Resist pattern formation method

Abstract

The present invention addresses the problem of providing a method that makes it possible, when forming a resist pattern, to enhance the sensitivity of a resist layer and improve resolution and roughness. The present invention provides, as a solution, a resist pattern formation method comprising: a formation step for forming, on a base material, a resist layer that contains a polymer which has an iodine atom; an exposure step for exposing the resist layer formed in the formation step; and a development step for using an aqueous developing solution that contains an amphiphilic molecule to develop the resist layer exposed in the exposure step.

Description

Method for forming a resist pattern

[0001] The present invention relates to a method for forming a resist pattern, a method for manufacturing an electronic device, an aqueous developer, a resist composition, and a kit containing the aqueous developer and the resist composition.

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of semiconductors (patterns) and pixels in the manufacturing of semiconductor devices and liquid crystal display elements. To achieve this miniaturization, the wavelength of the exposure light source is generally shortened. Specifically, while ultraviolet light, represented by g-line and i-line ultraviolet light, was conventionally used, methods using far-ultraviolet light such as KrF excimer lasers and ArF excimer lasers are now becoming the focus of mass production, and the introduction of extreme ultraviolet (EUV) lithography is also progressing. In addition, electron beams (EB) are used to form fine patterns.

[0003] Conventional resist materials are polymer-based resist materials capable of forming amorphous films. In the past, line patterns of approximately 10 to 100 nm were formed on resist thin films prepared by coating a substrate with a solution of a resist composition using these resist materials, and then irradiating these films with ultraviolet light, far ultraviolet light, electron beams, extreme ultraviolet light, etc.

[0004] Furthermore, electron beam or extreme ultraviolet lithography has a reaction mechanism different from that of conventional photolithography. Moreover, electron beam or extreme ultraviolet lithography aims to form fine patterns of several nanometers to tens of nanometers. As the dimensions of the resist pattern become smaller in this way, a resist composition that is even more sensitive to the exposure light source is required. In particular, in extreme ultraviolet lithography, there is a need to further increase sensitivity in terms of throughput. The use of halogen-containing polymers has been proposed as a resist material that can achieve high sensitivity, and among them, iodine-containing polymers with a large absorption cross-section for extreme ultraviolet light are considered particularly promising (Patent Documents 1 and 2).

[0005] Meanwhile, various studies have been conducted on developers for forming resist patterns (Patent Documents 3-5). For example, an approach has been taken to add amphiphilic molecules to the developer in order to improve lithography performance. In this method, it is known that amphiphilic molecules reduce the surface tension of the solvent, and when used in a developer, they reduce the stress acting on the resist pattern during drying, thereby suppressing pattern collapse (Non-Patent Document 1). However, it is also known that developers containing amphiphilic molecules generally tend to cause swelling of the resist film, which carries the risk of degrading lithography performance, such as thicker patterns and the occurrence of bridge defects (Non-Patent Document 1).

[0006] Japanese Patent Publication No. 2021-188041, International Publication No. 2020 / 137935, Japanese Patent Publication No. 2024-127229, Japanese Patent Publication No. 2024-120951, International Publication No. 2023-248933

[0007] Proceedings of SPIE, Vol. 11854, 1185409 (2021)Japanese Journal of Applied Physics, Vol. 63, No. 7, 076501 (2024)

[0008] When forming resist patterns using iodine-containing polymers, it was known that the interaction between halogens and Lewis bases can lead to insufficient dissolving power in conventional developers compared to iodine-free solutions during development. This can easily cause swelling of the pattern, resulting in reduced resolution and worsened roughness.

[0009] Non-patent document 2 describes how the dissolution rate is evaluated by tracking the change in film thickness during the development process, and mentions that the graph showing the dissolution rate only for iodine-containing polymers is multi-stage rather than linear, indicating the formation of a swollen layer.

[0010] For these reasons, using a developer containing amphiphilic molecules that further promote swelling in iodine-containing polymers, where swelling of the resist film is already a problem, was not considered practical from a technical standpoint, as it would easily lead to a deterioration in lithography performance.

[0011] The object of the present invention is to provide a method for forming a resist pattern that can further improve the sensitivity of the resist layer and improve the resolution and roughness.

[0012] In order to achieve the objectives of the present invention, the inventors conducted diligent studies and, unexpectedly, discovered that the above-mentioned problems could be solved by developing a resist layer containing a polymer having iodine atoms using an aqueous developer containing an amphiphilic molecule, thus completing the present invention.

[0013] In other words, the present invention is as follows: [1] A method for forming a resist pattern, comprising: a forming step of forming a resist layer containing a polymer having iodine atoms on a substrate; an exposure step of exposing the resist layer formed in the forming step to light; and a developing step of developing the resist layer exposed in the exposure step using an aqueous developer containing an amphiphilic molecule. [2] The method for forming a resist pattern according to [1], wherein the amphiphilic molecule contains a surfactant. [3] The method for forming a resist pattern according to [2], wherein the amphiphilic molecule contains an ionic surfactant. [4] The method for forming a resist pattern according to [2], wherein the amphiphilic molecule contains a nonionic surfactant having an HLB value of 27 or less. [5] The method for forming a resist pattern according to [4], wherein the amphiphilic molecule contains a nonionic surfactant having an HLB value of 6 or more and 27 or less. [6] The method for forming a resist pattern according to [2], wherein the amphiphilic molecule comprises a surfactant having a LogS value of -2.5 or less calculated according to ChemDraw® Professional 23.0.1.10. [7] The method for forming a resist pattern according to [6], wherein the amphiphilic molecule comprises an ionic surfactant having a LogS value of -2.5 or less calculated according to ChemDraw® Professional 23.0.1.10. [8] The method for forming a resist pattern according to [7], wherein the amphiphilic molecule comprises an amphoteric surfactant having a LogS value of -2.5 or less calculated according to ChemDraw® Professional 23.0.1.10. [9] The method for forming a resist pattern according to any one of [1] to [8], wherein the amphiphilic molecule has a carbon chain with 6 or more carbon atoms.

[10] The method for forming a resist pattern according to any one of [1] to [9] above, wherein the amphiphilic molecule has a carbon chain with 10 or more carbon atoms.

[11] The method for forming a resist pattern according to any one of [1] to

[10] above, wherein the content of the amphiphilic molecule is 0.001% to 1% by mass with respect to 100% by mass of the aqueous developer.

[12] The method for forming a resist pattern according to any one of [1] to

[11] above, wherein the aqueous developer further contains an organic base.

[13] The organic base is of formula (II):

[0014]

[0015] A method for forming a resist pattern according to

[12] above, comprising a compound represented by [wherein R independently represents an alkyl group which may have substituents].

[14] A method for forming a resist pattern according to [1] above, wherein the polymer (the polymer having the iodine atom) has repeating units derived from at least one compound selected from styrene compounds having an iodine atom, (meth)acrylic acid ester compounds having an iodine atom, and polymerizable compounds having an iodine atom and an adamantane skeleton.

[15] A method for forming a resist pattern according to [1] above, wherein the polymer (the polymer having the iodine atom) is represented by formula (I):

[0016]

[0017] [In the formula, ring A represents an aromatic ring, a non-aromatic ring, or a fused ring thereof; L is a single bond or a divalent linking group, R １ R represents a hydrogen atom, a methyl group, or a halogen atom; ２A method for forming a resist pattern according to [1] above, wherein each independently represents a substituent; a represents an integer of 1 or more; and b represents 0 or an integer of 1 or more.

[16] A method for forming a resist pattern according to

[14] or

[15] above, wherein the polymer (the polymer having iodine atoms) further has repeating units derived from at least one compound selected from a polymerizable compound having an acid-dissociable group, a compound having a hydroxystyrene skeleton, and a (meth)acrylic acid ester compound having a lactone skeleton.

[17] A method for manufacturing an electronic device, comprising a forming step of forming a resist layer containing a polymer having iodine atoms on a substrate; an exposure step of exposing the resist layer formed in the forming step; and a developing step of developing the resist layer exposed in the exposure step using an aqueous developer containing an amphiphilic molecule.

[18] An aqueous developer containing an amphiphilic molecule for developing a resist layer containing a polymer having iodine atoms after exposure.

[19] A resist composition comprising a polymer having an iodine atom, for forming a resist layer to be developed with an aqueous developer containing an amphiphilic molecule after exposure.

[20] A kit comprising an aqueous developer containing an amphiphilic molecule and a resist composition comprising a polymer having an iodine atom.

[0018] According to the present invention, in the formation of a resist pattern, the sensitivity of the resist layer can be further improved, and the resolution and roughness can be further improved.

[0019] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be modified and implemented as appropriate without departing from the scope of the claims and equivalents of the present invention.

[0020] This embodiment provides a method for forming a resist pattern. The resist pattern formation method of this embodiment includes a forming step of forming a resist layer containing a polymer having iodine atoms on a substrate, an exposure step of exposing the resist layer formed in the forming step to light, and a developing step of developing the resist layer exposed in the exposure step using an aqueous developer containing amphiphilic molecules.

[0021] Such a resist pattern formation method is suitable for manufacturing semiconductor elements and liquid crystal display elements having finer wiring patterns, and is useful for manufacturing electronic devices equipped with semiconductor devices having such wiring patterns. This embodiment provides a method for manufacturing an electronic device equipped with a resist pattern. The method for manufacturing an electronic device according to this embodiment includes a formation step of forming a resist layer containing a polymer having iodine atoms on a substrate, an exposure step of exposing the resist layer formed in the formation step to light, and a development step of developing the resist layer exposed in the exposure step using an aqueous developer containing amphiphilic molecules.

[0022] Such electronic devices can be installed in electronic equipment such as personal computers, smartphones, smartwatches, digital cameras, televisions, car navigation systems, printers, LCD displays, electronic dictionaries, game consoles, automobiles, ships, trains, and aircraft.

[0023] [1. Formation process for forming the resist layer] In the formation process, the resist layer is formed by applying a resist composition containing, for example, a polymer having iodine atoms onto a substrate using a coating device such as a spin coater, dip coater, or roller coater. Before applying the resist composition onto the substrate, the substrate may be cleaned, and an anti-reflective film or the like may be formed on the substrate.

[0024] After applying the resist composition to the substrate, a resist layer is formed by heating the resist composition. The heating temperature is, for example, 50 to 200°C, and the heating time is, for example, 10 to 180 seconds. The thickness of the formed resist layer is, for example, 20 nm to 1 μm.

[0025] [1-1. Substrate] The substrate is not particularly limited and conventionally known substrates can be used, for example, substrates for electronic components, and substrates on which a predetermined wiring pattern has been formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, plastic substrates, glass substrates, and ceramic substrates. For the wiring pattern material, for example, copper, aluminum, nickel, and gold can be used.

[0026] [1-2. Organic solvents for resist compositions] It is preferable that the resist composition contains an organic solvent together with a polymer having iodine atoms. Examples of organic solvents used in the resist composition include glycol ether solvents, glycol ether ester solvents, aliphatic ether solvents, amide solvents, sulfoxide solvents, nitrile solvents, aliphatic ester solvents, halogen solvents, aliphatic ketone solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, and the like.

[0027] In this specification, glycol ether solvents include, for example, cellosolves such as ethylene glycol monomethyl ether (also known as methyl cellosolve), ethylene glycol monoethyl ether (also known as cellosolve), ethylene glycol monopropyl ether (also known as propyl cellosolve), ethylene glycol monobutyl ether (also known as butyl cellosolve), ethylene glycol monoisobutyl ether (also known as isobutyl cellosolve), ethylene glycol mono-tert-butyl ether (also known as tert-butyl cellosolve), and ethylene glycol monohexyl ether; diethylene glycol monomethyl ether (also known as methyl carbitol), diethylene glycol monoethyl ether Examples include carbitols such as carbitol (also known as propyl carbitol), diethylene glycol monopropyl ether (also known as propyl carbitol), and diethylene glycol monobutyl ether (DB) (also known as butyl carbitol); propylene glycol ethers such as propylene glycol monomethyl ether (PGM), propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether; and dipropylene glycol ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, and dipropylene glycol monobutyl ether.

[0028] In this specification, examples of glycol ether ester solvents include cellosolve esters such as ethylene glycol monomethyl ether acetate (also known as methyl cellosolve acetate), ethylene glycol monoethyl ether acetate (also known as cellosolve acetate), and ethylene glycol monobutyl ether acetate (also known as butyl cellosolve acetate); carbitol esters such as diethylene glycol monoethyl ether acetate (also known as carbitol acetate) and diethylene glycol monobutyl ether acetate (also known as butyl carbitol acetate); propylene glycol ether esters such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monoethyl ether acetate; and dipropylene glycol ether esters such as dipropylene glycol monomethyl ether acetate.

[0029] Examples of aliphatic ether solvents used herein include tetrahydrofuran, 1,2-dimethoxyethane, diethyl ether, diisopropyl ether, methyl tert-butyl ether, and cyclopentyl methyl ether.

[0030] Examples of amide solvents used herein include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0031] Examples of sulfoxide solvents used herein include dimethyl sulfoxide.

[0032] Examples of nitrile solvents used herein include acetonitrile and propionitrile.

[0033] Examples of aliphatic ester solvents in this specification include fatty acid alkyl esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, ethyl propionate, and isopropyl propionate; alkyl hydroxy acid esters such as methyl lactate, ethyl lactate, and butyl lactate; alkyl keto acid esters such as methyl acetoacetate and ethyl acetoacetate; and lactones such as γ-butyrolactone.

[0034] Examples of halogenated solvents used herein include dichloromethane and chloroform.

[0035] Examples of aliphatic ketone solvents used herein include acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, diisopropyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and isophorone.

[0036] Examples of aliphatic hydrocarbon solvents used herein include n-pentane, n-hexane, isohexane, n-heptane, n-octane, cyclopentane, cyclohexane, and methylcyclohexane.

[0037] Examples of aromatic hydrocarbon solvents used herein include benzene, toluene, o-xylene, m-xylene, p-xylene, and ethylbenzene.

[0038] [1-3. Additives for the resist composition] The resist composition may contain any additives along with the polymer having iodine atoms.

[0039] Examples of additives used in resist compositions include acid generators, acid diffusion controllers, acid crosslinking agents, dissolution accelerators, dissolution controllers, sensitizers, and surfactants. These can be used individually or in combination of two or more.

