Radiation-sensitive compositions, methods for forming resist patterns, polymers and compounds

Abstract

The polymer comprising a constituent unit (I) represented by formula (1) is included in a radiation-sensitive composition. R2 in formula (1) is a single bond, a divalent hydrocarbon group, or the like. R3 is a divalent group represented by formula (2) or formula (3). R4 is a divalent organic group. Y- is a monovalent anion that produces a sulfonic acid group, an imidic acid group, or a methide acid group as a result of light exposure. Ma+ is an a-valent cation. a is 1 or 2.

Description

[Technical Field]

[0001] [Cross-reference of related applications] This application claims priority under Japanese Patent Application No. 2021-109611, filed on 30 June 2021, which is incorporated herein by reference in its entirety. This disclosure relates to radiation-sensitive compositions, methods for forming resist patterns, polymers, and compounds. [Background technology]

[0002] In lithography, a technology used in the manufacturing processes of various electronic devices such as semiconductor devices and liquid crystal devices, a radiation-sensitive composition is irradiated with far ultraviolet light such as an ArF excimer laser, extreme ultraviolet (EUV), or an electron beam to generate acid in the exposed area. A chemical reaction involving the generated acid creates a difference in the dissolution rate in the developer between the exposed and unexposed areas. This forms a resist pattern on the substrate.

[0003] In various electronic device structures, further miniaturization is progressing rapidly, and consequently, there is a demand for even finer resist patterns in the lithography process. In response to these demands, various studies are being conducted to improve the sensitivity, resolution, and resist pattern shape of radiation-sensitive compositions used in microfabrication by lithography (see, for example, Patent Document 1).

[0004] Patent Document 1 discloses the inclusion of a resin having repeating units that decompose upon irradiation with active light or radiation to generate acid in a radiation-sensitive composition. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-154216 [Overview of the initiative]

Problems to be Solved by the Invention

[0006] With further miniaturization of the resist pattern, slight differences in process conditions such as exposure conditions and development conditions are likely to affect the shape of the resist pattern and the occurrence of defects. Therefore, the radiation-sensitive composition is required to have a margin that can absorb slight differences in process conditions, that is, a range of process conditions (hereinafter, also referred to as "process window") in which a pattern without bridge defects or collapse can be formed in the resist pattern forming process.

[0007] The present disclosure has been made in view of the above problems, and an object thereof is to provide a radiation-sensitive composition and a resist pattern forming method that are highly sensitive and have a wide process window.

Means for Solving the Problems

[0008] According to the present disclosure, the following means are provided. [1] A radiation-sensitive composition containing a polymer containing a structural unit (I) represented by the following formula (1). [Chemical formula] (In formula (1), R<​​​​​​​​​​​​​​​​​​​​, or a divalent hydrocarbon group or the aforementioned group F 3 A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds 4 That is. 1 " is R 1 This indicates that it is a bond that connects to the carbon atom to which it is bonded. 3 is a divalent group represented by the following formula (2) or formula (3). However, R 2 When R is bonded to the oxygen-containing heteromonocyclic ring in equations (2) and (3) below, 7 It does not form a single bond. 4 R is a divalent organic group. 4 When R is bonded to the oxygen-containing heteromonocyclic ring in equations (2) and (3) below, 4 R is a carbon atom 3 It is coupled to Y. - M is a monovalent anion that generates a sulfonic acid group, an imido acid group, or a methido acid group upon exposure. a+ (where a is an α-valent cation, and a is either 1 or 2.) [ka] (In equations (2) and (3), R 5 X is a hydrogen atom or a monovalent organic group. 1 It is -CH2-, -NH-, -O-, or -S-. 1 This represents the ring structure that forms a fused ring together with the oxygen-containing heteromonal ring in equation (3). 6 is a monovalent substituent. n is 0 or 1. m is 0 or 1. r is an integer between 0 and 2. "*" indicates a bond.

[0009] [2] A method for forming a resist pattern, comprising the steps of: forming a resist film on a substrate using the radiation-sensitive composition described in [1] above; exposing the resist film to light; and developing the exposed resist film. [3] A polymer containing the structural unit represented by formula (1) above.

[0010] [4] A compound represented by the following formula (4). [ka] (In formula (4), R 1 R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 2 This is a divalent group F, which consists of a single bond, a divalent hydrocarbon group, and any hydrogen atom on the divalent hydrocarbon group replaced by a monovalent substituent. 1 , a divalent hydrocarbon group or the aforementioned group F 1 A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds 2 , * 1 -COO-R 7 -, or * 1 -CONH-R 7 - is R 7 This is a divalent hydrocarbon group, and a divalent group F obtained by replacing any hydrogen atom of the divalent hydrocarbon group with a monovalent substituent. 3 , or a divalent hydrocarbon group or the aforementioned group F 3 A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds 4 That is. 1 " is R 1 This indicates that it is a bond that connects to the carbon atom to which it is bonded. 4 R is a divalent organic group. 5 X is a hydrogen atom or a monovalent organic group. 1 These are -CH2-, -NH-, -O-, or -S-. - M is a monovalent anion that generates a sulfonic acid group, an imido acid group, or a methido acid group upon exposure. a+ (where is an α-valent cation; n is 0 or 1; m is 0 or 1; a is 1 or 2.)

[0011] [5] A compound represented by the following formula (5). [ka] (In formula (5), R 1 R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 2This is a divalent group F, which consists of a single bond, a divalent hydrocarbon group, and any hydrogen atom on the divalent hydrocarbon group replaced by a monovalent substituent. 1 , a divalent hydrocarbon group or the aforementioned group F 1 A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds 2 , * 1 -COO-R 7 -, or * 1 -CONH-R 7 - is R 7 This is a divalent group F, which consists of a single bond, a divalent hydrocarbon group, and any hydrogen atom on the divalent hydrocarbon group replaced by a monovalent substituent. 3 , or a divalent hydrocarbon group or the aforementioned group F 3 A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds 4 That is. 1 " is R 1 Ar represents a bond that connects to the carbon atom it bonds to. 1 R represents the ring structure that forms a fused ring together with the oxygen-containing heteromonal ring in the formula. 4 R is a divalent organic group. 4 It is bonded to an oxygen-containing heteromonocyclic ring by a carbon atom. 5 R is a hydrogen atom or a monovalent organic group. 6 is a monovalent substituent. n is 0 or 1. r is an integer between 0 and 2. Y - M is a monovalent anion that generates a sulfonic acid group, an imido acid group, or a methido acid group upon exposure. a+ (where a is an α-valent cation, and a is either 1 or 2.) [Effects of the Invention]

[0012] The radiation-sensitive composition of this disclosure has high sensitivity, and therefore a good resist pattern can be formed with a small amount of exposure. Furthermore, because the radiation-sensitive composition of this disclosure has a wide process window, a resist pattern can be formed while suppressing the effects of fluctuations in process conditions. [Modes for carrying out the invention]

[0013] ≪Radiation-sensitive composition≫ The radiation-sensitive composition of this disclosure (hereinafter also referred to as "this composition") contains [A] a polymer. This composition may further contain one or more of the following preferred components: [B] an acid generator, [C] an acid diffusion control agent, [D] a solvent, [E] an acid-dissociable group-containing polymer, and [F] a high-fluorine-containing polymer. Each component will be described in detail below.

[0014] In this specification, "hydrocarbon group" includes linear hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. "Linear hydrocarbon group" means a linear hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure and consists only of a linear structure. However, linear hydrocarbon groups may be saturated or unsaturated. "Alicyclic hydrocarbon group" means a hydrocarbon group that contains only the structure of an alicyclic hydrocarbon as its ring structure and does not contain an aromatic ring structure. However, an alicyclic hydrocarbon group does not have to consist only of the structure of an alicyclic hydrocarbon, and may also include a linear structure as part of it. "Aromatic hydrocarbon group" means a hydrocarbon group that contains an aromatic ring structure as its ring structure. However, an aromatic hydrocarbon group does not have to consist only of an aromatic ring structure, and may include a linear structure or an alicyclic hydrocarbon structure as part of it. "Organic group" means an atomic group obtained by removing any hydrogen atom from a carbon-containing compound (i.e., an organic compound). "(meth)acrylic" includes "acrylic" and "methacrylic," "(meth)acryloyl" includes "acryloyl" and "methacryloyl," and "(meth)acrylate" includes "acrylate" and "methacrylate."

[0015] <[A] Polymer> [A] A polymer is a polymer that contains structural unit (I) represented by the following formula (1). [ka] (In formula (1), R 1 R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 2is a single bond, a divalent hydrocarbon group, or a divalent group F in which any hydrogen atom of the divalent hydrocarbon group is replaced by a monovalent substituent 1 , a divalent hydrocarbon group or group F 1 A divalent group F containing -O-, -CO-, -NH-, -COO- or -CONH- between the carbon-carbon bonds 2 , * 1 -COO-R 7 -, or * 1 -CONH-R 7 -. R 7 is a single bond, a divalent hydrocarbon group, or a divalent group F in which any hydrogen atom of the divalent hydrocarbon group is replaced by a monovalent substituent 3 , or a divalent hydrocarbon group or group F 3 A divalent group F containing -O-, -CO-, -NH-, -COO- or -CONH- between the carbon-carbon bonds 4 is. "* 1 " represents a bond that binds to the carbon atom to which R 1 is bonded. R 3 is a divalent group represented by the following formula (2) or formula (3). However, when R 2 is bonded to the oxygen-containing heteromonocyclic ring in the following formulas (2) and (3), R 7 is not a single bond. R 4 is a divalent organic group. However, when R 4 is bonded to the oxygen-containing heteromonocyclic ring in the following formulas (2) and (3), R 4 is a carbon atom bonded to R 3 . Y - is a monovalent anion that generates a sulfonic acid group, an imidic acid group or a methidic acid group upon exposure. M a+ is an a-valent cation. a is 1 or 2.)

Chemical formula

[0016] In the above equation (1), R 2 or R 7 Examples of divalent hydrocarbon groups represented by include divalent chain hydrocarbon groups having 1 to 20 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, and divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms.

[0017] Examples of divalent chain hydrocarbon groups having 1 to 20 carbon atoms include alkanediyl groups such as methylene, ethylene, n-propylene, and isopropylene; alkenediyl groups such as ethylenediyl, propylenediyl, and butylenediyl; and alkynediyl groups such as ethingiyl, propindiyl, and butynediyl. Of these, R 2 The divalent chain hydrocarbon group represented is preferably an alkanediyl group having 1 to 20 carbon atoms, more preferably an alkanediyl group having 1 to 5 carbon atoms, and even more preferably an alkanediyl group having 1 to 3 carbon atoms. 7 The divalent chain hydrocarbon group represented is preferably an alkanediyl group having 1 to 20 carbon atoms, more preferably an alkanediyl group having 1 to 10 carbon atoms, and even more preferably an alkanediyl group having 1 to 4 carbon atoms.

[0018] Examples of divalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include divalent monocyclic alicyclic saturated hydrocarbon groups such as cyclopentylene and cyclohexylene; divalent monocyclic alicyclic unsaturated hydrocarbon groups such as cyclopentenediyl and cyclohexenediyl; divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornanediyl and adamantanediyl; and divalent polycyclic alicyclic unsaturated hydrocarbon groups such as norbornenediyl. Of these, R 2 or R 7The divalent alicyclic hydrocarbon group represented by is preferably a divalent monocyclic alicyclic saturated hydrocarbon group or a divalent polycyclic alicyclic saturated hydrocarbon group, and more preferably a cyclopentylene group, a cyclohexylene group, a norbornanediyl group, or an adamantanediyl group.

