structural unit that provides structural unit (III) by hydrolysis is preferably the structural unit represented by formula (7-1) and the structural unit represented by formula (7-2) below. [Chemistry 8] (In formulas (7-1) and (7-2), RP1 is a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or an alkoxyalkyl group; A3 is a substituted or unsubstituted divalent aromatic cyclic group; RP2 is a monovalent hydrocarbon group or alkoxy group with 1 to 20 carbon atoms)

[0058] The aromatic ring group represented by A3 is a group consisting of two hydrogen atoms removed from the ring portion of a substituted or unsubstituted aromatic ring. The aromatic ring is preferably a hydrocarbon ring, such as those of benzene, naphthalene, anthracene, etc. Among these, A3 is preferably a group consisting of two hydrogen atoms removed from the ring portion of a substituted or unsubstituted benzene or naphthalene, and more preferably a substituted or unsubstituted phenyl group. Halogen atoms such as fluorine atoms can be listed as substituents.

[0059] As the monovalent hydrocarbon group with 1 to 20 carbon atoms represented by RP2, examples can be listed that are monovalent hydrocarbon groups with 1 to 20 carbon atoms in R12 of structural unit (I). As an alkoxy group, examples can be listed such as methoxy, ethoxy, and tributoxy. RP2 is preferably an alkyl or alkoxy group among these, with methyl or tributoxy being more preferred.

[0060] In obtaining a radiosensitive linear composition for exposure using radiation with a wavelength of 50 nm or less, the content of structural unit (III) in polymer (A) is preferably 15 mol% or more, more preferably 20 mol% or more, relative to all structural units constituting polymer (A). Furthermore, the content of structural unit (III) in polymer (A) is preferably 65 mol% or less, more preferably 55 mol% or less, relative to all structural units constituting polymer (A).

[0061] Other structural units, besides those mentioned above, may include, for example, structural units derived from styrene, structural units derived from vinylnaphthalene, structural units derived from monoliths having an alicyclic structure, and structural units derived from n-pentyl (meth)acrylate. The proportions of other structural units may be appropriately set according to each structural unit without impairing the effects of this disclosure.

[0062] Synthesis of polymer (A) Polymer (A) can be synthesized, for example, by using a free radical polymerization initiator or the like to polymerize monomers that provide each structural unit in a suitable solvent.

[0063] Examples of free radical polymerization initiators include: azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylpentanonitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2'-azobisisobutyrate, and other azo-based free radical initiators; and peroxide-based free radical initiators such as benzoyl peroxide, tert-butyl hydroperoxide, and cumene hydroperoxide. Among these, AIBN and dimethyl 2,2'-azobisisobutyrate are preferred, and AIBN is even more preferred. These free radical initiators can be used alone or in combination of two or more.

[0064] Examples of solvents used in polymerization include: alkanes, cycloalkanes, aromatic hydrocarbons, halogenated hydrocarbons, saturated carboxylic acid esters, ketones, ethers, and alcohols. Specific examples of these include: as alkanes, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, etc.; as cycloalkanes, cyclohexane, cycloheptane, cyclooctane, decahydronaphthalene, norbornane, etc.; as aromatic hydrocarbons, benzene, toluene, xylene, ethylbenzene, cumene, etc.; as halogenated hydrocarbons, chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene, etc.; as saturated carboxylic acid esters, ethyl acetate, n-butyl acetate, isobutyl acetate, methyl propionate, etc.; as ketones, acetone, methyl ethyl ketone, 4-methyl-2-pentanone, 2-heptanone, etc.; as ethers, tetrahydrofuran, dimethoxyethanes, diethoxyethanes, etc.; and as alcohols, methanol, ethanol, 1-propanol, 2-propanol, 4-methyl-2-pentanol, etc. The solvents used in the polymerization can be a single solvent or two or more solvents used in combination.

[0065] The reaction temperature in polymerization is typically 40℃ to 150℃, preferably 50℃ to 120℃. The reaction time is typically 1 hour to 48 hours, preferably 1 hour to 24 hours.

[0066] The weight-average molecular weight (Mw) of the polymer (A) obtained by gel permeation chromatography (GPC) from polystyrene is preferably 1,000 or more, more preferably 2,000 or more, further preferably 3,000 or more, and even more preferably 4,000 or more. Furthermore, 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 even more preferably 15,000 or less. By setting the Mw of the polymer (A) within the aforementioned range, the coatability of the composition can be improved, the heat resistance of the resulting resist film can be improved, and development defects can be sufficiently suppressed, which is therefore preferable.

[0067] The ratio (Mw / Mn) of polymer (A) to the equivalent number average molecular weight (Mn) of polystyrene obtained by GPC is preferably 5.0 or less, more preferably 3.0 or less, and even more preferably 2.0 or less. In addition, Mw / Mn is usually 1 or more.

[0068] In this composition, the proportion of polymer (A) relative to the total amount of solid components contained in the composition (i.e., the total mass of components other than solvent components contained in the composition) is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more. Furthermore, the proportion of polymer (A) relative to the total amount of solid components contained in the composition is preferably 99% by mass or less, more preferably 98% by mass or less, and even more preferably 95% by mass or less. Moreover, polymer (A) typically constitutes the base resin of this composition. In this specification, "base resin" refers to the polymer component that accounts for 50% or more by mass of the total amount of solid components contained in the composition. This composition may contain only one polymer (A), or it may contain two or more polymers (A).

[0069] <Compound(Q)> Compound (Q) is the compound represented by the following formula (1). [Chemistry 9] (In formula (1), L1 is an ester group, -CO-NR 3-, (thio)ether group, or sulfonyl group; when L1 is an ester group, (thio)ether group, or sulfonyl group, R1, R2, and R3 satisfy the following (i) or (ii); when L1 is -CO-NR 3-, R1, R2, and R3 satisfy the following (i), (ii), or (iii); (i) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 via a carbon atom; R2 is a substituted or unsubstituted divalent hydrocarbon group; wherein R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (ii) R1 and R2 represent groups comprising an aliphatic heterocyclic structure formed by mutual bonding and together with the bonded L1 groups; wherein R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (iii) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 via a carbon atom; R2 and R3 represent aliphatic heterocyclic structures formed by mutual bonding and together with L1; wherein the aliphatic heterocyclic structure does not have fluorine atoms; R4 is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group with 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, or a nitro group; R5 is a monovalent hydrocarbon group with 1 to 20 carbon atoms, a monovalent halide hydrocarbon group with 1 to 20 carbon atoms, or a halogen atom, or represents an alicyclic structure formed by two R5s bonded together with the bonded carbon atoms; L2 is a single bond or a divalent linker; n1 and n2 are independent integers from 1 to 4; n3 is an integer from 0 to 5; when n3 is 2 or more, multiple R5s may be the same or different; multiple R4s may be the same or different.

[0070] Compound (Q) functions as a photodegradable alkali, which is an acid diffusion control agent. The photodegradable alkali functions by inhibiting the diffusion of acid generated in the resist film due to exposure, thereby suppressing chemical reactions caused by acid in unexposed areas. This composition, containing polymer (A) and compound (Q), exhibits high sensitivity and excellent LWR, CDU, and pattern rectangularity when forming resist patterns. Furthermore, compound (Q) is stable over time. Therefore, this composition, containing compound (Q) as a photodegradable alkali, exhibits high sensitivity, excellent resist performance, and good storage stability.

[0071] Here, the acid generated by the photodegradable alkali upon exposure is an acid that does not induce the dissociation of acid-dissociating groups under normal conditions. Furthermore, "normal conditions" here refers to a 60-second exposure followed by a post-exposure bake (PEB) at 110°C. In the unexposed area, the photodegradable alkali exhibits an acid diffusion inhibition effect due to its alkalinity; however, in the exposed area, the protons and anions generated by cation decomposition produce a weak acid, thus reducing the acid diffusion inhibition effect. Therefore, in the resist film containing the photodegradable alkali, the generated acid effectively functions in the exposed area, causing the acid-dissociating groups of the polymer (A) to dissociate. On the other hand, in the unexposed area, the composition of the resist film does not change due to the acid. This makes the difference in solubility between the exposed and unexposed areas more clearly apparent. This composition, by including compound (Q), can exhibit high sensitivity while also providing excellent LWR performance, CDU performance, and pattern rectangularity.

[0072] Regarding anions In formula (1), L1 is an ester group (-C(=O)-O-), a amide group (-C(=O)-NR 3-), an ether group (-O-), a thioether group (-S-), or a sulfonyl group (-S(=O) 2-). Furthermore, the bonding direction of L1 is not limited. For example, when L1 is an ester group, the carbonyl group constituting the ester group can be bonded to R1 or R2. From the viewpoint of ease of synthesis of compound (Q), L1 is preferably an ester group or an amide group.

[0073] R1, R2 and R3 satisfy (i) or (ii) when L1 is an ester group, (thio) ether group or sulfonyl group, and satisfy (i), (ii) or (iii) when L1 is an amino group.

[0074] When R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 by a carbon atom, the monovalent organic group represented by R1 can be a group containing a chain structure (i.e., a chain organic group) or a group having a cyclic structure (i.e., a cyclic organic group).

[0075] Furthermore, the phrase "R1 is bonded to L1 via a carbon atom" means that the carbonyl group, oxygen atom, or sulfur atom in L1 is directly bonded to the carbon atom in R1. The carbon atom in R1 bonded to by the carbonyl group, oxygen atom, or sulfur atom in L1 can be a primary, secondary, or tertiary carbon atom. Additionally, the carbon atom in R1 bonded to by the carbonyl group, oxygen atom, or sulfur atom in L1 can also be adjacent to the oxygen atom or carbonyl group in R1.

[0076] When the monovalent organic group represented by R 1 is a chain organic group, examples of such chain organic groups include: straight-chain or branched saturated hydrocarbon groups with 1 to 20 carbon atoms; straight-chain or branched unsaturated hydrocarbon groups with 1 to 20 carbon atoms; monovalent groups with 2 to 20 carbon atoms having a (thio)ether or ester group between the carbon-carbon bonds of the straight-chain or branched hydrocarbon group; and monovalent groups with 1 to 20 carbon atoms in which any hydrogen atom of the straight-chain or branched hydrocarbon group is replaced. Examples of substituents include: halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.), hydroxyl groups, and nitro groups.

[0077] When the monovalent organic group represented by R 1 is a cyclic organic group, examples of cyclic structures that R 1 may possess include: alicyclic hydrocarbon structures with 3 to 20 carbon atoms, aliphatic heterocyclic structures with 3 to 20 carbon atoms, and aromatic ring structures with 6 to 20 carbon atoms. These cyclic structures may have substituents. Examples of substituents include: alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkoxycarbonyloxy groups, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.), hydroxyl groups, and side oxygen groups.

[0078] Examples of alicyclic hydrocarbon structures with 3 to 20 carbon atoms include: monocyclic alicyclic structures with 3 to 20 carbon atoms and polycyclic alicyclic structures with 6 to 20 carbon atoms. Monocyclic alicyclic structures with 3 to 20 carbon atoms and polycyclic alicyclic structures with 6 to 20 carbon atoms can be either saturated or unsaturated hydrocarbon structures. Furthermore, polycyclic alicyclic structures can be any of bridged ring structures, condensed ring structures, and spirocyclic structures. In this specification, a "bridged ring structure" refers to a polycyclic ring structure in which two non-adjacent carbon atoms of the ring are bonded together by a chain containing one or more carbon atoms. A "condensed ring structure" refers to a polycyclic ring structure in which multiple rings share a common edge (a bond between two adjacent carbon atoms). A "spiro ring structure" refers to a polycyclic ring structure in which two rings share a common atom. Spirocyclic structures can be composed of combinations of monocyclic structures and can include bridged ring structures or condensed ring structures.

[0079] Examples of saturated hydrocarbon structures in alicyclic monocyclic structures include cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Examples of unsaturated hydrocarbon structures include cyclopentene, cyclohexene, cycloheptene, cyclooctene, and cyclodecene. Preferred alicyclic polycyclic structures are bridged alicyclic saturated hydrocarbon structures or condensed alicyclic saturated hydrocarbon structures, such as bicyclic [2.2.1]heptane, bicyclic [2.2.2]octane, tricyclic [3.3.1.1 3,7]decane, and steroidal structures.

[0080] Examples of aliphatic heterocyclic structures with 3 to 20 carbon atoms include cyclic ether structures, lactone structures, cyclic acetal structures, cyclic carbonate structures, and sulfonyl lactone structures. These aliphatic heterocyclic structures can be either monocyclic or polycyclic. Furthermore, the polycyclic structure can be any of a bridged ring structure, a condensed ring structure, or a spirocyclic structure. Moreover, the aliphatic heterocyclic structure with 3 to 20 carbon atoms represented by R 1 can be a combination of two or more of the bridged ring structure, condensed ring structure, and spirocyclic structure. When the aliphatic heterocyclic structure with 3 to 20 carbon atoms represented by R 1 has a spirocyclic structure, the two or more rings constituting the spirocyclic structure can be either solely aliphatic heterocycles or a combination of aliphatic heterocycles and alicyclic hydrocarbon rings.