[0040] The acid generator used in the resist composition may be either nonionic or ionic. Examples of nonionic acid generators include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate) and sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane). Examples of ionic acid generators include onium salts containing onium cations (e.g., diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of onium salt anions include sulfonic acid anions, sulfonylimide anions, and sulfonylmethide anions.

[0041] Specific examples of acid generators used in resist compositions are not limited to triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, diphenyltolylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, di-2,4,6-trimethylphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t-butoxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-t-butoxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate, bis(4-fluorophenyl)-4-hydroxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium nonafluoro-n-butanesulfonate, bis(4-hydroxyphenyl)-phenylsulfonium trifluoromethanesulfonate Sodium, tri(4-methoxyphenyl)sulfonium trifluoromethanesulfonate, tri(4-fluorophenyl)sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium benzenesulfonate, diphenyl-2,4,6-trimethylphenyl-p-toluenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-2-trifluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-4-trifluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-2,4-difluorobenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium hexafluorobenzenesulfonate, diphenylnaphthylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium-p-toluenesulfonate, triphenylsulfonium 10-camphorsulfonate, diphenyl-4-hydroxyphenylsulfonium 10-camphorsulfonate and cyclo(1,Examples include 3-perfluoropropanedisulfone (imidate). The acid generator can be used alone or in combination of two or more. The amount of acid generator added to the resist composition is preferably 0.001 to 49% by mass, more preferably 1 to 40% by mass, even more preferably 3 to 30% by mass, and even more preferably 10 to 25% by mass, relative to the total mass of the solid components of the resist composition. In this specification, "solid components of the resist composition" refers to components other than the solvent contained in the resist composition.

[0042] Specific examples of acid diffusion control agents used in resist compositions are not limited to triphenylsulfonium hydroxide, triphenylsulfonium acetate, triphenylsulfonium salicylate, diphenyl-4-hydroxyphenylsulfonium hydroxide, diphenyl-4-hydroxyphenylsulfonium acetate, diphenyl-4-hydroxyphenylsulfonium salicylate, bis(4-t-butylphenyl)iodonium hydroxide, bis(4-t-butylphenyl)iodonium acetate, bis(4-t-butylphenyl)iodonium hydroxide, bis(4-t-butylphenyl)iodonium acetate, bis(4-t-butylphenyl)iodonium salicylate, 4-t-butylphenyl-4-hydroxyphenyliodonium hydroxide, 4-t-butylphenyl-4-hydroxyphenyliodonium acetate, and 4-t-butylphenyl-4-hydroxyphenyliodonium salicylate. The acid diffusion control agent can be used alone or in combination of two or more types. The amount of acid diffusion control agent added to the resist composition is preferably 0.001 to 49% by mass, more preferably 0.01 to 10% by mass, even more preferably 0.01 to 5% by mass, and particularly preferably 0.01 to 3% by mass, based on the total mass of the solid components of the resist composition.

[0043] Examples of acid crosslinking agents used in resist compositions include methylol group-containing compounds such as methylol group-containing melamine compounds, methylol group-containing benzoguanamine compounds, methylol group-containing urea compounds, methylol group-containing glycoluryl compounds, and methylol group-containing phenol compounds; alkoxyalkyl group-containing compounds such as alkoxyalkyl group-containing melamine compounds, alkoxyalkyl group-containing benzoguanamine compounds, alkoxyalkyl group-containing urea compounds, alkoxyalkyl group-containing glycoluryl compounds, and alkoxyalkyl group-containing phenol compounds; carboxymethyl group-containing compounds such as carboxymethyl group-containing melamine compounds, carboxymethyl group-containing benzoguanamine compounds, carboxymethyl group-containing urea compounds, carboxymethyl group-containing glycoluryl compounds, and carboxymethyl group-containing phenol compounds; and epoxy compounds such as bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, novolac resin-based epoxy compounds, resol resin-based epoxy compounds, and poly(hydroxystyrene)-based epoxy compounds. Acid crosslinking agents can be used individually or in combination of two or more types. The amount of acid crosslinking agent added to the resist composition is preferably 0 to 49% by mass, more preferably 0 to 40% by mass, even more preferably 0 to 30% by mass, and particularly preferably 0 to 20% by mass, based on the total mass of the solid components of the resist composition.

[0044] Examples of dissolution accelerators used in resist compositions include low molecular weight phenolic compounds, such as bisphenols and tris(hydroxyphenyl)methane. Dissolution accelerators can be used individually or in combination of two or more. The amount of dissolution accelerator added to the resist composition is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, and even more preferably 0 to 1% by mass, based on the total mass of the solid components of the resist composition.

[0045] Examples of dissolution control agents used in resist compositions include aromatic hydrocarbons such as phenanthrene, anthracene, and acenaphthene; aromatic ketones such as acetophenone, benzophenone, and phenylnaphthyl ketone; and aromatic sulfones such as methylphenyl sulfone, diphenyl sulfone, and dinaphthyl sulfone. Dissolution control agents can be used individually or in combination of two or more. The amount of dissolution control agent added to the resist composition is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, and even more preferably 0 to 1% by mass, relative to the total mass of the solid components of the resist composition.

[0046] Examples of sensitizers used in the resist composition include benzophenones, biacetyls, pyrenes, phenothiazines, fluorenes, etc., but are not particularly limited. One sensitizer or two or more sensitizers can be used. The amount of sensitizer added to the resist composition is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, and even more preferably 0 to 1% by mass, based on the total mass of the solid components of the resist composition.

[0047] The surfactant used in the resist composition may be anionic, cationic, nonionic, or amphoteric, but nonionic surfactants are preferred. Examples of nonionic surfactants include polyoxyethylene higher alkyl ethers, polyoxyethylene higher alkylphenyl ethers, and higher fatty acid diesters of polyethylene glycol. One surfactant or two or more surfactants can be used. The amount of surfactant added to the resist composition is preferably 0 to 49% by mass, more preferably 0 to 5% by mass, and even more preferably 0 to 1% by mass, based on the total mass of the solid components of the resist composition.

[0048] The resist composition may further contain known components commonly used in resist compositions, such as dyes, pigments, adhesion aids, anti-halation agents, preservatives, defoamers, and shape modifiers.

[0049] [1-4. Polymers containing iodine atoms] The polymers containing iodine atoms included in the resist composition will be described in detail below. As polymers containing iodine atoms, a wide range of iodine-containing polymers commonly used in resist materials can be used. A polymer containing iodine atoms may be, for example, a polymer obtained by polymerizing a monomer containing at least one monomer having at least one iodine atom and at least one terminal unsaturated bond (e.g., a terminal carbon double bond). The monomer may further contain at least one monomer that does not contain an iodine atom and has at least one terminal unsaturated bond.

[0050] A polymer having an iodine atom is, in one embodiment, of formula (I):

[0051]

[0052] [In the formula, ring A represents an aromatic ring, a non-aromatic ring, or a fused ring thereof; L is a single bond or a divalent linking group; R １ R represents a hydrogen atom, a methyl group, or a halogen atom; ２ Each of the following independently represents a substituent; a represents an integer of 1 or more; and b represents 0 or an integer of 1 or more. It is preferable to have a repeating unit represented by ].

[0053] R １ This represents a hydrogen atom, a methyl group, or a halogen atom. The halogen atom can be a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a chlorine atom is preferred.

[0054] In this specification, an aromatic ring means a ring that obeys Hückel's rule, in which the number of electrons in the π-electron system on the ring is 4p + 2 (where p is a natural number). The aromatic ring may be an aromatic carbocyclic ring having only carbon atoms as ring constituent atoms, or an aromatic heterocyclic ring having 1 to 4 heteroatoms such as oxygen, nitrogen, and sulfur atoms in addition to carbon atoms as ring constituent atoms, but in one embodiment, it is preferably an aromatic carbocyclic ring. The aromatic ring may be a monocyclic aromatic ring or a polycyclic fused aromatic ring formed by the fusion of two or more monocyclic aromatic rings. The aromatic ring is preferably an aromatic ring with 5 to 18 members, more preferably an aromatic ring with 5 to 14 members, and even more preferably an aromatic carbocyclic ring with 6 to 14 members. Examples of aromatic rings include, but are not limited to, the rings represented by the following formulas (A1) to (A11).

[0055]

[0056] In this specification, a non-aromatic ring means a ring other than an aromatic ring that has aromaticity throughout the entire ring. A non-aromatic ring may be a non-aromatic carbocyclic ring having only carbon atoms as ring constituent atoms, or a non-aromatic heterocyclic ring having 1 to 4 heteroatoms such as oxygen, nitrogen, or sulfur atoms in addition to carbon atoms as ring constituent atoms. A non-aromatic ring may be a monocyclic or polycyclic non-aromatic ring. A non-aromatic ring may be a saturated ring consisting only of single bonds, or an unsaturated ring having double bonds in addition to single bonds. A non-aromatic ring may be substituted with 1 to 3 oxo groups (=O). A non-aromatic ring is preferably 3 to 21 membered, more preferably 4 to 18 membered, and even more preferably 5 to 14 membered. Examples of non-aromatic rings include, but are not limited to, the rings represented by the following formulas (B1) to (B77).

[0057]

[0058] Examples of fused rings of aromatic and non-aromatic rings include, but are not limited to, the rings represented by the following formulas (C1) to (C29).

[0059]

[0060] In this specification, the divalent linking group is not particularly limited. In one embodiment, for example, it is a divalent group composed of one or more (e.g., 1 to 100, preferably 1 to 50, particularly preferably 1 to 20) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms, and silicon atoms. When non-skeletal atoms are present, they are composed of atoms selected from hydrogen atoms and halogen atoms, and may include a linear structure, a branched structure, and / or a cyclic structure, and may be a group that does not contain an aromatic ring or a group that contains an aromatic ring. Examples of the divalent linking group include, but are not limited to, groups represented by formulas (L1) to (L44).

[0061]

[0062]

[0063] [In the formula, R Ｌ each independently represents a substituent; s represents 0, 1, 2, 3, or ].

[0064] In this specification, the substituent is, for example, a monovalent group composed of one or more (e.g., 1 to 100, preferably 1 to 50, particularly preferably 1 to 20) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, sulfur atoms, and silicon atoms or a monovalent group consisting only of a halogen atom. When non-skeletal atoms are present, they are composed of atoms selected from hydrogen atoms and halogen atoms, and may include a linear structure, a branched structure, and / or a cyclic structure, and may be a group that does not contain an aromatic ring or a group that contains an aromatic ring. When there is no particular specification, the number of substituents for the substitution target is, for example, 1 to 10. Examples of the substituent are not particularly limited, but for example, halogen atom, -NO ２ , -CN, -CHO, -OH, -SH, -NH ２ , -COOH, -R Ｘ , -COR Ｘ , -OR Ｘ , -SR Ｘ , -SOR Ｘ , -SO ２ R Ｘ , -NHR Ｘ , -N(R Ｘ ), ２ , -COORＸ , -OCOR Ｘ , -OCOOR Ｘ , -CONH ２ , -CONHR Ｘ , -CON(R Ｘ ) ２ ,-NHCOR Ｘ Examples of monovalent groups include (where R Ｘ (The details are as follows.)

[0065] R Ｘ Each of these is independently an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group, more specifically, (1) an optionally substituted alkyl group selected from the following groups (a) to (x); (2) an optionally substituted alkenyl group selected from the following groups (a) to (x); or (3) an optionally substituted aryl group selected from the following groups (a) to (aa), but is not limited to these.

[0066] (a) halogen atom, (b) nitro group (-NO ２(c) cyano group (-CN), (d) hydroxyl group (-OH), (e) aryl group which may be substituted with a halogen atom, (f) alkyl-substituted aryl group which may be substituted with a halogen atom, (g) alkoxy group which may be substituted with a halogen atom, (h) alkenyloxy group which may be substituted with a halogen atom, (i) aryloxy group which may be substituted with a halogen atom, (j) aralkyloxy group which may be substituted with a halogen atom, (k) alkylcarbonyl group which may be substituted with a halogen atom, (l) alkenylcarbonyl group which may be substituted with a halogen atom, (m) arylcarbonyl group which may be substituted with a halogen atom, (n) aralkylcarbonyl group which may be substituted with a halogen atom, (o) alkylcarbonyloxy group which may be substituted with a halogen atom, (p) halogen atom (q) A arylcarbonyloxy group which may be substituted with a halogen atom, (r) Aalkylcarbonyloxy group which may be substituted with a halogen atom, (s) An alkoxycarbonyl group which may be substituted with a halogen atom, (t) An alkenyloxycarbonyl group which may be substituted with a halogen atom, (u) An aryloxycarbonyl group which may be substituted with a halogen atom, (v) An aralkyloxycarbonyl group which may be substituted with a halogen atom, (w) An alkylcarbonylamino group which may be substituted with a halogen atom, (x) An alkylcarbamoyl group which may be substituted with a halogen atom, (y) An alkyl group which may be substituted with a halogen atom, (z) An alkenyl group which may be substituted with a halogen atom, (aa) An aralkyl group which may be substituted with a halogen atom.

[0067] In this specification, halogen atoms mean fluorine atoms, chlorine atoms, bromine atoms, or iodine atoms.

[0068] In this specification, alkyl groups mean linear, branched, and / or cyclic monovalent aliphatic saturated hydrocarbon groups. Unless otherwise specified, the number of carbon atoms in an alkyl group is preferably 1 to 18, more preferably 1 to 10, and even more preferably 1 to 6. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, sec-pentyl, neopentyl, tert-pentyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl, tert-octyl, cyclopentyl, cyclopentylmethyl, and 2-cyclopentylethyl. Examples include the group, cyclohexyl group, cyclohexylmethyl group, 2-cyclohexylethyl group, adamantan-1-yl group, adamantan-1-ylmethyl group, 2-(adamantan-1-yl)ethyl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-isopropyladamantan-2-yl group, norbornan-2-yl group, norbornan-2-ylmethyl group, and 2-(norbornan-2-yl)ethyl group.