[0019] Examples of divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include arylene groups such as phenylene, torylene, xylylene, trimethylphenylene, naphthylene, and methylnaphthylene;-A 10 -R 10 -( However, A 10 R is a phenylene group or a naphthylene group, 10 Examples include aralkylene groups (which are alkanediyl groups with 1 to 3 carbon atoms).

[0020] Of the above, R 2 The divalent hydrocarbon group represented is preferably a divalent aromatic hydrocarbon group, more preferably an arylene group, and even more preferably a phenylene group or a naphthylene group. 7 The divalent hydrocarbon group represented is preferably a divalent chain hydrocarbon group, more preferably an alkanediyl group having 1 to 20 carbon atoms, and even more preferably an alkanediyl group having 1 to 4 carbon atoms.

[0021] R 2 or R 7 However, a divalent group (F) is formed when any hydrogen atom of a divalent hydrocarbon group is replaced by a monovalent substituent. 1 F 3 In the case of ), examples of substituents that substitute for hydrogen atoms include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.), hydroxyl groups, cyano groups, nitro groups, and alkoxy groups having 1 to 3 carbon atoms. A specific example of a divalent hydrocarbon group is R 2 or R 7 The group shown as an example of a divalent hydrocarbon group represented by is F. 1 and base F 3 In this case, the number of hydrogen atoms to be substituted is not particularly limited, for example, 1 to 6.

[0022] Also, R2 and R 7 One or both of them are divalent hydrocarbon groups, group F 1 or base F 3 A divalent group (F) containing -O-, -CO-, -NH-, -COO-, or -CONH- is present between the carbon-carbon bonds. 2 F 4 ) may also be a specific example of a divalent hydrocarbon group, R 2 or R 7 The group shown is an example of a divalent hydrocarbon group represented by R. 2 When R is bonded to the oxygen-containing heteromonocyclic ring in formulas (2) and (3) above, 7 It will not form a single bond.

[0023] R 3 R is a divalent group represented by formula (2) or formula (3) above. In formulas (2) and (3) above, 5 The monovalent organic group represented by is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. In the above formula (2), X 1 The group is preferably -CH2-, -NH-, or -O-, with -CH2- being more preferred.

[0024] In the above equation (3), Ar 1 The ring structure represented is preferably an aromatic ring structure, such as a benzene ring structure and a naphthalene structure. 6 Examples of monovalent substituents represented by include C1-C3 alkyl groups, C1-C3 alkoxy groups, hydroxyl groups, halogen atoms, and the like.

[0025] R 4 Examples of divalent organic groups represented by include divalent hydrocarbon groups and divalent groups containing a fluorine atom. 4 A specific example of a case where the divalent organic group represented by is a divalent hydrocarbon group is R 2 or R 7 The same groups as those exemplified in the description of the divalent hydrocarbon group represented by can be cited. Among these, R 4The divalent hydrocarbon group represented is preferably an aromatic hydrocarbon group from the viewpoint of ease of synthesis of the monomer that gives structural unit (I).

[0026] R 4 If the divalent organic group represented by is a divalent group having a fluorine atom, then R 4 Preferably, the group is represented by the following formula (6). * 2 -R 8 -R f1 - …(6) (In formula (6), R 8 R is a single bond or a divalent linking group. f1 This is a fluorinated alkanediyl group having 1 to 10 carbon atoms. 2 " is R in equation (1) above 3 This indicates a bonding hand that connects to R. 4 When R is bonded to the oxygen-containing heteromonocyclic ring in formulas (2) and (3) above, 8 R is a carbon atom 3 (It is connected to it.)

[0027] In the above equation (6), R 8 As a divalent linking group represented by R, 4 If the element is not directly bonded to the oxygen-containing heteromonal ring in formulas (2) and (3) above (i.e., the bridging ring in formula (2) or the Ar in formula (3) above), 1 Specific examples of cases where it is bonded include alkanediyl groups having 1 to 6 carbon atoms, and divalent groups formed by replacing any methylene group on an alkanediyl group having 1 to 6 carbon atoms with -O- or -COO-. Also, R 4 When R is directly bonded to the oxygen-containing heteromonocyclic ring in formulas (2) and (3) above, 8 The divalent linking group represented by is preferably an alkanediyl group having 1 to 6 carbon atoms.

[0028] R f1 The fluorinated alkanediyl group represented by is preferably the group represented by the following formula (f-1). [ka] (In formula (f-1), R 11 and R 12 Each of these is independently a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms. 13 and R 14 Each of these is independently either a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms. p is an integer from 0 to 3. 3 " is R in equation (6) above 8 (This indicates a bonding operation.)

[0029] In the above equation (f-1), R 13 and R 14 It is preferably a fluorine atom or a trifluoromethyl group. 12 R is preferably a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, and more preferably a fluorine atom or a trifluoromethyl group. 11 It is preferably a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom, a fluorine atom, or a trifluoromethyl group.

[0030] R f1 Specific examples of fluorinated alkanediyl groups represented by include, for example, fluoromethanediyl group, difluoromethanediyl group, 1,2-difluoroethane-1,2-diyl group, 1,1,2-trifluoroethane-1,2-diyl group, 1,1,2,2-tetrafluoroethane-1,2-diyl group, and 1,1,3,3,3-pentafluoropropane-1,2-diyl group.

[0031] From the viewpoint of improving the sensitivity of this composition and the ease of synthesis of monomers that provide structural unit (I), Y - If it is a monovalent anion that generates a sulfonic acid group or a methidonic acid group upon exposure, then R 4 It is preferable that it is a divalent group having a fluorine atom. Also, Y - If it is a monovalent anion that generates an imido acid group upon exposure, then R 4It is preferable that this is a divalent hydrocarbon group or a divalent group having a fluorine atom.

[0032] Y - Y is a monovalent anion that generates a sulfonic acid group, imido acid group, or methido acid group upon exposure. Specifically, Y - Preferably, the group is represented by the following formula (Y-1), the following formula (Y-2), or the following formula (Y-3). [ka] (In formulas (Y-1) to (Y-3), X 10 , X 11 , X 12 , X 13 and X 14 These are, independently, -CO- or -SO2-. 50 , R 51 and R 52 Each of these is independently a monovalent hydrocarbon group, or a monovalent group formed by replacing any hydrogen atom of a monovalent hydrocarbon group with a substituent. (* indicates a bond.)

[0033] In the above equations (Y-1) to (Y-3), R 50 , R 51 and R 52 Examples of monovalent hydrocarbon groups represented by this formula include monovalent linear hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms.

[0034] Examples of monovalent chain hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, and i-propyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; and alkynyl groups such as ethynyl, propynyl, and butynyl groups. Of these, R 50 , R 51 and R 52 The monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by is preferably an alkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms.

[0035] Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monovalent monocyclic alicyclic saturated hydrocarbon groups such as cyclopentyl and cyclohexyl groups; monovalent monocyclic alicyclic unsaturated hydrocarbon groups such as cyclopentenyl and cyclohexenyl groups; monovalent polycyclic alicyclic saturated hydrocarbon groups such as norbornyl, adamantyl, and tricyclodecyl groups; and monovalent polycyclic alicyclic unsaturated hydrocarbon groups such as norbornenyl and tricyclodecenyl groups.

[0036] Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthryl, and methylanthryl; and aralkyl groups such as benzyl, phenethyl, naphthylmethyl, and anthrylmethyl.

[0037] R 50 , R 51 and R 52 Preferably, the group is one in which any hydrogen atom of the monovalent hydrocarbon group is replaced by a fluorine atom, and more preferably, it is a fluoroalkyl group having 1 to 10 carbon atoms.

[0038] Structural unit (I) is preferably at least one selected from the group consisting of structural units derived from the compound represented by the following formula (4) (hereinafter also referred to as "compound (a1)") and structural units derived from the compound represented by the following formula (5) (hereinafter also referred to as "compound (a2)"). [ka] (In equations (4) and (5), R 1 , R 2 , R 4 , R 5 , R 6 , Y - M a+ , X 1 Ar 1 a, n, m, and r are equivalent to those in equations (1) to (3) above.

[0039] The monomer constituting structural unit (I) is preferably at least one selected from the group consisting of styrene monomers and (meth)acrylic monomers, due to its high copolymerizability. Preferred specific examples of monomers constituting structural unit (I) include the compound represented by the following formula (4-1A), the compound represented by the following formula (4-2A), and the compound represented by the following formula (5-1A). [ka] (In equations (4-1A), (4-2A), and (5-1A), R 9 This is a divalent group F, which consists of a single bond, a divalent hydrocarbon group, and any hydrogen atom on the divalent hydrocarbon group replaced by a monovalent substituent. 5 , or a divalent hydrocarbon group or group F 5 A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds 6 That is. R 1 , R 4 , R 5 , R 6 , R 7 , Y - M a+ , X 1 a, n, m, and r are equivalent to those in equations (1) to (3) above.

[0040] In the above equation (4-1A), R 9 Examples of divalent hydrocarbon groups represented by include divalent chain hydrocarbon groups having 1 to 14 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 14 carbon atoms, and divalent aromatic hydrocarbon groups having 6 to 14 carbon atoms. 9 The divalent hydrocarbon group represented is preferably a divalent chain hydrocarbon group, and more preferably an alkanediyl group having 1 to 5 carbon atoms.

[0041] R 9 However, a divalent group F is formed when any hydrogen atom of a divalent hydrocarbon group is replaced by a monovalent substituent. 5 In this case, examples of substituents that substitute for hydrogen atoms include halogen atoms, hydroxyl groups, cyano groups, nitro groups, and alkoxy groups having 1 to 3 carbon atoms.9 is a divalent hydrocarbon group or group F 5 A divalent group (F) containing -O-, -CO-, -NH-, -COO-, or -CONH- is present between the carbon-carbon bonds. 6 ) is also acceptable.

[0042] Specific examples of monomers constituting structural unit (I) include, as compounds represented by formula (4) above, the compounds represented by formulas (4-1) to (4-12) below, and as compounds represented by formula (5) above, the compounds represented by formulas (5-1) to (5-4) below, respectively.

[0043] [ka] [ka]

[0044] [ka] (In equations (4-1) to (4-12) and equations (5-1) to (5-4), M a+ (where a is an α-valent cation, and a is either 1 or 2.)

[0045] Regarding the cation in formula (1) above In the above formula (1), M a+ It is preferably an organic cation, and is particularly preferably a radiation-sensitive onium cation. a+ If is a radiation-sensitive onium cation, then compounds (a1) and (a2) are onium salts.

[0046] M a+ The structure is not particularly limited, but from the viewpoint of improving the lithographic properties of this composition, it is preferably a sulfonium cation, iodonium cation, or ammonium cation, and more preferably a sulfonium cation or iodonium cation.