[0081] Examples of aromatic ring structures with 6 to 20 carbon atoms include those of benzene, naphthalene, anthracene, indene, and fluorene.

[0082] Furthermore, when R1 is a monovalent cyclic organic group, R1 can have both cyclic and chain structures. Specific examples of R1 having both chain and cyclic structures include: a group formed by removing a hydrogen atom from the monovalent chain organic group (preferably a monovalent linear or branched saturated hydrocarbon group) to obtain a divalent group with a cyclic structure.

[0083] From the viewpoint of achieving good transparency in the resist film obtained from this composition, the monovalent organic group represented by R1 preferably does not have an aromatic ring. Specifically, it is preferable that R1 is a substituted or unsubstituted monovalent chain hydrocarbon group, or a monovalent group having an alicyclic hydrocarbon structure, or a monovalent group having an aliphatic heterocyclic structure, and is bonded to L1 via a carbon atom. Furthermore, from the viewpoint of improving the hydrophobicity of the film and further increasing the difference in dissolution rate between the exposed and unexposed areas relative to the developer, R1 is more preferably a monovalent group having an alicyclic hydrocarbon structure or an aliphatic heterocyclic structure, and even more preferably a bridged alicyclic saturated hydrocarbon structure or a bridged aliphatic heterocyclic structure.

[0084] When R2 is a substituted or unsubstituted divalent hydrocarbon group, examples of such divalent hydrocarbon groups include: divalent chain hydrocarbon groups with 1 to 10 carbon atoms, divalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, and divalent aromatic hydrocarbon groups with 6 to 20 carbon atoms. Specific examples of these include groups derived from the monovalent hydrocarbon groups exemplified in the description of R12 in formula (3) by removing one hydrogen atom. Preferably, the divalent hydrocarbon group with 1 to 20 carbon atoms represented by R2 is a divalent chain hydrocarbon group or an alicyclic hydrocarbon group, preferably a divalent chain hydrocarbon group with 1 to 6 carbon atoms or a divalent alicyclic hydrocarbon group with 3 to 12 carbon atoms, more preferably a straight-chain or branched alkyl group with 1 to 6 carbon atoms, or a cycloalkyl group with 3 to 8 carbon atoms.

[0085] When R2 has a substituent, examples of such substituents include: iodine atoms, cyano groups, and monovalent organic groups having 1 to 20 carbon atoms. Examples of monovalent organic groups having 1 to 20 carbon atoms include: substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and monovalent groups formed by substituting any methylene group of the hydrocarbon group with an ester group, amide group, or (thio)ether group. The monovalent hydrocarbon group may be substituted with halogen atoms, hydroxyl groups, etc.

[0086] When R1 and R2 represent groups (hereinafter also referred to as "group RM") that contain aliphatic heterocyclic structures that are mutually bonded and together with the L1 groups, examples of such aliphatic heterocyclic structures include: cyclic (thio)ether structures, lactone structures, sulfonyl lactone structures, etc. The aliphatic heterocyclic structure in the group RM can be directly bonded to the sulfonic acid anion (-SO3-), or it can be bonded to the sulfonic acid anion (-SO3-) via a divalent group (preferably a chain hydrocarbon group).

[0087] When L1 is -CO-NR 3-, examples of monovalent hydrocarbon groups represented by R3 include: monovalent chain hydrocarbon groups with 1 to 10 carbon atoms, monovalent alicyclic hydrocarbon groups with 3 to 10 carbon atoms, and monovalent aromatic hydrocarbon groups with 6 to 10 carbon atoms. Among these, the monovalent hydrocarbon group represented by R3 is preferably an alkyl group with 1 to 5 carbon atoms, a cycloalkyl group with 3 to 10 carbon atoms, or an aryl group with 6 to 10 carbon atoms.

[0088] When R2 and R3 represent aliphatic heterocyclic structures that are mutually bonded and together with L1 (-CO-NR3-), examples of such aliphatic heterocyclic structures include cyclic amide structures and cyclic amide imine structures.

[0089] From the viewpoint of obtaining a highly transparent resist film, R2 is preferably a group that does not have an aromatic ring. Specifically, R2 is preferably a substituted or unsubstituted divalent chain hydrocarbon group, or a substituted or unsubstituted divalent alicyclic hydrocarbon group, or represents an aliphatic heterocyclic structure in which R2 and R3 are combined with L1.

[0090] As specific examples of anions in the above formula (1), anions represented by the following formulas can be listed. [Chemistry 10] [Chemistry 11]

[0091] Regarding cations In formula (1), when R5 is a monovalent hydrocarbon group with 1 to 20 carbon atoms, examples of such monovalent hydrocarbon groups include: monovalent chain hydrocarbon groups with 1 to 10 carbon atoms, monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups with 6 to 20 carbon atoms. Specific examples of these include groups identical to those exemplified in the description of R12 in formula (3). Preferably, the monovalent hydrocarbon group with 1 to 20 carbon atoms represented by R5 is a monovalent hydrocarbon group with 1 to 8 carbon atoms, more preferably a straight-chain or branched monovalent saturated hydrocarbon group with 1 to 8 carbon atoms, a monovalent alicyclic hydrocarbon group with 3 to 8 carbon atoms, or a monovalent aromatic hydrocarbon group with 6 to 8 carbon atoms.

[0092] As the monovalent halogenated hydrocarbon group with 1 to 20 carbon atoms represented by R 5, examples include groups in which any hydrogen atom of the monovalent halogenated hydrocarbon group with 1 to 20 carbon atoms is substituted with a halogen atom. Examples of halogen atoms in the monovalent halogenated hydrocarbon group with 1 to 20 carbon atoms represented by R 5 include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. The halogen atom is preferably a fluorine atom.

[0093] When two R5 atoms combine with each other and together with the bonded carbon atoms to form an alicyclic structure, this alicyclic structure forms a condensed ring with the benzene ring bonded to the two R5 atoms. Examples of alicyclic structures include cyclopentane rings and cyclohexane rings.

[0094] In the above, R5 is preferably an alkyl group having 1 to 8 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, or a halogen atom.

[0095] When R4 is a monovalent hydrocarbon group with 1 to 20 carbon atoms, whether substituted or unsubstituted, examples of such monovalent hydrocarbon groups include: monovalent chain hydrocarbon groups with 1 to 10 carbon atoms, monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups with 6 to 20 carbon atoms. Specific examples of these include groups identical to those exemplified in the description of R12 in formula (2). When R4 is a substituted monovalent hydrocarbon group with 1 to 20 carbon atoms, examples of such substituents include: halogen atoms, hydroxyl groups, and nitro groups. Examples of halogen atoms represented by R4 include: fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0096] R4 is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a halogen atom, a hydroxyl group or a nitro group, and more preferably a hydrogen atom, a methyl group or an ethyl group.

[0097] When L2 is a divalent linker, examples of such linkers include alkyl dienes, ester groups, and (thio)ether groups with 1 to 3 carbon atoms. From the viewpoint of improving sensitivity, it is preferable that L2 is a single bond.

[0098] The values ​​of n1 and n2 are preferably 1 to 3, and even more preferably 2. The optimal value for n3 is 0-4, and even better is 0-3.

[0099] As specific examples of cations in the above formula (1), cations represented by the following formulas can be listed. [Chemistry 12]

[0100] As a specific example of compound (Q), examples include onium salt compounds formed by combining any one of the examples of anions in formula (1) with any one of the examples of cations in formula (1).

[0101] The content of compound (Q) in this composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to 100 parts by mass of polymer (A). Furthermore, the content of compound (Q) is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to 100 parts by mass of polymer (A). By setting the content of compound (Q) within the aforementioned range, the LWR performance, CDU performance, and pattern rectangularity of this composition can be improved, thereby further enhancing the lithography performance. Moreover, compound (Q) can be used alone or in combination of two or more.

[0102] <Other arbitrary ingredients> In addition to polymer (A) and compound (Q), this composition may also contain other components different from polymer (A) and compound (Q) (hereinafter also referred to as "other arbitrary components"). Examples of other arbitrary components that may be contained in this composition include radiosensitive linear acid generators, solvents, and polymers with high fluorine content.

[0103] [Radiosensitive linear acid generator] A radiosensitive linear acid generator (hereinafter, also simply referred to as "acid generator") is a substance that generates acid by exposing the composition to light. Typically, an acid generator is a ononium salt containing a radiosensitive linear ononium cation and an organic anion, and is a compound (hereinafter, also referred to as "compound (B)") that induces the dissociation of acid-dissociating groups under the stated normal conditions, thereby generating an acid (preferably a strong acid such as sulfonic acid, acetylinic acid, or methyl acid) in the composition with a higher acidity than that generated by compound (Q). Preferably, polymer (A) and compound (B) are formulated in the composition, and the acid generated by compound (B) causes the acid-dissociating groups of polymer (A) to dissociate, generating acid groups. This results in different solubility of polymer (A) in the developing solution between the exposed and unexposed areas.

[0104] Furthermore, the degree of acidity can be evaluated by the acid dissociation constant (pKa). The acid dissociation constant of the acid produced by photodegradation of alkali is usually above -3, preferably -1≦pKa≦7, and even more preferably 0≦pKa≦5.

[0105] The compound (B) contained in this composition is not particularly limited, and a known radiosensitive linear acid generator used in resist pattern formation can be used. Preferably, the compound (B) formulated in this composition is the compound represented by the following formula (2). [Chemistry 13] (In formula (2), W2 is a monovalent organic group with 3 to 40 carbon atoms; L3 is a single bond or a divalent linker; R6, R7, R8, and R9 are independently hydrogen atoms, hydrocarbon groups with 1 to 10 carbon atoms, fluorine atoms, or fluoroalkyl groups with 1 to 10 carbon atoms; a is an integer from 0 to 8; when a is 2 or more, there are multiple R6 and R7 that are the same or different from each other; among them, at least one of the (a×2+2) groups constituting the group composed of R6, R7, R8, and R9 in the formula is a fluorine atom or a fluoroalkyl group; X+ is a monovalent cation)

[0106] In formula (2), the monovalent organic group with 1 to 20 carbon atoms represented by W 2 can be either chain-like or cyclic. In the case that W 2 is a monovalent chain organic group, specific examples include: straight-chain or branched saturated hydrocarbon groups with 1 to 20 carbon atoms, straight-chain or branched unsaturated hydrocarbon groups with 2 to 20 carbon atoms, monovalent groups with 1 to 20 carbon atoms in chain hydrocarbon groups that have one or more hydrogen atoms replaced by halogen atoms, hydroxyl groups, cyano groups, etc., and monovalent groups with 2 to 20 carbon atoms in chain hydrocarbon groups that contain ester groups, (thio) ether groups, amide groups, etc. between carbon-carbon bonds.

[0107] When W2 is a monovalent cyclic organogroup, the cyclic organogroup can be any group having a cyclic structure with 3 to 20 carbon atoms, without particular limitation. Examples of cyclic structures that W2 can possess include alicyclic hydrocarbon structures with 3 to 20 carbon atoms, aliphatic heterocyclic structures with 3 to 20 carbon atoms, and aromatic ring structures with 6 to 20 carbon atoms. These cyclic structures may have substituents. Examples of substituents include: alkoxy groups, alkoxycarbonyl groups, halogen atoms (fluorine, chlorine, bromine, iodine, etc.), hydroxyl groups, and cyano groups. Furthermore, when W2 is a monovalent cyclic organogroup, W2 can have both cyclic and chain structures.

[0108] Examples of alicyclic hydrocarbon structures with 3 to 20 carbon atoms include: monocyclic alicyclic structures with 3 to 20 carbon atoms and polycyclic alicyclic structures with 6 to 20 carbon atoms. Both monocyclic alicyclic structures with 3 to 20 carbon atoms and polycyclic alicyclic structures with 6 to 20 carbon atoms can be either saturated or unsaturated hydrocarbon structures. Furthermore, polycyclic alicyclic structures can be either bridged alicyclic hydrocarbon structures or condensed alicyclic hydrocarbon structures.

[0109] Examples of saturated hydrocarbon structures in alicyclic monocyclic structures include cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Examples of unsaturated hydrocarbon structures include cyclopentene, cyclohexene, cycloheptene, cyclooctene, and cyclodecene. For alicyclic polycyclic structures, bridged alicyclic saturated hydrocarbon structures are preferred, particularly those with bicyclic [2.2.1]heptane, bicyclic [2.2.2]octane, or tricyclic [3.3.1.1 3,7]decane structures.

[0110] Examples of aliphatic heterocyclic structures with 3-20 carbon atoms include: cyclic ether structures, lactone structures, cyclic carbonate structures, sulfonyl lactone structures, and thioxanthate structures. These aliphatic heterocyclic structures can be monocyclic or polycyclic, and can also be bridged ring structures, condensed ring structures, or spirocyclic structures. The aliphatic heterocyclic structures with 3-20 carbon atoms represented by W2 can be combinations of two or more of bridged ring structures, condensed ring structures, and spirocyclic structures. Examples of aromatic ring structures with 6-20 carbon atoms include: benzene, naphthalene, anthracene, indene, and fluorene.