[0069] In this specification, an alkenyl group means a linear, branched, and / or cyclic monovalent aliphatic unsaturated hydrocarbon group having at least one carbon-carbon double bond. Unless otherwise specified, the number of carbon atoms in the alkenyl group is preferably 2 to 18, more preferably 2 to 10, and even more preferably 2 to 6. Examples of alkenyl groups include vinyl groups, propenyl groups (allyl group, 1-propenyl group, isopropenyl group), butenyl groups (1-butenyl group, clotyl group, methallyl group, isoclotyl group, etc.), pentenyl groups (1-pentenyl group, etc.), hexenyl groups (1-hexenyl group, etc.), heptenyl groups (1-heptenyl group, etc.), octenyl groups (1-octenyl group, etc.), cyclopentenyl groups (2-cyclopentenyl group, etc.), cyclohexenyl groups (3-cyclohexenyl group, etc.), and the like.

[0070] In this specification, an aryl group means a monovalent aromatic hydrocarbon group consisting of an aromatic carbocyclic ring with one hydrogen atom removed. Unless otherwise specified, the number of carbon atoms in the aryl group is preferably 6 to 18, and particularly preferably 6 to 10. Examples of aryl groups include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, and the like.

[0071] In this specification, an aralkyl group means an alkyl group substituted with one or more (preferably one) aryl groups. Unless otherwise specified, the number of carbon atoms in the aralkyl group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of aralkyl groups include benzyl group, phenethyl group, hydrocinnamyl group, α-methylbenzyl group, α-cumyl group, 1-naphthylmethyl group, and 2-naphthylmethyl group.

[0072] In this specification, an alkyl-substituted aryl group means an aryl group substituted with one or more alkyl groups. Unless otherwise specified, the number of carbon atoms in the alkyl-substituted aryl group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of alkyl-substituted aryl groups include 4-methylphenyl, 3-methylphenyl, 2-methylphenyl, 2,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4,6-trimethylphenyl, 4-ethylphenyl, 3-ethylphenyl, and 2-ethylphenyl.

[0073] In this specification, an alkoxy group means a monovalent group in which an alkyl group is bonded to an oxygen atom (i.e., -O-R Ｙ１ (R here) Ｙ１ The group is represented by an alkyl group. Unless otherwise specified, the number of carbon atoms in the alkoxy group is preferably 1 to 18, more preferably 1 to 10, and even more preferably 1 to 6. Examples of alkoxy groups include methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, isobutyloxy, sec-butyloxy, and tert-butyloxy groups.

[0074] In this specification, an alkenyloxy group means a monovalent group (i.e., -O-R) in which an alkenyl group is bonded to an oxygen atom. Ｙ２ (R here) Ｙ２The term "alkenyloxy group" refers to a group represented by an alkenyl group. Unless otherwise specified, the number of carbon atoms in the alkenyloxy group is preferably 2 to 18, more preferably 2 to 10, and even more preferably 2 to 6. Examples of alkenyloxy groups include vinyloxy groups and propenyloxy groups (allyloxy group, 1-propenyloxy group, isopropenyloxy group).

[0075] In this specification, an aryloxy group means a monovalent group formed by the bonding of an aryl group to an oxygen atom (i.e., -O-R Ｙ３ (R here) Ｙ３ The group represented by aryloxy is a group. Unless otherwise specified, the number of carbon atoms in the aryloxy group is preferably 6 to 18, and particularly preferably 6 to 10. Examples of aryloxy groups include phenoxy, 1-naphthoxy, and 2-naphthoxy groups.

[0076] In this specification, an aralkyloxy group means a monovalent group (i.e., -O-R) formed by the bonding of an aralkyl group to an oxygen atom. Ｙ４ (R here) Ｙ４ The group represented by aralkyloxy is a group. Unless otherwise specified, the number of carbon atoms in the aralkyloxy group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of aralkyloxy groups include the benzyloxy group and the α-methylbenzyloxy group.

[0077] In this specification, an alkylcarbonyl group means a monovalent group in which an alkyl group is bonded to one carbonyl group (i.e., -C(=O)-R Ｙ１ (R here) Ｙ１ The group is represented by an alkyl group. Unless otherwise specified, the number of carbon atoms in the alkylcarbonyl group is preferably 2 to 19, more preferably 2 to 11, and even more preferably 2 to 7. Examples of alkylcarbonyl groups include acetyl, propanoyl, butanoyl, pivaloyl, and valeryl groups.

[0078] In this specification, an alkenylcarbonyl group means a monovalent group (i.e., -C(=O)-R) in which an alkenyl group is bonded to one carbonyl group. Ｙ２ (R here) Ｙ２The group is represented by an alkenyl group. Unless otherwise specified, the number of carbon atoms in the alkenylcarbonyl group is preferably 3 to 19, more preferably 3 to 11, and even more preferably 3 to 7. Examples of alkenylcarbonyl groups include acryloyl group, propenylcarbonyl group (allylcarbonyl group, 1-propenylcarbonyl group, metacloyl group), etc.

[0079] In this specification, an arylcarbonyl group means a monovalent group in which an aryl group is bonded to one carbonyl group (i.e., -C(=O)-R Ｙ３ (R here) Ｙ３ The group represented by aryl carbonyl is a group. Unless otherwise specified, the number of carbon atoms in the arylcarbonyl group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of arylcarbonyl groups include benzoyl, 1-naphthoyl, and 2-naphthoyl groups.

[0080] In this specification, an aralkylcarbonyl group means a monovalent group (i.e., -C(=O)-R) formed by the bonding of an aralkyl group to one carbonyl group. Ｙ４ (R here) Ｙ４ The group represented by aralkyl carbonyl is a group. Unless otherwise specified, the number of carbon atoms in the aralkyl carbonyl group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of aralkyl carbonyl groups include the benzyl carbonyl group and the α-methylbenzyl carbonyl group.

[0081] In this specification, an alkylcarbonyloxy group means a monovalent group formed by the bonding of an alkylcarbonyl group to an oxygen atom (i.e., -O-C(=O)-R Ｙ１ (R here) Ｙ１ The group is represented by an alkyl group. Unless otherwise specified, the number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 19, more preferably 2 to 11, and even more preferably 2 to 7. Examples of alkylcarbonyloxy groups include acetoxy, propanoyloxy, butanoyloxy, pivaloyloxy, and valeryloxy groups.

[0082] In this specification, an alkenylcarbonyloxy group means a monovalent group formed by the bonding of an alkenylcarbonyl group to an oxygen atom (i.e., -O-C(=O)-R Ｙ２ (R here) Ｙ２ The group is represented by an alkenyl group. Unless otherwise specified, the number of carbon atoms in the alkenylcarbonyloxy group is preferably 3 to 19, more preferably 3 to 11, and even more preferably 3 to 7. Examples of alkenylcarbonyloxy groups include acryloyloxy group, propenylcarbonyloxy group (allylcarbonyloxy group, 1-propenylcarbonyloxy group, metacloyloxy group), etc.

[0083] In this specification, an arylcarbonyloxy group means a monovalent group formed by the bonding of an arylcarbonyl group to an oxygen atom (i.e., -O-C(=O)-R Ｙ３ (R here) Ｙ３ The group represented by aryl carbonyloxy is a group. Unless otherwise specified, the number of carbon atoms in the arylcarbonyloxy group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of arylcarbonyloxy groups include benzoyloxy, 1-naphthoyloxy, and 2-naphthoyloxy groups.

[0084] In this specification, an aralkylcarbonyloxy group means a monovalent group formed by the bonding of an aralkylcarbonyl group to an oxygen atom (i.e., -O-C(=O)-R Ｙ４ (R here) Ｙ４ The group represented by aralkyl carbonyl is a group that is preferably 7 to 19 carbon atoms, and most preferably 7 to 11 carbon atoms, unless otherwise specified. Examples of aralkyl carbonyloxy groups include benzyl carbonyloxy group and α-methylbenzylcarbonyloxy group.

[0085] In this specification, an alkoxycarbonyl group means a monovalent group in which an alkoxy group is bonded to one carbonyl group (i.e., -C(=O)-O-R Ｙ１ (R here) Ｙ１The group is represented by an alkyl group. Unless otherwise specified, the number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 19, more preferably 2 to 11, and even more preferably 2 to 7. Examples of alkoxycarbonyl groups include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, and so on.

[0086] In this specification, an alkenyloxycarbonyl group means a monovalent group in which an alkenyloxy group is bonded to one carbonyl group (i.e., -C(=O)-O-R Ｙ２ (R here) Ｙ２ The group is represented by an alkenyl group. Unless otherwise specified, the number of carbon atoms in the alkenyloxycarbonyl group is preferably 3 to 19, more preferably 3 to 11, and even more preferably 3 to 7. Examples of alkenyloxycarbonyl groups include vinyloxycarbonyl group, propenyloxycarbonyl group (allyloxycarbonyl group, 1-propenyloxycarbonyl group, isopropenyloxycarbonyl group), etc.

[0087] In this specification, an aryloxycarbonyl group means a monovalent group in which an aryloxy group is bonded to one carbonyl group (i.e., -C(=O)-O-R Ｙ３ (R here) Ｙ３ The group is represented by an aryl group. Unless otherwise specified, the number of carbon atoms in the aryloxycarbonyl group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of aryloxycarbonyl groups include phenoxycarbonyl group, 1-naphthoxycarbonyl group, and 2-naphthoxycarbonyl group.

[0088] In this specification, an aralkyloxycarbonyl group means a monovalent group (i.e., -C(=O)-O-R) formed by the bonding of an aralkyloxy group to one carbonyl group. Ｙ４ (R here) Ｙ４ The group represented by aralkyl carbonyl is a group that is aralkyl carbonyl. Unless otherwise specified, the number of carbon atoms in the aralkyl carbonyl group is preferably 7 to 19, and particularly preferably 7 to 11. Examples of aralkyl oxycarbonyl groups include the benzyl oxycarbonyl group and the α-methylbenzyl oxycarbonyl group.

[0089] In this specification, an alkylcarbonylamino group means an amino group monosubstituted with an alkylcarbonyl group (i.e., -NH-C(=O)-R Ｙ１ (R here) Ｙ１ The group is represented by an alkyl group. Unless otherwise specified, the number of carbon atoms in the alkylcarbonylamino group is preferably 2 to 19, more preferably 2 to 11, and even more preferably 2 to 7. Examples of alkylcarbonylamino groups include N-acetylamino group, N-propanoylamino group, and N-butanoylamino group.

[0090] In this specification, an alkylcarbamoyl group means a carbamoyl group mono- or disubstituted with an alkyl group (i.e., -C(=O)-NHR Ｙ１ or -C(=O)-N(R Ｙ１ ) ２ (This R Ｙ１ Each of these independently represents an alkyl group. Unless otherwise specified, the number of carbon atoms in the alkylcarbamoyl group is preferably 2 to 19, more preferably 2 to 11, and even more preferably 2 to 7. Examples of alkylcarbamoyl groups include N-methylcarbamoyl group, N-ethylcarbamoyl group, and N-propylcarbamoyl group.

[0091] In the embodiment, the total content of repeating units represented by formula (I) in the polymer having iodine atoms is not particularly limited, but when the total repeating units in the polymer are considered to be 100 mol%, in one embodiment it is preferably 5 mol% or more, more preferably 8 mol% or more, even more preferably 10 mol% or more, with an upper limit of 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 30 mol% or less.

[0092] a represents an integer of 1 or more; in one embodiment, it is preferably 1, 2, 3, or 4; more preferably 1, 2, or 3.

[0093] b represents 0 or an integer greater than or equal to 1; in one embodiment, it is preferably 0, 1, 2, or 3; more preferably 0, 1, or 2.

[0094] Note that the sum of a and b does not exceed the number of permutable positions in the ring.

[0095] In another embodiment, the polymer having an iodine atom has repeating units derived from at least one compound selected from styrene-based compounds having an iodine atom, (meth)acrylic acid ester compounds having an iodine atom, and polymerizable compounds having an iodine atom and an adamantane skeleton.

[0096] The repeating units derived from styrene-based compounds containing iodine atoms are not particularly limited, but for example, formula (Ia):

[0097]

[0098] Examples of repeating units represented by [In the formulas, the symbols are the same as above.] include formulas (Ia-1) to (Ia-40):

[0099]

[0100] Examples include repeating units represented by the symbols shown.

[0101] The repeating units derived from (meth)acrylic acid ester compounds containing an iodine atom are not particularly limited, but for example, formulas (Iba) to (Ibe):

[0102]

[0103] [In the formula, X independently represents a bond or an alkylene group; Y represents -O-, -S-, -NH-, -NR Ｎ -, -N(COR) Ｎ )-, -CO-, -O-CO-, -CO-O-, -S-CO-, -CO-S-, -NH-CO-, -CO-NH-, -NR Ｎ -CO-, -CO-NR Ｎ -, -N(COR) Ｎ )-CO-, or -CO-N(COR Ｎ ) - indicates; R Ｎ R indicates an alkyl group;３ each independently represents a substituent; c represents 0 or an integer of 1 or more; and the other symbols are as defined above. Examples of the repeating unit represented by any of ]] are repeating units represented by formulas (Ib-1) to (Ib-42):

[0104]

[0105]

[0106] and the like.

[0107] In the present specification, the alkylene group means a linear, branched and / or cyclic divalent aliphatic saturated hydrocarbon group. The number of carbon atoms of the alkylene group is preferably 1 to 18, more preferably 1 to 10, and still more preferably 1 to 6, unless otherwise specified. Examples of the alkylene group include, for example, —CH ２ —, —C(CH ３ )H—, —C(CH ３ ) ２ —, —C(C ２ H ５ )H—, —C(C ２ H ５ )(CH ３ )—, —C(C ２ H ５ )<000008​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​In this specification, a polymerizable compound means a compound that can be polymerized by cationic polymerization, anionic polymerization, radical polymerization, etc., and preferably a radical polymerizable compound (for example, a compound having a radically polymerizable unsaturated double bond).

[0109] The repeating units derived from polymerizable compounds having an iodine atom and an adamantane skeleton are not particularly limited, but for example, formula (Ica) to (Icc):

[0110]

[0111] [In the formulas, each symbol is as described above.] Examples of repeating units represented by any of the following are given, and specific examples include formulas (Ic-1) to (Ic-56):

[0112]

[0113]

[0114]

[0115] Examples include repeating units represented by the symbols shown.