[0047] If a in equation (1) above is 1, then M a+ Specific examples include the cation represented by formula (7) below, the cation represented by formula (8) below, and the cation represented by formula (9) below. [ka] (In formula (7), R 1a and R 2a Each of these is either an independent monovalent substituent, or R 1a and R 2a These represent single or divalent groups that combine with each other to form a ring. 3a is a monovalent substituent. a1 and a2 are each independent integers between 0 and 5. a3 is an integer between 0 and (2 × r + 5). r is either 0 or 1. In formula (8), R 4a and R 5a A4 and A5 are each independently monovalent substituents. A4 and A5 are each independently integers between 0 and 5. In equation (9), a6 is an integer from 0 to 7. When a6 is 1, R 6a is a monovalent organic group, hydroxyl group, nitro group, or halogen group having 1 to 20 carbon atoms. If a6 is 2 or more, there are multiple R 6a These are either identical or different monovalent organic groups, hydroxyl groups, nitro groups, or halogen groups having 1 to 20 carbon atoms, or multiple R groups. 6a Two of these are combined together, and these, along with the carbon atoms to which they are bonded, represent a ring structure with 4 to 20 members. a7 is an integer from 0 to 6. When a7 is 1, R 7a is a monovalent organic group, hydroxyl group, nitro group, or halogen group having 1 to 20 carbon atoms. If a7 is 2 or more, multiple R 7a These are either identical or different monovalent organic groups, hydroxyl groups, nitro groups, or halogen groups having 1 to 20 carbon atoms, or multiple R groups. 7a This represents a ring structure with 3 to 20 members, where two of the elements are combined with each other and bonded together with the carbon atoms. t1 is an integer from 0 to 3. 8a(This refers to a single bond or a divalent organic group with 1 to 20 carbon atoms. t2 is 0 or 1.)

[0048] In equations (7) and (8) above, R 1a , R 2a , R 3a , R 4a and R 5a (Hereinafter referred to as “R 1a ~R 5a Examples of monovalent substituents represented as (indicated as ) include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted cycloalkyl groups, substituted or unsubstituted cycloalkyloxy groups, ester groups, alkylsulfonyl groups, cycloalkylsulfonyl groups, hydroxyl groups, carboxyl groups, cyano groups, and nitro groups.

[0049] R 1a ~R 5a The alkyl group represented by may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms, and examples include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-pentyl, and neopentyl groups. Of these, R 1a ~R 5a The alkyl group represented by is preferably having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, an n-butyl group, or a t-butyl group. 1a ~R 5a If the substituent is a substituted alkyl group, examples of substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, and alkoxy groups having 1 to 5 carbon atoms.

[0050] R 1a ~R 5a Specific examples of groups where the alkoxy group is substituted or unsubstituted include groups having the substituted or unsubstituted alkyl group as exemplified above in the alkyl group portion constituting the alkoxy group. The alkoxy group is particularly preferably a methoxy group, an ethoxy group, an n-propoxy group, or an n-butoxy group.

[0051] R 1a ~R 5a The cycloalkyl group represented by may be monocyclic or polycyclic. Examples of monocyclic cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. Examples of polycyclic cycloalkyl groups include norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl groups. 1a ~R 5a When the cycloalkyl group represented by has substituents, examples of substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, and alkoxy groups having 1 to 5 carbon atoms.

[0052] R 1a ~R 5a Specific examples of cases where is a substituted or unsubstituted cycloalkyloxy group include groups in which the cycloalkyl group constituting the cycloalkyl group has the substituted or unsubstituted cycloalkyl group exemplified above. 1a ~R 5a The cycloalkyloxy group represented is preferably a cyclopentyloxy group or a cyclohexyloxy group.

[0053] R 1a ~R 5a When is an ester group (-COOR), the hydrocarbon portion (R) of the ester group may be a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group, as exemplified above. Of these, R 1a ~R 5a If R is an ester group, 1a ~R 5a It is preferable that this is a methoxycarbonyl group, an ethoxycarbonyl group, or an n-butoxycarbonyl group.

[0054] R 1a ~R 5aWhen is an alkylsulfonyl group, the alkyl group portion constituting the alkylsulfonium group can be the substituted or unsubstituted alkyl groups exemplified above. 1a ~R 5a When the group is a cycloalkylsulfonyl group, the alkyl group portion constituting the cycloalkylsulfonium group can be the substituted or unsubstituted cycloalkyl groups exemplified above.

[0055] R 1a and R 2a When R represents a divalent group that is combined with others to link the rings they bond to, examples of such divalent groups include -COO-, -OCO-, -CO-, -O-, -SO-, -SO2-, -S-, alkanediyl groups with 1 to 3 carbon atoms, alkenediyl groups with 2 or 3 carbon atoms, and groups having -O-, -S-, -COO-, -OCO-, -CO-, -SO-, or -SO2- between the carbon-carbon bonds of an ethylene group. Among these, R 1a and R 2a If they are combined with each other and form a single bond or a divalent group that connects the rings they join, then R 1a and R 2a It is preferable that the bond is a single bond connecting the rings, or that it forms an -O- or -S- bond.

[0056] a1 is preferably an integer between 0 and 2, and a1 is 1 or 2 and at least one R 1a It is more preferable that is a fluorine atom or a trifluoromethyl group. a2 is preferably an integer from 0 to 2, and a2 is 1 or 2 and at least one R 2a It is more preferable that is a fluorine atom or a trifluoromethyl group. a3 is preferably an integer from 0 to 2, and a3 is 1 or 2 and at least one R 3a It is more preferable that is a fluorine atom or a trifluoromethyl group. In particular, it is preferable that all of a1, a2 and a3 are integers from 0 to 2 independently of each other, and that all of a1, a2 and a3 are 1 or 2 independently of each other and at least one R 1a , at least one R 2a and at least one R3a It is more preferable that the atom is a fluorine atom or a trifluoromethyl group.

[0057] In equation (9) above, R 6a and R 7a Examples include substituted or unsubstituted monovalent hydrocarbon groups with 1 to 20 carbon atoms, -OR k ,-COOR k ,-O-CO-R k , -OR kk -COOR k , -R kk -CO-R k -OSO2-R k or -SO2-R k R is preferable. k R is a monovalent hydrocarbon group having 1 to 10 carbon atoms. kk R is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms. 6a and R 7a As a monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the above formulas (Y-1) to (Y-3), for example, R 50 , R 51 and R 52 Examples of monovalent hydrocarbon groups represented by include groups similar to those exemplified above. Also, R 6a and R 7a In this, the substituent that substitutes the hydrogen atom of the hydrocarbon group is the above R 3a The substituents on the group represented by the symbol can be similar to those exemplified above. R 8a Examples of divalent organic groups represented by R 6a and R 7a Examples include groups obtained by removing one hydrogen atom from a monovalent organic group having 1 to 20 carbon atoms, as exemplified above.

[0058] R 6a and R 7a This includes, among the above, unsubstituted linear or branched monovalent alkyl groups, monovalent fluoroalkyl groups, unsubstituted monovalent aromatic hydrocarbon groups, and -OSO2-R k or -SO2-R kThis is preferable. a6 is preferably an integer between 0 and 2, more preferably 0 or 1, and even more preferably 0. a7 is preferably an integer between 0 and 2, more preferably 0 or 1, and even more preferably 0. t2 is preferably 0. t1 is preferably 2 or 3, and more preferably 2.

[0059] If a in equation (1) above is 1, then M a+ It is preferably a sulfonium cation or an iodonium cation, more preferably a cation represented by formula (7) or formula (9), and even more preferably a cation represented by formula (7).

[0060] If a in equation (1) above is 2, then M a+ It is preferable that the sulfonium cation is a sulfonium cation. Specific examples of the sulfonium cation include the cation represented by the following formula (10). [ka] (In formula (10), R b1 R is a single bond or a divalent organic group having 1 to 20 carbon atoms. b2 and R b3 Each of these is either an independent monovalent organic group with 1 to 20 carbon atoms, or these groups are combined with each other and bonded together as S + -R b1 -S + This represents a ring structure with 4 to 20 members, composed of the following: b4 is an integer from 0 to 9. When b4 is 1, R b4 is a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, or a halogen atom. If b4 is 2 or more, multiple R b4 The elements are either identical or different, and represent a monovalent organic group, hydroxyl group, nitro group, or halogen atom having 1 to 20 carbon atoms, or a ring structure with 4 to 20 members formed by these groups combined with the carbon atoms to which they are bonded. b5 is an integer from 0 to 9. If b5 is 1, R b5 is a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, or a halogen atom. If b5 is 2 or more, multiple R b5The elements are either identical or different, and represent a monovalent organic group, hydroxyl group, nitro group, or halogen atom having 1 to 20 carbon atoms, or a ring structure with 4 to 20 members formed by these groups combined with the carbon atoms to which they are bonded. b1 is an integer between 0 and 2. b2 is an integer between 0 and 2.

[0061] M a+ Specific examples include the cations represented by the following formulas, where M a+ This is not limited to these. [ka] [ka] [ka] [ka]

[0062] In polymer [A], the content of structural unit (I) is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to the total structural units constituting polymer [A]. Furthermore, the content of structural unit (I) is preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less, relative to the total structural units constituting polymer [A]. Setting the content of structural unit (I) within the above range makes it possible to improve the sensitivity of the composition, suppress excessive dissolution of the exposed area into the developer, and is preferable in that it can further expand the process window.

[0063] [Other structural units] [A] The polymer may contain structural unit (I) as well as structural units other than structural unit (I) (hereinafter also referred to as "other structural units"). Examples of other structural units include the following structural units (II) to (V).

[0064] • Structural Unit (II) [A] The polymer may contain structural unit (II) having an acid-dissociable group. An acid-dissociable group is a group that substitutes a hydrogen atom on an acidic group such as a carboxyl group or a hydroxyl group, and dissociates upon the action of an acid. [A] The presence of an acid-dissociable group in the polymer causes the acid-dissociable group to dissociate upon exposure of the composition to acid, resulting in the formation of an acidic group, which changes the solubility of the polymer components in the developer. As a result, the composition can be given good lithography properties.

[0065] Structural unit (II) is not particularly limited as long as it has an acid-dissociable group. Examples of structural unit (II) include the structural unit represented by the following formula (ii-1) (hereinafter also referred to as "structural unit (II-1)"), the structural unit represented by the following formula (ii-2) (hereinafter also referred to as "structural unit (II-2)"), and the structural unit represented by the following formula (ii-3) (hereinafter also referred to as "structural unit (II-3)"). [ka] (In formula (ii-1), R 12 R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 13 R is a monovalent hydrocarbon group having 1 to 20 carbon atoms. 14 and R 15 Each of these is independently either a monovalent hydrocarbon group having 1 to 20 carbon atoms, or R 14 and R 15 They are combined with each other R 14 and R 15 This represents an alicyclic structure with 3 to 20 carbon atoms, formed together with the carbon atoms to which it is bonded. In formula (ii-2), R 16 L is a hydrogen atom or a methyl group. 3 This is a single bond, -COO- or -CONH-. 17 , R 18 and R 19 Each of these is independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxy hydrocarbon group having 1 to 20 carbon atoms. 35g1 is a monovalent substituent. g1 is an integer between 0 and 4. In formula (ii-3), R 31 L is a hydrogen atom or a methyl group. 4 This is a single bond, -COO- or -CONH-. 32 , R 33 and R 34 Each of these is independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent oxy hydrocarbon group having 1 to 20 carbon atoms. 36 (where g2 is an integer between 0 and 4.)

[0066] In the above equation (ii-1), R 12 From the viewpoint of copolymerizability of the monomer that gives structural unit (II-1), a hydrogen atom or a methyl group is preferred, and a methyl group is more preferred. In the above formula (ii-2), R 16 From the viewpoint of copolymerizability of the monomer that gives structural unit (II-2), a hydrogen atom is preferred. Similarly, in the above formula (ii-3), R 31 A hydrogen atom is preferred.

[0067] R 13 ~R 15 , R 17 ~R 19 and R 32 ~R 34 Examples of monovalent hydrocarbon groups having 1 to 20 carbon atoms represented by include monovalent linear hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms. Specific examples of these include, in formulas (Y-1) to (Y-3) above, R 50 , R 51 and R 52 Examples of monovalent hydrocarbon groups represented by the formula include groups similar to those exemplified above.