[0111] From the viewpoint of improving the water repellency of the resist film obtained from this composition while simultaneously enhancing its transparency, thereby further increasing the difference in solubility between the exposed and unexposed portions in the developer, W2 in formula (2) is preferably a monovalent cyclic organic group, more preferably having an alicyclic hydrocarbon structure or an aliphatic heterocyclic structure, and even more preferably having a bridged alicyclic saturated hydrocarbon structure or a bridged aliphatic heterocyclic structure. Furthermore, from the viewpoint of sensitivity, W2 is preferably free of fluorine atoms.

[0112] The divalent linker represented by L3 is preferably -O-, -CO-, -COO-, -O-CO-O-, -S-, -SO2- or -CONH-.

[0113] The hydrocarbon groups representing 1 to 10 carbon atoms, as indicated by R6, R7, R8, and R9, are preferably alkyl and cycloalkyl, and particularly preferably alkyl. Among these, the hydrocarbon groups represented by R6, R7, R8, and R9 are more preferably methyl, ethyl, or isopropyl. Examples of fluoroalkyl groups representing 1 to 10 carbon atoms include: trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, 2,2,3,3,3-pentafluoropropyl, 1,1,1,3,3,3-hexafluoropropyl, heptafluoro-n-propyl, heptafluoroisopropyl, nonafluoro-n-butyl, nonafluoroisobutyl, nonafluorotert-butyl, 2,2,3,3,4,4,5,5-octafluoro-n-pentyl, tridecafluoro-n-hexyl, and 5,5,5-trifluoro-1,1-diethylpentyl. Of these, the fluoroalkyl groups represented by R6, R7, R8, and R9 are preferably fluoroalkyl groups having 1 to 3 carbon atoms, and more preferably trifluoromethyl.

[0114] One or more of the (a×2+2) groups constituting the group consisting of R6, R7, R8, and R9 in the formula are fluorine atoms or fluoroalkyl groups. In particular, when R8, R9, or both of them are fluorine atoms or trifluoromethyl groups, the acidity of the resulting acid increases, which is therefore preferred. It is especially preferred that both R8 and R9 are fluorine atoms or trifluoromethyl groups. The optimal value for a is 0-5, and even better is 0-2.

[0115] As a specific example of anion possessed by compound (B), anions represented by the following formulas can be listed. [Chemistry 14] [Chemistry 15]

[0116] In formula (2), X+ is a monovalent cation. The monovalent cation represented by X+ is preferably a monovalent radiosensitive linear onium cation, such as radiodegradable onium cations containing elements like S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, Te, and Bi. Specific examples of radiodegradable onium cations containing these elements include strontium cations, tetrahydrothiophene onium cations, iodoonium cations, phosphonium cations, diazonium cations, and pyridinium cations. Among these, X+ is preferably a strontium cation or an iodoonium cation; specifically, the cations represented by formulas (X-1) to (X-6) below can be listed.

[0117] [Chemistry 16]

[0118] In formula (X-1), Ra1, Ra2, and Ra3 are independently substituted or unsubstituted alkyl, alkoxy, alkylcarbonyloxy, or cycloalkylcarbonyloxy groups having 1 to 12 carbon atoms, monocyclic or polycyclic cycloalkyl groups having 3 to 12 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms, hydroxyl groups, halogen atoms, -OSO2-RP, -SO2-RQ, -SRT, or represent a ring structure formed by the combination of two or more of Ra1, Ra2, and Ra3. This ring structure may contain heteroatoms (oxygen atoms or sulfur atoms, etc.) between the carbon-carbon bonds forming the backbone. RP, RQ, and RT are independently substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms, substituted or unsubstituted monovalent alicyclic hydrocarbon groups having 5 to 25 carbon atoms, or substituted or unsubstituted monovalent aromatic hydrocarbon groups having 6 to 12 carbon atoms. k1, k2, and k3 are independently integers from 0 to 5. When Ra1~Ra3 and RP, RQ and RT are multiple, the multiple Ra1~Ra3 and RP, RQ and RT may be the same or different. When Ra1, Ra2 and Ra3 have substituents, the substituents may be hydroxyl, halogen atom, carboxyl group, protected hydroxyl group, protected carboxyl group, -OSO 2-RP, -SO 2-RQ, -SR T.

[0119] In formula (X-2), Rb1 is a substituted or unsubstituted alkyl or alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted acetyl group with 2 to 8 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon group with 6 to 8 carbon atoms, a halogen atom, or a hydroxyl group. nk is 0 or 1. When nk is 0, k4 is an integer from 0 to 4; when nk is 1, k4 is an integer from 0 to 7. When there are multiple Rb1 groups, they may be identical or different, and they may also form a ring structure by bonding together. Rb2 is a substituted or unsubstituted alkyl group with 1 to 7 carbon atoms, or a substituted or unsubstituted monovalent aromatic hydrocarbon group with 6 or 7 carbon atoms. LC is a single bond or a divalent linker. k5 is an integer from 0 to 4. When there are multiple Rb2 groups, they may be identical or different; they may also form a ring structure by bonding together. q is an integer from 0 to 3. In the formula, the ring structure containing S+ can contain heteroatoms (oxygen atoms or sulfur atoms, etc.) between the carbon-carbon bonds that form the framework.

[0120] In formula (X-3), Rc1, Rc2 and Rc3 are independently substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms.

[0121] In formula (X-4), R g1 is a substituted or unsubstituted alkyl or alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted acetyl group with 2 to 8 carbon atoms, an substituted or unsubstituted aromatic hydrocarbon group with 6 to 8 carbon atoms, or a hydroxyl group. n k2 is 0 or 1. When n k2 is 0, k10 is an integer from 0 to 4, and when n k2 is 1, k10 is an integer from 0 to 7. When there are multiple R g1s, the multiple R g1s may be the same or different. In addition, multiple R g1s may also be a ring structure formed by mutual bonding. R g2 and R g3 are independently substituted or unsubstituted alkyl, alkoxy or alkoxycarbonyloxy groups with 1 to 12 carbon atoms, substituted or unsubstituted monocyclic or polycyclic cycloalkyl groups with 3 to 12 carbon atoms, substituted or unsubstituted aromatic hydrocarbon groups with 6 to 12 carbon atoms, hydroxyl groups, halogen atoms, or represent a ring structure formed by mutual bonding of R g2 and R g3. k11 and k12 are independent integers from 0 to 4. When there are multiple R g2 and R g3, the multiple R g2 and R g3 are either the same or different from each other.

[0122] In formula (X-5), Rd1 and Rd2 are independently substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms, alkoxy or alkoxycarbonyl groups, substituted or unsubstituted aromatic hydrocarbon groups having 6 to 12 carbon atoms, halogen atoms, halogenated alkyl groups having 1 to 4 carbon atoms, nitro groups, or a ring structure formed by the combination of two or more of these groups. k6 and k7 are independently integers from 0 to 5. When there are multiple Rd1 and Rd2, the multiple Rd1 and Rd2 may be the same or different.

[0123] In formula (X-6), Re1 and Re2 are independently halogen atoms, substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms, or substituted or unsubstituted aromatic hydrocarbon groups having 6 to 12 carbon atoms. k8 and k9 are independently integers from 0 to 4.

[0124] In the above, the cation represented by X+ in formula (2) is preferably an onium cation represented by formula (X-1), formula (X-2), or formula (X-5). Specific examples of the cation represented by X+ include structures represented by the following formulas.

[0125] [Chemistry 17] [Chemistry 18]

[0126] [Chemistry 19] [Chemistry 20]

[0127] Specific examples of compounds represented by formula (2) include: onium salt compounds formed by combining any one of the examples of anions in formula (2) with any one of the examples of monovalent cations represented by X+. However, the compounds represented by formula (2) are not limited to these combinations. A single compound may be used, or two or more may be used in combination.

[0128] In this composition, the proportion of the acid generating agent can be appropriately selected according to the type of polymer (A) used, exposure conditions, and required sensitivity. The proportion of the acid generating agent relative to 100 parts by mass of polymer (A) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 5 parts by mass or more. Furthermore, the proportion of the acid generating agent relative to 100 parts by mass of polymer (A) is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. By setting the proportion of the acid generating agent within the aforementioned range, high sensitivity can be exhibited when forming resist patterns, and good LWR performance, CDU performance, and pattern rectangularity can be demonstrated.

[0129] Solvent Solvents are any medium capable of dissolving or dispersing the components formulated in this composition; there are no particular limitations. Examples of solvents include: alcohols, ethers, ketones, amides, esters, and hydrocarbons.

[0130] Examples of alcohols include: aliphatic monools with 1 to 18 carbon atoms, such as 4-methyl-2-pentanol and n-hexanol; alicyclic monools with 3 to 18 carbon atoms, such as cyclohexanol; polyols with 2 to 18 carbon atoms, such as 1,2-propanediol; and polyol ethers with 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, dipentyl ether, diisopentyl ether, dihexyl ether, and diheptyl ether; cyclic ethers, such as tetrahydrofuran and tetrahydropyran; and ethers containing aromatic rings, such as diphenyl ether and anisole.

[0131] Examples of ketones include: 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, trimethylnonanone, and other chain ketones; cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone, and other cyclic ketones; 2,4-pentanedione, acetone-acetone, acetophenone, diacetone alcohol, etc. Examples of amides include: N,N'-dimethylimidazolidineone, N-methylpyrrolidone, and other cyclic amides; N-methylmethamide, N,N-dimethylmethamide, N,N-diethylmethamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionic acid, and other chain amides.

[0132] 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; polycarboxylic acid diesters such as diethyl oxalate; carbonates such as dimethyl carbonate and diethyl carbonate; and cyclic esters such as γ-butyrolactone. Examples of hydrocarbons include: aliphatic hydrocarbons with 5-12 carbon atoms such as n-pentane and n-hexane; and aromatic hydrocarbons with 6-16 carbon atoms such as toluene and xylene.

[0133] As a solvent, it is preferably at least one selected from the group consisting of esters and ketones, more preferably at least one selected from the group consisting of polyol partial ether carboxylic acid esters and cyclic ketones, and even more preferably at least one selected from propylene glycol monomethyl ether acetate, ethyl lactate, and cyclohexanone. One or more solvents may be used.

[0134] <High Fluorine Polymers> The high-fluorine-content polymer (hereinafter also referred to as "polymer (E)") is a polymer with a higher mass content of fluorine atoms than polymer (A). When this composition contains polymer (E), polymer (E) can be more concentrated on the surface of the resist film relative to polymer (A), thereby improving the water repellency of the resist film surface during immersion exposure.

[0135] The fluorine atom content of polymer (E) is only required to be greater than that of polymer (A), and there are no particular limitations. Preferably, the fluorine atom content of polymer (E) is 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. Furthermore, the fluorine atom content of polymer (E) is preferably 60% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. The structure of the polymer can be determined by methods such as 13C nuclear magnetic resonance (NMR) spectroscopy, and the fluorine atom content (by mass%) of the polymer can be calculated based on this structure.

[0136] As structural units containing fluorine atoms in polymer (E) (hereinafter also referred to as "structural units (F)"), examples include structural units (fa) and structural units (fb) shown below. Polymer (E) may have either structural unit (fa) or structural unit (fb) as structural unit (F), or it may have both structural unit (fa) and structural unit (fb).

[0137] [Structural Unit (fa)] The structural unit (fa) is the structural unit represented by the following formula (8-1). The polymer (E) can adjust the fluorine atom content by having the structural unit (fa). [Chemistry 21] (In formula (8-1), RC is a hydrogen atom, a fluorine group, a methyl group, or a trifluoromethyl group; G is a single bond, an oxygen atom, a sulfur atom, -COO-, -SO 2-O-NH-, -CONH-, or -O-CO-NH-; RE is a monovalent fluorinated chain hydrocarbon group with 1 to 20 carbon atoms or a monovalent fluorinated alicyclic hydrocarbon group with 3 to 20 carbon atoms)

[0138] In formula (8-1), from the viewpoint of providing copolymerization of RC and structural unit (fa) monomers, hydrogen atoms and methyl groups are preferred, and methyl groups are more preferred. Furthermore, from the viewpoint of providing copolymerization of structural unit (fa) monomers, G is preferably a single bond or -COO-, and more preferably -COO-.

[0139] As a monovalent fluorinated chain hydrocarbon group with 1 to 20 carbon atoms represented by RE, examples include those formed by substituting some or all of the hydrogen atoms of a straight-chain or branched alkyl group with 1 to 20 carbon atoms with fluorine atoms. As a monovalent fluorinated alicyclic hydrocarbon group with 3 to 20 carbon atoms represented by RE, examples include those formed by substituting some or all of the hydrogen atoms of a monocyclic or polycyclic alicyclic hydrocarbon group with 3 to 20 carbon atoms with fluorine atoms. Among these, RE is preferably a monovalent fluorinated chain hydrocarbon group, more preferably a monovalent fluorinated alkyl group, and even more preferably 2,2,2-trifluoroethyl, 1,1,1,3,3,3-hexafluoropropyl, or 5,5,5-trifluoro-1,1-diethylpentyl.