[0116] In the embodiment, the total content of repeating units derived from iodine atoms-containing styrene compounds, iodine atoms-containing (meth)acrylic acid ester compounds, and polymerizable compounds having iodine atoms and an adamantane skeleton in the polymer having iodine atoms is not particularly limited, but when the total repeating units in the polymer are set to 100 mol%, in one embodiment it is preferably 5 mol% or more, more preferably 8 mol% or more, even more preferably 10 mol% or more, with an upper limit of 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 30 mol% or less.

[0117] The polymer having an iodine atom may further have, and preferably has, repeating units derived from at least one compound selected from polymerizable compounds having an acid-dissociable group, compounds having a hydroxystyrene skeleton, and (meth)acrylic acid ester compounds having a lactone skeleton.

[0118] The repeating units derived from polymerizable compounds having acid-dissociable groups are not particularly limited, but for example, formulas (Xaa) to (Xae):

[0119]

[0120]

[0121] [In the formula, R ４ Each of these independently represents a substituent (excluding the iodine atom); R ５ Each of these independently exhibits an acid-dissociable group relative to the hydroxyl group; R ６ represents an alkyl group which may have substituents (excluding iodine atoms); d represents 0 or an integer of 1 or more; e represents 0 or an integer of 1 or more; m represents 0, 1, 2, 3, 4, 5, or 6; other symbols are as described above. Examples of repeating units represented by any of the above are:

[0122] In this specification, an acid-dissociable group means a group that forms an inert group (i.e., a neutral and unreactive group) by bonding to an oxygen atom derived from a hydroxyl group or an oxygen atom derived from a carboxyl group, and which generates a hydroxyl group or a carboxyl group by treatment with an acid (for example, organic acids such as methanesulfonic acid, ethanesulfonic acid, 10-camphorsulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoroacetic acid, or inorganic acids such as hydrochloric acid). An acid-dissociable group may be, for example, a group commonly known in the field of organic chemistry as a protecting group for hydroxyl or carboxyl groups that can be deprotected with an acid. Here, as a hydroxyl group, for example, a phenolic hydroxyl group bonded to an aromatic carbon atom, as shown in formula (A):

[0123]

[0124] Examples include alcoholic hydroxyl groups represented by the formulas (Xad) and (Xae). Acid-dissociable groups play a role in the lithography process by generating hydroxyl or carboxyl groups with the acid produced by exposure, thereby increasing solubility in the developer. In the repeating units represented by the formulas (Xad) and (Xae) above, the ester structure of the side chain shown in those formulas itself is acid-dissociable.

[0125] -OR ５(Here, R ５ A suitable example of a group that exhibits acid dissociation relative to a hydroxyl group is, for example, formula (G1):

[0126]

[0127] [In the formula, R ａ R represents an alkyl group which may have substituents, and ｂ This represents a hydrogen atom, or an alkyl group which may have a substituent, or R ａ and R ｂ They bond together to form a non-aromatic heterocycle which may have substituents; R ｃ represents a hydrogen atom or an alkyl group which may have substituents; Y represents -O- or -S-; and * represents a bonding site. The group represented by formula (G2):

[0128]

[0129] [In the formula, R ｄ and R ｅ Each independently represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group, or R ｄ and R ｅ They bond together to form a non-aromatic ring which may have substituents; R ｆ represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group; * represents a bonding site. The group represented by ], formula (G3):

[0130]

[0131] [In the formula, R g and R ｈ Each independently represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group, or R g and R ｈ They bond together to form a non-aromatic ring which may have substituents; R ｉrepresents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group; * represents a bonding site. The group represented by ], formula (G4):

[0132]

[0133] [In the formula, R ｊ and R ｋ Each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group, or R ｊ and R ｋ They bond together to form a non-aromatic ring which may have substituents; R ｌ represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group; * represents a bonding site. Examples include groups represented by ].

[0134] The base represented by formula (G1) is not particularly limited, but for example, formulas (G1-1) to (G1-104):

[0135]

[0136] Examples of groups represented by [wherein * indicates a bonding site] include:

[0137] The base represented by formula (G2) is not particularly limited, but for example, formulas (G2-1) to (G2-35):

[0138]

[0139] Examples of groups represented by [wherein * indicates a bonding site] include:

[0140] The base represented by formula (G3) is not particularly limited, but for example, formulas (G3-1) to (G3-41):

[0141]

[0142] Examples of groups represented by [wherein * indicates a bonding site] include:

[0143] The base represented by formula (G4) is not particularly limited, but for example, formulas (G4-1) to (G4-40):

[0144]

[0145] Examples of groups represented by [wherein * indicates a bonding site] include:

[0146] Specific examples of repeating units derived from polymerizable compounds having acid-dissociable groups include formulas (Xa-1) to (Xa-40):

[0147]

[0148]

[0149] Examples include repeating units represented by the symbols shown.

[0150] The content of repeating units derived from polymerizable compounds having acid-dissociable groups in a polymer containing iodine atoms is not particularly limited, but when the total number of repeating units in the polymer is 100 mol%, in one embodiment it is, for example, 0 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and may be 50 mol% or more. The upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 50 mol% or less, and may be 40 mol% or less.

[0151] Repeating units derived from compounds having a hydroxystyrene skeleton are not particularly limited, but for example, formula (Xb):

[0152]

[0153] [In the formula, R ７ Each independently represents a hydrogen atom, an optionally substituted alkyl group (excluding acid-dissociable groups), an optionally substituted alkenyl group, or an optionally substituted aryl group; f represents an integer of 1 or more; and other symbols are as described above. Examples of repeating units represented by ] include formulas (Xb-1) to (Xb-8):

[0154]

[0155] Examples include repeating units represented by the symbols shown.

[0156] The content of repeating units derived from compounds having a hydroxystyrene skeleton in a polymer having an iodine atom is not particularly limited, but when the total number of repeating units in the polymer is 100 mol%, in one embodiment it is, for example, 0 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and may be 50 mol% or more. The upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 50 mol% or less, and may be 40 mol% or less.

[0157] The repeating units derived from (meth)acrylic acid ester compounds having a lactone skeleton are not particularly limited, but for example, formula (Xca) to (Xcd):

[0158]

[0159] [In the formula, Z is -CH ２ The repeating units can be represented by any of the following: - or -O-; n represents 1 or 2; and other symbols are as described above. Examples include formulas (Xc-1) to (Xc-8):

[0160]

[0161] Examples include repeating units represented by the symbols shown.

[0162] The content of repeating units derived from (meth)acrylic acid ester compounds having a lactone skeleton in a polymer having an iodine atom is not particularly limited, but when the total number of repeating units in the polymer is 100 mol%, in one embodiment it is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, with an upper limit of, for example, 90 mol% or less, preferably 40 mol% or less, more preferably 30 mol% or less, and even more preferably 20 mol% or less.

[0163] In one embodiment, the polymer having an iodine atom may further have repeating units derived from other compounds. The repeating units derived from other compounds are not particularly limited, but for example, formula (Xd):

[0164]

[0165] Examples of repeating units, etc., represented by [In the formulas, each symbol is as described above.] are given by formulas (Xd-1) to (Xd-8):

[0166]

[0167] Examples include repeating units represented by the symbols shown.

[0168] When a polymer containing iodine atoms includes two or more repeating units, it is preferable that these repeating units are arranged randomly.

[0169] The weight-average molecular weight (Mw) of the polymer having iodine atoms is not particularly limited, but is preferably 5,000 to 30,000, more preferably 8,000 to 20,000, and most preferably 10,000 to 15,000.

[0170] The degree of dispersion (Mw / Mn) of the polymer containing iodine atoms is not particularly limited, but is preferably 1.1 to 5.0, more preferably 1.4 to 3.0, and most preferably 1.6 to 2.5.

[0171] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polymers containing iodine atoms are measured by gel permeation chromatography and are expressed as polystyrene-based weight-average molecular weight or number-average molecular weight.

[0172] [2. Exposure process for exposing the resist layer] In the exposure process, the resist layer formed in the formation process is exposed by irradiating it with radiation. As for the exposure method, for example, a method using an exposure machine equipped with an exposure light source can be used. The exposure machine may be an immersion exposure machine.

[0173] As exposure light sources, you can use light sources that emit ultraviolet laser light such as KrF excimer lasers, ArF excimer lasers, and F2 excimer lasers; light sources that emit far-ultraviolet or vacuum ultraviolet harmonic laser light by wavelength conversion of laser light from solid-state laser sources (such as YAG or semiconductor lasers); and light sources that irradiate with extreme ultraviolet (EUV), vacuum ultraviolet (VUV), electron beams (EB), X-rays, or soft X-rays.

[0174] The method for exposing the resist layer may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Liquid immersion lithography is an exposure method in which the space between the resist layer and the lens at the lowest position of the exposure apparatus is filled in advance with a solvent (liquid immersion medium) having a refractive index greater than that of air, and exposure (immersion exposure) is performed in that state. The liquid immersion medium is preferably a solvent having a refractive index greater than that of air and smaller than that of the resist layer to be exposed, and examples include water, fluorine-based inert liquids, silicon-based solvents, hydrocarbon-based solvents, etc.

[0175] During exposure, exposure may be performed through a mask of the desired pattern, or exposure may be performed by direct drawing without using a mask. In order to stably form high-precision fine patterns, after exposure, a heat treatment may be performed at a temperature of, for example, 50 to 200°C, preferably 70 to 150°C, for 30 seconds or more.

[0176] [3. Development process for developing the resist layer] In the development process, the resist layer exposed in the exposure process is developed with an aqueous developer containing amphiphilic molecules to form a resist pattern. The formed resist pattern may be a positive-type resist pattern.

[0177] Development methods include the dip method, paddle method, spray method, and dynamic dispensing method. Development can be carried out, for example, at 10 to 50°C for 10 to 200 seconds, preferably at 20 to 25°C for 15 to 90 seconds.

[0178] After development, rinsing may be performed, preferably using pure water. After development or rinsing, drying is performed.

[0179] [3-1. Amphiphilic Molecules in Aqueous Developers] Amphiphilic molecules are molecules that have both hydrophobic and hydrophilic parts within their molecule.

[0180] The amphiphilic molecule preferably contains a surfactant. The surfactant may be an ionic surfactant or a nonionic surfactant. The surfactant may be an anionic surfactant, a cationic surfactant, a nonionic surfactant, or an amphoteric surfactant, but it is preferable to include one or more selected from the group consisting of anionic surfactants, nonionic surfactants, and amphoteric surfactants.

[0181] Examples of anionic surfactants include carboxylic acid-type anionic surfactants such as aliphatic monocarboxylates, polyoxyethylene alkyl ether carboxylates, N-acyl sarcosine salts, and N-acyl glutamate salts; sulfonic acid-type anionic surfactants such as alkyl sulfosuccinates, alkyl sulfonates, α-olefin sulfonates, alkylbenzene sulfonates, polynaphthylmethanesulfonates (naphthalene sulfonate formalin condensate), alkylnaphthalene sulfonates, and N-acyl methyl taurate salts; sulfate ester-type anionic surfactants such as alkyl sulfates and polyoxyethylene alkyl ether sulfates; and phosphate ester-type anionic surfactants such as alkyl phosphates and polyoxyethylene alkyl ether phosphates.

[0182] In aliphatic monocarboxylates, the number of carbon atoms in the aliphatic monocarboxylic acid is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of aliphatic monocarboxylates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of aliphatic monocarboxylic acids (e.g., monoethanolammonium salt, diethanolammonium salt, triethanolammonium salt, triisopropanolammonium salt, etc., and so on). Examples of aliphatic monocarboxylic acids include saturated aliphatic monocarboxylic acids such as hexanoic acid, octanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and arachidic acid; unsaturated aliphatic monocarboxylic acids such as palmitoleic acid, oleic acid, linoleic acid, and arachidonic acid; hydroxymonocarboxylic acids such as 12-hydroxystearic acid; and mixed aliphatic monocarboxylic acids such as coconut oil fatty acids, palm kernel oil fatty acids, and soybean oil fatty acids.

[0183] The number of carbon atoms in the alkyl group of the polyoxyethylene alkyl ether carboxylate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of polyoxyethylene alkyl ether carboxylates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of polyoxyethylene alkyl ether carboxylic acid. Examples of polyoxyethylene alkyl ether carboxylic acid include polyoxyethylene octyl ether carboxylic acid, polyoxyethylene decyl ether carboxylic acid, polyoxyethylene lauryl ether carboxylic acid (polyoxyethylene dodecyl ether carboxylic acid), polyoxyethylene myristyl ether carboxylic acid, polyoxyethylene palmityl ether carboxylic acid, and polyoxyethylene stearyl ether carboxylic acid.

[0184] The number of carbon atoms in the acyl of the N-acyl sarcosine salt is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of N-acyl sarcosine salts include sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, and alkanolammonium salt of N-acyl sarcosine. Examples of N-acyl sarcosines include N-saturated aliphatic acyl sarcosines such as N-caproyl sarcosine, N-lauroyl sarcosine, N-myristoyl sarcosine, N-palmitoyl sarcosine, and N-stearoyl sarcosine; N-unsaturated aliphatic acyl sarcosines such as N-oleoyl sarcosine; and N-mixed aliphatic acyl sarcosines such as N-cocoyl sarcosine.

[0185] The number of carbon atoms in the acyl of the N-acyl glutamate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of N-acyl glutamates include sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, and alkanolammonium salt of N-acyl glutamate. Examples of N-acyl glutamates include N-saturated aliphatic acyl glutamates such as N-caproyl glutamate, N-lauroyl glutamate, N-myristoyl glutamate, N-palmitoyl glutamate, and N-stearoyl glutamate; N-unsaturated aliphatic acyl glutamates such as N-oleoyl glutamate; and N-mixed aliphatic acyl glutamates such as N-cocoyl glutamate.

[0186] The number of carbon atoms in each alkyl group of the dialkyl sulfosuccinate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of dialkyl sulfosuccinates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of dialkyl sulfosuccinate. Examples of dialkyl sulfosuccinates include di(2-ethylhexyl) sulfosuccinate, dioctyl sulfosuccinate, didecyl sulfosuccinate, dilauryl sulfosuccinate (didodecyl sulfosuccinate), dimyristyl sulfosuccinate, dipalmytil sulfosuccinate, and distearyl sulfosuccinate.