[0068] R 14 and R 15 They are combined with each other R 14 and R 15Examples of alicyclic structures with 3 to 20 carbon atoms that are bonded to each other include monocyclic alicyclic structures such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane; and polycyclic alicyclic structures such as norbornane, adamantane, tricyclodecane, and tetracyclododecane.

[0069] R 17 ~R 19 and R 32 ~R 34 Examples of monovalent oxy hydrocarbon groups having 1 to 20 carbon atoms represented by the above R 13 ~R 15 , R 17 ~R 19 and R 32 ~R 34 Examples include monovalent hydrocarbon groups with 1 to 20 carbon atoms, which include those containing an oxygen atom at the bonding end. 17 ~R 19 and R 32 ~R 34 Of these, the monovalent oxy hydrocarbon group represented is preferably an alkoxy group, a cycloalkoxy group, or a cycloalkylalkoxy group.

[0070] R 35 and R 36 Examples of monovalent substituents represented by include C1-C3 alkyl groups, C1-C3 alkoxy groups, hydroxyl groups, halogen atoms, etc. g1 and g2 are preferably 0-2, and more preferably 0 or 1.

[0071] Specific examples of structural units (II-1) include structural units represented by the following formula. [ka] [ka] (In the formula, R 12 (This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)

[0072] Specific examples of structural units (II-2) include structural units represented by the following formula. [ka] (In the formula, R 16 (This is either a hydrogen atom or a methyl group.)

[0073] Specific examples of structural units (II-3) include structural units represented by the following formula. [ka] (In the formula, R 31 (This is either a hydrogen atom or a methyl group.)

[0074] [A]When the polymer has structural unit (II), the content of structural unit (II) is preferably 20 mol% or more, more preferably 25 mol% or more, and even more preferably 30 mol% or more, relative to the total structural units constituting the polymer. Furthermore, the content of structural unit (II) is preferably 80 mol% or less, more preferably 75 mol% or less, and even more preferably 70 mol% or less, relative to the total structural units constituting the polymer. Setting the content of structural unit (II) within the above range is advantageous because it allows for a sufficiently large difference in dissolution rate in the developer between the exposed and unexposed areas, resulting in a good pattern shape for the resist film.

[0075] • Structural Unit (III) [A] The polymer preferably further contains structural units having hydroxyl groups bonded to an aromatic ring (hereinafter also referred to as "structural unit (III)"). The inclusion of structural unit (III) in the polymer of [A] is preferable in that it can further improve the lithography properties of the composition, such as LWR (Line Width Roughness) performance and CDU (Critical Dimension Uniformity) performance, and is also preferable in that it has a high effect in suppressing the dissolution of unexposed areas into the developer, thereby sufficiently reducing development defects.

[0076] In structural unit (III), examples of aromatic rings to which hydroxyl groups are bonded include benzene rings, naphthalene rings, and anthracene rings. Of these, benzene rings or naphthalene rings are preferred, and benzene rings are more preferred. The number of hydroxyl groups bonded to the aromatic ring is not particularly limited, but is preferably 1 to 3, and more preferably 1 or 2. Examples of structural unit (III) include the structural unit represented by the following formula (iii). [ka] (In formula (iii), R P1 L is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 2 The bond is a single bond, -O-, -CO-, -COO-, or -CONH-. 1 (This is a monovalent group having a hydroxyl group bonded to an aromatic ring.)

[0077] In the above equation (iii), R P1 From the viewpoint of copolymerization of the monomer that gives structural unit (III), a hydrogen atom or a methyl group is preferred. 2 A single bond or -COO- is preferred. Furthermore, when obtaining a polymer containing structural unit (III) as the [A] polymer, the polymerization may be carried out with the phenolic hydroxyl group protected by a protecting group such as an alkali-dissociable group, and then hydrolysis may be performed to deprotect it and obtain the polymer containing structural unit (III).

[0078] Specific examples of structural unit (III) include structural units represented by the following formula. [ka] (In the formula, R P1 (This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)

[0079] When polymer [A] contains structural unit (III), the content of structural unit (III) in polymer [A] is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more, relative to the total structural units constituting polymer [A]. Furthermore, the content of structural unit (III) is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 60 mol% or less, relative to the total structural units constituting polymer [A]. Setting the content of structural unit (III) within the above range is preferable because it can further improve the lithographic properties of the composition.

[0080] Furthermore, the [A] polymer may contain structural units having both a hydroxyl group and an acid-dissociable group bonded to the aromatic ring. In this specification, structural units having both a hydroxyl group and an acid-dissociable group bonded to the aromatic ring are classified as structural unit (II).

[0081] • Structural Units (IV) [A] The polymer may further contain structural units having a lactone structure, a cyclic carbonate structure, a sultone structure, or a ring structure combining two or more of these (hereinafter also referred to as "structural unit (IV)"). The inclusion of structural unit (IV) in the polymer of [A] is preferable because it allows for adjustment of its solubility in the developer, thereby further improving the lithography properties of the composition. Furthermore, the inclusion of structural unit (IV) in the polymer of [A] can improve the adhesion between the resist film obtained using the composition and the substrate.

[0082] Examples of structural units (IV) include structural units represented by the following formula. [ka] [ka]

[0083] [ka]

[0084] [Chemical formula] (In the formula, R L1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.)

[0085] When the [A] polymer contains the structural unit (IV), the content ratio of the structural unit (IV) is preferably 1 mol% or more, more preferably 3 mol% or more, and still more preferably 5 mol% or more with respect to all the structural units constituting the [A] polymer. Further, the content ratio of the structural unit (IV) is preferably 50 mol% or less, more preferably 30 mol% or less, and still more preferably 15 mol% or less with respect to all the structural units constituting the [A] polymer. By setting the content ratio of the structural unit (IV) within the above range, it is suitable in terms of improving the lithography characteristics of the present composition and improving the adhesion of the resist film obtained using the present composition to the substrate.

[0086] · Structural unit (V) The [A] polymer may further have a structural unit having an alcoholic hydroxyl group (however, excluding the cases corresponding to the structural units (I) to (IV); hereinafter, also referred to as "structural unit (V)"). Here, in the present specification, the "alcoholic hydroxyl group" is a group having a structure in which a hydroxyl group is directly bonded to an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be a chain hydrocarbon group or an alicyclic hydrocarbon group. By the [A] polymer further containing the structural unit (V), the solubility in the developer can be improved, and as a result, it is suitable in terms of further improving the lithography characteristics of the present composition.

[0087] The structural unit (V) is preferably a structural unit derived from an unsaturated monomer having an alcoholic hydroxyl group. Examples of the structural unit (V) include structural units represented by the following formulae. [Chemical formula] (In the formula, R L2is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.)

[0088] When the [A] polymer contains the structural unit (V), the content ratio of the structural unit (V) is preferably 1 mol% or more, more preferably 3 mol% or more, based on all the structural units constituting the [A] polymer. Also, the content ratio of the structural unit (V) is preferably 30 mol% or less, more preferably 20 mol% or less, based on all the structural units constituting the [A] polymer.

[0089] Examples of other structural units include, in addition to the above, the following structural units (VI) and structural units (VII). · Structural unit (VI) containing a cyano group, a nitro group or a sulfonamide group (for example, a structural unit derived from 2-cyanomethyladamantan-2-yl (meth)acrylate, etc.) · Structural unit (VII) containing a non-acid dissociable hydrocarbon group (for example, a structural unit derived from styrene, a structural unit derived from vinylnaphthalene, a structural unit derived from n-pentyl (meth)acrylate, etc.) The content ratios of these structural units can be appropriately set according to each structural unit as long as the effects of the present disclosure are not impaired.

[0090] In this composition, the content ratio of the [A] polymer is preferably 50% by mass or more, more preferably 55% by mass or more, still more preferably 60% by mass or more, based on the total amount of the solid content contained in this composition. Also, the content ratio of the [A] polymer is preferably 99% by mass or less, more preferably 98% by mass or less, still more preferably 95% by mass or less, based on the total amount of the solid content contained in this composition. Incidentally, the [A] polymer usually constitutes the base resin of this composition. Here, in this specification, the "base resin" means a polymer component that occupies 50% by mass or more of the total amount of the solid content contained in this composition. This composition may contain only one kind of the [A] polymer or may contain two or more kinds. The "solid content" means components other than the [D] solvent contained in this composition.

[0091] <Synthesis of Polymer> [A] Polymers can be synthesized, for example, by polymerizing monomers that give each structural unit in a suitable solvent using a radical polymerization initiator or the like.

[0092] Examples of radical polymerization initiators include azo-based radical initiators such as azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2'-azobisisobutyrate, and 2,2'-azobis(methyl isobutyrate); and peroxide-based radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. Of these, azo-based radical initiators are preferred. Radical polymerization initiators can be used individually or in combination of two or more.

[0093] Examples of solvents used in polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, and norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and cumene; halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylenedibromide, and chlorobenzene; saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, and methyl propionate; ketones such as acetone, butanone, 4-methyl-2-pentanone, and 2-heptanone; ethers such as tetrahydrofuran, dimethoxyethanes, and diethoxyethanes; and alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. These solvents can be used individually or in combination of two or more.

[0094] The reaction temperature in polymerization is preferably 40°C or higher, and more preferably 50°C or higher. Furthermore, the reaction temperature is preferably 150°C or lower, and more preferably 120°C or lower. The reaction time in polymerization is preferably 1 hour or more, and more preferably 2 hours or more. Furthermore, the reaction time is preferably 48 hours or less, and more preferably 24 hours or less.

[0095] The weight-average molecular weight (Mw) of the polymer in terms of polystyrene, determined by gel permeation chromatography (GPC), is preferably 1,000 or more, more preferably 2,000 or more, even more preferably 3,000 or more, and even more preferably 4,000 or more. Furthermore, the Mw of the polymer is preferably 50,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, and even more preferably 15,000 or less. Setting the Mw of the polymer within the above range is advantageous in that it improves the coating properties of the composition and sufficiently suppresses development defects.

[0096] The ratio of Mw to the polystyrene-equivalent number-average molecular weight (Mn) (Mw / Mn) of the polymer (A) by GPC is preferably 5.0 or less, more preferably 3.0 or less, even more preferably 2.0 or less, and even more preferably 1.8 or less. In addition, the Mw / Mn of the polymer (A) is usually 1 or more, and preferably 1.3 or more.

[0097] <Synthesis of compound (a1) and compound (a2)> Compounds (a1) and (a2) can be synthesized by appropriately combining standard organic chemistry methods. For example, R in formulas (4) and (5) above 2 Depending on the formula, an aldehyde compound having a (meth)acryloyl group or a vinylphenyl group, and the R in formulas (4) and (5) above. 4 A method of reacting a diol compound having a corresponding substructure with a (meth)acryloyl group or a vinylphenyl group with the R in formulas (4) and (5) above under acidic conditions; 4It can be synthesized by reacting an aldehyde compound having the corresponding substructure under acidic conditions. However, the synthesis methods for compound (a1) and compound (a2) are not limited to those described above.

[0098] <[B] Acid Generator> [B] The acid generator is a substance that generates acid when the composition is exposed to light. [B] The acid generator is typically an onium salt containing an onium cation and an organic anion. [A] The acid generator may be incorporated into the composition together with the polymer, and the acid generated by the polymer and the acid generator (preferably a strong acid such as sulfonic acid, imido acid, or methidoic acid) will cause the acid-dissociable groups in the polymer components to be removed, thereby creating acidic groups and changing the solubility of the polymer components in the developer.