[0140] When the polymer (E) has structural units (fa), the content of structural units (fa) relative to all structural units constituting the polymer (E) is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more. Furthermore, the content of structural units (fa) relative to all structural units constituting the polymer (E) is preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 85 mol% or less. By setting the content of structural units (fa) within the aforementioned range, the mass content of fluorine atoms in the polymer (E) can be more appropriately adjusted, further promoting their biased presence on the surface of the resist film, thereby further improving the water repellency of the resist film during immersion exposure.

[0141] [Structural Unit (fb)] The structural unit (fb) is the structural unit represented by the following formula (8-2). By having structural units (fb), the polymer (E) has improved solubility in alkaline developing solutions, thereby further suppressing the generation of developing defects. [Chemistry 22] In formula (8-2), RF is a hydrogen atom, a fluorine group, a methyl group, or a trifluoromethyl group; R 59 is a (s+1) valent hydrocarbon group with 1 to 20 carbon atoms, or a group formed by an oxygen atom, a sulfur atom, -NR'-, a carbonyl group, -CO-O-, or -CO-NH- bonded to the end of the hydrocarbon group on the R 60 side; R' is a hydrogen atom or a monovalent organic group; R 60 is a single bond or a divalent organic group with 1 to 20 carbon atoms. X 12 is a single bond, a divalent hydrocarbon group with 1 to 20 carbon atoms, or a divalent fluorinated chain hydrocarbon group with 1 to 20 carbon atoms. A 11 is an oxygen atom, -NR''-, -CO-O-*, or -SO 2-O-*; R" is a hydrogen atom or a monovalent hydrocarbon group with 1 to 10 carbon atoms; "*" indicates the bonding site with R 61; R 61 represents a hydrogen atom or a monovalent organic group with 1 to 30 carbon atoms; s is an integer from 1 to 3; where s is 2 or 3, multiple R 60, X 12, A 11, and R 61 may be the same or different.

[0142] The structural unit (fb) is divided into two types: one with an alkali-soluble group and the other with a group that dissociates under the action of alkali and thus increases its solubility in alkaline developing solution (hereinafter also referred to as "alkali-dissociatable group").

[0143] When the structural unit (fb) has a base-soluble group, R61 is a hydrogen atom, and A11 is an oxygen atom, -COO-*, or -SO2O-*. "*" indicates the site bonded to R61. X12 is a single bond, a divalent hydrocarbon group with 1-20 carbon atoms, or a divalent fluorinated chain hydrocarbon group with 1-20 carbon atoms. When A11 is an oxygen atom, X12 is a fluorinated hydrocarbon group with a fluorine atom or fluoroalkyl group bonded to the carbon atom of A11. R60 is a single bond or a divalent organic group with 1-20 carbon atoms. When s is 2 or 3, multiple R60, X12, A11, and R61 may be the same or different. By having a base-soluble group in the structural unit (fb), the affinity for alkaline developers can be increased, thereby suppressing development defects.

[0144] When the structural unit (fb) has a base-dissociable group, R61 is a monovalent organic group with 1 to 30 carbon atoms, and A11 is an oxygen atom, -NR''-, -COO-*, or -SO2O-*. "*" indicates the site bonded to R61. X12 is a single bond or a divalent fluorinated chain hydrocarbon group with 1 to 20 carbon atoms. R60 is a single bond or a divalent organic group with 1 to 20 carbon atoms. When A11 is -COO-* or -SO2O-*, X12 or R61 has a fluorine atom on the carbon atom bonded to A11 or on a carbon atom adjacent to it. When A11 is an oxygen atom, X12 or R60 is a single bond, R59 is a structure formed by a carbonyl group bonded to the end of the R60 side of a hydrocarbon group with 1 to 20 carbon atoms, and R61 is an organic group with a fluorine atom. When s is 2 or 3, the multiple R 60, X 12, A 11, and R 61 may be identical or different from each other. By having an alkaline dissociative group in the structural unit (fb), the self-hydrophobicity of the resist film surface changes to hydrophilicity during the alkaline development step. This improves the affinity for the developer and more effectively suppresses development defects. Preferably, as the structural unit (fb) with an alkaline dissociative group, A 11 is -COO-* and R 61 or X 12, or both, have fluorine atoms.

[0145] When the polymer (E) has structural units (fb), the content of structural units (fb) relative to all structural units constituting the polymer (E) is preferably 40 mol% or more, more preferably 50 mol% or more, and even more preferably 60 mol% or more. Furthermore, the content of structural units (fb) relative to all structural units constituting the polymer (E) is preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 85 mol% or less. By setting the content of structural units (fb) within the aforementioned range, the water repellency of the resist film during immersion exposure can be further improved.

[0146] In addition to structural units (fa) and structural units (fb), polymer (E) may also include structural units (I) with acid-dissociable groups and structural units with alicyclic hydrocarbon structures represented by the following formula (9) (hereinafter also referred to as "structural units (G)"). [Chemistry 23] (In formula (9), RG1 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; RG2 is a monovalent alicyclic hydrocarbon group with 3 to 20 carbon atoms)

[0147] In the formula (9), the monovalent alicyclic hydrocarbon group with 3 to 20 carbon atoms represented by RG2 can be exemplified by the monovalent alicyclic hydrocarbon group with 3 to 20 carbon atoms represented by R13 to R15 in the formula (3).

[0148] When the polymer (E) contains the structural unit represented by formula (9), the content of the structural unit is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, relative to all the structural units constituting the polymer (E). Furthermore, the content of the structural unit represented by formula (9) is preferably 70 mol% or less, more preferably 60 mol% or less, and even more preferably 50 mol% or less, relative to all the structural units constituting the polymer (E).

[0149] The molecular weight (Mw) of polymer (E) obtained by GPC is preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 4,000 or more. Furthermore, the Mw of polymer (E) is preferably 50,000 or less, more preferably 30,000 or less, and even more preferably 20,000 or less. The molecular weight distribution (Mw / Mn) represented by the ratio of Mn to Mw of polymer (E) obtained by GPC is preferably 1 or more and 5 or less, and even more preferably 1 or more and 3 or less.

[0150] When this composition contains polymer (E), the proportion of polymer (E) in this composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1 part by mass or more, relative to 100 parts by mass of polymer (A). Furthermore, the proportion of polymer (E) in this composition is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less, relative to 100 parts by mass of polymer (A). Moreover, this composition may contain only one type of polymer (E), or it may contain two or more types in combination.

[0151] <Other arbitrary ingredients> This composition may contain components different from the polymer (A), compound (Q), compound (B), solvent, and polymer (E) described herein (hereinafter also referred to as "other arbitrary components"). Examples of other arbitrary components include: acid diffusion control agents other than compound (Q) (e.g., nitrogen-containing compounds represented by "N(RN1)(RN2)(RN3)" (wherein RN1, RN2, and RN3 are independently hydrogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted cycloalkyl groups, substituted or unsubstituted aryl groups, or substituted or unsubstituted aralkyl groups), photodegradable bases different from those represented by the compound (1), surfactants, compounds containing alicyclic skeletons (e.g., 1-adamantane carboxylic acid, 2-adamantane ketone, deoxycholic acid tributyl ester, etc.), sensitizers, pre-existence accelerators, etc. The proportion of other arbitrary components in this composition may be appropriately selected according to each component without impairing the effects of this disclosure.

[0152] Furthermore, from the viewpoint that a radiosensitive linear composition exhibiting good sensitivity, excellent CDU performance, and pattern rectangularity can be obtained by incorporating an acid diffusion control agent other than compound (Q) into the composition, the content of the acid diffusion control agent other than compound (Q) is preferably 60% by mass or less, and more preferably 50% by mass or less, relative to the total amount of acid diffusion control agent contained in the composition.

[0153] <Method for manufacturing radioactive linear components> This composition can be manufactured, for example, by mixing components such as solvents in desired proportions, in addition to polymer (A) and compound (Q), and filtering the resulting mixture using a filter (e.g., a filter with a pore size of approximately 0.2 μm). The solid content concentration of this composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. Furthermore, the solid content concentration of this composition is preferably 50% by mass or less, more preferably 20% by mass or less, and even more preferably 5% by mass or less. By setting the solid content concentration of this composition within the aforementioned range, good coatability and a good resist pattern shape can be achieved.

[0154] The composition thus obtained can be used as a composition for positive pattern forming using alkaline developer, and also as a composition for negative pattern forming using developer containing organic solvent. Among these, this composition is particularly suitable as a composition for negative pattern forming using organic solvent developer, in terms of exhibiting high sensitivity and superior pattern rectangularity through the development of the resist film after exposure.

[0155] Method for forming resist patterns The resist pattern forming method disclosed herein includes: a step of coating the composition onto one side of a substrate (hereinafter also referred to as the "coating step"); a step of exposing the resist film obtained by the coating step (hereinafter also referred to as the "exposure step"); and a step of developing the exposed resist film (hereinafter also referred to as the "development step"). Examples of patterns formed by the resist pattern forming method disclosed herein include line and space patterns, hole patterns, etc. By using the composition to form the resist film in the resist pattern forming method disclosed herein, resist patterns with good sensitivity and photolithography properties, and few development defects can be formed. Each step will be described below.

[0156] [Application Steps] In this step, a resist film is formed on the substrate by coating one side of the composition. The substrate for forming the resist film can be any conventionally known substrate, such as silicon wafers, silicon dioxide wafers, or aluminum-clad wafers. Alternatively, organic or inorganic antireflective films disclosed in Japanese Patent Publication No. 6-12452 or Japanese Patent Publication No. 59-93448 can be formed on the substrate. The coating method for this composition can include, for example, spin coating, cast coating, or roll coating. After coating, a pre-bake (PB) can be performed to allow the solvent in the coating to evaporate. The PB temperature is preferably 60°C or higher, more preferably 80°C or higher. Furthermore, the PB temperature is preferably 140°C or lower, more preferably 120°C or lower. The PB time is preferably 5 seconds or higher, more preferably 10 seconds or higher. In addition, the PB time is preferably less than 600 seconds, more preferably less than 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.

[0157] In particular, this composition can form a resist film exhibiting high sensitivity and high transparency, thus allowing radiation to fully penetrate deep into the film during pattern formation by exposure. This composition also exhibits excellent lithography properties (LWR performance, CDU performance, etc.) when used to form thick-film resists, making it particularly suitable for forming thick-film resists. When obtaining thick-film resists, the average thickness of the resist film is preferably 50 nm or more, more preferably 70 nm or more. Furthermore, the average thickness of the resist film is, for example, 1,000 nm or less, preferably 500 nm or less.

[0158] In subsequent exposure steps involving immersion exposure, regardless of the presence or absence of water-repellent polymer additives such as polymer (E) in this composition, a immersion protective film that is insoluble in the immersion liquid can be further provided on the resist film formed by this composition to avoid direct contact between the immersion liquid and the resist film. As the immersion protective film, either a solvent-removable protective film that is peeled off with a solvent before the development step (e.g., see Japanese Patent Application Publication No. 2006-227632) or a developer-removable protective film that is peeled off simultaneously with the development step (e.g., see International Publication No. 2005 / 069076 and International Publication No. 2006 / 035790) can be used. From the viewpoint of yield, a developer-removable immersion protective film is preferred.

[0159] [Exposure Steps] In this step, the resist film obtained by the coating step is exposed. This exposure is performed by irradiating the resist film with radiation through a photomask, which may be used as a liquid immersion medium such as water, depending on the situation. The radiation can be, for example, electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and gamma rays, or charged particle beams such as electron beams and alpha rays, depending on the linewidth of the target pattern. Among these, the radiation used to irradiate the resist film formed using this composition is preferably far ultraviolet light, EUV, or an electron beam; more preferably, it is ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV, or an electron beam; and even more preferably, it is ArF excimer laser light, EUV, or an electron beam.

[0160] Preferably, post-exposure baking (PEB) is performed after exposure, in which acid generated by a self-induced radioactive linear acid generator during exposure is used to promote the dissociation of acid-dissociating groups in the exposed portion of the resist film. This PEB increases the difference in solubility of the developer between the exposed and unexposed portions. The PEB temperature is preferably 50°C or higher, more preferably 80°C or higher. Furthermore, the PEB temperature is preferably 180°C or lower, more preferably 130°C or lower. The PEB time is preferably 5 seconds or higher, more preferably 10 seconds or higher. Furthermore, the PEB time is preferably 600 seconds or lower, more preferably 300 seconds or lower.

[0161] [Developing Steps] In this step, the exposed resist film is developed using a developer. This allows the desired resist pattern to be formed. The developer can be an alkaline developer or an organic solvent developer. The developer can be appropriately selected depending on the target pattern (positive or negative).

[0162] Examples of alkaline developing solutions include alkaline aqueous solutions prepared by dissolving at least one of the following alkaline compounds: sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl diethylamine, ethyl dimethylamine, 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, an aqueous solution of TMAH is preferred, and a 2.38% by mass aqueous solution of TMAH is more preferred.