[0187] The number of carbon atoms in the alkyl sulfonate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of alkyl sulfonates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of alkyl sulfonic acids. Examples of alkyl sulfonic acids include octyl sulfonic acid, decyl sulfonic acid, lauryl sulfonic acid (dodecyl sulfonic acid), myristyl sulfonic acid, palmityl sulfonic acid, and stearyl sulfonic acid.

[0188] The number of carbon atoms in the olefin of the α-olefin sulfonate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of α-olefin sulfonates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of α-olefin sulfonic acid.

[0189] The number of carbon atoms in the alkylbenzenesulfonate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of alkylbenzenesulfonates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of alkylbenzenesulfonic acid. Examples of alkylbenzenesulfonic acid include linear alkylbenzenesulfonic acids such as octylbenzenesulfonic acid, decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, cetylbenzenesulfonic acid, myristylbenzenesulfonic acid, palmitylbenzenesulfonic acid, and stearylbenzenesulfonic acid.

[0190] Examples of polynaphthylmethanesulfonates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of polynaphthylmethanesulfonic acid.

[0191] The number of carbon atoms in the alkylnaphthalene sulfonate is preferably 2 to 30, more preferably 2 to 20, and even more preferably 2 to 10. Examples of alkylnaphthalene sulfonates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of alkylnaphthalene sulfonic acid. Examples of alkylnaphthalene sulfonic acid include propylnaphthalene sulfonic acid, isopropylnaphthalene sulfonic acid, and butylnaphthalene sulfonic acid.

[0192] The number of carbon atoms in the acyl of the N-acylmethyltaurine salt is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of N-acylmethyltaurine salts include sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, and alkanolammonium salt of N-acylmethyltaurine. Examples of N-acylmethyltaurine include N-saturated aliphatic acylmethyltaurine such as N-caproylmethyltaurine, N-lauroylmethyltaurine, N-myristoylmethyltaurine, N-palmitoylmethyltaurine, and N-stearoylmethyltaurine; N-unsaturated aliphatic acylmethyltaurine such as N-oleoylmethyltaurine; and N-mixed aliphatic acylmethyltaurine such as N-cocoylmethyltaurine.

[0193] The number of carbon atoms in the alkyl sulfate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of alkyl sulfates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of alkyl sulfates. Examples of alkyl sulfates include octyl sulfate, decyl sulfate, lauryl sulfate (dodecyl sulfate), myristyl sulfate, palmityl sulfate, and stearyl sulfate.

[0194] The number of carbon atoms in the alkyl group of the polyoxyethylene alkyl ether sulfate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to the polyoxyethylene alkyl ether sulfate is, for example, 0.5 to 100, and preferably 3 to 40. Examples of polyoxyethylene alkyl ether sulfates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of polyoxyethylene alkyl ether sulfate. Examples of polyoxyethylene alkyl ether sulfates include polyoxyethylene octyl ether sulfate, polyoxyethylene decyl ether sulfate, polyoxyethylene lauryl ether sulfate (polyoxyethylene dodecyl ether sulfate), polyoxyethylene myristyl ether sulfate, polyoxyethylene palmityl ether sulfate, and polyoxyethylene stearyl ether sulfate.

[0195] The number of carbon atoms in the alkyl group of the alkyl phosphate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of alkyl phosphates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of alkyl phosphates. Examples of alkyl phosphates include octyl phosphate, decyl phosphate, lauryl phosphate (dodecyl phosphate), myristyl phosphate, palmityl phosphate, and stearyl phosphate.

[0196] The number of carbon atoms in the alkyl group of the polyoxyethylene alkyl ether phosphate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to the polyoxyethylene alkyl ether phosphate is, for example, 0.5 to 100, and preferably 3 to 40. Examples of polyoxyethylene alkyl ether phosphates include sodium salts, potassium salts, calcium salts, magnesium salts, ammonium salts, and alkanolammonium salts of polyoxyethylene alkyl ether phosphate. Examples of polyoxyethylene alkyl ether phosphates include polyoxyethylene octyl ether phosphate, polyoxyethylene decyl ether phosphate, polyoxyethylene lauryl ether phosphate (polyoxyethylene dodecyl ether phosphate), polyoxyethylene myristyl ether phosphate, polyoxyethylene palmityl ether phosphate, and polyoxyethylene stearyl ether phosphate.

[0197] Examples of nonionic surfactants include ester-type nonionic surfactants such as glycerin fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters; ether-type nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene polyoxypropylene glycol; ester-ether-type nonionic surfactants such as fatty acid polyethylene glycol, fatty acid polyoxyethylene sorbitan, and polyoxyethylene hydrogenated castor oil; amide-type nonionic surfactants such as fatty acid alkanolamides and polyoxyethylene fatty acid amides; amine-type nonionic surfactants such as alkylamine ethylene oxide adducts; and acetylene glycol-type nonionic surfactants such as acetylene glycol and acetylene glycol ethylene oxide adducts.

[0198] The number of carbon atoms in the fatty acid of the glycerin fatty acid ester is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Glycerin fatty acid esters include polyglycerin fatty acid esters such as monoglycerin fatty acid esters, diglycerin fatty acid esters, triglycerin fatty acid esters, tetraglycerin fatty acid esters, pentaglycerin fatty acid esters, and hexaglycerin fatty acid esters. Glycerin fatty acid esters include monoesters, diesters, etc. Examples of glycerin fatty acid esters include monoglycerin saturated fatty acid esters such as glycerin monocaprylate, glycerin monolaurate, glycerin monomyristate, glycerin monopalmitate, and glycerin monostearate; polyglycerin saturated fatty acid esters such as diglycerin monocaprylate, diglycerin monolaurate, diglycerin monomyristate, diglycerin monopalmitate, diglycerin monostearate, triglycerin monocaprylate, triglycerin monolaurate, triglycerin monomyristate, triglycerin monopalmitate, and triglycerin monostearate; monoglycerin unsaturated fatty acid esters such as glycerin monooleate; polyglycerin unsaturated fatty acid esters such as diglycerin monooleate and triglycerin monooleate; monoglycerin mixed fatty acid esters such as glycerin monococolate; and polyglycerin mixed fatty acid esters such as diglycerin monococolate and triglycerin monococolate.

[0199] The number of carbon atoms in the fatty acid of the sorbitan fatty acid ester is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Sorbitan fatty acid esters include monoesters, diesters, etc. Examples of sorbitan fatty acid esters include sorbitan saturated fatty acid esters such as sorbitan alkanol monocaprylate, sorbitan monolaurate, sorbitan monomyristate, sorbitan monopalmitate, and sorbitan monostearate; sorbitan unsaturated fatty acid esters such as sorbitan monooleate; and sorbitan mixed fatty acid esters such as sorbitan monococolate.

[0200] The number of carbon atoms in the fatty acid of the sucrose fatty acid ester is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Sucrose fatty acid esters include monoesters, diesters, etc. Examples of sucrose fatty acid esters include sucrose saturated fatty acid esters such as sucrose caprate, sucrose laurate, sucrose myristate, sucrose palmitate, sucrose stearate, sucrose dicaprate, sucrose dilaurate, sucrose dimyristate, sucrose dipalmitate, and sucrose distearate; sucrose unsaturated fatty acid esters such as sucrose oleate and sucrose dioleate; and sucrose mixed fatty acid esters such as sucrose cocoate and sucrose dicocoate.

[0201] The number of carbon atoms in the alkyl group of the polyoxyethylene alkyl ether is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to the polyoxyethylene alkyl ether is, for example, 0.5 to 100, and preferably 3 to 40. Examples of polyoxyethylene alkyl ethers include polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether (polyoxyethylene dodecyl ether), polyoxyethylene myristyl ether, polyoxyethylene palmityl ether, and polyoxyethylene stearyl ether.

[0202] The number of carbon atoms in the alkyl group of the polyoxyethylene alkylphenyl ether is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to the polyoxyethylene alkylphenyl ether is, for example, 0.5 to 100, and preferably 3 to 40. Examples of polyoxyethylene alkylphenyl ethers include polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene decylphenyl ether, polyoxyethylene laurylphenyl ether (polyoxyethylene dodecylphenyl ether), polyoxyethylene myristylphenyl ether, polyoxyethylene palmitylphenyl ether, and polyoxyethylene stearylphenyl ether.

[0203] The average number of moles of ethylene oxide added to polyoxyethylene polyoxypropylene glycol is, for example, 0.5 to 100, preferably 3 to 40. The average ratio of moles of propylene oxide to ethylene oxide added to polyoxyethylene polyoxypropylene glycol is, for example, 1:0.1 to 1:10.

[0204] The number of carbon atoms in the fatty acid of fatty acid polyethylene glycol is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to fatty acid polyethylene glycol is, for example, 0.5 to 100, and preferably 3 to 40. Examples of fatty acid polyethylene glycols include saturated fatty acid polyethylene glycols such as polyethylene glycol caprate, polyethylene glycol laurate, polyethylene glycol myristate, polyethylene glycol palmitate, and polyethylene glycol stearate; unsaturated fatty acid polyethylene glycols such as polyethylene glycol oleate; and mixed fatty acid polyethylene glycols such as polyethylene glycol coconut oil fatty acid, polyethylene glycol palm kernel oil fatty acid, and polyethylene glycol soybean oil fatty acid.

[0205] The number of carbon atoms in the fatty acid of fatty acid polyoxyethylene sorbitan is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to fatty acid polyoxyethylene sorbitan is, for example, 0.5 to 100, and preferably 3 to 40. Examples of fatty acid polyoxyethylene sorbitan include saturated fatty acid polyoxyethylene sorbitan such as capric acid polyoxyethylene sorbitan, laurate polyoxyethylene sorbitan, myristate polyoxyethylene sorbitan, palmitate polyoxyethylene sorbitan, and stearate polyoxyethylene sorbitan; unsaturated fatty acid polyoxyethylene sorbitan such as oleate polyoxyethylene sorbitan; and mixed fatty acid polyoxyethylene sorbitan such as coconut oil fatty acid polyoxyethylene sorbitan, palm kernel oil fatty acid polyoxyethylene sorbitan, and soybean oil fatty acid polyoxyethylene sorbitan.

[0206] The average number of moles of ethylene oxide added to polyoxyethylene hydrogenated castor oil is, for example, 10 to 100, preferably 10 to 80, and more preferably 10 to 40.

[0207] The number of carbon atoms in the fatty acid of the fatty acid alkanolamide is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Fatty acid alkanolamides include fatty acid monoalkanolamides and fatty acid dialkanolamides. The number of carbon atoms in the alkanol of the fatty acid alkanolamide is preferably 2 or 3. Examples of fatty acid diethanolamides include saturated fatty acid alkanolamides such as capric acid diethanolamide, lauric acid diethanolamide, myristic acid diethanolamide, palmitic acid diethanolamide, stearic acid diethanolamide, capric acid monoethanolamide, lauric acid monoethanolamide, myristic acid monoethanolamide, palmitic acid monoethanolamide, and stearic acid monoethanolamide; unsaturated fatty acid alkanolamides such as oleic acid diethanolamide and oleic acid monoethanolamide; and mixed fatty acid alkanolamides such as coconut oil fatty acid diethanolamide, palm kernel oil fatty acid diethanolamide, coconut oil fatty acid monoethanolamide, and palm kernel oil fatty acid monoethanolamide.

[0208] The number of carbon atoms in the fatty acid of the polyoxyethylene fatty acid amide is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to the polyoxyethylene fatty acid amide is, for example, 0.5 to 100, and preferably 3 to 40. Examples of alkylamine ethylene oxide adducts include polyoxyethylene fatty acid amides such as polyoxyethylene capric acid amide, polyoxyethylene lauric acid amide, polyoxyethylene myristic acid amide, polyoxyethylene palmitic acid amide, and polyoxyethylene stearic acid amide; polyoxyethylene unsaturated fatty acid amides such as polyoxyethylene oleic acid amide; and polyoxyethylene mixed fatty acid amides such as polyoxyethylene coconut oil fatty acid amide, polyoxyethylene palm kernel oil fatty acid amide, and polyoxyethylene soybean oil fatty acid amide.

[0209] The number of carbon atoms in the alkylamine ethylene oxide adduct is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. The average number of moles of ethylene oxide added to the alkylamine ethylene oxide adduct is, for example, 0.5 to 100, and preferably 3 to 40. Examples of alkylamine ethylene oxide adducts include polyoxyethylene octylamine, polyoxyethylene decylamine, polyoxyethylene laurylamine (polyoxyethylenedodecylamine), polyoxyethylene myristylamine, polyoxyethylene palmitylamine, and polyoxyethylene stearylamine.

[0210] Examples of acetylene glycols include 2,5,8,11-tetramethyl-6-dodecine-5,8-diol, 5,8-dimethyl-6-dodecine-5,8-diol, 2,4,7,9-tetramethyl-5-decine-4,7-diol, 8-hexadecin-7,10-diol, 7-tetradecine-6,9-diol, 2,3,6,7-tetramethyl-4-octin-3,6-diol, 3,6-dimethyl-4-octin-3,6-diol, and 2,5-dimethyl-3-hexyn-2,5-diol.

[0211] Examples of acetylene glycol ethylene oxide adducts include the acetylene glycol ethylene oxide adducts mentioned above. The average number of moles of ethylene oxide added to the acetylene glycol ethylene oxide adduct is, for example, 0.5 to 100, preferably 3 to 40.

[0212] Examples of amphoteric surfactants include alkylbetaine-type amphoteric surfactants such as alkyldimethylaminoacetic acid; amidebetaine-type amphoteric surfactants such as fatty acid amidopropyldimethylaminoacetic acid; imidazolinium betaine-type amphoteric surfactants such as 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium; sulfobetaine-type amphoteric surfactants such as N,N-dimethyl-N-alkyl-N-(3-sulfopropyl)ammonium; amine oxide-type amphoteric surfactants such as alkylamine oxides; and amphodiacetic acid-type amphoteric surfactants such as fatty acid amphodiacetates.