[0099] The [B] acid generator to be included in this composition is not particularly limited, and known acid generators used for resist pattern formation can be used. The onium cation of the [B] acid generator is preferably a radiation-sensitive onium cation. From the viewpoint of improving the lithography properties of this composition, sulfonium cations or iodonium cations are particularly preferred, and examples include the cation represented by formula (7), the cation represented by formula (8), and the cation represented by formula (9).

[0100] [B] The organic anion possessed by the acid generator is not particularly limited. Examples of such organic anions include those having a sulfonate anion structure, an imide anion structure, or a methide anion structure. Of these, organic anions having a sulfonate anion structure are preferred, and specifically, organic anions represented by the following formula (11) can be preferably used. [ka] (In formula (11), R p1 R is a monovalent group containing a ring structure with 5 or more members. p2 R is a divalent linking group.p3 and R p4 Each of these is independently a hydrogen atom, a fluoro group, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. p5 and R p6 Each of these is independently a hydrogen atom, a fluoro group, or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. n1 is an integer from 0 to 10. n2 is an integer from 0 to 10. n3 is an integer from 1 to 10. n1 + n2 + n3 is between 1 and 30. If n1 is 2 or greater, multiple R p2 They are the same or different. If n2 is 2 or more, there are multiple R p3 They are the same or different, multiple R p4 They are the same or different. If n3 is 2 or more, there are multiple R p5 They are the same or different, multiple R p6 They are the same or different. However, if n3 is 1, R p5 and R p6 Both are not hydrogen atoms, and when n3 is 2 or more, multiple R p5 and R p6 (Not all of them are hydrogen atoms.)

[0101] In the above equation (11), R p1 Examples of monovalent groups containing a ring structure with 5 or more members, as represented by , include monovalent groups containing an alicyclic hydrocarbon structure with 5 or more members, monovalent groups containing an aliphatic heterocyclic structure with 5 or more members, monovalent groups containing an aromatic ring structure with 5 or more members, and monovalent groups containing an aromatic heterocyclic structure with 5 or more members.

[0102] Examples of alicyclic hydrocarbon structures with five or more ring members include monocyclic cycloalkane structures such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, and cyclododecane; monocyclic cycloalkene structures such as cyclopentene, cyclohexene, cycloheptene, cyclooctene, and cyclodecene; polycyclic cycloalkane structures such as norbornane, adamantane, tricyclodecane, and tetracyclododecane; and polycyclic cycloalkene structures such as norbornene and tricyclodecene.

[0103] Examples of aliphatic heterocyclic structures with five or more ring members include lactone structures such as hexanolactone and norbornanelactone; sultone structures such as hexanosultone and norbornanesultone; oxygen-containing heterocyclic structures such as oxacycloheptane, oxanorbornane, and cyclic acetal; nitrogen-containing heterocyclic structures such as azacyclohexane and diazabicyclooctane; and sulfur-containing heterocyclic structures such as thiacyclohexane and thianorbornane.

[0104] Examples of aromatic ring structures with five or more members include benzene structures, naphthalene structures, phenanthrene structures, and anthracene structures.

[0105] Examples of aromatic heterocyclic structures with five or more members include oxygen-containing heterocyclic structures such as furan, pyran, and benzopyran structures; and nitrogen-containing heterocyclic structures such as pyridine, pyrimidine, and indole structures.

[0106] Note, R p1 Some or all of the hydrogen atoms in the ring structure may be substituted with substituents. Examples of such substituents include fluoro groups, chloro groups, bromo groups, iodo groups, hydroxy groups, carboxyl groups, cyano groups, nitro groups, alkoxy groups, alkoxycarbonyl groups, alkoxycarbonyloxy groups, acyl groups, acyloxy groups, and the like. p1Among these, an aromatic ring structure having 6 or more ring members in which at least some of the hydrogen atoms are substituted with iodine groups is preferable.

[0107] R p2 Examples of the divalent linking group represented by include a carbonyl group, an ether group, a carbonyloxy group, a sulfide group, a thiocarbonyl group, a sulfonyl group, a divalent hydrocarbon group, and the like. Among these, a carbonyloxy group, a sulfonyl group, an alkanediyl group or a cycloalkanediyl group is preferable, a carbonyloxy group, a sulfonyl group or a cycloalkanediyl group is more preferable, and a carbonyloxy group, a sulfonyl group or a norbornanediyl group is still more preferable.

[0108] R p3 and R p4 Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by include an alkyl group having 1 to 20 carbon atoms and the like. R p3 and R p4 Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by include a fluorinated alkyl group having 1 to 20 carbon atoms and the like. R p3 and R p4 are preferably a hydrogen atom, a fluoro group or a fluoroalkyl group, more preferably a fluoro group or a perfluoroalkyl group, and still more preferably a fluoro group or a trifluoromethyl group.

[0109] R p5 and R p6 Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by include a fluorinated alkyl group having 1 to 20 carbon atoms and the like. R p5 and R p6 are preferably a fluoro group or a fluoroalkyl group, more preferably a fluoro group or a perfluoroalkyl group, still more preferably a fluoro group or a trifluoromethyl group, and particularly preferably a fluoro group. When n3 is 1, R p5 and R p6 are both fluoro groups, or R p5 is a fluoro group and R p6 is a trifluoromethyl group, which is preferable.

[0110] n1 is preferably 0 to 5, more preferably 0 to 3, even more preferably 0 to 2, and particularly preferably 0 or 1. n2 is preferably 0 to 5, more preferably 0 to 2, even more preferably 0 or 1, and particularly preferably 0. n3 is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. By setting n3 within the above range, the strength of the acid generated from the [B] acid generator can be increased, and as a result, the defect suppression, LWR performance and sensitivity of the composition can be further improved. n1 + n2 + n3 is preferably 2 or more. Also, n1 + n2 + n3 is preferably 10 or less, and more preferably 5 or less.

[0111] [B]Specific examples of acid generators include compounds represented by the following formula. However, [B]acid generators are not limited to the following structure. [ka] [ka] [ka] (In the formula, X + (This is a cation represented by formula (7), a cation represented by formula (8), or a cation represented by formula (9).)

[0112] In this composition, the content of [B] acid generator is preferably 20% by mass or less, and more preferably 15% by mass or less, per 100 parts by mass of [A] polymer. Setting the content of [B] acid generator within the above range is preferable because it allows for good sensitivity of the composition while suppressing excessive dissolution of the exposed area into the developer, thereby expanding the process window. [B] acid generator may be used alone or in combination of two or more types.

[0113] <[C] Acid diffusion control agent> [C] The acid diffusion control agent is incorporated into the composition with the aim of suppressing chemical reactions caused by acid in the unexposed areas by inhibiting the diffusion of acid generated by exposure to the composition into the resist film. Incorporating the [C] acid diffusion control agent into the composition is preferable because it can further improve the lithography properties of the composition. Furthermore, it is possible to suppress changes in the line width of the resist pattern due to variations in the holding time from exposure to development, and to obtain a radiation-sensitive composition with excellent process stability. Examples of [C] acid diffusion control agents include nitrogen-containing compounds and photodecayable bases.

[0114] ·Nitrogen-containing compounds Examples of nitrogen-containing compounds include compounds represented by the following formula (12) (hereinafter also referred to as "nitrogen-containing compounds (12A)"), compounds having two nitrogen atoms (hereinafter also referred to as "nitrogen-containing compounds (12B)"), compounds having three nitrogen atoms (hereinafter also referred to as "nitrogen-containing compounds (12C)"), compounds containing amide groups, urea compounds, nitrogen-containing heterocyclic compounds, and nitrogen-containing compounds having acid-dissociable groups. [ka] (In formula (12), R 41 , R 42 and R 43 Each of these is independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group.

[0115] Specific examples of nitrogen-containing compounds include, for example, monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and tri-n-pentylamine; and aromatic amines such as aniline and 2,6-diisopropylaniline. Examples of nitrogen-containing compounds (12B) include ethylenediamine and N,N,N',N'-tetramethylethylenediamine. Examples of nitrogen-containing compounds (12C) include polyamine compounds such as polyethyleneimine and polyallylamine; and polymers such as dimethylaminoethylacrylamide.

[0116] Examples of amide group-containing compounds include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, and N-methylpyrrolidone. Examples of urea compounds include urea, methyl urea, 1,1-dimethyl urea, 1,3-dimethyl urea, 1,1,3,3-tetramethyl urea, 1,3-diphenyl urea, and tributylthiourea. Examples of nitrogen-containing heterocyclic compounds include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N-(undecane-1-ylcarbonyloxyethyl)morpholine; and pyrazines and pyrazoles.

[0117] Examples of nitrogen-containing compounds having acid-dissociable groups include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, N-(t-butoxycarbonyl)di-n-octylamine, N-(t-butoxycarbonyl)diethanolamine, N-(t-butoxycarbonyl)dicyclohexylamine, N-(t-butoxycarbonyl)diphenylamine, Nt-butoxycarbonyl-4-hydroxypiperidine, and Nt-amyloxycarbonyl-4-hydroxypiperidine.

[0118] [C] The nitrogen-containing compound used as an acid diffusion control agent is preferably at least one selected from the group consisting of nitrogen-containing compounds (12A) and nitrogen-containing heterocyclic compounds, more preferably at least one selected from the group consisting of trialkylamines, aromatic amines and morpholines, and even more preferably at least one selected from the group consisting of tri-n-pentylamine, 2,6-diisopropylaniline and N-(undecane-1-ylcarbonyloxyethyl)morpholine.

[0119] Photodecayable bases Photodecayable bases are compounds that generate acid upon irradiation with radiation, and this acid does not undergo or undergoes little dissociation of acid-dissociating groups under the conditions of use. Examples of photodecayable bases include compounds that generate a weaker acid than the acid generated by the [B] acid generator upon exposure. Among photodecayable bases, onium salts that generate carboxylic acids, sulfonic acids, or sulfonamides upon irradiation with radiation are preferably used.

[0120] A preferred example of a photodecayable base is an onium salt having a carboxylate anion structure. A specific example of an onium salt having a carboxylate anion structure is an onium salt compound represented by the following formula (13). [ka] (In formula (13), R 61 Z is a monovalent organic group with 1 to 30 carbon atoms. + (It is a monovalent cation.)

[0121] In the above equation (13), R 61 Examples of monovalent organic groups having 1 to 30 carbon atoms represented by include monovalent hydrocarbon groups having 1 to 30 carbon atoms, monovalent groups b having 1 to 30 carbon atoms containing a divalent heteroatom-containing group between the carbon-carbon bonds of the hydrocarbon group or at the terminal end on the bonding side, and monovalent groups in which at least one hydrogen atom of the hydrocarbon group or monovalent group b is replaced with a monovalent heteroatom-containing group. 61The monovalent organic group having 1 to 30 carbon atoms represented by is preferably a monovalent group having an aromatic ring structure. The aromatic ring structure may have some or all of its hydrogen atoms substituted with substituents. Examples of substituents that substitute for the hydrogen atoms of the aromatic ring include iodine atoms, hydroxyl groups, trifluoromethyl groups, and monovalent groups including a benzene ring substituted with at least one iodine atom.

[0122] Z + The cation represented by is preferably an organic cation, and is particularly preferably a radiation-sensitive onium cation. From the viewpoint of improving the lithographic properties of the composition, it is especially preferably a sulfonium cation or an iodonium cation, for example, the cation represented by formula (7), the cation represented by formula (8), and the cation represented by formula (9).

[0123] Examples of photodecayable bases include compounds represented by the following formula. However, photodecayable bases are not limited to the following structure. [ka] (In the formula, Z + (This is a cation represented by formula (7), a cation represented by formula (8), or a cation represented by formula (9).)