[0163] As a developing solution for organic solvent development, examples include: organic solvents such as hydrocarbons, ethers, esters, ketones, and alcohols, or solvents containing such organic solvents. Examples of organic solvents include: one or more solvents listed as solvents that can be formulated into this composition. Among these, ethers, esters, and ketones are preferred. As ethers, glycol ethers are preferred, more preferably ethylene glycol monomethyl ether or propylene glycol monomethyl ether. As esters, acetate esters are preferred, more preferably n-butyl acetate or amyl acetate. As ketones, chain ketones are preferred, more preferably 2-heptanone. The content of organic solvent in the developing solution is preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably 99% by mass or more. Other components in the developing solution besides organic solvents include, for example, water and silicone oil.

[0164] Examples of development methods include: immersing a substrate in a tank filled with developer for a fixed time (immersion method); developing a substrate by using surface tension to accumulate developer on the substrate surface and then allowing it to stand still for a fixed time (puddle method); spraying developer onto the substrate surface (spray method); and continuously spraying developer onto a substrate rotating at a fixed speed while scanning the developer nozzle at a fixed speed (dynamic distribution method).

[0165] The composition described above, comprising a polymer (A) and a compound (Q), exhibits high sensitivity in forming resist patterns, while also demonstrating excellent LWR performance, CDU performance, and pattern rectangularity. Therefore, this composition is well-suited for use in the fabrication processes of semiconductor devices that are expected to undergo further miniaturization in the future.

[0166] The following methods are provided by the above detailed disclosure. [1] A radiosensitive linear composition comprising: a polymer having an acid-dissociable group, and a compound (Q) represented by the formula (1). [2] The radiosensitive linear composition as described in [1], wherein R2 is a substituted or unsubstituted divalent chain hydrocarbon group, or a substituted or unsubstituted divalent alicyclic hydrocarbon group, or represents an aliphatic heterocyclic structure formed together with R3 and L1. [3] The radiosensitive linear composition as described in [1] or [2], wherein R1 is a substituted or unsubstituted monovalent chain hydrocarbon group, or a monovalent group having an alicyclic hydrocarbon structure, or a monovalent group having an aliphatic heterocyclic structure, and is bonded to L1 by means of a carbon atom. [4] The radioactive linear composition as described in any one of [1] to [3], wherein the L2 is a single bond. [5] The radiosensitive linear composition as described in any one of [1] to [4] further contains compound (B), which, upon exposure, produces an acid with a higher degree of acidity in the composition compared to compound (Q). [6] The radiosensitive linear composition as described in [5], wherein the compound (B) is the compound represented by formula [2]. [7] A pattern forming method, comprising: a step of coating a photosensitive linear composition as described in any one of [1] to [6] onto a substrate to form a resist film; a step of exposing the resist film; and a step of developing the exposed resist film. [8] The pattern forming method as described in [7], wherein the developing step is a step of developing the exposed resist film using an organic solvent developer. [9] A photodegradable alkali, represented by the formula (1). [Example]

[0167] The present invention will now be specifically described based on embodiments, but the present invention is not limited to these embodiments. Furthermore, unless otherwise specified, "parts" and "%" in the following examples refer to mass measurements. Methods for determining various physical properties are shown below.

[0168] [Weight-average molecular weight (Mw), number-average molecular weight (Mn), and dispersion (Mw / Mn)] The Mw and Mn of the polymer were determined using gel permeation chromatography (GPC) with monodisperse polystyrene as the standard, under the following analytical conditions: flow rate: 1.0 mL / min; dissolution solvent: tetrahydrofuran; sample concentration: 1.0% by mass; sample injection volume: 100 μL; column temperature: 40 °C; detector: differential refractometer. The dispersion (Mw / Mn) was calculated based on the Mw and Mn determination results.

[0169] [13C-NMR Analysis] 13C-NMR analysis of the polymer was performed using a nuclear magnetic resonance apparatus (JNM-Delta400 of Nippon Electron Ltd).

[0170] The [A] resin, [B] radiosensitive linear acid generator, [C] acid diffusion control agent, [D] solvent, and [E] high fluorine content resin used in the preparation of the radiosensitive linear resin composition in each example are shown below.

[0171] <[A] Resin and [E] High Fluorine Content Resin> Synthesis of [A] resin and [E] high fluorine content resin The following shows the monomers used in the synthesis of various resins and high-fluorine-content resins. Furthermore, 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 "moles %" refers to the value when the total number of moles of the monomers used is set to 100 moles %.

[0172] [Chemistry 24]

[0173] [Synthesis example 1] (Synthesis of resin (A-1)) Monomers (M-1), (M-4), (M-5), (M-11), and (M-14) were dissolved in 200 parts by mass of 2-butanone at a mole ratio of 40 / 10 / 20 / 20 / 10 (moles%). Azobisisobutyronitrile (AIBN) (3 moles relative to the total 100 moles of the monomers used) was added as an initiator to prepare a monomer solution. 100 parts by mass of 2-butanone were placed in a reaction vessel, purged with nitrogen for 30 minutes, and the reaction vessel was set to 80°C. The monomer solution was added dropwise over 3 hours with stirring. The start of the dropwise addition was defined 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 to below 30°C. The cooled polymerization solution was then added to methanol (2,000 parts by mass), and the precipitated white powder was filtered off. The filtered white powder was washed twice with methanol, then filtered again, and dried at 50°C for 24 hours to obtain a white powdery resin (A-1) (yield: 80%). The Mw of resin (A-1) was 9,100, and the Mw / Mn ratio was 1.54. Furthermore, 13C-NMR analysis showed that the content of each structural unit derived from monomers (M-1), (M-4), (M-5), (M-11), and (M-14) was 40.6 mol%, 9.7 mol%, 21.1 mol%, 20.5 mol%, and 8.1 mol, respectively.

[0174] [Synthesis Example 2~Synthesis Example 11] (Synthesis of resins (A-2) to (A-11)) Except for the monomers of the types and proportions shown in Table 1 below, resins (A-2) to (A-11) were synthesized in the same manner as in Synthesis Example 1. The content proportions (moles%) and physical property values ​​(Mw and Mw / Mn) of each structural unit of the obtained resins are shown in Table 1 below. Furthermore, "-" in Table 1 below indicates that the corresponding monomer was not used (the same applies to subsequent tables).

[0175] [Table 1] [A] Resin Provides a single volume of structural unit (I) Provides a single volume of structural unit (II-1) Provides a single volume of structural unit (II-2) Mw Mw / Mn type Mixing ratio (mol%) Structural unit Contains proportion (mol%) type Mixing ratio (mol%) Structural unit Contains proportion (mol%) type Mixing ratio (mol%) Structural unit Contains proportion (mol%) Synthesis example 1 A-1 M-1 40 40.6 M-5 20 21.1 M-14 10 8.1 9100 1.54 M-4 10 9.7 M-11 20 20.5 Synthesis example 2 A-2 M-1 30 31.4 M-6 60 60.6 - - - 9000 1.44 M-2 10 8.0 Synthesis example 3 A-3 M-1 30 31.9 M-5 60 59.2 - - - 8600 1.51 M-3 10 8.9 Synthesis example 4 A-4 M-1 35 34.8 M-12 45 46.4 - - - 7700 1.56 M-3 20 18.8 Synthesis example 5 A-5 M-1 40 41.1 M-10 45 46.8 - - - 7900 1.44 M-4 15 12.1 Synthesis example 6 A-6 M-1 40 40.7 M-11 45 46.1 - - - 8100 1.45 M-4 15 13.2 Synthesis Example 7 A-7 M-1 40 40.2 M-10 30 29.6 M-14 10 10.5 8000 1.57 M-13 20 19.7 Synthesis example 8 A-8 M-1 40 40.2 M-7 40 41.1 M-15 20 18.7 8500 1.61 Synthesis example 9 A-9 M-1 50 51.0 M-8 50 49.0 - - - 7800 1.55 Synthesis example 10 A-10 M-1 40 41.3 M-9 60 58.7 - - - 8200 1.55 Synthesis example 11 A-11 M-1 40 42.8 M-6 60 57.2 - - - 8000 1.43

[0176] [Synthesis Example 12] (Synthesis of resin (A-12)) Monomers (M-1) and (M-18) were dissolved in 1-methoxy-2-propanol (200 parts by mass) at a molar ratio of 50 / 50 (molar%), and AIBN (5 molar%) was added as an initiator to prepare a monomer solution. 1-methoxy-2-propanol (100 parts by mass) was placed in a reaction vessel, purged with nitrogen for 30 minutes, and the reaction vessel was set to 80°C. The monomer solution was added dropwise over 3 hours with stirring. The start of the dropwise addition was defined 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 to below 30°C. The cooled polymerization solution was added to hexane (2,000 parts by mass), and the precipitated white powder was filtered and separated. The filtered white powder was washed twice with hexane, filtered again, and dissolved in 1-methoxy-2-propanol (300 parts by mass). Subsequently, 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 with stirring. After the reaction was completed, the remaining solvent was removed by distillation, and the obtained solid was dissolved in acetone (100 parts by mass) and added dropwise to water (500 parts by mass) to solidify the resin. The obtained solid was separated by filtration and dried at 50°C for 13 hours to obtain a white powdery resin (A-12) (yield 79%). The Mw of resin (A-12) was 5,200, and the Mw / Mn ratio was 1.60. In addition, the 13C-NMR analysis results showed that the content of each structural unit derived from monolith (M-1) and monolith (M-18) was 51.3 mol% and 48.7 mol%, respectively.

[0177] [Synthesis Example 13~Synthesis Example 15] (Synthesis of resins (A-13) to (A-15)) Resins (A-13) to (A-15) were synthesized in the same manner as in Synthesis Example 12, except that the monomers of the types and proportions shown in Table 2 below were used. The content ratio (moles%) and physical property values ​​(Mw and Mw / Mn) of each structural unit of the obtained resins are shown in Table 2 below.

[0178] [Table 2] [A] Resin Provides a single volume of structural unit (I) Provides a single volume of structural unit (II-2) Provides a single volume of structural unit (III) Mw Mw / Mn type Mixing ratio (mol%) Structural unit Contains proportion (mol%) type Mixing ratio (mol%) Structural unit Contains proportion (mol%) type Mixing ratio (mol%) Structural unit Contains proportion (mol%) Synthesis example 12 A-12 M-1 50 51.3 - - - M-18 50 48.7 5200 1.60 Synthesis example 13 A-13 M-3 50 47.9 M-14 10 10.3 M-19 40 41.8 5500 1.53 Synthesis example 14 A-14 M-2 50 48.1 M-17 20 21.3 M-18 30 30.6 5100 1.59 Synthesis Example 15 A-15 M-1 55 55.7 M-17 15 15.1 M-19 30 29.2 6100 1.50

[0179] [Synthesis Example 16] (Synthesis of high-fluoride resin (E-1)) Monomers (M-1) and (M-20) were dissolved in 200 parts by mass of 2-butanone at a molar ratio of 20 / 80 (molar%), and AIBN (4 molar%) was added as an initiator to prepare a monomer solution. 100 parts by mass of 2-butanone was placed in a reaction vessel, purged with nitrogen for 30 minutes, and the reaction vessel was set to 80°C. The monomer solution was added dropwise over 3 hours while stirring. The start of the dropwise addition was defined 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 replacing the solvent with acetonitrile (400 parts by mass), hexane (100 parts by mass) was added, stirred, and the acetonitrile layer was recovered. This process was repeated three times. By replacing the solvent with propylene glycol monomethyl ether acetate, a solution of high-fluorine resin (E-1) was obtained (yield: 69%). The high-fluorine content resin (E-1) has a Mw of 6,000 and an Mw / Mn ratio of 1.62. 13C-NMR analysis showed that the content of each structural unit derived from monoliths (M-1) and (M-20) was 19.9 mol% and 80.1 mol%, respectively.

[0180] [Synthesis Example 17~Synthesis Example 20] (Synthesis of high-fluorine content resins (E-2) to high-fluorine content resins (E-5)) Using the types and proportions of monomers shown in Table 3 below, high-fluorine content resins (E-2) to (E-5) were synthesized in the same manner as in Synthesis Example 16. The content proportions (moles%) and physical property values ​​(Mw and Mw / Mn) of each structural unit of the obtained high-fluorine content resins are shown in Table 3 below.