[0213] The alkyl group of alkyldimethylaminoacetic acid preferably has 4 to 30 carbon atoms, more preferably 6 to 20, and even more preferably 8 to 18 carbon atoms. Examples of alkyldimethylaminoacetic acid include octyldimethylaminoacetic acid (octyl betaine), decyldimethylaminoacetic acid (decyl betaine), lauryldimethylaminoacetic acid (lauryl betaine), myristyldimethylaminoacetic acid (myristyl betaine), palmityldimethylaminoacetic acid (palmityl betaine), and stearyldimethylaminoacetic acid (stearyl betaine).

[0214] The number of carbon atoms in the fatty acid of fatty acid amidopropyldimethylaminoacetic acid is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of fatty acid amidopropyldimethylaminoacetic acid include saturated fatty acid amidopropyldimethylaminoacetic acid such as capric acid amidopropyl betaine, lauric acid amidopropyl betaine, myristate acid amidopropyl betaine, palmitic acid amidopropyl betaine, and stearic acid amidopropyl betaine; unsaturated fatty acid amidopropyldimethylaminoacetic acid such as oleic acid amidopropyl betaine; and mixed fatty acid amidopropyldimethylaminoacetic acid such as coconut oil fatty acid amidopropyl betaine and palm kernel oil fatty acid amidopropyl betaine.

[0215] The number of carbon atoms in the alkyl group of 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium include 2-octyl-N-carboxymethyl-N-hydroxyethylimidazolium, 2-decyl-N-carboxymethyl-N-hydroxyethylimidazolium, 2-lauryl-N-carboxymethyl-N-hydroxyethylimidazolium, 2-myristyl-N-carboxymethyl-N-hydroxyethylimidazolium, 2-palmityl-N-carboxymethyl-N-hydroxyethylimidazolium, and 2-stearyl-N-carboxymethyl-N-hydroxyethylimidazolium.

[0216] The number of carbon atoms in the alkyl group of N,N-dimethyl-N-alkyl-N-(3-sulfopropyl)ammonium is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of N,N-dimethyl-N-alkyl-N-(3-sulfopropyl)ammonium include N,N-dimethyl-N-octyl-N-(3-sulfopropyl)ammonium, N,N-dimethyl-N-decyl-N-(3-sulfopropyl)ammonium, N,N-dimethyl-N-lauryl-N-(3-sulfopropyl)ammonium, N,N-dimethyl-N-myristyl-N-(3-sulfopropyl)ammonium, N,N-dimethyl-N-palmityl-N-(3-sulfopropyl)ammonium, and N,N-dimethyl-N-stearyl-N-(3-sulfopropyl)ammonium.

[0217] The number of carbon atoms in the alkylamine oxide (i.e., alkyldimethylamine oxide) is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of alkylamine oxides include octyldimethylamine oxide (octylamine oxide), decyldimethylamine oxide (decylamine oxide), lauryldimethylamine oxide (laurylamine oxide), myristyldimethylamine oxide (myristylamine oxide), palmityldimethylamine oxide (palmitylamine oxide), and stearyldimethylamine oxide (stearylamine oxide).

[0218] The number of carbon atoms in the fatty acid amphodiacetate is preferably 4 to 30, more preferably 6 to 20, and even more preferably 8 to 18. Examples of fatty acid amphodiacetates include sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, and alkanolammonium salt of dialkyl sulfosuccinate. Examples of fatty acid amphodiacetic acids include saturated fatty acid amphodiacetic acids such as capric acid amphodiacetic acid, lauric acid amphodiacetic acid, myristate acid amphodiacetic acid, palmitic acid amphodiacetic acid, and stearate amphodiacetic acid; unsaturated fatty acid amphodiacetic acids such as oleic acid amphodiacetic acid; and mixed fatty acid amphodiacetic acids such as coconut oil fatty acid amphodiacetic acid (cocoamphodiacetic acid), palm kernel oil fatty acid amphodiacetic acid, and soybean oil fatty acid amphodiacetic acid.

[0219] Examples of cationic surfactants include primary to tertiary amine salt type cationic surfactants such as alkylamine salts; and quaternary ammonium salt type cationic surfactants such as alkyl tolmethylammonium salts, dialkyldimethylammonium salts, benzalkonium salts, and alkylpyridinium salts.

[0220] The alkyl group of the alkylamine salt preferably has 1 to 20 carbon atoms. Examples of alkylamine oxides include primary alkylamine salts such as methylamine hydrochloride; secondary alkylamine salts such as dimethylamine hydrochloride; and tertiary alkylamine salts such as trimethylamine hydrochloride, didecyl monomethylamine hydrochloride, octyldimethylamine hydrochloride, decyldimethylamine hydrochloride, lauryldimethylamine hydrochloride, myristyldimethylamine hydrochloride, palmityldimethylamine hydrochloride, and stearyldimethylamine hydrochloride.

[0221] The alkyl group of the alkyltrimethylammonium salt preferably has 1 to 20 carbon atoms. Examples of alkyltrimethylammonium salts include tetramethylammonium chloride, octyltrimethylammonium chloride, decyltrimethylammonium chloride, dodecyltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, and hexadecyltrimethylammonium bromide.

[0222] The alkyl group of the dialkyldimethylammonium salt preferably has 1 to 20 carbon atoms. Examples of dialkyldimethylammonium salts include didecyldimethylammonium chloride and distearyldimethylammonium chloride.

[0223] Examples of benzalkonium salts include benzalkonium chloride and benzyldodecyldimethylammonium chloride.

[0224] The alkyl group of the alkylpyridinium salt preferably has 1 to 20 carbon atoms. Examples of alkylpyridinium salts include butylpyridinium chloride, laurylpyridinium chloride, and cetylpyridinium chloride.

[0225] In one embodiment, the amphiphilic molecule preferably contains one or more selected from the group consisting of carboxylic acid-type anionic surfactants, sulfonic acid-type anionic surfactants, sulfate ester-type anionic surfactants, ether-type nonionic surfactants, ester-type nonionic surfactants, ester ether-type nonionic surfactants, acetylene glycol-type nonionic surfactants, alkyl betaine-type amphoteric surfactants, amide betaine-type amphoteric surfactants, amine oxide-type amphoteric surfactants, and primary to tertiary amine salt-type cationic surfactants, and also includes aliphatic monocarboxylates, alkyl sulfonates, alkylamine salts, polyoxyethylene polyoxypropylene glycol, acetylene glycol ethylene oxide adducts, acetylene glycol, alkyldimethylaminoacetic acid, alkylbenzene sulfonates, and alkyl sulfates. It is more preferable to include one or more selected from the group consisting of polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, sorbitan fatty acid ester, fatty acid amidopropyl dimethylaminoacetic acid, and alkylamine oxide, and from the viewpoint of further reducing roughness and further improving EB sensitivity, EUV sensitivity, resolution, and contrast, it is even more preferable to include one or more selected from the group consisting of polyoxyethylene polyoxypropylene glycol, acetylene glycol ethylene oxide adduct, acetylene glycol, alkyldimethylaminoacetic acid, alkylbenzene sulfonate, alkyl sulfate, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, sorbitan fatty acid ester, fatty acid amidopropyl dimethylaminoacetic acid, and alkylamine oxide with an HLB value of 27 or less. In this specification, the HLB value is a measured value calculated from the critical micelle concentration (CMC) based on the following formula (1): HLB value = 7 + 4.02 × log(1 / CMC) ... (1)

[0226] In one preferred embodiment, the amphiphilic molecule is more preferably selected from the group consisting of polyoxyethylene polyoxypropylene glycol, acetylene glycol ethylene oxide adduct, acetylene glycol, alkyldimethylaminoacetic acid, alkylbenzene sulfonate, alkyl sulfate, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, sorbitan saturated fatty acid ester, fatty acid amidopropyl dimethylaminoacetic acid, and alkylamine oxide, with an HLB value of 27 or less. It is even more preferably selected from the group consisting of acetylene glycol ethylene oxide adduct, acetylene glycol, alkyldimethylaminoacetic acid, alkylbenzene sulfonate, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, sorbitan saturated fatty acid ester, and fatty acid amidopropyl dimethylaminoacetic acid, with an average number of moles of ethylene oxide added of 8 to 15. It is particularly preferably selected from the group consisting of acetylene glycol ethylene oxide adduct and polyoxyethylene alkyl ether, with an average number of moles of ethylene oxide added of 8 to 15.

[0227] In another preferred embodiment, the amphiphilic molecule is more preferably selected from the group consisting of polyoxyethylene polyoxypropylene glycol, acetylene glycol ethylene oxide adduct, acetylene glycol, alkyldimethylaminoacetic acid, alkylbenzene sulfonate, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, sorbitan saturated fatty acid ester, fatty acid amidopropyldimethylaminoacetic acid, and alkylamine oxide, with an HLB value of 27 or less. It is even more preferably selected from the group consisting of acetylene glycol ethylene oxide adduct, alkyldimethylaminoacetic acid, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, sorbitan saturated fatty acid ester, fatty acid amidopropyldimethylaminoacetic acid, and alkylamine oxide, with an average number of added moles of ethylene oxide of 16 to 40. It is particularly preferably selected from the group consisting of alkyldimethylaminoacetic acid and polyoxyethylene alkyl ether.

[0228] In another preferred embodiment, the amphiphilic molecule is particularly preferably one or more selected from the group consisting of polyoxyethylene polyoxypropylene glycol, acetylene glycol ethylene oxide adduct, acetylene glycol, alkyldimethylaminoacetic acid, alkylbenzene sulfonate, alkyl sulfate, sorbitan unsaturated fatty acid ester, fatty acid amidopropyldimethylaminoacetic acid, and alkylamine oxide, from the viewpoint of further improving resolution, with an HLB value of 27 or less.

[0229] In another preferred embodiment, the amphiphilic molecule is more preferably one or more selected from the group consisting of acetylene glycol ethylene oxide adducts, acetylene glycol, alkyldimethylaminoacetic acid, alkyl sulfates, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ethers, sorbitan saturated fatty acid esters, fatty acid amidopropyldimethylaminoacetic acid, and alkylamine oxides, from the viewpoint of further reducing roughness, and even more preferably one or more selected from the group consisting of acetylene glycol, polyoxyethylene alkyl ethers, and sorbitan saturated fatty acid esters, with acetylene glycol being particularly preferred.

[0230] In another preferred embodiment, the amphiphilic molecule is more preferably selected from the group consisting of polyoxyethylene polyoxypropylene glycol, acetylene glycol ethylene oxide adducts, acetylene glycol, alkyldimethylaminoacetic acid, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ethers, sorbitan saturated fatty acid esters, fatty acid amidopropyl dimethylaminoacetic acid, and alkylamine oxides, from the viewpoint of further improving contrast. It is even more preferably selected from the group consisting of polyoxyethylene polyoxypropylene glycol, acetylene glycol ethylene oxide adducts with an average number of ethylene oxide additions of 8 to 40, acetylene glycol, alkyldimethylaminoacetic acid, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ethers, fatty acid amidopropyl dimethylaminoacetic acid, and alkylamine oxides, and is particularly preferably selected from the group consisting of acetylene glycol ethylene oxide adducts with an average number of additions of 8 to 15, and alkyldimethylaminoacetic acid.

[0231] In another embodiment, the amphiphilic molecule preferably contains a nonionic surfactant having an HLB value of 27 or less, more preferably contains a nonionic surfactant having an HLB value of 6 to 27, and even more preferably contains a nonionic surfactant having an HLB value of 6 to 23.

[0232] In another embodiment, the amphiphilic molecule preferably includes a surfactant having a LogS value of -2.5 or less calculated according to ChemDraw® Professional 23.0.1.10, more preferably an ionic surfactant having the same LogS value of -2.5 or less, and even more preferably an amphoteric surfactant having the same LogS value of -2.5 or less.

[0233] In another embodiment, the amphiphilic molecule preferably has a carbon chain with 6 or more carbon atoms, more preferably has a carbon chain with 8 or more carbon atoms, and even more preferably has a carbon chain with 10 or more carbon atoms.

[0234] The content of amphiphilic molecules in the aqueous developer is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, even more preferably 0.001% by mass or more, and particularly preferably 0.005% by mass or more, based on 100% by mass of the aqueous developer. On the other hand, the content of amphiphilic molecules is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less, based on 100% by mass of the aqueous developer.

[0235] [3-2. Other components in aqueous developer] The aqueous developer may further contain a base, and preferably further contain an organic base.

[0236] Examples of bases include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine, methyldiethylamine, dimethylethanolamine, and triethanolamine; cyclic amines such as pyrrole, piperidine, 1,8-diazabicyclo[5,4,0]-7-undecene, and 1,5-diazabicyclo[4,3,0]-5-nonane; formula (II):

[0237]

[0238] Examples of organic bases include quaternary ammonium salts of compounds represented by [wherein R independently represents an alkyl group which may have substituents]. In particular, it is preferable to include compounds represented by formula (II). Examples of compounds represented by formula (II) include tetramethylammonium hydroxide, tetraethylammonium hydroxide, and triethylmethylammonium hydroxide.

[0239] The content of a base (preferably an organic base) in the aqueous developer 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, based on 100% by mass of the aqueous developer. On the other hand, the content of amphiphilic molecules is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, based on 100% by mass of the aqueous developer.

[0240] The aqueous developer may also contain other components.

[0241] This embodiment relates to the resist pattern formation method described above and provides an aqueous developer containing an amphiphilic molecule for developing a resist layer containing a polymer having an iodine atom after exposure.

[0242] Furthermore, relating to the resist pattern formation method described above, this embodiment provides a resist composition comprising a polymer having iodine atoms, for forming a resist layer that is developed with an aqueous developer containing amphiphilic molecules after exposure.

[0243] Furthermore, this embodiment relates to the resist pattern formation method described above and provides a kit comprising an aqueous developer containing an amphiphilic molecule and a resist composition containing a polymer having an iodine atom.

[0244] The present invention will be described in detail below with reference to examples. The present invention is not limited to these examples. In the following, the room temperature will be 25°C ± 5°C. Unless otherwise specified, the temperature condition is room temperature (25°C ± 5°C), and unless otherwise specified, the pressure condition is atmospheric pressure (1 atm).

[0245] [Preparation Example 1: Preparation of developer D1 that does not contain amphiphilic molecules] 300 g of 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution was used as developer D1.