[0124] If the composition contains a [C] acid diffusion control agent, the content of the [C] acid diffusion control agent in the composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, per 100 parts by mass of the [A] polymer. Furthermore, the content of the [C] acid diffusion control agent is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, per 100 parts by mass of the [A] polymer. Setting the content of the [C] acid diffusion control agent within the above range is preferable because it can further improve the LWR performance of the composition. The [C] acid diffusion control agent may be used alone or in combination of two or more types.

[0125] <[D] Solvent> [D] The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing the components incorporated into this composition. Examples of [D] solvents include alcohols, ethers, ketones, amides, esters, hydrocarbons, and the like.

[0126] Examples of alcohols include aliphatic monoalcohols with 1 to 18 carbon atoms such as 4-methyl-2-pentanol and n-hexanol; alicyclic monoalcohols with 3 to 18 carbon atoms such as cyclohexanol; polyhydric alcohols with 2 to 18 carbon atoms such as 1,2-propylene glycol; and polyhydric alcohol partial 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, diisoamyl ether, dihexyl ether, and diheptyl ether; cyclic ethers such as tetrahydrofuran and tetrahydropyran; and aromatic ring-containing ethers such as diphenyl ether and anisole.

[0127] Examples of ketones include linear ketones such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-iso-butyl ketone, and trimethylnonanone; cyclic ketones such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and methylcyclohexanone; and 2,4-pentanedione, acetonylacetone, acetophenone, and diacetone alcohol. Examples of amides include cyclic amides such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone; and linear amides such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.

[0128] Examples of esters include monocarboxylic acid esters such as n-butyl acetate and ethyl lactate; polyhydric alcohol carboxylates such as propylene glycol acetate; polyhydric alcohol partial ether carboxylates such as propylene glycol monomethyl ether acetate; polyhydric carboxylic 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 to 12 carbon atoms such as n-pentane and n-hexane; and aromatic hydrocarbons with 6 to 16 carbon atoms such as toluene and xylene.

[0129] [D] The solvent preferably contains at least one selected from the group consisting of esters and ketones, more preferably at least one selected from the group consisting of polyhydric alcohol partial ether carboxylates and cyclic ketones, and even more preferably at least one of propylene glycol monomethyl ether acetate, ethyl lactate, and cyclohexanone. [D] One or more solvents may be used.

[0130] <[E] Acid-dissociable group-containing polymer> [E] Acid-dissociable group-containing polymer (hereinafter also simply referred to as "[E] polymer") is a polymer that has an acid-dissociable group and does not contain structural unit (I). In this composition, it is preferable that at least one polymer selected from the group consisting of [A] polymer and polymers different from [A] polymer contains a structural unit (II) having an acid-dissociable group. Note that [E] polymer is a polymer different from [A] polymer. By the polymer component of this composition containing structural unit (II), the acid-dissociable group dissociates due to the acid generated by exposure of this composition, producing an acidic group, which can change the solubility of the polymer component in the developer. This can impart good lithography properties to this composition.

[0131] [E] The structural units (II) contained in polymer [E] are the same structural units as those described as structural units (II) that polymer [A] may contain. In addition, polymer [E] may contain at least one of structural units (III) to (VII) described as structural units that polymer [A] may contain. The preferred range for the content ratio of each structural unit (II) to (VII), as well as the preferred range for the weight-average molecular weight and molecular weight distribution of the polymer, are the same as those for polymer [A].

[0132] In this composition, the content of the [E] polymer is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the [A] polymer. This composition may contain the [E] polymer alone or in combination of two or more types.

[0133] <[F] High fluorine-containing polymer> [F] High fluorine-containing polymers (hereinafter also simply referred to as "[F] polymers") are polymers with a higher mass content of fluorine atoms than [A] polymers. [F] polymers are included in this composition, for example, as a water-repellent additive.

[0134] The fluorine atom content of the polymer [F] is not particularly limited as long as it is greater than that of the polymer [A]. The fluorine atom content of the polymer [F] is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 4% by mass or more, and particularly preferably 7% by mass or more. Furthermore, the fluorine atom content of the polymer [F] is preferably 60% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. The fluorine atom content (by mass) of the polymer is: 13 The polymer structure can be determined by methods such as 1C-NMR spectroscopy, and the calculation can be derived from that structure.

[0135] Examples of structural units included in the [F] polymer include structural unit (Fa) and structural unit (Fb) shown below. The [F] polymer may contain one or more types of structural unit (Fa) and structural unit (Fb).

[0136] [Structural Unit (Fa)] The structural unit (Fa) is a structural unit represented by the following formula (14a). [F] polymers can have their fluorine atom content adjusted by including the structural unit (Fa). [ka] (In formula (14a), R C G is a hydrogen atom, a fluoro group, a methyl group, or a trifluoromethyl group. G is a single bond, an oxygen atom, a sulfur atom, -CO-O-, -SO2-O-NH-, -CO-NH-, or -O-CO-NH-. R E This is a monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms or a monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms.

[0137] R E Examples of monovalent fluorinated chain hydrocarbon groups having 1 to 6 carbon atoms, represented by , include trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, perfluoro-n-propyl group, perfluoroisopropyl group, perfluoro-n-butyl group, perfluoroisobutyl group, perfluoro-t-butyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, and perfluorohexyl group.

[0138] R E Examples of monovalent fluorinated alicyclic hydrocarbon groups having 4 to 20 carbon atoms, represented by , include monofluorocyclopentyl group, difluorocyclopentyl group, perfluorocyclopentyl group, monofluorocyclohexyl group, difluorocyclohexyl group, perfluorocyclohexylmethyl group, fluoronorbornyl group, fluoroadamantyl group, fluorobornyl group, fluoroisobornyl group, fluorotricyclodecyl group, and fluorotetracyclodecyl group.

[0139] Examples of monomers that provide the structural unit (Fa) include (meth)acrylic acid esters having fluorinated linear hydrocarbon groups and (meth)acrylic acid esters having fluorinated alicyclic hydrocarbon groups. Specific examples of these include (meth)acrylic acid esters having fluorinated linear hydrocarbon groups, such as linear partially fluorinated alkyl (meth)acrylic acid esters like 2,2,2-trifluoroethyl (meth)acrylic acid ester; branched partially fluorinated alkyl (meth)acrylic acid esters like 1,1,1,3,3,3-hexafluoroisopropyl (meth)acrylic acid ester; linear perfluoroalkyl (meth)acrylic acid esters like perfluoroethyl (meth)acrylic acid ester; and branched perfluoroalkyl (meth)acrylic acid esters like perfluoroisopropyl (meth)acrylic acid ester.

[0140] Examples of (meth)acrylic acid esters having fluorinated alicyclic hydrocarbon groups include (meth)acrylic acid esters having monocyclic fluorinated alicyclic saturated hydrocarbon groups such as perfluorocyclohexylmethyl (meth)acrylic acid ester, monofluorocyclopentyl (meth)acrylic acid ester, and perfluorocyclopentyl (meth)acrylic acid ester; and (meth)acrylic acid esters having polycyclic fluorinated alicyclic saturated hydrocarbon groups such as fluoronorbornyl (meth)acrylic acid ester.

[0141] [F]When the polymer contains structural units (Fa), the content of structural units (Fa) is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, relative to the total structural units constituting the [F] polymer.

[0142] [Structural Unit (Fb)] The structural unit (Fb) is a structural unit represented by the following formula (14b). The [F] polymer becomes more hydrophobic by containing the structural unit (Fb), and therefore the dynamic contact angle of the resist film surface formed from this composition can be further improved. [ka] (In formula (14b), R F R is a hydrogen atom, a fluoro group, a methyl group, or a trifluoromethyl group. 59 is a (s+1) valent hydrocarbon group having 1 to 20 carbon atoms, or the R of said hydrocarbon group. 60 It is a group to which an oxygen atom, sulfur atom, -NR'-, carbonyl group, -CO-O-, or -CO-NH- is bonded at one end. R' is a hydrogen atom or a monovalent organic group. 60 This refers to a single bond, a divalent chain hydrocarbon group having 1 to 10 carbon atoms, or a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms. 12 A is a divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms. 11 R is an oxygen atom, -NR''-, -CO-O-*, or -SO2-O-*. R'' is a hydrogen atom or a monovalent organic group. * is R 61 This shows the binding site. 61 is a hydrogen atom or a monovalent organic group. s is an integer from 1 to 3. However, if s is 2 or 3, multiple R 60 , X 12 , A 11 and R 61 (These are either the same or different.)

[0143] R 61 When R is a hydrogen atom, it is preferable in that it can improve the solubility of the [F] polymer in an alkaline developer. 61 Examples of monovalent organic groups represented by this formula include acid-dissociable groups, alkali-dissociable groups, or hydrocarbon groups having 1 to 30 carbon atoms that may have substituents.

[0144] [F]When the polymer contains structural units (Fb), the content of structural units (Fb) is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, relative to the total structural units constituting the [F] polymer.

[0145] [F] The polymer may further contain structural units (Fa) and (Fb), as well as structural units (Fc) that have acid-dissociable groups and are different from structural units (Fa) and (Fb). The presence of structural units (Fc) in the [F] polymer results in a better shape of the resulting resist pattern. Examples of structural units (Fc) include structural unit (II) described in the [A] polymer.

[0146] [F]When the polymer contains structural units (Fc), the content of structural units (Fc) is preferably 5 mol% or more, more preferably 25 mol% or more, and even more preferably 50 mol% or more, relative to the total structural units constituting the [F] polymer. Furthermore, the content of structural units (Fc) is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less, relative to the total structural units constituting the [F] polymer.

[0147] The Mw of the [F] polymer determined 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 the [F] polymer 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), expressed as the ratio of Mn to Mw determined by GPC of the [F] polymer, is usually 1 or more, and preferably 1.2 or more. Furthermore, the Mw / Mn is preferably 5 or less, and more preferably 3 or less.

[0148] If the composition contains a polymer [F], the content of the polymer [F] in the composition is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the polymer [A]. Furthermore, the content of the polymer [F] is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of the polymer [A]. Note that the composition may contain one type of polymer [F] alone, or two or more types in combination.

[0149] <Other optional ingredients> This composition may further contain components other than the above-mentioned [A] polymer, [B] acid generator, [C] acid diffusion control agent, [D] solvent, [E] acid dissociable group-containing polymer, and [F] high fluorine-containing polymer (hereinafter also referred to as "other optional components"). Examples of other optional components include surfactants, alicyclic skeleton-containing compounds (e.g., 1-adamantanecarboxylic acid, 2-adamantanone, t-butyl deoxycholate, etc.), sensitizers, and segregation promoters. The content ratio of the other optional components in this composition can be appropriately selected according to each component, as long as it does not impair the effects of this disclosure.

[0150] <Method for producing a radiation-sensitive composition> This composition can be produced, for example, by mixing a polymer [A] and, if necessary, a solvent [D] in desired proportions, and filtering the resulting mixture, preferably using a filter (for example, a filter with a pore size of about 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. Setting the solid content concentration of this composition within the above range is advantageous because it allows for good coatability and good shape of the resist pattern.

[0151] The resulting composition can be used as a positive-type pattern-forming composition for forming patterns using an alkaline developer, or as a negative-type pattern-forming composition for using a developer containing an organic solvent.