[0181] [Table 3] [E] Resin Provides a single volume of structural unit (F) Provides a single volume of structural unit (I) Provides a single volume of structural unit (II-2) Provide single volume for other structural units Mw Mw / Mn type Mixing ratio (mol%) Structural unit Contains proportion (mol%) type Mixing ratio (mol%) Structural unit Contains proportion (mol%) type Mixing ratio (mol%) Structural unit Contains proportion (mol%) type Mixing ratio (mol%) Structural unit Contains proportion (mol%) Synthesis Example 16 E-1 M-20 80 80.1 M-1 20 19.9 - - - - - - 6000 1.62 Synthesis Example 17 E-2 M-21 80 81.9 M-1 20 18.1 - - - - - - 7200 1.77 Synthesis example 18 E-3 M-22 60 61.3 - - - - - - M-16 40 38.7 6300 1.82 Synthesis example 19 E-4 M-22 60 60.3 M-4 20 18.7 M-14 20 21.0 - - - 7000 1.84 Synthesis example 20 E-5 M-20 60 59.2 M-2 10 10.3 M-17 30 30.5 - - - 6100 1.86

[0182] <[C] Acid diffusion control agent> Synthesis of [C] Acid diffusion control agents [Synthesis Example 21] (Synthesis of compound (C-1-a)) Compound (C-1-a) was synthesized according to the following synthetic procedure. [Chemistry 25]

[0183] 20.0 mmol of bis(4-(tert-butyl)phenyl)iodonium chloride, 20.0 mmol of 1,4-thioxanol, 2.00 mmol of copper(II) acetate, and 50 g of chloroform were added to a reaction vessel and stirred at ice temperature for 24 hours. After removing impurities by filtration through diatomaceous earth, the solvent was removed by distillation, and the mixture was purified by recrystallization to obtain the compound represented by formula (C-1-a) in good yield (hereinafter referred to as "compound (C-1-a)").

[0184] [Synthesis example 22] (Synthesis of compound (C-1)) Compound (C-1) was synthesized according to the following synthetic procedure. [Chemistry 26]

[0185] 20.0 mmol of sodium ethanesulfonate, 20.0 mmol of 2-adamantanone-5-carboxylic acid, 20.0 mmol of dicyclohexylcarbodiimide, and 50 g of dichloromethane were added to a reaction vessel and stirred at room temperature for 4 hours. Then, after dilution with water, extraction with dichloromethane was performed, and the organic layer was separated. The solvent was removed by distillation after drying with sodium sulfate, thus obtaining the sodium sulfonate compound in good yield.

[0186] 20.0 mmol of compound (C-1-a) was added to the sodium sulfonate compound, and a mixture of water and dichloromethane (1:3 by mass) was added to prepare a 0.5 M 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 removed by distillation, and the solution was purified by column chromatography to obtain the compound represented by formula (C-1) in good yield (hereinafter referred to as "compound (C-1)").

[0187] [Synthesis Example 23~Synthesis Example 30] (Synthesis of compounds (C-2) to (C-9)) Except for the appropriate changes to the raw materials and precursors, the onium salts represented by the following formulas (C-2) to (C-9) were synthesized in the same manner as in Synthesis Example 22 (these shall be referred to as "Compound (C-2)" to "Compound (C-9)" respectively). [Chemistry 27]

[0188] [Synthesis Example 31] (Synthesis of compound (C-10)) The compound (C-10) was synthesized according to the following synthetic procedure. [Chemistry 28]

[0189] 20.0 mmol of 2-hydroxy-4-oxatricyclo[4.3.1.1]undecane-5-one, 20.0 mmol of bromoacetyl bromide, 20.0 mmol of triethylamine, and 50 g of tetrahydrofuran were added to a reaction vessel and stirred at room temperature for 1 hour. Then, a saturated aqueous solution of ammonium chloride was added to the reaction solution to allow the reaction to complete. Ethyl acetate was then added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous solution of sodium chloride, followed by washing with water. After drying with sodium sulfate, the solvent was removed by distillation, and the solution was purified by column chromatography to obtain the bromide in good yield.

[0190] An acetonitrile:water mixture (1:1 mass ratio) was added to the bromide gas to prepare a 1M solution. Then, 30.0 mmol of sodium dithionite and 30.0 mmol of sodium bicarbonate were added, and the reaction was carried out at 70°C for 4 hours. After removing the solvent by extraction with acetonitrile and distillation, an acetonitrile:water mixture (3:1 mass ratio) was added to prepare a 0.5M solution. 60.0 mmol of hydrogen peroxide solution and 2.00 mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. The solvent was then removed by extraction with acetonitrile and distillation to obtain a sodium sulfonate compound. 20.0 mmol of the intermediate salt represented by formula (C-1-a) was added to the sodium sulfonate compound, along with a water:dichloromethane mixture (1:3 mass ratio) 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 solvent was removed by distillation and purified by column chromatography to obtain the compound represented by formula (C-10) in good yield (hereinafter referred to as "compound (C-10)").

[0191] [Synthesis Example 32~Synthesis Example 36] (Synthesis of compounds (C-11) to (C-15)) Except for suitable changes to the raw materials and precursors, the onium salts represented by the following formulas (C-11) to (C-15) were synthesized in the same manner as in Synthesis Example 31 (these are referred to as "Compound (C-11)" to "Compound (C-15)" respectively). [Chemistry 29]

[0192] [Synthesis Example 37] (Synthesis of compound (C-16)) The compound (C-16) was synthesized according to the following synthetic procedure. [Chemistry 30]

[0193] 20.0 mmol of 5-norbornene-2,3-dicarboxylic anhydride, 40.0 mmol of 2,2,2-trifluoroethanol, 60.0 mmol of triethylamine, and 50 g of tetrahydrofuran were added to a reaction vessel and stirred at room temperature for 15 hours. Then, a saturated aqueous solution of ammonium chloride was added to the reaction solution to complete the reaction. 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, followed by washing with water. After drying with sodium sulfate, the solvent was removed by distillation, and the mixture was purified by column chromatography to obtain the diester in good yield.

[0194] An acetonitrile:water mixture (1:1, mass ratio) was added to the diester to prepare a 1M solution. 30.0 mmol of sodium sulfite was then added, and the reaction was carried out at 100°C for 12 hours. Extraction was performed using acetonitrile, and the solvent was removed by distillation to obtain a sodium sulfonate compound. 20.0 mmol of the intermediate salt represented by formula (C-1-a) was added to the sodium sulfonate compound, along with a water:dichloromethane mixture (1:3, mass ratio) 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, and the solvent was removed by distillation. Purification was performed by column chromatography to obtain the compound represented by formula (C-16) in good yield (referred to as "Compound (C-16)").

[0195] [Synthesis Example 38~Synthesis Example 46] (Synthesis of compounds (C-17) to (C-25)) Except for suitable changes to the raw materials and precursors, the onium salts represented by the following formulas (C-17) to (C-25) were synthesized in the same manner as in Synthesis Example 37 (these are respectively referred to as "Compound (C-17)" to "Compound (C-25)"). [Chemistry 31]

[0196] ·Onium salts other than Compound (C-1) to Compound (C-25) cc-1 to cc-12: Compounds represented by the following formulas (cc-1) to (cc-12) (hereinafter, the compounds represented by formulas (cc-1) to (cc-12) may be sometimes described as "Compound (cc-1)" to "Compound (cc-12)") [Chemical formula 32]

[0197] <[B] Radiation-sensitive acid generator> B-1 to B-10: Compounds represented by the following formulas (B-1) to (B-10) (hereinafter, the compounds represented by formulas (B-1) to (B-10) may be sometimes described as "Compound (B-1)" to "Compound (B-10)") [Chemical formula 33]

[0198] <[D] Solvent> D-1: Propylene glycol monomethyl ether acetate D-2: Propylene glycol monomethyl ether D-3: γ-Butyrolactone D-4: Ethyl lactate

[0199] <Preparation of negative-type radiation-sensitive resin composition for ArF exposure> [Example 1] 100 parts by mass of (A-1) as [A] resin, 10.0 parts by mass of (B-1) as [B] radiation-sensitive acid generator, 8.0 parts by mass of (C-1) as [C] acid diffusion controller, 3.0 parts by mass (solid content) of (E-1) as [E] high fluorine content resin, and 3,230 parts by mass of a mixed solvent of (D-1) / (D-2) / (D-3) as [D] solvent (2,240 / 960 / 30 (parts by mass)) were mixed and filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive resin composition (J-1).

[0200] [Examples 2 to 59 and Comparative Examples 1 to 12] Except for using the types and amounts of each component shown in Tables 4 and 5 below, the same procedures were performed as in Example 1 to prepare radiosensitive linear resin compositions (J-2) to (J-59) and radiosensitive linear resin compositions (CJ-1) to (CJ-12).

[0201] [Table 4] Inductively linear resin composition [A] Resin [B] Acid generating agent [C] Acid diffusion control agent [E] Resin [D] Solvent type content (parts by weight) type content (parts by weight) type content (parts by weight) type content (parts by weight) type content (parts by weight) Example 1 J-1 A-1 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 2 J-2 A-1 100 B-1 10.0 C-2 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 3 J-3 A-1 100 B-1 10.0 C-3 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 4 J-4 A-1 100 B-1 10.0 C-4 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 5 J-5 A-1 100 B-1 10.0 C-5 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 6 J-6 A-1 100 B-1 10.0 C-6 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 7 J-7 A-1 100 B-1 10.0 C-7 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 8 J-8 A-1 100 B-1 10.0 C-8 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 9 J-9 A-1 100 B-1 10.0 C-9 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 10 J-10 A-1 100 B-1 10.0 C-10 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 11 J-11 A-1 100 B-1 10.0 C-11 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 12 J-12 A-1 100 B-1 10.0 C-12 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 13 J-13 A-1 100 B-1 10.0 C-13 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 14 J-14 A-1 100 B-1 10.0 C-14 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 15 J-15 A-1 100 B-1 10.0 C-15 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 16 J-16 A-1 100 B-1 10.0 C-16 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 17 J-17 A-1 100 B-1 10.0 C-17 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 18 J-18 A-1 100 B-1 10.0 C-18 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 19 J-19 A-1 100 B-1 10.0 C-19 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 20 J-20 A-1 100 B-1 10.0 C-20 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 21 J-21 A-1 100 B-1 10.0 C-21 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 22 J-22 A-1 100 B-1 10.0 C-22 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 23 J-23 A-1 100 B-1 10.0 C-23 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 24 J-24 A-1 100 B-1 10.0 C-24 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 25 J-25 A-1 100 B-1 10.0 C-25 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 26 J-26 A-2 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 27 J-27 A-3 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 28 J-28 A-4 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 29 J-29 A-5 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 30 J-30 A-6 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 31 J-31 A-7 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 32 J-32 A-8 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 33 J-33 A-9 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 34 J-34 A-10 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 35 J-35 A-11 100 B-1 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 36 J-36 A-1 100 B-2 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 37 J-37 A-1 100 B-3 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 38 J-38 A-1 100 B-4 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 39 J-39 A-1 100 B-5 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 40 J-40 A-1 100 B-6 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30

[0202] [Table 5] Inductively linear resin composition [A] Resin [B] Acid generating agent [C] Acid diffusion control agent [E] Resin [D] Solvent type content (parts by weight) type content (parts by weight) type content (parts by weight) type content (parts by weight) type content (parts by weight) Example 41 J-41 A-1 100 B-7 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 42 J-42 A-1 100 B-8 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 43 J-43 A-1 100 B-9 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 44 J-44 A-1 100 B-10 10.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 45 J-45 A-1 100 B-1 10.0 C-1 8.0 E-2 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 46 J-46 A-1 100 B-1 10.0 C-1 8.0 E-3 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 47 J-47 A-1 100 B-1 10.0 C-1 8.0 E-4 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 48 J-48 A-1 100 B-1 10.0 C-1 0.5 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 49 J-49 A-1 100 B-1 10.0 C-1 4.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 50 J-50 A-1 100 B-1 10.0 C-1 15.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 51 J-51 A-1 100 B-1 10.0 C-1 / C-11 4.0 / 4.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 52 J-52 A-1 100 B-1 10.0 C-1 / C-16 4.0 / 4.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 53 J-53 A-1 100 B-1 10.0 C-4 / C-21 4.0 / 4.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 54 J-54 A-1 100 B-1 10.0 C-1 / cc-1 4.0 / 4.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 55 J-55 A-1 100 B-1 / B-2 5.0 / 5.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 56 J-56 A-1 100 B-1 / B-5 5.0 / 5.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 57 J-57 A-1 100 B-1 / B-7 5.0 / 5.0 C-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 58 J-58 A-1 100 B-8 / B-9 5.0 / 5.0 C-9 / C-25 4.0 / 4.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Example 59 J-59 A-1 100 B-4 / B-10 5.0 / 5.0 C-6 / C-24 4.0 / 4.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 1 CJ-1 A-1 100 B-1 10.0 cc-1 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 2 CJ-2 A-1 100 B-1 10.0 cc-2 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 3 CJ-3 A-1 100 B-1 10.0 cc-3 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 4 CJ-4 A-1 100 B-1 10.0 cc-4 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 5 CJ-5 A-1 100 B-1 10.0 cc-5 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 6 CJ-6 A-1 100 B-1 10.0 cc-6 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 7 CJ-7 A-1 100 B-1 10.0 cc-7 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 8 CJ-8 A-1 100 B-1 10.0 cc-8 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 9 CJ-9 A-1 100 B-1 10.0 cc-9 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 10 CJ-10 A-1 100 B-1 10.0 cc-10 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 11 CJ-11 A-1 100 B-1 10.0 cc-11 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30 Comparative Example 12 CJ-12 A-1 100 B-1 10.0 cc-12 8.0 E-1 3.0 D-1 / D-2 / D-3 2240 / 960 / 30

[0203] <Formation of resist patterns using ArF exposure for negative-sensitivity linear resin compositions> Using a spin coater (Tokyo Electron's "CLEAN TRACK ACT12"), a lower layer film forming composition (Brewer Science's "ARC66") was coated onto a 12-inch silicon wafer, followed by heating at 205°C for 60 seconds to form a lower layer film with an average thickness of 100 nm. The prepared ArF exposure negative-type radiosensitive linear resin composition was then coated onto this lower layer film using the same spin coater and pre-baked at 100°C for 60 seconds (PB). Afterward, it was cooled at 23°C for 30 seconds to form a resist film with an average thickness of 90 nm. Next, using an ArF excimer laser immersion exposure system (ASML's "TWINSCAN XT-1900i"), with optical conditions of NA=1.35 and dipole (σ=0.9 / 0.7), a mask pattern with 40 nm apertures and 120 nm spacing was exposed to the resist film. After exposure, it was baked at 100°C for 60 seconds (PEB). Subsequently, the resist film was developed using n-butyl acetate as an organic solvent and dried to form a negative resist pattern (40 nm apertures, 120 nm spacing).