[0246] [Preparation Example 2: Preparation of Developer D2 containing an Aliphatic Monocarboxylate] Developer D2 was prepared by adding 0.30 g of sodium n-octanoate to 300 g of a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) placed in a glass container and ultrasonically treating it using an ultrasonic cleaner.

[0247] [Preparation Example 3: Preparation of developer D3 containing alkyl sulfonate] Developer D3 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of sodium 1-hexanesulfonate was used instead of 0.30 g of sodium n-octanoate.

[0248] [Preparation Example 4: Preparation of developer D4 containing alkylamine salt] Developer D4 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of methylamine hydrochloride was used instead of 0.30 g of sodium n-octanoate.

[0249] [Preparation Example 5: Preparation of developer D5 containing sorbitan unsaturated fatty acid ester] Developer D5 was prepared in the same manner as in Preparation Example 2, except that 0.030 g of sorbitan monooleate was used instead of 0.30 g of sodium n-octanoate.

[0250] [Preparation Example 6: Preparation of developer D6 containing polyoxyethylene polyoxypropylene glycol (HLB value 29)] Developer D6 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of Kolliphor® P188 (HLB value 29) was used instead of 0.30 g of sodium n-octanoate.

[0251] [Preparation Example 7: Preparation of developer D7 containing polyoxyethylene polyoxypropylene glycol (HLB value 18-23)] Developer D7 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of Pluronic® F-127 (HLB value 18-23) was used instead of 0.30 g of sodium n-octanoate.

[0252] [Preparation Example 8: Preparation of developer D8 containing acetylene glycol ethylene oxide adduct (average number of moles of EO added: 4)] Developer D8 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of OLFINE E1004 (average number of moles of EO added: 4) manufactured by Nisshin Chemical Industry Co., Ltd. was used instead of 0.30 g of sodium n-octanoate.

[0253] [Preparation Example 9: Preparation of developer D9 containing acetylene glycol ethylene oxide adduct (average number of moles of EO added: 10)] Developer D9 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of OLFINE E1010 (average number of moles of EO added: 10) manufactured by Nisshin Chemical Industry Co., Ltd. was used instead of 0.30 g of sodium n-octanoate.

[0254] [Preparation Example 10: Preparation of developer D10 containing acetylene glycol ethylene oxide adduct (average number of moles of EO added: 20)] Developer D10 was prepared in the same manner as in Preparation Example 2, except that OLFINE E1020 (average number of moles of EO added: 20) manufactured by Nisshin Chemical Industry Co., Ltd. was used instead of 0.30 g of sodium n-octanoate.

[0255] [Preparation Example 11: Preparation of developer D11 containing acetylene glycol] Developer D11 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of OLFINE PD-002W manufactured by Nisshin Chemical Industry Co., Ltd. was used instead of 0.30 g of sodium n-octanoate.

[0256] [Preparation Example 12: Preparation of developer D12 containing alkyldimethylaminoacetic acid] Developer D12 was prepared in the same manner as in Preparation Example 2, except that 0.030 g of 35% lauryldimethylaminoacetic acid aqueous solution was used instead of 0.30 g of sodium n-octanoate.

[0257] [Preparation Example 13: Preparation of developer D13 containing alkylbenzene sulfonate] Developer D13 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of sodium dodecylbenzene sulfonate was used instead of 0.30 g of sodium n-octanoate.

[0258] [Preparation Example 14: Preparation of developer D14 containing alkyl sulfate (sodium salt)] Developer D14 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of sodium dodecyl sulfate was used instead of 0.30 g of sodium n-octanoate.

[0259] [Preparation Example 15: Preparation of developer D15 containing alkyl sulfate (ammonium salt)] Developer D15 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of 30% ammonium lauryl sulfate aqueous solution was used instead of 0.30 g of sodium n-octanoate.

[0260] [Preparation Example 16: Preparation of developer D16 containing polyoxyethylene hydrogenated castor oil] Developer D16 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of Aoki Oil & Fat Co., Ltd.'s Brownon RCW-20 was used instead of 0.30 g of sodium n-octanoate.

[0261] [Preparation Example 17: Preparation of developer D17 containing polyoxyethylene alkyl ether] Developer D17 was prepared in the same manner as in Preparation Example 2, except that 0.30 g of Aoki Oil & Fat Co., Ltd.'s Brownon RL-1507 was used instead of 0.30 g of sodium n-octanoate.

[0262] [Preparation Example 18: Preparation of developer D18 containing sorbitan saturated fatty acid ester] Developer D18 was prepared in the same manner as in Preparation Example 2, except that 0.030 g of sorbitan monopalmitate was used instead of 0.30 g of sodium n-octanoate.

[0263] [Preparation Example 19: Preparation of developer D19 containing fatty acid amidopropyldimethylaminoacetic acid] Developer D19 was prepared in the same manner as in Preparation Example 2, except that 0.030 g of lauramidopropyl betaine was used instead of 0.30 g of sodium n-octanoate.

[0264] [Preparation Example 20: Preparation of developer D20 containing alkylamine oxide] Developer D20 was prepared in the same manner as in Preparation Example 2, except that 0.030 g of laurylamine oxide was used instead of 0.30 g of sodium n-octanoate.

[0265] Table 1 below summarizes the component names, types, HLB values, and LogS values ​​of the amphiphilic molecules in developer solutions D1 to D20 of preparation examples 1 to 20. The HLB value is an actual value calculated from the critical micelle concentration (CMC) based on the following formula (1): HLB value = 7 + 4.02 × log(1 / CMC) ... (1) The LogS value is a value calculated according to ChemDraw® Professional 23.0.1.10.

[0266]

[0267] [Synthesis Example 1: Synthesis of polymer P1 having constituent units P1a and P1b]

[0268]

[0269] 3.0 g of 2-iodo-6-methoxy-4-vinylphenol and 2.7 g of 2-ethyl-2-adamantyl methacrylate were dissolved in 40 mL of tetrahydrofuran, and 0.09 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. Then, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P1. The mass-average molecular weight (Mw) of polymer P1 was 12,000, and the dispersion degree (Mw / Mn) was 1.90. １３ 13C-NMR measurements revealed that the molar ratio of P1a, a constituent unit of 2-iodo-6-methoxy-4-vinylphenol, to P1b, a constituent unit derived from 2-ethyl-2-adamantyl methacrylate, in polymer P1 was 50:50. Polymer P1 is a random polymer of each constituent unit.

[0270] [Synthesis Example 2: Synthesis of Polymer P2 Having Constituent Units P2a and P2b]

[0271]

[0272] 1.3 g of 4-vinylphenol and 3.6 g of 2-(4-iodophenyl)propane-2-yl methacrylate were dissolved in 40 mL of tetrahydrofuran, and 0.09 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. The reaction solution was then added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P2. The mass-average molecular weight (Mw) of polymer P2 was 12,000, and the degree of dispersion (Mw / Mn) was 1.90. １３ 13C-NMR measurements revealed that the molar ratio of structural units P2a derived from 4-vinylphenol and P2b derived from 2-(4-iodophenyl)propane-2-yl methacrylate in polymer P2 was 50:50. Polymer P2 is a random polymer of each structural unit.

[0273] [Synthesis Example 3: Synthesis of Polymer P3 Having Constituent Units P3a and P3b]

[0274]

[0275] 3.0 g of 2-iodo-6-methoxy-4-vinylphenol and 2.1 g of 1-isopropylcyclopentyl methacrylate were dissolved in 40 mL of tetrahydrofuran, and 0.09 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. The reaction solution was then added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P3. The mass-average molecular weight (Mw) of polymer P3 was 12,000, and the degree of dispersion (Mw / Mn) was 1.90. １３ 13C-NMR measurements revealed that the molar ratio of structural unit P3a derived from 2-iodo-6-methoxy-4-vinylphenol to structural unit P3b derived from 1-isopropylcyclopentyl methacrylate in polymer P3 was 50:50. Polymer P3 is a random polymer of each structural unit.

[0276] [Synthesis Example 4: Synthesis of Polymer P4 Having Constituent Units P4a to P4d]

[0277]

[0278] 1.5 g of 3,5-di(tetrahydro-2H-pyran-2-yloxy)-4-iodostyrene, 4.0 g of 2-methyl-2-adamantyl methacrylate, 0.9 g of γ-butyrolactone methacrylate, and 1.5 g of hydroxyadamantyl methacrylate were dissolved in 45 mL of tetrahydrofuran, and 0.20 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. The reaction solution was then added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain a white powdery polymer P4. The mass-average molecular weight (Mw) of polymer P4 was 12,000, and the dispersion (Mw / Mn) was 1.90. 1313C-NMR measurements revealed that the molar ratio of constituent units P4a derived from 2-methyl-2-adamantyl methacrylate, P4b derived from γ-butyrolactone methacrylate, P4c derived from hydroxyadamantyl methacrylate, and P4d derived from 3,5-di(tetrahydro-2H-pyran-2-yloxy)-4-iodostyrene (after hydrolysis) in polymer P4 was 45:10:15:30. Polymer P4 is a random polymer of each constituent unit.

[0279] [Synthesis Example 5: Synthesis of Polymer P5 Having Constituent Units P5a to P5d]

[0280]

[0281] 4.4 g of 2,6-diiodo-4-vinylphenyl (2-(4-iodophenyl)propan-2-yl) ether, 1.8 g of 2-ethyl-2-adamantyl methacrylate, 0.4 g of γ-butyrolactone methacrylate, and 1.2 g of 4-vinylphenyl acetate were dissolved in 45 mL of cyclohexanone, and 0.20 g of azobisisobutyronitrile was added. After stirring at an internal temperature of 80°C for 12 hours, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off, rinsed with 20 mL of methanol, and then dried under reduced pressure to obtain 7.5 g of a white powder.

[0282] The obtained white powder was dissolved in 50 mL of tetrahydrofuran. While stirring at 120 rpm using a stirring blade, 40 mL of 1 M sodium hydroxide aqueous solution was gradually added, and the internal temperature was raised to 40°C and stirred for 8 hours. The internal temperature was cooled to 10°C and stirring was continued, and 40 mL of 1 M ammonium chloride aqueous solution was gradually added and stirred for 30 minutes. After that, extraction was performed twice using 60 mL of ethyl acetate, and the obtained organic phase was concentrated by vacuum distillation. To the obtained concentrate, 20 mL of ethyl acetate was added, followed by 100 mL of hexane, crystallization, recovery by filtration, rinsing with hexane, and vacuum drying to obtain 6.8 g of polymer P5 as a white solid. The weight-average molecular weight (Mw) of polymer P5 was 11318, and the dispersion degree (Mw / Mn) was 1.89. １３13C-NMR measurements revealed that the molar ratio of constituent units P5a derived from 2,6-diiodo-4-vinylphenyl (2-(4-iodophenyl)propan-2-yl) ether, P5b derived from 2-ethyl-2-adamantyl methacrylate, P5c derived from γ-butyrolactone methacrylate, and P5d derived from 4-vinylphenyl acetate (after hydrolysis) in polymer P5 was 30:30:10:30. Polymer P5 is a random polymer of each constituent unit.

[0283] [Synthesis Example 6: Synthesis of Polymer P6 Having Constituent Units P6a to P6c]

[0284]

[0285] 7.06 g of 2-propyl-2-methacrylroyloxy-5-iodoadamantane, 1.24 g of γ-butyrolactone methacrylate, and 1.31 g of 4-vinylphenol were dissolved in 50 mL of tetrahydrofuran, and 0.20 g of azobisisobutyronitrile was added. After refluxing for 12 hours, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated resin was filtered off and dried under reduced pressure to obtain a white powdery polymer P6. The molecular weight (Mw) of polymer P6 was 12500, and the dispersion degree (Mw / Mn) was 1.66. １３ 13C-NMR measurements revealed that the molar ratio of structural units P6a derived from γ-butyrolactone methacrylate, P6b derived from 4-vinylphenol, and P6c derived from 2-propyl-2-methacrylloyloxy-5-iodoadamantane in polymer P6 was 20:30:50. Polymer P6 is a random polymer of each constituent unit.

[0286] [Synthesis Example 7: Synthesis of Polymer P7 Having Constituent Units P7a to P7d]

[0287]

[0288] 4.9 g of 3,5-diiodo-2-(ethoxymethoxy)benzyl methacrylate, 3.6 g of 2-ethyl-2-adamantyl methacrylate, 0.8 g of γ-butyrolactone methacrylate, and 0.8 g of hydroxyadamantyl methacrylate were dissolved in 45 mL of tetrahydrofuran, and 0.20 g of azobisisobutyronitrile was added. After refluxing for 12 hours, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated resin was filtered off and dried under reduced pressure to obtain a white powdery polymer P7. The weight-average molecular weight (Mw) of polymer P7 was 12000, and the dispersion (Mw / Mn) was 1.78. １３ 13C-NMR measurements revealed that the molar ratio of constituent units P7a (derived from 2-ethyl-2-adamantyl methacrylate), P7b (derived from γ-butyrolactone methacrylate), P7c (derived from hydroxyadamantyl methacrylate), and P7d (derived from 3,5-diiodo-2-(ethoxymethoxy)benzyl methacrylate) in polymer P7 was 45:15:10:20. Polymer P7 is a random polymer of each constituent unit.

[0289] [Synthesis Example 8: Synthesis of polymer P8 having constituent units P8a to P8d]

[0290]

[0291] 1.5 g of 6-(1-ethoxyethoxy)-7-iodo-2,3-dihydrobenzofuran-3-yl methacrylate, 4.0 g of 2-methyl-2-adamantyl methacrylate, 0.9 g of γ-butyrolactone methacrylate, and 1.5 g of hydroxyadamantyl methacrylate were dissolved in 45 mL of tetrahydrofuran, and 0.20 g of 2,2'-azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. Then, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P8. The weight-average molecular weight (Mw) of polymer P8 was 12,000, and the dispersion degree (Mw / Mn) was 1.90. １３13C-NMR measurements revealed that the molar ratio of constituent units P8a derived from 2-methyl-2-adamantyl methacrylate, P8b derived from γ-butyrolactone methacrylate, P8c derived from hydroxyadamantyl methacrylate, and P8d derived from 6-(1-ethoxyethoxy)-7-iodo-2,3-dihydrobenzofuran-3-yl methacrylate (after hydrolysis) in polymer P8 was 60:10:15:15. Polymer P8 is a random polymer of each constituent unit.