[0152] ≪Method for forming a resist pattern≫ The resist pattern formation method of this disclosure 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 in 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 obtained by the resist pattern formation method of this disclosure include line-and-space patterns and hole patterns. Since the resist film is formed using the composition in the resist pattern formation method of this disclosure, it is possible to form a resist pattern with good sensitivity and lithography characteristics, and with few development defects. In particular, the composition has a wide process findow, and therefore, the resist pattern formation method of this disclosure, which forms a resist film using the composition, can suppress the occurrence of defects due to fluctuations in process conditions. Each step will be described below.

[0153] [Coating Process] In this process, a resist film is formed on a substrate by coating one side of the substrate with the composition. Conventional known substrates can be used as the substrate on which the resist film is formed, such as silicon wafers, silicon dioxide wafers, and aluminum-coated wafers. Alternatively, an organic or inorganic anti-reflective film, such as those disclosed in Japanese Patent Publication No. 6-12452 or Japanese Patent Publication No. 59-93448, may be formed on the substrate and used. Examples of coating methods for the composition include rotary coating (spin coating), casting coating, and roll coating. After coating, a soft bake (SB) may be performed to volatilize the solvent in the coating film. The SB temperature is preferably 60°C or higher, more preferably 80°C or higher. Furthermore, the SB temperature is preferably 140°C or lower, more preferably 120°C or lower. The SB time is preferably 5 seconds or more, more preferably 10 seconds or more. Furthermore, the SB time is preferably 600 seconds or less, more preferably 300 seconds or less. The average thickness of the formed resist film is preferably 10 to 1,000 nm, and more preferably 20 to 500 nm.

[0154] [Synthesis process] In this step, the resist film obtained by the above coating step is exposed. This exposure is performed by irradiating the resist film with radiation through a photomask, and possibly through an immersion medium such as water. Examples of radiation include electromagnetic waves such as visible light, near ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and gamma rays, depending on the line width of the desired pattern; and charged particle beams such as electron beams and alpha rays. Of these, the radiation irradiated onto the resist film formed using this composition is preferably far ultraviolet light, EUV, or an electron beam; more preferably ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV, or an electron beam; still preferably ArF excimer laser light, EUV, or an electron beam; even more preferably EUV or an electron beam; and particularly preferably EUV.

[0155] After the exposure described above, it is preferable to perform a post-exposure bake (PEB) to promote the dissociation of acid-dissociable groups of the [A] polymer, etc., in the exposed portion of the resist film. This PEB can increase the difference in solubility in the developer between the exposed and unexposed portions. The PEB temperature is preferably 50°C or higher, more preferably 70°C or higher. Furthermore, the PEB temperature is preferably 180°C or lower, more preferably 130°C or lower. The PEB duration is preferably 5 seconds or more, more preferably 10 seconds or more. Furthermore, the PEB duration is preferably 600 seconds or less, more preferably 300 seconds or less.

[0156] [Development process] In this step, the exposed resist film is developed. This allows for the formation of the desired resist pattern. After development, it is common to wash with a rinsing solution such as water or alcohol and then dry the film. The development method in the development step may be alkaline development or organic solvent development.

[0157] In the case of alkaline development, examples of developer solutions used for development include alkaline aqueous solutions containing at least one alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene. Among these, aqueous TMAH solutions are preferred, and 2.38% by mass aqueous TMAH solutions are more preferred.

[0158] In the case of organic solvent development, the developer can be one or more of the following: organic solvents such as hydrocarbons, ethers, esters, ketones, and alcohols, or solvents containing the above organic solvents. Examples of organic solvents used as the developer include the solvents listed as [D] solvent in the description of this composition. Among these, esters and ketones are preferred. Among esters, acetic acid esters are preferred, and n-butyl acetate is more preferred. Among ketones, chain ketones are preferred, and 2-heptanone is more preferred. In the developer, the content of the organic solvent is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more. Examples of components other than organic solvents in the developer include water and silicone oil.

[0159] Examples of development methods include immersing the substrate in a tank filled with developer solution for a certain period of time (dip method), developing by piling the developer solution onto the substrate surface using surface tension and letting it remain still for a certain period of time (paddle method), spraying the developer solution onto the substrate surface (spray method), and continuously dispensing the developer solution while scanning a developer solution dispensing nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispensing method).

[0160] According to the disclosure described above, the following means are provided. [1] A radiation-sensitive composition containing a polymer comprising the structural unit (I) represented by the above formula (1). [2] The radiation-sensitive composition according to [1], wherein the structural unit (I) is at least one selected from the group consisting of structural units derived from the compound represented by formula (4) and structural units derived from the compound represented by formula (5). [3] The radiation-sensitive composition according to [1] or [2] above, wherein at least one selected from the group consisting of a polymer containing the structural unit (I) and a polymer different from the polymer containing the structural unit (I) contains a structural unit (II) having an acid-dissociable group. [4] The radiation-sensitive composition according to any one of [1] to [3] above, wherein the polymer containing the structural unit (I) further contains a structural unit (III) having a hydroxyl group bonded to an aromatic ring. [5] A method for forming a resist pattern, comprising the steps of: forming a resist film on a substrate using a radiation-sensitive composition described in any of [1] to [4] above; exposing the resist film; and developing the exposed resist film. [6] A polymer containing the structural unit represented by the above formula (1). [7] A compound represented by the above formula (4). [8] A compound represented by the above formula (5). [Examples]

[0161] The present disclosure will be described in detail below based on examples. However, the present disclosure is not limited to the following examples. In the following examples, "parts" and "%" refer to mass unless otherwise specified. Each measurement in the examples and comparative examples was performed by the following methods.

[0162] [Weight-average molecular weight (Mw) and number-average molecular weight (Mn)] The analysis was performed using Tosoh Corporation's GPC columns (G2000HXL: 2 columns, G3000HXL: 1 column, G4000HXL: 1 column), under the following analytical conditions: flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, sample concentration: 1.0% by mass, sample injection volume: 100 μL, column temperature: 40°C, and detector: differential refractometer. The measurement was performed by gel permeation chromatography (GPC) with monodisperse polystyrene as the standard. The degree of dispersion (Mw / Mn) was calculated from the measured results of Mw and Mn.

[0163] [ 13 C-NMR analysis] Using a JEOL JNM-ECX400 instrument and DMSO-d6 as the measurement solvent, the content percentage (mol%) of each structural unit in each polymer was determined.

[0164] <Synthesis of Compounds> [Synthesis Example 1] Synthesis of Compound (M-1) 12 g of 4-vinylbenzaldehyde, 40 g of triphenylsulfonium=α,α,β,β-tetrafluoro-2-(5,6-dihydroxybicyclo[2.2.1]heptan-2-yl)ethanesulfonate, 9 g of trimethyl orthoformate, and 2.7 g of p-toluenesulfonic acid monohydrate were dissolved in 240 g of dichloromethane and reacted at room temperature for 5 hours. After the reaction was complete, the reaction solution was washed five times with 200 g of water, and the dichloromethane was removed by distillation to obtain 64 g of crude product. Subsequently, 50 g of compound (M-1) was obtained by column purification. The purity was 99.3% by HPLC. [ka]

[0165] <Synthesis of polymers> The monomers used in the synthesis of the polymer are shown below. [ka]

[0166] [ka] [ka]

[0167] [Synthesis Example 1] (Synthesis of polymer (A-1)) A monomer solution was prepared by dissolving 15 mol% of compound (M-1), 55 mol% of compound (M-6), 30 mol% of compound (M-9), and 2,2'-azobis(methyl isobutyrate) (12 mol% of total monomers) as a polymerization initiator in 40 g of propylene glycol monomethyl ether. Separately, a 100 mL three-necked flask containing 20 g of propylene glycol monomethyl ether was prepared. This flask was purged with nitrogen for 30 minutes and then heated to 85°C with stirring. Subsequently, the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. After the addition was complete, the mixture was stirred for another 3 hours at 85°C. After the polymerization reaction was complete, 56 g of ethyl acetate, 24 g of methanol, 6.4 g of water, and 200 g of hexane were added to the polymerization solution and mixed, then transferred to a 1 L separatory funnel. After standing for 30 minutes, the lower layer was collected. The recovered material was subjected to solvent replacement with propylene glycol monomethyl ether to obtain 80 g of solution. Next, 100 g of methanol, 10 g of triethylamine, and 2 g of water were added. The hydrolysis reaction was carried out for 6 hours under reflux at the boiling point. After the reaction was complete, the solvent and triethylamine were removed by distillation under reduced pressure. The obtained polymer was dissolved in propylene glycol monomethyl ether to obtain a 15% solids solution of polymer (A-1). The Mw of polymer (A-1) was 8,200, and the Mw / Mn ratio was 1.6. 13 13C-NMR analysis revealed that the content of structural units derived from compound (M-1), compound (M-6), and p-hydroxystyrene units derived from compound (M-9) was 16.2 mol%, 53.3 mol%, and 30.5 mol%, respectively.

[0168] [Synthesis Examples 2-8, 10-13] (Synthesis of polymers (A-2)-(A-8), (A-10)-(A-13)) By appropriately selecting monomers and performing the same procedure as in Synthesis Example 1, polymer solutions with a solid content of 15% containing polymers (A-2) to (A-8) and (A-10) to (A-13) were obtained. The types and amounts of monomers used are shown in Table 1. The content ratio of each structural unit in the obtained polymers is shown in Table 2.

[0169] [Synthesis Example 9] (Synthesis of polymer (A-9)) A monomer solution was prepared by dissolving 15 mol% of compound (M-1), 55 mol% of compound (M-6), 30 mol% of compound (M-10), and 2,2'-azobis(methyl isobutyrate) (12 mol% of total monomers) as a polymerization initiator in 40 g of propylene glycol monomethyl ether. Separately, a 500 mL three-necked flask containing 20 g of propylene glycol monomethyl ether was prepared. This flask was purged with nitrogen for 30 minutes and then heated to 85°C with stirring. Subsequently, the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. After the addition was complete, the mixture was stirred for another 3 hours at 85°C. After the polymerization reaction was complete, 56 g of ethyl acetate, 24 g of methanol, 6.4 g of water, and 200 g of hexane were added to the polymerization solution and mixed. The mixture was transferred to a 1 L separatory funnel, allowed to stand for 30 minutes, and the lower layer was collected. The recovered material was dissolved in propylene glycol monomethyl ether acetate to obtain a polymer (A-9) solution with a solid content of 15%. The Mw of polymer (A-9) was 6,700, and the Mw / Mn ratio was 1.5. 13 13C-NMR analysis revealed that the content percentages of each structural unit derived from compound (M-1), compound (M-6), and compound (M-10) were 15.7 mol%, 53.2 mol%, and 31.1 mol%, respectively.

[0170] [Table 1]

[0171] [Table 2]

[0172] <Preparation of radiation-sensitive resin composition> The following are the [B] acid generator, [C] acid diffusion control agent, and [D] solvent used in the preparation of the radiation-sensitive resin compositions of Examples 1 to 20 and Comparative Example 1.

[0173] • [B] Acid Generator PAG-1: Compound represented by the following formula (PAG-1) PAG-2: Compound represented by the following formula (PAG-2) PAG-3: Compound represented by the following formula (PAG-3) PAG-4: Compound represented by the following formula (PAG-4) PAG-5: Compound represented by the following formula (PAG-5) [ka]

[0174] • [C] Acid diffusion control agent Q-1: Compound represented by the following formula (Q-1) Q-2: Compound represented by the following formula (Q-2) Q-3: Compound represented by the following formula (Q-3) Q-4: Compound represented by the following formula (Q-4) [ka]

[0175] • [D] Solvent D-1: Propylene glycol monomethyl ether acetate D-2: Propylene glycol monomethyl ether

[0176] [Example 1] A radiation-sensitive resin composition (J-1) was prepared by mixing 670 parts by mass of polymer (A-1) solution, 15 parts by mass of acid diffusion control agent (Q-1), 1,700 parts by mass of solvent (D-1), and 6,230 parts by mass of solvent (D-2), and filtering the mixture through a membrane filter with a pore size of 0.2 μm.