[0204] <Evaluation> For the resist patterns formed using the aforementioned ArF exposure negative-type radiosensitive linear resin composition, sensitivity, CDU performance, depth of focus, pattern rectangularity, and storage stability were evaluated according to the following methods. The results are shown in Tables 6 and 7 below. Furthermore, the length of the resist patterns was measured using a scanning electron microscope (Hitachi High-Technologies, Inc.'s "CG-5000").

[0205] [sensitivity] In the formation of resist patterns using the aforementioned ArF exposure negative-type radiosensitive linear resin composition, the exposure amount for forming a 40 nm hole pattern is taken as the optimal exposure amount, and this optimal exposure amount is taken as the sensitivity (mJ / cm 2). Regarding sensitivity, cases below 30 mJ / cm 2 are evaluated as "good", and cases exceeding 30 mJ / cm 2 are evaluated as "poor".

[0206] [CDU Performance] For resist patterns with 40 nm apertures and 105 nm spacing, the length of a total of 1,800 resist patterns formed was measured at arbitrary points from the top of the pattern using the aforementioned scanning electron microscope. The dimensional deviation (3σ) was calculated and set as the CDU performance (nm). Regarding CDU performance, the smaller the CDU value, the smaller the aperture deviation over a long period, indicating better performance. For CDU performance, cases below 3.0 nm were evaluated as "good," and cases exceeding 3.0 nm were evaluated as "poor."

[0207] [Focus Depth] In the resist pattern resolved at the optimal exposure determined in the sensitivity evaluation, the size when the focal length changes in the depth direction is observed. The margin in the depth direction where the pattern size falls within 90% to 110% of the reference value in a state without bridging or residue is measured, and this measured value is taken as the focal depth (nm). A larger focal depth value indicates better performance. A focal depth of 100 nm or more is rated as "good," and a focal depth of less than 100 nm is rated as "poor."

[0208] [Pattern Rectangularity] The resist pattern formed by irradiating the optimal exposure amount determined in the sensitivity evaluation was observed using the scanning electron microscope, and the cross-sectional shape of the hole pattern was evaluated. Regarding the rectangularity of the resist pattern, if the ratio of the length of the upper side to the length of the lower side in the cross-sectional shape is greater than 1.00 and less than 1.05, it is rated "A" (extremely good); if it exceeds 1.05 and is less than 1.10, it is rated "B" (good); and if it exceeds 1.10, it is rated "C" (poor).

[0209] [Maintain stability] After storing the ArF exposure negative-type radiosensitive linear resin composition at 35°C for 30 days, the optimal exposure (i.e., sensitivity) for forming a 40 nm aperture pattern was determined again. If the difference between the sensitivity after 30 days of storage and the sensitivity before storage is 0% or more and 1.0% or less, it is rated "A" (Excellent); if it exceeds 1.0% but is less than 2.0%, it is rated "B" (Good); and if it exceeds 2.0%, it is rated "C" (Poor).

[0210] [Table 6] Inductively linear resin composition Sensitivity (mJ / cm 2) CDU (nm) Focus Depth (nm) pattern Rectangular Preservation stability Example 1 J-1 25 2.4 130 A A Example 2 J-2 twenty two 2.6 120 A A Example 3 J-3 26 2.7 130 A A Example 4 J-4 28 2.5 120 A A Example 5 J-5 27 2.5 120 A A Example 6 J-6 27 2.6 120 A A Example 7 J-7 twenty two 2.7 120 A A Example 8 J-8 26 2.8 130 A A Example 9 J-9 28 2.7 130 A A Example 10 J-10 27 2.7 140 A A Example 11 J-11 27 2.4 120 A A Example 12 J-12 26 2.5 130 A A Example 13 J-13 25 2.7 120 A A Example 14 J-14 26 2.6 130 A A Example 15 J-15 25 2.6 120 A A Example 16 J-16 20 2.5 120 A A Example 17 J-17 twenty three 2.7 120 A A Example 18 J-18 28 2.5 120 A A Example 19 J-19 25 2.8 130 A A Example 20 J-20 twenty three 2.4 120 A A Example 21 J-21 twenty four 2.3 120 A A Example 22 J-22 twenty three 2.3 120 A A Example 23 J-23 twenty four 2.2 130 A A Example 24 J-24 25 2.4 120 A A Example 25 J-25 twenty four 2.5 120 A A Example 26 J-26 twenty three 2.5 120 A A Example 27 J-27 27 2.5 120 A A Example 28 J-28 26 2.4 120 A A Example 29 J-29 28 2.5 130 A A Example 30 J-30 twenty four 2.5 130 A A Example 31 J-31 26 2.6 120 A A Example 32 J-32 26 2.7 130 A A Example 33 J-33 twenty three 2.4 130 A A Example 34 J-34 twenty two 2.5 130 A A Example 35 J-35 26 2.6 120 A A Example 36 J-36 28 2.4 120 A A Example 37 J-37 twenty three 2.5 120 A A Example 38 J-38 28 2.4 120 A A Example 39 J-39 twenty three 2.7 120 A A Example 40 J-40 27 2.4 130 A A

[0211] [Table 7] Inductively linear resin composition Sensitivity (mJ / cm 2) CDU (nm) Focus Depth (nm) pattern Rectangular Preservation stability Example 41 J-41 twenty one 2.6 120 A A Example 42 J-42 28 2.7 120 A A Example 43 J-43 twenty one 2.5 120 A A Example 44 J-44 twenty four 2.2 120 A A Example 45 J-45 26 2.4 130 A A Example 46 J-46 25 2.4 130 A A Example 47 J-47 25 2.4 130 A A Example 48 J-48 twenty two 2.6 110 A A Example 49 J-49 twenty four 2.8 120 A A Example 50 J-50 27 2.7 130 A A Example 51 J-51 27 2.5 120 A A Example 52 J-52 25 2.6 130 A A Example 53 J-53 28 2.7 130 A A Example 54 J-54 27 2.9 130 A A Example 55 J-55 27 2.5 130 A A Example 56 J-56 twenty three 2.3 130 A A Example 57 J-57 twenty two 2.4 120 A A Example 58 J-58 twenty three 2.5 130 A A Example 59 J-59 twenty four 2.4 120 A A Comparative Example 1 CJ-1 27 3.2 30 B A Comparative Example 2 CJ-2 28 3.3 70 C A Comparative Example 3 CJ-3 28 3.4 80 C A Comparative Example 4 CJ-4 36 3.2 70 A C Comparative Example 5 CJ-5 32 3.5 60 A C Comparative Example 6 CJ-6 42 4.2 30 B C Comparative Example 7 CJ-7 32 3.2 70 A C Comparative Example 8 CJ-8 35 3.6 60 A C Comparative Example 9 CJ-9 37 3.2 50 B B Comparative Example 10 CJ-10 35 3.5 60 B B Comparative Example 11 CJ-11 42 4.5 30 C C Comparative Example 12 CJ-12 40 3.9 50 C A

[0212] As is evident from the results in Tables 6 and 7, when the radiosensitive linear resin compositions of Examples 1 to 59 were used for ArF exposure, they exhibited good sensitivity, CDU performance, depth of focus, pattern rectangularity, and storage stability. In contrast, the radiosensitive linear resin compositions of Comparative Examples 1 to 12 showed poorer performance in more than one of the following characteristics: sensitivity, CDU performance, depth of focus, pattern rectangularity, and storage stability compared to Examples 1 to 59. Therefore, it can be said that when the radiosensitive linear resin compositions of Examples 1 to 59 were used for negative ArF exposure, they exhibited good CDU performance and pattern rectangularity while maintaining high sensitivity, and also demonstrated excellent storage stability.

[0213] <Preparation of Positive Radiation-Inducing Linear Resin Compositions for Extreme Ultraviolet (EUV) Exposure> [Example 60] A positive-type radiosensitive linear resin composition (J-60) for EUV exposure was prepared by mixing 100 parts by mass of (A-12) as [A] resin, 16.0 parts by mass of (B-1) as [B] radiosensitive linear acid generator, 10.0 parts by mass of (C-1) as [C] acid diffusion control agent, 3.0 parts by mass of (E-5) as [E] high-fluorine content resin (solid component), and 6,110 parts by mass of (D-1) / (D-4) as [D] solvent (4,280 / 1,830 (parts by mass)). The mixture was filtered through a membrane filter with a pore size of 0.2 μm.

[0214] [Examples 61-72 and Comparative Examples 13-18] Using the types and amounts of each component shown in Table 8 below, except that, the same as in Example 60, radiosensitive linear resin compositions (J-61) to (J-72) and radiosensitive linear resin compositions (CJ-13) to (CJ-18) were prepared respectively.

[0215] [Table 8] Inductively linear resin composition [A] Resin [B] Acid generating agent [C] Acid diffusion control agent [E] Resin [D] Solvent type content (parts by weight) type content (parts by weight) type content (parts by weight) type content (parts by weight) type content (parts by weight) Example 60 J-60 A-12 100 B-1 16.0 C-1 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 61 J-61 A-12 100 B-1 16.0 C-4 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 62 J-62 A-12 100 B-1 16.0 C-10 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 63 J-63 A-12 100 B-1 16.0 C-11 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 64 J-64 A-12 100 B-1 16.0 C-16 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 65 J-65 A-12 100 B-1 16.0 C-19 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 66 J-66 A-12 100 B-1 16.0 C-20 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 67 J-67 A-13 100 B-1 16.0 C-1 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 68 J-68 A-14 100 B-1 16.0 C-1 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 69 J-69 A-15 100 B-1 16.0 C-1 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 70 J-70 A-12 100 B-3 16.0 C-1 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 71 J-71 A-12 100 B-7 16.0 C-1 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Example 72 J-72 A-12 100 B-2 / B-6 8.0 / 8.0 C-1 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Comparative Example 13 CJ-13 A-12 100 B-1 16.0 cc-3 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Comparative Example 14 CJ-14 A-12 100 B-1 16.0 cc-4 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Comparative Example 15 CJ-15 A-12 100 B-1 16.0 cc-5 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Comparative Example 16 CJ-16 A-12 100 B-1 16.0 cc-6 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Comparative Example 17 CJ-17 A-12 100 B-1 16.0 cc-7 10.0 E-5 3.0 D-1 / D-4 4280 / 1830 Comparative Example 18 CJ-18 A-12 100 B-1 16.0 cc-10 10.0 E-5 3.0 D-1 / D-4 4280 / 1830

[0216] <Formation of resist patterns using EUV exposure with positive-type radiosensitive linear resin compositions> Using a spin coater (Tokyo Electron's "CLEAN TRACK ACT12"), a base film forming composition (Brewer Science's "ARC66") was coated onto a 12-inch silicon wafer, and then heated at 205°C for 60 seconds to form a base film with an average thickness of 105 nm. The prepared EUV exposure-inducing linear resin composition was then coated onto the base film using the same spin coater, and subjected to photolithography (PB) at 130°C for 60 seconds. Afterward, it was cooled at 23°C for 30 seconds to form a resist film with an average thickness of 55 nm. Next, the resist film was exposed using an EUV exposure apparatus (ASML's "NXE3300") with NA=0.33, illumination conditions: Conventional s=0.89, and mask: imecDEFECT32FFR02. After exposure, it was subjected to photolithography (PEB) at 120°C for 60 seconds. Subsequently, the resist film was developed using a 2.38% by mass TMAH aqueous solution as an alkaline developer. After development, the film was washed with water and then dried to form a positive resist pattern (32 nm line and spatial pattern).

[0217] <Evaluation> For the resist patterns formed using the aforementioned positive-type radiosensitive linear resin composition for EUV exposure, the sensitivity, LWR performance, and storage stability were evaluated according to the following methods. The results are shown in Table 9 below. Furthermore, the length of the resist patterns was measured using a scanning electron microscope (Hitachi High-Technologies, Inc.'s "CG-5000").