[0292] [Synthesis Example 9: Synthesis of Polymer P9 Having Constituent Units P9a and P9b]

[0293]

[0294] 1.3 g of 4-vinylphenol and 2.7 g of 2-ethyl-2-adamantyl methacrylate were dissolved in 40 mL of tetrahydrofuran, and 0.09 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. Then, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P9. The mass-average molecular weight (Mw) of polymer P9 was 12,000, and the degree of dispersion (Mw / Mn) was 1.90. １３ 13C-NMR measurements revealed that the molar ratio of 4-vinylphenol constituent unit P9a to 2-ethyl-2-adamantyl methacrylate constituent unit P9b in polymer P9 was 50:50. Polymer P9 is a random polymer of each constituent unit.

[0295] [Synthesis Example 10: Synthesis of polymer P10 (fluorine-substituted polymer P1) having constituent units P10a and P10b]

[0296]

[0297] 1.8 g of 2-fluoro-6-methoxy-4-vinylphenol and 2.7 g of 2-ethyl-2-adamantyl methacrylate were dissolved in 40 mL of tetrahydrofuran, and 0.07 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. Then, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P10. The mass-average molecular weight (Mw) of polymer P10 was 12,000, and the dispersion degree (Mw / Mn) was 1.90. １３ 13C-NMR measurements revealed that the molar ratio of 2-fluoro-6-methoxy-4-vinylphenol constituent unit P10a to 2-ethyl-2-adamantyl methacrylate constituent unit P10b in polymer P10 was 50:50. Polymer P10 is a random polymer of each constituent unit.

[0298] [Synthesis Example 11: Synthesis of polymer P11 (fluorine-substituted polymer P2) having constituent units P11a and P11b]

[0299]

[0300] 1.3 g of 4-vinylphenol and 2.4 g of 2-(4-fluorophenyl)propane-2-yl methacrylate were dissolved in 40 mL of tetrahydrofuran, and 0.07 g of azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. The reaction solution was then added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P11. The mass-average molecular weight (Mw) of polymer P11 was 12,000, and the degree of dispersion (Mw / Mn) was 1.90. １３ 13C-NMR measurements revealed that the molar ratio of constituent units P11a derived from 4-vinylphenol and P11b derived from 2-(4-fluorophenyl)propane-2-yl methacrylate in polymer P11 was 50:50. Polymer P11 is a random polymer of each constituent unit.

[0301] [Synthesis Example 12: Synthesis of polymer P12 (fluorine-substituted polymer P6) having constituent units P12a, P12b, and P12c]

[0302]

[0303] 5.10 g of 2-propyl-2-methacrylroyloxy-5-fluoroadamantane, 1.24 g of γ-butyrolactone methacrylate, and 1.31 g of 4-vinylphenol were dissolved in 50 mL of tetrahydrofuran, and 0.17 g of azobisisobutyronitrile was added. After refluxing for 12 hours, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated resin was filtered off and dried under reduced pressure to obtain a white powdery polymer P12. The molecular weight (Mw) of polymer P12 was 12500, and the dispersion degree (Mw / Mn) was 1.66. １３ 13C-NMR measurements revealed that the molar ratio of structural units P12a derived from γ-butyrolactone methacrylate, P12b derived from 4-vinylphenol, and P12c derived from 2-propyl-2-methacrylloyloxy-5-fluoroadamantane in polymer P12 was 20:30:50. Polymer P12 is a random polymer of each constituent unit.

[0304] [Synthesis Example 13: Synthesis of polymer P13 (fluorine-substituted polymer P8) having constituent units P13a, P13b, P13c, and P13d]

[0305]

[0306] 1.0 g of 6-(1-ethoxyethoxy)-7-fluoro-2,3-dihydrobenzofuran-3-yl methacrylate, 4.0 g of 2-methyl-2-adamantyl methacrylate, 0.9 g of γ-butyrolactone methacrylate, and 1.5 g of hydroxyadamantyl methacrylate were dissolved in 45 mL of tetrahydrofuran, and 0.18 g of 2,2'-azobisisobutyronitrile was added. The mixture was refluxed for 12 hours. After cooling to room temperature, 15 mL of 5% p-toluenesulfonic acid aqueous solution was added, and the mixture was stirred for 3 hours. Then, the reaction solution was added dropwise to 2 L of n-heptane. The precipitated polymer was filtered off and dried under reduced pressure to obtain polymer P13. The weight-average molecular weight (Mw) of polymer P13 was 12,000, and the dispersion degree (Mw / Mn) was 1.90. １３13C-NMR measurements revealed that the molar ratio of constituent units P13a derived from 2-methyl-2-adamantyl methacrylate, P13b derived from γ-butyrolactone methacrylate, P13c derived from hydroxyadamantyl methacrylate, and P13d derived from 6-(1-ethoxyethoxy)-7-fluoro-2,3-dihydrobenzofuran-3-yl methacrylate (after hydrolysis) in polymer P13 was 60:10:15:15. Polymer P13 is a random polymer of each constituent unit.

[0307] [Examples 1-26 and Comparative Examples 1-22: Formation of Resist Patterns] 1. Evaluation of EB Sensitivity, Resolution, and Roughness A resist composition was prepared by blending 5 parts by mass of any one of polymers P1-P13 obtained in Synthesis Examples 1-13, 1 part by mass of triphenylsulfonium nonafluorobutanesulfonate, 0.1 parts by mass of triphenylsulfonium salicylate, and 94 parts by mass of propylene glycol monomethyl ether acetate (PGMEA). Furthermore, the prepared resist composition was filtered in a cleanroom using a PTFE filter with a pore size of 0.45 μm (manufactured by GL Sciences Inc.) to obtain a filtered composition. The obtained resist composition was coated onto a silicon wafer and baked at 110-130°C for 60 seconds to form a resist layer with a thickness of 100 nm.

[0308] Next, the image was exposed using an electron beam lithography system (ELS-7500, 100 keV, manufactured by Elionix Corporation), baked at 105°C for 60 seconds (PEB), and then paddle developed for 60 seconds with one of the developers prepared in Preparation Examples 1 to 20 according to Table 2 below. After rinsing with pure water and rotating at 1500 rpm for 30 seconds, a positive pattern was obtained. The obtained pattern was observed using a SEM (S4800, manufactured by Hitachi, Ltd.) to evaluate its resolution and EB sensitivity.

[0309] Regarding EB sensitivity, the lower limit of exposure (μC / cm²) required to form a pattern with a line width of 40 nm and a half-pitch of 40 nm is... ２ The EB sensitivity was determined as ). The results are shown in Table 2 below.

[0310] Regarding resolution, a pattern layout condition PL was used in which patterns with an L (line) / S (space) ratio of 1 / 1 were reduced in increments of 1 nm from a half-pitch of 60 nm, and the exposure dose was 60 μC / cm². ２ From 1 μC / cm ２ Using exposure condition D, which was reduced in size for each step, the pattern formation properties were evaluated using a matrix of condition PL and condition D, and the line width that provided the minimum resolution was determined. The results are shown in Table 2 below.

[0311] Furthermore, for any 10 of the obtained line patterns, the roughness value was evaluated by taking 30 line width values ​​at 1 nm intervals per line, and multiplying this by three standard deviations. The results are shown in Table 2 below.

[0312] 2. Evaluation of EUV Sensitivity and Contrast The resist compositions prepared as described above were evaluated for their sensitivity to an EUV light source using the following method.

[0313] Specifically, the prepared resist compositions were coated onto separate silicon wafers using a spin coater, and then heated on a hot plate at 105°C for 60 seconds to form a resist layer with a thickness of 100 nm.

[0314] Next, using the extreme ultraviolet (EUV) exposure system "EUVES-7000" (product name, manufactured by Lithotech Japan Co., Ltd.), 1 mJ / cm² was measured. ２ From 1 mJ / cm ２ 80 mJ / cm ２ After performing maskless shot exposure across the entire wafer with the exposure dose increased to [value], the wafer was baked (PEB) at 105°C for 60 seconds, and then paddle developed for 60 seconds with one of the developers prepared in Preparation Examples 1 to 20 according to Table 2 below, to obtain a wafer with 80 shot exposures. For each shot exposure area obtained, the film thickness was measured using an optical interferometer "VM3200" (product name, manufactured by SCREEN Semiconductor Solutions Co., Ltd.), and profile data of film thickness against exposure dose was obtained. The exposure value at which the slope of the film thickness variation with respect to exposure dose was largest was set to the sensitivity value (mJ / cm²). ２ ), the slope contrast (nm / (mJ / cm) ２The values ​​were calculated as follows and used as indicators of the resist's EUV sensitivity and contrast.

[0315] 3. Evaluation of solid film exposure defects The resist composition used in the EUV exposure sensitivity measurement was applied to a 12-inch silicon wafer with a 100 nm thick oxide film formed on the outermost layer, and baked at 105°C for 60 seconds to form a 100 nm thick photoresist layer. Next, using an extreme ultraviolet (EUV) exposure apparatus "EUVES-7000" (product name, manufactured by Lithotech Japan Co., Ltd.), the entire wafer was shot exposed with the same exposure dose as the EUV sensitivity value obtained in the EUV sensitivity evaluation described above, and then baked at 105°C for 90 seconds (PEB). Paddle development was then performed for 60 seconds with one of the developer solutions prepared in Preparation Examples 1 to 20 according to Table 2 below, and a wafer was obtained in which the entire wafer was shot exposed for 80 shots.

[0316] The fabricated exposed wafer is then subjected to CH etching using the "Telius SCCM" etching system (product name, manufactured by Tokyo Electron Limited). ４ / CF ４ An etching process was performed using Ar gas until the oxide film was etched to 60 nm. The wafers fabricated by etching were evaluated for defects using the "Surfscan SP3" defect inspection system (product name, manufactured by KLA), and the number of cone defects larger than 25 nm was used as an indicator of etching defects.

[0317] (Evaluation Criteria) S: Number of cone defects ≤ 5 A: 5 < Number of cone defects ≤ 20 B: 20 ​​< Number of cone defects ≤ 60 C: 60 < Number of cone defects ≤ 400 D: 400 < Number of cone defects

[0318] The evaluation results, along with the combinations of polymers and developers for each example and comparative example, are summarized in Table 2 below. In Table 2, polymers are denoted as "iodine" if they contain iodine atoms, "fluorine" if they contain fluorine atoms, and "N" if they do not contain halogen atoms. In Table 2, developers are denoted as "anionic" if they contain anionic surfactants, "cationic" if they contain cationic surfactants, "nonionic" if they contain nonionic surfactants, "amphoteric" if they contain amphoteric surfactants, and "N" if they do not contain amphiphilic molecules.

[0319]

[0320] As shown in Table 2, when a resist layer containing a polymer with iodine atoms was developed using an aqueous developer containing amphiphilic molecules (Examples 1-26), improved sensitivity, improved resolution, and reduced etching defects were observed compared to when a polymer without iodine atoms was used, and / or when a developer without amphiphilic molecules was used (Comparative Examples 1-22).

[0321] Furthermore, when a resist layer containing a polymer with iodine atoms was developed using an aqueous developer containing amphiphilic molecules (Examples 1-26), improvements in roughness and contrast were observed compared to when a developer without amphiphilic molecules was used (Comparative Examples 1-8).

[0322] In particular, focusing on resolution, when a developer without amphiphilic molecules was used, the resolution of the polymers containing fluorine (Comparative Examples 16, 17, and 18) and the polymers containing iodine in their corresponding structural units (Comparative Examples 2, 6, and 8) was 57-60 nm L / S, while the resolution of the latter was 58-63 nm L / S, showing no significant difference. On the other hand, when a developer containing amphiphilic molecules was used, the resolution of the polymers containing fluorine (Comparative Examples 20, 21, and 22) and the polymers containing iodine in their corresponding structural units (Examples 20, 24, and 26) was 58-61 nm L / S, while the resolution of the latter was 40-42 nm L / S, indicating a significant improvement in resolution in the latter compared to the former. This result indicates that the improvement in resolution is a "specific effect" that is clearly manifested by development using a combination of a resist layer containing a polymer with iodine atoms and an aqueous developer containing amphiphilic molecules.

[0323] It is estimated that in the development of resists, the developer first penetrates the resist layer to a certain extent, and then dissolution proceeds in that penetrated area, thus driving the development process.

[0324] In resist layers that do not contain polymers with iodine atoms, it is presumed that after penetration proceeds, the resist layer becomes solubilized, and at the same time, polar interactions, including hydrogen bonds, within the resist layer are relaxed by the penetrating water molecules, thus promoting dissolution.

[0325] However, in the case of a resist layer containing a polymer with iodine atoms, halogen bonding (halogen-Lewis base interaction) is at work. While halogen bonding itself is a polar interaction, the iodine atoms that constitute it are highly hydrophobic substituents. Therefore, conventional developers that do not contain amphiphilic molecules cannot mitigate the polar interaction, making dissolution difficult. This is thought to cause swelling of the pattern, leading to pattern collapse and a deterioration of resolution. Furthermore, the reduced dissolving power is thought to cause a decrease in sensitivity. In addition, fluctuations in the amount of dissolution depending on the position within the pattern within a given development time are thought to cause a deterioration of roughness.

[0326] On the other hand, in the developer used in the present invention, which contains amphiphilic molecules, the amphiphilicity of the developer effectively contributes to the relaxation of halogen bonds acting between hydrophobic and hydrophilic groups, thus suppressing deterioration of developability and a decrease in sensitivity, and enabling the formation of a good pattern.

[0327] Furthermore, in the case of a resist layer containing a polymer with fluorine atoms, halogen bonding occurs similarly to that of a polymer with iodine atoms. However, since the halogen bonding strength is weaker for iodine atoms than for fluorine atoms, it is presumed that the amphiphilic molecules did not effectively contribute to relaxing the interactions in the resist film, and as a result, improvements in resolution and roughness were not achieved.

[0328] This application claims priority to Japanese Patent Application No. 2025-008610, filed on 21 January 2025, the entire contents of said application are deemed to be part of the disclosure of this application and are incorporated herein by reference.

Images