[0177] [Examples 2-20 and Comparative Example 1] Each radiation-sensitive resin composition was prepared in the same manner as in Example 1, except that the types and amounts of each component shown in Table 3 were used.

[0178] [Table 3]

[0179] <Formation of resist pattern (EB exposure, alkaline development)> A 12-inch silicon wafer had a base layer (Brewer Science's "DUV42") with an average thickness of 60 nm formed on it. The prepared radiation-sensitive resin composition was applied to this base layer using a spin coater (Tokyo Electron Limited's "CLEAN TRACK ACT12"). After soft baking (SB) at 110°C for 60 seconds, the film was cooled at 23°C for 30 seconds to form a resist film with an average thickness of 40 nm. Next, this resist film was exposed using an EB lithography system (Elionix's "ELS-F150") through a mask that formed a 20 nm line-and-space pattern, at a voltage of 150 keV and a current of 100 pA. After exposure, PEB was performed at 80°C for 60 seconds. Subsequently, development was performed at 23°C for 30 seconds using a 2.38 mass% TMAH aqueous solution as the alkaline developer. The film was washed with water and dried to form a positive-type resist pattern.

[0180] <Rating> The sensitivity and process window of the radiation-sensitive resin compositions prepared above were evaluated according to the following method. The resist patterns were formed using the method described above. A scanning electron microscope (Hitachi High-Tech Technology, Ltd.'s "CG-4100") was used to measure the length of the resist patterns. The evaluation results are shown in Table 4.

[0181] [sensitivity] In forming a resist pattern using the above radiation-sensitive resin composition, the exposure amount for forming a 20 nm line-and-space pattern is defined as the optimal exposure amount, and this optimal exposure amount is set to the sensitivity (μC / cm²). 2 (EB sensitivity) was used.

[0182] [Process window] Using a mask that forms a 20nm line-and-space pattern (1L / 1S), patterns were formed at exposure levels ranging from low to high. Generally, defects such as bridging between patterns were observed at low exposure levels, while defects such as pattern collapse were observed at high exposure levels. The difference between the maximum and minimum values ​​of the resist dimension (i.e., line width) where these defects were not observed was defined as the "CD (Critical Dimension) margin." A larger CD margin indicates a wider process window and better results. A CD margin of 1.5nm or more was evaluated as "good," and a CD margin of less than 1.5nm was evaluated as "poor."

[0183] [Table 4]

[0184] As is clear from the results in Table 4, the radiation-sensitive resin compositions of Examples 1 to 20 exhibited high sensitivity, a larger CD margin, and a wider process window compared to the radiation-sensitive resin composition of Comparative Example 1.

[0185] From the above results, the radiation-sensitive composition of this disclosure containing a polymer containing the structural unit (I) represented by formula (1) above, and the resist pattern formation method using this radiation-sensitive composition, can form a resist pattern that has good sensitivity to exposure light and a wide process window. Therefore, the radiation-sensitive composition and resist pattern formation method of this disclosure are suitable for processing processes of semiconductor devices, which are expected to become even more miniaturized in the future.

Claims

1. A radiation-sensitive composition containing a polymer comprising, as a structural unit (I) represented by the following formula (1), at least one selected from the group consisting of a structural unit derived from a compound represented by the following formula (4) and a structural unit derived from a compound represented by the following formula (5). 【Chemistry 1】 (In formula (1), R １ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ２ is a single bond, a divalent hydrocarbon group, a divalent group F obtained by replacing any hydrogen atom in the divalent hydrocarbon group with a monovalent substituent １ , a divalent hydrocarbon group or a divalent group F １ containing -O-, -CO-, -NH-, -COO- or -CONH- between carbon-carbon bonds of the group F ２ , * １ -COO-R ７ -, or * １ -CONH-R ７ -. R ７ is a single bond, a divalent hydrocarbon group, a divalent group F obtained by replacing any hydrogen atom in the divalent hydrocarbon group with a monovalent substituent ３ , or a divalent hydrocarbon group or a divalent group F ３ containing -O-, -CO-, -NH-, -COO- or -CONH- between carbon-carbon bonds of the group F ４ . "* １ " represents a bond that binds to the carbon atom to which R １ is bonded. R ３ is a divalent group represented by the following formula (2) or formula (3). However, when R ２ is bonded to the oxygen-containing heteromonocyclic ring in the following formula (2) and formula (3), R ７ is not a single bond. R ４ is a divalent organic group. However, when R ４ is bonded to the oxygen-containing heteromonocyclic ring in the following formula (2) and formula (3), R ４ is a carbon atom bonded to R ３ . Y － is a monovalent anion that generates a sulfonic acid group, an imidic acid group or a methidic acid group upon exposure. M ａ＋ is an a-valent cation. a is 1 or 2.) 【Chemistry 2】 (In equations (2) and (3), R ５ X is a hydrogen atom or a monovalent organic group. １ is, -CH ２ It is -, -NH-, -O-, or -S-. Ar １ R represents the ring structure that forms a fused ring together with the oxygen-containing heteromonal ring in equation (3). ６ is a monovalent substituent. n is 0 or 1. m is 0 or 1. r is an integer between 0 and 2. "*" indicates a bond. 【Transformation 3】 (In equations (4) and (5), R1, R2, R4, R5, R6, Y-, Ma+, X1, Ar1, a, n, m, and r are equivalent to those in equations (1) to (3) above.)

2. The radiation-sensitive composition according to claim 1, wherein at least one polymer selected from the group consisting of a polymer containing the structural unit (I) and a polymer different from the polymer containing the structural unit (I) contains a structural unit (II) having an acid-dissociable group.

3. The radiation-sensitive composition according to claim 1, wherein the polymer containing the structural unit (I) further comprises a structural unit (III) having a hydroxyl group bonded to an aromatic ring.

4. A step of forming a resist film on a substrate using the radiation-sensitive composition according to any one of claims 1 to 3, The steps include: exposing the resist film, A step of developing the exposed resist film, A method for forming a resist pattern, including the method described above.

5. A polymer comprising at least one selected from the group consisting of structural units derived from a compound represented by the following formula (4) and structural units derived from a compound represented by the following formula (5). 【Chemistry 4】 (In formula (4), R １ R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ２ This is a divalent group F, which consists of a single bond, a divalent hydrocarbon group, and any hydrogen atom on the divalent hydrocarbon group being replaced by a monovalent substituent. １ , a divalent hydrocarbon group or the aforementioned group F １ A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds ２ , * １ -COO-R ７ - or * １ -CONH-R ７ - is R ７ This is a divalent hydrocarbon group, and a divalent group F obtained by replacing any hydrogen atom of the divalent hydrocarbon group with a monovalent substituent. ３ , or a divalent hydrocarbon group or the aforementioned group F ３ A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds ４ That is. "* １ " is R １ This indicates a bond that connects to the carbon atom to which it is bonded. ４ R is a divalent organic group. ５ X is a hydrogen atom or a monovalent organic group. １ is, -CH ２ -, -NH-, -O-, or -S-. Y － M is a monovalent anion that generates a sulfonic acid group, imido acid group, or methido acid group upon exposure to light. ａ＋ (where is an α-valent cation; n is 0 or 1; m is 0 or 1; a is 1 or 2.) 【Transformation 5】 (In formula (5), R １ R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ２ This is a divalent group F, which consists of a single bond, a divalent hydrocarbon group, and any hydrogen atom on the divalent hydrocarbon group being replaced by a monovalent substituent. １ , a divalent hydrocarbon group or the aforementioned group F １ A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds ２ , * １ -COO-R ７ - or * １ -CONH-R ７ - is R ７ This is a divalent group F, which consists of a single bond, a divalent hydrocarbon group, and any hydrogen atom on the divalent hydrocarbon group being replaced by a monovalent substituent. ３ , or a divalent hydrocarbon group or the aforementioned group F ３ A divalent group F containing -O-, -CO-, -NH-, -COO-, or -CONH- between the carbon-carbon bonds ４ That is. "* １ " is R １ Ar represents a bond that connects to the carbon atom to which it is bonded. １ R represents the ring structure that forms a fused ring together with the oxygen-containing heteromonal ring in the formula. ４ R is a divalent organic group. ４ It is bonded to an oxygen-containing heteromonocyclic ring by a carbon atom. ５ R is a hydrogen atom or a monovalent organic group. ６ is a monovalent substituent. n is 0 or 1. r is an integer between 0 and 2. Y － M is a monovalent anion that generates a sulfonic acid group, imido acid group, or methido acid group upon exposure to light. ａ＋ (where a is an α-valent cation, and a is either 1 or 2.)

6. A compound represented by the following formula (4). 【Transformation 6】 (In formula (4), R １ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ２ is a single bond, a divalent hydrocarbon group, a divalent group F formed by replacing any hydrogen atom of the divalent hydrocarbon group with a monovalent substituent １ , a divalent hydrocarbon group or a divalent group F １ containing -O-, -CO-, -NH-, -COO- or -CONH- between the carbon-carbon bonds of the above group F ２ , * １ -COO-R ７ -, or * １ -CONH-R ７ -. R ７ is a divalent hydrocarbon group, a divalent group F formed by replacing any hydrogen atom of the divalent hydrocarbon group with a monovalent substituent ３ , or a divalent hydrocarbon group or a divalent group F ３ containing -O-, -CO-, -NH-, -COO- or -CONH- between the carbon-carbon bonds of the above group F ４ is. "* １ " represents a bond that binds to the carbon atom to which R １ binds. R ４ is a divalent organic group. R ５ is a hydrogen atom or a monovalent organic group. X １ is -CH ２ -, -NH-, -O- or -S-. Y － is a monovalent anion that generates a sulfonic acid group, an imidic acid group or a methidic acid group upon exposure. M ａ＋ is an a-valent cation. n is 0 or 1. m is 0 or 1. a is 1 or 2. )

7. A compound represented by the following formula (5). 【Transformation 7】 (In formula (5), R １ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ２ is a single bond, a divalent hydrocarbon group, a divalent group F in which any hydrogen atom of the divalent hydrocarbon group is replaced by a monovalent substituent １ , a divalent hydrocarbon group, or a divalent group F １ containing -O-, -CO-, -NH-, -COO- or -CONH- between carbon-carbon bonds of the group F ２ , * １ -COO-R ７ -, or * １ -CONH-R ７ -. R ７ is a single bond, a divalent hydrocarbon group, a divalent group F in which any hydrogen atom of the divalent hydrocarbon group is replaced by a monovalent substituent ３ , or a divalent hydrocarbon group or a divalent group F ３ containing -O-, -CO-, -NH-, -COO- or -CONH- between carbon-carbon bonds of the group F ４ . "* １ " represents a bond that binds to the carbon atom to which R １ is bonded. Ar １ represents a ring structure that forms a condensed ring together with the oxygen-containing heteromonocyclic ring in the formula. R ４ is a divalent organic group. However, R ４ is bonded to the oxygen-containing heteromonocyclic ring by a carbon atom. R ５ is a hydrogen atom or a monovalent organic group. R ６ is a monovalent substituent. n is 0 or 1. r is an integer from 0 to 2. Y － is a monovalent anion that generates a sulfonic acid group, an imidic acid group or a methidic acid group upon exposure. M ａ＋ is an a-valent cation. a is 1 or 2.)

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