[0218] [sensitivity] In the formation of the resist pattern using the positive-type radiosensitive linear resin composition for EUV exposure, the exposure amount for forming the 32 nm line and spatial pattern is set as the optimal exposure amount, and the optimal exposure amount is set as the sensitivity (mJ / cm 2). Regarding sensitivity, a value below 25 mJ / cm 2 is evaluated as "good", and a value exceeding 25 mJ / cm 2 is evaluated as "poor".

[0219] [LWR Performance] The optimal exposure, determined in the sensitivity evaluation, was used to adjust the mask size to form a 32 nm line and spatial pattern, thus creating a resist pattern. The resist pattern was observed from above using a scanning electron microscope. The linewidth deviation at a total of 500 points was measured, and a 3-sigma value was determined based on the distribution of these measurements. This 3-sigma value was set as LWR (nm). Regarding LWR performance, a smaller LWR value indicates a smaller and better line gap. For LWR performance, values ​​below 2.5 nm were evaluated as "good," and values ​​above 2.5 nm were evaluated as "poor."

[0220] [Maintain stability] After storing the EUV exposure positive-type linear resin composition at 35°C for 30 days, the optimal exposure (i.e., sensitivity) for forming the 32 nm line and spatial pattern was measured again. If the difference between the sensitivity after 30 days and the sensitivity before storage is 0% or more and 1.0% or less, it is rated "A" (Excellent); if it exceeds 1.0% but is less than 2.0%, it is rated "B" (Good); and if it exceeds 2.0%, it is rated "C" (Poor).

[0221] [Table 9] Inductively linear resin composition Sensitivity (mJ / cm 2) LWR (nm) Preservation stability Example 60 J-60 twenty two 2.2 A Example 61 J-61 20 2.1 A Example 62 J-62 twenty one 2.3 A Example 63 J-63 twenty three 2.3 A Example 64 J-64 twenty two 2.1 A Example 65 J-65 twenty one 2.0 A Example 66 J-66 20 2.3 A Example 67 J-67 twenty two 2.2 A Example 68 J-68 19 2.1 A Example 69 J-69 twenty three 2.3 A Example 70 J-70 19 2.3 A Example 71 J-71 19 2.3 A Example 72 J-72 twenty four 1.9 A Comparative Example 13 CJ-13 26 3.3 A Comparative Example 14 CJ-14 27 3.6 C Comparative Example 15 CJ-15 31 4.0 C Comparative Example 16 CJ-16 32 3.7 C Comparative Example 17 CJ-17 30 3.5 C Comparative Example 18 CJ-18 29 3.8 B

[0222] As is clear from the results in Table 9, when the radiation-sensitive resin compositions of Examples 60 to 72 are used for EUV exposure, the sensitivity, LWR performance, and storage stability are good. In contrast, the sensitivity and LWR performance of the radiation-sensitive resin composition of Comparative Example 13 are inferior to those of Examples 60 to 72, and the sensitivity, LWR performance, and storage stability of the radiation-sensitive resin compositions of Comparative Examples 14 to 18 are inferior to those of Examples 60 to 72.

[0223] <Preparation of a Positive-Type Radiation-Sensitive Resin Composition for ArF Exposure, and Formation and Evaluation of a Resist Pattern Using the Composition> [Example 73] Mix 100 parts by mass of (A-1) as the [A] resin, 10.0 parts by mass of (B-7) as the [B] radiation-sensitive acid generator, 9.0 parts by mass of (C-1) as the [C] acid diffusion controller, 5.0 parts by mass (solid content) of (E-2) as the [E] high-fluorine content resin, and 3,230 parts by mass of the mixed solvent of (D-1) / (D-2) / (D-3) (2,240 / 960 / 30 (parts by mass)), and filter through a membrane filter with a pore size of 0.2 μm to prepare a positive-type radiation-sensitive resin composition (J-73) for ArF exposure.

[0224] Using a spin coater ("CLEAN TRACK ACT12" from Tokyo Electron Limited), the composition for forming the lower layer film ("ARC66" from Brewer Science, Inc.) was coated on a 12-inch silicon wafer and then heated at 205°C for 60 seconds to form a lower layer film with an average thickness of 100 nm. Using the spin coater, the prepared positive-type radiation-sensitive resin composition for ArF exposure (J-73) was coated on the lower layer film and pre-baked (PB) at 100°C for 60 seconds. Thereafter, it was cooled at 23°C for 30 seconds to form a resist film with an average thickness of 90 nm. Next, using an ArF excimer laser immersion exposure apparatus ("TWINSCAN XT-1900i" from ASML), with optical conditions of NA = 1.35 and annular (σ = 0.8 / 0.6), a mask pattern with a 50 nm line and space was used to expose the resist film. After exposure, PEB (post-exposure bake) was performed at 100°C for 60 seconds. Thereafter, a 2.38 mass% aqueous TMAH solution was used as an alkaline developer to perform alkali development on the resist film, and after development, it was washed with water and then dried to form a positive-type resist pattern (50 nm line and space pattern).

[0225] Regarding the resist pattern using the positive-type radiation-sensitive resin composition for ArF exposure, the sensitivity, LWR performance, and storage stability were evaluated in the same manner as for the resist pattern using the positive-type radiation-sensitive resin composition for EUV exposure. As a result, even when a positive-type resist pattern was formed by ArF exposure, the radiation-sensitive resin composition of Example 73 had good sensitivity, LWR performance, and storage stability.

[0226] <Preparation of Negative-Type Radiation-Sensitive Resin Composition for EUV Exposure, and Formation and Evaluation of Resist Pattern Using the Composition> [Example 74] 100 parts by mass of (A-15) as the [A] resin, 15.0 parts by mass of (B-1) as the [B] radiation-sensitive acid generator, 10.0 parts by mass of (C-16) as the [C] acid diffusion controller, 1.0 part by mass (solid content) of (E-5) as the [E] high fluorine content resin, and 6,110 parts by mass of the mixed solvent (D-1) / (D-4) (4,280 / 1,830 (parts by mass)) as the [D] solvent were mixed and filtered through a membrane filter with a pore size of 0.2 μm to prepare a negative-type radiation-sensitive resin composition for EUV exposure (J-74).

[0227] Using a spin coater (Tokyo Electron's "CLEAN TRACK ACT12"), a base film forming composition (Brewer Science's "ARC66") was coated onto a 12-inch silicon wafer, and then heated at 205°C for 60 seconds to form a base film with an average thickness of 105 nm. The prepared EUV exposure negative-type radiosensitive linear resin composition (J-74) was then coated onto the base film using the same spin coater and subjected to a photoresist exposure at 130°C for 60 seconds. Afterward, it was cooled at 23°C for 30 seconds to form a photoresist film with an average thickness of 55 nm. Next, the photoresist film was exposed using an EUV exposure apparatus (ASML's "NXE3300") with NA=0.33, illumination conditions: Conventional s=0.89, and mask: imecDEFECT32FFR02. After exposure, PEB was applied at 120°C for 60 seconds. Subsequently, the resist film was developed using n-butyl acetate as an organic solvent and dried to form a negative resist pattern (40 nm holes, 105 nm spacing).

[0228] The sensitivity, CDU performance, and storage stability of the resist pattern using the EUV exposure negative radiosensitive linear resin composition were evaluated in the same manner as those of the ArF exposure negative radiosensitive linear resin composition. As a result, the radiosensitive linear resin composition of Example 74 exhibited good sensitivity, CDU performance, and storage stability even when a negative resist pattern was formed using EUV exposure.

[0229] The described method for forming photosensitive linear resin compositions and resist patterns exhibits good sensitivity to exposure light, excellent LWR performance, and superior CDU performance. Therefore, these are well-suited for use in the fabrication processes of semiconductor devices that are envisioned to undergo further miniaturization in the future.

[0230] none

Claims

1. A radiosensitive linear composition comprising: a polymer having an acid-dissociable group; and a compound (Q) represented by the following formula (1), wherein in formula (1), L1 is an ester group, -CO-NR3-, (thio)ether group, or sulfonyl group; for R1, R2, and R3, if L1 is an ester group, (thio)ether group, or sulfonyl group, the following (i) or (ii) is satisfied; if L1 is -CO-NR3-, the following (i), (ii), or (iii) is satisfied; (i) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 by a carbon atom and does not have an aromatic ring; R2 is a substituted or unsubstituted divalent hydrocarbon group and does not have an aromatic ring; wherein, R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (ii) R1 and R2 represent a group comprising an aliphatic heterocyclic structure formed by mutual bonding and together with the bonded L1; wherein R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (iii) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 by a carbon atom and does not have an aromatic ring; R2 and R3 represent an aliphatic heterocyclic structure formed by mutual bonding and together with L1; wherein the aliphatic heterocyclic structure does not have a fluorine atom; R4 is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group with 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, or a nitro group; R5 is a monovalent hydrocarbon group with 1 to 20 carbon atoms, a monovalent halide hydrocarbon group with 1 to 20 carbon atoms, or a halogen atom, or represents an alicyclic structure formed by two R5s bonded together with the carbon atoms they are bonded to; L2 is a single bond or a divalent linker; n1 and n2 are independent integers from 1 to 4; n3 is an integer from 0 to 5; when n3 is 2 or more, multiple R5s may be the same or different; multiple R4s may be the same or different.

2. The radiosensitive linear composition as claimed in claim 1, wherein R2 is a substituted or unsubstituted divalent chain hydrocarbon group, or a substituted or unsubstituted divalent alicyclic hydrocarbon group, or represents an aliphatic heterocyclic structure formed together with R3 and L1.

3. The radiosensitive linear composition as claimed in claim 1, wherein R1 is a substituted or unsubstituted monovalent chain hydrocarbon group, or a monovalent group having an alicyclic hydrocarbon structure, or a monovalent group having an aliphatic heterocyclic structure, and is bonded to L1 by means of a carbon atom.

4. The radiosensitive linear composition as claimed in claim 1, wherein R2 is a substituted or unsubstituted divalent chain hydrocarbon group, or a substituted or unsubstituted divalent alicyclic hydrocarbon group, or represents an aliphatic heterocyclic structure formed together with R3 and L1, wherein R1 is a substituted or unsubstituted monovalent chain hydrocarbon group, or a monovalent group having an alicyclic hydrocarbon structure, or a monovalent group having an aliphatic heterocyclic structure, and is bonded to L1 by means of a carbon atom.

5. The radiosensitive linear composition as claimed in claim 1, wherein L2 is a single bond.

6. The radiosensitive linear composition as claimed in claim 1, further comprising compound (B), which, upon exposure, produces an acid with higher acidity in the composition compared to compound (Q).

7. The radiosensitive linear composition as claimed in claim 6, wherein the compound (B) is a compound represented by the following formula (2), in which W2 is a monovalent organic group having 3 to 40 carbon atoms; L3 is a single bond or a divalent linker; R6, R7, R8 and R9 are independently hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms, fluorine atoms or fluoroalkyl groups having 1 to 10 carbon atoms; a is an integer from 0 to 8; when a is 2 or more, there are multiple R6 and R7 that are the same or different from each other; wherein, At least one of the (a×2+2) groups constituting the group consisting of R6, R7, R8 and R9 in the formula is a fluorine atom or a fluoroalkyl group; X+ is a monovalent cation.

8. A method for forming a pattern, comprising: The step of forming a resist film by coating a radiosensitive linear composition as described in any one of claims 1 to 7 onto a substrate; The step of exposing the resist film; The step of developing the exposed resist film.

9. The pattern forming method as claimed in claim 8, wherein the developing step is a step of developing the exposed resist film using an organic solvent developer.

10. A photodegradable base, represented by the following formula (1), wherein in formula (1), L1 is an ester group, -CO-NR3-, (thio)ether group, or sulfonyl group; for R1, R2, and R3, when L1 is an ester group, (thio)ether group, or sulfonyl group, the following (i) or (ii) is satisfied; when L1 is -CO-NR3-, the following (i), (ii), or (iii) is satisfied, wherein (i) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 by a carbon atom and does not have an aromatic ring; R2 is a substituted or unsubstituted divalent hydrocarbon group and does not have an aromatic ring; wherein, R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (ii) R1 and R2 represent a group comprising an aliphatic heterocyclic structure formed by mutual bonding and together with the bonded L1; wherein R2 does not have a fluorine atom; R3 is a hydrogen atom or a monovalent hydrocarbon group; (iii) R1 is a monovalent organic group with 1 to 20 carbon atoms bonded to L1 by a carbon atom and does not have an aromatic ring; R2 and R3 represent an aliphatic heterocyclic structure formed by mutual bonding and together with L1; wherein the aliphatic heterocyclic structure does not have a fluorine atom; R4 is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group with 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, or a nitro group; R5 is a monovalent hydrocarbon group with 1 to 20 carbon atoms, a monovalent halide hydrocarbon group with 1 to 20 carbon atoms, or a halogen atom, or represents an alicyclic structure formed by two R5s bonded together with the carbon atoms they are bonded to; L2 is a single bond or a divalent linker; n1 and n2 are independent integers from 1 to 4; n3 is an integer from 0 to 5; when n3 is 2 or more, multiple R5s may be the same or different; multiple R4s may be the same or different.